Science.gov

Sample records for agar overlay technique

  1. Recovery of Sublethally Injured Bacteria Using Selective Agar Overlays.

    ERIC Educational Resources Information Center

    McKillip, John L.

    2001-01-01

    This experiment subjects bacteria in a food sample and an environmental sample to conditions of sublethal stress in order to assess the effectiveness of the agar overlay method to recover sublethally injured cells compared to direct plating onto the appropriate selective medium. (SAH)

  2. Envelopment technique and topographic overlays in bite mark analysis

    PubMed Central

    Djeapragassam, Parimala; Daniel, Mariappan Jonathan; Srinivasan, Subramanian Vasudevan; Ramadoss, Koliyan; Jimsha, Vannathan Kumaran

    2015-01-01

    Aims and Objectives: The aims and objectives of our study were to compare four sequential overlays generated using the envelopment technique and to evaluate inter- and intraoperator reliability of the overlays obtained by the envelopment technique. Materials and Methods: Dental stone models were prepared from impressions made from healthy individuals; photographs were taken and computer-assisted overlays were generated. The models were then enveloped in a different-color dental stone. After this, four sequential cuts were made at a thickness of 1mm each. Each sectional cut was photographed and overlays were generated. Thus, 125 overlays were generated and compared. Results: The scoring was done based on matching accuracy and the data were analyzed. The Kruskal-Wallis one-way analysis of variance (ANOVA) test was used to compare four sequential overlays and Spearman's rank correlation tests were used to evaluate the inter- and intraoperator reliability of the overlays obtained by the envelopment technique. Conclusion: Through our study, we conclude that the third and fourth cuts were the best among the four cuts and inter- and intraoperator reliability were found to be statistically significant at 5% level that is 95% confidence interval (P < 0.05). PMID:26816458

  3. Agar-Gel Precipitin Technique in Anthrax Antibody Determinations1

    PubMed Central

    Ray, John G.; Kadull, Paul J.

    1964-01-01

    A modification of the agar-gel precipitation inhibition technique of Thorne and Belton for detecting anthrax antibodies reduces inconsistency of visually determined end points on the same sera observed by different technicians. Determination of the minimal reacting concentrations of the anthrax antigen and antibody reagents, modifications of the visualization apparatus, methods for combining reagents, and length of incubation periods contribute to the ease of the end-point determinations and the uniformity of results. When compared with the previous technique, the modified procedure is less time-consuming while retaining satisfactory reproducibility, simplicity, specificity, and sensitivity. Images FIG. 1 FIG. 2 PMID:14201088

  4. Diffusion of Methylene Blue in Phantoms of Agar Using a Photoacoustic Technique

    NASA Astrophysics Data System (ADS)

    Vilca-Quispe, L.; Alvarado-Gil, J. J.; Quintana, P.; Ordonez-Miranda, J.

    2010-05-01

    In this work, the kinetics of diffusion of methylene blue in agar aqueous solution is studied using a photoacoustic technique. Two agar phantoms solutions in water with a relation of mass/volume of 0.01% and 0.05% were analyzed. The study was performed using a modified Rosencwaig photoacoustic cell that is enclosed by transparent windows, on both sides. The sample is deposited directly on top of the upper window. A red light beam, at a fixed modulation frequency, is sent through the lower window illuminating the sample and inducing the photoacoustic effect inside the closed chamber of the cell. At the beginning of the experiment, a droplet of 100μL of agar solution is deposited; afterwards, the signal stabilizes, and 10μL of methylene blue aqueous solution (0.0125 g · mL-1) is added to the surface of the agar. During the first seconds of the experiment, the photoacoustic signal amplitude increases followed by a gradual and long decay. Results for modulation frequencies in the range from 10Hz to 80Hz for both agar concentrations are presented. A simple theoretical approach is presented to analyze the experimental data. It is demonstrated that the kinetics of the process can be parameterized as a function of the changes of an effective optical absorption coefficient. From these results, the characteristic time, in which the dye diffusion process stabilizes, is obtained. It is found that this time is larger for samples with a higher agar concentration. These differences provide important results for biomedical sciences in which agar gels are used as phantoms resembling some of the properties of living organs and tissues.

  5. Assessment of rhinoplasty techniques by overlay of before-and-after 3D images.

    PubMed

    Toriumi, Dean M; Dixon, Tatiana K

    2011-11-01

    This article describes the equipment and software used to create facial 3D imaging and discusses the validation and reliability of the objective assessments done using this equipment. By overlaying preoperative and postoperative 3D images, it is possible to assess the surgical changes in 3D. Methods are described to assess the 3D changes from the rhinoplasty techniques of nasal dorsal augmentation, increasing tip projection, narrowing the nose, and nasal lengthening. PMID:22004862

  6. Monoplane 3D Overlay Roadmap versus Conventional Biplane 2D Roadmap Technique for Neurointervenional Procedures

    PubMed Central

    Jang, Dong-Kyu; Stidd, David A.; Schafer, Sebastian; Chen, Michael; Moftakhar, Roham

    2016-01-01

    Purpose We investigated whether a 3D overlay roadmap using monoplane fluoroscopy offers advantages over a conventional 2D roadmap using biplane fluoroscopy during endovascular aneurysm treatment. Materials and Methods A retrospective chart review was conducted for 131 consecutive cerebral aneurysm embolizations by three neurointerventionalists at a single institution. Allowing for a transition period, the periods from January 2012 to August 2012 (Time Period 1) and February 2013 to July 2013 (Time Period 2) were analyzed for radiation exposure, contrast administration, fluoroscopy time, procedure time, angiographic results, and perioperative complications. Two neurointerventionalists (Group 1) used a conventional 2D roadmap for both Time Periods, and one neurointerventionalist (Group 2) transitioned from a 2D roadmap during Time Period 1 to a 3D overlay roadmap during Time Period 2. Results During Time Period 2, Group 2 demonstrated reduced fluoroscopy time (p<0.001), procedure time (P=0.023), total radiation dose (p=0.001), and fluoroscopy dose (P=0.017) relative to Group 1. During Time Period 2, there was no difference of immediate angiographic results and procedure complications between the two groups. Through the transition from Time Period 1 to Time Period 2, Group 2 demonstrated decreased fluoroscopy time (p< 0.001), procedure time (p=0.022), and procedure complication rate (p=0.041) in Time Period 2 relative to Time Period 1. Conclusion The monoplane 3D overlay roadmap technique reduced fluoroscopy dose and fluoroscopy time during neurointervention of cerebral aneurysms with similar angiographic occlusions and complications rate relative to biplane 2D roadmap, which implies possible compensation of limitations of monoplane fluoroscopy by 3D overlay technique. PMID:27621947

  7. A Production Proven Technique For Machine-To-Machine Overlay Matching

    NASA Astrophysics Data System (ADS)

    Cummings, Michael J.; Haley, Norman; Ngo, Ken; Schaller, John

    1989-01-01

    The natural progression of today's semiconductor industry is toward smaller device features and tighter registration requirements. Typically, this progression results in high capital equipment investments, along with a large capacity reduction per investment dollar for most lithographic exposure processes. One major cause for the capacity loss is the industry's willingness to migrate from full-field scanning projection printers to a lower throughput field-by-field alignment step-and-repeat exposure system. Standard Microsystems Corporation (SMC) sought to achieve higher performance on its scanners without compromising throughput. The original goal at SMC was to improve Perkin-Elmer's specified Micralign 641 HT machine-to-machine registration performance from ± 0.30 micron to less than ± 0.25 micron. With this in mind, we set out to investigate the true alignment and registration limitations of a Micralign Model 600 HT Series Projection Aligner. Although SMC was apparently successful at matching two Micralign 641 HT systems to ± 0.25 micron by manually reading verniers, this technique proved to be time consuming and prone to human error. Electrical probing of wafers was considered, but the special masks and processing steps and its destructive nature were considered undesirable. For this study, an automatic optical overlay measurement system was used to optimize overlay on the SMC Micralign systems. The results were enlightening. The specified overlay of ± 0.30 micron for 98% of the data improved to better than ± 0.25 micron, 3 sigma. These results were achieved without the use of Automatic Magnification Compensation (AVM/AMC). We.also discovered that many otherwise transparent mechanical/optical anomalies, such as contamination and scan interference, could be readily identified. Experimental data is presented and the beneficial application of this technique to a production process is discussed.

  8. A Production Proven Technique For Machine-To-Machine Overlay Matching

    NASA Astrophysics Data System (ADS)

    Cummings, Michael J.; Haley, Norman J.; Ngo, Ken T.; Schaller, John W.

    1989-07-01

    The natural progression of today's semiconductor industry is toward smaller geometric features and registration requirements. Typically, this progression results in high capital equipment investments, along with a large capacity reduction per investment dollar for most lithographic exposure processes. One major cause for the capacity loss is the industry's willingness to migrate from full-field scanning projection printers to a lower throughput field-by-field alignment step-and-repeat exposure system. Standard Microsystems Corporation (SMC) sought to achieve higher performance on its scanners without compromising throughput. The original goal at SMC was to improve Perkin-Elmer's Micralign 641 HT machine-to-machine registration specification of ± 0.30 micron to less than ± 0.25 micron. With this in mind, we set out to investigate the true alignment and registration limitations of a Micralign Model 600 HT Series Projection Aligner. Although SMC was apparently successful at matching two Micralign 641 HT systems to ± 0.25 micron by manually reading verniers, this technique proved to be time consuming and prone to human error. Electrical probing of wafers was considered, but the special masks and processing steps and its destructive nature were considered undesirable. For this study, an automatic optical overlay measurement system was used to optimize overlay on the SMC Micralign systems. The results were enlightening. The specified overlay of ± 0.30 micron for 98% of the data improved to better than ± 0.25 micron, 3 sigma. These results were achieved without the use of Automatic Magnification Compensation (AVM/AMC). We also discovered that many otherwise transparent mechanical/optical anomalies, such as contamination and scan interference, could be readily identified. Experimental data is presented and the beneficial application of this technique to a production process is discussed.

  9. Laboratory detection of extended-spectrum-beta-lactamase-producing Enterobacteriaceae: evaluation of two screening agar plates and two confirmation techniques.

    PubMed

    Overdevest, I T M A; Willemsen, I; Elberts, S; Verhulst, C; Kluytmans, J A J W

    2011-02-01

    The worldwide prevalence of extended-spectrum-beta-lactamase-producing ESBL-producing Enterobacteriaceae (ESBL-E) is increasing, making the need for optimized detection techniques more urgent. In this study we investigated the performance of two ESBL-E screening and two ESBL-E confirmation techniques. In accordance with the Dutch national guidelines (www.wip.nl), a collection of 642 highly resistant Enterobacteriaceae strains, as identified by Vitek2, was used to test the performances of two screening techniques (EbSA ESBL agar plate and ChromID ESBL agar plate) and of two confirmation techniques (MIC-strip ESBL and Vitek2 ESBL test panel). The individual test results were compared by using Etest, followed by a combination disk test if Etest results were inconclusive. Among group 1 isolates (Escherichia coli, Klebsiella spp., Proteus spp., Salmonella spp., and Shigella spp.) 291 (57.6%) were ESBL-E, versus 65 (47.4%) in group 2 (Enterobacter spp., Citrobacter spp., Morganella morganii, Serratia spp., and Providencia spp.). The sensitivities of all four tests for group 1 were comparable (EbSA, 96.6%; ChromID, 97.3%; MIC-strip, 99.6%; and Vitek2, 95.1%). The specificities of the EbSA and ChromID were the same (93.9%). However, the confirmation techniques produced many inconclusive test results, which reduces the applicability in routine laboratories. Only the two screening agar plates were validated for ESBL testing of group 2 microorganisms. They showed comparable sensitivities; however, the EbSA screening agar plate had a significantly higher specificity (78.6% versus 44.3%). In conclusion the screening agar plates performed better than the two confirmation techniques. The EbSA agar plate had the best overall performance. PMID:21123527

  10. Validation system of MR image overlay and other needle insertion techniques.

    PubMed

    Fischer, Gregory S; Dyer, Eva; Csoma, Csaba; Deguet, Anton; Fichtinger, Gabor

    2007-01-01

    In order to develop accurate and effective augmented reality (AR) systems used in MR and CT guided needle placement procedures, a comparative validation environment is necessary. Clinical equipment is prohibitively expensive and often inadequate for precise measurement. Therefore, we have developed a laboratory validation system for measuring operator performance using different assistance techniques. Electromagnetically tracked needles are registered with the preoperative plan to measure placement accuracy and the insertion path. The validation system provides an independent measure of accuracy that can be applied to varying methods of assistance ranging from augmented reality guidance methods to tracked navigation systems and autonomous robots. In preliminary studies, this validation system is used to evaluate the performance of the image overlay, bi-plane laser guide, and traditional freehand techniques. PMID:17377250

  11. Pattern recognition and data mining techniques to identify factors in wafer processing and control determining overlay error

    NASA Astrophysics Data System (ADS)

    Lam, Auguste; Ypma, Alexander; Gatefait, Maxime; Deckers, David; Koopman, Arne; van Haren, Richard; Beltman, Jan

    2015-03-01

    On-product overlay can be improved through the use of context data from the fab and the scanner. Continuous improvements in lithography and processing performance over the past years have resulted in consequent overlay performance improvement for critical layers. Identification of the remaining factors causing systematic disturbances and inefficiencies will further reduce overlay. By building a context database, mappings between context, fingerprints and alignment & overlay metrology can be learned through techniques from pattern recognition and data mining. We relate structure (`patterns') in the metrology data to relevant contextual factors. Once understood, these factors could be moved to the known effects (e.g. the presence of systematic fingerprints from reticle writing error or lens and reticle heating). Hence, we build up a knowledge base of known effects based on data. Outcomes from such an integral (`holistic') approach to lithography data analysis may be exploited in a model-based predictive overlay controller that combines feedback and feedforward control [1]. Hence, the available measurements from scanner, fab and metrology equipment are combined to reveal opportunities for further overlay improvement which would otherwise go unnoticed.

  12. Development of hyperspectral imaging technique for salmonella enteritidis and typhimurium on agar plates

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Salmonella is a common cause of foodborne disease resulting from the consumption of contaminated food products. Although a direct plating method is widely used for presumptive positive screening of pathogenic Salmonella colonies on agar plates, it is labor-intensive, time-consuming and also prone to...

  13. New holographic overlays

    NASA Astrophysics Data System (ADS)

    Hopwood, Anthony I.

    1991-10-01

    This paper discusses a new type of holographic overlay, FLASHPRINT, which may be used in both security and packaging applications. Unlike the more common embossed holograms currently used, FLASHPRINT leads to reduced set-up costs and offers a simpler process. This reduces the long lead times characteristic of the existing technology and requires the customer to provide only two-dimensional artwork. The overlay material contains a covert 2-D image. The image may be switched on or off by simply tilting the overlay in a light source. The overlay is replayed in the 'on' position to reveal the encoded security message as a highly saturated gold colored image. This effect is operable for a wide range of lighting conditions and viewing geometries. In the 'off' position the overlay is substantially transparent. These features make the visual effect of the overlay attractive to incorporate into product design. They may be laminated over complex printed artwork such as labels and security passes without masking the printed message. When switched 'on' the image appears both sharp and more than seven times brighter than white paper. The image remains sharp and clear even in less favorable lighting conditions. Although the technique offers a low set-up cost for the customer, through its simplicity, it remains as technically demanding and difficult to counterfeit as any holographic process.

  14. A comparison of a new centrifuge sugar flotation technique with the agar method for the extraction of immature Culicoides (Diptera: Ceratopogonidae) life stages from salt marsh soils.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Two sampling techniques, agar extraction (AE) and centrifuge sugar flotation extraction (CSFE) were compared to determine their relative efficacy to recover immature stages of Culicoides spp from salt marsh substrates. Three types of samples (seeded with known numbers of larvae, homogenized field s...

  15. Layered mass geometry: a novel technique to overlay seeds and applicators onto patient geometry in Geant4 brachytherapy simulations.

