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  1. YEARBOOK CEC 1966.

    ERIC Educational Resources Information Center

    European Council for Education by Correspondence, Brussels (Belgium).

    AT THE 1965 ANNUAL MEETING OF THE EUROPEAN COUNCIL FOR EDUCATION BY CORRESPONDENCE (CEC), HELD IN PARIS IN OCTOBER, THE MODIFIED CEC CONSTITUTION WAS ADOPTED. AT THE 1966 ANNUAL MEETING, HELD IN LONDON IN MAY, THE DELEGATES DISCUSSED BUSINESS AND EDUCATIONAL ASPECTS OF A MODEL CODE OF ETHICS. TO INVESTIGATE METHODS OF EDUCATION BY CORRESPONDENCE,…

  2. CEC Today, 1998-1999.

    ERIC Educational Resources Information Center

    Voyles, Lynda C., Ed.

    1998-01-01

    This document is comprised of five issues of "CEC Today," a membership publication of the Council for Exceptional Children. Each issue usually contains a calendar of events, news items, and columns on member benefits, advocacy efforts of CEC, activities of Student CEC, CEC in Canada, activities of the CEC divisions, professional…

  3. CEC Council Sessions

    EPA Pesticide Factsheets

    Each year, the North American Ministers to the Commission for Environmental Cooperation meet at least once for the CEC Council Session to set the CEC’s overall direction, including budget, and activities pursued through the cooperative work plan.

  4. Cooperative Engagement Capability (CEC)

    DTIC Science & Technology

    2013-12-01

    100% of top - level IERs 100% of top -level IERs. 100% of top - level IERs designated critical 100% of top - level IERs designated critical 100...of top -level IERs designated critical Track File Consistency Integration will improve track file consistency in each host system CEC...2364.2 1843.6 Flyaway -- -- -- 1343.4 -- -- 1566.2 Recurring -- -- -- 1343.4 -- -- 1566.2 Non Recurring -- -- -- 0.0 -- -- 0.0 Support -- -- -- 216.4

  5. CEC's Position on School Vouchers

    ERIC Educational Resources Information Center

    Council for Exceptional Children (NJ3), 2011

    2011-01-01

    The Council for Exceptional Children (CEC) recognizes that children and youth with disabilities are entitled to equal access to the public education system and to all rights guaranteed by law. CEC advocates to ensure that children and youth with disabilities receive the equal access and opportunity that they deserve. By definition, vouchers…

  6. CEC's Position on School Vouchers

    ERIC Educational Resources Information Center

    Council for Exceptional Children (NJ3), 2011

    2011-01-01

    The Council for Exceptional Children (CEC) recognizes that children and youth with disabilities are entitled to equal access to the public education system and to all rights guaranteed by law. CEC advocates to ensure that children and youth with disabilities receive the equal access and opportunity that they deserve. By definition, vouchers…

  7. CEC Today, 1999-2000.

    ERIC Educational Resources Information Center

    Voyles, Lynda, Ed.

    2000-01-01

    The eight issues for volume 6 of the "CEC Today," a newsletter exclusively for members of the Council for Exceptional Children, include the following featured articles: (1) "How To Set up a Classroom on a Tight Budget"; (2) "Survival Tips for First-Year Teachers"; (3) Get the Training You Need To Stay Ahead of the…

  8. CEC Today, 2000-2001.

    ERIC Educational Resources Information Center

    Van Kuren, Lynda, Ed.

    2001-01-01

    Nine issues of the newsletter of the Council for Exceptional Children (CEC) include articles, news items, meeting announcements, news items of individual divisions, and professional advancement opportunities. Some major articles are: (1) "Home Schooling--A Viable Alternative for Students with Special Needs" (2) "High Stakes Testing…

  9. CEC's New Policy--Behind the Scenes

    ERIC Educational Resources Information Center

    TEACHING Exceptional Children, 2016

    2016-01-01

    CEC's new policy is a result of efforts begun in 2009 by members of CEC's Educators With Disabilities Policy Workgroup. The board-appointed workgroup was chaired by Jennifer Diliberto and included Mary Ruth Coleman, Marjorie Terhaar-Yonkers, Susan Osborne, and Stephanie Demayo. These CEC members' desire to create and support safe environments in…

  10. CEC's Policy on Educators with Disabilities

    ERIC Educational Resources Information Center

    Exceptional Children, 2016

    2016-01-01

    The Council for Exceptional Children (CEC) supports educators with disabilities including faculty, teacher candidates, and teachers in classrooms, schools, and institutions of higher education. Within the CEC membership, members embody a wide range of disabilities including learning, sensory, physical, and emotional areas. CEC recognizes the…

  11. CEC's Policy on Educators with Disabilities

    ERIC Educational Resources Information Center

    Exceptional Children, 2016

    2016-01-01

    The Council for Exceptional Children (CEC) supports educators with disabilities including faculty, teacher candidates, and teachers in classrooms, schools, and institutions of higher education. Within the CEC membership, members embody a wide range of disabilities including learning, sensory, physical, and emotional areas. CEC recognizes the…

  12. CEC's Policy on Educators with Disabilities

    ERIC Educational Resources Information Center

    TEACHING Exceptional Children, 2016

    2016-01-01

    The Council for Exceptional Children (CEC) supports educators with disabilities including faculty, teacher candidates, and teachers in classrooms, schools, and institutions of higher education. Many educators with disabilities have learned resiliency, overcoming adversity to succeed academically. However, without appropriate support this is often…

  13. CEC's Policy on Educators with Disabilities

    ERIC Educational Resources Information Center

    TEACHING Exceptional Children, 2016

    2016-01-01

    The Council for Exceptional Children (CEC) supports educators with disabilities including faculty, teacher candidates, and teachers in classrooms, schools, and institutions of higher education. Many educators with disabilities have learned resiliency, overcoming adversity to succeed academically. However, without appropriate support this is often…

  14. Requirements for CEC POP Machine Protection System

    SciTech Connect

    Pinayev, I.

    2015-02-18

    The requirements of CEC POP machine protection system are meant to prevent damage to a vacuum chamber by a missteered electron beam. In this example, beam energy = 22 MeV, Maximal bunch charge = 5 nC, Maximal repetition rate = 78 kHz, Normalized emittance = 5 mm mrad, Minimal β-function = 1 m. From this information the requirements of the protection system can be calculated by factoring the information into equations to find beam densities and temperature excursions.

  15. High Throughput Analysis of Chiral Compounds Using Capillary Electrochromatography (CEC) and CEC-Mass Spectrometry with Cellulose Based Stationary Phases

    PubMed Central

    Bragg, William; Shamsi, Shahab A.

    2014-01-01

    To fulfill the ever growing demand for rapid chiral analysis, this research presents an approach for highthroughput enantiomeric separations and sensitive detection of model chiral analytes using capillary electrochromatography (CEC) with UV and MS detection. This was achieved utilizing a short 7 cm CEC columns packed with cellulose tris (3,5-dimethyl-phenylcarbamate) (CDMPC) or sulfonated cellulose tris (3,5-dimethylphenylcarbamate) (CDMPC-SO3) chiral stationary phases (CSPs) applying outlet side injections in CEC-UV. The separation performance was compared between CDMPC and CDMPC-SO3 CSPs for rapid enantio-separation in CEC-UV mode. In addition, using a high sensitivity UV-flow cell in combination with outlet side injections, the S/N and hence the limit of detection of chiral drug could be improved. The 7-cm packed column was also used with traditional inlet injections for CEC coupled to a low-cost single-quadrupole MS. While outlet side injection was not possible in CEC-MS due to instrumentation constraints, the combined use of a short 7 cm column packed with CDMPC-SO3 CSP provided several fold higher throughput. Both CEC-UV and CEC-MS with short packed bed has the potential for a simple, sensitive and cost-effective method for enantiomeric drug profiling in biological samples. PMID:25264392

  16. UV-polymerized butyl methacrylate monoliths with embedded carboxylic single-walled carbon nanotubes for CEC applications.

    PubMed

    Navarro-Pascual-Ahuir, María; Lucena, Rafael; Cárdenas, Soledad; Ramis-Ramos, Guillermo; Valcárcel, Miguel; Herrero-Martínez, José Manuel

    2014-10-01

    The preparation of polymeric monoliths with embedded carboxy-modified single-walled carbon nanotubes (c-SWNTs) and their use for capillary electrochromatography (CEC) is described. Carbon nanotube composites were obtained by preparing a polymerization mixture in the presence of increasing c-SWNT concentrations, followed by UV initiation. The novel stationary phases were studied by optical microscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Raman spectroscopy. Using short UV-polymerization times, the optimized porogenic solvent (a binary mixture of 1,4-butanediol and 2-propanol) gave rise to polymeric beds with homogenously dispersed embedded c-SWNTs. The CEC features of these monoliths were evaluated using polycyclic aromatic hydrocarbons (PAHs), non-steroidal anti-inflammatory drugs (NSAIDs) and chiral compounds. The monolith prepared in the presence of c-SWNTs showed enhanced resolution of the text mixtures, including a remarkable capability to separate enantiomers.

  17. Educators' Perspectives: Survey on the 2009 CEC Advanced Content Standards

    ERIC Educational Resources Information Center

    Othman, Lama Bergstrand; Kieran, Laura; Anderson, Christine J.

    2015-01-01

    Educators who pursue an advanced degree or certification in special education must learn and master the Advanced Content Standards as set forth by the Council for Exceptional Children. These six content standards were validated by the CEC to guide educators through the process of assuming an advanced role in special education teaching or…

  18. Analysis of urinary metabolites for metabolomic study by pressurized CEC.

    PubMed

    Xie, Guoxiang; Su, Mingming; Li, Peng; Gu, Xue; Yan, Chao; Qiu, Yunping; Li, Houkai; Jia, Wei

    2007-12-01

    A new approach for the metabolomic study of urinary samples using pressurized CEC (pCEC) with gradient elution is proposed as an alternative chromatographic separation tool with higher degree of resolution, selectivity, sensitivity, and efficiency. The pCEC separation of urinary samples was performed on a RP column packed with C(18), 5 microm particles with an ACN/water mobile phase containing TFA. The effects of the acid modifiers, applied voltage, mobile phase, and detection wavelength were systematically evaluated using eight spiked standards, as well as urine samples. A typical analytical trial of urine samples from Sprague Dawley (S.D.) rats exposed to high-energy diet was carried out following sample pretreatment. Significant differences in urinary metabolic profiles were observed between the high energy diet-induced obesity rats and the healthy control rats at the 6th wk postdose. Multivariate statistical analysis revealed the differential metabolites in response to the diet, which were partially validated with the putative standards. This work suggests that such a pCEC-based separation and analysis method may provide a new and cost-effective platform for metabolomic study uniquely positioned between the conventional chromatographic tools such as HPLC, and hyphenated analytical techniques such as LC-MS.

  19. Educators' Perspectives: Survey on the 2009 CEC Advanced Content Standards

    ERIC Educational Resources Information Center

    Othman, Lama Bergstrand; Kieran, Laura; Anderson, Christine J.

    2015-01-01

    Educators who pursue an advanced degree or certification in special education must learn and master the Advanced Content Standards as set forth by the Council for Exceptional Children. These six content standards were validated by the CEC to guide educators through the process of assuming an advanced role in special education teaching or…

  20. CEC's Policy on Safe and Positive School Climate

    ERIC Educational Resources Information Center

    Council for Exceptional Children (NJ3), 2008

    2008-01-01

    The Council for Exceptional Children (CEC) recognizes the important impact a safe and positive school climate has on the personal development and academic achievement of all students. Research has shown that schools implementing supportive and positive school climate strategies are more successful in creating environments conducive to learning. As…

  1. News from CEC: High-Leverage Practices in Special Education

    ERIC Educational Resources Information Center

    TEACHING Exceptional Children, 2017

    2017-01-01

    In fall 2014, the Council for Exceptional Children's (CEC) Board of Directors approved a proposal from the Professional Standards and Practice Committee (PSPC) to develop a set of high-leverage practices (HLPs) for special education teachers. The CEEDAR Center at the University of Florida, which is funded by the U.S. Department of Education's…

  2. Enantioseparation of aromatic amino acids using CEC monolith with novel chiral selector, N-methacryloyl-L-histidine methyl ester.

    PubMed

    Aydoğan, Cemil; Yılmaz, Fatma; Cimen, Duygu; Uzun, Lokman; Denizli, Adil

    2013-07-01

    A new type of polymethacrylate-based monolithic column with chiral stationary phase was prepared for the enantioseparation of aromatic amino acids, namely D,L-phenylalanine, D,L-tyrosine, and D,L-tryptophan by CEC. The monolithic column was prepared by in situ polymerization of butyl methacrylate (BMA), N-methacryloyl-L-histidine methyl ester (MAH), and ethylene dimethacrylate (EDMA) in the presence of porogens. The porogen mixture included DMF and phosphate buffer. MAH was used as a chiral selector. FTIR spectrum of the polymethacrylate-based monolith showed that MAH was incorporated into the polymeric structure via in situ polymerization. Some experimental parameters including pH, concentration of the mobile phase, and MAH concentration with regard to the chiral CEC separation were investigated. Single enantiomers and enantiomer mixtures of the amino acids were separately injected into the monolithic column. It was observed that L-enantiomers of aromatic amino acids migrated before D-enantiomers. The reversal enantiomer migration order for tryptophan was observed upon changing of pH. Using the chiral monolithic column (100 μm id and 375 μm od), the best chiral separation was performed in 35:65% ACN/phosphate buffer (pH 8.0, 10 mM) with an applied voltage of 12 kV in CEC. SEM images showed that the chiral monolithic column has a continuous polymeric skeleton and large through-pore structure.

  3. Probabilistic Accident Consequence Uncertainty - A Joint CEC/USNRC Study

    SciTech Connect

    Gregory, Julie J.; Harper, Frederick T.

    1999-07-28

    The joint USNRC/CEC consequence uncertainty study was chartered after the development of two new probabilistic accident consequence codes, MACCS in the U.S. and COSYMA in Europe. Both the USNRC and CEC had a vested interest in expanding the knowledge base of the uncertainty associated with consequence modeling, and teamed up to co-sponsor a consequence uncertainty study. The information acquired from the study was expected to provide understanding of the strengths and weaknesses of current models as well as a basis for direction of future research. This paper looks at the elicitation process implemented in the joint study and discusses some of the uncertainty distributions provided by eight panels of experts from the U.S. and Europe that were convened to provide responses to the elicitation. The phenomenological areas addressed by the expert panels include atmospheric dispersion and deposition, deposited material and external doses, food chain, early health effects, late health effects and internal dosimetry.

  4. Proceedings of the CEC/USDOE workshop on uncertainty analysis

    SciTech Connect

    Elderkin, C.E. ); Kelly, G.N. )

    1990-09-01

    In recent years it has become increasingly important to specify the uncertainty inherent in consequence assessments and in the models that trace radionuclides from their source, through the environment, to their impacts on human health. European and US scientists have, been independently developing and applying methods for analyzing uncertainty. It recently became apparent that a scientific exchange on this subject would be beneficial as improvements are sought and as uncertainty methods find broader application. The Commission of the European Communities (CEC) and the Office of Health and Environmental Research of the US Department of Energy (OHER/DOE), through their continuing agreement for cooperation, decided to co-sponsor the CEC/USDOE Workshop on Uncertainty Analysis. CEC's Radiation Protection Research Programme and OHER's Atmospheric Studies in Complex Terrain Program collaborated in planning and organizing the workshop, which was held in Santa Fe, New Mexico, on November 13 through 16, 1989. As the workshop progressed, the perspectives of individual participants, each with their particular background and interests in some segment of consequence assessment and its uncertainties, contributed to a broader view of how uncertainties are introduced and handled. This proceedings contains, first, the editors' introduction to the problem of uncertainty analysis and their general summary and conclusions. These are then followed by the results of the working groups, and the abstracts of individual presentations.

  5. CEC separation of heterocyclic amines using methacrylate monolithic columns.

    PubMed

    Barceló-Barrachina, Elena; Moyano, Encarnación; Puignou, Lluís; Galceran, Maria Teresa

    2007-06-01

    Two methacrylate-based monolithic columns, one with a negatively charged group (sulfonic group) and another with a new monomer N,N-dimethylamino ethyl acrylate (DMAEA), were prepared and tested for the separation of basic compounds by CEC. This new monolithic stationary phase was prepared by the in situ polymerization of DMAEA with butyl methacrylate and ethylene dimethacrylate, using a ternary porogenic solvent consisting of water, 1-propanol and 1,4-butanediol. The performance of this column was evaluated by means of the analysis of a family of heterocyclic amines. Separation conditions such as pH, amount of organic modifier, ionic strength and elution mode (normal or counterdirectional flow) were studied. At the optimal running electrolyte composition, and using the counterdirectional mode, symmetrical electrochromatographic peaks were obtained, with the number of theoretical plates up to 30,000 and a good resolution between closely related peaks. The 2-acrylamido-2-methyl-1-propane-sulfonic acid column was used for CEC-MS, taking advantage of the compatibility of its elution mode (normal flow) with the MS coupling.

  6. Separation of delta-, gamma- and alpha-tocopherols by CEC.

    PubMed

    Fanali, Salvatore; Catarcini, Paolo; Quaglia, Maria Giovanna; Camera, Emanuela; Rinaldi, Mariarosa; Picardo, Mauro

    2002-08-01

    In this study capillary electrochromatography (CEC) was used for the separation of three tocopherols (TOHs), namely delta-, gamma- and alpha-TOH and the antioxidant compound, butylated hydroxytoluene (BHT). The CEC experiments were carried out using an octadecylsilica (ODS) stationary phase packed, in our laboratory, in a fused-silica capillary (100 microm I.D., 365 microm O.D. x 33 cm of total length and 24.6 or 8.4 cm effective length). The mobile phase was composed by a mixture of methanol (MeOH) and acetonitrile (ACN), at different concentrations and 0.01% (w/v) of ammonium acetate. Retention time (t(R)), retention factor (k), resolution (R(s)) of the three TOHs were strongly influenced by the organic solvent composition of the run buffer and by the effective length of the capillary. Optimum experimental conditions were found even employing the short effective length of the capillary achieving the baseline separation of the studied analytes in a relatively short time (less than 5 min). The optimized method was applied to the qualitative analysis of vitamin E (alpha-TOH) present in a human serum extract.

  7. PHOTOMICROPHOTOGRAPHY- GEOLOGY ( SEM)

    NASA Image and Video Library

    1972-10-13

    PHOTOMICROPHOTOGRAPHY -GEOLOGY (SEM) High magnification and resolution views of lunar, meteorite and terrestrial materials using the Scanning Electron MIcroscope (SEM), Bldg. 31 Planetary and Earth Science Laboratory.

  8. CEC's Policy on Physical Restraint and Seclusion Procedures in School Settings

    ERIC Educational Resources Information Center

    Council for Exceptional Children (NJ3), 2009

    2009-01-01

    The Council for Exceptional Children (CEC) recognizes access to the most effective educational strategies as the basic educational right of each child or youth with a disability. CEC believes that the least restrictive positive educational strategies should be always used to respect the child's or youth's dignity and that this especially pertains…

  9. A weak cation-exchange monolith as stationary phase for the separation of peptide diastereomers by CEC.

    PubMed

    Ludewig, Ronny; Nietzsche, Sandor; Scriba, Gerhard K E

    2011-01-01

    A CEC weak cation-exchange monolith has been prepared by in situ polymerization of acrylamide, methylenebisacrylamide and 4-acrylamidobutyric acid in a decanol-dimethylsulfoxide mixture as porogen. The columns were evaluated by SEM and characterized with regard to the separation of diastereomers and α/β-isomers of aspartyl peptides. Column preparation was reproducible as evidenced by comparison of the analyte retention times of several columns prepared simultaneously. Analyte separation was achieved using mobile phases consisting of acidic phosphate buffer and ACN. Under these conditions the peptides migrated due to their electrophoretic mobility but the EOF also contributed as driving force as a function of the pH of the mobile phase due to increasing dissociation of the carboxyl groups of the polymer. Raising the pH of the mobile phase also resulted in deprotonation of the peptides reducing analyte mobility. Due to these mechanisms each pair of diastereomeric peptides displayed the highest resolution at a different pH of the buffer component of the mobile phase. Comparing the weak-cation exchange monolith to an RP monolith and a strong cation-exchange monolith different elution order of some peptide diastereomers was observed, clearly illustrating that interactions with the stationary phase contribute to the CEC separations. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. What are Contaminants of Emerging Concern (CECs) ?Examples of Biological and Chemistry Approaches to their Detection, Exposure and Effects?

    EPA Science Inventory

    This presentation will overview what Contaminants of Emerging Concern (CECs) are, provide some examples of various CECs and some of the biological and chemistry approaches to assess their exposure and effects to aquatic life. The term CECs has been used since the 1990s to identif...

  11. What are Contaminants of Emerging Concern (CECs) ?Examples of Biological and Chemistry Approaches to their Detection, Exposure and Effects?

    EPA Science Inventory

    This presentation will overview what Contaminants of Emerging Concern (CECs) are, provide some examples of various CECs and some of the biological and chemistry approaches to assess their exposure and effects to aquatic life. The term CECs has been used since the 1990s to identif...

  12. Evaluation of a methacrylate bonded cyclodextrins as a monolithic chiral stationary phase for capillary electrochromatography (CEC)-UV and CEC coupled to mass spectrometry

    PubMed Central

    Gu, Congying; Shamsi, Shahab A.

    2012-01-01

    Glycidyl methacrylate bonded β-cyclodextin (GMA-β-CD) is synthesized as a new chiral monomer by direct chemical bonding with GMA using a fast and a simple alternative procedure. Very, rigid and homogenous monolithic columns were prepared by polymerization of GMA-β-CD monomer with ethylene dimethacrylate (EDMA), in the presence of commonly used porogens and a charged achiral monomer to form a versatile chiral monolith. This is the first report in which a preparation procedure for a methacrylate-bonded CD is introduced for chiral separations in CEC. The degree of substitution (DS) of GMA-β-CD monomer and mobile phase parameters were optimized to achieve highest enantioselectivity and plate number. To evaluate the GMA-β-CD monolithic column, different classes of chiral compounds were screened. Under the optimized β-CD monolith phase and the optimum mobile phase conditions, 30 neutral and basic chiral compounds and two acidic compounds could be separated. The high chemical and mechanical stability, homogenous microflow and no loss of material at the interface allows for the first time the feasibility of applying this polymer-based monolithic column for CEC coupled to ESI-MS. Compared to CEC-UV, CEC-ESI-MS showed higher sensitivity and lower resolution. However, resolution greater than 1.0 can still be obtained for majority of the select tested compound in CEC-ESI-MS with at least three out of seven compound providing Rs≥1.5. The results reinforce the potential of GMA-β-CD monolithic columns for chiral separations with high sensitivity in CEC-ESI-MS. Finally, using hexobarbital as model chiral analyte, the monolithic column demonstrated excellent stability and reproducibility of retention time and enantioselectivity. PMID:21983821

  13. EPA's Role in the North American Commission for Environmental Cooperation (CEC)

    EPA Pesticide Factsheets

    EPA takes a leadership role in the Commission for Environmental Cooperation (CEC), an international organization established by the United States, Canada, and Mexico under the North American Agreement on Environmental Cooperation (NAAEC).

  14. The Mussel Watch California pilot study on contaminants of emerging concern (CECs): synthesis and next steps.

    PubMed

    Maruya, Keith A; Dodder, Nathan G; Weisberg, Stephen B; Gregorio, Dominic; Bishop, Jonathan S; Klosterhaus, Susan; Alvarez, David A; Furlong, Edward T; Bricker, Suzanne; Kimbrough, Kimani L; Lauenstein, Gunnar G

    2014-04-30

    A multiagency pilot study on mussels (Mytilus spp.) collected at 68 stations in California revealed that 98% of targeted contaminants of emerging concern (CECs) were infrequently detectable at concentrations ≤ 1 ng/g. Selected chemicals found in commercial and consumer products were more frequently detected at mean concentrations up to 470 ng/g dry wt. The number of CECs detected and their concentrations were greatest for stations categorized as urban or influenced by storm water discharge. Exposure to a broader suite of CECs was also characterized by passive sampling devices (PSDs), with estimated water concentrations of hydrophobic compounds correlated with Mytilus concentrations. The results underscore the need for focused CEC monitoring in coastal ecosystems and suggest that PSDs are complementary to bivalves in assessing water quality. Moreover, the partnership established among participating agencies led to increased spatial coverage, an expanded list of analytes and a more efficient use of available resources.

  15. The Mussel Watch California pilot study on contaminants of emerging concern (CECs): synthesis and next steps

    USGS Publications Warehouse

    Maruya, Keith A.; Dodder, Nathan G.; Weisberg, Stephen B.; Gregorio, Dominic; Bishop, Jonathan S.; Klosterhaus, Susan; Alvarez, David A.; Furlong, Edward T.; Bricker, Suzanne B.; Kimbrough, Kimani L.; Lauenstein, Gunnar G.

    2014-01-01

    A multiagency pilot study on mussels (Mytilus spp.) collected at 68 stations in California revealed that 98% of targeted contaminants of emerging concern (CECs) were infrequently detectable at concentrations ⩽1 ng/g. Selected chemicals found in commercial and consumer products were more frequently detected at mean concentrations up to 470 ng/g dry wt. The number of CECs detected and their concentrations were greatest for stations categorized as urban or influenced by storm water discharge. Exposure to a broader suite of CECs was also characterized by passive sampling devices (PSDs), with estimated water concentrations of hydrophobic compounds correlated with Mytilus concentrations. The results underscore the need for focused CEC monitoring in coastal ecosystems and suggest that PSDs are complementary to bivalves in assessing water quality. Moreover, the partnership established among participating agencies led to increased spatial coverage, an expanded list of analytes and a more efficient use of available resources.

  16. Recent advances in nonpolar and polar organic monoliths for HPLC and CEC

    PubMed Central

    Jonnada, Murthy; Rathnasekara, Renuka; Rassi, Ziad El

    2015-01-01

    This article is aimed at providing a review of the progress made in the field over the period 2011 to present in order to expand in parts on two previous reviews (S. Karenga and Z. El Rassi, Electrophoresis, 2011, 32, 90-104; D. Gunasena and Z. El Rassi, Electrophoresis, 2012, 33, 251-261). In brief, this review article describes progress made in nonpolar and polar monoliths used in reversed phase HPLC and CEC (RPC/RP-CEC) and in hydrophilic interaction liquid chromatography/CEC (HILIC/HI-CEC), respectively. This article is by no means an exhaustive review of the literature; it is rather a survey of the recent progress made in the field with 69 references published on nonpolar and polar polymeric monoliths. PMID:25266173

  17. A note on bound constraints handling for the IEEE CEC'05 benchmark function suite.

    PubMed

    Liao, Tianjun; Molina, Daniel; de Oca, Marco A Montes; Stützle, Thomas

    2014-01-01

    The benchmark functions and some of the algorithms proposed for the special session on real parameter optimization of the 2005 IEEE Congress on Evolutionary Computation (CEC'05) have played and still play an important role in the assessment of the state of the art in continuous optimization. In this article, we show that if bound constraints are not enforced for the final reported solutions, state-of-the-art algorithms produce infeasible best candidate solutions for the majority of functions of the IEEE CEC'05 benchmark function suite. This occurs even though the optima of the CEC'05 functions are within the specified bounds. This phenomenon has important implications on algorithm comparisons, and therefore on algorithm designs. This article's goal is to draw the attention of the community to the fact that some authors might have drawn wrong conclusions from experiments using the CEC'05 problems.

  18. CEC-ESI ion trap MS of multiple drugs of abuse.

    PubMed

    Aturki, Zeineb; D'Orazio, Giovanni; Rocco, Anna; Bortolotti, Federica; Gottardo, Rossella; Tagliaro, Franco; Fanali, Salvatore

    2010-04-01

    This article describes a method for the separation and determination of nine drugs of abuse in human urine, including amphetamines, cocaine, codeine, heroin and morphine. This method was based on SPE on a strong cation exchange cartridge followed by CEC-MS. The CEC experiments were performed in fused silica capillaries (100 microm x 30 cm) packed with a 3 mum cyano derivatized silica stationary phase. A laboratory-made liquid junction interface was used for CEC-MS coupling. The outlet capillary column was connected with an emitter tip that was positioned in front of the MS orifice. A stable electrospray was produced at nanoliter per minute flow rates applying a hydrostatic pressure (few kPa) to the interface. The coupling of packed CEC columns with mass spectrometer as detector, using a liquid junction interface, provided several advantages such as better sensitivity, low dead volume and independent control of the conditions used for CEC separation and ESI analysis. For this purpose, preliminary experiments were carried out in CEC-UV to optimize the proper mobile phase for CEC analysis. Good separation efficiency was achieved for almost all compounds, using a mixture containing ACN and 25 mM ammonium formate buffer at pH 3 (30:70, v/v), as mobile phase and applying a voltage of 12 kV. ESI ion-trap MS detection was performed in the positive ionization mode. A spray liquid, composed by methanol-water (80:20, v/v) and 1% formic acid, was delivered at a nano-flow rate of approximately 200 nL/min. Under optimized CEC-ESI-MS conditions, separation of the investigated drugs was performed within 13 min. CEC-MS and CEC-MS(2) spectra were obtained by providing the unambiguous confirmation of these drugs in urine samples. Method precision was determined with RSDs values

  19. Commercial thermal distribution systems, Final report for CIEE/CEC

    SciTech Connect

    Xu, Tengfang; Bechu, Olivier; Carrie, Remi; Dickerhoff, Darryl; Fisk, William; Franconi, Ellen; Kristiansen, Oyvind; Levinson, Ronnen; McWilliams, Jennifer; Wang, Duo; Modera, Mark; Webster, Tom; Ring, Erik; Zhang, Qiang; Huizenga, Charlie; Bauman, Fred; Arens, Ed

    1999-12-01

    According to the California Energy Commission (CEC 1998a), California commercial buildings account for 35% of statewide electricity consumption, and 16% of statewide gas consumption. Space conditioning accounts for roughly 16,000 GWh of electricity and 800 million therms of natural gas annually, and the vast majority of this space conditioning energy passes through thermal distribution systems in these buildings. In addition, 8600 GWh per year is consumed by fans and pumps in commercial buildings, most of which is used to move the thermal energy through these systems. Research work at Lawrence Berkeley National Laboratory (LBNL) has been ongoing over the past five years to investigate the energy efficiency of these thermal distribution systems, and to explore possibilities for improving that energy efficiency. Based upon that work, annual savings estimates of 1 kWh/ft{sup 2} for light commercial buildings, and 1-2 kWh/ft{sup 2} in large commercial buildings have been developed for the particular aspects of thermal distribution system performance being addressed by this project. Those savings estimates, combined with a distribution of the building stock based upon an extensive stock characterization study (Modera et al. 1999a), and technical penetration estimates, translate into statewide saving potentials of 2000 GWh/year and 75 million thermal/year, as well as an electricity peak reduction potential of 0.7 GW. The overall goal of this research program is to provide new technology and application knowledge that will allow the design, construction, and energy services industries to reduce the energy waste associated with thermal distribution systems in California commercial buildings. The specific goals of the LBNL efforts over the past year were: (1) to advance the state of knowledge about system performance and energy losses in commercial-building thermal distribution systems; (2) to evaluate the potential of reducing thermal losses through duct sealing, duct

  20. Refocusing Mussel Watch on contaminants of emerging concern (CECs): the California pilot study (2009-10).

    PubMed

    Maruya, Keith A; Dodder, Nathan G; Schaffner, Rebecca A; Weisberg, Stephen B; Gregorio, Dominic; Klosterhaus, Susan; Alvarez, David A; Furlong, Edward T; Kimbrough, Kimani L; Lauenstein, Gunnar G; Christensen, John D

    2014-04-30

    To expand the utility of the Mussel Watch Program, local, regional and state agencies in California partnered with NOAA to design a pilot study that targeted contaminants of emerging concern (CECs). Native mussels (Mytilus spp.) from 68 stations, stratified by land use and discharge scenario, were collected in 2009-10 and analyzed for 167 individual pharmaceuticals, industrial and commercial chemicals and current use pesticides. Passive sampling devices (PSDs) and caged Mytilus were co-deployed to expand the list of CECs, and to assess the ability of PSDs to mimic bioaccumulation by Mytilus. A performance-based quality assurance/quality control (QA/QC) approach was developed to ensure a high degree of data quality, consistency and comparability. Data management and analysis were streamlined and standardized using automated software tools. This pioneering study will help shape future monitoring efforts in California's coastal ecosystems, while serving as a model for monitoring CECs within the region and across the nation.

  1. Asymmetric design for Compound Elliptical Concentrators (CEC) and its geometric flux implications

    NASA Astrophysics Data System (ADS)

    Jiang, Lun; Winston, Roland

    2015-08-01

    The asymmetric compound elliptical concentrator (CEC) has been a less discussed subject in the nonimaging optics society. The conventional way of understanding an ideal concentrator is based on maximizing the concentration ratio based on a uniformed acceptance angle. Although such an angle does not exist in the case of CEC, the thermodynamic laws still hold and we can produce concentrators with the maximum concentration ratio allowed by them. Here we restate the problem and use the string method to solve this general problem. Built on the solution, we can discover groups of such ideal concentrators using geometric flux field, or flowline method.

  2. ARPSO and fk-PSO on CEC 15 benchmark - Comparative study

    NASA Astrophysics Data System (ADS)

    Pluhacek, Michal; Kadavy, Tomas; Senkerik, Roman

    2017-07-01

    In this study we compare the performance of two popular variants of PSO algorithm the diversity guided PSO and heterogeneous PSO. The IEEE CEC 2015 benchmark set is used to test and compare the performance of the methods. The results are statistically evaluated and discussed.

  3. On the impact of cognitive factor in PSO - Testing on selected functions from CEC 15 benchmark

    NASA Astrophysics Data System (ADS)

    Pluhacek, Michal; Senkerik, Roman; Viktorin, Adam

    2017-07-01

    In this study we investigate the effect of the cognitive factor setting on the performance of the PSO algorithm. The cognitive factor is one of the few control parameters of the original PSO algorithm that has direct effect on the trajectories of the particles. The IEEE CEC 2015 benchmark set is used to test the performance.

  4. Education for Sustainability--Looking Backward and Looking Forward--IUCN CEC Perspective on the United Nations Decade of ESD

    ERIC Educational Resources Information Center

    Wheeler, Keith A.; Hesselink, Frits; Goldstein, Wendy

    2015-01-01

    A network of volunteers, the International Union for Conservation of Nature Commission on Education and Communication (CEC), present some reflections on their contributions towards the field of education for sustainability from 1992 to the present. Many CEC members have been thought leaders to this multidimensional field, and advocates for a more…

  5. Education for Sustainability--Looking Backward and Looking Forward--IUCN CEC Perspective on the United Nations Decade of ESD

    ERIC Educational Resources Information Center

    Wheeler, Keith A.; Hesselink, Frits; Goldstein, Wendy

    2015-01-01

    A network of volunteers, the International Union for Conservation of Nature Commission on Education and Communication (CEC), present some reflections on their contributions towards the field of education for sustainability from 1992 to the present. Many CEC members have been thought leaders to this multidimensional field, and advocates for a more…

  6. Etched succinate-functionalized silica hydride stationary phase for open-tubular CEC.

    PubMed

    Chen, Jian-Lian

    2009-11-01

    An open-tubular (OT) CEC column was designed to anchor ionizable succinate-functionalized ligands onto a silica hydride-based stationary phase through surface etching, silanization, and hydrosilation reactions beginning from a bare fused-silica tube. The modified columns that were produced in each step were monitored by analysis of the effect of performance of EOF on the changes of pH values, concentrations, and the amount of ACN added in the running buffers. By tracking the EOF patterns between columns, the author determined that the surface composition of the final product column was a combination of silanols, silica hydrides, and succinate ligands. Furthermore, lower loading volumes of the succinate ligands prepared for the hydrosilation reaction served to complete the mixed-mode OT-CEC columns, and subsequently to carry out the separation of six phenyl alcohols. Studies on the elution order of these alcohols identified the presence of chromatographic interactions in addition to electrophoresis. Based on the employment of a solvation parameter model, these interactions likely included dispersion interactions, dipole-type interactions, and interactions arising through the polarizable electrons in the solute. The optimum buffer conditions for CEC separations of phenyl alcohols, carbonyl-substituted phenols, and a mixture of nucleosides and thymine were a phosphate buffer (50 mM, pH 10.51), a borate buffer (50 mM, pH 8.62), and a borate buffer (50 mM, pH 9.50), respectively. Overall, the hydride-based stationary phases with ionizable ligands were successfully applied to the OT-CEC separations, and these results confidently propose an ideal route to the synthesis of novel OT-CEC columns.

  7. Space Experiment Module (SEM)

    NASA Technical Reports Server (NTRS)

    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. Validation of the CERTS Microgrid Concept The CEC/CERTS MicrogridTestbed

    SciTech Connect

    Nichols, David K.; Stevens, John; Lasseter, Robert H.; Eto,Joseph H.

    2006-06-01

    The development of test plans to validate the CERTSMicrogrid concept is discussed, including the status of a testbed.Increased application of Distributed Energy Resources on the Distributionsystem has the potential to improve performance, lower operational costsand create value. Microgrids have the potential to deliver these highvalue benefits. This presentation will focus on operationalcharacteristics of the CERTS microgrid, the partners in the project andthe status of the CEC/CERTS microgrid testbed. Index Terms DistributedGeneration, Distributed Resource, Islanding, Microgrid,Microturbine

  9. Multimedia screening of contaminants of emerging concern (CECS) in coastal urban watersheds in southern California (USA).

    PubMed

    Maruya, Keith A; Dodder, Nathan G; Sengupta, Ashmita; Smith, Deborah J; Lyons, J Michael; Heil, Ann T; Drewes, Jörg E

    2016-08-01

    To examine the occurrence and fate of contaminants of emerging concern (CECs) and inform future monitoring of CECs in coastal urban waterways, water, sediment, and fish tissue samples were collected and analyzed for a broad suite of pharmaceuticals and personal care products (PPCPs), commercial and/or household chemicals, current use pesticides, and hormones in an effluent-dominated river and multiple embayments in southern California (USA). In the Santa Clara River, which receives treated wastewater from several facilities, aqueous phase CECs were detectable at stations nearest discharges from municipal wastewater treatment plants but were attenuated downstream. Sucralose and the chlorinated phosphate flame retardants tris(1-chloro-2-propyl) phosphate (TCPP), tris(1,3-dichloro-2-propyl) phosphate (TDCPP), and tris(2-chloroethyl) phosphate (TCEP) were most abundant in water, with maximum concentrations of 35 μg/L, 3.3 μg/L, 1.4 μg/L, and 0.81 μg/L, respectively. Triclocarban, an antimicrobial agent in use for decades, was more prevalent in water than triclosan or nonylphenol. Maximum concentrations of bifenthrin, permethrin, polybrominated diphenyl ethers (PBDEs), and degradates of fipronil exceeded CEC-specific monitoring trigger levels recently established for freshwater and estuarine sediments by factors of 10 to 1000, respectively. Maximum fish tissue concentrations of PBDEs varied widely (370 ng/g and 7.0 ng/g for the Santa Clara River and coastal embayments, respectively), with most species exhibiting concentrations at the lower end of this range. These results suggest that continued monitoring of pyrethroids, PBDEs, and degradates of fipronil in sediment is warranted in these systems. In contrast, aqueous pharmaceutical concentrations in the Santa Clara River were not close to exceeding current monitoring trigger levels, suggesting a lower priority for targeted monitoring in this medium. Environ Toxicol Chem 2016;35:1986-1994. © 2016 SETAC.

  10. Refocusing Mussel Watch on contaminants of emerging concern (CECs): the California pilot study (2009-10)

    USGS Publications Warehouse

    Maruya, Keith A.; Dodder, Nathan G.; Schaffner, Rebecca A.; Weisberg, Stephen B.; Gregorio, Dominic; Klosterhaus, Susan; Alvarez, David A.; Furlong, Edward T.; Kimbrough, Kimani L.; Lauenstein, Gunnar G.; Christensen, John D.

    2014-01-01

    To expand the utility of the Mussel Watch Program, local, regional and state agencies in California partnered with NOAA to design a pilot study that targeted contaminants of emerging concern (CECs). Native mussels (Mytilus spp.) from 68 stations, stratified by land use and discharge scenario, were collected in 2009–10 and analyzed for 167 individual pharmaceuticals, industrial and commercial chemicals and current use pesticides. Passive sampling devices (PSDs) and caged Mytilus were co-deployed to expand the list of CECs, and to assess the ability of PSDs to mimic bioaccumulation by Mytilus. A performance-based quality assurance/quality control (QA/QC) approach was developed to ensure a high degree of data quality, consistency and comparability. Data management and analysis were streamlined and standardized using automated software tools. This pioneering study will help shape future monitoring efforts in California’s coastal ecosystems, while serving as a model for monitoring CECs within the region and across the nation.

  11. CEC with new monolithic stationary phase based on a fluorinated monomer, trifluoroethyl methacrylate.

    PubMed

    Yurtsever, Arda; Saraçoğlu, Berna; Tuncel, Ali

    2009-02-01

    A new, fluorinated monolithic stationary phase for CEC was first synthesized by a single-stage, thermally initiated copolymerization of a fluorinated monomer, 2,2,2-trifluoroethyl methacrylate (TFEM) and ethylene dimethacrylate (EDMA) in the presence of a porogen mixture. In this preparation, 2-acrylamido-2-methyl-1-propanesulfonic acid was used as the charge-bearing monomer. The porogen mixture was prepared by mixing isoamylalcohol and 1,4-butanediol. A clear increase in the electroosmotic mobility was observed with increasing pH. The electroosmotic mobility decreased with increasing ACN concentration. Poly(TFEM-co-EDMA) monolith prepared under optimized polymerization conditions was successfully used in the separation of alkylbenzenes and phenols by CEC. The best chromatographic separation for alkylbenzenes was performed with lower ACN concentrations (i.e. 60% v/v) with respect to the common acrylic-based CEC monoliths. The theoretical plate numbers up to 220 000 plates/m were achieved in the reversed phase separation of phenols. Poly(TFEM-co-EDMA) monolith also allowed the simultaneous separation of aniline and benzoic acid derivatives by a single run and by using a lower ACN concentration in the mobile phase with respect to the similar electrochromatographic separations. A stable retention behaviour in reversed phase separation of alkylbenzenes was obtained with the poly(TFEM-co-EDMA) monolith.

  12. Impact of hydraulic and carbon loading rates of constructed wetlands on contaminants of emerging concern (CECs) removal.

    PubMed

    Sharif, Fariya; Westerhoff, Paul; Herckes, Pierre

    2014-02-01

    Constructed wetlands remove trace organic contaminants via synergistic processes involving plant biomass that include hydrolysis, volatilization, sorption, biodegradation, and photolysis. Wetland design conditions, such as hydraulic loading rates (HLRs) and carbon loading rates (CLRs), influence these processes. Contaminant of emerging concern (CEC) removal by wetland plants was investigated at varying HLRs and CLRs. Rate constants and parameters obtained from batch-scale studies were used in a mechanistic model to evaluate the effect of these two loading rates on CEC removal. CLR significantly influenced CEC removal when wetlands were operated at HLR >5 cm/d. High values of CLR increased removal of estradiol and carbamazepine but lowered that of testosterone and atrazine. Without increasing the cumulative HLR, operating two wetlands in series with varying CLRs could be a way to improve CEC removal.

  13. [Distribution characteristics of soil pH, CEC and organic matter in a small watershed of the Loess Plateau].

    PubMed

    Wei, Xiao-Rong; Shao, Ming-An

    2009-11-01

    Soil chemical properties play important roles in soil ecological functioning. In this study, 207 surface soil (0-20 cm) samples were collected from different representative landscape units in a gully watershed of the Loess Plateau to examine the distribution characteristics of soil pH, cation exchange capacity (CEC) and organic matter, and their relations to land use type, landform, and soil type. The soil pH, CEC and organic matter content ranged from 7.7 to 8.6, 11.9 to 28.7 cmol x kg(-1), and 3.0 to 27.9 g x kg(-1), and followed normal distribution, log-normal distribution, and negative binomial distribution, respectively. These three properties were significantly affected by land use type, landform, and soil type. Soil CEC and organic matter content were higher in forestland, grassland and farmland than in orchard land, and soil pH was lower in forestland than in other three land use types. Soil pH, CEC and organic matter content were higher in plateau land and sloping land than in gully bottom and terrace land. Soil CEC and organic matter content were higher in dark loessial soil and rebified soil, while soil pH was higher in yellow loessial soil. Across all the three landscape factors, soil CEC and organic matter content showed the similar distribution pattern, but an opposite distribution pattern was observed for soil pH.

  14. PREFACE: Advances in Cryogenic Engineering: Proceedings of the Cryogenic Engineering Conference (CEC) 2015

    NASA Astrophysics Data System (ADS)

    Kittel, Peter; Sumption, Michael

    2015-12-01

    The 2015 joint Cryogenic Engineering and International Cryogenic Materials Conferences were held from June 28 through July 2 at the JW Marriott Starr Pass Resort & Spa in Tucson, Arizona. As at past conferences, the international scope of these meetings was strongly maintained with 26 countries being represented by 561 attendees who gathered to enjoy the joint technical programs, industrial exhibits, special events, and natural beauty of the surrounding Sonoran Desert. The program for the joint conferences included a total of 363 presentations in the plenary, oral, and poster sessions. Four plenary talks gave in-depth discussions of the readiness of bulk superconductors for applications, the role of cryogenics in the development of the hydrogen bomb and vice versa, superconducting turboelectric aircraft propulsion and UPS's uses and plans for LNG fuel. Contributed papers covered a wide range of topics including large-scale and small-scale cryogenics, advances in superconductors and their applications. In total, 234 papers were submitted for publication of which 224 are published in these proceedings. The CEC/ICMC Cryo Industrial Expo displayed the products and services of 38 industrial exhibitors and provided a congenial venue for a reception and refreshments throughout the week as well as the conference poster sessions. Spectacular panoramic views of Saguaro National Park, the Sonoran Desert and the night time lights of Tucson set the stage for a memorable week in the American Southwest. Conference participants enjoyed scenic hikes and bike rides, exploring Old Town Tucson, hot and spicy southwestern cuisine, a nighttime lightning display and a hailstorm. Conference Chairs for 2015 were Peter Kittel, Consultant, for CEC and Michael Sumption from The Ohio State University, Materials Science Department for ICMC. Program Chairs were Jonathan Demko from the LeTourneau University for CEC and Timothy Haugan from AFRL/RQQM for ICMC, assisted by the CEC Program Vice Chair

  15. Analysis of FEL-based CeC amplification at high gain limit

    SciTech Connect

    Wang, G.; Litvinenko, V.; Jing, Y.

    2015-05-03

    An analysis of Coherent electron Cooling (CeC) amplifier based on 1D Free Electron Laser (FEL) theory was previously performed with exact solution of the dispersion relation, assuming electrons having Lorentzian energy distribution. At high gain limit, the asymptotic behavior of the FEL amplifier can be better understood by Taylor expanding the exact solution of the dispersion relation with respect to the detuning parameter. In this work, we make quadratic expansion of the dispersion relation for Lorentzian energy distribution and investigate how longitudinal space charge and electrons’ energy spread affect the FEL amplification process.

  16. Peak parking determination of the obstruction factor in lauryl acrylate monolithic CEC columns.

    PubMed

    Anderson, Gwendolyn J; LaPier, Zoe; Cammarata, Michael B; Cullum, Tae Sun; Bushey, Michelle M

    2010-05-01

    The peak parking method was used to determine the obstruction factor of lauryl acrylate porous polymer monoliths. Polymers were prepared in situ in fused-silica capillaries using thermally initiated polymerization. These columns have been used for CEC of neutral analytes. Thiourea, which is unretained, was used as the test analyte for the obstruction factor measurement. The obstruction factor was determined to be 0.72 with a SD of (+/-0.01), which is consistent with the concept that organic porous polymer monoliths are more permeable than traditional LC stationary phases.

  17. Development and testing of the questionnaire CEC-61: Knowledge about cervical cancer in Chilean adolescents.

    PubMed

    Urrutia, María Teresa; Gajardo, Macarena; Padilla, Oslando

    2017-05-22

    Despite a clear association between human papillomavirus and cervical cancer, knowledge in adolescent populations regarding the disease and methods for its detection and prevention is deficient. The aim of this study was to develop and test a new questionnaire concerning knowledge on cervical cancer. An instrument was developed and validated to measure knowledge in 226 Chilean adolescents between April and June 2011. Content validity, construct validity, and reliability analysis of the instrument were performed. The new, validated instrument, called CEC-61 (Conocimientos en Cancer Cérvicouterino-61 items/Knowledge in Cervical Cancer-61 items), contains nine factors and 61 items. The new questionnaire explained 81% of the variance with a reliability of 0.96. The assessment of knowledge with a valid and reliable instrument is the first step in creating interventions for a population and to encourage appropriate preventive behavior. CEC-61 is highly reliable and has a clear factorial structure to evaluate knowledge in nine domains related to cervical cancer disease, cervical cancer risk, papilloma virus infection, the Papanicolaou test, and the papilloma virus vaccine.

  18. New dual asymmetric CEC linear Fresnel concentrator for evacuated tubular receivers

    NASA Astrophysics Data System (ADS)

    Canavarro, Diogo; Chaves, Julio; Collares-Pereira, Manuel

    2017-06-01

    Linear Fresnel Reflector concentrators (LFR) are a potential solution for low-cost electricity production. Nevertheless in order to become more competitive with other CSP (Concentrated Solar Power) technologies, in particular with the Parabolic Trough concentrator, their overall solar to electricity efficiencies must increase. A possible path to achieve this goal is to increase the concentration factor, hence increasing the working temperatures for higher thermodynamic efficiency (more energy collection) and decrease the total number of rows of the solar field (less parasitic losses and corresponding cost reduction). This paper presents a dual asymmetric CEC-type (Compound Elliptical Concentrator) LFR (Linear Fresnel Concentrator) for evacuated tubular receivers. The concentrator is designed for a high concentration factor, presenting an asymmetric configuration enabling a very compact solution. The CEC-type secondary mirror is introduced to accommodate very high concentration values with a wide enough acceptance-angle (augmenting optical tolerances) for simple mechanical tracking solutions, achieving a higher CAP (Concentration Acceptance Product) in comparison with conventional LFR solutions. The paper presents an optical and thermal analysis of the concentrator using two different locations, Faro (Portugal) and Hurghada (Egypt).

