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Sample records for esquerda sem cec

  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 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.

  3. Cooperative Engagement Capability (CEC)

    DTIC Science & Technology

    2015-12-01

    Selected Acquisition Report (SAR) RCS: DD-A&T(Q&A)823-582 Cooperative Engagement Capability (CEC) As of FY 2017 President’s Budget Defense...RDT&E - Research, Development, Test, and Evaluation SAR - Selected Acquisition Report SCP - Service Cost Position TBD - To Be Determined TY - Then...JLENS), and select coalition partners into a single fire control quality air track picture. Radar measurement data from individual CUs within a CEC

  4. 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…

  5. 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…

  6. 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…

  7. 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…

  8. 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…

  9. 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…

  10. 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.

  11. 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

  12. 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.

  13. 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…

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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...

  1. 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.

  2. 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).

  3. 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.

  4. 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.

  5. 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

  6. 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

  7. 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

  8. 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.

  9. 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.

  10. 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…

  11. 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.

  12. 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

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. [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.

  18. 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

  19. 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.

  20. 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.

  1. 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.

  2. [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.

  3. [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.

  4. (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.

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  8. 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.

  9. 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.

  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. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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....

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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

  7. 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°.

  8. 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…

  9. 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

  10. Cooperative Engagement Capability (CEC)

    DTIC Science & Technology

    2013-12-01

    Authority/Budget Activity BY - Base Year DAMIR - Defense Acquisition Management Information Retrieval Dev Est - Development Estimate DoD - Department...Development Contract Medii ... Preliminary Design Review .. Baseline System Initial Oper. .. Critical Design Review Com ... IOT &E (DT-118/0 T...IIA1) Start Complete LRIP Decision Low Rate Production Contra ... Service Depot Support Date Service Final DT&E Start Complete IOT &E - OPEVAL

  11. 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.

  12. 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.

  13. 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.

  14. 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

  15. 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.

  16. 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.

  17. 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.

  18. 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

  19. 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

  20. 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.

  1. 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.

  2. 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.

  3. 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

  4. 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.

  5. 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.

  6. 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.

  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. 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…

  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. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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).

  17. 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)

  18. 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…

  19. 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

  20. 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.

  1. 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.

  2. 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.

  3. 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

  4. 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

  5. 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.

  6. 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.

  7. 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.

  8. 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…

  9. 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…

  10. 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.

  11. 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.

  12. MicroDiffraction in the Scanning Electron Microscope (SEM)

    SciTech Connect

    Goehner, R.P.; Michael, J.R.; Schlienger, M.E.

    1997-12-31

    The identification of crystallographic phases in the scanning electron microscope (SEM) has been limited by the lack of a simple way to obtain electron diffraction data of an unknown while observing the micro structure of the specimen. With the development of Charge Coupled Device (CCD) based detectors, backscattered electron Kikuchi patterns (BEKP), alternately referred to as electron backscattered diffraction patterns (EBSP), can be easily collected. Previously, BEKP has been limited to crystallographic orientation studies due to the poor pattern quality collected with video rate detector systems. With CCD detectors, a typical BEKP can now be acquired from a micron or sub-micron-sized crystal using an exposure time of 1-10 seconds with an accelerating voltage of 10-40 kV and a beam current as low as 0.1 nA. Crystallographic phase analysis using BEKP is unique in that the properly equipped SEM permits high magnification images, BEKP`s, and elemental information to be collected from bulk specimens. BEKP in the SEM has numerous advantages over other electron microscopy crystallographic techniques. The large angular view ( 70 degrees) provided by BEKP and the lack of difficult specimen preparation are distinct advantages of the technique. No sample preparation beyond what is commonly used for SEM specimens is required for BEKP.

  13. 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

  14. 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.

  15. Potassium determinations using SEM, FAAS and XRF: some experimental notes

    NASA Astrophysics Data System (ADS)

    Liritzis, I.; Mavrikis, D.; Zacharias, N.; Sakalis, A.; Tsirliganis, N.; Polymeris, G.S.

    The calibration of Scanning Electron Microscopy coupled with Energy Dispersive X- Rays Spec-trometry (SEM-EDS) for elemental quantitative analysis is an important task for characterization, provenance and absolute dating purposes. In particular the potassium determination is an im-portant contributor to dose rate assessments in luminescence and Electron Spin Resonance (ESR) dating. Here a SEM-EDX is calibrated on different archaeological and geoarchaeological materials against standard laboratory samples as well as measured by micro X-Rays Fluorescence (μXRF) and flame atomic absorption spectroscopy (FAAS) techniques. A common linear relationship is obtained for most elements and certain rock types used and two clear linear regressions for two types of rocks; one for granite, diorite, microgranite and sediments and another ceramic sherds, soils, marble schists, breccia. Such linear regressions become readily available for a future fast, efficient and accu-rate way of potassium determination.

  16. 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.

  17. 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.

  18. 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...

  19. 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...

  20. 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

  1. 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.

  2. 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.

  3. 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.

  4. 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

  5. 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.

  6. 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

  7. 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.

  8. Enhancing OPC model stability and predictability using SEM image contours

    NASA Astrophysics Data System (ADS)

    Habib, Mohamed Serag El-Din

    2008-10-01

    The process model is a major factor affecting the quality of the Model Based Optical Proximity Correction (OPC). Better process model directly leads to better OPC, hence better yield and more profit. While the traditional way in calibrating these process models is using CD measurements at sample locations in the test chip, however, the use of Scanning Electron Microscope (SEM) image contours for process model calibration and optimization has been recently introduced in trial to build more predictable models. In this study, we characterize the traditional flow models versus the contour calibrated models and study the effect of using different combinations and weighting schemes on the quality of the resulting process models, its stability and its ability to correctly predict the process.

  9. 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

  10. 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

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

    NASA Astrophysics Data System (ADS)

    Zhu, Yuan Yuan; Ding, Gu Qiao; Ding, Jian Ning; Yuan, Ning Yi

    2010-04-01

    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.

  12. 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...

  13. 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...

  14. 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...

  15. 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

  16. 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

  17. 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

  18. 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...

  19. 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...

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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…

  10. 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…

  11. 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.

  12. 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.

  13. 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...

  14. 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... the required knowledge and skills to carry out their duties and responsibilities, including startup... operating procedures, using periodic drills, to verify adequate retention of the required knowledge...

  15. 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... the required knowledge and skills to carry out their duties and responsibilities, including startup... operating procedures, using periodic drills, to verify adequate retention of the required knowledge...

  16. 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...

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 2015 CEC Annual Workshop on Electrochemistry

    DTIC Science & Technology

    2015-12-30

    for Diabetes Management. 11:30a-1:10p Lunch break. 1:10-2:00p Rebecca Lai, University of Nebraska-Lincoln Folding- and Dynamics-based...University of Texas at Austin “Glucose Monitoring for Diabetes Management” Adam Heller is Professor Emeritus in the McKetta Department of Chemical...Engineering at UT- Austin and consultant to Abbot Diabetes Care. Generally considered to represent the greatest triumph in the commercialization of

  2. 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…

  3. 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.

  4. 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

  5. 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.

  6. 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.

  7. 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

  8. 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

  9. 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.

  10. 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...

  11. 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.

  12. 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.

  13. 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).

  14. 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.

  15. 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.

  16. 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.

  17. 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;…

  18. 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

  19. 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

  20. 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.

  1. 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

  2. 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.

  3. 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.

  4. 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.

  5. 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).

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. [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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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;

  17. 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

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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…

  3. 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.)

  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. 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…

  6. 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,…

  7. 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,…

  8. 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...

  9. 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 ...

  10. 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,...

  11. 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,...

  12. 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...

  13. 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,...

  14. 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…

  15. 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.

  16. 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…

  17. 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…

  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 250.1902 - 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)...

  20. 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)...

  1. 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)...

  2. 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.

  3. 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...

  4. 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...

  5. 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...

  6. 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...

  7. 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...

  8. 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

  9. 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.

  10. 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.

  11. 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.

  12. 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

  13. 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.

  14. 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

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. [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.

  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. GW-SEM: A Statistical Package to Conduct Genome-Wide Structural Equation Modeling.

    PubMed

    Verhulst, Brad; Maes, Hermine H; Neale, Michael C

    2017-03-15

    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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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).

  8. 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

  9. 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.

  10. 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.

  11. 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.

  12. 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

  13. 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.

  14. 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.

  15. 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

  16. 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.

  17. 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.

  18. 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.

  19. SEM observation of hydrous superabsorbent polymer pretreated with room-temperature ionic liquids.

    PubMed

    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 ([P(4, 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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

  9. 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.

  10. 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.

  11. 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.

  12. 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

  13. 30 CFR 250.1919 - What criteria for investigation of incidents must be in my SEMS program?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... MANAGEMENT, REGULATION, AND ENFORCEMENT, DEPARTMENT OF THE INTERIOR OFFSHORE OIL AND GAS AND SULPHUR OPERATIONS IN THE OUTER CONTINENTAL SHELF Safety and Environmental Management Systems (SEMS) § 250.1919 What criteria for investigation of incidents must be in my SEMS program? To learn from incidents and...

  14. 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

  15. 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...

  16. 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…

  17. 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...

  18. 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

  19. 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

  20. 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.

  1. 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.

  2. 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

  3. 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.

  4. 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.

  5. 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.

  6. 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

  7. 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.

  8. 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

  9. 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.

  10. 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.

  11. 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

  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. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2014-08-01

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

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

    PubMed

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

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

  2. Automated Transmission-Mode Scanning Electron Microscopy (tSEM) for Large Volume Analysis at Nanoscale Resolution

    PubMed Central

    Kuwajima, Masaaki; Mendenhall, John M.; Lindsey, Laurence F.; Harris, Kristen M.

    2013-01-01

    Transmission-mode scanning electron microscopy (tSEM) on a field emission SEM platform was developed for efficient and cost-effective imaging of circuit-scale volumes from brain at nanoscale resolution. Image area was maximized while optimizing the resolution and dynamic range necessary for discriminating key subcellular structures, such as small axonal, dendritic and glial processes, synapses, smooth endoplasmic reticulum, vesicles, microtubules, polyribosomes, and endosomes which are critical for neuronal function. Individual image fields from the tSEM system were up to 4,295 µm2 (65.54 µm per side) at 2 nm pixel size, contrasting with image fields from a modern transmission electron microscope (TEM) system, which were only 66.59 µm2 (8.160 µm per side) at the same pixel size. The tSEM produced outstanding images and had reduced distortion and drift relative to TEM. Automated stage and scan control in tSEM easily provided unattended serial section imaging and montaging. Lens and scan properties on both TEM and SEM platforms revealed no significant nonlinear distortions within a central field of ∼100 µm2 and produced near-perfect image registration across serial sections using the computational elastic alignment tool in Fiji/TrakEM2 software, and reliable geometric measurements from RECONSTRUCT™ or Fiji/TrakEM2 software. Axial resolution limits the analysis of small structures contained within a section (∼45 nm). Since this new tSEM is non-destructive, objects within a section can be explored at finer axial resolution in TEM tomography with current methods. Future development of tSEM tomography promises thinner axial resolution producing nearly isotropic voxels and should provide within-section analyses of structures without changing platforms. Brain was the test system given our interest in synaptic connectivity and plasticity; however, the new tSEM system is readily applicable to other biological systems. PMID:23555711

  3. Sealing Capability and SEM Observation of the Implant-Abutment Interface.

    PubMed

    Lorenzoni, Fabio C; Coelho, Paulo G; Bonfante, Gerson; Carvalho, Ricardo M; Silva, Nelson R F A; Suzuki, Marcelo; Silva, Thelma Lopes; Bonfante, Estevam A

    2011-01-01

    To evaluate the sealing capability of external hexagon implant systems and assess the marginal fit, two groups (n = 10 each) were employed: SIN (Sistema de Implantes Nacional, Brazil) and Osseotite, (Biomet 3i, USA). Sealing capability was determined by placing 0.7 μL of 1% acid-red solution in the implant wells before the torque of their respective abutments. Specimens were then placed into 2.5 mL vials filled with 1.3 mL of distilled water with the implant-abutment interface submerged. Three samples of 100 μL water were collected at previously determinate times. The absorbance was measured with a spectrophotometer, and the data were analyzed by Two-way ANOVA (P < .05) and Tukey's test. Marginal fit was determined using SEM. Leakage was observed for both groups at all times and was significantly higher at 144 hrs. SEM analysis depicted gaps in the implant-abutment interface of both groups. Gaps in the implant-abutment interface were observed along with leakage increased at the 144 hrs evaluation period.

  4. SEM-contour shape analysis based on circuit structure for advanced systematic defect inspection

    NASA Astrophysics Data System (ADS)

    Toyoda, Yasutaka; Shindo, Hiroyuki; Hojo, Yutaka; Fuchimoto, Daisuke

    2014-04-01

    We have developed a practicable measurement technique that can help to achieve reliable inspections for systematic defects in advanced semiconductor devices. Systematic defects occurring in the design and mask processes are a dominant component of integrated circuit yield loss in nano-scaled technologies. Therefore, it is essential to ensure systematic defects are detected at an early stage of wafer fabrication. In the past, printed pattern shapes have been evaluated by human eyes or by taking manual critical dimension (CD) measurements. However, these operations are sometimes unstable and inaccurate. Last year, we proposed a new technique for taking measurements by using a SEM contour [1]. This technique enables a highly precise quantification of various complex 2D shaped patterns by comparing a contour extracted from a SEM image using a CD measurement algorithm and an ideal pattern. We improved this technique to enable the carrying out of inspections suitable for every pattern structure required for minimizing the process margin. This technique quantifies a pattern shape of a target-layer pattern using information on a multi-layered circuit structure. This enabled it to confirm the existence of a critical defect in a circuit connecting upper/lower-layers. This paper describes the improved technique and the evaluation results obtained in evaluating it in detail.

  5. Defect analysis and classification in process control using an SEM and EDX review station

    NASA Astrophysics Data System (ADS)

    Perret, Pascal; Zinssner, Vincent

    1996-09-01

    For process control and yield improvement, in-line inspection and defect review are required in the semiconductor industry. In order to monitor the process and be able to identify and solve any production related problems, the review must use a precise defect classification. For effective classification, the defects must first of all be analyzed and identified and the defect classes created. Defect characterization can be performed using different kinds of tools: optical microscope, electron microscope with x-ray analysis and others. In-line review and classification are mainly achieved using optical systems because of their throughput. However this technique is not efficient enough for advanced technologies. Scanning electron microscopy with EDX analysis must be used in order to accurately determine the defect classes. The SEM resolution, type of image contrast and the possibility of performing chemical analyses using the EDX system can lead to a change in the classification, set up by optical review. Defect characterizations are presented and on some examples the limitations of optical classification and the interest of SEM and EDX analyses in determining the defect classes are highlighted.

  6. The survival of metallic residues from gunshot wounds in cremated bone: a SEM-EDX study.

    PubMed

    Amadasi, Alberto; Brandone, Alberto; Rizzi, Agostino; Mazzarelli, Debora; Cattaneo, Cristina

    2012-07-01

    The research and analysis of gunshot residues has a relevant role in the examination of gunshot wounds. Nevertheless, very little literature exists concerning gunshot wounds on charred material. In this study, 16 adult bovine ribs (eight still with soft tissues and eight totally skeletonized) underwent a shooting test with two types of projectiles (9 mm full metal-jacketed bullet and 9 mm unjacketed bullet). Each rib then underwent a charring process in an electric oven, reaching the stage of complete calcination at 800°C. The area of each entrance wound was analyzed before and after the carbonization process via a scanning electron microscope (SEM) equipped with an energy dispersive X-ray analyzer (EDX). In each sample, metallic residues composed of lead, barium, and antimony were found. These metallic residues were thus preserved also after exposure to the extremely high temperatures reached within the oven, especially with unjacketed bullets, although the particles seem to be more irregular in shape as a result of the heating process. In conclusion, this study proved that gunshot residues survive extremely high temperatures and can be detected via SEM/EDX even in cases of charred tissues.

  7. Qualitative and quantitative interpretation of SEM image using digital image processing.

    PubMed

    Saladra, Dawid; Kopernik, Magdalena

    2016-10-01

    The aim of the this study is improvement of qualitative and quantitative analysis of scanning electron microscope micrographs by development of computer program, which enables automatic crack analysis of scanning electron microscopy (SEM) micrographs. Micromechanical tests of pneumatic ventricular assist devices result in a large number of micrographs. Therefore, the analysis must be automatic. Tests for athrombogenic titanium nitride/gold coatings deposited on polymeric substrates (Bionate II) are performed. These tests include microshear, microtension and fatigue analysis. Anisotropic surface defects observed in the SEM micrographs require support for qualitative and quantitative interpretation. Improvement of qualitative analysis of scanning electron microscope images was achieved by a set of computational tools that includes binarization, simplified expanding, expanding, simple image statistic thresholding, the filters Laplacian 1, and Laplacian 2, Otsu and reverse binarization. Several modifications of the known image processing techniques and combinations of the selected image processing techniques were applied. The introduced quantitative analysis of digital scanning electron microscope images enables computation of stereological parameters such as area, crack angle, crack length, and total crack length per unit area. This study also compares the functionality of the developed computer program of digital image processing with existing applications. The described pre- and postprocessing may be helpful in scanning electron microscopy and transmission electron microscopy surface investigations.

  8. Study of pharmaceutical coatings by means of NMR cryoporometry and SEM image analysis.

    PubMed

    Boissier, Catherine; Feidt, François; Nordstierna, Lars

    2012-07-01

    Nuclear magnetic resonance (NMR) cryoporometry and scanning electron microscopy (SEM) image analysis have been used to investigate the size and shape distribution of pores in pharmaceutical coatings. The coatings were made from a mixture of hydroxypropylcellulose (HPC) and ethylcellulose (EC). Upon solvent evaporation from a solution consisting of both the polymers, a solid polymer film is formed, which after removal of the water-soluble HPC consists of a skeleton of EC. A change in the amount of HPC enables modification of the water permeability through the films. By means of NMR cryoporometry, the presence of small pores (radius below 400 nm) was revealed with no significant change in the pore size distribution (PSD) as the HPC content in the films were changed. NMR cryoporometry showed the presence of channels of a characteristic 30-nm length scale in the films that contained more than 22% HPC. Below this threshold, the lack of interconnecting channels seems to prevent complete HPC dissolution and thereby the water permeability. SEM image analysis showed pore sizes that ranged from hundreds of nanometers up to few micrometers. Above the 22% threshold, further increase of HPC in the films resulted in an increased pore volume and wider PSD.

  9. Modification of the microstructure of the films formed by gamma irradiated starch examined by SEM

    NASA Astrophysics Data System (ADS)

    Cieśla, K.; Sartowska, B.

    2016-01-01

    The paper concerns the effect of gamma irradiation carried out for starch on the microstructure of the films prepared using the starch and its composition with sodium laurate (NaLau) and cetyltrimethylammonium bromide (CTAB) studied by scanning electron microscopy (SEM). Potato starch was irradiated with 60Co gamma rays applying a dose of 30 kGy. Films were prepared by the solution casting method with the addition of 30 wt% glycerol as a plasticizer. Films containing NaLau and CTAB were prepared after performing the procedure, leading to starch-surfactant complexes. Mechanical tests and wetting angle measurements were performed for the films. SEM observations were carried out for the surfaces, fractures and/or sections of the films subjected to chemical fixation and for the dried films. The films obtained using irradiated starch are characterized by a smoother and more homogeneous structure as compared to those based on the non-irradiated starch. Besides, a number of small precipitates were observed on the films surfaces after drying and the number of those precipitates seemed to be higher after irradiation. The results can be related to differences in the microstructure of gels formed on the intermediate step of the films preparation and to the presence of two phases in the system and might serve for explanation of the radiation induced improvement of the hydrophilic/hydrophobic properties, a modification of the mechanical properties of the films, as well as for the changes of those properties resulting after storage.

  10. A robust SEM auto-focus algorithm using multiple band-pass filters

    NASA Astrophysics Data System (ADS)

    Harada, Minoru; Obara, Kenji; Nakamae, Koji

    2017-01-01

    An auto-focus algorithm using multiple band-pass filters for a scanning electron microscope (SEM) is proposed. To acquire sharp images of various kinds of defects by SEM defect observation in semiconductor manufacturing, the auto-focus process must be robust. A method for designing a band-pass filter for calculating the ‘focus measure’ (a key parameter of the auto-focus process) is proposed. To achieve an optimal specific frequency response for various images, multiple band-pass filters are introduced. As for the proposed method, two series of focus measures are calculated by using multiple band-pass filters independently, and it is selected according to reliability of the series of focus measures. The signal-to-noise ratio of an image for acceptable auto-focus precision is determined by simulation using pseudo images. In an experiment using the proposed method with real images, the success rate of auto focus is improved from 79.4% to 95.6%.

  11. Enhancing nanoscale SEM image segmentation and reconstruction with crystallographic orientation data and machine learning

    SciTech Connect

    Converse, Matthew I. Fullwood, David T.

    2013-09-15

    Current methods of image segmentation and reconstructions from scanning electron micrographs can be inadequate for resolving nanoscale gaps in composite materials (1–20 nm). Such information is critical to both accurate material characterizations and models of piezoresistive response. The current work proposes the use of crystallographic orientation data and machine learning for enhancing this process. It is first shown how a machine learning algorithm can be used to predict the connectivity of nanoscale grains in a Nickel nanostrand/epoxy composite. This results in 71.9% accuracy for a 2D algorithm and 62.4% accuracy in 3D. Finally, it is demonstrated how these algorithms can be used to predict the location of gaps between distinct nanostrands — gaps which would otherwise not be detected with the sole use of a scanning electron microscope. - Highlights: • A method is proposed for enhancing the segmentation/reconstruction of SEM images. • 3D crystallographic orientation data from a nickel nanocomposite is collected. • A machine learning algorithm is used to detect trends in adjacent grains. • This algorithm is then applied to predict likely regions of nanoscale gaps. • These gaps would otherwise be unresolved with the sole use of an SEM.

  12. Effect of bleaching agents on enamel surface of bovine teeth: A SEM study

    PubMed Central

    Pimenta-Dutra, Ana-Cristina; Albuquerque, Rodrigo-de Castro; Morgan, Luís-Fernando-dos Santos-Alves; Pereira, Geraldo-Magela; Nunes, Eduardo; Horta, Martinho-Campolina-Rebello

    2017-01-01

    Background This study aimed to evaluate changes in the enamel surface of bovine teeth after whitening with exogenous bleaching agents: 10% carbamide peroxide (group 1), 16% carbamide peroxide (group 2) and 35% hydrogen peroxide activated by a light-emitting diode (LED) (group 3). The evaluations were performed by scanning electron microscopy (SEM). Material and Methods Ninety bovine teeth were divided into five groups (n = 18). The bleaching agents 10% and 16% carbamide peroxide were applied for eight hours a day for 14 consecutive days. The third agent, LED-activated 35% hydrogen peroxide, was used four times at seven-day intervals. Each of the four time points consisted of three applications of 10 minutes each. A 37% phosphoric acid solution and artificial saliva were used as positive and negative controls, respectively. Results The evaluations by SEM showed changes in the enamel surfaces of the specimens. Based on the Mann-Whitney statistical test, the data showed significant differences (p<0.05) between groups 1 and 2 and between groups 2 and 3. However, no significant difference (p>0.05) was observed between groups 1 and 3. Conclusions Based on these results, it can be concluded that bleaching agents can cause changes in the structure of tooth enamel and that these changes are related to the concentration and the duration of contact with the tooth surface. Key words:Bovine teeth, carbamide peroxide, enamel, hydrogen peroxide, scanning electronic microscopy. PMID:28149462

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

    PubMed Central

    Lo Giudice, Giuseppe; Lizio, Angelo; Giudice, Roberto Lo; Centofanti, Antonio; Rizzo, Giuseppina; Runci, Michele; Alibrandi, Angela

    2016-01-01

    Aim. Purpose of the present paper is to analyze the efficiency of different post-space irrigation protocols. Methods. 28 single rooted teeth were endodontically treated. After post-space preparation every sample was assigned to one of three experimental groups and to one control group. In each group different irrigation protocols were performed as follows: EDTA (Group A), 37% orthophosphoric acid (Group B), and EDTA + 37% orthophosphoric acid with ultrasounds activation (Group C). In the control group (Group D) the irrigate association was not activated by ultrasounds. Three zones (coronal, middle, and apical) of each sample were analyzed by using Scan Electron Microscopy (SEM) without any metallization procedures. The presence of smear layer on the canal surface was qualitatively evaluated by applying Serafino's score with values included between 0 and 2. Results. The results of the research showed how Group C recorded the better results (0.81 ± 0.72). Group A and Group B showed lower mean scores (1.06 ± 0.69 and 1.08 ± 0.77); Group D showed the lowest mean score of 1.30 ± 0.69. The SEM observation analysis demonstrated how the smear layer presence decreased in the crown-apical direction. Conclusions. The different post-space treatments statistically determine significant differences on the dentinal surfaces cleansing. The absence of ultrasonic activation lowers the cleansing efficacy of endocanalar irrigants, showing sensible differences among each post-space zone. PMID:27766106

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

    PubMed Central

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

    2016-01-01

    Aim: This in vitro study evaluated and compared the marginal adaptation of three newer root canal sealers to root dentin. Materials and Methods: Thirty freshly extracted human single-rooted teeth with completely formed apices were taken. Teeth were decoronated, and root canals were instrumented. The specimens were randomly divided into three groups (n = 10) based upon the sealer used. Group 1 - teeth were obturated with epoxy resin sealer (MM-Seal). Group 2 - teeth were obturated with mineral trioxide aggregate (MTA) based sealer (MTA Fillapex), Group 3 - teeth were obturated with bioceramic sealer (EndoSequence BC sealer). Later samples were vertically sectioned using hard tissue microtome and marginal adaptation of sealers to root dentin was evaluated under coronal and apical halves using scanning electron microscopy (SEM) and marginal gap values were recorded. Results: The data were statistically analyzed by two-way ANOVA and Tukey's multiple post hoc test. The highest marginal gap was seen in Group 2 (apical-16680.00 nm, coronal-10796 nm) and the lowest marginal gap was observed in Group 1 (apical-599.42 nm, coronal-522.72 nm). Coronal halves showed superior adaptation compared to apical halves in all the groups under SEM. Conclusion: Within the limitations of this study epoxy resin-based MM-Seal showed good marginal adaptation than other materials tested. PMID:27563187

  15. Ecosystem Models as Support to Eutrophication Management in the North Atlantic Ocean (EMoSEM)

    NASA Astrophysics Data System (ADS)

    Lacroix, Geneviève; Billen, Gilles; Desmit, Xavier; Garnier, Josette; Gypens, Nathalie; Lancelot, Christiane; Lenhart, Hermann; Los, Hans; Mateus, Marcos; Ménesguen, Alain; Neves, Ramiro; Troost, Tineke; van der Molen, Johan

    2013-04-01

    One of the leading challenges in marine science and governance is to improve scientific guidance of management measures to mitigate eutrophication nuisances in the EU seas. Existing approaches do not integrate the eutrophication process in space (continuum river-ocean) and in time (past, present and future status). A strong need remains for (i) knowledge/identification of all the processes that control eutrophication and its consequences, (ii) consistent and harmonized reference levels assigned to each eutrophication-related indicator, (iii) identification of the main rivers directly or indirectly responsible for eutrophication nuisances in specific areas, (iv) an integrated transboundary approach and (v) realistic and scientific-based nutrient reduction scenarios. The SEAS-ERA project EMoSEM aims to develop and combine the state-of-the-art modelling tools describing the river-ocean continuum in the North-East Atlantic (NEA) continental seas. This will allow to link the eutrophication nuisances in specific marine regions to anthropogenic inputs, trace back their sources up to the watersheds, then test nutrient reduction options that might be implemented in these watersheds, and propose consistent indicators and reference levels to assess the Good Environmental Status (GES). At the end, EMoSEM will deliver coupled river-coastal-sea mathematical models and will provide guidance to end-users (policy- and decision makers) for assessing and combating eutrophication problems in the NEA continental waters.

  16. GSR2005--continuity of the ENFSI proficiency test on identification of GSR by SEM/EDX.

    PubMed

    Niewoehner, Ludwig; Andrasko, Jan; Biegstraaten, Jan; Gunaratnam, Lawrence; Steffen, Sylvia; Uhlig, Steffen; Antoni, Sabine

    2008-01-01

    Within the framework of the ENFSI Expert Working Group "Firearms" a proficiency test on the detection and identification of GSR by energy-dispersive scanning electron microanalysis (SEM/EDX) is carried out in a 2 years term. The latest test was performed in 2005/2006 and was denoted as GSR2005. Seventy-five laboratories from 28 countries participated in this proficiency test and submitted in total 83 independent data-sets. The participating laboratories were requested to determine the total number of PbSbBa containing particles on a synthetic test sample following their own laboratory specific methods of automated GSR particle search and detection by SEM/EDX. Furthermore size and position of the detected particles had to be reported by the laboratories and were evaluated statistically. The results were compiled by means of z-scores according to the IUPAC and EURACHEM guidelines-assessing individual laboratory achievements (inter-laboratory) as well as intra-laboratory performance-and were compared to the results of the previous proficiency test run GSR2003 (1). The comparison shows that there is a noticeable improvement in the method's detection capability.

  17. Characterization of dentifrices containing desensitizing agents, triclosan or whitening agents: EDX and SEM analysis.

