WorldWideScience

Sample records for sem results show

  1. Search Engine Marketing (SEM): Financial & Competitive Advantages of an Effective Hotel SEM Strategy

    OpenAIRE

    Leora Halpern Lanz

    2015-01-01

    Search Engine Marketing and Optimization (SEO, SEM) are keystones of a hotels marketing strategy, in fact research shows that 90% of travelers start their vacation planning with a Google search. Learn five strategies that can enhance a hotels SEO and SEM strategies to boost bookings.

  2. Search Engine Marketing (SEM: Financial & Competitive Advantages of an Effective Hotel SEM Strategy

    Directory of Open Access Journals (Sweden)

    Leora Halpern Lanz

    2015-05-01

    Full Text Available Search Engine Marketing and Optimization (SEO, SEM are keystones of a hotels marketing strategy, in fact research shows that 90% of travelers start their vacation planning with a Google search. Learn five strategies that can enhance a hotels SEO and SEM strategies to boost bookings.

  3. From the SEM (IAEA) to the SIMS (ITU): Re-location experiment of μm-size particles - first results

    International Nuclear Information System (INIS)

    Admon, U.; Donohue, D.; Aigner, H.; Tamborini, G.; Bildstein, O.; Betti, M.

    2002-01-01

    . There, their stage coordinates were taken. The deviation of the actual from the predicted location of each particle was calculated. Preliminary data analysis shows that whereas the re-location accuracy obtained in the M/M case is in good agreement with the previously reported results, 5-10 μm, in the A/M experiments it was about 5 times worse. In other words, the expanded uncertainty of the predicted locations based on the data from the automated search was higher than expected, in contrast to the M/M experiments. The reason is not yet understood. The second test was a 'SEM to SIMS' experiment. The sample was brought to the ITU Cameca-6F SIMS, where the same reference marks have been identified, their stage coordinates measured, and fed to the coordinate transformation algorithm. The same 22 U-containing and 8 other particles were then re-located in the SIMS, and positively identified both visually and by mass analysis. The preliminary results agree with those quoted above. In conclusion, the experiment reported in this paper demonstrates the feasibility of the method for precise re-location of single μm-size particles, a problem of practical importance in nuclear forensics. Particles identified in automated or manual SEM screening can be relocated for further analysis in the SIMS or another instrument (Shortened by AK)

  4. Shocked quartz in the SEM: Distinction between amorphous and healed PDFs

    NARCIS (Netherlands)

    Hamers, M.F.; Pennock, G.M.; Drury, M.R.

    2012-01-01

    Combined SEM techniques show that different CL signatures of PDFs are related to fresh and healed microstructures of PDFs and host quartz. This is confirmed by TEM results. A combination of SEM techniques can give the same type of information as TEM

  5. The Effect of Nonnormality on CB-SEM and PLS-SEM Path Estimates

    OpenAIRE

    Z. Jannoo; B. W. Yap; N. Auchoybur; M. A. Lazim

    2014-01-01

    The two common approaches to Structural Equation Modeling (SEM) are the Covariance-Based SEM (CB-SEM) and Partial Least Squares SEM (PLS-SEM). There is much debate on the performance of CB-SEM and PLS-SEM for small sample size and when distributions are nonnormal. This study evaluates the performance of CB-SEM and PLS-SEM under normality and nonnormality conditions via a simulation. Monte Carlo Simulation in R programming language was employed to generate data based on the theoretical model w...

  6. Willis PM 10-2.5 Precision Results, pdf has summary table and SEM images

    Data.gov (United States)

    U.S. Environmental Protection Agency — Precision data from the SEM and SEM images from the samples. This dataset is associated with the following publication: Peters, T., E. Sawvel, R. Willis, R. West,...

  7. DETECTION OF DELAMINATION IN A COMPOSITE PLATE BY SEM

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A numerical method of integration of Green's functi ons of strip element method (SEM) is proposed. The response of ultrasonic sourc e generated by a transducer on the surface of a multi-ply composite plate conta ining a delamination is analyzed by the use of SEM. The numerical results show that the scanning features of the ultrasonic waves may be used to identify the d elamination inside the composite plate .

  8. A comparison of sediment quality results with acid volatile sulfide (AVS) and simultaneously extracted metals (SEM) ratio in Vojvodina (Serbia) sediments.

    Science.gov (United States)

    Prica, M; Dalmacija, B; Roncević, S; Krcmar, D; Becelić, M

    2008-01-25

    The acid-volatile sulfide (AVS), simultaneously extracted metals (SEM), total metals, and pore-water metal concentrations were studied in Vojvodina (Serbia) sediments. In Serbia, there are no regulations concerning sediment quality standards and sediment management. Harmonization of legislation in the domain of environmental protection with EU requirements will increase the significance of the sediment issue. Sediment quality was assessed according to Dutch standards, but the results were also compared with Canadian and USEPA (United States Environmental Protection Agency) guidelines for sediment quality. A comparison of the results based on different criteria for sediment quality assessment shows that they are sometimes contradictory. Therefore, a single approach to quality assessment may be insufficient. The Sigma[SEM]/[AVS] ratio was found to be greater than one at several locations that were already recognized as places of high risk based on Dutch standards. Some other samples had Sigma[SEM]/[AVS]AVS]>1 can cause increased toxicity because there are many other metal-binding phases in sediments. Metals that are associated with AVS may be released within sediments through storms, dredging activities, oxidation, etc., and may have adverse environmental impacts. This has to be taken into account during dredging, which is for some sediments necessary because the sediment is of class 4 (Dutch evaluation), because the dredging process will certainly increase the concentration of bioavailable heavy metals and disturb the sedimentation dynamics. The obtained results will be invaluable for future activities regarding dredging and sediment management in the country.

  9. An electron moiré method for a common SEM

    Institute of Scientific and Technical Information of China (English)

    Y.M.Xing; S.Kishimoto; Y.R.Zhao

    2006-01-01

    In the electron moiré method,a high-frequency grating is used to measure microscopic deformation,which promises significant potential applications for the method in the microscopic analysis of materials.However,a special beam scanning control device is required to produce a grating and generate a moiré fringe pattern for the scanning electron microscope (SEM).Because only a few SEMs used in the material science studies are equipped with this device,the use of the electron moiré method is limited.In this study,an electron moiré method for a common SEM without the beam control device is presented.A grating based on a multi-scanning concept is fabricated in any observing mode.A real-time moiré pattern can also be generated in the SEM or an optical filtering system.Without the beam control device being a prerequisite,the electron moiré method can be more widely used.The experimental results from three different types of SEMS show that high quality gratings with uniform lines and less pitch error can be fabricated by this method,and moiré patterns can also be correctly generated.

  10. SEM Anthology

    Science.gov (United States)

    Rodgers, Michelle; Zimar, Heather

    2004-01-01

    The "SEM Anthology" is a compilation of articles by more than 30 enrollment management professionals from a variety of institutions across the country. This collection, which has appeared in SEM Monthly over the past year, chronicles Strategic Enrollment Management efforts at campuses nationwide. The book illustrates the successes and challenges…

  11. GAGG:ce single crystalline films: New perspective scintillators for electron detection in SEM.

    Science.gov (United States)

    Bok, Jan; Lalinský, Ondřej; Hanuš, Martin; Onderišinová, Zuzana; Kelar, Jakub; Kučera, Miroslav

    2016-04-01

    Single crystal scintillators are frequently used for electron detection in scanning electron microscopy (SEM). We report gadolinium aluminum gallium garnet (GAGG:Ce) single crystalline films as a new perspective scintillators for the SEM. For the first time, the epitaxial garnet films were used in a practical application: the GAGG:Ce scintillator was incorporated into a SEM scintillation electron detector and it showed improved image quality. In order to prove the GAGG:Ce quality accurately, the scintillation properties were examined using electron beam excitation and compared with frequently used scintillators in the SEM. The results demonstrate excellent emission efficiency of the GAGG:Ce single crystalline films together with their very fast scintillation decay useful for demanding SEM applications. Copyright © 2016 Elsevier B.V. All rights reserved.

  12. GAGG:ce single crystalline films: New perspective scintillators for electron detection in SEM

    International Nuclear Information System (INIS)

    Bok, Jan; Lalinský, Ondřej; Hanuš, Martin; Onderišinová, Zuzana; Kelar, Jakub; Kučera, Miroslav

    2016-01-01

    Single crystal scintillators are frequently used for electron detection in scanning electron microscopy (SEM). We report gadolinium aluminum gallium garnet (GAGG:Ce) single crystalline films as a new perspective scintillators for the SEM. For the first time, the epitaxial garnet films were used in a practical application: the GAGG:Ce scintillator was incorporated into a SEM scintillation electron detector and it showed improved image quality. In order to prove the GAGG:Ce quality accurately, the scintillation properties were examined using electron beam excitation and compared with frequently used scintillators in the SEM. The results demonstrate excellent emission efficiency of the GAGG:Ce single crystalline films together with their very fast scintillation decay useful for demanding SEM applications. - Highlights: • First practical application of epitaxial garnet films demonstrated in SEM. • Improved image quality of SEM equipped with GAGG:Ce single crystalline thin film scintillator. • Scintillation properties of GAGG:Ce films compared with standard bulk crystal scintillators.

  13. Advanced SEM imaging

    International Nuclear Information System (INIS)

    Joy, D. C.; Newbury, D. E.

    1998-01-01

    The scanning electron microscope (SEM) represents the most promising tool for metrology, defect review, and for the analysis of ULSI structures, but both fundamental problems such as electron-solid interactions, and practical considerations such as electron-optical constraints, are now setting a limit to performance. This paper examines the directions in which an advanced SEM might be developed to overcome these constraints. The SEM also offers considerable promise as a tool for the high spatial resolution X-ray microanalysis, especially for those situations where a thin cross-section is not practical and first surface analysis is required. The ways in which this capability can be incorporated in an advanced SEM are examined

  14. Advanced SEM imaging

    International Nuclear Information System (INIS)

    Joy, D.C.; Newbury, D.E.; Newbury, D.E.

    1998-01-01

    The scanning electron microscope (SEM) represents the most promising tool for metrology, defect review, and for the analysis of ULSI structures, but both fundamental problems such as electron-solid interactions, and practical considerations such as electron-optical constraints, are now setting a limit to performance. This paper examines the directions in which an advanced SEM might be developed to overcome these constraints. The SEM also offers considerable promise as a tool for the high spatial resolution X-ray microanalysis, especially for those situations where a thin cross-section is not practical and first surface analysis is required. The ways in which this capability can be incorporated in an advanced SEM are examined. copyright 1998 American Institute of Physics

  15. Multi-scale characterization by FIB-SEM/TEM/3DAP.

    Science.gov (United States)

    Ohkubo, T; Sepehri-Amin, H; Sasaki, T T; Hono, K

    2014-11-01

    In order to improve properties of functional materials, it is important to understand the relation between the structure and the properties since the structure has large effect to the properties. This can be done by using multi-scale microstructure analysis from macro-scale to nano and atomic scale. Scanning electron microscope (SEM) equipped with focused ion beam (FIB), transmission electron microscope (TEM) and 3D atom probe (3DAP) are complementary analysis tools making it possible to know the structure and the chemistry from micron to atomic resolution. SEM gives us overall microstructural and chemical information by various kinds of detectors such as secondary electron, backscattered electron, EDS and EBSD detectors. Also, it is possible to analyze 3D structure and chemistry via FIB serial sectioning. In addition, using TEM we can focus on desired region to get more complementary information from HRTEM/STEM/Lorentz images, SAED/NBD patterns and EDS/EELS to see the detail micro or nano-structure and chemistry. Especially, combination of probe Cs corrector and split EDS detectors with large detector size enable us to analyze the atomic scale elemental distribution. Furthermore, if the specimen has a complicated 3D nanostructure, or we need to analyze light elements such as hydrogen, lithium or boron, 3DAP can be used as the only technique which can visualize and analyze distribution of all constituent atoms of our materials within a few hundreds nm area. Hence, site-specific sample preparation using FIB/SEM is necessary to get desired information from region of interest. Therefore, this complementary analysis combination works very well to understand the detail of materials.In this presentation, we will show the analysis results obtained from some of functional materials by Carl Zeiss CrossBeam 1540EsB FIB/SEM, FEI Tecnai G(2) F30, Titan G2 80-200 TEMs and locally build laser assisted 3DAP. As the one of the example, result of multi-scale characterization for

  16. FIB/SEM and SEM/EDS microstructural analysis of metal-ceramic and zirconia-ceramic interfaces.

    Science.gov (United States)

    Massimi, F; Merlati, G; Sebastiani, M; Battaini, P; Menghini, P; Bemporad, E

    2012-01-10

    Recently introduced FIB/SEM analysis in microscopy seems to provide a high-resolution characterization of the samples by 3D (FIB) cross-sectioning and (SEM) high resolution imaging. The aim of this study was to apply the FIB/SEM and SEM/EDS analysis to the interfaces of a metal-ceramic vs. two zirconia-ceramic systems. Plate samples of three different prosthetic systems were prepared in the dental lab following the manufacturers' instructions, where metal-ceramic was the result of a ceramic veneering (porcelain-fused-to-metal) and the two zirconia-ceramic systems were produced by the dedicated CAD-CAM procedures of the zirconia cores (both with final sintering) and then veneered by layered or heat pressed ceramics. In a FIB/SEM equipment (also called DualBeam), a thin layer of platinum (1 μm) was deposited on samples surface crossing the interfaces, in order to protect them during milling. Then, increasingly deeper trenches were milled by a focused ion beam, first using a relatively higher and later using a lower ion current (from 9 nA to 0.28 nA, 30KV). Finally, FEG-SEM (5KV) micrographs (1000-50,000X) were acquired. In a SEM the analysis of the morphology and internal microstructure was performed by 13KV secondary and backscattered electrons signals (in all the samples). The compositional maps were then performed by EDS probe only in the metal-ceramic system (20kV). Despite the presence of many voids in all the ceramic layers, it was possible to identify: (1) the grain structures of the metallic and zirconia substrates, (2) the thin oxide layer at the metal-ceramic interface and its interactions with the first ceramic layer (wash technique), (3) the roughness of the two different zirconia cores and their interactions with the ceramic interface, where the presence of zirconia grains in the ceramic layer was reported in two system possibly due to sandblasting before ceramic firing.

  17. Cryo-SEM studies of latex/ceramic nanoparticle coating microstructure development.

    Science.gov (United States)

    Luo, Hui; Scriven, L E; Francis, Lorraine F

    2007-12-15

    Cryogenic scanning electron microscopy (cryo-SEM) was used to investigate microstructure development of composite coatings prepared from dispersions of antimony-doped tin oxide (ATO) nanoparticles (approximately 30 nm) or indium tin oxide (ITO) nanoparticles (approximately 40 nm) and latex particles (polydisperse, D(v): approximately 300 nm). Cryo-SEM images of ATO/latex dispersions as-frozen show small clusters of ATO and individual latex particles homogeneously distribute in a frozen water matrix. In contrast, cryo-SEM images of ITO/latex dispersions as-frozen show ITO particles adsorb onto latex particle surfaces. Electrostatic repulsion between negatively charged ATO and negatively charged latex particles stabilizes the ATO/latex dispersion, whereas in ITO/latex dispersion, positively charged ITO particles are attracted onto surfaces of negatively charged latex particles. These results are consistent with calculations of interaction potentials from past research. Cryo-SEM images of frozen and fractured coatings reveal that both ceramic nanoparticles and latex become more concentrated as drying proceeds; larger latex particles consolidate with ceramic nanoparticles in the interstitial spaces. With more drying, compaction flattens the latex-latex particle contacts and shrinks the voids between them. Thus, ceramic nanoparticles are forced to pack closely in the interstitial spaces, forming an interconnected network. Finally, latex particles partially coalesce at their flattened contacts, thereby yielding a coherent coating. The research reveals how nanoparticles segregate and interconnect among latex particles during drying.

  18. The influence of environment temperature on SEM image quality

    International Nuclear Information System (INIS)

    Chen, Li; Liu, Junshan

    2015-01-01

    As the structure dimension goes down to the nano-scale, it often requires a scanning electron microscope (SEM) to provide image magnification up to 100 000  ×. However, SEM images at such a high magnification usually suffer from high resolution value and low signal-to-noise ratio, which results in low quality of the SEM image. In this paper, the quality of the SEM image is improved by optimizing the environment temperature. The experimental results indicate that at 100 000  ×, the quality of the SEM image is influenced by the environment temperature, whereas at 50 000  × it is not. At 100 000  × the best SEM image quality can be achieved from the environment temperature ranging 292 from 294 K, and the SEM image quality evaluated by the double stimulus continuous quality scale method can increase from grade 1 to grade 5. It is expected that this image quality improving method can be used in routine measurements with ordinary SEMs to get high quality images by optimizing the environment temperature. (paper)

  19. In Situ Characterization of Boehmite Particles in Water Using Liquid SEM.

    Science.gov (United States)

    Yao, Juan; Arey, Bruce W; Yang, Li; Zhang, Fei; Komorek, Rachel; Chun, Jaehun; Yu, Xiao-Ying

    2017-09-27

    In situ imaging and elemental analysis of boehmite (AlOOH) particles in water is realized using the System for Analysis at the Liquid Vacuum Interface (SALVI) and Scanning Electron Microscopy (SEM). This paper describes the method and key steps in integrating the vacuum compatible SAVLI to SEM and obtaining secondary electron (SE) images of particles in liquid in high vacuum. Energy dispersive x-ray spectroscopy (EDX) is used to obtain elemental analysis of particles in liquid and control samples including deionized (DI) water only and an empty channel as well. Synthesized boehmite (AlOOH) particles suspended in liquid are used as a model in the liquid SEM illustration. The results demonstrate that the particles can be imaged in the SE mode with good resolution (i.e., 400 nm). The AlOOH EDX spectrum shows significant signal from the aluminum (Al) when compared with the DI water and the empty channel control. In situ liquid SEM is a powerful technique to study particles in liquid with many exciting applications. This procedure aims to provide technical know-how in order to conduct liquid SEM imaging and EDX analysis using SALVI and to reduce potential pitfalls when using this approach.

  20. SEM analysis for irradiated materials

    International Nuclear Information System (INIS)

    Liu Xiaosong; Yao Liang

    2008-06-01

    A radiation-proof Scanning Electron Microscope (SEM) system is introduced. It has been widely used in various areas. For analyzing radioactive samples, normal SEM system needs lots of alterations. Based on KYKY-2800B SEM, the sample room, belt line, operating table and aerator were updated. New radiation-proof SEM system has used to analytic surface contaminated samples and RPV materials samples. An elementary means of SEM analysis for radioactive samples was studied, and this examination supported some available references for further irradiated fuel researches. (authors)

  1. Characterization of Yeast Biofilm by Cryo-SEM and FIB-SEM

    Czech Academy of Sciences Publication Activity Database

    Hrubanová, Kamila; Nebesářová, Jana; Růžička, F.; Dluhoš, J.; Krzyžánek, Vladislav

    2013-01-01

    Roč. 19, S2 (2013), s. 226-227 ISSN 1431-9276 R&D Projects: GA MŠk EE.2.3.20.0103; GA TA ČR TE01020118; GA ČR GAP205/11/1687 Institutional support: RVO:68081731 ; RVO:60077344 Keywords : yeast biofilm * cryo-SEM * FIB-SEM Subject RIV: BH - Optics, Masers, Lasers Impact factor: 1.757, year: 2013

  2. Combination of FTIR and SEM for Identifying Freshwater-Cultured Pearls from Different Quality

    Science.gov (United States)

    Satitkune, Somruedee; Monarumit, Natthapong; Boonmee, Chakkrich; Phlayrahan, Aumaparn; Promdee, Kittiphop; Won-in, Krit

    2016-03-01

    The freshwater-cultured pearl ( Chamberlainia hainesiana species) is an organic gemstone mainly composed of calcium carbonate mineral including calcite, aragonite and vaterite phases. Generally, the quality of freshwater-cultured pearl is based on its luster. The high luster pearl is full of the aragonite phase without vaterite phase. On the other hand, the low luster pearl consists of aragonite and vaterite phases. These data could be proved by the Fourier Transform Infrared (FTIR) spectroscopy combined with the scanning electron microscopy (SEM). As the results, the high luster pearl similarly shows the FTIR spectrum of aragonite phase, and also, it shows the hexagonal shape of aragonite for the SEM image. On the other hand, the FTIR spectrum of low luster pearl has been pointed to the mixture component among aragonite and vaterite phases, and based on the SEM image; the irregular form is also interpreted to the mixture of aragonite and vaterite phases. This research concludes that the quality of freshwater-cultured pearls can be identified by the combination data of FTIR spectra and SEM images. These techniques are suitable for applied gemology.

  3. Blistering and exfoliation of 304 stainless steel studied by SEM and RBS

    International Nuclear Information System (INIS)

    Braun, M.; Emmoth, B.; Whitton, J.L.

    1981-01-01

    Blistering and exfoliation induced by helium irradiation have been studied in polycrystalline stainless steel with the aim of measuring flake or blister skin thicknesses for different implantation energies in the keV region. The authors present measurements of skin thicknesses determined both by direct SEM observations and RBS techniques. The results of the RBS studies show for all implantation energies used that the thickness measured in target atoms/unit area of a flake equals the calculated implantation range with an accuracy of about 10%. Conversely, the SEM measurements show that swelling gives rise to a geometrical skin thickness much greater than the corresponding implantation range. Thus from the SEM and RBS data swelling as a function of the implantation energy is obtained and the linear relative swelling is shown to be strongly dependent on the energy. In addition a comparison between the skin thickness of blisters and flakes has been made for the same material. Blisters were observed at low implantation temperatures and room temperature while exfoliation occurs at elevated temperatures. The result of this comparison is that within the experimental accuracy the flake and blister thicknesses are the same. (Auth.)

  4. Framework for SEM contour analysis

    Science.gov (United States)

    Schneider, L.; Farys, V.; Serret, E.; Fenouillet-Beranger, C.

    2017-03-01

    SEM images provide valuable information about patterning capability. Geometrical properties such as Critical Dimension (CD) can be extracted from them and are used to calibrate OPC models, thus making OPC more robust and reliable. However, there is currently a shortage of appropriate metrology tools to inspect complex two-dimensional patterns in the same way as one would work with simple one-dimensional patterns. In this article we present a full framework for the analysis of SEM images. It has been proven to be fast, reliable and robust for every type of structure, and particularly for two-dimensional structures. To achieve this result, several innovative solutions have been developed and will be presented in the following pages. Firstly, we will present a new noise filter which is used to reduce noise on SEM images, followed by an efficient topography identifier, and finally we will describe the use of a topological skeleton as a measurement tool that can extend CD measurements on all kinds of patterns.

  5. The C. elegans Spalt-like protein SEM-4 functions through the SoxC transcription factor SEM-2 to promote a proliferative blast cell fate in the postembryonic mesoderm.

    Science.gov (United States)

    Shen, Qinfang; Shi, Herong; Tian, Chenxi; Ghai, Vikas; Liu, Jun

    2017-09-01

    Proper development of a multicellular organism relies on well-coordinated regulation of cell fate specification, cell proliferation and cell differentiation. The C. elegans postembryonic mesoderm provides a useful system for uncovering factors involved in these processes and for further dissecting their regulatory relationships. The single Spalt-like zinc finger containing protein SEM-4/SALL is known to be involved in specifying the proliferative sex myoblast (SM) fate. We have found that SEM-4/SALL is sufficient to promote the SM fate and that it does so in a cell autonomous manner. We further showed that SEM-4/SALL acts through the SoxC transcription factor SEM-2 to promote the SM fate. SEM-2 is known to promote the SM fate by inhibiting the expression of two BWM-specifying transcription factors. In light of recent findings in mammals showing that Sall4, one of the mammalian homologs of SEM-4, contributes to pluripotency regulation by inhibiting differentiation, our work suggests that the function of SEM-4/SALL proteins in regulating pluripotency versus differentiation appears to be evolutionarily conserved. Copyright © 2017 Elsevier Inc. All rights reserved.

  6. Quantitative Analysis of Micro-porosity of Eco-material by Using SEM Technique

    Institute of Scientific and Technical Information of China (English)

    ZHANG Ji-ru; LIU Yuan-zhi; LIU Zu-de

    2004-01-01

    Microstructure of the eco-material combining vegetation recovery with slope protection is important for determining plant-growing properties.Several techniques for analyzing the eco-material microstructure are presented,including the freeze-cut-drying method of preparing samples for scanning electronic microscopy (SEM),the SEM image processing technique and quantifying analysis method of the SEM images,and etc.The aggregates and pores in SEM images are identified using the different mathematics operators,and their effects are compared.The areas of aggregates and pores are obtained using the operator of morphology,and the influences of different thresholds in image segmentation are also discussed.The results show that the method,in which the variation of non-maximum grey-level gradient is limited,improves the effect of edge detections due to a weak distinction existing at the edge between the aggregates and pores in image.The determination of the threshold should combine the image characteristic with filling operation,so as to assure the precision of the image analysis,in which the contact-segmentation is the simplest and most effective method.The results also show that the pore areas in eco-materials are generally larger than those in the correlative soils,and their increment is large as soil fabric being fine.These differences are related to admixture of expansive perliticThe operator of morphology provides a new method for the image analysis of other porous material microstructure such as soils and concretes.

  7. Inter-operator and inter-device agreement and reliability of the SEM Scanner.

    Science.gov (United States)

    Clendenin, Marta; Jaradeh, Kindah; Shamirian, Anasheh; Rhodes, Shannon L

    2015-02-01

    The SEM Scanner is a medical device designed for use by healthcare providers as part of pressure ulcer prevention programs. The objective of this study was to evaluate the inter-rater and inter-device agreement and reliability of the SEM Scanner. Thirty-one (31) volunteers free of pressure ulcers or broken skin at the sternum, sacrum, and heels were assessed with the SEM Scanner. Each of three operators utilized each of three devices to collect readings from four anatomical sites (sternum, sacrum, left and right heels) on each subject for a total of 108 readings per subject collected over approximately 30 min. For each combination of operator-device-anatomical site, three SEM readings were collected. Inter-operator and inter-device agreement and reliability were estimated. Over the course of this study, more than 3000 SEM Scanner readings were collected. Agreement between operators was good with mean differences ranging from -0.01 to 0.11. Inter-operator and inter-device reliability exceeded 0.80 at all anatomical sites assessed. The results of this study demonstrate the high reliability and good agreement of the SEM Scanner across different operators and different devices. Given the limitations of current methods to prevent and detect pressure ulcers, the SEM Scanner shows promise as an objective, reliable tool for assessing the presence or absence of pressure-induced tissue damage such as pressure ulcers. Copyright © 2015 Bruin Biometrics, LLC. Published by Elsevier Ltd.. All rights reserved.

  8. Ao leitor sem medo

    Directory of Open Access Journals (Sweden)

    José Eisenberg

    2000-05-01

    Full Text Available O texto resenha Ao leitor sem medo, de Renato Janine Ribeiro (Belo Horizonte, UFMG, 1999.This text is a review of Ao leitor sem medo by Renato Janine Ribeiro (Belo Horizonte, UFMG, 1999

  9. In-situ SEM microchip setup for electrochemical experiments with water based solutions

    International Nuclear Information System (INIS)

    Jensen, E.; Købler, C.; Jensen, P.S.; Mølhave, K.

    2013-01-01

    Studying electrochemical (EC) processes with electron microscopes offers the possibility of achieving much higher resolution imaging of nanoscale processes in real time than with optical microscopes. We have developed a vacuum sealed liquid sample electrochemical cell with electron transparent windows, microelectrodes and an electrochemical reference electrode. The system, called the EC-SEM Cell, is used to study electrochemical reactions in liquid with a standard scanning electron microscope (SEM). The central component is a microfabricated chip with a thin (50 nm) Si-rich silicon nitride (SiNx) window with lithographically defined platinum microelectrodes. We show here the design principles of the EC-SEM system, its detailed construction and how it has been used to perform a range of EC experiments, two of which are presented here. It is shown that the EC-SEM Cell can survive extended in-situ EC experiments. Before the EC experiments we characterized the beam current being deposited in the liquid as this will affect the experiments. The first EC experiment shows the influence of the electron-beam (e-beam) on a nickel solution by inducing electroless nickel deposition on the window when increasing the current density from the e-beam. The second experiment shows electrolysis in EC-SEM Cell, induced by the built-in electrodes. - Highlights: • New in-situ SEM system for electrochemistry. • In-situ Beam current measurements through liquid. • In-situ SEM E-beam-induced electroless deposition of Ni. • In-situ electrolysis

  10. In-situ SEM microchip setup for electrochemical experiments with water based solutions

    Energy Technology Data Exchange (ETDEWEB)

    Jensen, E., E-mail: eric.jensen@nanotech.dtu.dk [DTU Nanotech, Technical University of Denmark, Ørsteds Plads, Building 345E, 2800 Kongens Lyngby (Denmark); DTU CEN, Technical University of Denmark, Fysikvej, Building 307, 2800 Kongens Lyngby (Denmark); Købler, C., E-mail: carsten.kobler@nanotech.dtu.dk [DTU Nanotech, Technical University of Denmark, Ørsteds Plads, Building 345E, 2800 Kongens Lyngby (Denmark); DTU CEN, Technical University of Denmark, Fysikvej, Building 307, 2800 Kongens Lyngby (Denmark); Jensen, P.S., E-mail: psj@kemi.dtu.dk [DTU Kemi, Technical University of Denmark, Kemitorvet, Building 207, 2800 Kongens Lyngby (Denmark); Mølhave, K., E-mail: kristian.molhave@nanotech.dtu.dk [DTU Nanotech, Technical University of Denmark, Ørsteds Plads, Building 345E, 2800 Kongens Lyngby (Denmark)

    2013-06-15

    Studying electrochemical (EC) processes with electron microscopes offers the possibility of achieving much higher resolution imaging of nanoscale processes in real time than with optical microscopes. We have developed a vacuum sealed liquid sample electrochemical cell with electron transparent windows, microelectrodes and an electrochemical reference electrode. The system, called the EC-SEM Cell, is used to study electrochemical reactions in liquid with a standard scanning electron microscope (SEM). The central component is a microfabricated chip with a thin (50 nm) Si-rich silicon nitride (SiNx) window with lithographically defined platinum microelectrodes. We show here the design principles of the EC-SEM system, its detailed construction and how it has been used to perform a range of EC experiments, two of which are presented here. It is shown that the EC-SEM Cell can survive extended in-situ EC experiments. Before the EC experiments we characterized the beam current being deposited in the liquid as this will affect the experiments. The first EC experiment shows the influence of the electron-beam (e-beam) on a nickel solution by inducing electroless nickel deposition on the window when increasing the current density from the e-beam. The second experiment shows electrolysis in EC-SEM Cell, induced by the built-in electrodes. - Highlights: • New in-situ SEM system for electrochemistry. • In-situ Beam current measurements through liquid. • In-situ SEM E-beam-induced electroless deposition of Ni. • In-situ electrolysis.

  11. Automated CD-SEM metrology for efficient TD and HVM

    Science.gov (United States)

    Starikov, Alexander; Mulapudi, Satya P.

    2008-03-01

    CD-SEM is the metrology tool of choice for patterning process development and production process control. We can make these applications more efficient by extracting more information from each CD-SEM image. This enables direct monitors of key process parameters, such as lithography dose and focus, or predicting the outcome of processing, such as etched dimensions or electrical parameters. Automating CD-SEM recipes at the early stages of process development can accelerate technology characterization, segmentation of variance and process improvements. This leverages the engineering effort, reduces development costs and helps to manage the risks inherent in new technology. Automating CD-SEM for manufacturing enables efficient operations. Novel SEM Alarm Time Indicator (SATI) makes this task manageable. SATI pulls together data mining, trend charting of the key recipe and Operations (OPS) indicators, Pareto of OPS losses and inputs for root cause analysis. This approach proved natural to our FAB personnel. After minimal initial training, we applied new methods in 65nm FLASH manufacture. This resulted in significant lasting improvements of CD-SEM recipe robustness, portability and automation, increased CD-SEM capacity and MT productivity.

  12. The use of SEM/EDS method in mineralogical analysis of ordinary chondritic meteorite

    Directory of Open Access Journals (Sweden)

    Breda Mirtič

    2009-12-01

    Full Text Available The aim of this study was to evaluate the potential of scanning electron microscopy coupled with energy dispersiveX-ray spectroscopy (SEM/EDS for determination of mineral phases according to their stoichiometry and assessment of mineral composition of ordinary chondritic meteorite. For the purposes of this study, H3 type ordinary chondritic meteorite Abbott was selected. SEM/EDS allows identification and characterisation of mineralphases, whose size is below the resolution of an optical microscope. Mineral phases in chondrules and interstitial matrix were located in backscattered electron (BSE mode and were assessed from atomic proportions of constituent elements, obtained by the EDS analysis. SEM/EDS analyses of mineral phases showed that Abbott meteorite is characterised by Fe-rich (Fe, Ni-alloy kamacite, Fe-sulphide troilite or pyrrhotite, chromite, Mg-rich olivine, orthopyroxene bronzite or hypersthene, clinopyroxene Al-diopside, acid plagioclase oligoclase, accessory mineral chlorapatite and secondary minerals Fe-hydroxides (goethite or lepidocrocite. Results of semi-quantitative analyses confirmed that most of analysed mineralphases conform well to stoichiometric minerals with minor deviations of oxygen from stoichiometric proportions. Comparison between mineral phases in chondrules and interstitial matrix was also performed, however it showed no significant differences in elemental composition.Differences in chemical composition between minerals in interstitial matrix and chondrules are sometimes too small to be discernedby the SEM/EDS, therefore knowledge of SEM/EDS capabilities is important for correct interpretation of chondrite formation.

  13. Simulation of FIB-SEM images for analysis of porous microstructures.

    Science.gov (United States)

    Prill, Torben; Schladitz, Katja

    2013-01-01

    Focused ion beam nanotomography-scanning electron microscopy tomography yields high-quality three-dimensional images of materials microstructures at the nanometer scale combining serial sectioning using a focused ion beam with SEM. However, FIB-SEM tomography of highly porous media leads to shine-through artifacts preventing automatic segmentation of the solid component. We simulate the SEM process in order to generate synthetic FIB-SEM image data for developing and validating segmentation methods. Monte-Carlo techniques yield accurate results, but are too slow for the simulation of FIB-SEM tomography requiring hundreds of SEM images for one dataset alone. Nevertheless, a quasi-analytic description of the specimen and various acceleration techniques, including a track compression algorithm and an acceleration for the simulation of secondary electrons, cut down the computing time by orders of magnitude, allowing for the first time to simulate FIB-SEM tomography. © Wiley Periodicals, Inc.

  14. SEM Analysis of Surface Impact on Biofilm Antibiotic Treatment.

    Science.gov (United States)

    Gomes, Luciana Calheiros; Mergulhão, Filipe José

    2017-01-01

    The aim of this work was to use scanning electron microscopy (SEM) to investigate the effect of ampicillin treatment on Escherichia coli biofilms formed on two surface materials with different properties, silicone (SIL) and glass (GLA). Epifluorescence microscopy (EM) was initially used to assess biofilm formation and killing efficiency on both surfaces. This technique showed that higher bacterial colonization was obtained in the hydrophobic SIL than in the hydrophilic GLA. It has also shown that higher biofilm inactivation was attained for GLA after the antibiotic treatment (7-log reduction versus 1-log reduction for SIL). Due to its high resolution and magnification, SEM enabled a more detailed analysis of the antibiotic effect on biofilm cells, complementing the killing efficiency information obtained by EM. SEM micrographs revealed that ampicillin-treated cells have an elongated form when compared to untreated cells. Additionally, it has shown that different materials induced different levels of elongation on cells exposed to antibiotic. Biofilms formed on GLA showed a 37% higher elongation than those formed on SIL. Importantly, cell elongation was related to viability since ampicillin had a higher bactericidal effect on GLA-formed biofilms. These findings raise the possibility of using SEM for understanding the efficacy of antimicrobial treatments by observation of biofilm morphology.

  15. Probability-of-Superiority SEM (PS-SEM—Detecting Probability-Based Multivariate Relationships in Behavioral Research

    Directory of Open Access Journals (Sweden)

    Johnson Ching-Hong Li

    2018-06-01

    Full Text Available In behavioral research, exploring bivariate relationships between variables X and Y based on the concept of probability-of-superiority (PS has received increasing attention. Unlike the conventional, linear-based bivariate relationship (e.g., Pearson's correlation, PS defines that X and Y can be related based on their likelihood—e.g., a student who is above mean in SAT has 63% likelihood of achieving an above-mean college GPA. Despite its increasing attention, the concept of PS is restricted to a simple bivariate scenario (X-Y pair, which hinders the development and application of PS in popular multivariate modeling such as structural equation modeling (SEM. Therefore, this study addresses an empirical-based simulation study that explores the potential of detecting PS-based relationship in SEM, called PS-SEM. The simulation results showed that the proposed PS-SEM method can detect and identify PS-based when data follow PS-based relationships, thereby providing a useful method for researchers to explore PS-based SEM in their studies. Conclusions, implications, and future directions based on the findings are also discussed.

  16. FIB-SEM cathodoluminescence tomography: practical and theoretical considerations.

    Science.gov (United States)

    De Winter, D A M; Lebbink, M N; Wiggers De Vries, D F; Post, J A; Drury, M R

    2011-09-01

    Focused ion beam-scanning electron microscope (FIB-SEM) tomography is a powerful application in obtaining three-dimensional (3D) information. The FIB creates a cross section and subsequently removes thin slices. The SEM takes images using secondary or backscattered electrons, or maps every slice using X-rays and/or electron backscatter diffraction patterns. The objective of this study is to assess the possibilities of combining FIB-SEM tomography with cathodoluminescence (CL) imaging. The intensity of CL emission is related to variations in defect or impurity concentrations. A potential problem with FIB-SEM CL tomography is that ion milling may change the defect state of the material and the CL emission. In addition the conventional tilted sample geometry used in FIB-SEM tomography is not compatible with conventional CL detectors. Here we examine the influence of the FIB on CL emission in natural diamond and the feasibility of FIB-SEM CL tomography. A systematic investigation establishes that the ion beam influences CL emission of diamond, with a dependency on both the ion beam and electron beam acceleration voltage. CL emission in natural diamond is enhanced particularly at low ion beam and electron beam voltages. This enhancement of the CL emission can be partly explained by an increase in surface defects induced by ion milling. CL emission enhancement could be used to improve the CL image quality. To conduct FIB-SEM CL tomography, a recently developed novel specimen geometry is adopted to enable sequential ion milling and CL imaging on an untilted sample. We show that CL imaging can be manually combined with FIB-SEM tomography with a modified protocol for 3D microstructure reconstruction. In principle, automated FIB-SEM CL tomography should be feasible, provided that dedicated CL detectors are developed that allow subsequent milling and CL imaging without manual intervention, as the current CL detector needs to be manually retracted before a slice can be milled

  17. SEM facility for examination of reactive and radioactive materials

    International Nuclear Information System (INIS)

    Downs, G.L.; Tucker, P.A.

    1977-01-01

    A scanning electron microscope (SEM) facility for the examination of tritium-containing materials is operational at Mound Laboratory. The SEM is installed with the sample chamber incorporated as an integral part of an inert gas glovebox facility to enable easy handling of radioactive and pyrophoric materials. A standard SEM (ETEC Model B-1) was modified to meet dimensional, operational, and safety-related requirements. a glovebox was designed and fabricated which permitted access with the gloves to all parts of the SEM sample chamber to facilitate director and accessory replacement and repairs. A separate console combining the electron optical column and specimen chamber was interfaced to the glovebox by a custom-made, neoprene bellows so that the vibrations normally associated with the blowers and pumps were damped. Photomicrographs of tritiated pyrophoric materials show the usefulness of this facility. Some of the difficulties involved in the investigation of these materials are also discussed. The SEM is also equipped with an energy dispersive x-ray detector (ORTEC) and a Secondary Ion Mass Spectrometer (3M) attachments. This latter attachment allows analysis of secondary ions with masses ranging from 1-300 amu. (Auth.)

  18. Spin-polarized SEM

    International Nuclear Information System (INIS)

    Konoto, Makoto

    2007-01-01

    Development of highly effective evaluation technology of magnetic structures on a nanometric scale is a key to understanding spintronics and related phenomena. A high-resolution spin-polarized scanning electron microscope (spin SEM) developed recently is quite suitable for probing such nanostructures because of the capability of analyzing local magnetization vectors in three dimensions. Utilizing the spin SEM, a layered antiferromagnetic structure with the 1nm-alternation of bilayer-sheet magnetization has been successfully resolved. The real-space imaging with full analysis of the temperature-dependent magnetization vectors will be demonstrated. (author)

  19. Analysis list: sem-4 [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available sem-4 Larvae + ce10 http://dbarchive.biosciencedbc.jp/kyushu-u/ce10/target/sem-4.1....tsv http://dbarchive.biosciencedbc.jp/kyushu-u/ce10/target/sem-4.5.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/ce10/target/sem...-4.10.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/ce10/colo/sem-4.Larvae.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/ce10/colo/Larvae.gml ...

  20. Carotene location in processed food samples measured by cryo In-SEM Raman.

    Science.gov (United States)

    Lopez-Sanchez, Patricia; Schumm, Stephan; Pudney, Paul D A; Hazekamp, Johan

    2011-09-21

    Cryo In-SEM Raman has been used for the first time to localise carotene compounds in a food matrix. Raman spectra of lycopene and β-carotene have been obtained from sampling oil droplets and plant cell structures visualised with cryo-SEM in tomato and carrot based emulsions containing 5% oil. It was possible to identify the carotenoids in both the oil droplets and the cell walls. Furthermore our results gave some indication that the carotenoids were in the non-crystalline state. It has been suggested that a higher amount of carotenes solubilised into the oil phase of the food matrix would lead to a higher bioaccessibility, thus understanding the effect of processing conditions on micronutrients distribution in a food matrix might help the design of plant based food products with a better nutritional quality. This shows improved structural characterisation of the cryo-SEM with the molecular sensitivity of Raman spectroscopy as a promising approach for complex biological problems.

  1. Automated SEM and TEM sample preparation applied to copper/low k materials

    Science.gov (United States)

    Reyes, R.; Shaapur, F.; Griffiths, D.; Diebold, A. C.; Foran, B.; Raz, E.

    2001-01-01

    We describe the use of automated microcleaving for preparation of both SEM and TEM samples as done by SELA's new MC500 and TEMstation tools. The MC500 is an automated microcleaving tool that is capable of producing cleaves with 0.25 μm accuracy resulting in SEM-ready samples. The TEMstation is capable of taking a sample output from the MC500 (or from SELA's earlier MC200 tool) and producing a FIB ready slice of 25±5 μm, mounted on a TEM-washer and ready for FIB thinning to electron transparency for TEM analysis. The materials selected for the tool set evaluation mainly included the Cu/TaN/HOSP low-k system. The paper is divided into three sections, experimental approach, SEM preparation and analysis of HOSP low-k, and TEM preparation and analysis of Cu/TaN/HOSP low-k samples. For the samples discussed, data is presented to show the quality of preparation provided by these new automated tools.

  2. Recent improvement of a FIB-SEM serial-sectioning method for precise 3D image reconstruction - application of the orthogonally-arranged FIB-SEM.

    Science.gov (United States)

    Hara, Toru

    2014-11-01

    IntroductionWe installed the first "orthogonally-arranged" FIB-SEM in 2011. The most characteristic point of this instrument is that the FIB and SEM columns are perpendicularly mounted; this is specially designed to obtain a serial-sectioning dataset more accurately and precisely with higher contrast and higher spatial resolution compare to other current FIB-SEMs [1]. Since the installation in 2011, we have developed the hardware and methodology of the serial-sectioning based on this orthogonal FIB-SEM. In order to develop this technique, we have widely opened this instrument to every researcher of all fields. In the presentation, I would like to introduce some of application results that are obtained by users of this instrument. The characteristic points of the orthogonal systemFigure 1 shows a difference between the standard and the orthogonal FIB-SEM systems: In the standard system, shown in Fig.1(a), optical axes of a FIB and a SEM crosses around 60deg., while in the orthogonal system (Fig.1(b)), they are perpendicular to each other. The standard arrangement (a) is certainly suitable for TEM lamellae preparation etc. because the FIB and the SEM can see the same position simultaneously. However, for a serial-sectioning, it is not to say the best arrangement. One of the reasons is that the sliced plane by the FIB is not perpendicular to the electron beam so that the background contrast is not uniform and observed plane is distorted. On the other hand, in case of the orthogonally-arranged system,(b), these problems are resolved. In addition, spatial resolution can keep high enough even in a low accelerating voltage (e.g. 500V) because a working distance is set very small, 2mm. From these special design, we can obtain the serial-sectioning dataset from rather wide area (∼100um) with high spatial resolution (Max. 2×2×2nm). As this system has many kinds of detectors: SE, ET, Backscatter Electron(Energy-selective), EDS, EBSD, STEM(BF&ADF), with Ar+ ion-gun and a

  3. On some contrast reversals in SEM: Application to metal/insulator systems

    International Nuclear Information System (INIS)

    Cazaux, Jacques

    2008-01-01

    Contrast changes of SEM images with experimental conditions (beam energy, angle of detection, etc.) are analyzed by combining physical arguments based on secondary electron emission (SEE) to instrumental arguments involving detection. Possible occurrences of contrast reversals are explored to illustrate these changes in a striking manner. Deduced from SEE yield data, simulated SEM images show a material contrast reversal for a Pt/quartz specimen, a result partly supported by real images of a Cr/quartz integrated circuit. A shift of reversal energy with the detector's position is deduced from a difference in secondary electrons (SE) angular distributions between metals and insulators. Similarly, changes of topographic contrast with detection conditions, specimen composition and angle of tilt are investigated and a possible contrast reversal is again indicated. Finally, it is shown how charging contrast deduced from the expected evolution of SEE yield during irradiation is amplified by in-lens detection: a point illustrated by a contrast reversal of images of SiC particles. The main application concerns a proper interpretation of SEM images that is essential in the investigation of devices obtained from lithographic processes. The discussion on material contrast outlines the difficulty in generalizing the present analysis based on published data and experimental strategies based on implementing specific attachments in the SEM or on biasing the specimen holder are suggested.

  4. Comparing the detection of iron-based pottery pigment on a carbon-coated sherd by SEM-EDS and by Micro-XRF-SEM.

    Science.gov (United States)

    Pendleton, Michael W; Washburn, Dorothy K; Ellis, E Ann; Pendleton, Bonnie B

    2014-03-01

    The same sherd was analyzed using a scanning electron microscope with energy dispersive spectroscopy (SEM-EDS) and a micro X-ray fluorescence tube attached to a scanning electron microscope (Micro-XRF-SEM) to compare the effectiveness of elemental detection of iron-based pigment. To enhance SEM-EDS mapping, the sherd was carbon coated. The carbon coating was not required to produce Micro-XRF-SEM maps but was applied to maintain an unbiased comparison between the systems. The Micro-XRF-SEM analysis was capable of lower limits of detection than that of the SEM-EDS system, and therefore the Micro-XRF-SEM system could produce elemental maps of elements not easily detected by SEM-EDS mapping systems. Because SEM-EDS and Micro-XRF-SEM have been used for imaging and chemical analysis of biological samples, this comparison of the detection systems should be useful to biologists, especially those involved in bone or tooth (hard tissue) analysis.

  5. Viewing Integrated-Circuit Interconnections By SEM

    Science.gov (United States)

    Lawton, Russel A.; Gauldin, Robert E.; Ruiz, Ronald P.

    1990-01-01

    Back-scattering of energetic electrons reveals hidden metal layers. Experiment shows that with suitable operating adjustments, scanning electron microscopy (SEM) used to look for defects in aluminum interconnections in integrated circuits. Enables monitoring, in situ, of changes in defects caused by changes in temperature. Gives truer picture of defects, as etching can change stress field of metal-and-passivation pattern, causing changes in defects.

  6. Performance of SEM scintillation detector evaluated by modulation transfer function and detective quantum efficiency function.

    Science.gov (United States)

    Bok, Jan; Schauer, Petr

    2014-01-01

    In the paper, the SEM detector is evaluated by the modulation transfer function (MTF) which expresses the detector's influence on the SEM image contrast. This is a novel approach, since the MTF was used previously to describe only the area imaging detectors, or whole imaging systems. The measurement technique and calculation of the MTF for the SEM detector are presented. In addition, the measurement and calculation of the detective quantum efficiency (DQE) as a function of the spatial frequency for the SEM detector are described. In this technique, the time modulated e-beam is used in order to create well-defined input signal for the detector. The MTF and DQE measurements are demonstrated on the Everhart-Thornley scintillation detector. This detector was alternated using the YAG:Ce, YAP:Ce, and CRY18 single-crystal scintillators. The presented MTF and DQE characteristics show good imaging properties of the detectors with the YAP:Ce or CRY18 scintillator, especially for a specific type of the e-beam scan. The results demonstrate the great benefit of the description of SEM detectors using the MTF and DQE. In addition, point-by-point and continual-sweep e-beam scans in SEM were discussed and their influence on the image quality was revealed using the MTF. © 2013 Wiley Periodicals, Inc.

  7. A methodology for extending domain coverage in SemRep.

    Science.gov (United States)

    Rosemblat, Graciela; Shin, Dongwook; Kilicoglu, Halil; Sneiderman, Charles; Rindflesch, Thomas C

    2013-12-01

    We describe a domain-independent methodology to extend SemRep coverage beyond the biomedical domain. SemRep, a natural language processing application originally designed for biomedical texts, uses the knowledge sources provided by the Unified Medical Language System (UMLS©). Ontological and terminological extensions to the system are needed in order to support other areas of knowledge. We extended SemRep's application by developing a semantic representation of a previously unsupported domain. This was achieved by adapting well-known ontology engineering phases and integrating them with the UMLS knowledge sources on which SemRep crucially depends. While the process to extend SemRep coverage has been successfully applied in earlier projects, this paper presents in detail the step-wise approach we followed and the mechanisms implemented. A case study in the field of medical informatics illustrates how the ontology engineering phases have been adapted for optimal integration with the UMLS. We provide qualitative and quantitative results, which indicate the validity and usefulness of our methodology. Published by Elsevier Inc.

  8. SEM evaluation of human gingival fibroblasts growth onto CAD/CAM zirconia and veneering ceramic for zirconia

    Science.gov (United States)

    Zizzari, Vincenzo; Borelli, Bruna; De Colli, Marianna; Tumedei, Margherita; Di Iorio, Donato; Zara, Susi; Sorrentino, Roberto; Cataldi, Amelia; Gherlone, Enrico Felice; Zarone, Fernando; Tetè, Stefano

    2013-01-01

    Summary Aim To evaluate the growth of Human Gingival Fibroblasts (HGFs) cultured onto sample discs of CAD/CAM zirconia and veneering ceramic for zirconia by means of Scanning Electron Microscope (SEM) analysis at different experimental times. Methods A total of 26 experimental discs, divided into 2 groups, were used: Group A) CAD/CAM zirconia (3Y-TZP) discs (n=13); Group B) veneering ceramic for zirconia discs (n=13). HGFs were obtained from human gingival biopsies, isolated and placed in culture plates. Subsequently, cells were seeded on experimental discs at 7,5×103/cm2 concentration and cultured for a total of 7 days. Discs were processed for SEM observation at 3h, 24h, 72h and 7 days. Results In Group A, after 3h, HGFs were adherent to the surface and showed a flattened profile. The disc surface covered by HGFs resulted to be wider in Group A than in Group B samples. At SEM observation, after 24h and 72h, differences in cell attachment were slightly noticeable between the groups, with an evident flattening of HGFs on both surfaces. All differences between Group A and group B became less significant after 7 days of culture in vitro. Conclusions SEM analysis of HGFs showed differences in terms of cell adhesion and proliferation, especially in the early hours of culture. Results showed a better adhesion and cell growth in Group A than in Group B, especially up to 72h in vitro. Differences decreased after 7 days, probably because of the rougher surface of CAD/CAM zirconia, promoting better cell adhesion, compared to the smoother surface of veneering ceramic. PMID:24611089

  9. SEM investigation of heart tissue samples

    International Nuclear Information System (INIS)

    Saunders, R; Amoroso, M

    2010-01-01

    We used the scanning electron microscope to examine the cardiac tissue of a cow (Bos taurus), a pig (Sus scrofa), and a human (Homo sapiens). 1mm 3 blocks of left ventricular tissue were prepared for SEM scanning by fixing in 96% ethanol followed by critical point drying (cryofixation), then sputter-coating with gold. The typical ridged structure of the myofibrils was observed for all the species. In addition crystal like structures were found in one of the samples of the heart tissue of the pig. These structures were investigated further using an EDVAC x-ray analysis attachment to the SEM. Elemental x-ray analysis showed highest peaks occurred for gold, followed by carbon, oxygen, magnesium and potassium. As the samples were coated with gold for conductivity, this highest peak is expected. Much lower peaks at carbon, oxygen, magnesium and potassium suggest that a cystallized salt such as a carbonate was present in the tissue before sacrifice.

  10. SEM investigation of heart tissue samples

    Energy Technology Data Exchange (ETDEWEB)

    Saunders, R; Amoroso, M [Physics Department, University of the West Indies, St. Augustine, Trinidad and Tobago, West Indies (Trinidad and Tobago)

    2010-07-01

    We used the scanning electron microscope to examine the cardiac tissue of a cow (Bos taurus), a pig (Sus scrofa), and a human (Homo sapiens). 1mm{sup 3} blocks of left ventricular tissue were prepared for SEM scanning by fixing in 96% ethanol followed by critical point drying (cryofixation), then sputter-coating with gold. The typical ridged structure of the myofibrils was observed for all the species. In addition crystal like structures were found in one of the samples of the heart tissue of the pig. These structures were investigated further using an EDVAC x-ray analysis attachment to the SEM. Elemental x-ray analysis showed highest peaks occurred for gold, followed by carbon, oxygen, magnesium and potassium. As the samples were coated with gold for conductivity, this highest peak is expected. Much lower peaks at carbon, oxygen, magnesium and potassium suggest that a cystallized salt such as a carbonate was present in the tissue before sacrifice.

  11. Why semicarbazide (SEM) is not an appropriate marker for the usage of nitrofurazone on agricultural animals.

    Science.gov (United States)

    Stadler, Richard H; Verzegnassi, Ludovica; Seefelder, Walburga; Racault, Lucie

    2015-01-01

    A comprehensive global database on semicarbazide (SEM) in foodstuffs and food ingredients is presented, with over 4000 data collected in foods such as seafood (crustaceans, fish powders), meat (beef, chicken powders), dairy products (e.g. raw milk, milk powders, whey, sweet buttermilk powder, caseinate, yoghurt, cheese), honey and other ingredients. The results provide evidence that the presence of SEM in certain dairy ingredients (whey, milk protein concentrates) is a by-product of chemical reactions taking place during the manufacturing process. Of the dairy ingredients tested (c. 2000 samples), 5.3% showed traces of SEM > 0.5 µg/kg. The highest incidence of SEM-positive samples in the dairy category were whey (powders, liquid) and milk protein concentrates (35% positive), with up to 13 µg/kg measured in a whey powder. Sweet buttermilk powder and caseinate followed, with 27% and 9.3% positives, respectively. SEM was not detected in raw milk, or in yoghurt or cheese. Of the crustacean products (shrimp and prawn powders) tested, 44% were positive for SEM, the highest value measured at 284 µg/kg. Fish powders revealed an unexpectedly high incidence of positive samples (25%); in this case, fraudulent addition of shellfish shells or carry-over during processing cannot be excluded. Overall, the data provide new insights into the occurrence of SEM (for dairy products and fish powders), substantially strengthening the arguments that SEM in certain food categories is not a conclusive marker of the use of the illegal antibiotic nitrofurazone.

  12. Mathematical model of the seismic electromagnetic signals (SEMS) in non crystalline substances

    Energy Technology Data Exchange (ETDEWEB)

    Dennis, L. C. C.; Yahya, N.; Daud, H.; Shafie, A. [Electromagnetic cluster, Universiti Teknologi Petronas, 31750 Tronoh, Perak (Malaysia)

    2012-09-26

    The mathematical model of seismic electromagnetic waves in non crystalline substances is developed and the solutions are discussed to show the possibility of improving the electromagnetic waves especially the electric field. The shear stress of the medium in fourth order tensor gives the equation of motion. Analytic methods are selected for the solutions written in Hansen vector form. From the simulated SEMS, the frequency of seismic waves has significant effects to the SEMS propagating characteristics. EM waves transform into SEMS or energized seismic waves. Traveling distance increases once the frequency of the seismic waves increases from 100% to 1000%. SEMS with greater seismic frequency will give seismic alike waves but greater energy is embedded by EM waves and hence further distance the waves travel.

  13. Mathematical model of the seismic electromagnetic signals (SEMS) in non crystalline substances

    International Nuclear Information System (INIS)

    Dennis, L. C. C.; Yahya, N.; Daud, H.; Shafie, A.

    2012-01-01

    The mathematical model of seismic electromagnetic waves in non crystalline substances is developed and the solutions are discussed to show the possibility of improving the electromagnetic waves especially the electric field. The shear stress of the medium in fourth order tensor gives the equation of motion. Analytic methods are selected for the solutions written in Hansen vector form. From the simulated SEMS, the frequency of seismic waves has significant effects to the SEMS propagating characteristics. EM waves transform into SEMS or energized seismic waves. Traveling distance increases once the frequency of the seismic waves increases from 100% to 1000%. SEMS with greater seismic frequency will give seismic alike waves but greater energy is embedded by EM waves and hence further distance the waves travel.

  14. The Effect of Different Cleaning Protocols on Post Space: A SEM Study

    Directory of Open Access Journals (Sweden)

    Giuseppe Lo Giudice

    2016-01-01

    Full Text Available Aim. Purpose of the present paper is to analyze the efficiency of different post-space irrigation protocols. Methods. 28 single rooted teeth were endodontically treated. After post-space preparation every sample was assigned to one of three experimental groups and to one control group. In each group different irrigation protocols were performed as follows: EDTA (Group A, 37% orthophosphoric acid (Group B, and EDTA + 37% orthophosphoric acid with ultrasounds activation (Group C. In the control group (Group D the irrigate association was not activated by ultrasounds. Three zones (coronal, middle, and apical of each sample were analyzed by using Scan Electron Microscopy (SEM without any metallization procedures. The presence of smear layer on the canal surface was qualitatively evaluated by applying Serafino’s score with values included between 0 and 2. Results. The results of the research showed how Group C recorded the better results (0.81±0.72. Group A and Group B showed lower mean scores (1.06±0.69 and 1.08±0.77; Group D showed the lowest mean score of 1.30±0.69. The SEM observation analysis demonstrated how the smear layer presence decreased in the crown-apical direction. Conclusions. The different post-space treatments statistically determine significant differences on the dentinal surfaces cleansing. The absence of ultrasonic activation lowers the cleansing efficacy of endocanalar irrigants, showing sensible differences among each post-space zone.

  15. FIB-SEM tomography in biology.

    Science.gov (United States)

    Kizilyaprak, Caroline; Bittermann, Anne Greet; Daraspe, Jean; Humbel, Bruno M

    2014-01-01

    Three-dimensional information is much easier to understand than a set of two-dimensional images. Therefore a layman is thrilled by the pseudo-3D image taken in a scanning electron microscope (SEM) while, when seeing a transmission electron micrograph, his imagination is challenged. First approaches to gain insight in the third dimension were to make serial microtome sections of a region of interest (ROI) and then building a model of the object. Serial microtome sectioning is a tedious and skill-demanding work and therefore seldom done. In the last two decades with the increase of computer power, sophisticated display options, and the development of new instruments, an SEM with a built-in microtome as well as a focused ion beam scanning electron microscope (FIB-SEM), serial sectioning, and 3D analysis has become far easier and faster.Due to the relief like topology of the microtome trimmed block face of resin-embedded tissue, the ROI can be searched in the secondary electron mode, and at the selected spot, the ROI is prepared with the ion beam for 3D analysis. For FIB-SEM tomography, a thin slice is removed with the ion beam and the newly exposed face is imaged with the electron beam, usually by recording the backscattered electrons. The process, also called "slice and view," is repeated until the desired volume is imaged.As FIB-SEM allows 3D imaging of biological fine structure at high resolution of only small volumes, it is crucial to perform slice and view at carefully selected spots. Finding the region of interest is therefore a prerequisite for meaningful imaging. Thin layer plastification of biofilms offers direct access to the original sample surface and allows the selection of an ROI for site-specific FIB-SEM tomography just by its pronounced topographic features.

  16. The Antiphagocytic Activity of SeM of Streptococcus equi Requires Capsule.

    Science.gov (United States)

    Timoney, John F; Suther, Pranav; Velineni, Sridhar; Artiushin, Sergey C

    2014-01-01

    Resistance to phagocytosis is a crucial virulence property of Streptococcus equi (Streptococcus equi subsp. equi; Se), the cause of equine strangles. The contribution and interdependence of capsule and SeM to killing in equine blood and neutrophils were investigated in naturally occurring strains of Se. Strains CF32, SF463 were capsule and SeM positive, strains Lex90, Lex93 were capsule negative and SeM positive and strains Se19, Se1-8 were capsule positive and SeM deficient. Phagocytosis and killing of Se19, Se1-8, Lex90 and Lex93 in equine blood and by neutrophils suspended in serum were significantly (P ≤ 0.02) greater compared to CF32 and SF463. The results indicate capsule and SeM are both required for resistance to phagocytosis and killing and that the anti-phagocytic property of SeM is greatly reduced in the absence of capsule.

  17. Sexual Arousal and Sexually Explicit Media (SEM)

    DEFF Research Database (Denmark)

    Hald, Gert Martin; Stulhofer, Aleksandar; Lange, Theis

    2018-01-01

    -mainstream and mainstream SEM groups, and (iii) to explore the validity and predictive accuracy of the Non-Mainstream Pornography Arousal Scale (NPAS). METHODS: Online cross-sectional survey of 2,035 regular SEM users in Croatia. MAIN OUTCOMES MEASURES: Patterns of sexual arousal to 27 different SEM themes, sexual...

  18. Human cardiac telocytes: 3D imaging by FIB-SEM tomography.

    Science.gov (United States)

    Cretoiu, D; Hummel, E; Zimmermann, H; Gherghiceanu, M; Popescu, L M

    2014-11-01

    Telocyte (TC) is a newly identified type of cell in the cardiac interstitium (www.telocytes.com). TCs are described by classical transmission electron microscopy as cells with very thin and long telopodes (Tps; cellular prolongations) having podoms (dilations) and podomers (very thin segments). TCs' three-dimensional (3D) morphology is still unknown. Cardiac TCs seem to be particularly involved in long and short distance intercellular signalling and, therefore, their 3D architecture is important for understanding their spatial connections. Using focused ion beam scanning electron microscopy (FIB-SEM) we show, for the first time, the whole ultrastructural anatomy of cardiac TCs. 3D reconstruction of cardiac TCs by FIB-SEM tomography confirms that they have long, narrow but flattened (ribbon-like) telopodes, with humps generated by the podoms. FIB-SEM tomography also confirms the network made by TCs in the cardiac interstitium through adherens junctions. This study provides the first FIB-SEM tomography of a human cell type. © 2014 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.

  19. The detection of metallic residues in skin stab wounds by means of SEM-EDS: A pilot study.

    Science.gov (United States)

    Palazzo, Elisa; Amadasi, Alberto; Boracchi, Michele; Gentile, Guendalina; Maciocco, Francesca; Marchesi, Matteo; Zoja, Riccardo

    2018-05-01

    The morphological analysis of stab wounds may often not be accurate enough to link it with the type of wounding weapon, but a further evaluation may be performed with the search for metallic residues left during the contact between the instrument and the skin. In this study, Scanning Electron Microscopy-Energy Dispersive Spectroscopy (SEM-EDS) was applied to the study of cadaveric stab wounds performed with kitchen knives composed of iron, chromium and nickel, in order to verify the presence of metallic residues on the wound's edge. Two groups of 10 corpses were selected: group A, including victims of stab wounds and a control group B (died of natural causes). Samplings were performed on the lesions and in intact areas of group A, whereas in group B sampling were performed in non-exposed intact skin. Samples were then analysed with optical microscopy and SEM-EDS. In group A, optical microscopic analysis showed the presence of vital haemorrhagic infiltration, while SEM-EDS showed evidence of microscopic metal traces, isolated or clustered, consisting of iron, chromium and nickel. Moreover, in two cases organic residues of calcium and phosphate were detected, as a probable sign of bone lesion. Control samples (group A in intact areas and group B), were negative for the search of exogenous material to optical microscopy and SEM-EDS. The results show the utility and possible application of the SEM-EDS in theidentification of metallic residues from sharp weapons on the skin. Copyright © 2017 The Chartered Society of Forensic Sciences. Published by Elsevier B.V. All rights reserved.

  20. Oxford CyberSEM: remote microscopy

    International Nuclear Information System (INIS)

    Rahman, M; Kirkland, A; Cockayne, D; Meyer, R

    2008-01-01

    The Internet has enabled researchers to communicate over vast geographical distances, sharing ideas and documents. e-Science, underpinned by Grid and Web Services, has enabled electronic communications to the next level where, in addition to document sharing, researchers can increasingly control high precision scientific instruments over the network. The Oxford CyberSEM project developed a simple Java applet via which samples placed in a JEOL 5510LV Scanning Electron Microscope (SEM) can be manipulated and examined collaboratively over the Internet. Designed with schoolchildren in mind, CyberSEM does not require any additional hardware or software other than a generic Java-enabled web browser. This paper reflects on both the technical and social challenges in designing real-time systems for controlling scientific equipments in collaborative environments. Furthermore, it proposes potential deployment beyond the classroom setting.

  1. The Effectiveness of Self-Expandable Metallic Stent Insertion in Treating Right-Sided Colonic Obstruction: A Comparison between SEMS and Decompression Tube Placement and an Investigation of the Safety and Difficulties of SEMS Insertion in Right Colons

    Directory of Open Access Journals (Sweden)

    Rintaro Moroi

    2014-01-01

    Full Text Available Objectives. Self-expandable metallic stent (SEMS is widely used to treat malignant colonic obstruction. However, most reports about SEMS insertion have concentrated on the left colon. This study aimed to (1 investigate the effectiveness of SEMS insertion compared with conventional decompression tube for right-sided colonic obstruction and (2 compare the safety and technical success of SEMS insertion between left- and right-sided colonic obstructions. Methods. The data from thirty-seven patients who underwent SEMS or conventional decompression tube placement for malignant colonic obstruction in our hospital were analyzed retrospectively. Technical and clinical success, complications, and technical difficulties were analyzed. We compared the results between SEMS insertion and decompression tube placement in right colons and the outcomes of SEMS insertion between right- and left-sided colonic obstructions. Results. For right colons, the clinical success rate of SEMS insertion (100% was significantly higher than that of decompression tube placement (55.9%. Concerning SEMS insertion, the technical difficulty and safety of SEMS insertion were similar between right- and left-sided colonic obstructions. Conclusion. SEMS insertion for right-sided colon is significantly more effective than conventional decompression tube placement, and this procedure was safer and less technically challenging than expected. SEMS insertion should be considered for treating right-sided malignant colonic obstruction.

  2. SEM-based characterization techniques

    International Nuclear Information System (INIS)

    Russell, P.E.

    1986-01-01

    The scanning electron microscope is now a common instrument in materials characterization laboratories. The basic role of the SEM as a topographic imaging system has steadily been expanding to include a variety of SEM-based analytical techniques. These techniques cover the range of basic semiconductor materials characterization to live-time device characterization of operating LSI or VLSI devices. This paper introduces many of the more commonly used techniques, describes the modifications or additions to a conventional SEM required to utilize the techniques, and gives examples of the use of such techniques. First, the types of signals available from a sample being irradiated by an electron beam are reviewed. Then, where applicable, the type of spectroscopy or microscopy which has evolved to utilize the various signal types are described. This is followed by specific examples of the use of such techniques to solve problems related to semiconductor technology. Techniques emphasized include: x-ray fluorescence spectroscopy, electron beam induced current (EBIC), stroboscopic voltage analysis, cathodoluminescnece and electron beam IC metrology. Current and future trends of some of the these techniques, as related to the semiconductor industry are discussed

  3. Development of a SEM-based low-energy in-line electron holography microscope for individual particle imaging.

    Science.gov (United States)

    Adaniya, Hidehito; Cheung, Martin; Cassidy, Cathal; Yamashita, Masao; Shintake, Tsumoru

    2018-05-01

    A new SEM-based in-line electron holography microscope has been under development. The microscope utilizes conventional SEM and BF-STEM functionality to allow for rapid searching of the specimen of interest, seamless interchange between SEM, BF-STEM and holographic imaging modes, and makes use of coherent low-energy in-line electron holography to obtain low-dose, high-contrast images of light element materials. We report here an overview of the instrumentation and first experimental results on gold nano-particles and carbon nano-fibers for system performance tests. Reconstructed images obtained from the holographic imaging mode of the new microscope show substantial image contrast and resolution compared to those acquired by SEM and BF-STEM modes, demonstrating the feasibility of high-contrast imaging via low-energy in-line electron holography. The prospect of utilizing the new microscope to image purified biological specimens at the individual particle level is discussed and electron optical issues and challenges to further improve resolution and contrast are considered. Copyright © 2018 Elsevier B.V. All rights reserved.

  4. Surface topography characterization using 3D stereoscopic reconstruction of SEM images

    Science.gov (United States)

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

    2018-06-01

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

  5. SEM based overlay measurement between resist and buried patterns

    Science.gov (United States)

    Inoue, Osamu; Okagawa, Yutaka; Hasumi, Kazuhisa; Shao, Chuanyu; Leray, Philippe; Lorusso, Gian; Baudemprez, Bart

    2016-03-01

    With the continuous shrink in pattern size and increased density, overlay control has become one of the most critical issues in semiconductor manufacturing. Recently, SEM based overlay of AEI (After Etch Inspection) wafer has been used for reference and optimization of optical overlay (both Image Based Overlay (IBO) and Diffraction Based Overlay (DBO)). Overlay measurement at AEI stage contributes monitor and forecast the yield after formation by etch and calibrate optical measurement tools. however those overlay value seems difficult directly for feedback to a scanner. Therefore, there is a clear need to have SEM based overlay measurements of ADI (After Develop Inspection) wafers in order to serve as reference for optical overlay and make necessary corrections before wafers go to etch. Furthermore, to make the corrections as accurate as possible, actual device like feature dimensions need to be measured post ADI. This device size measurement is very unique feature of CDSEM , which can be measured with smaller area. This is currently possible only with the CD-SEM. This device size measurement is very unique feature of CD-SEM , which can be measured with smaller area. In this study, we assess SEM based overlay measurement of ADI and AEI wafer by using a sample from an N10 process flow. First, we demonstrate SEM based overlay performance at AEI by using dual damascene process for Via 0 (V0) and metal 1 (M1) layer. We also discuss the overlay measurements between litho-etch-litho stages of a triple patterned M1 layer and double pattern V0. Second, to illustrate the complexities in image acquisition and measurement we will measure overlay between M1B resist and buried M1A-Hard mask trench. Finally, we will show how high accelerating voltage can detect buried pattern information by BSE (Back Scattering Electron). In this paper we discuss the merits of this method versus standard optical metrology based corrections.