    PubMed

    Enger, Shirin A; Landry, Guillaume; D'Amours, Michel; Verhaegen, Frank; Beaulieu, Luc; Asai, Makoto; Perl, Joseph

    2012-10-01

    A problem faced by all Monte Carlo (MC) particle transport codes is how to handle overlapping geometries. The Geant4 MC toolkit allows the user to create parallel geometries within a single application. In Geant4 the standard mass-containing geometry is defined in a simulation volume called the World Volume. Separate parallel geometries can be defined in parallel worlds, that is, alternate three dimensional simulation volumes that share the same coordinate system with the World Volume for geometrical event biasing, scoring of radiation interactions, and/or the creation of hits in detailed readout structures. Until recently, only one of those worlds could contain mass so these parallel worlds provided no solution to simplify a complex geometric overlay issue in brachytherapy, namely the overlap of radiation sources and applicators with a CT based patient geometry. The standard method to handle seed and applicator overlay in MC requires removing CT voxels whose boundaries would intersect sources, placing the sources into the resulting void and then backfilling the remaining space of the void with a relevant material. The backfilling process may degrade the accuracy of patient representation, and the geometrical complexity of the technique precludes using fast and memory-efficient coding techniques that have been developed for regular voxel geometries. The patient must be represented by the less memory and CPU-efficient Geant4 voxel placement technique, G4PVPlacement, rather than the more efficient G4NestedParameterization (G4NestedParam). We introduce for the first time a Geant4 feature developed to solve this issue: Layered Mass Geometry (LMG) whereby both the standard (CT based patient geometry) and the parallel world (seeds and applicators) may now have mass. For any area where mass is present in the parallel world, the parallel mass is used. Elsewhere, the mass of the standard world is used. With LMG the user no longer needs to remove patient CT voxels that would

  16. Layered mass geometry: a novel technique to overlay seeds and applicators onto patient geometry in Geant4 brachytherapy simulations

    NASA Astrophysics Data System (ADS)

    Enger, Shirin A.; Landry, Guillaume; D'Amours, Michel; Verhaegen, Frank; Beaulieu, Luc; Asai, Makoto; Perl, Joseph

    2012-10-01

    A problem faced by all Monte Carlo (MC) particle transport codes is how to handle overlapping geometries. The Geant4 MC toolkit allows the user to create parallel geometries within a single application. In Geant4 the standard mass-containing geometry is defined in a simulation volume called the World Volume. Separate parallel geometries can be defined in parallel worlds, that is, alternate three dimensional simulation volumes that share the same coordinate system with the World Volume for geometrical event biasing, scoring of radiation interactions, and/or the creation of hits in detailed readout structures. Until recently, only one of those worlds could contain mass so these parallel worlds provided no solution to simplify a complex geometric overlay issue in brachytherapy, namely the overlap of radiation sources and applicators with a CT based patient geometry. The standard method to handle seed and applicator overlay in MC requires removing CT voxels whose boundaries would intersect sources, placing the sources into the resulting void and then backfilling the remaining space of the void with a relevant material. The backfilling process may degrade the accuracy of patient representation, and the geometrical complexity of the technique precludes using fast and memory-efficient coding techniques that have been developed for regular voxel geometries. The patient must be represented by the less memory and CPU-efficient Geant4 voxel placement technique, G4PVPlacement, rather than the more efficient G4NestedParameterization (G4NestedParam). We introduce for the first time a Geant4 feature developed to solve this issue: Layered Mass Geometry (LMG) whereby both the standard (CT based patient geometry) and the parallel world (seeds and applicators) may now have mass. For any area where mass is present in the parallel world, the parallel mass is used. Elsewhere, the mass of the standard world is used. With LMG the user no longer needs to remove patient CT voxels that would

  17. New analytical algorithm for overlay accuracy

    NASA Astrophysics Data System (ADS)

    Ham, Boo-Hyun; Yun, Sangho; Kwak, Min-Cheol; Ha, Soon Mok; Kim, Cheol-Hong; Nam, Suk-Woo

    2012-03-01

    The extension of optical lithography to 2Xnm and beyond is often challenged by overlay control. With reduced overlay measurement error budget in the sub-nm range, conventional Total Measurement Uncertainty (TMU) data is no longer sufficient. Also there is no sufficient criterion in overlay accuracy. In recent years, numerous authors have reported new method of the accuracy of the overlay metrology: Through focus and through color. Still quantifying uncertainty in overlay measurement is most difficult work in overlay metrology. According to the ITRS roadmap, total overlay budget is getting tighter than former device node as a design rule shrink on each device node. Conventionally, the total overlay budget is defined as the square root of square sum of the following contributions: the scanner overlay performance, wafer process, metrology and mask registration. All components have been supplying sufficiently performance tool to each device nodes, delivering new scanner, new metrology tools, and new mask e-beam writers. Especially the scanner overlay performance was drastically decreased from 9nm in 8x node to 2.5nm in 3x node. The scanner overlay seems to reach the limitation the overlay performance after 3x nod. The importance of the wafer process overlay as a contribution of total wafer overlay became more important. In fact, the wafer process overlay was decreased by 3nm between DRAM 8x node and DRAM 3x node. We develop an analytical algorithm for overlay accuracy. And a concept of nondestructive method is proposed in this paper. For on product layer we discovered the layer has overlay inaccuracy. Also we use find out source of the overlay error though the new technique. In this paper, authors suggest an analytical algorithm for overlay accuracy. And a concept of non-destructive method is proposed in this paper. For on product layers, we discovered it has overlay inaccuracy. Also we use find out source of the overlay error though the new technique. Furthermore

  18. Identification of Actinomyces israelii and Actinomyces naeslundii by Fluorescent-Antibody and Agar-Gel Diffusion Techniques1

    PubMed Central

    Lambert, Frank W.; Brown, June M.; Georg, Lucille K.

    1967-01-01

    This study was an attempt to develop a fluorescent-antibody (FA) test to differentiate Actinomyces israelii and A. naeslundii as an aid in their laboratory identification. Two strains of A. israelii (X522 and A601) and two strains of A. naeslundii (X454 and X600), which had received intensive study by several investigators, were used for the immunization of rabbits. Working titers, based on tests with antigens prepared from the homologous strains and from well-established heterologous strains, were determined for each labeled antibody preparation. These conjugates and their normal serum control conjugates were used separately to stain 85 cultures of Actinomyes species and 23 strains of other species that might be confused with them. Acetone-precipitated soluble antigens from these same strains were tested with different antisera in the agar-gel diffusion test. Results showed that A. israelii (X522 and A601) and A. naeslundii (X454 and X600) labeled antiglobulins, when used at their working titers, stained most strains of their homologous species. Agar-gel diffusion results showed general agreement with those of the FA tests. The two tests appear to be equal in sensitivity, but the FA test is more specific, since several cross-reactions were noted with the agar-gel diffusion test whereas no cross-reactions were obtained with the FA reagents. Agar-gel and FA studies suggest that at least two serotypes of A. israelii may be associated with human disease. Although the majority of strains tested in this study appear to belong to a common serotype, “serotype 1,” two strains of an apparent second serotype, “serotype 2,” were encountered. FA staining of tissue impression smears from experimentally infected mice was successful when a counterstain, Evans Blue dye, was used. PMID:4964473

  19. Generic Overlay Framework

    2005-09-01

    This software provides a framework for building application layter overlay networks. It includes example overlays that can be used without modification. Also provided are example multicast and routing protocols that can be used with the overlays.

  20. Meeting overlay requirements for future technology nodes with in-die overlay metrology

    NASA Astrophysics Data System (ADS)

    Schulz, Bernd; Seltmann, Rolf; Busch, Jens; Hempel, Fritjof; Cotte, Eric; Alles, Benjamin

    2007-03-01

    As a consequence of the shrinking sizes of the integrated circuit structures, the overlay budget shrinks as well. Overlay is traditionally measured with relatively large test structures which are located in the scribe line of the exposure field, in the four corners. Although the performance of the overlay metrology tools has improved significantly over time it is questionable if this traditional method of overlay control will be sufficient for future technology nodes. For advanced lithography techniques like double exposure or double patterning, in-die overlay is critical and it is important to know how much of the total overlay budget is consumed by in-die components. We reported earlier that small overlay targets were included directly inside die areas and good performance was achieved. This new methodology enables a wide range of investigations. This provides insight into processes which were less important in the past or not accessible for metrology. The present work provides actual data from productive designs, instead of estimates, illustrating the differences between the scribe line and in-die registration and overlay. The influence of the pellicle on pattern placement on mask and wafer overlay is studied. Furthermore the registration overlay error of the reticles is correlated to wafer overlay residuals. The influence of scanner-induced distortions (tool to tool differences) on in-die overlay is shown. Finally, the individual contributors to in-die-overlay are discussed in the context of other overlay contributors. It is proposed to use in-die overlay and registration results to derive guidelines for future overlay and registration specifications. It will be shown that new overlay correction schemes which take advantage of the additional in-die overlay information need to be considered for production.

  1. Overlay accuracy fundamentals

    NASA Astrophysics Data System (ADS)

    Kandel, Daniel; Levinski, Vladimir; Sapiens, Noam; Cohen, Guy; Amit, Eran; Klein, Dana; Vakshtein, Irina

    2012-03-01

    Currently, the performance of overlay metrology is evaluated mainly based on random error contributions such as precision and TIS variability. With the expected shrinkage of the overlay metrology budget to < 0.5nm, it becomes crucial to include also systematic error contributions which affect the accuracy of the metrology. Here we discuss fundamental aspects of overlay accuracy and a methodology to improve accuracy significantly. We identify overlay mark imperfections and their interaction with the metrology technology, as the main source of overlay inaccuracy. The most important type of mark imperfection is mark asymmetry. Overlay mark asymmetry leads to a geometrical ambiguity in the definition of overlay, which can be ~1nm or less. It is shown theoretically and in simulations that the metrology may enhance the effect of overlay mark asymmetry significantly and lead to metrology inaccuracy ~10nm, much larger than the geometrical ambiguity. The analysis is carried out for two different overlay metrology technologies: Imaging overlay and DBO (1st order diffraction based overlay). It is demonstrated that the sensitivity of DBO to overlay mark asymmetry is larger than the sensitivity of imaging overlay. Finally, we show that a recently developed measurement quality metric serves as a valuable tool for improving overlay metrology accuracy. Simulation results demonstrate that the accuracy of imaging overlay can be improved significantly by recipe setup optimized using the quality metric. We conclude that imaging overlay metrology, complemented by appropriate use of measurement quality metric, results in optimal overlay accuracy.

  2. Total overlay analysis for designing future aligner

    NASA Astrophysics Data System (ADS)

    Magome, Nobutaka; Kawai, Hidemi

    1995-05-01

    We found total overlay with respect to optical lithography using an approach similar to quality control technique employed at a semiconductor factory. This approach involves an aligner performance, process quality, reticle error and overlay measurement. This paper further describes new ides for the number of machines to be used for matching and data collection period. Lastly, improvement on total overlay and a prospective view for a future aligner and its usage are also described.

  3. 21 CFR 582.7115 - Agar-agar.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Agar-agar. 582.7115 Section 582.7115 Food and..., FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Stabilizers § 582.7115 Agar-agar. (a) Product. Agar-agar. (b) Conditions of use. This substance is generally recognized as safe when used...

  4. 21 CFR 582.7115 - Agar-agar.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Agar-agar. 582.7115 Section 582.7115 Food and..., FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Stabilizers § 582.7115 Agar-agar. (a) Product. Agar-agar. (b) Conditions of use. This substance is generally recognized as safe when used...

  5. Disk Agar Diffusion Susceptibility Testing of Yeasts

    PubMed Central

    Saubolle, Michael A.; Hoeprich, Paul D.

    1978-01-01

    A disk agar diffusion method was developed for testing the susceptibility of rapidly growing yeasts in vitro. A totally defined, completely synthetic agar culture medium (synthetic amino acid medium, fungal) and clinical isolates of Candida spp. and Torulopsis glabrata were used. Turbidimetric adjustment of cell suspensions resulted in standard, reproducible inocula, which gave sharp, clear zones of inhibition when applied by an agar overlay method. Optimal disk loads were determined for amphotericin B, amphotericin B methyl ester, 5-fluorocytosine, clotrimazole, and miconazole. Disk potencies were stable over a 2-month period when stored in a vacuum desiccator at −30°C. Using an error ratebounded classification, the zones of inhibition were correlated with both broth dilution and agar dilution minimum inhibitory concentrations (MICs). With amphotericin B and amphotericin B methyl ester, all isolates were susceptible, yielding zone diameters which clustered within 5 mm. Overall correlations between zone diameters and broth dilution MICs with 5-fluorocytosine, miconazole, and clotrimazole were 97, 96, and 82% (excluding T. glabrata), respectively; correlations of zone diameters with agar dilution MICs were 96, 92, and 88%, respectively. Disk diffusion susceptibility testing of yeasts appears to be generally applicable. However, when results are equivocal, quantitative test methods should be used. PMID:568910

  6. Screening fungicides for use in fish culture: Evaluation of the agar plug transfer, cellophane transfer, and agar dilution methods

    USGS Publications Warehouse

    Bailey, Tom A.

    1983-01-01

    The reliability, reproducibility, and usefulness of three screening methods -- the cellophane transfer, the agar plug transfer, and the agar dilution -- to screen aquatic fungicides were evaluated. Achlya flagellata and Saprolegnia hypogyna were exposed to 1, 10, and 100 mg/L of malachite green to test each method. The cellophane transfer and agar plug transfer techniques had similar reliability and reproducibility in rating fungicidal activity, and were both superior to the agar dilution technique. The agar plug transfer and agar dilution techniques adequately projected in vivo activity of malachite green, but the cellophane transfer technique overestimated its activity. Overall, the agar plug transfer technique most accurately rated the activity of malachite green and was the easiest test to perform. It therefore appears to be the method of choice for testing aquatic fungicides.

  7. [Assessment of 2 automated microdilution techniques compared to an agar dilution method in determining sensitivity to fosfomycin in strains of carbapenem-resistant Pseudomonas aeruginosa].

    PubMed

    Gil-Romero, Yolanda; Regodón-Domínguez, Marta; Wilhelmi de Cal, Isabel; López-Fabal, Fátima; Gómez-Garcés, José Luis

    2016-01-01

    Carbapenems-resistance in Pseudomonas aeruginosa isolates has been widely reported. Fosfomycin has been shown to act synergistically with other antimicrobials. The agar dilution method was approved for susceptibility testing for fosfomycin and Pseudomonas aeruginosa. However, broth microdilution methods are the basis of systems currently used in clinical microbiology laboratories. The results of this study indicate that these methods are acceptable as susceptibility testing methods for fosfomycin against these organisms. PMID:26620604

  8. Electro-osmosis in gels: Application to Agar-Agar

    NASA Astrophysics Data System (ADS)

    Cherblanc, Fabien; Boscus, Jérôme; Bénet, Jean-Claude

    2008-10-01

    Widely used in food- and bio-engineering as a reference material, Agar-Agar gel is the focus of an experimental investigation concerning the electro-osmosis phenomenon. After presenting the experimental methods, one trial is discussed in detail. A fair reproducibility of results is obtained, and the averaged electro-osmotic permeability is provided. This value lies in the range generally measured on various kind of soils, even if Agar-Agar gel does not share any micro-structural characteristics with soils. To cite this article: F. Cherblanc et al., C. R. Mecanique 336 (2008).

  9. Standard operating procedure to prepare agar phantoms

    NASA Astrophysics Data System (ADS)

    Souza, R. M.; Santos, T. Q.; Oliveira, D. P.; Souza, R. M.; Alvarenga, A. V.; Costa-Felix, R. P. B.

    2016-07-01

    Agar phantoms are widely used as soft tissue mimics and some preparation techniques are described in the literature. There are also standards that describe the recipe of a soft tissue mimicking material (TMM). However some details of manufacture process are not clearly defined. The standardization of the phantom's preparation can produce a metrological impact on the results of the acoustic properties measured. In this direction, this paper presents a standard operating procedure (SOP) to prepare the agar TMM described on the IEC 60601-237.

  10. Overlay measurement accuracy enhancement by design and algorithm

    NASA Astrophysics Data System (ADS)

    Lee, Honggoo; Lee, Byongseog; Han, Sangjun; Kim, Myoungsoo; Kwon, Wontaik; Park, Sungki; Choi, DongSub; Lee, Dohwa; Jeon, Sanghuck; Lee, Kangsan; Itzkovich, Tal; Amir, Nuriel; Volkovich, Roie; Herzel, Eitan; Wagner, Mark; El Kodadi, Mohamed

    2015-03-01

    Advanced design nodes require more complex lithography techniques, such as double patterning, as well as advanced materials like hard masks. This poses new challenge for overlay metrology and process control. In this publication several step are taken to face these challenges. Accurate overlay metrology solutions are demonstrated for advanced memory devices.

  11. Improving agar electrospinnability with choline-based deep eutectic solvents.

    PubMed

    Sousa, Ana M M; Souza, Hiléia K S; Uknalis, Joseph; Liu, Shih-Chuan; Gonçalves, Maria P; Liu, LinShu

    2015-09-01

    Very recently our group has produced novel agar-based fibers by an electrospinning technique using water as solvent and polyvinyl alcohol (PVA) as co-blending polymer. Here, we tested the deep eutectic solvent (DES), (2-hydroxyethyl)trimethylammonium chloride/urea prepared at 1:2 molar ratio, as an alternative solvent medium for agar electrospinning. The electrospun materials were collected with an ethanol bath adapted to a previous electrospinning set-up. One weight percent agar-in-DES showed improved viscoelasticity and hence, spinnability, when compared to 1 wt% agar-in-water and pure agar nanofibers were successfully electrospun if working above the temperature of sol-gel transition (∼80 °C). By changing the solvent medium we decreased the PVA concentration (5 wt% starting solution) and successfully produced composite fibers with high agar contents (50/50 agar/PVA). Best composite fibers were formed with the 50/50 and 30/70 agar/PVA solutions. These fibers were mechanically resistant, showed tailorable surface roughness and diverse size distributions, with most of the diameters falling in the sub-micron range. Both nano and micro forms of agar fibers (used separately or combined) may have potential for the design of new and highly functional agar-based materials. PMID:26116384

  12. Solidification of an alloy 625 weld overlay

    SciTech Connect

    DuPont, J.N.