    PubMed

    Pinto, Shelon Cristina Souza; Hilgenberg, Sérgio Paulo; Wambier, Denise Stadler; Farago, Paulo Vitor; Bandéca, Matheus Coelho; Santos, Fábio André

    2014-01-01

    Dentifrices with different compositions are available on the market, but there is limited information about their properties. The aim of this in vitro study was to evaluate the physicochemical characteristics of 12 dentifrices divided into three categories, as containing desensitizing agents, Triclosan or whitening agents. Desiccation loss/residue analysis: 5 g of dentifrice was weighed five times for each group. pH analysis: 5 g of dentifrice were diluted in three parts of distilled water and analyzed using a digital potentiometer. Scanning electron microscopy (SEM): analysis of ashes, shape and size of the particles. Energy-dispersive x-ray spectroscopy (EDX): identification of the abrasive elements. Data were analyzed using ANOVA, Bonferroni post hoc test (α=0.05). Desiccation loss: 38.21% to 65.83%. Dentifrices containing Triclosan and desensitizing agents showed statistically significant differences among them (p<0.05). Whitening dentifrices showed statistically significant differences between Close-Up Whitening and Sensodyne Branqueador (44.72%, 65.83%, respectively). Most dentifrices presented neutral or basic pH. Different shape and size particles were observed in the SEM analysis. Abrasive elements were identified in the EDX. These results demonstrate that the evaluated dentifrices had different properties and their composition influences directly their characteristics, thus resulting in a more or less abrasive action on tooth surface. Knowing the characteristics of the dentifrices is important to indicate the ideal product for each case.

  18. SEM search for sound production and sound perception organs in a variety of Drosophila species.

    PubMed

    Hoikkala, A; Moro, S

    2000-07-15

    The discovery of new song types in Hawaiian Drosophila species has raised a question of alternative sound production and sound perception mechanisms in Drosophila. For example D. disjuncta males, which produce song with a carrier frequency of 5,000-6,000 Hz, do not vibrate their wings but only tremble them in a very small amplitude while singing. In our SEM search we found at the wing base of the flies of this species a special structure which could play a part in song production. Our search for auditory sense organs in Drosophila species revealed that the aristae on fly antennae are structurally not as simple as has been assumed. In Hawaiian D. planitibia subgroup species, the fly aristae are more regular than in other Drosophila species and they are also covered with small hairs. We did not find any sign of tympanic hearing organs in any of the studied species, but we discovered on fly legs and wings sensilla which could play a part in sound/vibration perception. Our SEM survey provides a good starting point in the search for alternative pathways for sound production and perception via transmission electron microscopy combined with behavioral studies and electrophysiological recordings in Hawaiian Drosophila species.

  19. SEM and profilometric evaluation of enamel surface after air rotor stripping--an in vitro study.

    PubMed

    Mikulewicz, Marcin; Szymkowski, Janusz; Matthews-Brzozowska, Teresa

    2007-01-01

    The aim of the study was to evaluate roughness of the enamel surface after Air Rotor Stripping (ARS). Thirty interproximal surfaces of human premolars were used as the biological material. Research was conducted using a contact profilometer and a scanning electron microscope (SEM). Sets of 3D parameters and topographical maps of enamel surface before and after ARS treatment were used to define roughness of the surfaces. SEM images of stripped surfaces were taken with microscopic magnification of 100x and 1000x. The data revealed a general roughness of enamel arising after ARS procedure. Summarized values of chosen parameters increased after ARS procedure compared to the values of untreated enamel. Topographical maps showed areas of both well polished and badly polished enamel. In conclusion, comparison of the mean values of the measured parameters of ARS treated enamel surfaces indicated that roughness of the enamel arises after ARS, but it must be emphasized that on every evaluated surface well polished areas were also present. Moreover, the well polished areas were smoother than those on the untreated enamel surfaces. Contact fluoridation and improved oral hygiene after ARS appear to be necessary because of the presence of areas of increased roughness on evaluated surfaces.

  20. Identification of possible sources of particulate matter in the personal cloud using SEM/EDX

    NASA Astrophysics Data System (ADS)

    Conner, Teri L.; Williams, Ronald W.

    2004-10-01

    The United States Environmental Protection Agency (US EPA) conducted the Baltimore Particulate Matter (PM) Epidemiology-Exposure Study of the Elderly during the summer of 1998. The study design included PM2.5 samples obtained from elderly (65+ years of age) retirement facility residents using personal exposure sampling devices. These sampling devices were also used to obtain PM2.5 samples at fixed locations within the personal monitoring subjects' apartments. Selected personal and apartment samples were examined using scanning electron microscopy with individual-particle X-ray analysis (SEM/EDX), providing a qualitative assessment of the chemical and physical characteristics of geological and trace element particles collected within these micro-environments at the retirement facility. This information was used to identify possible indoor source particles. The manual surveys of the personal samples revealed that some particles larger than 2.5 μm reached the filter surface. Using SEM/EDX, several particle types with possible indoor origins were identified. The Al-Zr-Cl particle is likely to have originated from a personal antiperspirant product. Particles with a talc or alumino-silicate composition point to cosmetics as a possible source. Large cadmium-containing particles were also found, which may indicate the use of art pigments or ceramic glazes, or emissions from television screen phosphors. A greater variety of particles was observed in a personal sample compared with its corresponding fixed-location apartment sample.

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

    PubMed Central

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

    2016-01-01

    Summary Aim The aim of the present in vitro study was to evaluate the protective effects of a zinc-hydroxyapatite toothpaste against an erosive challenge produced by a soft drink (Coca-Cola) using Scanning Electron Microscopy (SEM). Methods Forty specimens were assigned to 4 groups of 10 specimens each (group 1: no erosive challenge, no toothpaste treatment, group 2: erosive challenge, no toothpaste treatment, group 3: erosive challenge, fluoride toothpaste treatment, group 4: erosive challenge, zinc-hydroxyapatite toothpaste treatment). The surface of each specimen was imaged by SEM. A visual rating system was used to evaluate the condition of the enamel surface; results were analyzed by nonparametric statistical methods. Results Statistically significant differences were found between the samples untreated and those immersed in Coca-Cola (group 1, 2); the highest grade of damage was found in group 2, while the lowest grade was recorded in the samples of group 4. Comparing the groups, the two analyzed toothpaste tended to protect in different extend. Conclusions In this study treatment of erosively challenged enamel with Zn-Hap toothpaste showed a clear protective effect. This was greater than the effect observed for a normal fluoride toothpaste and confirmed the potential benefit the Zn-HAP technology can provide in protecting enamel from erosive acid challenges. PMID:28149449

  2. [Analysis of pine pollen by using FTIR, SEM and energy-dispersive X-ray analysis].

    PubMed

    Wang, Ya-min; Wang, Hong-jie; Zhang, Zhuo-yong

    2005-11-01

    Infrared spectroscopy (IR), scanning electron microscope (SEM) and energy-dispersive X-ray analysis (EDX) were used to analyze nutrients in four pine pollen powder samples. The IR fingerprints showed that each of the samples, pinus massoniana, pinus yunnanensis, pinus tabulaeformis, and pinus densiflora, respectively had its own characteristic infrared spectrum. Based on the difference of the relative intensity of those characteristic absorption peaks, the IR fingerprints can be used for the identification of the four kinds of pine pollen samples. The broken pollen of pinus was more easily to release nutritional components for the distinct difference IR fingerprints of natural and broken masson pine pollen samples. As a result of SEM, four kinds of pollen grains were oblong or subspheroidal in distal face and proximal face. The exine sculpture of the four kinds of samples were granulous and almost the same, but there was some difference of the size of pollen grains. The main morphologic change of the broken pollen was that the air bags were separated from pollen particles, and part of the main body of pollen particles was broken. The energy-dispersive X-ray analysis results showed that eleven elements, including Mg, Se, Si, Sr, P, S, Cl, K, Ca, Mn, and Fe, existed and the highest content in pollen of pinus was K element. The contents of trace elements were different in different kinds of pollen of pinus. The element intensity in broken masson pine pollen was distinctlyhigher than that innatural masson pine pollen.

  3. Sealing Capability and SEM Observation of the Implant-Abutment Interface

    PubMed Central

    Lorenzoni, Fabio C.; Coelho, Paulo G.; Bonfante, Gerson; Carvalho, Ricardo M.; Silva, Nelson R. F. A.; Suzuki, Marcelo; Silva, Thelma Lopes; Bonfante, Estevam A.

    2011-01-01

    To evaluate the sealing capability of external hexagon implant systems and assess the marginal fit, two groups (n = 10 each) were employed: SIN (Sistema de Implantes Nacional, Brazil) and Osseotite, (Biomet 3i, USA). Sealing capability was determined by placing 0.7 μL of 1% acid-red solution in the implant wells before the torque of their respective abutments. Specimens were then placed into 2.5 mL vials filled with 1.3 mL of distilled water with the implant-abutment interface submerged. Three samples of 100 μL water were collected at previously determinate times. The absorbance was measured with a spectrophotometer, and the data were analyzed by Two-way ANOVA (P < .05) and Tukey's test. Marginal fit was determined using SEM. Leakage was observed for both groups at all times and was significantly higher at 144 hrs. SEM analysis depicted gaps in the implant-abutment interface of both groups. Gaps in the implant-abutment interface were observed along with leakage increased at the 144 hrs evaluation period. PMID:21754934

  4. Dental materials as an aid for victim identification: examination of calcined remains by SEM/EDS

    NASA Astrophysics Data System (ADS)

    Bush, Mary A.; Bush, Peter J.

    2010-06-01

    Detection and identification of human remains in situations in which they are calcined, disarticulated, and fragmented may be a challenging task. In such situations the non-biological materials that may be present in the dentition can provide the best evidence available for potential identification. Four human jaw segments were utilized. A known combination of dental resins was placed in each segment, when possible. Other restorations, pre-existing in the cadavers, were retained. The jaw segments were cremated in a commercial cremation oven for 2.5 hrs at 1010C. Scanning Electron Microscopy with Energy Dispersive X-Ray Spectroscopy (SEM/EDS) was used to analyze the dentition and fragmented debris. Analysis with SEM/EDS demonstrated the ability to confirm brand of known dental resins placed in each cadaver. In addition, pre-existing materials in each jaw segment were profiled and a likely brand name suggested. It was shown that microscopic fragments of heat-altered materials could be identified and classified, adding another level of certainty in victim identification.

  5. Compositional and technological features of glazed pottery from Aosta Valley (Italy): a SEM-EDS investigation.

    PubMed

    Gulmini, Monica; Appolonia, Lorenzo; Framarin, Patrizia; Mirti, Piero

    2006-11-01

    Twelve finds from archaeological excavations carried out in the Aosta region (Italy) were studied by scanning electron microscopy coupled with energy-dispersive X-ray detection (SEM-EDS). The archaeological samples were shards of glazed pottery dating from the fourth to the seventh century AD. Analysis of ceramic bodies revealed a general homogeneity in composition among the studied samples and the use of a noncalcareous clay for their manufacture; however, two shards stand out due to their high iron contents. Glazes proved to be high-lead products with more than 70% PbO in all of the samples investigated but one. For the latter, a composition poorer in lead and richer in silicon, aluminium and iron was found. SEM observation of the contact region between body and glaze suggests that the vitreous coatings were mostly obtained by applying the glazing components onto the unfired clay body; moreover, a comparison between clay and glaze compositions suggests the use of a lead compound mixed with a silica-rich material, not a lead compound by itself.

  6. SEM evaluation of pulp reaction to different pulp capping materials in dog’s teeth

    PubMed Central

    Asgary, Saeed; Parirokh, Masoud; Eghbal, Mohammad Jafar; Ghoddusi, Jamileh

    2006-01-01

    Introduction: This investigation evaluates the effects of mineral trioxide aggregate (MTA), calcium hydroxide (CH) and calcium enriched mixture (CEM) as pulp capping materials on dental pulp tissues. Materials and Methods: The experimental procedures were performed on eighteen intact dog canine teeth. The pulps were exposed. Cavities were randomly filled with CEM, MTA, or CH followed by glass ionomer filling. After 2 months, animals were sacrificed, each tooth was sectioned into halves, and the interface between each capping material and pulp tissue was evaluated by scanning electron microscope (SEM) in profile view of the specimens. Results: Dentinal bridge formation as the most characteristic reaction was resulted from SEM observation in all examined groups. Odontoblast-like cells were formed and create dens collagen network, which was calcified gradually by deposition of calcosphirit structures to form newly dentinal bridge. Conclusion: Based on the results of this in vivo study, it was concluded that these test materials are able to produce calcified tissue in underlying pulp in the case of being used as a pulp capping agent. Additionally, it appears that CEM has the potential to be used as a direct pulp capping material during vital pulp therapy. PMID:24379876

  7. Signal-to-noise ratio estimation on SEM images using cubic spline interpolation with Savitzky-Golay smoothing.

    PubMed

    Sim, K S; Kiani, M A; Nia, M E; Tso, C P

    2014-01-01

    A new technique based on cubic spline interpolation with Savitzky-Golay noise reduction filtering is designed to estimate signal-to-noise ratio of scanning electron microscopy (SEM) images. This approach is found to present better result when compared with two existing techniques: nearest neighbourhood and first-order interpolation. When applied to evaluate the quality of SEM images, noise can be eliminated efficiently with optimal choice of scan rate from real-time SEM images, without generating corruption or increasing scanning time.

  8. Two-dimensional fully dynamic SEM simulations of the 2011 Tohoku earthquake cycle

    NASA Astrophysics Data System (ADS)

    Shimizu, H.; Hirahara, K.

    2014-12-01

    Earthquake cycle simulations have been performed to successfully reproduce the historical earthquake occurrences. Most of them are quasi-dynamic, where inertial effects are approximated using the radiation damping proposed by Rice [1993]. Lapusta et al. [2000, 2009] developed a methodology capable of the detailed description of seismic and aseismic slip and gradual process of earthquake nucleation in the entire earthquake cycle. Their fully dynamic simulations have produced earthquake cycles considerably different from quasi-dynamic ones. Those simulations have, however, never been performed for interplate earthquakes at subduction zones. Many studies showed that on dipping faults such as interplate earthquakes at subduction zones, normal stress is changed during faulting due to the interaction with Earth's free surface. This change in normal stress not only affects the earthquake rupture process, but also causes the residual stress variation that might affect the long-term histories of earthquake cycle. Accounting for such effects, we perform two-dimensional simulations of the 2011 Tohoku earthquake cycle. Our model is in-plane and a laboratory derived rate and state friction acts on a dipping fault embedded on an elastic half-space that reaches the free surface. We extended the spectral element method (SEM) code [Ampuero, 2002] to incorporate a conforming mesh of triangles and quadrangles introduced in Komatitsch et al. [2001], which enables us to analyze the complex geometry with ease. The problem is solved by the methodology almost the same as Kaneko et al. [2011], which is the combined scheme switching in turn a fully dynamic SEM and a quasi-static SEM. The difference is the dip-slip thrust fault in our study in contrast to the vertical strike slip fault. With this method, we can analyze how the dynamic rupture with surface breakout interacting with the free surface affects the long-term earthquake cycle. We discuss the fully dynamic earthquake cycle results

  9. The effects of various irrigating solutions on intra-radicular dentinal surface: An SEM analysis

    PubMed Central

    Karunakaran, J. V.; Kumar, S. Senthil; Kumar, Mohan; Chandrasekhar, S; Namitha, D.

    2012-01-01

    Aim: The action of irrigant solutions on intra- radicular dentinal surface were evaluated in an in vitro setting using a scanning electron microscope (SEM) and it was observed that sodium hypochlorite and MTAD produced the cleanest surface and that none of the irrigants were able to produce an ideal preparation of the dentinal surface when used individually. The primary objective of endodontic therapy is to achieve a clean, optimal environment in root canals to avoid unsuccessful treatment outcomes. The complexities of the root canal system necessitate the use of irrigating solutions which act on radicular dentin surface, modifying it. The action of irrigants can be beneficial, and yet at the same time, as they modify the surface structure of dentin, they can have an adverse impact on the properties of dentin. The present study was undertaken to assess the effect of various irrigants on the dentinal surface using an SEM. Materials and Methods: Forty-five roots were randomly divided into nine groups (n=5) and prepared by sectioning at the level of cemento-enamel junction (CEJ) and 10 mm from the CEJ and split longitudinally. The dentin surface was prepared and the cemental surfaces were coated with double layer of varnish. The irrigants tested were normal saline, de-ionized water, 17% ethylenediaminetetraacetic acid (EDTA), 5% sodium hypochlorite (NaOCl), 5% NaOCl with ultrasonic agitation, 3% hydrogen peroxide, 2% chlorhexidine (CHX), MTAD, and MTAD with ultrasonic agitation. The prepared samples were placed in the irrigant solution for 3 min, subsequently dehydrated, sputter coated, and observed under SEM. The images were subsequently analyzed for dentinal surface changes. Results: 17% EDTA and MTAD produced the cleanest dentinal surface. Ultrasonic agitation enhanced the effect of irrigants. 5% NaOCl and 3% hydrogen peroxide were efficient at removal of organic debris, but were unable to remove the smear layer. De-ionized water, normal saline, and 2

  10. 30 CFR 250.1914 - What criteria must be documented in my SEMS program for safe work practices and contractor...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... SULPHUR OPERATIONS IN THE OUTER CONTINENTAL SHELF Safety and Environmental Management Systems (SEMS) § 250... making certain that contractors have the skills and knowledge to perform their assigned duties and...

  11. 30 CFR 250.1914 - What criteria must be documented in my SEMS program for safe work practices and contractor...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... SULPHUR OPERATIONS IN THE OUTER CONTINENTAL SHELF Safety and Environmental Management Systems (SEMS) § 250... have the skills and knowledge to perform their assigned duties and are conducting these activities...

  12. Information or resolution: Which is required from an SEM to study bulk inorganic materials?: Evaluate SEMs’ practical performance

    SciTech Connect

    Xing, Q.

    2016-07-11

    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 energydispersive 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. Finally, for an SEM that is controlled/operated with a computer, the stable software and user-friendly interface significantly affect the usability of the SEM.

  13. Information or resolution: Which is required from an SEM to study bulk inorganic materials?: Evaluate SEMs’ practical performance

    DOE PAGES

    Xing, Q.

    2016-07-11

    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. Themore » 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 energydispersive 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. Finally, for an SEM that is controlled/operated with a computer, the stable software and user-friendly interface significantly affect the usability of the SEM.« less

  14. Pasting investigation, SEM observation and the possible interaction study on rice starch-pullulan combination.

    PubMed

    Chen, Long; Ren, Fei; Yu, Xueping; Zhang, Zipei; Xu, Dejun; Tong, Qunyi

    2015-02-01

    The pasting properties of rice starch (RS) with high concentration (10%, w/w) were investigated in the presence or absence of pullulan (PUL) using a rapid visco-analyzer (RVA). Addition of pullulan resulted in the reduction of peak viscosity, trough viscosity, final viscosity, and setback value of RS. Furthermore, an interesting phenomenon, i.e. a small viscosity peak appeared in the RVA curves of RS-PUL mixtures, was observed. It indicated that addition of pullulan might suppress the gelatinization of starch granules by maintaining the integration of some granules. The scanning electron microscope (SEM) observation of samples suggested that starch granules could be wrapped by a thin membrane composed of pullulan and/or pullulan-amylose associations. The coating ability of pullulan and/or the possible molecular interactions between pullulan and amylose could be responsible for these results.

  15. Characterization of diamond-like carbon films by SEM, XRD and Raman spectroscopy

    NASA Astrophysics Data System (ADS)

    Pang, Hua; Wang, Xingquan; Zhang, Guling; Chen, Huan; Lv, Guohua; Yang, Size

    2010-08-01

    Diamond-like carbon films were deposited by electrolysis of a water-ethanol solution on Cu at low voltages (60-100 V) at 2 mm interelectrode separation. The films were characterized by scanning electron microscopy (SEM), X-ray diffractometer (XRD) and Raman spectroscopy. The films were found to be continuous and compact with uniform grain distribution. Raman spectroscopy analysis revealed two broad bands at ˜1350 and ˜1580 cm -1. The downshift of the G band of graphite is indicative of the presence of DLC. For XRD analysis, the three strong peaks located at 2 θ values of 43.2°, 74.06° and 89.9° can be identified with reflections form (1 1 1), (2 2 0) and (3 1 1) plane of diamond.

  16. UV laser ablation of intraocular lenses: SEM and AFM microscopy examination of the biomaterial surface

    NASA Astrophysics Data System (ADS)

    Spyratou, E.; Asproudis, I.; Tsoutsi, D.; Bacharis, C.; Moutsouris, K.; Makropoulou, M.; Serafetinides, A. A.

    2010-02-01

    Several new materials and patterns are studied for the formation and etching of intraocular lenses (IOLs), in order to improve their optical properties, to reduce the diffractive aberrations and to decrease the incidence of posterior capsular opacification. The aim of this study is to investigate the use of UV ( λ = 266 nm) laser pulses to ablate the intraocular lenses materials, and thus to provide an alternative to conventional surface shaping techniques for IOLs fabrication. Ablation experiments were conducted using various polymer substrates of hydrophobic acrylic IOLs and PMMA IOLs. We investigated the ablation efficiency and the morphology of the ablated area by imaging the surface modification with atomic force microscopy (AFM) and scanning electron microscopy (SEM). The morphological appearance of IOL samples reveals the effect of a photochemical and photothermal ablation mechanism.

  17. Distinguishing shocked from tectonically deformed quartz by the use of the SEM and chemical etching

    USGS Publications Warehouse

    Gratz, A.J.; Fisler, D.K.; Bohor, B.F.

    1996-01-01

    Multiple sets of crystallographically-oriented planar deformation features (PDFs) are generated by high-strain-rate shock waves at pressures of > 12 GPa in naturally shocked quartz samples. On surfaces, PDFs appear as narrow (50-500 nm) lamellae filled with amorphosed quartz (diaplectic glass) which can be etched with hydrofluoric acid or with hydrothermal alkaline solutions. In contrast, slow-strain-rate tectonic deformation pressure produces wider, semi-linear and widely spaced arrays of dislocation loops that are not glass filled. Etching samples with HF before examination in a scanning electron microscope (SEM) allows for unambiguous visual distinction between glass-filled PDFs and glass-free tectonic deformation arrays in quartz. This etching also reveals the internal 'pillaring' often characteristic of shock-induced PDFs. This technique is useful for easily distinguishing between shock and tectonic deformation in quartz, but does not replace optical techniques for characterizing the shock features.

  18. Comparative study of carbonaceous meteoritic fragments by micro-Raman spectroscopy and SEM/EDS.

    NASA Astrophysics Data System (ADS)

    Dall'Asén, AnalíA.; Mittelstaedt, Jacob; Kim, Jin-Sun; Baer, Brandon; Paul, Raka; Gerton, Jordan; Bromley, Benjamin; Kenyon, Scott

    2017-01-01

    Meteorites provide precious clues about the formation of planets in the solar system. In particular, carbonaceous chondritic meteorites, considered the most primitive surviving materials from the early Solar System, can contribute to understand how planetisimals (the precursors to planets, of 1-100 km in radius) formed from dust (micron-size grains). These relics are mainly composed of chondrules (micro/millimeter-sized inclusions) surrounded by a matrix of microparticles. Here we present a comparative study of the structure and composition of the chondrules and surrounding matrix of different carbonaceous chondritic meteorites using low- and high-resolution micro-Raman spectroscopy and SEM/EDS (Scanning Electron Microscopy/Energy Dispersive X-ray Spectroscopy). We examine how these properties vary in different regions of the chondrules and matrix, capturing details from micrometer to millimeter scales. We compare the structure and composition between different samples, looking for signatures of the physical processes that drove their formation.

  19. (An)aerobic bacteria found in secondary-cataract material. A SEM/TEM study.

    PubMed

    Kalicharan, D; Jongebloed, W L; Los, L I; Worst, J G

    1992-01-01

    Twenty four patients, who had marked reduction of vision due to secondary-cataract developed after an ECCE, were treated by surgical cleaning of the posterior lens capsule. During this procedure globular secondary-cataract material was removed and collected for morphological examination by SEM and TEM. Fragments of various sizes and shapes, including some with a 'golf ball' structure, were seen; these closely resembled particles frequently found in cataractous lenses. In addition, in 18 patients micro-organisms were found: rod-shaped bacteria, cocci, and in 2 cases yeasts. These findings were the more remarkable because these were clinically quiet eyes with no signs of intra-ocular inflammation and cultures have been persistently negative. We imagine that these bacteria must have entered the eye during the cataract extraction and have settled there without causing an infection.

  20. Micro-Raman, FTIR, SEM-EDX and structural analysis of the Çanakkale meteorite.

    PubMed

    Unsalan, O; Yilmaz, A; Bolukbasi, O; Ozturk, B; Esenoglu, H H; Ildiz, G O; Ornek, C Y

    2012-06-15

    This study demonstrates for the first time, the spectroscopic characterization of Çanakkale Meteorite that fell at Çanakkale, Republic of Turkey (40°8'44″N; 26°24'23″E). The olivine group [(Mg, Fe)(2)SiO(4)], enstatite [Mg(2)Si(2)O(6)] (one of the orthopyroxene minerals) and plagioclase were identified by the micro-Raman and FTIR spectroscopies and EDX-SEM analyses. This meteorite has not yet been classified in the World's Database of Meteorites. The aim of this study is to investigate this meteorite by vibrational spectroscopic techniques and open the possibility to classify it and list in the World's Database of Meteorites.

  1. SEM and EDX studies of bioactive hydroxyapatite coatings on titanium implants.

    PubMed

    Ciobanu, Gabriela; Carja, Gabriela; Ciobanu, Octavian; Sandu, Ion; Sandu, Andrei

    2009-01-01

    This work presents a study on an alternative coating method based on biomimetic techniques which are designed to form a crystalline hydroxyapatite layer very similar to the process corresponding to the formation of natural bone. The HA formation on the surface of titanium alloy pretreated with NaOH solution is investigated. Two types of solutions such as supersaturated calcification solution (SCS) and modified SCS (M-SCS) were used to investigate bone-like apatite formation on alkali-treated titanium. The hydroxyapatite deposits are investigated by means of scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDX). The data suggest that the method utilized in this work can be successfully applied to obtain deposition of uniform coatings of crystalline hydroxyapatite on titanium substrates.

  2. Characterization of atmospheric particles in Seoul, Korea using SEM-EDX.

    PubMed

    Kang, Eunha; Park, Inji; Lee, Young Jae; Lee, Meehye

    2012-07-01

    Atmospheric particles in Seoul, Korea were investigated by scanning electron microscopy (SEM) equipped with energy dispersive X-ray analysis (EDX). Particles were identified and characterized by their morphology and elemental compositions. The morphology of particles was closely coupled with elemental compositions, which provided information on sources and transport processes of aerosols. There were various types of combustion-derived particles identified such as fly ashes, soot, organic matters, tar balls, chars, and sulfur-containing particles. These anthropogenic particles mainly have spherical shape with nano- to micro-meter size. Char was, however, distinguished by irregular shape with varying size up to several micrometers. The sulfur-containing aggregates show a wide range of size, shape, and elemental composition. In addition, bioaerosol and mineral dust were the most abundant particles from natural sources.

  3. SEM-EDX analysis of various sizes aerosols in Delhi India.

    PubMed

    Srivastava, Arun; Jain, V K; Srivastava, Anchal

    2009-03-01

    Scanning electron microscopy-energy dispersive X-ray analysis (SEM-EDX) was used to understand the differences in morphology, elemental composition and particle density of aerosols in different five size ranges to further investigate the potential sources as well as transport of pollutants from/at a much polluted and a very clean area of Delhi. Aerosol samples were obtained in five different size ranges viz. > or = 10.9, 10.9-5.4, 5.4-1.6, 1.6-0.7 and < or = 0.7 microm from a considerably very clean and a much polluted area of Delhi. It was observed that at polluted area most of the particles irrespective of size are of anthropogenic origin. At clean area, in coarse size fractions particles are of natural origin while in fine size range the presence of anthropogenic particles suggests the transport of particles from one area to the other.

  4. SEM, EDX, infrared and Raman spectroscopic characterization of the silicate mineral yuksporite.

    PubMed

    Frost, Ray L; López, Andrés; Scholz, Ricardo; Theiss, Frederick L; Romano, Antônio Wilson

    2015-02-25

    The mineral yuksporite (K,Ba)NaCa2(Si,Ti)4O11(F,OH)⋅H2O has been studied using the combination of SEM with EDX and vibrational spectroscopic techniques of Raman and infrared spectroscopy. Scanning electron microscopy shows a single pure phase with cleavage fragment up to 1.0 mm. Chemical analysis gave Si, Al, K, Na and Ti as the as major elements with small amounts of Mn, Ca, Fe and REE. Raman bands are observed at 808, 871, 930, 954, 980 and 1087 cm(-1) and are typical bands for a natural zeolite. Intense Raman bands are observed at 514, 643 and 668 cm(-1). A very sharp band is observed at 3668 cm(-1) and is attributed to the OH stretching vibration of OH units associated with Si and Ti. Raman bands resolved at 3298, 3460, 3562 and 3628 cm(-1) are assigned to water stretching vibrations.

  5. Discovering New Minerals at Micron to Nanoscales: A SEM-EBSD-EPMA Approach

    NASA Astrophysics Data System (ADS)

    Ma, C.