  6. The luminal surface of thyroid cysts in SEM

    DEFF Research Database (Denmark)

    Zelander, T; Kirkeby, S

    1978-01-01

    Four of the five kinds of cells constituting the walls of thyroid cysts can be identified in the SEM. These are cuboidal cells, mucous cells, cells with large granules and ciliated cells. A correlation between SEM and TEM observations is attempted.......Four of the five kinds of cells constituting the walls of thyroid cysts can be identified in the SEM. These are cuboidal cells, mucous cells, cells with large granules and ciliated cells. A correlation between SEM and TEM observations is attempted....

  7. Space Experiment Module (SEM)

    Science.gov (United States)

    Brodell, Charles L.

    1999-01-01

    The Space Experiment Module (SEM) Program is an education initiative sponsored by the National Aeronautics and Space Administration (NASA) Shuttle Small Payloads Project. The program provides nationwide educational access to space for Kindergarten through University level students. The SEM program focuses on the science of zero-gravity and microgravity. Within the program, NASA provides small containers or "modules" for students to fly experiments on the Space Shuttle. The experiments are created, designed, built, and implemented by students with teacher and/or mentor guidance. Student experiment modules are flown in a "carrier" which resides in the cargo bay of the Space Shuttle. The carrier supplies power to, and the means to control and collect data from each experiment.

  8. Sexual Arousal and Sexually Explicit Media (SEM): Comparing Patterns of Sexual Arousal to SEM and Sexual Self-Evaluations and Satisfaction Across Gender and Sexual Orientation.

    Science.gov (United States)

    Hald, Gert Martin; Stulhofer, Aleksandar; Lange, Theis

    2018-03-01

    Investigations of patterns of sexual arousal to certain groups of sexually explicit media (SEM) in the general population in non-laboratory settings are rare. Such knowledge could be important to understand more about the relative specificity of sexual arousal in different SEM users. (i) To investigate whether sexual arousal to non-mainstream vs mainstream SEM contents could be categorized across gender and sexual orientation, (ii) to compare levels of SEM-induced sexual arousal, sexual satisfaction, and self-evaluated sexual interests and fantasies between non-mainstream and mainstream SEM groups, and (iii) to explore the validity and predictive accuracy of the Non-Mainstream Pornography Arousal Scale (NPAS). Online cross-sectional survey of 2,035 regular SEM users in Croatia. Patterns of sexual arousal to 27 different SEM themes, sexual satisfaction, and self-evaluations of sexual interests and sexual fantasies. Groups characterized by sexual arousal to non-mainstream SEM could be identified across gender and sexual orientation. These non-mainstream SEM groups reported more SEM use and higher average levels of sexual arousal across the 27 SEM themes assessed compared with mainstream SEM groups. Only few differences were found between non-mainstream and mainstream SEM groups in self-evaluative judgements of sexual interests, sexual fantasies, and sexual satisfaction. The internal validity and predictive accuracy of the NPAS was good across most user groups investigated. The findings suggest that in classified non-mainstream SEM groups, patterns of sexual arousal might be less fixated and category specific than previously assumed. Further, these groups are not more judgmental of their SEM-related sexual arousal patterns than groups characterized by patterns of sexual arousal to more mainstream SEM content. Moreover, accurate identification of non-mainstream SEM group membership is generally possible across gender and sexual orientation using the NPAS. Hald GM

  9. Observation of interactions between hydrophilic ionic liquid and water on wet agar gels by FE-SEM and its mechanism

    International Nuclear Information System (INIS)

    Takahashi, Chisato; Shirai, Takashi; Fuji, Masayoshi

    2012-01-01

    Highlights: ► The mechanism of SEM observation of agar gel using ionic liquid was investigated. ► Weak hydrogen bond between ionic liquid and water exist even under vacuum condition. ► Ionic liquid binding ability with water is useful for observing wet material using FE-SEM. ► We could optimize the water concentrations of sample of IL and wet material mixtures. ► SEM observation of fine morphology of agar gel in optimum water content. - Abstract: In the present study, an attempt is made to understand the mechanism of field emission electron microscopy (FE-SEM) observation of wet agar gel using a typical hydrophilic ionic liquid (IL) 1-butyl-3-methylimidazolium tetrafluoroborate; [BMIM][BF 4 ]. The IL interaction with water molecules within agar gel during sample preparation condition for FE-SEM observation was investigated using Raman spectroscopy. Results showed that water molecules within agar gel form weak hydrogen bond such as BF 4 − ⋯HOH⋯BF 4 − by interaction with BF 4 − of IL, and, it remained stable even under vacuum condition at 60 °C, 24 h. This interaction was found to be helpful for IL displacement of the water molecules within agar gel. From this study, it was found that the exact morphology of gel materials in FE-SEM condition can be observed by optimization of water concentrations of IL and gel mixtures. Thus, using IL, agar gel or any other material under wet condition can be observed without drying in FE-SEM chamber, and, present result gives an insight to the mechanism of FE-SEM observation of agar gel using IL without any conducting coating.

  10. Refinement of Monte Carlo simulations of electron-specimen interaction in low-voltage SEM

    International Nuclear Information System (INIS)

    Kieft, Erik; Bosch, Eric

    2008-01-01

    A Monte Carlo tool is presented for the simulation of secondary electron (SE) emission in a scanning electron microscope (SEM). The tool is based on the Geant4 platform of CERN. The modularity of this platform makes it comparatively easy to add and test individual physical models. Our aim has been to develop a flexible and generally applicable tool, while at the same time including a good description of low-energy (<50 eV) interactions of electrons with matter. To this end we have combined Mott cross-sections with phonon-scattering based cross-sections for the elastic scattering of electrons, and we have adopted a dielectric function theory approach for inelastic scattering and generation of SEs. A detailed model of the electromagnetic fields from an actual SEM column has been included in the tool for ray tracing of secondary and backscattered electrons. Our models have been validated against experimental results through comparison of the simulation results with experimental yields, SE spectra and SEM images. It is demonstrated that the resulting simulation package is capable of quantitatively predicting experimental SEM images and is an important tool in building a deeper understanding of SEM imaging.

  11. Microstructural Characterization of a Mg Matrix U-Mo Dispersion Fuel Plate Irradiated in the Advanced Test Reactor to High Fission Density: SEM Results

    Science.gov (United States)

    Keiser, Dennis D.; Jue, Jan-Fong; Miller, Brandon D.; Gan, Jian; Robinson, Adam B.; Medvedev, Pavel G.; Madden, James W.; Moore, Glenn A.

    2016-06-01

    Low-enriched (U-235 RERTR-8 experiment at high temperature, high fission rate, and high power, up to high fission density. This paper describes the results of the scanning electron microscopy (SEM) analysis of an irradiated fuel plate using polished samples and those produced with a focused ion beam. A follow-up paper will discuss the results of transmission electron microscopy (TEM) analysis. Using SEM, it was observed that even at very aggressive irradiation conditions, negligible chemical interaction occurred between the irradiated U-7Mo fuel particles and Mg matrix; no interconnection of fission gas bubbles from fuel particle to fuel particle was observed; the interconnected fission gas bubbles that were observed in the irradiated U-7Mo particles resulted in some transport of solid fission products to the U-7Mo/Mg interface; the presence of microstructural pathways in some U-9.1 Mo particles that could allow for transport of fission gases did not result in the apparent presence of large porosity at the U-7Mo/Mg interface; and, the Mg-Al interaction layers that were present at the Mg matrix/Al 6061 cladding interface exhibited good radiation stability, i.e. no large pores.

  12. Tillandsia stricta Sol (Bromeliaceae) leaves as monitors of airborne particulate matter-A comparative SEM methods evaluation: Unveiling an accurate and odd HP-SEM method.

    Science.gov (United States)

    de Oliveira, Martha Lima; de Melo, Edésio José Tenório; Miguens, Flávio Costa

    2016-09-01

    Airborne particulate matter (PM) has been included among the most important air pollutants by governmental environment agencies and academy researchers. The use of terrestrial plants for monitoring PM has been widely accepted, particularly when it is coupled with SEM/EDS. Herein, Tillandsia stricta leaves were used as monitors of PM, focusing on a comparative evaluation of Environmental SEM (ESEM) and High-Pressure SEM (HPSEM). In addition, specimens air-dried at formaldehyde atmosphere (AD/FA) were introduced as an SEM procedure. Hydrated specimen observation by ESEM was the best way to get information from T. stricta leaves. If any artifacts were introduced by AD/FA, they were indiscernible from those caused by CPD. Leaf anatomy was always well preserved. PM density was determined on adaxial and abaxial leaf epidermis for each of the SEM proceedings. When compared with ESEM, particle extraction varied from 0 to 20% in air-dried leaves while 23-78% of particles deposited on leaves surfaces were extracted by CPD procedures. ESEM was obviously the best choice over other methods but morphological artifacts increased in function of operation time while HPSEM operation time was without limit. AD/FA avoided the shrinkage observed in the air-dried leaves and particle extraction was low when compared with CPD. Structural and particle density results suggest AD/FA as an important methodological approach to air pollution biomonitoring that can be widely used in all electron microscopy labs. Otherwise, previous PM assessments using terrestrial plants as biomonitors and performed by conventional SEM could have underestimated airborne particulate matter concentration. © 2016 Wiley Periodicals, Inc.

  13. TEM and SEM observation of uranium induced renal necrosis and the result of chelates treatment on rats

    International Nuclear Information System (INIS)

    Sun Shiquan; Li Baoxing; Lai Chixiang; You Zhanyun

    1987-01-01

    The TEM (transmission electron microscope) and SEM (scanning electron microscope) observation of uranium induced renal necrosis and the result of chelates treatment on rats are reported. Ultrastructural changes in kidney related with the impairment of intracellular fluid transportation can be found after acute uranium intoxication in rats, such as: condensation and swelling of mitochondria, matrix edema, dilatation of intercellular space, disappearance of basal folds, thickening of basal web, intensification of basal lamina of the proximal convoluted tubule epithelium cells, and foot processes swelling, diminishing of endothelium fenestrae of the renal glomerulus. Heavy metal chelates DTPA and H-73-10 treatment may result in intracellular fluid accumulation and condensed grannule formation in lysosome. Treatment with these chelates in the critical stage of uranium intoxication may accelerate the necrosis instead of diminishing. This may be related to the augment of the load of lysosome and intracellular system of fluid transportation

  14. The application of SEM in analyzing the damage to the petroleum reservoirs caused by drilling fluids

    International Nuclear Information System (INIS)

    Abdul Razak Ismail

    1996-01-01

    An experimental study has been conducted to analyze the damage to the potential oil and gas reservoirs due to the invasion of drilling fluid during drilling operation. Two types of rock samples representing low and high permeability were used to stimulate the petroleum reservoirs. Sea water based drilling fluids were used in this study. Detail observations to the rock samples were analyzed using scanning electron microscope (SEM). The results of both permeability restoration and SEM observation showed that severe permeability impairments were obtained for high permeability rock. These results indicate that the relative size of the barite particles and the pore size distribution and characteristics of the formation play an important role in determining the damage caused by the drilling fluids

  15. In-SEM Raman microspectroscopy coupled with EDX - a case study of uranium reference particles

    International Nuclear Information System (INIS)

    Stefaniak, Elzbieta A.; Pointurier, Fabien; Marie, Olivier; Truyens, Jan; Aregbe, Yetunde

    2014-01-01

    Information about the molecular composition of airborne uranium-bearing particles may be useful as an additional tool for nuclear safeguards. In order to combine the detection of micrometer-sized particles with the analysis of their molecular forms, we used a hybrid system enabling Raman microanalysis in high vacuum inside a SEM chamber (SEM-SCA system). The first step involved an automatic scan of a sample to detect and save coordinates of uranium particles, along with X-ray microanalysis. In the second phase, the detected particles were relocated in a white light image and subjected to Raman microanalysis. The consecutive measurements by the two beams showed exceptional fragility of uranium particles, leading to their ultimate damage and change of uranium oxidation state. We used uranium reference particles prepared by hydrolysis of uranium hexafluoride to test the reliability of the Raman measurements inside the high vacuum. The results achieved by the hybrid system were verified by using a standalone Raman micro spectrometer. When deposited on exceptionally smooth substrates, uranyl fluoride particles smaller than 1000 nm could successfully be analyzed with the SEM-SCA system. (authors)

  16. The relationship between cost estimates reliability and BIM adoption: SEM analysis

    Science.gov (United States)

    Ismail, N. A. A.; Idris, N. H.; Ramli, H.; Rooshdi, R. R. Raja Muhammad; Sahamir, S. R.

    2018-02-01

    This paper presents the usage of Structural Equation Modelling (SEM) approach in analysing the effects of Building Information Modelling (BIM) technology adoption in improving the reliability of cost estimates. Based on the questionnaire survey results, SEM analysis using SPSS-AMOS application examined the relationships between BIM-improved information and cost estimates reliability factors, leading to BIM technology adoption. Six hypotheses were established prior to SEM analysis employing two types of SEM models, namely the Confirmatory Factor Analysis (CFA) model and full structural model. The SEM models were then validated through the assessment on their uni-dimensionality, validity, reliability, and fitness index, in line with the hypotheses tested. The final SEM model fit measures are: P-value=0.000, RMSEA=0.0790.90, TLI=0.956>0.90, NFI=0.935>0.90 and ChiSq/df=2.259; indicating that the overall index values achieved the required level of model fitness. The model supports all the hypotheses evaluated, confirming that all relationship exists amongst the constructs are positive and significant. Ultimately, the analysis verified that most of the respondents foresee better understanding of project input information through BIM visualization, its reliable database and coordinated data, in developing more reliable cost estimates. They also perceive to accelerate their cost estimating task through BIM adoption.

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

    Science.gov (United States)

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

    2017-08-01

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

  18. Sparsity-Based Super Resolution for SEM Images.

    Science.gov (United States)

    Tsiper, Shahar; Dicker, Or; Kaizerman, Idan; Zohar, Zeev; Segev, Mordechai; Eldar, Yonina C

    2017-09-13

    The scanning electron microscope (SEM) is an electron microscope that produces an image of a sample by scanning it with a focused beam of electrons. The electrons interact with the atoms in the sample, which emit secondary electrons that contain information about the surface topography and composition. The sample is scanned by the electron beam point by point, until an image of the surface is formed. Since its invention in 1942, the capabilities of SEMs have become paramount in the discovery and understanding of the nanometer world, and today it is extensively used for both research and in industry. In principle, SEMs can achieve resolution better than one nanometer. However, for many applications, working at subnanometer resolution implies an exceedingly large number of scanning points. For exactly this reason, the SEM diagnostics of microelectronic chips is performed either at high resolution (HR) over a small area or at low resolution (LR) while capturing a larger portion of the chip. Here, we employ sparse coding and dictionary learning to algorithmically enhance low-resolution SEM images of microelectronic chips-up to the level of the HR images acquired by slow SEM scans, while considerably reducing the noise. Our methodology consists of two steps: an offline stage of learning a joint dictionary from a sequence of LR and HR images of the same region in the chip, followed by a fast-online super-resolution step where the resolution of a new LR image is enhanced. We provide several examples with typical chips used in the microelectronics industry, as well as a statistical study on arbitrary images with characteristic structural features. Conceptually, our method works well when the images have similar characteristics, as microelectronics chips do. This work demonstrates that employing sparsity concepts can greatly improve the performance of SEM, thereby considerably increasing the scanning throughput without compromising on analysis quality and resolution.

  19. Advanced metrology by offline SEM data processing

    Science.gov (United States)

    Lakcher, Amine; Schneider, Loïc.; Le-Gratiet, Bertrand; Ducoté, Julien; Farys, Vincent; Besacier, Maxime

    2017-06-01

    Today's technology nodes contain more and more complex designs bringing increasing challenges to chip manufacturing process steps. It is necessary to have an efficient metrology to assess process variability of these complex patterns and thus extract relevant data to generate process aware design rules and to improve OPC models. Today process variability is mostly addressed through the analysis of in-line monitoring features which are often designed to support robust measurements and as a consequence are not always very representative of critical design rules. CD-SEM is the main CD metrology technique used in chip manufacturing process but it is challenged when it comes to measure metrics like tip to tip, tip to line, areas or necking in high quantity and with robustness. CD-SEM images contain a lot of information that is not always used in metrology. Suppliers have provided tools that allow engineers to extract the SEM contours of their features and to convert them into a GDS. Contours can be seen as the signature of the shape as it contains all the dimensional data. Thus the methodology is to use the CD-SEM to take high quality images then generate SEM contours and create a data base out of them. Contours are used to feed an offline metrology tool that will process them to extract different metrics. It was shown in two previous papers that it is possible to perform complex measurements on hotspots at different process steps (lithography, etch, copper CMP) by using SEM contours with an in-house offline metrology tool. In the current paper, the methodology presented previously will be expanded to improve its robustness and combined with the use of phylogeny to classify the SEM images according to their geometrical proximities.

  20. Cryo-Scanning Electron Microscopy (SEM) and Scanning Transmission Electron Microscopy (STEM)-in-SEM for Bio- and Organo-Mineral Interface Characterization in the Environment.

    Science.gov (United States)

    Wille, Guillaume; Hellal, Jennifer; Ollivier, Patrick; Richard, Annie; Burel, Agnes; Jolly, Louis; Crampon, Marc; Michel, Caroline

    2017-12-01

    Understanding biofilm interactions with surrounding substratum and pollutants/particles can benefit from the application of existing microscopy tools. Using the example of biofilm interactions with zero-valent iron nanoparticles (nZVI), this study aims to apply various approaches in biofilm preparation and labeling for fluorescent or electron microscopy and energy dispersive X-ray spectrometry (EDS) microanalysis for accurate observations. According to the targeted microscopy method, biofilms were sampled as flocs or attached biofilm, submitted to labeling using 4',6-diamidino-2-phenylindol, lectins PNA and ConA coupled to fluorescent dye or gold nanoparticles, and prepared for observation (fixation, cross-section, freezing, ultramicrotomy). Fluorescent microscopy revealed that nZVI were embedded in the biofilm structure as aggregates but the resolution was insufficient to observe individual nZVI. Cryo-scanning electron microscopy (SEM) observations showed nZVI aggregates close to bacteria, but it was not possible to confirm direct interactions between nZVI and cell membranes. Scanning transmission electron microscopy in the SEM (STEM-in-SEM) showed that nZVI aggregates could enter the biofilm to a depth of 7-11 µm. Bacteria were surrounded by a ring of extracellular polymeric substances (EPS) preventing direct nZVI/membrane interactions. STEM/EDS mapping revealed a co-localization of nZVI aggregates with lectins suggesting a potential role of EPS in nZVI embedding. Thus, the combination of divergent microscopy approaches is a good approach to better understand and characterize biofilm/metal interactions.

  1. Secondary emission monitor (SEM) grids.

    CERN Multimedia

    Patrice Loïez

    2002-01-01

    A great variety of Secondary Emission Monitors (SEM) are used all over the PS Complex. At other accelerators they are also called wire-grids, harps, etc. They are used to measure beam density profiles (from which beam size and emittance can be derived) in single-pass locations (not on circulating beams). Top left: two individual wire-planes. Top right: a combination of a horizontal and a vertical wire plane. Bottom left: a ribbon grid in its frame, with connecting wires. Bottom right: a SEM-grid with its insertion/retraction mechanism.

  2. International Conference on SEMS 2012

    CERN Document Server

    Liu, Chuang; Scientific explanation and methodology of science; SEMS 2012

    2014-01-01

    This volume contains the contributed papers of invitees to SEMS 2012 who have also given talks at the conference. The invitees are experts in philosophy of science and technology from Asia (besides China), Australia, Europe, Latin America, North America, as well as from within China. The papers in this volume represent the latest work of each researcher in his or her expertise; and as a result, they give a good representation of the cutting-edge researches in diverse areas in different parts of the world.

  3. Bases de Datos Semánticas

    Directory of Open Access Journals (Sweden)

    Irving Caro Fierros

    2016-12-01

    Full Text Available En 1992, cuando Tim Berners-Lee dio a conocer la primera  versión  de  la  Web,  su  visión  a  futuro  era  incorporar metadatos  con  información  semántica  en  las  páginas  Web.  Es precisamente   a   principios   de   este   siglo   que   inicia   el   auge repentino  de  la  Web  semántica  en  el  ambiente  académico  e Internet. El modelo de datos semántico se define como un modelo conceptual que permite definir el significado de los datos a través de  sus  relaciones  con  otros.  En  este  sentido,  el  formato  de representación  de  los  datos  es  fundamental  para  proporcionar información de carácter semántico. La tecnología enfocada en las bases de datos semánticas se encuentra actualmente en un punto de  inflexión,  al  pasar  del  ámbito  académico  y  de  investigación  a ser una opción comercial completa. En este artículo se realiza un análisis  del  concepto  de  base  de  datos  semántica.  También  se presenta  un  caso  de  estudio  donde  se  ejemplifican  operaciones básicas  que  involucran  la  gestión  de  la  información  almacenada en este tipo de base de datos.

  4. Three dimensional rock microstructures: insights from FIB-SEM tomography

    Science.gov (United States)

    Drury, Martyn; Pennock, Gill; de Winter, Matthijs

    2016-04-01

    Most studies of rock microstructures investigate two-dimensional sections or thin slices of three dimensional grain structures. With advances of X-ray and electron tomography methods the 3-D microstructure can be(relatively) routinely investigated on scales from a few microns to cm. 3D studies are needed to investigate the connectivity of microstructures and to test the assumptions we use to calculate 3D properties from 2D sections. We have used FIB-SEM tomography to study the topology of melts in synthetic olivine rocks, 3D crystal growth microstructures, pore networks and subgrain structures. The technique uses a focused ion beam to make serial sections with a spacing of tens to hundreds of nanometers. Each section is then imaged or mapped using the electron beam. The 3D geometry of grains and subgrains can be investigated using orientation contrast or EBSD mapping. FIB-SEM tomography of rocks and minerals can be limited by charging of the uncoated surfaces exposed by the ion beam. The newest generation of FIB-SEMs have much improved low voltage imaging capability allowing high resolution charge free imaging. Low kV FIB-SEM tomography is now widely used to study the connectivity of pore networks. In-situ fluids can also be studied using cryo-FIB-SEM on frozen samples, although special freezing techniques are needed to avoid artifacts produced by ice crystallization. FIB-SEM tomography is complementary, in terms of spatial resolution and sampled volume, to TEM tomography and X-ray tomography, and the combination of these methods can cover a wide range of scales. Our studies on melt topology in synthetic olivine rocks with a high melt content show that many grain boundaries are wetted by nanometre scale melt layers that are too thin to resolve by X-ray tomography. A variety of melt layer geometries occur consistent with several mechanisms of melt layer formation. The nature of melt geometries along triple line junctions and quadruple points can be resolved

  5. PAT and SEM study of porous silicon formed by anodization methods

    International Nuclear Information System (INIS)

    Liu Jian; Wei Long; Wang Huiyao; Ma Chuangxin; Wang Baoyi

    2000-01-01

    The porous silicon formed by anodization of crystal silicon was studied by positron annihilation technique (PAT) and scanning electron microscopy (SEM). The PAT experiments showed that the mean life and vacancy defects increased with the increasing anodization time. While the intensities of the longest lifetime, several ns-tens ns (ortho-positronium) dropped down. Small single-crystal Si spheres with mean radius of a few μm were observed by SEM after anodization. Pits with mean radius of a few μm from the divorcement of single-crystal spheres were also observed after further anodization. The increases of vacancy defects might be that the extension of structures of porous silicon towards inner layer with anodization time and caused more vacancy defects in inner layer. The SEM observation presented another possibility of the increase of density of vacancy defects in surface layer induced by the change of structures

  6. Partial Least Squares Strukturgleichungsmodellierung (PLS-SEM)

    DEFF Research Database (Denmark)

    Hair, Joseph F.; Hult, G. Tomas M.; Ringle, Christian M.

    (PLS-SEM) hat sich in der wirtschafts- und sozialwissenschaftlichen Forschung als geeignetes Verfahren zur Schätzung von Kausalmodellen behauptet. Dank der Anwenderfreundlichkeit des Verfahrens und der vorhandenen Software ist es inzwischen auch in der Praxis etabliert. Dieses Buch liefert eine...... anwendungsorientierte Einführung in die PLS-SEM. Der Fokus liegt auf den Grundlagen des Verfahrens und deren praktischer Umsetzung mit Hilfe der SmartPLS-Software. Das Konzept des Buches setzt dabei auf einfache Erläuterungen statistischer Ansätze und die anschauliche Darstellung zahlreicher Anwendungsbeispiele anhand...... einer einheitlichen Fallstudie. Viele Grafiken, Tabellen und Illustrationen erleichtern das Verständnis der PLS-SEM. Zudem werden dem Leser herunterladbare Datensätze, Aufgaben und weitere Fachartikel zur Vertiefung angeboten. Damit eignet sich das Buch hervorragend für Studierende, Forscher und...

  7. OpenCV-Based Nanomanipulation Information Extraction and the Probe Operation in SEM

    Directory of Open Access Journals (Sweden)

    Dongjie Li

    2015-02-01

    Full Text Available Aimed at the established telenanomanipulation system, the method of extracting location information and the strategies of probe operation were studied in this paper. First, the machine learning algorithm of OpenCV was used to extract location information from SEM images. Thus nanowires and probe in SEM images can be automatically tracked and the region of interest (ROI can be marked quickly. Then the location of nanowire and probe can be extracted from the ROI. To study the probe operation strategy, the Van der Waals force between probe and a nanowire was computed; thus relevant operating parameters can be obtained. With these operating parameters, the nanowire in 3D virtual environment can be preoperated and an optimal path of the probe can be obtained. The actual probe runs automatically under the telenanomanipulation system's control. Finally, experiments were carried out to verify the above methods, and results show the designed methods have achieved the expected effect.

  8. Protons, ions, electrons and the future of the SEM

    International Nuclear Information System (INIS)

    Joy, D C

    2010-01-01

    The Scanning Electron Microscope (SEM) is the most widely used high performance microscope in all fields of science but it is now reaching the theoretical limits of its performance. While advances in sources, optics, and detectors, can result in some improvement in performance the ultimate resolution is limited by fundamental physical constraints. One potential alternative is a scanning microscope utilizing light ions such as H+ and He+ . Such an instrument shares all of the benefits of the conventional SEM but is free from the constraints encountered when using electrons and could significantly extend the scope and success of scanning microscopy.

  9. Characterization of some biological specimens using TEM and SEM

    Science.gov (United States)

    Ghosh, Nabarun; Smith, Don W.

    2009-05-01

    The advent of novel techniques using the Transmission and Scanning Electron Microscopes improved observation on various biological specimens to characterize them. We studied some biological specimens using Transmission and Scanning Electron Microscopes. We followed negative staining technique with Phosphotungstic acid using bacterial culture of Bacillus subtilis. Negative staining is very convenient technique to view the structural morphology of different samples including bacteria, phage viruses and filaments in a cell. We could observe the bacterial cell wall and flagellum very well when trapped the negative stained biofilm from bacterial culture on a TEM grid. We cut ultra thin sections from the fixed root tips of Pisum sativum (Garden pea). Root tips were pre fixed with osmium tetroxide and post fixed with uranium acetate and placed in the BEEM capsule for block making. The ultrathin sections on the grid under TEM showed the granular chromatin in the nucleus. The protein bodies and large vacuoles with the storage materials were conspicuous. We followed fixation, critical point drying and sputter coating with gold to view the tissues with SEM after placing on stubs. SEM view of the leaf surface of a dangerous weed Tragia hispida showed the surface trichomes. These trichomes when break on touching releases poisonous content causing skin irritation. The cultured tissue from in vitro culture of Albizia lebbeck, a tree revealed the regenerative structures including leaf buds and stomata on the tissue surface. SEM and TEM allow investigating the minute details characteristic morphological features that can be used for classroom teaching.

  10. The LER/LWR metrology challenge for advance process control through 3D-AFM and CD-SEM

    Science.gov (United States)

    Faurie, P.; Foucher, J.; Foucher, A.-L.

    2009-12-01

    The continuous shrinkage in dimensions of microelectronic devices has reached such level, with typical gate length in advance R&D of less than 20nm combine with the introduction of new architecture (FinFET, Double gate...) and new materials (porous interconnect material, 193 immersion resist, metal gate material, high k materials...), that new process parameters have to be well understood and well monitored to guarantee sufficient production yield in a near future. Among these parameters, there are the critical dimensions (CD) associated to the sidewall angle (SWA) values, the line edge roughness (LER) and the line width roughness (LWR). Thus, a new metrology challenge has appeared recently and consists in measuring "accurately" the fabricated patterns on wafers in addition to measure the patterns on a repeatable way. Therefore, a great effort has to be done on existing techniques like CD-SEM, Scatterometry and 3D-AFM in order to develop them following the two previous criteria: Repeatability and Accuracy. In this paper, we will compare the 3D-AFM and CD-SEM techniques as a mean to measure LER and LWR on silicon and 193 resist and point out CD-SEM impact on the material during measurement. Indeed, depending on the material type, the interaction between the electron beam and the material or between the AFM tip and the material can vary a lot and subsequently can generate measurements bias. The first results tend to show that depending on CD-SEM conditions (magnification, number of acquisition frames) the final outputs can vary on a large range and therefore show that accuracy in such measurements are really not obvious to obtain. On the basis of results obtained on various materials that present standard sidewall roughness, we will show the limit of each technique and will propose different ways to improve them in order to fulfil advance roadmap requirements for the development of the next IC generation.

  11. High resolution SEM characterization of nano-precipitates in ODS steels.

    Science.gov (United States)

    Jóźwik, Iwona; Strojny-Nędza, Agata; Chmielewski, Marcin; Pietrzak, Katarzyna; Kurpaska, Łukasz; Nosewicz, Szymon

    2018-05-01

    The performance of the present-day scanning electron microscopy (SEM) extends far beyond delivering electronic images of the surface topography. Oxide dispersion strengthened (ODS) steel is on of the most promising materials for the future nuclear fusion reactor because of its good radiation resistance, and higher operation temperature up to 750°C. The microstructure of ODS should not exceed tens of nm, therefore there is a strong need in a fast and reliable technique for their characterization. In this work, the results of low-kV SEM characterization of nanoprecipitates formed in the ODS matrix are presented. Application of highly sensitive photo-diode BSE detector in SEM imaging allowed for the registration of single nm-sized precipitates in the vicinity of the ODS alloys. The composition of the precipitates has been confirmed by TEM-EDS. © 2018 Wiley Periodicals, Inc.

  12. Correlative SEM SERS for quantitative analysis of dimer nanoparticles.

    Science.gov (United States)

    Timmermans, F J; Lenferink, A T M; van Wolferen, H A G M; Otto, C

    2016-11-14

    A Raman microscope integrated with a scanning electron microscope was used to investigate plasmonic structures by correlative SEM-SERS analysis. The integrated Raman-SEM microscope combines high-resolution electron microscopy information with SERS signal enhancement from selected nanostructures with adsorbed Raman reporter molecules. Correlative analysis is performed for dimers of two gold nanospheres. Dimers were selected on the basis of SEM images from multi aggregate samples. The effect of the orientation of the dimer with respect to the polarization state of the laser light and the effect of the particle gap size on the Raman signal intensity is observed. Additionally, calculations are performed to simulate the electric near field enhancement. These simulations are based on the morphologies observed by electron microscopy. In this way the experiments are compared with the enhancement factor calculated with near field simulations and are subsequently used to quantify the SERS enhancement factor. Large differences between experimentally observed and calculated enhancement factors are regularly detected, a phenomenon caused by nanoscale differences between the real and 'simplified' simulated structures. Quantitative SERS experiments reveal the structure induced enhancement factor, ranging from ∼200 to ∼20 000, averaged over the full nanostructure surface. The results demonstrate correlative Raman-SEM microscopy for the quantitative analysis of plasmonic particles and structures, thus enabling a new analytical method in the field of SERS and plasmonics.

  13. Bases de Datos Semánticas

    OpenAIRE

    Irving Caro Fierros; Víctor Hugo Menéndez Domínguez; María Enriqueta Castellanos Bolaños

    2016-01-01

    En 1992, cuando Tim Berners-Lee dio a conocer la primera  versión  de  la  Web,  su  visión  a  futuro  era  incorporar metadatos  con  información  semántica  en  las  páginas  Web.  Es precisamente   a   principios   de   este   siglo   que   inicia   el   auge repentino  de  la  Web  semántica  en  el  ambiente  académico  e Internet. El modelo de datos semántico se define como un modelo conceptual que permite definir el significado de los datos a través de  sus  relaciones  con  otros.  E...

  14. Development and application of loop-mediated isothermal amplification methods targeting the seM gene for detection of Streptococcus equi subsp. equi.

    Science.gov (United States)

    Hobo, Seiji; Niwa, Hidekazu; Oku, Kazuomi

    2012-03-01

    Loop-mediated isothermal amplification (LAMP) constitutes a potentially valuable diagnostic tool for rapid diagnosis of contagious diseases. In this study, we developed a novel LAMP method (seM-LAMP) to detect the seM gene of Streptococcus equi subsp. equi (S. equi), the causative agent of strangles in equids. The seM-LAMP successfully amplified the target sequence of the seM gene at 63°C within 60 min. The sensitivity of the seM-LAMP was slightly lower than the 2nd reaction of the seM semi-nested PCR. To evaluate the species specificity of the seM-LAMP, we tested 100 S. equi and 189 non-S. equi strains. Significant amplification of the DNA originating from S. equi was observed within 60 min incubation, but no amplification of non-S. equi DNA occurred. The results were identical to those of seM semi-nested PCR. To investigate the clinical usefulness of the methods, the seM-LAMP and the seM semi-nested PCR were used to screen 590 nasal swabs obtained during an outbreak of strangles. Both methods showed that 79 and 511 swabs were S. equi positive and negative, respectively, and the results were identical to those of the culture examination. These results indicate that the seM-LAMP is potentially useful for the reliable routine diagnosis of Streptococcus equi subsp. equi infections.

  15. Quantitative Determination of Noa (Naturally Occurring Asbestos) in Rocks : Comparison Between Pcom and SEM Analysis

    Science.gov (United States)

    Baietto, Oliviero; Amodeo, Francesco; Giorgis, Ilaria; Vitaliti, Martina

    2017-04-01

    The quantification of NOA (Naturally Occurring Asbestos) in a rock or soil matrix is complex and subject to numerous errors. The purpose of this study is to compare two fundamental methodologies used for the analysis: the first one uses Phase Contrast Optical Microscope (PCOM) while the second one uses Scanning Electron Microscope (SEM). The two methods, although they provide the same result, which is the asbestos mass to total mass ratio, have completely different characteristics and both present pros and cons. The current legislation in Italy involves the use of SEM, DRX, FTIR, PCOM (DM 6/9/94) for the quantification of asbestos in bulk materials and soils and the threshold beyond which the material is considered as hazardous waste is a concentration of asbestos fiber of 1000 mg/kg.(DM 161/2012). The most used technology is the SEM which is the one among these with the better analytical sensitivity.(120mg/Kg DM 6 /9/94) The fundamental differences among the analyses are mainly: - Amount of analyzed sample portion - Representativeness of the sample - Resolution - Analytical precision - Uncertainty of the methodology - Operator errors Due to the problem of quantification of DRX and FTIR (1% DM 6/9/94) our Asbestos Laboratory (DIATI POLITO) since more than twenty years apply the PCOM methodology and in the last years the SEM methodology for quantification of asbestos content. The aim of our research is to compare the results obtained from a PCOM analysis with the results provided by SEM analysis on the base of more than 100 natural samples both from cores (tunnel-boring or explorative-drilling) and from tunnelling excavation . The results obtained show, in most cases, a good correlation between the two techniques. Of particular relevance is the fact that both techniques are reliable for very low quantities of asbestos, even lower than the analytical sensitivity. This work highlights the comparison between the two techniques emphasizing strengths and weaknesses of

  16. The SEM description of interaction of a transient electromagnetic wave with an object

    Science.gov (United States)

    Pearson, L. W.; Wilton, D. R.

    1980-01-01

    The singularity expansion method (SEM), proposed as a means for determining and representing the transient surface current density induced on a scatterer by a transient electromagnetic wave is described. The resulting mathematical description of the transient surface current on the object is discussed. The data required to represent the electromagnetic scattering properties of a given object are examined. Experimental methods which were developed for the determination of the SEM description are discussed. The feasibility of characterizing the surface current induced on aircraft flying in proximity to a lightning stroke by way of SEM is examined.

  17. In-line CD metrology with combined use of scatterometry and CD-SEM

    Science.gov (United States)

    Asano, Masafumi; Ikeda, Takahiro; Koike, Toru; Abe, Hideaki

    2006-03-01

    Measurement characteristics in scatterometry and CD-SEM for lot acceptance sampling of inline critical dimension (CD) metrology were investigated by using a statistical approach with Monte Carlo simulation. By operation characteristics curve analysis, producer's risk and consumer's risk arising from sampling were clarified. Single use of scatterometry involves a higher risk, such risk being particularly acute in the case of large intra-chip CD variation because it is unable to sufficiently monitor intra-chip CD variation including local CD error. Substituting scatterometry for conventional SEM metrology is accompanied with risks, resulting in the increase of unnecessary cost. The combined use of scatterometry and SEM metrology in which the sampling plan for SEM is controlled by scatterometry is a promising metrology from the viewpoint of the suppression of risks and cost. This is due to the effect that CD errors existing in the distribution tails are efficiently caught.

  18. Automated CD-SEM recipe creation technology for mass production using CAD data

    Science.gov (United States)

    Kawahara, Toshikazu; Yoshida, Masamichi; Tanaka, Masashi; Ido, Sanyu; Nakano, Hiroyuki; Adachi, Naokaka; Abe, Yuichi; Nagatomo, Wataru

    2011-03-01

    Critical Dimension Scanning Electron Microscope (CD-SEM) recipe creation needs sample preparation necessary for matching pattern registration, and recipe creation on CD-SEM using the sample, which hinders the reduction in test production cost and time in semiconductor manufacturing factories. From the perspective of cost reduction and improvement of the test production efficiency, automated CD-SEM recipe creation without the sample preparation and the manual operation has been important in the production lines. For the automated CD-SEM recipe creation, we have introduced RecipeDirector (RD) that enables the recipe creation by using Computer-Aided Design (CAD) data and text data that includes measurement information. We have developed a system that automatically creates the CAD data and the text data necessary for the recipe creation on RD; and, for the elimination of the manual operation, we have enhanced RD so that all measurement information can be specified in the text data. As a result, we have established an automated CD-SEM recipe creation system without the sample preparation and the manual operation. For the introduction of the CD-SEM recipe creation system using RD to the production lines, the accuracy of the pattern matching was an issue. The shape of design templates for the matching created from the CAD data was different from that of SEM images in vision. Thus, a development of robust pattern matching algorithm that considers the shape difference was needed. The addition of image processing of the templates for the matching and shape processing of the CAD patterns in the lower layer has enabled the robust pattern matching. This paper describes the automated CD-SEM recipe creation technology for the production lines without the sample preparation and the manual operation using RD applied in Sony Semiconductor Kyusyu Corporation Kumamoto Technology Center (SCK Corporation Kumamoto TEC).

  19. Recent advances in 3D SEM surface reconstruction.

    Science.gov (United States)

    Tafti, Ahmad P; Kirkpatrick, Andrew B; Alavi, Zahrasadat; Owen, Heather A; Yu, Zeyun

    2015-11-01

    The scanning electron microscope (SEM), as one of the most commonly used instruments in biology and material sciences, employs electrons instead of light to determine the surface properties of specimens. However, the SEM micrographs still remain 2D images. To effectively measure and visualize the surface attributes, we need to restore the 3D shape model from the SEM images. 3D surface reconstruction is a longstanding topic in microscopy vision as it offers quantitative and visual information for a variety of applications consisting medicine, pharmacology, chemistry, and mechanics. In this paper, we attempt to explain the expanding body of the work in this area, including a discussion of recent techniques and algorithms. With the present work, we also enhance the reliability, accuracy, and speed of 3D SEM surface reconstruction by designing and developing an optimized multi-view framework. We then consider several real-world experiments as well as synthetic data to examine the qualitative and quantitative attributes of our proposed framework. Furthermore, we present a taxonomy of 3D SEM surface reconstruction approaches and address several challenging issues as part of our future work. Copyright © 2015 Elsevier Ltd. All rights reserved.

  20. Characterisation of nanoparticles by means of high-resolution SEM/EDS in transmission mode

    International Nuclear Information System (INIS)

    Hodoroaba, V-D; Rades, S; Mielke, J; Ortel, E; Salge, T; Schmidt, R

    2016-01-01

    Advances in scanning electron microscopy (SEM) enable the high-resolution imaging of single nanoparticles (NPs) with sizes well below 10 nm. The SEM analysis in transmission mode (T-SEM) of NPs on thin film supports has many benefits when compared to the analysis of NPs on bulk substrates. The enhanced material (mass - thickness) contrast of the T-SEM imaging mode is well suited for in-depth and, particularly valuable, to very accurate, traceable, lateral dimensional measurements of NPs. Compared to samples prepared on bulk substrates, T-SEM with energy dispersive X-ray spectroscopy (EDS) achieves a drastically improved spatial resolution of the emitted X-rays. The poor signal-to-noise ratio of the X-ray spectra emitted by a single nanoparticle (NP) can be improved by the use of high-sensitivity (high collection solid angle) silicon drift (SDD), energy-dispersive X-ray spectrometers (EDS). The EDS spectral imaging of a single NP with a spatial resolution below 10 nm has become possible. This is demonstrated by means of various examples of nanostructures. Advanced data processing of T-SEM/EDS results sets the stage for the automated classification of NPs by feature analysis. This method combines the detection of morphological structures of interest by image processing of T-SEM micrographs with the chemical classification by EDS. (paper)

  1. CD-SEM real time bias correction using reference metrology based modeling

    Science.gov (United States)

    Ukraintsev, V.; Banke, W.; Zagorodnev, G.; Archie, C.; Rana, N.; Pavlovsky, V.; Smirnov, V.; Briginas, I.; Katnani, A.; Vaid, A.

    2018-03-01

    Accuracy of patterning impacts yield, IC performance and technology time to market. Accuracy of patterning relies on optical proximity correction (OPC) models built using CD-SEM inputs and intra die critical dimension (CD) control based on CD-SEM. Sub-nanometer measurement uncertainty (MU) of CD-SEM is required for current technologies. Reported design and process related bias variation of CD-SEM is in the range of several nanometers. Reference metrology and numerical modeling are used to correct SEM. Both methods are slow to be used for real time bias correction. We report on real time CD-SEM bias correction using empirical models based on reference metrology (RM) data. Significant amount of currently untapped information (sidewall angle, corner rounding, etc.) is obtainable from SEM waveforms. Using additional RM information provided for specific technology (design rules, materials, processes) CD extraction algorithms can be pre-built and then used in real time for accurate CD extraction from regular CD-SEM images. The art and challenge of SEM modeling is in finding robust correlation between SEM waveform features and bias of CD-SEM as well as in minimizing RM inputs needed to create accurate (within the design and process space) model. The new approach was applied to improve CD-SEM accuracy of 45 nm GATE and 32 nm MET1 OPC 1D models. In both cases MU of the state of the art CD-SEM has been improved by 3x and reduced to a nanometer level. Similar approach can be applied to 2D (end of line, contours, etc.) and 3D (sidewall angle, corner rounding, etc.) cases.

  2. Epigallocatechin-3-gallate rapidly remodels PAP85-120, SEM1(45-107, and SEM2(49-107 seminal amyloid fibrils

    Directory of Open Access Journals (Sweden)

    Laura M. Castellano

    2015-09-01

    Full Text Available Semen harbors amyloid fibrils formed by proteolytic fragments of prostatic acid phosphatase (PAP248-286 and PAP85-120 and semenogelins (SEM1 and SEM2 that potently enhance HIV infectivity. Amyloid but not soluble forms of these peptides enhance HIV infection. Thus, agents that remodel these amyloid fibrils could prevent HIV transmission. Here, we confirm that the green tea polyphenol, epigallocatechin-3-gallate (EGCG, slowly remodels fibrils formed by PAP248-286 termed SEVI (semen derived enhancer of viral infection and also exerts a direct anti-viral effect. We elucidate for the first time that EGCG remodels PAP85-120, SEM1(45-107, and SEM2(49-107 fibrils more rapidly than SEVI fibrils. We establish EGCG as the first small molecule that can remodel all four classes of seminal amyloid. The combined anti-amyloid and anti-viral properties of EGCG could have utility in preventing HIV transmission.

  3. SEM-EBSP能知道些什么

    Institute of Scientific and Technical Information of China (English)

    张唯敏

    2003-01-01

    @@ 1 SEM-EBSP是什么 所谓SEM-EBSP是指采用在扫描电子显微镜(SEM)镜体中的反射电子菊池线衍射的结晶方位分析.被称为菊池图形的衍射图形可因结晶的稍许倾斜而大大地改变其位置,因此,通过解析菊池图形就能正确地知道结晶方位.

  4. Stirling Energy Module (SEM) as Micro-CHP; Stirling Energy Module (SEM) als Mini-BHKW

    Energy Technology Data Exchange (ETDEWEB)

    Schlegel, A.

    2006-07-01

    Since many years, a lot of effort is being put into the development of combined heat and power units (CHP) for the decentralised production of electric power. For long time, the main focus was on fuel cells. In the meantime, the Stirling technology, which is based upon classical mechanical engineering and innovative technical concepts, proceeded in its development as well. The following article describes the technology and the actual state of the development of the Stirling Energy Module (SEM) for the application as Micro-CHP in one-family-houses. SEM is based on a free-piston engine with a linear power generator, producing electric power while heating. The Stirling engine is planned the be introduced into the market as a replacement for the conventional heating systems within a couple of years. (author)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-10-01

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

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

    International Nuclear Information System (INIS)

    Dhillon, Shweta; Kant, Rama

    2013-01-01

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

  7. lsnjbhakta@gmail.com A Comparative SEM-EDS Elemental

    African Journals Online (AJOL)

    Michael Horsfall

    effect on food production in terrestrial and aquatic compartment in ... Processing and SEM-EDS analysis of mud: In the laboratory, the ... and for SEM image observation was 15 kV, applying .... by weathering in the Omi acid clay deposit, Japan.

  8. SEM Characterization of an Irradiated Monolithic U-10Mo Fuel Plate

    International Nuclear Information System (INIS)

    Keiser, D.D. Jr.; Jue, J.F.; Robinson, A.B.

    2010-01-01

    Results of scanning electron microscopy (SEM) characterization of irradiated U-7Mo dispersion fuel plates with differing amounts of matrix Si have been reported. However, to date, no results of SEM analysis of irradiated U-Mo monolithic fuel plates have been reported. This paper describes the first SEM characterization results for an irradiated monolithic U-10Mo fuel plate. Two samples from this fuel plate were characterized. One sample was produced from the low-flux side of the fuel plate, and another was produced at the high-flux side of the fuel plate. This characterization focused on the microstructural features present at the U-10Mo foil/cladding interface, particularly the interaction zone that had developed during fabrication and irradiation. In addition, the microstructure of the foil itself was investigated, along with the morphology of the observed fission gas bubbles. It was observed that a Si-rich interaction layer was present at the U-10Mo foil/cladding interface that exhibited relatively good irradiation behavior, and within the U-10Mo foil the microstructural features differed in some respects from what is typically seen in the U-Mo powders of an irradiated dispersion fuel.

  9. SEM and Raman studies of CNT films on porous Si

    Science.gov (United States)

    Belka, R.; Keczkowska, J.; Suchańska, M.; Firek, P.; Wronka, H.; Kozłowski, M.; Radomska, J.; Czerwosz, E.; Craciunoiu, F.

    2017-08-01

    Carbon nanotube (CNT) films deposited on different porous silica substrates were studied by Scanning Electron Microscopy (SEM) and Raman Spectroscopy (RS). The films samples were prepared by a two-step method consisting of PVD and CVD processes. In the first step the nanocomposite Ni-C film was obtained by evaporation in dynamic vacuum from two separated sources of fullerenes and nickel acetate. Those films were deposited on porous silica and DLC/porous silica substrates. Analysis of SEM imaging showed that the obtained film are composed of carbon nanotubes, the distribution, size and quality of which depend on the type of substrate. The CNT films were studied by RS method to determine the influence of the substrate type on disordering of carbonaceous structure and quality of CNT in deposited films.

  10. Preliminary SEM Observations on the Surface of Elastomeric Impression Materials after Immersion or Ozone Disinfection

    Science.gov (United States)

    Prombonas, Anthony; Yannikakis, Stavros; Karampotsos, Thanasis; Katsarou, Martha-Spyridoula; Drakoulis, Nikolaos

    2016-01-01

    Introduction Surface integrity of dental elastomeric impression materials that are subjected to disinfection is of major importance for the quality of the final prosthetic restorations. Aim The aim of this qualitative Scanning Electronic Microscopy (SEM) study was to reveal the effects of immersion or ozone disinfection on the surface of four dental elastomeric impression materials. Materials and Methods Four dental elastomeric impression material brands were used (two vinyl polysiloxane silicones, one polyether, and one vinyl polyether silicone). Total of 32 specimens were fabricated, eight from each impression material. Specimens were immersion (0.525% sodium hypochlorite solution or 0.3% benzalkonium chloride solution) or ozone disinfected or served as controls and examined with SEM. Results Surface degradation was observed on several speci-mens disinfected with 0.525% sodium hypochlorite solution. Similar wavy-wrinkling surface structures were observed in almost all specimens, when treated either with 0.3% benzalkonium chloride solution or ozone. Conclusion The SEM images obtained from this study revealed that both immersion disinfectants and ozone show similar impression material surface alterations. Ozone seems to be non-inferior as compared to immersion disinfectants, but superior as to environmental protection. PMID:28208993

  11. Feature evaluation of complex hysteresis smoothing and its practical applications to noisy SEM images.

    Science.gov (United States)

    Suzuki, Kazuhiko; Oho, Eisaku

    2013-01-01

    Quality of a scanning electron microscopy (SEM) image is strongly influenced by noise. This is a fundamental drawback of the SEM instrument. Complex hysteresis smoothing (CHS) has been previously developed for noise removal of SEM images. This noise removal is performed by monitoring and processing properly the amplitude of the SEM signal. As it stands now, CHS may not be so utilized, though it has several advantages for SEM. For example, the resolution of image processed by CHS is basically equal to that of the original image. In order to find wide application of the CHS method in microscopy, the feature of CHS, which has not been so clarified until now is evaluated correctly. As the application of the result obtained by the feature evaluation, cursor width (CW), which is the sole processing parameter of CHS, is determined more properly using standard deviation of noise Nσ. In addition, disadvantage that CHS cannot remove the noise with excessively large amplitude is improved by a certain postprocessing. CHS is successfully applicable to SEM images with various noise amplitudes. © Wiley Periodicals, Inc.

  12. SEM Evaluation of Internal Adaptation of Bases and Liners under Composite Restorations

    Directory of Open Access Journals (Sweden)

    Dimitrios Dionysopoulos

    2014-04-01

    Full Text Available The aim of this study was to evaluate the interfacial microgaps generating between different materials and between materials and dentin after polymerization of the composite restorations, using SEM. Methods: The materials investigated were a composite, an adhesive, a RMGI, and a calcium hydroxide. Thirty third molars were selected and two circular class V cavities (5 mm × 3 mm for each tooth were made. The teeth were randomly assigned into six groups and restored with a combination of the materials. The specimens were subjected to thermocycling and each tooth was sectioned mesiodistally in two halves. Each half was sectioned along the longitudinal axis through the center of the restorations to obtain a slice of 2 mm. The specimens were examined under SEM. The interfaces between the liners, the liners and dentin, and between the liners and the composite were examined for microgaps. Results: The results showed that there was not any significant difference in the mean width of microgaps in the interfaces between Dycal-dentin and Vitrebond-dentin (p>0.05. However, the width of microgaps in the interfaces between dentin-Clearfil Tri-S Bond was significantly smaller (p<0.05. The use of Clearfil Tri-S Bond reduced the possibility of microgap formation between the bonded interface and the materials tested.

  13. AFM and SEM study of the effects of etching on IPS-Empress 2 TM dental ceramic

    Science.gov (United States)

    Luo, X.-P.; Silikas, N.; Allaf, M.; Wilson, N. H. F.; Watts, D. C.

    2001-10-01

    The aim of this study was to investigate the effects of increasing etching time on the surface of the new dental material, IPS-Empress 2 TM glass ceramic. Twenty one IPS-Empress 2 TM glass ceramic samples were made from IPS-Empress 2 TM ingots through lost-wax, hot-pressed ceramic fabrication technology. All samples were highly polished and cleaned ultrasonically for 5 min in acetone before and after etching with 9.6% hydrofluoric acid gel. The etching times were 0, 10, 20, 30, 60, 90 and 120 s respectively. Microstructure was analysed by scanning electron microscopy (SEM) and atomic force microscopy (AFM) was used to evaluate the surface roughness and topography. Observations with SEM showed that etching with hydrofluoric acid resulted in preferential dissolution of glass matrix, and that partially supported crystals within the glass matrix were lost with increasing etching time. AFM measurements indicated that etching increased the surface roughness of the glass-ceramic. A simple least-squares linear regression was used to establish a relationship between surface roughness parameters ( Ra, RMS), and etching time, for which r2>0.94. This study demonstrates the benefits of combining two microscopic methods for a better understanding of the surface. SEM showed the mode of action of hydrofluoric acid on the ceramic and AFM provided valuable data regarding the extent of surface degradation relative to etching time.

  14. Classification and printability of EUV mask defects from SEM images

    Science.gov (United States)

    Cho, Wonil; Price, Daniel; Morgan, Paul A.; Rost, Daniel; Satake, Masaki; Tolani, Vikram L.

    2017-10-01

    Classification and Printability of EUV Mask Defects from SEM images EUV lithography is starting to show more promise for patterning some critical layers at 5nm technology node and beyond. However, there still are many key technical obstacles to overcome before bringing EUV Lithography into high volume manufacturing (HVM). One of the greatest obstacles is manufacturing defect-free masks. For pattern defect inspections in the mask-shop, cutting-edge 193nm optical inspection tools have been used so far due to lacking any e-beam mask inspection (EBMI) or EUV actinic pattern inspection (API) tools. The main issue with current 193nm inspection tools is the limited resolution for mask dimensions targeted for EUV patterning. The theoretical resolution limit for 193nm mask inspection tools is about 60nm HP on masks, which means that main feature sizes on EUV masks will be well beyond the practical resolution of 193nm inspection tools. Nevertheless, 193nm inspection tools with various illumination conditions that maximize defect sensitivity and/or main-pattern modulation are being explored for initial EUV defect detection. Due to the generally low signal-to-noise in the 193nm inspection imaging at EUV patterning dimensions, these inspections often result in hundreds and thousands of defects which then need to be accurately reviewed and dispositioned. Manually reviewing each defect is difficult due to poor resolution. In addition, the lack of a reliable aerial dispositioning system makes it very challenging to disposition for printability. In this paper, we present the use of SEM images of EUV masks for higher resolution review and disposition of defects. In this approach, most of the defects detected by the 193nm inspection tools are first imaged on a mask SEM tool. These images together with the corresponding post-OPC design clips are provided to KLA-Tencor's Reticle Decision Center (RDC) platform which provides ADC (Automated Defect Classification) and S2A (SEM

  15. Assessment of engineered surfaces roughness by high-resolution 3D SEM photogrammetry

    Energy Technology Data Exchange (ETDEWEB)

    Gontard, L.C., E-mail: lionelcg@gmail.com [Departamento de Ciencia de los Materiales e Ingeniería Metalúrgica y Química Inorgánica, Universidad de Cádiz, Puerto Real 11510 (Spain); López-Castro, J.D.; González-Rovira, L. [Departamento de Ciencia de los Materiales e Ingeniería Metalúrgica y Química Inorgánica, Escuela Superior de Ingeniería, Laboratorio de Corrosión, Universidad de Cádiz, Puerto Real 11519 (Spain); Vázquez-Martínez, J.M. [Departamento de Ingeniería Mecánica y Diseño Industrial, Escuela Superior de Ingeniería, Universidad de Cádiz, Puerto Real 11519 (Spain); Varela-Feria, F.M. [Servicio de Microscopía Centro de Investigación, Tecnología e Innovación (CITIUS), Universidad de Sevilla, Av. Reina Mercedes 4b, 41012 Sevilla (Spain); Marcos, M. [Departamento de Ingeniería Mecánica y Diseño Industrial, Escuela Superior de Ingeniería, Universidad de Cádiz, Puerto Real 11519 (Spain); and others

    2017-06-15

    Highlights: • We describe a method to acquire a high-angle tilt series of SEM images that is symmetrical respect to the zero tilt of the sample stage. The method can be applied in any SEM microscope. • Using the method, high-resolution 3D SEM photogrammetry can be applied on planar surfaces. • 3D models of three surfaces patterned with grooves are reconstructed with high resolution using multi-view freeware photogrammetry software as described in LC Gontard et al. Ultramicroscopy, 2016. • From the 3D models roughness parameters are measured • 3D SEM high-resolution photogrammetry is compared with two conventional methods used for roughness characetrization: stereophotogrammetry and contact profilometry. • It provides three-dimensional information with high-resolution that is out of reach for any other metrological technique. - Abstract: We describe a methodology to obtain three-dimensional models of engineered surfaces using scanning electron microscopy and multi-view photogrammetry (3DSEM). For the reconstruction of the 3D models of the surfaces we used freeware available in the cloud. The method was applied to study the surface roughness of metallic samples patterned with parallel grooves by means of laser. The results are compared with measurements obtained using stylus profilometry (PR) and SEM stereo-photogrammetry (SP). The application of 3DSEM is more time demanding than PR or SP, but it provides a more accurate representation of the surfaces. The results obtained with the three techniques are compared by investigating the influence of sampling step on roughness parameters.

  16. A Data-Driven Approach to SEM Development at a Two-Year College

    Science.gov (United States)

    Pirius, Landon K.

    2014-01-01

    This article explores implementation of strategic enrollment management (SEM) at a two-year college and why SEM is critical to the long-term viability of an institution. This article also outlines the five initial steps needed to implement SEM, including identifying SEM leadership, building a SEM committee, developing a common understanding of…

  17. Minimal resin embedding of multicellular specimens for targeted FIB-SEM imaging.

    Science.gov (United States)

    Schieber, Nicole L; Machado, Pedro; Markert, Sebastian M; Stigloher, Christian; Schwab, Yannick; Steyer, Anna M

    2017-01-01

    Correlative light and electron microscopy (CLEM) is a powerful tool to perform ultrastructural analysis of targeted tissues or cells. The large field of view of the light microscope (LM) enables quick and efficient surveys of the whole specimen. It is also compatible with live imaging, giving access to functional assays. CLEM protocols take advantage of the features to efficiently retrace the position of targeted sites when switching from one modality to the other. They more often rely on anatomical cues that are visible both by light and electron microscopy. We present here a simple workflow where multicellular specimens are embedded in minimal amounts of resin, exposing their surface topology that can be imaged by scanning electron microscopy (SEM). LM and SEM both benefit from a large field of view that can cover whole model organisms. As a result, targeting specific anatomic locations by focused ion beam-SEM (FIB-SEM) tomography becomes straightforward. We illustrate this application on three different model organisms, used in our laboratory: the zebrafish embryo Danio rerio, the marine worm Platynereis dumerilii, and the dauer larva of the nematode Caenorhabditis elegans. Here we focus on the experimental steps to reduce the amount of resin covering the samples and to image the specimens inside an FIB-SEM. We expect this approach to have widespread applications for volume electron microscopy on multiple model organisms. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. Distinction between amorphous and healed planar deformation features in shocked quartz using composite color scanning electron microscope cathodoluminescence (SEM-CL) imaging

    Science.gov (United States)

    Hamers, Maartje F.; Pennock, Gill M.; Herwegh, Marco; Drury, Martyn R.

    2016-10-01

    Planar deformation features (PDFs) in quartz are one of the most reliable and most widely used forms of evidence for hypervelocity impact. PDFs can be identified in scanning electron microscope cathodoluminescence (SEM-CL) images, but not all PDFs show the same CL behavior: there are nonluminescent and red luminescent PDFs. This study aims to explain the origin of the different CL emissions in PDFs. Focused ion beam (FIB) thin foils were prepared of specific sample locations selected in composite color SEM-CL images and were analyzed in a transmission electron microscope (TEM). The FIB preparation technique allowed a direct, often one-to-one correlation between the CL images and the defect structure observed in TEM. This correlation shows that composite color SEM-CL imaging allows distinction between amorphous PDFs on one hand and healed PDFs and basal Brazil twins on the other: nonluminescent PDFs are amorphous, while healed PDFs and basal Brazil twins are red luminescent, with a dominant emission peak at 650 nm. We suggest that the red luminescence is the result of preferential beam damage along dislocations, fluid inclusions, and twin boundaries. Furthermore, a high-pressure phase (possibly stishovite) in PDFs can be detected in color SEM-CL images by its blue luminescence.

  19. Improvement of CD-SEM mark position measurement accuracy

    Science.gov (United States)

    Kasa, Kentaro; Fukuhara, Kazuya

    2014-04-01

    CD-SEM is now attracting attention as a tool that can accurately measure positional error of device patterns. However, the measurement accuracy can get worse due to pattern asymmetry as in the case of image based overlay (IBO) and diffraction based overlay (DBO). For IBO and DBO, a way of correcting the inaccuracy arising from measurement patterns was suggested. For CD-SEM, although a way of correcting CD bias was proposed, it has not been argued how to correct the inaccuracy arising from pattern asymmetry using CD-SEM. In this study we will propose how to quantify and correct the measurement inaccuracy affected by pattern asymmetry.

  20. Analysis of microtraces in invasive traumas using SEM/EDS.

    Science.gov (United States)

    Vermeij, E J; Zoon, P D; Chang, S B C G; Keereweer, I; Pieterman, R; Gerretsen, R R R

    2012-01-10

    Scanning electron microscopy in combination with energy-dispersive X-ray spectrometry (SEM/EDS) is a proven forensic tool and has been used to analyze several kinds of trace evidence. A forensic application of SEM/EDS is the examination of morphological characteristics of tool marks that tools and instruments leave on bone. The microtraces that are left behind by these tools and instruments on the bone are, however, often ignored or not noticed at all. In this paper we will describe the use of SEM/EDS for the analysis of microtraces in invasive sharp-force, blunt-force and bone-hacking traumas in bone. This research is part of a larger multi-disciplinary approach in which pathologists, forensic anthropologists, toolmark and microtrace experts work together to link observed injuries to a suspected weapon or, in case of an unknown weapon, to indicate a group of objects that could have been used as a weapon. Although there are a few difficulties one have to consider, the method itself is rather simple and straightforward to apply. A sample of dry and clean bone is placed into the SEM sample chamber and brightness and contrast are set such that bone appears grey, metal appears white and organic material appears black. The sample is then searched manually to find relevant features. Once features are found their elemental composition is measured by an energy dispersive X-ray spectrometer (EDS). This method is illustrated using several cases. It is shown that SEM/EDS analysis of microtraces in bone is a valuable tool to get clues about an unknown weapon and can associate a specific weapon with injuries on the basis of appearance and elemental composition. In particular the separate results from the various disciplines are complementary and may be combined to reach a conclusion with a stronger probative value. This is not only useful in the courtroom but above all in criminal investigations when one have to know for what weapon or object to look for. Copyright © 2011

  1. SEM characterization of an irradiated monolithic U-10Mo fuel plate

    International Nuclear Information System (INIS)

    Keiser, D.D. Jr.; Jue, J.F.; Robinson, A.B.; Finlay, M.R.

    2010-01-01

    Results of scanning electron microscopy (SEM) characterization of irradiated U-7Mo dispersion fuel plates with differing amounts of matrix Si have been reported. However, to date, no results of SEM analysis of irradiated U-Mo monolithic fuel plates have been reported. This paper describes the first SEM characterization results for an irradiated monolithic U-10Mo fuel plate. Two samples from this fuel plate were characterized. One sample was produced from the low-flux side of the fuel plate, and another was produced at the high-flux side of the fuel plate. This characterization focused on the microstructural features present at the U-10Mo foil/AA6061 cladding interface, particularly the interaction zone that had developed during fabrication and any continued development during irradiation. In addition, the microstructure of the foil itself was investigated, along with the morphology of the observed fission gas bubbles. It was observed that a Si-rich interaction layer was present at the U-10Mo foil/cladding interface that exhibited relatively good irradiation behavior, and within the U-10Mo foil the microstructural features differed in some respects from what is typically seen in the U-7Mo powders of an irradiated dispersion fuel. (author)

  2. Adapted methods for scanning electron microscopy (SEM in assessment of human sperm morphology

    Directory of Open Access Journals (Sweden)

    Petra Nussdorfer

    2018-02-01

    Full Text Available Infertility is a widespread problem, and in some cases, the routine basic semen analysis is not sufficient to detect the cause of male infertility. The use of the scanning electron microscope (SEM could provide a detailed insight into spermatozoa morphology, but it requires specific sample preparation techniques. The purpose of this study was to select, adjust, and optimize a method for the preparation of spermatozoa samples prior to SEM analysis, and to establish the protocol required for its use in clinical practice. We examined sperm samples of 50 men. The samples were fixed with modified iso-osmolar aldehyde solution followed by osmium post-fixation. In the first method, dehydration of the cells and subsequent critical point drying (CPD were performed on a coverslip. In the second method, the samples were dehydrated in centrifuge tubes; hexamethyldisilazane (HMDS was used as a drying agent instead of CPD, and the samples were air-dried. The third procedure was based on a membrane filter. The samples were dehydrated and dried with HMDS in a Gooch crucible, continuously, without centrifugation or redispersion of the sample. Our results showed that the fixation with modified iso-osmolar aldehyde solution followed by osmium post-fixation, and combined with dehydration and CPD on a coverslip, is the most convenient procedure for SEM sample preparation. In the case of small-size samples or low sperm concentration, dehydration and drying with HMDS on the membrane filter enabled the best reliability, repeatability, and comparability of the results. The presented procedures are suitable for routine use, and they can be applied to confirm as well as to correct a diagnosis.

  3. Three-dimensional ultrastructure of osteocytes assessed by focused ion beam-scanning electron microscopy (FIB-SEM).

    Science.gov (United States)

    Hasegawa, Tomoka; Yamamoto, Tomomaya; Hongo, Hiromi; Qiu, Zixuan; Abe, Miki; Kanesaki, Takuma; Tanaka, Kawori; Endo, Takashi; de Freitas, Paulo Henrique Luiz; Li, Minqi; Amizuka, Norio

    2018-04-01

    The aim of this study is to demonstrate the application of focused ion beam-scanning electron microscopy, FIB-SEM for revealing the three-dimensional features of osteocytic cytoplasmic processes in metaphyseal (immature) and diaphyseal (mature) trabeculae. Tibiae of eight-week-old male mice were fixed with aldehyde solution, and treated with block staining prior to FIB-SEM observation. While two-dimensional backscattered SEM images showed osteocytes' cytoplasmic processes in a fragmented fashion, three-dimensional reconstructions of FIB-SEM images demonstrated that osteocytes in primary metaphyseal trabeculae extended their cytoplasmic processes randomly, thus maintaining contact with neighboring osteocytes and osteoblasts. In contrast, diaphyseal osteocytes extended thin cytoplasmic processes from their cell bodies, which ran perpendicular to the bone surface. In addition, these osteocytes featured thick processes that branched into thinner, transverse cytoplasmic processes; at some point, however, these transverse processes bend at a right angle to run perpendicular to the bone surface. Osteoblasts also possessed thicker cytoplasmic processes that branched off as thinner processes, which then connected with cytoplasmic processes of neighboring osteocytes. Thus, FIB-SEM is a useful technology for visualizing the three-dimensional structures of osteocytes and their cytoplasmic processes.

  4. Quantitative approach on SEM images of microstructure of clay soils

    Institute of Scientific and Technical Information of China (English)

    施斌; 李生林; M.Tolkachev

    1995-01-01

    The working principles of Videolab Image Processing System (VIPS), the examining methods of orientation of microstructural units of clay soils and analysing results on SEM images of some typical microstructures of clay soils using the VIPS are introduced.

  5. Novel field emission SEM column with beam deceleration technology

    International Nuclear Information System (INIS)

    Jiruše, Jaroslav; Havelka, Miloslav; Lopour, Filip

    2014-01-01

    A novel field-emission SEM column has been developed that features Beam Deceleration Mode, high-probe current and ultra-fast scanning. New detection system in the column is introduced to detect true secondary electron signal. The resolution power at low energy was doubled for conventional SEM optics and moderately improved for immersion optics. Application examples at low landing energies include change of contrast, imaging of non-conductive samples and thin layers. - Highlights: • A novel field-emission SEM column has been developed. • Implemented beam deceleration improves the SEM resolution at 1 keV two times. • New column maintains high analytical potential and wide field of view. • Detectors integrated in the column allow gaining true SE and BE signal separately. • Performance of the column is demonstrated on low energy applications

  6. Novel field emission SEM column with beam deceleration technology

    Energy Technology Data Exchange (ETDEWEB)

    Jiruše, Jaroslav; Havelka, Miloslav; Lopour, Filip

    2014-11-15

    A novel field-emission SEM column has been developed that features Beam Deceleration Mode, high-probe current and ultra-fast scanning. New detection system in the column is introduced to detect true secondary electron signal. The resolution power at low energy was doubled for conventional SEM optics and moderately improved for immersion optics. Application examples at low landing energies include change of contrast, imaging of non-conductive samples and thin layers. - Highlights: • A novel field-emission SEM column has been developed. • Implemented beam deceleration improves the SEM resolution at 1 keV two times. • New column maintains high analytical potential and wide field of view. • Detectors integrated in the column allow gaining true SE and BE signal separately. • Performance of the column is demonstrated on low energy applications.