    1996-11-01

    The solidification behavior (microsegregation, secondary phase formation, and solidification temperature range) of an Alloy 625 weld overlay deposited on 2.25Cr-1Mo steel by gas metal arc welding was investigated by light and electron optical microscopy, electron microprobe, and differential thermal analysis techniques. The overlay deposit was found to terminate solidification at {approx}1,216 C by a {gamma}/Laves eutectic-type reaction. The Laves phase was highly enriched in Nb, Mo, and Si. The solidification reaction and microsegregation potential of major alloying elements in the overlay deposit are compared to other Nb-bearing Ni base alloys and found to be very similar to those for Alloy 718. Solidification cracks observed in the overlay were attributed to the wide solidification temperature range ({approx}170 C) and formation of interdendritic ({gamma} + Laves) constituent. Reasonable agreement is obtained between the calculated and measured volume percent ({gamma} + Laves) constituent with the Scheil equation by treating the overlay system as a simple {gamma}-Nb binary and using an experimentally determined k{sub Nb} value from electron microprobe data.

  13. 21 CFR 184.1115 - Agar-agar.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Agar-agar. 184.1115 Section 184.1115 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) DIRECT FOOD SUBSTANCES AFFIRMED AS GENERALLY RECOGNIZED AS SAFE Listing of...

  14. 21 CFR 184.1115 - Agar-agar.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Agar-agar. 184.1115 Section 184.1115 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) DIRECT FOOD SUBSTANCES AFFIRMED AS GENERALLY RECOGNIZED AS SAFE Listing of Specific Substances Affirmed as GRAS §...

  15. 21 CFR 184.1115 - Agar-agar.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Agar-agar. 184.1115 Section 184.1115 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) DIRECT FOOD SUBSTANCES AFFIRMED AS GENERALLY RECOGNIZED AS SAFE Listing of Specific Substances Affirmed as GRAS § 184.1115...

  16. 21 CFR 184.1115 - Agar-agar.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Agar-agar. 184.1115 Section 184.1115 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) DIRECT FOOD SUBSTANCES AFFIRMED AS GENERALLY RECOGNIZED AS SAFE Listing of...

  17. 21 CFR 184.1115 - Agar-agar.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Agar-agar. 184.1115 Section 184.1115 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) DIRECT FOOD... ingredient meets the specifications of the “Food Chemicals Codex,” 3d Ed. (1981), p. 11, which...

  18. Automatic agar tray inoculation device

    NASA Technical Reports Server (NTRS)

    Wilkins, J. R.; Mills, S. M.

    1972-01-01

    Automatic agar tray inoculation device is simple in design and foolproof in operation. It employs either conventional inoculating loop or cotton swab for uniform inoculation of agar media, and it allows technician to carry on with other activities while tray is being inoculated.

  19. Accuracy in optical overlay metrology

    NASA Astrophysics Data System (ADS)

    Bringoltz, Barak; Marciano, Tal; Yaziv, Tal; DeLeeuw, Yaron; Klein, Dana; Feler, Yoel; Adam, Ido; Gurevich, Evgeni; Sella, Noga; Lindenfeld, Ze'ev; Leviant, Tom; Saltoun, Lilach; Ashwal, Eltsafon; Alumot, Dror; Lamhot, Yuval; Gao, Xindong; Manka, James; Chen, Bryan; Wagner, Mark

    2016-03-01

    In this paper we discuss the mechanism by which process variations determine the overlay accuracy of optical metrology. We start by focusing on scatterometry, and showing that the underlying physics of this mechanism involves interference effects between cavity modes that travel between the upper and lower gratings in the scatterometry target. A direct result is the behavior of accuracy as a function of wavelength, and the existence of relatively well defined spectral regimes in which the overlay accuracy and process robustness degrades (`resonant regimes'). These resonances are separated by wavelength regions in which the overlay accuracy is better and independent of wavelength (we term these `flat regions'). The combination of flat and resonant regions forms a spectral signature which is unique to each overlay alignment and carries certain universal features with respect to different types of process variations. We term this signature the `landscape', and discuss its universality. Next, we show how to characterize overlay performance with a finite set of metrics that are available on the fly, and that are derived from the angular behavior of the signal and the way it flags resonances. These metrics are used to guarantee the selection of accurate recipes and targets for the metrology tool, and for process control with the overlay tool. We end with comments on the similarity of imaging overlay to scatterometry overlay, and on the way that pupil overlay scatterometry and field overlay scatterometry differ from an accuracy perspective.

  20. Characterization of overlay mark fidelity

    NASA Astrophysics Data System (ADS)

    Adel, Mike; Ghinovker, Mark; Poplawski, Jorge M.; Kassel, Elyakim; Izikson, Pavel; Pollentier, Ivan K.; Leray, Philippe; Laidler, David W.

    2003-05-01

    In this publication we introduce a new metric for process robustness of overlay metrology in microelectronic manufacturing. By straightforward statistical analysis of overlay metrology measurements on an array of adjacent, nominally identical overlay targets the Overlay Mark Fidelity (OMF) can be estimated. We present the results of such measurements and analysis on various marks, which were patterned using a DUV scanner. The same reticle set was used to pattern wafers on different process layers and process conditions. By appropriate statistical analysis, the breakdown of the total OMF into a reticle-induced OMF component and a process induced OMF component was facilitated. We compare the OMF of traditional box-in-box overlay marks with that of new gratingbased overlay marks and show that in all cases the grating marks are superior. The reticle related OMF showed an improvement of 30 % when using the new grating-based overlay mark. Furthermore, in a series of wafers run through an STI-process with different Chemical Mechanical Polish (CMP) times, the random component of the OMF of the new grating-based overlay mark was observed to be 40% lower and 50% less sensitive to process variation compared with Box in Box marks. These two observations are interpreted as improved process robustness of the grating mark over box in box, specifically in terms of reduced site by site variations and reduced wafer to wafer variations as process conditions change over time. Overlay Mark Fidelity, as defined in this publication, is a source of overlay metrology uncertainty, which is statistically independent of the standard error contributors, i.e. precision, TIS variability, and tool to tool matching. Current overlay metrology budgeting practices do not take this into consideration when calculating total measurement uncertainty (TMU). It is proposed that this be reconsidered, given the tightness of overlay and overlay metrology budgets at the 70 nm design rule node and below.

  1. Electrically conductive polymer concrete overlays

    NASA Astrophysics Data System (ADS)

    Fontana, J. J.; Webster, R. P.

    1984-08-01

    The use of cathodic protection to prevent the corrosion of reinforcing steel in concrete structures has been well established. Application of a durable, skid-resistant electrically conductive polymer concrete overlay would advance the use of cathodic protection for the highway industry. Laboratory studies indicate that electrically conductive polymer concrete overlays using conductive fillers, such as calcined coke breeze, in conjunction with polyester or vinyl ester resins have resistivities of 1 to 10 ohm-cm. Both multiple-layer and premixed mortar-type overlays were made. Shear bond strengths of the conductive overlays to concrete substrates vary from 600 to 1300 psi, with the premixed overlays having bond strengths 50 to 100% higher than the multiple-layer overlays.

  2. Growth kinetics of three species of Tetrahymena on solid agar

    SciTech Connect

    Dobra, K.W.; McArdle, E.W.; Ehret, C.F.

    1980-01-01

    A nutrient-agar method without liquid overlay has been developed for cultivation of ciliates. Three species of Tetrahymena-T. pyriformis strain W, T. rostrata strain UNI, and T. vorax strain V/sub 2/S, representing the 3 main groups of Tetrahymena species, were used; however the method should apply to other ciliates. Growth on the surface of the agar was facilitated by an optimal surface-to-volume ratio yielding a high density of ciliates and short generation times. At the highest density achieved, the cells became irregularly hexagonal and formed a monolayer tissue on the agar. Ciliates grown on agar were like those in liquid culture, typical oral ciliature, food-vacuole formation, and typical cortical patterns being retained. Advantages of this method include high cell density, easy recovery, and optimal O/sub 2/ supply. The organisms can also be cultivated on the surface of sterile cellulose-nitrate filters, facilitating in situ fixation and staining as well as transfer into different media by transfer of filters with cells, without prior centrifugation and resuspension.

  3. Fluorogenic membrane overlays to enumerate total coliforms, Escherichia coli, and total Vibrionaceae in shellfish and seawater

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Three assays were developed to enumerate total coliforms, Escherichia coli, and total Vibrionaceae in shellfish and other foods and in seawater and other environmental samples. Assays involve membrane overlays of overnight colonies on non-selective agar plates to detect ß-glucuronidase and lysyl am...

  4. Fastidious anaerobe agar compared with Wilkins-Chalgren agar, brain heart infusion agar, and brucella agar for susceptibility testing of Fusobacterium species.

    PubMed

    Brazier, J S; Goldstein, E J; Citron, D M; Ostovari, M I

    1990-11-01

    Fastidious anaerobe agar supported the growth of 82 strains of fusobacteria better than brain heart infusion agar, brucella agar, and Wilkins-Chalgren agar. Fastidious anaerobe agar showed less hazing and fewer tailing endpoints with beta-lactam antibiotics. Whole-blood supplementation improved the performance of all media. Wilkins-Chalgren agar without blood failed to support the growth of 17% of the strains. All Fusobacterium ulcerans strains were resistant to clindamycin. PMID:2073122

  5. DEVELOPMENT OF AN AGAR LIFT-DNA/DNA HYBRIDIZATION TECHNIQUE FOR USE IN VISUALIZATION OF THE SPATIAL DISTRIBUTION OF EUBACTERIA ON SOIL SURFACES. (R825415)

    EPA Science Inventory

    Abstract

    While microbial growth is well-understood in pure culture systems, less is known about growth in intact soil systems. The objective of this work was to develop a technique to allow visualization of the two-dimensional spatial distribution of bacterial growth o...

  6. Electrospinning of agar/PVA aqueous solutions and its relation with rheological properties

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In this work, we report the successful fabrication of agar-based nanofibers by an electrospinning technique using water as the solvent media. A tubeless spinneret was attached inside the electrospinning chamber, operated at 50 deg C, to avoid agar gelation. Pure agar solution 1% (w/w) showed inadequ...

  7. Characteristic features and dye degrading capability of agar-agar gel immobilized manganese peroxidase.

    PubMed

    Bilal, Muhammad; Asgher, Muhammad; Shahid, Muhammad; Bhatti, Haq Nawaz

    2016-05-01

    Immobilization of enzymes has been regarded as an efficient approach to develop biocatalyst with improved activity and stability characteristics under reaction conditions. In the present study, purified manganese peroxidase (MnP) from Ganoderma lucidum IBL-05 was immobilized in agar-agar support using entrapment technique. Maximum immobilization yield was accomplished at 4.0% agar-agar gel. The immobilized MnP exhibited better resistance to changes in pH and temperature than the free enzyme, with optimal conditions being pH 6.0 and 50 °C. The kinetic parameters Km and Kcat/Km for free and entrapped MnP were calculated to be 65.6 mM and 6.99 M(-1) s(-1), and 82 mM and 8.15 M(-1) s(-1), respectively. Thermo-stability was significantly improved after immobilization. After 120 h, the insolubilized MnP retained its activity up to 71.9% and 60.3% at 30 °C and 40 °C, respectively. It showed activity until 10th cycle and retained 74.3% residual activity after 3th cycle. The effects of H2O2, ionic strength and potential inhibitors on activity of free and immobilized enzyme were investigated. Moreover, the decolorization of three structurally different dyes was monitored in order to assess the degrading capability of the entrapped MnP. The decolorization efficiencies for all the tested dyes were 78.6-84.7% after 12h. The studies concluded that the toxicity of dyes aqueous solutions was significantly reduced after treatment. The remarkable catalytic, thermo-stability and re-cycling features of the agar-agar immobilized MnP display a high potential for biotechnological applications. PMID:26854887

  8. 48 CFR 401.371 - AGAR Advisories.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 48 Federal Acquisition Regulations System 4 2011-10-01 2011-10-01 false AGAR Advisories. 401.371... ACQUISITION REGULATION SYSTEM Agency Acquisition Regulations 401.371 AGAR Advisories. The SPE may issue AGAR Advisories, consistent with the policies of the FAR and the AGAR, for the following purposes: (a)...

  9. 48 CFR 401.371 - AGAR Advisories.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 4 2010-10-01 2010-10-01 false AGAR Advisories. 401.371... ACQUISITION REGULATION SYSTEM Agency Acquisition Regulations 401.371 AGAR Advisories. The SPE may issue AGAR Advisories, consistent with the policies of the FAR and the AGAR, for the following purposes: (a)...

  10. Using overlays to improve network security

    NASA Astrophysics Data System (ADS)

    Keromytis, Angelos D.; Misra, Vishal; Rubenstein, Daniel

    2002-07-01

    As we increase our dependency upon networked communication, the incentive to compromise and degrade network performance increases for those who wish to disrupt the flow of information. Attacks that lead to such compromise and degradation can come in a variety of forms, including distributed denial of service (DDoS) attacks, cutting wires, jamming transmissions, and monitoring/eavesdropping. Users can protect themselves from monitoring by applying cryptographic techniques, and the recent work has explored developing networks that react to DDoS attacks by locating the source(s) of the attack. However, there has been little work that addresses preventing the other kinds of attacks as opposed to reacting to them. Here, we discuss how network overlays can be used to complicate the job of an attacker that wishes to prevent communication. To amplify our point, we focus briefly on a study of preventing DDoS attacks by using overlays.

  11. Overlay similarity: a new overlay index for metrology tool and scanner overlay fingerprint methodology

    NASA Astrophysics Data System (ADS)

    Ke, Chih-Ming; Kao, Ching-Pin; Wang, Yu-Hsi; Hu, Jimmy; Chang, Chen-Yu; Tsai, Ya-Jung; Yen, Anthony; Lin, Burn J.

    2009-03-01

    For different CD metrologies like average CD from CD SEM and optical CD (OCD) from scatterometry, CD point-to-point R2 has been well adopted as the CD correlation index. For different overlay metrologies like image-based box-in-box overlay and scatterometry-based overlay, we propose the cosine similarity as the correlation index of overlay. The cosine similarity is a measure of similarity between two vectors of n dimensions by finding the cosine of the angle between them, often used to compare documents in text mining. It has been widely used in web and document search engines and can be used as the similarity index of overlay tool-to-tool matching and scanner tool-to-tool or day-to-day fingerprint. In this paper, we demonstrate that the cosine similarity has a very high sensitivity to the overly tool performance. We compared the similarities of three generations (A1, A2, A3) of the overlay tools of venders A and B and found that after target re-training and TIS correction on each tool A1 similarity to A3 can be improved from 0.9837 to 0.9951. Overlay point-to-point matching with A3 vs. A1 can be reduced from 4.8 to 2.1 nm. The tool precision similarities, i.e. tool self best similarity, for A1, A2, A3 and B are 0.9986, 0.9990, 0.9995, and 0.9994 respectively. From this table, we demonstrate that we can use old-generation overlay tool with suitable hardware maintenance, to match to the latest-generation overlay tool.

  12. Diffraction based overlay metrology for α-carbon applications

    NASA Astrophysics Data System (ADS)

    Saravanan, Chandra Saru; Tan, Asher; Dasari, Prasad; Goelzer, Gary; Smith, Nigel; Woo, Seouk-Hoon; Shin, Jang Ho; Kang, Hyun Jae; Kim, Ho Chul

    2008-03-01

    Applications that require overlay measurement between layers separated by absorbing interlayer films (such as α- carbon) pose significant challenges for sub-50nm processes. In this paper scatterometry methods are investigated as an alternative to meet these stringent overlay metrology requirements. In this article, a spectroscopic Diffraction Based Overlay (DBO) measurement technique is used where registration errors are extracted from specially designed diffraction targets. DBO measurements are performed on detailed set of wafers with varying α-carbon (ACL) thicknesses. The correlation in overlay values between wafers with varying ACL thicknesses will be discussed. The total measurement uncertainty (TMU) requirements for these layers are discussed and the DBO TMU results from sub-50nm samples are reviewed.

  13. Residual stresses in weld overlay tubes: A finite element study

    SciTech Connect

    Taljat, B.; Zacharia, T.; Wang, X.L.; Keiser, J.R.; Feng, Z.; Jirinec, M.J.