  19. Update on the CeC PoP 704 MHz 5-cell cavity cryomodule design and fabrication

    SciTech Connect

    Brutus, J. C.; Belomestnykh, S.; Ben-Zvi, I.; Grimm, T.; Huang, Y.; Jecks, R.; Kelly, M.; Litvinenko, V.; Pinayev, I.; Reid, T.; Skaritka, J.; Snydstrup, L.; Than, R.; Tuozzolo, J.; Xu, W.; Yancey, J.; Gerbick, S.

    2015-05-03

    A 5-cell SRF cavity operating at 704 MHz will be used for the Coherent Electron Cooling Proof of Principle (CeC PoP) system under development for the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory. The CeC PoP experiment will demonstrate the new technique of cooling proton and ion beams that may increase the beam luminosity in certain cases, by as much as tenfold. The 704 MHz cavity will accelerate 2 MeV electrons from a 112 MHz SRF gun up to 22MeV. This paper provides an overview of the design, the project status and schedule of the 704 MHz 5-cell SRF for CeC PoP experiment.

  20. [The clinical ethics committee (CEC) in the area of conflict between hospital certification, moral pragmatics and scientific approach].

    PubMed

    Bauer, Axel W

    2007-01-01

    During the last decade numerous consultative bodies for bioethical and medical ethical issues have been established. In this study we will introduce the clinical ethics committee (CEC), which can be mainly brought into action for three purposes: discussing moral problems in a hospital's everyday work, developing guidelines for the clinic, and giving further education to the hospital's staff. Starting with the denominational hospitals at the end of the 1990s, CECs have been established in the meantime at a large number of German clinics, often in an interrelation with hospital certification. We will describe the process of establishing a CEC at the university hospital in Mannheim (Baden-Württemberg) and examine its formal structure given by the statutes and the standing orders. An important issue of the CEC's activities consists in individual consultation, for instance concerning withholding or withdrawing life-supporting therapy from comatose patients. First and foremost it has to be clarified whether there is really an ethical problem which cannot be solved by those seeking advice or whether the CEC is just asked a rhetorical question in order to attain allies. In this case disappointment will often be the consequence. The quality of an ethical consultation cannot be treated as equivalent to the correspondence with preconceived moral attitudes. The CEC is not a "moral police" but a multi-professional body, in which scientific medical ethics should play an important but under no circumstances a dominating role. Meaningful criteria and measuring methods to study the effectiveness of clinical ethics committees will have to be evolved and tested in practice as soon as possible.

  1. (S)-Ibuprofen-imprinted polymers incorporating gamma-methacryloxypropyl-trimethoxysilane for CEC separation of ibuprofen enantiomers.

    PubMed

    Deng, Qi-Liang; Lun, Zhi-Hong; Gao, Ru-Yu; Zhang, Li-Hua; Zhang, Wei-Bing; Zhang, Yu-Kui

    2006-11-01

    In this report, a novel preparation method of molecularly imprinted polymers (MIPs) for CEC was developed. Molecularly imprinted monolithic columns for (S)-ibuprofen were prepared and evaluated, in which charged entities responsible for establishing EOF have been derived from gamma-methacryloxypropyltrimethoxysilane (gamma-MAPS), which was hydrolyzed following copolymerization with 4-vinylpyridine (4-VPY) and ethylene glycol dimethacrylate (EDMA). The EOF and molecular recognition of the stationary phase were investigated in aqueous and nonaqueous media, respectively. The experimental results indicated that the material showed a reasonably stable EOF and the prepared separation materials were capable of separating racemic ibuprofen, a task that could not be accomplished by MIPs prepared in parallel, using methacrylic acid (MAA) as a functional monomer. The efficiency at pH 3.2 for the first-eluted enantiomer and the last-eluted enantiomer (the imprinted analyte) were 128,700 and 2100 plates/m, respectively.

  2. [Cecílio Romaña, Romaña's sign and Chagas' disease].

    PubMed

    Dias, J C

    1997-01-01

    Cecílio Romaña was an important Argentinean researcher dedicated to tropical diseases in the period 1930-1960, recently died in Barcelona. Working mainly on the epidemiological, clinical and pathological aspects of American trypanosomiasis, Romaña became very famous in 1935 when he accurately described the most typical portal recognized in all the endemic area with the cognomen of "Romaña sign". This description caused an enormous polemic with Romaña's then director, the great Salvador Mazza, who never accepted the specificity of the sign and, much less, its popular name (which was proposed by the Brazilian researchers Emmanuel Dias and Evandro Chagas). This history is briefly summarized in the present article, as well as the great impact of Romaña's discovery in the recognition of the acute Chagas' disease in all the endemic area.

  3. CE-C(4)D method development and validation for the assay of ciprofloxacin.

    PubMed

    Paul, Prasanta; Van Laeken, Christophe; Sänger-van de Griend, Cari; Adams, Erwin; Van Schepdael, Ann

    2016-09-10

    A capillary electrophoresis method with capacitively coupled contactless conductivity detection (CE-C(4)D) has been developed, optimized and validated for the determination of ciprofloxacin. Ciprofloxacin is a member of the fluoroquinolone antibiotics with a broad spectrum bactericidal activity and recommended for complicated respiratory infections, sexually transmitted diseases, tuberculosis, bacterial diarrhea etc. Method development was conducted with major focus on the quality by design (QbD) approach. During method development, multiple buffers were tried at different ionic strength. However, the optimized method finally involved a very simple background electrolyte, monosodium citrate at a concentration of 10mM without pH adjustment. The optimized CE-C(4)D method involved an uncoated fused silica capillary (59/39cm, 50μm i.d.) and hydrodynamic sample injection at a pressure of 0.5 p.s.i. for 5s. The actual separation was conducted for 10min at normal polarity with a voltage of 20kV corresponding to 5.9μA current. LiCl (1mg/mL) was used as an internal standard. The optimized method is robust and accurate (recovery >98%) which rendered the ciprofloxacin peak within five minutes with good linearity (R(2)>0.999) in the concentration range of 0.0126-0.8mg/mL. The repeatability is expressed by percentage relative standard deviation (%RSD) of the relative peak areas (RPA) and it showed good repeatability both intra-day (<3%) and inter-day (3.1%). This method, proven to be free of matrix interference, showed that the estimated percent content of ciprofloxacin (102%) was within the official requirements. Moreover, due to its ease of use and robustness, the method should also be applicable in less well controlled laboratory environments. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. Modeling fate and transport of "Contaminants of Emerging Concern" (CECs): is the Soil Water Assessment Tool (SWAT) the appropriate model?

    USDA-ARS?s Scientific Manuscript database

    Background/Question/Methods As the scientific and regulatory communities realize the significant environmental impacts and ubiquity of “contaminants of emerging concern” (CECs), it is increasingly imperative to develop quantitative assessment tools to evaluate and predict the fate and transport of...

  5. Can I Read between the Lines? An Outsider's Observations on the CEC-CED Joint Knowledge and Skills Statement.

    ERIC Educational Resources Information Center

    Saur, Rosemary

    This commentary on the Council for Exceptional Children-Council on Education of the Deaf's (CEC-CED's) Joint Knowledge and Skills Statement, which sets forth qualifications needed by those who teach deaf and hard of hearing students, discusses key issues impacting the education of students who are deaf or hard-of-hearing: cultural flexibility,…

  6. Superfund Record of Decision (EPA Region 1): Cannon's Engineering Corporation (CEC) Plymouth Site, Plymouth, Massachusetts, September 1985. Final report

    SciTech Connect

    Not Available

    1985-09-30

    The Cannon Engineering Corporation (CEC) Plymouth Site is located in Cordage Park, a business and industrial park bordering Plymouth Harbor, in Plymouth, Massachusetts. The site consists of 2.5 acres which includes three above-ground storage tanks, two of which are estimated to have nominal storage capacities in excess of 250,000 gallons each, and one which has an estimated 500,000-gallon capacity. The tanks were originally used for the storage of 6 marine fuel oil and bunker C oil. In 1976, CEC rented one tank for the reported storage of waste oil and later rented a second tank. Allegedly, CEC used the tanks to store hazardous wastes. In 1979, CEC was licensed by the Massachusetts Department of Environmental Quality Engineering (DEOE) to store motor oils, industrial oils and emulsions, solvents, laquers, organic chemicals, inorganic chemicals, cyanide and plating waste, clay and filter media containing chemicals, plating sludge, oily solids and pesticides. Potential problems observed at the site included slow leakage at the bottom seams of one of the tanks; adequacy of earthen dikes surrounding the tanks; odor complaints; and leaks from tank side valves.

  7. Synthesis and secretory expression of hybrid antimicrobial peptide CecA-mag and its mutants in Pichia pastoris.

    PubMed

    Wang, Xiuqing; Zhu, Mingxing; Zhang, Aijun; Yang, Fengqin; Chen, Puyan

    2012-03-01

    The hybrid peptide CA(1-7)-M(2-12) gene was designed according to the N-terminal 1-7 amino acid sequence of the antimicrobial peptide cecropin A (CA) and the N-terminal 2-12 amino acid sequence of maganin (M) and synthesized using Pichia pastoris preferred codons. The gene was cloned into pPICZαA and transformed into the P. pastoris recipient bacterium SMD1168, regulated by the alcohol oxidase (AOX). Expression of the cecA-mag hybrid antimicrobial peptide (MW, 1.9 kDa) revealed broad-spectrum antibiotic activity and to the ability to inhibit growth of most G(-) and G(+) bacteria. Three mutants of cecA-mag were designed and synthesized by recombination polymerase chain reaction site-directed mutagenesis to investigate the relationship between the structure and function of this antimicrobial peptide. The inhibition titers of these mutants against Staphylococcus aureus were evaluated using the agar diffusion method. Under the conditions of the same concentration and volume, the bacteriostatic diameters of three cecA-mag mutants were 1.2, 1.2 and 1.5 times, respectively, compared with the diameters of wild-type cecA-mag.

  8. Enantioseparation of glycyl-dipeptides by CEC using particle-loaded monoliths prepared by ring-opening metathesis polymerization (ROMP).

    PubMed

    Gatschelhofer, Christina; Schmid, Martin G; Schreiner, Karin; Pieber, Thomas R; Sinner, Frank M; Gübitz, Gerald

    2006-11-30

    Novel particle-loaded monolithic capillary electrochromatography (CEC) phases for chiral separations were prepared via ring-opening metathesis polymerization (ROMP) within the confines of fused silica columns with 200 microm i.d. using norborn-2-ene (NBE), 1,4,4a,5,8,8a-hexahydro-1,4,5,8,exo,endo-dimethanonaphthalene (DMN-H6) as monomers, 2-propanol and toluene as porogens, RuCl2(PCy3)2(CHPh) as initiator and silica-based particles containing the chiral selector. By suspending silica particles bearing the chiral selector in the polymerization mixture, particle-based monoliths are easily prepared. This approach has several advantages compared to particle-based separation media: (i) the concept of particle-based monoliths is broadly applicable, as any silica-based chiral phase can be used; (ii) they are inexpensive to prepare; and (iii) the manufacturing process is very simple, no sophisticated packing procedures or the preparation of end frits are required. To show the usefulness of this concept for chiral CEC, the chiral separation performance of particle-loaded CEC monoliths bearing teicoplanin aglycone, chemically bonded to 3 microm silica gel, was investigated for a set of glycyl-dipeptides. Particle-loaded ROMP CEC monoliths showed good separation performance for glycyl-dipeptides.

  9. Oxygen Isotope Fractionation Effects in Soil Water via Cations Adsorbed to High-CEC Clays

    NASA Astrophysics Data System (ADS)

    Oerter, E.; Finstad, K.; Schaefer, J.; Goldsmith, G. R.; Dawson, T. E.; Amundson, R.

    2012-12-01

    In isotope-based approaches to hydrology, soil and sediment are implicitly considered to be an inert matrix in which water resides or moves. Yet, this assumption is inconsistent with the fact that soils contain a wide range of solutes, and highly variable concentrations of chemically reactive clay particles, all of which may react with bulk water and create pools of energetically differing water with varying isotope compositions. The empirical basis of this hypothesis is the work of Sofer and Gat (1972, EPSL, 15(3)), who showed that the formation of hydration spheres around cations in aqueous solutions fractionate oxygen isotopes of water in ways that appear to be dependent on the cation's ionic potential and concentration. Because soil solutions commonly have high solid to fluid ratios, the potential for solids to create substantial pools of low free energy water, with corresponding isotope fractionation of the free and low energy waters, may be a common process. The potential for this to create measurable isotopic effects would be most evident in soils with high Cation Exchange Capacity (CEC). In order to test this hypothesis, montmorillonite (CEC ≈ 100 meq/100g), kaolinite (CEC≈10) and quartz (CEC≈0) mineral powders were saturated with 3M MgCl2 and KCl solutions (separately), rinsed with methanol and dried to saturate all available CEC sites with either Mg or K cations. Triplicate sets of monominerallic-deionized water mixtures were created at 5, 25, 50, 75 and 95% gravimetric water content. Each set of samples was then subjected to one of three water extraction techniques designed to access specific "pools" of soil water: (1) direct equilibration with CO2 to sample the soil's "free water", i.e. water not adsorbed to cations via hydration spheres; (2) centrifugation to simulate permanent wilting point conditions, thereby yielding most micro-pore, macro-pore, and free water; and (3) cryogenic vacuum distillation to recover all the soil water (free, pore and

  10. SEM: A Cultural Change Agent

    ERIC Educational Resources Information Center

    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. SEM: A Cultural Change Agent

    ERIC Educational Resources Information Center

    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…

  12. High CEC generation and surface modification in mica and vermiculite minerals

    NASA Astrophysics Data System (ADS)

    Mittal, Vikas

    2013-03-01

    Montmorillonite layered silicate has been commonly used to reinforce polymer matrices. Due to its swelling in water, organic modification of the mineral surface is easily achieved which makes the surface compatible with polymers. Other minerals like mica and vermiculite though can also lead to high aspect ratio platelets in nanocomposites, but they do not swell in water owing to much stronger electrostatic forces of attraction holding their platelets together (layer charge density >0.5 eq . mol-1 in comparison with 0.25-0.5 eq . mol-1 for montmorillonite). In current study, milling, delamination and cation exchange processing of mica and vermiculite minerals has been reported to explore their potential as reinforcement materials. Wet grinding and subsequent sieving of the coarse minerals led to fine-sized particles suitable to perform chemical delamination in water. The delamination process resulted in Li-mica and Na-vermiculite with enhanced access to the interlayer cations, thus, higher CEC. Successful surface modification of the delaminated minerals with alkyl ammonium ions could be achieved which resulted in significant enhancements in their basal plane spacing. Peak degradation temperatures of 260°C were measured for C18 and 2C18 modified vermiculite, whereas 300°C and 275°C were observed respectively for C18 and 2C18 modified mica minerals which make them suitable for compounding with polymers at high temperature.

  13. A potential food biopreservative, CecXJ-37N, non-covalently intercalates into the nucleotides of bacterial genomic DNA beyond membrane attack.

    PubMed

    Liu, Dongliang; Liu, Jun; Li, Jinyao; Xia, Lijie; Yang, Jianhua; Sun, Surong; Ma, Ji; Zhang, Fuchun

    2017-02-15

    The antibacterial activities and mechanism of an amide-modified peptide CecXJ-37N were investigated in this study. CecXJ-37N showed small MICs (0.25-7.8μM) against eight harmful strains common in food industry. The α-helix proportion of CecXJ-37N increased by 11-fold in prokaryotic membrane comparable environments; cytotoxicity studies demonstrated the MHC was significantly higher than that of non-amidated isoform. Moreover, CecXJ-37N possessed stronger capacities to resist trypsin and pepsin hydrolysis within two hours. Flow cytometry and scanning electron microscopy demonstrated that CecXJ-37N induced pore-formation, morphological changes, and lysed E. coli cells. Fluorescence microscopy indicated that CecXJ-37N penetrated E. coli membrane and accumulated in cytoplasm. Further ultraviolet-visible spectroscopy suggested that CecXJ-37N changed the action mode of parental peptide interacting with bacterial genome from outside binding to a tightly non-covalent intercalation into nucleotides. Overall, this study suggested that amide-modification enhanced antimicrobial activity and reduced the cytotoxicity, thus could be potential strategies for developing novel food preservatives. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Framework for SEM contour analysis

    NASA Astrophysics Data System (ADS)

    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.

  15. Monolithic silica capillary columns with immobilized cellulose tris(3,5-dimethylphenylcarbamate) for enantiomer separations in CEC.

    PubMed

    He, Chiyang; Hendrickx, Ans; Mangelings, Debby; Smeyers-Verbeke, Johanna; Vander Heyden, Yvan

    2009-11-01

    Two types of monolithic silica capillary columns with an immobilized cellulose tris(3,5-dimethylphenylcarbamate) (CDMPC) selector were prepared for enantiomer separations in CEC. The monolithic columns were prepared by a sol-gel process in fused-silica capillaries. CDMPC was then either immobilized on a silica monolith through an intermolecular polycondensation of the cellulose derivative containing a triethoxysilyl group, or on a vinylized silica monolith through radical copolymerization of the cellulose derivative, which also contained a vinyl group. IR spectra confirmed the successful immobilization of CDMPC on both columns. Eleven chiral compounds were used to evaluate the enantioselectivity on both column types. Results indicated that the columns obtained via polycondensation had higher separation ability than those obtained via radical polymerization, and that they showed satisfactory run-to-run repeatability and stability. These new techniques thus provide strategies for preparing immobilized polysaccharide-based chiral silica monolithic capillary columns for chiral separations by means of CEC.

  16. The titration of clay minerals I. Discontinuous backtitration technique combined with CEC measurements.

    PubMed

    Tournassat, Christophe; Greneche, Jean-Marc; Tisserand, Delphine; Charlet, Laurent

    2004-05-01

    Previous experimental studies on clay potentiometric titration have been unable to distinguish inorganic cation exchange in the interlayer and on basal plane surfaces from specific pH-dependent sorption of cations and anions on the edges. In this study, we refined a titration technique, combining discontinuous backtitration and cation exchange capacity (CEC) measurements, and applied it to the potentiometric titration of Na- and Ca-conditioned montmorillonites. This technique can be used to accurately measure cation exchange, edge surface proton charge, dissolution of clay, and precipitation of new phases. Thus, a precise measurement of the variations of net proton surface charge is possible. This has important implications for clay surface modeling (see part II of this article) and for processes that depend on the clay surface charge, e.g., alteration, rheological processes, and contamination retention applications. In addition, this study confirms the adsorption of ionic pairs such as CaCl+ in exchange site positions and shows that CaOH+ could behave like CaCl+. This result, together with the evidence of precipitation of a Ca?Si phase over a short time-scale (1 week) at high pH and low temperature, can be used to model clay-concrete interactions more accurately. We confirmed and quantified the H+/Na+ exchange reaction at low pH. Finally, we demonstrate that both the edge surface charge and the permanent structural charge are compensated for by the nonspecific sorption of cations from solution across the entire pH range from 4 to 11. Under these conditions, the surface potential is fully screened and does not need to be invoked in modeling sorption processes on clay particles in dilute suspensions.

  17. Preparation and evaluation of a sulfoalkylbetaine-based zwitterionic monolithic column for CEC of polar analytes.

    PubMed

    Wang, Xiaochun; Lin, Xucong; Xie, Zenghong

    2009-08-01

    A novel polymethacrylate-based monolithic column with covalently bonded zwitterionic functional groups was prepared by in situ copolymerization of N,N-dimethyl-N-methacryloxyethyl N-(3-sulfopropyl) ammonium betaine (SPE), pentaerythritol triacrylate (PETA), and vinylsulfonic acid (VS) in a binary porogenic solvent consisting of cyclohexanol and ethylene glycol. This monolith was developed as a separation column for CEC. While SPE functioned as both an electrostatic interaction stationary phase and the polar ligand provider, VS was employed to generate EOF. PETA, which has much more hydrophilicity due to a hydroxyl sub-layer, was used to replace ethylene dimethacrylate as a cross-linker. The monolith provided an adequate EOF when VS level was maintained at 0.6% w/w. Different monolithic stationary phases were easily prepared by adjusting the ratio of PETA/SPE in the polymerization solution as well as the composition of the porogenic solvent. The observed RSD were

  18. Sorption of organic cations to phyllosilicate clay minerals: CEC-normalization, salt dependency, and the role of electrostatic and hydrophobic effects.

    PubMed

    Droge, Steven T J; Goss, Kai-Uwe

    2013-12-17

    Sorption to the phyllosilicate clay minerals Illite, kaolinite, and bentonite has been studied for a wide variety of organic cations using a flow-through method with fully aqueous medium as the eluent. Linear isotherms were observed at concentrations below 10% of the cation-exchange capacity (CEC) for Illite and kaolinite and below 1 mmol/kg (<1% CEC) for bentonite. Sorption to clays was strongly influenced by the electrolyte composition of the eluent but with a consistent trend for a diverse set of compounds on all clays, thus allowing for empirical correction factors. When sorption affinities for a given compound to a given clay are normalized to the CEC of the clay, the differences in sorption affinities between clays are reduced to less than 0.5 log units for most compounds. Although CEC-normalized sorption of quaternary ammonium compounds to clay was up to 10-fold higher than CEC-normalized sorption to soil organic matter, CEC-normalized sorption for most compounds was comparable between clays and soil organic matter. The clay fraction is thus a potentially relevant sorption phase for organic cations in many soils. The sorption data for organic cations to clay showed several regular trends with molecular structure but also showed quite a few systematic effects that we cannot explain. A model on the basis of the molecular size and charge density at the ionized nitrogen is used here as a tool to obtain benchmark values that elucidate the effect of specific polar moieties on the sorption affinity.

  19. Measurement of cation exchange capacity (CEC) of plant cell walls by X-ray microanalysis (EDX) in the transmission electron microscope.

    PubMed

    Fritz, Eberhard

    2007-08-01

    Cation exchange capacity (CEC) characterizes the number of fixed negative charges of plant cell walls and is an important parameter in studies dealing with the uptake of ions into plant tissues, especially in roots. Conventional methods of CEC determination use bulk tissue, the results are the mean of many cells, and differences in the CEC of different tissue types are masked. Energy-dispersive microanalysis (EDX) in the transmission electron microscope allows CEC determinations on much finer scales. Shoot and fine root tissue of Picea abies was acid washed to remove exchangeable cations. Tissue blocks or semithin tissue sections were loaded with 0.2 mM CaCl2, AlCl3, or Pb(NO3)2 at pH 4.0. The amount of Ca, Al, or Pb adsorbed to the exchange sites of cell walls was determined by EDX. The CEC of cell walls of different tissue types was highly different, ranging in shoot tissues from 0 to 856 mM Ca and 5.8 to 1463 mM Al (block loading) or 4.3 to 1116 mM Ca and 0 to 2830 mM Al (section loading). In root tissue, Pb adsorption to semithin sections yielded CEC values between 29.1 and 954 mM Pb. In most P. abies shoot tissues, the binding capacity was clearly higher for Al than for Ca.

  20. Novel use of magnetic biochars for the remediation of soils contaminated by contaminants of emerging concerns (CECs)

    NASA Astrophysics Data System (ADS)

    Sani, Badruddeen; Mrozik, Wojciech; Werner, David

    2016-04-01

    The advantage of using magnetic biochar over nonmagnetic biochar in amendments of contaminated soils is in the fact that the former can be easily removed from the soil matrix whenever the need arises, using simple principles of magnetism. In this study, magnetic biochar was produced using a simple co-precipitation technique. The resulting composite has about 33% (w/w) magnetic iron oxides, the presence of which resulted in modification of the biochar's surface characteristics such as BET surface area, porosity and point of zero charge. Modifications in these properties will most likely alter the CEC sorption properties of the biochar, hence the necessity for the proper evaluation of the possible trade off that exist between the need for magnetisation and altered sorption characteristics of the biochar. To achieve this, bottle point sorption experiments in aqueous solutions were conducted using activated and non-activated biochars in magnetic and nonmagnetic forms as sorbents and two pharmaceuticals -ibuprofen and diclofenac- as representative CECs. Sorption isotherms were evaluated and the data was fitted to Langmuir, Freundlich, Redlich-Peterson, Dubinin-Ashtakov and Polanyi-Dubinin-Manes isotherm models. Removal efficiencies and sorption capacities correlated well with the effective mass of pristine biochar used, therefore the sorption characteristics of both magnetic and nonmagnetic biochars are not detrimentally affected by the magnetite impregnation. Biochars in activated form show superior sorption capacities due to amplified surface area and better developed pores. Also, non-activated biochars needed to be used in higher amounts to achieve considerable level of CEC removal, thus they are more easily exhausted. Sorption was observed to decrease with a corresponding increase in solution pH. This suggests that sorption is favoured within the acidic pH range when the surfaces of the sorbents have net positive charge and the sorbates are in their neutral forms.

  1. Fast determination of prominent carotenoids in tomato fruits by CEC using methacrylate ester-based monolithic columns.

    PubMed

    Adalid, Ana Maria; Herrero-Martínez, José Manuel; Roselló, Salvador; Maquieira, Angel; Nuez, Fernando

    2007-11-01

    In this study, the major carotenoids (beta-carotene and lycopene) present in tomato fruits were analyzed by CEC with a methacrylate ester-based monolithic column. The effects of the porogenic solvent ratio, and the hydrophobicity of bulk monomer employed were examined on carotenoids separations. A fast separation of these analytes was achieved in less than 5.0 min in a mobile phase containing 35% THF, 30% ACN, 30% methanol, and 5% of a 5 mM Tris aqueous buffer, pH 8, with lauryl methacrylate-based monoliths. The CEC method was evaluated in terms of detection limit and reproducibility (retention time, area, and column preparation) with values below 1.6 microg/mL and 7.2%, respectively. The proposed procedure was successfully applied to the determination of both carotenoids in fruits of several tomato-related species and its usefulness to analyze large series of samples for nutritional quality screening trials in tomato breeding programs is demonstrated. To our knowledge, this is the first work that exploits the powerful and user-friendly monolithic technology for quality breeding and germplasm evaluation program purposes.

  2. A note on the use of the CEC L-33-A-93 test to predict the potential biodegradation of mineral oil based lubricants in soil.

    PubMed

    Battersby, N S; Morgan, P

    1997-10-01

    The biodegradabilities of five unformulated mineral oils (brightstock, 150 SN base oil, white oil and two gas oils) were determined in the CEC L-33-A-93 test and during 20 weeks incubation in nutrient-supplemented soil microcosms. Biodegradation in both studies was measured as the loss of extractable hydrocarbon ('primary' biodegradation). There was a statistically significant (P < 0.01) rectilinear relationship between the extents of biodegradation in both test systems. The results indicate that the CEC method could be used as a relatively simple, quick and inexpensive test for assessing the potential biodegradation of mineral oil based lubricants in soil.

  3. SEM signal emulation for 2D patterns

    NASA Astrophysics Data System (ADS)

    Sukhov, Evgenii; Muelders, Thomas; Klostermann, Ulrich; Gao, Weimin; Braylovska, Mariya

    2016-03-01

    The application of accurate and predictive physical resist simulation is seen as one important use model for fast and efficient exploration of new patterning technology options, especially if fully qualified OPC models are not yet available at an early pre-production stage. The methodology of using a top-down CD-SEM metrology to extract the 3D resist profile information, such as the critical dimension (CD) at various resist heights, has to be associated with a series of presumptions which may introduce such small, but systematic CD errors. Ideally, the metrology effects should be carefully minimized during measurement process, or if possible be taken into account through proper metrology modeling. In this paper we discuss the application of a fast SEM signal emulation describing the SEM image formation. The algorithm is applied to simulated resist 3D profiles and produces emulated SEM image results for 1D and 2D patterns. It allows estimating resist simulation quality by comparing CDs which were extracted from the emulated and from the measured SEM images. Moreover, SEM emulation is applied for resist model calibration to capture subtle error signatures through dose and defocus. Finally, it should be noted that our SEM emulation methodology is based on the approximation of physical phenomena which are taking place in real SEM image formation. This approximation allows achieving better speed performance compared to a fully physical model.

  4. Scientific disputes that spill over into Research Ethics: interview with Maria Cecília de Souza Minayo.

    PubMed

    Minayo, Maria Cecília de Souza

    2015-09-01

    This is an interview with Maria Cecília de Souza Minayo, by university lecturers Iara Coelho Zito Guerriero and Maria Lúcia Magalhães Bosi. It reflects the heat of the current debates surrounding implementation of a specific protocol for evaluation of research in the Human and Social Sciences (HSS), vis-à-vis the current rules set by the National Health Council, which have a clearly biomedical bias. The interview covers the difficulties of introducing appropriate and fair rules for judgment of HSS projects, in the face of a hegemonic understanding of the very concept of science by biologists and medical doctors, who tend not to recognize other approaches unless those approaches adopt their frames of reference. In this case, the National Health Council becomes the arena of this polemic, leading researchers in the human and social sciences to ask themselves whether the health sector has the competency to create rules for other areas of knowledge.

  5. A Multi-Agency Effort for Assessing the Occurrence and Biological Impacts of CECs in Support of the Great Lakes Restoration Initiative

    EPA Science Inventory

    In recent years, there has been a substantial increase in the detection of a variety of contaminants for which little is known regarding their potential impact(s) on Great Lakes ecosystems. These contaminants of emerging concern, or CECs, include an assortment of industrial (e.g....

  6. A Multi-Agency Effort for Assessing the Occurrence and Biological Impacts of CECs in Support of the Great Lakes Restoration Initiative

    EPA Science Inventory

    In recent years, there has been a substantial increase in the detection of a variety of contaminants for which little is known regarding their potential impact(s) on Great Lakes ecosystems. These contaminants of emerging concern, or CECs, include an assortment of industrial (e.g....

  7. SEM probe of IC radiation sensitivity

    NASA Technical Reports Server (NTRS)

    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.

  8. Pressurized CEC with amperometric detection using mixed-mode monolithic column for rapid analysis of chlorophenols and phenol.

    PubMed

    Lu, Lanxiang; Chen, Yankai; Yu, Xiaowei; Wu, Xiangzong; Tang, Fengxiang; Wu, Xiaoping

    2013-07-01

    A simple analysis of chlorophenols (2-chlorophenol, 2,4-dichlorophenol, 2,4,6-trichlorophenol, and pentachlorophenol) and phenol was accomplished by coupling a pressurized CEC with amperometric detection (AD). Efficient and reproducible separation of these compounds was achieved within 9 min on a capillary monolithic stationary phase bonded with octadecyl ligands and sulfonate groups, where the selectivity and the retention of analytes can be functionally controlled by optimizing experimental variables, including organic modifier content, mobile phase pH, ionic strength, working electrode potential, separation voltage, and supplementary pressure. A mixed-mode retention mechanism consisting of reverse-phase chromatographic partition, electrostatic repulsion, and electrophoresis is considered to play roles in the separation. The use of ACN-based media seems effectual in preventing the unfavorable irreversible adsorption on both wall and electrode, and offer higher sensitivity and less electrode fouling in AD of phenols. The LODs were in the range from 0.02 to 0.2 μg/mL with a wide linear dynamic range of 5000-fold, while the peak area precision ranged from 3.2 to 7.5%. The feasibility of using this method in real analysis was evaluated by recovery estimates and comparative experiment on spiked tap water samples. Good recoveries of 80-110% were achieved. Additionally, a paired t-test was used to correlate the two methods.

  9. Optimized mobile phase for CEC of acetylsalicylic acid and its impurities using a methacrylate-based monolithic column.

    PubMed

    Tanret, Indiana; Mangelings, Debby; Vander Heyden, Yvan

    2011-08-01

    In the past few years, monolithic methacrylate-based columns have attracted some attention in separation science. The mobile-phase optimization on these columns for drug analysis has not yet been thoroughly examined. This paper evaluates the separation of acetylsalicylic acid and its impurities as a case study. First, the best pH was determined as 2.3. Methacrylate-based phases can be employed at such pH because they remain charged, necessary to generate electro-osmotic flow. Then, a suitable solvent strength was determined. Trifluoroacetic acid (0.1%) was added to the mobile phase to improve peak shapes. The optimal organic modifier composition was then determined, using isoeluotropic mobile phases, based on the theory of Snyder's solvent triangle. Quadratic models were built to predict the retention of the compounds at all mobile-phase compositions within the triangle. The predictions were tested and found appropriate. Eventually, a baseline separation of acetylsalicylic acid and its impurities was not obtained. However, it could be concluded that one can optimize the mobile phase on methacrylate-based monolithic columns in CEC using Snyder's solvent triangle approach. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Safety in the SEM laboratory--1981 update

    SciTech Connect

    Bance, G.N.; Barber, V.C.; Sholdice, J.A.

    1981-01-01

    The article reviews recent information on hazards as they relate to safety in SEM laboratories. The first section lists the safety equipment that should be available in a SEM laboratory. Flammable and combustible liquids are discussed, and particular warnings are given concerning the fire and explosion risks associated with diethyl ether and diisopropyl ether. The possible hazards associated with electrical equipment, and the risk of X-ray emissions from EM's are briefly outlined. The hazards associated with acute and chronic toxicity of chemicals used in the EM laboratory are discussed. The need to reduce exposure to a growing list of recognizable hazardous chemicals is emphasized. This reduction can be accomplished by more extensive use of functioning fume hoods, and the use of more appropriate and effective protective gloves. Allergies and the hazards of dangerous pathogens in the SEM laboratory are discussed. The explosion and other hazards associated with cryogens, vacuum evaporators, critical point dryers, and compressed gas cylinders are emphasized.

  11. Oxford CyberSEM: remote microscopy

    NASA Astrophysics Data System (ADS)

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

    2008-08-01

    The Internet has enabled researchers to communicate over vast geographical distances, sharing ideas and documents. e-Science, underpinned by Grid [1] 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.

  12. FIB-SEM tomography in biology.

    PubMed

    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.

  13. pCEC coupling with ESI-MS for the analysis of beta(2)-agonists and narcotics using a poly-(1-hexadecene-co-TMPTMA) monolithic column.

    PubMed

    Cheng, Jintian; Zhang, Lan; Lu, Qiaomei; Lu, Minghua; Chen, Zongbao; Chen, Guonan

    2010-06-01

    A pressure-assisted CEC with ESI-MS based on poly(1-hexadecene-co-trimethylolpropane trimethacrylate) monolithic column for rapid analysis of two beta(2)-agonists and three narcotics was established in this article. After the organic polymer-based monolithic column was prepared by an in-situ polymerization procedure, a systematic investigation of the pressure-assisted CEC separation and ESI-MS detection parameters was performed. Baseline separation of the studied analytes could be obtained using the solution containing 75% ACN v/v and 20 mmol/L ammonium acetate with pH 8.0 as running buffer, when applying separation voltage of 20 kV and assisted pressure of 5 bar. Under the optimized conditions, two beta(2)-agonists and three narcotics could be completely resolved and accurately determined within 15 min. Finally, the proposed method was successfully used for real urine samples detection.

  14. Commissioning of the 112 MHz SRF Gun and 500 MHz bunching cavities for the CeC PoP Linac

    SciTech Connect

    Belomestnykh, S.; Ben-Zvi, I.; Brutus, J. C.; Litvinenko, V.; McIntosh, P.; Moss, A.; Narayan, G.; Orfin, P.; Pinayev, I.; Rao, T.; Skaritka, J.; Smith, K.; Than, R.; Tuozzolo, J.; Wang, E.; Wheelhouse, A.; Wu, Q.; Xiao, B.; Xin, T.; Xu, W.; Zaltsman, A.

    2015-05-03

    The Coherent electron Cooling Proof-of-Principle (CeC PoP) experiment at BNL includes a short electron linac. During Phase 1, a 112 MHz superconducting RF photo-emission gun and two 500 MHz normal conducting bunching cavities were installed and are under commissioning. The paper describes the Phase1 linac layout and presents commissioning results for the cavities and associated RF, cryogenic and other sub-systems

  15. Building a SEM Analytics Reporting Portfolio

    ERIC Educational Resources Information Center

    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…

  16. Building a SEM Analytics Reporting Portfolio

    ERIC Educational Resources Information Center

    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…

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

    SciTech Connect

    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.

  18. CD-SEM utility with double patterning

    NASA Astrophysics Data System (ADS)

    Bunday, Benjamin; Lipscomb, Pete; Koshihara, Shunsuke; Sukegawa, Shigeki; Kawai, Yasuo; Ojima, Yuki; Self, Andy; Page, Lorena

    2010-03-01

    Requirements for increasingly integrated metrology solutions continue to drive applications that incorporate process characterization tools, as well as the ability to improve metrology production capability and cycle time, with a single application. All of the most critical device layers today, and even non-critical layers, now require optical proximity correction (OPC), which must be rigorously modeled and calibrated as part of process development and extensively verified once new product reticles are released using critical dimension-scanning electron microscopy (CD-SEM) tools. Automatic setup of complex recipes is one of the major trends in CD-SEM applications, which is adding much value to CD-SEM metrology. In addition, as integrated circuit dimensions and pitches continue to shrink, double patterning (DP) has become more common. Thus automatic recipe setup has needed to incorporate capabilities to deal simultaneously with two layers. This has the benefit of allowing the user to measure the two different CD populations and the image shift in the lithography (i.e., the overlay). Thus automatic recipe creation can be used to characterize the DP pattern for both CD and overlay. DesignGauge, the automatic recipe utility for Hitachi CG series CD-SEMs, is not only capable of offline recipe creation, but also can also directly transfer design-based recipes into standard CD-SEM recipes for use with DP processes. These recipes can be used for OPC model-building and verification as with previous DesignGauge applications. The software also provides design template-based recipe setup for production layer recipes, which improves production tool utilization, as production recipes can thus be written offline for new products, improving first silicon cycle time, engineering time to generate recipes, and CD-SEM utilization. Another benefit of the application is that recipes are more robust than with conventional direct image-based pattern recognition. This paper explores the

  19. Design of a solar collector system formed by a Fresnel lens and a CEC coupled to plastic fibers

    NASA Astrophysics Data System (ADS)

    Viera-González, Perla M.; Sánchez-Guerrero, Guillermo E.; Ceballos-Herrera, Daniel E.; Selvas-Aguilar, Romeo

    2015-08-01

    Among the main challenges for systems based in solar concentrators and plastic optical fibers (POF) the accuracy needed for the solar tracking is founded. One approach to overcome these requirements is increasing acceptance angle of the components, usually by secondary optical elements (SOE), however this technique is effective for photovoltaic applications but it has not been analyzed for systems coupled to POFs for indoor illumination. On this subject, it is presented a numerical analysis of a solar collector assembled by a Fresnel lens as primary optical element (POE) combined with a compound elliptical concentrator (CEC) coupled to POF in order to compare its performance under incidence angle direction and also to show a trade-off analysis for two different Fresnel lens shapes, imaging and nonimaging, used in the collector system. The description of the Fresnel lenses and its designs are included, in addition to the focal areas with space and angular distribution profiles considering the optimal alignment with the source and maximum permissible incident angle for each case. For both systems the coupling between the optical components is analyzed and the total performance is calculated, having as result its comparison for indoor illumination. In both cases, the systems have better performance increasing the final output power, but the angular tolerance only was improved for the system with nonimaging concentrator that had an efficiency over 80% with acceptance angles 𝜃𝑖 ≤ 2° and, the system integrated by the imaging lens, presented an efficiency ratio over 75% for acceptance angles 𝜃𝑖 ≤ 0.7°.

  20. An occupational hygiene investigation of exposure to acrylamide and the role for urinary S-carboxyethyl-cysteine (CEC) as a biological marker.

    PubMed

    Bull, Peter J; Brooke, Richard K; Cocker, John; Jones, Katharine; Warren, Nicholas

    2005-11-01

    Acrylamide has a range of toxicological hazards including neurotoxicity and reproductive toxicity; however, occupational risk management is driven by its genotoxic and carcinogenic potential (it is classified within the EU as a Category 2 carcinogen, R45 and Category 2 mutagen, R46). Since there is the potential for skin absorption and systemic toxicity, biological monitoring may be a useful aid for the assessment of exposure via inhalation, ingestion and dermal absorption. However, there are currently no biological monitoring guidance values (BMGVs). This study describes an extensive survey of potential workplace exposure to acrylamide at the Ciba (Bradford) site to gather data suitable for a BMGV. This manufacturing site is typical within the industry as a whole and includes a cross section of activities and tasks representative of acrylamide exposure. Acrylamide is used in the manufacture of polyacrylamide based products for applications in water treatment; oil and mineral extraction; paper, paint and textile processes. Workers (62 plus 6 controls) with varying potential exposures provided a total of 275 pre shift and 247 post-shift urine samples along with 260 personal air samples. A small non-exposed control group was similarly monitored. Urine samples were analysed for S-carboxyethyl-cysteine (CEC). Airborne, surface and glove samples were analysed for acrylamide. Inhalation exposures were well controlled with values consistently below one-tenth of the UK Workplace Exposure Limit. Engineering controls, personal protective equipment and work practice, all contributed to good control of occupational exposure. CEC was found in urine samples from both exposed workers and non-occupationally exposed controls. At the low levels of exposure found, smoking made a significant contribution to urinary CEC levels. Nevertheless a correlation between urinary CEC and airborne acrylamide was found. A mixed effects model incorporating inhalation concentrations of acrylamide

  1. Cooperative Engagement Capability (CEC)

    DTIC Science & Technology

    2015-12-01

    Mission and Description 6 Executive Summary 7 Threshold Breaches 8 Schedule 9 Performance 12 Track to Budget 14 Cost and Funding...Capability Production Document CY - Calendar Year DAB - Defense Acquisition Board DAE - Defense Acquisition Executive DAMIR - Defense Acquisition...13:59 UNCLASSIFIED 3 PB - President’s Budget PE - Program Element PEO - Program Executive Officer PM - Program Manager POE - Program Office Estimate

  2. SEM investigation of heart tissue samples

    NASA Astrophysics Data System (ADS)

    Saunders, R.; Amoroso, M.

    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). 1mm3 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.

  3. Seafloor earthquake measurement system, SEMS IV

    SciTech Connect

    Platzbecker, M.R.; Ehasz, J.P.; Franco, R.J.

    1997-07-01

    Staff of the Telemetry Technology Development Department (2664) have, in support of the U.S. Interior Department Mineral Management Services (MMS), developed and deployed the Seafloor Earthquake Measurement System IV (SEMS IV). The result of this development project is a series of three fully operational seafloor seismic monitor systems located at offshore platforms: Eureka, Grace, and Irene. The instrument probes are embedded from three to seven feet into the seafloor and hardwired to seismic data recorders installed top side at the offshore platforms. The probes and underwater cables were designed to survive the seafloor environment with an operation life of five years. The units have been operational for two years and have produced recordings of several minor earthquakes in that time. Sandia Labs will transfer operation of SEMS IV to MMS contractors in the coming months. 29 figs., 25 tabs.

  4. Viewing Integrated-Circuit Interconnections By SEM

    NASA Technical Reports Server (NTRS)

    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.

  5. Viewing Integrated-Circuit Interconnections By SEM

    NASA Technical Reports Server (NTRS)

    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. Curvelet Based Offline Analysis of SEM Images

    PubMed Central

    Shirazi, Syed Hamad; Haq, Nuhman ul; Hayat, Khizar; Naz, Saeeda; Haque, Ihsan ul

    2014-01-01

    Manual offline analysis, of a scanning electron microscopy (SEM) image, is a time consuming process and requires continuous human intervention and efforts. This paper presents an image processing based method for automated offline analyses of SEM images. To this end, our strategy relies on a two-stage process, viz. texture analysis and quantification. The method involves a preprocessing step, aimed at the noise removal, in order to avoid false edges. For texture analysis, the proposed method employs a state of the art Curvelet transform followed by segmentation through a combination of entropy filtering, thresholding and mathematical morphology (MM). The quantification is carried out by the application of a box-counting algorithm, for fractal dimension (FD) calculations, with the ultimate goal of measuring the parameters, like surface area and perimeter. The perimeter is estimated indirectly by counting the boundary boxes of the filled shapes. The proposed method, when applied to a representative set of SEM images, not only showed better results in image segmentation but also exhibited a good accuracy in the calculation of surface area and perimeter. The proposed method outperforms the well-known Watershed segmentation algorithm. PMID:25089617

  7. Modelling CEC variations versus structural iron reduction levels in dioctahedral smectites. Existing approaches, new data and model refinements.

    PubMed

    Hadi, Jebril; Tournassat, Christophe; Ignatiadis, Ioannis; Greneche, Jean Marc; Charlet, Laurent

    2013-10-01

    tetrahedral bearing nontronites (SWa-1, GAN and NAu-1) all exhibit the same behaviour at low reduction levels. Consequently, we restricted our model to the case of moderate reduction (<30%) in low tetrahedral Fe-bearing nontronites. Our adapted model provides the relative amounts of Na(+) (p) and H(+) (ni) cations incorporated in the structure as a function of the amount of Fe reduction. Two equations enable the investigated systems to be described: p=m/(1+Kr·ω·mrel) and ni=Kr·ω·m·mrel/(1+Kr·ω·mrel); where m is the Fe(II) content, mrel, the reduction level (m/mtot), ω, the cation exchange capacity (CEC, and Kr, an empirical constant specific to the system.

  8. Difficult removal of fully covered self expandable metal stents (SEMS) for benign biliary strictures: the "SEMS in SEMS" technique.

    PubMed

    Tringali, Andrea; Blero, Daniel; Boškoski, Ivo; Familiari, Pietro; Perri, Vincenzo; Devière, Jacques; Costamagna, Guido

    2014-06-01

    Removal of biliary Fully Covered Self Expandable Metal Stents can fail due to stent migration and/or hyperplastic ingrowth/overgrowth. A case series of 5 patients with benign biliary strictures (2 post-cholecystectomy, 2 following liver transplantation and 1 related to chronic pancreatitis) is reported. The biliary stricture was treated by temporary insertion of Fully Covered Self Expandable Metal Stents. Stent removal failed due to proximal stent migration and/or overgrowth. Metal stent removal was attempted a few weeks after the insertion of another Fully Covered Metal Stent into the first one. The inner Fully Covered Self Expandable Metal Stent compressed the hyperplastic tissue, leading to the extraction of both the stents in all cases. Two complications were reported as a result of the attempt to stents removal (mild pancreatitis and self-limited haemobilia). In the present series, the "SEMS in SEMS" technique revealed to be effective when difficulties are encountered during Fully Covered Self Expandable Metal Stents removal. Copyright © 2014 Editrice Gastroenterologica Italiana S.r.l. Published by Elsevier Ltd. All rights reserved.

  9. Nondestructive SEM testing of planar structures

    SciTech Connect

    Aristov, V.V.; Dremova, N.N.; Kireev, V.A.

    1995-01-01

    The potentialities of three hardware SEM tomography methods developed in this work that allow the reconstruction of the distributions of geometrical parameters and electrophysical properties with the conventional spatial resolution (determined by the primary electron penetration depth) and depth profiling of these parameters with a resolution within a range {approximately}10-100 nm are demonstrated. The paper covers such issues as the back scatter coefficient dependence on the electron energy, the BSE detection in narrow energy bands, electron-beam-induced current (EBIC) with space-charge region (SCR) width modulation, and cathodoluminescence with beam intensity and energy modulation. All these approaches show promise for nondestructive characterization of submicron structures.

  10. Variation in whole DNA methylation in red maple (Acer rubrum) populations from a mining region: association with metal contamination and cation exchange capacity (CEC) in podzolic soils.

    PubMed

    Kalubi, K N; Mehes-Smith, M; Spiers, G; Omri, A

    2017-02-15

    Although a number of publications have provided convincing evidence that abiotic stresses such as drought and high salinity are involved in DNA methylation reports on the effects of metal contamination, pH, and cation exchange on DNA modifications are limited. The main objective of the present study is to determine the relationship between metal contamination and Cation exchange capacity (CEC) on whole DNA modifications. Metal analysis confirms that nickel and copper are the main contaminants in sampled sites within the Greater Sudbury Region (Ontario, Canada) and liming has increased soil pH significantly even after 30 years following dolomitic limestone applications. The estimated CEC values varied significantly among sites, ranging between 1.8 and 10.5 cmol(+) kg(-1), with a strong relationship being observed between CEC and pH (r = 0.96**). Cation exchange capacity, significantly lower in highly metal contaminated sites compared to both reference and less contaminated sites, was higher in the higher organic matter limed compared to unlimed sites. There was a significant variation in the level of cytosine methylation among the metal-contaminated sites. Significant and strong negative correlations between [5mdC]/[dG] and bioavailable nickel (r = -0.71**) or copper (r = -0.72**) contents were observed. The analysis of genomic DNA for adenine methylation in this study showed a very low level of [6N-mdA]/dT] in Acer rubrum plants analyzed ranging from 0 to 0.08%. Significant and very strong positive correlation was observed between [6N-mdA]/dT] and soil bioavailable nickel (r = 0.78**) and copper (r = 0.88**) content. This suggests that the increased bioavailable metal levels associated with contamination by nickel and copper particulates are associated with cytosine and adenine methylation.

  11. Investigating SEM metrology effects using a detailed SEM simulation and stochastic resist model

    NASA Astrophysics Data System (ADS)

    Lawson, Richard A.; Henderson, Clifford L.