  7. semPLS: Structural Equation Modeling Using Partial Least Squares

    Directory of Open Access Journals (Sweden)

    Armin Monecke

    2012-05-01

    Full Text Available Structural equation models (SEM are very popular in many disciplines. The partial least squares (PLS approach to SEM offers an alternative to covariance-based SEM, which is especially suited for situations when data is not normally distributed. PLS path modelling is referred to as soft-modeling-technique with minimum demands regarding mea- surement scales, sample sizes and residual distributions. The semPLS package provides the capability to estimate PLS path models within the R programming environment. Different setups for the estimation of factor scores can be used. Furthermore it contains modular methods for computation of bootstrap confidence intervals, model parameters and several quality indices. Various plot functions help to evaluate the model. The well known mobile phone dataset from marketing research is used to demonstrate the features of the package.

  8. Critical factors in SEM 3D stereo microscopy

    DEFF Research Database (Denmark)

    Marinello, F.; Bariano, P.; Savio, E.

    2008-01-01

    This work addresses dimensional measurements performed with the scanning electron microscope (SEM) using 3D reconstruction of surface topography through stereo-photogrammetry. The paper presents both theoretical and experimental investigations, on the effects of instrumental variables and measure......This work addresses dimensional measurements performed with the scanning electron microscope (SEM) using 3D reconstruction of surface topography through stereo-photogrammetry. The paper presents both theoretical and experimental investigations, on the effects of instrumental variables...... factors are recognized: the first one is related to the measurement operation and the instrument set-up; the second concerns the quality of scanned images and represents the major criticality in the application of SEMs for 3D characterizations....

  9. SEM investigation of incandescent lamp mantle structure on durability

    International Nuclear Information System (INIS)

    Gerneke, D.; Lang, C.

    2002-01-01

    Full text: The incandescent mantle as used on pressure and non-pressure liquid fuel lamps has been in use for over 100 years. What remains unexplained is the way in which the resistance to mechanical shock and the decline in tensile strength with usage is experienced. It has been suggested that to improve durability it is necessary to continuously burn a new mantle for the first two to three hours. The known factors in mantle durability and mechanical strength are chemical composition and fabric weave. This study was undertaken to investigate the effects of burning time and temperature on thorium oxide mantles. The operating temperature of mantles on a range of kerosene pressure lamps was measured and found to be between 800 and 1100 deg C. Heat treatments of thorium based Coleman mantles were carried out in a laboratory furnace within these ranges of temperatures for periods ranging from 2 minutes to 2 hours. The mantles were then viewed in a LEO S440 analytical SEM. Results at 800 deg C show a distinct change in surface morphology with increasing exposure time. At the shorter times (2-5 minutes) the surface was relatively smooth. With increased time periods (15 - 120 minutes) the surface was observed to have a large lumpy structure. At 1100 deg C the difference in surface morphology was not apparent between the shortest and longest times. The surface appears much smoother and no lumpy structure was observed. This suggests that when a mantle is operated at the higher temperature of 1100 deg C the structure of the Thorium oxide is quickly transformed into the known stronger amorphous form. This is taken as the observed smooth structure seen in the SEM images of the 1100 deg C samples. Thus the mantle is expected to be more resistant to mechanical shock and have increased durability. Practical field test results confirm these observations. The mantle on a lamp that is operating efficiently, burns brightly, will far outlast a mantle on an inefficient lamp which bums

  10. SEM microcharacterization of semiconductors

    CERN Document Server

    Holt, D B

    1989-01-01

    Applications of SEM techniques of microcharacterization have proliferated to cover every type of material and virtually every branch of science and technology. This book emphasizes the fundamental physical principles. The first section deals with the foundation of microcharacterization in electron beam instruments and the second deals with the interpretation of the information obtained in the main operating modes of a scanning electron microscope.

  11. AxiSEM3D: broadband seismic wavefields in 3-D aspherical Earth models

    Science.gov (United States)

    Leng, K.; Nissen-Meyer, T.; Zad, K. H.; van Driel, M.; Al-Attar, D.

    2017-12-01

    Seismology is the primary tool for data-informed inference of Earth structure and dynamics. Simulating seismic wave propagation at a global scale is fundamental to seismology, but remains as one of most challenging problems in scientific computing, because of both the multiscale nature of Earth's interior and the observable frequency band of seismic data. We present a novel numerical method to simulate global seismic wave propagation in realistic 3-D Earth models. Our method, named AxiSEM3D, is a hybrid of spectral element method and pseudospectral method. It reduces the azimuthal dimension of wavefields by means of a global Fourier series parameterization, of which the number of terms can be locally adapted to the inherent azimuthal smoothness of the wavefields. AxiSEM3D allows not only for material heterogeneities, such as velocity, density, anisotropy and attenuation, but also for finite undulations on radial discontinuities, both solid-solid and solid-fluid, and thereby a variety of aspherical Earth features such as ellipticity, topography, variable crustal thickness, and core-mantle boundary topography. Such interface undulations are equivalently interpreted as material perturbations of the contiguous media, based on the "particle relabelling transformation". Efficiency comparisons show that AxiSEM3D can be 1 to 3 orders of magnitude faster than conventional 3-D methods, with the speedup increasing with simulation frequency and decreasing with model complexity, but for all realistic structures the speedup remains at least one order of magnitude. The observable frequency range of global seismic data (up to 1 Hz) has been covered for wavefield modelling upon a 3-D Earth model with reasonable computing resources. We show an application of surface wave modelling within a state-of-the-art global crustal model (Crust1.0), with the synthetics compared to real data. The high-performance C++ code is released at github.com/AxiSEM3D/AxiSEM3D.

  12. Detailed SEM-EPMA investigation of high specific radioactivity particles (hot particles)

    International Nuclear Information System (INIS)

    Burin, K.; Tsacheva, Ts.; Mandjoukov, I.; Mandjoukova, B.

    1993-01-01

    Scanning electron microscope (SEM) images and electron probe microanalysis (EPMA) spectra of a group of hot particles collected in Bulgaria after the Chernobyl accident have been obtained. A technique for hot particle localization is described. The object is irradiated for two days with a β source and the resulting autoradiographs show particles location precisely. High resolution x-ray spectrum of each particle has been obtained using EPMA. The distribution of chemical elements is visualized by colour dot maps representing the regions of interest of the spectrum. It is concluded that apart from reactor fuel the investigated hot particles come from either construction materials or materials used for the covering of the damaged reactor. 7 figs., 2 ref

  13. SemVisM: semantic visualizer for medical image

    Science.gov (United States)

    Landaeta, Luis; La Cruz, Alexandra; Baranya, Alexander; Vidal, María.-Esther

    2015-01-01

    SemVisM is a toolbox that combines medical informatics and computer graphics tools for reducing the semantic gap between low-level features and high-level semantic concepts/terms in the images. This paper presents a novel strategy for visualizing medical data annotated semantically, combining rendering techniques, and segmentation algorithms. SemVisM comprises two main components: i) AMORE (A Modest vOlume REgister) to handle input data (RAW, DAT or DICOM) and to initially annotate the images using terms defined on medical ontologies (e.g., MesH, FMA or RadLex), and ii) VOLPROB (VOlume PRObability Builder) for generating the annotated volumetric data containing the classified voxels that belong to a particular tissue. SemVisM is built on top of the semantic visualizer ANISE.1

  14. Are the evidences of forensic entomology preserved in ethanol suitable for SEM studies?

    Science.gov (United States)

    López-Esclapez, Raquel; García, María-Dolores; Arnaldos, María-Isabel; Presa, Juan José; Ubero-Pascal, Nicolás

    2014-07-01

    In forensic practice, the use of arthropod evidences to estimate the postmortem interval is a very good approach when the elapsed time from death is long, but it requires the correct identification of the specimens. This is a crucial step, not always easy to achieve, in particular when dealing with immature specimens. In this case, scanning electronic microscopy (SEM) can be useful, but the techniques used to preserve specimens in forensic practice are usually different from those used to prepare specimens for SEM studies. To determine whether forensic evidences preserving techniques are also compatible with SEM analysis, we have compared specimens of all the immature stages of Calliphora vicina Robineau-Desvoidy, 1830 (Diptera, Calliphoridae) preserved in 70% ethanol, with others prepared with aldehydic fixative techniques that are more appropriate for SEM studies. At the same time, two drying techniques have also been compared with both fixative techniques, the critical point drying and air-drying following with hexamethyldisilizane treatment (HMDS). Our results indicate that there are not basis against recommending the use of ethanol to preserve forensic entomological evidences and that both drying methods appear to offer good results for second and third instar larvae, although HMDS behaves better with eggs and pupae. Copyright © 2014 Elsevier Ltd. All rights reserved.

  15. Information or resolution: Which is required from an SEM to study bulk inorganic materials?

    Science.gov (United States)

    Xing, Q

    2016-11-01

    Significant technological advances in scanning electron microscopy (SEM) have been achieved over the past years. Different SEMs can have significant differences in functionality and performance. This work presents the perspectives on selecting an SEM for research on bulk inorganic materials. Understanding materials demands quantitative composition and orientation information, and informative and interpretable images that reveal subtle differences in chemistry, orientation/structure, topography, and electronic structure. The capability to yield informative and interpretable images with high signal-to-noise ratios and spatial resolutions is an overall result of the SEM system as a whole, from the electron optical column to the detection system. The electron optical column determines probe performance. The roles of the detection system are to capture, filter or discriminate, and convert signal electrons to imaging information. The capability to control practical operating parameters including electron probe size and current, acceleration voltage or landing voltage, working distance, detector selection, and signal filtration is inherently determined by the SEM itself. As a platform for various accessories, e.g. an energy-dispersive spectrometer and an electron backscatter diffraction detector, the properties of the electron optical column, specimen chamber, and stage greatly affect the performance of accessories. Ease-of-use and ease-of-maintenance are of practical importance. It is practically important to select appropriate test specimens, design suitable imaging conditions, and analyze the specimen chamber geometry and dimensions to assess the overall functionality and performance of an SEM. For an SEM that is controlled/operated with a computer, the stable software and user-friendly interface significantly improve the usability of the SEM. SCANNING 38:864-879, 2016. © 2016 Wiley Periodicals, Inc. © Wiley Periodicals, Inc.

  16. Enhanced EDX images by fusion of multimodal SEM images using pansharpening techniques.

    Science.gov (United States)

    Franchi, G; Angulo, J; Moreaud, M; Sorbier, L

    2018-01-01

    The goal of this paper is to explore the potential interest of image fusion in the context of multimodal scanning electron microscope (SEM) imaging. In particular, we aim at merging the backscattered electron images that usually have a high spatial resolution but do not provide enough discriminative information to physically classify the nature of the sample, with energy-dispersive X-ray spectroscopy (EDX) images that have discriminative information but a lower spatial resolution. The produced images are named enhanced EDX. To achieve this goal, we have compared the results obtained with classical pansharpening techniques for image fusion with an original approach tailored for multimodal SEM fusion of information. Quantitative assessment is obtained by means of two SEM images and a simulated dataset produced by a software based on PENELOPE. © 2017 The Authors Journal of Microscopy © 2017 Royal Microscopical Society.

  17. Study of medieval enamelling on gilded objects combining SEM-EDAX and PIXE

    International Nuclear Information System (INIS)

    Chamon, J.; Barrio, J.; Arroyo, M.; Gutierrez, P.C.; Climent-Font, A.

    2010-01-01

    A set of fragments of metallic artefacts from the medieval period excavated from Ciudad Real in Spain has been studied. The objects are gilded copper buckles with a champleve enamelling decoration. The composition of predominantly blue-coloured enamels has been analysed using three non-destructive techniques, SEM-EDAX (scanning electron microscopy coupled with energy-dispersive X-ray analysis), X-ray fluorescence (XRF) and PIXE (particle-induced X-ray emission). Analyses show that Co is responsible for the blue colour. The results of the two techniques are compared, as well as the main components which constitute the enamel. Analyses suggest that Cu is responsible for red colour. (orig.)

  18. Design and Use of the Simple Event Model (SEM)

    NARCIS (Netherlands)

    van Hage, W.R.; Malaisé, V.; Segers, R.H.; Hollink, L.

    2011-01-01

    Events have become central elements in the representation of data from domains such as history, cultural heritage, multimedia and geography. The Simple Event Model (SEM) is created to model events in these various domains, without making assumptions about the domain-specific vocabularies used. SEM

  19. Application of SEM and EDX in studying biomineralization in plant tissues.

    Science.gov (United States)

    He, Honghua; Kirilak, Yaowanuj

    2014-01-01

    This chapter describes protocols using formalin-acetic acid-alcohol (FAA) to fix plant tissues for studying biomineralization by means of scanning electron microscopy (SEM) and qualitative energy-dispersive X-ray microanalysis (EDX). Specimen preparation protocols for SEM and EDX mainly include fixation, dehydration, critical point drying (CPD), mounting, and coating. Gold-coated specimens are used for SEM imaging, while gold- and carbon-coated specimens are prepared for qualitative X-ray microanalyses separately to obtain complementary information on the elemental compositions of biominerals. During the specimen preparation procedure for SEM, some biominerals may be dislodged or scattered, making it difficult to determine their accurate locations, and light microscopy is used to complement SEM studies. Specimen preparation protocols for light microscopy generally include fixation, dehydration, infiltration and embedding with resin, microtome sectioning, and staining. In addition, microwave processing methods are adopted here to speed up the specimen preparation process for both SEM and light microscopy.

  20. Improvement of geometrical measurements from 3D-SEM reconstructions

    DEFF Research Database (Denmark)

    Carli, Lorenzo; De Chiffre, Leonardo; Horsewell, Andy

    2009-01-01

    The quantification of 3D geometry at the nanometric scale is a major metrological challenge. In this work geometrical measurements on cylindrical items obtained with a 3D-SEM were investigated. Two items were measured: a wire gauge having a 0.25 mm nominal diameter and a hypodermic needle having...... that the diameter estimation performed using the 3D-SEM leads to an overestimation of approx. 7% compared to the reference values obtained using a 1-D length measuring machine. Standard deviation of SEM measurements performed on the wire gauge is approx. 1.5 times lower than the one performed on the hypodermic...

  1. Canticum Novum: música sem palavras e palavras sem som no pensamento de Santo Agostinho

    Directory of Open Access Journals (Sweden)

    Lorenzo Mammì

    2000-04-01

    Full Text Available NO De Magistro, Santo Agostinho coloca a reza e o canto numa posição similar, à margem das funções imediatamente comunicativas da linguagem. A reflexão agostiniana sobre a reza se baseia nos hábitos cristãos da leitura, da oração e da meditação silenciosas. Há sobre o canto, na prática igualmente inovadora do jubilus, melodia sem palavra destinada aos momentos mais intensos e gaudiosos da liturgia. A oração silenciosa e o jubilus são temas recorrentes da literatura patrística, mas Agostinho os aborda de maneira original, desenhando, a partir das palavras sem som da oração e do som sem palavra do jubilus, o perfil de um discurso interior, que não se destina aos homens, mas a Deus.IN HIS De Magistro Saint Augustine places prayer and song on a similar level, alongside the language immediately communicative functions. His considerations on prayer are grounded on the Christian habits of silent reading, prayer and meditation; those on song, on the equally innovating practice called jubilus, which is melody without words designed for the intensest and most joyous liturgical moments. Silent prayer and jubilus are recurring topics in patristic literature, but Augustine deals with them in an original way, drawing from the soundless words of prayer and the wordless sound of jubilus an inner discourse, addressed not to men but to God.

  2. High resolution SEM imaging of gold nanoparticles in cells and tissues.

    Science.gov (United States)

    Goldstein, A; Soroka, Y; Frušić-Zlotkin, M; Popov, I; Kohen, R

    2014-12-01

    The growing demand of gold nanoparticles in medical applications increases the need for simple and efficient characterization methods of the interaction between the nanoparticles and biological systems. Due to its nanometre resolution, modern scanning electron microscopy (SEM) offers straightforward visualization of metallic nanoparticles down to a few nanometre size, almost without any special preparation step. However, visualization of biological materials in SEM requires complicated preparation procedure, which is typically finished by metal coating needed to decrease charging artefacts and quick radiation damage of biomaterials in the course of SEM imaging. The finest conductive metal coating available is usually composed of a few nanometre size clusters, which are almost identical to the metal nanoparticles employed in medical applications. Therefore, SEM monitoring of metal nanoparticles within cells and tissues is incompatible with the conventional preparation methods. In this work, we show that charging artefacts related to non-conductive biological specimen can be successfully eliminated by placing the uncoated biological sample on a conductive substrate. By growing the cells on glass pre-coated with a chromium layer, we were able to observe the uptake of 10 nm gold nanoparticles inside uncoated and unstained macrophages and keratinocytes cells. Imaging in back scattered electrons allowed observation of gold nanoparticles located inside the cells, while imaging in secondary electron gave information on gold nanoparticles located on the surface of the cells. By mounting a skin cross-section on an improved conductive holder, consisting of a silicon substrate coated with copper, we were able to observe penetration of gold nanoparticles of only 5 nm size through the skin barrier in an uncoated skin tissue. The described method offers a convenient modification in preparation procedure for biological samples to be analyzed in SEM. The method provides high

  3. A Data Matrix Method for Improving the Quantification of Element Percentages of SEM/EDX Analysis

    Science.gov (United States)

    Lane, John

    2009-01-01

    A simple 2D M N matrix involving sample preparation enables the microanalyst to peer below the noise floor of element percentages reported by the SEM/EDX (scanning electron microscopy/ energy dispersive x-ray) analysis, thus yielding more meaningful data. Using the example of a 2 3 sample set, there are M = 2 concentration levels of the original mix under test: 10 percent ilmenite (90 percent silica) and 20 percent ilmenite (80 percent silica). For each of these M samples, N = 3 separate SEM/EDX samples were drawn. In this test, ilmenite is the element of interest. By plotting the linear trend of the M sample s known concentration versus the average of the N samples, a much higher resolution of elemental analysis can be performed. The resulting trend also shows how the noise is affecting the data, and at what point (of smaller concentrations) is it impractical to try to extract any further useful data.

  4. To see or not to see: Imaging surfactant coated nano-particles using HIM and SEM

    International Nuclear Information System (INIS)

    Hlawacek, Gregor; Ahmad, Imtiaz; Smithers, Mark A.; Kooij, E. Stefan

    2013-01-01

    Nano-particles are of great interest in fundamental and applied research. However, their accurate visualization is often difficult and the interpretation of the obtained images can be complicated. We present a comparative scanning electron microscopy and helium ion microscopy study of cetyltrimethylammonium-bromide (CTAB) coated gold nano-rods. Using both methods we show how the gold core as well as the surrounding thin CTAB shell can selectively be visualized. This allows for a quantitative determination of the dimensions of the gold core or the CTAB shell. The obtained CTAB shell thickness of 1.0 nm–1.5 nm is in excellent agreement with earlier results using more demanding and reciprocal space techniques. - Author-Highlights: • CTAB coated gold nano-rods were imaged using high resolution imaging tools. • Selective imaging of either the gold core or CTAB shell is possible with HIM and SEM. • CTAB shell thickness measured using HIM and SEM agrees well with literature values

  5. Multiple-Group Analysis Using the sem Package in the R System

    Science.gov (United States)

    Evermann, Joerg

    2010-01-01

    Multiple-group analysis in covariance-based structural equation modeling (SEM) is an important technique to ensure the invariance of latent construct measurements and the validity of theoretical models across different subpopulations. However, not all SEM software packages provide multiple-group analysis capabilities. The sem package for the R…

  6. SEM studies of the structure of the gels prepared from untreated and radiation modified potato starch

    International Nuclear Information System (INIS)

    Cieśla, Krystyna; Sartowska, Bożena; Królak, Edward

    2015-01-01

    Potato starch was irradiated with a 60 Co gamma rays using doses of 5, 10, 20 and 30 kGy. Gels containing ca. 9.1% of starch were prepared by heating the starch suspensions in the heating chamber stabilized at 100 °C. Four procedures were applied for preparation of the samples in regard to SEM studies and the ability to observe the radiation effect by SEM was assessed for each method. Differences were observed between the SEM images recorded for the non-irradiated samples prepared using all the methods, and those irradiated. Images of the non-irradiated gels indicate generally a honey-comb structure, while smooth areas but with oriented fractures has appeared after irradiation. Modification of gel structure corresponds to the applied dose. The results were related to the process of gel formation (as observed by means of the hot stage microscope) to decrease in swelling power of the irradiated starch and to decreased viscosity of the resulting gels. It can be concluded that the differences in structural properties of gels shown by SEM result probably due to the better homogenization of the gels formed after radiation induced degradation. - Highlights: • Four procedures of the preservation of starch gels for SEM studies were applied. • The ability to observe the radiation effect by SEM was assessed for each method. • Dose dependent changes in the gel structure were discovered. • It was related to decrease in the swelling power and decreased viscosity of the gels. • A hot-stage microscope was applied in order to follow the gelatinization process

  7. XRD and SEM analysis of hydroxyapatite during immersion in stimulated physiological solutions

    International Nuclear Information System (INIS)

    Yusof Abdullah; Idris Besar; Rosmamuhamadani Ramli; Abd Razak Daud

    2000-01-01

    XRD and SEM techniques were used to analyse the apatite layer developed on the synthetic hydroxyapatite surface following immersion in the simulated body fluid (SBF) that mimics the conditions of material experiences after implantation in the human body. Initially, the new layers formed after 7 day's incubation and increased with immersion time as crystallization of apatite phase. The XRD confirmed that the deposited layer was hydroxyapatite and crystallographically. With time, the crystal growth become more random and the intensity of the peaks decreased. During immersion, hydroxyapatite was precipitated from the SBF and coherently scattered with very small crystal. The SEM observation shows that the new precipitates were increased as well as incubation period increased. Therefore, hydroxyapatite ceramics are suggested to have very good biocompatibility. (Author)

  8. Tumor suppressor protein SMAR1 modulates the roughness of cell surface: combined AFM and SEM study

    Directory of Open Access Journals (Sweden)

    Mamgain Hitesh

    2009-10-01

    Full Text Available Abstract Background Imaging tools such as scanning electron microscope (SEM and atomic force microscope (AFM can be used to produce high-resolution topographic images of biomedical specimens and hence are well suited for imaging alterations in cell morphology. We have studied the correlation of SMAR1 expression with cell surface smoothness in cell lines as well as in different grades of human breast cancer and mouse tumor sections. Methods We validated knockdown and overexpression of SMAR1 using RT-PCR as well as Western blotting in human embryonic kidney (HEK 293, human breast cancer (MCF-7 and mouse melanoma (B16F1 cell lines. The samples were then processed for cell surface roughness studies using atomic force microscopy (AFM and scanning electron microscopy (SEM. The same samples were used for microarray analysis as well. Tumors sections from control and SMAR1 treated mice as well as tissues sections from different grades of human breast cancer on poly L-lysine coated slides were used for AFM and SEM studies. Results Tumor sections from mice injected with melanoma cells showed pronounced surface roughness. In contrast, tumor sections obtained from nude mice that were first injected with melanoma cells followed by repeated injections of SMAR1-P44 peptide, exhibited relatively smoother surface profile. Interestingly, human breast cancer tissue sections that showed reduced SMAR1 expression exhibited increased surface roughness compared to the adjacent normal breast tissue. Our AFM data establishes that treatment of cells with SMAR1-P44 results into increase in cytoskeletal volume that is supported by comparative gene expression data showing an increase in the expression of specific cytoskeletal proteins compared to the control cells. Altogether, these findings indicate that tumor suppressor function of SMAR1 might be exhibited through smoothening of cell surface by regulating expression of cell surface proteins. Conclusion Tumor suppressor

  9. Human bloodstains on bone artefacts: an SEM intra- and inter-sample comparative study using ratite bird tibiotarsus.

    Science.gov (United States)

    Hortolà, Policarp

    2016-11-01

    Apart from their forensic significance in crime investigation, human bloodstains have an anthropological interest due to their occurrence on certain traditional weapons and ritual objects. Previously, a guiding study of erythrocytes in experimental samples including domestic sheep (Ovis aries) tibia was carried out using a scanning electron microscope (SEM). Here, a comparative SEM study to reveal the potential differences in bloodstain surface morphology as a function of intra-sample (smear region) and inter-sample (individual smear, smearing mechanism, bone origin) parameters is reported. A fragment of emu (Dromaius novaehollandiae) tibiotarsus was smeared with an adult man's peripheral blood. After air-drying and storing indoors, the boundary and neighbouring inner areas of the three individual bloodstains obtained were examined via secondary electrons in a variable-pressure SEM working in low-vacuum mode. As a whole, desiccation microcracks were present, the limits between the smear and the substrate appeared poorly defined, and no erythrocyte negative replicas were observed in the examined areas. In addition, a putative fibrin network, more or less embedded in the dried plasma matrix, was observed in the smears' boundary. Regarding the smear region in sliding smears, the periphery and boundary revealed to be different, while the head and tail were similar. Considering individual sliding smears, they had similar characteristics. Relating to the smear region as a function of the smearing mechanism, the periphery was different whether sliding or touching, while the boundary was similar in sliding and touching smears. Concerning the smear region as a function of the bone origin, the periphery revealed to be similar in both ratite and mammalian bone, while the boundary did different in ratite and mammalian bone. The results of this study show that SEM examination can be used fruitfully to detect bloodstains on ratite bone. Combined with previous SEM results in

  10. SEM: A Cultural Change Agent

    Science.gov (United States)

    Barnes, Bradley; Bourke, Brian

    2015-01-01

    The authors advance the concept that institutional culture is a purposeful framework by which to view SEM's utility, particularly as a cultural change agent. Through the connection of seemingly independent functions of performance and behavior, implications emerge that deepen the understanding of the influence of culture on performance outcomes…

  11. On the Nature of SEM Estimates of ARMA Parameters.

    Science.gov (United States)

    Hamaker, Ellen L.; Dolan, Conor V.; Molenaar, Peter C. M.

    2002-01-01

    Reexamined the nature of structural equation modeling (SEM) estimates of autoregressive moving average (ARMA) models, replicated the simulation experiments of P. Molenaar, and examined the behavior of the log-likelihood ratio test. Simulation studies indicate that estimates of ARMA parameters observed with SEM software are identical to those…

  12. Sobre la estructura semántica de las palabras autosemánticas

    Directory of Open Access Journals (Sweden)

    Morales Ascencio Bernardo

    1993-06-01

    Full Text Available

    A partir de los conceptos de semema o estructura semémica y de los conceptos tradicionales de afijos y los accidentes gramaticales se plantea una supuesta estructura semántica profunda de la palabra, análoga a la de la oración en el modelo de la gramática de casos. Con base en este supuesto se reinterpretan algunas funciones semánticas de los afijos (particularmente de los sufijos, entre otras, como formas de la expresión de la modalidad léxica; se plantea una correlación entre rasgos semánticos específicos y las relaciones semánticas de caso. Por último se deducen algunas consideraciones pertinentes y se demuestra un isomorfismo entre la estructura profunda de la oración y la supuesta estructura semántica profunda de las palabras auto  semánticas.

  13. Description and calibration beamline SEM/Ion Chamber Current Digitizer

    International Nuclear Information System (INIS)

    Schoo, D.

    1994-05-01

    This report discusses the following on beamline SEM/ion chamber current digitizers: Module description; testing and calibration; common setup procedures; summary of fault indications and associated causes; summary of input and output connections; SEM conversion constant table; ion chamber conversion constant table; hexadecimal to decimal conversion table; and schematic diagram

  14. Protective effects of a zinc-hydroxyapatite toothpaste on enamel erosion: SEM study.

    Science.gov (United States)

    Colombo, Marco; Beltrami, Riccardo; Rattalino, Davide; Mirando, Maria; Chiesa, Marco; Poggio, Claudio

    2016-01-01

    The aim of the present in vitro study was to evaluate the protective effects of a zinc-hydroxyapatite toothpaste against an erosive challenge produced by a soft drink (Coca-Cola) using Scanning Electron Microscopy (SEM). Forty specimens were assigned to 4 groups of 10 specimens each (group 1: no erosive challenge, no toothpaste treatment, group 2: erosive challenge, no toothpaste treatment, group 3: erosive challenge, fluoride toothpaste treatment, group 4: erosive challenge, zinc-hydroxyapatite toothpaste treatment). The surface of each specimen was imaged by SEM. A visual rating system was used to evaluate the condition of the enamel surface; results were analyzed by nonparametric statistical methods. Statistically significant differences were found between the samples untreated and those immersed in Coca-Cola (group 1, 2); the highest grade of damage was found in group 2, while the lowest grade was recorded in the samples of group 4. Comparing the groups, the two analyzed toothpaste tended to protect in different extend. In this study treatment of erosively challenged enamel with Zn-Hap toothpaste showed a clear protective effect. This was greater than the effect observed for a normal fluoride toothpaste and confirmed the potential benefit the Zn-HAP technology can provide in protecting enamel from erosive acid challenges.

  15. SEM-668-G2(日东科技)

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    SEM-668-G2比SEM-668在视觉技术上更加精湛,采用美国AGILENT(安提伦)LASER 5519A及HP的双重频率技术,加强运动;隹确性。在智能化印刷头上,SEM-668-G2印刷质量更加均匀、稳定,操作界面更加简易、更加人性化。在综合性能上更加卓越,保证实现现代化的生产效率。产品体具性能如下:SEM-668-G2视觉全自动印刷机

  16. Three-Dimensional (3D) Nanometrology Based on Scanning Electron Microscope (SEM) Stereophotogrammetry.

    Science.gov (United States)

    Tondare, Vipin N; Villarrubia, John S; Vlada R, András E

    2017-10-01

    Three-dimensional (3D) reconstruction of a sample surface from scanning electron microscope (SEM) images taken at two perspectives has been known for decades. Nowadays, there exist several commercially available stereophotogrammetry software packages. For testing these software packages, in this study we used Monte Carlo simulated SEM images of virtual samples. A virtual sample is a model in a computer, and its true dimensions are known exactly, which is impossible for real SEM samples due to measurement uncertainty. The simulated SEM images can be used for algorithm testing, development, and validation. We tested two stereophotogrammetry software packages and compared their reconstructed 3D models with the known geometry of the virtual samples used to create the simulated SEM images. Both packages performed relatively well with simulated SEM images of a sample with a rough surface. However, in a sample containing nearly uniform and therefore low-contrast zones, the height reconstruction error was ≈46%. The present stereophotogrammetry software packages need further improvement before they can be used reliably with SEM images with uniform zones.

  17. The importance of scanning electron microscopy (sem in taxonomy and morphology of Chironomidae (Diptera

    Directory of Open Access Journals (Sweden)

    Andrzej Kownacki

    2015-07-01

    Full Text Available The paper reports on the value of scanning electron microscopy (SEM in the taxonomy and morphology of Chironomidae. This method has been relatively rarely used in Chironomidae studies. Our studies suggest that the SEM method provides a lot of new information. For example, the plastron plate of the thoracic horn of Macropelopia nebulosa (Meigen under light microscopy is visible as points, while under SEM we have found that it consists of a reticular structure with holes. By using SEM a more precise picture of the body structure of Chironomidae can be revealed. It allows researchers to explain inconsistencies in the existing descriptions of species. Another advantage of the SEM method is obtaining spatial images of the body and organs of Chironomidae. However, the SEM method also has some limitations. The main problem is dirt or debris (e.g. algae, mud, secretions, mucus, bacteria, etc., which often settles on the external surface of structures, especially those which are uneven or covered with hair. The dirt should be removed after collection of chironomid material because if left in place it can become chemically fixed to various surfaces. It unnecessarily remains at the surface and final microscopic images may contain artifacts that obscure chironomid structures being investigated. In this way many details of the surface are thus unreadable. The results reported here indicate that SEM examination helps us to identify new morphological features and details that will facilitate the identification of species of Chironomidae and may help to clarify the function of various parts of the body. Fast development of electron microscope technique allows us to learn more about structure of different organisms.

  18. Evaluating Neighborhoods Livability in Nigeria: A Structural Equation Modelling (SEM Approach

    Directory of Open Access Journals (Sweden)

    Sule Abass Iyanda

    2018-01-01

    and housing unit characteristics first-order factors. The result shows that economic vitality (income, mobility and mobility cost most significantly measures neighborhood livability. Also, results of the model achieved good fit indices such as CFI of 0.907 and the RMSEA value of 0.096. Thus, SEM analyses in this study offer a methodological guide on the efficacy of CFA second-order factor.

  19. APLIKASI STRUCTURAL EQUATION MODEL (SEM DALAM PENENTUAN ALTERNATIF PENGELOLAAN LINGKUNGAN INDUSTRI KOMPONEN ALAT BERAT BERBASIS PARTISIPASI DAN KEMITRAAN MASYARAKAT

    Directory of Open Access Journals (Sweden)

    Budi Setyo Utomo

    2012-07-01

    Full Text Available As a company engaged in the industrial sector by producing certain components and localized in an industrial area, there will be an impact on the environment. These impacts can be positive in the form of employment, reducing dependence on imported heavy equipment, increase in foreign exchange due to reduced imports and increased exports, increased government revenue from taxes, public facilities improvement and supporting infrastructure, and opening up opportunities for other related industries. These impacts can also be negative in the form of environmental degradation such as noise disturbance, dust, and micro climate change, and changes in social and cultural conditions surrounding the industry. Data analysis was performed descriptively and with the Structural Equation Model (SEM. SEM is a multivariate statistical technique which is a combination of factor analysis and regression analysis (correlation, which aims to test the connections between existing variables in a model, whether it is between the indicator with the construct, or the connections between constructs. SEM model consists of two parts, which is the latent variable model and the observed variable model. In contrast to ordinary regression linking the causality between the observed variables, it is also possible in SEM to identify the causality between latent variables. The results of SEM analysis showed that the developed model has a fairly high level of validity that is shown by the minimum fit chi-square value of 93.15 (P = 0.00029. Based on said model, it shows that the company's performance in waste management is largely determined by employee integrity and objectivity of the new employees followed later by the independence of the employees in waste management. The most important factor that determines the employee integrity in waste management in the model is honesty, individual wisdom, and a sense of responsibility. The most important factor in the employee objectivity

  20. Assessing the impacts of human activities and climate variations on grassland productivity by partial least squares structural equation modeling (PLS-SEM)

    Institute of Scientific and Technical Information of China (English)

    SHA Zongyao; XIE Yichun; TAN Xicheng; BAI Yongfei; LI Jonathan; LIU Xuefeng

    2017-01-01

    The cause-effect associations between geographical phenomena are an important focus in ecological research.Recent studies in structural equation modeling (SEM) demonstrated the potential for analyzing such associations.We applied the variance-based partial least squares SEM (PLS-SEM) and geographically-weighted regression (GWR) modeling to assess the human-climate impact on grassland productivity represented by above-ground biomass (AGB).The human and climate factors and their interaction were taken to explain the AGB variance by a PLS-SEM developed for the grassland ecosystem in Inner Mongolia,China.Results indicated that 65.5% of the AGB variance could be explained by the human and climate factors and their interaction.The case study showed that the human and climate factors imposed a significant and negative impact on the AGB and that their interaction alleviated to some extent the threat from the intensified human-climate pressure.The alleviation may be attributable to vegetation adaptation to high human-climate stresses,to human adaptation to climate conditions or/and to recent vegetation restoration programs in the highly degraded areas.Furthermore,the AGB response to the human and climate factors modeled by GWR exhibited significant spatial variations.This study demonstrated that the combination of PLS-SEM and GWR model is feasible to investigate the cause-effect relation in socio-ecological systems.

  1. A combined optical, SEM and STM study of growth spirals

    Indian Academy of Sciences (India)

    Some novel results of a combined sequential study of growth spirals on the basal surface of the richly polytypic CdI2 crystals by optical microscopy, scanning electron microscopy (SEM) and scanning tunneling microscopy (STM) are presented and discussed. In confirmation of the known structural data, the STM pictures ...

  2. 3D reconstruction of SEM images by use of optical photogrammetry software.

    Science.gov (United States)

    Eulitz, Mona; Reiss, Gebhard

    2015-08-01

    Reconstruction of the three-dimensional (3D) surface of an object to be examined is widely used for structure analysis in science and many biological questions require information about their true 3D structure. For Scanning Electron Microscopy (SEM) there has been no efficient non-destructive solution for reconstruction of the surface morphology to date. The well-known method of recording stereo pair images generates a 3D stereoscope reconstruction of a section, but not of the complete sample surface. We present a simple and non-destructive method of 3D surface reconstruction from SEM samples based on the principles of optical close range photogrammetry. In optical close range photogrammetry a series of overlapping photos is used to generate a 3D model of the surface of an object. We adapted this method to the special SEM requirements. Instead of moving a detector around the object, the object itself was rotated. A series of overlapping photos was stitched and converted into a 3D model using the software commonly used for optical photogrammetry. A rabbit kidney glomerulus was used to demonstrate the workflow of this adaption. The reconstruction produced a realistic and high-resolution 3D mesh model of the glomerular surface. The study showed that SEM micrographs are suitable for 3D reconstruction by optical photogrammetry. This new approach is a simple and useful method of 3D surface reconstruction and suitable for various applications in research and teaching. Copyright © 2015 Elsevier Inc. All rights reserved.

  3. O Cinema sem Imagens

    Directory of Open Access Journals (Sweden)

    Paulo Andrade

    2001-12-01

    Full Text Available A obra cinematográfica de Marguerite Duras, praticamente desconhecida pelo grande público, estabeleça intricadas relações com sua obra literária, ao promover a indiscernibilidade entre os dois campo, sem, contudo, instituir qualquer tipo de subordinação de um ao outro. O processo de criação do filme Lê camion, de 1977, aponta para outras possibilidades de se pensar o cinema e a literatura.

  4. Orientation mapping by transmission-SEM with an on-axis detector

    International Nuclear Information System (INIS)

    Fundenberger, J.J.; Bouzy, E.; Goran, D.; Guyon, J.; Yuan, H.; Morawiec, A.

    2016-01-01

    Conventional orientation mapping in a scanning electron microscope (SEM) is a valuable technique for characterizing crystalline materials, but its application to ultrafine or nano-grain materials is limited by its spatial resolution. The resolution can be increased by collecting transmission diffraction patterns in SEM. In previous works, such patterns were collected using off-axis detectors in nearly vertical position. To avoid some drawbacks of such arrangement, a new configuration was devised in which the scintillator is located underneath the thin foil on the optical axis of the microscope, and the light is reflected towards the camera by a mirror. This simple configuration gives intense patterns even at very low probe currents, and can be potentially used for collecting maps of relatively high spatial resolution. Example maps reveal details with dimensions of about 5 nm. Because of its resolution and geometric simplicity, the proposed configuration will open new opportunities in SEM-based characterization of nanocrystalline materials. - Highlights: • New experimental configuration for SEM-based orientation mapping is presented. • The geometry of recording transmission Kikuchi patterns in SEM is simplified. • The new configuration allows for reaching relatively high spatial resolution.

  5. Role of scanning electron microscope )SEM) in metal failure analysis

    International Nuclear Information System (INIS)

    Shaiful Rizam Shamsudin; Hafizal Yazid; Mohd Harun; Siti Selina Abd Hamid; Nadira Kamarudin; Zaiton Selamat; Mohd Shariff Sattar; Muhamad Jalil

    2005-01-01

    Scanning electron microscope (SEM) is a scientific instrument that uses a beam of highly energetic electrons to examine the surface and phase distribution of specimens on a micro scale through the live imaging of secondary electrons (SE) and back-scattered electrons (BSE) images. One of the main activities of SEM Laboratory at MINT is for failure analysis on metal part and components. The capability of SEM is excellent for determining the root cause of metal failures such as ductility or brittleness, stress corrosion, fatigue and other types of failures. Most of our customers that request for failure analysis are from local petrochemical plants, manufacturers of automotive components, pipeline maintenance personnel and engineers who involved in the development of metal parts and component. This paper intends to discuss some of the technical concepts in failure analysis associated with SEM. (Author)

  6. SEM probe of IC radiation sensitivity

    Science.gov (United States)

    Gauthier, M. K.; Stanley, A. G.

    1979-01-01

    Scanning Electron Microscope (SEM) used to irradiate single integrated circuit (IC) subcomponent to test for radiation sensitivity can localize area of IC less than .03 by .03 mm for determination of exact location of radiation sensitive section.

  7. Sexual Arousal and Sexually Explicit Media (SEM: Comparing Patterns of Sexual Arousal to SEM and Sexual Self-Evaluations and Satisfaction Across Gender and Sexual Orientation

    Directory of Open Access Journals (Sweden)

    Gert Martin Hald, PhD

    2018-03-01

    Hald GM, Stulhofer A, Lange T, et al. Sexual Arousal and Sexually Explicit Media (SEM: Comparing Patterns of Sexual Arousal to SEM and Sexual Self-Evaluations and Satisfaction Across Gender and Sexual Orientation. Sex Med 2018;6:30–38.

  8. SemFunSim: a new method for measuring disease similarity by integrating semantic and gene functional association.

    Directory of Open Access Journals (Sweden)

    Liang Cheng

    Full Text Available Measuring similarity between diseases plays an important role in disease-related molecular function research. Functional associations between disease-related genes and semantic associations between diseases are often used to identify pairs of similar diseases from different perspectives. Currently, it is still a challenge to exploit both of them to calculate disease similarity. Therefore, a new method (SemFunSim that integrates semantic and functional association is proposed to address the issue.SemFunSim is designed as follows. First of all, FunSim (Functional similarity is proposed to calculate disease similarity using disease-related gene sets in a weighted network of human gene function. Next, SemSim (Semantic Similarity is devised to calculate disease similarity using the relationship between two diseases from Disease Ontology. Finally, FunSim and SemSim are integrated to measure disease similarity.The high average AUC (area under the receiver operating characteristic curve (96.37% shows that SemFunSim achieves a high true positive rate and a low false positive rate. 79 of the top 100 pairs of similar diseases identified by SemFunSim are annotated in the Comparative Toxicogenomics Database (CTD as being targeted by the same therapeutic compounds, while other methods we compared could identify 35 or less such pairs among the top 100. Moreover, when using our method on diseases without annotated compounds in CTD, we could confirm many of our predicted candidate compounds from literature. This indicates that SemFunSim is an effective method for drug repositioning.

  9. How Hedstrom files fail during clinical use? A retrieval study based on SEM, optical microscopy and micro-XCT analysis.

    Science.gov (United States)

    Zinelis, Spiros; Al Jabbari, Youssef S

    2018-05-01

    This study was conducted to evaluate the failure mechanism of clinically failed Hedstrom (H)-files. Discarded H-files (n=160) from #8 to #40 ISO sizes were collected from different dental clinics. Retrieved files were classified according to their macroscopic appearance and they were investigated under scanning electron microscopy (SEM) and X-ray micro-computed tomography (mXCT). Then the files were embedded in resin along their longitudinal axis and after metallographic grinding and polishing, studied under an incident light microscope. The macroscopic evaluation showed that small ISO sizes (#08-#15) failed by extensive plastic deformation, while larger sizes (≥#20) tended to fracture. Light microscopy and mXCT results coincided showing that unused and plastically deformed files were free of internal defects, while fractured files demonstrate the presence of intense cracking in the flute region. SEM analysis revealed the presence of striations attributed to the fatigue mechanism. Secondary cracks were also identified by optical microscopy and their distribution was correlated to fatigue under bending loading. Experimental results demonstrated that while overloading of cutting instruments is the predominating failure mechanism of small file sizes (#08-#15), fatigue should be considered the fracture mechanism for larger sizes (≥#20).

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

    Directory of Open Access Journals (Sweden)

    Francesco Mangano

    2017-12-01

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

  11. From patterns to causal understanding: Structural equation modeling (SEM) in soil ecology

    Science.gov (United States)

    Eisenhauer, Nico; Powell, Jeff R; Grace, James B.; Bowker, Matthew A.

    2015-01-01

    In this perspectives paper we highlight a heretofore underused statistical method in soil ecological research, structural equation modeling (SEM). SEM is commonly used in the general ecological literature to develop causal understanding from observational data, but has been more slowly adopted by soil ecologists. We provide some basic information on the many advantages and possibilities associated with using SEM and provide some examples of how SEM can be used by soil ecologists to shift focus from describing patterns to developing causal understanding and inspiring new types of experimental tests. SEM is a promising tool to aid the growth of soil ecology as a discipline, particularly by supporting research that is increasingly hypothesis-driven and interdisciplinary, thus shining light into the black box of interactions belowground.

  12. Structural Equations and Causal Explanations: Some Challenges for Causal SEM

    Science.gov (United States)

    Markus, Keith A.

    2010-01-01

    One common application of structural equation modeling (SEM) involves expressing and empirically investigating causal explanations. Nonetheless, several aspects of causal explanation that have an impact on behavioral science methodology remain poorly understood. It remains unclear whether applications of SEM should attempt to provide complete…

  13. Developing 3D SEM in a broad biological context

    Science.gov (United States)

    Kremer, A; Lippens, S; Bartunkova, S; Asselbergh, B; Blanpain, C; Fendrych, M; Goossens, A; Holt, M; Janssens, S; Krols, M; Larsimont, J-C; Mc Guire, C; Nowack, MK; Saelens, X; Schertel, A; Schepens, B; Slezak, M; Timmerman, V; Theunis, C; Van Brempt, R; Visser, Y; GuÉRin, CJ

    2015-01-01

    When electron microscopy (EM) was introduced in the 1930s it gave scientists their first look into the nanoworld of cells. Over the last 80 years EM has vastly increased our understanding of the complex cellular structures that underlie the diverse functions that cells need to maintain life. One drawback that has been difficult to overcome was the inherent lack of volume information, mainly due to the limit on the thickness of sections that could be viewed in a transmission electron microscope (TEM). For many years scientists struggled to achieve three-dimensional (3D) EM using serial section reconstructions, TEM tomography, and scanning EM (SEM) techniques such as freeze-fracture. Although each technique yielded some special information, they required a significant amount of time and specialist expertise to obtain even a very small 3D EM dataset. Almost 20 years ago scientists began to exploit SEMs to image blocks of embedded tissues and perform serial sectioning of these tissues inside the SEM chamber. Using first focused ion beams (FIB) and subsequently robotic ultramicrotomes (serial block-face, SBF-SEM) microscopists were able to collect large volumes of 3D EM information at resolutions that could address many important biological questions, and do so in an efficient manner. We present here some examples of 3D EM taken from the many diverse specimens that have been imaged in our core facility. We propose that the next major step forward will be to efficiently correlate functional information obtained using light microscopy (LM) with 3D EM datasets to more completely investigate the important links between cell structures and their functions. Lay Description Life happens in three dimensions. For many years, first light, and then EM struggled to image the smallest parts of cells in 3D. With recent advances in technology and corresponding improvements in computing, scientists can now see the 3D world of the cell at the nanoscale. In this paper we present the

  14. SEM-REV: A sea test site for Marine Energy Converter

    International Nuclear Information System (INIS)

    Berhault, Christian; Le Crom, Izan; Le Bihan, Gerard

    2015-01-01

    Thanks to a main funding of Region des Pays de la Loire, the sea test site SEM-REV has been developed by Ecole Centrale de Nantes since 2007 to test both Wave Energy Converters and Floating Wind Turbine in real sea conditions. The sea test site is equipped with a set of oceanographic sensors and with an electric cable of 8 MW, connected to the French grid. The project is located close to Le Croisic, Western coast of France. SEM-REV is one of the main test facilities operated by Ecole Centrale de Nantes to support MRE technologies development. After presenting the initial motivations of the SEM-REV development, the paper describes, in parts 1 and 2, the complete administrative and technical processes that were followed to reach SEM-REV commissioning in 2014. The third part is focused on the exploitation process, including technical and contractual specifications imposed to the MRE developers for installation, tests and decommissioning phases. Some words are given also on the R and D projects using the SEM-REV in-situ monitoring system: prediction of environmental conditions, bio-fooling, acoustic impact. Even if operational phase is not started, expected extensions of the tests site are listed. (authors)

  15. HUMAN CAPSULE EPITHELIAL-CELL DEGENERATION A LM, SEM AND TEM INVESTIGATION

    NARCIS (Netherlands)

    JONGEBLOED, WL; KALICHARAN, D; WORST, JGF

    1993-01-01

    The degeneration of the capsule epithelium of cataractous lenses has been studied with LM, SEM on TEM with emphases on TEM. The observed degeneration of the epithelial cells can be described as follows: The cell nucleus becomes picnotic and desintegrates as result of change of the chromatin.

  16. Investigation of hidden periodic structures on SEM images of opal-like materials using FFT and IFFT.

    Science.gov (United States)

    Stephant, Nicolas; Rondeau, Benjamin; Gauthier, Jean-Pierre; Cody, Jason A; Fritsch, Emmanuel

    2014-01-01

    We have developed a method to use fast Fourier transformation (FFT) and inverse fast Fourier transformation (IFFT) to investigate hidden periodic structures on SEM images. We focused on samples of natural, play-of-color opals that diffract visible light and hence are periodically structured. Conventional sample preparation by hydrofluoric acid etch was not used; untreated, freshly broken surfaces were examined at low magnification relative to the expected period of the structural features, and, the SEM was adjusted to get a very high number of pixels in the images. These SEM images were treated by software to calculate autocorrelation, FFT, and IFFT. We present how we adjusted SEM acquisition parameters for best results. We first applied our procedure on an SEM image on which the structure was obvious. Then, we applied the same procedure on a sample that must contain a periodic structure because it diffracts visible light, but on which no structure was visible on the SEM image. In both cases, we obtained clearly periodic patterns that allowed measurements of structural parameters. We also investigated how the irregularly broken surface interfered with the periodic structure to produce additional periodicity. We tested the limits of our methodology with the help of simulated images. © 2014 Wiley Periodicals, Inc.

  17. Two novel approaches to study arthropod anatomy by using dualbeam FIB/SEM.

    Science.gov (United States)

    Di Giulio, Andrea; Muzzi, Maurizio

    2018-03-01

    Transmission Electron Microscopy (TEM) has always been the conventional method to study arthropod ultrastructure, while the use of Scanning Electron Microscopy (SEM) was mainly devoted to the examination of the external cuticular structures by secondary electrons. The new generation field emission SEMs are capable to generate images at sub-cellular level, comparable to TEM images employing backscattered electrons. The potential of this kind of acquisition becomes very powerful in the dual beam FIB/SEM where the SEM column is combined with a Focused Ion Beam (FIB) column. FIB uses ions as a nano-scalpel to slice samples fixed and embedded in resin, replacing traditional ultramicrotomy. We here present two novel methods, which optimize the use of FIB/SEM for studying arthropod anatomy. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Soft tissue digestion of Paradiplozoon vaalense for SEM of sclerites and simultaneous molecular analysis.

    Science.gov (United States)

    Dos Santos, Q M; Avenant-Oldewage, A

    2015-02-01

    Classification of most monogeneans is primarily based on size, shape, and arrangement of haptoral sclerites. These structures are often obscured or misinterpreted when studied using light microscopy, leading to confusion regarding defining characters. Scanning electron microscopy (SEM) has predominantly been used to study haptoral sclerites in smaller monogeneans, focusing on hooks and anchors. In the Diplozoidae, SEM has not been used to study haptoral sclerites. Using new and modified techniques, the sclerites of diplozoids collected in South Africa were successfully studied using SEM. The digestion buffer from a DNA extraction kit was used to digest the surrounding tissue, and Poly-L-lysine-coated and concavity slides were employed to limit the movement and loss of sclerites, with the latter being more user-friendly. In addition to the success of visualizing the sclerites using SEM, the digested tissue from as little as half of the haptor provided viable genetic material for molecular characterization. From the results presented here, the study of the sclerites of larger monogeneans using SEM, including those bearing clamps, is a viable possibility for future research. Also, this method may be beneficial for the study of other, non-haptoral sclerites, such as cirri in other families of monogeneans. During this study, Labeo capensis was noted as a valid host of Paradiplozoon vaalense in a region of the Vaal River where the type host, Labeo umbratus, appears to be absent.

  19. SEM AutoAnalysis: enhancing photomask and NIL defect disposition and review

    Science.gov (United States)

    Schulz, Kristian; Egodage, Kokila; Tabbone, Gilles; Ehrlich, Christian; Garetto, Anthony

    2017-06-01

    For defect disposition and repair verification regarding printability, AIMS™ is the state of the art measurement tool in industry. With its unique capability of capturing aerial images of photomasks it is the one method that comes closest to emulating the printing behaviour of a scanner. However for nanoimprint lithography (NIL) templates aerial images cannot be applied to evaluate the success of a repair process. Hence, for NIL defect dispositioning scanning, electron microscopy (SEM) imaging is the method of choice. In addition, it has been a standard imaging method for further root cause analysis of defects and defect review on optical photomasks which enables 2D or even 3D mask profiling at high resolutions. In recent years a trend observed in mask shops has been the automation of processes that traditionally were driven by operators. This of course has brought many advantages one of which is freeing cost intensive labour from conducting repetitive and tedious work. Furthermore, it reduces variability in processes due to different operator skill and experience levels which at the end contributes to eliminating the human factor. Taking these factors into consideration, one of the software based solutions available under the FAVOR® brand to support customer needs is the aerial image evaluation software, AIMS™ AutoAnalysis (AAA). It provides fully automated analysis of AIMS™ images and runs in parallel to measurements. This is enabled by its direct connection and communication with the AIMS™tools. As one of many positive outcomes, generating automated result reports is facilitated, standardizing the mask manufacturing workflow. Today, AAA has been successfully introduced into production at multiple customers and is supporting the workflow as described above. These trends indeed have triggered the demand for similar automation with respect to SEM measurements leading to the development of SEM AutoAnalysis (SAA). It aims towards a fully automated SEM image

  20. A two-step FEM-SEM approach for wave propagation analysis in cable structures

    Science.gov (United States)

    Zhang, Songhan; Shen, Ruili; Wang, Tao; De Roeck, Guido; Lombaert, Geert

    2018-02-01

    Vibration-based methods are among the most widely studied in structural health monitoring (SHM). It is well known, however, that the low-order modes, characterizing the global dynamic behaviour of structures, are relatively insensitive to local damage. Such local damage may be easier to detect by methods based on wave propagation which involve local high frequency behaviour. The present work considers the numerical analysis of wave propagation in cables. A two-step approach is proposed which allows taking into account the cable sag and the distribution of the axial forces in the wave propagation analysis. In the first step, the static deformation and internal forces are obtained by the finite element method (FEM), taking into account geometric nonlinear effects. In the second step, the results from the static analysis are used to define the initial state of the dynamic analysis which is performed by means of the spectral element method (SEM). The use of the SEM in the second step of the analysis allows for a significant reduction in computational costs as compared to a FE analysis. This methodology is first verified by means of a full FE analysis for a single stretched cable. Next, simulations are made to study the effects of damage in a single stretched cable and a cable-supported truss. The results of the simulations show how damage significantly affects the high frequency response, confirming the potential of wave propagation based methods for SHM.

  1. Speciation of uranium in minerals by Sem, Tem, μ-PIXE, XPS and XAFS

    International Nuclear Information System (INIS)

    Toshihiko Ohnuki; Hiroshi Isobe; Tomihiro Kamiya; Takuro Sakai; Takashi Murakami

    2001-01-01

    Many kinds of electromagnetic waves and particle beams are used as analytical probes for the investigation of uranium-mineralogy and speciation. The representatives of the probes are SEM, TEM, μ-PIRE, XPS and XAFS. Each of these analytical probes has its own advantages and disadvantages. We have performed studies to compare the advantages and disadvantages on the basis of the analysis of the distribution and speciation of U containing rock samples collected at the Koongarra uranium deposit, Australia. The spatial resolutions of the probes are in the order of TEM>SEM, μ-PIXE>XFAS, XPS. The lower detection limits of the probes are in the order of μ-PIXE< TEM, SEM< XFAS, XPS. Oxidation state of U was determined by XFAS and XPS. These results indicate that combination of the above probes can give us sufficient data on U speciation not only in natural rock samples but in solid samples obtained in the laboratory. (authors)

  2. Direct comparison of AFM and SEM measurements on the same set of nanoparticles

    International Nuclear Information System (INIS)

    Delvallée, A; Feltin, N; Ducourtieux, S; Trabelsi, M; Hochepied, J F

    2015-01-01

    This article is the first step in the development of a hybrid metrology combining AFM and SEM techniques for measuring the dimensions of a nanoparticle population in 3D space (X,Y,Z). This method exploits the strengths of each technique on the same set of nanoparticles. AFM is used for measuring the nanoparticle height and the measurements along X and Y axes are deduced from SEM images. A sampling method is proposed in order to obtain the best deposition conditions of SiO 2 and gold nanoparticles on mica or silicon substrates. Only the isolated nanoparticles are taken into account in the histogram of size distribution. Moreover, a semi-automatic Matlab routine has also been developed to process the AFM and SEM images, measure and count the nanoparticles. This routine allows the user to exclusively select the isolated nanoparticles through a control interface. The measurements have been performed on spherical-like nanoparticles to test the method by comparing the results obtained with both techniques. (paper)

  3. Annual International DIC Society Conference and SEM Fall Conference

    CERN Document Server

    Reu, Phillip

    2017-01-01

    This collection represents a single volume of technical papers presented at the Annual International DIC Society Conference and SEM Fall Conference organized by the Society for Experimental Mechanics and Sandia National Laboratories and held in Philadelphia, PA, November 7-10, 2016. The volume presents early findings from experimental, standards development and various other investigations concerning digital image correlation - an important area within Experimental Mechanics. The area of Digital Image Correlation has been an integral track within the SEM Annual Conference spearheaded by Professor Michael Sutton from the University of South Carolina. In 2016, the SEM and Sandia joined their collaborative strengths to launch a standing fall meeting focusing specifically on developments in the area of Digital Image Correlation. The contributed papers within this volume span numerous technical aspects of DIC including standards development for the industry. .

  4. Quantifying Golgi structure using EM: combining volume-SEM and stereology for higher throughput.

    Science.gov (United States)

    Ferguson, Sophie; Steyer, Anna M; Mayhew, Terry M; Schwab, Yannick; Lucocq, John Milton

    2017-06-01

    Investigating organelles such as the Golgi complex depends increasingly on high-throughput quantitative morphological analyses from multiple experimental or genetic conditions. Light microscopy (LM) has been an effective tool for screening but fails to reveal fine details of Golgi structures such as vesicles, tubules and cisternae. Electron microscopy (EM) has sufficient resolution but traditional transmission EM (TEM) methods are slow and inefficient. Newer volume scanning EM (volume-SEM) methods now have the potential to speed up 3D analysis by automated sectioning and imaging. However, they produce large arrays of sections and/or images, which require labour-intensive 3D reconstruction for quantitation on limited cell numbers. Here, we show that the information storage, digital waste and workload involved in using volume-SEM can be reduced substantially using sampling-based stereology. Using the Golgi as an example, we describe how Golgi populations can be sensed quantitatively using single random slices and how accurate quantitative structural data on Golgi organelles of individual cells can be obtained using only 5-10 sections/images taken from a volume-SEM series (thereby sensing population parameters and cell-cell variability). The approach will be useful in techniques such as correlative LM and EM (CLEM) where small samples of cells are treated and where there may be variable responses. For Golgi study, we outline a series of stereological estimators that are suited to these analyses and suggest workflows, which have the potential to enhance the speed and relevance of data acquisition in volume-SEM.

  5. Evaluating the Use of Synthetic Replicas for SEM Identification of Bloodstains (with Emphasis on Archaeological and Ethnographic Artifacts).

    Science.gov (United States)

    Hortolà, Policarp

    2015-12-01

    Some archaeological or ethnographic specimens are unavailable for direct examination using a scanning electron microscope (SEM) due to methodological obstacles or legal issues. In order to assess the feasibility of using SEM synthetic replicas for the identification of bloodstains (BSs) via morphology of red blood cells (RBCs), three fragments of different natural raw material (inorganic, stone; plant, wood; animal, shell) were smeared with peripheral human blood. Afterwards, molds and casts of the bloodstained areas were made using vinyl polysiloxane (VPS) silicone impression and polyurethane (PU) resin casting material, respectively. Then, the original samples and the resulting casts were coated with gold and examined in secondary-electron mode using a high-vacuum SEM. Results suggest that PU resin casts obtained from VPS silicone molds can preserve RBC morphology in BSs, and consequently that synthetic replicas are feasible for SEM identification of BSs on cultural heritage specimens made of natural raw materials. Although the focus of this study was on BSs, the method reported in this paper may be applicable to organic residues other than blood, as well as to the surface of other specimens when, for any reason, the original is unavailable for an SEM.

  6. Enabling CD SEM metrology for 5nm technology node and beyond

    Science.gov (United States)

    Lorusso, Gian Francesco; Ohashi, Takeyoshi; Yamaguchi, Astuko; Inoue, Osamu; Sutani, Takumichi; Horiguchi, Naoto; Bömmels, Jürgen; Wilson, Christopher J.; Briggs, Basoene; Tan, Chi Lim; Raymaekers, Tom; Delhougne, Romain; Van den Bosch, Geert; Di Piazza, Luca; Kar, Gouri Sankar; Furnémont, Arnaud; Fantini, Andrea; Donadio, Gabriele Luca; Souriau, Laurent; Crotti, Davide; Yasin, Farrukh; Appeltans, Raf; Rao, Siddharth; De Simone, Danilo; Rincon Delgadillo, Paulina; Leray, Philippe; Charley, Anne-Laure; Zhou, Daisy; Veloso, Anabela; Collaert, Nadine; Hasumi, Kazuhisa; Koshihara, Shunsuke; Ikota, Masami; Okagawa, Yutaka; Ishimoto, Toru

    2017-03-01

    FETs,, metrology for vertical and horizontal NWs. With respect to memory, we discuss a STT-RAM statistical CD analysis and its comparison to electrical performance, ReRAM metrology for VMCO (Vacancy-modulated conductive oxide) with comparison with electrical performance, 3D NAND ONO (Oxide Nitride Oxide) thickness measurements. In addition, we report on 3D morphological reconstruction using CD SEM in conjunction with FIB (Focused Ion Beam), on optimized BKM (Best Known Methods) development methodologies, and on CD SEM overlay. The large variety of results reported here gives a clear overview of the creative effort put in place to ensure that the critical potential of CD SEM metrology tools is fully enabled for the 5nm node and beyond.

  7. SEM observations of particle track membrane surfaces modificated using plasma treatment

    International Nuclear Information System (INIS)

    Sartowska, B.; Buczkowski, M.; Starosta, W.

    2003-01-01

    This work presents results of scanning electron microscopy (SEM) observations of 0.4 μm membranes after plasma treatment with different parameters. The morphology changes at the surfaces and at the pore walls were observed. The character of changes in the membrane parameters according to the process conditions was determined

  8. The SEM Risk Behavior (SRB) Model: A New Conceptual Model of how Pornography Influences the Sexual Intentions and HIV Risk Behavior of MSM.

    Science.gov (United States)

    Wilkerson, J Michael; Iantaffi, Alex; Smolenski, Derek J; Brady, Sonya S; Horvath, Keith J; Grey, Jeremy A; Rosser, B R Simon

    2012-01-01

    While the effects of sexually explicit media (SEM) on heterosexuals' sexual intentions and behaviors have been studied, little is known about the consumption and possible influence of SEM among men who have sex with men (MSM). Importantly, conceptual models of how Internet-based SEM influences behavior are lacking. Seventy-nine MSM participated in online focus groups about their SEM viewing preferences and sexual behavior. Twenty-three participants reported recent exposure to a new behavior via SEM. Whether participants modified their sexual intentions and/or engaged in the new behavior depended on three factors: arousal when imagining the behavior, pleasure when attempting the behavior, and trust between sex partners. Based on MSM's experience, we advance a model of how viewing a new sexual behavior in SEM influences sexual intentions and behaviors. The model includes five paths. Three paths result in the maintenance of sexual intentions and behaviors. One path results in a modification of sexual intentions while maintaining previous sexual behaviors, and one path results in a modification of both sexual intentions and behaviors. With this model, researchers have a framework to test associations between SEM consumption and sexual intentions and behavior, and public health programs have a framework to conceptualize SEM-based HIV/STI prevention programs.

  9. Building a SEM Analytics Reporting Portfolio

    Science.gov (United States)

    Goff, Jay W.; Williams, Brian G.; Kilgore, Wendy

    2016-01-01

    Effective strategic enrollment management (SEM) efforts require vast amounts of internal and external data to ensure that meaningful reporting and analysis systems can assist managers in decision making. A wide range of information is integral for leading effective and efficient student recruitment and retention programs. This article is designed…

  10. Attempt of correlative observation of morphological synaptic connectivity by combining confocal laser-scanning microscope and FIB-SEM for immunohistochemical staining technique.

    Science.gov (United States)

    Sonomura, Takahiro; Furuta, Takahiro; Nakatani, Ikuko; Yamamoto, Yo; Honma, Satoru; Kaneko, Takeshi

    2014-11-01

    Ten years have passed since a serial block-face scanning electron microscopy (SBF-SEM) method was developed [1]. In this innovative method, samples were automatically sectioned with an ultramicrotome placed inside a scanning electron microscope column, and the block surfaces were imaged one after another by SEM to capture back-scattered electrons. The contrast-inverted images obtained by the SBF-SEM were very similar to those acquired using conventional TEM. SFB-SEM has made easy to acquire image stacks of the transmission electron microscopy (TEM) in the mesoscale, which is taken with the confocal laser-scanning microcopy(CF-LSM).Furthermore, serial-section SEM has been combined with the focused ion beam (FIB) milling method [2]. FIB-incorporated SEM (FIB-SEM) has enabled the acquisition of three-dimensional images with a higher z-axis resolution com- pared to ultramicrotome-equipped SEM.We tried immunocytochemistry for FIB-SEM and correlated this immunoreactivity with that in CF-LSM. Dendrites of neurons in the rat neostriatum were visualized using a recombinant viral vector. Moreover, the thalamostriatal afferent terminals were immunolabeled with Cy5 fluorescence for vesicular glutamate transporter 2 (VGluT2). After detection of the sites of terminals apposed to the dendrites by using CF-LSM, GFP and VGluT2 immunoreactivities were further developed for EM by using immunogold/silver enhancement and immunoperoxidase/diaminobenzidine (DAB) methods, respectively.We showed that conventional immuno-cytochemical staining for TEM was applicable to FIB-SEM. Furthermore, several synaptic contacts, which were thought to exist on the basis of CF-LSM findings, were confirmed with FIB-SEM, revealing the usefulness of the combined method of CF-LSM and FIB-SEM. © The Author 2014. Published by Oxford University Press on behalf of The Japanese Society of Microscopy. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  11. A Teoria dos Blocos Semânticos em revisão

    Directory of Open Access Journals (Sweden)

    Julio Cesar Machado

    2017-08-01

    Full Text Available A Teoria dos Blocos Semânticos ocupa lugar significativo nos trabalhos mundiais em Semântica, Argumentação e Enunciação, dentre outros. Por isso sua pertinência para a Linguística reclama uma reflexão. O presente trabalho pretende refletir algumas reformulações na Teoria dos Blocos Semânticos nas últimas duas décadas, a saber: (a polifonia, (b bloco semântico, e (c quadrado argumentativo. Especificamente, trataremos das seguintes relações: (a’ da Teoria Polifônica da Enunciação à Teoria Argumentativa da Polifonia; (b’ do bloco semântico ao semi-bloco; e (c’ do quadrado argumentativo ao cubo argumentativo. A necessidade deste trabalho é duplamente justificada: (i devido à constante revisão teórica do arcabouço teórico deste saber, sobretudo na sua última década, característica de Marion Carel e de Oswald Ducrot; e (ii pela falta de tradução/circulação no Brasil de obras fundamentais no que tange à re-elaboração das noções chaves desta teoria.

  12. FIB/SEM study of AA2024 corrosion under a seawater drop, part II

    International Nuclear Information System (INIS)

    King, Peter C.; Cole, Ivan S.; Corrigan, Penny A.; Hughes, Anthony E.; Muster, Tim H.; Thomas, Sebastian

    2012-01-01

    Highlights: ► Dealloying has a directional nature, exhibits banding. ► Oxidation state of copper in sponge remnants found to be variable. ► Dissolution and breakdown of copper sponge structure observed. ► Crystalline defects imaged in dealloyed S-phase. - Abstract: The dissolution of S-phase clusters in aluminium alloy 2024 (AA2024) exposed to a 0.5 μl seawater droplet is presented. Foils for transmission electron microscopy (TEM) were made from local attack sites using a focussed ion beam/scanning electron microscope (FIB/SEM). The sections showed that clusters of S-phase particles underwent dealloying. The resulting copper sponge morphology, banding, preferred orientation and crystal defect structure as a result of plastic deformation have been characterised. With build-up of amorphous corrosion product, physical and electrical isolation of parts of the clusters developed, with the result of copper dissolution from the S-phase remnants.