    1997-01-03

    Residual stresses and strains in a tube with circumferential weld overlay were analyzed by the finite element (FE) method. The objective of this work was to develop and verify a FE model, to determine the magnitude and distribution of residual stresses in the weld overlay tube, and to evaluate the significance of two contributing factors to residual stress: (1) difference in material properties between tube and weld material, and (2) thermal gradients in the weld. An axisymmetric FE model was developed to simulate the circumferential two-layer welding process of alloy 625 overlay on SA210 tube. The first layer was modeled as a gas metal arc welding process with filler metal, whereas the autogenous gas tungsten arc welding process was modeled for the second layer. Neutron diffraction technique was used to experimentally determine residual elastic strains in the weld overlay tube. Comparison with the FE results shows overall good agreement. Both the experimental and FE results show high compressive stresses at the inside tube surface and high tensile stresses in the weld overlay. This suggests that weld overlay may be used to relieve tensile or produce compressive stresses at the inside tube surface, which is significant for applications where crack initiation is found at the root pass of the joining weld.

  14. Constructing Overlay Networks with Short Paths and Low Communication Cost

    NASA Astrophysics Data System (ADS)

    Makikawa, Fuminori; Tsuchiya, Tatsuhiro; Kikuno, Tohru

    A Peer-To-Peer (P2P) application uses an overlay network which is a virtual network constructed over the physical network. Traditional overlay construction methods do not take physical location of nodes into consideration, resulting in a large amount of redundant traffic. Some proximity-aware construction methods have been proposed to address this problem. These methods typically connect nearby nodes in the physical network. However, as the number of nodes increases, the path length of a route between two distant nodes rapidly increases. To alleviate this problem, we propose a technique which can be incorporated in existing overlay construction methods. The idea behind this technique is to employ long links to directly connect distant nodes. Through simulation experiments, we show that using our proposed technique, networks can achieve small path length and low communication cost while maintaining high resiliency to failures.

  15. Syneresis and delayed detachment in agar plates.

    PubMed

    Divoux, Thibaut; Mao, Bosi; Snabre, Patrick

    2015-05-14

    Biogels made of crosslinked polymers such as proteins or polysaccharides behave as porous soft solids and store large amounts of solvent. These gels undergo spontaneous aging, called syneresis, which consists of the shrinkage of the gel matrix and the progressive expulsion of solvent. As a result, a biogel originally casted in a container often loses contact with the container sidewalls, and the detachment time is difficult to anticipate a priori, since it may occur over variable time spans (from hours to days). Here we report on syneresis phenomena in agar plates, which consist of Petri dishes filled with a gel mainly composed of agar. Direct observations and speckle pattern correlation analysis allow us to rationalize the delayed detachment of the gel from the sidewall of the Petri dish. The detachment time t* is surprisingly not controlled by the mass loss as one would intuitively expect. Instead, t* is strongly correlated to the gel minimum thickness emin measured along the sidewall of the plate, and increases as a robust function of emin, independently of the prior mass-loss history. Time-resolved correlation spectroscopy atypically applied to such weakly diffusive media gives access to the local thinning rate of the gel. This technique also allows us to detect the gel micro-displacements that are triggered by water evaporation prior to the detachment, and even to anticipate the latter from a few hours. Our work provides observables to predict the detachment time of agar gels in dishes, and highlights the relevance of speckle pattern correlation analysis for the quantitative investigation of the syneresis dynamics in biopolymer gels. PMID:25812667

  16. Fabrication of magnetic bubble memory overlay

    NASA Technical Reports Server (NTRS)

    1973-01-01

    Self-contained magnetic bubble memory overlay is fabricated by process that employs epitaxial deposition to form multi-layered complex of magnetically active components on single chip. Overlay fabrication comprises three metal deposition steps followed by subtractive etch.

  17. Crystal formation in furunculosis agar

    USGS Publications Warehouse

    Bullock, G.L.; Ross, A.J.

    1964-01-01

    SINCE ITS INTRODUCTION SOME MONTHS AGO, FURUNCULOSIS AGAR has been employed in the diagnosis of suspect furunculosis and also as a general purpose medium. During our work with this medium we have noticed discrete "colonies," of crystalline material, which very closely resemble microbial colonies. These crystal colonies are compact and appear on both the surface and subsurface; they occur in inoculated slants and plates incubated for long periods (2 to 3 weeks), as well as in uninoculated stored medium. As the crystal colonies could be confusing to workers using this medium, we decided to attempt to identify them and also to determine whether storage conditions and different lots of medium affect crystal formation.

  18. A quantitative comet assay: imaging and analysis of virus plaques formed with a liquid overlay.

    PubMed

    Zhu, Ying; Yin, John

    2007-01-01

    Although the plaque assay defines a "gold-standard" for measuring virus infectivity, its reliance on plaque counting limits its sensitivity. When the assay is performed with a liquid overlay, instead of agar overlay, spontaneous flows can promote a uni-directional spread of infection, creating elongated regions of cytopathology that resemble comets. As a model system comet and plaque cultures of vesicular stomatitis virus (VSV) on baby hamster kidney (BHK-21) cells were compared. Host-cell monolayers were infected with VSV particles, incubated 15 h in the presence of liquid or agar overlays and stained. VSV formed significantly larger comets than plaques, consistent with a mechanism of flow-enhanced spread. When antiviral drug (5-fluorouracil) was incorporated into the liquid overlay, comet sizes were reduced in a dose-dependent manner. Images of infected monolayers, acquired using a simple digital scanner, enabled a quantification of the inhibitory effect of the drug on infectivity. The resulting measure of drug susceptibility was found to be 18-fold more sensitive than the IC(50) measure attained by the traditional plaque-reduction assay. This quantitative comet assay has the potential to similarly enhance the sensitivity of infection measures for other plaque-forming viruses. PMID:17092573

  19. Instructional geographic information science Map overlay and spatial abilities

    NASA Astrophysics Data System (ADS)

    Tricot, Thomas Alexander, II

    The fundamental goal of this study is to determine if the complex spatial concept of map overlay can be effectively learned by young adolescents through the utilization of an instructional technique based within the foundations of Instructional Geographic Information Science (InGIScience). Percent correct and reaction times were the measures used to analyze the ability of young adolescents to learn the intersect, erase, and union functions of map overlay. The ability to solve for missing inputs, output, or function was also analyzed. Young adolescents of the test group scored higher percent correct and recorded faster reaction times than those of the control group or adults of the expert group by the end of the experiment. The intersect function of map overlay was more difficult in terms of percent correct and reaction time than the erase or union functions. Solving for the first or second input consistently resulted in lower percent correct and higher reaction times throughout the experiment. No overall performance differences were shown to exist between males and females. Results of a subjective "real-world" test also indicated learning by young adolescents. This study has shown that the practice of repetitive instruction and testing has proven effective for enhancing spatial abilities with regard to the map overlay concept. This study found that with practice, young adolescents can learn the map overlay concept and perform at levels equal to or greater than adults. This study has helped to answer the question of whether this development of spatial abilities is possible.

  20. Extending the range of low energy electron diffraction (LEED) surface structure determination: Co-adsorbed molecules, incommensurate overlayers and alloy surface order studied by new video and electron counting LEED techniques

    SciTech Connect

    Ogletree, D.F.

    1986-11-01

    LEED multiple scattering theory is briefly summarized, and aspects of electron scattering with particular significance to experimental measurements such as electron beam coherence, instrument response and phonon scattering are analyzed. Diffuse LEED experiments are discussed. New techniques that enhance the power of LEED are described, including a real-time video image digitizer applied to LEED intensity measurements, along with computer programs to generate I-V curves. The first electron counting LEED detector using a ''wedge and strip'' position sensitive anode and digital electronics is described. This instrument uses picoampere incident beam currents, and its sensitivity is limited only by statistics and counting times. Structural results on new classes of surface systems are presented. The structure of the c(4 x 2) phase of carbon monoxide adsorbed on Pt(111) has been determined, showing that carbon monoxide molecules adsorb in both top and bridge sites, 1.85 +- 0.10 A and 1.55 +- 0.10 A above the metal surface, respectively. The structure of an incommensurate graphite overlayer on Pt(111) is analyzed. The graphite layer is 3.70 +- 0.05 A above the metal surface, with intercalated carbon atoms located 1.25 +- 0.10 A above hollow sites supporting it. The (2..sqrt..3 x 4)-rectangular phase of benzene and carbon monoxide coadsorbed on Pt(111) is analyzed. Benzene molecules adsorb in bridge sites parallel to and 2.10 +- 0.10 A above the surface. The carbon ring is expanded, with an average C-C bond length of 1.72 +- 0.15 A. The carbon monoxide molecules also adsorb in bridge sites. The structure of the (..sqrt..3 x ..sqrt..3) reconstruction on the (111) face of the ..cap alpha..-CuAl alloy has been determined.

  1. Hyperspectral Imaging for Detecting Pathogens Grown on Agar Plates

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This paper is concerned with the development of a hyperspectral imaging technique for detecting and identifying one of the most common foodborne pathogens, Campylobacter. Direct plating using agars is an effective tool for laboratory tests and analyses of microorganisms. The morphology (size, growth...

  2. Hyperspectral imaging for detecting pathogens grown on agar plates

    NASA Astrophysics Data System (ADS)

    Yoon, Seung Chul; Lawrence, Kurt C.; Siragusa, Gregory R.; Line, John E.; Park, Bosoon; Windham, William R.

    2007-09-01

    This paper is concerned with the development of a hyperspectral imaging technique for detecting and identifying one of the most common foodborne pathogens, Campylobacter. Direct plating using agars is an effective tool for laboratory tests and analyses of microorganisms. The morphology (size, growth pattern, color, etc.) of colonies grown on agar plates has been widely used to tentatively differentiate organisms. However, it is sometimes difficult to differentiate target organisms like Campylobacters from other contaminants grown together on the same agar plates. A hyperspectral imaging system operating at the visible and near infrared (VNIR) spectral region from 400 nm to 900 nm was set up to measure spectral signatures of 17 different Campylobacter and non-Campylobacter subspecies. Protocols for culturing, imaging samples and for calibrating measured data were developed. The VNIR spectral library of all 17 organisms commonly encountered in poultry was established from calibrated hyperspectral images. A classification algorithm was developed to locate and identify Campylobacters, non-Campylobacter contaminants, and background agars with 99.29% accuracy. This research has a potential to be expanded to detect other pathogens grown on agar media.

  3. Weld overlay cladding with iron aluminides

    SciTech Connect

    Goodwin, G.M.

    1995-08-01

    The hot and cold cracking tendencies of some early iron aluminide alloy compositions have limited their use in applications where good weldability is required. Using hot crack testing techniques invented at ORNL, and experimental determinations of preheat and postweld heat treatment needed to avoid cold cracking, we have developed iron aluminide filler metal compositions which can be successfully used to weld overlay clad various substrate materials, including 9Cr-1Mo steel, 2-1/4Cr-1Mo steel, and 300-series austenitic stainless steels. Dilution must be carefully controlled to avoid crack-sensitive deposit compositions. The technique used to produce the current filler metal compositions is aspiration-casting, i.e. drawing the liquid from the melt into glass rods. Future development efforts will involve fabrication of composite wires of similar compositions to permit mechanized gas tungsten arc (GTA) and/or gas metal arc (GMA) welding.

  4. Agar-agar entrapment increases the stability of endo-β-1,4-xylanase for repeated biodegradation of xylan.

    PubMed

    Bibi, Zainab; Shahid, Faiza; Ul Qader, Shah Ali; Aman, Afsheen

    2015-04-01

    Microbial xylanases, specially endo-β-1,4-xylanase catalyzes the hydrolysis of xylan, is considered one of the most significant hydrolases. It has numerous applications but most extensively is utilized in paper and pulp industry as a bio-bleaching agent. Immobilization technique is comprehensively studied with the expectation of modifying and improving enzyme stability and characteristics for commercial purposes. Currently, matrix entrapment technique is applied to immobilize endo-β-1,4-xylanase within agar-agar gel beads produced by Geobacillus stearothermophilus KIBGE-IB29. Maximal enzyme immobilization yield was achieved at 2.5% of agar-agar concentration. Optimized conditions demonstrated an increase in the optimal reaction time from 05 min to 30 min and incubation temperature from 50 °C to 60 °C with reference to free enzyme whereas; no effect was observed for optimum pH. Entrapment technique uniquely changed the kinetic parameters of immobilized endo-β-1,4-xylanase (Km: 0.5074 mg min(-1) to 0.5230 mg min(-1) and Vmax: 4773 U min(-1) to 968 U min(-1)) as compared to free enzyme. However, immobilized enzyme displayed broad thermal stability and retained 79.0% of its initial activity at 80 °C up to 30 min whereas; free enzyme completely lost its activity at this temperature. With respect to economic feasibility, the immobilized enzyme showed impressive recycling efficiency up to six reaction cycles. PMID:25603143

  5. Virtual overlay metrology for fault detection supported with integrated metrology and machine learning

    NASA Astrophysics Data System (ADS)

    Lee, Hong-Goo; Schmitt-Weaver, Emil; Kim, Min-Suk; Han, Sang-Jun; Kim, Myoung-Soo; Kwon, Won-Taik; Park, Sung-Ki; Ryan, Kevin; Theeuwes, Thomas; Sun, Kyu-Tae; Lim, Young-Wan; Slotboom, Daan; Kubis, Michael; Staecker, Jens

    2015-03-01

    While semiconductor manufacturing moves toward the 7nm node for logic and 15nm node for memory, an increased emphasis has been placed on reducing the influence known contributors have toward the on product overlay budget. With a machine learning technique known as function approximation, we use a neural network to gain insight to how known contributors, such as those collected with scanner metrology, influence the on product overlay budget. The result is a sufficiently trained function that can approximate overlay for all wafers exposed with the lithography system. As a real world application, inline metrology can be used to measure overlay for a few wafers while using the trained function to approximate overlay vector maps for the entire lot of wafers. With the approximated overlay vector maps for all wafers coming off the track, a process engineer can redirect wafers or lots with overlay signatures outside the standard population to offline metrology for excursion validation. With this added flexibility, engineers will be given more opportunities to catch wafers that need to be reworked, resulting in improved yield. The quality of the derived corrections from measured overlay metrology feedback can be improved using the approximated overlay to trigger, which wafers should or shouldn't be, measured inline. As a development or integration engineer the approximated overlay can be used to gain insight into lots and wafers used for design of experiments (DOE) troubleshooting. In this paper we will present the results of a case study that follows the machine learning function approximation approach to data analysis, with production overlay measured on an inline metrology system at SK hynix.

  6. Agar polysaccharides from Gracilaria species (Rhodophyta, Gracilariaceae).

    PubMed

    Marinho-Soriano, E

    2001-07-26

    Yield, physical and chemical properties of agar from three agarophytes species (Gracilaria gracilis, G. dura and G. bursa-pastoris) were determined. The agar yield from the three species varied significantly (P<0.01). The highest yields of agar (34.8%) and the lowest (30%) were obtained from G. bursa-pastoris and G. gracilis, respectively. Highest gel strength (630+/-15 g cm(-2)) was obtained from agar extracted from G. gracilis and lowest from G. bursa-pastoris (26+/-3.6 g cm(-2)). The values of 3,6-anhydrogalactose were similar for G. gracilis and G. dura and there were no significant differences among the species. The sulfate contents varied significantly (P<0.01) and the higher value was obtained from G. bursa-pastoris. Among the three species, G. gracilis showed superior agar quality than the other two species, hence it can be considered a good potential source for industrial use. PMID:11472802

  7. TES overlayed on MOLA DEM

    NASA Technical Reports Server (NTRS)

    1999-01-01

    This image is TES thermal data (Orbit 222) overlayed on the MOLA DEM. The color scale is TES T18-T25, which is a cold spot index. The grey scale is MOLA elevation in kilometers. Most cold spots can be attributed to surface spectral emissivity effects. Regions that are colored black-violet-blue have near unity emissivity and are coarse grained CO2. Regions that are yellow-red are fined grained CO2. The red-white spot located approximately 300W85N is our most likely candidate for a CO2 snow storm.

  8. Overlays for classroom and optometric use.

    PubMed

    Wilkins, A

    1994-01-01

    Perceptual distortion of printed text can sometimes be reduced by placing upon the page a sheet of coloured plastic (overlay). The colour that best reduces the distortion differs from one individual to another and may need to be selected with precision. A set of overlays has been developed that samples the CIE UCS diagram systematically. The overlays are robust and have a matte finish. They can be combined in an intuitive way to provide a wide range of chromaticities. PMID:7512256

  9. A modified agar plate method for detection of Strongyloides stercoralis.

    PubMed

    Koga, K; Kasuya, S; Khamboonruang, C; Sukhavat, K; Ieda, M; Takatsuka, N; Kita, K; Ohtomo, H

    1991-10-01

    The agar plate method is a new technique with high detection rates for coprological diagnosis of human strongyloidiasis. This report details modifications of the technique and establishes a standardized procedure. We recommend that all plates should be carefully observed using a microscope because macroscopic observation can lead to false negative results. It is also advisable to pour formalin solution directly into microscopically positive dishes to collect worms by sedimentation. This procedure enables one to observe worms otherwise hidden. Sealing dishes with adhesive tape prevents larvae from crawling out of the dishes, eliminating any possibility in the reduction of detection rates, and greatly improves the safety conditions for the technician performing the procedure. We consider the agar plate method to be superior to the filter paper method in detecting Strongyloides, and we believe that it will eventually become the technique of choice. PMID:1951861

  10. Analysis Of Overlay Distortion Patterns

    NASA Astrophysics Data System (ADS)

    Armitage, John D.; Kirk, Joseph P.