    2015-03-01

    A Monte Carlo electron scattering simulation tool that can create SEM images of 3D features with arbitrary geometry has been developed. This is combined with both a stochastic resist model and synthetic 3D features to probe the effect of the effect of roughness on SEM measurements. Sidewall roughness makes it difficult to precisely identify the true feature width of a line because the roughness increases the SEM signal non-proportionally to the amount of material with which it is interacting. LER generally under predicts sidewall surface roughness because the SEM has an averaging effect as the electron beam interacts with a volume of material. LER becomes a better measure of surface roughness as the correlation length of the surface roughness increases. Decreasing film thickness causes a decrease in the linewidth and increase in LER measured by SEM, especially for features 35 nm thick and below. This occurs even if the true 3D feature width and roughness is approximately constant, meaning that the apparent change in linewidth and LER is a metrology effect. Threshold based estimations of line edges are difficult because the threshold choice that best matches the true feature width changes with the feature geometry. Model based library fits of linescans do not appear to provide a solution because sidewall roughness and sidewall angle have similar effects on the linescan meaning no unique linescan likely exists.

  12. semQA: SPARQL with Idempotent Disjunction

    PubMed Central

    Shironoshita, E. Patrick; Jean-Mary, Yves R.; Bradley, Ray M.; Kabuka, Mansur R.

    2009-01-01

    The SPARQL LeftJoin abstract operator is not distributive over Union; this limits the algebraic manipulation of graph patterns, which in turn restricts the ability to create query plans for distributed processing or query optimization. In this paper, we present semQA, an algebraic extension for the SPARQL query language for RDF, which overcomes this issue by transforming graph patterns through the use of an idempotent disjunction operator Or as a substitute for Union. This permits the application of a set of equivalences that transform a query into distinct forms. We further present an algorithm to derive the solution set of the original query from the solution set of a query where Union has been substituted by Or. We also analyze the combined complexity of SPARQL, proving it to be NP-complete. It is also shown that the SPARQL query language is not, in the general case, fixed-parameter tractable. Experimental results are presented to validate the query evaluation methodology presented in this paper against the SPARQL standard to corroborate the complexity analysis and to illustrate the gains in processing cost reduction that can be obtained through the application of semQA. PMID:19915690

  13. Polyketide Ring Expansion Mediated by a Thioesterase, CEC Domain, in Azinomycin Biosynthesis: Characterization of AziB and AziG

    PubMed Central

    Mori, Shogo; Simkhada, Dinesh; Zhang, Huitu; Erb, Megan S.; Zhang, Yang; Williams, Howard; Fedoseyenko, Dmytro; Russell, William K.; Kim, Doyong; Fleer, Nathan; Ealick, Steve E.; Watanabe, Coran M. H.

    2016-01-01

    The azinomycins are a family of potent anti-tumor agents with the ability to form interstrand crosslinks with DNA. This study reports on the unusual biosynthetic formation of the 5-methyl naphthoate moiety, which is essential for effective DNA association. While sequence analysis predicts that the polyketide synthase (AziB) catalyzes the formation of this naphthoate, 2-methylbenzoic acid, a truncated single-ring product, is formed instead. We demonstrate that the thioesterase (AziG) acts as a chain elongation and cyclization (CEC) domain and is required for the additional two rounds of chain extension to form the expected product. PMID:26731610

  14. Scanning Electron Microscopy (SEM) Procedure for HE Powders on a Zeiss Sigma HD VP SEM

    SciTech Connect

    Zaka, F.

    2016-11-15

    This method describes the characterization of inert and HE materials by the Zeiss Sigma HD VP field emission Scanning Electron Microscope (SEM). The SEM uses an accelerated electron beam to generate high-magnification images of explosives and other materials. It is fitted with five detectors (SE, Inlens, STEM, VPSE, HDBSD) to enable imaging of the sample via different secondary electron signatures, angles, and energies. In addition to imaging through electron detection, the microscope is also fitted with two Oxford Instrument Energy Dispersive Spectrometer (EDS) 80 mm detectors to generate elemental constituent spectra and two-dimensional maps of the material being scanned.

  15. Calibrating etch model with SEM contours

    NASA Astrophysics Data System (ADS)

    Weisbuch, François; Omran, A.; Jantzen, Kenneth

    2015-03-01

    To ensure a high patterning quality, the etch effects have to be corrected within the OPC recipe in addition to the traditional lithographic effects. This requires the calibration of an accurate etch model and optimization of its implementation in the OPC flow. Using SEM contours is a promising approach to get numerous and highly reliable measurements especially for 2D structures for etch model calibration. A 28nm active layer was selected to calibrate and verify an etch model with 50 structures in total. We optimized the selection of the calibration structures as well as the model density. The implementation of the etch model to adjust the litho target layer allows a significant reduction of weak points. We also demonstrate that the etch model incorporated to the ORC recipe and run on large design can predict many hotspots.

  16. SEMS: System for Environmental Monitoring and Sustainability

    NASA Technical Reports Server (NTRS)

    Arvidson, Raymond E.

    1998-01-01

    The goal of this project was to establish a computational and data management system, SEMS, building on our existing system and MTPE-related research. We proposed that the new system would help support Washington University's efforts in environmental sustainability through use in: (a) Problem-based environmental curriculum for freshmen and sophomores funded by the Hewlett Foundation that integrates scientific, cultural, and policy perspectives to understand the dynamics of wetland degradation, deforestation, and desertification and that will develop policies for sustainable environments and economies; (b) Higher-level undergraduate and graduate courses focused on monitoring the environment and developing policies that will lead to sustainable environmental and economic conditions; and (c) Interdisciplinary research focused on the dynamics of the Missouri River system and development of policies that lead to sustainable environmental and economic floodplain conditions.

  17. Sem analysis zirconia-ceramic adhesion interface

    PubMed Central

    CARDELLI, P.; VERTUCCI, V.; MONTANI, M.; ARCURI, C.

    2015-01-01

    SUMMARY Objectives Modern dentistry increasingly tends to use materials aesthetically acceptable and biomimetic. Among these are zirconia and ceramics for several years, a combination that now has becoming synonym of aesthetic; however, what could be the real link between these two materials and especially its nature, remains a controversial topic debated in the literature. The aim of our study was to “underline” the type of bonding that could exist between these materials. Materials and methods To investigate the nature of this bond we used a SEM microscopy (Zeiss SUPRA 25). Different bilaminar specimens: “white” zirconia Zircodent® and ceramic “Noritake®”, after being tested with loading test in bending (three-point-bending) and FEM analysis, were analyzed by SEM. Fragments’ analysis in closeness of the fracture’s point has allowed us to be able to “see” if at large magnifications between these two materials, and without the use of linear, could exist a lasting bond and the possible type of failure that could incur. Results From our analysis of the specimens’ fragments analyzed after test Equipment, it is difficult to highlight a clear margin and no-adhesion zones between the two materials, although the analysis involving fragments adjacent to the fracture that has taken place at the time of Mechanical test Equipment. Conclusions According to our analysis and with all the clarification of the case, we can assume that you can obtain a long and lasting bond between the zirconia and ceramics. Agree to the data present in the literature, we can say that the type of bond varies according to the type of specimens and of course also the type of failure. In samples where the superstructure envelops the ceramic framework Zirconium we are in the presence of a cohesive failure, otherwise in a presence of adhesive failure. PMID:27555905

  18. Sem analysis zirconia-ceramic adhesion interface.

    PubMed

    Cardelli, P; Vertucci, V; Montani, M; Arcuri, C

    2015-01-01

    Modern dentistry increasingly tends to use materials aesthetically acceptable and biomimetic. Among these are zirconia and ceramics for several years, a combination that now has becoming synonym of aesthetic; however, what could be the real link between these two materials and especially its nature, remains a controversial topic debated in the literature. The aim of our study was to "underline" the type of bonding that could exist between these materials. To investigate the nature of this bond we used a SEM microscopy (Zeiss SUPRA 25). Different bilaminar specimens: "white" zirconia Zircodent® and ceramic "Noritake®", after being tested with loading test in bending (three-point-bending) and FEM analysis, were analyzed by SEM. Fragments' analysis in closeness of the fracture's point has allowed us to be able to "see" if at large magnifications between these two materials, and without the use of linear, could exist a lasting bond and the possible type of failure that could incur. From our analysis of the specimens' fragments analyzed after test Equipment, it is difficult to highlight a clear margin and no-adhesion zones between the two materials, although the analysis involving fragments adjacent to the fracture that has taken place at the time of Mechanical test Equipment. According to our analysis and with all the clarification of the case, we can assume that you can obtain a long and lasting bond between the zirconia and ceramics. Agree to the data present in the literature, we can say that the type of bond varies according to the type of specimens and of course also the type of failure. In samples where the superstructure envelops the ceramic framework Zirconium we are in the presence of a cohesive failure, otherwise in a presence of adhesive failure.

  19. Nondestructive SEM for surface and subsurface wafer imaging

    NASA Technical Reports Server (NTRS)

    Propst, Roy H.; Bagnell, C. Robert; Cole, Edward I., Jr.; Davies, Brian G.; Dibianca, Frank A.; Johnson, Darryl G.; Oxford, William V.; Smith, Craig A.

    1987-01-01

    The scanning electron microscope (SEM) is considered as a tool for both failure analysis as well as device characterization. A survey is made of various operational SEM modes and their applicability to image processing methods on semiconductor devices.

  20. [Contextualized editorial practices: Maria Cecília de Souza Minayo and the journal Ciência & Saúde Coletiva].

    PubMed

    Spinelli, Hugo; Martinovich, Viviana

    2016-01-01

    This interview forms part of a series of dialogues that Salud Colectiva has been holding with key editors in the field, with the purpose of examining the similar difficulties confronted by Latin American journals and the diverse ways the journals have faced these difficulties as a likely starting point for uncovering contextualized solutions. In this interview, carried out in 2015 in the Instituto de Salud Colectiva of the Universidad Nacional de Lanús, Maria Cecília de Souza Minayo speaks to us about the context in which the journal Ciência & Saúde Coletiva emerged, the political disputes existing within the collective health field, and the relevance of debate as a constitutive process of science itself. Additionally, Minayo analyzes both the importance of funding to the growth of a journal and the problems and difficulties in obtaining funds, which puts into evidence the lack of policy regarding scientific publishing in Brazil.

  1. Rapid evaluation of particle properties using inverse SEM simulations

    NASA Astrophysics Data System (ADS)

    Bekar, Kursat B.; Miller, Thomas M.; Patton, Bruce W.; Weber, Charles F.

    2017-09-01

    The characteristic X-rays produced by the interactions of the electron beam with the sample in a scanning electron microscope (SEM) are usually captured with a variable-energy detector, a process termed energy dispersive spectrometry (EDS). The purpose of this work is to exploit inverse simulations of SEM-EDS spectra to enable rapid determination of sample properties, particularly elemental composition. This is accomplished using penORNL, a modified version of PENELOPE, and a modified version of the traditional Levenberg-Marquardt nonlinear optimization algorithm, which together is referred to as MOZAIK-SEM. The overall conclusion of this work is that MOZAIK-SEM is a promising method for performing inverse analysis of X-ray spectra generated within a SEM. As this methodology exists now, MOZAIK-SEM has been shown to calculate the elemental composition of an unknown sample within a few percent of the actual composition.

  2. Rapid evaluation of particle properties using inverse SEM simulations

    SciTech Connect

    Bekar, Kursat B; Miller, Thomas Martin; Patton, Bruce W; Weber, Charles F

    2017-01-01

    The characteristic X-rays produced by the interactions of the electron beam with the sample in a scanning electron microscope (SEM) are usually captured with a variable-energy detector, a process termed energy dispersive spectrometry (EDS). The purpose of this work is to exploit inverse simulations of SEM-EDS spectra to enable rapid determination of sample properties, particularly elemental composition. This is accomplished using penORNL, a modified version of PENELOPE, and a modified version of the traditional Levenberg Marquardt nonlinear optimization algorithm, which together is referred to as MOZAIK-SEM. The overall conclusion of this work is that MOZAIK-SEM is a promising method for performing inverse analysis of X-ray spectra generated within a SEM. As this methodology exists now, MOZAIK-SEM has been shown to calculate the elemental composition of an unknown sample within a few percent of the actual composition.

  3. Further advancing the throughput of a multi-beam SEM

    NASA Astrophysics Data System (ADS)

    Kemen, Thomas; Malloy, Matt; Thiel, Brad; Mikula, Shawn; Denk, Winfried; Dellemann, Gregor; Zeidler, Dirk

    2015-03-01

    Multiple electron beam SEMs enable detecting structures of few nanometer in diameter at much higher throughputs than possible with single beam electron microscopes at comparable electron probe parameters. Although recent multiple beam SEM development has already demonstrated a large speed increase1, higher throughputs are still required to match the needs of many semiconductor applications2. We demonstrate the next step in the development of multi-beam SEMs by increasing the number of beams and the current per beam. The modularity of the multi-beam concept ensures that design changes in the multi-beam SEM are minimized.

  4. EPA Region 2 SEMS_CERCLIS Sites All [R2] and SEMS_CERCLIS Sites NPL [R2] GIS Layers

    EPA Pesticide Factsheets

    The Region 2 SEMS_CERCLIS Sites All [R2] GIS layer contains unique Superfund Enterprise Management System (SEMS) site records. These records have the following NPL_STATUS designations: CURRENTLY ON FINAL NPL, DELETED FROM FINAL NPL, NOT ON NPL, PROPOSED FOR NPL, REMOVED FROM PROPOSED NPL, and SITE IS PART OF NPL SITE. The Region 2 SEMS_CERCLIS NPL Sites [R2] GIS layer only has SEMS records with the following NPL_STATUS designations: 'CURRENTLY ON FINAL NPL', 'DELETED FROM FINAL NPL', 'PROPOSED FOR NPL'.The Superfund Enterprise Management System (SEMS) is EPA's official record for tracking hazardous waste sites, potentially hazardous waste sites, and remedial activities performed in support of the Superfund Program across the nation. This includes sites that are on the National Priorities List (NPL) or are being considered for the NPL. SEMS represents a joint development and ongoing collaboration between Superfund's Remedial, Removal, Federal Facilities, Enforcement, and Emergency Response programs. It provides its wide audience base with a means of ongoing analysis of Superfund Program activities and informational needs at the site, regional management, and national management levels. The customers of SEMS or SEMS data are five EPA Headquarters offices and regional staff, citizens, the regulated community, other Federal agencies, States, Tribes, local agencies, and industry. SEMS stakeholders are States, Congress, other Federal agencies, industry groups, and cit

  5. Connecting SEM Analysis and Profile Analysis via MDS.

    ERIC Educational Resources Information Center

    Kim, Se-Kang; Davison, Mark L.

    This study was designed to explain how Profile Analysis via Multidimensional Scaling (PAMS) could be viewed as a structural equations model (SEM). The study replicated the major profiles extracted from PAMS in the context of the latent variables in SEM. Data involved the Basic Theme Scales of the Strong Campbell Interest Inventory (Campbell and…

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

    ERIC Educational Resources Information Center

    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…

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

    ERIC Educational Resources Information Center

    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…

  8. Comprehensive Minority SEM Programs at Santa Fe Community College.

    ERIC Educational Resources Information Center

    Pantano, John

    Santa Fe Community College (SFCC) has developed a series of minority science, engineering, and mathematics (SEM) programs to address the growing need for students receiving college and advanced degrees in science-based career fields and the underrepresentation of minorities in these fields. The goals of the SEM programs are to interest more women…

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

    ERIC Educational Resources Information Center

    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…

  10. Scanning electron microscopy: preparation and imaging for SEM.

    PubMed

    Jones, Chris G

    2012-01-01

    Scanning electron microscopy (SEM) has been almost universally applied for the surface examination and characterization of both natural and man-made objects. Although an invasive technique, developments in electron microscopy over the years has given the microscopist a much clearer choice in how invasive the technique will be. With the advent of low vacuum SEM in the 1970s (The environmental cold stage, 1970) and environmental SEM in the late 1980s (J Microsc 160(pt. 1):9-19, 1989), it is now possible in some circumstances to examine samples without preparation. However, for the examination of biological tissue and cells it is still advisable to chemically fix, dehydrate, and coat samples for SEM imaging and analysis. This chapter aims to provide an overview of SEM as an imaging tool, and a general introduction to some of the methods applied for the preparation of samples.

  11. Smart flexible microrobots for scanning electron microscope (SEM) applications

    NASA Astrophysics Data System (ADS)

    Schmoeckel, Ferdinand; Fatikow, Sergej

    2000-06-01

    In the scanning electron microscope (SEM), specially designed microrobots can act as a flexible assembly facility for hybrid microsystems, as probing devices for in-situ tests on IC structures or just as a helpful teleoperated tool for the SEM operator when examining samples. Several flexible microrobots of this kind have been developed and tested. Driven by piezoactuators, these few cubic centimeters small mobile robots perform manipulations with a precision of up to 10 nm and transport the gripped objects at speeds of up to 3 cm/s. In accuracy, flexibility and price they are superior to conventional precision robots. A new SEM-suited microrobot prototype is described in this paper. The SEM's vacuum chamber has been equipped with various elements like flanges and CCD cameras to enable the robot to operate. In order to use the SEM image for the automatic real-time control of the robots, the SEM's electron beam is actively controlled by a PC. The latter submits the images to the robots' control computer system. For obtaining three-dimensional information in real time, especially for the closed-loop control of a robot endeffector, e.g. microgripper, a triangulation method with the luminescent spot of the SEM's electron beam is being investigated.

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

    NASA Astrophysics Data System (ADS)

    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.

  13. Alternative SEM techniques for observing pyritised fossil material.

    PubMed

    Poole; Lloyd

    2000-11-01

    Two scanning electron microscopy (SEM) electron-specimen interactions that provide images based on sample crystal structure, electron channelling and electron backscattered diffraction, are described. The SEM operating conditions and sample preparation are presented, followed by an example application of these techniques to the study of pyritised plant material. The two approaches provide an opportunity to examine simultaneously, at higher magnifications normally available optically, detailed specimen anatomy and preservation state. Our investigation suggests that whereas both techniques have their advantages, the electron channelling approach is generally more readily available to most SEM users. However, electron backscattered diffraction does afford the opportunity of automated examination and characterisation of pyritised fossil material.

  14. Patterns of use and toxicity of new para-halogenated substituted cathinones: 4-CMC (clephedrone), 4-CEC (4-chloroethcatinone) and 4-BMC (brephedrone).

    PubMed

    Grifell, Marc; Ventura, Mireia; Carbón, Xoán; Quintana, Pol; Galindo, Liliana; Palma, Álvaro; Fornis, Ivan; Gil, Cristina; Farre, Magi; Torrens, Marta

    2017-05-01

    This paper aims to present results of the analysis of clephedrone (4-CMC), 4-chloroethcathinone (4-CEC), and brephedrone (4-BMC) on recreational drug markets and a systematic review of all the available information concerning these substances. Samples collected by the drug checking service of the Spanish harm reduction NGO-Energy Control were analyzed and systematic research was conducted. Between June 2014 and October 2016, 1,471 samples with at least one NPS were analyzed, 397 of which contained cathinones. Clephedrone was found in 29 samples, brephedrone in 8, and both were present in 2 samples. 4-Chloroethcathinone was detected in 5 samples. Eleven out of the 47 purchased samples (23.4%) were tested to contain the substance the user expected. Samples received were mainly sold as 3-MMC, MDMA, ketamine, and other cathinones. No literature on the effects or toxicity of these substances was found; the only information available was on internet fora. On many posts, users exhibit concerns about potential toxicity and side effects of using these substances. Since the emergence of these substances could prove to be the next step to the cat-and-mouse game existing between drug producers and legislation, further clinical and epidemiological research should be carried out in order to build evidence to support policy for public health issues. Copyright © 2017 John Wiley & Sons, Ltd.

  15. CEC/CIS collaboration projects on the consequences of the Chernobyl accident preliminary results on the project dealing with strategies of decontamination

    SciTech Connect

    Jouve, A.; Maubert, H.; Kutlakhmedov, Y.

    1994-12-31

    In 1992, an agreement was signed between the Commission of the European Communities (CEC) and the relevant Ministries of Belarus, Russia and Ukraine in order to mitigate the consequences of the Chernobyl accident, through the implementation of a collaboration program involving the participation of about 200 CIS (Commonwealth of Independent States) and EU (European Union) Institutes and Research Centers. In such a context, a collaboration project aiming at evaluating strategies of decontamination for the territories affected by the accident was launched. This project not only dealt with decontamination of agricultural soils, urban areas and forests but also included treatment of contaminated foodstuff. To date, the project comprised both experimental and theoretical activities. It is expected that the results of this project can be used for the development of practical strategies for decontaminating the relevant CIS territories, as well as for the definition of appropriate policies in the event of a future nuclear accident. Relying on a strong collaboration network which was progressively established between EU and CIS scientists, field experiments mainly dealt with decontamination of meadows using a turf harvester, and forests while producing valuable wood derivatives.

  16. Development and validation of a capillary electrophoresis method with capacitively coupled contactless conductivity detection (CE-C(4) D) for the analysis of amikacin and its related substances.

    PubMed

    El-Attug, Mohamed Nouri; Adams, Erwin; Van Schepdael, Ann

    2012-09-01

    Amikacin is a semisynthetic aminoglycoside antibiotic derived from kanamycin A that lacks a strong UV absorbing chromophore or fluorophore. Due to the physicochemical properties of amikacin and its related substances, CE in combination with capacitively coupled contactless conductivity detection (CE-C(4) D) was chosen. The optimized separation method uses a BGE composed of 20 mM MES adjusted to pH 6.6 by l-histidine and 0.3 mM CTAB that was added as flow modifier in a concentration below the CMC. Ammonium acetate 20 mg.L(-1) was used as internal standard. 30 kV was applied in reverse polarity on a fused silica capillary (73/48 cm; 75 μm id). The optimized separation was obtained in less than 6 min with good linearity (R(2) = 0.9996) for amikacin base. It shows a good precision expressed as RSD on relative peak areas equal to 0.1 and 0.7% for intraday and interday, respectively. The LOD and LOQ are 0.5 mg.L(-1) and 1.7 mg.L(-1) , respectively.

  17. Enantiomers Recognition of Propranolol Based on Organic-Inorganic Hybrid Open-Tubular MIPs-CEC Column Using 3-(Trimethoxysilyl)Propyl Methacrylate as a Cross-Linking Monomer.

    PubMed

    Chen, Guo-Ning; Li, Ning; Luo, Tian; Dong, Yu-Ming

    2017-01-10

    In this study, 3-(trimethoxysilyl)propyl methacrylate (γ-MPS), a bifunctional group compound, was used as a single cross-linking agent to prepare molecular imprinted inorganic-organic hybrid polymers by in situ polymerization for open-tubular capillary electro chromatography (CEC) column. The optimal preparation conditions were: the ratio between template molecule and functional monomer was 1:4; the volume proportion of porogen toluene and methanol was 1:1 and the volume of cross-linking agent γ-MPS was 69 μL. The optimal separation conditions were separation voltage of 15 kV; detection wavelength at 215 nm and background electrolyte composed of 70% acetonitrile/20 mmol/L boric acid salt (pH 6.9). Under the optimized conditions, the propranolol enantiomers can be separated well by CEC. The method is simple and fast, it can be a potentially useful approach for propranolol enantiomers separation.

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

    PubMed

    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

  19. Sparsity-Based Super Resolution for SEM Images.

    PubMed

    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.

  20. Transcription factor CecR (YbiH) regulates a set of genes affecting the sensitivity of Escherichia coli against cefoperazone and chloramphenicol.

    PubMed

    Yamanaka, Yuki; Shimada, Tomohiro; Yamamoto, Kaneyoshi; Ishihama, Akira

    2016-07-01

    Genomic SELEX (systematic evolution of ligands by exponential enrichment) screening was performed for identification of the binding site of YbiH, an as yet uncharacterized TetR-family transcription factor, on the Escherichia coli genome. YbiH was found to be a unique single-target regulator that binds in vitro within the intergenic spacer located between the divergently transcribed ybiH-ybhGFSR and rhlE operons. YbhG is an inner membrane protein and YbhFSR forms a membrane-associated ATP-binding cassette (ABC) transporter while RhlE is a ribosome-associated RNA helicase. Gel shift assay and DNase footprinting analyses indicated one clear binding site of YbiH, including a complete palindromic sequence of AATTAGTT-AACTAATT. An in vivo reporter assay indicated repression of the ybiH operon and activation of the rhlE operon by YbiH. After phenotype microarray screening, YbiH was indicated to confer resistance to chloramphenicol and cefazoline (a first-generation cephalosporin). A systematic survey of the participation of each of the predicted YbiH-regulated genes in the antibiotic sensitivity indicated involvement of the YbhFSR ABC-type transporter in the sensitivity to cefoperazone (a third-generation cephalosporin) and of the membrane protein YbhG in the control of sensitivity to chloramphenicol. Taken together with the growth test in the presence of these two antibiotics and in vitro transcription assay, it was concluded that the hitherto uncharacterized YbiH regulates transcription of both the bidirectional transcription units, the ybiH-ybhGFSR operon and the rhlE gene, which altogether are involved in the control of sensitivity to cefoperazone and chloramphenicol. We thus propose to rename YbiH as CecR (regulator of cefoperazone and chloramphenicol sensitivity).

  1. High sensitivity tracking of CD-SEM performance: QSEM

    NASA Astrophysics Data System (ADS)

    Babin, S.; Huang, Jaffee; Yushmanov, P.

    2015-03-01

    The performance of CD-SEMs directly affects the measured values of critical dimensions (CDs) at the time of their measurement. Tracking the performance of CD-SEMs is necessary to establish trust in their results and provide guidance for preventive maintenance and tune-ups. When the measured CDs are out of specification in manufacturing, it is crucial to determine whether this is due to process variation or the metrology tool itself. Multiple methods that use linewidth measurements have been employed thus far; however, they suffer from linewidth variations on the wafer, as well as from variations of line edge and linewidth roughness. Here, we report a method that is capable of providing a quantitative extraction of the SEM performance based on advanced algorithms. The method is independent of linewidth, line edge roughness and linewidth roughness, and has high sensitivity. This software, QSEM, was developed to automatically evaluate image quality and assign a value to that quality. The image quality value is based on multiple factors such as noise, sharpness, analysis of histograms, and contrast. The sensitivity of the software was evaluated; a good correlation between image quality results and linewidth variation due to SEM performance was established. Using QSEM to analyze SEM images allows the performance of CDSEMs to be tracked for proper calibration and preventive maintenance, as well as to resolve the dispute between failure in the process or the metrology.

  2. 3DSEM++: Adaptive and intelligent 3D SEM surface reconstruction.

    PubMed

    Tafti, Ahmad P; Holz, Jessica D; Baghaie, Ahmadreza; Owen, Heather A; He, Max M; Yu, Zeyun

    2016-08-01

    Structural analysis of microscopic objects is a longstanding topic in several scientific disciplines, such as biological, mechanical, and materials sciences. The scanning electron microscope (SEM), as a promising imaging equipment has been around for decades to determine the surface properties (e.g., compositions or geometries) of specimens by achieving increased magnification, contrast, and resolution greater than one nanometer. Whereas SEM micrographs still remain two-dimensional (2D), many research and educational questions truly require knowledge and facts about their three-dimensional (3D) structures. 3D surface reconstruction from SEM images leads to remarkable understanding of microscopic surfaces, allowing informative and qualitative visualization of the samples being investigated. In this contribution, we integrate several computational technologies including machine learning, contrario methodology, and epipolar geometry to design and develop a novel and efficient method called 3DSEM++ for multi-view 3D SEM surface reconstruction in an adaptive and intelligent fashion. The experiments which have been performed on real and synthetic data assert the approach is able to reach a significant precision to both SEM extrinsic calibration and its 3D surface modeling. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. Recent advances in 3D SEM surface reconstruction.

    PubMed

    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.

  4. CEC Teacher of the Year.

    ERIC Educational Resources Information Center

    Voyles, Lynda

    1995-01-01

    This interview with Brenda Jean Robbins, a Florida music therapist and teacher selected as 1995 Teacher of the Year by the Council for Exceptional Children, reveals her views about music therapy, goals, relationship of music therapy to the special education classroom, musical performance, and getting parents involved. (DB)

  5. CEC Special Education Advocacy Handbook.

    ERIC Educational Resources Information Center

    Bootel, Jaclyn A.

    This handbook, for individuals working with people who have disabilities, is designed to empower them to be a force for meeting the policy challenges in the communities in which they live and work. It is designed to help in channeling one's strength, commitment, and knowledge of the special education field into effective advocacy efforts. The…

  6. SemVisM: semantic visualizer for medical image

    NASA Astrophysics Data System (ADS)

    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

  7. STEM mode in the SEM: a practical tool for nanotoxicology.

    PubMed

    Hondow, Nicole; Harrington, John; Brydson, Rik; Doak, Shareen H; Singh, Neenu; Manshian, Bella; Brown, Andy

    2011-06-01

    The addition of a transmitted electron detector to a scanning electron microscope (SEM) allows the recording of bright and dark field scanning transmission electron microscope (STEM) images and the corresponding in-lens secondary electron images from the same region of a thin sample. These combined imaging techniques have been applied here to the analysis of ultrathin sections of cells exposed in vitro to nanomaterials for toxicology investigation. Electron microscopy in general permits the exact nature of the interaction of nanomaterials and cells to be elucidated, and in addition the use of STEM mode in the SEM enables the easy identification and exclusion of artefacts produced by ultramicrotome sectioning. The imaging and analysis obtained by using the STEM mode in the SEM configuration from three different nanomaterial systems of importance (iron oxide nanoparticles, single-walled carbon nanotubes and cadmium selenide quantum dots) indicate that it is a simple, practical and cost-effective tool for nanotoxicological research.

  8. Three-dimensional simulations of SEM imaging and charging

    NASA Astrophysics Data System (ADS)

    Grella, Luca; Lorusso, Gian; Niemi, Tim; Chuang, Tzu-chin; Adler, David L.

    2001-08-01

    SEM based CD control and wafer inspection has an increasingly active role in the semiconductor industry. Current design rules require a CD control with a precision in the nanometer range. In order to achieve this precision, a complete model of the image formation mechanism is desirable. For this reason we present a three-dimensional simulation of scanning electron microscope (SEM) images. The simulations include Monte Carlo electron scattering, charging in the substrate and electron ray-tracing in the column. We investigate some specific cases in CD-SEM metrology: We will describe the effect of scan orientation relative to the orientation of the imaged feature on the apparent beam width (ABW), the effect of magnification on contact imaging, and the effect of residue in resist trenches. Our results, regarding these examples, clearly indicate that a fully three-dimensional numerical simulation is needed to obtain an understanding of image formation and resolution limiting factors.

  9. Cryo-SEM of hydrated high temperature proton exchange membranes

    SciTech Connect

    Perry, Kelly A; More, Karren Leslie; Walker, Larry R; Benicewicz, Brian

    2009-01-01

    Alternative energy technologies, such as high temperature fuel cells and hydrogen pumps, rely on proton exchange membranes (PEM). A chemically and thermally stable PEM with rapid proton transport is sol-gel phosphoric acid (PA)-doped polybenzimidazole (PBI) membranes. It is believed that the key to the high ionic conductivity of PA-doped PBI membranes is related to the gel morphology. However, the gel structure and general morphology of this PA-doped PBI membrane has not been widely investigated. In an effort to understand the gel morphology, two SEM sample preparation methodologies have been developed for PA-doped PBI membranes. Due to the high vacuum environment of conventional SEM, the beam-sensitivity of these membranes was reduced with a mild 120 C heat treatment to remove excess water without structural rearrangement (as verified from wide angle X-ray scattering). Cryo-SEM has also been implemented for both initial and heated membranes. Cryo-SEM is known to prevent dehydration of the specimen and reduce beam-sensitivity. The SEM cross-section image (Fig. 1A) of the heated samples exhibit 3{micro}m spheroidal features that are elongated in the direction of the casting blade. These features are distorted to 2{micro}m under conventional SEM conditions (Fig. 1B). The fine-scale gel morphology image (Fig. 2) is composed of 65nm diameter domains and 30nm walls, which resembles a cellular structure. In the future, the PA-doped PBI membranes will be cryo-microtomed and cryotransferred for elemental analysis in a TEM.

  10. SEM based overlay measurement between resist and buried patterns

    NASA Astrophysics Data System (ADS)

    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.

  11. CD-SEM precision: improved procedure and analysis

    NASA Astrophysics Data System (ADS)

    Menaker, Mina

    1999-06-01

    Accurate precision assessment becomes increasingly important as we proceed along the SIA road map, in to more advanced processes and smaller critical dimensions. Accurate precision is necessary in order to determine the P/T ratio which is used to decide whether a specific CD-SEM is valid for controlling a specific process. The customer's needs, as been presented by the SEMATECH Advanced Metrology Advisory Group, are to receive a detailed precision report, in the form of a full repeatability and reproducibility (RR) analysis. The 3 sigma single tool RR, of an in-line SEM, are determined in the same operational modes as used in production, and should include the effects of time and process variants on the SEM performance. We hereby present an RR procedure by a modulate approach which enables the user extending the evaluation according to her/his needs. It includes direct assessment of repeatability, reproducibility and stability analysis. It also allows for a study of wafer non homogeneity, induced process variation and a measured feature type effect on precision. The procedure is based on the standard ISO RR procedure, and includes a modification for a correct compensation for bias, or so called measurement turned. A close examination of the repeatability and reproducibility variations, provides insight to the possible sources of those variations, such as S/N ratio, SEM autofocus mechanism, automation etc. For example, poor wafer alignment might not effect the repeatability, but severally reduce reproducibility. Therefore the analysis is a key to better understanding and improving of CD-SEM performance, on production layers. The procedure is fully implemented on an automated CD-SEM, providing on line precision assessment. RR < 1 nm has been demonstrated on well defined resist and etched structures. Examples of the automatic analysis results, using the new procedure are presented.

  12. Automated SEM-EDS GSR Analysis for Turkish Ammunitions

    NASA Astrophysics Data System (ADS)

    Cakir, Ismail; Uner, H. Bulent

    2007-04-01

    In this work, Automated Scanning Electron Microscopy with Energy Dispersive X-ray Spectrometry (SEM-EDS) was used to characterize 7.65 and 9mm cartridges Turkish ammunition. All samples were analyzed in a SEM Jeol JSM-5600LV equipped BSE detector and a Link ISIS 300 (EDS). A working distance of 20mm, an accelerating voltage of 20 keV and gunshot residue software was used in all analysis. Automated search resulted in a high number of particles analyzed containing gunshot residues (GSR) unique elements (PbBaSb). The obtained data about the definition of characteristic GSR particles was concordant with other studies on this topic.

  13. Automated SEM-EDS GSR Analysis for Turkish Ammunitions

    SciTech Connect

    Cakir, Ismail; Uner, H. Bulent

    2007-04-23

    In this work, Automated Scanning Electron Microscopy with Energy Dispersive X-ray Spectrometry (SEM-EDS) was used to characterize 7.65 and 9mm cartridges Turkish ammunition. All samples were analyzed in a SEM Jeol JSM-5600LV equipped BSE detector and a Link ISIS 300 (EDS). A working distance of 20mm, an accelerating voltage of 20 keV and gunshot residue software was used in all analysis. Automated search resulted in a high number of particles analyzed containing gunshot residues (GSR) unique elements (PbBaSb). The obtained data about the definition of characteristic GSR particles was concordant with other studies on this topic.

  14. SEM image contouring for OPC model calibration and verification

    NASA Astrophysics Data System (ADS)

    Tabery, Cyrus; Morokuma, Hidetoshi; Matsuoka, Ryoichi; Page, Lorena; Bailey, George E.; Kusnadi, Ir; Do, Thuy

    2007-03-01

    Lithography models for leading-edge OPC and design verification must be calibrated with empirical data, and this data is traditionally collected as a one-dimensional quantification of the features acquired by a CD-SEM. Two-dimensional proximity features such as line-end, bar-to-bar, or bar-to-line are only partially characterized because of the difficulty in transferring the complete information of a SEM image into the OPC model building process. A new method of two-dimensional measurement uses the contouring of large numbers of SEM images acquired within the context of a design based metrology system to drive improvement in the quality of the final calibrated model. Hitachi High-Technologies has continued to develop "full automated EPE measurement and contouring function" based on design layout and detected edges of SEM image. This function can measure edge placement error everywhere in a SEM image and pass the result as a design layout (GDSII) into Mentor Graphics model calibration flow. Classification of the critical design elements using tagging scripts is used to weight the critical contours in the evaluation of model fitness. During process of placement of the detected SEM edges of into the coordinate system of the design, coordinate errors inevitably are introduced because of pattern matching errors. Also, line edge roughness in 2D features introduces noise that is large compared to the model building accuracy requirements of advanced technology nodes. This required the development of contour averaging algorithms. Contours from multiple SEM images are acquired of a feature and averaged before passing into the model calibration. This function has been incorporated into the prototype Calibre Workbench model calibration flow. Based on these methods, experimental data is presented detailing the model accuracy of a 45nm immersion lithography process using traditional 1D calibration only, and a hybrid model calibration using SEM image contours and 1D measurement

  15. Studies of beam heating of proton beam profile monitor SEM's

    SciTech Connect

    Pavlovich, Zarko; Osiecki, Thomas H.; Kopp, Sacha E.; /Texas U.

    2005-05-01

    The authors present calculations of the expected temperature rise of proton beam profile monitors due to beam heating. The profile monitors are secondary emission monitors (SEM's) to be made of Titanium foils. The heating is studied to understand whether there is any loss of tension or alignment of such devices. Additionally, calculations of thermally-induced dynamic stress are presented. Ti foil is compared to other materials and also to wire SEM's. The calculations were initially performed for the NuMI beam, where the per-pulse intensity is quite high; for completeness the calculations are also performed for other beam energies and intensities.

  16. SEM imaging of acoustically stimulated charge transport in solids

    NASA Astrophysics Data System (ADS)

    Emelin, Evgeny; Cho, H. D.; Insepov, Zeke; Lee, J. C.; Kang, Tae Won; Panin, Gennady; Roshchupkin, Dmitry; Tynyshtykbayev, Kurbangali

    2017-06-01

    Acoustically stimulated charge transport in solids was studied using the scanning electron microscopy method (SEM). The surface acoustic wave on the surface of the YZ-cut of a LiNbO3 crystal was visualized by registration of low-energy secondary electrons in SEM, and the charge distribution on the crystal surface was visualized using the electron beam induced current method. To register the induced current, an interdigital transducer structure was formed from graphene on the crystal surface. It was shown that the charge distribution on the crystal surface corresponds to the distribution of the acoustic wave field on the crystal surface.

  17. Major trends in extending CD-SEM utility

    NASA Astrophysics Data System (ADS)

    Bunday, Benjamin; Allgair, John; Yang, Kyoungmo; Koshihara, Shunsuke; Morokuma, Hidetoshi; Danilevsky, Alex; Parker, Cindy; Page, Lorena

    2007-03-01

    Requirements for increasingly integrated metrology solutions continue to drive applications that incorporate process characterization tools, as well as the ability to improve metrology production capability and cycle time, with a single application. All of the most critical device layers today, along with even non-critical layers, now require optical proximity correction (OPC), which must be rigorously modeled and calibrated as part of process development and extensively verified once new product reticles are released using critical dimension-scanning electron microscopy (CD-SEM) tools. Automatic setup of complex recipes is one of the major trends in CD-SEM applications, which is adding much value to CD-SEM metrology. In addition, as integrated circuit dimensions continue to shrink, local line width variation influences the statistical confidence of a measured CD's representation of the process. A feature, called "Average CD (ACD)," measures multiple targets within the field of view (FOV). ACD allows not only measurements of a single data point representing one discrete feature, but also sampling of the mean and variance of the process. These two applications, automatic recipe creation and ACD, are combined in the second version of the DesignGauge software, which is available for the latest-generation Hitachi S-9380II CD-SEMs. DesignGauge V2 is not only capable of offline recipe creation and CD-SEM control, but it also has the ability to directly transfer design-based recipes into standard CD-SEM recipes. These recipes can be used for OPC model-building and verification as with previous DesignGauge applications. The software also provides design template-based recipe setup for production layer recipes, which yields much needed improvement to production tool utilization, as production recipes can thus be written offline for new products, improving first silicon cycle time, reducing engineering time required to generate recipes, and improving CD-SEM utilization

  18. Challenges of OPC model calibration from SEM contours

    NASA Astrophysics Data System (ADS)

    Granik, Yuri; Kusnadi, Ir

    2008-03-01

    Traditionally OPC models are calibrated to match CD measurements from selected test pattern locations. This demand for massive CD data drives advances in metrology. Considerable progress has recently been achieved in complimenting this CD data with SEM contours. Here we propose solutions to some challenges that emerge in calibrating OPC models from the experimental contours. We discuss and state the minimization objective as a measure of the distance between simulation and experimental contours. The main challenge is to correctly process inevitable gaps, discontinuities and roughness of the SEM contours. We discuss standardizing the data interchange formats and procedures between OPC and metrology vendors.

  19. Novel field emission SEM column with beam deceleration technology.

    PubMed

    Jiruše, Jaroslav; Havelka, Miloslav; Lopour, Filip

    2014-11-01

    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. Copyright © 2014 Elsevier B.V. All rights reserved.

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

    ERIC Educational Resources Information Center

    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…

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

    ERIC Educational Resources Information Center

    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…

  2. Novel CD-SEM measurement methodology for complex OPCed patterns

    NASA Astrophysics Data System (ADS)

    Lee, Hyung-Joo; Park, Won Joo; Choi, Seuk Hwan; Chung, Dong Hoon; Shin, Inkyun; Kim, Byung-Gook; Jeon, Chan-Uk; Fukaya, Hiroshi; Ogiso, Yoshiaki; Shida, Soichi; Nakamura, Takayuki

    2014-07-01

    As design rules of lithography shrink: accuracy and precision of Critical Dimension (CD) and controllability of hard OPCed patterns are required in semiconductor production. Critical Dimension Scanning Electron Microscopes (CD SEM) are essential tools to confirm the quality of a mask such as CD control; CD uniformity and CD mean to target (MTT). Basically, Repeatability and Reproducibility (R and R) performance depends on the length of Region of Interest (ROI). Therefore, the measured CD can easily fluctuate in cases of extremely narrow regions of OPCed patterns. With that premise, it is very difficult to define MTT and uniformity of complex OPCed masks using the conventional SEM measurement approach. To overcome these difficulties, we evaluated Design Based Metrology (DBM) using Large Field Of View (LFOV) of CD-SEM. DBM can standardize measurement points and positions within LFOV based on the inflection/jog of OPCed patterns. Thus, DBM has realized several thousand multi ROI measurements with average CD. This new measurement technique can remove local CD errors and improved statistical methodology of the entire mask to enhance the representativeness of global CD uniformity. With this study we confirmed this new technique as a more reliable methodology in complex OPCed patterns compared to conventional technology. This paper summarizes the experiments of DBM with LFOV using various types of the patterns and compares them with current CD SEM methods.

  3. Metrology algorithms for machine matching in different CD SEM configurations

    NASA Astrophysics Data System (ADS)

    Reilly, Terrence W.

    1992-06-01

    Within semiconductor companies, there may be many different critical dimension (CD) measurement instruments. They could be optical, electrical, confocal laser, or scanning electron microscopes (SEM). Often times, they are not only different configurations, but different brands as well. These variations of type and brand have created the need for a measurement algorithm that has the ability to deliver the same measurement between two instruments. It is possible the development group within a semiconductor company would use a CD SEM with expanded capabilities when compared to the production group's CD SEM. In this case, a measurement algorithm unaffected by the differences in signal outputs from the varying microscope designs would enhance system matching. One would believe that two identical CD systems should produce nearly the same measurement. However, when two totally different systems are compared, only a robust algorithm would give good machine to machine matching of measurements. This paper examines two measurement algorithms using two completely different CD and inspection SEMs. The purpose is to examine the algorithm's ability to deliver good machine to machine matching regardless of how the secondary waveform signal is generated.

  4. Some Reflections on SEM Structures and Strategies. Part One

    ERIC Educational Resources Information Center

    Kalsbeek, David H.

    2006-01-01

    This article is a pre-conference paper prepared for participants at AACRAO's Fifteenth Annual Strategic Enrollment Management Conference (SEM XV), held November 13-16, 2005, in Chicago, Illinois. This is the first of a three-part series. In this series of papers, David Kalsbeek introduces a four-fold construct for differentiating and comparing…

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

    PubMed

    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.

  6. Some Reflections on SEM Structures and Strategies. Part One

    ERIC Educational Resources Information Center

    Kalsbeek, David H.

    2006-01-01

    This article is a pre-conference paper prepared for participants at AACRAO's Fifteenth Annual Strategic Enrollment Management Conference (SEM XV), held November 13-16, 2005, in Chicago, Illinois. This is the first of a three-part series. In this series of papers, David Kalsbeek introduces a four-fold construct for differentiating and comparing…

  7. Expanding the Conversation about SEM: Advancing SEM Efforts to Improve Student Learning and Persistence--Part II

    ERIC Educational Resources Information Center

    Yale, Amanda

    2010-01-01

    The first article in this two-part series focused on the need for enrollment management conceptual and organizational models to focus more intentionally and purposefully on efforts related to improving student learning, success, and persistence. Time and again, SEM is viewed from a conventional lens comprising marketing, recruitment and …

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

    PubMed

    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.

  9. Faster root cause analysis with integrated SEM-FIB application

    NASA Astrophysics Data System (ADS)

    Wee, S. K.; Cheung, D.; Chua, D.; Ng, S. L.; Keisari, S.

    2006-03-01

    Integration of FIB (focused ion beam) into an automatic defect review SEM provide new dimension to defect root cause analysis. It brings out defect cross-section application from failure analysis lab to the clean room process, providing sub-surface information of the defect in addition to defect surface information, therefore closing the defect analysis loop on the same platform. Sub-surface defects such as embedded defects and electrical defects are often yield limiting nature and require cross-section information to determine failure mode and the root cause. The main advantage of integrated SEM-FIB is it provides much shorter root cause analysis cycle time and thus improve yield and fab productivity. Feedback time can be cut from typically 1-2 days to several hours, saving valuable time for process trouble-shooting. It eliminates the risk of damaging the samples due to handling and the need to re-localize the defect of interest prior to cross-section. Moreover, the cross-sectioned wafer can be returned to production by excluding the affected die instead of scrapping the whole wafer which is often desirable especially for 300mm wafer. FIB milling principle of operation is displacement of surface materials through atom sputtering effect by bombardment of the surface with high energy gallium ions. Defect analysis flow begins with wafer inspection which generates defect map followed by defect review on SEM-FIB tool. Defect of interest was identified and can be located easily when switching to FIB microscope since the exact defect location has been established during SEM review, which is sometimes very challenging for offline FIB tool especially for electrical defects and tiny defects. Defect surface area usually coated with a thin layer of platinum or tungsten to protect the surface from milling damage. Defect cross-sectioning by FIB milling are then performed. Decoration effect by XeF II gas etching is often required to enhance the contrast between the layers. Cross

  10. Payload isolation and stabilization by a Suspended Experiment Mount (SEM)

    NASA Technical Reports Server (NTRS)

    Bailey, Wayne L.; Desanctis, Carmine E.; Nicaise, Placide D.; Schultz, David N.

    1992-01-01

    Many Space Shuttle and Space Station payloads can benefit from isolation from crew or attitude control system disturbances. Preliminary studies have been performed for a Suspended Experiment Mount (SEM) system that will provide isolation from accelerations and stabilize the viewing direction of a payload. The concept consists of a flexible suspension system and payload-mounted control moment gyros. The suspension system, which is rigidly locked for ascent and descent, isolates the payload from high frequency disturbances. The control moment gyros stabilize the payload orientation. The SEM will be useful for payloads that require a lower-g environment than a manned vehicle can provide, such as materials processing, and for payloads that require stabilization of pointing direction, but not large angle slewing, such as nadir-viewing earth observation or solar viewing payloads.

  11. Rapid Evaluation of Particle Properties using Inverse SEM Simulations

    SciTech Connect

    Bekar, Kursat B.; Miller, Thomas Martin; Patton, Bruce W.; Weber, Charles F.

    2016-01-01

    This report is the final deliverable of a 3 year project whose purpose was to investigate the possibility of using simulations of X-ray spectra generated inside a scanning electron microscope (SEM) as a means to perform quantitative analysis of the sample imaged in the SEM via an inverse analysis methodology. Using the nine point Technology Readiness Levels (TRL) typically used by the US Department of Defense (DOD) and the National Aeronautics and Space Administration (NASA), this concept is now at a TRL of 3. In other words, this work has proven the feasibility of this concept and is ready to be further investigated to address some of the issues highlighted by this initial proof of concept.

  12. Developing 3D SEM in a broad biological context.

    PubMed

    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, M K; Saelens, X; Schertel, A; Schepens, B; Slezak, M; Timmerman, V; Theunis, C; VAN Brempt, R; Visser, Y; Guérin, C J

    2015-08-01

    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.

  13. Beam test of a segmented foil sem grid

    SciTech Connect

    Kopp, S.; Indurthy, D.; Pavlovich, Z.; Proga, M.; Zwaska, R.; Childress, S.; Ford, R.; Kendziora, C.; Kobilarcik, T.; Moore, Craig D.; Tassotto, G.

    2005-07-01

    A prototype Secondary-electron Emission Monitor (SEM) was installed in the 8 GeV proton transport line for the MiniBooNE experiment at Fermilab. The SEM is a segmented grid made with 5 {micro}m Ti foils, intended for use in the 120 GeV NuMI beam at Fermilab. Similar to previous workers, we found that the full collection of the secondary electron signal requires a bias voltage to draw the ejected electrons cleanly off the foils, and this effect is more pronounced at larger beam intensity. The beam centroid and width resolutions of the SEM were measured at beam widths of 3, 7, and 8 mm, and compared to calculations. Extrapolating the data from this beam test, we expect a centroid and width resolutions of {delta}x{sub beam} = 20 {micro}m and {delta}{sigma}{sub beam} = 25 {micro}m, respectively, in the NuMI beam which has 1 mm spot size.

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

    PubMed

    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.

  15. Characterization of some biological specimens using TEM and SEM

    NASA Astrophysics Data System (ADS)

    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.