  13. Comparison of SEM and VPSEM imaging techniques with respect to Streptococcus mutans biofilm topography.

    Science.gov (United States)

    Weber, Kathryn; Delben, Juliana; Bromage, Timothy G; Duarte, Simone

    2014-01-01

    The study compared images of mature Streptococcus mutans biofilms captured at increasing magnification to determine which microscopy method is most acceptable for imaging the biofilm topography and the extracellular polymeric substance (EPS). In vitro S. mutans biofilms were imaged using (1) scanning electron microscopy (SEM), which requires a dehydration process; (2) SEM and ruthenium red (SEM-RR), which has been shown to support the EPS of biofilms during the SEM dehydration; and (3) variable pressure scanning electron microscopy (VPSEM), which does not require the intensive dehydration process of SEM. The dehydration process and high chamber vacuum of both SEM techniques devastated the biofilm EPS, removed supporting structures, and caused cracking on the biofilm surface. The VPSEM offered the most comprehensive representation of the S. mutans biofilm morphology. VPSEM provides similar contrast and focus as the SEM, but the procedure is far less time-consuming, and the use of hazardous chemicals associated with SEM dehydration protocol is avoided with the VPSEM. The inaccurate representations of the biofilm EPS in SEM experimentation is a possible source of inaccurate data and impediments in the study of S. mutans biofilms. © 2013 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

  14. Characterization of wet precipitation by X-ray diffraction (XRD) and scanning electron microscopy (SEM) in the metropolitan area of Porto Alegre, Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Montanari Migliavacca, Daniela [Instituto de Biociencias, Programa de Pos-Graduacao em Ecologia, Universidade Federal do Rio Grande do Sul, Av. Bento Goncalves 9500, 91509-900 Porto Alegre, RS (Brazil); Fundacao Estadual de Protecao Ambiental Henrique Luis Roessler, RS. Rua Carlos Chagas 55/802, 90030-020 Porto Alegre, RS (Brazil); Calesso Teixeira, Elba, E-mail: gerpro.pesquisa@fepam.rs.gov.br [Fundacao Estadual de Protecao Ambiental Henrique Luis Roessler, RS. Rua Carlos Chagas 55/802, 90030-020 Porto Alegre, RS (Brazil); Gervasoni, Fernanda; Vieira Conceicao, Rommulo [Instituto de Geociencias, Universidade Federal do Rio Grande do Sul, Av. Bento Goncalves 9500, 91509-900 Porto Alegre, RS (Brazil); Raya Rodriguez, Maria Teresa [Instituto de Biociencias, Programa de Pos-Graduacao em Ecologia, Universidade Federal do Rio Grande do Sul, Av. Bento Goncalves 9500, 91509-900 Porto Alegre, RS (Brazil)

    2009-11-15

    The purpose of this study is to assess the composition of wet precipitation in three sites of the metropolitan area of Porto Alegre. Besides the variables usually considered, such as pH, conductivity, major ions (Cl{sup -}, NO{sub 3}{sup -}, F{sup -}, SO{sub 4}{sup 2-}, Na{sup +}, K{sup +}, Mg{sup 2+}, NH{sub 4}{sup +} and Ca{sup 2+}) and metallic elements (Cd, Co, Cr, Cu, Fe, Mn and Ni), the suspended matter was examined by X-ray diffraction (XRD) and scanning electron microscopy (SEM), with energy dispersive system (EDS), for better identification of possible anthropogenic material in this wet precipitation. Results showed an alkaline pH in the samples analyzed and higher concentrations for Na{sup +}, Cl{sup -} and SO{sub 4}{sup 2-}. The acidification and neutralization potential between anions (SO{sub 4}{sup 2-} + NO{sub 3}{sup -}) and cations (Ca{sup 2+} + Mg{sup 2+} + K{sup +} + NH{sub 4}{sup +}) showed a good correlation (0.922). The metallic elements with highest values were Zn, Fe and Mn. Results of XRD identified the presence of some minerals such as quartz, feldspar, mica, clay, carbonates and sulfates. In samples analyzed with SEM, we detected pyroxene, biotite, amphibole and oxides. Cluster analysis (CA) was applied to the data matrix to identify potential pollution sources of metals (natural or anthropogenic) and the association with minerals found in the analysis of SEM.

  15. Diversity of seM in Streptococcus equi subsp. equi isolated from strangles outbreaks.

    Science.gov (United States)

    Libardoni, Felipe; Vielmo, Andréia; Farias, Luana; Matter, Letícia Beatriz; Pötter, Luciana; Spilki, Fernando Rosado; de Vargas, Agueda Castagna

    2013-03-23

    Strangles is the main upper respiratory tract disease of horses. There are currently no studies on the changes in alleles of the M protein gene (seM) in Brazilian isolates of Streptococcus equi ssp. equi (S. equi). This study aimed to analyze and differentiate molecularly S. equi isolates from equine clinical specimens from southern Brazil, between 1994 and 2010. seM alleles were analyzed in 47 isolates of S. equi obtained from clinical cases of strangles (15 Thoroughbred horses, 29 Crioulo breed horses and three Brasileiro de Hipismo--BH). seM alleles characterization was performed by comparing variable region sequences of the seM gene. The alleles were also phylogenetically grouped by Neighbor-joining analysis, which demonstrated the geographic distribution of those in properties from southern Brazil. Fifteen alleles of the gene seM were found among the 47 S. equi isolates analyzed. Among these, only one allele (seM-61), which was identified in seven isolates (14.9%), was found in the database PubMLST-seM. Within the new alleles, allele seM-115 was the most prevalent, having been found in 13 isolates (27.7%), followed by allele seM-117 in 10 isolates (21.3%). In the Brazilian horse population studied, there is greater diversity of M protein alleles in S. equi isolates compared to worldwide data deposited in PubMLST-seM. Among the 15 seM alleles identified, only one allele sequence was previously published. The alleles identification is important to control the disease by guiding selection of strains for the manufacture of commercial and autogenous vaccines. Copyright © 2012 Elsevier B.V. All rights reserved.

  16. Mapping chemical elements on the surface of orthodontic appliance by SEM-EDX.

    Science.gov (United States)

    Mikulewicz, Marcin; Wołowiec, Paulina; Michalak, Izabela; Chojnacka, Katarzyna; Czopor, Wojciech; Berniczei-Royko, Adam; Vegh, Andras; Gedrange, Thomas

    2014-05-25

    During orthodontic treatment, the various elements that constitute the fixed appliance undergo different processes. As a result of a change of the surface, elution/coverage of metals on the surface can be observed in the process of corrosion/passivation. Scanning electron microscopy with an energy-dispersive X-ray analytical system (SEM-EDX) was used to analyze the composition of stainless steel elements of orthodontic fixed appliances (before and after orthodontic treatment), to obtain the composition of the surface of the elements. The analyzed elements were: brackets (Victory Series APC PLUS 022, 3M Unitek, Monrovia, CA, USA); wires (0.017×0.025, 3M Unitek, Monrovia, CA, USA); and bands (37+, 3M Unitek, Monrovia, CA, USA). The results showed a decrease of chromium and iron contribution to the surface, with increase of oxygen content in used vs. new elements of the appliance. Our results confirm the formation of oxides (passivation layer) on the surface of stainless steel as a result of the presence of the orthodontic appliance in patients' oral cavities.

  17. SemGroup acquisition of central Alberta midstream : case study

    International Nuclear Information System (INIS)

    Purcell, T.

    2005-01-01

    A case study of SemGroup's acquisition of Central Alberta Midstream was presented. SemCAMS specializes in providing more efficient supply, storage, and distribution assets and services. Seminole Canada Gas is a leading independent natural gas marketing and energy asset management company that currently markets 369 MMbtu per day. The company purchases natural gas in western Canada for fee-based marketing services while also managing firm transportation contracts and providing gas storage for third party customers. SemCAMS owns the largest sour gas processor in Alberta as well as 3 sour gas processing plants, 600 miles of gathering pipeline, and a sweet gas processing plant. the company is also planning increased drilling and production activities and is now pursuing aggressive land acquisition policies. Over 25,000 square miles of land have been acquired. It was concluded that midstream companies should be customer-focused, provide reliability and guarantees, infrastructure investment and optimization. tabs., figs

  18. Assessment of metal pollution sources by SEM/EDS analysis of solid particles in snow: a case study of Žerjav, Slovenia.

    Science.gov (United States)

    Miler, Miloš; Gosar, Mateja

    2013-12-01

    Solid particles in snow deposits, sampled in mining and Pb-processing area of Žerjav, Slovenia, have been investigated using scanning electron microscopy/energy-dispersive X-ray spectroscopy (SEM/EDS). Identified particles were classified as geogenic-anthropogenic, anthropogenic, and secondary weathering products. Geogenic-anthropogenic particles were represented by scarce Zn- and Pb-bearing ore minerals, originating from mine waste deposit. The most important anthropogenic metal-bearing particles in snow were Pb-, Sb- and Sn-bearing oxides and sulphides. The morphology of these particles showed that they formed at temperatures above their melting points. They were most abundant in snow sampled closest to the Pb-processing plant and least abundant in snow taken farthest from the plant, thus indicating that Pb processing was their predominant source between the last snowfall and the time of sampling. SEM/EDS analysis showed that Sb and Sn contents in these anthropogenic phases were higher and more variable than in natural Pb-bearing ore minerals. The most important secondary weathering products were Pb- and Zn-containing Fe-oxy-hydroxides whose elemental composition and morphology indicated that they mostly resulted from oxidation of metal-bearing sulphides emitted from the Pb-processing plant. This study demonstrated the importance of single particle analysis using SEM/EDS for differentiation between various sources of metals in the environment.

  19. A Proposal on the Quantitative Homogeneity Analysis Method of SEM Images for Material Inspections

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Song Hyun; Kim, Jong Woo; Shin, Chang Ho [Hanyang University, Seoul (Korea, Republic of); Choi, Jung-Hoon; Cho, In-Hak; Park, Hwan Seo [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-05-15

    A scanning electron microscope (SEM) is a method to inspect the surface microstructure of materials. The SEM uses electron beams for imaging high magnifications of material surfaces; therefore, various chemical analyses can be performed from the SEM images. Therefore, it is widely used for the material inspection, chemical characteristic analysis, and biological analysis. For the nuclear criticality analysis field, it is an important parameter to check the homogeneity of the compound material for using it in the nuclear system. In our previous study, the SEM was tried to use for the homogeneity analysis of the materials. In this study, a quantitative homogeneity analysis method of SEM images is proposed for the material inspections. The method is based on the stochastic analysis method with the information of the grayscales of the SEM images.

  20. A Proposal on the Quantitative Homogeneity Analysis Method of SEM Images for Material Inspections

    International Nuclear Information System (INIS)

    Kim, Song Hyun; Kim, Jong Woo; Shin, Chang Ho; Choi, Jung-Hoon; Cho, In-Hak; Park, Hwan Seo

    2015-01-01

    A scanning electron microscope (SEM) is a method to inspect the surface microstructure of materials. The SEM uses electron beams for imaging high magnifications of material surfaces; therefore, various chemical analyses can be performed from the SEM images. Therefore, it is widely used for the material inspection, chemical characteristic analysis, and biological analysis. For the nuclear criticality analysis field, it is an important parameter to check the homogeneity of the compound material for using it in the nuclear system. In our previous study, the SEM was tried to use for the homogeneity analysis of the materials. In this study, a quantitative homogeneity analysis method of SEM images is proposed for the material inspections. The method is based on the stochastic analysis method with the information of the grayscales of the SEM images

  1. In-Situ tensile testing of propellants in SEM: influence of temperature

    NARCIS (Netherlands)

    Di Benedetto, G.L.; Ramshorst, M.C.J.; Duvalois, W.; Hooijmeijer, P.; Heijden, A. van der

    2017-01-01

    A tensile module system placed within a Scanning Electron Microscope (SEM) was utilized to conduct insitu tensile testing of propellant samples. The tensile module system allows for real-time in-situ SEM analysis of the samples to determine the failure mechanism of the propellant material under

  2. Captura de enxames de abelhas sem ferrão (Hymenoptera, Apidae, Meliponinae sem destruição de árvores Capturing stingless bee nests (Hymenoptera, Apidae, Meliponinae without destroying the trees

    Directory of Open Access Journals (Sweden)

    Alexandre Coletto-Silva

    2005-09-01

    Full Text Available No Brasil a criação racional de abelhas sem ferrão é denominada meliponicultura. As abelhas sem ferrão possuem diferentes comportamentos de nidificação, com ninhos internos (cavidades naturais ou não e externos. Um dos principais problemas apresentados na meliponicultura é a captura de uma colônia com o objetivo de iniciar um meliponário sem "destruir as árvores" ou mesmo as próprias colônias durante a captura. O presente trabalho apresenta um método alternativo para captura de colônias de abelhas sem ferrão, especialmente, do gênero Melipona Illiger, 1806, que são as espécies mais utilizadas para produção de mel e pólen, na região Amazônica. O método consiste em abrir uma janela na árvore, coletar o material e fechar a abertura utilizando a resina vegetal conhecida como breu.Meliponiculture is the name for stingless beekeeping in Brazil. Stingless bees have different nest behaviors showing external and internal nests (natural cavities or not. One of the main problems of meliponiculture is the capture of a colony in order to begin a meliponary without destroying trees or the colonies during the capture. A new alternative method for the capture of stingless bee colonies is presented for the genus Melipona Illiger, 1806, which are the species mostly used for producing honey and pollen. The method is to open the tree, collect the colony, and then close the tree with natural resins known as "breu".

  3. The risk assessment of heavy metals in Futian mangrove forest sediment in Shenzhen Bay (South China) based on SEM-AVS analysis.

    Science.gov (United States)

    Chai, Minwei; Shen, Xiaoxue; Li, Ruili; Qiu, Guoyu

    2015-08-15

    The risks of heavy metal in Futian mangrove forest sediment were assessed using the acid-volatile sulfide (AVS) and simultaneously extracted metals (SEM) methods. The results indicated that AVS distributions were more variable than the SEM distributions at all 16 sampling sites. The positive correlation between AVS and SEM indicated that their similar formative and existing conditions and that AVS acted as an important carrier for SEM. The major SEM component was Zn (69.7.3-94.2%), whereas the Cd contribution (the most toxic metal present) to SEM was no more than 1%. The possible adverse effects caused by heavy metals at ten sampling sites may be due to higher levels of SEMs, rather than AVSs. The total organic carbon (TOC) was an important metal-binding phase in the sediments. Taking into account the TOC concentration, there were no adverse effects due to heavy metals in any of the Futian mangrove forest sediments. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. Marginal adaptation of newer root canal sealers to dentin: A SEM study.

    Science.gov (United States)

    Polineni, Swapnika; Bolla, Nagesh; Mandava, Pragna; Vemuri, Sayesh; Mallela, Madhusudana; Gandham, Vijaya Madhuri

    2016-01-01

    This in vitro study evaluated and compared the marginal adaptation of three newer root canal sealers to root dentin. Thirty freshly extracted human single-rooted teeth with completely formed apices were taken. Teeth were decoronated, and root canals were instrumented. The specimens were randomly divided into three groups (n = 10) based upon the sealer used. Group 1 - teeth were obturated with epoxy resin sealer (MM-Seal). Group 2 - teeth were obturated with mineral trioxide aggregate (MTA) based sealer (MTA Fillapex), Group 3 - teeth were obturated with bioceramic sealer (EndoSequence BC sealer). Later samples were vertically sectioned using hard tissue microtome and marginal adaptation of sealers to root dentin was evaluated under coronal and apical halves using scanning electron microscopy (SEM) and marginal gap values were recorded. The data were statistically analyzed by two-way ANOVA and Tukey's multiple post hoc test. The highest marginal gap was seen in Group 2 (apical-16680.00 nm, coronal-10796 nm) and the lowest marginal gap was observed in Group 1 (apical-599.42 nm, coronal-522.72 nm). Coronal halves showed superior adaptation compared to apical halves in all the groups under SEM. Within the limitations of this study epoxy resin-based MM-Seal showed good marginal adaptation than other materials tested.

  5. O ciberativismo sem bússola

    Directory of Open Access Journals (Sweden)

    Francisco Rüdiger

    2014-07-01

    Full Text Available Questiona-se no texto se uma abordagem que, no essencial, relata a trajetória do chamado ciberativismo de acordo com seus próprios termos se justifica academicamente ou, em vez disso, se mantém prisioneira de uma mitologia que o fenômeno, em si mesmo, já construiu e, por isso, autoriza seus sujeitos a dispensarem sem prejuízo eventual contribuição de origem universitária.

  6. Study of SEM preparation artefacts with correlative microscopy: Cell shrinkage of adherent cells by HMDS-drying.

    Science.gov (United States)

    Katsen-Globa, Alisa; Puetz, Norbert; Gepp, Michael M; Neubauer, Julia C; Zimmermann, Heiko

    2016-11-01

    One of the often reported artefacts during cell preparation to scanning electron microscopy (SEM) is the shrinkage of cellular objects, that mostly occurs at a certain time-dependent stage of cell drying. Various methods of drying for SEM, such as critical point drying, freeze-drying, as well as hexamethyldisilazane (HMDS)-drying, were usually used. The latter becomes popular since it is a low cost and fast method. However, the correlation of drying duration and real shrinkage of objects was not investigated yet. In this paper, cell shrinkage at each stage of preparation for SEM was studied. We introduce a shrinkage coefficient using correlative light microscopy (LM) and SEM of the same human mesenchymal stem cells (hMSCs). The influence of HMDS-drying duration on the cell shrinkage is shown: the longer drying duration, the more shrinkage is observed. Furthermore, it was demonstrated that cell shrinkage is inversely proportional to cultivation time: the longer cultivation time, the more cell spreading area and the less cell shrinkage. Our results can be applicable for an exact SEM quantification of cell size and determination of cell spreading area in engineering of artificial cellular environments using biomaterials. SCANNING 38:625-633, 2016. © 2016 Wiley Periodicals, Inc. © Wiley Periodicals, Inc.

  7. Morphology of the adult male and pupal exuviae of Glyptotendipes (Glyptotendipes) glaucus (Meigen 1818) (Diptera, Chironomidae) using scanning electron microscope (SEM).

    Science.gov (United States)

    Kownacki, Andrzej; Woznicka, Olga; Szarek-Gwiazda, Ewa; Michailova, Paraskeva; Czaplicka, Anna

    2017-02-27

    In this paper, a study of the morphology of the pupa and male imago of Glyptotendipes (G.) glaucus (Meigen 1818) was carried out, with the aid of a scanning electron microscope (SEM). The SEM provided additional valuable information on the morphology of the species. Adult male head, antenna, wing, leg, abdomen, hypopygium, pupal cephalothorax and abdomen were examined. It is emphasized that SEM was not often used in Chironomidae studies. The present results confirm SEM as a suitable approach in carrying out morphological and taxonomical descriptions of Chironomidae species.

  8. Three-dimensional intracellular structure of a whole rice mesophyll cell observed with FIB-SEM.

    Science.gov (United States)

    Oi, Takao; Enomoto, Sakiko; Nakao, Tomoyo; Arai, Shigeo; Yamane, Koji; Taniguchi, Mitsutaka

    2017-07-01

    Ultrathin sections of rice leaf blades observed two-dimensionally using a transmission electron microscope (TEM) show that the chlorenchyma is composed of lobed mesophyll cells, with intricate cell boundaries, and lined with chloroplasts. The lobed cell shape and chloroplast positioning are believed to enhance the area available for the gas exchange surface for photosynthesis in rice leaves. However, a cell image revealing the three-dimensional (3-D) ultrastructure of rice mesophyll cells has not been visualized. In this study, a whole rice mesophyll cell was observed using a focused ion beam scanning electron microscope (FIB-SEM), which provides many serial sections automatically, rapidly and correctly, thereby enabling 3-D cell structure reconstruction. Rice leaf blades were fixed chemically using the method for conventional TEM observation, embedded in resin and subsequently set in the FIB-SEM chamber. Specimen blocks were sectioned transversely using the FIB, and block-face images were captured using the SEM. The sectioning and imaging were repeated overnight for 200-500 slices (each 50 nm thick). The resultant large-volume image stacks ( x = 25 μm, y = 25 μm, z = 10-25 μm) contained one or two whole mesophyll cells. The 3-D models of whole mesophyll cells were reconstructed using image processing software. The reconstructed cell models were discoid shaped with several lobes around the cell periphery. The cell shape increased the surface area, and the ratio of surface area to volume was twice that of a cylinder having the same volume. The chloroplasts occupied half the cell volume and spread as sheets along the cell lobes, covering most of the inner cell surface, with adjacent chloroplasts in close contact with each other. Cellular and sub-cellular ultrastructures of a whole mesophyll cell in a rice leaf blade are demonstrated three-dimensionally using a FIB-SEM. The 3-D models and numerical information support the hypothesis that rice mesophyll

  9. Evaluation of bone formation in calcium phosphate scaffolds with μCT-method validation using SEM.

    Science.gov (United States)

    Lewin, S; Barba, A; Persson, C; Franch, J; Ginebra, M-P; Öhman-Mägi, C

    2017-10-05

    There is a plethora of calcium phosphate (CaP) scaffolds used as synthetic substitutes to bone grafts. The scaffold performance is often evaluated from the quantity of bone formed within or in direct contact with the scaffold. Micro-computed tomography (μCT) allows three-dimensional evaluation of bone formation inside scaffolds. However, the almost identical x-ray attenuation of CaP and bone obtrude the separation of these phases in μCT images. Commonly, segmentation of bone in μCT images is based on gray scale intensity, with manually determined global thresholds. However, image analysis methods, and methods for manual thresholding in particular, lack standardization and may consequently suffer from subjectivity. The aim of the present study was to provide a methodological framework for addressing these issues. Bone formation in two types of CaP scaffold architectures (foamed and robocast), obtained from a larger animal study (a 12 week canine animal model) was evaluated by μCT. In addition, cross-sectional scanning electron microscopy (SEM) images were acquired as references to determine thresholds and to validate the result. μCT datasets were registered to the corresponding SEM reference. Global thresholds were then determined by quantitatively correlating the different area fractions in the μCT image, towards the area fractions in the corresponding SEM image. For comparison, area fractions were also quantified using global thresholds determined manually by two different approaches. In the validation the manually determined thresholds resulted in large average errors in area fraction (up to 17%), whereas for the evaluation using SEM references, the errors were estimated to be less than 3%. Furthermore, it was found that basing the thresholds on one single SEM reference gave lower errors than determining them manually. This study provides an objective, robust and less error prone method to determine global thresholds for the evaluation of bone formation in

  10. Critical factors in SEM 3D stereo microscopy

    International Nuclear Information System (INIS)

    Marinello, F; Savio, E; Bariani, P; Horsewell, A; De Chiffre, L

    2008-01-01

    This work addresses dimensional measurements performed with the scanning electron microscope (SEM) using 3D reconstruction of surface topography through stereo-photogrammetry. The paper presents both theoretical and experimental investigations, on the effects of instrumental variables and measurement parameters on reconstruction accuracy. Investigations were performed on a novel sample, specifically developed and implemented for the tests. The description is based on the model function introduced by Piazzesi and adapted for eucentrically tilted stereopairs. Two main classes of influencing factors are recognized: the first one is related to the measurement operation and the instrument set-up; the second concerns the quality of scanned images and represents the major criticality in the application of SEMs for 3D characterizations

  11. Neuropsicología de la demencia semántica

    OpenAIRE

    Andrade Quintero, Luz Helena

    2012-01-01

    La Demencia Semántica causa alteraciones en la capacidad para recordar el significado de las palabras, rostros y objetos, producto de atrofia asimétrica o bilateral de los lóbulos temporales anteriores. Clínicamente se han observado múltiples síndromes clínicos superpuestos con otras enfermedades degenerativas como la Afasia Primaria Progresiva y la Demencia tipo Alzheimer. El propósito de este estudio fue identificar alteraciones lingüísticas y semánticas en un grupo de pacientes con Demenci...

  12. What Determines Lean Manufacturing Implementation? A CB-SEM Model

    Directory of Open Access Journals (Sweden)

    Tan Ching Ng

    2018-02-01

    Full Text Available This research aims to ascertain the determinants of effective Lean Manufacturing (LM. In this research, Covariance-based Structural Equation Modeling (CB-SEM analysis will be used in order to analyze the determinants. Through CB-SEM analysis, the significant key determinants can be determined and the direct relationships among determinants can be analyzed. Thus, the findings of this research can act as guidelines for achievement of LM effectiveness, not only providing necessary steps for successful implementation of lean, but also helping lean companies to achieve higher level of lean cost and time savings.

  13. In-situ SEM electrochemistry and radiolysis

    DEFF Research Database (Denmark)

    Møller-Nilsen, Rolf Erling Robberstad; Norby, Poul

    are backscattered and an image is reconstructed by the microscope. But the high energy electrons are a form of ionising radiation which can significantly affect the chemistry in liquid experiments. Ionising radiation can split water, produce radicals, reduce dissolved metal ions to metal particles, and more...... experiments. During the course of these studies it has also been possible to improve on the EC-SEM system. This has resulted in pyrolysed carbon electrodes, which offer the benefit of stability at 0.75 V higher potentials than traditional gold thin-film electrodes. With the quantitative insight...... microelectrodes on the windows to enable studies of electrohcemical processes. In this way it is possible to perform in-situ electrochemical experiments such as electroplating and charge and discharge analysis of battery electrodes. In a typical liquid cell, electrons are accelerated to sufficiently high energies...

  14. Does your SEM really tell the truth? How would you know? Part 2.

    Science.gov (United States)

    Postek, Michael T; Vladár, András E; Purushotham, Kavuri P

    2014-01-01

    The scanning electron microscope (SEM) has gone through a tremendous evolution to become indispensable for many and diverse scientific and industrial applications. The improvements have significantly enriched and augmented the overall SEM performance and have made the instrument far easier to operate. But, the ease of operation also might lead, through operator complacency, to poor results. In addition, the user friendliness has seemingly reduced the need for thorough operator training for using these complex instruments. One might then conclude that the SEM is just a very expensive digital camera or another peripheral device for a computer. Hence, a person using the instrument may be lulled into thinking that all of the potential pitfalls have been eliminated and they believe everything they see on the micrograph is always correct. But, this may not be the case. An earlier paper (Part 1), discussed some of the potential issues related to signal generation in the SEM, instrument calibration, electron beam interactions and the need for physics-based modeling to understand the actual image formation mechanisms. All these were summed together in a discussion of how these issues effect measurements made with the instrument. This second paper discusses another major issue confronting the microscopist: electron-beam-induced specimen contamination. Over the years, NIST has done a great deal of research into the issue of sample contamination and its removal and elimination and some of this work is reviewed and discussed here. © 2013 Wiley Periodicals, Inc.

  15. Sem-EDAX'S Application For Characterization Of Superconductor Material Of (Bi,Pb)-Sr-Ca-Cu-O

    International Nuclear Information System (INIS)

    Handayani, Ari; Wuryanto; Prambudi, Bambang

    1996-01-01

    The microstructure and composition analysis of superconductor material of (Bi,Pb)-Sr-Ca-Cu-O which were synthesized by two different processes (CA and CD Process) by varying the sintering time, i.e. 20,60 and 100 hours were done by using SEM-EDAX method. The standard sample of superconductor material of Bi-Sr-Ca-Cu-O with 1112, 2212 and 2223 phase from Stream has been used for comparison, At 25 kV, the composition analysis showed that, at 20 and 60 hours of sintering, a mixture of phases existed while 100 hours of sintering resulted in a phase close to phase 2223. The result of microstructure observation showed significant differences. At synthesized CA process, 100 hours of sintering gives bigger and clearer platelet microstructure shape than that given by 20 and 60 hours of sintering. Also from the synthesized CD process, the 60 and 100 hours of sintering gives bigger and clearer platelet microstructure shape than that given by the 20 hours of sintering

  16. Does Sexually Explicit Media (SEM) Affect Me?

    DEFF Research Database (Denmark)

    Hald, Gert Martin; Træen, Bente; Noor, Syed W

    2015-01-01

    and understanding of one’s sexual orientation.First-person effects refer to self-perceived and self-reported effects of SEM consumptionas experienced by the consumer. In addition, the study examined and provided athorough validation of the psychometric properties of the seven-item PornographyConsumption Effect...

  17. SEM Characterization of Extinguished Grains from Plasma-Ignited M30 Charges

    Science.gov (United States)

    Kinkennon, A.; Birk, A.; DelGuercio, M.; Kaste, P.; Lieb, R.; Newberry, J.; Pesce-Rodriguez, R.; Schroeder, M.

    2000-01-01

    M30 propellant grains that had been ignited in interrupted closed bomb experiments were characterize by scanning electron microscopy (SEM). Previous chemical analysis of extinguished grains had given no indications of plasma-propellant chemical interactions that could explain the increased burning rates that had been previously observed in full-pressure closed bomb experiments. (This does not mean that there is no unique chemistry occurring with plasma ignition. It may occur very early in the ignition event and then become obscured by the burning chemistry.) In this work, SEM was used to look at grain morphologies to determine if there were increases in the surface areas of the plasma-ignited grains which would contribute to the apparent increase in the burning rate. Charges were made using 30 propellant grains (approximately 32 grams) stacked in two tiers and in two concentric circles around a plastic straw. Each grain was notched so that, when the grains were expelled from the bomb during extinguishment, it could be determined in which tier and which circle each grain was originally packed. Charges were ignited in a closed bomb by either a nickel wire/Mylar-capillary plasma or black powder. The bomb contained a blowout disk that ruptured when the pressure reached 35 MPa, and the propellant was vented into a collection chamber packed with polyurethane foam. SEM analysis of the grains fired with a conventional black powder igniter showed no signs of unusual burning characteristics. The surfaces seemed to be evenly burned on the exteriors of the grains and in the perforations. Grains that had been subjected to plasma ignition, however, had pits, gouges, chasms, and cracks in the surfaces. The sides of the grains closest to the plasma had the greatest amount of damage, but even surfaces facing the outer wall of the bomb had small pits. The perforations contained gouges and abnormally burned regions (wormholes) that extended into the web. The SEM photos indicated that

  18. A brief discussion about image quality and SEM methods for quantitative fractography of polymer composites.

    Science.gov (United States)

    Hein, L R O; Campos, K A; Caltabiano, P C R O; Kostov, K G

    2013-01-01

    The methodology for fracture analysis of polymeric composites with scanning electron microscopes (SEM) is still under discussion. Many authors prefer to use sputter coating with a conductive material instead of applying low-voltage (LV) or variable-pressure (VP) methods, which preserves the original surfaces. The present work examines the effects of sputter coating with 25 nm of gold on the topography of carbon-epoxy composites fracture surfaces, using an atomic force microscope. Also, the influence of SEM imaging parameters on fractal measurements is evaluated for the VP-SEM and LV-SEM methods. It was observed that topographic measurements were not significantly affected by the gold coating at tested scale. Moreover, changes on SEM setup leads to nonlinear outcome on texture parameters, such as fractal dimension and entropy values. For VP-SEM or LV-SEM, fractal dimension and entropy values did not present any evident relation with image quality parameters, but the resolution must be optimized with imaging setup, accompanied by charge neutralization. © Wiley Periodicals, Inc.

  19. 3D SEM for surface topography quantification – a case study on dental surfaces

    International Nuclear Information System (INIS)

    Glon, F; Flys, O; Lööf, P-J; Rosén, B-G

    2014-01-01

    3D analysis of surface topography is becoming a more used tool for industry and research. New ISO standards are being launched to assist in quantifying engineering surfaces. The traditional optical measuring instrumentation used for 3D surface characterization has been optical interferometers and confocal based instrumentation. However, the resolution here is limited in the lateral dimension to the wavelength of visible light to about 500 nm. The great advantage using the SEM for topography measurements is the high flexibility to zoom from low magnifications and locating interesting areas to high magnification of down to nanometer large surface features within seconds. This paper presents surface characterization of dental implant micro topography. 3D topography data was created from SEM images using commercial photogrammetric software. A coherence scanning interferometer was used for reference measurements to compare with the 3D SEM measurements on relocated areas. As a result of this study, measurements emphasizes that the correlation between the accepted CSI measurements and the new technology represented by photogrammetry based on SEM images for many areal characterization parameters are around or less than 20%. The importance of selecting sampling and parameter sensitivity to varying sampling is high-lighted. Future work includes a broader study of limitations of the photogrammetry technique on certified micro-geometries and more application surfaces at different scales

  20. Is scanning electron microscopy/energy dispersive X-ray spectrometry (SEM/EDS) quantitative?

    Science.gov (United States)

    Newbury, Dale E; Ritchie, Nicholas W M

    2013-01-01

    Scanning electron microscopy/energy dispersive X-ray spectrometry (SEM/EDS) is a widely applied elemental microanalysis method capable of identifying and quantifying all elements in the periodic table except H, He, and Li. By following the "k-ratio" (unknown/standard) measurement protocol development for electron-excited wavelength dispersive spectrometry (WDS), SEM/EDS can achieve accuracy and precision equivalent to WDS and at substantially lower electron dose, even when severe X-ray peak overlaps occur, provided sufficient counts are recorded. Achieving this level of performance is now much more practical with the advent of the high-throughput silicon drift detector energy dispersive X-ray spectrometer (SDD-EDS). However, three measurement issues continue to diminish the impact of SEM/EDS: (1) In the qualitative analysis (i.e., element identification) that must precede quantitative analysis, at least some current and many legacy software systems are vulnerable to occasional misidentification of major constituent peaks, with the frequency of misidentifications rising significantly for minor and trace constituents. (2) The use of standardless analysis, which is subject to much broader systematic errors, leads to quantitative results that, while useful, do not have sufficient accuracy to solve critical problems, e.g. determining the formula of a compound. (3) EDS spectrometers have such a large volume of acceptance that apparently credible spectra can be obtained from specimens with complex topography that introduce uncontrolled geometric factors that modify X-ray generation and propagation, resulting in very large systematic errors, often a factor of ten or more. © Wiley Periodicals, Inc.

  1. Nanosilver microalgae biosynthesis: cell appearance based on SEM and EDX methods

    Science.gov (United States)

    Pancasakti Kusumaningrum, Hermin; Zainuri, Muhammad; Marhaendrajaya, Indras; Subagio, Agus

    2018-05-01

    Microbial contamination has caused public health problems in the world population. This problem has spurred the development of methods to overcome and prevent microbial invasion. The extensive use of antibiotics has facilitated the continued emergence and spread of resistant organisms. Synthesized of silver nanoparticle (AgNPs) on microalgae Chlorella pyrenoidosa offer environmentally safe antimicrobial agent. The present study is focused on the biosynthesis of AgNPs using microalgae C. pyrenoidosa. The research methods was conducted by insertion of nanosilver particle into microalgae cells with and without agitation to speed up the process of formation nanosilver microalgae. The formation of microalgae SNP was analyzes by UV-Vis spectrophotometer, Scanning Electron Micrograph (SEM) and Energy-dispersive X-ray spectroscopy (EDX) methods. The research result showed that nanosilver microalgae biosynthesis using the agitation treatment was exhibited better performance in particle insertion and cell stability, comparing with no agitation treatment. However, synthesis of nanosilver microalgae tend to reduce the cell size.

  2. A methodological basis for SEM autoradiography: biosynthesis and radioligand binding

    International Nuclear Information System (INIS)

    Cheng, G.; Hodges, G.M.; Trejdosiewicz, L.K.

    1985-01-01

    A method is described for scanning electron microscope (SEM) autoradiography whereby preservation of high resolution cell surface details is retained together with degelatination of the emulsion without gross loss or redistribution of silver grains. This method should provide a convenient medium-sized marker for SEM (using secondary, backscattered electron and X-ray imaging) topographic studies of biosynthesized molecules, and of cell surface receptors and antigens, using indirect or direct labelling procedures with radio-labelled ligands. (author)

  3. In situ SEM and ToF-SIMS analysis of IgG conjugated gold nanoparticles at aqueous surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Li; Zhu, Zihua; Yu, Xiao-Ying; Rodek, Gene; Saraf, Laxmikant V.; Thevuthasan, Suntharampillai; Cowin, James P.

    2014-04-01

    In this study, we report new results of in situ study of 5 nm goat anti-mouse IgG gold nanoparticles in a novel portable vacuum compatible microfluidic device using scanning electron microscope (SEM) and time-of-flight secondary ion mass spectrometry (ToF-SIMS). The unique feature of the liquid flow cell is that the detection window is open to the vacuum allowing direct probing of the liquid surface. The flow cell is composed of a silicon nitride (SiN) membrane and polydimethylsiloxane (PDMS), and it is fully compatible with vacuum operations for surface analysis. The aperture can be drilled through the 100 nm SiN membrane using a focused ion beam. Characteristic signals of the conjugated gold nanoparticles were successfully observed through the aperture by both energy-dispersive X-ray spectroscopy (EDX) in SEM and ToF-SIMS. Comparison was also made among wet samples, dry samples, and liquid sample in the flow cell using SEM/EDX. Stronger gold signal can be observed in our novel portable device by SEM/EDX compared with the wet or dry samples, respectively. Our results indicate that analyses of the nanoparticle components are better made in their native liquid environment. This is made possible using our unique microfluidic flow cell.

  4. A detailed TEM and SEM study of Ni-base alloys oxide scales formed in primary conditions of pressurized water reactor

    International Nuclear Information System (INIS)

    Sennour, Mohamed; Marchetti, Loic; Martin, Frantz; Perrin, Stephane; Molins, Regine; Pijolat, Michele

    2010-01-01

    The oxide film formed on nickel-based alloys in pressurized water reactors (PWR) primary coolant conditions (325 o C, aqueous media) is very thin, in the range of 1-100 nm thick, depending on the surface state and on the corrosion test duration. The nature and the structure of this scale have been investigated by Transmission Electron Microscopy (TEM) and Scanning Electron Microscopy (SEM). TEM observations revealed an oxide layer divided in two parts. The internal layer was mainly composed of a continuous spinel layer, identified as a mixed iron and nickel chromite (Ni (1-x) Fe x Cr 2 O 4 ). Moreover, nodules of Cr 2 O 3 , with a size about 5 nm, were present at the interface between this spinel and the alloy. No chromium depletion was observed in the alloy, at the alloy/oxide interface. The external layer is composed of large crystallites corresponding to a spinel structure rich in iron (Ni (1-z) Fe (2+z) O 4 ) resulting from precipitation phenomena. SEM and TEM observations showed a link between the nucleation and/or the growth of crystallites of nickel ferrite and the crystallographic orientation of the substrate. A link between the presence of surface defects and the nucleation of the crystallites was also underlined by SEM observations. Partially hydrated nickel hydroxide, was also observed by TEM in the external scale. Based on these results, some considerations about the mechanism of formation of this oxide layer are discussed.

  5. Gun Shows and Gun Violence: Fatally Flawed Study Yields Misleading Results

    Science.gov (United States)

    Hemenway, David; Webster, Daniel; Pierce, Glenn; Braga, Anthony A.

    2010-01-01

    A widely publicized but unpublished study of the relationship between gun shows and gun violence is being cited in debates about the regulation of gun shows and gun commerce. We believe the study is fatally flawed. A working paper entitled “The Effect of Gun Shows on Gun-Related Deaths: Evidence from California and Texas” outlined this study, which found no association between gun shows and gun-related deaths. We believe the study reflects a limited understanding of gun shows and gun markets and is not statistically powered to detect even an implausibly large effect of gun shows on gun violence. In addition, the research contains serious ascertainment and classification errors, produces results that are sensitive to minor specification changes in key variables and in some cases have no face validity, and is contradicted by 1 of its own authors’ prior research. The study should not be used as evidence in formulating gun policy. PMID:20724672

  6. Sem-edx and ftir studies of chlorinated rubber coating

    International Nuclear Information System (INIS)

    Bano, H.; Khan, M.I.

    2013-01-01

    Summary: Anticorrosive performance of chlorinated rubber coating has been investigated by visual examination, Scanning electron microscopy (SEM)/Energy dispersive X-ray (EDX) analysis and Fourier transform infrared (FTIR) spectroscopy. After surface preparation, commercially available coating system based on chlorinated rubber (primer)/chlorinated rubber (topcoat) formulation was applied on mild steel test panels (10cm x 15cm sizes). Prepared coated panels were exposed at marine, industrial and urban test sites located in Karachi, Pakistan according to ISO 8565 norm. Accelerated testing was performed by using a salt spray chamber (ASTM B117 norm). Accelerated weathering methods are the methods in which the factors responsible for the degradation of coatings are artificially intensified in order to achieve the rapid degradation of coatings. Visual examination of blistering and rusting as well as SEM micrographs indicated a more severe degradation of the coating surface characteristics at natural exposure testing sites (particularly at marine test site) than for accelerated (salt spray) testing. EDX determination of the Oxygen/Carbon (O/C) ratios also indicated increased degradation at natural test sites compared to the accelerated (salt spray) testing. Photooxidation of the binder results in the formation of carbonyl compounds as revealed by FTIR spectroscopy which also indicated dehydrochlorination. (author)

  7. Comparison of multilayered nanowire imaging by SEM and Helium Ion Microscopy

    International Nuclear Information System (INIS)

    Inkson, B J; Peng, Y; Jepson, M A E; Rodenburg, C; Liu, X

    2010-01-01

    The helium ion microscope (HeIM) is capable of probe sizes smaller than SEM and, with intrinsically small ion/sample interaction volumes, may therefore potentially offer higher spatial resolution secondary electron (SE) imaging of nanostructures. Here 55 nm diameter CoPt/Pt multilayered nanowires have been imaged by HeIM, SEM and TEM. It is found that there is an increased resolution of nanowire surface topography in HeIM SE images compared to SEM, however there is a reduction of materials contrast of the alternating Pt and CoPt layers. This can be attributed to the increased contribution of surface contamination layers to the ion-induced SE signal, and carbon is also observed to grow on the nanowires under prolonged HeIM scanning.

  8. High incorrect use of the standard error of the mean (SEM) in original articles in three cardiovascular journals evaluated for 2012.

    Science.gov (United States)

    Wullschleger, Marcel; Aghlmandi, Soheila; Egger, Marcel; Zwahlen, Marcel

    2014-01-01

    In biomedical journals authors sometimes use the standard error of the mean (SEM) for data description, which has been called inappropriate or incorrect. To assess the frequency of incorrect use of SEM in articles in three selected cardiovascular journals. All original journal articles published in 2012 in Cardiovascular Research, Circulation: Heart Failure and Circulation Research were assessed by two assessors for inappropriate use of SEM when providing descriptive information of empirical data. We also assessed whether the authors state in the methods section that the SEM will be used for data description. Of 441 articles included in this survey, 64% (282 articles) contained at least one instance of incorrect use of the SEM, with two journals having a prevalence above 70% and "Circulation: Heart Failure" having the lowest value (27%). In 81% of articles with incorrect use of SEM, the authors had explicitly stated that they use the SEM for data description and in 89% SEM bars were also used instead of 95% confidence intervals. Basic science studies had a 7.4-fold higher level of inappropriate SEM use (74%) than clinical studies (10%). The selection of the three cardiovascular journals was based on a subjective initial impression of observing inappropriate SEM use. The observed results are not representative for all cardiovascular journals. In three selected cardiovascular journals we found a high level of inappropriate SEM use and explicit methods statements to use it for data description, especially in basic science studies. To improve on this situation, these and other journals should provide clear instructions to authors on how to report descriptive information of empirical data.

  9. Effect of solvent on anodization of Zr-4 in L-ascorbic acid - SEM studies

    International Nuclear Information System (INIS)

    Jeevana Jyothi, V.; Ch Anjaneyulu

    2013-01-01

    Anodization of Zircaloy-4 in 0.1 M L-ascorbic acid has been carried out. Kinetics of anodic oxidation of Zircaloy-4 has been studied at a constant current density of 8 mA.cm -2 and at room temperature. The plots of formation voltage vs time, reciprocal capacitance vs time and reciprocal capacitance vs formation voltage were drawn. From these plots, formation rate, current efficiency and differential field were calculated. The addition of solvent (ethylene glycol) showed better kinetic results for 20, 40, 60 and 80% aquo-glycolic media, the dielectric constant values are low leading to the marked improvement in the kinetics. The surface morphology of the anodic films was also studied by Scanning Electron Micrographs (SEM). (author)

  10. Comparative evaluation of surface changes in four Ni-Ti instruments with successive uses - An SEM study.

    Science.gov (United States)

    Subha, N; Sikri, Vimal K

    2011-07-01

    To evaluate the surface alterations seen in four kinds of Nickel-Titanium (Ni-Ti) instruments using a scanning electron microscope (SEM) for five successive uses in preparing root canals of extracted human molars and also to determine whether the design of the instrument influenced the appearance of defects on the instrument surface. Four different types of instruments namely; ProFile, ProTaper Rotary, ProTaper Hand and K3 Endo were used in 300 mesio-buccal canals. The instruments were examined under the SEM, after every use, to assess the progress of changes on their surfaces for a maximum of five uses. Chi-square test. The most prevalent defects observed were pitting, followed by metal strips. Signs of discontinuity, microfractures and disruption of cutting edge were also evident. Number of defects increased with successive uses. ProTaper Hand showed significantly more microfractures and metal strips than other instruments from third use onwards. ProTaper Rotary and K3 Endo also showed significant changes.

  11. Hacia una visión generativista de la semántica lexical

    Directory of Open Access Journals (Sweden)

    Morales A. Bernardo

    1992-06-01

    Full Text Available

    Uno de los objetivos de la teoría semántica de una lengua natural es dar información satisfactoria sobre el significado de las formas lingüísticas. Consideramos que de éstas, las de mayor  importancia significativa son la palabra, la oración y el texto. La palabra, porque en virtud de su compleja estructura semántica y psicológica funciona como el principal medio para la abstracción y conformación de los conceptos destinados para la comunicación; la oración, porque es la unidad de la lengua viva que expresa relaciones de conceptos; el texto, porque es la explicitación del pensamiento en la interacción humana. Las semánticas lexical, oracional y textual son los tres grandes capítulos de la semántica lingüística.


  12. Evaluation of depth of field in SEM images in terms of the information-passing capacity (IPC) and contrast gradient in SEM image

    International Nuclear Information System (INIS)

    Sato, Mitsugu; Ishitani, Tohru; Watanabe, Shunya; Nakagawa, Mine

    2004-01-01

    The depth of field (DoF) in scanning electron microscope (SEM) images has been determined by estimating the change of image sharpness or resolution near the exact focus position. The image sharpness or resolution along the optical axis is determined by calculating the information-passing capacity (IPC) of an optical system taking into account the effect of pixel size of the image. The change of image sharpness near the exact focus position is determined by measuring the slope gradient of the line profile in SEM images obtained at various focal positions of beam. The change of image sharpness along the optical axis determined by the IPC agrees well with those determined by the slope gradient of line profiles in SEM images when a Gaussian distribution having radius 0.86L p (L p : pixel size in image) at which the intensity has fallen to 1/e of the maximum is applied to the IPC calculation for each pixel intensity. The change of image sharpness near the exact focus position has also been compared with those determined by the CG (Contrast-to-Gradient) method. The CG method slightly underestimates the change of image sharpness compared with those determined by the IPC method

  13. Application of SEM/EBSD and FEG-TEM/CBED to determine eutectic solidification mechanisms

    International Nuclear Information System (INIS)

    Nogita, K.; Dahle, A.K.; Drennan, J.

    2002-01-01

    Full text: This study shows the application of electron backscatter diffraction (EBSD) in SEM and convergent beam electron diffraction (CBED) in FEG-TEM to determine eutectic nucleation and growth in hypoeutectic Al-Si foundry alloys. Because the eutectic reaction is often the final stage of solidification it can be expected to have a significant impact on the formation of casting defects, particularly porosity. Previous EBSD work by Nogita and Dahle (2001), Dahle et al (2001), has shown that the eutectic nucleates on the primary phase in the unmodified alloy, and eutectic grains are nucleated in the intergranular liquid, instead of filling the dendrite envelopes, when Sr or Sb is added. However, the orientation relationship between silicon and aluminium in the eutectic has so far not been determined because of difficulties with sample preparation for EBSD and also detection limitations of Kikuchi refraction of silicon and aluminium, particularly in modified alloys with a refined eutectic. The combination of the EBSD technique in SEM and CBED in TEM analyses can provide crystallographic orientation relationships between primary aluminium dendrites, eutectic aluminium and silicon, which are important to explicitly define the solidification mode of the eutectic in hypoeutectic Al-Si alloys. These relationships are influenced, and altered, by the addition of certain elements. This paper also describes the sample preparation techniques for SEM and TEM for samples with different eutectic structures. The advantages the techniques are discussed. Copyright (2002) Australian Society for Electron Microscopy Inc

  14. QEM*SEM: a necessary tool in the metallurgical evaluation of ore bodies

    International Nuclear Information System (INIS)

    Creelman, R.A.; Gottlieb, P.; Sutherland, D.; Jackson, R.

    1989-01-01

    The QEM*SEM system for automated image analysis of mineral samples is described. Details of the equipment are given together with information on the methods of measurement. Finally some practical applications are described where QEM*SEM has been used for the solution of metallurgical problems. 14 refs., 1 fig

  15. Quantification of silver nanoparticle uptake and distribution within individual human macrophages by FIB/SEM slice and view.

    Science.gov (United States)

    Guehrs, Erik; Schneider, Michael; Günther, Christian M; Hessing, Piet; Heitz, Karen; Wittke, Doreen; López-Serrano Oliver, Ana; Jakubowski, Norbert; Plendl, Johanna; Eisebitt, Stefan; Haase, Andrea

    2017-03-21

    Quantification of nanoparticle (NP) uptake in cells or tissues is very important for safety assessment. Often, electron microscopy based approaches are used for this purpose, which allow imaging at very high resolution. However, precise quantification of NP numbers in cells and tissues remains challenging. The aim of this study was to present a novel approach, that combines precise quantification of NPs in individual cells together with high resolution imaging of their intracellular distribution based on focused ion beam/ scanning electron microscopy (FIB/SEM) slice and view approaches. We quantified cellular uptake of 75 nm diameter citrate stabilized silver NPs (Ag 75 Cit) into an individual human macrophage derived from monocytic THP-1 cells using a FIB/SEM slice and view approach. Cells were treated with 10 μg/ml for 24 h. We investigated a single cell and found in total 3138 ± 722 silver NPs inside this cell. Most of the silver NPs were located in large agglomerates, only a few were found in clusters of fewer than five NPs. Furthermore, we cross-checked our results by using inductively coupled plasma mass spectrometry and could confirm the FIB/SEM results. Our approach based on FIB/SEM slice and view is currently the only one that allows the quantification of the absolute dose of silver NPs in individual cells and at the same time to assess their intracellular distribution at high resolution. We therefore propose to use FIB/SEM slice and view to systematically analyse the cellular uptake of various NPs as a function of size, concentration and incubation time.

  16. Elevated temperature transmission Kikuchi diffraction in the SEM

    DEFF Research Database (Denmark)

    Fanta, Alice Bastos; Todeschini, Matteo; Burrows, Andrew

    2018-01-01

    heating associated with this system enables reliable TKD measurements at elevated temperatures without notable disturbance from infrared radiation. The dewetting of an Au thin film into Au nanoparticles upon heating is followed with orientation mapping in a temperature range between 20 °C and 900 °C....... The local thickness variation associated with the dewetting is observed qualitatively by observing the intensity of the transmitted beam, which decreases as the film thickness increases locally. The results of this study reveal that TKD is a well suited technique to study thin-film stability and solid state...... dewetting. Moreover, the outcome of this methodological study provides a baseline for further in-situ crystallographic studies of electron transparent samples in the SEM....

  17. Specimen's plane misaligned installation solution based on charge fluctuation inside SEM

    Science.gov (United States)

    Lu, Haojian; Liu, Yanting; Yang, Yuanyuan; Wang, Panbing; Shen, Yajing

    2018-04-01

    Precise specimen's installation is a sticking point to ensure the characterization accuracy of the in-situ material property test. Although it is common knowledge that specimen's plane misaligned installation (PMI) would cause extra force loading during mechanical testing, there are few effective solutions available to deal with it at the current stage, especially during the in-situ scanning electron microscopy (SEM) test. Taking into consideration the charge fluctuation phenomenon under SEM, this paper proposes a highlight area variation (HAV) method for specimen deformation judgment, i.e., the specimen deformation is defined when the highlight area changes greater than 20% of the initial value of the specimen surface. Three types of specimens with different resistivities, i.e., human hair (electrical resistivity ˜3 × 1012 Ω cm), optical fiber (electrical resistivity ˜1017 Ω cm), and magnetic wire (electrical resistivity ˜2 × 10-5 Ω cm), are chosen to verify the effectiveness of the HAV method. Furthermore, combined with the developed robot-aided alignment system, the specimen's PMI problem can also be solved. In the demonstration, the human hair specimen is installed across two specimen stages and its in-situ twisting (in 360°) test is implemented. The results clearly indicate that the HAV method and the robot-aided alignment system are practical and reliable, and the specimen can be aligned on the same plane and installed precisely with accuracy up to 3 μm. This method will benefit the in-situ SEM material mechanical property test and has a significant impact in fundamental material research.

  18. Experimental investigation on 3D-SEM reconstructions of a wire gauge using stereo-pair technique

    DEFF Research Database (Denmark)

    Carli, Lorenzo; Genta, G.; Cantatore, Angela

    2011-01-01

    In this work an experimental investigation is addressed concerning 3D-SEM reconstructions obtained from the so-called stereo-pair technique. Three-dimensional topography of an object can be derived from two SEM images acquired from two different angles, through item rotation by means of the SEM...

  19. Characterisation of early medieval frescoes by μ-PIXE, SEM and Raman spectroscopy

    International Nuclear Information System (INIS)

    Zucchiatti, A.; Prati, P.; Bouquillon, A.; Giuntini, L.; Massi, M.; Migliori, A.; Cagnana, A.; Roascio, S.

    2004-01-01

    We have studied the VIII-IX century frescoes of the Longobard temple of Cividale del Friuli in Italy with noninvasive sampling and, for the first time in such a context, with high chemical and spatial sensitivity techniques (PIXE, SEM and Raman). Results demonstrate richness of manufacturing details and integrate in a substantial way the historic and artistic framework of this early medieval monument

  20. Characterisation of early medieval frescoes by {mu}-PIXE, SEM and Raman spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Zucchiatti, A. E-mail: zucc@ge.infn.it; Prati, P.; Bouquillon, A.; Giuntini, L.; Massi, M.; Migliori, A.; Cagnana, A.; Roascio, S

    2004-06-01

    We have studied the VIII-IX century frescoes of the Longobard temple of Cividale del Friuli in Italy with noninvasive sampling and, for the first time in such a context, with high chemical and spatial sensitivity techniques (PIXE, SEM and Raman). Results demonstrate richness of manufacturing details and integrate in a substantial way the historic and artistic framework of this early medieval monument.

  1. SEM: A user's manual for materials science

    International Nuclear Information System (INIS)

    Gabriel, B.L.

    1985-01-01

    This book provides a reference of techniques used by the metallurgical microscopist. It contains an introduction to the instrumentation and methods of scanning electron microscopy with historical as well as state-of-the-art methodologies. Topics covered include: SEM instrumentation, photography, energy dispersive spectroscopy, introduction to sample preparation, polished samples, fracture surfaces, replicas and thin films

  2. 3D imaging of cells and tissues by focused ion beam/scanning electron microscopy (FIB/SEM).

    Science.gov (United States)

    Drobne, Damjana

    2013-01-01

    Integration of a scanning electron microscope (SEM) and focused ion beam (FIB) technology into a single FIB/SEM system permits use of the FIB as a nano-scalpel to reveal site-specific subsurface microstructures which can be examined in great detail by SEM. The FIB/SEM technology is widely used in the semiconductor industry and material sciences, and recently its use in the life sciences has been initiated. Samples for FIB/SEM investigation can be either embedded in a plastic matrix, the traditional means of preparation of transmission electron microscopy (TEM) specimens, or simply dried as in samples prepared for SEM imaging. Currently, FIB/SEM is used in the life sciences for (a) preparation by the lift-out technique of lamella for TEM analysis, (b) tomography of samples embedded in a matrix, and (c) in situ site-specific FIB milling and SEM imaging using a wide range of magnifications. Site-specific milling and imaging has attracted wide interest as a technique in structural research of single eukaryotic and prokaryotic cells, small animals, and different animal tissue, but it still remains to be explored more thoroughly. In the past, preparation of samples for site-specific milling and imaging by FIB/SEM has typically adopted the embedding techniques used for TEM samples, and which have been very well described in the literature. Sample preparation protocols for the use of dried samples in FIB/SEM have been less well investigated. The aim of this chapter is to encourage application of FIB/SEM on dried biological samples. A detailed description of conventional dried sample preparation and FIB/SEM investigation of dried biological samples is presented. The important steps are described and illustrated, and direct comparison between embedded and dried samples of same tissues is provided. The ability to discover links between gross morphology of the tissue or organ, surface characteristics of any selected region, and intracellular structural details on the nanometer

  3. Fuzzy Control and Connected Region Marking Algorithm-Based SEM Nanomanipulation

    Directory of Open Access Journals (Sweden)

    Dongjie Li

    2012-01-01

    Full Text Available The interactive nanomanipulation platform is established based on fuzzy control and connected region marking (CRM algorithm in SEM. The 3D virtual nanomanipulation model is developed to make up the insufficiency of the 2D SEM image information, which provides the operator with depth and real-time visual feedback information to guide the manipulation. The haptic device Omega3 is used as the master to control the 3D motion of the nanopositioner in master-slave mode and offer the force sensing to the operator controlled with fuzzy control algorithm. Aiming at sensing of force feedback during the nanomanipulation, the collision detection method of the virtual nanomanipulation model and the force rending model are studied to realize the force feedback of nanomanipulation. The CRM algorithm is introduced to process the SEM image which provides effective position data of the objects for updating the virtual environment (VE, and relevant issues such as calibration and update rate of VE are also discussed. Finally, the performance of the platform is validated by the ZnO nanowire manipulation experiments.

  4. Enhanced FIB-SEM systems for large-volume 3D imaging

    Science.gov (United States)

    Xu, C Shan; Hayworth, Kenneth J; Lu, Zhiyuan; Grob, Patricia; Hassan, Ahmed M; García-Cerdán, José G; Niyogi, Krishna K; Nogales, Eva; Weinberg, Richard J; Hess, Harald F

    2017-01-01

    Focused Ion Beam Scanning Electron Microscopy (FIB-SEM) can automatically generate 3D images with superior z-axis resolution, yielding data that needs minimal image registration and related post-processing. Obstacles blocking wider adoption of FIB-SEM include slow imaging speed and lack of long-term system stability, which caps the maximum possible acquisition volume. Here, we present techniques that accelerate image acquisition while greatly improving FIB-SEM reliability, allowing the system to operate for months and generating continuously imaged volumes > 106 µm3. These volumes are large enough for connectomics, where the excellent z resolution can help in tracing of small neuronal processes and accelerate the tedious and time-consuming human proofreading effort. Even higher resolution can be achieved on smaller volumes. We present example data sets from mammalian neural tissue, Drosophila brain, and Chlamydomonas reinhardtii to illustrate the power of this novel high-resolution technique to address questions in both connectomics and cell biology. DOI: http://dx.doi.org/10.7554/eLife.25916.001 PMID:28500755

  5. Structure and surface morphology studies of cerium oxide system using XRD and SEM analysis

    International Nuclear Information System (INIS)

    Ahmad Jais Alimin; Farid Nasir Ani; Wan Azelee Wan Abu Bakar

    2000-01-01

    Conventional Precious Group Materials (PGM) catalyst systems have been using CeO 2 as an Oxygen Storage Capacity component in the catalyst washcoat. Due to the limitations of the PGM catalyst, researches are now focusing on improving or replacing this conventional system. In a previous work, the potential of a copper-ceria (Cu-Ce) oxide as a catalyst system has been identified. In this paper, the morphology and characterisation of Cu-Ce oxides analysed using XRD and SEM will be described. The Cu-Ce samples were prepared at a fixed ratio under temperatures of 400 o C and 800 o C. XRD diffractograms showed CeO 2 is in a cubic phase at 400 o C and 800 o C. At 800 o C, the CuO particle is visible, presumably has incorporated with the lattice structure of ceria, indicating an absent of solid state condition between copper and ceria. Analysis by SEM revealed significant increase in particle sizes with increasing calcination temperatures. (Author)

  6. A combined technique using SEM and TOPSIS for the commercialization capability of R&D project evaluation

    Directory of Open Access Journals (Sweden)

    Charttirot Karaveg

    2015-07-01

    Full Text Available There is a high risk of R&D based innovation being commercialized, especially in the innovation transfer process which is a concern to many entrepreneurs and researchers. The purpose of this research is to develop the criteria of R&D commercialization capability and to propose a combined technique of Structural Equation Modelling (SEM and Technique for Order Preference by Similarity to Ideal Solution (TOPSIS for R&D project evaluation. The research utilized a mixed-method approach. The first phase comprised a qualitative study on commercialization criteria development though the survey research of 272 successful entrepreneurs and researchers in all industrial sectors in Thailand. The data was collected with a structured questionnaire and analyzed by SEM. The second phase was involved with SEM-TOPSIS technique development and a case study of 45 R&D projects in research institutes and incubators for technique validation. The research results reveal that there were six criteria for R&D project commercialization capability, these are arranged according to the significance; marketing, technology, finance, non-financial impact, intellectual property, and human resource. The holistic criteria is presented in decreasing order on the ambiguous subjectivity of the fuzzy-expert system, to help with effectively funding R&D and to prevent a resource meltdown. This study applies SEM to the relative weighting of hierarchical criteria. The TOPSIS approach is employed to rank the alternative performance. An integrated SEM-TOPSIS is proposed for the first time and applied to present R&D projects shown to be effective and feasible in evaluating R&D commercialization capacity.

  7. Optimization study of direct morphology observation by cold field emission SEM without gold coating.

    Science.gov (United States)

    He, Dan; Fu, Cheng; Xue, Zhigang

    2018-06-01

    Gold coating is a general operation that is generally applied on non-conductive or low conductive materials, during which the morphology of the materials can be examined by scanning electron microscopy (SEM). However, fatal deficiencies in the materials can result in irreversible distortion and damage. The present study directly characterized different low conductive materials such as hydroxyapatite, modified poly(vinylidene fluoride) (PVDF) fiber, and zinc oxide nanopillar by cold field emission scanning electron microscopy (FE-SEM) without a gold coating. According to the characteristics of the low conductive materials, various test conditions, such as different working signal modes, accelerating voltages, electron beam spots, and working distances, were characterized to determine the best morphological observations of each sample. Copyright © 2018 Elsevier Ltd. All rights reserved.

  8. Automated transmission-mode scanning electron microscopy (tSEM for large volume analysis at nanoscale resolution.

    Directory of Open Access Journals (Sweden)

    Masaaki Kuwajima

    Full Text Available Transmission-mode scanning electron microscopy (tSEM on a field emission SEM platform was developed for efficient and cost-effective imaging of circuit-scale volumes from brain at nanoscale resolution. Image area was maximized while optimizing the resolution and dynamic range necessary for discriminating key subcellular structures, such as small axonal, dendritic and glial processes, synapses, smooth endoplasmic reticulum, vesicles, microtubules, polyribosomes, and endosomes which are critical for neuronal function. Individual image fields from the tSEM system were up to 4,295 µm(2 (65.54 µm per side at 2 nm pixel size, contrasting with image fields from a modern transmission electron microscope (TEM system, which were only 66.59 µm(2 (8.160 µm per side at the same pixel size. The tSEM produced outstanding images and had reduced distortion and drift relative to TEM. Automated stage and scan control in tSEM easily provided unattended serial section imaging and montaging. Lens and scan properties on both TEM and SEM platforms revealed no significant nonlinear distortions within a central field of ∼100 µm(2 and produced near-perfect image registration across serial sections using the computational elastic alignment tool in Fiji/TrakEM2 software, and reliable geometric measurements from RECONSTRUCT™ or Fiji/TrakEM2 software. Axial resolution limits the analysis of small structures contained within a section (∼45 nm. Since this new tSEM is non-destructive, objects within a section can be explored at finer axial resolution in TEM tomography with current methods. Future development of tSEM tomography promises thinner axial resolution producing nearly isotropic voxels and should provide within-section analyses of structures without changing platforms. Brain was the test system given our interest in synaptic connectivity and plasticity; however, the new tSEM system is readily applicable to other biological systems.

  9. Inconmensurabilidad semántica y progreso científico

    Directory of Open Access Journals (Sweden)

    Vázquez, Juan

    1997-08-01

    Full Text Available Not available.En la primera parte del trabajo se hace una presentación de las nociones de «inconmensurabilidad», tal como han sido formuladas por Feyerabend y Kuhn; y en la segunda parte, después de analizar los presupuestos semánticos con los que indudablemente han ido asociadas, se presenta un modelo alternativo de análisis semántico de la ‘inconmensurabilidad’, que permite desligarla de las nociones de «incomunicabilidad» e «incomparabilidad» interteóricas. Con ese propósito se hace uso de una doble noción de objeto formulada por C. S. Peirce, en sus Collected Papers, y por E. Husserl, en el parágrafo 131 de las Ideas.

  10. SemEHR: A general-purpose semantic search system to surface semantic data from clinical notes for tailored care, trial recruitment, and clinical research.

    Science.gov (United States)

    Wu, Honghan; Toti, Giulia; Morley, Katherine I; Ibrahim, Zina M; Folarin, Amos; Jackson, Richard; Kartoglu, Ismail; Agrawal, Asha; Stringer, Clive; Gale, Darren; Gorrell, Genevieve; Roberts, Angus; Broadbent, Matthew; Stewart, Robert; Dobson, Richard J B

    2018-05-01

    Unlocking the data contained within both structured and unstructured components of electronic health records (EHRs) has the potential to provide a step change in data available for secondary research use, generation of actionable medical insights, hospital management, and trial recruitment. To achieve this, we implemented SemEHR, an open source semantic search and analytics tool for EHRs. SemEHR implements a generic information extraction (IE) and retrieval infrastructure by identifying contextualized mentions of a wide range of biomedical concepts within EHRs. Natural language processing annotations are further assembled at the patient level and extended with EHR-specific knowledge to generate a timeline for each patient. The semantic data are serviced via ontology-based search and analytics interfaces. SemEHR has been deployed at a number of UK hospitals, including the Clinical Record Interactive Search, an anonymized replica of the EHR of the UK South London and Maudsley National Health Service Foundation Trust, one of Europe's largest providers of mental health services. In 2 Clinical Record Interactive Search-based studies, SemEHR achieved 93% (hepatitis C) and 99% (HIV) F-measure results in identifying true positive patients. At King's College Hospital in London, as part of the CogStack program (github.com/cogstack), SemEHR is being used to recruit patients into the UK Department of Health 100 000 Genomes Project (genomicsengland.co.uk). The validation study suggests that the tool can validate previously recruited cases and is very fast at searching phenotypes; time for recruitment criteria checking was reduced from days to minutes. Validated on open intensive care EHR data, Medical Information Mart for Intensive Care III, the vital signs extracted by SemEHR can achieve around 97% accuracy. Results from the multiple case studies demonstrate SemEHR's efficiency: weeks or months of work can be done within hours or minutes in some cases. SemEHR provides a more

  11. Risk assessment of heavy metals in Vembanad Lake sediments (south-west coast of India), based on acid-volatile sulfide (AVS)-simultaneously extracted metal (SEM) approach.

    Science.gov (United States)

    Shyleshchandran, Mohanachandran Nair; Mohan, Mahesh; Ramasamy, Eswara Venkatesaperumal

    2018-03-01

    Contamination of estuarine system due to heavy metals is a severe issue in tropical countries, especially in India. For the evaluation of the risk due to heavy metals, the current study assessed spatial and temporal variation of acid-volatile sulfide (AVS), simultaneously extracted metal (SEM), and total metal concentration as toxicity indicator of aquatic sediments in Vembanad Lake System (VLS), India. Surface sediment samples collected from 12 locations from the northern portion of VLS for 4 years during different seasons. The results suggest, in post-monsoon season, 91% of the sampling locations possessed high bioavailability of metals and results in toxicity to aquatic biota. The average seasonal distribution of SEM during the period of observations was in the order post-monsoon > pre-monsoon > monsoon (1.76 ± 2.00 > 1.35 ± 0.60 > 0.80 ± 0.54 μmol/g). The concentration of individual metals on ∑SEM are in the order SEM Zn > SEM Cu> SEM Cd ≈ SEM Pb > SEM Hg. Considering annual ΣSEM/AVS ratio, 83% of the sites cross the critical value of 'One,' reveals that active sulfide phase of the sediment for fixing the metals is saturated. The molar ratio (differences between SEM and AVS) and its normalized organic carbon ratio reveals that in the post-monsoon season, about 42% of the sites are in the category of adverse effects are possible. The study suggests the toxicity and mobility of the metals largely depend on the available AVS, and the current situation may pose harm to benthic organisms.

  12. El semáforo loco

    OpenAIRE

    González de Zachrisson, Hena

    2016-01-01

    El semáforo lo acababan de instalar en Vía Brasil y Calle 50 y estaba contento de poder mantener el orden del tránsito en tan importante calle. Sin embargo, pronto descubrió que su tarea no era fácil. Su territorio estaba atestado de muchachos que vendían frutas y vegetales y para escapar de ellos, los conductores hacían regatas para cruzar la calle antes de que la luz cambiara a rojo. —Todo a un dólar! —gritaban los chicos mostrando su bolsa de guineo, naranja, melón, maíz, papaya, c...

  13. Raman-in-SEM, a multimodal and multiscale analytical tool: performance for materials and expertise.

    Science.gov (United States)

    Wille, Guillaume; Bourrat, Xavier; Maubec, Nicolas; Lahfid, Abdeltif

    2014-12-01

    The availability of Raman spectroscopy in a powerful analytical scanning electron microscope (SEM) allows morphological, elemental, chemical, physical and electronic analysis without moving the sample between instruments. This paper documents the metrological performance of the SEMSCA commercial Raman interface operated in a low vacuum SEM. It provides multiscale and multimodal analyses as Raman/EDS, Raman/cathodoluminescence or Raman/STEM (STEM: scanning transmission electron microscopy) as well as Raman spectroscopy on nanomaterials. Since Raman spectroscopy in a SEM can be influenced by several SEM-related phenomena, this paper firstly presents a comparison of this new tool with a conventional micro-Raman spectrometer. Then, some possible artefacts are documented, which are due to the impact of electron beam-induced contamination or cathodoluminescence contribution to the Raman spectra, especially with geological samples. These effects are easily overcome by changing or adapting the Raman spectrometer and the SEM settings and methodology. The deletion of the adverse effect of cathodoluminescence is solved by using a SEM beam shutter during Raman acquisition. In contrast, this interface provides the ability to record the cathodoluminescence (CL) spectrum of a phase. In a second part, this study highlights the interest and efficiency of the coupling in characterizing micrometric phases at the same point. This multimodal approach is illustrated with various issues encountered in geosciences. Copyright © 2014 Elsevier Ltd. All rights reserved.

  14. SD-SEM: sparse-dense correspondence for 3D reconstruction of microscopic samples.

    Science.gov (United States)

    Baghaie, Ahmadreza; Tafti, Ahmad P; Owen, Heather A; D'Souza, Roshan M; Yu, Zeyun

    2017-06-01

    Scanning electron microscopy (SEM) imaging has been a principal component of many studies in biomedical, mechanical, and materials sciences since its emergence. Despite the high resolution of captured images, they remain two-dimensional (2D). In this work, a novel framework using sparse-dense correspondence is introduced and investigated for 3D reconstruction of stereo SEM images. SEM micrographs from microscopic samples are captured by tilting the specimen stage by a known angle. The pair of SEM micrographs is then rectified using sparse scale invariant feature transform (SIFT) features/descriptors and a contrario RANSAC for matching outlier removal to ensure a gross horizontal displacement between corresponding points. This is followed by dense correspondence estimation using dense SIFT descriptors and employing a factor graph representation of the energy minimization functional and loopy belief propagation (LBP) as means of optimization. Given the pixel-by-pixel correspondence and the tilt angle of the specimen stage during the acquisition of micrographs, depth can be recovered. Extensive tests reveal the strength of the proposed method for high-quality reconstruction of microscopic samples. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Three dimensional imaging of surface geometry in SEM

    International Nuclear Information System (INIS)

    Slowko, W.