    1988-01-01

    A comprehensive geometrical approach is presented for the least-squares analysis of overlay distortion patterns into useful, physically meaningful systematic distortion subpatterns and an essentially non-systematic residue. A scheme of generally useful distortion sub-patterns is presented in graphic and algorithmic form; some of these sub-patterns are additions to those already in widespread use. A graphic and geometric approach is emphasized rather than an algebraic or statistical approach, and an example illustrates the value in utilizing the pattern-detecting ability of the eye-brain system. The conditions are described under which different distortion sub-patterns may interact, possibly leading to misleading or erroneous conclusions about the types and amounts of different distortions present. Examples of typical interaction situations are given, and recommendations are made for analytic procedures to avoid misinterpretation. It is noted that the lower-order distortion patterns preserve straight-line linearity, but that higher-order distortion may result in straight lines becoming curved. The principle of least-squares analysis is outlined and a simple polynomial data-fitting example is used to illustrate the method. Algorithms are presented for least-squares distortion analysis of overlay patterns, and an APL2 program is given to show how this may easily be implemented on a digital computer. The appendix extends the treatment to cases where small-angle approximation is not permissible.

  11. BWR pipe crack and weld clad overlay studies

    SciTech Connect

    Shack, W.J.; Kassner, T.F.; Maiya, P.S.; Park, J.Y.; Ruther, W.E.; Rybicki, E.F.

    1985-10-01

    This paper presents results on (a) the influence of simulated BWR environments and temperature on the intergranular-stress-corrosion cracking (IGSCC) susceptibility of sensitized stainless steels (SS), (b) the stress-corrosion susceptibility of alternative piping materials, (c) analysis of field components to assess the effectiveness of in-service inspection techniques and the in-reactor performance of weld overlay repairs, and (d) finite-element analyses and experimental measurement of residual stresses in weldments with weld overlays. Fracture-mechanics crack-growth data are presented to confirm correlations between the critical corrosion potentials required to inhibit IGSCC and the level of impurities in the environment. Slow-strain-rate tests show that very low levels of impurities (25 ppb of sulfate) can produce suseptibility to transgranular-stress-corrosion cracking (TGSCC) in Type 316NG SS and that nitrogen levels is SS above 0.1 wt. % appear to increase susceptibility to TGSCC. Preliminary results on a German Type 347NG SS suggest that it is at least as resistant to TGSCC in impurity environments as Type 316NG SS. Measurements on overlay weldments removed from the Hatch-2 reactor confirm that compressive residual stresses are produced on the inner surface of the weldments by the overlay.

  12. Weld overlay cladding with iron aluminides

    SciTech Connect

    Goodwin, G.M.

    1996-11-01

    The hot and cold cracking tendencies of some early iron aluminide alloy compositions limited their use to applications where good weldability was not required. Considerable progress has been made toward improving this situation. Using hot crack testing techniques developed at ORNL and a systematic study of alloy compositional effects, we have established a range of compositions within which hot cracking resistance is very good, essentially equivalent to stainless steel. Cold cracking, however, remains an issue, and extensive efforts are continuing to optimize composition and welding parameters, especially preheat and postweld heat treatment, to minimize its occurrence. In terms of filler metal and process development, we have progressed from sheared strip through aspiration cast rod and shielded metal arc electrodes to the point where we can now produce composite wire with a steel sheath and aluminum core in coil form, which permits the use of both the gas tungsten arc and gas metal arc processes. This is a significant advancement in that the gas metal arc process lends itself well to automated welding, and is the process of choice for commercial weld overlay applications. Using the newly developed filler metals, we have prepared clad specimens for testing in a variety of environments both in-house and outside ORNL, including laboratory and commercial organizations. As a means of assessing the field performance of this new type of material, we have modified several non-pressure boundary boiler components, including fuel nozzles and port shrouds, by introducing areas of weld overlay in strategic locations, and have placed these components in service in operating boilers for a side-by-side comparison with conventional corrosion-resistant materials.

  13. CFDP for Interplanetary Overlay Network

    NASA Technical Reports Server (NTRS)

    Burleigh, Scott C.

    2011-01-01

    The CCSDS (Consultative Committee for Space Data Systems) File Delivery Protocol for Interplanetary Overlay Network (CFDP-ION) is an implementation of CFDP that uses IO' s DTN (delay tolerant networking) implementation as its UT (unit-data transfer) layer. Because the DTN protocols effect automatic, reliable transmission via multiple relays, CFDP-ION need only satisfy the requirements for Class 1 ("unacknowledged") CFDP. This keeps the implementation small, but without loss of capability. This innovation minimizes processing resources by using zero-copy objects for file data transmission. It runs without modification in VxWorks, Linux, Solaris, and OS/X. As such, this innovation can be used without modification in both flight and ground systems. Integration with DTN enables the CFDP implementation itself to be very simple; therefore, very small. Use of ION infrastructure minimizes consumption of storage and processing resources while maximizing safety.

  14. Some Experiments With Agar-Grown Seedlings

    ERIC Educational Resources Information Center

    Freeland, P. W.

    1973-01-01

    Two percent agar gel is reported as a better medium for germination and growth studies. Students can be encouraged to undertake many simple experiments and make precise observations by using this medium. (PS)

  15. Comparison of a new, bismuth-iron-sulfite-cycloserine agar for isolation of Clostridium perfringens with the tryptose-sulfite-cycloserine and blood agars.

    PubMed

    Gubash, S M; Ingham, L

    1997-02-01

    A new differential and selective, bismuth-iron-sulfite-cycloserine (BISC) medium, for isolation and enumeration of Clostridium perfringens from food and feces, was developed. The medium was compared with the widely-used tryptose-sulfite-cycloserine (TSC) medium and blood agar (BA) in recovering actively growing cells, cold- (refrigerated and frozen) stressed, and heat-stressed C. perfringens cells, and heat-activated spores from human feces. Both selective media were satisfactory in recovering actively growing cells and heat-activated spores of C. perfringens. Both were inferior to non-inhibitory blood agar in recovering heat or cold-stressed cells. The advantages of the new BISC medium over the TSC medium were: elimination of the need to prepare pour- or overlay-agar plates, which simplified inoculation of specimens on the medium and simplified the subcultures of colonies for confirmatory identification. All colonies of C. perfringens developed on BISC were black or dark gray. This was contrary to TSC medium, which gave, on average, 39.6% of white colonies when inoculated with the pure cultures of C. perfringens. PMID:9084113

  16. Electrospinning of agar/PVA aqueous solutions and its relation with rheological properties.

    PubMed

    Sousa, Ana M M; Souza, Hiléia K S; Uknalis, Joseph; Liu, Shih-Chuan; Gonçalves, Maria P; Liu, LinShu

    2015-01-22

    In this work, we report the successful fabrication of agar-based nanofibers by electrospinning technique, using water as solvent media. A tubeless spinneret was attached inside the electrospinning chamber, operating at 50°C, to avoid agar gelation. Agar pure solution (1 wt%) showed inadequate spinnability regardless of the used electrospinning conditions. The addition of a co-blending polymer such as PVA (10 wt% starting solution) improved the solutions viscoelasticity and hence, the solutions spinnability. Agar/PVA solutions were prepared with different mass ratios (100/0, 50/50, 40/60, 30/70, 20/80 and 0/100) and electrospun at various sets of electrospinning conditions. Best nanofibers were obtained with 30/70 and 20/80 agar/PVA blends while samples with higher agar contents (50/50 and 40/60 agar/PVA) were harder to process and led to discontinuous fibrous mats. This first set of encouraging results can open a new window of opportunities for agar-based biomaterials in the form of nanofibers. PMID:25439904

  17. Device overlay method for high volume manufacturing

    NASA Astrophysics Data System (ADS)

    Lee, Honggoo; Han, Sangjun; Kim, Youngsik; Kim, Myoungsoo; Heo, Hoyoung; Jeon, Sanghuck; Choi, DongSub; Nabeth, Jeremy; Brinster, Irina; Pierson, Bill; Robinson, John C.

    2016-03-01

    Advancing technology nodes with smaller process margins require improved photolithography overlay control. Overlay control at develop inspection (DI) based on optical metrology targets is well established in semiconductor manufacturing. Advances in target design and metrology technology have enabled significant improvements in overlay precision and accuracy. One approach to represent in-die on-device as-etched overlay is to measure at final inspection (FI) with a scanning electron microscope (SEM). Disadvantages to this approach include inability to rework, limited layer coverage due to lack of transparency, and higher cost of ownership (CoO). A hybrid approach is investigated in this report whereby infrequent DI/FI bias is characterized and the results are used to compensate the frequent DI overlay results. The bias characterization is done on an infrequent basis, either based on time or triggered from change points. On a per-device and per-layer basis, the optical target overlay at DI is compared with SEM on-device overlay at FI. The bias characterization results are validated and tracked for use in compensating the DI APC controller. Results of the DI/FI bias characterization and sources of variation are presented, as well as the impact on the DI correctables feeding the APC system. Implementation details in a high volume manufacturing (HVM) wafer fab will be reviewed. Finally future directions of the investigation will be discussed.

  18. Interacting epidemics on overlay networks

    NASA Astrophysics Data System (ADS)

    Funk, Sebastian; Jansen, Vincent A. A.

    2010-03-01

    The interaction between multiple pathogens spreading on networks connecting a given set of nodes presents an ongoing theoretical challenge. Here, we aim to understand such interactions by studying bond percolation of two different processes on overlay networks of arbitrary joint degree distribution. We find that an outbreak of a first pathogen providing immunity to another one spreading subsequently on a second network connecting the same set of nodes does so most effectively if the degrees on the two networks are positively correlated. In that case, the protection is stronger the more heterogeneous the degree distributions of the two networks are. If, on the other hand, the degrees are uncorrelated or negatively correlated, increasing heterogeneity reduces the potential of the first process to prevent the second one from reaching epidemic proportions. We generalize these results to cases where the edges of the two networks overlap to arbitrary amount, or where the immunity granted is only partial. If both processes grant immunity to each other, we find a wide range of possible situations of coexistence or mutual exclusion, depending on the joint degree distribution of the underlying networks and the amount of immunity granted mutually. These results generalize the concept of a coexistence threshold and illustrate the impact of large-scale network structure on the interaction between multiple spreading agents.

  19. Agar agar-stabilized milled zerovalent iron particles for in situ groundwater remediation.

    PubMed

    Velimirovic, Milica; Schmid, Doris; Wagner, Stephan; Micić, Vesna; von der Kammer, Frank; Hofmann, Thilo

    2016-09-01

    Submicron-scale milled zerovalent iron (milled ZVI) particles produced by grinding macroscopic raw materials could provide a cost-effective alternative to nanoscale zerovalent iron (nZVI) particles for in situ degradation of chlorinated aliphatic hydrocarbons in groundwater. However, the aggregation and settling of bare milled ZVI particles from suspension presents a significant obstacle to their in situ application for groundwater remediation. In our investigations we reduced the rapid aggregation and settling rate of bare milled ZVI particles from suspension by stabilization with a "green" agar agar polymer. The transport potential of stabilized milled ZVI particle suspensions in a diverse array of natural heterogeneous porous media was evaluated in a series of well-controlled laboratory column experiments. The impact of agar agar on trichloroethene (TCE) removal by milled ZVI particles was assessed in laboratory-scale batch reactors. The use of agar agar significantly enhanced the transport of milled ZVI particles in all of the investigated porous media. Reactivity tests showed that the agar agar-stabilized milled ZVI particles were reactive towards TCE, but that their reactivity was an order of magnitude less than that of bare, non-stabilized milled ZVI particles. Our results suggest that milled ZVI particles could be used as an alternative to nZVI particles as their potential for emplacement into contaminated zone, their reactivity, and expected longevity are beneficial for in situ groundwater remediation. PMID:26596889

  20. Pigments of fly agaric (Amanita muscaria).

    PubMed

    Stintzing, Florian; Schliemann, Willibald

    2007-01-01

    The complex pigment pattern of fly agaric (Amanita muscaria) cap skins has been studied by LC-DAD and mass spectrometry. Among the betaxanthins the corresponding derivatives of serine, threonine, ethanolamine, alanine, Dopa, phenylalanine and tryptophan are reported for the first time to contribute to the pigment pattern of fly agarics. Betalamic acid, the chromophoric precursor of betaxanthins and betacyanins, muscaflavin and seco-dopas were also detected. Furthermore, the red-purple muscapurpurin and the red muscarubrin were tentatively assigned while further six betacyanin-like components could not be structurally allocated. Stability studies indicated a high susceptibility of pigment extracts to degradation which led to rapid colour loss thus rendering a complete characterization of betacyanin-like compounds impossible at present. Taking into account these difficulties the presented results may be a starting point for a comprehensive characterization of the pigment composition of fly agarics. PMID:18274277

  1. A moving overlay shrinks the attentional blink.

    PubMed

    Chua, Fook K

    2015-01-01

    This report describes a study examining the effects of overlaying a veil of spots on the letters in a central rapid serial visual presentation stream. Observers identified two target letters (T1 and T2, respectively) embedded in a stream of distractor letters printed in a different color. In Experiment 1, the attentional blink (AB) diminished when a different overlay veiled each letter, such that the spots appeared to move as the letters changed. Experiment 2 concerned whether the performance enhancement occurred because the overlay hampered processing of the lag 1 distractor, thus weakening the distractor's interference with T1. Experiment 3 focused on how changing the overlay at or around T1 affected the AB. The attention disengagement hypothesis was proposed to explain the common theme in the results-that performance was only enhanced when different overlays were applied to the T1 and lag 1 frames. The claim is that the AB reflects a failure of prompt attentional disengagement from T1, which, in turn, delays reengagement when T2 appears shortly thereafter. When T1's disappearance is accompanied by an overlay change, the perceptual system gets an additional cue signaling that the visual scene has changed, thereby inducing attentional disengagement. Apart from facilitating prompt reengagement at the next target, earlier disengagement also improves target recovery by excluding features of the trailing item, likely to be a distractor, from working memory. PMID:25245077

  2. Weld overlay cladding with iron aluminides

    SciTech Connect

    Goodwin, G.M.

    1997-12-01

    The author has established a range of compositions for these alloys within which hot cracking resistance is very good, and within which cold cracking can be avoided in many instances by careful control of welding conditions, particularly preheat and postweld heat treatment. For example, crack-free butt welds have been produced for the first time in 12-mm thick wrought Fe{sub 3}Al plate. Cold cracking, however, still remains an issue in many cases. The author has developed a commercial source for composite weld filler metals spanning a wide range of achievable aluminum levels, and are pursuing the application of these filler metals in a variety of industrial environments. Welding techniques have been developed for both the gas tungsten arc and gas metal arc processes, and preliminary work has been done to utilize the wire arc process for coating of boiler tubes. Clad specimens have been prepared for environmental testing in-house, and a number of components have been modified and placed in service in operating kraft recovery boilers. In collaboration with a commercial producer of spiral weld overlay tubing, the author is attempting to utilize the new filler metals for this novel application.

  3. The Effect of Colored Overlays on Reading Fluency in Individuals with Dyslexia.

    PubMed

    Denton, Tiffany Freeze; Meindl, James N

    2016-09-01

    Colored overlays, one type of tinted filter, are plastic reading sheets tinted with color and placed over text to eliminate or alleviate a wide range of reading difficulties such as low reading rate, accuracy, and comprehension. The effects of colored overlays on reading problems associated with dyslexia were investigated in this study via a multielement design. Reading fluency was assessed when participants read with and without colored overlays. Undifferentiated responding, or decreased accuracy, resulted across three participants, suggesting that colored overlays were ineffective and potentially detrimental to participants' reading abilities. As a result, empirically validated reading techniques were implemented across individuals. These findings are discussed and recommendations are made in regards to the use of research-based reading interventions. PMID:27622123

  4. Enumeration of food-borne Clostridium perfringens in egg yolk-free tryptose-sulfite-cycloserine agar.

    PubMed

    Hauschild, A H; Hilsheimer, R

    1974-03-01

    The SFP (Shahidi-Ferguson perfringens), TSC (tryptose-sulfite-cycloserine), EY (egg yolk)-free TSC, and OPSP (oleandomycin-polymyxin-sulfadiazine perfringens) agars have been tested for their suitability to enumerate Clostridium perfringens in naturally contaminated foods. Complete recoveries of C. perfringens were obtained in each of the four media, but only the TSC and EY-free TSC agars were sufficiently selective to ensure subsequent confirmatory tests without interference from facultative anaerobes. Because of some disadvantages associated with the use of egg yolk, EY-free TSC agar is recommended for enumeration of C. perfringens in foods. Several conditions for convenient shipment of foods and C. perfringens isolates with minimum loss of viability have been tested. The highest viable counts were preserved when foods were mixed 1:1 (wt/vol) with 20% glycerol and kept in a container with dry ice. Isolated C. perfringens strains remained viable for at least 2 weeks at ambient temperatures on blood agar slopes with a 2% agar overlay in screw-cap culture tubes. PMID:4363368

  5. Enumeration of Food-Borne Clostridium perfringens in Egg Yolk-Free Tryptose-Sulfite-Cycloserine Agar

    PubMed Central

    Hauschild, A. H. W.; Hilsheimer, R.