  16. Marginal integrity of class V restorations: SEM versus dye penetration.

    PubMed

    Ernst, Claus-Peter; Galler, Pia; Willershausen, Brita; Haller, Bernd

    2008-03-01

    To perform an in vitro investigation on the marginal integrity of different adhesives (Optibond FL, Scotchbond 1XT, Clearfil SE Bond, Adper Prompt L-Pop, S(3) Bond, iBond exp., Adper Prompt L-Pop) in combination with Tetric Ceram as well as an experimental silorane-restorative (Hermes, Hermes Bond; 3M ESPE) using SEM and dye penetration (2% methylene blue) in a comparative manner. Standardized class V-cavities (3 mm x 1.5 mm) were prepared in 70 extracted human teeth (n=10). The adhesives were applied according to manufacturers' instructions. The cavities were restored with three increments. After finishing and polishing (Sof-Lex discs) and thermocycling (5000x, 5/55 degrees C), replicas were taken and the teeth immersed in the dye for 10s (D10) and evaluated. After another penetration of 30 min (D30) a final evaluation of the percentage of dye-penetrated margins was conducted. The median percentages in marginal gaps (%) at the enamel margins for the three methods investigated (D10/D30/SEM) were--Optibond FL: 0/0/4, Scotchbond 1 XT: 5/16/11, Clearfil SE Bond: 0/0/0, S(3) Bond: 0/0/1, iBond exp.: 20/42/12, Adper Prompt L-Pop: 5/23/8, Hermes/Hermes Bond: 5/45/24. Cementum margins--Optibond FL: 0/1/0, Scotchbond 1 XT: 0/21/23, Clearfil SE Bond: 0/0/4, S(3) Bond: 0/0/0, iBond exp.: 0/0/0, Adper Prompt L-Pop: 10/32/23, Hermes/Hermes Bond: 0/0/13. After pooling the data of all groups, a Spearmann's rho test showed a good correlation between the methods D10 and D30 at the enamel margins and at the entire cavity margins (correlation coefficient 0.8 and 0.7). SEM did not correlate with the results obtained from D10 (correlation coefficient <0.5). A fair correlation was found between SEM and D30 for the entire cavity margin but a good correlation for the enamel margins. No correlation between investigation methods was determined at the cementum margins. D30 showed a better correlation to SEM than D10 did. Therefore, 30 min of dye penetration time seems to be more suitable

  17. 30 CFR 250.1900 - Must I have a SEMS program?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 2 2011-07-01 2011-07-01 false Must I have a SEMS program? 250.1900 Section... Environmental Management Systems (SEMS) § 250.1900 Must I have a SEMS program? You must develop, implement, and...) You must comply with the provisions of this subpart and have your SEMS program in effect on or...

  18. 30 CFR 250.1900 - Must I have a SEMS program?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 2 2012-07-01 2012-07-01 false Must I have a SEMS program? 250.1900 Section... Management Systems (SEMS) § 250.1900 Must I have a SEMS program? You must develop, implement, and maintain a... provisions of this subpart and have your SEMS program in effect on or before November 15, 2011, except...

  19. Robust surface reconstruction by design-guided SEM photometric stereo

    NASA Astrophysics Data System (ADS)

    Miyamoto, Atsushi; Matsuse, Hiroki; Koutaki, Gou

    2017-04-01

    We present a novel approach that addresses the blind reconstruction problem in scanning electron microscope (SEM) photometric stereo for complicated semiconductor patterns to be measured. In our previous work, we developed a bootstrapping de-shadowing and self-calibration (BDS) method, which automatically calibrates the parameter of the gradient measurement formulas and resolves shadowing errors for estimating an accurate three-dimensional (3D) shape and underlying shadowless images. Experimental results on 3D surface reconstruction demonstrated the significance of the BDS method for simple shapes, such as an isolated line pattern. However, we found that complicated shapes, such as line-and-space (L&S) and multilayered patterns, produce deformed and inaccurate measurement results. This problem is due to brightness fluctuations in the SEM images, which are mainly caused by the energy fluctuations of the primary electron beam, variations in the electronic expanse inside a specimen, and electrical charging of specimens. Despite these being essential difficulties encountered in SEM photometric stereo, it is difficult to model accurately all the complicated physical phenomena of electronic behavior. We improved the robustness of the surface reconstruction in order to deal with these practical difficulties with complicated shapes. Here, design data are useful clues as to the pattern layout and layer information of integrated semiconductors. We used the design data as a guide of the measured shape and incorporated a geometrical constraint term to evaluate the difference between the measured and designed shapes into the objective function of the BDS method. Because the true shape does not necessarily correspond to the designed one, we use an iterative scheme to develop proper guide patterns and a 3D surface that provides both a less distorted and more accurate 3D shape after convergence. Extensive experiments on real image data demonstrate the robustness and effectiveness

  20. Microcircuit failure analysis using the SEM. [Scanning Electron Microscopes

    NASA Technical Reports Server (NTRS)

    Nicolas, D. P.

    1974-01-01

    The scanning electron microscope adds a new dimension to the knowledge that can be obtained from a failed microcircuit. When used with conventional techniques, SEM assists and clarifies the analysis, but it does not replace light microscopy. The most advantageous features for microcircuit analysis are long working distances and great depth of field. Manufacturer related failure modes of microcircuits are metallization defects, poor bonding, surface and particle contamination, and design and fabrication faults. User related failure modes are caused by abuse, such as overstress. The Physics of Failure Procedure followed by the Astrionics Laboratory in failure analysis is described, which is designed to obtain maximum information available from each step.

  1. Microcircuit failure analysis using the SEM. [Scanning Electron Microscopes

    NASA Technical Reports Server (NTRS)

    Nicolas, D. P.

    1974-01-01

    The scanning electron microscope adds a new dimension to the knowledge that can be obtained from a failed microcircuit. When used with conventional techniques, SEM assists and clarifies the analysis, but it does not replace light microscopy. The most advantageous features for microcircuit analysis are long working distances and great depth of field. Manufacturer related failure modes of microcircuits are metallization defects, poor bonding, surface and particle contamination, and design and fabrication faults. User related failure modes are caused by abuse, such as overstress. The Physics of Failure Procedure followed by the Astrionics Laboratory in failure analysis is described, which is designed to obtain maximum information available from each step.

  2. Line Edge Detection and Characterization in SEM Images using Wavelets

    SciTech Connect

    Sun, W; Romagnoli, J A; Tringe, J W; L?tant, S E; Stroeve, P; Palazoglu, A

    2008-10-07

    Edge characterization has become increasingly important in nanotechnology due to the growing demand for precise nanoscale structure fabrication and assembly. Edge detection is often performed by thresholding the spatial information of a top-down image obtained by Scanning Electron Microscopy (SEM) or other surface characterization techniques. Results are highly dependent on an arbitrary threshold value, which makes it difficult to reveal the nature of the real surface and to compare results among images. In this paper, we present an alternative edge boundary detection technique based on the wavelet framework. Our results indicate that the method facilitates nano-scale edge detection and characterization, by providing a systematic threshold determination step.

  3. SEM and AFM imaging of solar cells defects

    NASA Astrophysics Data System (ADS)

    Škarvada, Pavel; Macků, Robert; Dallaeva, Dinara S.; Sedlák, Petr; Grmela, Lubomír.; Tománek, Pavel

    2015-01-01

    The paper deals with the successive localization and imaging of solar cell defects, going from macroscale to microscale. For the purpose of localization, the light emission from reversed bias samples is used. After rough macroscopic localization, microscopic localization by scanning probe microscopy combined with a photomultiplier (shadow mapping) is performed. The type of microscopic defects are discernable from their current-voltage plot or from noise measurements. Two specific defects, both of the avalanche type, with different voltage threshold, are presented in this paper. Current voltage plots and radiant flux versus voltage characteristics for two temperatures, topography, shadow map and corresponding SEM micrographs are shown for both samples.

  4. SEM analysis of rock varnish chemistry: A geomorphic age discriminator

    SciTech Connect

    Harrington, C.D.; Raymond, R. Jr.

    1989-07-01

    Rock varnish, a manganese- and iron-rich coating commonly found on rock surfaces in arid and semiarid regions, has long been of interest as a potential age indicator. Rock varnish has been shown to be an effective medium for dating of geomorphic surfaces over a time range of several thousand to over a million years, utilizing a ratio among minor cations ((K + Ca)/Ti) for the total volume of rock varnish. We have recently, developed a technique using the scanning electron microscope (SEM) equipped with an energy dispersive x-ray analyzer (EDAX) to analyze the chemistry of rock varnish. This technique has several advantages over the earlier cation ratio technique.

  5. Developing 3D SEM in a broad biological context

    PubMed Central

    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

  6. Endobacterial morphotypes in nudibranch cerata tips: a SEM analysis

    NASA Astrophysics Data System (ADS)

    Schuett, Christian; Doepke, Hilke

    2013-06-01

    The SEM investigation of nudibranch cerata material exhibits endobacterial morphotypes found in 12 out of 13 species tested: Aeolidia papillosa, Berghia caerulescens, Coryphella brownii, Coryphella lineata, Coryphella verrucosa, Cuthona amoena, Facelina coronata, Flabellina pedata, Dendronotus frondosus, Doto coronata, Tritonia plebeia and Janolus cristatus. Endobacteria could not be detected inside Tritonia hombergi. Endobacterial morphology found inside nudibranch species was compared to bacterial morphotypes detected earlier in tentacles of cnidarian species. SEM micrographs show endobacterial analogy among nudibranch species, but also similarity to cnidarian endobacteria investigated earlier. Of course, morphological data of microbes do not allow their identification. However, since most of these nudibranch species prey on cnidaria, it cannot be excluded that many of the endobacteria detected inside nudibranch species may originate from their cnidarian prey. Our previous data describing genetic affiliation of endobacteria from nudibranchian and cnidarian species support this assumption. Dominant coccoid endobacteria mostly exhibit smooth surface and are tightly packed as aggregates and/or wrapped in envelopes. Such bacterial aggregate type has been described previously in tentacles of the cnidarian species Sagartia elegans. Similar coccoid bacteria, lacking envelopes were also found in other nudibranch species. A different type of coccoid bacteria, characterized by a rough surface, was detected inside cerata of the nudibranch species Berghia caerulescens, and surprisingly, inside tentacles of the cnidarian species Tubularia indivisa. In contrast to cnidarian endobacteria, rod-shaped microorganisms are largely absent in nudibranch cerata.

  7. Prophylometric and SEM analyses of four different finishing methods

    PubMed Central

    CHIODERA, G.; CERUTTI, F.; CERUTTI, A.; PUTIGNANO, A.; MANGANI, F.

    2013-01-01

    Summary Adhesion is the pivot of the modern restorative dentistry. Inlays, onlays and veneers have become a valid alternative to the traditional prosthetic treatments even in the rehabilitation of extremely damaged teeth, allowing a consistent saving of sound tooth tissues. Composite resins and dental adhesive are continously investigated and improved, nevertheless the optimization of the tooth-adhesive interface has to be considered: in fact, the long-term stability of adhesion between tooth and composite material depends on the treatment of the amelo-dentinal surfaces. This study investigated the quality of the occlusal walls of a cavity prepared to receive an inlay and finished with four different systems: thin and extra-thin diamond coated burs, a 12-blades carbide burs and a diamond-coated tip driven by sonic instrument. Consequently, prophylometric and SEM analyses were performed on the samples. The average roughness values recorded by the prophylometer were expressed by the parameters Ra and RZ: there is a correspondence between the numeric values and the pictures of the SEM. The results show a better quality (low roughness values) of the surface treated with multi-blade burs, followed by the this and extra-thin diamond coated burs. The 25 micron diamond-coated tip of the sonic instrument obtains the roughest surface and a sensibly higher amount of smear layer than the other tested systems. PMID:23741601

  8. SEM analysis as a diagnostic tool for photovoltaic cell degradation

    NASA Astrophysics Data System (ADS)

    Osayemwenre, Gilbert; Meyer, E. L.

    2013-04-01

    The importance of scanning electron microscopy (SEM) analysis as a diagnostic tool for analyzing the degradation of a polycrystalline Photovoltaic cell has been studied. The main aim of this study is to characterize the surface morphology of hot spot regions (degraded) cells in photovoltaic solar cells. In recent years, production of hetero and multi-junction solar cells has experience tremendous growth as compared to conventional silicon (Si) solar cells. Thin film photovoltaic solar cells generally are more prone to exhibiting defects and associated degradation modes. To improve the lifetime of these cells and modules, it is imperative to fully understand the cause and effect of defects and degradation modes. The objective of this paper is to diagnose the observed degradation in polycrystalline silicon cells, using scanning electron microscopy (SEM). In this study poly-Si cells were characterize before and after reverse biasing, the reverse biasing was done to evaluate the cells' susceptibility to leakage currents and hotspots formation. After reverse biasing, some cells were found to exhibit hotspots as confirmed by infrared thermography. The surface morphology of these hotspots re

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

    PubMed

    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.

  10. Comparing the Detection of Iron-Based Pottery Pigment on a Carbon-Coated Sherd by SEM-EDS and by Micro-XRF-SEM

    PubMed Central

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

    2014-01-01

    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. PMID:24600333

  11. Extending SemRep to the Public Health Domain

    PubMed Central

    Rosemblat, Graciela; Resnick, Melissa P.; Auston, Ione; Shin, Dongwook; Sneiderman, Charles; Fizsman, Marcelo; Rindflesch, Thomas C.

    2014-01-01

    We describe the use of a domain-independent methodology to extend a natural language processing (NLP) application, SemRep (Rindflesch, Fiszman, & Libbus, 2005), based on the knowledge sources afforded by the Unified Medical Language System (UMLS®) (Humphreys, Lindberg, Schoolman, & Barnett, 1998) to support the area of health promotion within the public health domain. Public health professionals require good information about successful health promotion policies and programs that might be considered for application within their own communities. Our effort seeks to improve access to relevant information for the public health profession, to help those in the field remain an information-savvy workforce. NLP and semantic techniques hold promise to help public health professionals navigate the growing ocean of information by organizing and structuring this knowledge into a focused public health framework paired with a user-friendly visualization application as a way to summarize results of PubMed searches in this field of knowledge. PMID:24729747

  12. AFM, SEM and TEM Studies on Porous Anodic Alumina

    PubMed Central

    2010-01-01

    Porous anodic alumina (PAA) has been intensively studied in past decade due to its applications for fabricating nanostructured materials. Since PAA’s pore diameter, thickness and shape vary too much, a systematical study on the methods of morphology characterization is meaningful and essential for its proper development and utilization. In this paper, we present detailed AFM, SEM and TEM studies on PAA and its evolvements with abundant microstructures, and discuss the advantages and disadvantages of each method. The sample preparation, testing skills and morphology analysis are discussed, especially on the differentiation during characterizing complex cross-sections and ultrasmall nanopores. The versatility of PAAs is also demonstrated by the diversity of PAAs’ microstructure. PMID:20672104

  13. Extending SemRep to the Public Health Domain.

    PubMed

    Rosemblat, Graciela; Resnick, Melissa P; Auston, Ione; Shin, Dongwook; Sneiderman, Charles; Fizsman, Marcelo; Rindflesch, Thomas C

    2013-10-01

    We describe the use of a domain-independent methodology to extend a natural language processing (NLP) application, SemRep (Rindflesch, Fiszman, & Libbus, 2005), based on the knowledge sources afforded by the Unified Medical Language System (UMLS®) (Humphreys, Lindberg, Schoolman, & Barnett, 1998) to support the area of health promotion within the public health domain. Public health professionals require good information about successful health promotion policies and programs that might be considered for application within their own communities. Our effort seeks to improve access to relevant information for the public health profession, to help those in the field remain an information-savvy workforce. NLP and semantic techniques hold promise to help public health professionals navigate the growing ocean of information by organizing and structuring this knowledge into a focused public health framework paired with a user-friendly visualization application as a way to summarize results of PubMed searches in this field of knowledge.

  14. Automatic evaluation of nickel alloy secondary phases from SEM images.

    PubMed

    de Albuquerque, Victor Hugo C; Silva, Cleiton Carvalho; Menezes, Thiago Ivo de S; Farias, Jesualdo Pereira; Tavares, João Manuel R S

    2011-01-01

    Quantitative metallography is a technique to determine and correlate the microstructures of materials with their properties and behavior. Generic commercial image processing and analysis software packages have been used to quantify material phases from metallographic images. However, these all-purpose solutions also have some drawbacks, particularly when applied to segmentation of material phases. To overcome such limitations, this work presents a new solution to automatically segment and quantify material phases from SEM metallographic images. The solution is based on a neuronal network and in this work was used to identify the secondary phase precipitated in the gamma matrix of a Nickel base alloy. The results obtained by the new solution were validated by visual inspection and compared with the ones obtained by a commonly used commercial software. The conclusion is that the new solution is precise, reliable and more accurate and faster than the commercial software. © 2010 Wiley-Liss, Inc.

  15. Filler segmentation of SEM paper images based on mathematical morphology.

    PubMed

    Ait Kbir, M; Benslimane, Rachid; Princi, Elisabetta; Vicini, Silvia; Pedemonte, Enrico

    2007-07-01

    Recent developments in microscopy and image processing have made digital measurements on high-resolution images of fibrous materials possible. This helps to gain a better understanding of the structure and other properties of the material at micro level. In this paper SEM image segmentation based on mathematical morphology is proposed. In fact, paper models images (Whatman, Murillo, Watercolor, Newsprint paper) selected in the context of the Euro Mediterranean PaperTech Project have different distributions of fibers and fillers, caused by the presence of SiAl and CaCO3 particles. It is a microscopy challenge to make filler particles in the sheet distinguishable from the other components of the paper surface. This objectif is reached here by using switable strutural elements and mathematical morphology operators.

  16. Mechanical and SEM analysis of artificial comet nucleus samples

    NASA Technical Reports Server (NTRS)

    Thiel, K.; Kochan, H.; Roessler, K.; Gruen, E.; Schwehm, G.; Hellmann, H.; Hsiung, P.; Koelzer, G.

    1989-01-01

    Since 1987 experiments dealing with comet nucleus phenomena have been carried out in the DFVLR space simulation chambers. The main objective of these experiments is a better understanding of thermal behavior, surface phenomena and especially the gas dust interaction. As a function of different sample compositions and exposure to solar irradiation (xenon-bulbs) crusts of different hardness and thickness were measured. The measuring device consists of a motor driven pressure foot (5 mm diameter), which is pressed into the sample. The applied compressive force is electronically monitored. The microstructure of the crust and dust residuals is investigated by scanning electron microscopy (SEM) techniques. Stress-depth profiles of an unirradiated and an irradiated model comet are given.

  17. [Biofilm from patients with chronic rhinosinusitis. Morphological SEM studies].

    PubMed

    Głowacki, Roman; Strek, Paweł; Zagórska-Swiezy, Katarzyna; Składzień, Jacek; Oleś, Krzysztof; Hydzik-Sobocińska, Karolina; Miodoński, Adam

    2008-01-01

    Bacterial biofilm is a three-dimensional structure made of aggregates of bacterial cells (microcolonies) and the extra cellular matrix released by them, adhering to organic and inorganic surfaces. It is estimated that 99% of all bacteria exist in biofilms, and only 1% live in a free-floating or planktonic state at any given time. The aim of the study was to demonstrate biofilms in mucosal specimens of patients undergoing endoscopic sinus surgery for chronic rhinosinusitis and co-occurrence of such illnesses as nasal polyps, bronchial asthma, NSAIDs allergy, and aspirin-induced asthma. A prospective study of 25 patients suffering from chronic rhinosinusitis. All patients underwent completed a otolaryngological examination and paranasal sinus CT scans. Endoscopic surgery of nasal sinuses (ESS) was performed in all patients. The mucous membrane samples were taken from the inside of the sinus and concha bullosa. They were prepared and examined with a scanning electron microscope (SEM). The images were then compared with the available database of the biofilm images. Using SEM morphologic criteria, the biofilms were identified in the studied material in nineteen patients (83%). In four patients with chronic rhinosinusitis, no biofilms were found on the samples taken. A bacteriological examination of smears from inside of the sinus, revealed the presence of various types of bacteria. In two patients no bacteria was found in the smears. It is supposed that bacterial biofilms perform an essential role in the pathogenesis of chronic sinusitis. One may speculate that, the presence of biofilms in patients with chronic rhinosinusitis could induce the co-occurrence of such illnesses as nasal polyps, bronchial asthma, aspirin-induced asthma or a NSAIDs allergy. In order to evaluate better the role of biofilms in chronic rhinosinusitis, it seems justified to extend the research to a larger group of patients and a control group.

  18. 30 CFR 250.1909 - What are management's general responsibilities for the SEMS program?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... of safety hazards and environmental impacts is an integral part of the design, construction... personnel are employed to carry out all aspects of the SEMS program. (j) Ensure that the SEMS program...

  19. 30 CFR 250.1909 - What are management's general responsibilities for the SEMS program?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... of safety hazards and environmental impacts is an integral part of the design, construction... personnel are employed to carry out all aspects of the SEMS program. (j) Ensure that the SEMS program...

  20. 30 CFR 250.1909 - What are management's general responsibilities for the SEMS program?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... of safety hazards and environmental impacts is an integral part of the design, construction... personnel are employed to carry out all aspects of the SEMS program. (j) Ensure that the SEMS program...

  1. Combining poly (methacrylic acid-co-ethylene glycol dimethacrylate) monolith microextraction and octadecyl phosphonic acid-modified zirconia-coated CEC with field-enhanced sample injection for analysis of antidepressants in human plasma and urine.

    PubMed

    Wei, Fang; Fan, Jin; Zheng, Ming-Ming; Feng, Yu-Qi

    2010-01-01

    A method based on poly (methacrylic acid-co-ethylene glycol dimethacrylate) monolith microextraction and octadecylphosphonic acid-modified zirconia-coated CEC followed by field-enhanced sample injection preconcentration technique was proposed for sensitive CE-UV analysis of six antidepressants (doxepin, clozapine, imipramine, paroxetine, fluoxetine and chlorimipramine) in human plasma and urine. A poly(methacrylic acid-co-ethylene glycol dimethacrylate) monolithic capillary column was introduced for the extraction of antidepressants from urine and plasma samples. The hydrophobic main chains and acidic pendant groups of the monolithic column make it a superior material for extraction of basic analytes from aqueous matrix. After extraction, the desorption solvent, which normally provided an excellent medium to ensure direct compatibility for field-enhanced sample injection in CE, was analyzed by CE directly. By the use of alkylphosphonate-modified zirconia-coated CEC for separation of the basic compounds of antidepressants, high separation efficiency and resolution were achieved because that both hydrophobic interaction between analytes and alkylphosphonate-modified zirconia coat and electrophoretic effect work on the separation of antidepressants. The best separation was achieved using a buffer composed of 0.3 M ammonium acetate (adjusted to pH 4.5 with 1 M acetic acid) and 35% ACN v/v, with a temperature and voltage of 20 degrees C and 20 kV, respectively. By applying both preconcentration procedures, LODs of 11.4-51.5 and 3.7-17.0 microg/L were achieved for the six antidepressants in human plasma and urine, respectively. Excellent method of reproducibility was found over a linear range of 50-5000 microg/L in plasma and urine sample.

  2. SEM-EDS analysis and discrimination of forensic soil.

    PubMed

    Cengiz, Salih; Cengiz Karaca, Ali; Cakir, Ismail; Bülent Uner, H; Sevindik, Aytekin

    2004-04-20

    Soils vary among different areas, and have some characteristics because of the natural effects and transfers made by human and other living beings in time. So that forensic examination of soil is not only concerned with the analysis of naturally occurring rocks, minerals, vegetation, and animal matter. It also includes the detection of such manufactured materials such as ions from synthetic fertilizers and from different environments (e.g., nitrate, phosphate, and sulfate) as environmental artifacts (e.g., lead or objects as glass, paint chips, asphalt, brick fragments, and cinders) whose presence may impart soil with characteristics that will make it unique to a particular location. Many screening and analytical methods have been applied for determining the characteristics which differentiate and discriminate the forensic soil samples but none of them easily standardized. Some of the methods that applied in forensic laboratories in forensic soil discrimination are the color comparison of the normal air-dried (dehumidified) and overheated soil samples, macroscopic observation, and low-power stereo-microscopic observation, determination of anionic composition by capillary electrophoresis (CE), and the elemental composition by scanning electron microscope (SEM)-energy dispersive X-ray spectrometer (EDS) and other high sensitivity techniques. The objective of this study was to show the effect of the application of 9 tonnes/cm2 pressure on the elemental compositions obtained by SEM-EDS technique and comparing the discrimination power of the pressed-homogenized and not homogenized forensic soil samples. For this purpose soil samples from 17 different locations of Istanbul were collected. Aliquots of the well mixed samples were dried in an oven at 110-120 degrees C and sieved by using 0.5 mm sieve and then the undersieve fraction(<0.5 mm) of these samples put on an adhesive tape placed on a stub. About 100-150 mg aliquots of dried, sieved samples were pressed under 9

  3. 30 CFR 250.1900 - Must I have a SEMS program?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 2 2014-07-01 2014-07-01 false Must I have a SEMS program? 250.1900 Section 250.1900 Mineral Resources BUREAU OF SAFETY AND ENVIRONMENTAL ENFORCEMENT, DEPARTMENT OF THE INTERIOR... Management Systems (SEMS) § 250.1900 Must I have a SEMS program? You must develop, implement, and maintain...

  4. 30 CFR 250.1900 - Must I have a SEMS program?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 2 2013-07-01 2013-07-01 false Must I have a SEMS program? 250.1900 Section 250.1900 Mineral Resources BUREAU OF SAFETY AND ENVIRONMENTAL ENFORCEMENT, DEPARTMENT OF THE INTERIOR... Management Systems (SEMS) § 250.1900 Must I have a SEMS program? You must develop, implement, and maintain...

  5. 30 CFR 250.1901 - What is the goal of my SEMS program?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Environmental Management Systems (SEMS) § 250.1901 What is the goal of my SEMS program? The goal of your SEMS program is to promote safety and environmental protection by ensuring all personnel aboard a facility are... Section 250.1901 Mineral Resources BUREAU OF SAFETY AND ENVIRONMENTAL ENFORCEMENT, DEPARTMENT OF THE...

  6. 30 CFR 250.1924 - How will BSEE determine if my SEMS program is effective?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... and Environmental Management Systems (SEMS) § 250.1924 How will BSEE determine if my SEMS program is... 30 Mineral Resources 2 2013-07-01 2013-07-01 false How will BSEE determine if my SEMS program is effective? 250.1924 Section 250.1924 Mineral Resources BUREAU OF SAFETY AND ENVIRONMENTAL ENFORCEMENT...

  7. 30 CFR 250.1901 - What is the goal of my SEMS program?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Environmental Management Systems (SEMS) § 250.1901 What is the goal of my SEMS program? The goal of your SEMS program is to promote safety and environmental protection by ensuring all personnel aboard a facility are... Section 250.1901 Mineral Resources BUREAU OF SAFETY AND ENVIRONMENTAL ENFORCEMENT, DEPARTMENT OF THE...

  8. 30 CFR 250.1924 - How will BSEE determine if my SEMS program is effective?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... and Environmental Management Systems (SEMS) § 250.1924 How will BSEE determine if my SEMS program is... 30 Mineral Resources 2 2014-07-01 2014-07-01 false How will BSEE determine if my SEMS program is effective? 250.1924 Section 250.1924 Mineral Resources BUREAU OF SAFETY AND ENVIRONMENTAL ENFORCEMENT...

  9. 30 CFR 250.1931 - What must be included in my SEMS program for UWA?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... and Environmental Management Systems (SEMS) § 250.1931 What must be included in my SEMS program for... 30 Mineral Resources 2 2014-07-01 2014-07-01 false What must be included in my SEMS program for UWA? 250.1931 Section 250.1931 Mineral Resources BUREAU OF SAFETY AND ENVIRONMENTAL ENFORCEMENT...

  10. 30 CFR 250.1924 - How will BSEE determine if my SEMS program is effective?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... and Environmental Management Systems (SEMS) § 250.1924 How will BSEE determine if my SEMS program is... 30 Mineral Resources 2 2012-07-01 2012-07-01 false How will BSEE determine if my SEMS program is effective? 250.1924 Section 250.1924 Mineral Resources BUREAU OF SAFETY AND ENVIRONMENTAL ENFORCEMENT...

  11. 30 CFR 250.1911 - What criteria for hazards analyses must my SEMS program meet?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... and Environmental Management Systems (SEMS) § 250.1911 What criteria for hazards analyses must my SEMS... 30 Mineral Resources 2 2012-07-01 2012-07-01 false What criteria for hazards analyses must my SEMS program meet? 250.1911 Section 250.1911 Mineral Resources BUREAU OF SAFETY AND ENVIRONMENTAL ENFORCEMENT...

  12. 30 CFR 250.1931 - What must be included in my SEMS program for UWA?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... and Environmental Management Systems (SEMS) § 250.1931 What must be included in my SEMS program for... 30 Mineral Resources 2 2013-07-01 2013-07-01 false What must be included in my SEMS program for UWA? 250.1931 Section 250.1931 Mineral Resources BUREAU OF SAFETY AND ENVIRONMENTAL ENFORCEMENT...

  13. 30 CFR 250.1901 - What is the goal of my SEMS program?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Environmental Management Systems (SEMS) § 250.1901 What is the goal of my SEMS program? The goal of your SEMS program is to promote safety and environmental protection by ensuring all personnel aboard a facility are... Section 250.1901 Mineral Resources BUREAU OF SAFETY AND ENVIRONMENTAL ENFORCEMENT, DEPARTMENT OF THE...

  14. 30 CFR 250.1901 - What is the goal of my SEMS program?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... and Environmental Management Systems (SEMS) § 250.1901 What is the goal of my SEMS program? The goal of your SEMS program is to promote safety and environmental protection by ensuring all personnel... Section 250.1901 Mineral Resources BUREAU OF OCEAN ENERGY MANAGEMENT, REGULATION, AND ENFORCEMENT...

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

    ERIC Educational Resources Information Center

    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…

  16. Challenges of SEM-based critical dimension metrology of interconnect

    NASA Astrophysics Data System (ADS)

    Ukraintsev, Vladimir A.; Jessen, Scott; Mikeska, Brian; Sallee, Chris; Khvatkov, Vitali

    2011-03-01

    Semiconductor technology is advancing below 50 nm critical dimensions bringing unprecedented challenges to process engineering, control and metrology. Traditionally, interconnect metrology is put behind high-priority gate metrology; however, considering metrology, process and yield control challenges this decision is not always justified. Optical scatterometry is working its way to interconnect manufacturing process control, but scanning electron microscopy (SEM) remains the number one critical dimension (CD) metrology for interconnect process engineering and optical proximity correction (OPC) modeling. Recently, several publications have described secondary electron (SE) trapping within narrow high-aspect ratio interconnect structures. In these papers, pre-dosing of the sample helped to extract SE from the bottom of the hole and measure its diameter. Based on current understanding of the phenomenon, one should expect that high-aspect ratio interconnect structures (holes and trenches) with critical dimensions below 100 nm may show signs of SE trapping of various degree. As a result, there may be an uncontrolled effect on SE waveform and, therefore, bias of CDSEM measurement. CD atomic force microscopy (AFM) was employed in this work as a reference metrology for evaluation of uncertainty of trench and hole measurements by CDSEM. As the data indicates, CDSEM bias shows a strong dependence on pitch of periodic interconnect structure starting from drawn CD of 50 nm. CDSEM bias variation for the evaluated set of samples is about 19 nm. A typical OPC sample consists of both photoresist and etched interlayer materials. As the AFM data for photoresist material indicates, the hole diameter changes quite significantly with depth and the hole profile varies from one OPC structure to another. Abe et al. [1] have used a clever way to correlate physical bottom diameter of holes with CDSEM measurements and demonstrated that for their process and dimensions the SEM "top" diameter

  17. SEM/EDS Characterization of Ambient PM during Agricultural Burns

    NASA Astrophysics Data System (ADS)

    Wagner, J.; Wall, S.

    2010-12-01

    Ambient particulate matter (PM) samples were collected with UNC passive samplers during agricultural burns in Imperial Valley, California. Four Bermuda grass field burn events were sampled at 3-8 locations surrounding each burn. Sampling began at the start of each burn (30-60 min) and continued for 24-120 hours. During 3 of the 4 burn events, winds were calm and plumes were observed to travel straight up to the inversion layer. In one event, winds created a ground-level plume that enveloped two UNC samplers mounted on telephone poles very close to the field (0.2-0.3 miles away). Computer-controlled scanning electron microscopy / energy-dispersive x-ray spectroscopy (CCSEM/EDS) was used to measure particle sizes and elemental composition, from which mass concentrations and size distributions were calculated. The median PM2.5 and PM10 levels measured in this study were 3.4 and 20 ug/m3, respectively. To determine quantitative accuracy, UNC sampler PM2.5 results (PM< 2.5 um) were compared to PM2.5 results from four co-located, continuous-reading beta-attenuation monitors (EBAMs). The median agreement (EBAM - UNC) was 3.8 ug/m3. Manual SEM/EDS detected various distinctive species in these samples, including sea salt, spores, plant fragments, and large soot agglomerates. During the ‘plume event’, 24-hour PM2.5 exposures downwind were up to 17 times higher than that measured upwind. Numerous submicron combustion particles with carbon and oxygen only were directly observed by manual SEM/EDS in the two plume-impacted samples, along with larger ash particles enriched in potassium, sulfur, chlorine, calcium, sodium, and phosphorus. CCSEM/EDS data from this event was grouped into 5 particle classes to generate size-fraction-specific pie charts. Burn-related particle types contributed 95% of the PM2.5 in the location directly impacted by the ground-level plume, compared to only 12% in the upwind location. A sample of Imperial County Bermuda grass analyzed in bulk and

  18. SEM observations of porcelain Y-TZP interface.

    PubMed

    Tholey, Michael J; Swain, Michael V; Thiel, Norbert

    2009-07-01

    The metastability of the tetragonal phase of yttria tetragonal zirconia polycrystalline (Y-TZP) ceramics is a cause for concern in dental crown and bridge applications. One specific problematic area is the nature of the interface between the veneering porcelain and the Y-TZP framework and whether the associated preparation procedures and reactions result in a reduction of the stability of the zirconia. To investigate this aspect, high-resolution SEM observations were made of polished and etched (HF content gel) cross-sections of the interface area. Dry and moist veneering porcelain powders were built up on the zirconia base. In some instances the zirconia grains at the interface appear to show multiplicity of subgrain faceting whereas in other instances they do not. The latter indicate destabilisation of the tetragonal phase occurs and in addition that the porcelain veneering material wets and some dissolution of the Y-TZP occurs. These results and their relevance to the long-term stability of the interface adhesion to the veneering porcelain as well as possible tetragonal to monoclinic crystal transformations at the interface are discussed.

  19. Ultrasound effects after post space preparation: An SEM study.

    PubMed

    Serafino, Cinzia; Gallina, Giuseppe; Cumbo, Enzo; Monticelli, Francesca; Goracci, Cecilia; Ferrari, Marco

    2006-06-01

    The aim of this study was to evaluate the effect of ultrasonic treatment on occlusion of dentine tubules in root canal walls after post space preparation in endodontically treated teeth. Twenty-four premolars were instrumented and filled using warm vertical condensation; after post space preparation, they were divided into two groups. The control group was treated using the etching procedure. The experiment samples were treated with EDTA irrigation and ultrasound activation for 30 s before the etching procedure. The roots were divided and the canal walls were examined under SEM at 1000x magnification. The debris and open tubule marks were observed at 2, 6, and 10 mm levels using a three-step scale and the differences in marks among the groups were tested for statistical significance. The following were observed: (a) A decrease in debris and open tubule marks in the samples treated with ultrasounds and the control group (p < 0.05), (b) no significant differences between the three levels of post space in debris and open tubule marks in the experiment samples, and (c) significant differences between the apical and coronal levels in debris and open tubule marks in the control group.

  20. Early Experiments with a New In Situ SEM Heating Technology

    SciTech Connect

    Howe, Jane Y; Walker, Larry R; Allard Jr, Lawrence Frederick; Demers, Hendrix

    2011-01-01

    A new heating technology (Protochips, Inc.) has recently been introduced for in situ electron microscopy studies, including both TEM and SEM applications. Aduro{trademark} heater devices, fabricated using MEMS-based processing, offer numerous advantages for in situ SEM applications over those using a miniaturized furnace. The device supports a sample on a thin ceramic membrane that is directly heated by passing a current of a few mA, thereby also heating the sample. The entire heated area of the device is only 500um x 500um, so it is operated without circulating cooling water. The extremely small heated zone enables a rapid temperature response (10{sup 6} C/s) for both heating and cooling, and it emits a far lower signal of photons and thermal electrons than a typical furnace-type heating device. This allows heating to temperatures in excess of 1000 C without totally degrading the secondary electron signal. The purpose of the present work is to characterize the factors that influence the image quality and resolution of the SEM during heating. We are interested in understanding relative changes of signal-to-noise levels and contrast in secondary electron (SE) and backscattered electron (BSE) images as a function of increasing the heating temperature. We have also assessed the capability for performing energy dispersive X-ray spectroscopy (EDS) during heating experiments. The in situ holder and the structure of a standard heater chip used in this study are shown in Fig. 1. The chip has an array of 5 {micro}m holes in the electrically conductive heater membrane, separated by electrode 'fingers' in this case. A C-flat{trademark} holey carbon film is overlaid on top of the heater membrane. The heating experiments were conducted in a Hitachi S3400 VP-SEM, operated at 15kV and equipped with an EDAX Si(Li) detector. Fig. 2 shows an Ir-doped FeSi particle situated near the edge of the hole in the membrane, imaged with secondary electrons through an Everhart-Thornley (ET

  1. Copper Bronze Powder Surface Studied by XPS and HR SEM

    NASA Astrophysics Data System (ADS)

    Shvab, R.; Hryha, E.; Tahir, A. M.; Nyborg, L.

    2016-10-01

    The state of the powder surface represents one of the main interests in the whole cycle of components' production using powder metallurgy (PM) route. Large specific surface area of the powder in combination with often alloying with oxygen sensitive elements results in oxidation of the powder surface in most of the cases. The information about surface chemistry of the powder is of vital importance for further consolidation and sintering steps. Surface sensitive analytical techniques - X-ray photoelectron spectroscopy (XPS) and high-resolution scanning electron microscopy combined with energy dispersive X-ray analysis (HR SEM+EDX) were used for surface chemical analysis of the 60Cu-40Sn bronze powder. Determination of the compositional profiles and estimation of the surface oxide layer thickness was done by altering of ion etching and XPS analysis. The results showed tin oxide enrichment and presence of copper hydroxide on the surface of the powder particles. The impurities of P, Zn and Ca were also detected on the top surface of the powder in trace amounts.

  2. FIB/SEM cell sectioning for intracellular metal granules characterization

    NASA Astrophysics Data System (ADS)

    Milani, Marziale; Brundu, Claudia; Santisi, Grazia; Savoia, Claudio; Tatti, Francesco

    2009-05-01

    Focused Ion Beams (FIBs) provide a cross-sectioning tool for submicron dissection of cells and subcellular structures. In combination with Scanning Electron Microscope (SEM), FIB provides complementary morphological information, that can be further completed by EDX (Energy Dispersive X-ray Spectroscopy). This study focus onto intracellular microstructures, particularly onto metal granules (typically Zn, Cu and Fe) and on the possibility of sectioning digestive gland cells of the terrestrial isopod P. scaber making the granules available for a compositional analysis with EDX. Qualitative and quantitative analysis of metal granules size, amount and distribution are performed. Information is made available of the cellular storing pattern and, indirectly, metal metabolism. The extension to human level is of utmost interest since some pathologies of relevance are metal related. Apart from the common metal-overload-diseases (hereditary hemochromatosis, Wilson's and Menkes disease) it has been demonstrated that metal in excess can influence carcinogenesis in liver, kidney and breast. Therefore protocols will be established for the observation of mammal cells to improve our knowledge about the intracellular metal amount and distribution both in healthy cells and in those affected by primary or secondary metal overload or depletion.

  3. Tensile experiments and SEM fractography on bovine subchondral bone.

    PubMed

    Braidotti, P; Bemporad, E; D'Alessio, T; Sciuto, S A; Stagni, L

    2000-09-01

    Subchondral bone undecalcified samples, extracted from bovine femoral heads, are subjected to a direct tensile load. The Young's modulus of each sample is determined from repeated tests within the elastic limit. In a last test, the tensile load is increased up to the specimen failure, determining the ultimate tensile strength. The investigation is performed on both dry and wet specimens. The measured Young's modulus for dry samples is 10.3+/-2.5GPa, while that of wet samples is 3.5+/-1.2GPa. The ultimate tensile strengths are 36+/-10 and 30+/-7.5MPa for dry and wet specimens, respectively. SEM micrographs of failure surfaces show characteristic lamellar bone structures, with lamellae composed of calcified collagen fibers. Rudimentary osteon-like structures are also observed. Failure surfaces of wet samples show a marked fiber pull-out, while delamination predominates in dry samples. The obtained results are interpreted on the basis of the deformation mechanisms typical of fiber-reinforced laminated composite materials.

  4. Automated SEM Modal Analysis Applied to the Diogenites

    NASA Technical Reports Server (NTRS)

    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.

  5. Automatic visual inspection of integrated circuits using an SEM

    SciTech Connect

    Kayaalp, A.E.

    1988-01-01

    The author investigates the complex problem of designing an integrated-circuit inspection system that will be used in controlling an automated semiconductor manufacturing facility. To satisfy the accuracy requirements, he proposes a system that integrates information supplied by multiple intelligent (virtual) sensors. Most of his work concentrated on the design of two scanning-electron-microscope (SEM)-based, intelligent sensors. One of them extracts 3D IC surface-topography information using computer stereo-vision techniques, and the other identifies shape defects in IC patterns using the IC design file as the reference. Both of these problems are viewed as constrained contour-matching problems. In stereo matching, feature contours extracted from the left and right stereo images are matched, where in pattern-shape inspection, pattern boundary contours extracted from the image and the IC design file are matched. An optimization technique is presented for solving the matching problem that results in both cases. This general approach simplifies the task of transforming the specifications of a physical problem into a computational form and results in a modular system.

  6. Automated SEM Modal Analysis Applied to the Diogenites

    NASA Technical Reports Server (NTRS)

    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.

  7. SEM examination of the eggs of five British Aedes species.

    PubMed

    Service, M W; Duzak, D; Linley, J R

    1997-03-01

    Ultrastructure descriptions are given of the eggs of five British Aedes species, namely Aedes (Aedes) cinereus Meigen, Aedes (Ochlerotatus) cantans (Meigen), Aedes (Ochlerotatus) punctor (Kirby), Aedes (Ochlerotatus) detritus (Haliday), and Aedes (Ochlerotatus) rusticus (Rossi). Eggs of the first 4 species are broadly cigar/boat-shaped, with those of Ae. cinereus being characteristically long and narrow, in contrast to the overall shape of Ae. rusticus, which is quite distinct, being in profile almost subtriangular with rounded corners, and is completely species-diagnostic. In Ae. cantans, Ae. punctor, and Ae. rusticus there is usually a single large tubercle in each chorionic cell and there is little, if any, difference in the sculpturing of the ventral and dorsal surfaces, whereas in Ae. detritus each cell contains more than 20 tubercles, and in Ae. cinereus there are usually 6 tubercles per cell ventrally, but dorsally there are no tubercles or distinct cells but numerous cone-shaped papillae. All 5 species can be separated from each other by SEM examination of their chorionic patterns.

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

    PubMed

    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.

  9. Volume Measurement of Small Particles Using SEM Images

    NASA Astrophysics Data System (ADS)

    Trappitsch, R.; Davis, A. M.; Heck, P. R.

    2011-12-01

    Many important measurements applying concentration determinations for small particles (e.g., determining cosmogenic exposure ages of presolar grains [1]) depend on the mass of a given particle. Masses of small μm-sized samples such as extraterrestrial dust returned by space missions are often not well constrained due to measurement limitations, and can be often only estimated. Although many of these particles have a known average density, their volume is hardly ever known with enough precision. Our project objective is therefore to develop a nondestructive method for quantitative volume determination of small dust particles. We start with volume analyses of small standard shapes using scanning electron microscope (SEM) images taken under different tilting angles. Aluminum and titanium spheres with three different diameters (0.794, 2.38, and 3.18 mm) were weighted on a micro-balance. Their volumes were determined using the dimensions given by the manufacturer, as well as by using the weights and the respective densities of the materials. The spheres were then imaged in an SEM under different tilting angles ranging from -50 to +50 degrees. Images were subsequently analyzed using the software MeX (Alicona, http://www.alicona.com), which was successfully used for comet dust impact craters [2]. The volumes determined using the diameters given by the manufacturer and by weighing the samples are consistent within uncertainties. With the software MeX we were able to reconstruct 3D objects that resembled hemispheres. This is expected because by looking at the sample under a total angle difference of 14 degrees, about 54% of the sphere is visible to the software. To improve the rendering process we masked the imaged sphere with a black background using ImageJ (http://rsbweb.nih.gov/ij/). Since the 3D model only showed the upper half of the sample, we assumed symmetry with the lower part that was not visible and multiplied the volume returned from MeX by a factor of two

  10. SEM observations of resected root canal ends following apicoectomy.

    PubMed

    Furusawa, Masahiro; Asai, Yasuhiro

    2002-02-01

    The purpose of this study was to examine the apical foramen of root apices extracted during apicotomies. A total of 25 teeth extracted from 25 patients admitted to the Department of Conservative Dentistry at Tokyo Dental College's Chiba Hospital were used for the study. All patients were between 22 to 56 years of age at the time of the study, and each of the 25 cases was determined clinically on radiographs to be chronic apical suppurative periodontitis. Microsurgery was performed on all cases, and the extracted root apices were then observed using SEM. The results demonstrated a wide opening, greater than 350 microns as measured along the major axis, of the apical foramen in 80% of the cases. Various characteristics indicative of resorption were observed around the apical foramen. These features included those believed to have been caused by overinstrumentation during root canal treatment as well as irregularly shaped areas presumed to be apical lesions that had enlarged and eroded. We observed a high frequency of manifestations of cementum resorption surrounding the root apices of teeth with apical lesions. Furthermore, we concluded that in the majority of cases in the present study, due to the fact that the apical foramen exceeded normal opening dimensions as a result of overinstrumentation during root canal treatment or resorption around the root apex, prolongation of the lesions had occurred in response to direct contact of microbial infectious matter and tissues surrounding the root apex over a large area. The above finding suggested that, in cases in which the apical foramen is destroyed through overinstrumentation larger than #35 or in which the apical foramen opens up to dimensions greater than 350 microns due to pathologic resorption, surgical intervention may be indicated. On the other hand, in 64% of the cases, an accessory canal was observed in the root apical lesion. Based on this observation, the presence of an accessory canal in the root apex may

  11. SEM investigation of Er:YAG laser apical preparation

    NASA Astrophysics Data System (ADS)

    Bǎlǎbuc, Cosmin; Todea, Carmen; Locovei, Cosmin; RǎduÅ£ǎ, Aurel

    2016-03-01

    Endodontic surgery involves the incision and flap elevation, the access to the root tip, its resection, the cavity retrograde preparation and filling it with biocompatible material that provides a good seal of the apex[1]. Apicoectomy is compulsory in endodontic surgery. The final stage involves the root retropreparation and the carrying out of the retrograde obturation. In order to perform the retrograde preparation the endodontist can use various tools such as lowspeed conventional handpieces, sonic and ultrasonic equipment. The ideal depth of the preparation should be 3 mm, exceeding this value may affect the long-term success of the obturation [2]. Resection at the depth of 3 mm reduces apical ramifications by 98% and lateral root canals by 93%. The ultrasonic retropreparation has numerous advantages compared to the dental drill. Firstly, the cavity will be in the axis of the tooth which implies a minimum destruction of the root canal morphology. The preparations are precise, and the cutting pattern is perpendicular to the long axis of the root, the advantage being the reduction in the number of dentinal tubules exposed at the resected area [3]. Therefore, the retrograde filling is the procedure when an inert and non-toxic material is compacted in the apically created cavity.[4,5]. The Er:YAG laser is the most common wavelength indicated for dental hard tissue preparation. Its natural selectivity offers a significant advantage compared to the conventional hard tissue preparation [6-9].The purpose of this in vitro study was to investigate the quality of Er:YAG laser apical third preparation using Scanning Electron Microscopy (SEM), in comparison with the conventional ultrasonic method.

  12. Localization of the regulatory particle subunit Sem1 in the 26S proteasome

    SciTech Connect

    Bohn, Stefan; Sakata, Eri; Beck, Florian; Pathare, Ganesh R.; Schnitger, Jérôme; Nágy, Istvan; Baumeister, Wolfgang Förster, Friedrich

    2013-05-31

    Highlights: •26S proteasome subunit Sem1 was mapped using cryo-EM and cross-linking data. •C-terminal helix of Sem1 located near winged helix motif of Rpn7. •N-terminal part of Sem1 tethers Rpn7, Rpn3 and lid helical bundle. •Sem1 binds differently to PCI-domains of proteasome subunit Rpn7 and TREX-2 subunit Thp1. -- Abstract: The ubiquitin–proteasome system is responsible for regulated protein degradation in the cell with the 26S proteasome acting as its executive arm. The molecular architecture of this 2.5 MDa complex has been established recently, with the notable exception of the small acidic subunit Sem1. Here, we localize the C-terminal helix of Sem1 binding to the PCI domain of the subunit Rpn7 using cryo-electron microscopy single particle reconstruction of proteasomes purified from yeast cells with sem1 deletion. The approximate position of the N-terminal region of Sem1 bridging the cleft between Rpn7 and Rpn3 was inferred based on site-specific cross-linking data of the 26S proteasome. Our structural studies indicate that Sem1 can assume different conformations in different contexts, which supports the idea that Sem1 functions as a molecular glue stabilizing the Rpn3/Rpn7 heterodimer.

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

    PubMed

    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.

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

    PubMed

    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.