    1997-01-01

    A great advantage of scanning electron microscopy (SEM) is its ability of the surface topography in the way as a human eye is accustomed to see lights and shadows on macroobjects. However, SEM's can hardly display vertical dimensions of the structures. One of possible solutions is reconstruction of the surface profiles by directional detection of secondary electrons and proper signal processing. However, the surface profile still gives two dimensional information and the method should be extended to obtain fully three dimensional imaging. The extension consists in a simultaneous reconstruction of the surface profiles in two perpendicular directions (x and y) and their superposition. The solution proposed is based on a quadrupole detector system and a computer or analogue system for signal processing. Quantitative data of the surface topography can be displayed in many manners in the system of two or three co-ordinates with use of pseudo-colour for the altitude coding. (author)

  16. Canticum Novum: música sem palavras e palavras sem som no pensamento de Santo Agostinho

    OpenAIRE

    Mammì, Lorenzo

    2000-01-01

    NO De Magistro, Santo Agostinho coloca a reza e o canto numa posição similar, à margem das funções imediatamente comunicativas da linguagem. A reflexão agostiniana sobre a reza se baseia nos hábitos cristãos da leitura, da oração e da meditação silenciosas. Há sobre o canto, na prática igualmente inovadora do jubilus, melodia sem palavra destinada aos momentos mais intensos e gaudiosos da liturgia. A oração silenciosa e o jubilus são temas recorrentes da literatura patrística, mas Agostinho o...

  17. Effect of two bleaching agents on enamel morphology: a SEM study

    Directory of Open Access Journals (Sweden)

    Ghavam M.

    2005-05-01

    Full Text Available Statement of Problem: Bleaching materials are able to change the surface morphology as well as mineral and organic content of tooth structure. Considering that bleaching is done for aesthetic purpose, awareness of the possible effect of these materials on hard tissue is important, because it may affect the restorative treatments. Purpose: The aim of this study was comparing the effect of two bleaching materials, Kimia and Ultradent both containing 35% H2O2, on tooth enamel by SEM. Materials and Methods: Five intact central incisors were cut into three sections vertically and each part was randomly divided into three groups. Group 1 (control, without any bleaching. Group 2, bleached with Kimia 35% H2O2. Group 3, bleached with Ultradent 35% H2O2. Each tooth served as its own control. Then the samples were observed by SEM with 250 and 500 magnifications. Results: In the control group some scratches and small white grains were observed which seems to be the result of mastication trauma and pumice powder. In the other groups, morphologic changes like increased surface roughness, deepening of cracks, rod exposure and presence of new cracks were observed. The two experimental materials did not differ in these regards. Conclusion: It seems that both studied materials have limited destructive effects on tooth enamel which seems to be of no clinical importance.

  18. Graphene-supporting films and low-voltage STEM in SEM toward imaging nanobio materials without staining: Observation of insulin amyloid fibrils.

    Science.gov (United States)

    Ogawa, Takashi; Gang, Geun Won; Thieu, Minh Thu; Kwon, Hyuksang; Ahn, Sang Jung; Ha, Tai Hwan; Cho, Boklae

    2017-05-01

    Utilization of graphene-supporting films and low-voltage scanning transmission electron microscopy (LV-STEM) in scanning electron microscopy (SEM) is shown to be an effective means of observing unstained nanobio materials. Insulin amyloid fibrils, which are implicated as a cause of type II diabetes, are formed in vitro and observed without staining at room temperature. An in-lens cold field-emission SEM, equipped with an additional homemade STEM detector, provides dark field (DF)-STEM images in the low energy range of 5-30keV, together with secondary electron (SE) images. Analysis based on Lenz's theory is used to interpret the experimental results. Graphene films, where the fibrils are deposited, reduce the background level of the STEM images compared with instances when conventional amorphous carbon films are used. Using 30keV, which is lower than that for conventional TEM (100-300keV), together with low detection angles (15-55mrad) enhances the signals from the fibrils. These factors improve image quality, which enables observation of thin fibrils with widths of 7-8nm. STEM imaging clearly reveals a twisted-ribbon structure of a fibril, and SE imaging shows an emphasized striped pattern of the fibril. The LV-STEM in SEM enables acquisition of two types of images of an identical fibril in a single instrument, which is useful for understanding the structure. This study expands the application of SEM to other systems of interest, which is beneficial to a large number of users. The method in this study can be applied to the observation of various nanobio materials and analysis of their native structures, thus contributing to research in materials and life sciences. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Infrared spectra, Raman laser, XRD, DSC/TGA and SEM ...

    Indian Academy of Sciences (India)

    Administrator

    cussed and the X-ray diffraction, scanning electron microscopy (SEM) and atomic force microscope (AFM) ... acetamide as a simple organic compound at high tempera- ture has less ..... properties of selenium surface, AFM-microscopy tapping.

  20. Revolving SEM images visualising 3D taxonomic characters

    DEFF Research Database (Denmark)

    Akkari, Nesrine; Cheung, David Koon-Bong; Enghoff, Henrik

    2013-01-01

    images taken consecutively while rotating the SEM stage 360°, which allows the structure in question to be seen from all angles of view in one plane. Seven new species of the genus Ommatoiulus collected in Tunisia are described: O. chambiensis, O. crassinigripes, O. kefi, O. khroumiriensis, O. xerophilus...

  1. Enhanced defect of interest [DOI] monitoring by utilizing sensitive inspection and ADRTrue SEM review

    Science.gov (United States)

    Kirsch, Remo; Zeiske, Ulrich; Shabtay, Saar; Beyer, Mirko; Yerushalmi, Liran; Goshen, Oren

    2011-03-01

    As semiconductor process design rules continue to shrink, the ability of optical inspection tools to separate between true defects and nuisance becomes more and more difficult. Therefore, monitoring Defect of Interest (DOI) become a real challenge (Figure 1). This phenomenon occurs due to the lower signal received from real defects while noise levels remain almost the same, resulting in inspection high nuisance rate, which jeopardizes the ability to provide a meaningful, true defect Pareto. A non-representative defect Pareto creates a real challenge to a reliable process monitoring (Figure 4). Traditionally, inspection tool recipes were optimized to keep data load at a manageable level and provide defect maps with ~10% nuisance rate, but as defects of interest get smaller with design rule shrinkage, this requirement results in a painful compromise in detection sensitivity. The inspection is usually followed by defect review and classification using scanning electron microscope (SEM), the classification done manually and it is performed on a small sample of the inspection defect map due to time and manual resources limitations. Sample is usually 50~60 randomly selected locations, review is performed manually most of the times, and manual classification is performed for all the reviewed locations. In the approach described in this paper, the inspection tool recipe is optimized for sensitivity rather than low nuisance rate (i.e. detect all DOI with compromising on a higher nuisance rate). Inspection results with high nuisance rate introduce new challenges for SEM review methodology & tools. This paper describe a new approach which enhances process monitoring quality and the results of collaborative work of the Process Diagnostic & Control Business Unit of Applied Materials® and GLOBALFOUNDRIES® utilizing Applied Materials ADRTrueTM & SEMVisionTM capabilities. The study shows that the new approach reveals new defect types in the Pareto, and improves the ability to

  2. Labyrinths, columns and cavities: new internal features of pollen grain walls in the Acanthaceae detected by FIB-SEM.

    Science.gov (United States)

    House, Alisoun; Balkwill, Kevin

    2016-03-01

    External pollen grain morphology has been widely used in the taxonomy and systematics of flowering plants, especially the Acanthaceae which are noted for pollen diversity. However internal pollen wall features have received far less attention due to the difficulty of examining the wall structure. Advancing technology in the field of microscopy has made it possible, with the use of a focused ion beam-scanning electron microscope (FIB-SEM), to view the structure of pollen grain walls in far greater detail and in three dimensions. In this study the wall structures of 13 species from the Acanthaceae were investigated for features of potential systematic relevance. FIB-SEM was applied to obtain precise cross sections of pollen grains at selected positions for examining the wall ultrastructure. Exploratory studies of the exine have thus far identified five basic structural types. The investigations also show that similar external pollen wall features may have a distinctly different internal structure. FIB-SEM studies have revealed diverse internal pollen wall features which may now be investigated for their systematic and functional significance.

  3. Assessment of heavy metals pollution using AVS-SEM and fractionation techniques in Edku Lagoon sediments, Mediterranean Sea, Egypt.

    Science.gov (United States)

    El Zokm, Gehan M; Okbah, Mohamed A; Younis, Alaa M

    2015-01-01

    A method is presented to evaluate the fractionation of metals (Fe, Zn, Cu, Pb, Cd and Ni), acid volatile sulfide (AVS) and simultaneously extracted metals (SEM) in Edku lagoon sediments. Thirteen sediment samples were collected from the study area in the period of 2010-2011 to assess the potential bioavailability and toxicity of the selected metals. According to classification of the Interim Sediment Quality Quidelines (ISQG), five stations near the drains exhibited 10% toxic probability. The high AVS and low ∑SEM ranges in Summer were identified as 6-138 and 0.86-3.3 µmol g(-1) dry wet, respectively which are referring to the low mobility of heavy metals in this season and vice versa for winter (2.5-23.9 and 1.16-3.82 µmol g(-1) dry wet, respectively). According to the evaluation of USEPA, all sediment samples showedSEM/AVS heavy metals in Edku lagoon sediments posed a low risk of adverse biological effects due to cadmium, copper, lead, nickel and zinc in all evaluated stations.

  4. A semântica formal das línguas naturais: histórias e desafios

    Directory of Open Access Journals (Sweden)

    José Borges Neto

    2014-03-01

    Full Text Available Este artigo faz um resumo da história dos estudos semânticos noBrasil e no mundo, sobretudo das transformações iniciadas nadécada de 1970 e da abertura para uma semântica formalautônoma, que, hoje em dia, comporta diferentes visões sobre arelação sintaxe e semântica, da centralidade da sintaxe aoisomorfismo sintaxe semântica. Mostramos como as ideias do lógicoRichard Montague impulsionaram, através de Barbara Partee eEmmon Bach entre outros, tais estudos, estimulando o surgimentode novas vertentes, e como essas novas tendências foram inseridasno Brasil pela Unicamp com a ajuda de pesquisadores comoMarcelo Dascal, Rodolfo Ilari e Carlos Franchi. O artigo iniciacom uma breve descrição do que é a semântica formal,diferenciando-a de outras semânticas e, principalmente, dasemântica lógica, praticada pelos filósofos, cujo objetivo é descreverraciocínios válidos. A semântica formal é uma ciência empíricaque busca explicar o conhecimento semântico que um falante tem– sua capacidade de relacionar linguagem a algo que não élinguagem (mundos, modelos, conceitos, a composicionalidade e relações sistemáticas entre sentenças – através de umametalinguagem lógico-matemática. Esse empreendimento temsido bem sucedido, se expandindo para além da semântica emdireção a uma maior interação com a pragmática formal. Astendências atuais são de interação com outras disciplinas – apsicolinguística, por exemplo – e a preocupação com línguas poucodescritas, como as línguas indígenas brasileiras. No Brasil, asemântica formal ganhou impulso com a criação dos workshops etem conseguido um espaço cada vez mais significativo na linguísticanacional e internacional.

  5. Resolving Differences in Absolute Irradiance Measurements Between the SOHO/CELIAS/SEM and the SDO/EVE.

    Science.gov (United States)

    Wieman, S R; Didkovsky, L V; Judge, D L

    The Solar EUV Monitor (SEM) onboard SOHO has measured absolute extreme ultraviolet (EUV) and soft X-ray solar irradiance nearly continuously since January 1996. The EUV Variability Experiment (EVE) on SDO, in operation since April of 2010, measures solar irradiance in a wide spectral range that encompasses the band passes (26 - 34 nm and 0.1 - 50 nm) measured by SOHO/SEM. However, throughout the mission overlap, irradiance values from these two instruments have differed by more than the combined stated uncertainties of the measurements. In an effort to identify the sources of these differences and eliminate them, we investigate in this work the effect of reprocessing the SEM data using a more accurate SEM response function (obtained from synchrotron measurements with a SEM sounding-rocket clone instrument taken after SOHO was already in orbit) and time-dependent, measured solar spectral distributions - i.e ., solar reference spectra that were unavailable prior to the launch of the SDO. We find that recalculating the SEM data with these improved parameters reduces mean differences with the EVE measurements from about 20 % to less than 5 % in the 26 - 34 nm band, and from about 35 % to about 15 % for irradiances in the 0.1 - 7 nm band extracted from the SEM 0.1 - 50 nm channel.

  6. Diferenciador semántico: bipolaridad del espacio semántico, un problema de medida del significado

    OpenAIRE

    Álvarez C., Ramiro

    2012-01-01

    En relación con el supuesto de bipolaridad y su aspecto recíprocamente antagónico, Osgood y otros (1957) han ligado su modelo de espacio semántico a la teoría del aprendizaje. Plantean la hipótesis de que cierto estimulo externo, o signo, desencadena un proceso mediacional interno (nn) el cual se constituye en emisor de estímulos (rm 15m). Este es el rm mediacional que contendría el significado del signo. La teoría de mediación la relacionan con el supuesto de bipolaridad en los siguientes té...

  7. Influence of hydroxyapatite granule size, porosity, and crystallinity on tissue reaction in vivo. Part A: synthesis, characterization of the materials, and SEM analysis.

    Science.gov (United States)

    Maté Sánchez de Val, José E; Calvo-Guirado, José L; Gómez-Moreno, Gerardo; Pérez-Albacete Martínez, Carlos; Mazón, Patricia; De Aza, Piedad N

    2016-11-01

    The aim of this study was the synthesis and analysis of the tissue reaction to three different Hydroxyapatite (HA)-based bone substitute materials differing only in granule size, porosity, and crystallinity through an animal experimental model at 60 days. Three different HA-based biomaterials were synthesized and characterized by X-ray diffraction, SEM, and EDS analysis, the resultant product was ground in three particle sizes: Group I (2000-4000 μm), Group II (1000-2000 μm), and Group III (600-1000 μm). Critical size defects were created in both tibias of 15 rabbits. Four defects per rabbit for a total of 60 defects were grafted with the synthesized materials as follows: Group I (15 defects), Group II (15 defects), Group III (15 defects), and empty (15 defects control). After animals sacrifice at 60 days samples were obtained and processed for SEM and EDS evaluation of Ca/P ratios, elemental mapping was performed to determine the chemical degradation process and changes to medullary composition in all the four study groups. The tendency for the density was to increase with the increasing annealing temperature; in this way it was possible to observe that the sample that shows highest crystallinity and crystal size corresponding to that of group I. The SEM morphological examination showed that group III implant showed numerous resorption regions, group II implant presented an average resorption rate of all the implants. The group I displayed smoother surface features, in comparison with the other two implants. The data from this study show that changing the size, porosity, and crystallinity of one HA-based bone substitute material can influence the integration of the biomaterials within the implantation site and the new bone formation. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  8. Validation of cell-free culture using scanning electron microscopy (SEM) and gene expression studies.

    Science.gov (United States)

    Yang, R; Elankumaran, Y; Hijjawi, N; Ryan, U

    2015-06-01

    A cell-free culture system for Cryptosporidium parvum was analysed using scanning electron microscopy (SEM) to characterise life cycle stages and compare gene expression in cell-free culture and cell culture using HCT-8 cells. Cryptosporidium parvum samples were harvested at 2 h, 8 h, 14 h, 26 h, 50 h, 74 h, 98 h, 122 h and 170 h, chemically fixed and specimens were observed using a Zeiss 1555 scanning electron microscope. The presence of sporozoites, trophozoites and type I merozoites were identified by SEM. Gene expression in cell culture and cell-free culture was studied using reverse transcriptase quantitative PCR (RT-qPCR) of the sporozoite surface antigen protein (cp15), the glycoprotein 900 (gp900), the Cryptosporidium oocyst wall protein (COWP) and 18S ribosomal RNA (rRNA) genes in both cell free and conventional cell culture. In cell culture, cp15 expression peaked at 74 h, gp900 expression peaked at 74 h and 98 h and COWP expression peaked at 50 h. In cell-free culture, CP15 expression peaked at 98 h, gp900 expression peaked at 74 h and COWP expression peaked at 122 h. The present study is the first to compare gene expression of C. parvum in cell culture and cell-free culture and to characterise life cycle stages of C. parvum in cell-free culture using SEM. Findings from this study showed that gene expression patterns in cell culture and cell-free culture were similar but in cell-free culture, gene expression was delayed for CP15 and COWP in cell free culture compared with the cell culture system and was lower. Although three life cycle stageswere conclusively identified, improvements in SEM methodology should lead to the detection of more life cycle stages. Copyright © 2015 Elsevier Inc. All rights reserved.

  9. Development of an Economical Interfacing Circuit for Upgrading of SEM Data Printing System

    International Nuclear Information System (INIS)

    Punnachaiya, S.; Thong-Aram, D.

    2002-01-01

    The operating conditions of a Scanning Electron Microscope (SEM) i.e., magnification, accelerating voltage, micron mark and film identification labeling, are very important for the accurate interpretation of a micrograph picture. In the old model SEM, the built-in data printing system for film identification can be inputted only the numerical number. This will be made a confusing problems when various operating conditions were applied in routine work. An economical interfacing circuit, therefore, was developed to upgrade the data printing system for capable of alphanumerical labeling. The developed circuit was tested on both data printing systems of JSM-T220 and JSM-T330 (JEOL SEM). It was found that the interfacing function worked properly and easily installed

  10. Elemental analyses of bulk and individual particles by PIXE and SEM-EDX

    International Nuclear Information System (INIS)

    Kasahara, Mikio; Shinoda, Kazuyuki; Takahashi, Kanji; Yoshida, Kouji.

    1993-01-01

    The atmospheric aerosol samples were collected by a stacked filter method under the various environmental conditions. The elemental concentrations of aerosol particles were measured using PIXE analysis as a bulk sample. And also elemental compositions of about 200 individual particles per each sample were measured by SEM-EDX analysis. In this study, the correspondencies of analytical results measured by both analyses as well as chemical characteristics of individual and bulk aerosols were investigated. (author)

  11. Understanding the Online : Jewellery Retail Market : an integrated model to conduct SEM

    OpenAIRE

    Wu, Yihong

    2013-01-01

    Research into e-commerce is becoming more and more popular; however the jewellery industry is somewhat special. There are very few studies having adapted a strategic marketing perspective on the online jewellery retail market. This study suggested an integrated online marketing strategy which focuses on the search engine marketing (SEM) approach. A detailed procedure of conducting search engine marketing (SEM) is introduced. Through the method of online questionnaires, with the help of soc...

  12. Improvement in the Characterization of the 2099 Al-Li Alloy by FE-SEM

    Science.gov (United States)

    Brodusch, Nicolas; Trudeau, Michel L.; Michaud, Pierre; Brochu, Mathieu; Rodrigue, Lisa; Boselli, Julien; Gauvin, Raynald

    This paper describes how state-of-the-art Field-Emission Scanning Electron Microscopy (FE-SEM) can contribute to the characterization of the 2099 aluminum-lithium alloy, and metallic alloys in general. Investigations were carried out on bulk and thinned samples. BSE imaging at 3kV and STEM imaging at 30kV along with highly efficient microanalysis permitted to correlate experimental and expected structures. Although our results confirm previous studies, this work points out possible substitutions of Mg and Zn with Li, Al and Cu in the T1 precipitates. Zinc and magnesium are also present in "rice grain" shaped precipitates at the grain boundaries. The versatility of the FE-SEM is highlighted in that it can provide information at the macro and micro scales with relevant details. Its ability to probe the distribution of precipitates from nano-to micro-sizes throughout the matrix makes Field-Emission Scanning Electron Microscopy a suitable technique for the characterization of metallic alloys.

  13. The principle of electron microscopy; SEM and TEM

    International Nuclear Information System (INIS)

    Fauzi, S.H.

    1992-01-01

    The article reviews the principle of electron microscopy which is used in scanning electron microscope (SEM) and transmission electron microscope (TEM). These instruments are important for the examination and analysis of the microstructural properties of solid objects. Relevance physical concept lies behind the devices are given. The main components of each device are also discussed

  14. Modelo de web semántica para universidades

    Directory of Open Access Journals (Sweden)

    Karla Abad

    2015-12-01

    Full Text Available A raíz del estudio de estado actual de micrositios y repositorios en la Universidad Estatal Península de Santa Elena se encontró que su información carecía de semántica óptima y adecuada. Bajo estas circunstancias, se plantea entonces la necesidad de crear un modelo de estructura de web semántica para Universidades, el cual posteriormente fue aplicado a micrositios y repositorio digital de la UPSE, como caso de prueba. Parte de este proyecto incluye la instalación de módulos de software con sus respectivas configuraciones y la utilización de estándares de metadatos como DUBLIN CORE, para la mejora del SEO (optimización en motores de búsqueda; con ello se ha logrado la generación de metadatos estandarizados y la creación de políticas para la subida de información. El uso de metadatos transforma datos simples en estructuras bien organizadas que aportan información y conocimiento para generar resultados en buscadores web. Al culminar la implementación del modelo de web semántica es posible decir que la universidad ha mejorado su presencia y visibilidad en la web a través del indexamiento de información en diferentes motores de búsqueda y posicionamiento en la categorización de universidades y de repositorios de Webometrics (ranking que proporciona clasificación de universidades de todo el mundo.   Abstract After examining the current microsites and repositories situation in University, Peninsula of Santa Elena´s, it was found that information lacked optimal and appropriate semantic. Under these circumstances, there is a need to create a semantic web structure model for Universities, which was subsequently applied to UPSE´s microsites and digital repositories, as a test study case. Part of this project includes the installation of software modules with their respective configurations and the use of metadata standards such as DUBLIN CORE, to improve the SEO (Search Engine Optimization; with these applications, it was

  15. SEM/TIMS analysis trials on hotswipe samples taken from a shielded cell at Harwell

    International Nuclear Information System (INIS)

    Tushingham, J.; Vatter, I.; Cooke, R.

    1998-09-01

    The IAEA require advanced techniques and procedures for the detection of traces of actinides to be applied to their environmental sampling programme for nuclear safeguards as a means to detect undeclared activities. 'Swipe' samples taken from within nuclear facilities by IAEA inspectors require analysis to determine their actinide content and composition by bulk and particle measurements. The use of analytical equipment capable of analysing individual particles, particularly of actinides, is essential to optimise the IAEA's aim to monitor Member State's nuclear activities more proficiently. A trial has been undertaken at the Harwell Laboratory of AEA Technology to establish the efficacy of scanning electron microscopy (SEM) and thermal ionisation mass spectrometry (TIMS) for the particle and bulk characterisation, respectively, of actinides on samples taken from within a shielded cell. These measurements were supported by γ-spectrometry and α-spectrometry. 'Hotswipe' samples taken from within a shielded cell with a well-known recent history have been prepared for particle and bulk analysis. SEM has been used to characterise individual particles from the swipe samples and the results have been related to known cell activities. Samples were prepared for SEM using a simple procedure to minimise the potential for sample contamination. The method proved to be capable of identifying 1 μm particles that contained U, Pu, Pa and Np. The measurement of U/Pu ratios was limited to particles that contained >2% Pu in U by weight. TIMS, together with alpha spectrometry, has been used to determine the bulk actinide composition of the samples whilst gamma spectrometry has been used to determine the fission product composition. Further work to improve the potential of SEM, and also secondary ionisation mass spectrometry (SIMS), for the measurement of hotswipe samples has been proposed. (author)

  16. Sediment nickel bioavailability and toxicity to estuarine crustaceans of contrasting bioturbative behaviors--an evaluation of the SEM-AVS paradigm.

    Science.gov (United States)

    Chandler, G Thomas; Schlekat, Christian E; Garman, Emily R; He, Lijian; Washburn, Katherine M; Stewart, Emily R; Ferry, John L

    2014-11-04

    Robust sediment quality criteria require chemistry and toxicity data predictive of concentrations where population/community response should occur under known geochemical conditions. Understanding kinetic and geochemical effects on toxicant bioavailability is key, and these are influenced by infaunal sediment bioturbation. This study used fine-scale sediment and porewater measurement of contrasting infaunal effects on carbon-normalized SEM-AVS to evaluate safe or potentially toxic nickel concentrations in a high-binding Spartina saltmarsh sediment (4%TOC; 35-45 μmol-S2-·g(-1)). Two crustaceans producing sharply contrasting bioturbation--the copepod Amphiascus tenuiremis and amphipod Leptocheirus plumulosus--were cultured in oxic to anoxic sediments with SEM[Ni]-AVS, TOC, porewater [Ni], and porewater DOC measured weekly. From 180 to 750 μg-Ni·g(-1) sediment, amphipod bioturbation reduced [AVS] and enhanced porewater [Ni]. Significant amphipod uptake, mortality, and growth-depression occurred at the higher sediment [Ni] even when [SEM-AVS]/foc suggested acceptable risk. Less bioturbative copepods produced higher AVS and porewater DOC but exhibited net population growth despite porewater [Ni] 1.3-1.7× their aqueous [Ni] LOEC. Copepod aqueous tests with/without dissolved organic matter showed significant aqueous DOC protection, which suggests porewater DOC attenuates sediment Ni toxicity. The SEM[Ni]-AVS relationship was predictive of acceptable risk for copepods at the important population-growth level.

  17. Cultivo sem solo do morangueiro Strawberry soilless cultivation

    Directory of Open Access Journals (Sweden)

    Gustavo Giménez

    2008-02-01

    Full Text Available O morangueiro é uma cultura importante em vários países, principalmente nos Estados Unidos e na Europa, por suas características sensoriais, propriedades nutritivas e por sua rentabilidade. O cultivo comercial sem solo de morangueiro está bem desenvolvido na Europa, onde tem permitido um aumento da produtividade e qualidade da produção assim como a ampliação da oferta do produto ao longo do ano. Predomina o sistema aberto, em sacolas ou vasos com diferentes tipos de substratos, utilizando-se densidades de 8 a 12plantas m-2. As produtividades obtidas estão entre 5 e 10kg m-2. Para isolar as plantas do solo e facilitar o manejo da cultura, os vasos ou sacolas são suspensos a uma altura entre 0,8 e 1m da superfície do solo. A composição da solução nutritiva é variável, refletindo as diferentes condições produtivas. As mudas são produzidas principalmente em bandejas com substrato, a partir de pontas de estolões obtidas da multiplicação de plantas matrizes provenientes da propagação in vitro. No Brasil, o cultivo sem solo de morangueiro é ainda incipiente e os resultados produtivos e econômicos têm sido insatisfatórios, principalmente por falta de informações de pesquisas capazes de indicar sistemas apropriados de cultivo para as condições locais. É necessário desenvolver sistemas sustentáveis, preferencialmente fechados, combinando alta produtividade e elevada eficiência de utilização da água e dos nutrientes. No presente trabalho, são revisados os principais aspectos da produção em sistemas de cultivo sem solo de mudas e fruta de morangueiro. São descritos a produção de mudas, os sistemas e as soluções nutritivas empregadas em diferentes países. Ao final, são feitas inferências sobre a possibilidade de adoção e geração do sistema de cultivo sem solo apropriado para as condições brasileiras.Strawberry is a very important crop in Europe and USA due to its nutritional and sensorial

  18. Wi-Fi Salvador: mapeamento colaborativo e redes sem fio no Brasil

    OpenAIRE

    Lemos, André; Pastor, Leonardo; Oliveira, Nelson

    2012-01-01

    O trabalho faz uma breve demonstração de políticas públicas para inclusão digital por meio da disponibilização do acesso à internet por meio de redes sem fio e discute a forma como as pessoas se relacionam com os lugares, de acordo com a existência ou inexistência de acessibilidade à internet. O objetivo é discutir o acesso à internet pelas redes sem fio no Brasil e, mais especificamente, na cidade de Salvador. Este trabalho é fruto de pesquisa realizada no âmbito do Grupo de Pesquisa em Cibe...

  19. Determination of chemical content of PM10 and TSP using SEM-EDAX

    International Nuclear Information System (INIS)

    Masitah Alias; Zaini Hamzah

    2007-01-01

    The growing concern over the workers safety and health has lead many factories and organizations do the air monitoring to ensure the airborne at their workplace is safe for the worker's health and complying the Occupational Safety and Health Act 1994 (Act 514). In this study, the monitoring covers an indoor air quality and chemical exposure to the workers in one of the power plant repair shop. A few workers from different sections namely blasting, welding, grinding, fitting and maintenance area were chosen to assist in the personal monitoring for 8 hours measurement. PM10 were measured at a few sampling points to collect dusts for 24 hours duration. The samples were brought back to the laboratory for gravimetric and SEM-EDAX analysis. The results were certainly exceed the limit for air quality, and many elements were detected such as Fe, Ni, Al, Si, Ca, K, Ba, S, Cr, Zn and Cl. The present of these elements shows that exposure to these particulate matters is quite risky and some measure needs to be taken for remedial action. (Author)

  20. Three-dimensional analysis of somatic mitochondrial dynamics in fission-deficient injured motor neurons using FIB/SEM.

    Science.gov (United States)

    Tamada, Hiromi; Kiryu-Seo, Sumiko; Hosokawa, Hiroki; Ohta, Keisuke; Ishihara, Naotada; Nomura, Masatoshi; Mihara, Katsuyoshi; Nakamura, Kei-Ichiro; Kiyama, Hiroshi

    2017-08-01

    Mitochondria undergo morphological changes through fusion and fission for their quality control, which are vital for neuronal function. In this study, we examined three-dimensional morphologies of mitochondria in motor neurons under normal, nerve injured, and nerve injured plus fission-impaired conditions using the focused ion beam/scanning electron microscopy (FIB/SEM), because the FIB/SEM technology is a powerful tool to demonstrate both 3D images of whole organelle and the intra-organellar structure simultaneously. Crossing of dynamin-related protein 1 (Drp1) gene-floxed mice with neuronal injury-specific Cre driver mice, Atf3:BAC Tg mice, allowed for Drp1 ablation specifically in injured neurons. FIB/SEM analysis demonstrated that somatic mitochondrial morphologies in motor neurons were not altered before or after nerve injury. However, the fission impairment resulted in prominent somatic mitochondrial enlargement, which initially induced complex morphologies with round regions and long tubular processes, subsequently causing a decrease in the number of processes and further enlargement of the round regions, which eventually resulted in big spheroidal mitochondria without processes. The abnormal mitochondria exhibited several degradative morphologies: local or total cristae collapse, vacuolization, and mitophagy. These suggest that mitochondrial fission is crucial for maintaining mitochondrial integrity in injured motor neurons, and multiple forms of mitochondria degradation may accelerate neuronal degradation. © 2017 Wiley Periodicals, Inc.

  1. Cryogenic-SEM investigation of CO{sub 2} hydrate morphologies

    Energy Technology Data Exchange (ETDEWEB)

    Camps, A.P.; Milodowski, A.; Rochelle, C.; Williams, J.F.; Jackson, P. D. [British Geological Survey, Keyworth, Nottinghamshire (United Kingdom); Camps, A.P; Lovell, M.; Williams, J.F. [Leicester Univ., Leicester (United Kingdom). Dept. of Geology

    2008-07-01

    Gas hydrates occur naturally around the world in the shallow-marine geosphere, and are seen as a drilling hazard in the petroleum industry due to their role in the carbon cycle, and their possible contribution in past and present climate change. Hydrates are ice-like structures composed of cages of water molecules containing one or more guest molecules, such as methane and carbon dioxide (CO{sub 2}). CO{sub 2} hydrates also occur naturally on earth and are being investigated for their potential to store large volumes of CO{sub 2} to reduce atmospheric emissions of greenhouse gases as a climate change mitigation strategy. However, the mineralogy and formation processes of hydrates are relatively poorly understood. Different imaging techniques have been utilized to study gas hydrates, such as nuclear magnetic resonance, magnetic resonance imaging, and x-ray computed tomography. Scanning Electron Microscopy (SEM) at cryogenic temperatures is another technique to study hydrates, and has been used successfully for investigation of methane and CO{sub 2} hydrates. This paper presented a study that investigated CO{sub 2} hydrates formed in laboratories, using a cryogenic-SEM. The paper presented the study methods and observations, including euhedral crystalline carbon dioxide hydrate; acicular carbon dioxide hydrate; granoblastic carbon dioxide hydrate; and gas rich carbon dioxide hydrate. It was concluded that the investigation produced various different hydrate morphologies resulting from different formation conditions. Morphologies ranged from well-defined euhedral crystals to acicular needles, and more complex, intricate forms. 22 refs., 6 figs., 1 appendix.

  2. SEM-EDX--a useful tool for forensic examinations

    International Nuclear Information System (INIS)

    Zadora, G.; Brozek-Mucha, Z.

    2003-01-01

    There are two main aims of forensic examination of the physical evidences. The first aim is comparison of the evidence with the reference material (called discrimination). The task is to find out whether they could have come from the same object. The second aim, when there is no comparative material available, is a classification of the evidence sample into a group of objects taking into account its specific chemical and physical properties. Scanning electron microscopy with energy dispersive X-ray spectrometry (SEM-EDX) is a powerful tool for forensic scientists to classify and discriminate evidence material because they can simultaneously examine the morphology and the elemental composition of objects. Moreover, the obtained results could be enhanced using some methods of chemometric analysis. A few examples of problems related to the classification and discrimination of selected types of microtraces are presented

  3. Chemical and structural analysis of the bone-implant interface by TOF-SIMS, SEM, FIB and TEM: Experimental study in animal

    International Nuclear Information System (INIS)

    Palmquist, Anders; Emanuelsson, Lena; Sjövall, Peter

    2012-01-01

    Although bone-anchored implants are widely used in reconstructive medicine, the mechanism of osseointegration is still not fully understood. Novel analytical tools are needed to further understand this process, where both the chemical and structural aspects of the bone-implant interface are important. The aim of this study was to evaluate the advantages of combining time-of-flight secondary ion mass spectroscopy (TOF-SIMS) with optical (LM), scanning (SEM) and transmission electron microscopy (TEM) techniques for studying the bone-implant interface of bone-anchored implants. Laser-modified titanium implants with surrounded bone retrieved after 8 weeks healing in rabbit were dehydrated and resin embedded. Three types of sample preparation were studied to evaluate the information gained by combining TOF-SIMS, SEM, FIB and TEM. The results show that imaging TOF-SIMS can provide detailed chemical information, which in combination with structural information from microscopy methods provide a more complete characterization of anatomical structures at the bone-implant interface. By investigating various sample preparation techniques, it is shown that grinded cross section samples can be used for chemical imaging using TOF-SIMS, if careful consideration of potential preparation artifacts is taken into account. TOF-SIMS analysis of FIB-prepared bone/implant cross section samples show distinct areas corresponding to bone tissue and implant with a sharp interface, although without chemical information about the organic components.

  4. La semántica en la Web

    OpenAIRE

    Roger, Sandra

    2004-01-01

    El propósito de este trabajo es presentar la motivación de nuestra línea de investigación, metas y desarrollos futuros. Fundamentalmente, nuestro interés se centrará en poder capturar el potencial de las técnicas y paradigmas basadas en conocimiento semántico para la representación de conocimiento, la localización, compartición e integración de recursos a mediante la WWW.

  5. Structuring Consumer Preferences with the SEM Method

    OpenAIRE

    Rosa, Franco

    2002-01-01

    Structuring preferences has been developed with econometric models using functional flexible parametric form and the exploring the perceptions about expressed and latent needs using different multivariate approaches. Purpose of this research is to explore the demand for a new drink using the mean-end chain (MEC) theory and multivariate SEM procedure. The first part is dedicated to description of specialty foods for their capacity to create new niche markets. The MEC theory is introduced to ex...

  6. SEM Investigation of Superheater Deposits from Biomass-Fired Boilers

    DEFF Research Database (Denmark)

    Jensen, Peter Arendt; Frandsen, Flemming; Hansen, Jørn

    2004-01-01

    , mature superheater deposit samples were extracted from two straw-fired boilers, Masnedø and Ensted, with fuel inputs of 33 MWth and 100 MWth, respectively. SEM (scanning electron microscopy) images and EDX (energy dispersive X-ray) analyses were performed on the deposit samples. Different strategies...

  7. Exploring the interior of cuticles and compressions of fossil plants by FIB-SEM milling and image microscopy.

    Science.gov (United States)

    Sender, L M; Escapa, I; Benedetti, A; Cúneo, R; Diez, J B

    2018-01-01

    We present the first study of cuticles and compressions of fossil leaves by Focused Ion Beam Scanning Electron Microscopy (FIB-SEM). Cavities preserved inside fossil leaf compressions corresponding to substomatal chambers have been observed for the first time and several new features were identified in the cross-section cuts. These results open a new way in the investigation of the three-dimensional structures of both micro- and nanostructural features of fossil plants. Moreover, the application of the FIB-SEM technique to both fossils and extant plant remains represent a new source of taxonomical, palaeoenvironmental and palaeoclimatic information. © 2017 The Authors Journal of Microscopy © 2017 Royal Microscopical Society.

  8. Interpretation of secondary electron images obtained using a low vacuum SEM

    International Nuclear Information System (INIS)

    Toth, M.; Thiel, B.L.; Donald, A.M.

    2003-01-01

    Charging of insulators in a variable pressure environment was investigated in the context of secondary electron (SE) image formation. Sample charging and ionized gas molecules present in a low vacuum specimen chamber can give rise to SE image contrast. 'Charge-induced' SE contrast reflects lateral variations in the charge state of a sample caused by electron irradiation during and prior to image acquisition. This contrast corresponds to SE emission current alterations produced by sub-surface charge deposited by the electron beam. 'Ion-induced' contrast results from spatial inhomogeneities in the extent of SE signal inhibition caused by ions in the gaseous environment of a low vacuum scanning electron microscope (SEM). The inhomogeneities are caused by ion focusing onto regions of a sample that correspond to local minima in the magnitude of the surface potential (generated by sub-surface trapped charge), or topographic asperities. The two types of contrast exhibit characteristic dependencies on microscope operating parameters such as scan speed, beam current, gas pressure, detector bias and working distance. These dependencies, explained in terms of the behavior of the gaseous environment and sample charging, can serve as a basis for a correct interpretation of SE images obtained using a low vacuum SEM

  9. Assessment of Paint Layers by FE-SEM and EDS Examination

    National Research Council Canada - National Science Library

    Harris, Donovan

    2004-01-01

    .... The approach was to remove free-film samples from each panel, fracture the films, and then examine at high magnification the cross sections using a field emission-scanning electron microscope (FE-SEM...

  10. Detection of glass particles on bone lesions using SEM-EDS.

    Science.gov (United States)

    Montoriol, Romain; Guilbeau-Frugier, Céline; Chantalat, Elodie; Roumiguié, Mathieu; Delisle, Marie-Bernadette; Payré, Bruno; Telmon, Norbert; Savall, Frédéric

    2017-09-01

    The problem of identifying the wounding agent in forensic cases is recurrent. Moreover, when several tools are involved, distinguishing the origin of lesions can be difficult. Scanning electron microscopy (SEM)/energy dispersive X-ray analysis (EDS) equipment is increasingly available to the scientific and medical community, and some studies have reported its use in forensic anthropology. However, at our knowledge, no study has reported the use of SEM-EDS in forensic cases involving glass tools, whether in case reports or experiments. We performed an experimental study on human rib fragments, on which we manually created wounds using fragments of window and mirror glass. SEM-EDS was executed on samples without any further preparation on low vacuum mode, then on the same samples after defleshing them completely by boiling them. Window and mirror glass particles were detected on experimental wounds. Both had silica in their spectra, and the opaque side of the mirror contained titanium, allowing for their identification. Boiling and defleshing the bone samples involved a loss of information in terms of the number of wounds detected as positive for glass particles and in the number of glass particles detected, for both window and mirror glass. We suggest the analysis of wounds with suspected glass particles using low vacuum mode and with no defleshment by boiling.

  11. Surface characteristics of isopod digestive gland epithelium studied by SEM.

    Science.gov (United States)

    Millaku, Agron; Leser, Vladka; Drobne, Damjana; Godec, Matjaz; Torkar, Matjaz; Jenko, Monika; Milani, Marziale; Tatti, Francesco

    2010-05-01

    The structure of the digestive gland epithelium of a terrestrial isopod Porcellio scaber has been investigated by conventional scanning electron microscopy (SEM), focused ion beam-scanning electron microscopy (FIB/SEM), and light microscopy in order to provide evidence on morphology of the gland epithelial surface in animals from a stock culture. We investigated the shape of cells, extrusion of lipid droplets, shape and distribution of microvilli, and the presence of bacteria on the cell surface. A total of 22 animals were investigated and we found some variability in the appearance of the gland epithelial surface. Seventeen of the animals had dome-shaped digestive gland "normal" epithelial cells, which were densely and homogeneously covered by microvilli and varying proportions of which extruded lipid droplets. On the surface of microvilli we routinely observed sparsely distributed bacteria of different shapes. Five of the 22 animals had "abnormal" epithelial cells with a significantly altered shape. In three of these animals, the cells were much smaller, partly or completely flat or sometimes pyramid-like. A thick layer of bacteria was detected on the microvillous border, and in places, the shape and size of microvilli were altered. In two animals, hypertrophic cells containing large vacuoles were observed indicating a characteristic intracellular infection. The potential of SEM in morphological investigations of epithelial surfaces is discussed.

  12. SEM based CARMA time series modeling for arbitrary N

    NARCIS (Netherlands)

    Oud, J.H.L.; Völkle, M.C.; Driver, C.C.

    2018-01-01

    This article explains in detail the state space specification and estimation of first and higher-order autoregressive moving-average models in continuous time (CARMA) in an extended structural equation modeling (SEM) context for N = 1 as well as N > 1. To illustrate the approach, simulations will be

  13. La semántica del adjetivo y su representación mediante estructura de rasgos

    OpenAIRE

    Climent Roca, Salvador

    1995-01-01

    Por el trabajo que se describe se ha formulado un marco general de representación semántica de los adjetivos en una base de conocimiento léxica basada en estructuras de rasgos en la que operan la herencia y la unificación. Como principales aportaciones cabe destacar el propio diseño de un marco representativo suficientemente expresivo como para abarcar múltiples aspectos del significado del adjetivo, tales como orden superficial, restricciones selectivas, semántica léxica y semántica formal. ...

  14. SEM in situ laboratory investigations on damage growth in GFRP composite under three-point bending tests

    DEFF Research Database (Denmark)

    Zhou, Hong Wei; Mishnaevsky, Leon; Brøndsted, Povl

    2010-01-01

    Glass fiber-reinforced polymer (GFRP) composites are widely used in low-weight constructions. SEM (scanning electron microscopy) in situ experiments of damage growth in GFRP composite under three-point bending loads are carried out. By summarizing the experimental results of three groups of samples...

  15. Application of SEM/EDS to environmental geochemistry of heavy metals

    Directory of Open Access Journals (Sweden)

    Mateja Gosar

    2009-06-01

    Full Text Available Heavy metals represent a ubiquitous constituent of the near-surface environment, present in widely varyingconcentrations that typically have little impact on human behaviour and health. However, the mining of metals anduse of these metals in industrial processes has produced significant anthropogenic inputs of metals to both localand global environments. As such, a rigorous overview of the current accumulation of heavy metals and knowledgeof mineralogy of heavy metal-bearing phases is important for understanding their stability, solubility, mobility,bioavailability and toxicity. These data are of fundamental importance for environmental risk assessment and evaluationof future scenarios. Since conventional geochemical analyses provide limited information, other analyticalmethods have to be utilized for the characterisation of heavy metal-bearing phases. Significant analytical methodfor identification and characterisation of heavy metals in environmental media is a scanning electron microscopecoupled with energy dispersive X-ray spectrometer (SEM/EDS, an apparatus for qualitative and semi-quantitative chemical analysis at microne level, newly introduced to Geological Survey of Slovenia. Use of SEM/EDS was already introduced to environmental studies world-wide. In Slovenia, SEM/EDS analyses of environmental media werefirstly carried out on the Meža River stream sediments and snow deposits from Ljubljana urban area.Heavy metal-bearing phases in the Meža River stream sediments were apportioned to three source areas: Mežica mining/smelting area (geogenic-technogenic origin, Ravne ironworks area (technogenic origin and the Meža River catchment area (geogenic origin, which corresponds to data obtained by conventional geochemical and multivariate statistical methods. Airborne particles, identified in urban snow deposits, were interpreted as geogenic particles, represented by fragments of heavy metal-bearing minerals, and technogenic particles that

  16. A Miniaturized Variable Pressure Scanning Electron Microscope (MVP-SEM) for In-Situ Mars Surface Sample Analysis

    Science.gov (United States)

    Edmunson, J.; Gaskin, J. A.; Jerman, G. A.; Harvey, R. P.; Doloboff, I. J.; Neidholdt, E. L.

    2016-01-01

    The Miniaturized Variable Pressure Scanning Electron Microscope (MVP-SEM) project, funded by the NASA Planetary Instrument Concepts for the Advancement of Solar System Observations (PICASSO) Research Opportunities in Space and Earth Sciences (ROSES), will build upon previous miniaturized SEM designs and recent advancements in variable pressure SEM's to design and build a SEM to complete analyses of samples on the surface of Mars using the atmosphere as an imaging medium. This project is a collaboration between NASA Marshall Space Flight Center (MSFC), the Jet Propulsion Laboratory (JPL), electron gun and optics manufacturer Applied Physics Technologies, and small vacuum system manufacturer Creare. Dr. Ralph Harvery and environmental SEM (ESEM) inventor Dr. Gerry Danilatos serve as advisors to the team. Variable pressure SEMs allow for fine (nm-scale) resolution imaging and micron-scale chemical study of materials without sample preparation (e.g., carbon or gold coating). Charging of a sample is reduced or eliminated by the gas surrounding the sample. It is this property of ESEMs that make them ideal for locations where sample preparation is not yet feasible, such as the surface of Mars. In addition, the lack of sample preparation needed here will simplify the sample acquisition process and allow caching of the samples for future complementary payload use.

  17. The effect of home bleaching agents on the surface roughness of five different composite resins: A SEM evaluation.

    Science.gov (United States)

    Cengiz, Esra; Kurtulmus-Yilmaz, Sevcan; Ulusoy, Nuran; Deniz, Sule Tugba; Yuksel-Devrim, Ece

    2016-05-01

    The aim of this study was to investigate the effect of hydrogen peroxide (HP) and carbamide peroxide (CP) on the surface roughness of five different composite resins using profilometer and scanning electron microscope (SEM). Thirty-six specimens (1 mm thick, 10 mm in diameter) of five composite resins were fabricated. Each composite group was equally divided into three subgroups as control, CP and HP. In control group, specimens were stored in daily refreshed distilled water during the 14-day testing period. In other groups, 10% HP (Opalescence Treswhite) and 10% CP (Opalescence PF) were applied and surface roughness values (Ra) of each specimen were measured with a profilometer at the end of 14 days. Additionally, SEM analysis was performed to evaluate the surface deformations of composite resins. Data were analyzed with Kruskal-Wallis and Mann-Whitney U tests. Ra values of composite groups exposed to bleaching agents were statistically higher than control group (p composite group while SEM micrographs showed higher surface alterations at HP group compared to CP. Among the composite resins tested, Ceram-X Mono revealed the lowest Ra values after CP and HP applications as seen at SEM images. Home bleaching agents increased the surface roughness of all composites. Except CP applied Ceram-X mono specimens, Ra values of all composite resins evaluated in this study exceeded the critical limit of 0.2 μm. Ceram-X mono was the least affected composite material after bleaching application. SCANNING 38:277-283, 2016. © 2016 Wiley Periodicals, Inc. © Wiley Periodicals, Inc.

  18. Recent Advances on In Situ SEM Mechanical and Electrical Characterization of Low-Dimensional Nanomaterials.

    Science.gov (United States)

    Jiang, Chenchen; Lu, Haojian; Zhang, Hongti; Shen, Yajing; Lu, Yang

    2017-01-01

    In the past decades, in situ scanning electron microscopy (SEM) has become a powerful technique for the experimental study of low-dimensional (1D/2D) nanomaterials, since it can provide unprecedented details for individual nanostructures upon mechanical and electrical stimulus and thus uncover the fundamental deformation and failure mechanisms for their device applications. In this overview, we summarized recent developments on in situ SEM-based mechanical and electrical characterization techniques including tensile, compression, bending, and electrical property probing on individual nanostructures, as well as the state-of-the-art electromechanical coupling analysis. In addition, the advantages and disadvantages of in situ SEM tests were also discussed with some possible solutions to address the challenges. Furthermore, critical challenges were also discussed for the development and design of robust in situ SEM characterization platform with higher resolution and wider range of samples. These experimental efforts have offered in-depth understanding on the mechanical and electrical properties of low-dimensional nanomaterial components and given guidelines for their further structural and functional applications.

  19. Recent Advances on In Situ SEM Mechanical and Electrical Characterization of Low-Dimensional Nanomaterials

    Directory of Open Access Journals (Sweden)

    Chenchen Jiang

    2017-01-01

    Full Text Available In the past decades, in situ scanning electron microscopy (SEM has become a powerful technique for the experimental study of low-dimensional (1D/2D nanomaterials, since it can provide unprecedented details for individual nanostructures upon mechanical and electrical stimulus and thus uncover the fundamental deformation and failure mechanisms for their device applications. In this overview, we summarized recent developments on in situ SEM-based mechanical and electrical characterization techniques including tensile, compression, bending, and electrical property probing on individual nanostructures, as well as the state-of-the-art electromechanical coupling analysis. In addition, the advantages and disadvantages of in situ SEM tests were also discussed with some possible solutions to address the challenges. Furthermore, critical challenges were also discussed for the development and design of robust in situ SEM characterization platform with higher resolution and wider range of samples. These experimental efforts have offered in-depth understanding on the mechanical and electrical properties of low-dimensional nanomaterial components and given guidelines for their further structural and functional applications.

  20. An SEM/EDX study of bed agglomerates formed during fluidized bed combustion of three biomass fuels

    International Nuclear Information System (INIS)

    Scala, Fabrizio; Chirone, Riccardo

    2008-01-01

    The agglomeration behaviour of three biomass fuels (exhausted and virgin olive husk and pine seed shells) during fluidized bed combustion in a lab-scale reactor was studied by means of SEM/EDX analysis of bed agglomerate samples. The effect of the fuel ash composition, bed temperature and sand particle size on agglomeration was investigated. The study was focused on the main fuel ash components and on their interaction with the bed sand particles. Agglomeration was favoured by high temperature, small sand size, a high fraction of K and Na and a low fraction of Ca and Mg in the fuel ash. An initial fuel ash composition close to the low-melting point eutectic composition appears to enhance agglomeration. The agglomerates examined by SEM showed a hollow structure, with an internal region enriched in K and Na where extensive melting is evident and an external one where sand particles are only attached by a limited number of fused necks. Non-molten or partially molten ash structures deposited on the sand surface and enriched in Ca and Mg were also observed. These results support an ash deposition-melting mechanism: the ash released by burning char particles inside the agglomerates is quantitatively deposited on the sand surface and then gradually embedded in the melt. The low-melting point compounds in the ash migrate towards the sand surface enriching the outermost layer, while the ash structure is progressively depleted of these compounds

  1. The advancement of the built environment research through employment of structural equation modeling (SEM)

    Science.gov (United States)

    Wasilah, S.; Fahmyddin, T.

    2018-03-01

    The employment of structural equation modeling (SEM) in research has taken an increasing attention in among researchers in built environment. There is a gap to understand the attributes, application, and importance of this approach in data analysis in built environment study. This paper intends to provide fundamental comprehension of SEM method in data analysis, unveiling attributes, employment and significance and bestow cases to assess associations amongst variables and constructs. The study uses some main literature to grasp the essence of SEM regarding with built environment research. The better acknowledgment of this analytical tool may assist the researcher in the built environment to analyze data under complex research questions and to test multivariate models in a single study.

  2. El adjetivo en el Nuevo Testamento: clasificación semántica

    OpenAIRE

    Romero González, Dámaris

    2011-01-01

    El adjetivo ha sido estudiado habitualmente desde el punto de vista del sustantivo, como una subclase de éste, ya que ambos poseen una morfología similar. Semánticamente, la mayoría de las gramáticas los clasifican según su capacidad para calificar o determinar al sustantivo, denominándolo calificativo y determinativo respectivamente. Dentro de esta clasificación, se han establecido subgrupos basados en criterios semánticos. Por tanto, el propósito de esta tesis es esbozar una nueva...

  3. FIB/SEM technology and high-throughput 3D reconstruction of dendritic spines and synapses in GFP-labeled adult-generated neurons

    Directory of Open Access Journals (Sweden)

    Carles eBosch

    2015-05-01

    Full Text Available The fine analysis of synaptic contacts is usually performed using transmission electron microscopy (TEM and its combination with neuronal labeling techniques. However, the complex 3D architecture of neuronal samples calls for their reconstruction from serial sections. Here we show that focused ion beam/scanning electron microscopy (FIB/SEM allows efficient, complete, and automatic 3D reconstruction of identified dendrites, including their spines and synapses, from GFP/DAB-labeled neurons, with a resolution comparable to that of TEM. We applied this technology to analyze the synaptogenesis of labeled adult-generated granule cells (GCs in mice. 3D reconstruction of spines in GCs aged 3–4 and 8–9 weeks revealed two different stages of spine development and unexpected features of synapse formation, including vacant and branched spines and presynaptic terminals establishing synapses with up to 10 spines. Given the reliability, efficiency, and high resolution of FIB/SEM technology and the wide use of DAB in conventional EM, we consider FIB/SEM fundamental for the detailed characterization of identified synaptic contacts in neurons in a high-throughput manner.

  4. SEM/EDS and optical microscopy analyses of microplastics in ocean trawl and fish guts.

    Science.gov (United States)

    Wang, Zhong-Min; Wagner, Jeff; Ghosal, Sutapa; Bedi, Gagandeep; Wall, Stephen

    2017-12-15

    Microplastic particles from Atlantic and Pacific Ocean trawls, lab-fed fish guts and ocean fish guts have been characterized using optical microscopy and SEM/EDS in terms of size, morphology, and chemistry. We assessed whether these measurements could serve as a rapid screening process for subsequent identification of the likely microplastic candidates by micro-spectroscopy. Optical microscopy enabled morphological classification of the types of particles or fibers present in the sample, as well as the quantification of particle size ranges and fiber lengths. SEM/EDS analysis was used to rule out non-plastic particles and screen the prepared samples for potential microplastic, based on their element signatures and surface characteristics. Chlorinated plastics such as polyvinyl chloride (PVC) could be easily identified with SEM/EDS due to their unique elemental signatures including chlorine, as could mineral species that are falsely identified as plastics by optical microscopy. Particle morphology determined by optical microscopy and SEM suggests the fish ingested particles contained both degradation fragments from larger plastic pieces and also manufactured microplastics. SEM images of microplastic particle surfaces revealed characteristic cracks consistent with environmental exposure, as well as pigment particles consistent with manufactured materials. Most of the microplastic surfaces in the fish guts and ocean trawls were covered with biofilms, radiolarians, and crustaceans. Many of the fish stomachs contained micro-shell pieces which visually resembled microplastics. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Processing a Biological Tissue from Cryo-SEM to Replica

    Czech Academy of Sciences Publication Activity Database

    Vaškovicová, Naděžda; Hrubanová, Kamila; Krzyžánek, Vladislav

    2016-01-01

    Roč. 22, S3 (2016), s. 236-237 ISSN 1431-9276 R&D Projects: GA MŠk(CZ) LO1212; GA MŠk ED0017/01/01 Institutional support: RVO:68081731 Keywords : Cryo-SEM * ACE600 Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 1.891, year: 2016

  6. Fast three-dimensional nanoscale metrology in dual-beam FIB-SEM instrumentation

    International Nuclear Information System (INIS)

    Repetto, Luca; Buzio, Renato; Denurchis, Carlo; Firpo, Giuseppe; Piano, Emanuele; Valbusa, Ugo

    2009-01-01

    A quantitative surface reconstruction technique has been developed for the geometric characterization of three-dimensional structures by using a combined focused ion beam-scanning electron microscopy (FIB-SEM) instrument. A regular pattern of lines is milled at normal incidence on the sample to be characterized and an image is acquired at a large tilt angle. By analyzing the pattern under the tilted view, a quantitative estimation of surface heights is obtained. The technique has been applied to a test sample and nanoscale resolution has been achieved. The reported results are validated by a comparison with atomic force microscopy measurements.

  7. New airtight transfer box for SEM experiments: Application to lithium and sodium metals observation and analyses.

    Science.gov (United States)

    Stephant, Nicolas; Grissa, Rabeb; Guillou, Fanch; Bretaudeau, Mickaël; Borjon-Piron, Yann; Guillet, Jacques; Moreau, Philippe

    2018-04-18

    The surface of some materials reacts very quickly on contact with air, either because it is oxidized or because it gets humidity from the air. For the sake of original surface observation by scanning electron microscopy (SEM), we conceived an airtight transfer box to keep the samples under vacuum from the place of manufacturing to the SEM chamber. This object is designed to fit in all the models of SEM including those provided with an airlock chamber. The design is voluntarily simplified to allow the manufacturing of the object by a standard mechanical workshop. The transfer box can be easily opened by gravity inside the SEM and allows the preservation of the best vacuum inside, before opening. SEM images and energy dispersive spectroscopy (EDX) analyses of metallic lithium and sodium samples are presented prior and after exposure to the air. X-ray Photoelectron Spectroscopy (XPS) analyses of all samples are also discussed in order to investigate the chemical environments of the detected elements. Copyright © 2018 Elsevier Ltd. All rights reserved.

  8. Seasonal AVS-SEM relationship in sediments and potential bioavailability of metals in industrialized estuary, southeastern Brazil.

    Science.gov (United States)

    Nizoli, Erico Casare; Luiz-Silva, Wanilson

    2012-04-01

    In anoxic sediments, as those found in estuaries, the mobility of metals can be controlled by the formation of stable sulfide complexes. The potential bioavailability of a metal can then be predicted on the basis of the acid volatile sulfide (AVS) and simultaneously extracted metals (SEM) criterion. Distributions of AVS and SEM (Hg, Cu, Pb, Cd, Zn, and Ni) along the sediment profiles were determined seasonally for three rivers that constitute the Santos-Cubatão estuarine system (SE Brazil), which is located in one of the most industrialized areas of Latin America. AVS and SEM concentrations varied significantly, from 0.04 to 31.9 μmol g(-1) and 0.086-6.659 μmol g(-1), respectively. The highest AVS levels in sediments were detected in the winter, whereas high SEM values predominated in the summer. Considering SEM-AVS molar differences as a parameter to evaluate potential bioavailability, sediments nearest to the industrial area represent higher risk to biota, especially during the summer. It is due to relatively low AVS values and not necessarily high concentrations of metals.

  9. GammaSem Proceedings. A Nordic seminar for users of gamma spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Straalberg, E. (ed.) (Institute for Energy Technolgy (Norway)); Berg, K. (National Institute of Radiation Protection (Denmark)); Dowdall, M. (Norwegian Radiation Protection Authority (Norway)) (and others)

    2010-11-15

    The project GammaSem was proposed to the NKS in 2008. The aim of the project was to arrange two seminars for users of gamma spectrometry, in 2009 and 2010. The seminars were meant to provide a forum for discussions and sharing of information on practical issues concerning gamma spectrometry and initiate a network of gamma spectrometry users in the Nordic countries. Such a Nordic network should strengthen the collaboration between laboratories and improve all participants' competence in practical gamma spectrometry. Both seminars' focus was practical challenges met by the users themselves, rather than theoretical matters. Scientists and users of gamma spectrometry from all five Nordic countries were invited to the seminar, as well as scientist from the Baltic countries. A total of 65 people signed up for GammaSem 2010; representing 30 different universities, commercial companies, research institutes and authorities. The working group concept as presented at last year's GammaSem, has not worked out as intended. The reason for this is probably because most of the laboratories that signed up to join the working groups, signed up because they wanted to learn more about the different subjects. In combination with the fact that no funding was made available for the working groups, it was difficult to establish goals on what to achieve. None of the working groups applied for funding from the NKS (or elsewhere) to establish separate projects. There is a big need for more cooperation and for training within the field of gamma spectrometry. This fact has been proved through these two seminars, both by the many different topics that have been discussed, but also by the huge interest for participating in the suggested series of workshop. The GammaSem seminars have thus provided a much welcomed starting point for a broader Nordic collaboration. (Author)

  10. GammaSem Proceedings. A Nordic seminar for users of gamma spectrometry

    International Nuclear Information System (INIS)

    Straelberg, E.; Berg, K.; Dowdall, M.

    2010-11-01

    The project GammaSem was proposed to the NKS in 2008. The aim of the project was to arrange two seminars for users of gamma spectrometry, in 2009 and 2010. The seminars were meant to provide a forum for discussions and sharing of information on practical issues concerning gamma spectrometry and initiate a network of gamma spectrometry users in the Nordic countries. Such a Nordic network should strengthen the collaboration between laboratories and improve all participants' competence in practical gamma spectrometry. Both seminars' focus was practical challenges met by the users themselves, rather than theoretical matters. Scientists and users of gamma spectrometry from all five Nordic countries were invited to the seminar, as well as scientist from the Baltic countries. A total of 65 people signed up for GammaSem 2010; representing 30 different universities, commercial companies, research institutes and authorities. The working group concept as presented at last year's GammaSem, has not worked out as intended. The reason for this is probably because most of the laboratories that signed up to join the working groups, signed up because they wanted to learn more about the different subjects. In combination with the fact that no funding was made available for the working groups, it was difficult to establish goals on what to achieve. None of the working groups applied for funding from the NKS (or elsewhere) to establish separate projects. There is a big need for more cooperation and for training within the field of gamma spectrometry. This fact has been proved through these two seminars, both by the many different topics that have been discussed, but also by the huge interest for participating in the suggested series of workshop. The GammaSem seminars have thus provided a much welcomed starting point for a broader Nordic collaboration. (Author)

  11. The effect of 17% EDTA and MTAD on smear layer removal and on erosion of root canal dentin when used as final rinse: An in vitro SEM study

    Directory of Open Access Journals (Sweden)

    Vishal A Mahajan

    2010-01-01

    Full Text Available Background: The aim of the present study was to evaluate and compare the ability of a mixture of tetracycline isomer, citric acid and detergent (MTAD and ethylene diamine tetra-acetic acid (EDTA in removing the smear layer along with their effects on peritubular and intertubular dentinal structures by scanning electron microscopic (SEM examination. Materials and Methods: Thirty recently extracted maxillary and mandibular single-rooted human teeth were divided into 3 groups and prepared to an apical size of 30. In Group 1, 2, and 3, MTAD, EDTA, and distilled water were used, respectively, as a final rinse solution to remove the smear layer. The specimens were subjected to SEM evaluation for the presence or absence of the smear layer and degree of erosion using a scoring system. Results: The result showed that MTAD shows better smear layer removing ability and does not significantly change the structure of dentinal tubules. Conclusion: MTAD is an efficient solution for the removal of the smear layer, especially in the apical third of root canals, and does not significantly change the structure of the dentinal tubules.

  12. Electronic structure and optical properties of (BeTen/(ZnSem superlattices

    Directory of Open Access Journals (Sweden)

    Caid M.

    2016-03-01

    Full Text Available The structural, electronic and optical properties of (BeTen/(ZnSem superlattices have been computationally evaluated for different configurations with m = n and m≠n using the full-potential linear muffin-tin method. The exchange and correlation potentials are treated by the local density approximation (LDA. The ground state properties of (BeTen/(ZnSem binary compounds are determined and compared with the available data. It is found that the superlattice band gaps vary depending on the layers used. The optical constants, including the dielectric function ε(ω, the refractive index n(ω and the refractivity R(ω, are calculated for radiation energies up to 35 eV.

  13. SEM and XPS study of layer-by-layer deposited polypyrrole thin films

    Science.gov (United States)

    Pigois-Landureau, E.; Nicolau, Y. F.; Delamar, M.

    1996-01-01

    Layer-by-layer deposition of thin films (a few nm) of polypyrrole was carried out on various substrates such as silver, platinum, electrochemically oxidized aluminum and pretreated glass. SEM micrographs showed that the deposited layers nucleate by an island-type mechanism on hydrated alumina and KOH-pretreated (hydrophilic) glass before forming a continuous film. However, continuous thin films are obtained on chromic acid pretreated (hydrophobic) glass and sputtered Ag or Pt on glass after only 3-4 deposition cycles. The mean deposition rate evaluated by XPS for the first deposition cycles on Ag and Pt is 3 and 4 nm/cycle, respectively, in agreement with previous gravimetric determinations on thicker films, proving the constancy of the deposition rate. The XPS study of the very thin films obtained by a few deposition cycles shows that the first polypyrrole layers are dedoped by hydroxydic (basic) substrate surfaces.

  14. Precise and economic FIB/SEM for CLEM: with 2 nm voxels through mitosis.

    Science.gov (United States)

    Luckner, Manja; Wanner, Gerhard

    2018-05-23

    A portfolio is presented documenting economic, high-resolution correlative focused ion beam scanning electron microscopy (FIB/SEM) in routine, comprising: (i) the use of custom-labeled slides and coverslips, (ii) embedding of cells in thin, or ultra-thin resin layers for correlative light and electron microscopy (CLEM) and (iii) the claim to reach the highest resolution possible with FIB/SEM in xyz. Regions of interest (ROIs) defined in light microscope (LM), can be relocated quickly and precisely in SEM. As proof of principle, HeLa cells were investigated in 3D context at all stages of the cell cycle, documenting ultrastructural changes during mitosis: nuclear envelope breakdown and reassembly, Golgi degradation and reconstitution and the formation of the midzone and midbody.

  15. Pulse electrochemical machining on Invar alloy: Optical microscopic/SEM and non-contact 3D measurement study of surface analyses

    International Nuclear Information System (INIS)

    Kim, S.H.; Choi, S.G.; Choi, W.K.; Yang, B.Y.; Lee, E.S.

    2014-01-01

    Highlights: • Invar alloy was electrochemically polished and then subjected to PECM (Pulse Electro Chemical Machining) in a mixture of NaCl, glycerin, and distilled water. • Optical microscopic/SEM and non-contact 3D measurement study of Invar surface analyses. • Analysis result shows that applied voltage and electrode shape are factors that affect the surface conditions. - Abstract: In this study, Invar alloy (Fe 63.5%, Ni 36.5%) was electrochemically polished by PECM (Pulse Electro Chemical Machining) in a mixture of NaCl, glycerin, and distilled water. A series of PECM experiments were carried out with different voltages and different electrode shapes, and then the surfaces of polished Invar alloy were investigated. The polished Invar alloy surfaces were investigated by optical microscope, scanning electron microscope (SEM), and non-contact 3D measurement (white light microscopes) and it was found that different applied voltages produced different surface characteristics on the Invar alloy surface because of the locally concentrated applied voltage on the Invar alloy surface. Moreover, we found that the shapes of electrode also have an effect on the surface characteristics on Invar alloy surface by influencing the applied voltage. These experimental findings provide fundamental knowledge for PECM of Invar alloy by surface analysis

  16. Surface ultrastructural (SEM) characteristics of oropharyngeal cavity of house sparrow (Passer domesticus).

    Science.gov (United States)

    Abumandour, Mohamed M A

    2018-06-01

    The focus of the present study is to provide a full morphological description of the oropharyngeal cavity of the house sparrow. The head of six birds was prepared for gross examination and by stereo and electron microscopy. The bifid lingual apex has multiple long, rostrally directed needle-like processes. The lateral border of the apex carries rostromedially directed needle-like processes. The dorsal lingual surface of the apex and body carries numerous caudomedially directed filiform papillae and many orifices of lingual salivary glands. The lingual body is divided into two parts: rostral and caudal. The caudal part is divided into two laterally elevated regions by a median groove, while the rostral part is bounded laterally by a rostrodorsally directed papillary row, which on SEM is formed from two rows. On SEM, the lingual root has many orifices of posterior salivary glands. The pharyngeal papillary row is located at the caudal border of the laryngeal mound, but this single papillary row is formed from two rows at SEM magnification. The laryngeal cleft continues caudally as a laryngeal fissure bounded by two longitudinal rows of caudally directed papillae; at high SEM magnification, this fissure is divided into two halves by a median ridge which carries caudally directed papillae on its posterior part. The choanal cleft proceeds rostrally by the median tubercle. There are a small number of orifices of palatine salivary glands. The morphological characters of the oropharyngeal cavity of the sparrow confirm its adaptation to surrounding environmental conditions and available food particles.

  17. 3D reconstruction and characterization of carbides in Ni-based high carbon alloy in a FIB-SEM system

    Energy Technology Data Exchange (ETDEWEB)

    Bala, Piotr [AGH Univ. of Science and Technology, Faculty of Metals Engineering and Industrial Computer Science, Krakow (Poland); AGH Univ. of Science and Technology, Academic Centre of Materials and Nanotechnology, Krakow (Poland); Tsyrulin, Katja; Jaksch, Heiner [Carl-Zeiss, Oberkochen (Germany); Stepien, Milena [AGH Univ. of Science and Technology, Academic Centre of Materials and Nanotechnology, Krakow (Poland)

    2015-07-15

    Dual beam focused ion beam scanning electron microscopes (FIB-SEMs) are well suited for characterizing micron and submicron size microstructural features in three dimensions throughout a serial-sectioning experiment. In this article, a FIB-SEM instrument was used to collect morphological, crystallographic, and chemical information for an Ni-Ta-Al-Cr alloy of high carbon content. The alloy has been designed to have excellent tribological properties at elevated temperatures. The morphology, spatial distribution, scale, and degree of interconnection of primary carbides in the Ni-Ta-Al-Cr-C alloy was assessed via serial sectioning in a casting cross-section. The 3D reconstructions showed that the primary carbides and dendrites were forming a dendrite surrounded by primary carbide network over the entire cross-section. Additionally, the morphology and spatial distribution of secondary carbides after heat treatment was determined.