    1974-01-01

    The SFP (Shahidi-Ferguson perfringens), TSC (tryptose-sulfite-cycloserine), EY (egg yolk)-free TSC, and OPSP (oleandomycin-polymyxin-sulfadiazine perfringens) agars have been tested for their suitability to enumerate Clostridium perfringens in naturally contaminated foods. Complete recoveries of C. perfringens were obtained in each of the four media, but only the TSC and EY-free TSC agars were sufficiently selective to ensure subsequent confirmatory tests without interference from facultative anaerobes. Because of some disadvantages associated with the use of egg yolk, EY-free TSC agar is recommended for enumeration of C. perfringens in foods. Several conditions for convenient shipment of foods and C. perfringens isolates with minimum loss of viability have been tested. The highest viable counts were preserved when foods were mixed 1:1 (wt/vol) with 20% glycerol and kept in a container with dry ice. Isolated C. perfringens strains remained viable for at least 2 weeks at ambient temperatures on blood agar slopes with a 2% agar overlay in screw-cap culture tubes. PMID:4363368

  6. Scatterometry or imaging overlay: a comparative study

    NASA Astrophysics Data System (ADS)

    Hsu, Simon C. C.; Pai, Yuan Chi; Chen, Charlie; Yu, Chun Chi; Hsing, Henry; Wu, Hsing-Chien; Kuo, Kelly T. L.; Amir, Nuriel

    2015-03-01

    Most fabrication facilities today use imaging overlay measurement methods, as it has been the industry's reliable workhorse for decades. In the last few years, third-generation Scatterometry Overlay (SCOL™) or Diffraction Based Overlay (DBO-1) technology was developed, along another DBO technology (DBO-2). This development led to the question of where the DBO technology should be implemented for overlay measurements. Scatterometry has been adopted for high volume production in only few cases, always with imaging as a backup, but scatterometry overlay is considered by many as the technology of the future. In this paper we compare imaging overlay and DBO technologies by means of measurements and simulations. We outline issues and sensitivities for both technologies, providing guidelines for the best implementation of each. For several of the presented cases, data from two different DBO technologies are compared as well, the first with Pupil data access (DBO-1) and the other without pupil data access (DBO-2). Key indicators of overlay measurement quality include: layer coverage, accuracy, TMU, process robustness and robustness to process changes. Measurement data from real cases across the industry are compared and the conclusions are also backed by simulations. Accuracy is benchmarked with reference OVL, and self-consistency, showing good results for Imaging and DBO-1 technology. Process sensitivity and metrology robustness are mostly simulated with MTD (Metrology Target Designer) comparing the same process variations for both technologies. The experimental data presented in this study was done on ten advanced node layers and three production node layers, for all phases of the IC fabrication process (FEOL, MEOL and BEOL). The metrology tool used for most of the study is KLA-Tencor's Archer 500LCM system (scatterometry-based and imaging-based measurement technologies on the same tool) another type of tool is used for DBO-2 measurements. Finally, we conclude that

  7. Use of agar agar stabilized milled zero-valent iron particles for in situ groundwater remediation

    NASA Astrophysics Data System (ADS)

    Schmid, Doris; Velimirović, Milica; Wagner, Stephan; Micić Batka, Vesna; von der Kammer, Frank; Hofmann, Thilo

    2015-04-01

    A major obstacle for use of nanoscale zero-valent iron (nZVI) particles as a nontoxic material for effective in situ degradation of chlorinated aliphatic hydrocarbons (CAHs) is the high production cost. For that reason, submicro-scale milled zero-valent iron particles were recently developed (milled ZVI, UVR-FIA, Germany) by grinding macroscopic raw materials of elementary iron as a cheaper alternative to products produced by solid-state reduction. However, milled ZVI particles tend to aggregate and due to the rather large particle size (d50= 11.9 µm) also rapidly sediment. To prevent aggregation and consequently sedimentation of milled ZVI particles and therefore improve the mobility after in situ application, the use of a stabilizer is considered in literature as a most promising option. In this study, milled ZVI particles (1 g L-1 of particle concentration) were stabilized by environmentally friendly polymer agar agar (>0.5 g L-1), which had a positive impact on the milled ZVI stability. Sedimentation rate was significantly decreased by increasing the suspension viscosity. Column transport experiments were performed for bare and agar agar stabilized milled ZVI particles in commercially available fine grained quartz sand (DORSILIT® Nr.8, Gebrüder Dorfner GmbH Co, Germany) and different porous media collected from brownfields. The experiments were carried out under field relevant injection conditions of 100 m d-1. The maximal travel distance (LT) of less than 10 cm was determined for non-stabilized suspension in fine grained quartz sand, while agar agar (1 g L-1) stabilized milled ZVI suspension revealed LT of 12 m. Similar results were observed for porous media from brownfields showing that mobility of agar agar stabilized particle suspensions was significantly improved compared to bare particles. Based on the mobility data, agar agar stabilized milled zero-valent iron particles could be used for in situ application. Finally, lab-scale batch degradation

  8. Polymer concrete overlay on SH-51, bridge deck

    NASA Astrophysics Data System (ADS)

    Borg, T. M.

    1982-06-01

    A thin resinous overlay was placed on a sound bridge deck in Oklahoma to evaluate its performance over one year using various physical tests. The evaluation shows how well the overlay protects the reinforcing steel from corrosion due to deicing salts. The steps leading to the construction of the overlay are detailed as well as the actual placing of the overlay. The results of various physical tests are reported for both before and after the overlay.

  9. Ductile film delamination from compliant substrates using hard overlayers

    PubMed Central

    Cordill, M.J.; Marx, V.M.; Kirchlechner, C.

    2014-01-01

    Flexible electronic devices call for copper and gold metal films to adhere well to polymer substrates. Measuring the interfacial adhesion of these material systems is often challenging, requiring the formulation of different techniques and models. Presented here is a strategy to induce well defined areas of delamination to measure the adhesion of copper films on polyimide substrates. The technique utilizes a stressed overlayer and tensile straining to cause buckle formation. The described method allows one to examine the effects of thin adhesion layers used to improve the adhesion of flexible systems. PMID:25641995

  10. Epitaxial interactions between molecular overlayers and ordered substrates

    NASA Astrophysics Data System (ADS)

    Hillier, Andrew C.; Ward, Michael D.

    1996-11-01

    A framework for evaluating the epitaxy of crystalline organic overlayers of generic symmetry on ordered substrates is described, which combines a computationally efficient analytical method for explicit determination of the type of epitaxy (i.e., commensurism, coincidence, or incommensurism) and overlayer azimuthal orientation with an analysis of the elastic properties of the overlayer and the overlayer-substrate interface. The azimuthal orientations predicted by the analytical method agree with values predicted by semiempirical potential-energy calculations and observed experimentally for previously reported organic overlayers which are demonstrated here to be coincident. Calculations based on this analytical approach are much less computationally intensive than potential-energy calculations, as the number of computational operations is independent of the overlayer size chosen for analysis. This enables analyses to be performed for the large overlayer basis sets common for molecular overlayers. Furthermore, this facilitates the analysis of coincident overlayers, for which the overlayer size needs to be large enough to establish a phasing relationship between a substrate and a large nonprimitive overlayer supercell so that the global minimum with respect to azimuthal angle can be determined. The computational efficiency of this method also enables a convenient examination of numerous possible reconstructed overlayer configurations in which the lattice parameters are bracketed around those of the native overlayer, thereby allowing examination of possible epitaxy-driven overlayer reconstructions. When combined with calculated intralayer- and overlayer-substrate elastic constants, this method provides a strategy for the design of heteroepitaxial molecular films.

  11. [THE APPLICATION OF SELECTIVE CHROMOGENIC AGAR FOR DETECTING ENTEROBACTERIA WITH PRODUCTION OF BETA-LACTAMASES].

    PubMed

    Korobova, A G; Frolova, L N; Kliasova, G A

    2015-11-01

    The detection of enterobacteria with production of beta-lactamases of extended spectrum in selective chromogenic agar was analyzed The results ofdetection of beta-lactamases of extended spectrum was compared with "double disc" technique. The smears from mucous membrane of guttur and rectum from patients were analyzed in parallel on solid growth agar (Endo or Mac Conkey) and on selective agar CHROMagartm ESBL (CHROMagar France). The production of beta-lactamases of extended spectrum was confirmed using "double discs" technique. To exclude hyper-production of ampC beta-lactamases E-test was applied containing cefotetan and cefotetan with cloxacillin. The sampling consisted of 1552 samples from patients. The study permitted to isolate 1243 strains of enterobacteria on agar Endo or Mac Conkey and 409 strains of enterobacteria on selective agar CHROMagartm ESBL (Escherichia coli n = 226, Klebsiella pneumoniae n = 105, enterobacter spp. n = 35, Citrobacter spp. n = 21, others n = 22). The application of "double discs" technique confirmed production of beta-lactamases of extended spectrum in 386 (94%) out of 409 strains isolated on agar CHROMagartm ESBL. In 23 (6%) of strains no confirmation was established and hyper-production of ampC of beta-lactamases was established 15 out of total. Additionally, 8 were sensitive to cephalosporin of third generation. All enterobacteria isolated on agar Endo or Mac Conkey also were tested by "double discs" technique. Overall, 394 strains of enterobacteria with production of beta-lactamases of extended spectrum were obtained. On all agars (agar Endo or Mac Conkey and CHROMagartm ESBL)--263 (67%) strains; only on CHROMagartm ESBL--123 (31%) and only on agar Endo or Mac Conkey--8 (2%) (p < 0.0001). The sensitivity of selective agar CHROMagartm ESBL made up to 98% and specificity--97%. The resolution about detection of enterobacteria producing beta-lactamases of extended spectrum were submitted to clinic in 18-24 hours after arrival

  12. Enhacement of intrafield overlay using a design based metrology system

    NASA Astrophysics Data System (ADS)

    Jo, Gyoyeon; Ji, Sunkeun; Kim, Shinyoung; Kang, Hyunwoo; Park, Minwoo; Kim, Sangwoo; Kim, Jungchan; Park, Chanha; Yang, Hyunjo; Maruyama, Kotaro; Park, Byungjun

    2016-03-01

    As the scales of the semiconductor devices continue to shrink, accurate measurement and control of the overlay have been emphasized for securing more overlay margin. Conventional overlay analysis methods are based on the optical measurement of the overlay mark. However, the overlay data obtained from these optical methods cannot represent the exact misregistration between two layers at the circuit level. The overlay mismatch may arise from the size or pitch difference between the overlay mark and the real pattern. Pattern distortion, caused by CMP or etching, could be a source of the overlay mismatch as well. Another issue is the overlay variation in the real circuit pattern which varies depending on its location. The optical overlay measurement methods, such as IBO and DBO that use overlay mark on the scribeline, are not capable of defining the exact overlay values of the real circuit. Therefore, the overlay values of the real circuit need to be extracted to integrate the semiconductor device properly. The circuit level overlay measurement using CDSEM is time-consuming in extracting enough data to indicate overall trend of the chip. However DBM tool is able to derive sufficient data to display overlay tendency of the real circuit region with high repeatability. An E-beam based DBM(Design Based Metrology) tool can be an alternative overlay measurement method. In this paper, we are going to certify that the overlay values extracted from optical measurement cannot represent the circuit level overlay values. We will also demonstrate the possibility to correct misregistration between two layers using the overlay data obtained from the DBM system.

  13. Robotic weld overlay coatings for erosion control

    SciTech Connect

    Not Available

    1994-11-01

    The erosion of materials by the impact of solid particles has received increasing attention during the past twenty years. Recently, research has been initiated with the event of advanced coal conversion processes in which erosion plays an important role. The resulting damage, termed Solid Particle Erosion (SPE), is of concern primarily because of the significantly increased operating costs which result in material failures. Reduced power plant efficiency due to solid particle erosion of boiler tubes and waterfalls has led to various methods to combat SPE. One method is to apply coatings to the components subjected to erosive environments. Protective weld overlay coatings are particularly advantageous in terms of coating quality. The weld overlay coatings are essentially immune to spallation due to a strong metallurgical bond with the substrate material. By using powder mixtures, multiple alloys can be mixed in order to achieve the best performance in an erosive environment. However, a review of the literature revealed a lack of information on weld overlay coating performance in erosive environments which makes the selection of weld overlay alloys a difficult task. The objective of this project is to determine the effects of weld overlay coating composition and microstructure on erosion resistance. These results will lead to a better understanding of erosion mitigation in CFB`s.

  14. Robotic weld overlay coatings for erosion control

    NASA Astrophysics Data System (ADS)

    The erosion of materials by the impact of solid particles has received increasing attention during the past twenty years. Recently, research has been initiated with the event of advanced coal conversion processes in which erosion plays an important role. The resulting damage, termed Solid Particle Erosion (SPE), is of concern primarily because of the significantly increased operating costs which result in material failures. Reduced power plant efficiency due to solid particle erosion of boiler tubes and waterfalls has led to various methods to combat SPE. One method is to apply coatings to the components subjected to erosive environments. Protective weld overlay coatings are particularly advantageous in terms of coating quality. The weld overlay coatings are essentially immune to spallation due to a strong metallurgical bond with the substrate material. By using powder mixtures, multiple alloys can be mixed in order to achieve the best performance in an erosive environment. However, a review of the literature revealed a lack of information on weld overlay coating performance in erosive environments which makes the selection of weld overlay alloys a difficult task. The objective of this project is to determine the effects of weld overlay coating composition and microstructure on erosion resistance. These results will lead to a better understanding of erosion mitigation in CFB's.

  15. Culture of Piscirickettsia salmonis on enriched blood agar.

    PubMed

    Mauel, Michael J; Ware, Cynthia; Smith, Pedro A

    2008-03-01

    Piscirickettsia salmonis is the etiologic agent of piscirickettsiosis, an economically significant disease of fish. Isolation of P. salmonis by culturing on fish cell lines has been the standard technique since the initial isolation of the organism. The ability to grow P. salmonis on artificial media would relieve facilities of the cost of maintaining cell lines, permit isolation at fish culture sites with fewer contamination problems, and allow easier transport of isolates to diagnostic facilities for confirmation assays. This report describes the successful culture of P. salmonis on enriched blood agar. PMID:18319435

  16. Weld overlay coatings for erosion control

    SciTech Connect

    Levin, B.; DuPont, J.N.; Marder, A.R.

    1993-03-03

    A literature review was made. In spite of similarities between abrasive wear and solid particle erosion, weld overlay hardfacing alloys that exhibit high abrasion resistance may not necessarily have good erosion resistance. The performance of weld overlay hardfacing alloys in erosive environments has not been studied in detail. It is believed that primary-solidified hard phases such as carbides and intermetallic compounds have a strong influence on erosion resistance of weld overlay hardfacing alloys. However, relationships between size, shape, and volume fraction of hard phases in a hardfacing alloys and erosion resistance were not established. Almost all hardfacing alloys can be separated into two major groups based upon chemical compositions of the primary solidified hard phases: (a) carbide hardening alloys (Co-base/carbide, WC-Co and some Fe base superalloys); and (b) intermetallic hardening alloys (Ni-base alloys, austenitic steels, iron-aluminides).