    2014-12-01

    With high-resolution analytical field emission scanning electron microscope and electron probe microanalyzer, we are now capable to characterize Earth and planetary materials easier and faster down to nanoscales. Nanofeatures (such as inclusions, exsolution, zonation, coatings, pores) in minerals and rocks are being discovered. Nanominerals and nanoparticles are being revealed. New minerals and new materials are being identified. During our ongoing nanomineralogy investigation since 2006, more than twenty five new minerals have been discovered at micron to nanoscales. Fifteen of them are from the Allende meteorite, including new refractory minerals like allendeite, hexamolybdenum, tistarite, panguite and kangite, which are among the first solids formed in our solar system. Each of the new extraterrestrial minerals reveals distinctive forming environments, providing insights into nebula or parent-body processes. Presented here are a few nanomineralogy projects demonstrating how to find and characterize new minerals with an integrated SEM-EBSD-EPMA approach.

  6. Formation of nickel-manganese oxide thermistors studied by XRD, SEM and auger spectroscopy

    NASA Astrophysics Data System (ADS)

    Azimi-Nam, S.; Golestani-Fard, F.; Hashemi, T.

    1987-03-01

    This paper describes the formation of nickel-manganeses oxide thermistor bodies at 1000 1340° C, employing analytical techniques of XRD, SEM/EPMA and AES. The micro-structural studies revealed that the main phase of nickel manganite coexists with a solid solution of NiO in Mn3O4 in the final product. The optimum firing conditions to achieve the necessary electrical properties as well as the development of the desired microstructure could be selected around 1200° C, for 4 hrs in an ambient atmosphere. Above this temperature, the density begins to decrease while the resistivity increases. These anomalous electrical resistivity variations could be partly attributed to the trapped oxygen which was evolved from the decomposition of the unreacted α-Mn2O3. At-lower temperatures, unreacted nickel oxide residuals as well as a high porosity of the samples would yield specimens with high resistivity.

  7. SEM observation and wettability of variously processed and fractured surface of dental zirconia

    NASA Astrophysics Data System (ADS)

    Tarumi, Naoyoshi; Uo, Motohiro; Yamaga, Eiji; Watari, Fumio

    2012-12-01

    Current dental zirconia has several problems in clinical application such as chipping, fracture and detachment. To reduce these problems the surface after various treatments was analyzed by SEM observation, contact angle measurement and surface roughness measurement, and compared. The surface after mirror polishing was smooth. Porcelain layering was smooth except large formed grooves by bubbles. After sandblast and tribochemical treatments, the surfaces showed several micron-sized caving with micron to submicron-level irregularities. Sandblast and tribochemical treatments with the lager roughness had the smaller water contact angle than silicone wheel polishing. Clinically fractured surface of zirconia showed a more complex structure than manually fractured surface, which may be due to the various mode of stress to be imposed repetitively to various direction.

  8. Using the Hitachi SEM to engage learners and promote next generation science standards inquiry

    NASA Astrophysics Data System (ADS)

    Menshew, D. E.

    2014-09-01

    In this study participants will learn how the Hitachi TM3000 scanning electron microscope (SEM) played a central role in one school's movement towards Next Generation Science Standards (NGSS) and promoted exceptional student engagement. The device was used to create high quality images that were used by students in a variety of lab activities including a simulated crime scene investigation focusing on developing evidence based arguments as well as a real world conservation biology study. It provided opportunities for small group and independent investigations in support of NGSS, and peer-peer mentoring. Furthermore, use of the device was documented and were included to enhance secondary students' college and scholarship applications, all of which were successful.

  9. In situ TEM/SEM electronic/mechanical characterization of nano material with MEMS chip

    NASA Astrophysics Data System (ADS)

    Yuelin, Wang; Tie, Li; Xiao, Zhang; Hongjiang, Zeng; Qinhua, Jin

    2014-08-01

    Our investigation of in situ observations on electronic and mechanical properties of nano materials using a scanning electron microscope (SEM) and a transmission electron microscope (TEM) with the help of traditional micro-electro-mechanical system (MEMS) technology has been reviewed. Thanks to the stability, continuity and controllability of the loading force from the electrostatic actuator and the sensitivity of the sensor beam, a MEMS tensile testing chip for accurate tensile testing in the nano scale is obtained. Based on the MEMS chips, the scale effect of Young's modulus in silicon has been studied and confirmed directly in a tensile experiment using a transmission electron microscope. Employing the nanomanipulation technology and FIB technology, Cu and SiC nanowires have been integrated into the tensile testing device and their mechanical, electronic properties under different stress have been achieved, simultaneously. All these will aid in better understanding the nano effects and contribute to the designation and application in nano devices.

  10. SEM, EDX, Infrared and Raman spectroscopic characterization of the silicate mineral yuksporite

    NASA Astrophysics Data System (ADS)

    Frost, Ray L.; López, Andrés; Scholz, Ricardo; Theiss, Frederick L.; Romano, Antônio Wilson

    2015-02-01

    The mineral yuksporite (K,Ba)NaCa2(Si,Ti)4O11(F,OH)ṡH2O has been studied using the combination of SEM with EDX and vibrational spectroscopic techniques of Raman and infrared spectroscopy. Scanning electron microscopy shows a single pure phase with cleavage fragment up to 1.0 mm. Chemical analysis gave Si, Al, K, Na and Ti as the as major elements with small amounts of Mn, Ca, Fe and REE. Raman bands are observed at 808, 871, 930, 954, 980 and 1087 cm-1 and are typical bands for a natural zeolite. Intense Raman bands are observed at 514, 643 and 668 cm-1. A very sharp band is observed at 3668 cm-1 and is attributed to the OH stretching vibration of OH units associated with Si and Ti. Raman bands resolved at 3298, 3460, 3562 and 3628 cm-1 are assigned to water stretching vibrations.

  11. Studying Cellulose Fiber Structure by SEM, XRD, NMR and Acid Hydrolysis

    SciTech Connect

    Zhao, Haibo; Kwak, Ja Hun; Zhang, Z. Conrad; Brown, Heather M.; Arey, Bruce W.; Holladay, John E.

    2007-03-21

    Cotton linters were partially hydrolyzed in dilute acid and the morphology of remaining macrofibrils studied with Scanning Electron Microscopy (SEM) under various magnifications. The crystal region (microfibril bundles) in the macrofibrils was not altered by hydrolysis, and only amorphous cellulose was hydrolyzed and leached out from the macrofibrils. The diameter of microfibril bundles was 20-30 nm after the amorphous cellulose was removed by hydrolysis. XRD experiments confirm the unaltered diameter of the microfibrils after hydrolysis. The strong stability of these microfibril bundles in hydrolysis limits both the total sugar monomer yield and the size of nano particles or rods produced in hydrolysis. The large surface potential on the remaining microfibril bundles drives the agglomeration of macrofibrils.

  12. Comparison and SEM-characterization of novel solvents of DNA/carbon nanotube

    NASA Astrophysics Data System (ADS)

    Sadeghi, Babak; Vahdati, R. A. R.

    2012-01-01

    There have been many applications proposed for carbon nanotubes (CNTs). In spite of these applications they are not being used vastly for a few fundamental difficulties in utilizing them including not being soluble in aqueous and non-aqueous solutions. One method for dispersing and solubilizing them in aqueous solutions is attaching single stranded DNA to the outer wall of single walled carbon nanotubes. The effective parameter in the solubility (efficiency in gel filtration) is the strength of hydrogen bonds between CNTs and DNA in three solvents possessing strong hydrogen bonds: H2O, methanol (MeOH) and N,N'-dimethyl formamide (DMF). Electronic absorption spectra, Superdex TM 200 10/300 gel-filtration and scanning electronic microscopy (SEM) also support van der Waals wrapping of DNA on CNTs. It was found that DMF exhibit higher solubility than MeOH and H2O.

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

    PubMed

    Gontard, L C; López-Castro, J D; González-Rovira, L; Vázquez-Martínez, J M; Varela-Feria, F M; Marcos, M; Calvino, J J

    2017-03-07

    We describe a methodology to obtain three-dimensional models of engineered surfaces using scanning electron microscopy and multi-view photogrammetry (3DSEM). For the reconstruction of the 3D models of the surfaces we used freeware available in the cloud. The method was applied to study the surface roughness of metallic samples patterned with parallel grooves by means of laser. The results are compared with measurements obtained using stylus profilometry (PR) and SEM stereo-photogrammetry (SP). The application of 3DSEM is more time demanding than PR or SP, but it provides a more accurate representation of the surfaces. The results obtained with the three techniques are compared by investigating the influence of sampling step on roughness parameters.

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

    NASA Technical Reports Server (NTRS)

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

    2016-01-01

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

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

    PubMed

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

    2014-01-01

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

  16. Confirmatory analysis of field-presumptive GSR test sample using SEM/EDS

    NASA Astrophysics Data System (ADS)

    Toal, Sarah J.; Niemeyer, Wayne D.; Conte, Sean; Montgomery, Daniel D.; Erikson, Gregory S.

    2014-09-01

    RedXDefense has developed an automated red-light/green-light field presumptive lead test using a sampling pad which can be subsequently processed in a Scanning Electron Microscope for GSR confirmation. The XCAT's sampling card is used to acquire a sample from a suspect's hands on the scene and give investigators an immediate presumptive as to the presence of lead possibly from primer residue. Positive results can be obtained after firing as little as one shot. The same sampling card can then be sent to a crime lab and processed on the SEM for GSR following ASTM E-1588-10 Standard Guide for Gunshot Residue Analysis by Scanning Electron Microscopy/Energy Dispersive X-Ray Spectrometry, in the same manner as the existing tape lifts currently used in the field. Detection of GSR-characteristic particles (fused lead, barium, and antimony) as small as 0.8 microns (0.5 micron resolution) has been achieved using a JEOL JSM-6480LV SEM equipped with an Oxford Instruments INCA EDS system with a 50mm2 SDD detector, 350X magnification, in low-vacuum mode and in high vacuum mode after coating with carbon in a sputter coater. GSR particles remain stable on the sampling pad for a minimum of two months after chemical exposure (long term stability tests are in progress). The presumptive result provided by the XCAT yields immediate actionable intelligence to law enforcement to facilitate their investigation, without compromising the confirmatory test necessary to further support the investigation and legal case.

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

    NASA Astrophysics Data System (ADS)

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

    2011-03-01

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

  18. An In-vitro Comparison of Nano Hydroxyapatite, Novamin and Proargin Desensitizing Toothpastes - A SEM Study

    PubMed Central

    Jayanti, Ipsita; Sambashivaiah, Savita; Bilchodmath, Shivaprasad

    2016-01-01

    Introduction Dentinal Hypersensitivity (DH) is commonly encountered clinical condition in dental practice which affects 8-57% of the adult population presenting for dental treatment, but the treatment of the same remains doubtful. Aim The purpose of this study was to evaluate and compare the effects of three different desensitizing agents (15% nano hydroxyapatite crystals; 5% novamin and 8% proargin) on dentinal permeability and tubule occlusion in-vitro. Scanning Electron Microscope (SEM) was used to evaluate the effect of these commercially available desensitizing toothpastes. Materials and Methods A total of 40 disc shaped dentin specimens were dissected from extracted premolars. Dentin discs of 1mm were obtained with the help of diamond discs. Ten specimens were randomly selected and allocated to the evaluation groups A (control group), B (Nano-hydroxyapatite), C (Novamin) and D (Proargin). Each treatment group dentine disc specimen was treated with the respective slurry for two minutes for a period of seven days. Each disc was subjected to a pre- and post-treatment SEM analysis to evaluate the changes occurring in the dentinal tubules. Results The qualitative analysis showed no occlusion of the dentinal tubules in Group A (control group) and Group B (nano-hydroxyapatite) showed 98.1% tubule occlusion. Group C (Novamin) and D (Proargin) showed 83.1% and 69.1% tubule occlusion respectively. Quantitative analysis showed a statistical significant difference between Group B and D (p< 0.005) and no statistical significant difference between group B and C (p= 0.235). Similarly, there was no significant difference between Group C and D as (p=0.235). Conclusion It was concluded that all the three desensiting agents were effective in the dentine tubule occlusion. In addition efficacy of nano-hydroxyapatite toothpaste was greater compared to the other desensiting agents. PMID:27891458

  19. Comparative study of dental enamel loss after debonding braces by analytical scanning electron microscopy (SEM).

    PubMed

    Rodríguez-Chávez, Jacqueline Adelina; Arenas-Alatorre, Jesús; Belio-Reyes, Irma Araceli

    2017-02-05

    Clinical procedures when shear forces are applied to brackets suggest adhesion forces between 2.8 and 10.0 MPa as appropriate. In this study dental enamel was evaluated by scanning electron microscopy (SEM) before and after removing the brackets. Thirty bicuspids (previous prophylaxis) with metallic brackets (Roth Inovation 0.022 GAC), Transbond Plus SEP 3M Unitek adhesive and Transbond XT 3M resin were used. The samples were preserved to 37°C during 24 hr and submited to tangential forces with the Instron Universal machine 1.0 mm/min speed load strength resistance debonding. Also the Adhesive Remanent Index (ARI) test was made, evaluating the bracket base and the bicuspid surface. All the bracket SEM images were processed with AutoCAD to determine the enamel detached area. The average value was 6.86 MPa (SD ± 3.2 MPa). ARI value 1= 63.3%, value 2= 20%, value 3= 13.3% and 33% presented value 0. All those samples with dental enamel loss, presented different situations as fractures, ledges, horizontal, and vertical loss in some cases, and some scratch lines. There is no association between the debonding resistance and enamel presence. Less than half of the remanent adhesive on the dental enamel was present in most of the samples when the ARI test was applied. When the resin area increases, the debonding resistance also increases, and when the enamel loss increases, the resin free metallic area of the bracket base decreases in the debonding.

  20. Detection of metal residues on bone using SEM-EDS--part II: Sharp force injury.

    PubMed

    Gibelli, D; Mazzarelli, D; Porta, D; Rizzi, A; Cattaneo, C

    2012-11-30

    Scanning electron microscopy coupled with X-ray energy dispersive spectrometry (SEM-EDS) is extensively seen in the literature for the improvement of the macroscopic analysis of sharp lesions, but very few indications concerning its real potential in the forensic context, particularly in forensic anthropology, are at the moment available. This paper represents a pilot study for the analysis of the behaviour of metallic residues found on bone after sharp force injury. Fourteen lesions were made on human bone (radius), cleaned of all soft tissues, with seven different sharp tools (three metal instruments, three metal saws and a baked-clay knife). Tools and lesions underwent SEM-EDS. From 3 to 18 particles were detected on each lesion, whose diameter was included between 0.5 and 150 μm. In 58% of cases, particle composition was concordant with the instrument used. The results seem to suggest that sharp force injury frequently leaves relatively few residues on bone, particularly in the case of common types of metal. Saws showed slightly more contamination with other residues than knives, which may be explained by the capability of the saw's teeth to retain the residues of previously encountered material. In addition, metal residues related to the tool used to cut the bone were located on the edges/walls of lesions in the case of saw marks, whereas they were more frequently found on the kerf floor in the case of knives/scissors, with the exception of the baked clay knife which when it leaves residues at all, seemed to leave them equally divided between the floor, the edges and the surrounding bone.

  1. Hematite/silver nanoparticle bilayers on mica--AFM, SEM and streaming potential studies.

    PubMed

    Morga, Maria; Adamczyk, Zbigniew; Oćwieja, Magdalena; Bielańska, Elżbieta

    2014-06-15

    Bilayers of hematite/silver nanoparticles were obtained in the self-assembly process and thoroughly characterized using scanning electron microscopy (SEM), atomic force microscopy (AFM), and in situ streaming potential measurements. The hematite nanoparticles, forming a supporting layer, were 22 nm in diameter, exhibiting an isoelectric point at pH 8.9. The silver nanoparticles, used to obtain an external layer, were 29 nm in diameter, and remained negative within the pH range 3 to 11. In order to investigate the particle deposition, mica sheets were used as a model solid substrate. The coverage of the supporting layer was adjusted by changing the bulk concentration of the hematite suspension and the deposition time. Afterward, silver nanoparticle monolayers of controlled coverage were deposited under the diffusion-controlled transport. The coverage of bilayers was determined by a direct enumeration of deposited particles from SEM micrographs and AFM images. Additionally, the formation of the hematite/silver bilayers was investigated by streaming potential measurements carried out under in situ conditions. The effect of the mica substrate and the coverage of a supporting layer on the zeta potential of bilayers was systematically studied. It was established that for the coverage exceeding 0.20, the zeta potential of bilayers was independent on the substrate and the supporting layer coverage. This behavior was theoretically interpreted in terms of the 3D electrokinetic model. Beside significance for basic sciences, these measurements allowed to develop a robust method of preparing nanoparticle bilayers of controlled properties, having potential applications in catalytic processes.

  2. SemFunSim: A New Method for Measuring Disease Similarity by Integrating Semantic and Gene Functional Association

    PubMed Central

    Ju, Peng; Peng, Jiajie; Wang, Yadong

    2014-01-01

    Background Measuring similarity between diseases plays an important role in disease-related molecular function research. Functional associations between disease-related genes and semantic associations between diseases are often used to identify pairs of similar diseases from different perspectives. Currently, it is still a challenge to exploit both of them to calculate disease similarity. Therefore, a new method (SemFunSim) that integrates semantic and functional association is proposed to address the issue. Methods SemFunSim is designed as follows. First of all, FunSim (Functional similarity) is proposed to calculate disease similarity using disease-related gene sets in a weighted network of human gene function. Next, SemSim (Semantic Similarity) is devised to calculate disease similarity using the relationship between two diseases from Disease Ontology. Finally, FunSim and SemSim are integrated to measure disease similarity. Results The high average AUC (area under the receiver operating characteristic curve) (96.37%) shows that SemFunSim achieves a high true positive rate and a low false positive rate. 79 of the top 100 pairs of similar diseases identified by SemFunSim are annotated in the Comparative Toxicogenomics Database (CTD) as being targeted by the same therapeutic compounds, while other methods we compared could identify 35 or less such pairs among the top 100. Moreover, when using our method on diseases without annotated compounds in CTD, we could confirm many of our predicted candidate compounds from literature. This indicates that SemFunSim is an effective method for drug repositioning. PMID:24932637

  3. The Role of Sexually Explicit Material (SEM) in the Sexual Development of Black Young Same-Sex-Attracted Men

    PubMed Central

    Morgan, Anthony; Ogunbajo, Adedotun; Trent, Maria; Harper, Gary W.; Fortenberry, J. Dennis

    2015-01-01

    Sexually explicit material (SEM) (including Internet, video, and print) may play a key role in the lives of Black same-sex sexually active youth by providing the only information to learn about sexual development. There is limited school-and/or family-based sex education to serve as models for sexual behaviors for Black youth. We describe the role SEM plays in the sexual development of a sample of Black same-sex attracted (SSA) young adolescent men ages 15–19. Adolescents recruited from clinics, social networking sites, and through snowball sampling were invited to participate in a 90-min, semi-structured qualitative interview. Most participants described using SEM prior to their first same-sex sexual experience. Participants described using SEM primarily for sexual development, including learning about sexual organs and function, the mechanics of same-gender sex, and to negotiate one’s sexual identity. Secondary functions were to determine readiness for sex; to learn about sexual performance, including understanding sexual roles and responsibilities (e.g., “top” or “bottom”); to introduce sexual performance scripts; and to develop models for how sex should feel (e.g., pleasure and pain). Youth also described engaging in sexual behaviors (including condom non-use and/or swallowing ejaculate) that were modeled on SEM. Comprehensive sexuality education programs should be designed to address the unmet needs of young, Black SSA young men, with explicit focus on sexual roles and behaviors that may be inaccurately portrayed and/or involve sexual risk-taking (such as unprotected anal intercourse and swallowing ejaculate) in SEM. This work also calls for development of Internet-based HIV/STI prevention strategies targeting young Black SSA men who maybe accessing SEM. PMID:25677334

  4. Identification of tobacco smoke components in indoor breathable particles by SEM-EDS

    NASA Astrophysics Data System (ADS)

    Slezakova, K.; Pires, J. C. M.; Martins, F. G.; Pereira, M. C.; Alvim-Ferraz, M. C.

    2011-02-01

    Tobacco smoke is one of the greatest sources of indoor particles, which has been linked with serious health effects. Consequently, there has been a widespread interest in analysing tobacco related indoor particulate matter (PM). Nevertheless, the majority of performed studies focused on bulk chemical composition of tobacco related PM, but the knowledge of individual tobacco smoke particles is still limited. Therefore, more information on PM should be provided, namely concerning morphological and chemical characterisation of individual particles. Aiming to further understand the impact of tobacco smoke on human health, this work studied the influence of tobacco smoke on chemical and morphological characteristics of PM 10 and PM 2.5, collected at one site influenced by smoking and at one reference (non-smoking) site. Chemical and morphological characteristics of 4000 individual particles were determined by Scanning Electron Microscopy (SEM) combined with X-ray microanalysis (by Energy Dispersive Spectrometer - EDS). Cluster analysis (CA) was used to classify different particle groups that occurred in PM, aiming the identification of the respective emission sources. The results showed that tobacco smoke influenced the characteristics of both fine and coarse particles, this influence being stronger for fine fraction. The abundance of particles associated with tobacco smoke was 27% and 5% for PM 2.5 and PM 2.5-10, respectively; as expected, those particles were not identified in PM 2.5 and PM 2.5-10 of the reference (non-smoking) site. The results showed that at both sites PM was also influenced by outdoor sources. For PM 2.5-10, outdoor particles essentially originated from natural sources accounting for 35% and 15% at the smoking and reference sites, respectively. For PM 2.5, outdoor particles account for 38% and 29% at the smoking and reference sites, respectively; these particles showed considerable contribution (13% and 17%) from anthropogenic sources (mainly from

  5. F360 and F6 Skytaper: SEM evaluation of cleaning efficiency

    PubMed Central

    Dagna, Alberto; Gastaldo, Giulia; Beltrami, Riccardo; Chiesa, Marco; Poggio, Claudio

    2015-01-01

    Summary Aim Root canal preparation may produce a large quantity of smear layer that covers canal walls. Single-file systems have recently appeared, with the aim of reducing the number of steps and files to reach a correct endodontic treatment. The purpose of this study was to evaluate by SEM the root canal walls after instrumentation with F360 (Komet, Brasseler GmbH & Co., Lemgo, Germany) and F6 Skytaper (Komet, Brasseler GmbH & Co., Lemgo, Germany), in order to evaluate the presence/absence of smear layer and the presence/absence of open tubules on the root canal walls at coronal, middle, and apical third of each sample. Methods Twenty single-rooted freshly extracted teeth were selected and divided into 2 groups. For each group root canals were shaped with F360 (Komet, Brasseler GmbH & Co., Lemgo, Germany) and F6 Skytaper (Komet, Brasseler GmbH & Co., Lemgo, Germany) instruments under irrigation with 5,25% NaOCl and 17% EDTA. Specimens were fractured longitudinally and analyzed by SEM at standard magnification of 5000x. The presence/absence of smear layer and the presence/absence of open tubules at the coronal, middle, and apical third of each canal were evaluated using a 5-step scale for scores. Numeric data were analyzed using Kruskall-Wallis and Mann-Whitney U statistical tests and significance was predetermined at P <0.05. Results This study did not reveal differences among two groups at the coronal and apical third. The apical third showed the highest values of scores for all Ni-Ti systems used. Significant differences in smear layer scores were recorded among the Ni-Ti systems at middle canal level (P < 0.05), where F6 Skytaper showed significantly lower scores than F360. Conclusions Within the limitation of this study, F360 and F6 Skytaper rotary instruments seem to be effective in shaping root canals with good debridement from canal walls, without significant differences between the two systems as it regards the coronal third and the apical third, the area

  6. Antireflux versus conventional self-expanding metallic Stents (SEMS) for distal esophageal cancer: results of a multicenter randomized trial

    PubMed Central

    Coron, E.; David, G.; Lecleire, S.; Jacques, J.; Le Sidaner, A.; Barrioz, T.; Coumaros, D.; Volteau, C.; Vedrenne, B.; Bichard, P.; Boustière, C.; Touchefeu, Y.; Brégeon, J.; Prat, F.; Le Rhun, M.

    2016-01-01

    Introduction: Self-expanding metal stents (SEMS) are commonly used in the palliation of dysphagia in patients with inoperable esophageal carcinoma. However, they predispose to gastroesophageal reflux when deployed across the gastroesophageal junction. The aims of this study were to: 1) assess the influence of the antireflux valve on trans-prosthetic reflux (primary outcome); and 2) compare the results of SEMS with and without antireflux valve in terms of reflux symptoms, quality of life (QOL), improvement of dysphagia and adverse events (secondary outcomes). Patients and methods: Thirty-eight patients were enrolled in nine centers. Carcinomas were locally advanced (47 %) or metastatic. After randomization, patients received either a covered SEMS with antireflux valve (n = 20) or a similar type of SEMS with no antireflux device but assigned to standard proton pump inhibitor therapy and postural advice (n = 18). Trans-prosthetic reflux was assessed at day 2 using a radiological score based on barium esophagography performed after Trendelenburg maneuver and graded from 0 (no reflux) to 12 (maximum). Monthly telephone interviews were conducted for Organisation Mondiale de la Santé (OMS) scoring from 0 (excellent) to 5 (poor), QOL assessment (based on the Reflux-Qual Simplifié scoring system) from 0 (poor) to 100 (excellent), dysphagia scoring from 0 (no dysphagia) to 5 (complete dysphagia) and regurgitation scoring from 0 (no regurgitation) to 16 (maximum). Results: No difference was noted in terms of age, sex, size of lesion, prosthesis length or need for dilation prior to SEMS placement. No difficulty in placing SEMS nor complications were noted. Radiological scores of reflux were found to be significantly lower in patients with an antireflux stent compared to the conventional stent and associated measures. The regurgitation scores were significantly decreased in patients with antireflux stents during the first 2 months after stent placement and

  7. Toward global waveform tomography of the whole mantle using SEM: Efficient simulation of the global wavefield using a homogenized crust

    NASA Astrophysics Data System (ADS)

    French, S. W.; Lekic, V.; Romanowicz, B. A.

    2010-12-01

    As global waveform-modeling schemes rooted in perturbation theory are supplanted by fully numerical alternatives, such as the Spectral Element Method (e.g. SEM: Komatitsch and Tromp, 2002), the improved wavefield accuracy for complex 3D structures also carries increased computational cost. Lekic and Romanowicz (2010) inverted waveforms of fundamental and higher mode surface waves for a radially anisotropic upper-mantle Vs model using SEM (SEMum). The SEM computations were made feasible by an appropriate choice of cutoff period (T≥ 60 s.), as well as the implementation of a homogenized anisotropic crustal layer based on fitting of short period group velocity dispersion curves. These choices allowed for an efficient SEM mesh undeformed by true Moho topography. Further, instead of homogenization of a possibly biased a priori crustal model, Lekic and Romanowicz jointly inverted for the crustal layer, constrained by surface wave group velocity dispersion maps for T≥ 25 s. We are currently developing a radially anisotropic Vs model of the whole mantle using SEM, following an approach broadly similar to that employed in SEMum. Extension of this methodology to imaging of lower-mantle structure requires the inclusion of a body wave dataset, and thus shorter-period modeling of the global wavefield (T≥ 32 s.). While this period range dictates finer sampling of our SEM mesh, reduced computational cost is still possible through the crustal homogenization scheme. Here, we first discuss the development of an analogous homogenized crustal model and its validity for both the fundamental and higher mode surface wave and the body wave datasets. We focus on maintaining a simplified Moho topography, thus obviating expensive deformation of the SEM mesh, while accurately treating valuable surface-reflected body wave phases (ex: multiple ScS). Second, we discuss implications of treating the crust in this manner for the overall inversion methodology. In particular, we intend to

  8. Characterizing the 65nm through-pitch sensitivity to scanner parameters by CD SEM and scatterometry metrologies

    NASA Astrophysics Data System (ADS)

    Shieh, Jason; Chen, Alek

    2009-12-01

    Processes of 65nm node are applied on a scanner (TWINSCAN XT1700i) for this experiment. The five adjustable scanner parameters investigated are dose, focus scan range, NA, σ_width, and σ_center of the illumination pupil. The test reticle contains a range of pitches, each with a variety of biases sufficient for selecting the target CD at each pitch. It can be used for exposing patterns for both CD SEM and scatterometry. The minimum and maximum pitches of the 1D line/space pattern are 135 and 500nm, respectively, and no assist feature is added for the isolated pitches. Seventeen pitches are selected for generating the through-pitch curve, and they are the most sensitive ones to this illumination setting. Two metrology tools are used to measure the printed features, i.e. CD SEM and scatterometry. MCD (Middle CD) measured by scatterometry is compared with CD SEM data for the OPE curve. A very consistent offset between two metrologies is presented through the pitches; the R2 value is greater than 0.98 for point to point of CD SEM versus MCD correlation. In addition to the CD measurements, scatterometry provides SWA information, which is verified to correlate linearly with focus variations. Based on the metrology data, results of this study demonstrate that the OCD data are as reliable as the CD SEM measurements.