  18. On the importance of FIB-SEM specific segmentation algorithms for porous media

    Energy Technology Data Exchange (ETDEWEB)

    Salzer, Martin, E-mail: martin.salzer@uni-ulm.de [Institute of Stochastics, Faculty of Mathematics and Economics, Ulm University, D-89069 Ulm (Germany); Thiele, Simon, E-mail: simon.thiele@imtek.uni-freiburg.de [Laboratory for MEMS Applications, IMTEK, Department of Microsystems Engineering, University of Freiburg, D-79110 Freiburg (Germany); Zengerle, Roland, E-mail: zengerle@imtek.uni-freiburg.de [Laboratory for MEMS Applications, IMTEK, Department of Microsystems Engineering, University of Freiburg, D-79110 Freiburg (Germany); Schmidt, Volker, E-mail: volker.schmidt@uni-ulm.de [Institute of Stochastics, Faculty of Mathematics and Economics, Ulm University, D-89069 Ulm (Germany)

    2014-09-15

    A new algorithmic approach to segmentation of highly porous three dimensional image data gained by focused ion beam tomography is described which extends the key-principle of local threshold backpropagation described in Salzer et al. (2012). The technique of focused ion beam tomography has shown to be capable of imaging the microstructure of functional materials. In order to perform a quantitative analysis on the corresponding microstructure a segmentation task needs to be performed. However, algorithmic segmentation of images obtained with focused ion beam tomography is a challenging problem for highly porous materials if filling the pore phase, e.g. with epoxy resin, is difficult. The gray intensities of individual voxels are not sufficient to determine the phase represented by them and usual thresholding methods are not applicable. We thus propose a new approach to segmentation that pays respect to the specifics of the imaging process of focused ion beam tomography. As an application of our approach, the segmentation of three dimensional images for a cathode material used in polymer electrolyte membrane fuel cells is discussed. We show that our approach preserves significantly more of the original nanostructure than a thresholding approach. - Highlights: • We describe a new approach to the segmentation of FIB-SEM images of porous media. • The first and last occurrences of structures are detected by analysing the z-profiles. • The algorithm is validated by comparing it to a manual segmentation. • The new approach shows significantly less artifacts than a thresholding approach. • A structural analysis also shows improved results for the obtained microstructure.

  19. Estudo comparativo entre histerectomia abdominal e vaginal sem prolapso uterino

    OpenAIRE

    Lisboa, Vânio Cardoso

    2002-01-01

    Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Ciências da Saúde. Programa de Pós-Graduação em Ciências Médicas. Objetivo: Comparar a histerectomia abdominal e vaginal sem prolapso uterino.

  20. Sem-observation of developing plant organs using deep-frozen specimens

    NARCIS (Netherlands)

    NN,

    1982-01-01

    The SEM-observation of plant material normally requires dehydrated, dry specimens coated with carbon or metal. Unfortunately, the standard drying methods (including the critical-point-drying-technique) often cause shrinking and deformation of the specimen surface; therefore, SEMstudies on plant

  1. A ‘NanoSuit’ surface shield successfully protects organisms in high vacuum: observations on living organisms in an FE-SEM

    Science.gov (United States)

    Takaku, Yasuharu; Suzuki, Hiroshi; Ohta, Isao; Tsutsui, Takami; Matsumoto, Haruko; Shimomura, Masatsugu; Hariyama, Takahiko

    2015-01-01

    Although extremely useful for a wide range of investigations, the field emission scanning electron microscope (FE-SEM) has not allowed researchers to observe living organisms. However, we have recently reported that a simple surface modification consisting of a thin extra layer, termed ‘NanoSuit’, can keep organisms alive in the high vacuum (10−5 to 10−7 Pa) of the SEM. This paper further explores the protective properties of the NanoSuit surface-shield. We found that a NanoSuit formed with the optimum concentration of Tween 20 faithfully preserves the integrity of an organism's surface without interfering with SEM imaging. We also found that electrostatic charging was absent as long as the organisms were alive, even if they had not been coated with electrically conducting materials. This result suggests that living organisms possess their own electrical conductors and/or rely on certain properties of the surface to inhibit charging. The NanoSuit seems to prolong the charge-free condition and increase survival time under vacuum. These findings should encourage the development of more sophisticated observation methods for studying living organisms in an FE-SEM. PMID:25631998

  2. Marginal adaptation of a low-shrinkage silorane-based composite: A SEM-analysis

    DEFF Research Database (Denmark)

    Schmidt, Malene; Bindslev, Preben Hørsted; Poulsen, Sven

    2012-01-01

    shrinkage, has been marketed. Objective. To investigate whether reduced polymerization shrinkage improves the marginal adaptation of composite restorations. Material and methods. A total of 156 scanning electron microscopy (SEM) pictures (78 baseline, 78 follow-up) of the occlusal part of Class II......-casts of the restorations were used for SEM pictures at x 16 magnification. Pictures from baseline and follow-up (398 days, SD 29 days) were randomized and the examiner was blinded to the material and the age of the restoration. Stereologic measurements were used to calculate the length and the width of the marginal...

  3. Does your SEM really tell the truth?--How would you know? Part 1.

    Science.gov (United States)

    Postek, Michael T; Vladár, András E

    2013-01-01

    The scanning electron microscope (SEM) has gone through a tremendous evolution to become a critical tool for many and diverse scientific and industrial applications. The high resolution of the SEM is especially suited for both qualitative and quantitative applications especially for nanotechnology and nanomanufacturing. Quantitatively, measurement, or metrology is one of the main uses. It is likely that one of the first questions asked before even the first scanning electron micrograph was ever recorded was: "… how big is that?" The quality of that answer has improved a great deal over the past few years especially since today these instruments are being used as a primary measurement tool on semiconductor processing lines to monitor the manufacturing processes. The well-articulated needs of semiconductor production prompted a rapid evolution of the instrument and its capabilities. Over the past 20 years or so, instrument manufacturers, through substantial semiconductor industry investment of research and development (R&D) money, have vastly improved the performance of these instruments. All users have benefited from this investment, especially where quantitative measurements with an SEM are concerned. But, how good are these data? This article discusses some of the most important aspects and larger issues associated with imaging and measurements with the SEM that every user should know, and understand before any critical quantitative work is attempted. © Wiley Periodicals, Inc.

  4. Frames e dicionários onomasiológicos: uma proposta na interface entre semântica cognitiva e lexicografia

    Directory of Open Access Journals (Sweden)

    Diego Spader de Souza

    2017-09-01

    Full Text Available O objetivo do presente artigo é tecer algumas considerações iniciais a respeito de uma proposta teórico-metodológica situada na interface entre a Semântica Cognitiva e a Lexicografia. Tal proposta, atualmente sendo desenvolvida em tese de doutorado, busca a aproximação entre a teoria da Semântica de Frames, de Charles J. Fillmore, com a onomasiologia e com a produção de dicionários onomasiológicos. A onomasiologia, tema de grande importância para a Semântica Estrutural, pode ser abordada, sob nosso viés, a partir do conceito de frame semântico introduzido por Fillmore. O artigo apresenta uma discussão teórica, buscando mostrar o potencial da interface, bem como as formas através das quais a Semântica de Frames pode auxiliar a prática lexicográfica. Por se tratar de uma teoria semântica baseada em conhecimento enciclopédico, a Semântica de Frames oportuniza um modelo de dicionário onomasiológico que leva em consideração o papel da experiência e da estrutura conceptual na descrição semântica.

  5. Development of Focused Ion Beam technique for high speed steel 3D-SEM artefact fabrication

    DEFF Research Database (Denmark)

    Carli, Lorenzo; MacDonald, A. Nicole; De Chiffre, Leonardo

    2009-01-01

    The work describes preliminary manufacture by grinding, followed by machining on a Focused Ion Beam (FIB), of a high speed steel step artefact for 3D-SEM calibration. The FIB is coupled with a SEM in the so called dual beam instrument. The milling capabilities of FIB were checked from a qualitative...... point of view, using the dual beam SEM imaging, and quantitatively using a reference stylus instrument, to establish traceability. A triangular section having a depth of about 10 μm was machined, where the 50 μm curvature radius due to grinding was reduced to about 2 μm by FIB milling...

  6. Agency theory in a nonprofit organization Teoria de agência em uma organização sem fins lucrativos

    Directory of Open Access Journals (Sweden)

    Ivan Luiz Ecco

    2010-10-01

    Full Text Available The aim of this paper is to analyze, based on the agency theory, the existence of agency conflicts in management by results in a professional education nonprofit organization. For the program, the case study method was used in a nonprofit professional education organization, located in the state of Santa Catarina. The study examined the contract between the Headquarters of the Organization (which represents in this study, according to theory of agency, the principal and its School Units (representing, the agents to accomplish goals. The results show that the asymmetry of information and organizational culture are factors that contribute to the problem of agency and the determination of an optimal contract should take into consideration such situations. The main conclusion is that agency problems are also present in nonprofit organizations, even when an instrument for the management by results is implemented.O objetivo deste artigo é analisar, à luz da teoria da agência, a existência de conflitos de agência, em uma gestão por resultados, de uma organização educacional sem fins lucrativos. Para sua realização utilizou-se o método de estudo de caso em uma organização de educação profissional sem fins lucrativos, situada no Estado de Santa Catarina. O estudo analisou o contrato celebrado entre a Sede da Organização (que representa neste estudo, segundo a teoria da agência, o principal e suas Unidades Escolares (consideradas os agentes para o cumprimento de metas. Os resultados demonstram que a assimetria de informação e a cultura organizacional são fatores quecontribuem para que o problema de agência ocorra e a determinação de um contrato ótimo deveria levar em consideração tais situações. A principal conclusão é de que os problemas de agência também estão presentes nas organizações sem fins lucrativos, mesmo quando se implanta um instrumento para realizar a gestão por resultados.

  7. SEM-EDX analysis of an unknown "known" white powder found in a shipping container from Peru

    Science.gov (United States)

    Albright, Douglas C.

    2009-05-01

    In 2008, an unknown white powder was discovered spilled inside of a shipping container of whole kernel corn during an inspection by federal inspectors in the port of Baltimore, Maryland. The container was detained and quarantined while a sample of the powder was collected and sent to a federal laboratory where it was screened using chromatography for the presence of specific poisons and pesticides with negative results. Samples of the corn kernels and the white powder were forwarded to the Food and Drug Administration, Forensic Chemistry Center for further analysis. Stereoscopic Light Microscopy (SLM), Scanning Electron Microscopy/Energy Dispersive X-ray Spectrometry (SEM/EDX), and Polarized Light Microscopy/Infrared Spectroscopy (PLM-IR) were used in the analysis of the kernels and the unknown powder. Based on the unique particle analysis by SLM and SEM as well as the detection of the presence of aluminum and phosphorous by EDX, the unknown was determined to be consistent with reacted aluminum phosphide (AlP). While commonly known in the agricultural industry, aluminum phosphide is relatively unknown in the forensic community. A history of the use and acute toxicity of this compound along with some very unique SEM/EDX analysis characteristics of aluminum phosphide will be discussed.

  8. High-performance serial block-face SEM of nonconductive biological samples enabled by focal gas injection-based charge compensation.

    Science.gov (United States)

    Deerinck, T J; Shone, T M; Bushong, E A; Ramachandra, R; Peltier, S T; Ellisman, M H

    2018-05-01

    A longstanding limitation of imaging with serial block-face scanning electron microscopy is specimen surface charging. This charging is largely due to the difficulties in making biological specimens and the resins in which they are embedded sufficiently conductive. Local accumulation of charge on the specimen surface can result in poor image quality and distortions. Even minor charging can lead to misalignments between sequential images of the block-face due to image jitter. Typically, variable-pressure SEM is used to reduce specimen charging, but this results in a significant reduction to spatial resolution, signal-to-noise ratio and overall image quality. Here we show the development and application of a simple system that effectively mitigates specimen charging by using focal gas injection of nitrogen over the sample block-face during imaging. A standard gas injection valve is paired with a precisely positioned but retractable application nozzle, which is mechanically coupled to the reciprocating action of the serial block-face ultramicrotome. This system enables the application of nitrogen gas precisely over the block-face during imaging while allowing the specimen chamber to be maintained under high vacuum to maximise achievable SEM image resolution. The action of the ultramicrotome drives the nozzle retraction, automatically moving it away from the specimen area during the cutting cycle of the knife. The device described was added to a Gatan 3View system with minimal modifications, allowing high-resolution block-face imaging of even the most charge prone of epoxy-embedded biological samples. © 2017 The Authors Journal of Microscopy © 2017 Royal Microscopical Society.

  9. Comparative SEM analysis of nine F22 aligner cleaning strategies

    Directory of Open Access Journals (Sweden)

    Luca Lombardo

    2017-09-01

    Full Text Available Abstract Background The orthodontics industry has paid great attention to the aesthetics of orthodontic appliances, seeking to make them as invisible as possible. There are several advantages to clear aligner systems, including aesthetics, comfort, chairside time reduction, and the fact that they can be removed for meals and oral hygiene procedures. Methods Five patients were each given a series of F22 aligners, each to be worn for 14 days and nights, with the exception of meal and brushing times. Patients were instructed to clean each aligner using a prescribed strategy, and sections of the used aligners were observed under SEM. One grey-scale SEM image was saved per aligner in JPEG format with an 8-bit colour depth, and a total of 45 measurements on the grey scale (“Value” variable were made. This dataset was analysed statistically via repeated measures ANOVA to determine the effect of each of the nine cleaning strategies in each of the five patients. Results A statistically significant difference in the efficacy of the cleaning strategies was detected. Specifically, rinsing with water alone was significantly less efficacious, and a combination of cationic detergent solution and ultrasonication was significantly more efficacious than the other methods (p < 0.05. Conclusions Of the nine cleaning strategies examined, only that involving 5 min of ultrasonication at 42 k Hz combined with a 0.3% germicidal cationic detergent was observed to be statistically effective at removing the bacterial biofilm from the surface of F22 aligners.

  10. Continuous observation of cavity growth and coalescence by creep-fatigue tests in SEM

    International Nuclear Information System (INIS)

    Arai, Masayuki; Ogata, Takashi; Nitta, Akito

    1995-01-01

    Structural components operating at high temperatures in power plants are subjected to interaction of thermal fatigue and creep which results in creep-fatigue damage. In evaluating the life of those components, it is important to understand microscopic damage evolution under creep-fatigue conditions. In this study, static creep and creep-fatigue tests with tensile holdtime were conducted on SUS304 stainless steel by using a high-temperature fatigue machine combined with a scanning electron microscope (SEM), and cavity growth and coalescence behaviors on surface grain boundaries were observed continuously by the SEM. Quantitative analysis of creep cavity growth based on the observation was made for comparison with theoretical growth models. As a result, it was found that grain boundary cavities nucleate at random and grow preferentially on grain boundaries in a direction almost normal to the stress axis. Under the creep condition, the cavities grow monotonously on grain boundaries while they remain the elliptical shape. On the other hand, under the creep-fatigue condition the cavities grow with an effect of local strain distribution around the grain boundary due to cyclic loading and the micro cracks of one grain-boundary length were formed by coalescence of the cavities. Also, cavity nucleation and growth rates for creep-fatigue were more rapid than those for static creep and the constrained cavity growth model coincided well with the experimental data for creep. (author)

  11. TEM/SEM investigation of microstructural changes within the white etching area under rolling contact fatigue and 3-D crack reconstruction by focused ion beam

    International Nuclear Information System (INIS)

    Grabulov, A.; Ziese, U.; Zandbergen, H.W.

    2007-01-01

    The white etching area (WEA) surrounding the cracks formed under high-cycle rolling contact fatigue was investigated by transmission electron microscopy (TEM) and Dual Beam (scanning electron microscopy (SEM)/focused ion beam). SEM revealed the initiation of cracks formed around artificially introduced Al 2 O 3 inclusions in the model steel (composition similar to SAE 52100). TEM investigations showed a microstructural difference between the WEA (formation of nanocrystalline ferrite) and the steel matrix (tempered martensitic structure). A three-dimensional image of the crack reconstructed from ∼400 Dual Beam cross-section images is reported

  12. Establishing aeolian particulate 'fingerprints' in an airport environment using magnetic measurements and SEM/EDAX

    Science.gov (United States)

    Jones, Sue; Hoon, Stephen R.; Richardson, Nigel; Bennett, Michael

    2016-04-01

    investigate source attribution. The results indicate that the dusts collected from the various aircraft sources (i.e. engines, brakes and tyres) are significantly different in terms of magnetic mineral type and grain size. Furthermore, particulates deposited at different locations on the runway surface show significant differentiation in magnetic grain size and mineralogy which when compared with the results from the different aircraft sources suggest that they may relate to emissions from different sources at various stages of the take/off landing cycle. Results of SEM/EDAX analysis show that aircraft engine, brake and tyre dust particulates vary significantly in terms of morphology and chemical composition. All sources include respirable (sub 10 micron) particulates. Engine dusts are carbon and silicon rich dominated by angular particulates. They have a distinctive chemical composition including Chromium, Cobalt and Nickel. Tyre dusts are predominantly carbon based dominated by spherical particulates and a unique presence of Zinc. Brake dusts, carbon and oxygen dominated and trace metals, include sub-angular particulates but an absence of the characteristic engine and tyre dusts metals. By combining SEM/EDAX measurements and magnetic measurements we are establishing potential fingerprints for particulates from ground based air transport activities to enable identification of potential health hazards. This will help inform management plans for reduction of associated risks to the environment and health. References Bucko, M., Magiera, T., Pesonen, L., Janus, B. (2010) 'Magnetic, geochemical and microstructural characteristics of road dust on roadsides with different traffic volumes - Case study from Finland' Water, Air and Soil Pollution 209, pp. 295-306. Hunt, A., Jones, J. and Oldfield, F. (1984) 'Magnetic measurements and heavy metals in atmospheric particulates of anthropogenic origin' The Science of the Total Environment 33, 129-139. Jones, S., Richardson, N., Bennett, M

  13. SEM and XPS study of layer-by-layer deposited polypyrrole thin films

    International Nuclear Information System (INIS)

    Pigois-Landureau, E.; Nicolau, Y.F.; Delamar, M.

    1996-01-01

    Layer-by-layer deposition of thin films (a few nm) of polypyrrole was carried out on various substrates such as silver, platinum, electrochemically oxidized aluminum and pretreated glass. SEM micrographs showed that the deposited layers nucleate by an island-type mechanism on hydrated alumina and KOH-pretreated (hydrophilic) glass before forming a continuous film. However, continuous thin films are obtained on chromic acid pretreated (hydrophobic) glass and sputtered Ag or Pt on glass after only 3 endash 4 deposition cycles. The mean deposition rate evaluated by XPS for the first deposition cycles on Ag and Pt is 3 and 4 nm/cycle, respectively, in agreement with previous gravimetric determinations on thicker films, proving the constancy of the deposition rate. The XPS study of the very thin films obtained by a few deposition cycles shows that the first polypyrrole layers are dedoped by hydroxydic (basic) substrate surfaces. copyright 1996 American Institute of Physics

  14. A time-resolved current method and TSC under vacuum conditions of SEM: Trapping and detrapping processes in thermal aged XLPE insulation cables

    Science.gov (United States)

    Boukezzi, L.; Rondot, S.; Jbara, O.; Boubakeur, A.

    2017-03-01

    Thermal aging of cross-linked polyethylene (XLPE) can cause serious concerns in the safety operation in high voltage system. To get a more detailed picture on the effect of thermal aging on the trapping and detrapping process of XLPE in the melting temperature range, Thermal Stimulated Current (TSC) have been implemented in a Scanning Electron Microscope (SEM) with a specific arrangement. The XLPE specimens are molded and aged at two temperatures (120 °C and 140 °C) situated close to the melting temperature of the material. The use of SEM allows us to measure both leakage and displacement currents induced in samples under electron irradiation. The first represents the conduction process of XLPE and the second gives information on the trapping of charges in the bulk of the material. TSC associated to the SEM leads to show spectra of XLPE discharge under thermal stimulation using both currents measured after electron irradiation. It was found that leakage current in the charging process may be related to the physical defects resulting in crystallinity variation under thermal aging. However the trapped charge can be affected by the carbonyl groups resulting from the thermo-oxidation degradation and the disorder in the material. It is evidenced from the TSC spectra of unaged XLPE that there is no detrapping charge under heat stimulation. Whereas the presence of peaks in the TSC spectra of thermally aged samples indicates that there is some amount of trapped charge released by heating. The detrapping behavior of aged XLPE is supported by the supposition of the existence of two trap levels: shallow traps and deep traps. Overall, physico-chemical reactions under thermal aging at high temperatures leads to the enhancement of shallow traps density and changes in range of traps depth. These changes induce degradation of electrical properties of XLPE.

  15. Strategic Enrolment Management (SEM) in Self-Financed Higher Education of Hong Kong: Evaluation and Measurement

    Science.gov (United States)

    Ng, Peggy; Galbraith, Craig

    2016-01-01

    The purpose of this study is to examine how the dimensions of strategic enrolment management (SEM) tie to the success metrics in the area of enrolment, retention and graduation from senior and programme management perspectives of a self-financed institution in Hong Kong. The literature on SEM has demonstrated that managing enrolment is a global…

  16. Cuticle scale measurement of animal fibers by SEM and AFM

    CSIR Research Space (South Africa)

    Notayi, M

    2013-12-01

    Full Text Available -1 51st Microscopy Society of Southern Africa (MSSA) Conference, Farm Inn, Pretoria, 3-6 December 2013 Cuticle scale measurement of animal fibers by SEM and AFM Notayi M, Engelbrechts JAA, Lee ME, Goosen WE, Hunter L and Botha AF Abstract...

  17. A novel approach to TEM preparation with a (7-axis stage) triple-beam FIB-SEM system

    Science.gov (United States)

    Clarke, Jamil J.

    2015-10-01

    Preparation of lamellae from bulk to grid for Cs-corrected Transmission Electron Microscope (TEM) observation has mostly become routine work on the latest FIB-SEM systems, with standardized techniques that often are left to automation for the initial steps. The finalization of lamellae however, has mostly become, non-routine, non-repeatable and often driven by user experience level in most cases to produce high quality damage-less cross section. Materials processing of the latest technologies, with ever-shrinking Nano-sized structures pose challenges to modern FIB-SEM systems. This can often lead to specialized techniques and hyper-specific functions for producing ultra-thin high quality lamellae that often are lab specific, preventing practical use of such techniques across multiple materials and applications. Several factors that should be incorporated in processing fine structured materials successfully include how the use of electron and ion scan conditions can affect a thin section during ion milling, the type of ion species applied for material processing during the finalization of lamellae with gallium ions or of a smaller ion species type such as Ar/Xe, sample orientation of the lamella during the thinning process which is linked to ion beam incident angle as a direct relationship in the creation of waterfall effects or curtain effects, and how software can be employed to aid in the reduction of these artifacts with reproducible results regardless of FIB-SEM experience for site-specific lift outs. A traditional TEM preparation was performed of a fine structure specimen in pursuit of a process technique to produce a high quality TEM lamella which would address all of the factors mentioned. These new capabilities have been refined and improved upon during the FIB-SEM design and development stages with an end result of a new approach that yields an improvement in quality by the reduction of common ion milling artifacts such as curtain effects, amorphous

  18. Valores e motivações para responder sem preconceito frente a homossexuais

    Directory of Open Access Journals (Sweden)

    Valdiney Veloso Gouveia

    2012-06-01

    Full Text Available Neste artigo se objetivou conhecer os correlatos valorativos das motivações interna e externa para encarar sem preconceito a homossexualidade. Foram realizados dois estudos. No Estudo 1 participaram 234 pessoas de João Pessoa, com idade média de 26 anos, que responderam à Escala de Motivações para Responder sem Precocietos Frente a Gays e ao Questionário dos Valores Básicos e perguntas demográficas. A motivação interna se correlacionou com as subfunções suprapessoal (+ e normativa (-, enquanto a motivação externa o fez com existência (+ e normativa (+. O Estudo 2 reuniu 202 pessoas da mesma população, com idade média de 25 anos. Elas responderam os mesmos instrumentos, tendo as lésbicas como grupo-alvo. As motivações interna e externa se correlacionaram com a subfunção normativa (- e +, respectivamente. Concluindo, os valores predisseram adequadamente as motivações para olhar sem preconceito a homossexualidade e os achados foram discutidos a partir do modelo dual de valores.

  19. The innovation of cryo-SEM freeze-fracturing methodology demonstrated on high pressure frozen biofilm.

    Science.gov (United States)

    Hrubanova, Kamila; Nebesarova, Jana; Ruzicka, Filip; Krzyzanek, Vladislav

    2018-04-22

    In this study we present an innovative method for the preparation of fully hydrated samples of microbial biofilms of cultures Staphylococcus epidermidis, Candida parapsilosis and Candida albicans. Cryo-scanning electron microscopy (cryo-SEM) and high-pressure freezing (HPF) rank among cutting edge techniques in the electron microscopy of hydrated samples such as biofilms. However, the combination of these techniques is not always easily applicable. Therefore, we present a method of combining high-pressure freezing using EM PACT2 (Leica Microsystems), which fixes hydrated samples on small sapphire discs, with a high resolution SEM equipped with the widely used cryo-preparation system ALTO 2500 (Gatan). Using a holder developed in house, a freeze-fracturing technique was applied to image and investigate microbial cultures cultivated on the sapphire discs. In our experiments, we focused on the ultrastructure of the extracellular matrix produced during cultivation and the relationships among microbial cells in the biofilm. The main goal of our investigations was the detailed visualization of areas of the biofilm where the microbial cells adhere to the substrate/surface. We show the feasibility of this technique, which is clearly demonstrated in experiments with various freeze-etching times. Copyright © 2018 Elsevier Ltd. All rights reserved.

  20. Cryo-FIB SEM for Characterization of the Structure of Fish Oil Emulsions

    DEFF Research Database (Denmark)

    Jensen, Louise Helene Søgaard; Horn, Anna Frisenfeldt; Jacobsen, Charlotte

    2011-01-01

    layers. The emulsion fractures are random and impossible to control when using freeze-fracture cryo-SEM. We have previously shown that some types of emulsifiers tend to break along the interface layer, while others cause the fractures to be perpendicular to the interface layer [3]. To control the field...... of view more specifically and to ensure the access to the desired part of the sample, we propose now the use of cryo-FIB SEM. This method allows us to access the interface layers as needed, see figure 1. Emulsions with high oil content, i.e. 70%, and relatively large oil droplets, i.e. μm range, have been...

  1. Corrigendum to: Bayesian evaluation of informative hypotheses in SEM using Mplus

    NARCIS (Netherlands)

    van de Schoot, R.; Verhoeven, Marjolein; Hoijtink, H.

    2014-01-01

    This paper corrects: van de Schoot, R., Verhoeven, M., & Hoijtink, H. (2013). Bayesian evaluation ofinformative hypotheses in SEM using Mplus: A black bear story. EuropeanJournal of Developmental Psychology, 10, 81 –98.

  2. A measuring system for mechanical characterization of thin films based on a compact in situ micro-tensile tester and SEM moiré method

    International Nuclear Information System (INIS)

    Li, Yanjie; Tang, Minjin; Xie, Huimin; Zhu, Ronghua; Luo, Qiang; Gu, Changzhi

    2013-01-01

    A measuring system for mechanical characterization of thin films based on a compact in situ micro-tensile tester and scanning electron microscope (SEM) moiré method is proposed. The load is exerted by the tensile tester and the full field strain is measured by SEM moiré method. The configuration of the tensile tester and the principle of SEM moiré method are introduced. In the tensile tester, a lever structure is designed to amplify the displacement imposed by lead–zirconate–titanate (PZT) actuator. The SEM moiré method is applied to measure the strain of the thin film, including both the average strain in the gage section and the local strain distribution at a specific region. As an application, the measuring system is applied to characterize the mechanical property of the free-standing aluminum thin film. The experimental results demonstrate the feasibility of the system and its good application potential for mechanical behavior analysis of film-like materials. (paper)

  3. Effect of cement dosage and early curing towards Kuala Perlis dredged marine sediments: a ɛv - σv and SEM-EDX approach

    Science.gov (United States)

    Syakeera Nordin, Nurul; Chan, Chee-Ming

    2017-11-01

    Cement is the primary material used in solidifying the soft soils. This material was applied in solidifying Kuala Perlis dredged marine sediments (DMS). These unwanted sediments are classified as high plasticity silt, MH with 3.36 LL of wc/LL value. At dosage 10 and 20 % of cemented-DMS and 3 days curing time, compression curve results shows the settlement criteria were enhanced than the natural DMS. Unfortunately, the settlement criteria are not complies with the permissible settlement limit and applicable pressure. The formation of cementing compounds appears in the SEM micrograph for 10 and 20 % of cemented-DMS. EDX analysis shows the Ca:Si ratio were increased for cemented-DMS due to the formation of C-S-H gel.

  4. Encontros e desvios nos semáforos: investigando artistas em Florianópolis/SC

    Directory of Open Access Journals (Sweden)

    Beatriz S. Albino

    2013-03-01

    Full Text Available http://dx.doi.org/10.5007/2178-4582.2012v46n2p469 A ideia de investigar artistas que atuam em semáforos de Florianópolis/SC teve sua origem em um estranhamento que nos fez vê-los na forma de uma alteridade radical. A pesquisa etnográfica permitiu descobrir relações simbólicas de pertencimentoe de desvio entre os artistas, destacando-se a figura de um “outro”, próximo, mas perigoso, que partilha simbolicamente os semáforos: o micróbio, estrangeiro que faria confundir o artista com a marginalidade. No semáforo ocorre também, no entanto, a reafirmação, por meio das performances dos artistas, do que deles é esperado: a comicidade, o virtuosismo, a aparência adequada.

  5. Afasia global sem hemiparesia: relato de caso

    OpenAIRE

    SILVA,MARCUS TULIUS TEIXEIRA DA; CAVALCANTI,JOSÉ LUÍS DE SÁ; MOREIRA,DENISE MADEIRA

    2000-01-01

    Afasia global geralmente é acompanhada por hemiparesia direita devido à extensão da lesão subjacente. Recentemente têm sido registrados na literatura casos em que tal síndrome ou não se acompanha do déficit motor ou este é apenas transitório, sendo esta condição conhecida como afasia global sem hemiparesia (AGSH). Relatamos caso de AGSH devido a infarto cerebral embólico cardiogênico, corroborando a tese de que esta condição pode ter valor preditivo para o diagnóstico de infartos embólicos....

  6. Repetitive Observation of Coniferous Samples in ESEM and SEM

    Czech Academy of Sciences Publication Activity Database

    Tihlaříková, Eva; Neděla, Vilém

    2015-01-01

    Roč. 21, S3 (2015), s. 1695-1696 ISSN 1431-9276 R&D Projects: GA ČR(CZ) GA14-22777S; GA MŠk(CZ) LO1212; GA MŠk ED0017/01/01 Institutional support: RVO:68081731 Keywords : SEM * ESEM * biological samples * repetitive observation Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 1.730, year: 2015

  7. Mapping the Complex Morphology of Cell Interactions with Nanowire Substrates Using FIB-SEM

    DEFF Research Database (Denmark)

    Wierzbicki, Rafal; Købler, Carsten; Jensen, Mikkel Ravn Boye

    2013-01-01

    Using high resolution focused ion beam scanning electron microscopy (FIB-SEM) we study the details of cell-nanostructure interactions using serial block face imaging. 3T3 Fibroblast cellular monolayers are cultured on flat glass as a control surface and on two types of nanostructured scaffold...... substrates made from silicon black (Nanograss) with low- and high nanowire density. After culturing for 72 hours the cells were fixed, heavy metal stained, embedded in resin, and processed with FIB-SEM block face imaging without removing the substrate. The sample preparation procedure, image acquisition...

  8. SEM and EBSD characterization of bi-layered functionally graded hard metal composites; REM- und EBSD-Charakterisierung von zweischichtigen, funktionell abgestuften Metallverbundwerkstoffen

    Energy Technology Data Exchange (ETDEWEB)

    Prat, Orlando; Sanhueza, Felipe [Univ. de Concepcion (Chile). Dept. de Ingenieria de Materiales; Suarez, Sebastian [Saarland Univ., Saarbruecken (Germany). Chair of Functional Materials; Garcia, Jose [AB Sandvik Coromant R and D, Stockholm (Sweden)

    2016-11-15

    WC-Co bi-layer functionally graded composites were produced by powder metallurgy techniques. The influence of WC particle size and the grain growth inhibitor on the formation of the functionally graded composite was investigated. SEM images show that all sintered samples present a graded microstructure after sintering, with two side regions of extra-coarse and coarse WC-Co and a clear, dense interface without defects or other phases. EBSD results showed a change of WC particle size depending on the processing and the addition of Mo{sub 2}C. Cobalt binder distribution corresponds to WC particle size. Hardness values correlate to WC particle size and binder content. It is shown that tailored hardness/toughness can be produced by adjusting the WC particle size and binder content on both sides of the bi-layer composite.

  9. Evaluating the oxidation of shale during hydraulic fracturing using SEM-EDS and spectrocolorimetry

    Science.gov (United States)

    Tan, X. Y.; Nakashima, S.

    2017-12-01

    During hydraulic fracturing (fracking) for shale gas/oil extraction, oxygen is introduced into deep oxygen-poor environments, and Fe2+-bearing minerals in rocks can be oxidized thus leading to the degradation of rock quality. Akita diatomaceous shale is considered to be one of the source rocks for oil and gas fields in northwestern Japan. Outcrops of Akita shale often show presence of jarosite (Fe sulfate: yellow) and/or goethite (Fe hydroxide: brown to orange) as oxidation products of pyrite (FeS2). Several series of oxidation experiments of Akita shale under dry, humid, and wet conditions were conducted at temperatures of around 30 oC and 50oC for 30-40 days. Portable color spectro-colorimeters were used to monitor color changes of the rock surfaces every hour. SEM-EDS, UV-Vis, and Raman spectroscopic analyses were performed on the rock sample surface to examine the chemical and mineralogical compositions of Akita shale before and after the dry, humid, and wet experiments. In SEM-EDS analyses before the humid experiment, Fe and S containing phases show their atomic ratio close to 1:2 indicating that this is pyrite (FeS2). After the experiment, the ratio changed to around 1:1 suggesting a conversion from pyrite (FeS2) to mackinawite-like mineral (FeS). In addition, the formation of Ca sulfate (possibly gypsum: CaSO4.2H2O) and goethite-like Fe hydroxide were identified which were not present initially. Therefore, oxidation pathways of iron sulfide (pyrite: FeS2) via FeS to sulfate is confirmed by our humid experiments around 30oC on Akita shale. These oxidation processes might occur during the fracking of shale within relatively short time periods associated with precipitation of sulfates and hydroxides. Therefore, further studies are needed for their effects on rock properties and gas/oil production.

  10. Continuous time modeling of panel data by means of SEM

    NARCIS (Netherlands)

    Oud, J.H.L.; Delsing, M.J.M.H.; Montfort, C.A.G.M.; Oud, J.H.L.; Satorra, A.

    2010-01-01

    After a brief history of continuous time modeling and its implementation in panel analysis by means of structural equation modeling (SEM), the problems of discrete time modeling are discussed in detail. This is done by means of the popular cross-lagged panel design. Next, the exact discrete model

  11. DSS1/Sem1, a multifunctional and intrinsically disordered protein

    DEFF Research Database (Denmark)

    Kragelund, Birthe Brandt; Schenstrøm, Signe Marie; Rebula, Caio A.

    2016-01-01

    DSS1/Sem1 is a versatile intrinsically disordered protein. Besides being a bona fide subunit of the 26S proteasome, DSS1 associates with other protein complexes, including BRCA2-RPA, involved in homologous recombination; the Csn12-Thp3 complex, involved in RNA splicing; the integrator, involved...

  12. Sediment quality assessment in a coastal lagoon (Ravenna, NE Italy) based on SEM-AVS and sequential extraction procedure.

    Science.gov (United States)

    Pignotti, Emanuela; Guerra, Roberta; Covelli, Stefano; Fabbri, Elena; Dinelli, Enrico

    2018-09-01

    Sediments from the Pialassa Piomboni coastal lagoon (NE Italy) were studied to assess the degree of contamination and ecological risk related to trace metals by combining a geochemical characterization of bulk sediments with the assessment of the bioavailable forms of trace metals. With this purpose, sediment contamination (Cd, Cu, Hg, Ni, Pb, and Zn) was assessed by Enrichment Factors (EFs), and potential bioavailability by the Simultaneously Extracted Metals and Acid Volatile Sulfides (SEM-AVS) approach (Cd, Cu, Ni, Pb, and Zn), and by Sequential Extraction Procedure (Co, Cr, Cu, Ni, Pb, and Zn). On average, Cr and Ni exhibited no contamination (EF ≤1.5), and a predominance in the residual fraction of the sediment, indicating natural origin for these metals. Cu, Pb and Zn displayed a local contamination, which resulted in a higher proportion of Cu bound to the reducible and oxidizable fractions (~30% and ~40% as median, respectively), and Pb mostly associated with the reducible phase (~60% as median). Hence, Cu and Pb could be mobilized when environmental conditions become reducing or oxidizing. Zn resulted mainly partitioned into the reducible and residual fractions (~50% as median, in both fractions). The Risk Assessment Code (RAC) indicated that approximately 30% of samples had >10% of total Zn weakly bound to the sediment, suggesting a medium risk of exposure for aquatic organisms. RAC results were consistent with the ∑SEM-AVS findings, pointing to possible adverse effects for aquatic biota in ~30% of samples, with Zn mostly accounting for the total metal bioavailability. Hg showed a moderate to very severe enrichment, indicating that a substantial amount of this metal derives from anthropogenic sources and may pose adverse effects on the aquatic biota of the Pialassa Piomboni lagoon. Copyright © 2018 Elsevier B.V. All rights reserved.

  13. Analysis of 19th century ceramic fragments excavated from Pirenópolis (Goiás, Brazil) using FT-IR, Raman, XRF and SEM

    Science.gov (United States)

    Freitas, Renato P.; Coelho, Filipe A.; Felix, Valter S.; Pereira, Marcelo O.; de Souza, Marcos André Torres; Anjos, Marcelino J.

    2018-03-01

    This study used Raman, FT-IR and XRF spectroscopy and SEM to analyze ceramic fragments dating from the 19th century, excavated from an old farm in the municipality of Pirenópolis, Goiás, Brazil. The results show that the samples were produced in an open oven at a firing temperature below 500 °C, using raw materials including kaolinite, hematite, magnetite, quartz, microcline, albite, anhydrite, calcite, illite, orthoclase and MnO2. Although the analyses showed similarities in the manufacturing process and the presence of many minerals was common in all samples, multivariate statistical methods (PCA) allowed a more detailed assessment of similarities and differences in the mineral composition of the samples. The results of the PCA showed that the samples excavated in one of the slave quarters (senzalas) group with those excavated at the farmhouse, where the landowner lived, which indicates a paternalistic attitude towards captives, including the sharing of ceramic materials of everyday use.

  14. Smear layer removal capacity of disinfectant solutions used with and without EDTA for the irrigation of canals: a SEM study

    Directory of Open Access Journals (Sweden)

    Menezes Ana Carolina Silveira Cardoso de

    2003-01-01

    Full Text Available The purpose of this study was to carry out a scanning electron microscopic (SEM analysis of the cleaning qualities and smear layer removal from root canal walls, instrumented and irrigated with 2.5% NaOCl, 2.0% chlorhexidine and saline solutions. Fifty extracted teeth were used in this study. All teeth were radiographed to determine the existence of a single canal. The crowns were cut at the cervical limit and the root canals were instrumented with K-type files up to size 45. During root canal preparation, irrigations were made with the different solutions being evaluated: Group 1: 2.5% NaOCl (10 roots; Group 2: 2.5% NaOCl and 17% EDTA for 2 minute (10 roots; Group 3: 2.0% chlorhexidine (10 roots; Group 4: 2.0% chlorhexidine and 17% EDTA for 2 minutes (10 roots; Group 5: saline solution (5 roots; Group 6: saline solution and 17% EDTA for 2 minutes (5 roots. After instrumentation, the canals were irrigated with each one of the solutions and the roots were cut in the buccolingual direction for SEM analysis, at the cervical, middle and apical thirds, to ascertain the presence or absence of smear layer and debris. SEM analysis was performed by three calibrated examiners and scores were submitted to Kruskal-Wallis test at the significance level of p = 5%. Results showed that the use of 17% EDTA decreased the smear layer significantly (p < 0.05 for all evaluated solutions in all thirds. When EDTA was not used, a significantly higher quantity of smear layer on the apical third was observed only in the NaOCl groups. The use of 17% EDTA was significant for debris removal except for the chlorhexidine groups. The following conclusion could be drawn: the use of 17% EDTA was necessary to enhance cleanness of the root canals.

  15. Assessment of engineered surfaces roughness by high-resolution 3D SEM photogrammetry.

    Science.gov (United States)

    Gontard, L C; López-Castro, J D; González-Rovira, L; Vázquez-Martínez, J M; Varela-Feria, F M; Marcos, M; Calvino, J J

    2017-06-01

    We describe a methodology to obtain three-dimensional models of engineered surfaces using scanning electron microscopy and multi-view photogrammetry (3DSEM). For the reconstruction of the 3D models of the surfaces we used freeware available in the cloud. The method was applied to study the surface roughness of metallic samples patterned with parallel grooves by means of laser. The results are compared with measurements obtained using stylus profilometry (PR) and SEM stereo-photogrammetry (SP). The application of 3DSEM is more time demanding than PR or SP, but it provides a more accurate representation of the surfaces. The results obtained with the three techniques are compared by investigating the influence of sampling step on roughness parameters. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. SEM method for direct visual tracking of nanoscale morphological changes of platinum based electrocatalysts on fixed locations upon electrochemical or thermal treatments.

    Science.gov (United States)

    Zorko, Milena; Jozinović, Barbara; Bele, Marjan; Hodnik, Nejc; Gaberšček, Miran

    2014-05-01

    A general method for tracking morphological surface changes on a nanometer scale with scanning electron microscopy (SEM) is introduced. We exemplify the usefulness of the method by showing consecutive SEM images of an identical location before and after the electrochemical and thermal treatments of platinum-based nanoparticles deposited on a high surface area carbon. Observations reveal an insight into platinum based catalyst degradation occurring during potential cycling treatment. The presence of chloride clearly increases the rate of degradation. At these conditions the dominant degradation mechanism seems to be the platinum dissolution with some subsequent redeposition on the top of the catalyst film. By contrast, at the temperature of 60°C, under potentiostatic conditions some carbon corrosion and particle aggregation was observed. Temperature treatment simulating the annealing step of the synthesis reveals sintering of small platinum based composite aggregates into uniform spherical particles. The method provides a direct proof of induced surface phenomena occurring on a chosen location without the usual statistical uncertainty in usual, random SEM observations across relatively large surface areas. Copyright © 2014 Elsevier B.V. All rights reserved.

  17. Testing Delays Resulting in Increased Identification Accuracy in Line-Ups and Show-Ups.

    Science.gov (United States)

    Dekle, Dawn J.

    1997-01-01

    Investigated time delays (immediate, two-three days, one week) between viewing a staged theft and attempting an eyewitness identification. Compared lineups to one-person showups in a laboratory analogue involving 412 subjects. Results show that across all time delays, participants maintained a higher identification accuracy with the showup…

  18. Super-resolution for asymmetric resolution of FIB-SEM 3D imaging using AI with deep learning.

    Science.gov (United States)

    Hagita, Katsumi; Higuchi, Takeshi; Jinnai, Hiroshi

    2018-04-12

    Scanning electron microscopy equipped with a focused ion beam (FIB-SEM) is a promising three-dimensional (3D) imaging technique for nano- and meso-scale morphologies. In FIB-SEM, the specimen surface is stripped by an ion beam and imaged by an SEM installed orthogonally to the FIB. The lateral resolution is governed by the SEM, while the depth resolution, i.e., the FIB milling direction, is determined by the thickness of the stripped thin layer. In most cases, the lateral resolution is superior to the depth resolution; hence, asymmetric resolution is generated in the 3D image. Here, we propose a new approach based on an image-processing or deep-learning-based method for super-resolution of 3D images with such asymmetric resolution, so as to restore the depth resolution to achieve symmetric resolution. The deep-learning-based method learns from high-resolution sub-images obtained via SEM and recovers low-resolution sub-images parallel to the FIB milling direction. The 3D morphologies of polymeric nano-composites are used as test images, which are subjected to the deep-learning-based method as well as conventional methods. We find that the former yields superior restoration, particularly as the asymmetric resolution is increased. Our super-resolution approach for images having asymmetric resolution enables observation time reduction.

  19. Consideraciones sobre la adquisición del adjetivo y su semántica

    OpenAIRE

    Millán Garrido, Mª del Rosario

    1988-01-01

    Con este trabajo se intenta profundizar en el adjetivo con un criterio semántico pero al ser difícil deslindarlo de sus estudios léxico y sintáctico, no vamos a excluir de él estos aspectos que se expondrán de forma breve y que nos ayudarán a sacar conclusiones más completas. Aunque la semántica ha ocupado la parte central de la investigación, ha tenido como apoyo el análisis léxico, reflejado en las gráficas, y un estudio sintáctico** previo.

  20. Automated SEM Modal Analysis Applied to the Diogenites

    Science.gov (United States)

    Bowman, L. E.; Spilde, M. N.; Papike, James J.

    1996-01-01

    Analysis of volume proportions of minerals, or modal analysis, is routinely accomplished by point counting on an optical microscope, but the process, particularly on brecciated samples such as the diogenite meteorites, is tedious and prone to error by misidentification of very small fragments, which may make up a significant volume of the sample. Precise volume percentage data can be gathered on a scanning electron microscope (SEM) utilizing digital imaging and an energy dispersive spectrometer (EDS). This form of automated phase analysis reduces error, and at the same time provides more information than could be gathered using simple point counting alone, such as particle morphology statistics and chemical analyses. We have previously studied major, minor, and trace-element chemistry of orthopyroxene from a suite of diogenites. This abstract describes the method applied to determine the modes on this same suite of meteorites and the results of that research. The modal abundances thus determined add additional information on the petrogenesis of the diogenites. In addition, low-abundance phases such as spinels were located for further analysis by this method.

  1. A combined SEM, CV and EIS study of multi-layered porous ceramic reactors for flue gas purification

    DEFF Research Database (Denmark)

    He, Zeming; Andersen, Kjeld Bøhm; Nygaard, Frederik Berg

    2013-01-01

    The effect of sintering temperature of 12-layered porous ceramic reactors (comprising 5 cells) was studied using scanning electron microscopy (SEM), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The difference in microstructures of the reactors was evaluated by SEM...

  2. A Comparative SEM-EDS Elemental Composition of Mud in Coastal ...

    African Journals Online (AJOL)

    The present study was aimed to understand the comparative abundance and source of elemental constituents in mud of four coastal shrimp farming areas, Vunh Tau (VT), Nha Trang (NT), Da Nang (DN) and Hue (HU) in Viet Nam using SEM-EDS analysis. Mud samples were collected from shrimp farming coastal zones ...

  3. SEM evaluation of the morphological changes in hard dental tissues prepared by Er: YAG laser and rotary instruments

    Directory of Open Access Journals (Sweden)

    Tomov Georgi

    2010-09-01

    Full Text Available Effective ablation of dental hard tissues by means of the erbium:yttrium-aluminum garnet (Er: YAG laser has been reported recently, and its application to caries removal and cavity preparation has been expected. However, few studies have investigated the morphological changes in hard dental tissues after Er: YAG laser caries treatment. In the present study the morphological changes in hard dental tissues after Er: YAG laser caries ablation in vitro was compared with that of conventional mechanical treatment. Thirty extracted human teeth with caries were used. Ten tooth was treated with the Er: YAG laser, and the other was treated with a conventional steel and diamond burs. Laser treatment was performed by means of a non-contact irradiation modes with cooling water spray, with a new Er: YAG laser (LiteTouch. Conventional bur treatment was conducted by means of a low-speed micromotor and air turbine with water cooling. Scanning electron microscope (SEM observations were performed for each treatment. The Er: YAG laser ablated carious dentin effectively with minimal thermal damage to the surrounding intact dentin, and removed infected and softened carious dentin to the same degree as the burtreatment. In addition, a lower degree of vibration was noted with the Er: YAG laser treatment. The SEM examination revealed characteristic micro-irregularities of the lased dentin and enamel surfaces with potential benefits for adhesive restorations. Our results show that the Er: YAG laser is promising as a new technical modality for caries treatment

  4. Characterization of internal structure of hydrated agar and gelatin matrices by cryo-SEM

    KAUST Repository

    Rahbani, Janane; Behzad, Ali Reza; Khashab, Niveen M.; Al-Ghoul, Mazen

    2012-01-01

    There has been a considerable interest in recent years in developing polymer gel matrices for many important applications such as 2DE for quantization and separation of a variety of proteins and drug delivery system to control the release of active agents. However, a well-defined knowledge of the ultrastructures of the gels has been elusive. In this study, we report the characterization of two different polymers used in 2DE: Gelatin, a naturally occurring polymer derived from collagen (protein) and agar, a polymer of polysaccharide (sugar) origin. Low-temperature SEM is used to examine the internal structure of these gels in their frozen natural hydrated states. Results of this study show that both polymers have an array of hollow cells that resembles honeycomb structures. While agar pores are almost circular, the corresponding Gaussian curve is very broad exhibiting a range of radii from nearly 370 to 700 nm. Gelatin pores are smaller and more homogeneous reflecting a narrower distribution from nearly 320 to 650 nm. Overall, these ultrastructural findings could be used to correlate with functions of the polymers. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Characterization of internal structure of hydrated agar and gelatin matrices by cryo-SEM

    KAUST Repository

    Rahbani, Janane

    2012-12-26

    There has been a considerable interest in recent years in developing polymer gel matrices for many important applications such as 2DE for quantization and separation of a variety of proteins and drug delivery system to control the release of active agents. However, a well-defined knowledge of the ultrastructures of the gels has been elusive. In this study, we report the characterization of two different polymers used in 2DE: Gelatin, a naturally occurring polymer derived from collagen (protein) and agar, a polymer of polysaccharide (sugar) origin. Low-temperature SEM is used to examine the internal structure of these gels in their frozen natural hydrated states. Results of this study show that both polymers have an array of hollow cells that resembles honeycomb structures. While agar pores are almost circular, the corresponding Gaussian curve is very broad exhibiting a range of radii from nearly 370 to 700 nm. Gelatin pores are smaller and more homogeneous reflecting a narrower distribution from nearly 320 to 650 nm. Overall, these ultrastructural findings could be used to correlate with functions of the polymers. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Characterization of internal structure of hydrated agar and gelatin matrices by cryo-SEM.

    Science.gov (United States)

    Rahbani, Janane; Behzad, Ali R; Khashab, Niveen M; Al-Ghoul, Mazen

    2013-02-01

    There has been a considerable interest in recent years in developing polymer gel matrices for many important applications such as 2DE for quantization and separation of a variety of proteins and drug delivery system to control the release of active agents. However, a well-defined knowledge of the ultrastructures of the gels has been elusive. In this study, we report the characterization of two different polymers used in 2DE: Gelatin, a naturally occurring polymer derived from collagen (protein) and agar, a polymer of polysaccharide (sugar) origin. Low-temperature SEM is used to examine the internal structure of these gels in their frozen natural hydrated states. Results of this study show that both polymers have an array of hollow cells that resembles honeycomb structures. While agar pores are almost circular, the corresponding Gaussian curve is very broad exhibiting a range of radii from nearly 370 to 700 nm. Gelatin pores are smaller and more homogeneous reflecting a narrower distribution from nearly 320 to 650 nm. Overall, these ultrastructural findings could be used to correlate with functions of the polymers. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. A multimodal microcharacterisation of trace-element zonation and crystallographic orientation in natural cassiterite by combining cathodoluminescence, EBSD, EPMA and contribution of confocal Raman-in-SEM imaging.

    Science.gov (United States)

    Wille, G; Lerouge, C; Schmidt, U

    2018-01-16

    In cassiterite, tin is associated with metals (titanium, niobium, tantalum, indium, tungsten, iron, manganese, mercury). Knowledge of mineral chemistry and trace-element distribution is essential for: the understanding of ore formation, the exploration phase, the feasibility of ore treatment, and disposal/treatment of tailings after the exploitation phase. However, the availability of analytical methods make these characterisations difficult. We present a multitechnical approach to chemical and structural data that includes scanning electron microscopy (SEM)-based imaging and microanalysis techniques such as: secondary and backscattered electrons, cathodoluminescence (CL), electron probe microanalyser (EPMA), electron backscattered diffraction (EBSD) and confocal Raman-imaging integrated in a SEM (RISE). The presented results show the complementarity of the used analytical techniques. SEM, CL, EBSD, EPMA provide information from the interaction of an electron beam with minerals, leading to atomistic information about their composition, whereas RISE, Raman spectroscopy and imaging completes the studies with information about molecular vibrations, which are sensitive to structural modifications of the minerals. The correlation of Raman bands with the presence/absence of Nb, Ta, Fe (heterovalent substitution) and Ti (homovalent substitution) is established at a submicrometric scale. Combination of the different techniques makes it possible to establish a direct link between chemical and crystallographic data of cassiterite. © 2018 The Authors Journal of Microscopy © 2018 Royal Microscopical Society.

  8. Dimensional verification of high aspect micro structures using FIB-SEM

    DEFF Research Database (Denmark)

    Zhang, Yang; Hansen, Hans Nørgaard

    2013-01-01

    -SEM) assisted by Spip®. The micro features are circular holes 10μm in diameter and 20μm deep, with a 20μm pitch. Various inspection methods were attempted to obtain dimensional information. Due to the dimension, neither optical instrument nor atomic force microscope (AFM) was capable to perform the measurement...

  9. Estructura social y semántica: la lógica de una distinción sistémica

    Directory of Open Access Journals (Sweden)

    Rudolf Stichweh

    2016-01-01

    Full Text Available El presente trabajo aborda de manera crítica la relación teórica entre estructura social y semántica, de modo de avanzar en una comprensión fructífera para las investigaciones. Se describen y analizan las diferentes concepciones de semántica y las relacion es de ésta con las estructuras sociales. Junto con lo anterior, se cuestiona la propuesta de una posible correlación entre ambos conceptos y se propone, en su lugar, una aproximación más cercana a la teoría de sistemas y la teoría de la evolución. El traba jo concluye con una propuesta para la distinción entre estructura social y semántica, en la cual se destaca la posibilidad que la sociedad describa sus estructuras posibles mediante su propia semántica. Este enfoque haría posible un a comprensión de la semá ntica en un sentido an ticipativo, reconstructivo y constitutivo respecto de las estructuras sociales.

  10. SEM and AFM studies of dip-coated CuO nanofilms.

    Science.gov (United States)

    Dhanasekaran, V; Mahalingam, T; Ganesan, V

    2013-01-01

    Cupric oxide (CuO) semiconducting thin films were prepared at various copper sulfate concentrations by dip coating. The copper sulfate concentration was varied to yield films of thicknesses in the range of 445-685 nm by surface profilometer. X-ray diffraction patterns revealed that the deposited films were polycrystalline in nature with monoclinic structure of (-111) plane. The surface morphology and topography of monoclinic-phase CuO thin films were examined using scanning electron microscopy (SEM) and atomic force microscopy (AFM), respectively. Surface roughness profile was plotted using WSxM software and the estimated surface roughness was about ∼19.4 nm at 30 mM molar concentration. The nanosheets shaped grains were observed by SEM and AFM studies. The stoichiometric compound formation was observed at 30 mM copper sulfate concentration prepared film by EDX. The indirect band gap energy of CuO films was increased from 1.08 to 1.20 eV with the increase of copper sulfate concentrations. Copyright © 2012 Wiley Periodicals, Inc.

  11. Site specific SEM/FIB/TEM for analysis of lubricated sliding wear of aluminium alloy composites

    International Nuclear Information System (INIS)

    Walker, J C; Jones, H; Rainforth, W M

    2006-01-01

    Although extensive research has been undertaken into the dry sliding wear of aluminium alloys, only limited work has been reported on lubricated wear. In this paper, the lubricated sliding wear of some powder derived aluminium alloy composites is reported. Stereo pairs of the worn surface were obtained in the SEM and digitally reconstructed to give an accurate projection of the surface topography. Analysis of the average surface roughness (R a ) along chosen sections provided quantitative information about the wear mechanism. Following this, dual beam focused ion beam (FIB) was undertaken to further explore the features revealed by the SEM surface reconstructions, with TEM sections removed from selected regions. Surface deformation was confined to a narrow layer, typically 1μm thick. Subgrain size within the subsurface layer was comparable to that found in dry sliding wear tests. Reinforcement fracture occurred in the surface particles only. The resultant fragments were often incorporated back into the surface following detachment, such that the total volume fraction reinforcement at the surface was greater than in the bulk. Thus, the dynamic surface topography was a result of three factors: surface deformation, local detachment of reinforcement and re-incorporation of the fragments back into the surface

  12. Replica of human dentin treated with different desensitizing agents: a methodological SEM study in vitro

    Directory of Open Access Journals (Sweden)

    Pereira Jose Carlos

    2002-01-01

    Full Text Available This is a preliminary study to determine a methodological sequence in vitro which may allow the reproduction of dentin for SEM analysis, after the use of different desensitizing agents. Dentin discs obtained from extracted human third molars were etched with 6% citric acid, an artificial smear layer was created and the surface dentin discs were divided into four quadrants. Quadrants 2, 3 and 4 of each disc were conditioned with 6% citric acid. The desensitizing agents (Oxa-Gel®, Gluma Desensitizer and an experimental agent were applied to quadrants 3 and 4. To evaluate the acid resistance of the treatment, quadrant 4 was etched again with 6% citric acid. An impression was then taken with Aquasil ULV. After a setting period of 6 min, each disc was removed from the impression and stored in a moist-free environment for 24 h at 37ºC. After that time, a low-viscosity epoxy resin (Araltec GY 1109 BR was poured into the impression and cured for 24 h. All specimens were metal-coated for SEM analysis. Comparison of the photomicrographs of dentin discs with their respective impressions and resin replicas showed that this technique can reproduce the characteristics of the dentin surface treated with desensitizing agents.

  13. Nanomanufacturing concerns about measurements made in the SEM Part III: vibration and drift

    Science.gov (United States)

    Postek, Michael T.; Vladár, András. E.; Cizmar, Petr

    2014-08-01

    Many advanced manufacturing processes employ scanning electron microscopes (SEM) for on-line critical measurements for process and quality control. This is the third of a series of papers discussing various causes of measurement uncertainty in scanned particle beam instruments, and some of the solutions researched and developed at NIST. Scanned particle beam instruments especially the scanning electron microscope have gone through tremendous evolution to become indispensable tools for many and diverse scientifi c and industrial applications. These improvements have signifi cantly enhanced their performance and made them far easier to operate. But, ease of operation has also fostered operator complacency. In addition, the user-friendliness has reduced the need for extensive operator training. Unfortunately, this has led to the concept that the SEM is just another expensive digital camera or another peripheral device connected to a computer and that all of the issues related to obtaining quality data have been solved. Hence, a person (or company) using these instruments may be lulled into thinking that all of the potential pitfalls have been fully eliminated and they believe everything they see on the micrograph is always correct. But, as described in this and the earlier presentations this may not be the case. The fi rst paper in this series discussed some of the issues related to signal generation in the SEM, including instrument calibration, electron beam-sample interactions and the need for physics-based modelling to understand the actual image formation mechanisms to properly interpret SEM images. The second paper, discussed another major issue confronting the microscopist: specimen contamination and methods of contamination elimination. This third paper, discusses vibration and drift and some useful solutions.

  14. Cross-Sectional Information on Pore Structure and Element Distribution of Sediment Particles by SEM and EDS

    Directory of Open Access Journals (Sweden)

    Minghong Chen

    2017-01-01

    Full Text Available The interaction between pollutants and sediment particles often occurs on the particle surface, so surface properties directly affect surface reaction. The physical and chemical processes occurring on sediment particle surfaces are microscopic processes and as such need to be studied from a microscopic perspective. In this study, field emission scanning electron microscopy (SEM and energy dispersive X-ray spectrometer (EDS were adopted to observe and analyze the pore structure and element distribution of sediment particles. In particular, a special method of sample preparation was used to achieve the corresponding cross-sectional information of sediment particles. Clear images of a particle profile and pore microstructure were obtained by high-resolution SEM, while element distribution maps of sediment particles were obtained by EDS. The results provide an intuitive understanding of the internal microenvironment and external behavior of sediment particles, in addition to revealing a significant role of pore microstructure in the adsorption and desorption of pollutants. Thus, a combination of different experimental instruments and observation methods can provide real images and information on microscopic pore structure and element distribution of sediment particles. These results should help to improve our understanding of sediment dynamics and its environmental effects.

  15. Extracção de relações semânticas. Recursos, ferramentas e estratégias

    OpenAIRE

    García González, Marcos

    2015-01-01

    A extracção de relações, enquadrada dentro das tarefas de extracção de informação, visa obter automaticamente exemplos de relações semânticas presentes em textos. Esta informação pode ser posteriormente organizada em formatos legíveis por computadores, sendo útil para diversas aplicações que necessitem conhecimento semântico estruturado. A presente tese avalia diferentes estratégias para a extracção automática de relações semânticas de textos em português, espanhol e galego. Co...

  16. Platinum 'opal eyes' - an upgraded high resolution imaging standard for performance monitoring of FEG SEM and FEG VPSEM

    International Nuclear Information System (INIS)

    Griffin, B.J.

    2003-01-01

    Full text: The new generation of field emission variable pressure and conventional scanning electron microscopes [FEG (VP)SEM] are capable of extremely high resolution (e.g. 1nm 15kV) and, in parallel, imaging at very low accelerating voltages (e.g. 4 nm 0.1 kV). Most of this level of performance is in conventional high vacuum modes of operation, the variable pressure performances are lower but under rapid development. A synthetic opal sample with fine gold decoration on the 400nm silica spheres was described previously as a suitable standard for the routine monitoring of SEM performance. The sample was named 'OPAL EYES'. Whilst ideal for tungsten and LaBo filament sourced SEMs the level of detail was marginal for field emission SEM performance measurement for two reasons. Firstly, the fine gold decoration was highly variable in grain size and inconsistent between samples making comparable image collection difficult. Secondly the sample was prone to self-contamination and damage during imaging at high accelerating voltages or high magnifications. Overall the 'OPAL EYES' sample has been successful in its adoption by a number of service engineers and laboratories world-wide. A new processing step has been added to the previously described preparation process for the OPAL-EYES standard; a light sputter coating with platinum. The effect is dramatic and results in growth of (presumably -to be checked and reported on) Au-Pt features of remarkably consistent size within the central EYE regions of the sample. These outgrowths are proud of the substrate and often equi-dimensional at a size of ∼ 10 nm. The substrate detail is at a scale of ∼2-3 nm. The new Pt OPAL EYES have been used as a resolution test specimen on a recently installed FEG VPSEM with excellent results. An important feature of this new sample is the high contrast sharp-edged nature of the detail as this not only allows resolution measurement but also definition of interference (vibration, electric fields

  17. Porosity and permeability determination of organic-rich Posidonia shales based on 3-D analyses by FIB-SEM microscopy

    Science.gov (United States)

    Grathoff, Georg H.; Peltz, Markus; Enzmann, Frieder; Kaufhold, Stephan

    2016-07-01

    The goal of this study is to better understand the porosity and permeability in shales to improve modelling fluid and gas flow related to shale diagenesis. Two samples (WIC and HAD) were investigated, both mid-Jurassic organic-rich Posidonia shales from Hils area, central Germany of different maturity (WIC R0 0.53 % and HAD R0 1.45 %). The method for image collection was focused ion beam (FIB) microscopy coupled with scanning electron microscopy (SEM). For image and data analysis Avizo and GeoDict was used. Porosity was calculated from segmented 3-D FIB based images and permeability was simulated by a Navier Stokes-Brinkman solver in the segmented images. Results show that the quantity and distribution of pore clusters and pores (≥ 40 nm) are similar. The largest pores are located within carbonates and clay minerals, whereas the smallest pores are within the matured organic matter. Orientation of the pores calculated as pore paths showed minor directional differences between the samples. Both samples have no continuous connectivity of pore clusters along the axes in the x, y, and z direction on the scale of 10 to 20 of micrometer, but do show connectivity on the micrometer scale. The volume of organic matter in the studied volume is representative of the total organic carbon (TOC) in the samples. Organic matter does show axis connectivity in the x, y, and z directions. With increasing maturity the porosity in organic matter increases from close to 0 to more than 5 %. These pores are small and in the large organic particles have little connection to the mineral matrix. Continuous pore size distributions are compared with mercury intrusion porosimetry (MIP) data. Differences between both methods are caused by resolution limits of the FIB-SEM and by the development of small pores during the maturation of the organic matter. Calculations show no permeability when only considering visible pores due to the lack of axis connectivity. Adding the organic matter with a

  18. Characterization of ash pond ashes from 3rd thermal power plant by SEM/EDX and XRD methods

    OpenAIRE

    A Minjigmaa; Ts Zolzaya; E Bayanjargal; B Davaabal; J Temuujin

    2014-01-01

      Coal combustion by products from ash pond of 3rdthermal power plant of Ulaanbaatar city have been collected in 2010 and 2013 years. The ash samples have been characterized by XRD, XRF and SEM-EDX methods in order to evaluate their chemical and mineralogical composition changes with disposed times. The mineralogical composition of ash varies with time though the chemical composition of the ashes were close each other. Possibly, inefficient operating condition of the TPS shows influence on th...

  19. In Depth Analyses of LEDs by a Combination of X-ray Computed Tomography (CT) and Light Microscopy (LM) Correlated with Scanning Electron Microscopy (SEM).

    Science.gov (United States)

    Meyer, Jörg; Thomas, Christian; Tappe, Frank; Ogbazghi, Tekie

    2016-06-16

    In failure analysis, device characterization and reverse engineering of light emitting diodes (LEDs), and similar electronic components of micro-characterization, plays an important role. Commonly, different techniques like X-ray computed tomography (CT), light microscopy (LM) and scanning electron microscopy (SEM) are used separately. Similarly, the results have to be treated for each technique independently. Here a comprehensive study is shown which demonstrates the potentials leveraged by linking CT, LM and SEM. In depth characterization is performed on a white emitting LED, which can be operated throughout all characterization steps. Major advantages are: planned preparation of defined cross sections, correlation of optical properties to structural and compositional information, as well as reliable identification of different functional regions. This results from the breadth of information available from identical regions of interest (ROIs): polarization contrast, bright and dark-field LM images, as well as optical images of the LED cross section in operation. This is supplemented by SEM imaging techniques and micro-analysis using energy dispersive X-ray spectroscopy.

  20. SEM analysis of ionizing radiation effects in linear integrated circuits. [Scanning Electron Microscope

    Science.gov (United States)

    Stanley, A. G.; Gauthier, M. K.

    1977-01-01

    A successful diagnostic technique was developed using a scanning electron microscope (SEM) as a precision tool to determine ionization effects in integrated circuits. Previous SEM methods radiated the entire semiconductor chip or major areas. The large area exposure methods do not reveal the exact components which are sensitive to radiation. To locate these sensitive components a new method was developed, which consisted in successively irradiating selected components on the device chip with equal doses of electrons /10 to the 6th rad (Si)/, while the whole device was subjected to representative bias conditions. A suitable device parameter was measured in situ after each successive irradiation with the beam off.

  1. Análise dos resultados imediatos da cirurgia de revascularização do miocárdio com e sem circulação extracorpórea Analysis of immediate results of on-pump versus off-pump coronary artery bypass grafting surgery

    Directory of Open Access Journals (Sweden)

    Marcos Antonio Cantero

    2012-03-01

    Full Text Available OBJETIVO: Comparar os resultados imediatos da cirurgia de revascularização do miocárdio com e sem circulação extracorpórea (CEC. MÉTODOS: De janeiro de 2007 a janeiro de 2009, 177 pacientes foram submetidos a cirurgia de revascularização do miocárdio (CRM, sendo 92, sem CEC e 85 com CEC. Foram avaliados distribuição demográfica, fatores de risco pré-operatórios, classe funcional e avaliação de risco pelo EuroSCORE. A evolução no pós-operatório foi comparada entre os grupos. RESULTADOS: A média de enxertos por paciente foi de 2,48 ± 0,43, no grupo sem CEC, e 2,90 ± 0,59, no com CEC. No grupo sem CEC, 97,8% dos pacientes receberam um enxerto de artéria torácica interna, enquanto que no grupo com CEC a porcentagem foi de 94,1% (P = 0,03. A taxa de revascularização completa foi similar em ambos os grupos. No grupo sem CEC, a artéria circunflexa foi revascularizada em 48,9% dos casos e, em 68,2%, no grupo com CEC (P = 0,01. A mortalidade hospitalar foi de 4,3% e 4,7%, respectivamente, no grupo sem CEC e com CEC (P = 0,92. Os pacientes operados sem CEC apresentaram menor índice de complicações em relação ao infarto perioperatório (P= 0,02 e ao uso de balão intra-aórtico (P= 0,01. CONCLUSÃO: A cirurgia coronariana sem CEC é um procedimento seguro, com mortalidade hospitalar similar a dos pacientes operados com CEC, com menores taxas de complicações e de incidência de infarto perioperatório, bem como menor necessidade de balão intra-aórtico.OBJECTIVE: The objective of this study is to compare the immediate results of patients undergoing on-pump versus off-pump coronary artery bypass graft (CABG surgery. METHODS: From January 2007 to January 2009, 177 patients underwent CABG, being 92 off-pump and 85 onpump. We evaluated the demographics, preoperative risk factors, preoperative functional class and risk assessment by the EuroSCORE. The postoperative evolution was compared between groups. RESULTS: The mean

  2. SEM-EDX IDENTIFICATION OF PARTICLES FROM FOG IN AN INDUSTRIALLY POLLUTED REGION OF CZECH REPUBLIC

    Czech Academy of Sciences Publication Activity Database

    Stoyanova, V.; Shoumkova, A.; Fišák, Jaroslav; Tsacheva, Ts.