  15. A PDZ protein regulates the distribution of the transmembrane semaphorin, M-SemF.

    PubMed

    Wang, L H; Kalb, R G; Strittmatter, S M

    1999-05-14

    M-SemF is a membrane-associated, neurally enriched member of the semaphorin family of axon guidance signals. We considered whether the cytoplasmic domain of M-SemF might possess a signaling function and/or might control the distribution of M-SemF on the cell surface. We identify a PDZ-containing neural protein as an M-SemF cytoplasmic domain-associated protein (SEMCAP-1). SEMCAP-2 is a closely related nonneuronal protein. SEMCAP-1 has recently also been identified as GIPC, by virtue of its interaction with the RGS protein GAIP in vitro (De Vries, L., Lou, X., Zhao, G., Zheng, B., and Farquhar, M. G. (1998) Proc. Natl. Acad. Sci. U. S. A. 95, 12340-12345). Expression studies support the notion that SEMCAP-1(GIPC) interacts with M-SemF, but not GAIP, in brain. Lung SEMCAP-2 and SEMCAP-1(GIPC) are potential partners for both GAIP and M-SemF. The protein interaction requires the single PDZ domain of SEMCAP-1(GIPC) and the carboxyl-terminal four residues of M-SemF, ESSV. While SEMCAP-1(GIPC) also interacts with SemC, it does not interact with other proteins containing a class I PDZ binding motif, nor does M-SemF interact with other class I PDZ proteins. Co-expression of SEMCAP-1(GIPC) induces the redistribution of dispersed M-SemF into detergent-resistant aggregates in HEK293 cells. Thus, SEMCAP-1(GIPC) appears to regulate the subcellular distribution of M-SemF in brain, and SEMCAPs could link M-SemF to G protein signal transduction pathways.

  16. Automatic 3D reconstruction of quasi-planar stereo Scanning Electron Microscopy (SEM) images.

    PubMed

    Roy, S; Meunier, J; Marian, A M; Vidal, F; Brunette, I; Costantino, S

    2012-01-01

    Scanning Electron Microscopy (SEM) is widely used in science to characterize the surface roughness of materials. Three-dimensional information can be obtained with SEM based on stereovision techniques. A stereo pair is typically obtained by tilting the sample by a few degrees. In this paper we present a fully automated method for 3D reconstruction from a SEM stereo pair without any particular constraint. Results are presented for corneal stromal surfaces.

  17. Using digital colour to increase the realistic appearance of SEM micrographs of bloodstains.

    PubMed

    Hortolà, Policarp

    2010-10-01

    Although in the scientific-research literature the micrographs from scanning electron microscopes (SEMs) are usually displayed in greyscale, the potential of colour resources provided by the SEM-coupled image-acquiring systems and, subsidiarily, by image-manipulation free softwares deserves be explored as a tool for colouring SEM micrographs of bloodstains. After acquiring greyscale SEM micrographs of a (dark red to the naked eye) human blood smear on grey chert, they were manually obtained in red tone using both the SEM-coupled image-acquiring system and an image-manipulation free software, as well as they were automatically generated in thermal tone using the SEM-coupled system. Red images obtained by the SEM-coupled system demonstrated lower visual-discrimination capability than the other coloured images, whereas those in red generated by the free software rendered better magnitude of scopic information than the red images generated by the SEM-coupled system. Thermal-tone images, although were further from the real sample colour than the red ones, not only increased their realistic appearance over the greyscale images, but also yielded the best visual-discrimination capability among all the coloured SEM micrographs, and fairly enhanced the relief effect of the SEM micrographs over both the greyscale and the red images. The application of digital colour by means of the facilities provided by an SEM-coupled image-acquiring system or, when required, by an image-manipulation free software provides a user-friendly, quick and inexpensive way of obtaining coloured SEM micrographs of bloodstains, avoiding to do sophisticated, time-consuming colouring procedures. Although this work was focused on bloodstains, well probably other monochromatic or quasi-monochromatic samples are also susceptible of increasing their realistic appearance by colouring them using the simple methods utilized in this study.

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

    PubMed

    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.

  19. CEC-CED Joint Knowledge and Skills statement for all becoming teachers of students who are deaf or hard of hearing. Joint Standards Committee of the National Council on Education of the Deaf and the Council for Exceptional Children.

    PubMed

    1996-07-01

    In 1992, the National Council on Education of the Deaf (CED) and the Council for Exceptional Children (CEC) began a collaborative process in which new standards were jointly developed and approved by a representation of members from all organizations engaged in the preparation of teachers and in the delivery of services to deaf and hard of hearing learners, including educational, professional/administrative and consumer organizations. A Joint Standards Committee was appointed, and in 1992 enunciated mutually acceptable standards for the preparation of teachers of students who are deaf and hard of hearing. Fundamental to the entire standards development process was respect for the continuum of educational options available for children who are deaf and hard of hearing. The intent of this committee was to provide standards which were credible for all university and college teacher preparation programs and which could serve as a foundation for the development and maintenance of strong and viable programs according to the specific stated philosophy and practice of each. Information regarding the new standards and University/College Program Evaluation can be obtained from: Dr. Harold Johnson, Program Evaluation Chair, Kent State University, Room 405 White Hall, Kent, Ohio 44242.

  20. 78 FR 48890 - Information Collection Activities: Safety and Environmental Management Systems (SEMS); Proposed...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-12

    ... INFORMATION: Title: 30 CFR 250, subpart S, Safety and Environmental Management Systems (SEMS). Forms: BSEE... Management Systems (SEMS); Proposed Collection; Comment Request ACTION: 60-day Notice. SUMMARY: To comply...) is inviting comments on a collection of information that we will resubmit to the Office of...

  1. 30 CFR 250.1924 - How will BOEMRE determine if my SEMS program is effective?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... third parties, your designated and qualified personnel, and audit reports, to assess your SEMS program... personnel; (3) The SEMS audits conducted of your program; (4) Documents or information relevant to whether you have addressed and corrected the deficiencies of your audit; and (5) Other relevant documents or...

  2. Scanning Electron Microscopy (SEM) Procedure for HE Powders on a LEO 438VP System

    SciTech Connect

    Zaka, Fowzia

    2016-03-08

    This method describes the characterization of HE powders by Scanning Electron Microscopy (SEM). HE particles are dispersed onto an aluminum standard SEM specimen mount. Electron micrographs are collected at various magnifications (150 to 10,000 X) depending on HE particle size.

  3. Scanning Electron Microscopy (SEM) Procedure for HE Powders on a LEO 438VP System

    SciTech Connect

    Zaka, Fowzia

    2016-03-21

    This method describes the characterization of HE powders by Scanning Electron Microscopy (SEM). HE particles are dispersed onto an aluminum standard SEM specimen mount. Electron micrographs are collected at various magnifications (150 to 10,000 X) depending on HE particle size.

  4. Some Esoteric Aspects of SEM that Its Practitioners Should Want to Know

    ERIC Educational Resources Information Center

    Rozeboom, William W.

    2009-01-01

    The topic of this article is the interpretation of structural equation modeling (SEM) solutions. Its purpose is to augment structural modeling's metatheoretic resources while enhancing awareness of how problematic is the causal significance of SEM-parameter solutions. Part I focuses on the nonuniqueness and consequent dubious interpretability of…

  5. 30 CFR 250.1927 - What happens if BOEMRE finds shortcomings in my SEMS program?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 2 2011-07-01 2011-07-01 false What happens if BOEMRE finds shortcomings in my SEMS program? 250.1927 Section 250.1927 Mineral Resources BUREAU OF OCEAN ENERGY MANAGEMENT, REGULATION... CONTINENTAL SHELF Safety and Environmental Management Systems (SEMS) § 250.1927 What happens if BOEMRE...

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

    ERIC Educational Resources Information Center

    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…

  7. 30 CFR 250.1927 - What happens if BSEE finds shortcomings in my SEMS program?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... SHELF Safety and Environmental Management Systems (SEMS) § 250.1927 What happens if BSEE finds... 30 Mineral Resources 2 2012-07-01 2012-07-01 false What happens if BSEE finds shortcomings in my SEMS program? 250.1927 Section 250.1927 Mineral Resources BUREAU OF SAFETY AND ENVIRONMENTAL...

  8. 30 CFR 250.1927 - What happens if BSEE finds shortcomings in my SEMS program?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... SHELF Safety and Environmental Management Systems (SEMS) § 250.1927 What happens if BSEE finds... 30 Mineral Resources 2 2013-07-01 2013-07-01 false What happens if BSEE finds shortcomings in my SEMS program? 250.1927 Section 250.1927 Mineral Resources BUREAU OF SAFETY AND ENVIRONMENTAL...

  9. 30 CFR 250.1927 - What happens if BSEE finds shortcomings in my SEMS program?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... SHELF Safety and Environmental Management Systems (SEMS) § 250.1927 What happens if BSEE finds... 30 Mineral Resources 2 2014-07-01 2014-07-01 false What happens if BSEE finds shortcomings in my SEMS program? 250.1927 Section 250.1927 Mineral Resources BUREAU OF SAFETY AND ENVIRONMENTAL...

  10. 30 CFR 250.1911 - What criteria for hazards analyses must my SEMS program meet?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... CONTINENTAL SHELF Safety and Environmental Management Systems (SEMS) § 250.1911 What criteria for hazards... 30 Mineral Resources 2 2011-07-01 2011-07-01 false What criteria for hazards analyses must my SEMS program meet? 250.1911 Section 250.1911 Mineral Resources BUREAU OF OCEAN ENERGY MANAGEMENT, REGULATION...

  11. 30 CFR 250.1902 - What must I include in my SEMS program?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... and Environmental Management Systems (SEMS) § 250.1902 What must I include in my SEMS program? You... Environmental Management Program Elements) (see §§ 250.1920) (13) Recordkeeping (Records and Documentation) and....1902 Section 250.1902 Mineral Resources BUREAU OF OCEAN ENERGY MANAGEMENT, REGULATION, AND ENFORCEMENT...

  12. 30 CFR 250.1920 - What are the auditing requirements for my SEMS program?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... and Environmental Management Systems (SEMS) § 250.1920 What are the auditing requirements for my SEMS... program? 250.1920 Section 250.1920 Mineral Resources BUREAU OF SAFETY AND ENVIRONMENTAL ENFORCEMENT... RP 75 to identify areas in which safety and environmental performance needs to be improved. (b) Your...

  13. 30 CFR 250.1915 - What training criteria must be in my SEMS program?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... and Environmental Management Systems (SEMS) § 250.1915 What training criteria must be in my SEMS... program? 250.1915 Section 250.1915 Mineral Resources BUREAU OF SAFETY AND ENVIRONMENTAL ENFORCEMENT... environmental impacts. Training must address such areas as operating procedures (§ 250.1913), safe work...

  14. 30 CFR 250.1915 - What training criteria must be in my SEMS program?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... and Environmental Management Systems (SEMS) § 250.1915 What training criteria must be in my SEMS... program? 250.1915 Section 250.1915 Mineral Resources BUREAU OF SAFETY AND ENVIRONMENTAL ENFORCEMENT... environmental impacts. Training must address such areas as operating procedures (§ 250.1913), safe work...

  15. 30 CFR 250.1930 - What must be included in my SEMS program for SWA?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... and Environmental Management Systems (SEMS) § 250.1930 What must be included in my SEMS program for... SWA? 250.1930 Section 250.1930 Mineral Resources BUREAU OF SAFETY AND ENVIRONMENTAL ENFORCEMENT... environmental harm to: (i) Land; (ii) Air; or (iii) Mineral deposits, marine, coastal, or human environment. (b...

  16. 30 CFR 250.1930 - What must be included in my SEMS program for SWA?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... and Environmental Management Systems (SEMS) § 250.1930 What must be included in my SEMS program for... SWA? 250.1930 Section 250.1930 Mineral Resources BUREAU OF SAFETY AND ENVIRONMENTAL ENFORCEMENT... environmental harm to: (i) Land; (ii) Air; or (iii) Mineral deposits, marine, coastal, or human environment. (b...

  17. 30 CFR 250.1909 - What are management's general responsibilities for the SEMS program?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... OUTER CONTINENTAL SHELF Safety and Environmental Management Systems (SEMS) § 250.1909 What are... 30 Mineral Resources 2 2011-07-01 2011-07-01 false What are management's general responsibilities for the SEMS program? 250.1909 Section 250.1909 Mineral Resources BUREAU OF OCEAN ENERGY MANAGEMENT...

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

    ERIC Educational Resources Information Center

    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…

  19. Some Esoteric Aspects of SEM that Its Practitioners Should Want to Know

    ERIC Educational Resources Information Center

    Rozeboom, William W.

    2009-01-01

    The topic of this article is the interpretation of structural equation modeling (SEM) solutions. Its purpose is to augment structural modeling's metatheoretic resources while enhancing awareness of how problematic is the causal significance of SEM-parameter solutions. Part I focuses on the nonuniqueness and consequent dubious interpretability of…

  20. 30 CFR 250.1915 - What criteria for training must be in my SEMS program?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... and Environmental Management Systems (SEMS) § 250.1915 What criteria for training must be in my SEMS... maintain the facility possess the required knowledge and skills to carry out their duties and... required knowledge and skills. (c) Communication requirements to ensure that whenever a change is made...

  1. SEM and FIB-SEM investigations on potential gas shales in the Dniepr-Donets Basin (Ukraine): pore space evolution in organic matter during thermal maturation

    NASA Astrophysics Data System (ADS)

    Misch, D.; Mendez-Martin, F.; Hawranek, G.; Onuk, P.; Gross, D.; Sachsenhofer, R. F.

    2016-02-01

    Porosity and permeability are essential parameters for reservoir rocks. Techniques developed for conventional reservoir rocks characterized by large pores, cannot be applied to study gas shales. Therefore, high resolution techniques are increasingly used to determine reservoir quality of shale gas plays. Within the frame of the recent study, Upper Visean black shales (“Rudov Beds”) from the Dniepr-Donets-Basin (DDB, Ukraine) were characterized by X-ray diffraction, conventional SEM imaging and FIB/BIB-SEM. According to SEM and FIB/BIB-SEM data, nanopores are not abundant in primary macerals (e.g., vitrinite) even in overmature rocks, whereas they develop within secondary organic matter (bitumen) formed mainly at gas window maturity. Frequently occurring sub-micrometre porosity, probably related to gas generation from bituminous organic matter, was detected within mudstones at a vitrinite reflectance > 2.0 % Rr. However, such pores have also been detected occasionally in solid bitumen at oil window maturity (0.9 % Rr). Authigenic nanoscale clay minerals and calcite occur within pyrobitumen at gas window maturity. Furthermore, Rudov Beds can be subdivided into mineralogical facies zones by SEM imaging and X-ray diffraction. A basin-centred, brittle siliceous facies is most likely caused by increased contribution from deeper water radiolaria and is separated from a marginal clayey and carbonate-rich facies.

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

    USGS Publications Warehouse

    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.

  3. metaSEM: an R package for meta-analysis using structural equation modeling.

    PubMed

    Cheung, Mike W-L

    2014-01-01

    The metaSEM package provides functions to conduct univariate, multivariate, and three-level meta-analyses using a structural equation modeling (SEM) approach via the OpenMx package in the R statistical platform. It also implements the two-stage SEM approach to conducting fixed- and random-effects meta-analytic SEM on correlation or covariance matrices. This paper briefly outlines the theories and their implementations. It provides a summary on how meta-analyses can be formulated as structural equation models. The paper closes with a conclusion on several relevant topics to this SEM-based meta-analysis. Several examples are used to illustrate the procedures in the supplementary material.

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

    PubMed

    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.

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

    PubMed

    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.

  6. Controlling retention, selectivity and magnitude of EOF by segmented monolithic columns consisting of octadecyl and naphthyl monolithic segments--applications to RP-CEC of both neutral and charged solutes.

    PubMed

    Karenga, Samuel; El Rassi, Ziad

    2011-04-01

    Monolithic capillaries made of two adjoining segments each filled with a different monolith were introduced for the control and manipulation of the electroosmotic flow (EOF), retention and selectivity in reversed phase-capillary electrochromatography (RP-CEC). These columns were called segmented monolithic columns (SMCs) where one segment was filled with a naphthyl methacrylate monolith (NMM) to provide hydrophobic and π-interactions, while the other segment was filled with an octadecyl acrylate monolith (ODM) to provide solely hydrophobic interaction. The ODM segment not only provided hydrophobic interactions but also functioned as the EOF accelerator segment. The average EOF of the SMC increased linearly with increasing the fractional length of the ODM segment. The neutral SMC provided a convenient way for tuning EOF, selectivity and retention in the absence of annoying electrostatic interactions and irreversible solute adsorption. The SMCs allowed the separation of a wide range of neutral solutes including polycyclic aromatic hydrocarbons (PAHs) that are difficult to separate using conventional alkyl-bonded stationary phases. In all cases, the k' of a given solute was a linear function of the fractional length of the ODM or NMM segment in the SMCs, thus facilitating the tailoring of a given SMC to solve a given separation problem. At some ODM fractional length, the fabricated SMC allowed the separation of charged solutes such as peptides and proteins that could not otherwise be achieved on a monolithic column made from NMM as an isotropic stationary phase due to the lower EOF exhibited by this monolith. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

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

    PubMed

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

    2017-09-18

    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.

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

    PubMed

    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.

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

    PubMed

    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.

  10. The intrinsically disordered Sem1 protein functions as a molecular tether during proteasome lid biogenesis.

    PubMed

    Tomko, Robert J; Hochstrasser, Mark

    2014-02-06

    The intrinsically disordered yeast protein Sem1 (DSS1 in mammals) participates in multiple protein complexes, including the proteasome, but its role(s) within these complexes is uncertain. We report that Sem1 enforces the ordered incorporation of subunits Rpn3 and Rpn7 into the assembling proteasome lid. Sem1 uses conserved acidic segments separated by a flexible linker to grasp Rpn3 and Rpn7. The same segments are used for protein binding in other complexes, but in the proteasome lid they are uniquely deployed for recognizing separate polypeptides. We engineered TEV protease-cleavage sites into Sem1 to show that the tethering function of Sem1 is important for the biogenesis and integrity of the Rpn3-Sem1-Rpn7 ternary complex but becomes dispensable once the ternary complex incorporates into larger lid precursors. Thus, although Sem1 is a stoichiometric component of the mature proteasome, it has a distinct, chaperone-like function specific to early stages of proteasome assembly. Copyright © 2014 Elsevier Inc. All rights reserved.

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

    PubMed

    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.

  12. Assessing the utility of FIB-SEM images for shale digital rock physics

    NASA Astrophysics Data System (ADS)

    Kelly, Shaina; El-Sobky, Hesham; Torres-Verdín, Carlos; Balhoff, Matthew T.

    2016-09-01

    Shales and other unconventional or low permeability (tight) reservoirs house vast quantities of hydrocarbons, often demonstrate considerable water uptake, and are potential repositories for fluid sequestration. The pore-scale topology and fluid transport mechanisms within these nanoporous sedimentary rocks remain to be fully understood. Image-informed pore-scale models are useful tools for studying porous media: a debated question in shale pore-scale petrophysics is whether there is a representative elementary volume (REV) for shale models? Furthermore, if an REV exists, how does it differ among petrophysical properties? We obtain three dimensional (3D) models of the topology of microscale shale volumes from image analysis of focused ion beam-scanning electron microscope (FIB-SEM) image stacks and investigate the utility of these models as a potential REV for shale. The scope of data used in this work includes multiple local groups of neighboring FIB-SEM images of different microscale sizes, corresponding core-scale (milli- and centimeters) laboratory data, and, for comparison, series of two-dimensional (2D) cross sections from broad ion beam SEM images (BIB-SEM), which capture a larger microscale field of view than the FIB-SEM images; this array of data is larger than the majority of investigations with FIB-SEM-derived microscale models of shale. Properties such as porosity, organic matter content, and pore connectivity are extracted from each model. Assessments of permeability with single phase, pressure-driven flow simulations are performed in the connected pore space of the models using the lattice-Boltzmann method. Calculated petrophysical properties are compared to those of neighboring FIB-SEM images and to core-scale measurements of the sample associated with the FIB-SEM sites. Results indicate that FIB-SEM images below ∼5000 μm3 volume (the largest volume analyzed) are not a suitable REV for shale permeability and pore-scale networks; i.e. field of view

  13. Application of the SEM to the measurement of solar cell parameters

    NASA Technical Reports Server (NTRS)

    Weizer, V. G.; Andrews, C. W.

    1977-01-01

    Techniques are described which make use of the SEM to measure the minority carrier diffusion length and the metallurgical junction depth in silicon solar cells. The former technique permits the measurement of the true bulk diffusion length through the application of highly doped field layers to the back surfaces of the cells being investigated. It is shown that the secondary emission contrast observed in the SEM on a reverse-biased diode can depict the location of the metallurgical junction if the diode has been prepared with the proper beveled geometry. The SEM provides the required contrast and the option of high magnification, permitting the measurement of extremely shallow junction depths.

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

    NASA Technical Reports Server (NTRS)

    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.

  15. The gigapixel image concept for graphic SEM documentation. Applications in archeological use-wear studies.

    PubMed

    Vergès, Josep M; Morales, Juan I

    2014-10-01

    In this paper, we propose a specific procedure to create gigapixel-like images from SEM (scanning electron microscope) micrographs. This methodology allows intensive SEM observations to be made for those disciplines that require of large surfaces to be analyzed at different scales once the SEM sessions have been completed (e.g., stone tools use-wear studies). This is also a very useful resource for academic purposes or as a support for collaborative studies, thus reducing the number of live observation sessions and the associated expense. Copyright © 2014 Elsevier Ltd. All rights reserved.

  16. Three-dimensional characterization of Gd nanoparticles using STEM-in-SEM tomography in a dual-beam FIB-SEM

    NASA Astrophysics Data System (ADS)

    Van Leer, Brandon; Bouchet-Marquis, Cedric; Cheng, Huikai

    2015-10-01

    Serial sectioning using the FIB and subsequent imaging of the same FIB-exposed surface by both FIB microscopy and scanning electron microscopy (SEM) in a DualBeam has proven especially useful to study the three-dimensional (3D) morphology of complex engineered materials systems. The technique was first introduced as an automated process in 2004 and since then has established itself as one of the primary applications for FIB and DualBeams. While state-of-the-art systems can produce datasets with a z-axis slice thickness of 3-5 nm, FIB nanotomography remains a destructive technique and is limited in resolution by the z-axis slice thickness. Electron tomography is another technique used to visualize 3D structures within a transmission electron microscope used in TEM or STEM mode. Using a thin sample focused on a region of interest, the electron beam passes through the specimen incrementally tilting around the center of the region of interest as images are acquired sequentially on a camera (TEM) or a Detector (STEM). The resulting images are reconstructed into a 3D volume using a variety of algorithms including Weighted Back Projection (WBP), or Serial Iterative Reconstruction Technique (SIRT). Low energy STEM in SEM is a routine analysis in SEMs and DualBeam FIB-SEM instrumentation for morphological characterization and ultra high-resolution imaging. With a DualBeam or SEM configured with a solid state silicon diode STEM detector and a stage with adequate tilt freedom, it is possible to acquire a sufficient number of images for 3D reconstruction using STEM tomography in SEMs and DualBeam instruments. A thin section sample of gadolinium nanoparticles ranging in size up to 50 nm mounted on an aluminum substrate was prepared using in-situ lift-out (INLO) by FIB. The sample was thinned using 30 kV Ga+ FIB to approximately 125 nm. Using an in-situ stage with 360 degree continuous tilt, the thin section was imaged every 1 degree with 30 keV SEM and the STEM detector through

  17. 2015 CEC Annual Workshop on Electrochemistry

    DTIC Science & Technology

    2015-12-30

    Street Suite 5.300 Austin, TX 78712 -1532 23-Aug-2015 ABSTRACT Number of Papers published in peer-reviewed journals: Number of Papers published in non peer...List the papers, including journal references, in the following categories: (b) Papers published in non -peer-reviewed journals (N/A for none) (c...Presentations Received Paper TOTAL: Received Paper TOTAL: Number of Non Peer-Reviewed Conference Proceeding publications (other than abstracts): Peer

  18. 2016 CEC Annual Workshop on Electrochemistry

    DTIC Science & Technology

    2016-08-31

    mechanism begins when molecular precursors in solution are reduced to zerovalent species at the liquid metal/solution interface. The reduced species then...room temperature in simple solvents like water and propylene carbonate from inexpensive precursors of low toxicity. The major practical advantages of...The presentation had four main topics: (1) The effect of Pt nanoparticles on kinetics of electron transfer (ET) through Al2O3 from an underlying

  19. Views and Reviews from CEC/ERIC.

    ERIC Educational Resources Information Center

    Nazzaro, Jean N.

    1979-01-01

    The article reviews programs/research on self-control which were announced in RIE (Resources in Education) and which cover three constructs: cognitive behavior modification using verbal mediation, biofeedback and relaxation training, and modeling. (SBH)

  20. CEC Handbook for Strengthening Grassroots Advocacy.

    ERIC Educational Resources Information Center

    Bootel, Jaclyn A.

    This handbook is designed: (1) to empower individuals working with people who have disabilities to be a force for meeting the policy challenges in the communities in which they live and work; and (2) to help them to channel their strength, commitment, and knowledge of the special education field into effective advocacy efforts. The handbook…

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

    SciTech Connect

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

    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.

  2. 78 FR 50079 - Information Collection Activities: Safety and Environmental Management Systems (SEMS); Proposed...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-16

    ...: 134E1700D2 EEEE500000 ET1SF0000.DAQ000] Information Collection Activities: Safety and Environmental Management Systems (SEMS); Proposed Collection; Comment Request Correction In notice document...

  3. Nanomanufacturing concerns about measurements made in the SEM Part V: dealing with noise

    NASA Astrophysics Data System (ADS)

    Postek, Michael T.; Vladár, András. E.

    2016-09-01

    Scanning electron microscopes (SEM) are used extensively in research and advanced manufacturing for materials characterization, metrology and process control. Unfortunately, noise can limit the specimen-specific detail and the information that can be acquired in any SEM micrograph, or measurement made from those data. The majority of SEM measurements are done at low primary electron beam currents and fast imaging mode resulting in rather noisy signals - often too noisy. The amount and the type of the noise and the steps taken to deal with it are critical to the quality and amount of the information gathered. This fifth presentation, in this series of SEM dimensional metrology tutorial papers, discusses some of the various causes of measurement uncertainty in scanned particle beam instruments specifically dealing with signal-to-noise (SNR) and its contribution to measurement imprecision.

  4. SEM (Symmetry Equivalent Molecules): a web-based GUI to generate and visualize the macromolecules

    PubMed Central

    Hussain, A. S. Z.; Kumar, Ch. Kiran; Rajesh, C. K.; Sheik, S. S.; Sekar, K.

    2003-01-01

    SEM, Symmetry Equivalent Molecules, is a web-based graphical user interface to generate and visualize the symmetry equivalent molecules (proteins and nucleic acids). In addition, the program allows the users to save the three-dimensional atomic coordinates of the symmetry equivalent molecules in the local machine. The widely recognized graphics program RasMol has been deployed to visualize the reference (input atomic coordinates) and the symmetry equivalent molecules. This program is written using CGI/Perl scripts and has been interfaced with all the three-dimensional structures (solved using X-ray crystallography) available in the Protein Data Bank. The program, SEM, can be accessed over the World Wide Web interface at http://dicsoft2.physics.iisc.ernet.in/sem/ or http://144.16.71.11/sem/. PMID:12824326

  5. Connected component analysis of review-SEM images for sub-10nm node process verification

    NASA Astrophysics Data System (ADS)

    Halder, Sandip; Leray, Philippe; Sah, Kaushik; Cross, Andrew; Parisi, Paolo

    2017-03-01

    Analysis of hotspots is becoming more and more critical as we scale from node to node. To define true process windows at sub-14 nm technology nodes, often defect inspections are being included to weed out design weak spots (often referred to as hotspots). Defect inspection sub 28 nm nodes is a two pass process. Defect locations identified by optical inspection tools need to be reviewed by review-SEM's to understand exactly which feature is failing in the region flagged by the optical tool. The images grabbed by the review-SEM tool are used for classification but rarely for quantification. The goal of this paper is to see if the thousands of review-SEM images which are existing can be used for quantification and further analysis. More specifically we address the SEM quantification problem with connected component analysis.

  6. Transport characteristics of a single multiwall carbon nanotube by bending in SEM and STM

    NASA Astrophysics Data System (ADS)

    Kim, Suenne; Kim, Jeehoon; Berg, Morgann; de Lozanne, Alex

    2007-03-01

    Multiwall carbon nanotubes(MWCNTs) were grown on a W wire by chemical vapor deposition(CVD). Two homebuilt xyz-walkers were employed to manipulate individual CNTs in our scanning electron microscope (SEM). To improve the electrical and mechanical contact to a second electrode, we welded the CNT by delivering gas to the welding point while focusing the SEM beam on the same spot. The bending dependent I-V characteristics were observed in situ in the SEM at room temperature. We will measure the transport properties by bending the same MWCNT (already measured in SEM) inside our ultrahigh vacuum low temperature scanning tunneling microscope (UHV-LTSTM). We will also compare the bending properties of MWCNTs at different temperatures.

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

    NASA Astrophysics Data System (ADS)

    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).

  8. Intrinsic TLI surface tag directly authenticated by a SEM (closeout report)

    SciTech Connect

    Zaluzec, N.J.; Philippedes, A.; Palm, R.G.; De Volpi, A.; Holland, J.W.

    1991-11-01

    The objective of this task was to develop a unique identifier (tag) for Treaty-Limited Items (TLIs) in arms control applications. This tag is authenticated by the direct attachment of a portable Scanning Electron Microscope (SEM) to the TLI. It is an intrinsic tag with two distinct TLI surface-authentication signatures, consisting of topography and atomic composition. Authentication is accomplished by comparing the field-inspection signature with the baseline signature. Because this tag has two unique signatures, it is considered extremely resistant to counterfeit attempts. Since commercial SEMs are large instruments intended to observe small samples introduced into a vacuum chamber integral to the instrument, it was initially necessary to demonstrate that interfacing an SEM to a large TLI was feasible. The first phase demonstrated that an SEM could obtain high- resolution images of a large, curved, simulated TLI surface. A used commercial SEM was modified to accomplish the first phase. The second phase began with a systematic evaluation of the design alternatives necessary to produce a portable SEM suitable for TLI tag authentication. Since the electron column design of the SEM was the central component that drove the selection of the rest of the system, this phase continued with a preliminary design of the column. A novel design of the column`s electromagnetic lenses combined both permanent magnets and magnetic coils, significantly reducing the required lens power and weight. Prototype condenser and objective lenses were built and tested to prove that this approach was viable. Based upon the results of the second phase, a 0.1-micrometer (4-micro-inch) resolution SEM is feasible. The total system would weigh 52-Kg including a 7-Kg electron column.

  9. Intrinsic TLI surface tag directly authenticated by a SEM (closeout report). [Treaty Limited Item (TLI)

    SciTech Connect

    Zaluzec, N.J.; Philippedes, A.; Palm, R.G.; De Volpi, A.; Holland, J.W.

    1991-11-01

    The objective of this task was to develop a unique identifier (tag) for Treaty-Limited Items (TLIs) in arms control applications. This tag is authenticated by the direct attachment of a portable Scanning Electron Microscope (SEM) to the TLI. It is an intrinsic tag with two distinct TLI surface-authentication signatures, consisting of topography and atomic composition. Authentication is accomplished by comparing the field-inspection signature with the baseline signature. Because this tag has two unique signatures, it is considered extremely resistant to counterfeit attempts. Since commercial SEMs are large instruments intended to observe small samples introduced into a vacuum chamber integral to the instrument, it was initially necessary to demonstrate that interfacing an SEM to a large TLI was feasible. The first phase demonstrated that an SEM could obtain high- resolution images of a large, curved, simulated TLI surface. A used commercial SEM was modified to accomplish the first phase. The second phase began with a systematic evaluation of the design alternatives necessary to produce a portable SEM suitable for TLI tag authentication. Since the electron column design of the SEM was the central component that drove the selection of the rest of the system, this phase continued with a preliminary design of the column. A novel design of the column's electromagnetic lenses combined both permanent magnets and magnetic coils, significantly reducing the required lens power and weight. Prototype condenser and objective lenses were built and tested to prove that this approach was viable. Based upon the results of the second phase, a 0.1-micrometer (4-micro-inch) resolution SEM is feasible. The total system would weigh 52-Kg including a 7-Kg electron column.

  10. Development of a web-based SEM specifically for K-12 education.

    PubMed

    Chumbley, L S; Cassucio, G; Kritikos, D; Lentz, H; Mannes, C; Mehta, K

    2002-03-15

    The scanning electron microscope (SEM) is uniquely suited for use in education due to its ability to produce clear three-dimensional-looking images of virtually any sample. Elementary and secondary science textbooks regularly contain SEM images of bugs, plants, human tissue, rocks, etc. as a means of illustrating the microscopic world to students. However, despite the widespread use of SEM images for educational purposes microscope companies have virtually ignored the area of education in their development and design of SEMs, due presumably to a perceived lack of marketing potential in this area. This article presents the results of a program aimed at developing a Web-based SEM that is specifically designed for educational use by students and teachers in pre-college classrooms. While virtually all companies tout some form of remote control, no concerted effort has been made to fully develop these capabilities for use by the education sector. The microscope under development, termed the WebSEM, seeks to remedy this situation and address this neglected market. Remote control of the WebSEM is possible by means of a simple web interface that allows the users a wide range of controls, depending on the skill of the operator at the remote site. The web interface is specifically designed to be simple and reliable such that little or no training is required for use. This joint effort between educators and a microscope manufacturer is the first attempt at the development of a truly education-oriented SEM suitable for use in the classroom.

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

    PubMed

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

    PubMed

    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.

  13. Steel Hardness Effects in Boundary Lubricated Sliding: An In-Situ SEM (Scanning Electron Microscope) Study

    DTIC Science & Technology

    1988-01-01

    in a scanning electron microscope (SEM). Through modifications to theSEM, these experiments could be run with a thin film of hydrocarbon oil applied to...as the number of sliding passes increases, plus agglomeration of wear debris interspersed with oil around the contact. Both of these effects lead to...24). [lhcse iments could be run with a thin film of hyvdrocarbon oil applied to were all basically unlubricated experiments that insol.t.d the sliding

  14. Generating connections and learning with SemNet, a tool for constructing knowledge networks

    NASA Astrophysics Data System (ADS)

    Gorodetsky, Malka; Fisher, Kathleen M.; Wyman, Barbara

    1994-09-01

    In this paper we examine the impact of using a Macintosh-based knowledge organization toll SemNet, with prospective elementary and middle school teachers enrolled in an upper division biology course. The course models for students the ways in which they will be able to teach hands-on, minds-on science in K-8 classrooms and provides them with an in-depth understanding of a relatively small number of biology topics. This study examines changes in learning habits, metacognitive processes, retention, retrieval, and learring among students enrolled in this course. Students using SemNet tend to exhibit a significant increase in deep processing as measured by self-report. Also on the basis of self-report, SemNet students appear to acquire some cognitive skills that transfer to other courses, such as identifying main ideas and tying ideas together. SemNet students retained and retrieved nearly twice as much information about a topic, the digestive system, as a reference group. Although neither the SemNet nor the reference group exhibited transfer skills as we meansured them, there is evidence that SemNet student changed their thinking strategies.

  15. A New Approach To 3-D Surface Texture Assessment On The Scanning Electron Microscope (Sem)

    NASA Astrophysics Data System (ADS)

    Rashed, A. F.; El-Sherbiny, M. G.; Falemban, H. M.

    1988-06-01

    The scanning electron microscope (SEM) JSM-T300 was modified to give an outiput signal of the average line signal display of any surface to a resolution of about 10A, which is in reality an average three-dimensional representation of the surface topography. The output signal was recorded and analyzed by an FFT narrow band spectrum analyzer coupled to HP disktop computer, for which a computer program based on a frequency spectrum analysis was developed for surface texture assessment , the computation of its different parameters; Ra, Rq, Rz,etc..... Two standard test specimens were used to calibrate the SEM measurements at any speci-fic operating conditions. Machined brass test specimens were made to give a wide range of surface finish of Ra range of 1.5 to 59 μm, and then used to correlate the SEM results with those obtained by the conventional stylus-tracing equipment such as Surtronic-3, and Talysurf-5 of RTH. The correlation was accomplished between the different parameters of the surface texture stylus-traced profiles "across + along" the lay of the tested surfaces and the corresponding parameters of the profile of the average line signal display of SEM. The results obtained were found to be in very good correlation and the small diffe-rences found are attributed to the influence of the micrometerology of the high resolution SEM. The technique adopted for SEM micrometerology could be classified as an automated procedure for the three-dimensional assessment of surface texture.

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

    PubMed

    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.

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

    PubMed

    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.

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

    PubMed

    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.

  19. SEM Leadership

    ERIC Educational Resources Information Center

    Pollock, Kevin

    2012-01-01

    Expectations of higher education leaders are high, varied, and numerous. Leaders are expected not only to be visionary, decisive, and articulate, but also to share information, purposes, commitments, and struggles. Effective leaders must know and understand their faculty and staff; insist on realism; set clear goals and priorities; follow through;…

  20. SEM Leadership

    ERIC Educational Resources Information Center

    Pollock, Kevin

    2012-01-01

    Expectations of higher education leaders are high, varied, and numerous. Leaders are expected not only to be visionary, decisive, and articulate, but also to share information, purposes, commitments, and struggles. Effective leaders must know and understand their faculty and staff; insist on realism; set clear goals and priorities; follow through;…

  1. The study of high-sensitivity metrology method by using CD-SEM

    NASA Astrophysics Data System (ADS)

    Ueda, K.; Koshihara, S.; Mizuno, T.; Miura, A.

    2011-03-01

    The earliest semiconductor device manufacturing employed optical microscopes for measurement and control of the manufacturing process. The introduction of the Critical Dimension Scanning Electron Microscope (CD-SEM) in 1984 provided a tremendous increase in capability for process monitoring and has been the standard for in-line metrology for over 25 years. The advantages of the CD-SEM are highly accurate and stable measurement reproducibility at very specific locations throughout the device. The evolution of the CD-SEM in Metrology has included improved resolution, development of advanced measurement and pattern recognition algorithms, all required by performance improvement demands from the market. Current conventional metrology using the in-line CD-SEM involves measuring about ten points per wafer (one point per one chip). at a magnification of over x150k(Field of View is about 1μm2). In contrast, the area of measurement pattern on chip is much larger than the area of CD-SEM measurement (mm2 : (on chip) versus μm2 : (CD-SEM measurement)). This would mean that the result of the CD-SEM measurement is influenced by local pattern variation. The very stringent requirements placed on in-line Metrology for the last couple of technology nodes has produced an additional metrology methodology, beyond the CD-SEM, that involves large area measurements with very high precision for the most critical levels. We will refer to this methodology as "Macro Area Measurements". We investigated the applicability of using a CD-SEM Macro Area Measurement methodology in this paper. The areas investigated focused on the following points: 1) Determining the optimum CD-SEM sampling plan for a macro area measurement. 2) Optimization of the measurement parameters. 3) Optimization of the measurement condition. 4) Verification of Macro Area Measurement with an FEM (Focus Exposure Matrix) wafer. In the results, we are able to validate a new methodology that we called "Macro Area Measurement

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

    PubMed

    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. The EUV spectrum of the Sun: SOHO, SEM, and CDS irradiances

    NASA Astrophysics Data System (ADS)

    Del Zanna, G.; Wieman, S. R.; Andretta, V.; Didkovsky, L.

    2015-09-01

    We use calibrated extreme-UV (EUV) spectral irradiances obtained from observations with the Solar & Heliospheric Observatory (SOHO) Coronal Diagnostics Spectrometer Normal Incidence Spectrometer (NIS) to estimate the signal measured by the Solar EUV Monitor (SEM) first-order band, 260 to 340 Å (SEM 1). The NIS observes the resonance lines He ii 304 Å and Si xi 303 Å directly in second order. The irradiances of the other lines in the band are estimated with a differential emission measure (DEM) modelling, using updated atomic data. The observations analysed here were obtained during 1998-2011, which means that they span the maximum and minimum of Cycle 23. The current knowledge of the SEM 1 degradation is used to find effective areas during the dates of the NIS observations and to predict the SEM 1 count rates across the band. The total count rates, estimated by folding the NIS-based spectra with the SEM 1 effective areas, agree very well (within 10-20%) with the observed ones during solar minimum conditions, when the He ii 304 Å is the dominant contribution to the band. Excellent agreement with the Solar Dynamics Observatory (SDO) Extreme ultraviolet Variability Experiment (EVE) observations is also found. On the other hand, the predicted SEM 1 count rates during the Cycle-23 maximum are significantly (by about 30%) lower than the observed ones. The solar spectrum in the SEM 1 band changes significantly during maximum conditions, with the He ii 304 Å only contributing about 40%. A significant fraction of the observed count rates comes from coronal emission in an off-band spectral region that has recently been discovered. An explanation for the discrepancy needs further investigation.

  4. BIB-SEM of representative area clay structures paving towards an alternative model of porosity

    NASA Astrophysics Data System (ADS)

    Desbois, G.; Urai, J. L.; Houben, M.; Hemes, S.; Klaver, J.

    2012-04-01

    A major contribution to understanding the sealing capacity, coupled flow, capillary processes and associated deformation in clay-rich geomaterials is based on detailed investigation of the rock microstructures. However, the direct characterization of pores in representative elementary area (REA) and below µm-scale resolution remains challenging. To investigate directly the mm- to nm-scale porosity, SEM is certainly the most direct approach, but it is limited by the poor quality of the investigated surfaces. The recent development of ion milling tools (BIB and FIB; Desbois et al, 2009, 2011; Heath et al., 2011; Keller et al., 2011) and cryo-SEM allows respectively producing exceptional high quality polished cross-sections suitable for high resolution porosity SEM-imaging at nm-scale and investigating samples under wet conditions by cryogenic stabilization. This contribution focuses mainly on the SEM description of pore microstructures in 2D BIB-polished cross-sections of Boom (Mol site, Belgium) and Opalinus (Mont Terri, Switzerland) clays down to the SEM resolution. Pores detected in images are statistically analyzed to perform porosity quantification in REA. On the one hand, BIB-SEM results allow retrieving MIP measurements obtained from larger sample volumes. On the other hand, the BIB-SEM approach allows characterizing porosity-homogeneous and -predictable islands, which form the elementary components of an alternative concept of porosity/permeability model based on pore microstructures. Desbois G., Urai J.L. and Kukla P.A. (2009) Morphology of the pore space in claystones - evidence from BIB/FIB ion beam sectioning and cryo-SEM observations. E-Earth, 4, 15-22. Desbois G., Urai J.L., Kukla P.A., Konstanty J. and Baerle C. (2011). High-resolution 3D fabric and porosity model in a tight gas sandstone reservoir: a new approach to investigate microstructures from mm- to nm-scale combining argon beam cross-sectioning and SEM imaging . Journal of Petroleum Science

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

    PubMed

    Lucchese, A; Storti, E

    2011-09-01

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

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

    PubMed

    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.

  7. Surgery on spinal epidural metastases (SEM) in renal cell carcinoma: a plea for a new paradigm.

    PubMed

    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.

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

    PubMed

    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.

  9. Detailed methodology for high resolution scanning electron microscopy (SEM) of murine malaria parasitized-erythrocytes.

    PubMed

    Hayakawa, Eri H; Matsuoka, Hiroyuki

    2016-10-01

    Scanning electron microscopy (SEM) is a powerful tool used to investigate object surfaces and has been widely applied in both material science and biology. With respect to the study of malaria, SEM revealed that erythrocytes infected with Plasmodium falciparum, a human parasite, display 'knob-like' structures on their surface comprising parasitized proteins. However, detailed methodology for SEM studies of malaria parasites is lacking in the literature making such studies challenging. Here, we provide a step-by-step guide to preparing Plasmodium-infected erythrocytes from two mouse strains for SEM analysis with minimal structural deterioration. We tested three species of murine malaria parasites, P. berghei, P. yoelii, and P. chabaudi, as well as non-parasitized human erythrocytes and P. falciparum-infected erythrocytes for comparisons. Our data demonstrated that the surface structures of parasitized erythrocytes between the three species of murine parasites in the two different strains of mice were indistinguishable and no surface alterations were observed in P. falciparum-erythrocytes. Our SEM observations contribute towards an understanding of the molecular mechanisms of parasite maturation in the erythrocyte cytoplasm and, along with future studies using our detailed methodology, may help to gain insight into the clinical phenomena of human malaria. Copyright © 2016 The Authors. Published by Elsevier Ireland Ltd.. All rights reserved.

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

    PubMed

    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.

  11. FE-SEM observation of swelled seaweed using hydrophilic ionic liquid; 1-butyl-3-methylimidazolium tetrafluoroborate.

    PubMed

    Takahashi, Chisato; Shirai, Takashi; Fuji, Masayoshi

    2013-01-01

    The method to observe the exact morphology of swelled seaweed as an example of biological material by field emission scanning electron microscopy (FE-SEM) with the aid of hydrophilic ionic liquid (IL); 1-butyl-3-methylimidazolium tetrafluoroborate is reported. Seaweed was first swelled in 3.5% NaCl solution and then treated with the IL and water mixture in 1:7 weight ratios and centrifuged to remove the excess IL solution. Thus treated seaweed maintained its morphology even at high magnification and did not show drying in the FE-SEM chamber. This observation technique might be useful for various kinds of biological materials to be observed under FE-SEM.

  12. Application of Replica Technique and SEM in Accuracy Measurement of Ceramic Crowns

    NASA Astrophysics Data System (ADS)

    Trifkovic, B.; Budak, I.; Todorovic, A.; Hodolic, J.; Puskar, T.; Jevremovic, D.; Vukelic, D.

    2012-01-01

    The paper presents a comparative study of the measuring values of the marginal gap related to the ceramic crowns made by dental CAD/CAM system using the replica technique and SEM. The study was conducted using three experimental groups, which consisted of ceramic crowns manufactured by the Cerec CAD/CAM system. The scanning procedure was carried out using three specialized dental 3D digitization systems from the Cerec family - two types of extraoral optical scanning systems and an intraoral optical scanner. Measurements of the marginal gap were carried out using the replica technique and SEM. The comparison of aggregate values of the marginal gap using the replica technique showed a statistically significant difference between the systems. The measured values of marginal gaps of ceramic crowns using the replica technique were significantly lower compared to those measured by SEM. The results indicate that the choice of technique for measuring the accuracy of ceramic crowns influences the final results of investigation.

  13. Documentation of environmental particulate exposures in humans using SEM and EDXA.

    PubMed

    Abraham, J L

    1979-01-01

    There is increasing awareness of health hazards from environmental and occupational exposures to particulates. Scanning electron microscopy (SEM) and energy dispersive x-ray analysis (EDXA) can document these exposures by analysis of small portions of cells, tissues and environmental samples. Previous work is briefly reviewed and special attention is given to discussion, with examples, of the various types of particulates which may be found in tissues (exogenous, endogenous, inhaled, injected, ingested, inorganic, organic), the different tissues in which they may be found (lung, heart, liver, skin, brain, kidney, lymph nodes, etc.), methods of tissue sampling (e.g. pulmonary lavage, transbronchial biopsy, open biopsy, percutaneous biopsy, autopsy), specimen preparation (fixation, embedding, sectioning, choice of substrate), SEM and EDXA data collection (backscattered electron imaging, etc.) data interpretation (artefacts, limitations of SEM and EDXA) and other new techniques (ion microprobe, laser Raman microprobe).

  14. Comparative analysis of dental enamel polyvinylsiloxane impression and polyurethane casting methods for SEM research.

    PubMed

    Galbany, Jordi; Estebaranz, Ferran; Martínez, Laura M; Romero, Alejandro; De Juan, Joaquín; Turbón, Daniel; Pérez-Pérez, Alejandro

    2006-04-01

    Dental casting is a very common procedure for making high-quality replicas of paleo-anthropological remains. Replicas are frequently used, instead of original remains, to study both fossil and extant Primate teeth in morphological and metrical analyses. Several commercial products can be used in molds. This study analyzed SEM image resolution and enamel surface feature definition of tooth molds at various magnification levels and obtained, with both Coltène and 3M low-viscosity body polyvinylsiloxane impression, materials and polyurethane casts. Results, through comparison with the original teeth, show that both the negative molds and the positive casts are highly reliable in replicating enamel surfaces. However, positive cast quality is optimal for SEM observation only till the fourth consecutive replica from the original mold, especially at high SEM magnification levels.

  15. FIB-SEM: an additional technique for investigating internal structure of pollen walls.

    PubMed

    House, Alisoun; Balkwill, Kevin

    2013-12-01

    Pollen grain morphology has been widely used in the classification of the Acanthaceae, where external pollen wall features have proved useful in determining relationships between taxa. Although detailed information has been accumulated using light microscopy, transmission electron microscopy and scanning electron microscopy (SEM) techniques, internal pollen wall features lack investigation and the techniques are cumbersome. A new technique involving precise cross sectioning or slicing of pollen grains at a selected position for examining wall ultrastructure, using a focused ion beam-scanning electron microscope (FIB-SEM), has been explored and promising results have been obtained. The FIB-SEM offers a good technique for reliable, high resolution, three-dimensional (3D) viewing of the internal structure of the pollen grain wall.

  16. Replica extraction method on nanostructured gold coatings and orientation determination combining SEM and TEM techniques.

    PubMed

    Bocker, Christian; Kracker, Michael; Rüssel, Christian

    2014-12-01

    In the field of electron microscopy the replica technique is known as an indirect method and also as an extraction method that is usually applied on metallurgical samples. This contribution describes a fast and simple transmission electron microscopic (TEM) sample preparation by complete removal of nanoparticles from a substrate surface that allows the study of growth mechanisms of nanostructured coatings. The comparison and combination of advanced diffraction techniques in the TEM and scanning electron microscopy (SEM) provide possibilities for operators with access to both facilities. The analysis of TEM-derived diffraction patterns (convergent beam electron diffraction) in the SEM/electron backscatter diffraction software simplifies the application, especially when the patterns are not aligned along a distinct zone axis. The study of the TEM sample directly by SEM and transmission Kikuchi diffraction allows cross-correlation with the TEM results.

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

    PubMed

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

    2017-08-16

    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.

  18. Application of the SEM to the measurement of solar cell parameters

    NASA Technical Reports Server (NTRS)

    Weizer, V. G.; Andrews, C. W.