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

    PubMed

    Hortolà, Policarp

    2015-12-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2016-04-01

    The significant increase in global air travel which has occurred during the last fifty years has generated growing concern regarding the potential impacts associated with increasing emissions of particulate matter (PM) from aviation activity on health and the environment. PM within the airport environment, in particular, may be derived from a wide range of potential sources including aircraft; vehicles; ground support equipment and buildings. In order to investigate and remediate potential problem sources, it is important to be able to identify characteristic particulate 'fingerprints' which would allow source attribution, particularly respirable particulates. To date the identification of such 'fingerprints' has remained elusive but remains a key research priority for the aviation industry (Webb et al, 2008). In previous PM studies, environmental magnetism has been used as a successful technique for discriminating between different emission types and particulate sources in both urban and industrial environments (e.g. Hunt et al 1984; Lecoanet et al 2003, Jones et al 2015). Environmental magnetism is a non-destructive and relatively rapid technique involving the use of non-directional, rock magnetic measurements to characterise the mineral magnetic properties of natural and anthropogenic materials. In other studies scanning electron microscopy (SEM) has also been used as an effective characterisation technique for the investigation of grain size and morphology of PM derived from vehicle emissions (e.g. Bucko et al 2010) and fossil fuel combustion sources (Kim et al 2009). In this study, environmental magnetic measurements and SEM/EDAX have been used to characterise dusts from specific aircraft sources including engines, brakes and tyres. Furthermore, these methods have also been applied to runway (both hard and grass covered surfaces), taxiway and apron dusts collected during extensive environmental sampling at Manchester International Airport, UK in order to

  11. Fabrication of digital rainbow holograms and 3-D imaging using SEM based e-beam lithography.

    PubMed

    Firsov, An; Firsov, A; Loechel, B; Erko, A; Svintsov, A; Zaitsev, S

    2014-11-17

    Here we present an approach for creating full-color digital rainbow holograms based on mixing three basic colors. Much like in a color TV with three luminescent points per single screen pixel, each color pixel of initial image is presented by three (R, G, B) distinct diffractive gratings in a hologram structure. Change of either duty cycle or area of the gratings are used to provide proper R, G, B intensities. Special algorithms allow one to design rather complicated 3D images (that might even be replacing each other with hologram rotation). The software developed ("RainBow") provides stability of colorization of rotated image by means of equalizing of angular blur from gratings responsible for R, G, B basic colors. The approach based on R, G, B color synthesis allows one to fabricate gray-tone rainbow hologram containing white color what is hardly possible in traditional dot-matrix technology. Budgetary electron beam lithography based on SEM column was used to fabricate practical examples of digital rainbow hologram. The results of fabrication of large rainbow holograms from design to imprinting are presented. Advantages of the EBL in comparison to traditional optical (dot-matrix) technology is considered.

  12. SEM/EDX and confocal microscopy analysis of novel and conventional enteric-coated systems.

    PubMed

    Liu, Fang; Lizio, Rosario; Schneider, Uwe J; Petereit, Hans-Ulrich; Blakey, Peter; Basit, Abdul W

    2009-03-18

    A novel double coating enteric system (comprising an inner layer of neutralised EUDRAGIT) L 30 D-55 and organic acid, and an outer layer of standard EUDRAGIT) L 30 D-55) was developed to provide fast dissolution in proximal small intestinal conditions. The mechanisms involved in the dissolution of the double coating were investigated and compared with a conventional single layer enteric coating and an hypromellose (HPMC) sub-coated enteric system. Rates of drug release from coated prednisolone pellets were established using USP II dissolution methods (0.1M HCl for 2h and subsequently pH 5.5 phosphate buffer) and the coating dissolution process was illustrated using confocal laser scanning microscopy (CLSM). The distribution of sodium, as a representative ion, in the double-coating system during dissolution was determined using scanning electron microscopy/energy dispersive X-ray spectroscopy (SEM/EDX). The double-coating system showed faster dissolution compared to the single coating and the HPMC sub-coated system in pH 5.5 buffer. The dissolution process of the double-coating was unusual; the inner coat dissolved before the outer coat and this accelerated the dissolution of the outer coat. During dissolution, sodium ions diffused from the inner coat to the outer coat. This migration of ions and the increased ionic strength and buffer capacity of the inner coat contribute to the rapid dissolution of the double-coating system.

  13. Osseointegration of zirconia implants: an SEM observation of the bone-implant interface

    PubMed Central

    Depprich, Rita; Zipprich, Holger; Ommerborn, Michelle; Mahn, Eduardo; Lammers, Lydia; Handschel, Jörg; Naujoks, Christian; Wiesmann, Hans-Peter; Kübler, Norbert R; Meyer, Ulrich

    2008-01-01

    Background The successful use of zirconia ceramics in orthopedic surgery led to a demand for dental zirconium-based implant systems. Because of its excellent biomechanical characteristics, biocompatibility, and bright tooth-like color, zirconia (zirconium dioxide, ZrO2) has the potential to become a substitute for titanium as dental implant material. The present study aimed at investigating the osseointegration of zirconia implants with modified ablative surface at an ultrastructural level. Methods A total of 24 zirconia implants with modified ablative surfaces and 24 titanium implants all of similar shape and surface structure were inserted into the tibia of 12 Göttinger minipigs. Block biopsies were harvested 1 week, 4 weeks or 12 weeks (four animals each) after surgery. Scanning electron microscopy (SEM) analysis was performed at the bone implant interface. Results Remarkable bone attachment was already seen after 1 week which increased further to intimate bone contact after 4 weeks, observed on both zirconia and titanium implant surfaces. After 12 weeks, osseointegration without interposition of an interfacial layer was detected. At the ultrastructural level, there was no obvious difference between the osseointegration of zirconia implants with modified ablative surfaces and titanium implants with a similar surface topography. Conclusion The results of this study indicate similar osseointegration of zirconia and titanium implants at the ultrastructural level. PMID:18990214

  14. Novel use of the CO2 laser on dental hard tissues: an SEM study

    NASA Astrophysics Data System (ADS)

    Wigdor, Harvey A.; Gilbert, Jeremy L.; Chomsky, Doron; Raif, Joshua

    1997-05-01

    There is great interest in dentistry to find a replacement for the dental drill which is a great source fear in dental patients. Lasers have been considered a potential replacement. Hard tissue use of lasers on dental tissues has been slow in development has had very limited acceptance by the dental community. The ultimate goal is to develop a laser which can remove both healthy and diseased dental hard tissues and dental materials. The CO2 laser surgical applications on sot tissues has been reported by many authors. It is hard tissue applications have had very few published reports. The thermal effects of this laser on hard tissues precluded its use on hard tissues. A new CO2 laser has been developed to reduce the thermal effects on dentin and enamel. Powers of 3-5 watts were used to ablate the buccal surface of extracted human molar teeth. These teeth were gold coated and evaluated under scanning electron microscopy. The results show some melting of the dentin and enamel, however patent dentinal tubules are evident and there appears to be a non-thermal cutting of the enamel at the boarder of the cut surface. In conclusion these very preliminary results appear to show that this new CO2 laser can cut dentin and enamel efficiently and with very little thermal effect as seen under SEM.

  15. Microorganism penetration in dentinal tubules of instrumented and retreated root canal walls. In vitro SEM study

    PubMed Central

    Al-Sulaiman, Alaa; Al-Rasheed, Fellwa; Alnajjar, Fatimah; Al-Abdulwahab, Bander; Al-Badah, Abdulhakeem

    2014-01-01

    Objectives This in vitro study aimed to investigate the ability of Candida albicans (C. albicans) and Enterococcus faecalis (E. faecalis) to penetrate dentinal tubules of instrumented and retreated root canal surface of split human teeth. Materials and Methods Sixty intact extracted human single-rooted teeth were divided into 4 groups, negative control, positive control without canal instrumentation, instrumented, and retreated. Root canals in the instrumented group were enlarged with endodontic instruments, while root canals in the retreated group were enlarged, filled, and then removed the canal filling materials. The teeth were split longitudinally after canal preparation in 3 groups except the negative control group. The teeth were inoculated with both microorganisms separately and in combination. Teeth specimens were examined by scanning electron microscopy (SEM), and the depth of penetration into the dentinal tubules was assessed using the SMILE view software (JEOL Ltd). Results Penetration of C. albicans and E. faecalis into the dentinal tubules was observed in all 3 groups, although penetration was partially restricted by dentin debris of tubules in the instrumented group and remnants of canal filling materials in the retreated group. In all 3 groups, E. faecalis penetrated deeper into the dentinal tubules by way of cell division than C. albicans which built colonies and penetrated by means of hyphae. Conclusions Microorganisms can easily penetrate dentinal tubules of root canals with different appearance based on the microorganism size and status of dentinal tubules. PMID:25383343

  16. Characterization of Airborne Particles Collected from Car Engine Air Filters Using SEM and EDX Techniques.

    PubMed

    Heredia Rivera, Birmania; Gerardo Rodriguez, Martín

    2016-10-01

    Particulate matter accumulated on car engine air-filters (CAFs) was examined in order to investigate the potential use of these devices as efficient samplers for collecting street level air that people are exposed to. The morphology, microstructure, and chemical composition of a variety of particles were studied using scanning electron microscopy (SEM) and energy-dispersive X-ray (EDX). The particulate matter accumulated by the CAFs was studied in two categories; the first was of removed particles by friction, and the second consisted of particles retained on the filters. Larger particles with a diameter of 74-10 µm were observed in the first category. In the second one, the detected particles had a diameter between 16 and 0.7 µm. These particles exhibited different morphologies and composition, indicating mostly a soil origin. The elemental composition revealed the presence of three groups: mineral (clay and asphalt), metallic (mainly Fe), and biological particles (vegetal and animal debris). The palynological analysis showed the presence of pollen grains associated with urban plants. These results suggest that CAFs capture a mixture of atmospheric particles, which can be analyzed in order to monitor urban air. Thus, the continuous availability of large numbers of filters and the retroactivity associated to the car routes suggest that these CAFs are very useful for studying the high traffic zones within a city.

  17. The effect of Salvadora persica extract (miswak) and chlorhexidine gluconate on human dentin: a SEM study.

    PubMed

    Almas, Khalid

    2002-08-15

    Bacterial plaque is solely responsible for the initiation and progression of periodontal diseases. There are different mechanical and chemical methods available for the maintenance of oral health through plaque control. Toothbrushes and miswak (chewing sticks) are widely used for the mechanical removal of plaque. Chlorhexidine gluconate (CHX) is one of the best-proven anti-plaque agents. The aim of this study was to evaluate the effects of CHX and miswak extract on healthy and periodontally involved human dentin. Sixteen human premolars recently extracted for orthodontic and periodontal reasons were used in the study. Teeth were free from caries, cervical restorations, or erosions. The dentin disc specimens were prepared and half of them were etched with 6% citric acid for 120 sec. Both etched and unetched were further treated with CHX and 50% miswak extract and prepared for Scanning Electron Microscopic (SEM) examination. It was concluded that CHX 0.2% and miswak extract 50% had a similar effect on dentin in the control group. Miswak extract removed more smear layer as compared to CHX. Further research is needed in vivo to compare the effects of CHX and miswak extract on periodontally involved teeth and teeth with dentinal hypersensitivity.

  18. SEM Characterization of the High Burn-up Microstructure of U-7Mo Alloy

    SciTech Connect

    Dennis D. Keiser, Jr.; Jan-Fong Jue; Jian Gan; Brandon Miller; Adam Robinson; Pavel Medvedev; James Madden; Dan Wachs; M. Teague

    2014-04-01

    During irradiation, the microstructure of U-7Mo evolves until at a fission density near 5x1021 f/cm3 a high-burnup microstructure exists that is very different than what was observed at lower fission densities. This microstructure is dominated by randomly distributed, relatively large, homogeneous fission gas bubbles. The bubble superlattice has collapsed in many microstructural regions, and the fuel grain sizes, in many areas, become sub-micron in diameter with both amorphous fuel and crystalline fuel present. Solid fission product precipitates can be found inside the fission gas bubbles. To generate more information about the characteristics of the high-fission density microstructure, three samples irradiated in the RERTR-7 experiment have been characterized using a scanning electron microscope equipped with a focused ion beam. The FIB was used to generate samples for SEM imaging and to perform 3D reconstruction of the microstructure, which can be used to look for evidence of possible fission gas bubble interlinkage.

  19. Raman, SEM-EDS and XRPD investigations on pre-Columbian Central America "estucado" pottery

    NASA Astrophysics Data System (ADS)

    Casanova Municchia, Annalaura; Micheli, Mario; Ricci, Maria Antonietta; Toledo, Michelle; Bellatreccia, Fabio; Lo Mastro, Sergio; Sodo, Armida

    2016-03-01

    Seventeen different colored fragments from six selected pre-Columbian estucado ceramics from El Salvador have been investigated by Raman spectroscopy, scanning electron microscope coupled to an energy dispersive spectrometer (SEM/EDS) and X-ray powder diffraction (XRPD). The peculiarity of this kind of ceramics consist of the unusual presence of a white engobe, traditionally termed stucco, between the ceramic body and the decoration elements, hence the name estucado ceramics. The aim of this work was to study the unusual manufacturing technique and to identify the chemical composition of the engobe and of the pigment palette. The results showed that the stucco layer is made of clay (kaolinite) with traces of titanium oxide (anatase). Remarkably, this is the same composition of the white pigments used for the decoration layer, thus excluding an early use of natural titanium oxide as a white pigment in the estucado productions as suggested in previous investigations. Moreover, the presence of kaolinite and anatase both in the stucco and in the decoration layer suggests a cold-working or low temperature technique. The red, yellow and green decorations were realized by the use of natural ochre, while in all the blue and gray decorations Maya blue pigment was identified. Finally, an amorphous carbon pigment of vegetal origin and manganese oxide were used to obtain black pigments.

  20. Raman, SEM-EDS and XRPD investigations on pre-Columbian Central America "estucado" pottery.

    PubMed

    Casanova Municchia, Annalaura; Micheli, Mario; Ricci, Maria Antonietta; Toledo, Michelle; Bellatreccia, Fabio; Lo Mastro, Sergio; Sodo, Armida

    2016-03-05

    Seventeen different colored fragments from six selected pre-Columbian estucado ceramics from El Salvador have been investigated by Raman spectroscopy, scanning electron microscope coupled to an energy dispersive spectrometer (SEM/EDS) and X-ray powder diffraction (XRPD). The peculiarity of this kind of ceramics consist of the unusual presence of a white engobe, traditionally termed stucco, between the ceramic body and the decoration elements, hence the name estucado ceramics. The aim of this work was to study the unusual manufacturing technique and to identify the chemical composition of the engobe and of the pigment palette. The results showed that the stucco layer is made of clay (kaolinite) with traces of titanium oxide (anatase). Remarkably, this is the same composition of the white pigments used for the decoration layer, thus excluding an early use of natural titanium oxide as a white pigment in the estucado productions as suggested in previous investigations. Moreover, the presence of kaolinite and anatase both in the stucco and in the decoration layer suggests a cold-working or low temperature technique. The red, yellow and green decorations were realized by the use of natural ochre, while in all the blue and gray decorations Maya blue pigment was identified. Finally, an amorphous carbon pigment of vegetal origin and manganese oxide were used to obtain black pigments.

  1. Low cost environmental sensors for Spaceflight : NMP Space Environmental Monitor (SEM) requirements

    NASA Technical Reports Server (NTRS)

    Garrett, Henry B.; Buelher, Martin G.; Brinza, D.; Patel, J. U.

    2005-01-01

    An outstanding problem in spaceflight is the lack of adequate sensors for monitoring the space environment and its effects on engineering systems. By adequate, we mean low cost in terms of mission impact (e.g., low price, low mass/size, low power, low data rate, and low design impact). The New Millennium Program (NMP) is investigating the development of such a low-cost Space Environmental Monitor (SEM) package for inclusion on its technology validation flights. This effort follows from the need by NMP to characterize the space environment during testing so that potential users can extrapolate the test results to end-use conditions. The immediate objective of this effort is to develop a small diagnostic sensor package that could be obtained from commercial sources. Environments being considered are: contamination, atomic oxygen, ionizing radiation, cosmic radiation, EMI, and temperature. This talk describes the requirements and rational for selecting these environments and reviews a preliminary design that includes a micro-controller data logger with data storage and interfaces to the sensors and spacecraft. If successful, such a sensor package could be the basis of a unique, long term program for monitoring the effects of the space environment on spacecraft systems.

  2. Low Cost Environmental Sensors for Spaceflight: NMP Space Environmental Monitor (SEM) Requirements

    NASA Technical Reports Server (NTRS)

    Garrett, Henry B.; Buehler, Martin G.; Brinza, D.; Patel, J. U.

    2005-01-01

    An outstanding problem in spaceflight is the lack of adequate sensors for monitoring the space environment and its effects on engineering systems. By adequate, we mean low cost in terms of mission impact (e.g., low price, low mass/size, low power, low data rate, and low design impact). The New Millennium Program (NMP) is investigating the development of such a low-cost Space Environmental Monitor (SEM) package for inclusion on its technology validation flights. This effort follows from the need by NMP to characterize the space environment during testing so that potential users can extrapolate the test results to end-use conditions. The immediate objective of this effort is to develop a small diagnostic sensor package that could be obtained from commercial sources. Environments being considered are: contamination, atomic oxygen, ionizing radiation, cosmic radiation, EMI, and temperature. This talk describes the requirements and rational for selecting these environments and reviews a preliminary design that includes a micro-controller data logger with data storage and interfaces to the sensors and spacecraft. If successful, such a sensor package could be the basis of a unique, long term program for monitoring the effects of the space environment on spacecraft systems.

  3. SEM Studies on Vessels in Ferns. XV. Selected Rosette Epiphytes (Aspleniaceae, Elaphoglossaceae, Vittariaceae).

    PubMed

    Schneider; Carlquist

    1999-09-01

    Tracheary elements from macerations of roots and rhizomes of Asplenium nidus, Elaphoglossum hirtum, and Vittaria lineata were studied by means of SEM. All of these have perforation plates in tracheary elements of both roots and rhizomes. The perforation plates in roots and rhizomes show greatest development of perforations (perforations a little wider than pits of tracheary elements) in E. hirtum roots and rhizomes and least in V. lineata roots and in rhizomes of A. nidus (porose pit membranes in many perforations). The secondary wall framework of perforation plates is little different from that of pitted wall areas in these three species. These rosette epiphytes have a lower degree of specialization of perforation plates that might accommodate rapid flow related to moisture availability fluctuations in comparison to perforation plates in vessels of rhizomatous epiphytic ferns. Generalizations are not warranted at this point, however. Rows of cushion-like structures occur adjacent to angles of the tracheary elements of E. hirtum. This is the first report of these in leptosporangiate ferns; they are known thus far only in a eusporangiate fern, Danaea elliptica (Marattiaceae). Raised frames of wall material around perforations are newly reported for tracheary elements of ferns in E. hirtum.

  4. Detection of metal residues on bone using SEM-EDS. Part I: Blunt force injury.

    PubMed

    Pechníková, Markéta; Porta, Davide; Mazzarelli, Debora; Rizzi, Agostino; Drozdová, Eva; Gibelli, Daniele; Cattaneo, Cristina

    2012-11-30

    Previous studies have indicated that metal particles remain on bone after sharp force injury or gunshot and that their detection by scanning electron microscopy with energy dispersive X-ray spectrometry (SEM-EDS) could greatly help in tool identification. However, the presence of metal particles on bone surfaces in the context of blunt force trauma has never been assessed experimentally. For this reason the present paper represents an experimental study of the behaviour of metal residues on bone following blunt force injury. Ten fresh sub-adult bovine metatarsal bones were manually cleaned of soft tissues. They were then struck by metal bars (copper, iron or aluminium) on the external surface of the mid-diaphysis. All blunt metal instruments used in this study left a sign in the form of single particles, a smear or a powder-like deposit on the bone surface. The residues of all three metal implements were detected on the bone surface, 0.3-10 mm from the fracture border. The presence of metal particles was confirmed in all samples struck with iron and copper and in two of six aluminium samples; no particles were detected on the negative control. Chemical composition of residues highly corresponded with the composition of applied bars.

  5. Characterization of mineral particles in winter fog of Beijing analyzed by TEM and SEM.

    PubMed

    Li, Weijun; Shao, Longyi

    2010-02-01

    Aerosol samples were collected during winter fog and nonfog episodes in Beijing. Transmission electron microscopy (TEM) and scanning electron microscopy (SEM) were applied to study morphologies, sizes, and compositions of aerosol particles. TEM observation indicates that most mineral particles collected in fog episode are scavenged in fog droplets. Number-size distributions of mineral particles collected in fog and nonfog episodes show two main peaks at the ranges of 0.1-0.3 and 1-2.5 microm, respectively. Based on their major compositions, mineral particles mainly include Si-rich, Ca-rich, and S-rich. Average S/Ca ratio of mineral particles collected in fog episode is 6.11, being eight times higher than that in nonfog episodes. Development mechanism of individual mineral particles in fog droplets is proposed. It is suggested that mineral particles with abundant alkaline components (e.g., "Ca-rich" particles) occurred in air should alleviate acidic degree of fog and contribute to complexity of fog droplets in Beijing.

  6. Characterization of ammonium retention processes onto cactus leaves fibers using FTIR, EDX and SEM analysis.

    PubMed

    Wahab, Mohamed Ali; Boubakri, Hatem; Jellali, Salah; Jedidi, Naceur

    2012-11-30

    In order to reduce the impact of nitrogen pollution and to increase the agronomic value of plant wastes to be reused as organic fertilizer, we have investigated the removal of ammonium from aqueous solutions onto cactus leave fibers (CLF), and the mechanisms involved in the retention of ammonium at CLF surface. The results showed that ammonium retention onto these fibers occurred for a wide pH (6-10) and temperature ranges (20-60°C) and the biosorption potential of CLF increased with temperature from 1.4 to 2.3 mg g(-1) for initial concentration of 50 mg L(-1). The modeling studies showed that the ammonium biosorption was well described by the pseudo-second-order model, predicting therefore, chemisorption interactions-type at earlier stages and by intraparticle diffusion at later stages. Biosorption is governed by film diffusion process at higher concentrations and by particle diffusion process at higher temperatures. The surface of CLF determined by SEM revealed the presence of cracks and cavities which may allow the intraparticle diffusion and the ion exchange processes. Moreover, FTIR and EDX analysis before and after ammonium retention showed that the main mechanisms involved in the removal of ammonium were the ionic exchange by calcium ions as well as H(+) and the complexation with carboxylic, alcoholic and phenolic groups.

  7. SEM technique for imaging and measuring electronic transport in nanocomposites based on electric field induced contrast

    DOEpatents

    Jesse, Stephen [Knoxville, TN; Geohegan, David B [Knoxville, TN; Guillorn, Michael [Brooktondale, NY

    2009-02-17

    Methods and apparatus are described for SEM imaging and measuring electronic transport in nanocomposites based on electric field induced contrast. A method includes mounting a sample onto a sample holder, the sample including a sample material; wire bonding leads from the sample holder onto the sample; placing the sample holder in a vacuum chamber of a scanning electron microscope; connecting leads from the sample holder to a power source located outside the vacuum chamber; controlling secondary electron emission from the sample by applying a predetermined voltage to the sample through the leads; and generating an image of the secondary electron emission from the sample. An apparatus includes a sample holder for a scanning electron microscope having an electrical interconnect and leads on top of the sample holder electrically connected to the electrical interconnect; a power source and a controller connected to the electrical interconnect for applying voltage to the sample holder to control the secondary electron emission from a sample mounted on the sample holder; and a computer coupled to a secondary electron detector to generate images of the secondary electron emission from the sample.

  8. Using SEM Analysis on Ion-Milled Shale Surface to Determine Shale-Fracturing Fluid Interaction

    NASA Astrophysics Data System (ADS)

    Lu, J.; Mickler, P. J.; Nicot, J. P.

    2014-12-01

    It is important to document and assess shale-fluid interaction during hydraulic fracturing (HF) in order to understand its impact on flowback water chemistry and rock property. A series of autoclave experiments were conducted to react shale samples from major oil and gas shales with synthetic HF containing various additives. To better determine mineral dissolution and precipitation at the rock-fluid interface, ion-milling technique was applied to create extremely flat rock surfaces that were examined before and after the autoclave experiments using a scanning electron microscope (SEM) coupled with energy dispersive spectroscopy (EDS) detectors. This method is able to reveal a level of detail not observable on broken surface or mechanically polished surface. It allows direct comparison of the same mineral and organic matter particles before and after the reaction experiments. Minerals undergone dissolution and newly precipitated materials are readily determined by comparing to the exact locations before reaction. The dissolution porosity and the thickness of precipitates can be quantified by tracing and measuring the geometry of the pores and precipitates. Changes in porosity and permeability were confirmed by mercury intrusion capillary tests.

  9. Kr implantation into heavy ion irradiated monolithic U-Mo/Al systems: SIMS and SEM investigations

    NASA Astrophysics Data System (ADS)

    Zweifel, T.; Valle, N.; Grygiel, C.; Monnet, I.; Beck, L.; Petry, W.

    2016-03-01

    Worldwide, high performance research and material test reactors are aiming to convert their fuel from high enriched uranium towards low enriched ones. High density U-Mo/Al based nuclear fuels are considered as a promising candidate for this conversion. However, during in-pile test irradiations, the formation of an interdiffusion layer (IDL) between the U-Mo and the Al matrix is observed, caused by irradiation enhanced U-Al interdiffusion processes. This IDL accumulates fission gases at the IDL/matrix interfaces. Together, these two effects strongly reduce the performance of this new fuel type. Recently, the out-of-pile technique of heavy ion irradiation (127I) on U-Mo/Al layer systems proved to be an alternative to time-consuming in-pile test irradiations for certain fuel behaviour aspects. Here we present SIMS and SEM investigations of non-conventional 82Kr implantation into previously heavy ion irradiated U-Mo/Al layer systems. It is shown that Kr accumulates inside μm large porosities at the IDL/matrix interfaces. This critical accumulation of μm-sized large gas bubbles is directly related to the presence of the irradiation induced IDL. Without IDL no critical accumulation of fission gas bubbles occurs.

  10. A holistic metrology approach: hybrid metrology utilizing scatterometry, CD-AFM, and CD-SEM

    NASA Astrophysics Data System (ADS)

    Vaid, Alok; Yan, Bin Bin; Jiang, Yun Tao; Kelling, Mark; Hartig, Carsten; Allgair, John; Ebersbach, Peter; Sendelbach, Matthew; Rana, Narender; Katnani, Ahmad; Mclellan, Erin; Archie, Chas; Bozdog, Cornel; Kim, Helen; Sendler, Michael; Ng, Susan; Sherman, Boris; Brill, Boaz; Turovets, Igor; Urensky, Ronen

    2011-03-01

    Shrinking design rules and reduced process tolerances require tight control of CD linewidth, feature shape, and profile of the printed geometry. The Holistic Metrology approach consists of utilizing all available information from different sources like data from other toolsets, multiple optical channels, multiple targets, etc. to optimize metrology recipe and improve measurement performance. Various in-line critical dimension (CD) metrology toolsets like Scatterometry OCD (Optical CD), CD-SEM (CD Scanning Electron Microscope) and CD-AFM (CD Atomic Force Microscope) are typically utilized individually in fabs. Each of these toolsets has its own set of limitations that are intrinsic to specific measurement technique and algorithm. Here we define "Hybrid Metrology" to be the use of any two or more metrology toolsets in combination to measure the same dataset. We demonstrate the benefits of the Hybrid Metrology on two test structures: 22nm node Gate Develop Inspect (DI) & 32nm node FinFET Gate Final Inspect (FI). We will cover measurement results obtained using typical BKM as well as those obtained by utilizing the Hybrid Metrology approach. Measurement performance will be compared using standard metrology metrics for example accuracy and precision.

  11. Characterization of Airborne Particles Collected from Car Engine Air Filters Using SEM and EDX Techniques

    PubMed Central

    Heredia Rivera, Birmania; Gerardo Rodriguez, Martín

    2016-01-01

    Particulate matter accumulated on car engine air-filters (CAFs) was examined in order to investigate the potential use of these devices as efficient samplers for collecting street level air that people are exposed to. The morphology, microstructure, and chemical composition of a variety of particles were studied using scanning electron microscopy (SEM) and energy-dispersive X-ray (EDX). The particulate matter accumulated by the CAFs was studied in two categories; the first was of removed particles by friction, and the second consisted of particles retained on the filters. Larger particles with a diameter of 74–10 µm were observed in the first category. In the second one, the detected particles had a diameter between 16 and 0.7 µm. These particles exhibited different morphologies and composition, indicating mostly a soil origin. The elemental composition revealed the presence of three groups: mineral (clay and asphalt), metallic (mainly Fe), and biological particles (vegetal and animal debris). The palynological analysis showed the presence of pollen grains associated with urban plants. These results suggest that CAFs capture a mixture of atmospheric particles, which can be analyzed in order to monitor urban air. Thus, the continuous availability of large numbers of filters and the retroactivity associated to the car routes suggest that these CAFs are very useful for studying the high traffic zones within a city. PMID:27706087

  12. Spectral, XRD, SEM and biological activities of transition metal complexes of polydentate ligands containing thiazole moiety

    NASA Astrophysics Data System (ADS)

    Neelakantan, M. A.; Marriappan, S. S.; Dharmaraja, J.; Jeyakumar, T.; Muthukumaran, K.