    Vol. II - BUA32, č. 1 (2010), s. 269-276 ISSN 1314-2704. [International Multidisciplinary Scientific GeoConference SGEM 2010 /10./. Albena, 20.06.2010-26.06.2010] Institutional research plan: CEZ:AV0Z30420517 Keywords : SEM-EDX * solid atmospheric pollutants * trace elements * heavy metals * Czech Republic Subject RIV: DG - Athmosphere Sciences, Meteorology http://www.ipc.bas.bg/PPages/Shoumkova/Publications/Articles/2010%20SEM-EDX%20identification%20of%20FP.pdf

  3. SEM method for direct visual tracking of nanoscale morphological changes of platinum based electrocatalysts on fixed locations upon electrochemical or thermal treatments

    Energy Technology Data Exchange (ETDEWEB)

    Zorko, Milena [National Institute of Chemistry, Hajdrihova 19, Ljubljana (Slovenia); Centre of Excellence for Low-Carbon Technologies, Hajdrihova 19, Ljubljana (Slovenia); Jozinović, Barbara [Centre of Excellence for Low-Carbon Technologies, Hajdrihova 19, Ljubljana (Slovenia); Bele, Marjan [National Institute of Chemistry, Hajdrihova 19, Ljubljana (Slovenia); Centre of Excellence for Low-Carbon Technologies, Hajdrihova 19, Ljubljana (Slovenia); Hodnik, Nejc, E-mail: nejc.hodnik@ki.si [National Institute of Chemistry, Hajdrihova 19, Ljubljana (Slovenia); Gaberšček, Miran [National Institute of Chemistry, Hajdrihova 19, Ljubljana (Slovenia); Centre of Excellence for Low-Carbon Technologies, Hajdrihova 19, Ljubljana (Slovenia)

    2014-05-01

    A general method for tracking morphological surface changes on a nanometer scale with scanning electron microscopy (SEM) is introduced. We exemplify the usefulness of the method by showing consecutive SEM images of an identical location before and after the electrochemical and thermal treatments of platinum-based nanoparticles deposited on a high surface area carbon. Observations reveal an insight into platinum based catalyst degradation occurring during potential cycling treatment. The presence of chloride clearly increases the rate of degradation. At these conditions the dominant degradation mechanism seems to be the platinum dissolution with some subsequent redeposition on the top of the catalyst film. By contrast, at the temperature of 60 °C, under potentiostatic conditions some carbon corrosion and particle aggregation was observed. Temperature treatment simulating the annealing step of the synthesis reveals sintering of small platinum based composite aggregates into uniform spherical particles. The method provides a direct proof of induced surface phenomena occurring on a chosen location without the usual statistical uncertainty in usual, random SEM observations across relatively large surface areas. - Highlights: • A new SEM method for observations of identical locations. • Nanoscale morphological consecutive changes on identical locations. • Electrochemical and thermal treatments on platinum based nanoparticles. • Potential cycling induces platinum dissolution with redeposition on top of the film. • At 1.4 V vs. RHE and 60 °C carbon corrosion and particle aggregation is observed.

  4. Separating topographical and chemical analysis of nanostructure of polymer composite in low voltage SEM

    International Nuclear Information System (INIS)

    Wan, Q; Plenderleith, R A; Claeyssens, F; Rodenburg, C; Dapor, M; Rimmer, S

    2015-01-01

    The possibility of separating the topographical and chemical information in a polymer nano-composite using low-voltage SEM imaging is demonstrated, when images are acquired with a Concentric Backscattered (CBS) detector. This separation of chemical and topographical information is based on the different angular distribution of electron scattering which were calculated using a Monte Carlo simulation. The simulation based on angular restricted detection was applied to a semi-branched PNIPAM/PEGDA interpenetration network for which a linear relationship of topography SEM contrast and feature height data was observed. (paper)

  5. SEM analysis of defects and wear on Ni-Ti rotary instruments.

    Science.gov (United States)

    Arantes, Werington Borges; da Silva, Celso Monteiro; Lage-Marques, José Luiz; Habitante, Sandramarcia; da Rosa, Luiz Carlos Laureano; de Medeiros, João Marcelo Ferreira

    2014-01-01

    SEM analysis of endodontic instruments from a Ni-Ti rotary system was assessed, before and after using them, considering their defects and deformations. Twenty Twisted File®, BioRąCe®, Mtwo®, and EndoWave® instruments were micrographed at 190× magnification. The files were washed and micrographed again to view alterations as to the presence or absence of irregular edges, grooves, microcavities, and scraping. Simulated root canal preparations were performed using these instruments. The instruments were cleaned and received a microscopic analysis after being used five times. After analysis tests were tested using Fisher's exact test and Kappa to evaluate the concordance among examiners. There was a statistically significant difference with respect to deformations between Twisted File® and other instruments (p  0.05). All Twisted File® instruments showed the same defects; however damage were lower than those found in BioRace® and Mtwo®. The Endowave® did not show the same defects. In accordance with the data we conclude that the presence of defects was higher in Twisted File® instruments as the instruments and BioRace® Mtwo® brand, the defect rate was smaller and Endowave® instruments had no defects. Regarding the presence of wear after five uses among the groups all instruments showed changes in their cutting blades. © 2014 Wiley Periodicals, Inc.

  6. Using BIB-SEM to determine pore morphology and pore size distributions in coal macerals

    Energy Technology Data Exchange (ETDEWEB)

    Giffin, S.; Littke, R. [RWTH Aachen Univ. (Germany). Inst. of Geology and Geochemistry of Petroleum and Coal; Klaver, J.; Urai, J.L. [RWTH Aachen Univ. (Germany). Structural Geology, Tectonics and Geomechanics

    2013-08-01

    The composition of coalbeds is considerably heterogeneous, affecting the transport pathways for fluids within the coal. Transport pathways include cleats and larger pores. However, only a few clues exist as the nature of these pores. This study examines the morphology and distribution of macro- and mesopores in coal samples, using broad ion beam (BIB) milling to prepare relief- and damage-free polished surfaces of coal samples for high-resolution SEM imaging. Broad ion beam milling is advantageous to focused ion beam milling in that a larger surface area can be milled. Combining that with SEM imaging results in a useful tool to study pore morphology and distributions in the size range between 10 nm and 10 {mu}m. Since BIB-sections of a few square millimeters are not large enough to be statistically representative, results cannot be easily interpreted from a coal seam standpoint. Therefore, porosity was investigated as a function of maceral type to characterize pore morphologies. Macerals from the vitrinite and inertinite groups were selected with a known relationship to bedding. BIB-sections were milled parallel to bedding and perpendicular to bedding, and the pores were evaluated in each section. The goal of this study is to (1) qualitatively describe pore morphology with respect to maceral type and (2) quantitatively characterize pore size distributions with respect to maceral and in relationship to bedding. Our results lead to a better understanding of bulk coal porosity due to the visual, spatial representation and quantification of pores in individual macerals. (orig.)

  7. FIB and MIP: understanding nanoscale porosity in molecularly imprinted polymers via 3D FIB/SEM tomography.

    Science.gov (United States)

    Neusser, G; Eppler, S; Bowen, J; Allender, C J; Walther, P; Mizaikoff, B; Kranz, C

    2017-10-05

    We present combined focused ion beam/scanning electron beam (FIB/SEM) tomography as innovative method for differentiating and visualizing the distribution and connectivity of pores within molecularly imprinted polymers (MIPs) and non-imprinted control polymers (NIPs). FIB/SEM tomography is used in cell biology for elucidating three-dimensional structures such as organelles, but has not yet been extensively applied for visualizing the heterogeneity of nanoscopic pore networks, interconnectivity, and tortuosity in polymers. To our best knowledge, the present study is the first application of this strategy for analyzing the nanoscale porosity of MIPs. MIPs imprinted for propranolol - and the corresponding NIPs - were investigated establishing FIB/SEM tomography as a viable future strategy complementing conventional isotherm studies. For visualizing and understanding the properties of pore networks in detail, polymer particles were stained with osmium tetroxide (OsO 4 ) vapor, and embedded in epoxy resin. Staining with OsO 4 provides excellent contrast during high-resolution SEM imaging. After optimizing the threshold to discriminate between the stained polymer matrix, and pores filled with epoxy resin, a 3D model of the sampled volume may be established for deriving not only the pore volume and pore surface area, but also to visualize the interconnectivity and tortuosity of the pores within the sampled polymer volume. Detailed studies using different types of cross-linkers and the effect of hydrolysis on the resulting polymer properties have been investigated. In comparison of MIP and NIP, it could be unambiguously shown that the interconnectivity of the visualized pores in MIPs is significantly higher vs. the non-imprinted polymer, and that the pore volume and pore area is 34% and approx. 35% higher within the MIP matrix. This confirms that the templating process not only induces selective binding sites, but indeed also affects the physical properties of such

  8. Macromolecular 3D SEM reconstruction strategies: Signal to noise ratio and resolution

    International Nuclear Information System (INIS)

    Woodward, J.D.; Wepf, R.A.

    2014-01-01

    Three-dimensional scanning electron microscopy generates quantitative volumetric structural data from SEM images of macromolecules. This technique provides a quick and easy way to define the quaternary structure and handedness of protein complexes. Here, we apply a variety of preparation and imaging methods to filamentous actin in order to explore the relationship between resolution, signal-to-noise ratio, structural preservation and dataset size. This information can be used to define successful imaging strategies for different applications. - Highlights: • F-actin SEM datasets were collected using 8 different preparation/ imaging techniques. • Datasets were reconstructed by back projection and compared/analyzed • 3DSEM actin reconstructions can be produced with <100 views of the asymmetric unit. • Negatively stained macromolecules can be reconstructed by 3DSEM to ∼3 nm resolution

  9. The superiority of PIXE compared to EDXRF, SEM/EDX and ICP-MS determining the provenance of medieval silver coins

    International Nuclear Information System (INIS)

    Linke, R.; Schreiner, M.; Demortier, G.; Schreiner, M.

    2001-01-01

    157 coins of the Tiroler Kreuzer, an Austrian mintage of the XIV century, were analyzed in order to determine their provenance. The silver coins were produced in the mints of Merano (Italy) and Hall (Austria) but have no markers or punches, which would enable a clear distinction. Therefore, non destructive EDXRF was applied in order to determine the Ag-content as well as minor (Cu, Pb, Bi) and trace elements (Fe, Au, Hg, Ni) Additionally investigation of cross sections using SEM/EDX were carried out to determine the Ag concentration of the core of the coins. Due to the fact that corrosion processes changed the chemical composition of the coins surfaces the analysis results showed differences up to 50% between the composition of the core and the surface

  10. The Role of Sexually Explicit Material (SEM) in the Sexual Development of Black Young Same-Sex-Attracted Men

    Science.gov (United States)

    Morgan, Anthony; Ogunbajo, Adedotun; Trent, Maria; Harper, Gary W.; Fortenberry, J. Dennis

    2015-01-01

    Sexually explicit material (SEM) (including Internet, video, and print) may play a key role in the lives of Black same-sex sexually active youth by providing the only information to learn about sexual development. There is limited school-and/or family-based sex education to serve as models for sexual behaviors for Black youth. We describe the role SEM plays in the sexual development of a sample of Black same-sex attracted (SSA) young adolescent men ages 15–19. Adolescents recruited from clinics, social networking sites, and through snowball sampling were invited to participate in a 90-min, semi-structured qualitative interview. Most participants described using SEM prior to their first same-sex sexual experience. Participants described using SEM primarily for sexual development, including learning about sexual organs and function, the mechanics of same-gender sex, and to negotiate one’s sexual identity. Secondary functions were to determine readiness for sex; to learn about sexual performance, including understanding sexual roles and responsibilities (e.g., “top” or “bottom”); to introduce sexual performance scripts; and to develop models for how sex should feel (e.g., pleasure and pain). Youth also described engaging in sexual behaviors (including condom non-use and/or swallowing ejaculate) that were modeled on SEM. Comprehensive sexuality education programs should be designed to address the unmet needs of young, Black SSA young men, with explicit focus on sexual roles and behaviors that may be inaccurately portrayed and/or involve sexual risk-taking (such as unprotected anal intercourse and swallowing ejaculate) in SEM. This work also calls for development of Internet-based HIV/STI prevention strategies targeting young Black SSA men who maybe accessing SEM. PMID:25677334

  11. Surgery on spinal epidural metastases (SEM) in renal cell carcinoma: a plea for a new paradigm.

    Science.gov (United States)

    Bakker, Nicolaas A; Coppes, Maarten H; Vergeer, Rob A; Kuijlen, Jos M A; Groen, Rob J M

    2014-09-01

    Prediction models for outcome of decompressive surgical resection of spinal epidural metastases (SEM) have in common that they have been developed for all types of SEM, irrespective of the type of primary tumor. It is our experience in clinical practice, however, that these models often fail to accurately predict outcome in the individual patient. To investigate whether decision making could be optimized by applying tumor-specific prediction models. For the proof of concept, we analyzed patients with SEM from renal cell carcinoma that we have operated on. Retrospective chart analysis 2006 to 2012. Twenty-one consecutive patients with symptomatic SEM of renal cell carcinoma. Predictive factors for survival. Next to established predictive factors for survival, we analyzed the predictive value of the Motzer criteria in these patients. The Motzer criteria comprise a specific and validated risk model for survival in patients with renal cell carcinoma. After multivariable analysis, only Motzer intermediate (hazard ratio [HR] 17.4, 95% confidence interval [CI] 1.82-166, p=.01) and high risk (HR 39.3, 95% CI 3.10-499, p=.005) turned out to be significantly associated with survival in patients with renal cell carcinoma that we have operated on. In this study, we have demonstrated that decision making could have been optimized by implementing the Motzer criteria next to established prediction models. We, therefore, suggest that in future, in patients with SEM from renal cell carcinoma, the Motzer criteria are also taken into account. Copyright © 2014 Elsevier Inc. All rights reserved.

  12. Blocos semânticos: o movimento argumentativo na construção do sentido no discurso

    Directory of Open Access Journals (Sweden)

    Ernani Cesar de FREITAS

    2008-07-01

    Full Text Available Este trabalho tem por objetivo sistematizar e aplicar conceitos da Semântica Argumentativa de Oswald Ducrot e Marion Carel, no que diz respeito ao modelo teórico dos Blocos Semânticos, de modo que dêem conta da construção do sentido de unidades mais complexas como o texto e o discurso. A tese concebida como norteadora deste estudo, seguindo a metodologia proposta por Ducrot (1987, pressupõe que o texto é um bloco semântico inscrito no nível teórico da produção e realizado pelo encadeamento argumentativo complexo que é o discurso, orientado argumentativamente pelo uso de conectores tipo DC e/ ou PT. As análises discursivas realizadas, neste trabalho, demonstram que os encadeamentos dos enunciados estão bem marcados pelos conectores donc e pourtant que dão sentido ao discurso complexo, pelas conexões semânticas produzidas em suas AI e AE. Esse movimento argumentativo resulta da interdependência dos segmentos argumentativos, dos encadeamentos e por conseqüência dos blocos semânticos, todos interconectados e interdependentes nas relações de sentido que estabelecem entre si, processo que culmina na realização linguística de nível complexo constituído pelo texto, entidade abstrata subjacente aos discursos realizados, e pelo discurso, como seqüência de enunciados interligados, por isso, também entendido como entidade concreta, ou seja, a manifestação e realização do texto.

  13. Blocos semânticos: o movimento argumentativo na construção do sentido no discurso

    Directory of Open Access Journals (Sweden)

    Ernani Cesar de FREITAS

    2013-10-01

    Full Text Available Este trabalho tem por objetivo sistematizar e aplicar conceitos da Semântica Argumentativa de Oswald Ducrot e Marion Carel, no que diz respeito ao modelo teórico dos Blocos Semânticos, de modo que dêem conta da construção do sentido de unidades mais complexas como o texto e o discurso. A tese concebida como norteadora deste estudo, seguindo a metodologia proposta por Ducrot (1987, pressupõe que o texto é um bloco semântico inscrito no nível teórico da produção e realizado pelo encadeamento argumentativo complexo que é o discurso, orientado argumentativamente pelo uso de conectores tipo DC e/ ou PT. As análises discursivas realizadas, neste trabalho, demonstram que os encadeamentos dos enunciados estão bem marcados pelos conectores donc e pourtant que dão sentido ao discurso complexo, pelas conexões semânticas produzidas em suas AI e AE. Esse movimento argumentativo resulta da interdependência dos segmentos argumentativos, dos encadeamentos e por conseqüência dos blocos semânticos, todos interconectados e interdependentes nas relações de sentido que estabelecem entre si, processo que culmina na realização linguística de nível complexo constituído pelo texto, entidade abstrata subjacente aos discursos realizados, e pelo discurso, como seqüência de enunciados interligados, por isso, também entendido como entidade concreta, ou seja, a manifestação e realização do texto.

  14. Minería de opiniones basada en patrones semánticos en Twitter

    OpenAIRE

    Artacho Torres, Pablo

    2014-01-01

    La minería de opinión o análisis de sentimiento es un tipo de análisis de texto que pretende ayudar a la toma de decisiones a través de la extracción y el análisis de opiniones, identificando las opiniones positivas, negativas y neutras; y midiendo su repercusión en la percepción de un tópico. En este trabajo se propone un modelo de análisis de sentimiento basado en diccionarios, que a través de la semántica y de los patrones semánticos que conforman el texto a clasificar, permite obtener la ...

  15. ASAPP: Alinhamento Semântico Automático de Palavras aplicado ao Português

    Directory of Open Access Journals (Sweden)

    Ana Oliveira Alves

    2016-12-01

    Full Text Available Apresentamos duas abordagens distintas à tarefa de avaliação conjunta ASSIN onde, dada uma coleção de pares de frases escritas em português, são colocados dois objectivos para cada par: (a calcular a similaridade semântica entre as duas frases; e (b verificar se uma frase do par é paráfrase ou inferência da outra. Uma primeira abordagem, apelidada de Reciclagem, baseia-se exclusivamente em heurísticas sobre redes semânticas para a língua portuguesa. A segunda abordagem, apelidada de ASAPP, baseia-se em aprendizagem automática supervisionada. Acima de tudo, os resultados da abordagem Reciclagem permitem comparar, de forma indireta, um conjunto de redes semânticas, através do seu desempenho nesta tarefa. Estes resultados, algo modestos, foram depois utilizados como características da abordagem ASAPP, juntamente com características adicionais, ao nível lexical e sintático. Após comparação com os resultados da coleção dourada, verifica-se que a abordagem ASAPP supera a abordagem Reciclagem de forma consistente. Isto ocorre tanto para o Português Europeu como para o Português Brasileiro, onde o desempenho atinge uma exatidão de 80.28% +- 0.019 para a inferência textual, enquanto que a correlação dos valores atribuídos para a similaridade semântica com aqueles atribuídos por humanos é de 66.5% +- 0.021.

  16. Application of FE-SEM with elemental analyzer for irradiated fuel materials

    International Nuclear Information System (INIS)

    Sasaki, Shinji; Maeda, Koji; Yamada, A.

    2012-01-01

    It is important to study the irradiation behavior of the uranium-plutonium mixed oxide fuels (MOX fuels) for development of fast reactor fuels. During irradiation in a fast reactor, the changes of microstructures and the changes of element distributions along radial direction occur in the MOX fuels because of a radial temperature gradient. In order to make detailed observations of microstructure and elemental analyses of fuel samples, a field emission scanning electron microscope (FE-SEM) equipped with a wavelength-dispersive X-ray spectrometer (WDX) and an energy-dispersive X-ray spectrometer (EDX) were installed in a hot laboratory. Because fuel samples have high radioactivities and emit α-particles, the instrument was modified correspondingly. The notable modified points were as follows. 1) To prevent leakage of radioactive materials, the instrument was attached to a remote control air-tight sample transfer unit between a shielded hot cell and the FE-SEM. 2) To protect operators and the instruments from radiation, the FE-SEM was installed in a lead shield box and the control unit was separately located outside the box. After the installation, the microscopy and elemental analyses were made on low burnup fuel samples. High resolution images were obtained on the fuel sample surface. The characteristic X-rays (U, Pu) emitted from the fuel sample surface measured along radial direction successfully. Thereby, it was able to grasp the change of U, Pu radial distribution after irradiation. The technique has the great advantage of being able to evaluate the changes of microstructures and the changes of element distributions of MOX fuels due to irradiation. In future work, samples of even higher radioactivity will be observed and analyzed. (author)

  17. Investigation of CPD and HMDS Sample Preparation Techniques for Cervical Cells in Developing Computer-Aided Screening System Based on FE-SEM/EDX

    Science.gov (United States)

    Ng, Siew Cheok; Abu Osman, Noor Azuan

    2014-01-01

    This paper investigated the effects of critical-point drying (CPD) and hexamethyldisilazane (HMDS) sample preparation techniques for cervical cells on field emission scanning electron microscopy and energy dispersive X-ray (FE-SEM/EDX). We investigated the visualization of cervical cell image and elemental distribution on the cervical cell for two techniques of sample preparation. Using FE-SEM/EDX, the cervical cell images are captured and the cell element compositions are extracted for both sample preparation techniques. Cervical cell image quality, elemental composition, and processing time are considered for comparison of performances. Qualitatively, FE-SEM image based on HMDS preparation technique has better image quality than CPD technique in terms of degree of spread cell on the specimen and morphologic signs of cell deteriorations (i.e., existence of plate and pellet drying artifacts and membrane blebs). Quantitatively, with mapping and line scanning EDX analysis, carbon and oxygen element compositions in HMDS technique were higher than the CPD technique in terms of weight percentages. The HMDS technique has shorter processing time than the CPD technique. The results indicate that FE-SEM imaging, elemental composition, and processing time for sample preparation with the HMDS technique were better than CPD technique for cervical cell preparation technique for developing computer-aided screening system. PMID:25610902

  18. Comparative SEM analysis of nine F22 aligner cleaning strategies.

    Science.gov (United States)

    Lombardo, Luca; Martini, Marco; Cervinara, Francesca; Spedicato, Giorgio Alfredo; Oliverio, Teresa; Siciliani, Giuseppe

    2017-12-01

    The orthodontics industry has paid great attention to the aesthetics of orthodontic appliances, seeking to make them as invisible as possible. There are several advantages to clear aligner systems, including aesthetics, comfort, chairside time reduction, and the fact that they can be removed for meals and oral hygiene procedures. Five patients were each given a series of F22 aligners, each to be worn for 14 days and nights, with the exception of meal and brushing times. Patients were instructed to clean each aligner using a prescribed strategy, and sections of the used aligners were observed under SEM. One grey-scale SEM image was saved per aligner in JPEG format with an 8-bit colour depth, and a total of 45 measurements on the grey scale ("Value" variable) were made. This dataset was analysed statistically via repeated measures ANOVA to determine the effect of each of the nine cleaning strategies in each of the five patients. A statistically significant difference in the efficacy of the cleaning strategies was detected. Specifically, rinsing with water alone was significantly less efficacious, and a combination of cationic detergent solution and ultrasonication was significantly more efficacious than the other methods (p aligners.

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

    International Nuclear Information System (INIS)

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

    2011-01-01

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

  20. A SEM-correlation of the anatomy of the vitreous body: making visible the invisible.

    Science.gov (United States)

    Jongebloed, W L; Humalda, D; Worst, J F

    1986-12-30

    The naked human vitreous (sclera, iris and cornea removed) suspended in water does not reveal inner structures. After ink injection into the vitreous, the presence of different compartments and the existence of cisterns becomes evident. A concept of the internal system of cisterns is given on the basis of stereoscopic-lightmicroscopic images. An attempt is made to correlate images of the complete vitreous body, obtained with a stereo-lightmicroscope, with images of segments of cisternal walls produced with a scanning electron-microscope (SEM). A comparison is made between SEM-images of the vitreous bodies of human and rabbit eyes.

  1. Bone matrix calcification during embryonic and postembryonic rat calvarial development assessed by SEM-EDX spectroscopy, XRD, and FTIR spectroscopy.

    Science.gov (United States)

    Henmi, Akiko; Okata, Hiroshi; Anada, Takahisa; Yoshinari, Mariko; Mikami, Yasuto; Suzuki, Osamu; Sasano, Yasuyuki

    2016-01-01

    Bone mineral is constituted of biological hydroxyapatite crystals. In developing bone, the mineral crystal matures and the Ca/P ratio increases. However, how an increase in the Ca/P ratio is involved in maturation of the crystal is not known. The relationships among organic components and mineral changes are also unclear. The study was designed to investigate the process of calcification during rat calvarial bone development. Calcification was evaluated by analyzing the atomic distribution and concentration of Ca, P, and C with scanning electron microscopy (SEM)-energy-dispersive X-ray (EDX) spectroscopy and changes in the crystal structure with X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy. Histological analysis showed that rat calvarial bone formation started around embryonic day 16. The areas of Ca and P expanded, matching the region of the developing bone matrix, whereas the area of C became localized around bone. X-ray diffraction and FTIR analysis showed that the amorphous-like structure of the minerals at embryonic day 16 gradually transformed into poorly crystalline hydroxyapatite, whereas the proportion of mineral to protein increased until postnatal week 6. FTIR analysis also showed that crystallization of hydroxyapatite started around embryonic day 20, by which time SEM-EDX spectroscopy showed that the Ca/P ratio had increased and the C/Ca and C/P ratios had decreased significantly. The study suggests that the Ca/P molar ratio increases and the proportion of organic components such as proteins of the bone matrix decreases during the early stage of calcification, whereas crystal maturation continues throughout embryonic and postembryonic bone development.

  2. Tracing outbreaks of Streptococcus equi infection (strangles) in horses using sequence variation in the seM gene and pulsed-field gel electrophoresis.

    Science.gov (United States)

    Lindahl, Susanne; Söderlund, Robert; Frosth, Sara; Pringle, John; Båverud, Viveca; Aspán, Anna

    2011-11-21

    Strangles is a serious respiratory disease in horses caused by Streptococcus equi subspecies equi (S. equi). Transmission of the disease occurs by direct contact with an infected horse or contaminated equipment. Genetically, S. equi strains are highly homogenous and differentiation of strains has proven difficult. However, the S. equi M-protein SeM contains a variable N-terminal region and has been proposed as a target gene to distinguish between different strains of S. equi and determine the source of an outbreak. In this study, strains of S. equi (n=60) from 32 strangles outbreaks in Sweden during 1998-2003 and 2008-2009 were genetically characterized by sequencing the SeM protein gene (seM), and by pulsed-field gel electrophoresis (PFGE). Swedish strains belonged to 10 different seM types, of which five have not previously been described. Most were identical or highly similar to allele types from strangles outbreaks in the UK. Outbreaks in 2008/2009 sharing the same seM type were associated by geographic location and/or type of usage of the horses (racing stables). Sequencing of the seM gene generally agreed with pulsed-field gel electrophoresis profiles. Our data suggest that seM sequencing as a epidemiological tool is supported by the agreement between seM and PFGE and that sequencing of the SeM protein gene is more sensitive than PFGE in discriminating strains of S. equi. Copyright © 2011 Elsevier B.V. All rights reserved.

  3. Staining plastic blocks with triiodide to image cells and soft tissues in backscattered electron SEM of skeletal and dental tissues

    Directory of Open Access Journals (Sweden)

    A Boyde

    2012-07-01

    Full Text Available Backscattered electron scanning electron microscopy (BSE SEM is an invaluable method for studying the histology of the hard, mineralised components of poly-methyl methacrylate (PMMA or other resin embedded skeletal and dental tissues. Intact tissues are studied in micro-milled or polished block faces with an electron-optical section thickness of the order of a half to one micron and with the area of the section as big as a whole – large or small – bone organ. However, BSE SEM does not give information concerning the distribution of uncalcified, ‘soft’, cellular and extracellular matrix components. This can be obtained by confocal microscopy of the same block and the two sorts of images merged but the blocks have to be studied in two microscope systems. The present work shows a new, simple and economic approach to visualising both components by using the triiodide ion in Lugol's iodine solution to stain the block surface prior to the application of any conductive coating – and the latter can be omitted if charging is suppressed by use of poor vacuum conditions in the SEM sample chamber. The method permits the use of archival tissue, and it will be valuable in studies of both normal growth and development and pathological changes in bones and joints, including osteoporosis and osteoarthritis, and tissue adaptation to implants.

  4. AxiSEM3D: a new fast method for global wave propagation in 3-D Earth models with undulating discontinuities

    Science.gov (United States)

    Leng, K.; Nissen-Meyer, T.; van Driel, M.; Al-Attar, D.

    2016-12-01

    We present a new, computationally efficient numerical method to simulate global seismic wave propagation in realistic 3-D Earth models with laterally heterogeneous media and finite boundary perturbations. Our method is a hybrid of pseudo-spectral and spectral element methods (SEM). We characterize the azimuthal dependence of 3-D wavefields in terms of Fourier series, such that the 3-D equations of motion reduce to an algebraic system of coupled 2-D meridional equations, which can be solved by a 2-D spectral element method (based on www.axisem.info). Computational efficiency of our method stems from lateral smoothness of global Earth models (with respect to wavelength) as well as axial singularity of seismic point sources, which jointly confine the Fourier modes of wavefields to a few lower orders. All boundary perturbations that violate geometric spherical symmetry, including Earth's ellipticity, topography and bathymetry, undulations of internal discontinuities such as Moho and CMB, are uniformly considered by means of a Particle Relabeling Transformation.The MPI-based high performance C++ code AxiSEM3D, is now available for forward simulations upon 3-D Earth models with fluid outer core, ellipticity, and both mantle and crustal structures. We show novel benchmarks for global wave solutions in 3-D mantle structures between our method and an independent, fully discretized 3-D SEM with remarkable agreement. Performance comparisons are carried out on three state-of-the-art tomography models, with seismic period going down to 5s. It is shown that our method runs up to two orders of magnitude faster than the 3-D SEM for such settings, and such computational advantage scales favourably with seismic frequency. By examining wavefields passing through hypothetical Gaussian plumes of varying sharpness, we identify in model-wavelength space the limits where our method may lose its advantage.

  5. The ITZ in concrete with natural and recycled aggregates : Study of microstructures based on image and SEM analysis

    NARCIS (Netherlands)

    Bonifazi, G.; Capobianco, G.; Serranti, S.; Eggimann, M.; Wagner, E.; Di Maio, F.; Lotfi, S.

    2015-01-01

    Aim of this work was to investigate the microstructure of the Interfacial Transition Zone (ITZ) between cement paste and aggregate in concrete utilizing Scanning Electron Microscope (SEM) in order to identify possible effects on the ITZ related to different recipes and production parameters. SEM is

  6. Morphological, chemical and structural characterisation of deciduous enamel: SEM, EDS, XRD, FTIR and XPS analysis.

    Science.gov (United States)

    Zamudio-Ortega, C M; Contreras-Bulnes, R; Scougall-Vilchis, R J; Morales-Luckie, R A; Olea-Mejía, O F; Rodríguez-Vilchis, L E

    2014-09-01

    The purpose of this study was to characterise the enamel surface of sound deciduous teeth in terms of morphology, chemical composition, structure and crystalline phases. The enamel of 30 human deciduous teeth was examined by: Scanning Electron Microscopy (SEM), Energy Dispersive X-Ray Spectroscopy (EDS), X-ray Powder Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), and X-ray Photoelectron Spectroscopy (XPS). Chemical differences between incisors and canines were statistically evaluated using the Mann-Whitney U test (p ≤ 0.05). Three enamel patterns were observed by SEM: 'mostly smooth with some groves', 'abundant microporosities' and 'exposed prisms'. The average Ca/P molar ratios were 1.37 and 1.03 by EDS and XPS, respectively. The crystallite size determined by XRD was 210.82 ± 16.78 Å. The mean ratio between Ca bonded to phosphate and Ca bonded to hydroxyl was approximately 10:1. The enamel of sound deciduous teeth showed two main patterns: 'mostly smooth with some groves' and 'abundant microporosities'. 'Exposed prisms' was a secondary pattern. There were slight variations among the Ca/P molar ratios found by EDS and XPS, suggesting differences in the mineral content from the enamel surface to the interior. The crystalline phases found in enamel were hydroxyapatite and carbonate apatite, with major type B than type A carbonate incorporation.

  7. Characterization of a millefiori glass find from Aquincum by SEM-EDX and micro-PIXE methods

    Energy Technology Data Exchange (ETDEWEB)

    Uzonyi, I., E-mail: uzonyi@atomki.hu [Institute of Nuclear Research of the Hungarian Academy of Sciences, H-4026 Debrecen, Bem ter 18/C (Hungary); Csontos, K.; Verebes, A. [Budapest History Museum, Aquincum Museum H-8211 Budapest, Zahony u. 4. (Hungary); Cserhati, C. [Department of Solid State Physics, University of Debrecen H-4032 Debrecen, Bem ter 18/B (Hungary); Csedreki, L.; Kis-Varga, M.; Kiss, A.Z. [Institute of Nuclear Research of the Hungarian Academy of Sciences, H-4026 Debrecen, Bem ter 18/C (Hungary)

    2011-10-15

    Research has been focused on the analysis of archaeological glasses from the Roman age and medieval times. Study of ancient millefiori type glasses from the collection of Hungarian Museums has been started. A test measurement, carried out on a glass fragment supposedly part of a dish, was performed by SEM-EDX and micro-PIXE methods. Complementary analytical data were obtained for texture and composition. Results suggest that Roman and Mesopotamian techniques were used together. Our data contribute to data bases of millefiori glasses.

  8. Characterization of a millefiori glass find from Aquincum by SEM-EDX and micro-PIXE methods

    International Nuclear Information System (INIS)

    Uzonyi, I.; Csontos, K.; Verebes, A.; Cserhati, C.; Csedreki, L.; Kis-Varga, M.; Kiss, A.Z.

    2011-01-01

    Research has been focused on the analysis of archaeological glasses from the Roman age and medieval times. Study of ancient millefiori type glasses from the collection of Hungarian Museums has been started. A test measurement, carried out on a glass fragment supposedly part of a dish, was performed by SEM-EDX and micro-PIXE methods. Complementary analytical data were obtained for texture and composition. Results suggest that Roman and Mesopotamian techniques were used together. Our data contribute to data bases of millefiori glasses.

  9. Enhancing nanoscale SEM image segmentation and reconstruction with crystallographic orientation data and machine learning

    International Nuclear Information System (INIS)

    Converse, Matthew I.; Fullwood, David T.

    2013-01-01

    Current methods of image segmentation and reconstructions from scanning electron micrographs can be inadequate for resolving nanoscale gaps in composite materials (1–20 nm). Such information is critical to both accurate material characterizations and models of piezoresistive response. The current work proposes the use of crystallographic orientation data and machine learning for enhancing this process. It is first shown how a machine learning algorithm can be used to predict the connectivity of nanoscale grains in a Nickel nanostrand/epoxy composite. This results in 71.9% accuracy for a 2D algorithm and 62.4% accuracy in 3D. Finally, it is demonstrated how these algorithms can be used to predict the location of gaps between distinct nanostrands — gaps which would otherwise not be detected with the sole use of a scanning electron microscope. - Highlights: • A method is proposed for enhancing the segmentation/reconstruction of SEM images. • 3D crystallographic orientation data from a nickel nanocomposite is collected. • A machine learning algorithm is used to detect trends in adjacent grains. • This algorithm is then applied to predict likely regions of nanoscale gaps. • These gaps would otherwise be unresolved with the sole use of an SEM

  10. Elemental composition study of heavy metal (Ni, Cu, Zn) in riverbank soil by electrokinetic-assisted phytoremediation using XRF and SEM/EDX

    International Nuclear Information System (INIS)

    Jamari, Suhailly; Embong, Zaidi; Bakar, Ismail

    2014-01-01

    Electrokinetic (EK)-assisted phytoremediation is one of the methods that have a big potential in enhancing the ability of plant uptake in soils remediation process. This research was conducted to investigate the difference in elemental composition concentration of riverbank soil and the change of pH between pre- and post-phytoremediation under the following condition: 1) control or as-receive sample; 2) Dieffenbachia spp plant with EK system (a pair of EK electrodes connected to a direct current (DC) power supply). After the electrodes were connected to a magnitude of 6V/cm −1 electric field for 4 hours/day, the soil and plant samples were analyzed using and X-ray Fluorescence Spectrometer (XRF) and Scanning Electron Microscope / Energy Dispersive X-ray Spectroscopy (SEM/EDX). The SEM/EDX analysis showed that concentration of elemental composition (Ni, Cu and Zn) in post-phytoremediation plant powder samples had increase while elemental concentrations in the post-phytoremediation soil samples were decreased. XRF analysis presented a variation in soil elemental composition concentration from anode to cathode where the concentration near anode region increased while decreased near the cathode region. A significant changes in soil pH were obtained where the soil pH increase in cathode region while decrease in anode region. The results reveal that the assistance of EK in phytoremediation process has increase the efficiency of plant uptake

  11. Elemental composition study of heavy metal (Ni, Cu, Zn) in riverbank soil by electrokinetic-assisted phytoremediation using XRF and SEM/EDX

    Energy Technology Data Exchange (ETDEWEB)

    Jamari, Suhailly [Faculty of Science, Technology and Human Development, Universiti Tun Hussein Onn Malaysia (UTHM) (Malaysia); Embong, Zaidi [Faculty of Science, Technology and Human Development, Universiti Tun Hussein Onn Malaysia (UTHM) and Research Center for Soft Soils (RECESS), Office of Research, Innovation, Commercialization and Consultancy Management - ORRIC, Universiti Tun Hussein (Malaysia); Bakar, Ismail [Research Center for Soft Soils (RECESS), Office of Research, Innovation, Commercialization and Consultancy Management (ORRIC), Universiti Tun Hussein Onn Malaysia -UTHM, 86400 Batu Pahat, Johor (Malaysia)

    2014-02-12

    Electrokinetic (EK)-assisted phytoremediation is one of the methods that have a big potential in enhancing the ability of plant uptake in soils remediation process. This research was conducted to investigate the difference in elemental composition concentration of riverbank soil and the change of pH between pre- and post-phytoremediation under the following condition: 1) control or as-receive sample; 2) Dieffenbachia spp plant with EK system (a pair of EK electrodes connected to a direct current (DC) power supply). After the electrodes were connected to a magnitude of 6V/cm{sup −1} electric field for 4 hours/day, the soil and plant samples were analyzed using and X-ray Fluorescence Spectrometer (XRF) and Scanning Electron Microscope / Energy Dispersive X-ray Spectroscopy (SEM/EDX). The SEM/EDX analysis showed that concentration of elemental composition (Ni, Cu and Zn) in post-phytoremediation plant powder samples had increase while elemental concentrations in the post-phytoremediation soil samples were decreased. XRF analysis presented a variation in soil elemental composition concentration from anode to cathode where the concentration near anode region increased while decreased near the cathode region. A significant changes in soil pH were obtained where the soil pH increase in cathode region while decrease in anode region. The results reveal that the assistance of EK in phytoremediation process has increase the efficiency of plant uptake.

  12. Automated Axis Alignment for a Nanomanipulator inside SEM and Its Error Optimization

    Directory of Open Access Journals (Sweden)

    Chao Zhou

    2017-01-01

    Full Text Available In the motion of probing nanostructures, repeating position and movement is frequently happing and tolerance for position error is stringent. The consistency between the axis of manipulators and image is very significant since the visual servo is the most important tool in the automated manipulation. This paper proposed an automated axis alignment method for a nanomanipulator inside the SEM by recognizing the position of a closed-loop controlling the end-effector, which can characterize the relationship of these two axes, and then the rotation matrix can be calculated accordingly. The error of this method and its transfer function are also calculated to compare the iteration method and average method. The method in this paper can accelerate the process of axis alignment to avoid the electron beam induced deposition effect on the end tips. Experiment demonstration shows that it can achieve a 0.1-degree precision in 90 seconds.

  13. Contrast of Backscattered Electron SEM Images of Nanoparticles on Substrates with Complex Structure.

    Science.gov (United States)

    Kowoll, Thomas; Müller, Erich; Fritsch-Decker, Susanne; Hettler, Simon; Störmer, Heike; Weiss, Carsten; Gerthsen, Dagmar

    2017-01-01

    This study is concerned with backscattered electron scanning electron microscopy (BSE SEM) contrast of complex nanoscaled samples which consist of SiO 2 nanoparticles (NPs) deposited on indium-tin-oxide covered bulk SiO 2 and glassy carbon substrates. BSE SEM contrast of NPs is studied as function of the primary electron energy and working distance. Contrast inversions are observed which prevent intuitive interpretation of NP contrast in terms of material contrast. Experimental data is quantitatively compared with Monte-Carlo- (MC-) simulations. Quantitative agreement between experimental data and MC-simulations is obtained if the transmission characteristics of the annular semiconductor detector are taken into account. MC-simulations facilitate the understanding of NP contrast inversions and are helpful to derive conditions for optimum material and topography contrast.

  14. Incorporating Latent Variables into Discrete Choice Models - A Simultaneous Estimation Approach Using SEM Software

    Directory of Open Access Journals (Sweden)

    Dirk Temme

    2008-12-01

    Full Text Available Integrated choice and latent variable (ICLV models represent a promising new class of models which merge classic choice models with the structural equation approach (SEM for latent variables. Despite their conceptual appeal, applications of ICLV models in marketing remain rare. We extend previous ICLV applications by first estimating a multinomial choice model and, second, by estimating hierarchical relations between latent variables. An empirical study on travel mode choice clearly demonstrates the value of ICLV models to enhance the understanding of choice processes. In addition to the usually studied directly observable variables such as travel time, we show how abstract motivations such as power and hedonism as well as attitudes such as a desire for flexibility impact on travel mode choice. Furthermore, we show that it is possible to estimate such a complex ICLV model with the widely available structural equation modeling package Mplus. This finding is likely to encourage more widespread application of this appealing model class in the marketing field.

  15. Vegetable processing wastes addition to improve swine manure anaerobic digestion: Evaluation in terms of methane yield and SEM characterization

    International Nuclear Information System (INIS)

    Molinuevo-Salces, Beatriz; González-Fernández, Cristina; Gómez, Xiomar; García-González, María Cruz; Morán, Antonio

    2012-01-01

    Highlights: ► Vegetable waste as co-substrate for swine manure anaerobic digestion. ► Two hydraulic retention times of 25 and 15 d, respectively. ► SEM characterization of anaerobic sludges to observe microbial composition. ► Vegetable waste as co-substrate increases methane yields up to three times. ► Microbial composition changes after 120 d of digestion. -- Abstract: The effect of adding vegetable waste as a co-substrate in the anaerobic digestion of swine manure was investigated. The study was carried out at laboratory scale using semi-continuous stirred tank reactors working at 37 °C. Organic loading rates (OLRs) of 0.4 and 0.6 g VS L −1 d −1 were evaluated, corresponding to hydraulic retention times (HRTs) of 25 and 15 d, respectively. The addition of vegetable wastes (50% dw/dw) resulted in an improvement of 3 and 1.4-fold in methane yields at HRTs of 25 and 15 d, respectively. Changes on microbial morphotypes were studied by Scanning Electron Microscopy (SEM). Samples analyzed were sludge used as inoculum and digestate obtained from swine manure anaerobic reactors. SEM pictures demonstrated that lignocellulosic material was not completely degraded. Additionally, microbial composition was found to change to cocci and rods morphotypes after 120 d of anaerobic digestion.

  16. (AN)AEROBIC BACTERIA FOUND IN SECONDARY-CATARACT MATERIAL - A SEM/TEM STUDY

    NARCIS (Netherlands)

    KALICHARAN, D; JONGEBLOED, WL; LOS, LI; WORST, JGF

    1992-01-01

    Twentyfour patients, who had marked reduction of vision due to secondary-cataract developed after an ECCE, were treated by surgical cleaning of the posterior lens capsule. During this procedure globular secondary-cataract material was removed and collected for morphological examination by SEM and

  17. Morphology of Poly lactide/Polycaprolactone (PLA/PCL) Nano composite by Scanning Electron Microscopy (SEM)

    International Nuclear Information System (INIS)

    Siti Zulaiha Hairaldin; Wan Md Zin Wan Yunus; Norazowa Ibrahim

    2011-01-01

    In this study, Octadecylamine Modified Montmorillonites (ODAMMT) were used to prepare Poly lactide/ Polycaprolactone (PLA/ PCL) nano composites. PLA and PCL mix in 90:10 ratios, using an internal mixer by melt blending technique. The other sample was blend with Natrium Montmorillonite (NaMMT) and Octadecylamine Modified Montmorillonite (ODA-MMT) to produce PLA/ PCL-NaMMT and PLA/ PCL ODAMMT. To characterize the polymer nano composites, X-ray diffraction (XRD), FTIR and SEM analysis were conducted. Comparison of morphology were made up between PLA/ PCL, PLA/ PCL with presence of 7 % of Na-MMT and 7 % ODA-MMT respectively based on SEM micrograph by calculate the number-average diameter. (author)

  18. SEM visualization of glycosylated surface molecules using lectin-coated microspheres

    Science.gov (United States)

    Duke, J.; Janer, L.; Campbell, M.

    1985-01-01

    There are several techniques currently used to localize glycosylated surface molecules by scanning electron microscopy (Grinnell, 1980; Molday, 1976; Linthicum and Sell, 1975; Nicolson, 1974; Lo Buglio, et al, 1972). A simple and rapid method, using a modification of Grinnell's technique is reported here. Essentially, microspheres coated with Concavalin A are used to bind to glycosylated regions of the palatal shelf epithelium and are visualized in the scanning electron microscope (SEM).

  19. Charging effects of PET under electron beam irradiation in a SEM

    International Nuclear Information System (INIS)

    Jbara, O; Rondot, S; Hadjadj, A; Patat, J M; Fakhfakh, S; Belhaj, M

    2008-01-01

    This paper deals with charge trapping and charge transport of polyethylene terephthalate (PET) polymer subjected to electron irradiation in a scanning electron microscope (SEM). Measurement of displacement current and leakage current using an arrangement adapted to the SEM allows the amount of trapped charge during and after electron irradiation to be determined and the charge mechanisms regulation to be studied. These mechanisms involve several parameters related to the electronic injection, the characteristics of insulator and the effects of the trapped charge itself. The dynamic trapping properties of PET samples are investigated and the time constants of charging are evaluated for various conditions of irradiation. The determination of the trapping cross section for electrons is possible by using the trapping rate at the onset of irradiation. Many physical processes are involved in the charging and discharging mechanisms; among them surface conduction is outlined. Through the control of irradiation conditions, various types of surface discharging (flashover phenomenon) behaviour are also observed. The strength of the electric field initiating surface discharge is estimated.

  20. Afasia global sem hemiparesia: AVC ou transtorno conversivo?

    OpenAIRE

    Negreiros,Daniel Philippi de; Fregni,Felipe; Scalco,Andréia Zavaloni

    2007-01-01

    CONTEXTO: A realização de diagnóstico neurológico e psiquiátrico em ambiente de emergência hospitalar com freqüência é uma tarefa complexa e exige colaboração interdisciplinar. Um dos diagnósticos diferenciais de doenças neurológicas é o transtorno conversivo, cuja característica principal é a presença de sintomas afetando funções motoras ou sensoriais, que sugerem desordem clínica ou neurológica, porém sem doença orgânica subjacente que explique o quadro. RELATO DE CASO: Os autores relatam o...

  1. Structural characterization of degradation of ODS composite using SEM and XRM techniques

    Directory of Open Access Journals (Sweden)

    Oladayo OLANIRAN

    2017-07-01

    Full Text Available The structural characteristics and mechanisms of corrosion and wear of oxide dispersion strengthened stainless steel composite were investigated. Insitu synchrotron x-ray tomography was used as experimental technique for degradation analysis from the corrosion and tribology studies. Corrosion study was carried out using potential dynamic techniques while the tribology experiments were conducted using a tribometer with ball on disc method. The x-ray micro tomography data gave chronological description of crack initiation and propagation in 3D and revealed that pitting did not result from the oxide inclusion. The results also revealed the surface imaging capacity of SEM and XRM’s capability for imaging internal structures. Taber index measurement was used as a complimenting tool for tribology measurements. Tribological behaviour of the sinter Oxide Dispersion Strengthened (ODS steel composite depends on both the composition of the composite and the loading system.

  2. Microstructure investigations of Ba-Sr mixed ferrites, using SEM technique

    International Nuclear Information System (INIS)

    Amighian, J.; Mozaffari, M.

    1996-01-01

    A series of isotropic Ba-Sr mixed ferrites were prepared, using a conventional dry technique. The starting materials were hematite by product of Isfahan steel factory, strontium carbonate from Merck company and barium carbonate obtained from local source. The principle phase of the samples was chosen to have a composition in the form of (BaO) sub 1-x (SrO) sub x nFe sub 2 O sub 3, in which x varied between 0 to l and n was varied between 5 to 6. The raw materials were thoroughly mixed and fired in an electrical furnace for 2 hours. They were then milled in an vibrating ball mill, in which the optimum milling time for each sample was obtained. After annealing at 750 degree C, the powders were compacted in a cylindrical die under 5 tons/cm sup 2. The compacts were then mixed with a binder and sintered in air for 10 minutes at their optimum temperatures. Using SEM technique, the microstructure of the samples were investigated. Using a permeameter, the coercive force Hc and remanent induction Br were measured. The microstructures obtained from SEM technique can be used to control the sintering stage in ferrite fabrication

  3. Los animales y el cuerpo en el refranero: un análisis semántico

    Directory of Open Access Journals (Sweden)

    María del Refugio Pérez Paredes

    2013-07-01

    Full Text Available ResumenEste trabajo muestra un análisis de las paremias en español conformadas por sustantivos anatómicos y faunísticos cuya interpretación es metafórica. La propuesta consiste en explicar el sentido de estas expresiones a partir de los marcos semánticos de los sustantivos de ambos dominios, ya que, aunque se ha señalado que este tipo de construcciones no son susceptibles de un análisis componencial, consideramos que, recurriendo a la semántica de marcos, es posible encontrar su motivación semántica. AbstractThis work presents an analysis of some proverbs in Spanish that are built upon anatomic and faunistic nouns, and that have a metaphoric interpretation. The approach consists in explaining these expressions’ meanings using noun semantic frames in both domains. Although there has been pointed out that these constructions can’t be analyzed componentially, we consider that using frame semantics it is possible to find their semantic motivation.Key words: proverb – metaphor – anatomic domain – faunistic domain

  4. Diseño y desarrollo de exámenes a través de herramientas de web semántica

    Directory of Open Access Journals (Sweden)

    María del Mar Sánchez Vera

    2011-12-01

    Full Text Available La Web Semántica no es una propuesta de futuro. Es una realidad. Frente al crecimiento caótico de recursos y la ausencia de una organización clara de la Web actual, la Web semántica aboga por clasificar, dotar de estructura y anotar los recursos con semántica explícita procesable por máquinas. En este artículo presentamos los resultados de una investigación realizada en la Universidad de Murcia por el grupo TECNOMOD y el GITE, que de manera multidisciplinar hemos abordado la aplicación de un programa semántico denominado OeLE en una asignatura virtual de la Titulación de Pedagogía. Se diseñó un entorno de evaluación en red compuesto por el programa OeLE y un sistema de consulta del feedback que OeLE proporciona con el fin de proponer una metodología referida al diseño y evaluación de situaciones en red con herramientas de Web Semántica.

  5. Contrast of Backscattered Electron SEM Images of Nanoparticles on Substrates with Complex Structure

    Directory of Open Access Journals (Sweden)

    Thomas Kowoll

    2017-01-01

    Full Text Available This study is concerned with backscattered electron scanning electron microscopy (BSE SEM contrast of complex nanoscaled samples which consist of SiO2 nanoparticles (NPs deposited on indium-tin-oxide covered bulk SiO2 and glassy carbon substrates. BSE SEM contrast of NPs is studied as function of the primary electron energy and working distance. Contrast inversions are observed which prevent intuitive interpretation of NP contrast in terms of material contrast. Experimental data is quantitatively compared with Monte-Carlo- (MC- simulations. Quantitative agreement between experimental data and MC-simulations is obtained if the transmission characteristics of the annular semiconductor detector are taken into account. MC-simulations facilitate the understanding of NP contrast inversions and are helpful to derive conditions for optimum material and topography contrast.

  6. Characterising palladium-silver and palladium-nickel alloy membranes using SEM, XRD and PIXE

    International Nuclear Information System (INIS)

    Keuler, J.N.; Lorenzen, L.; Sanderson, R.D.; Prozesky, V.; Przybylowicz, W.J.

    1999-01-01

    Palladium alloy membranes were prepared by successive electroless plating steps on an alumina-zirconia support membrane. Palladium, silver and nickel were deposited in layers and then the metal films were heat treated for 5 h in a hydrogen atmosphere at 650 deg. C. The topography of the metal coatings and cross-sections of the films (before and after heating) were characterised using scanning electron microscopy (SEM). XRD was used to determine the crystal phase of the alloy coatings. Both SEM and XRD provide only surface information and therefore micro-PIXE was used to extract depth information of the alloy coating. Concentration profiles across the thickness of the films were constructed to determine penetration of the coating into the support membrane pores during electroless plating and to investigate diffusion of coated layers during the heating step

  7. Nutrition, Balance and Fear of Falling as Predictors of Risk for Falls among Filipino Elderly in Nursing Homes: A Structural Equation Model (SEM)

    Science.gov (United States)

    de Guzman, Allan B.; Ines, Joanna Louise C.; Inofinada, Nina Josefa A.; Ituralde, Nielson Louie J.; Janolo, John Robert E.; Jerezo, Jnyv L.; Jhun, Hyae Suk J.

    2013-01-01

    While a number of empirical studies have been conducted regarding risk for falls among the elderly, there is still a paucity of similar studies in a developing country like the Philippines. This study purports to test through Structural Equation Modeling (SEM) a model that shows the interaction between and among nutrition, balance, fear of…

  8. Nanomanufacturing Concerns about Measurements Made in the SEM Part IV: Charging and its Mitigation.

    Science.gov (United States)

    Postek, Michael T; Vladár, András E

    2015-01-01

    This is the fourth part of a series of tutorial papers discussing various causes of measurement uncertainty in scanned particle beam instruments, and some of the solutions researched and developed at NIST and other research institutions. Scanned particle beam instruments especially the scanning electron microscope (SEM) have gone through tremendous evolution to become indispensable tools for many and diverse scientific and industrial applications. These improvements have significantly enhanced their performance and made them far easier to operate. But, the ease of operation has also fostered operator complacency. In addition, the user-friendliness has reduced the apparent need for extensive operator training. Unfortunately, this has led to the idea that the SEM is just another expensive "digital camera" or another peripheral device connected to a computer and that all of the problems in obtaining good quality images and data have been solved. Hence, one using these instruments may be lulled into thinking that all of the potential pitfalls have been fully eliminated and believing that, everything one sees on the micrograph is always correct. But, as described in this and the earlier papers, this may not be the case. Care must always be taken when reliable quantitative data are being sought. The first paper in this series discussed some of the issues related to signal generation in the SEM, including instrument calibration, electron beam-sample interactions and the need for physics-based modeling to understand the actual image formation mechanisms to properly interpret SEM images. The second paper has discussed another major issue confronting the microscopist: specimen contamination and methods to eliminate it. The third paper discussed mechanical vibration and stage drift and some useful solutions to mitigate the problems caused by them, and here, in this the fourth contribution, the issues related to specimen "charging" and its mitigation are discussed relative to

  9. Dialética da pratica e ação sem prática

    Directory of Open Access Journals (Sweden)

    Ubaldo Puppi

    1982-12-01

    Full Text Available O conceito de prática recobriria o de sistema de ação, não fosse a existência de sistemas de ação sem prática. Resta que uma prática é um sistema de ação. Como conseqüência, suposta a reciprocação de sistema com teoria e uma atenta inspeção nos termos da proposição, há equivalência semântica entre "prática teórica " e "sistema de ação prático". Num e noutro caso, a contradição interna aos pares de conceitos se resolve dialeticamente. Graças à dialética, são fundidos numa unidade de sentido, síntese de tensões opostas. Daí a proposta de uma dialética da prática global, conjuntamente abstrata e histórica. Destotalizada ou à margem dessa dialética, pode ser destacada a ação sem prática, exemplificada no drama. Dramática é precisamente uma ação que não é prática. O tempo e o lugar da prática são a história e o mundo do homem; o tempo e o lugar do drama são a ficção cultural e a substância simbólica. Mimese da prática, o drama, reproduz, não os traços do modelo, mas a sua produção, tornando-se por sua vez modelo do modelo. Mimese não é cópia, é forma autônoma de eficiência, paradoxalmente sem prática mas especular.

  10. Treatment of dentin with stannous fluoride - SEM and electron microprobe study

    International Nuclear Information System (INIS)

    Ellingsen, J.E.; Roella, G.

    1987-01-01

    The effect of SnF 2 -treatment of dentin surfaces was investigated by means of scanning electron microscopy (SEM) and electron microprobe analysis. Human dentin was treated with aqueous SnF 2 solutions of concentrations varying from 1 to 10%. The treatment periods lasted for 1, 5, 10 or 60 min. Both tin and fluoride were identified on the surfaces. The concentration varied depending on the extensiveness of the treatment. Immersion in 1 M KOH for 15 h removed both tin and fluoride from the surfaces. This reaction was not observed after immersion in H 2 O for the same time period. Examination of the SnF 2 -treated dentin surfaces showed a dense layer of globular particles and in addition some larger particles. The dentinal tubules were totally covered even after the treatment with the lowest concentration of SnF 2 . Deposition of tin- and fluoride-containing globules on dentin surfaces may be of clinical interest. This layer may have importance both for the caries resistance of dentin and for hypersensitivity reactions. (author)

  11. Modification of the microstructure of the films formed by gamma irradiated starch examined by SEM

    Science.gov (United States)

    Cieśla, K.; Sartowska, B.

    2016-01-01

    The paper concerns the effect of gamma irradiation carried out for starch on the microstructure of the films prepared using the starch and its composition with sodium laurate (NaLau) and cetyltrimethylammonium bromide (CTAB) studied by scanning electron microscopy (SEM). Potato starch was irradiated with 60Co gamma rays applying a dose of 30 kGy. Films were prepared by the solution casting method with the addition of 30 wt% glycerol as a plasticizer. Films containing NaLau and CTAB were prepared after performing the procedure, leading to starch-surfactant complexes. Mechanical tests and wetting angle measurements were performed for the films. SEM observations were carried out for the surfaces, fractures and/or sections of the films subjected to chemical fixation and for the dried films. The films obtained using irradiated starch are characterized by a smoother and more homogeneous structure as compared to those based on the non-irradiated starch. Besides, a number of small precipitates were observed on the films surfaces after drying and the number of those precipitates seemed to be higher after irradiation. The results can be related to differences in the microstructure of gels formed on the intermediate step of the films preparation and to the presence of two phases in the system and might serve for explanation of the radiation induced improvement of the hydrophilic/hydrophobic properties, a modification of the mechanical properties of the films, as well as for the changes of those properties resulting after storage.

  12. Frames e dicionários onomasiológicos: uma proposta na interface entre semântica cognitiva e lexicografia

    OpenAIRE

    Diego Spader de Souza; Rove Chishman

    2017-01-01

    O objetivo do presente artigo é tecer algumas considerações iniciais a respeito de uma proposta teórico-metodológica situada na interface entre a Semântica Cognitiva e a Lexicografia. Tal proposta, atualmente sendo desenvolvida em tese de doutorado, busca a aproximação entre a teoria da Semântica de Frames, de Charles J. Fillmore, com a onomasiologia e com a produção de dicionários onomasiológicos. A onomasiologia, tema de grande importância para a Semântica Estrutural, pode ser abordada, sob...

  13. El formalismo semántico en la interfaz de Lenguaje Natural de Prógenes

    OpenAIRE

    Díaz, Julia; Julio, Gonzalo; Rodríguez Marín, Pilar

    1994-01-01

    El presente artículo describe los mecanismos semánticos que ponen en relación el enunciado, en castellano, de un problema de matemáticas o física y su representación en el lenguaje formal Prógenes. Aunque inspirados en el formalismo semántico de UCG (Gramática Categorial de Unificación), la distancia entre sus principios generales y la aplicación práctica en nuestro dominio requiere su adaptación y modificación. En Prógenes, para incorporar las modificaciones se sigue un paradigma de represen...

  14. A Miniaturized Variable Pressure Scanning Electron Microscope (MVP-SEM) for the Surface of Mars: An Instrument for the Planetary Science Community

    Science.gov (United States)

    Edmunson, J.; Gaskin, J. A.; Danilatos, G.; Doloboff, I. J.; Effinger, M. R.; Harvey, R. P.; Jerman, G. A.; Klein-Schoder, R.; Mackie, W.; Magera, B.; hide

    2016-01-01

    The Miniaturized Variable Pressure Scanning Electron Microscope(MVP-SEM) project, funded by the NASA Planetary Instrument Concepts for the Advancement of Solar System Observations (PICASSO) Research Opportunities in Space and Earth Science (ROSES), will build upon previous miniaturized SEM designs for lunar and International Space Station (ISS) applications and recent advancements in variable pressure SEM's to design and build a SEM to complete analyses of samples on the surface of Mars using the atmosphere as an imaging medium. By the end of the PICASSO work, a prototype of the primary proof-of-concept components (i.e., the electron gun, focusing optics and scanning system)will be assembled and preliminary testing in a Mars analog chamber at the Jet Propulsion Laboratory will be completed to partially fulfill Technology Readiness Level to 5 requirements for those components. The team plans to have Secondary Electron Imaging(SEI), Backscattered Electron (BSE) detection, and Energy Dispersive Spectroscopy (EDS) capabilities through the MVP-SEM.

  15. Mars Methane at Gale Crater Shows Strong Seasonal Cycle: Updated Results from TLS-SAM on Curiosity

    Science.gov (United States)

    Webster, C. R.; Mahaffy, P. R.; Atreya, S. K.; Flesch, G.; Malespin, C.; McKay, C.; Martinez, G.; Moores, J.; Smith, C. L.; Martin-Torres, F. J.; Gomez-Elvira, J.; Zorzano, M. P.; Wong, M. H.; Trainer, M. G.; Eigenbrode, J. L.; Glavin, D. P.; Steele, A.; Archer, D., Jr.; Sutter, B.; Coll, P. J.; Freissinet, C.; Meslin, P. Y.; Pavlov, A.; Keymeulen, D.; Christensen, L. E.; Gough, R. V.; Schwenzer, S. P.; Navarro-Gonzalez, R.; Pla-García, J.; Rafkin, S. C.; Vicente-Retortillo, Á.; Kahanpää, H.; Viudez-Moreiras, D.; Smith, M. D.; Harri, A. M.; Genzer, M.; Hassler, D.; Lemmon, M. T.; Crisp, J. A.; Zurek, R. W.; Vasavada, A. R.

    2017-12-01

    In situ measurements of atmospheric methane have been made over a 5-year period at Gale Crater on Mars using the Tunable Laser Spectrometer (TLS) instrument in the Sample Analysis at Mars (SAM) suite on the Curiosity rover. We report two important observations: (i) a background level of mean value of 0.41 ±0.11 (2sem) that is about 5 times lower than some model predictions based on generation from UV degradation of micro-meteorites or interplanetary dust delivered to the martian surface; (ii) "spikes" of elevated levels of 7 ppbv attributed to episodic releases from small local sources, probably to the north of Gale crater1. Reports of plumes, patches or episodic releases of methane in the Martian atmosphere have to date eluded explanation in part because of their lack of repeatability in time or location. Our in situ measurements of the background methane levels exhibit a strong, repeatable seasonal variability. The amplitude of the observed seasonal cycle is 3 times greater than both that expected from the annual sublimation and freezing of polar carbon dioxide and that expected from methane production from ultraviolet (UV) degradation of exogenously-delivered surface material. The observed large seasonal variation in the background, and sporadic observations of higher pulses of 7 ppbv appear consistent with localized small sources of methane release from Martian surface reservoirs that may be occurring throughout the planet. We will present our updated data set, correlations of Mars methane with various other measurements from SAM, REMS, RAD and ChemCam instruments on Curiosity, as well as empirical models of UV surface insolation, and provide preliminary interpretation of results. 1 "Mars Methane Detection and Variability at Gale Crater", C. R. Webster et al., Science, 347, 415-417 (2015) and references therein. The research described here was carried out in part at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the

  16. Image contrast enhancement of Ni/YSZ anode during the slice-and-view process in FIB-SEM.

    Science.gov (United States)

    Liu, Shu-Sheng; Takayama, Akiko; Matsumura, Syo; Koyama, Michihisa

    2016-03-01

    Focused ion beam-scanning electron microscopy (FIB-SEM) is a widely used and easily operational equipment for three-dimensional reconstruction with flexible analysis volume. It has been using successfully and increasingly in the field of solid oxide fuel cell. However, the phase contrast of the SEM images is indistinct in many cases, which will bring difficulties to the image processing. Herein, the phase contrast of a conventional Ni/yttria stabilized zirconia anode is tuned in an FIB-SEM with In-Lens secondary electron (SE) and backscattered electron detectors. Two accessories, tungsten probe and carbon nozzle, are inserted during the observation. The former has no influence on the contrast. When the carbon nozzle is inserted, best and distinct contrast can be obtained by In-Lens SE detector. This method is novel for contrast enhancement. Phase segmentation of the image can be automatically performed. The related mechanism for different images is discussed. © 2015 The Authors Journal of Microscopy © 2015 Royal Microscopical Society.

  17. A study of equilibrium and FTIR, SEM/EDS analysis of trimethoprim adsorption onto K10

    Science.gov (United States)

    Bekçi, Zehra; Seki, Yoldaş; Kadir Yurdakoç, M.

    2007-02-01

    The sorption behavior of K10, a type of montmorillonite for trimethoprim (TMP) drug, was studied by using batch technique under different pH and temperature. The interaction between K10 and TMP was investigated using SEM, and FTIR. It was observed that adsorption was increased between pH 2.5 and 6.3. By performing kinetic experiments, the pseudo-second-order kinetic model provides the best fit for TMP adsorption onto K10 montmorillonite. The sorption of TMP reached the equilibrium state after 6 h sorption time and has been described by using Langmuir, Freundlich and Dubinin-Radushkevich equations to obtain adsorption capacity values. The results indicate that the relative adsorption capacity values ( Kf) are decreasing with the increase of temperature in the range of 298-318 K. The sorption energy values obtained from DR isotherm show that sorption of TMP onto K10 can be explained by ion exchange mechanism at 298, 308 and 318 K. The thermodynamic studies were conducted to find the thermodynamic parameters Δ H°, Δ S° and Δ G°. It was determined that adsorption process is spontaneous and exothermic in nature.

  18. Measuring topographies from conventional SEM acquisitions.

    Science.gov (United States)

    Shi, Qiwei; Roux, Stéphane; Latourte, Félix; Hild, François; Loisnard, Dominique; Brynaert, Nicolas

    2018-04-27

    The present study extends the stereoscopic imaging principle for estimating the surface topography to two orientations, namely, normal to the electron beam axis and inclined at 70° as suited for EBSD analyses. In spite of the large angle difference, it is shown that the topography can be accurately determined using regularized global Digital Image Correlation. The surface topography is compared to another estimate issued from a 3D FIB-SEM procedure where the sample surface is first covered by a Pt layer, and its initial topography is progressively revealed from successive FIB-milling. These two methods are successfully compared on a 6% strained steel specimen in an in situ mechanical test. This analysis is supplemented by a third approach estimating the change of topography from crystal rotations as measured from successive EBSD images. This last technique ignores plastic deformation, and thus only holds in an elastic regime. For the studied example, despite the large plastic flow, it is shown that crystal rotation already accounts for a significant part of the deformation-induced topography. Copyright © 2018 Elsevier B.V. All rights reserved.

  19. Linguagens documentárias e vocabulários semânticos para a web: elementos conceituais: resenha

    Directory of Open Access Journals (Sweden)

    Eliana Maria dos Santos Bahia

    2012-01-01

    Full Text Available José Antônio Moreiro González, Professor catedrático de Biblioteconomia e Documentação da Universidad Carlos III de Madrid na Espanha, com experiência na técnica de análise de conteúdo documental e sobre questões conceituais da documentação. O autor trata das Linguagens Documentárias e Vocabulários Semânticos para a Web, que a Editora da Universidade Federal da Bahia apresenta aos leitores. O resultado é um texto com a potencialidade tanto de servir como introdução ao tema para o leitor não especialista como apresentar uma síntese ampla e atualizada dos principais problemas e avanços no estudo das linguagens documentárias e vocabulários semânticos para a web. O livro compõe-se de onze (11 capítulos, delineados pelo autor, descrevendo os elementos conceituais das linguagens documentárias e dos vocabulários semânticos para a web. O primeiro capítulo trata das Bases Epistemológicas da Representação da Informação: origem da representação conceitual, no qual apresenta a origem das relações entre conceitos; os conceitos principais e sua organização em macroestruturas. Análise da leitura dos documentos na pesquisa para obter a informação, o resumo do autor, título, sumários, tabelas, índices, ilustrações, legendas para recuperar a informação. No segundo capítulo (Para Melhor Entender a Recuperação Léxica da Informação, o Autor pontua o acesso contemporâneo à informação dos documentos, com os respectivos conceitos - da representação do na era sociedade do conhecimento. O terceiro capítulo (Requerimentos Fundamentais da Nova Web, compreende-se três seções: dimensões da web social e da web semântica; finalidade da chamada web semântica, e; possibilidades de evolução. O autor aponta as mudanças especificando a web 2.0 e sua evolução para a web semântica; a web 2.0 e a web semântica convirjam para web 3.0; e a web 2.0 e a web semântica coexistindo harmoniosamente no ciberespa

  20. Linguagens documentárias e vocabulários semânticos para a web: elementos conceituais: resenha

    Directory of Open Access Journals (Sweden)

    Eliana Maria dos Santos Bahia

    2012-08-01

    Full Text Available http://dx.doi.org/10.5007/1518-2924.2012v17n34p193   José Antônio Moreiro González, Professor catedrático de Biblioteconomia e Documentação da Universidad Carlos III de Madrid na Espanha, com experiência na técnica de análise de conteúdo documental e sobre questões conceituais da documentação. O autor trata das Linguagens Documentárias e Vocabulários Semânticos para a Web, que a Editora da Universidade Federal da Bahia apresenta aos leitores. O resultado é um texto com a potencialidade tanto de servir como introdução ao tema para o leitor não especialista como apresentar uma síntese ampla e atualizada dos principais problemas e avanços no estudo das linguagens documentárias e vocabulários semânticos para a web. O livro compõe-se de onze (11 capítulos, delineados pelo autor, descrevendo os elementos conceituais das linguagens documentárias e dos vocabulários semânticos para a web. O primeiro capítulo trata das Bases Epistemológicas da Representação da Informação: origem da representação conceitual, no qual apresenta a origem das relações entre conceitos; os conceitos principais e sua organização em macroestruturas. Análise da leitura dos documentos na pesquisa para obter a informação, o resumo do autor, título, sumários, tabelas, índices, ilustrações, legendas para recuperar a informação. No segundo capítulo (Para Melhor Entender a Recuperação Léxica da Informação, o Autor pontua o acesso contemporâneo à informação dos documentos, com os respectivos conceitos - da representação do na era sociedade do conhecimento. O terceiro capítulo (Requerimentos Fundamentais da Nova Web, compreende-se três seções: dimensões da web social e da web semântica; finalidade da chamada web semântica, e; possibilidades de evolução. O autor aponta as mudanças especificando a web 2.0 e sua evolução para a web semântica; a web 2.0 e a web semântica convirjam para web 3.0; e a web 2.0 e a web

  1. Comparison of Enamel Morphologic Characteristics after Conditioning with Various Combinations of Acid Etchant and Er:YAG Laser in Bonding and Rebonding Procedures: A SEM Analysis

    Directory of Open Access Journals (Sweden)

    Mohammad Sadegh Ahmad Akhoundi

    2017-10-01

    Full Text Available Objectives: Many studies have evaluated re-etched enamel by using scanning electron microscopy (SEM; however, there is no evidence regarding the use of Erbium-doped yttrium aluminium garnet (Er:YAG laser at primary and secondary bonding instead of acid etching with regards to enamel surface changes. The purpose of the present study was to determine that whether or not the methods of primary and secondary enamel preparation affect enamel characteristics after rebonding, by using SEM analysis.Materials and Methods: Twelve freshly extracted premolars were divided into 4 groups. The samples in each group were conditioned by acid etchant or Er:YAG laser at primary conditioning, according to the instructions. Afterwards, they were bonded with orthodontic brackets. After debonding, the samples were prepared for second conditioning. Also, two samples were conditioned only once with acid etchant or laser, to compare enamel morphology changes with those after re-etching. Finally, buccal enamel surfaces were evaluated using SEM.Results: Enamel etching patterns were observed in the samples which had been acid-conditioned at first or at both conditionings. The samples irradiated by Er:YAG laser showed amorphous and irregular surfaces, with no signs of typical etching patterns. A large deep gap was seen in one of the samples irradiated with laser at primary and secondary conditionings, which might have penetrated the underling layers of enamel and dentin.Conclusions: Enamel surface preparation with Er:YAG laser produces irregular and indistinct morphologic changes, completely different from those produced after acid etching at both conditioning and reconditioning. Therefore, it is recommended to use this laser with caution to avoid permanent enamel damage.