    1977-01-01

    A pair of techniques are described which make use of the SEM to measure, respectively, the minority carrier diffusion length and the metallurgical junction depth in silicon solar cells. The former technique permits the measurement of the true bulk diffusion length through the application of highly doped field layers to the back surfaces of the cells being investigated. The technique yields an absolute value of the diffusion length from a knowledge of the collected fraction of the injected carriers and the cell thickness. It is shown that the secondary emission contrast observed in the SEM on a reverse-biased diode can depict the location of the metallurgical junction if the diode has been prepared with the proper beveled geometry. The SEM provides the required contrast and the option of high magnification, permitting the measurement of extremely shallow junction depths.

  19. [Revisiting the chemical diversity in prostatic calculi: a SEM and FT-IR investigation].

    PubMed

    Dessombz, A; Méria, P; Bazin, D; Foy, E; Rouzière, S; Weil, R; Daudon, M

    2011-12-01

    Revisiting the chemical diversity of the crystalline phases of prostatic calculi by means of SEM and FT-IR analysis. A set of 32 prostatic calculi has been studied by FT-IR and SEM. FT-IR analysis has determined the chemical composition of each prostatic calculus and the SEM observation has described the morphology of the calculi surfaces and layers. Infrared analysis revealed that 90.7% of the stones were mainly composed of calcium phosphates. However, several mineral phases previously not reported in prostatic calculi were observed, as brushite or octocalcium phosphate pentahydrate. Prostatic calculi exhibited a diversity of crystalline composition and morphology. As previously reported for urinary calculi, relationships between composition and morphology of prostatic stones and étiopathogenic conditions could be of interest in clinical practice. Copyright © 2011 Elsevier Masson SAS. All rights reserved.

  20. Self-Expanding Metal Stent (SEMS): an innovative rescue therapy for refractory acute variceal bleeding.

    PubMed

    Changela, Kinesh; Ona, Mel A; Anand, Sury; Duddempudi, Sushil

    2014-12-01

    Acute variceal bleeding (AVB) is a life-threatening complication of liver cirrhosis or less commonly splenic vein thrombosis. Pharmacological and endoscopic interventions are cornerstones in the management of variceal bleeding but may fail in 10 - 15 % of patients. Rescue therapy with balloon tamponade (BT) or transjugular intrahepatic portosystemic shunt (TIPS) may be required to control refractory acute variceal bleeding effectively but with some limitations. The self-expanding metal stent (SEMS) is a covered, removable tool that can be deployed in the lower esophagus under endoscopic guidance as a rescue therapy to achieve hemostasis for refractory AVB. To evaluate the technical feasibility, efficacy, and safety of SEMS as a rescue therapy for AVB. In this review article, we have performed an extensive literature search summarizing case reports and case series describing SEMS as a rescue therapy for AVB. Indications, features, technique, deployment, success rate, limitations, and complications are discussed. At present, 103 cases have been described in the literature. Studies have reported 97.08 % technical success rates in deployment of SEMS. Most of the stents were intact for 4 - 14 days with no major complications reported. Stent extraction had a success rate of 100 %. Successful hemostasis was achieved in 96 % of cases with only 3.12 % found to have rebleeding after placement of SEMS. Stent migration, which was the most common complication, was observed in 21 % of patients. SEMS is a safe and effective alternative approach as a rescue therapy for refractory AVB.

  1. Separating topographical and chemical analysis of nanostructure of polymer composite in low voltage SEM

    NASA Astrophysics Data System (ADS)

    Wan, Q.; Plenderleith, R. A.; Dapor, M.; Rimmer, S.; Claeyssens, F.; Rodenburg, C.

    2015-10-01

    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.

  2. SEM analysis of ionizing radiation effects in linear integrated circuits. [Scanning Electron Microscope

    NASA Technical Reports Server (NTRS)

    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.

  3. [The efficacy of SEMS for malignant upper gastrointestinal stenosis, evaluated by a "home index"].

    PubMed

    Yonechi, M; Sato, K; Saito, Y; Yamagiwa, T; Kikuchi, T; Kamiya, T; Saito, M; Nagase, K; Kashimura, J; Ikeya, S; Endo, T; Nakayama, H; Sugai, Y

    1999-12-01

    We used a self expandable metalic stent (SEMS) on 24 patients (average age 68.6 years, 20 males, 4 females) with malignant upper gastrointestinal stenosis from August, 1997 to March, 1999. The primary diseases of the 24 patients were gastric cancer (13 cases: 54%), esophageal cancer (10 cases: 42%) and paraesophageal lymph node metastasis of breast cancer (one case: 4%). In this study, we present a "Home Index" as an indicator to evaluate a patient's quality of life, and investigated the efficacy and problem of SEMS.

  4. STEM mode in the SEM for the analysis of cellular sections prepared by ultramicrotome sectioning

    NASA Astrophysics Data System (ADS)

    Hondow, N.; Harrington, J.; Brydson, R.; Brown, A.

    2012-07-01

    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.

  5. Characterization of Polycapillary Optics in a TES Microcalorimeter EDS System Installed on an SEM

    NASA Astrophysics Data System (ADS)

    Takano, A.; Maehata, K.; Iyomoto, N.; Yasuda, K.; Maeno, H.; Shiiyama, K.; Tanaka, K.

    2016-08-01

    Energy-dispersive spectroscopic measurements are performed using a superconducting transition-edge sensor (TES) microcalorimeter mounted on a scanning electron microscope (SEM) for advanced research at Kyushu University. Because the sensitive area of the TES microcalorimeter is about 0.02~mm2, polycapillary optics is used to collect the X-rays emitted by the SEM specimen on the TES microcalorimeter. The X-ray transmission efficiency of the polycapillary optics is obtained by analyzing the X-ray energy spectra measured by the TES microcalorimeter. The obtained transmission efficiency of the polycapillary optics is reproduced by the calculated results of the simulation.

  6. Characterization of SEM speckle pattern marking and imaging distortion by digital image correlation

    NASA Astrophysics Data System (ADS)

    Guery, Adrien; Latourte, Félix; Hild, François; Roux, Stéphane

    2014-01-01

    Surface patterning by e-beam lithography and scanning electron microscope (SEM) imaging distortions are studied via digital image correlation. The global distortions from the reference pattern, which has been numerically generated, are first quantified from a digital image correlation procedure between the (virtual) reference pattern and the actual SEM image both in secondary and backscattered electron imaging modes. These distortions result from both patterning and imaging techniques. These two contributions can be separated (without resorting to an external caliper) based on the images of the same patterned surface acquired at different orientations. Patterning distortions are much smaller than those due to imaging on wide field images.

  7. Comparison of critical dimension measurements of a mask inspection system with a CD-SEM

    NASA Astrophysics Data System (ADS)

    Heumann, Jan P.; Ullrich, Albrecht; Utzny, Clemens S.; Meusemann, Stefan; Kromer, Frank; Whittey, John M.; Garcia, Edgardo; Wagner, Mark; Schmidt, Norbert J.

    2012-11-01

    Critical dimension uniformity (CDU) is an important parameter for photomask and wafer manufacturing. In order to reduce long-range CD variation, compensation techniques for mask writers and scanners have been developed. Both techniques require mask CD measurements with high spatial sampling. Scanning electron microscopes (SEMs), which provide CD measurements at very high precision, cannot in practice provide the required spatial sampling due to their low speed. In contrast mask inspection systems, some of which have the ability to perform optical CD measurements with very high sampling frequencies, are an interesting alternative. In this paper we evaluate the CDU measurement results with those of a CD-SEM.

  8. Comparison of SEM and Optical Analysis of DT Neutron Tracks in CR-39 Detectors

    SciTech Connect

    Mosier-Boss, P A; Carbonelle, P; Morey, M S; Tinsley, J R; Hurley, J P; Godron, F E

    2012-01-01

    CR-39 detectors were exposed to DT neutrons generated by a Thermo Fisher model A290 neutron generator. Afterwards, the etched tracks were examined both optically and by SEM. The purpose of the analysis was to compare the two techniques and to determine whether additional information on track geometry could be obtained by SEM analysis. The use of these techniques to examine triple tracks, diagnostic of ≥9.6 MeV neutrons, observed in CR-39 used in Pd/D codeposition experiments will also be discussed.

  9. Comparison of SEM and Optical Analysis of DT Neutron Tracks in CR-39 Detectors

    SciTech Connect

    P.A. Mosier-Boss, L.P.G. Forsley, P. Carbonnelle, M.S. Morey, J.R. Tinsley, J. P. Hurley, F.E. Gordon

    2012-01-01

    A solid state nuclear track detector, CR-39, was exposed to DT neutrons. After etching, the resultant tracks were analyzed using both an optical microscope and a scanning electron microscope (SEM). In this communication, both methods of analyzing DT neutron tracks are discussed.

  10. Dental wax impressions of plant tissues for viewing with scanning electron microscopy (SEM).

    PubMed

    Beermann, Anke; Hülskamp, Martin

    2010-09-01

    Scanning electron microscopy (SEM) is a valuable method for examining surface structures. Taking wax impressions of plant structures, such as leaves, is a nondestructive procedure that makes it possible to view changes in surface structures over time, such as during development. This protocol describes a method for making dental wax impressions of plant tissues.

  11. The Application of SEM to Behavioral Research in Oncology: Past Accomplishments and Future Opportunities

    ERIC Educational Resources Information Center

    Schnoll, Robert A.; Fang, Carolyn Y.; Manne, Sharon L.

    2004-01-01

    The past decade has seen a tremendous growth in the use of structural equation modeling (SEM) to address research questions in 2 subfields of behavioral science: cancer prevention and control (e.g., determinants of cancer screening adherence) and behavioral oncology (e.g., determinants of psychosocial adjustment among cancer patients or…

  12. Effects of Missing Data Methods in SEM under Conditions of Incomplete and Nonnormal Data

    ERIC Educational Resources Information Center

    Li, Jian; Lomax, Richard G.

    2017-01-01

    Using Monte Carlo simulations, this research examined the performance of four missing data methods in SEM under different multivariate distributional conditions. The effects of four independent variables (sample size, missing proportion, distribution shape, and factor loading magnitude) were investigated on six outcome variables: convergence rate,…

  13. 30 CFR 250.1912 - What criteria for management of change must my SEMS program meet?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... change must my SEMS program meet? (a) You must develop and implement written management of change... approval procedures for the change. (e) Employees, including contractors whose job tasks will be affected by a change in the operation, must be informed of, and trained in, the change prior to startup of...

  14. 30 CFR 250.1912 - What criteria for management of change must my SEMS program meet?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... change must my SEMS program meet? (a) You must develop and implement written management of change... approval procedures for the change. (e) Employees, including contractors whose job tasks will be affected by a change in the operation, must be informed of, and trained in, the change prior to startup of...

  15. 30 CFR 250.1912 - What criteria for management of change must my SEMS program meet?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... change must my SEMS program meet? (a) You must develop and implement written management of change... approval procedures for the change. (e) Employees, including contractors whose job tasks will be affected by a change in the operation, must be informed of, and trained in, the change prior to startup of...

  16. 30 CFR 250.1920 - What are the auditing requirements for my SEMS program?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... (independent third party or your designated and qualified personnel) to submit an audit report of the findings... or your designated and qualified personnel according to the requirements of this subpart and API RP... implementation of the SEMS program and at least once every 3 years thereafter. The audit must be a comprehensive...

  17. Why Isn't Talent Development on the IEP? SEM and the Twice Exceptional Learner

    ERIC Educational Resources Information Center

    Baum, Susan; Novak, Cynthia

    2010-01-01

    Why isn't talent development included on the Individual Educational Plan of 2E students? Twice exceptional students have unique issues that respond especially well to a talent development approach especially within the context of the Schoolwide Enrichment Model. Through case studies and a review of successful projects using SEM with at risk…

  18. Teacher's Corner: Using SAS for Monte Carlo Simulation Research in SEM

    ERIC Educational Resources Information Center

    Fan, Xitao; Fan, Xiaotao

    2005-01-01

    This article illustrates the use of the SAS system for Monte Carlo simulation work in structural equation modeling (SEM). Data generation procedures for both multivariate normal and nonnormal conditions are discussed, and relevant SAS codes for implementing these procedures are presented. A hypothetical example is presented in which Monte Carlo…

  19. 30 CFR 250.1920 - What are the auditing requirements for my SEMS program?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... program? (a) Your SEMS program must be audited by an accredited ASP according to the requirements of this... agent of the ASP, and must not have any affiliation with the operator. The remaining team members may be chosen from your personnel and those of the ASP. The audit must be comprehensive and include all...

  20. 30 CFR 250.1920 - What are the auditing requirements for my SEMS program?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... program? (a) Your SEMS program must be audited by an accredited ASP according to the requirements of this... agent of the ASP, and must not have any affiliation with the operator. The remaining team members may be chosen from your personnel and those of the ASP. The audit must be comprehensive and include all...

  1. 30 CFR 250.1902 - What must I include in my SEMS program?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 2 2014-07-01 2014-07-01 false What must I include in my SEMS program? 250.1902 Section 250.1902 Mineral Resources BUREAU OF SAFETY AND ENVIRONMENTAL ENFORCEMENT, DEPARTMENT OF... § 250.1910) (3) Hazards Analysis (see § 250.1911) (4) Management of Change (see § 250.1912)...

  2. 30 CFR 250.1902 - What must I include in my SEMS program?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 2 2013-07-01 2013-07-01 false What must I include in my SEMS program? 250.1902 Section 250.1902 Mineral Resources BUREAU OF SAFETY AND ENVIRONMENTAL ENFORCEMENT, DEPARTMENT OF... § 250.1910) (3) Hazards Analysis (see § 250.1911) (4) Management of Change (see § 250.1912)...

  3. 30 CFR 250.1902 - What must I include in my SEMS program?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 2 2012-07-01 2012-07-01 false What must I include in my SEMS program? 250.1902 Section 250.1902 Mineral Resources BUREAU OF SAFETY AND ENVIRONMENTAL ENFORCEMENT, DEPARTMENT OF... § 250.1910) (3) Hazards Analysis (see § 250.1911) (4) Management of Change (see § 250.1912)...

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

    NASA Astrophysics Data System (ADS)

    Cieśla, Krystyna; Sartowska, Bożena; Królak, Edward

    2015-01-01

    Potato starch was irradiated with a 60Co 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.

  5. 30 CFR 250.1912 - What criteria for management of change must my SEMS program meet?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 2 2011-07-01 2011-07-01 false What criteria for management of change must my... management of change must my SEMS program meet? (a) You must develop and implement written management of...) Management of change procedures do not apply to situations involving replacement in kind (such...

  6. Mössbauer spectroscopic and SEM study of Campanian and Terra sigillata pottery from Spain

    NASA Astrophysics Data System (ADS)

    Gancedo, J. R.; Gracia, M.; Marco, J. F.; Palacios, J.

    1988-12-01

    A combination of Mössbauer spectroscopy (CEMS and transmission) and scanning electron microscopy (SEM) with energy dispersive X-ray analysis (EDAX) was employed to study the differences between coat and body in Campanian and Terra Sigillata wares. Conclusions about type of clay, origin of colour, and fabric and firing technology are established.

  7. The Application of SEM to Behavioral Research in Oncology: Past Accomplishments and Future Opportunities

    ERIC Educational Resources Information Center

    Schnoll, Robert A.; Fang, Carolyn Y.; Manne, Sharon L.

    2004-01-01

    The past decade has seen a tremendous growth in the use of structural equation modeling (SEM) to address research questions in 2 subfields of behavioral science: cancer prevention and control (e.g., determinants of cancer screening adherence) and behavioral oncology (e.g., determinants of psychosocial adjustment among cancer patients or…

  8. SEM of canine chromosomes: normal structure and the effects of whole-body irradiation

    SciTech Connect

    Niiro, G.K.; Seed, T.M.

    1988-09-01

    Canine chromosomes are not only numerous (38 autosomal pairs), but they are small (compared to human chromosomes) and morphologically similar as well. Analysis of the canine karyotype by light microscopy (LM) of banded chromosomes is, thus, difficult, and the literature on the canine karyotype is scanty. In this study, we describe examination of chromosomes from normal and chronically irradiated dogs with the scanning electron microscope (SEM). Metaphase chromosomes from bone marrow aspirates were Giemsa-banded with either 0.025% trypsin alone or 0.1% trypsin preceded by 10% H2O2 and prepared for SEM. Examination of chromosomes from normal dogs revealed cylindrical chromosome profiles with well-defined chromatids and centromeres. The chromosome arms were consistently marked by periodic grooves that had complementary structures on sister chromatids and may represent the trypsin-sensitive chromatic regions. The quality of the preservation varied from preparation to preparation and depended on the concentration and time of trypsin treatment. Chromosomes from irradiated dogs revealed translocations, deletions, and gaps. We conclude that SEM produces images superior to LM images of canine chromosomes; SEM images can be used not only to identify individual chromosomes, but also to identify genetic lesions in the chromosomes of chronically irradiated dogs. We further conclude that the two Giemsa-banding protocols used in the present study produced variable results, although 0.025% trypsin alone appeared to give better and more consistent results than 0.1% trypsin preceded by 10% H2O2.

  9. A Sandwich-Type Standard Error Estimator of SEM Models with Multivariate Time Series

    ERIC Educational Resources Information Center

    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…

  10. 3D SEM for surface topography quantification - a case study on dental surfaces

    NASA Astrophysics Data System (ADS)

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

    2014-03-01

    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.

  11. Situational Effects May Account for Gain Scores in Cognitive Ability Testing: A Longitudinal SEM Approach

    ERIC Educational Resources Information Center

    Matton, Nadine; Vautier, Stephane; Raufaste, Eric

    2009-01-01

    Mean gain scores for cognitive ability tests between two sessions in a selection setting are now a robust finding, yet not fully understood. Many authors do not attribute such gain scores to an increase in the target abilities. Our approach consists of testing a longitudinal SEM model suitable to this view. We propose to model the scores' changes…

  12. Situational Effects May Account for Gain Scores in Cognitive Ability Testing: A Longitudinal SEM Approach

    ERIC Educational Resources Information Center

    Matton, Nadine; Vautier, Stephane; Raufaste, Eric

    2009-01-01

    Mean gain scores for cognitive ability tests between two sessions in a selection setting are now a robust finding, yet not fully understood. Many authors do not attribute such gain scores to an increase in the target abilities. Our approach consists of testing a longitudinal SEM model suitable to this view. We propose to model the scores' changes…

  13. Simple and rapid methods for SEM observation and TEM immunolabeling of rubber particles.

    PubMed

    Singh, Adya P; Wi, Seung Gon; Kang, Hunseung; Chung, Gap Chae; Kim, Yoon Soo

    2003-08-01

    We developed a method involving air-drying of a rubber suspension after fixation in glutaraldehyde-tannic acid and postfixation in osmium tetroxide for SEM observation. For TEM immunolabeling the suspension was air-dried after osmium-only fixation. Whereas conventional methods failed to satisfactorily stabilize rubber particles, the methods described here proved successful in preserving their integrity.

  14. Effects of Missing Data Methods in SEM under Conditions of Incomplete and Nonnormal Data

    ERIC Educational Resources Information Center

    Li, Jian; Lomax, Richard G.

    2017-01-01

    Using Monte Carlo simulations, this research examined the performance of four missing data methods in SEM under different multivariate distributional conditions. The effects of four independent variables (sample size, missing proportion, distribution shape, and factor loading magnitude) were investigated on six outcome variables: convergence rate,…

  15. GUIDELINES FOR THE APPLICATION OF SEM/EDX ANALYTICAL TECHNIQUES FOR FINE AND COARSE PM SAMPLES

    EPA Science Inventory

    Scanning Electron Microscopy (SEM) coupled with Energy-Dispersive X-ray analysis (EDX) is a powerful tool in the characterization and source apportionment of environmental particulate matter (PM), providing size, chemistry, and morphology of particles as small as a few tenths ...

  16. The Great War and Remembrance in Jose Leon Machado's "Memoria das Estrelas sem Brilho"

    ERIC Educational Resources Information Center

    Azevedo, Milton M.

    2011-01-01

    This article analyzes Jose Leon Machado's novel, "Memoria das Estrelas sem Brilho," as a multilayered historical novel in which a war story provides a background for comments on aspects of early twentieth-century Portuguese society, such as male bonding, religion, sexual mores, and social stratification. (Contains 11 notes.)

  17. Promoting Positive Attitudes between Mainstreamed SEM Students and Regular Students in an Elementary School Setting.

    ERIC Educational Resources Information Center

    Shelby, Madge E.

    Because handicapped and nonhandicapped students in a Pennsylvania elementary school were not sucessfully mainstreamed and lacked social skills, a practicum was devised to (1) teach social behavior skills to socially/emotionally maladjusted (SEM) students, and (2) present social skill intervention strategies promoting a positive attitude between…

  18. The Capabilities and Applications of FY-3A/B SEM on Monitoring Space Weather Events

    NASA Astrophysics Data System (ADS)

    Huang, C.; Li, J.; Yu, T.; Xue, B.; Wang, C.; Zhang, X.; Cao, G.; Liu, D.; Tang, W.

    2012-12-01

    The Space Environment Monitor (SEM), on board the Chinese meteorological satellites, FengYun-3A/B has the abilities to measure proton flux in 3-300 Mev energy range and electron flux in 0.15-5.7 Mev energy range. SEM can also detect the heavy ion compositions, satellite surface potential, the radiation dose in sensors, and the single events. The space environment information derived from SEM can be utilized for satellite security designs, scientific studies, development of radiation belt models, and space weather monitoring and disaster warning. In this study, the SEM's instrument characteristics are introduced and the post-launch calibration algorithm is presented. The applications in monitoring space weather events and the service for manned spaceflights are also demonstrated.; The protons with particle energy over 10 Mev are called "killer particles". These particles may damage the satellite and cause disruption of satellite's system. The protons flux of 10 M-26 Mev energy band reached 5000 in the SPE caused by a solar flare with CME during the period of 2012.01.23 to 2012.01.27 as shown in the figure. THE COMPARISONS OF HEAVY IONS (2010.11.11-2010.12.15)t;

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

    PubMed

    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.

  20. Creating High-Resolution Multiscale Maps of Human Tissue Using Multi-beam SEM

    PubMed Central

    Hageman, Daniel J.; Garbowski, Tomasz; Riedesel, Christof; Knothe, Ulf; Zeidler, Dirk; Knothe Tate, Melissa L.

    2016-01-01

    Multi-beam scanning electron microscopy (mSEM) enables high-throughput, nano-resolution imaging of macroscopic tissue samples, providing an unprecedented means for structure-function characterization of biological tissues and their cellular inhabitants, seamlessly across multiple length scales. Here we describe computational methods to reconstruct and navigate a multitude of high-resolution mSEM images of the human hip. We calculated cross-correlation shift vectors between overlapping images and used a mass-spring-damper model for optimal global registration. We utilized the Google Maps API to create an interactive map and provide open access to our reconstructed mSEM datasets to both the public and scientific communities via our website www.mechbio.org. The nano- to macro-scale map reveals the tissue’s biological and material constituents. Living inhabitants of the hip bone (e.g. osteocytes) are visible in their local extracellular matrix milieu (comprising collagen and mineral) and embedded in bone’s structural tissue architecture, i.e. the osteonal structures in which layers of mineralized tissue are organized in lamellae around a central blood vessel. Multi-beam SEM and our presented methodology enable an unprecedented, comprehensive understanding of health and disease from the molecular to organ length scale. PMID:27870847

  1. Subjective Values of Quality of Life Dimensions in Elderly People. A SEM Preference Model Approach

    ERIC Educational Resources Information Center

    Elosua, Paula

    2011-01-01

    This article proposes a Thurstonian model in the framework of Structural Equation Modelling (SEM) to assess preferences among quality of life dimensions for the elderly. Data were gathered by a paired comparison design in a sample comprised of 323 people aged from 65 to 94 years old. Five dimensions of quality of life were evaluated: Health,…

  2. Teacher's Corner: Structural Equation Modeling with the Sem Package in R

    ERIC Educational Resources Information Center

    Fox, John

    2006-01-01

    R is free, open-source, cooperatively developed software that implements the S statistical programming language and computing environment. The current capabilities of R are extensive, and it is in wide use, especially among statisticians. The sem package provides basic structural equation modeling facilities in R, including the ability to fit…

  3. GUIDELINES FOR THE APPLICATION OF SEM/EDX ANALYTICAL TECHNIQUES FOR FINE AND COARSE PM SAMPLES

    EPA Science Inventory

    Scanning Electron Microscopy (SEM) coupled with Energy-Dispersive X-ray analysis (EDX) is a powerful tool in the characterization and source apportionment of environmental particulate matter (PM), providing size, chemistry, and morphology of particles as small as a few tenths ...

  4. 30 CFR 250.1916 - What criteria for mechanical integrity must my SEMS program meet?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 2 2013-07-01 2013-07-01 false What criteria for mechanical integrity must my... SHELF Safety and Environmental Management Systems (SEMS) § 250.1916 What criteria for mechanical... instructions to ensure the mechanical integrity and safe operation of equipment through inspection,...

  5. 30 CFR 250.1916 - What criteria for mechanical integrity must my SEMS program meet?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 2 2012-07-01 2012-07-01 false What criteria for mechanical integrity must my... SHELF Safety and Environmental Management Systems (SEMS) § 250.1916 What criteria for mechanical... instructions to ensure the mechanical integrity and safe operation of equipment through inspection,...

  6. 30 CFR 250.1916 - What criteria for mechanical integrity must my SEMS program meet?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 2 2011-07-01 2011-07-01 false What criteria for mechanical integrity must my... mechanical integrity must my SEMS program meet? You must develop and implement written procedures that provide instructions to ensure the mechanical integrity and safe operation of equipment through...

  7. 30 CFR 250.1916 - What criteria for mechanical integrity must my SEMS program meet?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 2 2014-07-01 2014-07-01 false What criteria for mechanical integrity must my... SHELF Safety and Environmental Management Systems (SEMS) § 250.1916 What criteria for mechanical... instructions to ensure the mechanical integrity and safe operation of equipment through inspection,...

  8. Subjective Values of Quality of Life Dimensions in Elderly People. A SEM Preference Model Approach

    ERIC Educational Resources Information Center

    Elosua, Paula

    2011-01-01

    This article proposes a Thurstonian model in the framework of Structural Equation Modelling (SEM) to assess preferences among quality of life dimensions for the elderly. Data were gathered by a paired comparison design in a sample comprised of 323 people aged from 65 to 94 years old. Five dimensions of quality of life were evaluated: Health,…

  9. About the Mechanisms of Charging in EPMA, SEM, and ESEM with Their Time Evolution

    NASA Astrophysics Data System (ADS)

    Cazaux, Jacques

    2004-12-01

    The physical mechanisms involved in electron irradiation of insulating specimens are investigated by combining some simple considerations of solid-state physics (trapping mechanisms of electrons and secondary electron emission) with basic equations of electrostatics. To facilitate the understanding of the involved mechanisms only widely irradiated samples having a uniform distribution of trapping sites are considered. This starting hypothesis allows development of simple models for the trapped charge distributions in ground-coated specimens as investigated in electron probe microanalysis (EPMA) as well as for the bare specimens investigated in scanning electron microscopy (SEM) and environmental SEM (ESEM). Governed by self-regulation processes, the evolution of the electric parameters during the irradiation are also considered for the first time and practical consequences in EPMA, SEM, and ESEM are deduced. In particular, the widespread idea that the noncharging condition of SEM is obtained at a critical energy E2 (where [delta] + [eta] = 1 with [delta] and [eta] yields obtained in noncharging experiments) is critically discussed.

  10. A Sandwich-Type Standard Error Estimator of SEM Models with Multivariate Time Series

    ERIC Educational Resources Information Center

    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…

  11. Maximum Likelihood Dynamic Factor Modeling for Arbitrary "N" and "T" Using SEM

    ERIC Educational Resources Information Center

    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…

  12. The Great War and Remembrance in Jose Leon Machado's "Memoria das Estrelas sem Brilho"

    ERIC Educational Resources Information Center

    Azevedo, Milton M.

    2011-01-01

    This article analyzes Jose Leon Machado's novel, "Memoria das Estrelas sem Brilho," as a multilayered historical novel in which a war story provides a background for comments on aspects of early twentieth-century Portuguese society, such as male bonding, religion, sexual mores, and social stratification. (Contains 11 notes.)

  13. 30 CFR 250.1915 - What criteria for training must be in my SEMS program?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... SHELF Safety and Environmental Management Systems (SEMS) § 250.1915 What criteria for training must be... program? 250.1915 Section 250.1915 Mineral Resources BUREAU OF OCEAN ENERGY MANAGEMENT, REGULATION, AND... personnel are trained to work safely and are aware of environmental considerations offshore, in accordance...

  14. Enamel and dentine of deciduous teeth Er:YAG laser prepared. A SEM study.

    PubMed

    Kornblit, R; Bossù, M; Mari, D; Rocca, J P; Polimeni, A

    2009-06-01

    The aim of this study was to observe dentine and enamel surfaces of deciduous teeth under SEM after cavity preparation with Er:YAG laser using different fluences. The results showed that when using Er:YAG laser for cavity preparation in deciduous teeth, no carbonisation or cracks were observed on the enamel and dentine surfaces using energy output between 150-250 Mj, and frequency 15 Hz. The SEM images of the dentine and enamel surfaces were similar to previous studies on permanent teeth: enamel with a typical "lava flow" appearance as a result of an open core of the prism that has lost its typical hexagonal aspect and the dentine with opened tubules plus a difference in the mineral thickness between peritubular and intertubular. The difference between the SEM images of deciduous enamel and dentine when using three different energies (150-200-250 mJ) is not significant in order to recommend the use of one type of output energy. In addition, the SEM images are similar TO those of permanent teeth.

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

    PubMed

    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.

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

    PubMed

    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.

  17. Morphological modelling of three-phase microstructures of anode layers using SEM images.

    PubMed

    Abdallah, Bassam; Willot, François; Jeulin, Dominique

    2016-07-01

    A general method is proposed to model 3D microstructures representative of three-phases anode layers used in fuel cells. The models are based on SEM images of cells with varying morphologies. The materials are first characterized using three morphological measurements: (cross-)covariances, granulometry and linear erosion. They are measured on segmented SEM images, for each of the three phases. Second, a generic model for three-phases materials is proposed. The model is based on two independent underlying random sets which are otherwise arbitrary. The validity of this model is verified using the cross-covariance functions of the various phases. In a third step, several types of Boolean random sets and plurigaussian models are considered for the unknown underlying random sets. Overall, good agreement is found between the SEM images and three-phases models based on plurigaussian random sets, for all morphological measurements considered in the present work: covariances, granulometry and linear erosion. The spatial distribution and shapes of the phases produced by the plurigaussian model are visually very close to the real material. Furthermore, the proposed models require no numerical optimization and are straightforward to generate using the covariance functions measured on the SEM images. © 2016 The Authors Journal of Microscopy © 2016 Royal Microscopical Society.

  18. Maximum Likelihood Dynamic Factor Modeling for Arbitrary "N" and "T" Using SEM

    ERIC Educational Resources Information Center

    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…

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

    PubMed

    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.

  20. Prescriptive Statements and Educational Practice: What Can Structural Equation Modeling (SEM) Offer?

    ERIC Educational Resources Information Center

    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,…

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

    PubMed

    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.

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

    PubMed

    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. Single-entry models (SEMs) for scheduled services: Towards a roadmap for the implementation of recommended practices.

    PubMed

    Lopatina, Elena; Damani, Zaheed; Bohm, Eric; Noseworthy, Tom W; Conner-Spady, Barbara; MacKean, Gail; Simpson, Chris S; Marshall, Deborah A

    2017-09-01

    Long waiting times for elective services continue to be a challenging issue. Single-entry models (SEMs) are used to increase access to and flow through the healthcare system. This paper provides a roadmap for healthcare decision-makers, managers, physicians, and researchers to guide implementation and management of successful and sustainable SEMs. The roadmap was informed by an inductive qualitative synthesis of the findings from a deliberative process (a symposium on SEMs, with clinicians, researchers, senior policy-makers, healthcare managers, and patient representatives) and focus groups with the symposium participants. SEMs are a promising strategy to improve the management of referrals and represent one approach to reduce waiting times. The SEMs roadmap outlines current knowledge about SEMs and critical success factors for SEMs' implementation and management. This SEM roadmap is intended to help clinicians, decision-makers, managers, and researchers interested in developing new or strengthening existing SEMs. We consider this roadmap to be a living document that will continue to evolve as we learn more about implementing and managing sustainable SEMs. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Counting Synapses Using FIB/SEM Microscopy: A True Revolution for Ultrastructural Volume Reconstruction.

    PubMed

    Merchán-Pérez, Angel; Rodriguez, José-Rodrigo; Alonso-Nanclares, Lidia; Schertel, Andreas; Defelipe, Javier

    2009-01-01

    The advent of transmission electron microscopy (TEM) in the 1950s represented a fundamental step in the study of neuronal circuits. The application of this technique soon led to the realization that the number of synapses changes during the course of normal life, as well as under certain pathological or experimental circumstances. Since then, one of the main goals in neurosciences has been to define simple and accurate methods to estimate the magnitude of these changes. Contrary to analysing single sections, TEM reconstructions are extremely time-consuming and difficult. Therefore, most quantitative studies use stereological methods to define the three-dimensional characteristics of synaptic junctions that are studied in two dimensions. Here, to count the exact number of synapses per unit of volume we have applied a new three-dimensional reconstruction method that involves the combination of focused ion beam milling and scanning electron microscopy (FIB/SEM). We show that the images obtained with FIB/SEM are similar to those obtained with TEM, but with the advantage that FIB/SEM permits serial reconstructions of large volumes of tissue to be generated rapidly and automatically. Furthermore, we compared the estimates of the number of synapses obtained with stereological methods with the values obtained by FIB/SEM reconstructions. We concluded that FIB/SEM not only provides the actual number of synapses per volume but it is also much easier and faster to use than other currently available TEM methods. More importantly, it also avoids most of the errors introduced by stereological methods and overcomes the difficulties associated with these techniques.

  5. FIB-SEM imaging of carbon nanotubes in mouse lung tissue.

    PubMed

    Købler, Carsten; Saber, Anne Thoustrup; Jacobsen, Nicklas Raun; Wallin, Håkan; Vogel, Ulla; Qvortrup, Klaus; Mølhave, Kristian

    2014-06-01

    Ultrastructural characterisation is important for understanding carbon nanotube (CNT) toxicity and how the CNTs interact with cells and tissues. The standard method for this involves using transmission electron microscopy (TEM). However, in particular, the sample preparation, using a microtome to cut thin sample sections for TEM, can be challenging for investigation of regions with agglomerations of large and stiff CNTs because the CNTs cut with difficulty. As a consequence, the sectioning diamond knife may be damaged and the uncut CNTs are left protruding from the embedded block surface excluding them from TEM analysis. To provide an alternative to ultramicrotomy and subsequent TEM imaging, we studied focused ion beam scanning electron microscopy (FIB-SEM) of CNTs in the lungs of mice, and we evaluated the applicability of the method compared to TEM. FIB-SEM can provide serial section volume imaging not easily obtained with TEM, but it is time-consuming to locate CNTs in the tissue. We demonstrate that protruding CNTs after ultramicrotomy can be used to locate the region of interest, and we present FIB-SEM images of CNTs in lung tissue. FIB-SEM imaging was applied to lung tissue from mice which had been intratracheally instilled with two different multiwalled CNTs; one being short and thin, and the other longer and thicker. FIB-SEM was found to be most suitable for detection of the large CNTs (Ø ca. 70 nm), and to be well suited for studying CNT agglomerates in biological samples which is challenging using standard TEM techniques.

  6. X-ray microscopy using reflection targets based on SEM with tungsten filament

    NASA Astrophysics Data System (ADS)

    Liu, Junbiao; Ma, Yutian; Zhao, Weixia; Niu, Geng; Chu, Mingzhang; Yin, Bohua; Han, Li; Liu, Baodong

    2016-10-01

    X-ray MicroandNano imaging is developed based on the conventional x-ray tomography, it can not only provide nondestructive testing with higher resolution measurement, but also be used to examine the material or the structure with low atomic number and low density. The source with micro-focal spot size is one of the key components of x-ray MicroandNano imaging. The focused electron beam from SEM bombarding the metal target can generate x-ray with ultra-small size. It is convenient to set up x-ray microscopy based on SEM for laboratory use. This paper describes a new x-ray microscopy using reflection targets based on FEI Quanta600 SEM with tungsten filament. The flat panel detector is placed outside of the vacuum chamber with 300μm thickness Be-window to isolate vacuum from the air. A stage with 3 DOFs is added to adjust the positions of the target, the SEM's sample stage is used to move sample. And the shape of target is designed as cone with 60° half cone angle to get the maximum x-ray dosage. The attenuation coefficient of Bewindow for x-ray is about 25%. Finally, the line pair card is used to evaluate the resolution and the result shows that the resolution of the system can receive less than 750nm, when the acceleration voltage is 30keV, the beam current is 160nA, the SEM working distance is 5mm and the acquisition time of the detector is 60s.

  7. Results of benchmarking of advanced CD-SEMs at the 90-nm CMOS technology node

    NASA Astrophysics Data System (ADS)

    Bunday, Benjamin D.; Bishop, Michael; Allgair, John A.

    2004-05-01

    The Advanced Metrology Advisory Group (AMAG) is a council composed of the chief CD-metrologists from the International SEMATECH Manufacturing Initiative (ISMI) consortium"s Member Companies and from the National Institute of Standards (NIST). The AMAG wrote and, in 2002, with CD-SEM supplier involvement, updated the "Unified Advanced CD-SEM Specification for Sub-130nm Technology (Version 2002)" to be a living document which outlines the required performance of advanced CD-SEMs for supplier compliance to the 2003 International Technology Roadmap for Semiconductors, and also conveys member companies" other collective needs to vendors. Through applying this specification during the mid-2003 timeframe, a benchmarking effort of the currently available advanced CD-SEMs has been performed. These results are presented here. The AMAG Unified Specification includes sections outlining the test methodologies, metrics, and wafer-target requirements for each parameter included in the benchmark, and, when applicable, prescribes a target specification compatible with the ITRS and methodologies compatible with the demands of 90nm technology. Parameters to be considered include: ×Precision, Repeatability and Reproducibility ×Accuracy, Apparent Beam Width and Resolution ×Charging and Contamination ×Tool-to-Tool Matching ×Pattern Recognition and Navigation Accuracy ×Throughput ×Instrumentation Outputs ×Tool Automation and Utility ×Precision and Accuracy of Profile Measurement ×Precision and Accuracy of Roughness Measurement. Previous studies under this same project have been published, with the initial version of the International Sematech Unified Specification in 1998, and multi-supplier benchmarks in 1999 and 2001. The results for the 2003 benchmark will be shown and compared to the ITRS, and composite viewpoints showing these 2003 benchmark results compared to the past results are also shown, demonstrating interesting CD-SEM industry trends.

  8. Intra-field CDU map correlation between SEMs and aerial image characterization

    NASA Astrophysics Data System (ADS)

    Ning, Guoxiang; Philipp, Peter; Litt, Lloyd C.; Meusemann, Stefan; Thaler, Thomas; Schulz, Kristian; Tschinkl, Martin; Ackmann, Paul

    2014-09-01

    Reticle critical dimension uniformity (CDU) is one of the major sources of wafer CD variations which include both inter-field variations and intra-field variations. Generally, wafer critical dimension (CD) measurement sample size interfield is much less than intra-field. Intra-field CDU correction requires time-consumption of metrology. In order to improve wafer intra-field CDU, several methods can be applied such as intra-field dose correction to improve wafer intra-field CDU. Corrections can be based on CD(SEM) or aerial image metrology data from the reticle. Reticle CDU and wafer CDU maps are based on scanning electron microscope (SEM) metrology, while reticle inspection intensity mapping (NuFLare 6000) and wafer level critical dimension (WLCD) utilize aerial images or optical techniques. Reticle inspecton tools such as those from KLA and NuFlare, offer the ability to collect optical measurement data to produce an optical CDU map. WLCD of Zeiss has the advantage of using the same illumination condition as the scanner to measure the aerial images or optical CD. In this study, the intra-field wafer CDU map correlation between SEMs and aerial images are characterized. The layout of metrology structures is very important for the correlation between wafer intra-field CDU, measured by SEM, and the CDU determined by aerial images. The selection of metrology structures effects on the correlation to SEM CD to wafer is also demonstrated. Both reticle CDU, intensity CDU and WLCD are candidates for intra-field wafer CDU characterization and the advantages and limitations of each approach are discussed.

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

    PubMed

    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. Counting Synapses Using FIB/SEM Microscopy: A True Revolution for Ultrastructural Volume Reconstruction

    PubMed Central

    Merchán-Pérez, Angel; Rodriguez, José-Rodrigo; Alonso-Nanclares, Lidia; Schertel, Andreas; DeFelipe, Javier

    2009-01-01

    The advent of transmission electron microscopy (TEM) in the 1950s represented a fundamental step in the study of neuronal circuits. The application of this technique soon led to the realization that the number of synapses changes during the course of normal life, as well as under certain pathological or experimental circumstances. Since then, one of the main goals in neurosciences has been to define simple and accurate methods to estimate the magnitude of these changes. Contrary to analysing single sections, TEM reconstructions are extremely time-consuming and difficult. Therefore, most quantitative studies use stereological methods to define the three-dimensional characteristics of synaptic junctions that are studied in two dimensions. Here, to count the exact number of synapses per unit of volume we have applied a new three-dimensional reconstruction method that involves the combination of focused ion beam milling and scanning electron microscopy (FIB/SEM). We show that the images obtained with FIB/SEM are similar to those obtained with TEM, but with the advantage that FIB/SEM permits serial reconstructions of large volumes of tissue to be generated rapidly and automatically. Furthermore, we compared the estimates of the number of synapses obtained with stereological methods with the values obtained by FIB/SEM reconstructions. We concluded that FIB/SEM not only provides the actual number of synapses per volume but it is also much easier and faster to use than other currently available TEM methods. More importantly, it also avoids most of the errors introduced by stereological methods and overcomes the difficulties associated with these techniques. PMID:19949485

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

    PubMed

    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

  12. AxiSEM and instaseis: Fast simulation of global wavefields across the frequency band

    NASA Astrophysics Data System (ADS)

    Nissen-Meyer, T.; van Driel, M.; Krischer, L.; Stähler, S. C.; Hosseini, K.; Leng, K.

    2015-12-01

    We present our seismic modeling methods AxiSEM and instaseis. These methods exploit recent developments in high-performance computing and suitable numerical methods for seismic wave propagation, while operating efficiently across the vast observable frequency spectrum of global waves in sparse yet realistic structures. AxiSEM (www.axisem.info and geodynamics.org) relies upon axisymmetric (including spherically symmetric) models, thereby satisfying a large fraction of observable data. The benefit of this method lies in the resultant dimensional collapse to two numerical dimensions, whereby the third azimuthal dimension is tackled analytically. For high-frequency wave propagation, this leads to 3-4 orders of magnitude speedup in computational cost compared to 3D domain discretizations. AxiSEM is highly scalable and accommodates efficient implementations of viscoelasticity and anisotropy. We will present benchmarks, data comparisons, a diverse range of applications from inner-core anisotropy to noise modeling and lowermost mantle structures, and wavefields for sensitivity kernels. We also touch upon ongoing efforts for linking computational cost to structural complexity in the vein of Occam's razor, eventually allowing for an adaptive rendition of 1D, 2D and 3D structures at optimally low computational cost, as well as 1D/3D hybrid approaches. Instaseis (www.instaseis.net) is a methodology to extract full, broadband and accurate waveforms instantaneously from wavefield databases computed with AxiSEM. This "once-and-for-all solution" relies on reciprocity and requires only two AxiSEM simulations to construct the databases, while allowing for arbitrary parameter changes (e.g. source, processing, structure) instantaneously with modest computational cost and storage requirements. The instaseis python package is integrated with ObsPy, contains a graphical user interface, and can be used for source inversion, noise simulations, finite-fault modeling, waveform tomography

  13. A semantic proteomics dashboard (SemPoD) for data management in translational research

    PubMed Central

    2012-01-01

    Background One of the primary challenges in translational research data management is breaking down the barriers between the multiple data silos and the integration of 'omics data with clinical information to complete the cycle from the bench to the bedside. The role of contextual metadata, also called provenance information, is a key factor ineffective data integration, reproducibility of results, correct attribution of original source, and answering research queries involving "What", "Where", "When", "Which", "Who", "How", and "Why" (also known as the W7 model). But, at present there is limited or no effective approach to managing and leveraging provenance information for integrating data across studies or projects. Hence, there is an urgent need for a paradigm shift in creating a "provenance-aware" informatics platform to address this challenge. We introduce an ontology-driven, intuitive Semantic Proteomics Dashboard (SemPoD) that uses provenance together with domain information (semantic provenance) to enable researchers to query, compare, and correlate different types of data across multiple projects, and allow integration with legacy data to support their ongoing research. Results The SemPoD platform, currently in use at the Case Center for Proteomics and Bioinformatics (CPB), consists of three components: (a) Ontology-driven Visual Query Composer, (b) Result Explorer, and (c) Query Manager. Currently, SemPoD allows provenance-aware querying of 1153 mass-spectrometry experiments from 20 different projects. SemPod uses the systems molecular biology provenance ontology (SysPro) to support a dynamic query composition interface, which automatically updates the components of the query interface based on previous user selections and efficientlyprunes the result set usinga "smart filtering" approach. The SysPro ontology re-uses terms from the PROV-ontology (PROV-O) being developed by the World Wide Web Consortium (W3C) provenance working group, the minimum

  14. A semantic proteomics dashboard (SemPoD) for data management in translational research.

    PubMed

    Jayapandian, Catherine P; Zhao, Meng; Ewing, Rob M; Zhang, Guo-Qiang; Sahoo, Satya S

    2012-01-01

    One of the primary challenges in translational research data management is breaking down the barriers between the multiple data silos and the integration of 'omics data with clinical information to complete the cycle from the bench to the bedside. The role of contextual metadata, also called provenance information, is a key factor ineffective data integration, reproducibility of results, correct attribution of original source, and answering research queries involving "What", "Where", "When", "Which", "Who", "How", and "Why" (also known as the W7 model). But, at present there is limited or no effective approach to managing and leveraging provenance information for integrating data across studies or projects. Hence, there is an urgent need for a paradigm shift in creating a "provenance-aware" informatics platform to address this challenge. We introduce an ontology-driven, intuitive Semantic Proteomics Dashboard (SemPoD) that uses provenance together with domain information (semantic provenance) to enable researchers to query, compare, and correlate different types of data across multiple projects, and allow integration with legacy data to support their ongoing research. The SemPoD platform, currently in use at the Case Center for Proteomics and Bioinformatics (CPB), consists of three components: (a) Ontology-driven Visual Query Composer, (b) Result Explorer, and (c) Query Manager. Currently, SemPoD allows provenance-aware querying of 1153 mass-spectrometry experiments from 20 different projects. SemPod uses the systems molecular biology provenance ontology (SysPro) to support a dynamic query composition interface, which automatically updates the components of the query interface based on previous user selections and efficiently prunes the result set usinga "smart filtering" approach. The SysPro ontology re-uses terms from the PROV-ontology (PROV-O) being developed by the World Wide Web Consortium (W3C) provenance working group, the minimum information required for

  15. GPU accelerated Monte-Carlo simulation of SEM images for metrology

    NASA Astrophysics Data System (ADS)

    Verduin, T.; Lokhorst, S. R.; Hagen, C. W.

    2016-03-01

    In this work we address the computation times of numerical studies in dimensional metrology. In particular, full Monte-Carlo simulation programs for scanning electron microscopy (SEM) image acquisition are known to be notoriously slow. Our quest in reducing the computation time of SEM image simulation has led us to investigate the use of graphics processing units (GPUs) for metrology. We have succeeded in creating a full Monte-Carlo simulation program for SEM images, which runs entirely on a GPU. The physical scattering models of this GPU simulator are identical to a previous CPU-based simulator, which includes the dielectric function model for inelastic scattering and also refinements for low-voltage SEM applications. As a case study for the performance, we considered the simulated exposure of a complex feature: an isolated silicon line with rough sidewalls located on a at silicon substrate. The surface of the rough feature is decomposed into 408 012 triangles. We have used an exposure dose of 6 mC/cm2, which corresponds to 6 553 600 primary electrons on average (Poisson distributed). We repeat the simulation for various primary electron energies, 300 eV, 500 eV, 800 eV, 1 keV, 3 keV and 5 keV. At first we run the simulation on a GeForce GTX480 from NVIDIA. The very same simulation is duplicated on our CPU-based program, for which we have used an Intel Xeon X5650. Apart from statistics in the simulation, no difference is found between the CPU and GPU simulated results. The GTX480 generates the images (depending on the primary electron energy) 350 to 425 times faster than a single threaded Intel X5650 CPU. Although this is a tremendous speedup, we actually have not reached the maximum throughput because of the limited amount of available memory on the GTX480. Nevertheless, the speedup enables the fast acquisition of simulated SEM images for metrology. We now have the potential to investigate case studies in CD-SEM metrology, which otherwise would take unreasonable

  16. In situ SEM study of lithium intercalation in individual V2O5 nanowires

    NASA Astrophysics Data System (ADS)

    Strelcov, Evgheni; Cothren, Joshua; Leonard, Donovan; Borisevich, Albina Y.; Kolmakov, Andrei

    2015-02-01

    Progress in rational engineering of Li-ion batteries requires better understanding of the electrochemical processes and accompanying transformations in the electrode materials on multiple length scales. In spite of recent progress in utilizing transmission electron microscopy (TEM) to analyze these materials, in situ scanning electron microscopy (SEM) was mostly overlooked as a powerful tool that allows probing these phenomena on the nano and mesoscale. Here we report on in situ SEM study of lithiation in a V2O5-based single-nanobelt battery with ionic liquid electrolyte. Coupled with cyclic voltammetry measurements, in situ SEM revealed the peculiarities of subsurface intercalation, formation of a solid-electrolyte interface (SEI) and electromigration of liquid. We observed that single-crystalline vanadia nanobelts do not undergo large-scale amorphization or fracture during electrochemical cycling, but rather transform topochemically with only a slight shape distortion. The SEI layer seems to have significant influence on the lithium ion diffusion and overall capacity of the single-nanobelt battery.Progress in rational engineering of Li-ion batteries requires better understanding of the electrochemical processes and accompanying transformations in the electrode materials on multiple length scales. In spite of recent progress in utilizing transmission electron microscopy (TEM) to analyze these materials, in situ scanning electron microscopy (SEM) was mostly overlooked as a powerful tool that allows probing these phenomena on the nano and mesoscale. Here we report on in situ SEM study of lithiation in a V2O5-based single-nanobelt battery with ionic liquid electrolyte. Coupled with cyclic voltammetry measurements, in situ SEM revealed the peculiarities of subsurface intercalation, formation of a solid-electrolyte interface (SEI) and electromigration of liquid. We observed that single-crystalline vanadia nanobelts do not undergo large-scale amorphization or fracture

  17. Solar EUV Monitor (SEM) absolute irradiance measurements and how they are affected by choice of reference spectrum

    NASA Astrophysics Data System (ADS)

    Wieman, Seth R.; Judge, Darrell L.; Didkovsky, Leonid V.