    2008-11-01

    Metal complexes of o-vanillidene-2-aminobenzothiazole have been prepared and characterized by elemental and spectral (vibrational, electronic, 1H NMR and EPR) data as well as magnetic susceptibility measurements and thermo gravimetric analysis (TG/DTA). The low molar conductance values reveal the non-electrolytic nature of these complexes. The elemental analysis suggests that the stoichiometry to be 1:2 (metal:ligand). Magnetic susceptibility data coupled with electronic spectra suggest that two ligands coordinate to each metal atom by phenolic oxygen and imino nitrogen to form high spin octahedral complex with Co(II), Mn(II) and Ni(II). The fifth and sixth position of metal ion is satisfied with water molecules. The thermal behaviour (TG/DTA) of the synthesised complexes shows that the complexes loss water molecules in the first step followed by decomposition of the ligand. Spin Hamiltonian parameters predict a distorted tetrahedral geometry for the copper complex. XRD and SEM analysis provide the crystalline nature and the morphology of the metal complexes. The in vitro biological activity of the metal chelates is tested against the Gram positive bacteria ( Bacillus amyloliquifacians) and gram negative bacteria ( Pseudomonas species), fungus ( Aspergillus niger) and yeast ( Sacchromyces cereviaceae). Most of the metal chelates exhibited higher biological activities.

  13. SEM-EBSD based Realistic Modeling and Crystallographic Homogenization FE Analyses of LDH Formability Tests

    SciTech Connect

    Kuramae, Hiroyuki; Nakamachi, Eiji; Ngoc Tam, Nguyen; Nakamura, Yasunori; Sakamoto, Hidetoshi; Morimoto, Hideo

    2007-05-17

    Homogenization algorithm is introduced to the elastic/crystalline viscoplastic finite element (FE) procedure to develop multi-scale analysis code to predict the formability of sheet metal in macro scale, and simultaneously the crystal texture and hardening evolutions in micro scale. The isotropic and kinematical hardening lows are employed in the crystalline plasticity constitutive equation. For the multi-scale structure, two scales are considered. One is a microscopic polycrystal structure and the other a macroscopic elastic plastic continuum. We measure crystal morphologies by using the scanning electron microscope (SEM) with electron back scattered diffraction (EBSD), and define a three dimensional representative volume element (RVE) of micro ploycrystal structure, which satisfy the periodicity condition of crystal orientation distribution. Since nonlinear multi-scale FE analysis requires large computation time, development of parallel computing technique is needed. To realize the parallel analysis on PC cluster system, the dynamic explicit FE formulations are employed. Applying the domain partitioning technique to FE mesh of macro continuum, homogenized stresses based on micro crystal structures are computed in parallel without solving simultaneous linear equation. The parallel FEM code is applied to simulate the limit dome height (LDH) test problem and hemispherical cup deep drawing problem of aluminum alloy AL6022, mild steel DQSK, high strength steel HSLA, and dual phase steel DP600 sheet metals. The localized distribution of thickness strain and the texture evolution are obtained.

  14. Characterization of Microstructure and Mechanical Properties of High Chromium Cast Irons Using SEM and Nanoindentation

    NASA Astrophysics Data System (ADS)

    Chen, Ling; Iyengar, Srinivasan; Zhou, Jinming; Turba, Krystof; Ståhl, Jan-Eric

    2015-01-01

    The effects of composition changes and heat treatment on the microstructure and mechanical properties of high-chromium white cast irons were studied in order to characterize possible improvements in product performance and machinability. Materials characterization was performed using nanoindentation, SEM, and EDS techniques. Present results show that changes in carbon and silicon contents as well as heat treatment strongly affect the mechanical properties and their variation in the material. In the as-cast condition, the sample with relatively lower carbon and silicon contents has an austenite-martensite matrix and is much harder than the sample with relatively higher carbon and silicon contents having more eutectic carbides in a bainite matrix. Annealing leads to softening of the materials relative to the as-cast condition, with the relatively higher carbon-silicon material being marginally harder due to the presence of more eutectic carbides. A similar trend is seen after the hardening treatment, and the presence of primary carbide can restrict the extent of hardening due to the loss of alloying elements from the matrix.

  15. Optical and microstructural characterization of porous silicon using photoluminescence, SEM and positron annihilation spectroscopy

    NASA Astrophysics Data System (ADS)

    Cheung, C. K.; Nahid, F.; Cheng, C. C.; Beling, C. D.; Fung, S.; Ling, C. C.; Djurisic, A. B.; Pramanik, C.; Saha, H.; Sarkar, C. K.

    2007-12-01

    We have studied the dependence of porous silicon morphology and porosity on fabrication conditions. N-type (100) silicon wafers with resistivity of 2-5 Ω cm were electrochemically etched at various current densities and anodization times. Surface morphology and the thickness of the samples were examined by scanning electron microscopy (SEM). Detailed information of the porous silicon layer morphology with variation of preparation conditions was obtained by positron annihilation spectroscopy (PAS): the depth-defect profile and open pore interconnectivity on the sample surface has been studied using a slow positron beam. Coincidence Doppler broadening spectroscopy (CDBS) was used to study the chemical environment of the samples. The presence of silicon micropores with diameter varying from 1.37 to 1.51 nm was determined by positron lifetime spectroscopy (PALS). Visible luminescence from the samples was observed, which is considered to be a combination effect of quantum confinement and the effect of Si = O double bond formation near the SiO2/Si interface according to the results from photoluminescence (PL) and positron annihilation spectroscopy measurements. The work shows that the study of the positronium formed when a positron is implanted into the porous surface provides valuable information on the pore distribution and open pore interconnectivity, which suggests that positron annihilation spectroscopy is a useful tool in the porous silicon micropores' characterization.

  16. [4 years of Microbiología SEM (1994-1997)].

    PubMed

    Mas-Castellà, J

    1997-12-01

    Different aspects of Microbiología SEM editorial process over the years 1994-1997 are analyzed: number of originals received, the process leading to their publication, rates of accepted and refused papers, time needed for each step of the editorial process--which comprises scientific, language editing, if needed--, as well as some characteristics that can define the patterns of the articles, such as number of authors, institutions where the authors work and mean number of references. The contents of the different sections (editorial, research and review articles, perspectives, opinion, books review) are commented on, as well as the role played by some of them as forums for the discussion of topics of current scientific interest, especially the editorials focusing on the state-of-the-art of microbiological research in Latin American countries. Characteristics and frequency of monographic issues are also presented. The information is complemented with data about the circulation and distribution of the journal, its inclusion in international indexes and its current electronic publication on the world wide web.

  17. Raman and SEM analysis of a biocolonised hot spring travertine terrace in Svalbard, Norway

    PubMed Central

    Jorge-Villar, Susana E; Benning, Liane G; Edwards, Howell GM

    2007-01-01

    Background A profile across 8 layers from a fossil travertine terrace from a low temperature geothermal spring located in Svalbard, Norway has been studied using both Raman spectroscopy and SEM (Scanning Electron Microscopy) techniques to identify minerals and organic life signals. Results Calcite, anatase, quartz, haematite, magnetite and graphite as well as scytonemin, three different carotenoids, chlorophyll and a chlorophyll-like compound were identified as geo- and biosignatures respectively, using 785 and/or 514 nm Raman laser excitation wavelengths. No morphological biosignatures representing remnant microbial signals were detected by high-resolution imaging, although spectral analyses indicated the presence of organics. In contrast, in all layers, Raman spectra identified a series of different organic pigments indicating little to no degradation or change of the organic signatures and thus indicating the preservation of fossil biomarker compounds throughout the life time of the springs despite the lack of remnant morphological indicators. Conclusion With a view towards planetary exploration we discuss the implications of the differences in Raman band intensities observed when spectra were collected with the different laser excitations. We show that these differences, as well as the different detection capability of the 785 and 514 nm laser, could lead to ambiguous compound identification. We show that the identification of bio and geosignatures, as well as fossil organic pigments, using Raman spectroscopy is possible. These results are relevant since both lasers have been considered for miniaturized Raman spectrometers for planetary exploration. PMID:17697380

  18. Using a university characterization facility to educate the public about microscopes: light microscopes to SEM

    NASA Astrophysics Data System (ADS)

    Healy, Nancy; Henderson, Walter

    2015-10-01

    The National Nanotechnology Infrastructure Network (NNIN)1is an integrated partnership of 14 universities across the US funded by NSF to support nanoscale researchers. The NNIN education office is located at the Institute of Electronics and Nanotechnology at the Georgia Institute of Technology. At Georgia Tech we offer programs that integrate the facility and its resources to educate the public about nanotechnology. One event that has proved highly successful involves using microscopes in our characterization suite to educate a diverse audience about a variety of imaging instruments. As part of the annual Atlanta Science Festival (ATLSF)2 we provided an event entitled: "What's all the Buzz about Nanotechnology?" which was open to the public and advertised through a variety of methods by the ATLSF. During the event, we provided hands-on demos, cleanroom tours, and activities with three of our microscopes in our recently opened Imaging and Characterization Facility: 1. Keyence VHX-600 Digital Microscope; 2. Hitachi SU823 FE-SEM; and 3. Hitachi TM 3000. During the two hour event we had approximately 150 visitors including many families with school-aged children. Visitors were invited to bring a sample for scanning with the TM-3000. This paper will discuss how to do such an event, lessons learned, and visitor survey results.

  19. Advantages and limitations of OM, SEM, TEM and AFM in the study of ancient decorated pottery

    NASA Astrophysics Data System (ADS)

    Arenas-Alatorre, J.; Silva-Velazquez, Y.; Alva Medina, A.; Rivera, M.

    2010-03-01

    This paper presents results from the study of two fragments of pre-Hispanic pottery, decorated with red pigment, using Optical Microscopy (OM), Scanning Electron Microscopy (SEM), High Resolution Transmission Electron Microscopy (HRTEM), Atomic Force Microscopy (AFM) and Magnetic Force Microscopy (MFM). Capabilities and limitations of these techniques in the analysis of archaeological material are highlighted with special emphasis on TEM, AFM and MFM due to their contribution in the study of the pigment layer at micro and nano scale. The analyzed samples come from the archaeological sites of El Tajin and Xochicalco, both in Mexico. Results of conventional TEM and HRTEM analysis of the red pigment showed nanometric Fe2O3 particles in both samples but different particle shape and size distributions: specimen from El Tajin presented irregular particles between 50-100 nm while that from Xochicalco exhibited semispherical shapes in the 3-25 nm range. AFM images showed the topography of the pigments, which are related to the texture of their surface and thus to the production process. Finally, MFM showed different contrast regions suggesting the presence of ferromagnetic elements forming clusters and domain orientations on the color layer.

  20. Integrated electrical and SEM-based defect characterization for rapid yield ramp

    NASA Astrophysics Data System (ADS)

    Orbon, Jacob; Levin, Lior; Bokobza, Ofer; Shimshi, Rinat; Dutta, Manjari; Zhang, Brian; Ciplickas, Dennis; Pham, Teri; Jensen, Jim

    2004-04-01

    Challenges of the new nanometer processes have complicated the yield enhancement process. The systematic yield loss component is increasing, due to the complexity and density of the new processes and the designs that are developed for them. High product yields can now only be achieved when process failure rates are on the order of a few parts per billion structures. Traditional yield ramping techniques cannot ramp yields to these levels and new methods are required. This paper presents a new systematic approach to yield loss pareto generation. The approach uses a sophisticated Design-of-Experiments (DOE) approach to characterize systematic and random yield loss mechanisms in the Back End Of the Line (BEOL). Sophisticated Characterization Vehicle (CV)TM test chips, fast electrical test and Automatic Defect Localization (ADL) are critical components of the method. Advanced statistical analysis and visualization of the detected and localized electrical defects provides a comprehensive view of the yield loss mechanisms. In situations where the defects are not visible in a SEM of the structure surface, automated FIB and imaging is used to characterize the defect. The combined approach provides the required resolution to appropriately characterize parts per billion failure rates.

  1. The influence of surface chemistry on GSR particles: using XPS to complement SEM/EDS analytical techniques

    NASA Astrophysics Data System (ADS)

    Schwoeble, A. J.; Strohmeier, Brian R.; Piasecki, John D.

    2010-06-01

    Gunshot residue particles (GSR) were examined using scanning electron microscopy/energy dispersive X-ray spectroscopy (SEM/EDS) to illustrate the size, shape, morphology, and elemental composition normally observed in particulate resulting from a discharged firearm. Determining the presence of lead (Pb), antimony (Sb), and barium (Ba), barring other elemental tags, fused together in a single particle with the correct morphology, is all that is required for the positive identification of GSR. X-ray photoelectron spectroscopy (XPS), however, can reveal more detailed information on surface chemistry than SEM/EDS. XPS is a highly surface-sensitive (<= ~10 nm), non-destructive, analytical technique that provides qualitative information for all elements except hydrogen and helium. Nanometer-scale sampling depth and its ability to provide unique chemical state information make XPS a potential technique for providing important knowledge on the surface chemistry of GSR that complements results obtained from SEM/EDS analysis.

  2. [Linear scanning analysis of prehistoric human bones in Xigongqiao Site, Tengzhou, Shandong Province by use of SEM-EDS].

    PubMed

    Hu, Yao-wu; He, De-liang; Dong, Yu; Wang, Chang-sui; Gao, Ming-kui; Lan, Yu-fu

    2006-06-01

    Ancient human bones in Xigongqiao Site, Tengzhou, Shandong Province, were analyzed by use of SEM-EDS. SEM indicated that the microstructure of Haversian system was destroyed under the impact of bone diagenesis. The apparent difference in elemental distribution in the bone cross section showed that the enrichment or loss of elements can occur not only in the inner and outer surface, but also in the middle. This study will have great influence on how to deal with the ancient human bones before any palaeodietary research in the future.

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

    PubMed

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

    2015-08-15

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

  4. Micro-mineralogical study with SEM on skarn mineralization at Geodo Mine, Korea

    NASA Astrophysics Data System (ADS)

    Son, H.; Lee, I.; Seo, J.

    2012-12-01

    The Geodo Mine was originally developed for Fe and Cu ores as a skarn type deposit. In 2003, however, the gold ore zones were discovered by Korea Resources Corporation (KORES). The estimated reservoir is 53,700 metric tons with 1.2 g/t Au and 63.9 g/t Ag in average. The Geodo Mine is located in the Taebaeksan Basin, which is one of the most important mineral deposit districts in the Korean Peninsula. The Sangdong Mine, well known World Class W-Mo skarn deposit, also belongs to this area. The Taebaeksan Basin is mainly composed of Precambrian metasedimentary rocks: the Yeongnam Massif, Cambrian-Ordovician sedimentary rocks: the Joseon Supergroup, Carboniferous-Triassic sedimentary rocks: the Pyongan Supergroup, and Mesozoic igneous intrusions. The Joseon Supergroup is host rocks of the Geodo Mine, which mainly consist of thick carbonates with less amounts of sandstone and shale. Especially, among the Mesozoic igneous intrusions, the Cretaceous Eopyeong granitoids are closely related with skarn zones of the Geodo Mine, which consist of quartz monzodiorite and granodiorite. The age of quartz monzodiorite (108 ± 1 and 111 ± 1 Ma) and granodiorite (107 ± 1, 108 ± 1, and 109 ± 1 Ma) has been reported. In order to establish the skarn mineral assemblage, polished thin sections prepared from the Geodo Mine were investigated by optical microscope and scanning electron microscope (SEM) at Seoul National University. Observed skarn mineral assemblage is predominated by garnet and pyroxene, which are partially altered to epidote and chlorite, respectively. The garnet has obvious oscillatory zoning. It is a typical hydrothermal metasomatic garnet, which formed during interaction of the hydrothermal fluid with the host rocks. Its characteristics suggest a cyclical history of alternating fluid circulation and stagnation or changes in the patterns, composition, oxidation state, and sources of fluid flow. Epidote occurs as an alteration product of garnet and can be observed in

  5. Combined SIMS, NanoSIMS, FTIR, and SEM Studies of OH in Nominally Anhydrous Minerals (NAMs)

    NASA Astrophysics Data System (ADS)

    Mosenfelder, J. L.; Le Voyer, M.; Rossman, G. R.; Guan, Y.; Bell, D. R.; Asimow, P. D.; Eiler, J.

    2010-12-01

    The accurate analysis of trace concentrations of hydrogen in NAMs is a long-standing problem, with wide-ranging implications in geology and planetology. SIMS and FTIR are two powerful and complementary analytical tools capable of measuring concentrations down to levels of less than 1 ppm H2O. Both methods, however, are subject to matrix effects and rely on other techniques such as manometry or nuclear reaction analysis (NRA) for quantitative calibration. We compared FTIR and SIMS data for a wide variety of NAMs: olivine, orthopyroxene, clinopyroxene, pyrope and grossular garnet, rutile, zircon, kyanite, andalusite, and sillimanite. Some samples were also characterized using high-resolution FE-SEM to assess the potential contribution of submicrocopic inclusions to the analyses. For SIMS, we use high mass resolution (≥5000 MRP) to measure 16O1H, using 30Si and/or 18O as reference isotopes. We use both primary standards, measured independently using manometry or NRA (e.g., [1]), and secondary standards, measured using polarized FTIR referenced back to calibrations developed on primary standards. Our major focus was on on olivine, for which we collected repeated calibration data with both SIMS and NanoSIMS, bracketing measurements of H diffusion profiles in both natural and experimentally annealed crystals at levels of 5-100 ppm H2O. With both instruments we establish low blanks (≤5 ppm) and high precision (typically less than 5% 2-σ errors in 16O1H/30Si), critical requirements for the low concentration levels being measured. Assessment of over 300 analyses on 11 olivines allows us to evaluate the suitability of different standards, several of which are in use in other laboratories [2,3,4]. Seven olivines, with 0-125 ppm H2O, give highly reproducible results and allow us to establish well-constrained calibration slopes with high correlation coefficients (r2 = 0.98-99), in contrast to previous studies [2,3,4]. However, four kimberlitic megacrysts with 140-243 ppm H

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

    SciTech Connect

    Salzer, Martin; Thiele, Simon; Zengerle, Roland; Schmidt, Volker

    2014-09-15

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

  7. Characterization of Pebax angioplasty balloon surfaces with AFM, SEM, TEM, and SAXS.

    PubMed

    Warner, Jacob A; Forsyth, Bruce; Zhou, Fang; Myers, Jason; Frethem, Chris; Haugstad, Greg

    2016-04-01

    In the medical device industry, angioplasty balloons have been widely used in the less invasive treatment of heart disease by expanding and relieving clogged structures in various arterial segments. However, new applications using thin coatings on the balloon surface have been explored to enhance therapeutic value in the delivery of pharmaceuticals (drug-elution) or control thermal energy output (RF ablation). In this study, angioplasty balloon materials comprised of poly(ether-block-amide) (Pebax) were investigated via atomic force microscopy (AFM), transmission electron microscopy (TEM), scanning electron microscopy (SEM), and small-angle X-ray scattering (SAXS) to characterize physical properties at the balloon surface that may affect coating adhesion. The soft segment of this Pebax 1074 material is polyethylene oxide (PEO) and the hard segment is nylon-12. The morphology of the hard segments of this block co-polymer are found via AFM stiffness measurements to be (40 ± 20) nm by (300 ± 150) nm and are oriented parallel to the surface of the balloon. SAXS measurements found the lamellar spacing to be (18.5 ± 0.5) nm, and demonstrate a preferential orientation in agreement with TEM and AFM measurements. Fixation of this balloon in resin, followed by cryo-sectioning is shown to provide a novel manner in which to investigate surface characteristics on the balloon such as material or coating thickness as well as uniformity in comparison to the bulk structure. These outputs were deemed critical to improve overall balloon processing such as molding and surface treatment options for robust designs toward better procedural outcomes targeting new therapeutic areas.

  8. Surface area and volume measurements of volcanic ash particles by SEM stereoscopic imaging

    NASA Astrophysics Data System (ADS)

    Ersoy, Orkun

    2010-05-01

    Surface area of volcanic ash particles is of great importance to research including plume dynamics, particle chemical and water reactions in the plume, modelling (i.e. plume shape, particle interactions , dispersion etc.), remote sensing of transport and SO2, HCl, H2O, CO2 levels, forecasting plume location, and transportation and deposition of ash particles. The implemented method presented in this study offer new insights for surface characterization of volcanic ash particles on macro-pore regions. Surface area and volumes of volcanic ash particles were measured using digital elevation models (DEM) reconstructed from stereoscopic images acquired from different angles by scanning electron microscope (SEM). The method was tested using glycidyl methacrylate (GMA) micro-spheres which exhibit low spherical imperfections. The differences between measured and geometrically calculated surface areas were introduced for both micro-spheres and volcanic ash particles in order to highlight the probable errors in modelling on volcanic ash behaviour. The specific surface areas of volcanic ash particles using this method are reduced by half (from mean values of 0.045 m2/g to 0.021 m2/g) for the size increment 63 μm to 125 μm. Ash particles mostly have higher specific surface area values than the geometric forms irrespective of particle size. The specific surface area trends of spheres and ash particles resemble for finer particles (63 μm). Approximation to sphere and ellipsoid have similar margin of error for coarser particles (125 μm) but both seem to be inadequate for representation of real ash surfaces.

  9. Surface area and volume measurements of volcanic ash particles by SEM stereoscopic imaging

    NASA Astrophysics Data System (ADS)

    Ersoy, Orkun

    2010-02-01

    Surface area of volcanic ash particles is of great importance to research including plume dynamics, particle chemical and water reactions in the plume, modelling (i.e. plume shape, particle interactions, dispersion etc.), remote sensing of transport and SO 2, HCl, H 2O, CO 2 levels, forecasting plume location, and transportation and deposition of ash particles. The implemented method presented in this study offers new insights for surface characterization of volcanic ash particles on macro-pore regions. Surface area and volumes of volcanic ash particles were measured using digital elevation models (DEM) reconstructed from stereoscopic images acquired from different angles by scanning electron microscope (SEM). The method was tested using glycidyl methacrylate (GMA) micro-spheres which exhibit low spherical imperfections. The differences between measured and geometrically calculated surface areas were introduced for both micro-spheres and volcanic ash particles in order to highlight the probable errors in modelling on volcanic ash behaviour. The specific surface areas of volcanic ash particles using this method are reduced by half (from mean values of 0.045 m 2/g to 0.021 m 2/g) for the size increment 63 µm to 125 µm. Ash particles mostly have higher specific surface area values than the geometric forms irrespective of particle size. The specific surface area trends of spheres and ash particles resemble for finer particles (63 µm). Approximation to sphere and ellipsoid have similar margin of error for coarser particles (125 µm) but both seem to be inadequate for representation of real ash surfaces.

  10. Signal of unusual large fluctuations in 32S-Em interactions at SPS energies

    NASA Astrophysics Data System (ADS)

    Rasool, Mir Hashim; Ahmad, Shafiq; Ahmad, M. Ayaz

    2015-08-01

    An investigation on the presence of large dynamical fluctuations was carried out in the pseudorapidity phase space ( η-space) of relativistic charged particles produced in 32S-Em interactions at 200 AGeV/c by the method of scaled factorial moments, F q , in terms of the new scaled variable X( η) suggested by Bialas and Gazdzicki. The Nuclear emulsion technique was employed to collect the experimental data. We compared our experimental results with those obtained from simulated events by using Monte Carlo Code FRITIOF. The variation of ln F q with ln M in pseudorapidity ( η) phase space revealed a power law behavior. The values of the slopes, α q , determined from the analyses of the F q moments are discussed. The generalized fractal dimensions, D q , determined from the above method are calculated and found to decrease with the order of the moments, q, indicating multifractality in multiparticle production. Also, the anomalous fractal dimension d q obtained was found to increase linearly with the order of moments, q suggesting a self-similar cascade mechanism. In order to check for the presence of the statistical fluctuations, we generated uncorrelated Monte Carlo events (MC-RAND) randomly in -space based on the assumption of independent emission of particles and compared the results with the experimental and FRITIOF data. The experimental data on intermittency were found to exhibit a remarkable proximity to the analogous data obtained from the FRITIOF code. However, the uncorrelated Monte Carlo events exhibited no such dependence on M, which indicates the absence of a statistical contribution in the experimental data. The flat behavior in the Monte Carlo events is expected for an independent emission of particles.

  11. Identify the injury implements by SEM/EDX and ICP-AES.

    PubMed

    Bai, Rufeng; Wan, Lihua; Li, Hongwei; Zhang, Zhong; Ma, Zhihua

    2007-02-14

    The forensic investigator is frequently confronted with the discrimination and deduction of injury implements, which is one of the most important physical testimonies in courts. The usual method used in actual cases is from points of morphology. In the forensic discrimination of injury implements, such as metal implements, the analysis and comparison of elements are expected to provide excellent results, and simultaneous multi-elemental analysis is required to analyze various kinds of elements. This study was designed to establish discrimination and deduction of metal injury implements by scanning electron microscope/energy disperse X-ray microanalyzer (SEM/EDX) and inductively coupled plasma atomic emission spectrometry (ICP-AES). Examined metal particles in five wounds made on the skin of domestic pigs, respectively, using Cu-Zn or Cr-Ni coated and carbon steel kitchen implements by EDX. For carbon steel kitchen implements, analyzed five samples from the back and blade separately in the contents and varieties of elements by ICP-AES. In the wounds by the coated implements, the special particles only containing Cu, Zn or Cr, Ni were found. In the wounds by carbon steel kitchen implements, the particles containing Fe, Cr, Si or Fe, Mn, Si were found. The differences of contents of elements between the back and blade was no significant except No. 5 for carbon steel kitchen implements, and the significant differences of elements exited in Cr, Mn, Si, Cu, Mo among the stainless kitchen knives, Mn, Si among the other kitchen implements and for the blade of No. 5 knife, relative standard deviations (R.S.D.s) were significantly different in Mn, Si, Mo, Ti, S, P, Ni. Using EDX to examine the particles in wounds can deduce the categories of metal injury implements, and we can still deduce the different implements in the same category by ICP-AES.

  12. Characterization of E. CHLOROTICUS Sea Urchin Tooth Using Nanoindentation and SEM

    NASA Astrophysics Data System (ADS)

    Laxminarayana, Radhika; Rodrigues, Samantha; Dickinson, Michelle

    The teeth of Evenchinus chloroticus are not only vital tools for their survival but also have fascinating structures in the world of science and engineering. Despite being compositionally similar to rocks, these teeth are still able to scrape along the hard surfaces of rocks for food, while having the unique ability to self-sharpen. Yet these abilities arise from the properties of the teeth, which are in turn dependent on their design and composition. Nanoindentation was used in this study to characterise the hardness across the sea urchin tooth in detail. It focuses on the chewing tip since the main grinding function is performed by this region. In addition, SEM and EDS were used to explore any correlations between the mechanical properties of the tooth and its composition. It was found that there were two main relatively hard regions (stone part in the centre of the top flange part and another similar region in the centre of the bottom keel zone). These regions are similar in structure, consisting of thin needles and matrix and have a higher magnesium content compared to other areas of the tooth, which is attributed to the greater proportion of matrix present. Furthermore, the regions below the stone part and at the start of the keel zone appear to be weaker, which might be due to the significant amount of pores in these areas. The sharp tip is maintained by shedding of the primary plates surrounding the stone part and the keel fibres, leaving only the stone part at the chewing tip.

  13. Porcelain laminate veneer conditioning for orthodontic bonding: SEM-EDX analysis.

    PubMed

    Aksakalli, Sertac; Ileri, Zehra; Yavuz, Tevfik; Malkoc, Meral Arslan; Ozturk, Nilgun

    2015-09-01

    The purpose of this in vitro study was to evaluate and compare the effects of different surface treatments and laser irradiation on the bond strength of brackets bonded to porcelain laminate veneer. Porcelain laminate veneer specimens were embedded in the centers of acrylic resin blocks. Thirty-nine teeth were used for shear bond strength testing and the remaining three (one tooth for each group) were used for evaluation of the debonded bracket interface. Specimens were randomly divided into three groups, each containing 13 specimens. The details of the groups are as follows: Group SB, sandblasting with alumina particles (50 μm); Group HFA, 9.6 % hydrofluoric acid etching; Group ER, erbium-doped yttrium-aluminum-garnet (Er: YAG) irradiation (from 1 mm distance, 2 W, 10 Hz for 10 s). After conditioning, the upper central brackets were bonded to the porcelain surfaces. Porcelain laminate veneers were examined under stereomicroscope for adhesive remnant index and surface damage after debonding. The highest shear bond strength values were obtained with Group HFA (10.8 ± 3.8 MPa) and Group ER (9.3 ± 1.5 MPa), whereas Group SB revealed the lowest values. Scanning electron microscopy energy-dispersive X-ray (SEM-EDX) analysis revealed that the silicon level in the porcelain decreased after debonding in all groups. The sandblasting method did not demonstrate any ideal bond strength values; however, the 9.6 % hydrofluoric acid etching and Er: YAG laser did. There were no significant differences among all groups in terms of laminate surface damages. The Er: YAG laser therefore can be selected for ideal bond strength and minimal damage to porcelain laminates.

  14. SEM and TEM Characterization of As-Fabricated U-7Mo Disperson Fuel Plates

    SciTech Connect

    D. D. Keiser, Jr.; B. Yao; E. Perez; Y. H. Sohn

    2009-11-01

    The starting microstructure of a dispersion fuel plate can have a dramatic impact on the overall performance of the plate during irradiation. To improve the understanding of the as-fabricated microstructures of dispersion fuel plates, SEM and TEM analysis have been performed on RERTR-9A archive fuel plates, which went through an additional hot isostatic procsssing (HIP) step during fabrication. The fuel plates had depleted U-7Mo fuel particles dispersed in either Al-2Si or 4043 Al alloy matrix. For the characterized samples, it was observed that a large fraction of the ?-phase U-7Mo alloy particles had decomposed during fabrication, and in areas near the fuel/matrix interface where the transformation products were present significant fuel/matrix interaction had occurred. Relatively thin Si-rich interaction layers were also observed around the U-7Mo particles. In the thick interaction layers, (U)(Al,Si)3 and U6Mo4Al43 were identified, and in the thin interaction layers U(Al,Si)3, U3Si3Al2, U3Si5, and USi1.88-type phases were observed. The U3Si3Al2 phase contained some Mo. Based on the results of this work, exposure of dispersion fuel plates to relatively high temperatures during fabrication impacts the overall microstructure, particularly the nature of the interaction layers around the fuel particles. The time and temperature of fabrication should be carefully controlled in order to produce the most uniform Si-rich layers around the U-7Mo particles.