  17. Luminescent DNA- and agar-based membranes.

    PubMed

    Leones, R; Fernandes, M; Ferreira, R A S; Cesarino, I; Lima, J F; Carlos, L D; Bermudez, V de Zea; Magon, C J; Donoso, J P; Silva, M M; Pawlicka, A

    2014-09-01

    Luminescent materials containing europium ions are investigated for different optical applications. They can be obtained using bio-macromolecules, which are promising alternatives to synthetic polymers based on the decreasing oil resources. This paper describes studies of the DNA- and Agar-europium triflate luminescent membranes and its potential technological applications are expanded to electroluminescent devices. Polarized optical microscopy demonstrated that the samples are birefringent with submicrometer anisotropy. The X-ray diffraction analysis revealed predominantly amorphous nature of the samples and the atomic force microscopy images showed a roughness of the membranes of 409.0 and 136.1 nm for the samples of DNA10Eu and Agar1.11Eu, respectively. The electron paramagnetic resonance spectra of the DNA(n)Eu membranes with the principal lines at g ≈ 2.0 and g ≈ 4.8 confirmed uniform distribution of rare earth ions in a disordered matrix. Moreover, these strong and narrow resonance lines for the samples of DNA(n)Eu when compared to the Agar(n)Eu suggested a presence of paramagnetic radicals arising from the DNA matrix. The emission spectra suggested that the Eu3+ ions occupy a single local environment in both matrices and the excitation spectra monitored around the Eu emission lines pointed out that the Eu3+ ions in the Agar host were mainly excited via the broad band component rather than by direct intra-4f(6) excitation, whereas the opposite case occurred for the DNA-based sample. PMID:25924317

  18. Thin agar film for enhanced fungal growth and microscopic viewing in a new sealable fungal culture case.

    PubMed

    Hill, D R

    1996-09-01

    This project was undertaken to find ways to enhance fungus colony maturation, to make viewing of fungal cultures easier, and to reduce disruption of the fungal structures to be observed for identification. Accordingly, a technique using a thin (0.2-mm) agar film that avoids problems inherent in traditional methods of fungal culture and identification was developed. In addition, to accommodate the 0.2-mm layer of agar film and a contiguous thicker 4-mm section of agar, a sealable fungal culture case that fits within microscope stage calipers and under the objective lenses was invented. The growth and identification of 28 organisms were evaluated in the sealable fungal culture cases and on double-pour agar plates by using potato dextrose agar in both. Compared with results obtained with the double-pour agar plates (rated as "good"), fungal growth and identification with the sealable fungal culture case were superior (rated as "excellent") (P < 0.05, chi-square test). The thin agar film limits excessive mycelial growth, while it often promotes complete sporulation or other forms of maturation of the fungal colony. More importantly, the thin agar film allows direct microscopic viewing of the developing fungal colonies. The portion of the sealable fungal culture case with the 4-mm layer of agar can be used for evaluation of colony pigment and texture. In conclusion, this new sealable fungal culture case allows direct viewing and earlier fungal species identification with greater intrinsic safety. PMID:8862573

  19. KML Super Overlay to WMS Translator

    NASA Technical Reports Server (NTRS)

    Plesea, Lucian

    2007-01-01

    This translator is a server-based application that automatically generates KML super overlay configuration files required by Google Earth for map data access via the Open Geospatial Consortium WMS (Web Map Service) standard. The translator uses a set of URL parameters that mirror the WMS parameters as much as possible, and it also can generate a super overlay subdivision of any given area that is only loaded when needed, enabling very large areas of coverage at very high resolutions. It can make almost any dataset available as a WMS service visible and usable in any KML application, without the need to reformat the data.

  20. Robotic weld overlay coatings for erosion control

    SciTech Connect

    Levin, B.F.; Dupont, J.N.; Marder, A.R.

    1993-04-18

    Twelve weld overlay hardfacing alloys have been selected for preliminary erosion testing based on a literature review These alloys have been separated into three major groups: (1) Cobalt containing alloys, (2) Nickel-base alloys, (3) Iron base alloys. These alloys are being applied to carbon steel substrates and will undergo preliminary erosion testing to identify candidates weld overlay alloys for erosion control in CFB boilers. The candidate alloys selected from the preliminary erosion tests will then undergo more detailed evaluations in future research.

  1. Hybrid overlay metrology for high order correction by using CDSEM

    NASA Astrophysics Data System (ADS)

    Leray, Philippe; Halder, Sandip; Lorusso, Gian; Baudemprez, Bart; Inoue, Osamu; Okagawa, Yutaka

    2016-03-01

    Overlay control has become one of the most critical issues for semiconductor manufacturing. Advanced lithographic scanners use high-order corrections or correction per exposure to reduce the residual overlay. It is not enough in traditional feedback of overlay measurement by using ADI wafer because overlay error depends on other process (etching process and film stress, etc.). It needs high accuracy overlay measurement by using AEI wafer. WIS (Wafer Induced Shift) is the main issue for optical overlay, IBO (Image Based Overlay) and DBO (Diffraction Based Overlay). We design dedicated SEM overlay targets for dual damascene process of N10 by i-ArF multi-patterning. The pattern is same as device-pattern locally. Optical overlay tools select segmented pattern to reduce the WIS. However segmentation has limit, especially the via-pattern, for keeping the sensitivity and accuracy. We evaluate difference between the viapattern and relaxed pitch gratings which are similar to optical overlay target at AEI. CDSEM can estimate asymmetry property of target from image of pattern edge. CDSEM can estimate asymmetry property of target from image of pattern edge. We will compare full map of SEM overlay to full map of optical overlay for high order correction ( correctables and residual fingerprints).

  2. Differential signal scatterometry overlay metrology: an accuracy investigation

    NASA Astrophysics Data System (ADS)

    Kandel, Daniel; Adel, Mike; Dinu, Berta; Golovanevsky, Boris; Izikson, Pavel; Levinski, Vladimir; Vakshtein, Irina; Leray, Philippe; Vasconi, Mauro; Salski, Bartlomiej

    2007-06-01

    The overlay control budget for the 32nm technology node will be 5.7nm according to the ITRS. The overlay metrology budget is typically 1/10 of the overlay control budget resulting in overlay metrology total measurement uncertainty (TMU) requirements of 0.57nm for the most challenging use cases of the 32nm node. The current state of the art imaging overlay metrology technology does not meet this strict requirement, and further technology development is required to bring it to this level. In this work we present results of a study of an alternative technology for overlay metrology - Differential signal scatterometry overlay (SCOL). Theoretical considerations show that overlay technology based on differential signal scatterometry has inherent advantages, which will allow it to achieve the 32nm technology node requirements and go beyond it. We present results of simulations of the expected accuracy associated with a variety of scatterometry overlay target designs. We also present our first experimental results of scatterometry overlay measurements, comparing this technology with the standard imaging overlay metrology technology. In particular, we present performance results (precision and tool induced shift) and address the issue of accuracy of scatterometry overlay. We show that with the appropriate target design and algorithms scatterometry overlay achieves the accuracy required for future technology nodes.

  3. Colors, colored overlays, and reading skills

    PubMed Central

    Uccula, Arcangelo; Enna, Mauro; Mulatti, Claudio

    2014-01-01

    In this article, we are concerned with the role of colors in reading written texts. It has been argued that colored overlays applied above written texts positively influence both reading fluency and reading speed. These effects would be particularly evident for those individuals affected by the so called Meares-Irlen syndrome, i.e., who experience eyestrain and/or visual distortions – e.g., color, shape, or movement illusions – while reading. This condition would interest the 12–14% of the general population and up to the 46% of the dyslexic population. Thus, colored overlays have been largely employed as a remedy for some aspects of the difficulties in reading experienced by dyslexic individuals, as fluency and speed. Despite the wide use of colored overlays, how they exert their effects has not been made clear yet. Also, according to some researchers, the results supporting the efficacy of colored overlays as a tool for helping readers are at least controversial. Furthermore, the very nature of the Meares-Irlen syndrome has been questioned. Here we provide a concise, critical review of the literature. PMID:25120525

  4. Robotic weld overlay coatings for erosion control

    NASA Astrophysics Data System (ADS)

    Levin, B. F.; Dupont, J. N.; Marder, A. R.

    1994-01-01

    Research is being conducted to develop criteria for selecting weld overlay coatings for erosion mitigation in circulated fluidized beds. Twelve weld overlay alloys were deposited on 1018 steel substrates using plasma arc welding. Ten samples from each coating were prepared for erosion testing. All selected coatings were erosion tested at 400C and their erosion resistance and microstructure evaluated. Steady state erosion rates were similar for several weld overlay coatings (Ultimet, Inconel-625, Iron-Aluminide, 316L SS, and High Chromium Cast Iron) and were considerably lower than the remaining coating evaluated. These coatings had different base (Co, Fe, Ni-base). No correlations were found between room temperature microhardness of the weld overlay coatings and their erosion resistance at elevated temperature, although this criteria is often thought to be an indicator of erosion resistance. It was suggested that the coatings that showed similar erosion rates may have similar mechanical properties such as fracture strength, toughness and work hardening rates at this temperature. During the past quarter, Iron-Aluminide, Inconel-625, and 316L SS coatings were selected for more detailed investigations based upon the preliminary erosion test results. Microhardness tests were performed on eroded samples to determine the size of the work hardened zone and change in coatings hardness due to erosion. The work hardened zone was correlated with erosion resistance of the coatings. Additional Iron-Aluminide, Inconel-625, and 316L SS coatings were deposited on 1018 steel substrates.

  5. Infrared differential interference contrast microscopy for overlay metrology on 3D-interconnect bonded wafers

    NASA Astrophysics Data System (ADS)

    Ku, Yi-sha; Shyu, Deh-Ming; Lin, Yeou-Sung; Cho, Chia-Hung

    2013-04-01

    Overlay metrology for stacked layers will be playing a key role in bringing 3D IC devices into manufacturing. However, such bonded wafer pairs present a metrology challenge for optical microscopy tools by the opaque nature of silicon. Using infrared microscopy, silicon wafers become transparent to the near-infrared (NIR) wavelengths of the electromagnetic spectrum, enabling metrology at the interface of bonded wafer pairs. Wafers can be bonded face to face (F2F) or face to back (F2B) which the stacking direction is dictated by how the stacks are carried in the process and functionality required. For example, Memory stacks tend to use F2B stacking enables a better managed design. Current commercial tools use single image technique for F2F bonding overlay measurement because depth of focus is sufficient to include both surfaces; and use multiple image techniques for F2B overlay measurement application for the depth of focus is no longer sufficient to include both stacked wafer surfaces. There is a need to specify the Z coordinate or stacking wafer number through the silicon when visiting measurement wafer sites. Two shown images are of the same (X, Y) but separate Z location acquired at focus position of each wafer surface containing overlay marks. Usually the top surface image is bright and clear; however, the bottom surface image is somewhat darker and noisier as an adhesive layer is used in between to bond the silicon wafers. Thus the top and bottom surface images are further processed to achieve similar brightness and noise level before merged for overlay measurement. This paper presents a special overlay measurement technique, using the infrared differential interference contrast (DIC) microscopy technique to measure the F2B wafer bonding overlay by a single shot image. A pair of thinned wafers at 50 and 150 μm thickness is bonded on top of a carrier wafer to evaluate the bonding overlay. It works on the principle of interferometry to gain information about the

  6. Combined overlay, focus and CD metrology for leading edge lithography

    NASA Astrophysics Data System (ADS)

    Ebert, Martin; Cramer, Hugo; Tel, Wim; Kubis, Michael; Megens, Henry

    2011-04-01

    and Focus measurements respectively. In addition CD profile information can be measured enabling proximity matching applications. By using a technique [2][3][4] to de-convolve dose and focus based on the profile measurement of a well-characterized process monitor target, we show that the dose and focus signature of a high NA 193nm immersion scanner can be effectively measured and corrected. A similar approach was also taken to address overlay errors using the diffraction based overlay capability [5] of the same metrology tool. We demonstrate the advantage of having a single metrology tool solution, which enables us to reduce dose, focus and overlay variability to their minimum non-correctable signatures. This technique makes use of the high accuracy and repeatability of the YieldStar tool and provides a common reference of scanner setup and user process. Using ASML's YieldStar in combination with ASML scanners, and control solutions allows for a direct link from the metrology tool to the system settings, ensuring that the appropriate system settings can be easily and directly updated.

  7. Improved agar diffusion method for detecting residual antimicrobial agents.

    PubMed

    Tsai, C E; Kondo, F

    2001-03-01

    The improved agar diffusion method for determination of residual antimicrobial agents was investigated, and the sensitivities of various combinations of test organisms and assay media were determined using 7 organisms, 5 media, and 31 antimicrobial agents. Bacillus stearothermophilus and synthetic assay medium (SAM) showed the greatest sensitivity for screening penicillins (penicillin G and ampicillin). The combination of Bacillus subtilis and minimum medium (MM) was the most sensitive for tetracyclines (oxytetracycline and chlortetracycline), B. stearothermophilus and SAM or Micrococcus luteus and Mueller-Hinton agar (MHA) for detecting tylosin and erythromycin, B. subtilis and MHA for aminoglycosides (streptomycin, kanamycin, gentamicin, and dihydrostreptomycin), B. stearothermophilus and SAM for polyethers (salinomycin and lasalocid), and B. subtilis and MM or Clostridium perfringens and GAM for polypeptides (thiopeptin, enramycin, virginiamycin, and bacitracin). However, gram-negative bacterium Escherichia coli ATCC 27166 and MM were better for screening for colistin and polymixin-B. For detecting the synthetic drugs tested, the best combination was B. subtilis and MM for sulfonamides, E. coli 27166 and MM for quinolones (oxolinic acid and nalidixic acid), B. subtilis and MM for furans (furazolidone), and the bioluminescent bacterium Photobacterium phosphoreum and luminescence assay medium for chloramphenicol and oxolinic acid. The results showed that the use of four assay plates, B. stearothermophilus and SAM, B. subtilis and MM, M. luteus and MHA, and E. coli 27166 and MM, was superior to the currently available techniques for screening for residual antimicrobial agents in edible animal tissues. PMID:11252480

  8. Homogeneous Matrix Deposition on Dried Agar for MALDI Imaging Mass Spectrometry of Microbial Cultures

    NASA Astrophysics Data System (ADS)

    Hoffmann, Thomas; Dorrestein, Pieter C.

    2015-11-01

    Matrix deposition on agar-based microbial colonies for MALDI imaging mass spectrometry is often complicated by the complex media on which microbes are grown. This Application Note demonstrates how consecutive short spray pulses of a matrix solution can form an evenly closed matrix layer on dried agar. Compared with sieving dry matrix onto wet agar, this method supports analyte cocrystallization, which results in significantly more signals, higher signal-to-noise ratios, and improved ionization efficiency. The even matrix layer improves spot-to-spot precision of measured m/z values when using TOF mass spectrometers. With this technique, we established reproducible imaging mass spectrometry of myxobacterial cultures on nutrient-rich cultivation media, which was not possible with the sieving technique.

  9. Biological treatment of textile dyes by agar-agar immobilized consortium in a packed bed reactor.

    PubMed

    Patel, Yogesh; Gupte, Akshaya

    2015-03-01

    The decolorization of Acid Maroon V was investigated using bacterial consortium EDPA containing Enterobacter dissolvens AGYP1 and Pseudomonas aeruginosa AGYP2 immobilized in different entrapment matrices. The consortium displayed 96% removal of dye (100 mg/l) within 6 h when immobilized in agar-agar. Under optimum concentrations of agar-agar (3.0% w/v) and cell biomass (0.9 g% w/v), the consortium displayed decolorization for 18 successive batches of Acid Maroon V and also decolorized 14 other different textile dyes. A packed bed reactor under batch mode showed 89% decolorization of dye after 56 repetitive cycles. Under continuous flow mode, maximum color removal was achieved with bed length of 36 cm, hydraulic retention time of 2.66 h, and dye concentration of 100 mg/l. Additionally, the reactor decolorized relatively higher concentrations (100-2000 mg/l) of dye. The synthetic dye wastewater containing five textile dyes was decolorized 92% with 62% COD reduction using an immobilized consortium. PMID:25842535

  10. In die mask overlay control for 14nm double-patterning lithography

    NASA Astrophysics Data System (ADS)

    Chou, William; Cheng, James; Tseng, Alex C. P.; Wu, J. K.; Chang, Chin Kuei; Cheng, Jeffrey; Lee, Adder; Huang, Chain Ting; Peng, N. T.; Hsu, Simon C. C.; Yu, Chun Chi; Lu, Colbert; Yu, Julia; Craig, Peter; Pollock, Chuck; Ham, Young; McMurran, Jeff

    2015-10-01

    According to the ITRS roadmap, semiconductor industry drives the 193nm lithography to its limits, using techniques like Double Pattern Technology (DPT), Source Mask Optimization (SMO) and Inverse Lithography Technology (ILT). In terms of considering the photomask metrology, full in-die measurement capability is required for registration and overlay control with challenging specifications for repeatability and accuracy. Double patterning using 193nm immersion lithography has been adapted as the solution to enable 14nm technology nodes. The overlay control is one of the key figures for the successful realization of this technology. In addition to the various error contributions from the wafer scanner, the reticles play an important role in terms of considering lithographic process contributed errors. Accurate pattern placement of the features on reticles with a registration error below 4nm is mandatory to keep overall photomask contributions to overlay of sub 20nm logic within the allowed error budget. In this paper, we show in-die registration errors using 14nm DPT product masks, by measuring in-die overlay patterns comparing with regular registration patterns. The mask measurements are used to obtain an accurate model to predict mask contribution on wafer overlay of double patterning technology.

  11. A Spatial Overlay Ranking Method for a Geospatial Search of Text Objects

    USGS Publications Warehouse

    Lanfear, Kenneth J.