    2011-10-01

    The SOHO/CELIAS Solar EUV Monitor (SEM) has measured absolute extreme ultraviolet (EUV) solar irradiance nearly continuously over a 15 year period that includes two solar cycle minima, 22/23 (1996) and 23/24 (2008). Calibration of the SEM flight instrument and verification of the data have been maintained through measurements from a series of sounding rocket calibration underflights that have included a NIST calibrated SEM clone instrument as well as a Rare Gas Ionization Cell (RGIC) absolute detector. From the beginning of SEM data collection in 1996, the SOLERS 22 fixed reference solar spectrum has been used to calculate absolute EUV flux values from SEM raw data. Specifically, the reference spectrum provides a set of weighting factors for determining a weighted average for the wavelength dependent SEM response. The spectrum is used for calculation of the second order contamination in the first order channel signals, and for the comparison between SEM flux measurements with broader-band absolute RGIC measurements. SOHO/SEM EUV flux measurements for different levels of solar activity will be presented to show how the choice of reference spectra now available affects these SEM data. Both fixed (i.e. SOLERS 22) and non-fixed (Solar Irradiance Platform/Solar 2000 and SDO/EVE/MEGS) reference spectra have been included in this analysis.

  18. Rotational Scanning Electron Micrographs (rSEM): A novel and accessible tool to visualize and communicate complex morphology.

    PubMed

    Cheung, David K-B; Brunke, Adam J; Akkari, Nesrine; Souza, Carina Mara; Pape, Thomas

    2013-01-01

    An accessible workflow is presented to create interactive, rotational scanning electron micrographs (rSEM). These information-rich animations facilitate the study and communication of complex morphological structures exemplified here by male arthropod genitalia. Methods are outlined for the publication of rSEMs on the web or in journal articles as SWF files. Image components of rSEMs were archived in MorphBank to ensure future data access. rSEM represents a promising new addition to the toolkit of a new generation of digital taxonomy.

  19. [The cervical third of deciduous teeth. An ultrastructural study of the heard tissues by SEM].

    PubMed

    Leonardi, R; Loreto, C; Caltabiano, R; Caltabiano, C

    1996-03-01

    As information on amelocemental junction of deciduous teeth is limited, this topographical area was investigated by scanning electron microscopy (SEM) to verify differences from that of permanent teeth. Twenty-six carious and non-carious human maxillary and mandibular primary teeth were placed in a fixative immediately after extraction. Pulpal tissue was removed from the pulpal chambers and root. The primary teeth blocked onto stubs and all specimens were platinum coated and examined by SEM. In these specimens an overlapping of cementum onto to enamel and an edge to edge relationship was dominant. No gaps between enamel and cementum were observed. The amelocemental junction of deciduous teeth seem to differ to that described for permanent teeth.

  20. X-ray diffraction, FTIR, UV-VIS and SEM studies on chromium (III) complexes

    SciTech Connect

    Mishra, Ashutosh; Dwivedi, Jagrati Shukla, Kritika

    2015-06-24

    Five Chromium (III) complexes have been prepared using Schiff base ligands which derived from benzoin and five different amino acids (H{sub 2}N-R). Samples were characterized by XRD, FTIR, UV-VIS and SEM method. X-Ray diffraction pattern analyzed that all chromium (III) complexes have hexagonal structure and crystalline, in nature, using Bruker D8 Advance instrument. Using VERTAX 70, FTIR spectroscopy reveals that Samples have (C=N), (C-O), (M-N) and (M-O) bonds in the range of 4000-400cm{sup −1}. UV-VIS spectroscopy give information that samples absorb the visible light which is in the range of 380-780nm. For this, Lambda 960 spectrometer used. SEM is designed for studying of the solid objects, using JEOL JSM 5600 instrument.

  1. FIB–SEM tomography of 4th generation PWA 1497 superalloy

    SciTech Connect

    Ziętara, Maciej Kruk, Adam Gruszczyński, Adam Czyrska-Filemonowicz, Aleksandra

    2014-01-15

    The effect of creep deformation on the microstructure of the PWA 1497 single crystal Ni-base superalloy developed for turbine blade applications was investigated. The aim of the present study was to characterize quantitatively a superalloy microstructure and subsequent development of rafted γ′ precipitates in the PWA 1497 during creep deformation at 982 °C and 248 MPa up to rupture. The PWA1497 microstructure was characterized by scanning electron microscopy and FIB–SEM electron tomography. The 3D reconstruction of the PWA1497 microstructure is presented and discussed. - Highlights: • The microstructure of PWA1497 superalloy was examined using FIB–SEM tomography. • In case of modern single crystal superalloys, measurements of A{sub A} are adequate for V{sub V}. • During creep the γ channel width increases from 65 to 193 nm for ruptured specimen. • Tomography is a useful technique for quantitative studies of material microstructure.

  2. SEM Analysis of Residual Dentin Surface in Primary Teeth Using Different Chemomechanical Caries Removal Agents.

    PubMed

    Thakur, Rachna; Patil, Sandya Devi S; Kush, Anil; Madhu, K

    The purpose of this in vitro study was to analyze the residual dentinal surfaces following caries removal using two chemomechanical methods (Papacarie Duo and Carie Care), by scanning electron microscopy (SEM). Twenty extracted primary molars with active occlusal carious lesions were randomly assigned two groups depending on the CMCR agent used for the caries excavation - Group 1 - with Papacarie Duo and Group - 2 with Carie Care. After the caries excavation, the specimens were subjected to SEM analysis. Though both the agents showed the minimal smear layer with the patent dentinal tubules, Carie care showed patent dentinal tubules with a clearly exposed peritubular and intertubular collagen network. Carie Care treated surface exhibited better surface morphology of residual dentin.

  3. Liquid substitution: a versatile procedure for SEM specimen preparation of biological materials without drying or coating.

    PubMed

    Ensikat, H J; Barthlott, W

    1993-12-01

    Certain liquids with a very low vapour pressure, such as glycerol or triethylene glycol, can be used to infiltrate biological specimens so that they may be observed in the scanning electron microscope (SEM) without drying. The conductive properties of the fluids allow specimens to be examined either uncoated or with very thin coatings. The advantages of liquid substitution include the retention of lipids, waxes, loose particles, and surface contaminants. Since the procedure does not require expensive equipment, it offers an alternative to critical point drying or cryopreparation. For certain types of specimens, liquid substitution may represent the best preparation procedure. In addition, the fluids themselves may be imaged directly in the SEM, or indirectly by cathodoluminescence following labelling with fluorochromes.

  4. Three-dimensional characterization of drug-encapsulating particles using STEM detector in FEG-SEM.

    PubMed

    Barkay, Zahava; Rivkin, Ilia; Margalit, Rimona

    2009-06-01

    New drug-encapsulating particles were investigated using bright field (BF) scanning transmission electron microscopy (STEM) in a field emission gun (FEG) scanning electron microscope (SEM). Thickness characterization was done based on measuring the effective cross-section for interaction in our sample-detector configuration using calibration particles. A simplified analytical model, taking account of BF-STEM contrast and effective cross-section for interaction, was utilized for transforming projected two-dimensional BF-STEM images into three-dimensional thickness images. The three-dimensional characterization is demonstrated on a new family of biological materials composed of submicron to micron drug-free and drug-encapsulating particles. The importance of using BF-STEM in SEM, relative to other electron microscopy methods, is discussed as well as the lateral and depth resolution.

  5. In situ SEM micro-indentation of single wood pulp fibres in transverse direction.

    PubMed

    Adusumalli, Ramesh-Babu; Raghavan, Rejin; Schwaller, Patrick; Zimmermann, Tanja; Michler, Johann

    2010-01-01

    Fibre deformations such as kinks and micro-compressions are significant parameters in determining the quality of industrial pulps. Undoubtedly, very little information has been obtained so far on fibre deformation because it is very tedious to handle the specimens. In this study, a novel in situ scanning electron microscope (SEM) micro-indentation technique was adopted for the first time to study the deformation of single industrial pulp fibres in the transverse direction. A one-to-one correspondence between load drops in load-displacement curve and cell wall deformation was obtained by using the SEM video sequence recorded during micro-indentation. The cell wall deformation occurred by 'elastic' sinking-in and lateral bulging of the microfibrils. Finally, the critical load (stress) required to initiate a crack in the cell wall was measured for different unbleached pulp fibres.

  6. An in situ SEM experimental study of the thermal stability of a LAST thermoelectric material

    SciTech Connect

    Ren, Fei; Howe, Jane Y; Walker, Larry R; Case, Eldon D; Lara-Curzio, Edgar

    2011-01-01

    Thermal stability is a key factor affecting the deployment of thermoelectric (TE) materials in the application of power generation. LAST (Lead-Antimony-Silver-Tellurium) is an emerging material with promising TE properties. The current study focused on the thermal stability of a LAST composition Ag0.86Pb19SbTe20 fabricated from a cast ingot. Using a customized heating stage, the morphology of LAST particles was studied via scanning electron microscopy (SEM) in situ, between room temperature and 575oC. The LAST material included in this study was stable below 550oC. The inclusion phase, which was antimony-rich, has a lower thermal stability than the PbTe-rich matrix. The SEM finding was also consistent with a thermogravimetrtic analysis.

  7. SEM studies on BSCCO superconducting ceramic produced by spray frozen, freeze drying technique

    NASA Astrophysics Data System (ADS)

    Bunescu, M.-C.; Aldica, G.; Badica, P.; Vasiliu, F.; Nita, P.; Mandache, S.

    1997-02-01

    Scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) have been used to evidence the occurrence, morphology and microcomposition of the superconducting phases (Bi,Pb) 2Sr 2Ca 2Cu 3O 10 + δ (2223) and (Bi,Pb) 2Sr 2CaCu 2O 8 + δ (2212), and of other non-superconducting phases, in the sintered pellets obtained from nitrate solution by spray frozen, freeze drying technique. For decomposition of the nitrate powder four different heat treatments were used. Superconducting and structure properties of the pellets have been tested by AC susceptibility measurments (610 Hz, 0.5 Oe) and X-ray diffraction analysis, respectively. A correlation between the SEM and EDS observations and the superconducting properties has been established.

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

    NASA Technical Reports Server (NTRS)

    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.

  9. In-situ thermal cycling in SEM of a graphite-aluminum composite

    NASA Technical Reports Server (NTRS)

    Cheong, Y. M.; Marcus, H. L.

    1987-01-01

    In situ SEM observations of a graphite-aluminum composite (unidirectional P100 graphite-fiber-reinforced 6061 aluminum MMC plates) were used to measure displacements within the graphite fiber relative to the interface between the graphite fiber and the aluminum matrix during thermal cycling. Specimens were thermally cycled from room temperature to 300 C or 500 C in a SEM chamber and then cooled to room temperature. The obtained shear strains within the fiber were then related to anomalous values of measured residual stresses and to the impact on the composite coefficient of expansion and potential damage under thermal fatigue loading. The shear mechanism was proposed as a source of temperature limits on the low coefficient of expansion of these composites, as well as a potential source of thermal fatigue degradation.

  10. Nanomanufacturing concerns about measurements made in the SEM part IV: charging and its mitigation

    NASA Astrophysics Data System (ADS)

    Postek, Michael T.; Vladár, András. E.

    2015-08-01

    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 scientifi c and industrial applications. These improvements have signifi cantly 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 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 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

  11. Testing the best method to prepare recent and fossil brachiopod shells for SEM analysis

    NASA Astrophysics Data System (ADS)

    Crippa, Gaia; Ye, Facheng

    2017-04-01

    The analysis of shell microstructures by Scanning Electron Microscope (SEM) is a method easily available to most palaeontologists and geochemists. This kind of analysis is a fundamental step in the study of the mineralised parts of marine and terrestrial organisms, and it provides invaluable information in different fields of palaeontology, from the comprehension of evolutionary taxonomy and biomineralisation processes to the screening of shell diagenetic alteration. In precipitating their low-magnesium calcite shells in isotopic equilibrium with ambient seawater, brachiopods are excellent archives of past seawater temperature and ocean chemistry. However, diagenetic processes may alter the original fabric and the original geochemical composition of the shells; the SEM analysis of the microstructure represents one of the most common method used to test fossil shell preservation and eventually exclude diagenetic alteration. Notwithstanding the importance of this analysis, only few and scattered data have been published about the preparation and cleaning of brachiopod shells for SEM analyses Here, we describe several tests performed on recent and fossil brachiopod shells, experimenting new and old methodologies in order to identify a general protocol to better highlight and analyze the shell fabric. Recent taxa include Liothyrella uva and Liothyrella neozelanica, respectively collected from Antarctica and New Zealand; fossil shells are those of Terebratula scillae collected from the lower Pleistocene Stirone River sedimentary succession in Northern Italy. We carried out several tests to check the response of the shell fabric to the resin used to embed the valves before cutting and to different times of exposure to hydrochloric acid; furthermore, as the presence of the organic matrix in recent shells represents the main obstacle to obtaining high quality SEM images, we used bleach and hydrogen peroxide with different concentrations and times of exposure to remove it

  12. Nanomanufacturing concerns about measurements made in the SEM Part III: vibration and drift

    NASA Astrophysics Data System (ADS)

    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.

  13. Does your SEM really tell the truth? How would you know? part 3: vibration and drift

    NASA Astrophysics Data System (ADS)

    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.

  14. SEM visualization of glycosylated surface molecules using lectin-coated microspheres

    NASA Technical Reports Server (NTRS)

    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).

  15. High Gain, Fast Scan, Broad Spectrum, Parallel Beam Wavelength Dispersive X-ray Spectrometer for SEM

    SciTech Connect

    David OHara; Dr. Eric Lochmer

    2003-09-12

    Parallax Research, Inc. proposes to produce a new type of x-ray spectrometer for use with Scanning Electron Microscopy (SEM) that would have the energy resolution of WDS and the ease of use of EDS with sufficient gain for lower energies that it can be used at low beam currents as is EDS. Parallax proposes to do this by development of new multiple reflection x-ray collimation optics, new diffractor technology, new detector technology and new scan algorithms.

  16. High gain, Fast Scan, Broad Spectrum Parallel Beam Wavelength Dispersive X-ray Spectrometer for SEM

    SciTech Connect

    OHara, David

    2009-05-08

    During contract # DE-FG02-ER83545, Parallax Research, Inc. developed a High gain, Fast Scan Broad Spectrum Parallel beam Wavelength Dispersive X-ray Spectrometer for use on Scanning Electron Microscopes (SEM). This new spectrometer allows very fast high resolution elemental analysis of samples in an electron microscope. By comparison to previous WDS spectrometers, it can change from one energy position to another very quickly and has an extended range compared to some similar products.

  17. The Surface Morphology Characterization of Electroless Nickel Immersion Gold Under Bump Metallurgy (UBM) Using SEM

    SciTech Connect

    Arshad, M. K. Md; Isa, M. N. Md; Sohiful, Z. M. A.

    2007-05-09

    This paper presents the surface morphology characterization at each process step in electroless nickel immersion gold (ENIG) deposition using Scanning Electron Microscope (SEM). The characterization start at initial bond pad, followed by cleaning, activation, first zincation, zinc removal, second zincation, electroless nickel and lastly immersion gold process. The result shows that the surface morphology of initial bond pad starts to change with deposition of zinc layer and further changes with deposition of nickel and gold layer.

  18. A new method using Scanning Electron Microscopy (SEM) for preparation of anisopterous odonates.

    PubMed

    Del Palacio, Alejandro; Sarmiento, Patricia Laura; Javier, Muzón

    2017-10-01

    Anisopterous odonate male's secondary genitalia is a complex of several structures, among them the vesica spermalis is the most informative with important specific characters. The observation of those characters, mostly of membranous nature, is difficult in the Scanning Electron Microscope due to dehydration and metallization processes. In this contribution, we discuss a new and low cost procedure for the observation of these characters in the SEM, compatible with the most common agents used for preserving specimens. © 2017 Wiley Periodicals, Inc.

  19. WebSEM: an assessment of K-12 remote microscopy efforts.

    PubMed

    Chumbley, A E; Chumbley, L S

    2007-01-01

    Within the past 10 years a number of institutions have developed and instituted systems and programs that enable remote control of a scanning electron microscope (SEM). Geared toward use by teachers and educators in K-12 classrooms, these systems have offered access to advanced instrumentation to thousands of students over the past decade. However, despite the enormous potential and promise associated with remote microscopy, the reality has been that most such systems are not utilized to their fullest extent. This is partly due to time constraints on the instrument; many such systems are an integral part of the research and/or teaching focus of the institution that offers the service, and as such, K-12 educators are forced to compete with institutional demands. Often this restricts the amount of lessons that can be conducted to a relatively small number, in rather narrowly defined windows of opportunity. However, even when such constraints do not exist, the number of lessons typically requested remains disappointingly low, and the lessons that are conducted are usually simple examinations lacking in depth. In an effort to determine why the promise of K-12 remote microscopy has not been fully realized, a number of assessments have been carried out at Iowa State University in relation to operation and use of the WebSEM, the Web-controllable SEM operated by the Materials Science and Engineering Department of Iowa State University as a part of Project ExCEL, the Extended Classroom for Enhanced Learning. These assessments indicate that the key to successful use of advanced equipment in K-12 classrooms depends less upon hardware than it does upon local instructional situations. Establishing a personal relationship between the SEM operator and the teacher in the classroom appears to be the best way to increase current use of remote microscopy.

  20. GW-SEM: A Statistical Package to Conduct Genome-Wide Structural Equation Modeling.

    PubMed

    Verhulst, Brad; Maes, Hermine H; Neale, Michael C

    2017-05-01

    Improving the accuracy of phenotyping through the use of advanced psychometric tools will increase the power to find significant associations with genetic variants and expand the range of possible hypotheses that can be tested on a genome-wide scale. Multivariate methods, such as structural equation modeling (SEM), are valuable in the phenotypic analysis of psychiatric and substance use phenotypes, but these methods have not been integrated into standard genome-wide association analyses because fitting a SEM at each single nucleotide polymorphism (SNP) along the genome was hitherto considered to be too computationally demanding. By developing a method that can efficiently fit SEMs, it is possible to expand the set of models that can be tested. This is particularly necessary in psychiatric and behavioral genetics, where the statistical methods are often handicapped by phenotypes with large components of stochastic variance. Due to the enormous amount of data that genome-wide scans produce, the statistical methods used to analyze the data are relatively elementary and do not directly correspond with the rich theoretical development, and lack the potential to test more complex hypotheses about the measurement of, and interaction between, comorbid traits. In this paper, we present a method to test the association of a SNP with multiple phenotypes or a latent construct on a genome-wide basis using a diagonally weighted least squares (DWLS) estimator for four common SEMs: a one-factor model, a one-factor residuals model, a two-factor model, and a latent growth model. We demonstrate that the DWLS parameters and p-values strongly correspond with the more traditional full information maximum likelihood parameters and p-values. We also present the timing of simulations and power analyses and a comparison with and existing multivariate GWAS software package.

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

    PubMed

    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.

  2. SEM visualization of glycosylated surface molecules using lectin-coated microspheres

    NASA Technical Reports Server (NTRS)

    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).

  3. Study of SEM induced current and voltage contrast modes to assess semiconductor reliability

    NASA Technical Reports Server (NTRS)

    Beall, J. R.

    1976-01-01

    The purpose of the scanning electron microscopy study was to review the failure history of existing integrated circuit technologies to identify predominant failure mechanisms, and to evaluate the feasibility of their detection using SEM application techniques. The study investigated the effects of E-beam irradiation damage and contamination deposition rates; developed the necessary methods for applying the techniques to the detection of latent defects and weaknesses in integrated circuits; and made recommendations for applying the techniques.

  4. Nanomanufacturing Concerns about Measurements Made in the SEM Part IV: Charging and its Mitigation.

    PubMed

    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

  5. SEM/EDS analysis for problem solving in the food industry

    NASA Astrophysics Data System (ADS)

    Niemeyer, Wayne D.

    2015-10-01

    For forensic investigation in the food industry, scanning electron microscopy (SEM) in conjunction with energy dispersive X-ray spectrometry (EDS) is a powerful, often non-destructive, instrumental analysis tool to provide information about: • Identification of inorganic (and some organic) materials found as foreign contaminants in food products returned by consumers or detected during quality control inspections in the production facilities • Identification of wear particles found in production lines • Distribution of materials within a matrix • Corrosion and failure analysis of production equipment The identification of materials by SEM/EDS is accomplished through a combination of morphology by SEM imaging and the elemental composition of the material by EDS. Typically, the EDS analysis provides a qualitative spectrum showing the elements present in the sample. Further analysis can be done to quantify the detected elements in order to further refine the material identification. Metal alloys can often be differentiated even within the same family such as 300 Series stainless steels. Glass types can be identified by the elemental composition where the detected elements are quantified as the oxides of each element. In this way, for example, common window glass is distinguishable from insulation glass used in many ovens. Wear particles or fragments from breakage can find their way into food products. SEM/EDS analysis of the materials is an important resource to utilize when trying to determine the original source. Suspected source materials can then be sampled for comparative analysis. EDS X-ray mapping is another tool that is available to provide information about the distribution of materials within a matrix. For example, the distribution of inorganic ingredients in a dried food helps to provide information about the grind and blend of the materials.

  6. SEM, magnetization and Mössbauer spectroscopic characterization of Fe-U sequestration

    NASA Astrophysics Data System (ADS)

    Pal, Sangita; Meena, Sher Singh; Chowdhury, Supratik Roy; Prajapat, C. L.; Goswami, D.

    2017-05-01

    The Jekyll and Hyde nature of iron and uranium loaded "IN-HOUSE' resin viz., Polyacrylamide hydroxamic acid (PAAHA) has been characterized by FT-IR, SEM, Mössbauer spectroscopy, EDXRF and magnetization measurements techniques. Among all Mössbauer spectra and magnetization properties indicates supportive documents of characteristic special acquaintance nature of iron w.r.t accumulated U within the matrix even after loading of Fe in vast.

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

    PubMed Central

    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

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

    PubMed

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

    2016-12-01

    Surface integrity of dental elastomeric impression materials that are subjected to disinfection is of major importance for the quality of the final prosthetic restorations. 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. 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. 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. 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.

  9. FIB/SEM technology and Alzheimer's disease: three-dimensional analysis of human cortical synapses.

    PubMed

    Blazquez-Llorca, Lidia; Merchán-Pérez, Ángel; Rodríguez, José-Rodrigo; Gascón, Jorge; DeFelipe, Javier

    2013-01-01

    The quantification and measurement of synapses is a major goal in the study of brain organization in both health and disease. Serial section electron microscopy (EM) is the ideal method since it permits the direct quantification of crucial features such as the number of synapses per unit volume or the distribution and size of synapses. However, a major limitation is that obtaining long series of ultrathin sections is extremely time-consuming and difficult. Consequently, quantitative EM studies are scarce and the most common method employed to estimate synaptic density in the human brain is indirect, by counting at the light microscopic level immunoreactive puncta using synaptic markers. The recent development of automatic EM methods in experimental animals, such as the combination of focused ion beam milling and scanning electron microscopy (FIB/SEM), are opening new avenues. Here we explored the utility of FIB/SEM to examine the cerebral cortex of Alzheimer's disease patients. We found that FIB/SEM is an excellent tool to study in detail the ultrastructure and alterations of the synaptic organization of the human brain. Using this technology, it is possible to reconstruct different types of plaques and the surrounding neuropil to find new aspects of the pathological process associated with the disease, namely; to count the exact number and types of synapses in different regions of the plaques, to study the spatial distribution of synapses, and to analyze the morphology and nature of the various types of dystrophic neurites and amyloid deposits.

  10. Evaluation of residual dentin after conventional and chemomechanical caries removal using SEM.

    PubMed

    Corrêa, Fernanda Nahás Pires; Rodrigues Filho, Leonardo Eloy; Rodrigues, Célia Regina Martins Delgado

    2008-01-01

    The purpose of this in vitro study was to analyze the residual dentinal surfaces following caries removal using rotatory instruments and two chemomechanical methods (Papacárie and Carisolv), by scanning electron microscopy (SEM). Thirty primary incisors were divided into three groups, according to the caries removal method used, and their residual dentin was examined under SEM (15). After caries removal, 15 of these teeth were restored with Single Bond (3M) adhesive system and Z100 Filtek composite resin (3M). The tags of the replicas were observed under SEM. The chemomechanical caries removal methods (Papacárie and Carisolv) formed an amorphous layer, similar to the smear layer and few exposed dentinal tubules; the conventional caries removal method produced a smooth and regular dentinal surface, with typical smear layer and exposed dentinal tubules. All groups showed abundant tag formation. Scanning electron microscopy analysis revealed a difference between dentin treated with rotatory instruments and that treated with chemomechanical methods in spite of the occurrence of a similar tag formation in both groups.

  11. Amalgam Surface Treatment by Different Output Powers of Er:YAG Laser:SEM Evaluation.

    PubMed

    Hosseini, Mohammad Hashem; Hassanpour, Mehdi; Etemadi, Ardavan; Ranjbar Omrani, Ladan; Darvishpour, Hojat; Chiniforush, Nasim

    2015-01-01

    The purpose of this study was to evaluate amalgam surfaces treated by different output powers of erbium-doped yttrium aluminum garnet (Er:YAG) laser by scanning electron microscope (SEM). Twenty-one amalgam blocks (8 mm × 8 mm, 3 mm thickness) were prepared by condensing silver amalgam (into putty impression material. After keeping them for 24 hours in distilled water, they were divided into 7 groups as follow: G1: Er:YAG laser (1 W, 50 mJ), G2: Er:YAG laser (2 W, 100 mJ), G3: Er:YAG laser (3 W, 150 mJ), G4: Sandblast, G5: Sandblast + Er:YAG laser (1 W, 50 mJ), G6: Sandblast +Er:YAG laser (2 W, 100 mJ) and G7: Sandblast +Er:YAG laser (3 W, 150 mJ). Then after preparation of all samples, they were examined by SEM. The SEM results of amalgam surfaces treated by different output powers of Er:YAG laser showed some pitting areas with non-homogenous irregularities Conclusion: It seems that the application of sandblasting accompanied by Er:YAG laser irradiation can provide proper surface for bonding of orthodontic brackets.

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

    PubMed

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

    2014-02-07

    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 microspectrometer. When deposited on exceptionally smooth substrates, uranyl fluoride particles smaller than 1000 nm could successfully be analyzed with the SEM-SCA system.

  13. Deep learning and shapes similarity for joint segmentation and tracing single neurons in SEM images

    NASA Astrophysics Data System (ADS)

    Rao, Qiang; Xiao, Chi; Han, Hua; Chen, Xi; Shen, Lijun; Xie, Qiwei

    2017-02-01

    Extracting the structure of single neurons is critical for understanding how they function within the neural circuits. Recent developments in microscopy techniques, and the widely recognized need for openness and standardization provide a community resource for automated reconstruction of dendritic and axonal morphology of single neurons. In order to look into the fine structure of neurons, we use the Automated Tape-collecting Ultra Microtome Scanning Electron Microscopy (ATUM-SEM) to get images sequence of serial sections of animal brain tissue that densely packed with neurons. Different from other neuron reconstruction method, we propose a method that enhances the SEM images by detecting the neuronal membranes with deep convolutional neural network (DCNN) and segments single neurons by active contour with group shape similarity. We joint the segmentation and tracing together and they interact with each other by alternate iteration that tracing aids the selection of candidate region patch for active contour segmentation while the segmentation provides the neuron geometrical features which improve the robustness of tracing. The tracing model mainly relies on the neuron geometrical features and is updated after neuron being segmented on the every next section. Our method enables the reconstruction of neurons of the drosophila mushroom body which is cut to serial sections and imaged under SEM. Our method provides an elementary step for the whole reconstruction of neuronal networks.

  14. Amalgam Surface Treatment by Different Output Powers of Er:YAG Laser:SEM Evaluation

    PubMed Central

    Hosseini, Mohammad Hashem; Hassanpour, Mehdi; Etemadi, Ardavan; Ranjbar Omrani, Ladan; Darvishpour, Hojat; Chiniforush, Nasim

    2015-01-01

    Introduction: The purpose of this study was to evaluate amalgam surfaces treated by different output powers of erbium-doped yttrium aluminum garnet (Er:YAG) laser by scanning electron microscope (SEM). Methods: Twenty-one amalgam blocks (8 mm × 8 mm, 3 mm thickness) were prepared by condensing silver amalgam (into putty impression material. After keeping them for 24 hours in distilled water, they were divided into 7 groups as follow: G1: Er:YAG laser (1 W, 50 mJ), G2: Er:YAG laser (2 W, 100 mJ), G3: Er:YAG laser (3 W, 150 mJ), G4: Sandblast, G5: Sandblast + Er:YAG laser (1 W, 50 mJ), G6: Sandblast +Er:YAG laser (2 W, 100 mJ) and G7: Sandblast +Er:YAG laser (3 W, 150 mJ). Then after preparation of all samples, they were examined by SEM. Results: The SEM results of amalgam surfaces treated by different output powers of Er:YAG laser showed some pitting areas with non-homogenous irregularities Conclusion: It seems that the application of sandblasting accompanied by Er:YAG laser irradiation can provide proper surface for bonding of orthodontic brackets. PMID:26705463

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

    SciTech Connect

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

    2010-03-01

    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.

  16. Morphological segmentation of FIB-SEM data of highly porous media.

    PubMed

    Prill, T; Schladitz, K; Jeulin, D; Faessel, M; Wieser, C

    2013-05-01

    Nanoporous materials play an important role in modern batteries as well as fuel cells. The materials microstructure needs to be analyzed as it determines the electrochemical properties. However, the microstructure is too fine to be resolved by microcomputed tomography. The method of choice to analyze the microstructure is focused ion beam nanotomography (FIB-SEM). However, the reconstruction of the porous 3D microstructure from FIB-SEM image data in general has been an unsolved problem so far. In this paper, we present a new method using morphological operations. First, features are extracted from the data. Subsequently, these features are combined to an initial segmentation, that is then refined by a constrained watershed transformation. We evaluate our method with synthetic data, generated by a simulation of the FIB-SEM imaging process. We compare the ground truth in the simulated data to the segmentation result. The new method is found to produce a much smaller error than existing techniques. © 2013 The Authors Journal of Microscopy © 2013 Royal Microscopical Society.

  17. Three-dimensional imaging of adherent cells using FIB/SEM and STEM.

    PubMed

    Villinger, Clarissa; Schauflinger, Martin; Gregorius, Heiko; Kranz, Christine; Höhn, Katharina; Nafeey, Soufi; Walther, Paul

    2014-01-01

    In this chapter we describe three different approaches for three-dimensional imaging of electron microscopic samples: serial sectioning transmission electron microscopy (TEM), scanning transmission electron microscopy (STEM) tomography, and focused ion beam/scanning electron microscopy (FIB/SEM) tomography. With these methods, relatively large volumes of resin-embedded biological structures can be analyzed at resolutions of a few nm within a reasonable expenditure of time. The traditional method is serial sectioning and imaging the same area in all sections. Another method is TEM tomography that involves tilting a section in the electron beam and then reconstruction of the volume by back projection of the images. When the scanning transmission (STEM) mode is used, thicker sections (up to 1 μm) can be analyzed. The third approach presented here is focused ion beam/scanning electron microscopy (FIB/SEM) tomography, in which a sample is repeatedly milled with a focused ion beam (FIB) and each newly produced block face is imaged with the scanning electron microscope (SEM). This process can be repeated ad libitum in arbitrary small increments allowing 3D analysis of relatively large volumes such as eukaryotic cells. We show that resolution of this approach is considerably improved when the secondary electron signal is used. However, the most important prerequisite for three-dimensional imaging is good specimen preparation. For all three imaging methods, cryo-fixed (high-pressure frozen) and freeze-substituted samples have been used.

  18. STEM-in-SEM high resolution imaging of gold nanoparticles and bivalve tissues in bioaccumulation experiments.

    PubMed

    García-Negrete, C A; Jiménez de Haro, M C; Blasco, J; Soto, M; Fernández, A

    2015-05-07

    The methodology termed scanning transmission electron microscopy in scanning electron microscopy (STEM-in-SEM) has been used in this work to study the uptake of citrate stabilized gold nanoparticles (AuNPs) (average particle sizes of 23.5 ± 4.0 nm) into tissue samples upon in vitro exposure of the dissected gills of the Ruditapes philippinarum marine bivalve to the nanoparticle suspensions. The STEM-in-SEM methodology has been optimized for achieving optimum resolution under SEM low voltage operating conditions (20-30 kV). Based on scanning microscope assessments and resolution testing (SMART), resolutions well below 10 nm were appropriately achieved by working at magnifications over 100k×, with experimental sample thickness between 300 and 200 nm. These relatively thick slices appear to be stable under the beam and help avoid NP displacement during cutting. We herein show that both localizing of the internalized nanoparticles and imaging of ultrastructural disturbances in gill tissues are strongly accessible due to the improved resolution, even at sample thicknesses higher than those normally employed in standard TEM techniques at higher voltages. Ultrastructural imaging of bio-nano features in bioaccumulation experiments have been demonstrated in this study.

  19. Tin amalgam mirrors: investigation by XRF, SEM-EDS, XRD and EPMA-WDS mapping

    NASA Astrophysics Data System (ADS)

    Arizio, E.; Orsega, E. F.; Sommariva, G.; Falcone, R.

    2013-06-01

    Ancient mirrors were constituted by a tin-mercury amalgam layer superimposed to a glass sheet. This was the only one method used until the nineteenth century, when the wet silvering process was invented. The tin amalgam is a binary alloy of tin and mercury constituted by two different phases: a mercury-rich liquid phase and a tin-rich solid phase. The amalgam alteration produces mercury loss and a general growth of the solid crystalline phase. In addition, tin dioxide and monoxide are formed with a consequent decrease of the amalgam adhesion to the glass. These degradation phenomena led to reduction or disappearance of the mirror reflective power. The aim of this study was the characterization of the amalgam layers of eight mirror samples dating during the seventeenth and nineteenth centuries. The samples were analyzed by X-ray diffraction and by a Scanning Electron Microscope with an Energy Dispersive Spectrometer (SEM-EDS), and for the first time on this type of alloy by X-ray Fluorescence and EPMA-WDS (Electron Probe Micro Analysis with Wavelength Dispersive Spectrometry) elemental mapping. The contents of tin, mercury, and some trace elements in the amalgam layers have been determined. The investigation of the superficial patterns of the amalgam by SEM, EPMA-WDS mapping, and SEM-EDS allowed a first understanding of some morphologies and processes of the degradation of the amalgam layer.

  20. SEM-induced shrinkage and site-selective modification of single-crystal silicon nanopores

    NASA Astrophysics Data System (ADS)

    Chen, Qi; Wang, Yifan; Deng, Tao; Liu, Zewen

    2017-07-01

    Solid-state nanopores with feature sizes around 5 nm play a critical role in bio-sensing fields, especially in single molecule detection and sequencing of DNA, RNA and proteins. In this paper we present a systematic study on shrinkage and site-selective modification of single-crystal silicon nanopores with a conventional scanning electron microscope (SEM). Square nanopores with measurable sizes as small as 8 nm × 8 nm and rectangle nanopores with feature sizes (the smaller one between length and width) down to 5 nm have been obtained, using the SEM-induced shrinkage technique. The analysis of energy dispersive x-ray spectroscopy and the recovery of the pore size and morphology reveal that the grown material along with the edge of the nanopore is the result of deposition of hydrocarbon compounds, without structural damage during the shrinking process. A simplified model for pore shrinkage has been developed based on observation of the cross-sectional morphology of the shrunk nanopore. The main factors impacting on the task of controllably shrinking the nanopores, such as the accelerating voltage, spot size, scanned area of e-beam, and the initial pore size have been discussed. It is found that single-crystal silicon nanopores shrink linearly with time under localized irradiation by SEM e-beam in all cases, and the pore shrinkage rate is inversely proportional to the initial equivalent diameter of the pore under the same e-beam conditions.

  1. In situ SEM Study of Lithium Intercalation in individual V2O5 Nanowires

    DOE PAGES

    Strelcov, Evgheni; Cothren, Joshua E.; Leonard, Donovan N.; ...

    2015-01-08

    Progress in rational engineering of Li-ion batteries requires better understanding of the electrochemical processes and accompanying transformations in the electrode materials on multiple length scales. In spite of recent progress in utilizing transmission electron microscopy (TEM) to analyze these materials, in situ scanning electron microscopy (SEM) was mostly overlooked as a powerful tool that allows probing these phenomena on the nano and mesoscale. In this paper, we report on in situ SEM study of lithiation in a V2O5-based single-nanobelt battery with ionic liquid electrolyte. Coupled with cyclic voltammetry measurements, in situ SEM revealed the peculiarities of subsurface intercalation, formation ofmore » solid-electrolyte interface (SEI) and electromigration of liquid. We observed that single-crystalline vanadia nanobelts do not undergo large-scale amorphization or fracture during electrochemical cycling, but rather transform topochemically with only a slight shape distortion. Lastly, the SEI layer seems to have significant influence on the lithium ion diffusion and overall capacity of the single-nanobelt battery.« less

  2. Combined AC-STEM and FIB-SEM Characterization of Shale

    NASA Astrophysics Data System (ADS)

    Dewers, T. A.; Heath, J. E.; Kotula, P.; Yoon, H.; Gardner, P.

    2013-12-01

    We examine shale samples with state-of-the-art aberration corrected scanning transmission electron microscopy (AC-STEM) and focused ion beam-scanning electron (FIB-SEM) microscopy. Three-dimensional reconstruction of pore space incorporates electron tomography using the AC-TEM and serial sectioning by FIB-SEM. Chemical analysis by X-ray energy dispersive microscopy reveals composition of pore-lining phases at ~ 1 nm resolution. Our methods reveal the left tail of the pore size distribution that FIB-SEM techniques typically do not capture (pore sizes < 7 nm). Water in pores of this size will deviate from those of bulk water, which can influence non-Darcy flow and mechanical response. The impact of these small pores on fluid and coupled tracer transport is examined by computation fluid dynamics using 3D pore reconstructions. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

  3. SEM Observation of Hydrous Superabsorbent Polymer Pretreated with Room-Temperature Ionic Liquids

    PubMed Central

    Tsuda, Tetsuya; Mochizuki, Eiko; Kishida, Shoko; Iwasaki, Kazuki; Tsunashima, Katsuhiko; Kuwabata, Susumu

    2014-01-01

    Room-temperature ionic liquid (RTIL), which is a liquid salt at or below room temperature, shows peculiar physicochemical properties such as negligible vapor pressure and relatively-high ionic conductivity. In this investigation, we used six types of RTILs as a liquid material in the pretreatment process for scanning electron microscope (SEM) observation of hydrous superabsorbent polymer (SAP) particles. Very clear SEM images of the hydrous SAP particles were obtained if the neat RTILs were used for the pretreatment process. Of them, tri-n-butylmethylphosphonium dimethylphosphate ([P4, 4, 4, 1][DMP]) provided the best result. On the other hand, the surface morphology of the hydrous SAP particles pretreated with 1-ethyl-3-methylimidazolium tetrafluoroborate ([C2mim][BF4]) and 1-butyl-3-methylimidazolium tetrafluoroborate ([C4mim][BF4]) was damaged. The results of SEM observation and thermogravimetry analysis of the hydrous SAP pretreated with the RTILs strongly suggested that most water in the SAP particles are replaced with RTIL during the pretreatment process. PMID:24621609

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

    PubMed Central

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

    DOE PAGES

    Xu, C. Shan; Hayworth, Kenneth J.; Lu, Zhiyuan; ...

    2017-05-13

    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 > 10 6 ?m 3 . These volumes are large enough for connectomics, where the excellent z resolution can help in tracing of small neuronalmore » 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.« less

  6. Surface treatment of glass fiber and carbon fiber posts: SEM characterization.

    PubMed

    Naves, Lucas Zago; Santana, Fernanda Ribeiro; Castro, Carolina Guimarães; Valdivia, Andréa Dolores Correia Miranda; Da Mota, Adérito Soares; Estrela, Carlos; Correr-Sobrinho, Lourenço; Soares, Carlos José

    2011-12-01

    Morphology, etching patterns, surface modification, and characterization of 2 different fiber posts: Gfp, Glass fiber post; and Cfp, carbon fiber were investigated by SEM analysis, after different surface treatments. Thirty fiber posts, being 15 Gfp and 15 Cfp were divided into a 5 surface treatments (n = 3): C-alcohol 70% (control); HF 4%-immersion in 4% hydrofluoric acid for 1min; H(3) PO(4) 37%-immersion in 37% phosphoric acid for 30s; H(2) O(2) 10%-immersion in 10% hydrogen peroxide for 20 min; H(2) O(2) 24%-immersion in 24% hydrogen peroxide for 10 min. Morphology, etching patterns, surface modification and surface characterization were acessed by SEM analysis. SEM evaluation revealed that the post surface morphology was modified following all treatment when compared with a control group, for both type of reinforced posts. HF seems to penetrate around the fibers of Gfp and promoted surface alterations. The Cfp surface seems to be inert to treatment with HF 4%. Dissolution of epoxy resin and exposure of the superficial fiber was observed in both post groups, regardless the type of reinforcing fiber, H(2) O(2) in both concentrations. Relative smooth surface area was produced by H(3) PO(4) 37% treatment, but with similar features to untreated group. Surface treatment of fiber post is a determinant factor on micromechanical entanglement to resin composite core. Post treatment with hydrogen peroxide resulted strength of carbon and glass/epoxy resin fiber posts to resin composite core. Copyright © 2011 Wiley Periodicals, Inc.

  7. CD-SEM measurement line-edge roughness test patterns for 193-nm lithography

    NASA Astrophysics Data System (ADS)

    Bunday, Benjamin D.; Bishop, Michael; Villarrubia, John S.; Vladar, Andras E.

    2003-05-01

    The measurement of line-edge roughness (LER) has recently become a major topic of concern in the litho-metrology community and the semiconductor industry as a whole, as addressed in the 2001 ITRS roadmap. The Advanced Metrology Advisory Group (AMAG, a council composed of the chief CD-metrologists from the International SEMATECH consortium's Member Companies and from the National Institute of Standards and Technology, NIST) has begun a project to investigate this issue and to direct the CD-SEM supplier community towards a semiconductor industry-backed solution for implementation. The AMAG group has designed and built a 193 nm reticle that includes structures implementing a number of schemes to intentionally cause line edge roughness of various spatial frequencies and amplitudes. The lithography of these structures is in itself of interest to the litho-metrology community and will be discussed here. Measurements on different CD-SEMs of major suppliers will be used to comparatively demonstrate the current state of LER measurement. These measurements are compared to roughness determined off-line by analysis of top-down images from these tools. While no official standard measurement algorithm or definition of LER measurement exists, definitions used in this work are presented and compared in use. Repeatability of the measurements and factors affecting their accuracy will be explored, as well as how CD-SEM parameters can effect the measurements.

  8. 3D nanostructure reconstruction based on the SEM imaging principle, and applications.

    PubMed

    Zhu, Fu-Yun; Wang, Qi-Qi; Zhang, Xiao-Sheng; Hu, Wei; Zhao, Xin; Zhang, Hai-Xia

    2014-05-09

    This paper addresses a novel 3D reconstruction method for nanostructures based on the scanning electron microscopy (SEM) imaging principle. In this method, the shape from shading (SFS) technique is employed, to analyze the gray-scale information of a single top-view SEM image which contains all the visible surface information, and finally to reconstruct the 3D surface morphology. It offers not only unobstructed observation from various angles but also the exact physical dimensions of nanostructures. A convenient and commercially available tool (NanoViewer) is developed based on this method for nanostructure analysis and characterization of properties. The reconstruction result coincides well with the SEM nanostructure image and is verified in different ways. With the extracted structure information, subsequent research of the nanostructure can be carried out, such as roughness analysis, optimizing properties by structure improvement and performance simulation with a reconstruction model. Efficient, practical and non-destructive, the method will become a powerful tool for nanostructure surface observation and characterization.

  9. Suppression of noise in SEM images using weighted local hysteresis smoothing filter.

    PubMed

    Mazhari, Mohadeseh; Hasanzadeh, Reza P R

    2016-11-01

    It has been proven that Hysteresis Smoothing (HS) has several advantages for Scanning Electron Microscopy (SEM) image noise reduction. HS uses hysteresis thresholding to remove noise besides preserving important details of images. Determination of optimal threshold values (cursor width) plays an effective role in improving the performance of HS based filters. Recently, a novel local technique, named Local Adaptive Hysteresis Smoothing (LAHS), has been proposed to compute an optimal cursor width. In this paper, a new method is proposed to improve the performance of LAHS in noise reduction and detail preservation. In the proposed approach which is based on weighted averaging, local statistical characteristics of the image are used in order to modify the final values of estimated pixels by LAHS method. Proposed method is applied to SEM images corrupted by different levels of noise. Noise reduction and detail preservation performance of the proposed method is compared in both objective and subjective manners with other HS based filters. Experimental results demonstrate that the proposed method is successful in improving the performance of LAHS and also it achieves better performance in noise reduction besides detail preservation of SEM images in comparison with other HS based filters. SCANNING 38:634-643, 2016. © 2016 Wiley Periodicals, Inc.

  10. Modelling and analysis of FMS productivity variables by ISM, SEM and GTMA approach

    NASA Astrophysics Data System (ADS)

    Jain, Vineet; Raj, Tilak

    2014-09-01

    Productivity has often been cited as a key factor in a flexible manufacturing system (FMS) performance, and actions to increase it are said to improve profitability and the wage earning capacity of employees. Improving productivity is seen as a key issue for survival and success in the long term of a manufacturing system. The purpose of this paper is to make a model and analysis of the productivity variables of FMS. This study was performed by different approaches viz. interpretive structural modelling (ISM), structural equation modelling (SEM), graph theory and matrix approach (GTMA) and a cross-sectional survey within manufacturing firms in India. ISM has been used to develop a model of productivity variables, and then it has been analyzed. Exploratory factor analysis (EFA) and confirmatory factor analysis (CFA) are powerful statistical techniques. CFA is carried by SEM. EFA is applied to extract the factors in FMS by the statistical package for social sciences (SPSS 20) software and confirming these factors by CFA through analysis of moment structures (AMOS 20) software. The twenty productivity variables are identified through literature and four factors extracted, which involves the productivity of FMS. The four factors are people, quality, machine and flexibility. SEM using AMOS 20 was used to perform the first order four-factor structures. GTMA is a multiple attribute decision making (MADM) methodology used to find intensity/quantification of productivity variables in an organization. The FMS productivity index has purposed to intensify the factors which affect FMS.

  11. Quantitative Fracture Strength of Lithiated Tin Oxide Nanowires by In-Situ SEM Tensile Experiments

    NASA Astrophysics Data System (ADS)

    Song, Bill S.

    The quantitative fracture strength of lithiated and pristine tin oxide (SnO2) nanowires was gathered from in situ scanning electron microscope (SEM) mechanical tests using a micro electromechanical system (MEMS) uniaxial tensile testing device. Stress values were calculated from load and displacement data from an inSEM nanoindenter tip while strain values were obtained using digital image correlation (DIC) from in situ SEM test images. The SnO2 nanowires were synthesized using the vapor-liquid-solid (VLS) growth mechanism on stainless steel substrates using a gold (Au) catalyst. Ex-situ lithiation of the SnO2 nanowires was performed directly using the stainless steel growth substrates by the electrochemical half-cell method which did not involve the use of binders or conductive agents. The fracture strength decreased from 2.4 GPa +/- 0.2 GPa for the pristine SnO2 nanowires to 814.8 MPa +/- 429.7 MPa for the lithiated SnO2 nanowires. This study provides the first quantitative mechanical data for pristine and lithiated SnO2 nanowires.

  12. Reduction of SEM noise and extended application to prediction of CD uniformity and its experimental validation

    NASA Astrophysics Data System (ADS)

    Kim, Hoyeon; Hwang, Chan; Oh, Seok-hwan; Yeo, Jeongho; Kim, Young hee

    2011-03-01

    As the design rule of Integrated Circuits(IC) becomes smaller, the precise measurement of Critical Dimension (CD) of features and minimization of deviation in CD measured becomes a vital issue. In this paper, a simple frequency analysis method to extract the noise from SEM images was used to evaluate the contribution of SEM noise in CD Uniformity. Multiple SEM images of simple Line and Space (L/S) patterns were analyzed and a model of frequency profile (Power Spectrum Density (PSD) model) was made using an offline analyzing tool based on Matlab®. From this profile, white noise and 1/f profile were separated. Noises are eliminated to generate a noise reduced PSD profile to make CD results. The contribution of white noise on CD measurement can be assessed using Line Width Roughness (LWR) measurement. Furthermore, CD uniformity can be also predicted from the model. This prediction is based on an assumption that CD uniformity is equal to LWR if the inspection area is extended to infinity and appropriate sampling method is applied. The results showed that the contribution of white noise on LWR can be up to around 70% (in power) without any noise reduction measures (sum line averaging) after imaging in photo resist image. For experimental validation, CD uniformity is predicted from the model for different measurement conditions and compared with real measurement. For a result, CD uniformity prediction (3sigma) from the model shows within 20% in accuracy with real CD uniformity value measured from the photo resist image.