  15. X-Ray Lithography Mask Metrology: Use of Transmitted Electrons in an SEM for Linewidth Measurement

    PubMed Central

    Postek, Michael T.; Lowney, Jeremiah R.; Vladar, Andras E.; Keery, William J.; Marx, Egon; Larrabee, Robert D.

    1993-01-01

    X-ray masks present a measurement object that is different from most other objects used in semiconductor processing because the support membrane is, by design, x-ray transparent. This characteristic can be used as an advantage in electron beam-based x-ray mask metrology since, depending upon the incident electron beam energies, substrate composition and substrate thickness, the membrane can also be essentially electron transparent. The areas of the mask where the absorber structures are located are essentially x-ray opaque, as well as electron opaque. This paper shows that excellent contrast and signal-to-noise levels can be obtained using the transmitted-electron signal for mask metrology rather than the more commonly collected secondary electron signal. Monte Carlo modeling of the transmitted electron signal was used to support this work in order to determine the optimum detector position and characteristics, as well as in determining the location of the edge in the image profile. The comparison between the data from the theoretically-modeled electron beam interaction and actual experimental data were shown to agree extremely well, particularly with regard to the wall slope characteristics of the structure. Therefore, the theory can be used to identify the location of the edge of the absorber line for linewidth measurement. This work provides one approach to improved x-ray mask linewidth metrology and a more precise edge location algorithm for measurement of feature sizes on x-ray masks in commercial instrumentation. This work also represents an initial step toward the first SEM-based accurate linewidth measurement standard from NIST, as well as providing a viable metrology for linewidth measurement instruments of x-ray masks for the lithography community. PMID:28053482

  16. Investigation of Mg and Zn doped 45S5 bioactive materials by XRD, FTIR and SEM techniques

    NASA Astrophysics Data System (ADS)

    Anand, Vikas; Singh, K. J.; Kaur, Kulwinder

    2014-04-01

    Magnesium and zinc doped 45S5 samples were prepared in the laboratory by sol gel technique., Structural properties of the samples have been studied by XRD, FTIR and SEM techniques. Both FTIR and XRD data indicate the primary bioactive behavior of the samples. Presented results may be useful to improve the antibacterial as well as osteoblast properties of the currently available bioactive materials.

  17. SEM with Missing Data and Unknown Population Distributions Using Two-Stage ML: Theory and Its Application

    ERIC Educational Resources Information Center

    Yuan, Ke-Hai; Lu, Laura

    2008-01-01

    This article provides the theory and application of the 2-stage maximum likelihood (ML) procedure for structural equation modeling (SEM) with missing data. The validity of this procedure does not require the assumption of a normally distributed population. When the population is normally distributed and all missing data are missing at random…

  18. 30 CFR 250.1918 - What criteria for emergency response and control must be in my SEMS program?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... ENVIRONMENTAL ENFORCEMENT, DEPARTMENT OF THE INTERIOR OFFSHORE OIL AND GAS AND SULPHUR OPERATIONS IN THE OUTER... drills carried out in accordance with a schedule defined by the SEMS training program (§ 250.1915). The... with access to the Emergency Action Plans, oil spill contingency plan, and other safety...

  19. 30 CFR 250.1918 - What criteria for emergency response and control must be in my SEMS program?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... ENVIRONMENTAL ENFORCEMENT, DEPARTMENT OF THE INTERIOR OFFSHORE OIL AND GAS AND SULPHUR OPERATIONS IN THE OUTER... drills carried out in accordance with a schedule defined by the SEMS training program (§ 250.1915). The... with access to the Emergency Action Plans, oil spill contingency plan, and other safety...

  20. 30 CFR 250.1918 - What criteria for emergency response and control must be in my SEMS program?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... ENVIRONMENTAL ENFORCEMENT, DEPARTMENT OF THE INTERIOR OFFSHORE OIL AND GAS AND SULPHUR OPERATIONS IN THE OUTER... drills carried out in accordance with a schedule defined by the SEMS training program (§ 250.1915). The... with access to the Emergency Action Plans, oil spill contingency plan, and other safety...

  1. Analyzing indirect secondary electron contrast of unstained bacteriophage T4 based on SEM images and Monte Carlo simulations

    SciTech Connect

    Ogura, Toshihiko

    2009-03-06

    The indirect secondary electron contrast (ISEC) condition of the scanning electron microscopy (SEM) produces high contrast detection with minimal damage of unstained biological samples mounted under a thin carbon film. The high contrast image is created by a secondary electron signal produced under the carbon film by a low acceleration voltage. Here, we show that ISEC condition is clearly able to detect unstained bacteriophage T4 under a thin carbon film (10-15 nm) by using high-resolution field emission (FE) SEM. The results show that FE-SEM provides higher resolution than thermionic emission SEM. Furthermore, we investigated the scattered electron area within the carbon film under ISEC conditions using Monte Carlo simulation. The simulations indicated that the image resolution difference is related to the scattering width in the carbon film and the electron beam spot size. Using ISEC conditions on unstained virus samples would produce low electronic damage, because the electron beam does not directly irradiate the sample. In addition to the routine analysis, this method can be utilized for structural analysis of various biological samples like viruses, bacteria, and protein complexes.

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

    SciTech Connect

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

    2014-04-01

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

  3. 30 CFR 250.1917 - What criteria for pre-startup review must be 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 criteria for pre-startup review must be in my SEMS program? 250.1917 Section 250.1917 Mineral Resources BUREAU OF SAFETY AND ENVIRONMENTAL... analysis recommendations have been implemented as appropriate. (e) Training of operating personnel has...

  4. 30 CFR 250.1919 - What criteria for investigation of incidents must be 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 criteria for investigation of incidents must be in my SEMS program? 250.1919 Section 250.1919 Mineral Resources BUREAU OF SAFETY AND...) Retain the findings of investigations for use in the next hazard analysis update or audit; (2)...

  5. 30 CFR 250.1919 - What criteria for investigation of incidents must be 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 criteria for investigation of incidents must be in my SEMS program? 250.1919 Section 250.1919 Mineral Resources BUREAU OF SAFETY AND...) Retain the findings of investigations for use in the next hazard analysis update or audit; (2)...

  6. 30 CFR 250.1917 - What criteria for pre-startup review must be 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 criteria for pre-startup review must be in my SEMS program? 250.1917 Section 250.1917 Mineral Resources BUREAU OF SAFETY AND ENVIRONMENTAL... analysis recommendations have been implemented as appropriate. (e) Training of operating personnel has...

  7. 30 CFR 250.1917 - What criteria for pre-startup review must be 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 criteria for pre-startup review must be in my SEMS program? 250.1917 Section 250.1917 Mineral Resources BUREAU OF SAFETY AND ENVIRONMENTAL... analysis recommendations have been implemented as appropriate. (e) Training of operating personnel has...

  8. 30 CFR 250.1919 - What criteria for investigation of incidents must be 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 criteria for investigation of incidents must be in my SEMS program? 250.1919 Section 250.1919 Mineral Resources BUREAU OF SAFETY AND...) Retain the findings of investigations for use in the next hazard analysis update or audit; (2)...

  9. Advanced SEM-EDX and Isotope Mapping of a Refractory Grain in a Fine-Grained IDP

    NASA Astrophysics Data System (ADS)

    Starkey, N. A.; Franchi, I. A.; Salge, T.; Brearley, A. J.

    2015-07-01

    We present high spatial resolution SEM-EDX and O isotope mapping to reveal the presence of a melilite-olivine refractory grain in a fine-grained IDP. We use this to discuss transport of material from the inner solar system and formation of comets.

  10. A SEM Model in Assessing the Effect of Convergent, Divergent and Logical Thinking on Students' Understanding of Chemical Phenomena

    ERIC Educational Resources Information Center

    Stamovlasis, D.; Kypraios, N.; Papageorgiou, G.

    2015-01-01

    In this study, structural equation modeling (SEM) is applied to an instrument assessing students' understanding of chemical change. The instrument comprised items on understanding the structure of substances, chemical changes and their interpretation. The structural relationships among particular groups of items are investigated and analyzed using…

  11. SEM characterization of anatomical variation in chitin organization in insect and arthropod cuticles.

    PubMed

    Chandran, Rakkiyappan; Williams, Lee; Hung, Albert; Nowlin, Kyle; LaJeunesse, Dennis

    2016-03-01

    The cuticles of insects and arthropods have some of the most diverse material properties observed in nature, so much so that it is difficult to imagine that all cutciles are primarily composed of the same two materials: a fibrous chitin network and a matrix composed of cuticle proteins. Various factors contribute to the mechanical and optical properties of an insect or arthropod cuticle including the thickness and composition. In this paper, we also identified another factor that may contribute to the optical, surface, and mechanical properties of a cuticle, i.e. the organization of chitin nanofibers and chitin fiber bundles. Self-assembled chitin nanofibers serve as the foundation for all higher order chitin structures in the cuticles of insects and other arthropods via interactions with structural cuticle proteins. Using a technique that enables the characterization of chitin organization in the cuticle of intact insects and arthropod exoskeletons, we demonstrate a structure/function correlation of chitin organization with larger scale anatomical structures. The chitin scaffolds in cuticles display an extraordinarily diverse set of morphologies that may reflect specific mechanical or physical properties. After removal of the proteinaceous and mineral matrix of a cuticle, we observe using SEM diverse nanoscale and micro scale organization of in-situ chitin in the wing, head, eye, leg, and dorsal and ventral thoracic regions of the periodical cicada Magicicada septendecim and in other insects and arthropods. The organization of chitin also appears to have a significant role in the organization of nanoscale surface structures. While microscale bristles and hairs have long been known to be chitin based materials formed as cellular extensions, we have found a nanostructured layer of chitin in the cuticle of the wing of the dog day annual cicada Tibicen tibicens, which may be the scaffold for the nanocone arrays found on the wing. We also use this process to examine

  12. Determination of optimal parameters for CD-SEM measurement of line-edge roughness

    NASA Astrophysics Data System (ADS)

    Bunday, Benjamin D.; Bishop, Michael; McCormack, Donald W., Jr.; Villarrubia, John S.; Vladar, Andras E.; Dixson, Ronald; Vorburger, Theodore V.; Orji, N. G.; Allgair, John A.

    2004-05-01

    The measurement of line-edge roughness (LER) has recently become a topic of concern in the litho-metrology community and the semiconductor industry as a whole. 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 a project to investigate LER metrics and to direct the critical dimension scanning electron microscope (CD-SEM) supplier community towards a semiconductor industry-backed, standardized solution for implementation. The 2003 International Technology Roadmap for Semiconductors (ITRS) has included a new definition for roughness. The ITRS envisions root mean square measurements of edge and width roughness. There are other possible metrics, some of which are surveyed here. The ITRS envisions the root mean square measurements restricted to roughness wavelengths falling within a specified process-relevant range and with measurement repeatability better than a specified tolerance. This study addresses the measurement choices required to meet those specifications. An expression for the length of line that must be measured and the spacing of measurement positions along that length is derived. Noise in the image is shown to produce roughness measurement errors that have both random and nonrandom (i.e., bias) components. Measurements are reported on both UV resist and polycrystalline silicon in special test patterns with roughness typical for those materials. These measurements indicate that the sensitivity of a roughness measurement to noise depends importantly both on the choice of edge detection algorithm and the quality of the focus. Measurements are less sensitive to noise when a model-based or sigmoidal fit algorithm is used and when the images are in good focus. Using the measured roughness characteristics for UV resist lines and applying the ITRS requirements for the 90 nm technology

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

    PubMed

    Hortolà, Policarp

    2016-11-01

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

  14. Sol-gel synthesis, phase composition, morphological and structural characterization of Ca10(PO4)6(OH)2: XRD, FTIR, SEM, 3D SEM and solid-state NMR studies

    NASA Astrophysics Data System (ADS)

    Kareiva, Simonas; Klimavicius, Vytautas; Momot, Aleksandr; Kausteklis, Jonas; Prichodko, Aleksandra; Dagys, Laurynas; Ivanauskas, Feliksas; Sakirzanovas, Simas; Balevicius, Vytautas; Kareiva, Aivaras

    2016-09-01

    Aqueous sol-gel chemistry route based on ammonium-hydrogen phosphate as the phosphorus precursor, calcium acetate monohydrate as source of calcium ions, and 1,2-ethylendiaminetetraacetic acid (EDTA), or 1,2-diaminocyclohexanetetracetic acid (DCTA), or tartaric acid (TA), or ethylene glycol (EG), or glycerol (GL) as complexing agents have been used to prepare calcium hydroxyapatite (Ca10(PO4)6(OH)2, CHAp). The phase transformations, composition, and structural changes in the polycrystalline samples were studied by infrared spectroscopy (FTIR), X-ray powder diffraction analysis (XRD), and scanning electron microscopy (SEM). The local short-range (nano- and mezo-) scale effects in CHAp were studied using solid-state NMR spectroscopy. The spatial 3D data from the SEM images of CHAp samples obtained by TA, EG and GL sol-gel routes were recovered for the first time to our knowledge.

  15. Iowa community college Science, Engineering and Mathematics (SEM) faculty: Demographics and job satisfaction

    NASA Astrophysics Data System (ADS)

    Rogotzke, Kathy

    hours a semester and are expected to conduct research and publish their findings. In addition, community colleges often have what is referred to as an "open door" policy of admission meaning that students are not required to have a particular score on a college placement test, such as the ACT or SAT, nor are they required to have a specified high school grade point average or rank. Most 4-year colleges and universities require a minimum score on a college placement test in addition to a minimum high school grade point average or rank. Because of these differing entrance requirements, or lack thereof, community colleges often have a higher percentage of students needing remedial or developmental coursework. This dissertation reports on data collected from a survey administered to full-time faculty at all 15 community colleges in Iowa. The survey was administered using Qualtrics software with assistance from the Office of Community College Research and Policy at Iowa State University. The results of the study were used to further examine who community college science, engineering and mathematics (SEM) faculty are in terms of their demographics and background, along with investigating factors from the survey that contribute to their overall job satisfaction. Multiple regression analysis on these variables along with gender and age examined different models for predicting overall job satisfaction.

  16. Application of Automated SEM-EDS Based Mineral Identification Systems to Problems in Metamorphic Petrology

    NASA Astrophysics Data System (ADS)

    Fairhurst, Robert; Barrow, Wendy; Rollinson, Gavyn

    2010-05-01

    Automated scanning electron microscopy-energy dispersive x-ray spectrometer (SEM-EDS) based mineral identification systems such as QEMSCAN have been in development for over 20 years, primarily as a tool to understand mineral liberation and element distribution in metal mining industry. This powerful technique is now being used in non mining applications such as metamorphic petrology where accurate mineral identification and metamorphic fabrics are key to deciphering the metamorphic history of samples. The QEMSCAN was developed by CSIRO for application in the mining industry where it is used to understand mineralogy, texture, mineral associations, the presence of gangue minerals and deleterious elements that may potentially interfere with mineral processing and planning, and the overall impact of mineralogy on grinding and flotation processes. It is capable of identifying most rock-forming minerals in milliseconds from their characteristic x-ray spectra. The collected x-ray spectra are compared to entries in a database containing the species identification profiles (SIPs) and are assigned a label accordingly. QEMSCAN is capable of searching large sample areas at high resolution resulting in the accurate and precise determination of all minerals present. Reports that were originally developed for the mining geologist can be equally useful to the petrologist, e.g. phase/mineral maps, modal mineral abundances and mineral association reports. Identification of key minerals is of great importance to determining the petrologic history of a sample. These key minerals may be few in number and present as small microinclusions (less than 100 μm) making them difficult to identify, if at all, with the petrographic microscope. Therefore, imaging by electron-microprobe or scanning electron microscope are the methods traditionally used. However, because of the small field of view available on these instruments at a magnification necessary to resolve micron sized relicts and

  17. CEC Selected Convention Papers; Annual International Convention: Behavioral Disorders.

    ERIC Educational Resources Information Center

    Council for Exceptional Children, Arlington, VA.

    Selected papers on behavioral disorders include the following: aggression as an indicator for rehabilitative efforts by Herbert Grossman; the evaluation of differential low rate conditioning procedures on destructive behavior by Christine Walken; a modification for non-directive therapy by Robert V. Turner; Piaget, Skinner and a comprehensive…

  18. Surface functionalization of silica microparticles for capillary electrochromatography (CEC)

    SciTech Connect

    Shepodd, T.J.; Anex, D.S.; Rognlien, J.

    1997-01-01

    We derivatized small (0.5 -3 {mu}m) silica particles by silating their surfaces with long-chain alkyl substituted silanes. These functionalized particles were packed into 100 {mu}m capillaries and used as stationary phases for capillary electrochromatography. The particles supported electroosmotic flow in mixtures of acetonitrile and aqueous buffer (4 mM sodium tetraborate or 2mM TRIS). The columns were used to separate mixtures of organic analytes demonstrating the effectiveness of the functionalized stationary phase.

  19. Report of CEC Study Committee on Construction Management.

    ERIC Educational Resources Information Center

    Consulting Engineers Council of the U.S., Washington, DC.

    Changing times place new demands on those involved in the implementation of construction projects. Within a relatively few years, the size and complexity of projects has grown substantially. Environmental and other public and social considerations are increasingly significant. With growing complexity, the requirements for effective project…

  20. Determination of organic acids by CE and CEC methods.

    PubMed

    Klampfl, Christian W

    2007-10-01

    A comprehensive overview of the analysis of low-molecular-mass organic acids employing electromigration methods in the capillary format is given. This review includes papers published since 2003 and can be seen as an update of the review paper published by Galli et al. in 2003. Tables included in this review contain application papers describing the determination of organic acids from a variety of fields like the analysis of food and beverages, environmental samples, samples from clinical origin, and from natural products.

  1. Effects of Citric Acid and Desensitizing Agent Application on Nonfluorosed and Fluorosed Dentin: An In Vitro Sem Study

    PubMed Central

    Neha, Mahajan; Vandana, Laxman K

    2015-01-01

    Fluorosis is one of the factors which bring about mineralisation changes in a dentinal structure leading to dentin. The purpose of the present study was to compare and evaluate the dentinal tubular changes in fluorosed and nonfluorosed teeth subsequent to the application of citric acid,strontium acetate based sodium fluoride (SAF) using scanning electron microscopy (SEM). Dentin specimens from healthy fluorosed and nonfluorosed teeth were included in the study. Each of them was grouped into acid treated and SAF treatment groups. Using SEM, the photomicrographs (3500x) of dentin specimens were evaluated. Results showed while there was a significant difference in tubular width of partial occlusion ≤ 25%, being more in fluorosed group compared to nonfluorosed group after application SAF. Application of desensitising agents demonstrated higher number of dentinal tubular occlusion and diameter reduction in nonfluorosed dentin compared to fluorosed dentin. Summary: Root biomodification and desensitising agent procedure brings in definite difference between fluorosed and non-fluorosed dentin specimens. PMID:25870716

  2. Characterization Of Multi-layered Fish Scales (Atractosteus spatula) Using Nanoindentation, X-ray CT, FTIR, and SEM

    PubMed Central

    Allison, Paul G.; Rodriguez, Rogie I.; Moser, Robert D.; Williams, Brett A.; Poda, Aimee R.; Seiter, Jennifer M.; Lafferty, Brandon J.; Kennedy, Alan J.; Chandler, Mei Q.

    2014-01-01

    The hierarchical architecture of protective biological materials such as mineralized fish scales, gastropod shells, ram’s horn, antlers, and turtle shells provides unique design principles with potentials for guiding the design of protective materials and systems in the future. Understanding the structure-property relationships for these material systems at the microscale and nanoscale where failure initiates is essential. Currently, experimental techniques such as nanoindentation, X-ray CT, and SEM provide researchers with a way to correlate the mechanical behavior with hierarchical microstructures of these material systems1-6. However, a well-defined standard procedure for specimen preparation of mineralized biomaterials is not currently available. In this study, the methods for probing spatially correlated chemical, structural, and mechanical properties of the multilayered scale of A. spatula using nanoindentation, FTIR, SEM, with energy-dispersive X-ray (EDX) microanalysis, and X-ray CT are presented. PMID:25046233

  3. SEM observations and differential scanning calorimetric studies of new and sterilized nickel-titanium rotary endodontic instruments.

    PubMed

    Alexandrou, Georgia B; Chrissafis, Konstantinos; Vasiliadis, Leonidas P; Pavlidou, Eleni; Polychroniadis, E K

    2006-07-01

    Scanning electron microscopy (SEM) and differential scanning calorimetric (DSC) studies were utilized to investigate surface and microstructure of two brands of rotary nickel-titanium (NiTi) endodontic instruments, in the as-received condition and after subjection to 1, 6, and 11 sterilization cycles. A total of 66 ProFile (n = 33) and Flexmaster (n = 33) files were examined. SEM observations indicated the presence of surface imperfections and adherent material in all new and sterilized instruments and an increase in surface roughness of the instruments that underwent multiple sterilizations. DSC measurements showed that the specimens of both brands, in the as-received condition and after 11 sterilizations, were completely austenite in the oral environment temperature, suggesting that they are capable of superelastic behavior in appropriate clinical conditions.

  4. High-density polyethylene facial implants show surface oxidation in SEM and EDX examination: a pilot study.

    PubMed

    Draenert, G F; Doeblinger, M; Draenert, M; Gosau, M

    2009-05-01

    Previous histopathological studies on explanted Medpor high-density polyethylene (HDPE) facial implants indicated signs of material destruction and claimed to observe phagocytized HDPE particles within the tissue samples beside the usual type IV reaction with severe fibrosis. We examined new and explanted Medpor material with scanning electron microscopy (SEM) and energy-dispersive X-ray analysis (EDX). The implant surface of three patient-derived specimens showed significantly higher oxygenation in EDX analysis and morphological changes in SEM compared to the new unused material directly after opening of the package and after 1 year of exposure to air. Our preliminary findings indicate a possible oxidative biocorrosion in HDPE surgical implants. Further studies should confirm these pilot project results.

  5. Trajectory reconstruction through analysis of trace evidence in bullet-intermediate target interaction by SEM/EDX.

    PubMed

    Hu, Sunlin; Shen, Hui; Wang, Songcai; Fang, Chao

    2009-11-01

    A young male was shot to death by a police officer with a Chinese Type 64 7.62 mm pistol when he was dealing with an aggravated assault arising from a traffic accident. By using scanning electron microscopy and energy dispersive X-ray spectroscopy (SEM/EDX), trace deposits on the discharged bullet and the intermediate target, i.e., a concrete telegraph pole at the scene, were identified to be from each other. The result demonstrated the bullet causing the death ricocheted from the concrete telegraph pole before striking the victim, thus indicating the incident was accidental. The case report illustrates the evidential value of trace materials derived, respectively, from discharged bullets and intermediate targets in bullet-intermediate target interaction for trajectory reconstruction. In addition, it indicates that the SEM/EDX method with its nondestructive nature, compared to other methods, may be more helpful in certain situations in determining the origins of trace evidentially valuable deposits on substrates.

  6. Complementing and adding to SEM performance with the addition of XRF, Raman, CL and PL spectroscopy and imaging

    NASA Astrophysics Data System (ADS)

    Leroy, E.; Mamedov, S.; Teboul, E.; Whitley, A.; Meyer, D.; Casson, L.

    2010-06-01

    Electron microscopy, along with many other surface science and analytical techniques, offers an array of complementary sub-techniques that provide additional information to enhance the primary analysis or imaging mode. Most electron microscopes are built with several additional ports for the installation of complementary analysis modules. One type of analysis which is particular useful in geology and semiconductor analysis is cathodoluminescence (CL). A new technique has been developed to allow complementary optical measurements using the electron beam from the SEM, compatible with most standard commercial SEM systems. Among the optical measurements accessible using the Cathodoluminescence Universal Extension (CLUE) module are CL, Raman, PL and EDX spectroscopy and imaging. This paper shows the advantages of using these complementary techniques, and how they can be applied to analysis of geological and semiconductor materials.

  7. An investigation of adhesive/adherend and fiber/matrix interactions. Part B: SEM/ESCA analysis of fracture surfaces

    NASA Technical Reports Server (NTRS)

    Beck, B.; Widyani, E.; Wightman, J. P.

    1983-01-01

    Adhesion was studied with emphasis on the characterization of surface oxide layers, the analysis of fracture surfaces, and the interaction of matrices and fibers. A number of surface features of the fractured lap shear samples were noted in the SEM photomicrographs including the beta phase alloy of the Ti 6-4 adherend, the imprint of the adherend on the adhesive failure surface, increased void density for high temperature samples, and the alumina filler particles. Interfacial failure of some of the fractured lap shear samples is invariably characterized by the appearance of an ESCA oxygen photopeak at 530.3 eV assigned to the surface oxide layer of Ti 6-4 adherend. The effect of grit blasting on carbon fiber composites is evident in the SEM analysis. A high surface fluorine concentration on the composite surface is reduced some ten fold by grit blasting.

  8. SEM-EDX and microFTIR studies on evaluation of protection capacity of some thin phosphate layers.

    PubMed

    Sandu, Andrei Victor; Ciomaga, Alexandra; Nemtoi, Gheorghe; Bejinariu, Costica; Sandu, Ion

    2012-12-01

    This article presents the SEM-EDX and microFTIR study and the corrosion behavior of new five types of phosphated coatings obtained by coprecipitation in acid aqueous medium of some metal cations, pursuing the influence of the addition of other cations and a moderator of precipitation, on the uniformity and compactness of the layers and on the morphology of dendritic structure of Zn(II) and Fe(II) phosphates.

  9. Histological and SEM analysis of root cementum following irradiation with Er:YAG and CO2 lasers.

    PubMed

    Almehdi, Aslam; Aoki, Akira; Ichinose, Shizuko; Taniguchi, Yoichi; Sasaki, Katia M; Ejiri, Kenichiro; Sawabe, Masanori; Chui, Chanthoeun; Katagiri, Sayaka; Izumi, Yuichi

    2013-01-01

    Recently, the Er:YAG and CO(2) lasers have been applied in periodontal therapy. However, the characteristics of laser-irradiated root cementum have not been fully analyzed. The aim of this study was to precisely analyze the alterations of root cementum treated with the Er:YAG and the CO(2) lasers, using non-decalcified thin histological sections. Eleven cementum plates were prepared from extracted human teeth. Pulsed Er:YAG laser contact irradiation was performed in a line at 40 mJ/pulse (14.2 J/cm(2)/pulse) and 25 Hz (1.0 W) under water spray. Continuous CO(2) laser irradiation was performed in non-contact mode at 1.0 W, and ultrasonic instrumentation was performed as a control. The treated samples were subjected to stereomicroscopy, scanning electron microscopy (SEM), light microscopy and SEM energy dispersive X-ray spectroscopy (SEM-EDS). The Er:YAG laser-treated cementum showed minimal alteration with a whitish, slightly ablated surface, whereas CO(2) laser treatment resulted in distinct carbonization. SEM analysis revealed characteristic micro-irregularities of the Er:YAG-lased surface and the melted, resolidified appearance surrounded by major and microcracks of the CO(2)-lased surface. Histological analysis revealed minimal thermal alteration and structural degradation of the Er:YAG laser-irradiated cementum with an affected layer of approximately 20-μm thickness, which partially consisted of two distinct affected layers. The CO(2)-lased cementum revealed multiple affected layers showing different structures/staining with approximately 140 μm thickness. Er:YAG laser irradiation used with water cooling resulted in minimal cementum ablation and thermal changes with a characteristic microstructure of the superficial layer. In contrast, CO(2) laser irradiation produced severely affected distinct multiple layers accompanied by melting and carbonization.

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

    PubMed

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

    2015-01-01

    A method is presented to evaluate the fractionation of metals (Fe, Zn, Cu, Pb, Cd and Ni), acid volatile sulfide (AVS) and simultaneously extracted metals (SEM) in Edku lagoon sediments. Thirteen sediment samples were collected from the study area in the period of 2010-2011 to assess the potential bioavailability and toxicity of the selected metals. According to classification of the Interim Sediment Quality Quidelines (ISQG), five stations near the drains exhibited 10% toxic probability. The high AVS and low ∑SEM ranges in Summer were identified as 6-138 and 0.86-3.3 µmol g(-1) dry wet, respectively which are referring to the low mobility of heavy metals in this season and vice versa for winter (2.5-23.9 and 1.16-3.82 µmol g(-1) dry wet, respectively). According to the evaluation of USEPA, all sediment samples showed ∑SEM/AVS < 1 and ΣSEM-AVS < 0 and this indicates that Edku lagoon sediments didn't cause any adverse effects. Meanwhile, the calculations of the global contamination factor (GCF) and the individual contamination factors (ICF) using fractionation technique gave values of 111.644 and 84.555 in El Bosily drain and station 1 near the cages of fish farm, respectively due to possible contamination. Interestingly, the collected data refer that the mobility and bioavailability of heavy metals in Edku lagoon sediments posed a low risk of adverse biological effects due to cadmium, copper, lead, nickel and zinc in all evaluated stations.