  2. MULTIMODALIDADE E A CONSTRUÇÃO DA IDENTIDADE DO SEM-TERRA

    Directory of Open Access Journals (Sweden)

    Vanderleiidalice J. Zacchi

    2009-12-01

    Full Text Available RESUMO: O objetivo deste trabalho é analisar a maneira como o movimento dos Trabalhadores Rurais Sem Terra (mST utiliza os diferentesmodos de produçãode significado e como, nesse processo, é construída sua identidade. A análise será efetuada principalmente a partir de textos impressos, digitais e eletrônicos produzidos pelos sem-terra. Apesar de fazer bom uso das diversas habilidades pressupostas na multimodalidade, o movimento ainda se apoia fortemente no modo linguístico tanto na autorrepresentação quanto na ação social. PALAVRAS-CHAVE: multiletramento, mST, identidade, Internet, mídia. ABSTRACT: This paper aims at analysing the identity construction of the Landless Rural Workers movement (mST by making use of different modes of meaning-construction. The data provided for analysis are based especially on printed, electronic, and digital texts produced by the movement. Although the mST uses multimodal texts extensively, it still relies heavily on the linguistic mode when engaging in both self-representation and social action. KEYWORDS: multiliteracies, landless movement, identity, Internet, media.

  3. Prescriptive Statements and Educational Practice: What Can Structural Equation Modeling (SEM) Offer?

    Science.gov (United States)

    Martin, Andrew J.

    2011-01-01

    Longitudinal structural equation modeling (SEM) can be a basis for making prescriptive statements on educational practice and offers yields over "traditional" statistical techniques under the general linear model. The extent to which prescriptive statements can be made will rely on the appropriate accommodation of key elements of research design,…

  4. Raman, SEM-EDS and XRPD investigations on pre-Columbian Central America "estucado" pottery

    Science.gov (United States)

    Casanova Municchia, Annalaura; Micheli, Mario; Ricci, Maria Antonietta; Toledo, Michelle; Bellatreccia, Fabio; Lo Mastro, Sergio; Sodo, Armida

    2016-03-01

    Seventeen different colored fragments from six selected pre-Columbian estucado ceramics from El Salvador have been investigated by Raman spectroscopy, scanning electron microscope coupled to an energy dispersive spectrometer (SEM/EDS) and X-ray powder diffraction (XRPD). The peculiarity of this kind of ceramics consist of the unusual presence of a white engobe, traditionally termed stucco, between the ceramic body and the decoration elements, hence the name estucado ceramics. The aim of this work was to study the unusual manufacturing technique and to identify the chemical composition of the engobe and of the pigment palette. The results showed that the stucco layer is made of clay (kaolinite) with traces of titanium oxide (anatase). Remarkably, this is the same composition of the white pigments used for the decoration layer, thus excluding an early use of natural titanium oxide as a white pigment in the estucado productions as suggested in previous investigations. Moreover, the presence of kaolinite and anatase both in the stucco and in the decoration layer suggests a cold-working or low temperature technique. The red, yellow and green decorations were realized by the use of natural ochre, while in all the blue and gray decorations Maya blue pigment was identified. Finally, an amorphous carbon pigment of vegetal origin and manganese oxide were used to obtain black pigments.

  5. A simplified method for scanning electron microscopy (SEM) autoradiography

    International Nuclear Information System (INIS)

    Shahar, A.; Lasher, R.

    1980-01-01

    The combination of autoradiography with SEM provides a valuable tool for the study of labeled biological materials, but the previously described methods are complicated because they call first for the removal of gelatin from the film emulsion and this is then followed by deposition of gold vapor on the specimen. The authors describe a much simpler method which can easily be adapted to routine examination of cell cultures. In this method, gelatin is not removed; the film is coated with vaporized carbon only. This procedure permits visualization of both cellular image and distribution of silver grains. (Auth.)

  6. Dynamic Correction of Higher-Order Deflection Aberrations in the Environmental SEM

    Czech Academy of Sciences Publication Activity Database

    Oral, Martin; Neděla, Vilém

    2015-01-01

    Roč. 21, S4 (2015), s. 194-199 ISSN 1431-9276 R&D Projects: GA ČR(CZ) GA14-22777S; GA MŠk(CZ) LO1212 Institutional support: RVO:68081731 Keywords : environmental SEM * ESEM * shifted deflection pivot point * Higher order deflection aberrations * vignetting * dynamic focusing * dynamic stigmator * dynamic correction Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 1.730, year: 2015

  7. SEM-analysis of grain boundary porosity in three S-176 specimens

    International Nuclear Information System (INIS)

    Malen, K.; Birath, S.; Mattsson, O.

    1980-10-01

    Porosity in UO 2 -fuel has been studied in scanning electron microscope (SEM). The aim was to obtain a basis for evaluation of porosity in high burnup power reactor fuel. Three specimens have been analyzed. In the high temperature zones porosity can be seen both on grain boundaries and at grain edges. In the low temperature regions very little changes seem to have occurred during irradiation. (author)

  8. Chapter 24: Strategic Energy Management (SEM) Evaluation Protocol. The Uniform Methods Project: Methods for Determining Energy Efficiency Savings for Specific Measures

    Energy Technology Data Exchange (ETDEWEB)

    Stewart, James [The Cadmus Group, Portland, OR (United States)

    2017-05-18

    Strategic energy management (SEM) focuses on achieving energy-efficiency improvements through systematic and planned changes in facility operations, maintenance, and behaviors (OM&B) and capital equipment upgrades in large energy-using facilities, including industrial buildings, commercial buildings, and multi-facility organizations such as campuses or communities. Facilities can institute a spectrum of SEM actions, ranging from a simple process for regularly identifying energy-savings actions, to establishing a formal, third-party recognized or certified SEM framework for continuous improvement of energy performance. In general, SEM programs that would be considered part of a utility program will contain a set of energy-reducing goals, principles, and practices emphasizing continuous improvements in energy performance or savings through energy management and an energy management system (EnMS).

  9. Julgar sem preceptivas, julgar pelo universal: glosas modernistas a Kant To judge without preceptive, to judge by universal: modernist comments about Kant

    Directory of Open Access Journals (Sweden)

    Priscila Rossinetti Rufinoni

    2010-01-01

    Full Text Available Este artigo busca pensar os juízos estéticos da Terceira crítica de Kant, em relação aos discursos sobre a arte moderna. Propomos, de maneira didática, relacionar tais juízos kantianos à utopia da modernidade e às suas consequências (e críticas contemporâneas. Não tencionamos, porém, fazer uma análise pormenorizada do pensamento de Kant, propriamente, mas expor as várias glosas que este recebeu, ao inaugurar um outro espaço para a Estética, principalmente no que se refere à arena comunitária na qual se agenciam os juízos e que torna possível uma arte ao mesmo tempo universal e sem regras fixas. Mais do que pensar a arte como "livre jogo", ou como "bela" e como "finalidade sem fim", pontos nodais da crítica de Kant, sem dúvida, interessa-nos investigar a perspectiva autorreflexiva que os juízos estéticos permitem. A interpretação do objeto-arte moderno não seria, em última instância, o exercício comunitário de um juízo?This article aims to show the aesthetic judgments of the Third critique of Kant in relation to the discourses on modern art. In didactic manner, we propose to show the relationship between the Kantians judgments and the artistic modernity, its development and its contemporary criticism. We do not propose, however, a detailed analysis of Kant's philosophy, but expose the various interpretations which this philosophy received when it opened another space for Aesthetic. This article does not show art as "free play" or as "beautiful" and as "finality without end", but investigates the autoreflexivity of the aesthetic judgments. The interpretation of the modern art could be, ultimately, an exercise of communal judgments?

  10. Mechatronic Development and Vision Feedback Control of a Nanorobotics Manipulation System inside SEM for Nanodevice Assembly

    Directory of Open Access Journals (Sweden)

    Zhan Yang

    2016-09-01

    Full Text Available Carbon nanotubes (CNT have been developed in recent decades for nanodevices such as nanoradios, nanogenerators, carbon nanotube field effect transistors (CNTFETs and so on, indicating that the application of CNTs for nanoscale electronics may play a key role in the development of nanotechnology. Nanorobotics manipulation systems are a promising method for nanodevice construction and assembly. For the purpose of constructing three-dimensional CNTFETs, a nanorobotics manipulation system with 16 DOFs was developed for nanomanipulation of nanometer-scale objects inside the specimen chamber of a scanning electron microscope (SEM. Nanorobotics manipulators are assembled into four units with four DOFs (X-Y-Z-θ individually. The rotational one is actuated by a picomotor. That means a manipulator has four DOFs including three linear motions in the X, Y, Z directions and a 360-degree rotational one (X-Y-Z-θ stage, θ is along the direction rotating with X or Y axis. Manipulators are actuated by picomotors with better than 30 nm linear resolution and <1 micro-rad rotary resolution. Four vertically installed AFM cantilevers (the axis of the cantilever tip is vertical to the axis of electronic beam of SEM served as the end-effectors to facilitate the real-time observation of the operations. A series of kinematic derivations of these four manipulators based on the Denavit-Hartenberg (D-H notation were established. The common working space of the end-effectors is 2.78 mm by 4.39 mm by 6 mm. The manipulation strategy and vision feedback control for multi-manipulators operating inside the SEM chamber were been discussed. Finally, application of the designed nanorobotics manipulation system by successfully testing of the pickup-and-place manipulation of an individual CNT onto four probes was described. The experimental results have shown that carbon nanotubes can be successfully picked up with this nanorobotics manipulation system.

  11. Mechatronic Development and Vision Feedback Control of a Nanorobotics Manipulation System inside SEM for Nanodevice Assembly

    Science.gov (United States)

    Yang, Zhan; Wang, Yaqiong; Yang, Bin; Li, Guanghui; Chen, Tao; Nakajima, Masahiro; Sun, Lining; Fukuda, Toshio

    2016-01-01

    Carbon nanotubes (CNT) have been developed in recent decades for nanodevices such as nanoradios, nanogenerators, carbon nanotube field effect transistors (CNTFETs) and so on, indicating that the application of CNTs for nanoscale electronics may play a key role in the development of nanotechnology. Nanorobotics manipulation systems are a promising method for nanodevice construction and assembly. For the purpose of constructing three-dimensional CNTFETs, a nanorobotics manipulation system with 16 DOFs was developed for nanomanipulation of nanometer-scale objects inside the specimen chamber of a scanning electron microscope (SEM). Nanorobotics manipulators are assembled into four units with four DOFs (X-Y-Z-θ) individually. The rotational one is actuated by a picomotor. That means a manipulator has four DOFs including three linear motions in the X, Y, Z directions and a 360-degree rotational one (X-Y-Z-θ stage, θ is along the direction rotating with X or Y axis). Manipulators are actuated by picomotors with better than 30 nm linear resolution and SEM) served as the end-effectors to facilitate the real-time observation of the operations. A series of kinematic derivations of these four manipulators based on the Denavit-Hartenberg (D-H) notation were established. The common working space of the end-effectors is 2.78 mm by 4.39 mm by 6 mm. The manipulation strategy and vision feedback control for multi-manipulators operating inside the SEM chamber were been discussed. Finally, application of the designed nanorobotics manipulation system by successfully testing of the pickup-and-place manipulation of an individual CNT onto four probes was described. The experimental results have shown that carbon nanotubes can be successfully picked up with this nanorobotics manipulation system. PMID:27649180

  12. Mechatronic Development and Vision Feedback Control of a Nanorobotics Manipulation System inside SEM for Nanodevice Assembly.

    Science.gov (United States)

    Yang, Zhan; Wang, Yaqiong; Yang, Bin; Li, Guanghui; Chen, Tao; Nakajima, Masahiro; Sun, Lining; Fukuda, Toshio

    2016-09-14

    Carbon nanotubes (CNT) have been developed in recent decades for nanodevices such as nanoradios, nanogenerators, carbon nanotube field effect transistors (CNTFETs) and so on, indicating that the application of CNTs for nanoscale electronics may play a key role in the development of nanotechnology. Nanorobotics manipulation systems are a promising method for nanodevice construction and assembly. For the purpose of constructing three-dimensional CNTFETs, a nanorobotics manipulation system with 16 DOFs was developed for nanomanipulation of nanometer-scale objects inside the specimen chamber of a scanning electron microscope (SEM). Nanorobotics manipulators are assembled into four units with four DOFs (X-Y-Z-θ) individually. The rotational one is actuated by a picomotor. That means a manipulator has four DOFs including three linear motions in the X, Y, Z directions and a 360-degree rotational one (X-Y-Z-θ stage, θ is along the direction rotating with X or Y axis). Manipulators are actuated by picomotors with better than 30 nm linear resolution and <1 micro-rad rotary resolution. Four vertically installed AFM cantilevers (the axis of the cantilever tip is vertical to the axis of electronic beam of SEM) served as the end-effectors to facilitate the real-time observation of the operations. A series of kinematic derivations of these four manipulators based on the Denavit-Hartenberg (D-H) notation were established. The common working space of the end-effectors is 2.78 mm by 4.39 mm by 6 mm. The manipulation strategy and vision feedback control for multi-manipulators operating inside the SEM chamber were been discussed. Finally, application of the designed nanorobotics manipulation system by successfully testing of the pickup-and-place manipulation of an individual CNT onto four probes was described. The experimental results have shown that carbon nanotubes can be successfully picked up with this nanorobotics manipulation system.

  13. STEM mode in the SEM for the analysis of cellular sections prepared by ultramicrotome sectioning

    International Nuclear Information System (INIS)

    Hondow, N; Harrington, J; Brydson, R; Brown, A

    2012-01-01

    The use of the dual imaging capabilities of a scanning electron microscope fitted with a transmitted electron detector is highlighted in the analysis of samples with importance in the field of nanotoxicology. Cellular uptake of nanomaterials is often examined by transmission electron microscopy of thin sections prepared by ultramicrotome sectioning. Examination by SEM allows for the detection of artefacts caused by sample preparation (eg. nanomaterial pull-out) and the complementary STEM mode permits study of the interaction between nanomaterials and cells. Thin sections of two nanomaterials of importance in nanotoxicology (cadmium selenide quantum dots and single walled carbon nanotubes) are examined using STEM mode in the SEM.

  14. Controlled dehydration of a biological sample using an alternative form of environmental SEM

    Czech Academy of Sciences Publication Activity Database

    Neděla, Vilém

    2010-01-01

    Roč. 237, č. 1 (2010), s. 7-11 ISSN 0022-2720 Institutional research plan: CEZ:AV0Z20650511 Keywords : biological sample * dehydration * environmental SEM * AQUASEM II * hydration system Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 1.872, year: 2010

  15. Applications of Real Space Crystallography in Characterization of Dislocations in Geological Materials in a Scanning Electron Microscope (SEM)

    Science.gov (United States)

    Kaboli, S.; Burnley, P. C.

    2017-12-01

    Imaging and characterization of defects in crystalline materials is of significant importance in various disciplines including geoscience, materials science, and applied physics. Linear defects such as dislocations and planar defects such as twins and stacking faults, strongly influence many of the properties of crystalline materials and also reflect the conditions and degree of deformation. Dislocations have been conventionally imaged in thin foils in a transmission electron microscope (TEM). Since the development of field emission scanning electron microscopes (FE-SEM) with high gun brightness and small spot size, extensive efforts have been dedicated to the imaging and characterization of dislocations in semi-conductors using electron channeling contrast imaging (ECCI) in the SEM. The obvious advantages of using SEM over TEM include easier and non-destructive sample preparation and a large field of view enabling statistical examination of the density and distribution of dislocations and other defects. In this contribution, we extend this technique to geological materials and introduce the Real Space Crystallography methodology for imaging and complete characterization of dislocations based on bend contour contrast obtained by ECCI in FE-SEM. Bend contours map out the distortion in the crystal lattice across a deformed grain. The contrast of dislocations is maximum in the vicinity of bend contours where crystal planes diffract at small and positive deviations from the Bragg positions (as defined by Bragg's law of electron diffraction). Imaging is performed in a commercial FE-SEM equipped with a standard silicon photodiode backscattered (BSE) detector and an electron backscatter diffraction (EBSD) system for crystal orientation measurements. We demonstrate the practice of this technique in characterization of a number of geological materials in particular quartz, forsterite olivine and corundum, experimentally deformed at high pressure-temperature conditions. This

  16. Hemorragia subaracnoídea com tomografia de crânio sem sinais de sangramento Subarachnoidal hemorrhage with cranial tomography without bleeding signals

    Directory of Open Access Journals (Sweden)

    Silvio Francisco

    1997-09-01

    Full Text Available Foram observados 23 casos de pacientes com suspeita clínica de hemorragia subaracnoídea (HSA, com tomografia de crânio (CT sem sinais de sangramento, com diagnóstico definitivo realizado por exame de líquido cefalorraquiano(LCR. Desses, 20 casos foram submetidos a angiografia cerebral. Estabeleceu-se a classificação clínica de Hunt & Hess. Os principais achados neste estudo foram:1 um terço dos pacientes apresentou intervalo de tempo entre o ictus e a realização da CT e do LCR entre 24 e 48 horas, período de maior sensiblidade da CT; 2 dos pacientes estudados com angiografia cerebral, 55% tiveram o diagnóstico de aneurisma com predomínio no território de carótida e cerebral anterior; 3 o grau clínico dominante foi Hunt & Hess I e II. Todos os achados encontrados demonstraram a necessidade da realização de LCR em suspeita de HSA sem sinais de sangramento na CT.We observed 23 pacients with clinical hypothesis of subarachnoidal hemorrhage (SAH having cranial tomography (CT without bleeding signals. The final diagnosis of SAH was made upon the cerebrospinal fluid (CSF results. Twenty cases were submitted to brain angiography. They were focused under the clinical classification of Hunt & Hess. The main results were: 1 1/3 of patients had interval time between 24 and 48 hours after ictus and before CT and CSF making; this was the most sensitive CT time; 2 55% of patients with brain angiography had aneurysm predominantly in the carotid and anterior cerebral artery territory; 3 the dominant clinical degree was Hunt & Hess I e II. Conclusion: the results demonstrate the need of CSF test in case of SAH clinical diagnosis with CT showing no bleeding signals.

  17. Maximum Likelihood Dynamic Factor Modeling for Arbitrary "N" and "T" Using SEM

    Science.gov (United States)

    Voelkle, Manuel C.; Oud, Johan H. L.; von Oertzen, Timo; Lindenberger, Ulman

    2012-01-01

    This article has 3 objectives that build on each other. First, we demonstrate how to obtain maximum likelihood estimates for dynamic factor models (the direct autoregressive factor score model) with arbitrary "T" and "N" by means of structural equation modeling (SEM) and compare the approach to existing methods. Second, we go beyond standard time…

  18. Quality control of clinker products by SEM and XRF analysis

    International Nuclear Information System (INIS)

    Ziad Abu Kaddourah; Khairun Azizi

    1996-01-01

    The microstructure and chemical properties of industrial Portland cement clinkers have been examined by SEM and XRF methods to establish the nature of the clinkers and how variations in the clinker characteristics can be used to control the clinker quality. The clinker nodules were found to show differences in the chemical composition and microstructure between the inner and outer parts of the clinker nodules. Microstructure studies of industrial Portland cement clinker have shown that the outer part of the nodules are enriched in silicate more than the inner part. There is better crystallization and larger alite crystal size in the outer part than in the inner part. The alite crystal size varied between 16.2 -46.12 μ m. The clinker chemical composition was found to affect the residual >45 μ m, where a higher belite content causes an increase in the residual >45 μ m in the the cement product and will cause a decrease in the concrete strength of the cement product. The aluminate and ferrite crystals and the microcracks within the alite crystal are clear in some clinker only. The quality of the raw material preparation, burning and cooling stages can be controlled using the microstructure of the clinker product

  19. Estimation of pattern shape based on CD-SEM image by using MPPC method

    Science.gov (United States)

    Onozuka, T.; Ojima, Y.; Meessen, J.; Rijpers, B.

    2006-03-01

    This study demonstrates the MPPC (Multiple Parameters Profile Characterization) measurement method utilizing ArF photo resist patterns. MPPC is a technique for estimating the three dimensional profile of patterns which are imaged and measured on the CD-SEM (critical dimension scanning electron microscope). MPPC utilizes the secondary electron signal to calculate several indices including top CD, peak CD, top rounding, bottom footing, etc. This primary focused of this study is to understand the variations in pattern profile caused by changes in exposure condition. The results demonstrate the ability to extract pattern profile shape information by MPPC measurement that could not otherwise be detected by a conventional bottom CD measurement method. Furthermore, the results were compared to cross sectional images collected by STEM (scanning transmission electron microscope) to verify the accuracy of the MPPC technique. The peak CD results accurately estimate the pattern width when the sidewall angle of the feature is nearly vertical. Additionally, line edge roughness (LER) caused by pattern profile variations was evaluated utilizing MPPC. The results suggest that MPPC may be utilized to evaluate the roughness over the entire profile.

  20. Módulos interactivos para el aprendizaje de la semántica.

    OpenAIRE

    Aquino Palacios, Ingrid

    2012-01-01

    Se proponen modulos interactivos para lograr el aprendizaje de la semantica en alumnos del V semestre de la Carrera de Lenguas, Literatura y Comunicacion de la Facultad de Educacion de la UNCP. Los metodos utilizados fueron el experimental y el bibliografico-documental. Los instrumentos utilizados fueron la prueba objetiva, prueba de ensayo y la prueba pedagogica. Se logró mejorar el aprendizaje de la semántica 

  1. Protective effect of fluoride varnish and fluoride gel on enamel erosion: roughness, SEM-EDS, and µ-EDXRF studies.

    Science.gov (United States)

    Soares, Luís Eduardo Silva; De Carvalho Filho, Antonio Carlos Belfort

    2015-03-01

    The effects of fluoride treatment on bovine enamel subjected to acid erosion were studied by roughness (Ra) measurements, scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and microenergy-dispersive X-ray fluorescence spectrometry (μ-EDXRF). Enamel samples (63) were divided into nine groups (n = 7): artificial saliva (AS), Pepsi Twist(®) (PT), orange juice (OJ), Duraphat(®)  + Pepsi Twist(®) (DPH/PT), Duraphat(®)  + orange juice (DPH/OJ), Duofluorid(®)  + Pepsi Twist(®) (DUO/PT), Duofluorid(®)  + orange juice (DUO/OJ), fluoride gel + Pepsi Twist(®) (FG/PT), and fluoride gel + orange juice (FG/OJ). Fluoride was applied and the samples were submitted to six cycles (demineralization: Pepsi Twist(®) or orange juice, 10 min; remineralization: saliva, 1 h). The enamel surface in depth was exposed and 63 line-scan maps were performed. The elemental analysis by EDS revealed that only fluoride treated groups had any detectable fluorine after erosion cycles (DPH/PT: 3.50 wt%; DPH/OJ: 3.37 wt%; DUO/PT: 2.69 wt%; DUO/OJ: 3.54 wt%; FG/PT: 2.17 wt%; FG/OJ: 2.77 wt%). PT treatment resulted in significantly higher Ra values than the artificial saliva (P < 0.001). Scanning electron microscopy (SEM) analysis of fluoride protected enamel showed areas with some globular structures or a residual layer of varnish. The enamel thickness was significantly lower in PT (0.63 ± 0.087 mm) than in DPH/PT (0.87 ± 0.16 mm) and DUO/PT (0.92 ± 0.14 mm) groups (P < 0.01). Fluoride treatments protected enamel without Ra increase and loss of enamel tissue. © 2015 Wiley Periodicals, Inc.

  2. Latent vs. Observed Variables : Analysis of Irrigation Water Efficiency Using SEM and SUR

    NARCIS (Netherlands)

    Tang, Jianjun; Folmer, Henk

    In this paper we compare conceptualising single factor technical and allocative efficiency as indicators of a single latent variable, or as separate observed variables. In the former case, the impacts on both efficiency types are analysed by means of structural equationmodeling (SEM), in the latter

  3. Experimental investigation on the influence of instrument settings on pixel size and nonlinearity in SEM image formation

    DEFF Research Database (Denmark)

    Carli, Lorenzo; Genta, Gianfranco; Cantatore, Angela

    2010-01-01

    The work deals with an experimental investigation on the influence of three Scanning Electron Microscope (SEM) instrument settings, accelerating voltage, spot size and magnification, on the image formation process. Pixel size and nonlinearity were chosen as output parameters related to image...... quality and resolution. A silicon grating calibrated artifact was employed to investigate qualitatively and quantitatively, through a designed experiment approach, the parameters relevance. SEM magnification was found to account by far for the largest contribution on both parameters under consideration...

  4. Does your SEM really tell the truth? How would you know? part 3: vibration and drift

    Science.gov (United States)

    Postek, Michael T.; Vladár, András. E.; Cizmar, Petr

    2014-09-01

    This is the third of a series of papers discussing various causes of measurement uncertainty in scanned particle beam instruments, and some of the solutions researched and developed at NIST. Scanned particle beam instruments especially the scanning electron microscope (SEM) have gone through tremendous evolution to become indispensable tools for many and diverse scientifi c and industrial applications. These improvements have signifi cantly enhanced their performance and made them far easier to operate. But, ease of operation has also fostered operator complacency. In addition, the user-friendliness has reduced the need for extensive operator training. Unfortunately, this has led to the concept that the SEM is just another expensive digital camera or another peripheral device connected to a computer and that all of the issues related to obtaining quality data have been solved. Hence, a person (or company) using these instruments may be lulled into thinking that all of the potential pitfalls have been fully eliminated and they believe everything they see on the micrograph is always correct. But, as described in this and the earlier presentations this may not be the case. The fi rst paper in this series discussed some of the issues related to signal generation in the SEM, including instrument calibration, electron beam-sample interactions and the need for physics-based modelling to understand the actual image formation mechanisms to properly interpret SEM images. The second paper, discussed another major issue confronting the microscopist: specimen contamination and methods of contamination elimination. This third paper, discusses vibration and drift and some useful solutions.

  5. Characterization of ash pond ashes from 3rd thermal power plant by SEM/EDX and XRD methods

    Directory of Open Access Journals (Sweden)

    A Minjigmaa

    2014-10-01

    Full Text Available   Coal combustion by products from ash pond of 3rdthermal power plant of Ulaanbaatar city have been collected in 2010 and 2013 years. The ash samples have been characterized by XRD, XRF and SEM-EDX methods in order to evaluate their chemical and mineralogical composition changes with disposed times. The mineralogical composition of ash varies with time though the chemical composition of the ashes were close each other. Possibly, inefficient operating condition of the TPS shows influence on the mineralogical composition.DOI: http://dx.doi.org/10.5564/mjc.v14i0.201Mongolian Journal of Chemistry 14 (40, 2013, p61-65

  6. A novel study based on adaptive metal tolerance behavior in fungi and SEM-EDX analysis.

    Science.gov (United States)

    Chen, Si Hui; Ng, Si Ling; Cheow, Yuen Lin; Ting, Adeline Su Yien

    2017-07-15

    Four fungal isolates: Simplicillium chinense (iso 9, accession no. KX425621), Penicillium simplicissimum (iso 10, KP713758), Trichoderma asperellum (iso 11, KP792512), and Coriolopsis sp. (1c3, KM403574) were subjected to a series of induced-tolerance training under high metal concentrations to determine if greater tolerance could be achieved from constant exposure to such conditions. Adaptive tolerance assay (Tolerance Index, TI) and Field-Emission Scanning Electron Microscopy with Energy Dispersive X-ray (SEM-EDX) characterized their metal tolerance. "Untrained" S. chinense, P. simplicissimum and T. asperellum showed tolerance towards 4000-4500ppm Al(III) (TI: 0.64-0.71), 1000ppm Cr(III) (0.52-0.83) and Pb(II) (0.32-0.88). With tolerance training, tolerance towards 2000-6000ppm Al(III), 500-3000ppm Pb(II) and 2000-3000ppm Cr(III) were achieved (TI: 0.01-0.82) compared to untrained cultures (0.00-0.59). In contrast, tolerance training for Coriolopsis sp. and P. simplicissimum was less successful, with TI values similar or lower than untrained cultures. SEM-EDX analysis proposed biosorption and bioaccumulation as mechanisms for metal removal. The latter was demonstrated with the removal of Cr(III) and Pb(II) by S. chinense (12.37 and 11.52mgg -1 , respectively) and T. asperellum (10.44 and 7.50mgg -1 ). Induced-tolerance training may render benefit in the long run, but this delicate approach is suggestively species and metal dependent. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Differences in SEM-AVS and ERM-ERL predictions of sediment impacts from metals in two US Virgin Islands marinas.

    Science.gov (United States)

    Hinkey, Lynne M; Zaidi, Baqar R

    2007-02-01

    Two US Virgin Islands marinas were examined for potential metal impacts by comparing sediment chemistry data with two sediment quality guideline (SQG) values: the ratio of simultaneously extractable metals to acid volatile sulfides (SEM-AVS), and effects range-low and -mean (ERL-ERM) values. ERL-ERMs predicted the marina/boatyard complex (IBY: 2118 microg/g dry weight total metals, two exceeded ERMs) would have greater impacts than the marina with no boatyard (CBM: 231 microg/g dry weight total metals, no ERMs exceeded). The AVS-SEM method predicted IBY would have fewer effects due to high AVS-forming metal sulfide complexes, reducing trace metal bioavailability. These contradictory predictions demonstrate the importance of validating the results of either of these methods with other toxicity measures before making any management or regulatory decisions regarding boating and marina impacts. This is especially important in non-temperate areas where sediment quality guidelines have not been validated.

  8. Non-oxidative and oxidative torrefaction characterization and SEM observations of fibrous and ligneous biomass

    International Nuclear Information System (INIS)

    Chen, Wei-Hsin; Lu, Ke-Miao; Lee, Wen-Jhy; Liu, Shih-Hsien; Lin, Ta-Chang

    2014-01-01

    Highlights: • Non-oxidative and oxidative torrefaction of biomass is studied. • Two fibrous biomasses and two ligneous biomasses are tested. • SEM observations of four biomasses are provided. • Fibrous biomass is more sensitive to O 2 concentration than ligneous biomass. • The performance of non-oxidative torrefaction is better than that of oxidative torrefaction. - Abstract: Oxidative torrefaction is a method to reduce the operating cost of upgrading biomass. To understand the potential of oxidative torrefaction and its impact on the internal structure of biomass, non-oxidative and oxidative torrefaction of two fibrous biomass materials (oil palm fiber and coconut fiber) and two ligneous ones (eucalyptus and Cryptomeria japonica) at 300 °C for 1 h are studied and compared with each other. Scanning electron microscope (SEM) observations are also performed to explore the impact of torrefaction atmosphere on the lignocellulosic structure of biomass. The results indicate that the fibrous biomass is more sensitive to O 2 concentration than the ligneous biomass. In oxidative torrefaction, an increase in O 2 concentration decreases the solid yield. The energy yield is linearly proportional to the solid yield, which is opposite to the behavior of non-oxidative torrefaction. The performance of non-oxidative torrefaction is better than that of oxidative torrefaction. As a whole, ligneous biomass can be torrefied in oxidative environments at lower O 2 concentrations, whereas fibrous biomass is more suitable for non-oxidative torrefaction

  9. Resistencia Artística Urbana: Pautas subculturales en la comunidad de artistas de semáforo

    OpenAIRE

    Albuquerque, Ranngner

    2016-01-01

    [ES]Este estudio busca investigar la comunidad de artistas de semáforo en Iberoamérica realizando una etnografía y buscando un acompañamiento participativo en la ciudad de Recife (Brasil) y e la ciudad de Madrid (España) con el objetivo también de crear un comparativo en la búsqueda por patrones de comportamiento y demográficos. En este aspecto el resultado sorprende por dos razones: que entre los artistas de semáforo la gran mayoría presentes en las ciudades estudiadas son de argentinos. Y t...

  10. Tracking calcification in tissue-engineered bone using synchrotron micro-FTIR and SEM.

    Science.gov (United States)

    Deegan, Anthony J; Cinque, Gianfelice; Wehbe, Katia; Konduru, Sandeep; Yang, Ying

    2015-02-01

    One novel tissue engineering approach to mimic in vivo bone formation is the use of aggregate or micromass cultures. Various qualitative and quantitative techniques, such as histochemical staining, protein assay kits and RT-PCR, have been used previously on cellular aggregate studies to investigate how these intricate arrangements lead to mature bone tissue. However, these techniques struggle to reveal spatial and temporal distribution of proliferation and mineralization simultaneously. Synchrotron-based Fourier transform infrared microspectroscopy (micro-FTIR) offers a unique insight at the molecular scale by coupling high IR sensitivity to organic matter with the high spatial resolution allowed by diffraction limited SR microbeam. This study is set to investigate the effects of culture duration and aggregate size on the dynamics and spatial distribution of calcification in engineered bone aggregates by a combination of micro-FTIR and scanning electron microscopy (SEM)/energy-dispersive X-ray spectroscopy (EDX). A murine bone cell line has been used, and small/large bone aggregates have been induced using different chemically treated culture substrates. Our findings suggest that bone cell aggregate culturing can greatly increase levels of mineralization over short culture periods. The size of the aggregates influences mineralisation rates with larger aggregates mineralizing at a faster rate than their smaller counterparts. The micro-FTIR mapping has demonstrated that mineralization in the larger aggregates initiated from the periphery and spread to the centre, whilst the smaller aggregates have more minerals in the centre at the early stage and deposited more in the periphery after further culturing, implying that aggregate size influences calcification distribution and development over time. SEM/EDX data correlates well with the micro-FTIR results for the total mineral content. Thus, synchrotron-based micro-FTIR can accurately track mineralization process

  11. Scanning electron microscopy (SEM) and X-ray dispersive spectrometry evaluation of direct laser metal sintering surface and human bone interface: a case series.

    Science.gov (United States)

    Mangano, Carlo; Piattelli, Adriano; Raspanti, Mario; Mangano, Francesco; Cassoni, Alessandra; Iezzi, Giovanna; Shibli, Jamil Awad

    2011-01-01

    Recent studies have shown that direct laser metal sintering (DLMS) produces structures with complex geometry and consequently that allow better osteoconductive properties. The aim of this patient report was to evaluate the early bone response to DLMS implant surface retrieved from human jaws. Four experimental DLMS implants were inserted in the posterior mandible of four patients during conventional dental implant surgery. After 8 weeks, the micro-implants and the surrounding tissue were removed and prepared for scanning electron microscopy (SEM) and histomorphometric analysis to evaluate the bone-implant interface. The SEM and EDX evaluations showed a newly formed tissue composed of calcium and phosphorus. The bone-to-implant contact presented a mean of 60.5 ± 11.6%. Within the limits of this patient report, data suggest that the DLMS surfaces presented a close contact with the human bone after a healing period of 8 weeks.

  12. XRD and SEM study of alumina silicate porcelain insulator

    Science.gov (United States)

    Duddi, Dharmender; Singh, G. P.; Kalra, Swati; Shekhawat, M. S.; Tak, S. K.

    2018-05-01

    Higher strength electrical porcelain is a requirement of industry. This will be achieved by a specific composition of raw materials, which is consisted of clays and feldspars. Water absorption, particle size and insulating properties are of special interest now a day. China clay, Ball clay and Quartz are widely used by ceramic industries in Bikaner district of Rajasthan. Sample for present study were prepared by mixing of above clay, feldspar with MnO2, then shrinkage is observed. Bar shaped samples were prepared and heated up to a temperature of about 1185° C to observe shrinkage. For phase study of XRD and SEM are observed.

  13. Elemental composition study of heavy metal (Ni, Cu, Zn) in riverbank soil by electrokinetic-assisted phyto remediation using XRF and SEM/EDX

    International Nuclear Information System (INIS)

    Suhailly Jamari; Zaidi Embong; Zaidi Embong; Ismail Bakar

    2013-01-01

    Full-text: Electrokinetic (EK)-assisted phyto remediation is one of the methods that have a big potential in enhancing the ability of plant uptake in soils remediation process. This research was conducted to investigate the difference in elemental composition concentration of riverbank soil and the change of pH between pre- and post-phyto remediation under the following condition: 1) control or as-receive sample; 2) Dieffenbachia spp plant with EK system (a pair of EK electrodes connected to a direct current (DC) power supply). After the electrodes were connected to a magnitude of 6 V/ cm -1 electric field for 4 hours/ day, the soil and plant samples were analyzed using and X-ray Fluorescence Spectrometer (XRF) and Scanning Electron Microscope/ Energy Dispersive X-ray Spectroscopy (SEM/ EDX). The SEM/EDX analysis showed that concentration of elemental composition (Ni, Cu and Zn) in post-phyto remediation plant powder samples had increase while elemental concentrations in the post-hydrotreatment soil samples were decreased. XRF analysis presented a variation in soil elemental composition concentration from anode to cathode where the concentration near anode region increased while decreased near the cathode region. A significant changes in soil pH were obtained where the soil pH increase in cathode region while decrease in anode region. The results reveal that the assistance of EK in phyto remediation process has increase the efficiency of plant uptake. (author)

  14. 78 FR 50079 - Information Collection Activities: Safety and Environmental Management Systems (SEMS); Proposed...

    Science.gov (United States)

    2013-08-16

    ... DEPARTMENT OF THE INTERIOR Bureau of Safety and Environmental Enforcement [Docket ID BSEE-2013-0005; OMB Control Number 1014-0017: 134E1700D2 EEEE500000 ET1SF0000.DAQ000] Information Collection Activities: Safety and Environmental Management Systems (SEMS); Proposed Collection; Comment Request...

  15. MORPHOLOGICAL ASPECTS OF HUMAN LENS CAPSULES - A COMPARATIVE LM, SEM AND TEM EXAMINATION

    NARCIS (Netherlands)

    JONGEBLOED, WL; KALICHARAN, D; LOS, LI; VANDERVEEN, G; WORST, JGF

    1991-01-01

    Lens capsules of patients of advanced age, obtained after extracapsular cataract surgery, were carefully prepared for a combined LM, TEM and SEM investigation, after preliminary washing and mounting onto a holder in a buffer solution. After pre-fixation with GA, samples were postfixed for LM/TEM and

  16. The influence of different skin types on GSR sampling by tape lifting for SEM analysis.

    Science.gov (United States)

    Kara, İlker

    2017-12-01

    In this study, the change in the amounts the gunshot residues (GSR) collected by the "swab" method from shooter's right hand was analyzed using Scanning Electron Microscope-Energy Dispersive Spectroscopy (SEM-EDS) to test dependency on various conditions (such as skin color of the shooter, various physical properties, hair density of hands, size of the hands, sweaty or creamy (oiliness) hands). As a result of the analysis, there was no significant difference in the amount of GSR according to skin color, however, there was a change in the amount of GSR depending on the physical characteristics of the shooter. These results thought to have practical benefits for the experts performing GSR analysis using the swab technique to assess the incidence. © 2017 Wiley Periodicals, Inc.

  17. Palyno-morphological characteristics of gymnosperm flora of pakistan and its taxonomic implications with LM and SEM methods.

    Science.gov (United States)

    Khan, Raees; Ul Abidin, Sheikh Zain; Ahmad, Mushtaq; Zafar, Muhammad; Liu, Jie; Amina, Hafiza

    2018-01-01

    The present study is intended to assess gymnosperms pollen flora of Pakistan using Light Microscope (LM) and Scanning Electron Microscopy (SEM) for its taxonomic significance in identification of gymnosperms. Pollens of 35 gymnosperm species (12 genera and five families) were collected from its various distributional sites of gymnosperms in Pakistan. LM and SEM were used to investigate different palyno-morphological characteristics. Five pollen types (i.e., Inaperturate, Monolete, Monoporate, Vesiculate-bisaccate and Polyplicate) were observed. Six In equatorial view seven types of pollens were observed, in which ten species were sub-angular, nine species were Traingular, six species were Perprolate, three species were Rhomboidal, three species were semi-angular, two species were rectangular and two species were prolate. While five types of pollen were observed in polar view, in which ten species were Spheroidal, nine species were Angular, eight were Interlobate, six species were Circular, two species were Elliptic. Eighteen species has rugulate and 17 species has faveolate ornamentation. Eighteen species has verrucate and 17 have gemmate type sculpturing. The data was analysed through cluster analysis. The study showed that these palyno-morphological features have significance value in classification and identification of gymnosperms. Based on these different palyno-morphological features, a taxonomic key was proposed for the accurate and fast identifications of gymnosperms from Pakistan. © 2017 Wiley Periodicals, Inc.

  18. A Computer-Controlled SEM-EDX Routine for Characterizing Respirable Coal Mine Dust

    Directory of Open Access Journals (Sweden)

    Victoria Johann-Essex

    2017-01-01

    Full Text Available A recent resurgence in coal workers’ pneumoconiosis (or “black lung” and concerns over other related respiratory illnesses have highlighted the need to elucidate characteristics of airborne particulates in occupational environments. A better understanding of particle size, aspect ratio, or chemical composition may offer new insights regarding causal factors of such illnesses. Scanning electron microscopy analysis using energy dispersive X-ray (SEM-EDX can be used to estimate these particle characteristics. If conducted manually, such work can be very time intensive, limiting the number of particles that can be analyzed. Moreover, potential exists for user bias in interpretation of EDX spectra. A computer-controlled (CC routine, on the other hand, can allow similar analysis at a much faster rate, increasing total particle counts and reproducibility of results. This paper describes a CCSEM-EDX routine specifically developed for analysis of respirable dust samples from coal mines. The routine is verified based on reliability of results obtained on samples of known materials, and reproducibility of results obtained on a set of 10 dust samples collected in the field. The characteristics of the field samples are also discussed with respect to mine occupational environments.

  19. Ontologías y Web Semántica 2005. Resumen del taller

    OpenAIRE

    Corcho, Oscar; Gómez-Pérez, A.; Fernández López, Mariano; Ramos Gargantilla, JA.

    2006-01-01

    En este artículo se resumen los resultados obtenidos en el taller “Ontologías y Web Semántica 2005”, que fue celebrado el día 14 de noviembre de 2005 en Santiago de Compostela, en el contexto de la Conferencia de la Asociación Española para la Inteligencia Artificial (CAEPIA2005).

  20. SemMat: Federated Semantic Services Platform for Open materials Science and Engineering

    Science.gov (United States)

    2017-01-01

    SEMMAT: FEDERATED SEMANTIC SERVICES PLATFORM FOR OPEN MATERIALS SCIENCE AND ENGINEERING WRIGHT STATE UNIVERSITY JANUARY 2017 FINAL TECHNICAL...COVERED (From - To) JUL 2013 – JUN 2016 4. TITLE AND SUBTITLE SemMat: FEDERATED SEMANTIC SERVICES PLATFORM FOR OPEN MATERIALS SCIENCE AND ENGINEERING...models to represent materials data. This provides a data exchange scheme for materials science , which also includes provenance information to promote

  1. Discopersicus n. gen., a New Member of the Family Tylenchidae Örley, 1880 with Detailed SEM Study on Two Known Species of the Genus Discotylenchus Siddiqi, 1980 (Nematoda; Tylenchidae) from Iran.

    Science.gov (United States)

    Yaghoubi, Ali; Pourjam, Ebrahim; Álvarez-Ortega, Sergio; Liébanas, Gracia; Atighi, Mohammad Reza; Pedram, Majid

    2016-09-01

    Discopersicus iranicus n. gen., n. comb., previously described from Iran as a new species under the genus Discotylenchus , is illustrated using light microscope and scanning electron microscope (SEM) observations and further studied using molecular characters. SEM studies revealed the newly proposed genus has oblique amphidial apertures on the lateral sides of the lip region. SEM images are also provided for two species of Discotylenchus , namely D. discretus and D. brevicaudatus , as the first SEM study of the genus . These results confirmed longitudinal amphidial aperture type on lateral sides of the lip region in genus Discotylenchus , as noted by Siddiqi while erecting the genus with D. discretus as the type species . Molecular phylogenetic analyses using partial small subunit (SSU) and large subunit (LSU) rDNA sequences revealed the affinity of the genus Discopersicus n. gen. with members of the subfamily Boleodorinae, as supported by morphological characters (mainly, the oblique amphidial opening).

  2. Optical and microstructural characterization of porous silicon using photoluminescence, SEM and positron annihilation spectroscopy

    International Nuclear Information System (INIS)

    Cheung, C K; Nahid, F; Cheng, C C; Beling, C D; Fung, S; Ling, C C; Djurisic, A B; Pramanik, C; Saha, H; Sarkar, C K

    2007-01-01

    We have studied the dependence of porous silicon morphology and porosity on fabrication conditions. N-type (100) silicon wafers with resistivity of 2-5 Ω cm were electrochemically etched at various current densities and anodization times. Surface morphology and the thickness of the samples were examined by scanning electron microscopy (SEM). Detailed information of the porous silicon layer morphology with variation of preparation conditions was obtained by positron annihilation spectroscopy (PAS): the depth-defect profile and open pore interconnectivity on the sample surface has been studied using a slow positron beam. Coincidence Doppler broadening spectroscopy (CDBS) was used to study the chemical environment of the samples. The presence of silicon micropores with diameter varying from 1.37 to 1.51 nm was determined by positron lifetime spectroscopy (PALS). Visible luminescence from the samples was observed, which is considered to be a combination effect of quantum confinement and the effect of Si = O double bond formation near the SiO 2 /Si interface according to the results from photoluminescence (PL) and positron annihilation spectroscopy measurements. The work shows that the study of the positronium formed when a positron is implanted into the porous surface provides valuable information on the pore distribution and open pore interconnectivity, which suggests that positron annihilation spectroscopy is a useful tool in the porous silicon micropores' characterization

  3. Redes semánticas poblacionales: un instrumento metodológico para la investigación educativa

    Directory of Open Access Journals (Sweden)

    Sofía Judith Garófalo

    2015-06-01

    Full Text Available Presentamos una propuesta metodológica cualitativa para indagar aprendizajes de una población de estudiantes. Utilizamos el concepto de red semántica para la representación gráfica de las respuestas individuales de los estudiantes frente a un problema determinado. Asimismo, el modelo de procesamiento de la información proporcionó la base teórico-práctica para la confección de los caminos cognitivos asociativos expresados por cada sujeto. Esta combinación teórico metodológica permitió elaborar redes semánticas poblacionales que representan la información acerca de los conocimientos declarativos de la población. Se propuso a estudiantes universitarios, de las asignaturas Biología y Química Biológica de distintas carreras, un problema de múltiples resoluciones acerca del metabolismo de los carbohidratos. Al ordenar las respuestas de todos los estudiantes en redes semánticas detectamos: (a tendencias generales de errores arraigados que se repiten en cada asignatura, y (b tendencias específicas de estrategias de respuestas o de errores que sólo aparecen en alguna de las poblaciones.

  4. e-Science Semântica: integração dos dados na comunicação científica

    Directory of Open Access Journals (Sweden)

    Elizabete Cristina de Souza de Aguiar Monteiro

    2016-06-01

    Full Text Available Nos paradigmas da ciência, as ciências experimentais, teóricas e computacionais estão sendo afetadas pelo grande quantidade de dados coletados ou simulados e emergi um novo paradigma, o paradigma do uso intensivo de dados, denominado por pesquisadores de e-Science, ou quarto paradigma da ciência. Dessa forma, tornar esse quarto paradigma em semântico, em que os dados e a literatura científica estejam integrados, lincados, disponíveis e interoperáveis, é um desafio.  Novas ferramentas e linguagens são necessárias e projetos para tornar isso possível estão sendo apresentados. Sendo assim, o artigo teve como objetivo a caracterização de 3 sitios, Molecular BioSystems, Solar-Terrestre Virtual e revista Nature que têm melhorias semânticas e uso de ontologias em suas páginas, verificando a correlação entre a Web semântica e e-Science. A metodologia utilizada consistiu no levantamento bibliográfico e revisão de literatura para discussão do tema, uso do método descritivo para descrever as características semânticas dos portais, além do método comparativo. Verificamos que a aplicação da web semântica em portais com características da e-science melhora consideravelmente a recuperação e, consequentemente a reutilização de dados primários de pesquisa.

  5. Study of Morphological Changes of The Lime Putties During Maturing by SEM/ESEM

    Czech Academy of Sciences Publication Activity Database

    Navrátilová, Eva; Neděla, Vilém

    2017-01-01

    Roč. 23, S1 (2017), s. 2186-2187 ISSN 1431-9276 R&D Projects: GA MŠk ED0017/01/01 Institutional support: RVO:68081731 Keywords : SEM * ESEM * morphological changes * lime putties Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering OBOR OECD: Civil engineering Impact factor: 1.891, year: 2016

  6. A Sandwich-Type Standard Error Estimator of SEM Models with Multivariate Time Series

    Science.gov (United States)

    Zhang, Guangjian; Chow, Sy-Miin; Ong, Anthony D.

    2011-01-01

    Structural equation models are increasingly used as a modeling tool for multivariate time series data in the social and behavioral sciences. Standard error estimators of SEM models, originally developed for independent data, require modifications to accommodate the fact that time series data are inherently dependent. In this article, we extend a…

  7. Designing MgFe{sub 2}O{sub 4} decorated on green mediated reduced graphene oxide sheets showing photocatalytic performance and luminescence property

    Energy Technology Data Exchange (ETDEWEB)

    Shetty, Krushitha [Department of Nanotechnology, PG Center, Bangalore Region, VIAT, VTU, Muddenahalli, Chikkaballapur 562101 (India); Dr. D. Premachandrasagar Centre for Advanced Materials, DSCE, Bangalore 560078 (India); Lokesh, S.V. [Department of Nanotechnology, PG Center, Bangalore Region, VIAT, VTU, Muddenahalli, Chikkaballapur 562101 (India); Rangappa, Dinesh, E-mail: dineshrangappa@gmail.com [Department of Nanotechnology, PG Center, Bangalore Region, VIAT, VTU, Muddenahalli, Chikkaballapur 562101 (India); Nagaswarupa, H.P., E-mail: nagaswarupa77@gmail.com [Research Center, Department of Science, East West Institute of Technology, Bangalore 560091 (India); Nagabhushana, H., E-mail: bhushanvlc@gmail.com [Prof. CNR Rao Centre for Advanced Materials, Tumkur University, Tumkur 572103 (India); Anantharaju, K.S., E-mail: iamananthkurupalya@gmail.com [Department of Chemistry, Dayananda Sagar College of Engineering, Shavige Malleshwara Hills, Kumaraswamy Layout, Bangalore 560078 (India); Dr. D. Premachandrasagar Centre for Advanced Materials, DSCE, Bangalore 560078 (India); Prashantha, S.C. [Research Center, Department of Science, East West Institute of Technology, Bangalore 560091 (India); Vidya, Y.S. [Department of Physics, Lal Bahadur Shastri Government First Grade College, Bangalore, 560032 (India); Sharma, S.C. [Dr. D. Premachandrasagar Centre for Advanced Materials, DSCE, Bangalore 560078 (India); Department of Mechanical Engineering, DSCE, Bangalore-560078 (India)

    2017-02-15

    Here, a green route has been reported to convert Graphene Oxide (GO) to reduced graphene oxide (RGO) using clove extract. A modest and eco-accommodating sol-gel strategy has been employed to prepare MgFe{sub 2}O{sub 4} nanoparticles, MgFe{sub 2}O{sub 4}–RGO nanocomposite samples. The samples were analyzed by Powder X-ray diffraction (PXRD), Fourier Transform Infrared Spectroscopy (FTIR), UV–Visible Spectroscopy, Scanning Electron Microcopy (SEM), Transmission Electron Microscopy (TEM), Photoluminescence (PL) and Electrochemical Impedance Spectroscopy (EIS). PXRD result revealed that the prepared samples were cubic spinel in nature. SEM results uncovered flake like surface morphology of the prepared nanomaterial. Better PL emission signature was observed when excited at 329 nm. PL studies demonstrated that the present samples were potential for the fabrication of white component of white light emitting diodes (WLEDs). Further, MgFe{sub 2}O{sub 4}–RGO nanocomposite showed enhanced photocatalytic movement (PCM) and photostability under Sunlight in the decomposition of Malachite Green (MG) compared to MgFe{sub 2}O{sub 4}. This can be attributed to the interaction of MgFe{sub 2}O{sub 4} surface with RGO sheets which results in PL quenching, demonstrates that the recombination of photo-induced electrons and holes in MgFe{sub 2}O{sub 4}–RGO nanocomposite is more effectively inhibited. A possible mechanism for the enhanced properties of MgFe{sub 2}O{sub 4}–RGO nanocomposite was discussed. Moreover, MgFe{sub 2}O{sub 4}–RGO photocatalyst also showed easy magnetic separation with high reusability. These results unveil that the synthesized sample can be used in display applications and also as a potential photocatalyst. - Graphical abstract: Green mediated reduced graphene oxide with MgFe{sub 2}O{sub 4} for display applications and also as a potential photocatalyst. - Highlights: • Synthesized GO was reduced to RGO by green route using clove extract. • Mg

  8. The Impact of Managerial and Adaptive Capabilities to Stimulate Organizational Innovation in SMEs: A Complementary PLS–SEM Approach

    Directory of Open Access Journals (Sweden)

    Zulfiqar Ali

    2017-11-01

    Full Text Available The aim of this study is to empirically explore and propose a rigorous model for the positive impact of managerial capability (in terms of decision-making, management style, people development, and succession planning and adaptive capability (in terms of horizon scanning, change management, and resilience on organizational innovation in the context of small and medium-sized enterprises (SMEs. The study uses partial least squares structural equation modeling (PLS–SEM to test the model hypotheses, and importance-performance matrix analysis (IPMA to provide information regarding the significance and relevance of the dimensions of managerial and adaptive capability in explaining organizational innovation in the proposed model. The empirical data is gathered through questionnaires from 210 SMEs. The results show a strong and significant relationship between managerial capability, adaptive capability, and organizational innovation. This study found that all of the dimensions of managerial capability and adaptive capability help to develop and improve the performance of organizational innovation in SMEs. The study concludes with a comprehensive discussion of the research limitations, and provides suggestions for future research.

  9. Um modelo semântico de publicações eletrônicas | A semantic model for electronic publishing

    Directory of Open Access Journals (Sweden)

    Carlos Henrique Marcondes

    2011-03-01

    Full Text Available Resumo Publicações eletrônicas, apesar dos avanços das Tecnologias da Informação, são ainda calcados no modelo impresso. O formato textual impede que programas possam ser usados para o processamento “semântico” desses conteúdos. È porposto um modelo “semântico” de publicações cientificas eletrônicas, no qual as conclusões contidas no texto do artigo fornecidas por autores e representadas em formato “inteligível” por programas, permitindo recuperação semântica, identificação de indícios de novas descobertas científicas e de incoerências sobre este conhecimento. O modelo se baseia nos conceitos de estrutura profunda, ou semântica, da linguagem (CHOMSKY, 1975, de microestrutura, macroestrutura e superestrutura, (KINTSH, VAN DIJK, 1972, na estrutura retórica de artigos científicos (HUTCHINS, 1977, (GROSS, 1990 e nos elementos de metodologia cientifica, como problema, questão, objetivo, hipótese, experimento e conclusão. Resulta da análise de 89 artigos biomédicos. Foi desenvolvido um protótipo de sistema que implementa parcialmente o modelo. Questionários foram usados com autores para embasar o desenvolvimento do protótipo. O protótipo foi testando com pesquisadores-autores. Foram identificados quatro padrões de raciocínio e encadeamento dos elementos semânticos em artigos científicos. O modelo de conteúdo foi implementado como uma ontologia computacional. Foi desenvolvido e avaliado um protótipo de uma interface web de submissão artigos pelos autores a um sistema eletrônico de publicação de periódicos que implementa o modelo. Palavras-chave publicações eletrônicas; metodológica científica; comunicação científica; representação do conhecimento; ontologias; processamento semântico de conteúdos; e-Ciência Abstract Electronic publishing, although Information Technologies advancements, are still based in the print text model. The textual format prevents programs to semantic process

  10. Fractionation of Pb in Soil of Abandoned Pb Mine by SEM-EDX and ...

    African Journals Online (AJOL)

    Therefore, scanning electron microscopy coupled with energy dispersive X-ray spectrometer (SEM-EDX) were used for the identification of fractional forms of Pb that are liable to leach out/down from the soil matrix of the abandoned mine site to surface-andunderground water bodies of the nearby localities, and to determine ...

  11. Changes in surface characteristics of two different resin composites after 1 year water storage: An SEM and AFM study.

    Science.gov (United States)

    Tekçe, Neslihan; Pala, Kansad; Demirci, Mustafa; Tuncer, Safa

    2016-11-01

    To evaluate changes in surface characteristics of two different resin composites after 1 year of water storage using a profilometer, Vickers hardness, scanning electron microscopy (SEM), and atomic force microscopy (AFM). A total of 46 composite disk specimens (10 mm in diameter and 2 mm thick) were fabricated using Clearfil Majesty Esthetic and Clearfil Majesty Posterior (Kuraray Medical Co, Tokyo, Japan). Ten specimens from each composite were used for surface roughness and microhardness tests (n = 10). For each composite, scanning electron microscope (SEM, n = 2) and atomic force microscope (AFM, n = 1) images were obtained after 24 h and 1 year of water storage. The data were analyzed using two-way analysis of variance and a post-hoc Bonferroni test. Microhardness values of Clearfil Majesty Esthetic decreased significantly (78.15-63.74, p = 0.015) and surface roughness values did not change after 1 year of water storage (0.36-0.39, p = 0.464). Clearfil Majesty Posterior microhardness values were quite stable (138.74-137.25, p = 0.784), and surface roughness values increased significantly (0.39-0.48, p = 0.028) over 1 year. One year of water storage caused microhardness values for Clearfil Majesty Esthetic to decrease and the surface roughness of Clearfil Majesty Posterior increased. AFM and SEM images demonstrated surface detoration of the materials after 1 year and ensured similar results with the quantitative test methods. SCANNING 38:694-700, 2016. © 2016 Wiley Periodicals, Inc. © Wiley Periodicals, Inc.

  12. XRD and SEM/EDS characterization of coconut fibers in raw and treated forms used in the treatment of strontium in aqueous solution

    Energy Technology Data Exchange (ETDEWEB)

    Fonseca, Heverton C.O.; Garcia, Rafael H.L.; Ferreira, Robson J.; Silva, Flavia R.O.; Potiens Junior, Ademar J.; Sakata, Solange K., E-mail: sksakata@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2015-07-01

    {sup 90}Sr, a radioactive isotope of strontium, is one of the fission products and quite often present in the radioactive waste produced by nuclear power plants. Recently, the removal efficiency of strontium by treated coconut fibers was evaluated and reached up to 95% in an aqueous solution. This work presents the characterization of raw and treated coconut fibers with different concentrations of hydrogen peroxide in basic medium using X-ray diffraction (XRD) and scanning electron microscopy/energy dispersive spectroscopy (SEM / EDS). The analysis of X-ray diffraction shows a crystallinity of 37.6% for raw coconut fiber and crystallinity of 45.4% and 50.6% for coconut fibers 1 and 2, respectively. These results showed that the different degrees of degradation of organic matter can affect the crystallinity of the treated. This study of morphology and crystallinity of theses biosorbent materials with strontium will help in comprehension of the effects of alkaline hydrogen peroxide treatment and it will demonstrate the potential of strontium uptake by coconut fibers. (author)

  13. XRD and SEM/EDS characterization of coconut fibers in raw and treated forms used in the treatment of strontium in aqueous solution

    International Nuclear Information System (INIS)

    Fonseca, Heverton C.O.; Garcia, Rafael H.L.; Ferreira, Robson J.; Silva, Flavia R.O.; Potiens Junior, Ademar J.; Sakata, Solange K.

    2015-01-01

    90 Sr, a radioactive isotope of strontium, is one of the fission products and quite often present in the radioactive waste produced by nuclear power plants. Recently, the removal efficiency of strontium by treated coconut fibers was evaluated and reached up to 95% in an aqueous solution. This work presents the characterization of raw and treated coconut fibers with different concentrations of hydrogen peroxide in basic medium using X-ray diffraction (XRD) and scanning electron microscopy/energy dispersive spectroscopy (SEM / EDS). The analysis of X-ray diffraction shows a crystallinity of 37.6% for raw coconut fiber and crystallinity of 45.4% and 50.6% for coconut fibers 1 and 2, respectively. These results showed that the different degrees of degradation of organic matter can affect the crystallinity of the treated. This study of morphology and crystallinity of theses biosorbent materials with strontium will help in comprehension of the effects of alkaline hydrogen peroxide treatment and it will demonstrate the potential of strontium uptake by coconut fibers. (author)

  14. Clinical outcomes of self-expandable metal stent (SEMS placement as palliative treatment for malignant colorectal obstruction: A single-center study from Japan

    Directory of Open Access Journals (Sweden)

    Toshikatsu Nitta

    2017-07-01

    Conclusion: SEMS placement as a palliative treatment is likely to fail within a year, leading to re-occlusion. It is very important to maintain vigilant monitoring using X-ray, CT, and colonoscopy after SEMS placement, with close cooperation between the endoscopist and surgeon. A logistic framework involving careful follow-up, even in the absence of symptoms, and a combined team involving endoscopists and surgeons should be established to support re-intervention and surgery. We recommend vigilant monitoring of patients who received SEMS placement for palliation of malignant colorectal obstruction.

  15. XRD, SEM and infrared study into the intercalation of sodium hexadecyl sulfate (SHS) into hydrocalumite.

    Science.gov (United States)

    Zhang, Ping; Wang, Tianqi; Zhang, Longlong; Wu, Daishe; Frost, Ray L

    2015-12-05

    Hydrocalumite (CaAl-LDH-Cl) interacted with a natural anionic surfactant, sodium hexadecyl sulfate (SHS), was performed using an intercalation method. To understand the intercalation behavior and characterize the resulting products, powder X-ray diffraction (XRD), scan electron microscopy (SEM) and mid-infrared (MIR) spectroscopy combined with near-infrared (NIR) spectroscopy technique were used. The XRD analysis indicated that SHS was intercalated into CaAl-LDH-Cl successfully, resulting in an expansion of the interlayer (from 0.78 nm to 2.74 nm). The bands of C-H stretching vibrations of SHS were observed in the near-infrared spectra, which indicated that the resulting products were indeed CaAl-LDH-SHS. In addition, the bands of water stretching vibrations and OH groups shifted to higher wavenumbers when SHS was intercalated into CaAl-LDH-Cl interlayer space. Copyright © 2015 Elsevier B.V. All rights reserved.

  16. Generación de modelos 3D a partir de imágenes SEM (Scanning Electron Microscopy)

    OpenAIRE

    MÍNGUEZ HERNÁNDEZ, MARÍA TERESA

    2017-01-01

    [ES] Con la realización del presente trabajo, se pretenden obtener Modelos Digitales 3D (MD-3D) de imágenes de muy alta resolución obtenidas con un Microscopio Electrónico de Barrido (SEM), utilizando la técnica fotogramétrica Structure from Motion (SfM) mediante el software Agisoft-PhotoScan. El objetivo es comprobar si este tipo de software, que utiliza la técnica SfM, es apto para imágenes obtenidas con equipos SEM y generar Modelos 3D. Esto permitiría poder realizar impr...

  17. Analyzing the scale of the bainitic ferrite plates by XRD, SEM and TEM

    International Nuclear Information System (INIS)

    Garcia-Mateo, Carlos; Jimenez, Jose A.; Lopez-Ezquerra, Belen; Rementeria, Rosalia; Morales-Rivas, Lucia; Kuntz, Matthias; Caballero, Francisca G.

    2016-01-01

    Since the major strengthening mechanisms in nanocrystalline bainitic steels arise from the exceptionally small size of the bainitc ferrite plate, accurate determination of this parameter is fundamental for quantitative relating the microstructure to the mechanical properties. In this work, the thickness of the bainitic ferrite subunits obtained by different bainitic heat treatments was determined in two steels, with carbon contents of 0.3 and 0.7 wt.%, from SEM and TEM micrographs. As these measurements were made on 2D images taken from random sections, the method includes some stereological correction factors to obtain accurate information. Finally, the determined thicknesses of bainitic ferrite plates were compared with the crystallite size calculated from the analysis of X-ray diffraction peak broadening. Although in some case the values obtained for crystallite size and plate thickness can be similar, this study confirms that indeed they are two different parameters. - Highlights: •Bainitic microstructure in a nanostructured and sub-micron steel •Bainitic ferrite plate thickness measured by SEM and TEM •Crystallite size determined by X-ray analysis

  18. Analyzing the scale of the bainitic ferrite plates by XRD, SEM and TEM

    Energy Technology Data Exchange (ETDEWEB)

    Garcia-Mateo, Carlos, E-mail: cgm@cenim.csic.es [Department of Physical Metallurgy, Spanish National Center for Metallurgical Research (CENIM-CSIC), Avda. Gregorio del Amo 8, E-28040 Madrid (Spain); Jimenez, Jose A.; Lopez-Ezquerra, Belen; Rementeria, Rosalia; Morales-Rivas, Lucia [Department of Physical Metallurgy, Spanish National Center for Metallurgical Research (CENIM-CSIC), Avda. Gregorio del Amo 8, E-28040 Madrid (Spain); Kuntz, Matthias [Robert-Bosch GmbH, Materials and Process Engineering Metals, Renningen, 70465 Stuttgart (Germany); Caballero, Francisca G. [Department of Physical Metallurgy, Spanish National Center for Metallurgical Research (CENIM-CSIC), Avda. Gregorio del Amo 8, E-28040 Madrid (Spain)

    2016-12-15

    Since the major strengthening mechanisms in nanocrystalline bainitic steels arise from the exceptionally small size of the bainitc ferrite plate, accurate determination of this parameter is fundamental for quantitative relating the microstructure to the mechanical properties. In this work, the thickness of the bainitic ferrite subunits obtained by different bainitic heat treatments was determined in two steels, with carbon contents of 0.3 and 0.7 wt.%, from SEM and TEM micrographs. As these measurements were made on 2D images taken from random sections, the method includes some stereological correction factors to obtain accurate information. Finally, the determined thicknesses of bainitic ferrite plates were compared with the crystallite size calculated from the analysis of X-ray diffraction peak broadening. Although in some case the values obtained for crystallite size and plate thickness can be similar, this study confirms that indeed they are two different parameters. - Highlights: •Bainitic microstructure in a nanostructured and sub-micron steel •Bainitic ferrite plate thickness measured by SEM and TEM •Crystallite size determined by X-ray analysis.

  19. Use of SEM and EDS analysis in the investigation of Al-Si-Cu piston alloy cast porosity

    Directory of Open Access Journals (Sweden)

    D. Kakaš

    2009-07-01

    Full Text Available Porosity formation was detected in the casting thinnest section in the proximity of the as cast surface and near the wall centerline. In order to investigate the cause of the porosity formation light microscopy was used to define as cast structure. After initial findings SEM and EDS analyses were performed. Based on the results it is possible to define cause of the observed porosity. A number of pores originates from the mould filling stage and entrainment of the oxide films, while others appear due to insufficient feeding during solidification.

  20. SEM-EDS Observation of Structure Changes in Synthetic Zeolites Modified for CO2 Capture Needs

    Science.gov (United States)

    Wdowin, Magdalena; Panek, Rafal; Franus, Wojciech

    Carbon dioxide is the main greenhouse gas and its amount still increase in the atmosphere. Air pollution and greenhouse effect caused by CO2 emission have become a major threat to the environment on a global scale. Carbon dioxide sequestration (i.e. capture and consequently geological storage) is the key strategy within the portfolio of actions to reduce CO2 emission to the atmosphere. The most costly stage is capture of CO2, therefore there is a need to search new solutions of this technology. For this purpose it was examined Na-X synthetic zeolites, that were silver and PEI (polyethyleneimine) activated. SEM-EDS investigation enable to find a changes in structure of this materials after treatment. Where, as a result of silver activation from EDS analysis it is seen that Ag occur in Na-X structure, what indicate a substitution of Ag2+ for Na+ ions in crystal lattice. Analysing wt% the EDS analysis has shown that zeolite Na-X after silver impregnation becomes Ag-X zeolite. For Na-X-PEI activated it is observed a distinct organic compound in the form of coatings on Na-X crystals causing a sealing of pores in tested zeolite. Further examination of these materials concern determination of surface properties and experiments of CO2 sorption. But SEM-EDS analysis enable to determine the extent of activation, what is very important in determination of optimal conditions for such treatment in order to obtain better sorbent of CO2.