  13. Empirically Corrected Rescaled Statistics for SEM with Small N and Large p.

    PubMed

    Yuan, Ke-Hai; Yang, Miao; Jiang, Ge

    2017-09-11

    Survey data often contain many variables. Structural equation modeling (SEM) is commonly used in analyzing such data. With typical nonnormally distributed data in practice, a rescaled statistic Trml proposed by Satorra and Bentler was recommended in the literature of SEM. However, Trml has been shown to be problematic when the sample size N is small and/or the number of variables p is large. There does not exist a reliable test statistic for SEM with small N or large p, especially with nonnormally distributed data. Following the principle of Bartlett correction, this article develops empirical corrections to Trml so that the mean of the empirically corrected statistics approximately equals the degrees of freedom of the nominal chi-square distribution. Results show that empirically corrected statistics control type I errors reasonably well even when N is smaller than 2p, where Trml may reject the correct model 100% even for normally distributed data. The application of the empirically corrected statistics is illustrated via a real data example.

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

    PubMed

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

    2017-05-23

    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.

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

    PubMed

    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.

  16. FIB-SEM tomography of human skin telocytes and their extracellular vesicles.

    PubMed

    Cretoiu, Dragos; Gherghiceanu, Mihaela; Hummel, Eric; Zimmermann, Hans; Simionescu, Olga; Popescu, Laurentiu M

    2015-04-01

    We have shown in 2012 the existence of telocytes (TCs) in human dermis. TCs were described by transmission electron microscopy (TEM) as interstitial cells located in non-epithelial spaces (stroma) of many organs (see www.telocytes.com). TCs have very long prolongations (tens to hundreds micrometers) named Telopodes (Tps). These Tps have a special conformation with dilated portions named podoms (containing mitochondria, endoplasmic reticulum and caveolae) and very thin segments (below resolving power of light microscopy), called podomers. To show the real 3D architecture of TC network, we used the most advanced available electron microscope technology: focused ion beam scanning electron microscopy (FIB-SEM) tomography. Generally, 3D reconstruction of dermal TCs by FIB-SEM tomography revealed the existence of Tps with various conformations: (i) long, flattened irregular veils (ribbon-like segments) with knobs, corresponding to podoms, and (ii) tubular structures (podomers) with uneven calibre because of irregular dilations (knobs) - the podoms. FIB-SEM tomography also showed numerous extracellular vesicles (diameter 438.6 ± 149.1 nm, n = 30) released by a human dermal TC. Our data might be useful for understanding the role(s) of TCs in intercellular signalling and communication, as well as for comprehension of pathologies like scleroderma, multiple sclerosis, psoriasis, etc. © 2015 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.

  17. Surface characteristics of reciprocating instruments before and after use--a SEM analysis.

    PubMed

    Hanan, Aida Rene Assayag; Meireles, Daniely Amorin de; Sponchiado Júnior, Emílio Carlos; Hanan, Simone; Kuga, Milton Carlos; Bonetti Filho, Idomeo

    2015-01-01

    The presence of debris, defects and deformations of endodontic reciprocating instruments before and after chemical-mechanical preparation (MCP) was analyzed using scanning electron microscopy (SEM). The following 26 instruments were divided into 2 groups: Waveone (n=13) and Reciproc (n=13) and examined by SEM (150 x magnification) prior to canal preparation at 2 and 4 mm from the tip. The instruments were used in the preparation of mesial root canals of 26 extracted human permanent mandibular molars. The instruments were then washed in ultrasonic bath and subjected to new microscopic analysis of debris and deformation by a score that used the presence or absence of irregular edges, grooves, microcavities and burrs as criteria. After the SEM analysis and with the scores of the examiners, the collected data were subjected to descriptive statistical analysis using the Kruskall-Walis and Mann Whitney test at a 5% significance level. All instruments examined presented debris before and after use. A statistically significant difference was found for defects and deformation between the groups (p<0.05). The presence of defects and deformities was higher in the WaveOne instruments, and Reciproc instruments presented a lower rate.

  18. Towards laboratory x-ray nanotomography: instrumental improvements on a SEM-based system

    NASA Astrophysics Data System (ADS)

    Gomes Perini, L. A.; Bleuet, P.; Buijsse, B.; Kwakman, L. F. Tz.; Parker, W.

    2016-10-01

    We aim at resolving deca-nanometer features in microelectronic samples using a laboratory SEM-based X-ray tomography microscope. Such a system produces X-rays through the interaction between a focused SEM electron beam and a metallic target. The effective source size of the X-ray beam can be adjusted by varying the target material and geometry. For instance, the use of tungsten nanowires (few hundred nanometers of length) combined with a high electron beam current leads to an increased X-ray flux generated in a reduced volume, necessary for detecting interface details of the analyzed object. It improves resolution and signal-to-noise ratio (SNR), but is also sensitive to electron beam-target instabilities during the scan. To improve robustness, a FFT-based image correlation is integrated in the process through a closed-loop control scheme. It allows stabilizing the electron beam on the target and to preserve the X-ray flux intensity and alignment. Also, a state of the art high-resolution scientific-CMOS (sCMOS) X-ray detector was installed, allowing to reduce noise and to increase quantum efficiency. Results show that such numerical and equipment improvements lead to significant gains in spatial resolution, SNR and scanning time of the SEM-based tomography. It paves the way to routine, high resolution, 3D X-ray imaging in the laboratory.

  19. Comparative SEM evaluation of three solvents used in endodontic retreatment: an ex vivo study.

    PubMed

    Scelza, Miriam F Zaccaro; Coil, Jeffrey M; Maciel, Ana Carolina de Carvalho; Oliveira, Lílian Rachel L; Scelza, Pantaleo

    2008-01-01

    This study compared, by scanning electron microscopy (SEM), the efficacy of three solvents on the removal of filling materials from dentinal tubules during endodontic retreatment. Forty human maxillary canines with straight canals were prepared according to a crown-down technique and enlarged to a#30 apical file size, before obturation with gutta-percha and a zinc-oxide-eugenol based sealer. The samples were stored for 3 months before being randomly assigned to four groups: chloroform (n=10), orange oil (n=10), eucalyptol (n=10) and control (n=10). Solvents were applied to a reservoir created on the coronal root third using Gates Glidden drills. The total time for retreatment using the solvents was 5 minutes per tooth. Following retreatment the roots were split longitudinally for SEM evaluation. SEM images were digitized, analyzed using Image ProPlus 4.5 software, and the number of dentinal tubules free of filling material from the middle and apical thirds was recorded. No significant difference was found among the solvent groups regarding the number of dentinal tubules free of root filling remnants in the middle and apical root thirds (p>0.05). However, the control group had fewer dentinal tubules free of filling material (p<0.05). Under the tested conditions, it may be concluded that there was no significant difference among the solvents used to obtain dentinal tubules free of filling material remnants.

  20. Spatial resolution of electron backscatter diffraction in a FEG-SEM

    SciTech Connect

    Kenik, E.A.

    1996-05-01

    Crystallographic information can be determined for bulk specimens in a SEM by utilizing electron backscatter diffraction (EBSD), which is also referred to as backscatter electron Kikuchi diffraction. This technique provides similar information to that provided by selected area electron channeling (SAEC). However, the spatial resolutions of the two techniques are limited by different processes. In SAEC patterns, the spatial resolution is limited to {approximately}2 {mu}m by the motion of the beam on the specimen, which results from the angular rocking of the beam and the aberration of the probe forming lens. Therefore, smaller incident probe sizes provide no improvement in spatial resolution of SAEC patterns. In contrast, the spatial resolution for EBSD, which uses a stationary beam and an area detector, is determined by (1) the incident probe size and (2) the size of the interaction volume from which significant backscattered electrons are produced in the direction of the EBSD detector. The second factor is influenced by the accelerating voltage, the specimen tilt, and the relative orientation of scattering direction and the specimen tilt axis. This study was performed on a Philips XL30/FEG SEM equipped with a TexSEM Orientation Imaging Microscopy (OIM) system. The signal from the EBSD detector (SIT camera) is flat- fielded and enhanced in a MTI frame storage/image processor. The Schottky FEG source provides the fine probe sizes ({approximately}10 nm) desired with sufficient probe current ({approximately}1 nA) needed for image processing with the low signal/noise EBSD signal.

  1. COMPARATIVE SEM EVALUATION OF THREE SOLVENTS USED IN ENDODONTIC RETREATMENT: AN EX VIVO STUDY

    PubMed Central

    Scelza, Miriam F. Zaccaro; Coil, Jeffrey M.; Maciel, Ana Carolina de Carvalho; Oliveira, Lílian Rachel L.; Scelza, Pantaleo

    2008-01-01

    This study compared, by scanning electron microscopy (SEM), the efficacy of three solvents on the removal of filling materials from dentinal tubules during endodontic retreatment. Forty human maxillary canines with straight canals were prepared according to a crown-down technique and enlarged to a#30 apical file size, before obturation with gutta-percha and a zinc-oxide-eugenol based sealer. The samples were stored for 3 months before being randomly assigned to four groups: chloroform (n=10), orange oil (n=10), eucalyptol (n=10) and control (n=10). Solvents were applied to a reservoir created on the coronal root third using Gates Glidden drills. The total time for retreatment using the solvents was 5 minutes per tooth. Following retreatment the roots were split longitudinally for SEM evaluation. SEM images were digitized, analyzed using Image ProPlus 4.5 software, and the number of dentinal tubules free of filling material from the middle and apical thirds was recorded. No significant difference was found among the solvent groups regarding the number of dentinal tubules free of root filling remnants in the middle and apical root thirds (p>0.05). However, the control group had fewer dentinal tubules free of filling material (p<0.05). Under the tested conditions, it may be concluded that there was no significant difference among the solvents used to obtain dentinal tubules free of filling material remnants. PMID:19089285

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

    NASA Astrophysics Data System (ADS)

    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

  3. Micro-fabric damages in Boom Clay inferred from cryo-BIB-SEM experiment: recent results

    NASA Astrophysics Data System (ADS)

    Desbois, Guillaume; Schmatz, Joyce; Klaver, Jop; Urai, Janos L.

    2017-04-01

    The Boom Clay is considered as a potential host rock in Belgium for nuclear waste disposal in a deep geological formation. One of the keys to understand the long-term performance of such a host rock is the fundamental understanding of coupling between microstructural evolution, poromechanical behaviour and the state of hydration of the system. At in situ conditions, Boom Clay is a nearly water-saturated (>94%) clay-rich geomaterial. Subsequently, for measurement of mechanical and transport properties in laboratory, cores of Boom Clay are vacuum-packed in Al-coated-poly-ethylene barrier foil to be best preserved at original hydric state. Because clay microstructures are very sensitive to dehydration, the validity of investigations done on such preserved or/and dried samples is often questionable. Desbois et al. (2009, 2013, 2014) showed the possibility to image fluid-filled porosity in Boom Clay, by using the FIB-cryo-SEM (FIB: Focussed Ion Beam) and FIB-cryo-SEM (BIB: Broad Ion Beam) techniques. However, surprisingly in Desbois et al. (2014), BIB-cryo-SEM experiments on Boom Clay, shown that the majority of the pores were fluid-free, contrasting with result in Desbois et al. (2009). In Desbois et al. (2014), several reasons were discussed to explain such discrepancies. The likely ones are the sealing efficiency of the Al-barrier foil at long term and the volume expansion due to the release of in-situ stress after core extraction, contributing both to dehydration and microfabric damage. This contribution presents the newest results based on cryo-BIB-SEM. Small pieces (30 mm3) of Boom Clay were preserved in liquid nitrogen after the core extraction at the MOL/Dessel Underground Research Laboratory in Belgium. A maximum of ten minutes time span was achieved between opening the core, the sub-sample extraction and the quenching of sub-samples in liquid nitrogen. First results show that all pores visible at cryo-SEM resolution are water saturated. However, water

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

    NASA Astrophysics Data System (ADS)

    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

    The CD SEM (Critical Dimension Scanning Electron Microscope) is one of the main tools used to estimate Critical Dimension (CD) in semiconductor manufacturing nowadays, but, as all metrology tools, it will face considerable challenges to keep up with the requirements of the future technology nodes. The root causes of these challenges are not uniquely related to the shrinking CD values, as one might expect, but to the increase in complexity of the devices in terms of morphology and chemical composition as well. In fact, complicated threedimensional device architectures, high aspect ratio features, and wide variety of materials are some of the unavoidable characteristics of the future metrology nodes. This means that, beside an improvement in resolution, it is critical to develop a CD SEM metrology capable of satisfying the specific needs of the devices of the nodes to come, needs that sometimes will have to be addressed through dramatic changes in approach with respect to traditional CD SEM metrology. In this paper, we report on the development of advanced CD SEM metrology at imec on a variety of device platform and processes, for both logic and memories. We discuss newly developed approaches for standard, IIIV, and germanium FinFETs (Fin Field Effect Transistors), for lateral and vertical nanowires (NW), 3D NAND (three-dimensional NAND), STT-MRAM (Spin Transfer Magnetic Torque Random-Access Memory), and ReRAM (Resistive Random Access Memory). Applications for both front-end of line (FEOL) and back-end of line (BEOL) are developed. In terms of process, S/D Epi (Source Drain Epitaxy), SAQP (Self-Aligned Quadruple Patterning), DSA (Dynamic Self-Assembly), and EUVL (Extreme Ultraviolet Lithography) have been used. The work reported here has been performed on Hitachi CG5000, CG6300, and CV5000. In terms of logic, we discuss here the S/D epi defect classification, the metrology optimization for STI (Shallow Trench Isolation) Ge FinFETs, the defectivity of III-V STI Fin

  5. 30 CFR 250.1918 - What criteria for emergency response and control must be in my SEMS program?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... control must be in my SEMS program? 250.1918 Section 250.1918 Mineral Resources BUREAU OF OCEAN ENERGY MANAGEMENT, REGULATION, AND ENFORCEMENT, DEPARTMENT OF THE INTERIOR OFFSHORE OIL AND GAS AND SULPHUR... must be validated by drills carried out in accordance with a schedule defined by the SEMS...

  6. 30 CFR 250.1917 - What criteria for pre-startup review must be in my SEMS program?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 2 2011-07-01 2011-07-01 false What criteria for pre-startup review must be in... pre-startup review must be in my SEMS program? Your SEMS program must require that the commissioning process include a pre-startup safety and environmental review for new and significantly...

  7. Structural Characterization of Semen Coagulum-Derived SEM1(86–107) Amyloid Fibrils That Enhance HIV-1 Infection

    PubMed Central

    2015-01-01

    SEM1(86–107) is a 22-residue peptide corresponding to residues 86–107 in the semenogelin I protein. SEM1(86–107) is an abundant component of freshly liquefied semen and forms amyloid fibrils capable of enhancing HIV infection. To probe the factors affecting fibril formation and gain a better understanding of how differences in pH between semen and vaginal fluid affect fibril stability, this study determined the effect of pH on SEM1(86–107) fibril formation and dissociation. The SEM1(86–107) fibril structure (i.e., residues that comprise the fibrillar core) was also probed using hydrogen–deuterium exchange mass spectrometry (HDXMS) and hydroxyl radical-mediated protein modification. The average percent exposure to hydroxyl radical-mediated modification in the SEM1(86–107) fibrils was determined without requiring tandem mass spectrometry spectral acquisition or complete separation of modified peptides. It was found that the residue exposures calculated from HDXMS and hydroxyl radical-mediated modification were similar. These techniques demonstrated that three regions of SEM1(86–107) comprise the amyloid fibril core and that positively charged residues are exposed, suggesting that electrostatic interactions between SEM1(86–107) and HIV or the cell surface may be responsible for mediating HIV infection enhancement by the SEM1(86–107) fibrils. PMID:24811874

  8. Effects of Data Nonnormality and Other Factors on Fit Indices and Parameter Estimates for True and Misspecified SEM Models.

    ERIC Educational Resources Information Center

    Fan, Xitao; And Others

    A Monte Carlo study was conducted to assess the effects of some potential confounding factors on structural equation modeling (SEM) fit indices and parameter estimates for both true and misspecified models. The factors investigated were data nonnormality, SEM estimation method, and sample size. Based on the fully crossed and balanced 3x3x4x2…

  9. SEM-microphotogrammetry, a new take on an old method for generating high-resolution 3D models from SEM images.

    PubMed

    Ball, A D; Job, P A; Walker, A E L

    2017-08-01

    The method we present here uses a scanning electron microscope programmed via macros to automatically capture dozens of images at suitable angles to generate accurate, detailed three-dimensional (3D) surface models with micron-scale resolution. We demonstrate that it is possible to use these Scanning Electron Microscope (SEM) images in conjunction with commercially available software originally developed for photogrammetry reconstructions from Digital Single Lens Reflex (DSLR) cameras and to reconstruct 3D models of the specimen. These 3D models can then be exported as polygon meshes and eventually 3D printed. This technique offers the potential to obtain data suitable to reconstruct very tiny features (e.g. diatoms, butterfly scales and mineral fabrics) at nanometre resolution. Ultimately, we foresee this as being a useful tool for better understanding spatial relationships at very high resolution. However, our motivation is also to use it to produce 3D models to be used in public outreach events and exhibitions, especially for the blind or partially sighted. © 2017 The Authors Journal of Microscopy © 2017 Royal Microscopical Society.

  10. 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.

    PubMed

    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.

  11. To Evaluate the Efficacy of an Innovative Irrigant on Smear Layer Removal – SEM Analysis

    PubMed Central

    Sukumaran, Vridhachalam Ganapathy; Subbiya, Arunajatesan

    2016-01-01

    Introduction The goal of endodontic therapy is to completely eliminate the microorganisms and the smear layer from the root canal in order to provide a good seal of the root filling materials. Aim The aim of this study was to find a viable alternative irrigant, which is easily available with less erosion and clinically acceptable smear layer removal by comparing the efficacy of EDTA and commercially available super-oxidized water, named Oxum, as a final rinse on smear layer removal and erosion in relation to coronal, middle and apical thirds of radicular dentin using Scanning Electron Microscope (SEM) analysis. Materials and Methods Freshly extracted 30 human lower second premolar teeth with straight roots and type I canal anatomy were selected. The root canals were cleaned and shaped using Universal Protaper Rotary System. Irrigation was performed with 1 ml of 2.5% of NaOCl solution after each instrument change. The final irrigation (5 ml) sequence was as follows: Group I- 17% EDTA, Group II – OXUM, and Group III - 0.9% saline (control) for one minute. Then, the root canals were finally irrigated with 5ml of distilled water to remove any precipitate. The roots were then gently split into two halves using a chisel and subjected to SEM analysis. Results The SEM photomicrographs were evaluated by two independent examiners and Mann Whitney results showed that there was no statistically significant difference between the two examiners. Non-parametric statistical analysis of all experimental groups showed significant difference between coronal, middle and apical third for smear layer removal with p-value<0.05. For erosion, in group II (oxum) showed statistically significant difference between coronal, middle and apical third and it showed significantly less dentine erosion when compared to EDTA. Conclusion Within the limitations of the present study, Oxum the commercially available super-oxidized water proved to be equally effective in smear layer removal with less

  12. Using ICP-OES and SEM-EDX in biosorption studies

    PubMed Central

    Chojnacka, Katarzyna; Marycz, Krzysztof

    2010-01-01

    We have compared the analytical results obtained by inductively coupled plasma optical emission spectroscopy (ICP-OES) and by scanning electron microscopy with an energy dispersive X-ray analytical system (SEM-EDX) in order to explore the mechanism of metal ions biosorption by biomass using two independent methods. The marine macroalga Enteromorpha sp. was enriched with Cu(II), Mn(II), Zn(II), and Co(II) ions via biosorption, and the biosorption capacity of alga determined from the solution and biomass composition before and after biosorption process was compared. The first technique was used to analyze the composition of the natural and metal-loaded biomass, and additionally the composition of the solution before and after biosorption. The second technique was used to obtain a picture of the surface of natural and metal ion-loaded macroalgae, to map the elements on the cell wall of dry biomass, and to determine their concentration before and after biosorption. ICP-OES showed a better precision and lower detection limit than EDX, but SEM-EDX gave more information regarding the sample composition of Enteromorpha sp. Both techniques confirmed that biosorption is a surface phenomenon, in which alkali and alkaline earth metal ions were exchanged by metal ions from aqueous solution. Figure The advantages and disadvantages of ICP-OES and SEM-EDX techniques Electronic supplementary material The online version of this article (doi:10.1007/s00604-010-0468-0) contains supplementary material, which is available to authorized users. PMID:21423317

  13. Using ICP-OES and SEM-EDX in biosorption studies.

    PubMed

    Michalak, Izabela; Chojnacka, Katarzyna; Marycz, Krzysztof

    2011-02-01

    We have compared the analytical results obtained by inductively coupled plasma optical emission spectroscopy (ICP-OES) and by scanning electron microscopy with an energy dispersive X-ray analytical system (SEM-EDX) in order to explore the mechanism of metal ions biosorption by biomass using two independent methods. The marine macroalga Enteromorpha sp. was enriched with Cu(II), Mn(II), Zn(II), and Co(II) ions via biosorption, and the biosorption capacity of alga determined from the solution and biomass composition before and after biosorption process was compared. The first technique was used to analyze the composition of the natural and metal-loaded biomass, and additionally the composition of the solution before and after biosorption. The second technique was used to obtain a picture of the surface of natural and metal ion-loaded macroalgae, to map the elements on the cell wall of dry biomass, and to determine their concentration before and after biosorption. ICP-OES showed a better precision and lower detection limit than EDX, but SEM-EDX gave more information regarding the sample composition of Enteromorpha sp. Both techniques confirmed that biosorption is a surface phenomenon, in which alkali and alkaline earth metal ions were exchanged by metal ions from aqueous solution.FigureThe advantages and disadvantages of ICP-OES and SEM-EDX techniques ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s00604-010-0468-0) contains supplementary material, which is available to authorized users.

  14. Apical microleakage and SEM analysis of dentin surface after 980 nm diode laser irradiation.

    PubMed

    Faria, Maria Isabel Anastácio; Souza-Gabriel, Aline Evangelista; Alfredo, Edson; Messias, Danielle Cristine Furtado; Silva-Sousa, Yara Teresinha Correa

    2011-01-01

    This study evaluated the effect of 980-nm diode laser on apical microleakage and intraradicular dentin morphology. Roots of 110 mandibular incisors were used in the study: 92 for microleakage test and 18 for scanning electron microscopy (SEM). Roots were randomly assigned to 3 groups according to the irrigating solution (water, NaOCl and NaOCl/EDTA) and were divided into 3 subgroups according to the laser irradiation protocol (without irradiation, irradiated at 1.5 W and irradiated at 3.0 W). Two specimens of each subgroup were prepared for SEM. The remaining roots were filled with AH Plus and gutta-percha. Apical leakage was assessed by ink penetration and data were analyzed statistically by ANOVA and Tukey-Krammer test (α=0.05). SEM analysis showed intensification of changes with increase of laser power as well as variations according to the irrigating solution. Modified smear layer was observed in specimens treated with water and irradiated with laser. Roots irrigated with NaOCl/EDTA had lower levels of infiltration (0.17 ± 0.18 mm) differing significantly (p<0.05) from those of roots irrigated with water (0.34 ± 0.30 mm), but similar (p>0.05) to those irrigated with NaOCl (0.28 ± 0.29 mm). Non-irradiated roots had lower levels of infiltration (0.10 ± 0.14 mm), differing (p<0.05) from those irradiated at 1.5 W (0.32 ± 0.22 mm) and 3.0 W (0.37 ± 0.32 mm). The 980 nm diode laser modified dentin morphology and increased apical microleakage.

  15. Pores in Marcellus Shale: A Neutron Scattering and FIB-SEM Study

    SciTech Connect

    Gu, Xin; Cole, David R.; Rother, Gernot; Mildner, David F. R.; Brantley, Susan L.

    2015-01-26

    The production of natural gas has become more and more important in the United States because of the development of hydraulic fracturing techniques, which significantly increase the permeability and fracture network of black shales. The pore structure of shale is a controlling factor for hydrocarbon storage and gas migration. In this work, we investigated the porosity of the Union Springs (Shamokin) Member of the Marcellus Formation from a core drilled in Centre County, PA, USA, using ultrasmall-angle neutron scattering (USANS), small-angle neutron scattering (SANS), focused ion beam scanning electron microscopy (FIB-SEM), and nitrogen gas adsorption. The scattering of neutrons by Marcellus shale depends on the sample orientation: for thin sections cut in the plane of bedding, the scattering pattern is isotropic, while for thin sections cut perpendicular to the bedding, the scattering pattern is anisotropic. The FIB-SEM observations allow attribution of the anisotropic scattering patterns to elongated pores predominantly associated with clay. The apparent porosities calculated from scattering data from the bedding plane sections are lower than those calculated from sections cut perpendicular to the bedding. A preliminary method for estimating the total porosity from the measurements made on the two orientations is presented. This method is in good agreement with nitrogen adsorption for both porosity and specific surface area measurements. Neutron scattering combined with FIB-SEM reveals that the dominant nanosized pores in organic-poor, clay-rich shale samples are water-accessible sheetlike pores within clay aggregates. In contrast, bubble-like organophilic pores in kerogen dominate organic-rich samples. Lastly, developing a better understanding of the distribution of the water-accessible pores will promote more accurate models of water–mineral interactions during hydrofracturing.

  16. Effect of CPP-ACP paste on tooth mineralization: an FE-SEM study.

    PubMed

    Oshiro, Maki; Yamaguchi, Kanako; Takamizawa, Toshiki; Inage, Hirohiko; Watanabe, Takayuki; Irokawa, Atsushi; Ando, Susumu; Miyazaki, Masashi

    2007-06-01

    Milk and milk products, such as cheese, have been shown to exhibit anticariogenic properties in human and animal models. CPP-ACP shows an anti-caries effect by suppressing demineralization, enhancing remineralization, or possibly a combination of both. The purpose of this study was to evaluate the effect of CPP-ACP paste on demineralization by observing the treated tooth surface using an FE-SEM. The specimens were prepared by cutting enamel and dentin of bovine teeth into blocks. A few specimens were stored in 0.1 M lactic acid buffer solution for 10 min and then in artificial saliva (negative control). The remaining specimens were stored in a 10 times-diluted solution of CPP-ACP paste or a placebo paste containing no CPP-ACP for 10 min, followed by 10 min immersion in a demineralizing solution (pH = 4.75, Ca) twice a day before storage in artificial saliva. After treatment of the specimens for 3, 7, 21 and 28 days, they were fixed in 2.5% glutaraldehyde in cacodylate buffer solution, dehydrated in ascending grades of tert-butyl alcohol, and then transferred to a critical-point dryer. The surfaces were coated with a thin film of Au in a vacuum evaporator, and were observed under field emission-scanning electron microscopy (FE-SEM). The SEM observations revealed different morphological features brought about by the various storage conditions. Demineralization of the enamel and dentin surfaces was more pronounced with the longer test period in the control and negative control specimens. On the other hand, enamel and dentin specimens treated with CPP-ACP paste revealed slight changes in their morphological features. From the morphological observations of the enamel and dentin surfaces, it could be considered that the CPP-ACP paste might prevent demineralization of the tooth structure.

  17. Nanosecond pulsed laser ablation of Ge investigated by employing photoacoustic deflection technique and SEM analysis

    NASA Astrophysics Data System (ADS)

    Yaseen, Nazish; Bashir, Shazia; Shabbir, Muhammad Kaif; Jalil, Sohail Abdul; Akram, Mahreen; Hayat, Asma; Mahmood, Khaliq; Haq, Faizan-ul; Ahmad, Riaz; Hussain, Tousif

    2016-06-01

    Nanosecond pulsed laser ablation phenomena of single crystal Ge (100) has been investigated by employing photoacoustic deflection as well as SEM analysis techniques. Nd: YAG laser (1064 nm, 10 ns, 1-10 Hz) at various laser fluences ranging from 0.2 to 11 J cm-2 is employed as pump beam to ablate Ge targets. In order to evaluate in-situe ablation threshold fluence of Ge by photoacoustic deflection technique, Continuous Wave (CW) He-Ne laser (632 nm, power 10 mW) is employed as a probe beam. It travels parallel to the target surface at a distance of 3 mm and after passing through Ge plasma it causes deflection due to density gradient of acoustic waves. The deflected signal is detected by photodiode and is recorded by oscilloscope. The threshold fluence of Ge, the velocity of ablated species and the amplitude of the deflected signal are evaluated. The threshold fluence of Ge comes out to be 0.5 J cm-2 and is comparable with the analytical value. In order to compare the estimated value of threshold with ex-situe measurements, the quantitative analysis of laser irradiated Ge is performed by using SEM analysis. For this purpose Ge is exposed to single and multiple shots of 5, 10, 50 and 100 at various laser fluences ranging from 0.2 to 11 J cm-2. The threshold fluence for single and multiple shots as well as incubation coefficients are evaluated. It is observed that the value of incubation co-efficient decreases with increasing number of pulses and is therefore responsible for lowering the threshold fluence of Ge. SEM analysis also reveals the growth of various features such as porous structures, non-uniform ripples and blisters on the laser irradiated Ge. It is observed that both the fluence as well as number of laser shots plays a significant role for the growth of these structures.

  18. Inorganic particulates associated with pulmonary alveolar proteinosis: SEM and X-ray microanalysis results.

    PubMed

    Abraham, J L; McEuen, D D

    1986-01-01

    Twenty-four cases of pulmonary alveolar proteinosis (PAP) were studied by light microscopy (LM) and scanning electron microscopy (SEM) to test the hypothesis that PAP was related to silica exposure. Increased numbers of birefringent particles (vs. controls) were found in 78% of PAP cases. SEM was used to locate inorganic particulates in situ, which were individually analyzed using energy dispersive X-ray analysis. When analyzed as an aggregate group of cases, no specific inorganic particulate was evidently associated with the PAP reaction. However, analysis of individual cases revealed more specific associations. The concentration of particles determined by SEM exceeded that found by LM by a factor ranging from 2.7 to 964. The concentration of inorganic particulates per cm3 in the areas of PAP ranged from 1.3 X 10(7) to 1.02 X 10(9). Controls all had less than 10(7) particles per cm3. Available environmental history correlated well with particulate analysis results, e.g., silica in a sandblaster, metal fumes in a welder, and cement particles in a cement finisher. Particulates with unique composition were also found in cases with unavailable histories, e.g. metal fumes suggestive of welding or soldering exposure, silicates suggestive of fine particle exposure (greater than 50% of particles less than 1 micron). Only 1 case (the sandblaster) showed greater than 50% of the particles to be silica. Of the 5 infants with PAP, 3 showed the major particulate to be talc, and 1 had evidence of toxic cadmium selenide fume exposure. These results are consistent with the hypothesis that PAP, at least in the majority of cases, is associated with exposure to small inorganic particulates of several types.

  19. Field emission scanning electron microscopy (FE-SEM) as an approach for nanoparticle detection inside cells.

    PubMed

    Havrdova, M; Polakova, K; Skopalik, J; Vujtek, M; Mokdad, A; Homolkova, M; Tucek, J; Nebesarova, J; Zboril, R

    2014-12-01

    When developing new nanoparticles for bio-applications, it is important to fully characterize the nanoparticle's behavior in biological systems. The most common techniques employed for mapping nanoparticles inside cells include transmission electron microscopy (TEM) and scanning transmission electron microscopy (STEM). These techniques entail passing an electron beam through a thin specimen. STEM or TEM imaging is often used for the detection of nanoparticles inside cellular organelles. However, lengthy sample preparation is required (i.e., fixation, dehydration, drying, resin embedding, and cutting). In the present work, a new matrix (FTO glass) for biological samples was used and characterized by field emission scanning electron microscopy (FE-SEM) to generate images comparable to those obtained by TEM. Using FE-SEM, nanoparticle images were acquired inside endo/lysosomes without disruption of the cellular shape. Furthermore, the initial steps of nanoparticle incorporation into the cells were captured. In addition, the conductive FTO glass endowed the sample with high stability under the required accelerating voltage. Owing to these features of the sample, further analyses could be performed (material contrast and energy-dispersive X-ray spectroscopy (EDS)), which confirmed the presence of nanoparticles inside the cells. The results showed that FE-SEM can enable detailed characterization of nanoparticles in endosomes without the need for contrast staining or metal coating of the sample. Images showing the intracellular distribution of nanoparticles together with cellular morphology can give important information on the biocompatibility and demonstrate the potential of nanoparticle utilization in medicine. Copyright © 2014 Elsevier Ltd. All rights reserved.

  20. FIB-SEM Tomography Probes the Mesoscale Pore Space of an Individual Catalytic Cracking Particle

    PubMed Central

    2016-01-01

    The overall performance of a catalyst particle strongly depends on the ability of mass transport through its pore space. Characterizing the three-dimensional structure of the macro- and mesopore space of a catalyst particle and establishing a correlation with transport efficiency is an essential step toward designing highly effective catalyst particles. In this work, a generally applicable workflow is presented to characterize the transport efficiency of individual catalyst particles. The developed workflow involves a multiscale characterization approach making use of a focused ion beam-scanning electron microscope (FIB-SEM). SEM imaging is performed on cross sections of 10.000 μm2, visualizing a set of catalyst particles, while FIB-SEM tomography visualized the pore space of a large number of 8 μm3 cubes (subvolumes) of individual catalyst particles. Geometrical parameters (porosity, pore connectivity, and heterogeneity) of the material were used to generate large numbers of virtual 3D volumes resembling the sample’s pore space characteristics, while being suitable for computationally demanding transport simulations. The transport ability, defined as the ratio of unhindered flow over hindered flow, is then determined via transport simulations through the virtual volumes. The simulation results are used as input for an upscaling routine based on an analogy with electrical networks, taking into account the spatial heterogeneity of the pore space over greater length scales. This novel approach is demonstrated for two distinct types of industrially manufactured fluid catalytic cracking (FCC) particles with zeolite Y as the active cracking component. Differences in physicochemical and catalytic properties were found to relate to differences in heterogeneities in the spatial porosity distribution. In addition to the characterization of existing FCC particles, our method of correlating pore space with transport efficiency does also allow for an up-front evaluation of

  1. Pores in Marcellus Shale: A Neutron Scattering and FIB-SEM Study

    DOE PAGES

    Gu, Xin; Cole, David R.; Rother, Gernot; ...

    2015-01-26

    The production of natural gas has become more and more important in the United States because of the development of hydraulic fracturing techniques, which significantly increase the permeability and fracture network of black shales. The pore structure of shale is a controlling factor for hydrocarbon storage and gas migration. In this work, we investigated the porosity of the Union Springs (Shamokin) Member of the Marcellus Formation from a core drilled in Centre County, PA, USA, using ultrasmall-angle neutron scattering (USANS), small-angle neutron scattering (SANS), focused ion beam scanning electron microscopy (FIB-SEM), and nitrogen gas adsorption. The scattering of neutrons bymore » Marcellus shale depends on the sample orientation: for thin sections cut in the plane of bedding, the scattering pattern is isotropic, while for thin sections cut perpendicular to the bedding, the scattering pattern is anisotropic. The FIB-SEM observations allow attribution of the anisotropic scattering patterns to elongated pores predominantly associated with clay. The apparent porosities calculated from scattering data from the bedding plane sections are lower than those calculated from sections cut perpendicular to the bedding. A preliminary method for estimating the total porosity from the measurements made on the two orientations is presented. This method is in good agreement with nitrogen adsorption for both porosity and specific surface area measurements. Neutron scattering combined with FIB-SEM reveals that the dominant nanosized pores in organic-poor, clay-rich shale samples are water-accessible sheetlike pores within clay aggregates. In contrast, bubble-like organophilic pores in kerogen dominate organic-rich samples. Lastly, developing a better understanding of the distribution of the water-accessible pores will promote more accurate models of water–mineral interactions during hydrofracturing.« less

  2. CD-SEM measurement line edge roughness test patterns for 193 nm lithography

    NASA Astrophysics Data System (ADS)

    Bunday, Benjamin D.; Bishop, Michael; Villarrubia, John S.; Vladar, Andras E.

    2003-07-01

    The measurement of line-edge roughness (LER) has recently become a major topic of concern in the litho-metrology community and the semiconductor industry as a whole, as addressed in the 2001 International Technology Roadmap for Semiconductors (ITRS) roadmap. The Advanced Metrology Advisory Group (AMAG, a council composed of the chief metrologists from the International SEMATECH (ISMT) consortium"s Member Companies and from the National Institute of Standards and Technology (NIST) has begun a project to investigate this issue and to direct the critical dimension scanning electron microscope (CD-SEM) supplier community towards a semiconductor industry-backed solution for implementation. The AMAG group has designed and built a 193 nm reticle that includes structures implementing a number of schemes to intentionally cause line edge roughness of various spatial frequencies and amplitudes. The lithography of these structures is in itself of interest to the litho-metrology community and will be discussed here. These structures, along with several other photolithography process variables, have been used to fabricate a set of features of varying roughness value and structure which span the LER process space of interest. These references are, in turn, useful for evaluation of LER measurement capability. Measurements on different CD-SEMs of major suppliers were used to demonstrate the current state of LER measurement. These measurements were compared to roughness determined off-line by analysis of top-down images from these tools. While no official standard measurement algorithm or definition of LER measurement exists, definitions used in this work are presented and compared in use. Repeatability of the measurements and factors affecting their accuracy were explored, as well as how CD-SEM parameters can affect the measurements.

  3. Hybrid OPC modeling with SEM contour technique for 10nm node process

    NASA Astrophysics Data System (ADS)

    Hitomi, Keiichiro; Halle, Scott; Miller, Marshal; Graur, Ioana; Saulnier, Nicole; Dunn, Derren; Okai, Nobuhiro; Hotta, Shoji; Yamaguchi, Atsuko; Komuro, Hitoshi; Ishimoto, Toru; Koshihara, Shunsuke; Hojo, Yutaka

    2014-03-01

    Hybrid OPC modeling is investigated using both CDs from 1D and simple 2D structures and contours extracted from complex 2D structures, which are obtained by a Critical Dimension-Scanning Electron Microscope (CD-SEM). Recent studies have addressed some of key issues needed for the implementation of contour extraction, including an edge detection algorithm consistent with conventional CD measurements, contour averaging and contour alignment. Firstly, pattern contours obtained from CD-SEM images were used to complement traditional site driven CD metrology for the calibration of OPC models for both metal and contact layers of 10 nm-node logic device, developed in Albany Nano-Tech. The accuracy of hybrid OPC model was compared with that of conventional OPC model, which was created with only CD data. Accuracy of the model, defined as total error root-mean-square (RMS), was improved by 23% with the use of hybrid OPC modeling for contact layer and 18% for metal layer, respectively. Pattern specific benefit of hybrid modeling was also examined. Resist shrink correction was applied to contours extracted from CD-SEM images in order to improve accuracy of the contours, and shrink corrected contours were used for OPC modeling. The accuracy of OPC model with shrink correction was compared with that without shrink correction, and total error RMS was decreased by 0.2nm (12%) with shrink correction technique. Variation of model accuracy among 8 modeling runs with different model calibration patterns was reduced by applying shrink correction. The shrink correction of contours can improve accuracy and stability of OPC model.

  4. Evaluation of Five Different Desensitizers: A Comparative Dentin Permeability and SEM Investigation In Vitro

    PubMed Central

    Yilmaz, Nasibe Aycan; Ertas, Ertan; Orucoğlu, Hasan

    2017-01-01

    Background/Objective: The purpose of this study was to evaluate the efficacy and durability of five different dentin desensitizers (Gluma Desensitizer Powergel, Bifluorid 12, Gluma Self Etch Bond, D/Sense Crystal, Nupro Sensodyne Prophylaxis Paste with Novamin) on tubule occlusion and dentin permeability reduction in vitro. Method: The quantitative changes in permeability of 100 dentin discs were measured after desensitizer treatments and following post-treatments of 6% citric acid challenge for 1 min or immersion in artificial saliva for 24 hours under hydrostatic pressure generated by a computerised fluid filtration meter. Qualitative SEM analyses were also carried out. Results: Dentin permeability decreased after desensitizer application in all groups. Nevertheless, only the difference between ‘Gluma Self Etch Bond’ and ‘Nupro Sensodyne Prophylaxis Paste with Novamin’ groups was significantly different (p<0.05). Dentin permeability increased significantly after post-treatments (p<0.05). There was no statistically difference among the citric acid-subgroups (p>0.05). Of all the artificial saliva-subgroups, only the difference between ‘D/Sense Crystal’ and ‘Bifluorid 12’ was significantly different (p<0.05). In SEM analysis, morphological changes were detected on the dentin surface and within the tubules following desensitizer treatments and post-treatments. Conclusion: All the desensitizers significantly reduced dentin permeability by changing the morphology of the dentin surface and/or dentinal tubules. Following post-treatments, there was some reduction in the efficacy of the desensitizers which was represented by the reduction in permeability values. SEM analysis revealed some physical changes in the dentin structure which can partly give an explanation to the reduced efficacy of tested desensitizers. PMID:28484578

  5. Mechatronic Development and Vision Feedback Control of a Nanorobotics Manipulation System inside SEM for Nanodevice Assembly

    PubMed Central

    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 <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. PMID:27649180

  6. Mechatronic Development and Vision Feedback Control of a Nanorobotics Manipulation System inside SEM for Nanodevice Assembly.

    PubMed

    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.

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

    NASA Technical Reports Server (NTRS)

    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

  8. Unveiling the Mysteries of Mars with a Miniaturized Variable Pressure Scanning Electron Microscope (MVP-SEM)

    NASA Technical Reports Server (NTRS)

    Edmunson, J.; Gaskin, J. A.; Doloboff, I. J.

    2017-01-01

    Development of a miniaturized scanning electron microscope that will utilize the martian atmosphere to dissipate charge during analysis continues. This instrument is expected to be used on a future rover or lander to answer fundamental Mars science questions. To identify the most important questions, a survey was taken at the 47th Lunar and Planetary Science Conference (LPSC). From the gathered information initial topics were identified for a SEM on the martian surface. These priorities are identified and discussed below. Additionally, a concept of operations is provided with the goal of maximizing the science obtained with the minimum amount of communication with the instrument.

  9. Argentinean prehistoric pigments' study by combined SEM/EDX and molecular spectroscopy.

    PubMed

    Darchuk, L; Tsybrii, Z; Worobiec, A; Vázquez, C; Palacios, O M; Stefaniak, E A; Gatto Rotondo, G; Sizov, F; Van Grieken, R

    2010-05-01

    Composition of the prehistoric pigments' (from Carriqueo rock shelter, Rio Negro province, Argentina) has been analysed by means of molecular spectroscopy (Fourier transform infrared (FTIR) and micro-Raman) and scanning electron microscopy (SEM) coupled to an energy-dispersive X-ray spectrometer (EDS). Red and yellow pigments were recognized as red and yellow ochre. The matrix of the pigments is composed of one or more substances. According to the matrix composition yellow and red pigments were also divided into two groups-i.e. those containing kaolinite or sulphates. Green pigment was detected as green earth, made up of celadonite as a chromophore.

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

    PubMed

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

    2009-10-01

    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.

  11. Recent Optical and SEM Characterization of Genesis Solar Wind Concentrator Diamond on Silicon Collector

    NASA Technical Reports Server (NTRS)

    Allton, Judith H.; Rodriquez, M. C.; Burkett, P. J.; Ross, D. K.; Gonzalez, C. P.; McNamara, K. M.

    2013-01-01

    One of the 4 Genesis solar wind concentrator collectors was a silicon substrate coated with diamond-like carbon (DLC) in which to capture solar wind. This material was designed for analysis of solar nitrogen and noble gases [1, 2]. This particular collector fractured during landing, but about 80% of the surface was recovered, including a large piece which was subdivided in 2012 [3, 4, 5]. The optical and SEM imaging and analysis described below supports the subdivision and allocation of the diamond-on-silicon (DOS) concentrator collector.

  12. Microorganisms found in secondary cataract material of ECCE patients, a study with SEM and TEM.

    PubMed

    Kalicharan, D; Jongebloed, W L; Los, L I; Worst, J G

    1993-01-01

    Globular secondary cataract material, removed from 24 patients with ECCE after ophthalmic cleaning of the anterior capsule, were investigated with SEM and TEM. Besides spherical, somewhat oval shaped bodies of various shape and size comparable with those found in cataractous lenses, (an)aerobic bacteria and yeast cells were found in approximately 70% of the cases, all of them in eyes without intra-ocular inflammation. Probably these bacteria have been transferred from the conjunctiva during IOL.-implantation and were encapsulated without starting an inflammation.

  13. Hydration Characteristics of Metakaolin Admixtured Cement using DTA, XRD and SEM Techniques

    NASA Astrophysics Data System (ADS)

    Govindarajan, D.; Gopalakrishnan, R.

    2008-04-01

    The paper aims to investigate hydration and pozzolanic reaction in Portland cement paste with different replacement percentages (0%, 10%, 20% and 30%) of metakaolin. The compressive strength of the metakaolin admixtured cement was measured at 1 day, 1 week and 4 weeks. The compressive strength developments of the metakaolin admixtured cement are compared with Portland cement. It is found that metakaolin contributes significantly to strength development as an accelerating admixture for Portland cement. The pozzolanic reactions and the reaction products were determined by DTA, XRD and SEM.

  14. [Identification of elephantopi herba and its adulterants by LM/SEM observation and TLC scanning].

    PubMed

    Cao, Hui; Li, Yao-Lan; Ye, Wen-Cai; Li, Yong-Xue; But, Pui-Hay; Shaw, Pang-Chui

    2013-08-01

    To provide identification basis for distinguishing Elephantopi Herba and its adulterants. Light microscopy (LM), scanning electron microscopy (SEM) and thin layer chromatography scanning (TLCS) methods were used to identify Didancao (Elephantopus scaber) and its adulterants Baihuadidancao (Elephantopus mollis) and Jiadidancao (Pseudelephantopus spicatus). Based on the microscopic features and TLC profiles, the commercial Didancao samples retailed in mainland China, Taiwan, Hong Kong and Macau markets were identified as Elephantopus scaber. These methods are accurate and reliable, which can be used for identification of Elephantopi Herba and its adulterants.

  15. Bayesian Evaluation of inequality-constrained Hypotheses in SEM Models using Mplus.

    PubMed

    van de Schoot, Rens; Hoijtink, Herbert; Hallquist, Michael N; Boelen, Paul A

    2012-10-01

    Researchers in the behavioural and social sciences often have expectations that can be expressed in the form of inequality constraints among the parameters of a structural equation model resulting in an informative hypothesis. The question they would like an answer to is "Is the Hypothesis Correct" or "Is the hypothesis incorrect?". We demonstrate a Bayesian approach to compare an inequality-constrained hypothesis with its complement in an SEM framework. The method is introduced and its utility is illustrated by means of an example. Furthermore, the influence of the specification of the prior distribution is examined. Finally, it is shown how the approach proposed can be implemented using Mplus.

  16. CD-SEM distortion quantification for EPE metrology and contour analysis

    NASA Astrophysics Data System (ADS)

    Dillen, Harm; Kiers, Ton; Halder, Sandip; Wallow, Thomas I.; van Roey, Frieda

    2017-03-01

    Given the potential impact of distortions within the Field Of View (FOV) of the SEM, we need a method to quantify and describe them. We will show a method to find the magnitude and directions of the distortions. This description will enable assessment of impact on local distance measurements like edge placement errors (EPE) analysis and contour measurements. Knowing the distortions with sufficient resolution and stability can also enable corrections for this phenomenon. We will show that applying this correction in post processing, we can bring back the absolute measurement error from 1.5 nm to 0.3 nm.

  17. Chemical Characterization of Bed Material Coatingsby LA-ICP-MS and SEM-EDS

    NASA Astrophysics Data System (ADS)

    Piispanen, M. H.; Mustonen, A. J.; Tiainen, M. S.; Laitinen, R. S.

    Bed material coatings and the consequent agglomeration of bed material are main ash-related problems in FB-boilers. The bed agglomeration is a particular problem when combusting biofuels and waste materials. Whereas SEM-EDS together with automated image processing has proven to be a convenient method to study compositional distribution in coating layers and agglomerates, it is a relatively expensive technique and is not necessarily widely available. In this contribution, we explore the suitability of LA-ICP-MS to provide analogous information of the bed.

  18. Unveiling the Mysteries of Mars with a Miniaturized Variable Pressure Scanning Electron Microscope (MVP-SEM)

    NASA Technical Reports Server (NTRS)

    Edmunson, J.; Gaskin, J. A.; Doloboff, I. J.; Jerman, G.

    2017-01-01

    Development of a miniaturized scanning electron microscope that will utilize the martian atmosphere to dissipate charge during analysis continues. This instrument is expected to be used on a future rover or lander to answer fundamental Mars science questions. To identify the most important questions, a survey was taken at the 47th Lunar and Planetary Science Conference (LPSC). From the gathered information initial topics were identified for a SEM on the martian surface. These priorities are identified and discussed below. Additionally, a concept of operations is provided with the goal of maximizing the science obtained with the minimum amount of communication with the instrument.

  19. In situ SEM observation of column-like and foam-like CNT array nanoindentation.

    PubMed

    Maschmann, Matthew R; Zhang, Qiuhong; Wheeler, Robert; Du, Feng; Dai, Liming; Baur, Jeffery

    2011-03-01

    Quantitative nanoindentation of nominally 7.5 and 600 μm tall vertically aligned carbon nanotube (VACNT) arrays is observed in situ within an SEM chamber. The 7.5 μm array consists of highly aligned and weakly interacting CNTs and deflects similarly to classically defined cylindrical columns, with deformation geometry and critical buckling force well estimated using the Euler-Bernoulli theory. The 600 μm array has a highly entangled foam-like morphology and exhibits sequential buckle formation upon loading, with a buckle first forming near the array bottom at approximately 2% strain, followed by accumulating coordinated buckling at the top surface at strains exceeding 5%.

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

    PubMed

    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.