  11. Morphological and Structural Changes on Human Dental Enamel After Er:YAG Laser Irradiation: AFM, SEM, and EDS Evaluation

    PubMed Central

    Rodríguez-Vilchis, Laura Emma; Olea-Mejìa, Oscar Fernando; Sánchez-Flores, Ignacio; Centeno-Pedraza, Claudia

    2011-01-01

    Abstract Objective: The purpose of this study was to evaluate, using atomic force microscopy (AFM), scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS), the morphological and structural changes of the enamel after irradiation with the Er:YAG laser. Background data: A previous study showed that subablative Er:YAG laser irradiation produced undesirable morphological changes on the enamel surface, such as craters and cracks; however, the enamel acid resistance was not increased. Methods: Fifty-two samples of human enamel were divided into four groups (n = 13): Group I was the control (no laser irradiation), whereas Groups II, III, and IV were irradiated with the Er:YAG 100 mJ (12.7 J/cm2), 100 mJ (7.5 J/cm2), and 150 mJ (11 J/cm2), respectively, at 10 Hz with water spray. The morphological changes were observed by AFM and SEM. The weight percentages (wt%) of calcium (Ca), phosphorus (P), oxygen (O) and chlorine (Cl) were determined in the resultant craters and their periphery using EDS. Kruskal–Wallis and Mann–Whitney U tests were performed (p ≤ 0.05) to distinguish significant differences among the groups. Results: The AFM images showed cracks with depths between 250 nm and 750 nm for Groups II and IV, respectively, and the widths of these cracks were 5.37 μm and 2.58 μm. The interior of the cracks showed a rough surface. The SEM micrographs revealed morphological changes. Significant differences were detected in Ca, P, and Cl in the crater and its periphery. Conclusions: AFM observations showed triangular-shaped cracks, whereas craters and cracks were evident by SEM in all irradiated samples. It was not possible to establish a characteristic chemical pattern in the craters. PMID:21417912

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

    NASA Astrophysics Data System (ADS)

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

    2001-10-01

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

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

    PubMed

    House, Alisoun; Balkwill, Kevin

    2016-03-01

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

  14. Microhardness, chemical etching, SEM, AFM and SHG studies of novel nonlinear optical crystal -L-threonine formate

    SciTech Connect

    Hanumantha Rao, Redrothu; Kalainathan, S.

    2012-04-15

    Highlights: Black-Right-Pointing-Pointer Microhardness studies of novel LTF crystal reported first time in the literature. Black-Right-Pointing-Pointer Surface studies are done by AFM, chemical etching and SEM. Black-Right-Pointing-Pointer From SHG studies, it is known that LTF is potential NLO crystal. -- Abstract: The crystal L-threonine formate, an organic NLO crystal was synthesized from aqueous solution by slow evaporation technique. The grown crystal surface has been analyzed by scanning electron microscopy (SEM), chemical etching and atomic force microscopy (AFM). SEM analysis reveals pyramidal shaped minute crystallites on the growth surface. The etching study indicates the occurrence of etch pit patterns like striations and step like pattern. The mechanical properties of LTF crystals were evaluated by mechanical testing which reveals certain mechanical characteristics like elastic stiffness constant (C{sub 11}) and young's modulus (E). The Vickers and Knoop microhardness studies have been carried out on LTF crystals over a range of 10-50 g. Hardness anisotropy has been observed in accordance with the orientation of the crystal. AFM image shows major hillock on growth surface. The second harmonic generation (SHG) efficiency has been tested by the Kurtz powder technique using Nd:YAG laser and found to be about 1.21 times in comparison with standard potassium dihydrogen phosphate (KDP) crystals.

  15. A novel approach for FE-SEM imaging of wood-matrix polymer interface in a biocomposite.

    PubMed

    Singh, Adya P; Anderson, Ross; Park, Byung-Dae; Nuryawan, Arif

    2013-01-01

    Understanding the interface between polymer and biomass in composite products is important for developing high performance products, as the quality of adhesion at the interface determines composite properties. For example, with greater stiffness compared to polymer matrix, such as that of high density polyethylene, the wood component enhances stiffness of wood-polymer composites, provided there is good adhesion between composite components. However, in composites made from wood flour (wood particles) and synthetic resins it is often difficult to clearly resolve particle-matrix interfaces in the conventionally employed microscopy method that involves SEM examination of fractured faces of composites. We developed a novel approach, where composites made from high density polyethylene and wood flour were examined and imaged with a FE-SEM (field emission scanning electron microscope) in transverse sections cut through the composites. Improved definition of the interface was achieved using this approach, which enabled a more thorough comparison to be made of the features of the interface between wood particles and the matrix in composites with and without a coupling agent, as it was possible to clearly resolve the interfaces for particles of all sizes, from large particles consisting of many cells down to tiny cell wall fragments, particularly in composites that did not incorporate the coupling agent used to enhance particle adhesion with the matrix polymer. The method developed would be suitable particularly for high definition SEM imaging of a wide range of composites made combining wood and agricultural residues with synthetic polymers.

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

    PubMed Central

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

    2012-01-01

    While the effects of sexually explicit media (SEM) on heterosexuals’ sexual intentions and behaviors have been studied, little is known about the consumption and possible influence of SEM among men who have sex with men (MSM). Importantly, conceptual models of how Internet-based SEM influences behavior are lacking. Seventy-nine MSM participated in online focus groups about their SEM viewing preferences and sexual behavior. Twenty-three participants reported recent exposure to a new behavior via SEM. Whether participants modified their sexual intentions and/or engaged in the new behavior depended on three factors: arousal when imagining the behavior, pleasure when attempting the behavior, and trust between sex partners. Based on MSM’s experience, we advance a model of how viewing a new sexual behavior in SEM influences sexual intentions and behaviors. The model includes five paths. Three paths result in the maintenance of sexual intentions and behaviors. One path results in a modification of sexual intentions while maintaining previous sexual behaviors, and one path results in a modification of both sexual intentions and behaviors. With this model, researchers have a framework to test associations between SEM consumption and sexual intentions and behavior, and public health programs have a framework to conceptualize SEM-based HIV/STI prevention programs. PMID:23185126

  17. High-resolution 3D analyses of the shape and internal constituents of small volcanic ash particles: The contribution of SEM micro-computed tomography (SEM micro-CT)

    NASA Astrophysics Data System (ADS)

    Vonlanthen, Pierre; Rausch, Juanita; Ketcham, Richard A.; Putlitz, Benita; Baumgartner, Lukas P.; Grobéty, Bernard

    2015-02-01

    The morphology of small volcanic ash particles is fundamental to our understanding of magma fragmentation, and in transport modeling of volcanic plumes and clouds. Until recently, the analysis of 3D features in small objects (< 250 μm) was either restricted to extrapolations from 2D approaches, partial stereo-imaging, or CT methods having limited spatial resolution and/or accessibility. In this study, an X-ray computed-tomography technique known as SEM micro-CT, also called 3D X-ray ultramicroscopy (3D XuM), was used to investigate the 3D morphology of small volcanic ash particles (125-250 μm sieve fraction), as well as their vesicle and microcrystal distribution. The samples were selected from four stratigraphically well-established tephra layers of the Meerfelder Maar (West Eifel Volcanic Field, Germany). Resolution tests performed on a Beametr v1 pattern sample along with Monte Carlo simulations of X-ray emission volumes indicated that a spatial resolution of 0.65 μm was obtained for X-ray shadow projections using a standard thermionic SEM and a bulk brass target as X-ray source. Analysis of a smaller volcanic ash particle (64-125 μm sieve fraction) showed that features with volumes > 20 μm3 (~ 3.5 μm in diameter) can be successfully reconstructed and quantified. In addition, new functionalities of the Blob3D software were developed to allow the particle shape factors frequently used as input parameters in ash transport and dispersion models to be calculated. This study indicates that SEM micro-CT is very well suited to quantify the various aspects of shape in fine volcanic ash, and potentially also to investigate the 3D morphology and internal structure of any object < 0.1 mm3.

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

    NASA Astrophysics Data System (ADS)

    Clarke, Jamil J.

    2015-10-01

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

  19. Scanning electron microscope-cathodoluminescence (SEM-CL) imaging of planar deformation features and tectonic deformation lamellae in quartz

    NASA Astrophysics Data System (ADS)

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

    2011-12-01

    Planar deformation features (PDFs) in quartz are essential proof for the correct identification of meteorite impact structures and related ejecta layers, but can be confused with tectonic deformation lamellae. The only completely reliable method to demonstrate the shock origin of suspected (sub-) planar microstructures, transmission electron microscope (TEM) observations, is costly and time consuming. We have used a cathodoluminescence (CL) detector attached to a scanning electron microscope (SEM) to image both PDFs and tectonic deformation lamellae in quartz to demonstrate the potential of a simple method to identify PDFs and define characteristics that allow their distinction from tectonic deformation lamellae. In both limited wavelength grayscale and composite color SEM-CL images, PDFs are easily identified. They are straight, narrow, well-defined features, whereas tectonic deformation lamellae are thicker, slightly curved, and there is often no clear boundary between lamella and host quartz. Composite color images reveal two types of CL behavior in PDFs: either they emit a red to infrared CL signal or they are nonluminescent. The color of the CL signal emitted by tectonic deformation lamellae ranges from blue to red. For comparison, we also imaged several shocked quartz grains at cryogenic temperature. In most cases, the PDF characteristics in cryo-CL images do not differ significantly from those in images recorded at room temperature. We conclude that SEM-CL imaging, especially when color composites are used, provides a promising, practical, low cost, and nondestructive method to distinguish between PDFs and tectonic lamellae, even when the simplest CL techniques available are used.

  20. In vivo localization of manganese in the hyperaccumulator Gossia bidwillii (Benth.) N. Snow & Guymer (Myrtaceae) by cryo-SEM/EDAX.

    PubMed

    Fernando, Denise R; Batianoff, George N; Baker, Alan J; Woodrow, Ian E

    2006-05-01

    Gossia bidwillii (Myrtaceae) is a manganese (Mn)-hyperaccumulating tree native to subtropical eastern Australia. It typically contains foliar Mn levels in excess of 1% dry weight. However, in G. bidwillii and other Mn-hyperaccumulating species, the cellular and subcellular localization of Mn has not been measured. Quantitative in vivo cryo-scanning electron microscopy (SEM)/energy dispersive X-ray analysis (EDAX) was used to localize Mn and other elements in tissue collected from mature trees growing in a natural population. Cryo-SEM showed that the leaf mesophyll is differentiated as a double-layer palisade mesophyll above spongy mesophyll. Transmission electron microscopy (TEM) revealed that the palisade and epidermal cells are highly vacuolated. EDAX data were used to estimate in situ vacuolar Mn concentrations of all cell types in fresh cryo-fixed leaf tissues. The highest average vacuolar Mn concentration of over 500 mM was found in the upper-layer palisade mesophyll, while the lowest concentration of around 100 mM was found in the spongy mesophyll. Qualitative in vivo cryo-SEM/EDAX was employed to further investigate the spatial distribution of Mn in fresh leaf tissues and young bark tissue, which was also found to have a high Mn concentration. It is concluded that Mn distribution in G. bidwillii is quantitatively different to metal distribution in other hyperaccumulating species where the highest localized concentrations of these elements occur in non-photosynthmetic tissues such as epidermal cells and associated dermal structures including trichomes and leaf hairs.

  1. [Criteria for between-care-level referrals of patients with vascular disease. semFYC-SEACV consensus document].

    PubMed

    Bellmunt Montoya, Sergio; Díaz Sánchez, Santiago; Sánchez Nevárez, Ignacio; Fuentes Camps, Eva; Fernández Quesada, Fidel; Piquer Farrés, Nuria

    2012-09-01

    The Spanish Society of Family and Community Medicine (semFYC) and the Spanish Society of Angiology and Vascular Surgery (SEACV), through a Joint Working Group, have prepared a document on between care-level referrals of patients with the main vascular diseases; peripheral arterial disease, venous insufficiency, and diabetic foot. The responsibilities and skills required at each care level have been defined, as well as the criteria for mutual referral and how to prioritise them. The preparation of this consensus document attempt to provide an efficient tool that may ensure the continuity of health care, always respecting the specific characteristics and needs of each health care area.

  2. Rapid characterisation of archaeological midden components using FT-IR spectroscopy, SEM-EDX and micro-XRD.

    PubMed

    Shillito, Lisa-Marie; Almond, Matthew J; Nicholson, James; Pantos, Manolis; Matthews, Wendy

    2009-07-01

    Samples taken from middens at the Neolithic site of Catalhöyük in Turkey have been analysed using IR spectroscopy backed up by powder XRD and SEM-EDX. Microcomponents studied include fossil hackberries (providing evidence of ancient diet and seasonality), mineral nodules (providing evidence of post-depositional change) and phytoliths (mineralised plant cells, providing evidence of usage of plant species). Finely laminated ashy deposits have also been investigated allowing chemical and mineralogical variations to be explored. It is found that many layers which appear visually to be quite distinctive have, in fact, very similar mineralogy.

  3. SEM-EDS-Based Elemental Identification on the Enamel Surface after the Completion of Orthodontic Treatment: In Vitro Studies

    PubMed Central

    Seeliger, Julia; Lipski, Mariusz; Wójcicka, Anna; Gedrange, Tomasz; Woźniak, Krzysztof

    2016-01-01

    Braces as foreign bodies in the mouth carry a risk of side effects and toxicity to the human body. This article presents the results indicating the possible toxic effects of tools used for cleaning the enamel after the completion of orthodontic treatment. The studies were carried out in vitro. The procedure of enamel etching, bonding orthodontic metal brackets, and enamel cleaning after their removal was performed under laboratory conditions. The enamel microstructure and elements present on its surface were evaluated using the scanning electron microscope (SEM). Silicon and aluminium were found in addition to the tooth building elements. PMID:27766265

  4. Development of a pattern to measure multiscale deformation and strain distribution via in situ FE-SEM observations.

    PubMed

    Tanaka, Y; Naito, K; Kishimoto, S; Kagawa, Y

    2011-03-18

    We investigated a method for measuring deformation and strain distribution in a multiscale range from nanometers to millimeters via in situ FE-SEM observations. A multiscale pattern composed of a grid as well as random and nanocluster patterns was developed to measure the localized deformation at the specimen surface. Our in situ observations of a carbon fiber-reinforced polymer matrix composite with a hierarchical microstructure subjected to loading were conducted to identify local deformation behaviors at various boundaries. We measured and analyzed the multiscale deformation and strain localizations during various stages of loading.

  5. Relation of expansion due to alkali silica reaction to the degree of reaction measured by SEM image analysis

    SciTech Connect

    Haha, M. Ben; Gallucci, E. Guidoum, A.; Scrivener, K.L.

    2007-08-15

    Scanning Electron Microscopy Image Analysis (SEM-IA) was used to quantify the degree of alkali silica reaction in affected microbars, mortar and concrete prisms. It was found that the degree of reaction gave a unique correlation with the macroscopic expansion for three different aggregates, stored at three temperatures and with two levels of alkali. The relationships found for the concretes and the mortars overlap when normalised by the aggregate content. This relationship seems to be linear up to a critical reaction degree which coincides with crack initiation within the reactive aggregates.

  6. A large dataset of synthetic SEM images of powder materials and their ground truth 3D structures.

    PubMed

    DeCost, Brian L; Holm, Elizabeth A

    2016-12-01

    This data article presents a data set comprised of 2048 synthetic scanning electron microscope (SEM) images of powder materials and descriptions of the corresponding 3D structures that they represent. These images were created using open source rendering software, and the generating scripts are included with the data set. Eight particle size distributions are represented with 256 independent images from each. The particle size distributions are relatively similar to each other, so that the dataset offers a useful benchmark to assess the fidelity of image analysis techniques. The characteristics of the PSDs and the resulting images are described and analyzed in more detail in the research article "Characterizing powder materials using keypoint-based computer vision methods" (B.L. DeCost, E.A. Holm, 2016) [1]. These data are freely available in a Mendeley Data archive "A large dataset of synthetic SEM images of powder materials and their ground truth 3D structures" (B.L. DeCost, E.A. Holm, 2016) located at http://dx.doi.org/10.17632/tj4syyj9mr.1[2] for any academic, educational, or research purposes.

  7. The effect of CO2 and Nd:YAP lasers on CAD/CAM Ceramics: SEM, EDS and thermal studies

    PubMed Central

    Fornaini, Carlo; Rocca, Jean Paul; Muhammad, Omid H; Medioni, Etienne; Cucinotta, Annamaria; Brulat-Bouchard, Nathalie

    2016-01-01

    Background and aims: The objective of this study was to investigate the interaction of infrared laser light on Computer Aided Design and Computer Aided Manufacturing (CAD/CAM) ceramic surfaces. Material and Methods: Sixty CAD/CAM ceramic discs were prepared and divided into two different groups: lithiumdisilicate ceramic (IPSe.maxCADs) and Zirconia ceramic (IPSe.maxZirCADs). The laser irradiation was performed on graphite and non-graphite surfaces with a Carbon Dioxide laser at 5W and 10W power in continuous mode (CW mode) and with Neodymium Yttrium Aluminum Perovskite (Nd:YAP) laser at 10W. Surface textures and compositions were examined using Scanning Electron Microscopy (SEM), and Energy Dispersive Spectroscopy (EDS). Thermal elevation was measured by thermocouple during laser irradiation. Results: The SEM observation showed a rough surface plus cracks and fissures on CO2 10W samples and melting areas in Nd:YAP samples; moreover, with CO2 5W smooth and shallow surfaces were observed. EDS analysis revealed that laser irradiation does not result in modifications of the chemical composition even if minor changes in the atomic mass percentage of the components were registered. Thermocouple showed several thermal changes during laser irradiation. Conclusion: CO2 and Nd:YAP lasers modify CAD/CAM ceramic surface without chemical composition modifications. PMID:27141152

  8. Seeing a Mycobacterium-Infected Cell in Nanoscale 3D: Correlative Imaging by Light Microscopy and FIB/SEM Tomography.

    PubMed

    Beckwith, Marianne Sandvold; Beckwith, Kai Sandvold; Sikorski, Pawel; Skogaker, Nan Tostrup; Flo, Trude Helen; Halaas, Øyvind

    2015-01-01

    Mycobacteria pose a threat to the world health today, with pathogenic and opportunistic bacteria causing tuberculosis and non-tuberculous disease in large parts of the population. Much is still unknown about the interplay between bacteria and host during infection and disease, and more research is needed to meet the challenge of drug resistance and inefficient vaccines. This work establishes a reliable and reproducible method for performing correlative imaging of human macrophages infected with mycobacteria at an ultra-high resolution and in 3D. Focused Ion Beam/Scanning Electron Microscopy (FIB/SEM) tomography is applied, together with confocal fluorescence microscopy for localization of appropriately infected cells. The method is based on an Aclar poly(chloro-tri-fluoro)ethylene substrate, micropatterned into an advantageous geometry by a simple thermomoulding process. The platform increases the throughput and quality of FIB/SEM tomography analyses, and was successfully applied to detail the intracellular environment of a whole mycobacterium-infected macrophage in 3D.

  9. The effects of extracts of chewing sticks (Salvadora persica) on healthy and periodontally involved human dentine: a SEM study.

    PubMed

    Almas, K

    2001-01-01

    The popularity and availability of chewing sticks (Salvadora persica) in the Asia, Middle East and Africa make them a commonly used oral hygiene tool in those societies. Salvador persica chewing stick called miswak is frequently used in Saudi Arabia. The antimicrobial effects of miswak has been well documented. The aim of this study is to find our the effect of aqueous extracts of miswak on healthy and periodontally involved human dentine with Scanning Electron Microscopy (SEM) in vitro. 25% aqueous extract of freshly prepared miswak solution was used for the study. Twelve human premolars teeth (6 healthy and 6 with periodontal disease) recently extracted for orthodontic and periodontal reasons were used. 24 SEM specimens were prepared and treated with miswak extract with different conditions e.g. soaking and burnishing with miswak extract. Soaking the healthy and periodontally diseased root dentine in miswak extract resulted in partial removal of smear layer and occlusion of dentinal tubules was observed in dentine specimens burnished with miswak solution. Further research is needed to evaluate the effect of aqueous extract of miswak on etched human dentine at higher concentrations.

  10. Oxidative alteration of spent fuel in a silica-rich environment: SEM/AEM investigation and geochemical modeling

    SciTech Connect

    WANG,YIFENG; XU,HUIFANG

    2000-03-14

    Correctly identifying the possible alteration products and accurately predicting their occurrence in a repository-relevant environment are the key for the source-term calculation in a repository performance assessment. Uraninite in uranium deposits has long been used as a natural analog to spent fuel in a repository because of their chemical and structural similarity. In this paper, a SEM/AEM investigation has been conducted on a partially alternated uraninite sample from a uranium ore deposit of Shinkolobwe of Congo. The mineral formation sequences were identified: uraninite {yields} uranyl hydrates {yields} uranyl silicates {yields} Ca-uranyl silicates or uraninite {yields} uranyl silicates {yields} Ca-uranyl silicates. Reaction-path calculations were conducted for the oxidative dissolution of spent fuel in a representative Yucca Mountain groundwater. The predicted sequence is in general consistent with the SEM observations. The calculations also show that uranium carbonate minerals are unlikely to become major solubility-controlling mineral phases in a Yucca Mountain environment. Some discrepancies between model predictions and field observations are observed. Those discrepancies may result from poorly constrained thermodynamic data for uranyl silicate minerals.

  11. Production of calcite nanocrystal by a urease-positive strain of enterobacter ludwigii and study of its structure by SEM.

    PubMed

    Ghashghaei, Sara; Emtiazi, Giti

    2013-10-01

    The present research aimed at evaluating the effects of urease enzyme and increasing pH on calcite nanocrystal formation. Unlike some researches, the results showed that CaCO3 precipitation is not a general phenomenon among the bacteria and if a bacterium has not this ability, it will not be able to produce calcite even with an increase in pH. All urease-positive bacteria had this ability, while only some urease-negative bacteria were able to produce calcite. Production and characterization of nanocrystals on precipitating medium were shown primarily by light microscopy and then confirmed by X-ray diffraction (XRD) analysis. Crystallite particle size was determined using Scherrer formula that was sub-100-nm in all samples. Based on qualitative and quantitative studies, strain C8 was selected as the best calcite-producing strain. Phylogenetic analysis indicated that this isolate has 99 % similarity with Enterobacter ludwigii. 16S rRNA sequence of isolate was deposited in GenBank with accession number JX666242. The morphology and exact composition of nanocrystalline particles were determined using scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX). According to data obtained by SEM, we suggest that nanocrystals of CaCO3 adhere to bacteria and each other to form small aggregates and then complex crystalline networks to trap bacteria. Many holes are present in these crystalline networks that seem to be due to the aggregation of nanocrystals.

  12. Short range shooting distance estimation using variable pressure SEM images of the surroundings of bullet holes in textiles.

    PubMed

    Hinrichs, Ruth; Frank, Paulo Ricardo Ost; Vasconcellos, M A Z

    2017-03-01

    Modifications of cotton and polyester textiles due to shots fired at short range were analyzed with a variable pressure scanning electron microscope (VP-SEM). Different mechanisms of fiber rupture as a function of fiber type and shooting distance were detected, namely fusing, melting, scorching, and mechanical breakage. To estimate the firing distance, the approximately exponential decay of GSR coverage as a function of radial distance from the entrance hole was determined from image analysis, instead of relying on chemical analysis with EDX, which is problematic in the VP-SEM. A set of backscattered electron images, with sufficient magnification to discriminate micrometer wide GSR particles, was acquired at different radial distances from the entrance hole. The atomic number contrast between the GSR particles and the organic fibers allowed to find a robust procedure to segment the micrographs into binary images, in which the white pixel count was attributed to GSR coverage. The decrease of the white pixel count followed an exponential decay, and it was found that the reciprocal of the decay constant, obtained from the least-square fitting of the coverage data, showed a linear dependence on the shooting distance.

  13. Inorganic composition and filler particles morphology of conventional and self-adhesive resin cements by SEM/EDX.

    PubMed

    Aguiar, Thaiane Rodrigues; Di Francescantonio, Marina; Bedran-Russo, Ana Karina; Giannini, Marcelo

    2012-10-01

    The purpose of this study was to characterize the inorganic components and morphology of filler particles of conventional and self-adhesive, dual-curing, resin luting cements. The main components were identified by energy dispersive X-ray spectroscopy microanalysis (EDX), and filler particles were morphologically analyzed by scanning electron microscopy (SEM). Four resin cements were used in this study: two conventional resin cements (RelyX ARC/3M ESPE and Clearfil Esthetic Cement/Kuraray Medical) and two self-adhesive resin cements (RelyX Unicem/3M ESPE and Clearfil SA Luting/Kuraray Medical). The materials (n = 5) were manipulated according to manufacturers' instructions, immersed in organic solvents to eliminate the organic phase and observed under SEM/EDX. Although EDX measurements showed high amount of silicon for all cements, differences in elemental composition of materials tested were identified. RelyX ARC showed spherical and irregular particles, whereas other cements presented only irregular filler shape. In general, self-adhesive cements contained higher filler size than conventional resin luting cements. The differences in inorganic components and filler particles were observed between categories of luting material and among them. All resin cements contain silicon, however, other components varied among them.

  14. Three-Phase 3D Reconstruction of a LiCoO2 Cathode via FIB-SEM Tomography.

    PubMed

    Liu, Zhao; Chen-Wiegart, Yu-Chen K; Wang, Jun; Barnett, Scott A; Faber, Katherine T

    2016-02-01

    Three-phase three-dimensional (3D) microstructural reconstructions of lithium-ion battery electrodes are critical input for 3D simulations of electrode lithiation/delithiation, which provide a detailed understanding of battery operation. In this report, 3D images of a LiCoO2 electrode are achieved using focused ion beam-scanning electron microscopy (FIB-SEM), with clear contrast among the three phases: LiCoO2 particles, carbonaceous phases (carbon and binder) and the electrolyte space. The good contrast was achieved by utilizing an improved FIB-SEM sample preparation method that combined infiltration of the electrolyte space with a low-viscosity silicone resin and triple ion-beam polishing. Morphological parameters quantified include phase volume fraction, surface area, feature size distribution, connectivity, and tortuosity. Electrolyte tortuosity was determined using two different geometric calculations that were in good agreement. The electrolyte tortuosity distribution versus position within the electrode was found to be highly inhomogeneous; this will lead to inhomogeneous electrode lithiation/delithiation at high C-rates that could potentially cause battery degradation.

  15. Three-Phase 3D Reconstruction of a LiCoO2 Cathode via FIB-SEM Tomography

    DOE PAGES

    Liu, Zhao; Chen-Wiegart, Yu-chen K.; Wang, Jun; ...

    2016-01-14

    Three-phase three-dimensional (3D) microstructural reconstructions of lithium-ion battery electrodes are critical input for 3D simulations of electrode lithiation/delithiation, which provide a detailed understanding of battery operation. In this report, 3D images of a LiCoO2electrode are achieved using focused ion beam-scanning electron microscopy (FIB-SEM), with clear contrast among the three phases: LiCoO2particles, carbonaceous phases (carbon and binder) and the electrolyte space. The good contrast was achieved by utilizing an improved FIB-SEM sample preparation method that combined infiltration of the electrolyte space with a low-viscosity silicone resin and triple ion-beam polishing. Morphological parameters quantified include phase volume fraction, surface area, feature sizemore » distribution, connectivity, and tortuosity. Electrolyte tortuosity was determined using two different geometric calculations that were in good agreement. In conclusion, the electrolyte tortuosity distribution versus position within the electrode was found to be highly inhomogeneous; this will lead to inhomogeneous electrode lithiation/delithiation at high C-rates that could potentially cause battery degradation.« less

  16. Seeing a Mycobacterium-Infected Cell in Nanoscale 3D: Correlative Imaging by Light Microscopy and FIB/SEM Tomography

    PubMed Central

    Beckwith, Marianne Sandvold; Beckwith, Kai Sandvold; Sikorski, Pawel; Skogaker, Nan Tostrup

    2015-01-01

    Mycobacteria pose a threat to the world health today, with pathogenic and opportunistic bacteria causing tuberculosis and non-tuberculous disease in large parts of the population. Much is still unknown about the interplay between bacteria and host during infection and disease, and more research is needed to meet the challenge of drug resistance and inefficient vaccines. This work establishes a reliable and reproducible method for performing correlative imaging of human macrophages infected with mycobacteria at an ultra-high resolution and in 3D. Focused Ion Beam/Scanning Electron Microscopy (FIB/SEM) tomography is applied, together with confocal fluorescence microscopy for localization of appropriately infected cells. The method is based on an Aclar poly(chloro-tri-fluoro)ethylene substrate, micropatterned into an advantageous geometry by a simple thermomoulding process. The platform increases the throughput and quality of FIB/SEM tomography analyses, and was successfully applied to detail the intracellular environment of a whole mycobacterium-infected macrophage in 3D. PMID:26406896

  17. Testicular microvascularization in the common tree shrew (Tupaia glis) as revealed by vascular corrosion cast/SEM and by TEM.

    PubMed

    Pradidarcheep, W; Kongstaponkit, S; Waraklang, P; Chunhabundit, P; Somana, R

    1998-08-01

    Testicular angioarchitecture in lower primates has not been established and the route of androgens from Leydig cells entering the systemic circulation is still a matter of controversy. In the present study, the common tree shrew (Tupaia glis) was used as the model for vascular corrosion cast/SEM and conventional TEM studies. With vascular corrosion cast/SEM, it was revealed that while coursing in the spermatic cord, the testicular artery convoluted and gave off branches to supply the epididymis, the coverings of the spermatic cord and the pampiniform plexus. Upon approaching the testis, it encircled the organ, then penetrated into the testicular parenchyma near the rostro-medial pole before further dividing into arterioles that gave rise to capillary plexuses looping around the seminiferous tubules. These capillaries converged into the intratesticular venules, then into larger venules on ventral and dorsal surfaces of the testis and finally into the collecting veins on medial and lateral borders of the testis. In addition, the capillaries in the central or medullary portion of the gland collected the blood into the medullary venules and central (medullary) vein, respectively. The collecting veins as well as central vein joined together before dividing into pampiniform plexus. With transmission electron microscopy, the capillaries in the testis were shown to be of the thick basement membrane and continuous type. The Leydig cells were found adjacent to lymphatic vessels among the seminiferous tubules. This structure is compatible with the idea that most of the androgens drain into the lymphatic vessels rather than into the capillaries.

  18. Advanced Characterization Techniques for Nanoparticles for Cancer Research: Applications of SEM and NanoSIMS for Locating Au Nanoparticles in Cells

    PubMed Central

    Kempen, Paul J; Hitzman, Chuck; Sasportas, Laura S; Gambhir, Sanjiv S; Sinclair, Robert

    2014-01-01

    The ability of nano secondary ion mass spectrometry (NanoSIMS) to locate and analyze Raman active gold core nanoparticles (R-AuNPs) in a biological system is compared with the standard analysis using the scanning electron microscope (SEM). The same cell with R-AuNPs on and inside the macrophage was analyzed with both techniques to directly compare them. SEM analysis showed a large number of nanoparticles within the cell. Subsequent NanoSIMS analysis showed fewer R-AuNPs with lower spatial resolution. SEM was determined to be superior to NanoSIMS for the analysis of inorganic nanoparticles in complex biological systems. PMID:25364091

  19. Advanced Characterization Techniques for Nanoparticles for Cancer Research: Applications of SEM and NanoSIMS for Locating Au Nanoparticles in Cells.

    PubMed

    Kempen, Paul J; Hitzman, Chuck; Sasportas, Laura S; Gambhir, Sanjiv S; Sinclair, Robert

    2013-05-13

    The ability of nano secondary ion mass spectrometry (NanoSIMS) to locate and analyze Raman active gold core nanoparticles (R-AuNPs) in a biological system is compared with the standard analysis using the scanning electron microscope (SEM). The same cell with R-AuNPs on and inside the macrophage was analyzed with both techniques to directly compare them. SEM analysis showed a large number of nanoparticles within the cell. Subsequent NanoSIMS analysis showed fewer R-AuNPs with lower spatial resolution. SEM was determined to be superior to NanoSIMS for the analysis of inorganic nanoparticles in complex biological systems.

  20. Young's modulus and SEM analysis of leg bones exposed to simulated microgravity by hind limb suspension (HLS)

    SciTech Connect

    Patel, Niravkumar D.; Mehta, Rahul; Ali, Nawab; Soulsby, Michael; Chowdhury, Parimal

    2013-04-19

    The aim of this study was to determine composition of the leg bone tissue of rats that were exposed to simulated microgravity by Hind-Limb Suspension (HLS) by tail for one week. The leg bones were cross sectioned, cleaned of soft tissues, dried and sputter coated, and then placed horizontally on the stage of a Scanning Electron Microscope (SEM) for analysis. Interaction of a 17.5 keV electron beam, incident from the vertical direction on the sample, generated images using two detectors. X-rays emitted from the sample during electron bombardment were measured with an Energy Dispersive Spectroscopy (EDS) feature of SEM using a liquid-nitrogen cooled Si(Li) detector with a resolution of 144 eV at 5.9 keV ({sub 25}Mn K{sub {alpha}} x-ray). K{sub {alpha}}- x-rays from carbon, oxygen, phosphorus and calcium formed the major peaks in the spectrum. Relative percentages of these elements were determined using a software that could also correct for ZAF factors namely Z(atomic number), A(X-ray absorption) and F(characteristic fluorescence). The x-rays from the control groups and from the experimental (HLS) groups were analyzed on well-defined parts (femur, tibia and knee) of the leg bone. The SEM analysis shows that there are definite changes in the hydroxyl or phosphate group of the main component of the bone structure, hydroxyapatite [Ca{sub 10}(PO{sub 4}){sub 6}(OH){sub 2}], due to hind limb suspension. In a separate experiment, entire leg bones (both from HLS and control rats) were subjected to mechanical stress by mean of a variable force. The stress vs. strain graph was fitted with linear and polynomial function, and the parameters reflecting the mechanical strength of the bone, under increasing stress, were calculated. From the slope of the linear part of the graph the Young's modulus for HLS bones were calculated and found to be 2.49 times smaller than those for control bones.

  1. Young's modulus and SEM analysis of leg bones exposed to simulated microgravity by hind limb suspension (HLS)

    NASA Astrophysics Data System (ADS)

    Patel, Niravkumar D.; Mehta, Rahul; Ali, Nawab; Soulsby, Michael; Chowdhury, Parimal

    2013-04-01

    The aim of this study was to determine composition of the leg bone tissue of rats that were exposed to simulated microgravity by Hind-Limb Suspension (HLS) by tail for one week. The leg bones were cross sectioned, cleaned of soft tissues, dried and sputter coated, and then placed horizontally on the stage of a Scanning Electron Microscope (SEM) for analysis. Interaction of a 17.5 keV electron beam, incident from the vertical direction on the sample, generated images using two detectors. X-rays emitted from the sample during electron bombardment were measured with an Energy Dispersive Spectroscopy (EDS) feature of SEM using a liquid-nitrogen cooled Si(Li) detector with a resolution of 144 eV at 5.9 keV (25Mn Kα x-ray). Kα- x-rays from carbon, oxygen, phosphorus and calcium formed the major peaks in the spectrum. Relative percentages of these elements were determined using a software that could also correct for ZAF factors namely Z(atomic number), A(X-ray absorption) and F(characteristic fluorescence). The x-rays from the control groups and from the experimental (HLS) groups were analyzed on well-defined parts (femur, tibia and knee) of the leg bone. The SEM analysis shows that there are definite changes in the hydroxyl or phosphate group of the main component of the bone structure, hydroxyapatite [Ca10(PO4)6(OH)2], due to hind limb suspension. In a separate experiment, entire leg bones (both from HLS and control rats) were subjected to mechanical stress by mean of a variable force. The stress vs. strain graph was fitted with linear and polynomial function, and the parameters reflecting the mechanical strength of the bone, under increasing stress, were calculated. From the slope of the linear part of the graph the Young's modulus for HLS bones were calculated and found to be 2.49 times smaller than those for control bones.

  2. Characterization of minerals in air dust particles in the state of Tamilnadu, India through FTIR, XRD and SEM analyses

    NASA Astrophysics Data System (ADS)

    Senthil Kumar, R.; Rajkumar, P.

    2014-11-01

    The abstract of this paper explains the presence of minerals in air which causes great concern regarding public health issues. The spectroscopic investigation of air dust particles of several samples in various locations in the state of Tamilnadu, India is reported. Qualitative analyses were carried out to determine the major and minor constituent minerals present in the samples based on the FTIR, XRD absorption peaks. This study also identified the minerals like quartz, asbestos, kaolinite, calcite, hematite, montmorillonite, nacrite and several other trace minerals in the air dust particles. The presents of quartz is mainly found in all the samples invariably. Hence the percentage of quartz and its crystalline nature were determined with the help of extinction co-efficient and crystallinity index respectively. The shape and size of the particulates are studied with SEM analysis.

  3. Investigation of structural resorption behavior of biphasic bioceramics with help of gravimetry, μCT, SEM, and XRD.

    PubMed

    de Wild, Michael; Amacher, Fabienne; Bradbury, Christopher R; Molenberg, Aart

    2016-04-01

    Resorbable bone substitute materials are widely used for bone augmentation after tumor resection, parallel to implant placement, or in critical size bone defects. In this study, the structural dissolution of a biphasic calcium phosphate bone substitute material with a hydroxyapatite (HA)/tricalcium phosphate (β-TCP) ratio of 60/40 was investigated by repeatedly placing porous blocks in EDTA solution at 37 °C. At several time points, the blocks were investigated by SEM, µCT, and gravimetry. It was found that always complete 2-3 µm sized grains were removed from the structure and that the β-TCP is dissolved more rapidly. This selective dissolution of the β-TCP grains was confirmed by XRD measurements. The blocks were eroded from the outside toward the center. The structure remained mechanically stable because the central part showed a delayed degradation and because the slower dissolving HA grains preserved the integrity of the structure.

  4. SEM in situ MiniCantilever Beam Bending of U-10Mo/Zr/Al Fuel Elements

    SciTech Connect

    Mook, William; Baldwin, Jon K.; Martinez, Ricardo M.; Mara, Nathan A.

    2014-06-16

    In this work, the fracture behavior of Al/Zr and Zr/dU-10Mo interfaces was measured via the minicantilever bend technique. The energy dissipation rates were found to be approximately 3.7-5 mj/mm2 and 5.9 mj/mm2 for each interface, respectively. It was found that in order to test the Zr/U-10Mo interface, location of the hinge of the cantilever was a key parameter. While this test could be adapted to hot cell use through careful alignment fixturing and measurement of crack lengths with an optical microscope (as opposed to SEM, which was used here out of convenience), machining of the cantilevers via MiniMill in such a way as to locate the interfaces at the cantilever hinge, as well as proper placement of a femtosecond laser notch will continue to be key challenges in a hot cell environment.

  5. Furthering Chemical and Geophysical Computations: Analysis of SACROC SEM and CT images to obtain pore percentage, size, and connectivity data

    NASA Astrophysics Data System (ADS)

    Mur, A. J.; Purcell, C. C.; Harbert, W. P.; Soong, Y.; Kutchko, B. G.; Kennedy, S.; McIntryre, D.

    2009-12-01

    The National Energy Technology Laboratory of the United States Department of Energy, in collaboration with the Bureau of Economic Geology in Austin, Texas has been involved in an extensive study of the many aspects involved in the injection of CO2 into the 2042 meter deep Permian reef structure at the SACROC field. Subsamples of reef limestone cores used for seismic velocity measurements were obtained. XRD determined the sample to be ~99% Calcite and ~1% Dolomite with a small amount of impurities. Preliminary petrographic slides revealed a vuggy porosity. We acquired CT scans of a SACROC limestone core at the Morgantown NETL site. We also acquired a high pixel resolution (112 MB) SEM secondary electron image of the reef limestone at RJ Lee Group. By using ArcMap , we created a tool that groups grayscale ranges into three categories, cleans boundaries between groups, and produces a polygon map of the macropores, micropores, and matrix. The darkest areas in the SEM image were cavern-like pores and were thus called macropores. Micropores, the brightest regions, are textured micrite faces that create many, small pore spaces. Using ImageJ, the CT and Arc pore maps were analyzed to reveal pore shape statistics. Average pore perimeter, average pore area, and pore connectivity is essential for chemistry experiments that will emulate time exposure of CO2 to limestone. Further, ImageJ allows us to obtain pore orientation information. This is important in understanding the anisotropic conditions that may or may not affect seismic data. The image is 10240x11264 pixels which correspond to ~ 8890.00x9780.00 micrometers. Micro- and macropores combined, there were 613744 pores mapped. Differing statistical methods revealed differing results. For example, the average pore perimeter was ~28 microns while the average pore area was <1 square micron. This inconsistency is due to pores sharing boundaries, being contained by one another, or being lighter colored crystals. We used two

  6. In situ electromigration damage in Al interconnect lines in the SEM and the influence of grain orientation

    SciTech Connect

    Buerke, Axel; Wendrock, Horst; Wetzig, Klaus

    1999-11-03

    Unpassivated AlSiCu interconnects (thickness 1 {mu}m, width 8 and 1.4 {mu}m, on SiO{sub 2}) were tested for electromigration in situ in the SEM under accelerated loading conditions. To examine the influence of grain orientation on electromigration damage, orientation mapping of the interconnects was carried out prior to testing using the EBSD technique (Electron BackScatter Diffraction or Backscatter Kikuchi Pattern). Damage micrographs and orientation data were correlated with respect to microstructure (polycrystalline/bamboo), deviation from <111> fibre texture and grain boundary properties (axis/angle, CSL model). It was found that not the deviation from <111> fibre texture, but the misorientation class of individual grain boundaries and their course in relation to the current direction are decisive factors for the damage location where the fatal defects occur.

  7. Combined FTIR and SEM-EDS study of Bi2O3 doped ZnO-SnO2 ceramics.

    PubMed

    Ivetić, T; Nikolić, M V; Paraskevopoulos, K M; Pavlidou, E; Zorba, T T; Nikolić, P M; Ristić, M M

    2008-12-01

    The effects of Bi(2)O(3) addition on the phase composition, microstructure and optical properties of ZnO-SnO(2) ceramics were investigated. Starting powders of ZnO and SnO(2) were mixed in the molar ratio 2:1. After adding Bi(2)O(3) (1.0 mol.%) this mixture was mechanically activated for 10 min in a planetary ball mill, uniaxially pressed and sintered at 1300 degrees C for 2 h. Far-infrared reflection spectra were measured (100-1000 cm(-1)). To investigate the occurred differences in FTIR spectra, the Bi(2)O(3)-doped sample was examined more carefully with a Perkin-Elmer FTIR spectrometer (Perkin Elmer, Waltham, MA, USA) connected with a Perkin-Elmer FTIR microscope and itemized points of interest were also studied with SEM-EDS.

  8. Utilization of profilometry, SEM, AFM and contact angle measurements in describing surfaces of plastic floor coverings and explaining their cleanability

    NASA Astrophysics Data System (ADS)

    Kuisma, R.; Pesonen-Leinonen, E.; Redsven, I.; Kymäläinen, H.-R.; Saarikoski, I.; Sjöberg, A.-M.; Hautala, M.

    2005-06-01

    The tendency to soil and cleanability of ten commercial plastic floor coverings: eight vinyl (PVC) floor coverings, one vinyl composite tile and one plastic composite tile, were examined. Floor coverings were soiled with inorganic, organic and biological soil. The cleanability was measured both by bioluminescence of ATP (adenosine triphosphate) and colorimetrically. The surface topography was studied by AFM, SEM and with a profilometer. From the 2D- and 3D-profilometric measurements several characteristic parameters of the surface profiles were extracted. The tendency to soil and cleanability were compared with the characteristics of the surface. A weak correlation was found between roughness and soilability but no correlation between roughness and cleanability. Roughness had no correlation with contact angle.

  9. Distribution of coniferin in freeze-fixed stem of Ginkgo biloba L. by cryo-TOF-SIMS/SEM

    NASA Astrophysics Data System (ADS)

    Aoki, Dan; Hanaya, Yuto; Akita, Takuya; Matsushita, Yasuyuki; Yoshida, Masato; Kuroda, Katsushi; Yagami, Sachie; Takama, Ruka; Fukushima, Kazuhiko

    2016-08-01

    To clarify the role of coniferin in planta, semi-quantitative cellular distribution of coniferin in quick-frozen Ginkgo biloba L. (ginkgo) was visualized by cryo time-of-flight secondary ion mass spectrometry and scanning electron microscopy (cryo-TOF-SIMS/SEM) analysis. The amount and rough distribution of coniferin were confirmed through quantitative chromatography measurement using serial tangential sections of the freeze-fixed ginkgo stem. The lignification stage of the sample was estimated using microscopic observations. Coniferin distribution visualized at the transverse and radial surfaces of freeze-fixed ginkgo stem suggested that coniferin is stored in the vacuoles, and showed good agreement with the assimilation timing of coniferin to lignin in differentiating xylem. Consequently, it is suggested that coniferin is stored in the tracheid cells of differentiating xylem and is a lignin precursor.

  10. Combined SEM/EDX and micro-Raman spectroscopy analysis of uranium minerals from a former uranium mine.

    PubMed

    Stefaniak, Elzbieta A; Alsecz, Anita; Frost, Ray; Máthé, Zoltán; Sajó, István E; Török, Szabina; Worobiec, Anna; Van Grieken, René

    2009-08-30

    Samples of the secondary uranium minerals collected in the abandoned uranium mine at Pecs (Hungary) were investigated by two micro-techniques: scanning electron microscopy (SEM/EDX) and micro-Raman spectroscopy (MRS). They were applied to locate U-rich particles and identify the chemical form and oxidation state of the uranium compounds. The most abundant mineral was a K and/or Na uranyl sulphate (zippeite group). U(VI) was also present in the form showing intensive Raman scattering at 860 cm(-1) which can be attributed to uranium trioxide. This research has shown the successful application of micro-Raman spectroscopy for the identification of uranyl mineral species on the level of individual particles.

  11. Analysis on micro-regional characters of the resistance wires surface in electrical immersion heater by SEM/EDX.

    PubMed

    Gu, Haixin; Xue, Lin; Zhang, Yongfeng; Cao, Liying; Ding, Minju; Huang, Hao; Bao, Renlie

    2014-05-01

    We present a novel method for identifying the conditions of electrical resistance wires before fire basing on micro-regional characters. The morphology and elemental compositions of resistance wires surface under normally used, misused and external heating conditions were respectively studied by scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX). The results show that the normally used wire has a smooth surface and stable metal composition. While the resistance wire under misused condition for the certain time could be characterized as a coarse surface covered by compacted and silica-embedded oxide layer, and the proportion of elemental compositions of different metals is also changed with higher content of Al and lower content of Fe and Cr. The external heating condition has little influence on inside wires. The mechanism of changes formed under misused condition was explained. We demonstrate that this approach is practical and functional to aid fire investigators in determining the cause of related fires.

  12. SEM-EDS Analyses of Small Craters in Stardust Aluminum Foils: Implications for the Wild-2 Dust Distribution

    NASA Technical Reports Server (NTRS)

    Borg, J.; Horz, F.; Bridges, J. C.; Burchell, M. J.; Djouadi, Z.; Floss, C.; Graham, G. A.; Green, S. F.; Heck, P. R.; Hoppe, P.; Huth, J.; Kearsley, A; Leroux, H.; Marhas, K.; Stadermann, F. J.; Teslich, N.

    2007-01-01

    Aluminium foils were used on Stardust to stabilize the aerogel specimens in the modular collector tray. Part of these foils were fully exposed to the flux of cometary grains emanating from Wild 2. Because the exposed part of these foils had to be harvested before extraction of the aerogel, numerous foil strips some 1.7 mm wide and 13 or 33 mm long were generated during Stardusts's Preliminary Examination (PE). These strips are readily accommodated in their entirety in the sample chambers of modern SEMs, thus providing the opportunity to characterize in situ the size distribution and residue composition - employing EDS methods - of statistically more significant numbers of cometary dust particles compared to aerogel, the latter mandating extensive sample preparation. We describe here the analysis of nearly 300 impact craters and their implications for Wild 2 dust.

  13. Surface-enhanced molecular spectroscopy (SEMS) based on perfect-absorber metamaterials in the mid-infrared

    NASA Astrophysics Data System (ADS)

    Li, Yongqian; Su, Lei; Shou, Chen; Yu, Chunmeng; Deng, Jinjun; Fang, Yu

    2013-10-01

    Surface-enhanced infrared absorption spectroscopy has attracted increased attention for direct access to molecular vibrational fingerprints in the mid-infrared. Perfect-absorber metamaterials (PAMs) with multi-band spectral responses and significant enhancement of the local near-field intensity were developed to improve the intrinsic absorption cross sections of absorption spectrum to identify the vibrational spectra of biomolecules. To verify its performance, the proposed infrared PAM array was used to identify the molecular stretches of a Parylene C film. The resonant responses of the infrared PAMs were accurately tuned to the vibrational modes of the C = C target bonds. The vibrational stretches of the C = C moiety were observed and the auto-fluorescence mechanisms of the Parylene C film were monitored. The unique properties of the PAMs indicate that this approach is a promising strategy for surface-enhanced molecular absorption spectroscopy (SEMS) in the mid-infrared region and for the tracking of characteristic molecular vibrational modes.

  14. Distribution of coniferin in freeze-fixed stem of Ginkgo biloba L. by cryo-TOF-SIMS/SEM

    PubMed Central

    Aoki, Dan; Hanaya, Yuto; Akita, Takuya; Matsushita, Yasuyuki; Yoshida, Masato; Kuroda, Katsushi; Yagami, Sachie; Takama, Ruka; Fukushima, Kazuhiko

    2016-01-01

    To clarify the role of coniferin in planta, semi-quantitative cellular distribution of coniferin in quick-frozen Ginkgo biloba L. (ginkgo) was visualized by cryo time-of-flight secondary ion mass spectrometry and scanning electron microscopy (cryo-TOF-SIMS/SEM) analysis. The amount and rough distribution of coniferin were confirmed through quantitative chromatography measurement using serial tangential sections of the freeze-fixed ginkgo stem. The lignification stage of the sample was estimated using microscopic observations. Coniferin distribution visualized at the transverse and radial surfaces of freeze-fixed ginkgo stem suggested that coniferin is stored in the vacuoles, and showed good agreement with the assimilation timing of coniferin to lignin in differentiating xylem. Consequently, it is suggested that coniferin is stored in the tracheid cells of differentiating xylem and is a lignin precursor. PMID:27510918

  15. In-plane strain measurements on a microscopic scale by coupling digital image correlation and an in situ SEM technique

    SciTech Connect

    Lagattu, Fabienne . E-mail: lagattu@lmpm.ensma.fr; Bridier, Florent; Villechaise, Patrick; Brillaud, Jean

    2006-01-15

    The purpose of this paper is to present a method based on the correlation of digital images obtained on a microscopic scale. A specific grainy pattern has been developed. The use of the scanning electron microscopy (SEM) allowed the determination of full-field 2D displacements on an object surface with a spatial resolution of about 1 {mu}m. Validation tests were performed in order to quantify performances and limits of this method. An example of its application is presented for a Ti-6Al-4V titanium alloy. Results show that it is possible to obtain in-plane displacement values on the object surface with efficient spatial resolution and accuracy. Thus, such a technique can be used to highlight on a relevant scale the role of the microstructure in material deformation processes.

  16. Calibration of ultra high speed laser engraving processes by correlating influencing variables including correlative evaluation with SEM and CLSM

    NASA Astrophysics Data System (ADS)

    Bohrer, Markus; Vaupel, Matthias; Nirnberger, Robert; Weinberger, Bernhard

    2016-03-01

    Laser engraving is used for decades as a well-established process e. g. for the production of print and embossing forms for many goods in daily life, e. g. decorated cans and printed bank notes. Up to now it is more or less a so-called fire-and-forget process. From the original artist's plan to the digitization, then from the laser source itself (with electronic signals, RF and plasma discharge regarding CO2 lasers) to the behavior of the optical beam delivery — especially if an AOM is used — to the interaction of the laser beam with the material itself is a long process chain. The most recent results using CO2 lasers with AOMs and the research done with scanning electron microscope (SEM) and confocal laser scanning microscope (CLSM) — as a set for correlative microscopy to evaluate the high speed engraving characteristics — are presented in this paper.

  17. Heterogeneous uptake and reactivity of formic acid on calcium carbonate particles: a Knudsen cell reactor, FTIR and SEM study.

    PubMed

    Al-Hosney, Hashim A; Carlos-Cuellar, Sofia; Baltrusaitis, Jonas; Grassian, Vicki H

    2005-10-21

    The heterogeneous uptake and reactivity of formic acid (HCOOH), a common gas-phase organic acid found in the environment, on calcium carbonate (CaCO(3)) particles have been investigated using a Knudsen cell reactor, Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM). FTIR measurements show that the adsorption of formic acid on the surface of calcium carbonate results in the formation of calcium formate. Besides calcium formate, carbonic acid is also a reaction product under dry conditions (<1% RH). Under dry conditions and at low pressures, the initial uptake coefficient of formic acid on CaCO(3) particles is measured to be 3 +/- 1 x 10(-3) and decreases as the surface saturates with adsorbed products. The maximum surface coverage of formic acid under dry conditions is determined to be (3 +/- 1)x 10(14) molecules cm(-2). Under humidified conditions (RH >10%), adsorbed water on the surface of the carbonate particles participates in the surface reactivity of these particles, which results in the enhanced uptake kinetics and extent of reaction of this organic acid on CaCO(3) as well as opens up several new reaction pathways. These reaction pathways include: (i) the water-assisted dissociation of carbonic acid to CO(2) and H(2)O and (ii) the formation of calcium formate islands and crystallites, as evident by SEM images. The results presented here show that adsorbed water plays a potentially important role in the surface chemistry of gas-phase organic acids on calcium carbonate particles.

  18. Precise CD-SEM metrology of resist patterns at around 20 nm for 0.33NA EUV lithography

    NASA Astrophysics Data System (ADS)

    Okai, Nobuhiro; Lavigne, Erin; Hitomi, Keiichiro; Halle, Scott; Hotta, Shoji; Koshihara, Shunsuke; Petrillo, Karen; Yamaguchi, Atsuko; Tanaka, Junichi; Bailey, Todd

    2014-04-01

    Evaluation of resist shrinkage and precision by critical dimension scanning electron microscope (CD-SEM) for EUV resist patterns at around 20 nm exposed by 0.33 NA EUV tool was conducted. To investigate interaction between EUV resist and electron beam, an accurate and fast measurement method of resist shrinkage was established. Our method can avoid saturation of shrinkage at large dose conditions which was a demerit in conventional method. By applying the new method, pattern size dependence of shrinkage was measured with various line and space (L/S) patterns down to 20 nm. The result shows that resist shrinkage of fine L/S EUV resist pattern largely depends on line width rather than space width. A well-known trade-off relationship between shrinkage and precision was observed for EUV resist pattern as well as ArF resist pattern. Shrinkage of 1.6 nm and precision of 0.13 nm for 18 nm EUV resist pattern were obtained at a typical CD-SEM condition. We also measured shrinkage and precision for a dense L/S pattern at various exposure focus and dose conditions using a FEM wafer to examine the impact of process variability. To investigate the influence of EUV shadowing effect, we measured them for both horizontal and vertical patterns at different slit locations in exposure field. No systematic change of shrinkage and precision was observed through exposure focus and dose in the process window across slit location for both horizontal and vertical L/S patterns.

  19. Bone matrix calcification during embryonic and postembryonic rat calvarial development assessed by SEM-EDX spectroscopy, XRD, and FTIR spectroscopy.

    PubMed

    Henmi, Akiko; Okata, Hiroshi; Anada, Takahisa; Yoshinari, Mariko; Mikami, Yasuto; Suzuki, Osamu; Sasano, Yasuyuki

    2016-01-01

    Bone mineral is constituted of biological hydroxyapatite crystals. In developing bone, the mineral crystal matures and the Ca/P ratio increases. However, how an increase in the Ca/P ratio is involved in maturation of the crystal is not known. The relationships among organic components and mineral changes are also unclear. The study was designed to investigate the process of calcification during rat calvarial bone development. Calcification was evaluated by analyzing the atomic distribution and concentration of Ca, P, and C with scanning electron microscopy (SEM)-energy-dispersive X-ray (EDX) spectroscopy and changes in the crystal structure with X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy. Histological analysis showed that rat calvarial bone formation started around embryonic day 16. The areas of Ca and P expanded, matching the region of the developing bone matrix, whereas the area of C became localized around bone. X-ray diffraction and FTIR analysis showed that the amorphous-like structure of the minerals at embryonic day 16 gradually transformed into poorly crystalline hydroxyapatite, whereas the proportion of mineral to protein increased until postnatal week 6. FTIR analysis also showed that crystallization of hydroxyapatite started around embryonic day 20, by which time SEM-EDX spectroscopy showed that the Ca/P ratio had increased and the C/Ca and C/P ratios had decreased significantly. The study suggests that the Ca/P molar ratio increases and the proportion of organic components such as proteins of the bone matrix decreases during the early stage of calcification, whereas crystal maturation continues throughout embryonic and postembryonic bone development.

  20. SEM and microCT validation for en face OCT imagistic evaluation of endodontically treated human teeth

    NASA Astrophysics Data System (ADS)

    Negrutiu, Meda L.; Nica, Luminita; Sinescu, Cosmin; Topala, Florin; Ionita, Ciprian; Bradu, Adrian; Petrescu, Emanuela L.; Pop, Daniela M.; Rominu, Mihai; Podoleanu, Adrian Gh.

    2011-03-01

    Successful root canal treatment is based on diagnosis, treatment planning, knowledge of tooth anatomy, endodontic access cavity design, controlling the infection by thorough cleaning and shaping, methods and materials used in root canal obturation. An endodontic obturation must be a complete, three-dimensional filling of the root canal system, as close as possible to cemento-dentinal junction, without massive overfilling or underfilling. There are several known methods which are used to assess the quality of the endodontic sealing, but most are invasive. These lead to the destruction of the samples and often no conclusion could be drawn in respect to the existence of any microleakage in the investigated areas of interest. Using an time domain en-face OCT system, we have recently demonstrated real time thorough evaluation of quality of root canal fillings. The purpose of this in vitro study was to validate the en face OCT imagistic evaluation of endodontically treated human teeth by using scanning electron microscopy (SEM) and microcomputer tomography (μCT). SEM investigations evidenced the nonlinear aspect of the interface between the endodontic filling material and the root canal walls and materials defects in some samples. The results obtained by μCT revealed also some defects inside the root-canal filling and at the interfaces between the material and the root canal walls. The advantages of the OCT method consist in non-invasiveness and high resolution. In addition, en face OCT investigations permit visualization of the more complex stratified structure at the interface between the filling material and the dental hard tissue.