    2006-01-01

    Earth-science researchers need the capability to find relevant information by location and topic. Conventional geographic techniques that simply check whether polygons intersect can efficiently achieve a high recall on location, but can not achieve precision for ranking results in likely order of importance to the reader. A spatial overlay ranking based upon how well an object's footprint matches the search area provides a more effective way to spatially search a collection of reports, and avoids many of the problems associated with an 'in/out' (True/False) boolean search. Moreover, spatial overlay ranking appears to work well even when spatial extent is defined only by a simple bounding box.

  12. Recovery of spores of Clostridium botulinum in yeast extract agar and pork infusion agar after heat treatment.

    PubMed

    Odlaug, T E; Pflug, I J

    1977-10-01

    Yeast extract agar, pork infusion agar, and modifications of these media were used to recover heated Clostridium botulinum spores. The D- and z-values were determined. Two type A strains and one type B strain of C. botulinum were studied. In all cases the D-values were largest when the spores were recovered in yeast extract agar, compared to the D-values for spores recovered in pork infusion agar. The z-values for strains 62A and A16037 were largest when the spores were recovered in pork infusion agar. The addition of sodium bicarbonate and sodium thioglycolate to pork infusion agar resulted in D-values for C. botulinum 62A spores similar to those for the same spores recovered in yeast extract agar. The results suggest that sodium bicarbonate and sodium thioglycolate should be added to recovery media for heated C. botulinum spores to obtain maximum plate counts. PMID:335970

  13. A study of swing-curve physics in diffraction-based overlay

    NASA Astrophysics Data System (ADS)

    Bhattacharyya, Kaustuve; den Boef, Arie; Storms, Greet; van Heijst, Joost; Noot, Marc; An, Kevin; Park, Noh-Kyoung; Jeon, Se-Ra; Oh, Nang-Lyeom; McNamara, Elliott; van de Mast, Frank; Oh, SeungHwa; Lee, Seung Yoon; Hwang, Chan; Lee, Kuntack

    2016-03-01

    With the increase of process complexity in advanced nodes, the requirements of process robustness in overlay metrology continues to tighten. Especially with the introduction of newer materials in the film-stack along with typical stack variations (thickness, optical properties, profile asymmetry etc.), the signal formation physics in diffraction-based overlay (DBO) becomes an important aspect to apply in overlay metrology target and recipe selection. In order to address the signal formation physics, an effort is made towards studying the swing-curve phenomena through wavelength and polarizations on production stacks using simulations as well as experimental technique using DBO. The results provide a wealth of information on target and recipe selection for robustness. Details from simulation and measurements will be reported in this technical publication.

  14. Overlay Tolerances For VLSI Using Wafer Steppers

    NASA Astrophysics Data System (ADS)

    Levinson, Harry J.; Rice, Rory

    1988-01-01

    In order for VLSI circuits to function properly, the masking layers used in the fabrication of those devices must overlay each other to within the manufacturing tolerance incorporated in the circuit design. The capabilities of the alignment tools used in the masking process determine the overlay tolerances to which circuits can be designed. It is therefore of considerable importance that these capabilities be well characterized. Underestimation of the overlay accuracy results in unnecessarily large devices, resulting in poor utilization of wafer area and possible degradation of device performance. Overestimation will result in significant yield loss because of the failure to conform to the tolerances of the design rules. The proper methodology for determining the overlay capabilities of wafer steppers, the most commonly used alignment tool for the production of VLSI circuits, is the subject of this paper. Because cost-effective manufacturing process technology has been the driving force of VLSI, the impact on productivity is a primary consideration in all discussions. Manufacturers of alignment tools advertise the capabilities of their equipment. It is notable that no manufacturer currently characterizes his aligners in a manner consistent with the requirements of producing very large integrated circuits, as will be discussed. This has resulted in the situation in which the evaluation and comparison of the capabilities of alignment tools require the attention of a lithography specialist. Unfortunately, lithographic capabilities must be known by many other people, particularly the circuit designers and the managers responsible for the financial consequences of the high prices of modern alignment tools. All too frequently, the designer or manager is confronted with contradictory data, one set coming from his lithography specialist, and the other coming from a sales representative of an equipment manufacturer. Since the latter generally attempts to make his

  15. Media delivery and media service overlays

    NASA Astrophysics Data System (ADS)

    Wee, Susie

    2005-03-01

    Multimedia communication and streaming media services will become mainstream network infrastructure applications in the coming decade. However, there are many challenges that must be overcome. These challenges include the Internet"s limited ability to handle real-time, low-latency media streams, the need for media security, and an uncertainty of the killer app. The nature of these challenges lends itself to enabling technology innovations in the media delivery and media processing space. Specifically, we envision an overlay infrastructure that supports networked media services that couple media delivery with in-network media processing. The media overlay should be programmable to allow rapid deployment of new applications and services and manageable so as to support the evolving requirements of the resulting usage models. Furthermore, the media overlay should allow for the delivery of protected media content for applications that have security requirements. A properly architected infrastructure can enable real-time multimedia communication and streaming media services in light of the inherent challenges.

  16. Evaluation of CP Chromo Select Agar for the enumeration of Clostridium perfringens from water.

    PubMed

    Manafi, Mammad; Waldherr, Kerstin; Kundi, Michael

    2013-10-01

    The European Directive on drinking water quality has included mCP agar as the reference method for recovering Clostridium perfringens from drinking waters. In the present study, three media (mCP, TSCF and CP Chromo Select Agar) were evaluated for recovery of C. perfringens in different surface water samples. Out of 139 water samples, using a membrane filtration technique, 131 samples (94.2%) were found to be presumptively positive for C. perfringens in at least one of the culture media. Green colored colonies on CP Chromo Select Agar (CCP agar) were counted as presumptive C. perfringens isolates. Out of 483 green colonies on CCP agar, 96.3% (465 strains, indole negative) were identified as C. perfringens, and 15 strains (3.1%) were indole positive and were identified as Clostridium sordellii, Clostridium bifermentans or Clostridium tetani. Only 3 strains (0.6%) gave false positive results and were identified as Clostridium fallax, Clostridium botulinum, and Clostridium tertium. Variance analysis of the data obtained shows statistically no significant differences in the counts obtained between media employed in this work. The mCP method is very onerous for routine screening and bacterial colonies could not be used for further biochemical testing. The colonies on CCP and TSCF were easy to count and subculture for confirmation tests. TSCF detects sulfite-reducing clostridia, including species other than C. perfringens, and in some cases excessive blackening of the agar frustrated counting of the colonies. If the contamination was too high, TSCF did not consistently produce black colonies and as a consequence, the colonies were white and gave false negative results. On the other hand, the identification of typical and atypical colonies isolated from all media demonstrated that CCP agar was the most useful medium for C. perfringens recovery in water samples. PMID:23816139

  17. Automatic Surface Inoculation of Agar Trays1

    PubMed Central

    Wilkins, Judd R.; Mills, Stacey M.; Boykin, Elizabeth H.

    1972-01-01

    A machine is described which automatically inoculates a plastic tray containing agar media with a culture by use of either a conventional inoculating loop or a cotton swab. Isolated colonies were obtained with an inoculating loop when a heavy inoculum (109 cells/ml) was used or with a cotton swab when a light inoculum (ca. 104 cells/ml) was used. Trays containing combinations of differential or selective media were used to (i) separate mixtures of gram-positive and gram-negative bacteria, (ii) facilitate isolation of organisms from clinical specimens, and (iii) compare colony growth characteristics of pure cultures. The design of the machine is simple, it is easy to use, and it relieves the operator from the manual task of streaking cultures. Images PMID:16349943

  18. Poisoning with brown fly agaric, Amanita regalis.

    PubMed

    Elonen, E; Tarssanen, L; Härkönen, M

    1979-01-01

    Three patients ate different amounts of a common northern mushroom, brown fly agaric, Amanita regalis. All of them believed they had eaten delicious parasol mushrooms, Macrolepiota procera. The symptoms of poisoning began 1--2 hours after ingestion of the mushrooms. All the patients had marked gastrointestinal symptoms: nausea and heavy vomiting. Two had central nervous system manifestations and cholinergic symptoms: hallucinations, confusion, or loss of consciousness as well as copious salivation, or sweating. All patients recovered within 4--24 hours without any damage to liver, kidneys or central nervous system. It seems that cooking the mushrooms does not completely neutralize the toxic agents of Amanita regalis. The analysis of fried mushrooms shows that it may be possible to identify mushrooms reliably from the remains of a meal. PMID:760400

  19. Blot overlays with 32P-labeled fusion proteins.

    PubMed

    Zhao, Z; Lim, L; Manser, E

    2001-07-01

    Proteins labeled with 32P can be used as sensitive "prime" in blot overlays to detect binding proteins or domains. Small G-protein Ras can bind GTP with extremely high affinity (Kd approximately 10(-11)-10(-12) M) in the presence of Mg2+. We have taken advantage of this property of Ras to develop a vector that expresses proteins of interest such as glutathione S-transferase (GST)/Ras fusion proteins for noncovalent labeling with [gamma-32P]GTP. The labeling efficiency of this method is >60% and involves a single short incubation step. We have previously identified several binding proteins for the second SH3 domain of the adaptor Nck using this method. Here we illustrate the overlay method using the GST/Ras system and compare results with the SH3 domain labeled by phosphorylation with [gamma-32P]ATP. Both methods are similarly specific and sensitive; however, we show that signals are dependent primarily on GST-mediated probe dimerization. These dimeric probes allow a more stable probe-target complex similar to immunoglobulin interactions, thus significantly improving the sensitivity of the technique. PMID:11403569

  20. Lecithin-agar assay for lecithinase antibodies in serum.

    PubMed

    Sibinovic, K H; Brown, F A; Pettigrew, K D; Vought, R L

    1971-01-01

    A technique for assay of lecithinase antibodies in serum was developed in this laboratory by using a lecithin-agar plate diffusion procedure based on a combination of described plate assays. Egg yolk lipoprotein composed primarily of lecithin was used as a substrate for reaction with free or non-neutralized lecithinase C after incubation of known amounts of lecithinase C with various dilutions of control and test sera. It was found that the size of the reaction zone was a function of enzyme concentration and inversely proportional to the antibody concentration. Accuracy and precision of the assay were determined. In addition, lecithinase antibody levels in sera from experimentally inoculated rats and rabbits and sera from randomly selected human patients were studied. PMID:4322282

  1. Lecithin-Agar Assay for Lecithinase Antibodies in Serum

    PubMed Central

    Sibinovic, Kyle H.; Brown, Freddie A.; Pettigrew, Karen D.; Vought, Robert L.

    1971-01-01

    A technique for assay of lecithinase antibodies in serum was developed in this laboratory by using a lecithin-agar plate diffusion procedure based on a combination of described plate assays. Egg yolk lipoprotein composed primarily of lecithin was used as a substrate for reaction with free or non-neutralized lecithinase C after incubation of known amounts of lecithinase C with various dilutions of control and test sera. It was found that the size of the reaction zone was a function of enzyme concentration and inversely proportional to the antibody concentration. Accuracy and precision of the assay were determined. In addition, lecithinase antibody levels in sera from experimentally inoculated rats and rabbits and sera from randomly selected human patients were studied. Images PMID:4322282

  2. Hyperspectral image reconstruction using RGB color for foodborne pathogen detection on agar plates

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This paper reports the latest development of a color vision technique for detecting colonies of foodborne pathogens grown on agar plates with a hyperspectral image classification model that was developed using full hyperspectral data. The hyperspectral classification model depended on reflectance sp...

  3. Overlay improvement by ASML HOWA 5th alignment strategy

    NASA Astrophysics Data System (ADS)

    Wang, Raf; Chiang, CY; Hsu, Wilson; Yang, Richer; Shih, Todd; Chen, Jackie; Chiu, Jonathan; Lin, Wythe

    2009-12-01

    Overlay control is more challenging when DRAM volume production continues to shrink its critical dimention (CD) to 70nm and beyond. Effected by process, the overlay behavior at wafer edge is quite different from wafer center. The big contribution to worse overlay at wafer edge which causes yield loss is misalignment. The analysis in wafer edge suggests that high order uncorrectable overlay residuals are often observed by certain process impact. Therefore, the basic linear model used for alignment correction is not sufficient and it is necessary to introduce an advanced alignment correction model for wafer edge overlay improvement. In this study, we demonstrated the achievement of moderating the poor overlay at wafer edge area by using a high order wafer alignment strategy. The mechanism is to use non-linear correction methods of high order models ( up to 5th order), with support by the function High Order Wafer Alignment (known as HOWA) in scanner. Instead of linear model for the 6 overlay parameters which come from average result, HOWA alignment strategy can do high order fitting through the wafer to get more accurate overlay parameters which represent the local wafer grid distortion better. As a result, the overlay improvement for wafer edge is achieved. Since alignment is a wafer dependent correction, with HOWA the wafer to wafer overlay variation can be improved dynamically as well. In addition, the effects of different mark quantity and sampling distribution from HOWA are also introduced in this paper. The results of this study indicate that HOWA can reduce uncorrectable overlay residual by 30~40% and improve wafer-to-wafer overlay variation significantly. We conclude that HOWA is a noteworthy strategy for overlay improvement. Moreover, optimized alignment mark numbers and distribution layout are also key factors to make HOWA successful.

  4. AgarTrap-mediated genetic transformation using intact gemmae/gemmalings of the liverwort Marchantia polymorpha L.

    PubMed

    Tsuboyama-Tanaka, Shoko; Kodama, Yutaka

    2015-03-01

    The dioecious liverwort, Marchantia polymorpha L., is an emerging model plant. Various molecular biological techniques have been optimized for M. polymorpha for the past several years, and recently we reported a simplified Agrobacterium-mediated transformation method using sporelings (immature thalli from spores) of M. polymorpha. This method, termed AgarTrap (Agar-utilized Transformation with Pouring Solutions), completed by exchanging appropriate solutions on a single Petri dish to produce a sufficient number of independent transgenic sporelings. However, because spores are produced by crosses between males and females, the genetic backgrounds of resulting transgenic sporelings are not uniform. To easily produce transgenic liverworts with a uniform genetic background using AgarTrap, we developed an AgarTrap-mediated transformation method using intact gemmae/gemmalings produced by asexual reproduction. Using AgarTrap with male and female gemmae/gemmalings produced a sufficient number of independent transgenic gemmalings with uniform genetic backgrounds. The optimized transformation efficiencies were approximately 30 and 50 % in males and females, respectively. As with AgarTrap using sporelings, AgarTrap using intact gemmae/gemmalings will be useful in promoting studies of the molecular biology of M. polymorpha. PMID:25663453

  5. Experimental AC (Asphalt Concrete) overlays of PCC pavement

    NASA Astrophysics Data System (ADS)

    Smith, R. D.

    1983-11-01

    A series of experimental asphalt concrete (AC) overlays was constructed over an existing distressed portland cement concrete pavement on Interstate 80 near Boca, California. The experimental overlays included rubberized dense-graded AC, rubberized open-graded AC, a rubber flush coat interlayer, dense-graded AC with short polyester fibers and Bituthene interlayer strips. The report presents a description and discussion of AC mix batching, construction observations, laboratory testing, overlay covering, and initial performance evaluation.

  6. Highly corrosion resistant weld overlay for oil patch applications

    SciTech Connect

    Hibner, E.L.; Maligas, M.N.; Vicic, J.C.

    1994-12-31

    Petroleum equipment companies currently sell 4130 and 4140 steel pipe with alloy 625 (UNS N06625) weld overlay for Oil Patch applications. Alloy 686 (UNS N06686), because of it`s superior corrosion resistance, is currently being evaluated as a replacement material for alloy 625. Mechanical properties and Slow Strain Rate test results for the alloy 686 weld overlay are discussed relative to the alloy 625 weld overlay.

  7. Sampling for advanced overlay process control

    NASA Astrophysics Data System (ADS)

    Choi, DongSub; Izikson, Pavel; Sutherland, Doug; Sherman, Kara; Manka, Jim; Robinson, John C.

    2008-03-01

    Overlay metrology and control have been critical for successful advanced microlithography for many years, and are taking on an even more important role as time goes on. Due to throughput constraints it is necessary to sample only a small subset of overlay metrology marks, and typical sample plans are static over time. Standard production monitoring and control involves measuring sufficient samples to calculate up to 6 linear correctables. As design rules shrink and processing becomes more complex, however, it is necessary to consider higher order modeled terms for control, fault detection, and disposition. This in turn, requires a higher level of sampling. Due to throughput concerns, however, careful consideration is needed to establish a base-line sampling, and higher levels of sampling can be considered on an exception-basis based on automated trigger mechanisms. The goal is improved scanner control and lithographic cost of ownership. This study addresses tools for establishing baseline sampling as well as motivation and initial results for dynamic sampling for application to higher order modeling.

  8. Sampling for advanced overlay process control

    NASA Astrophysics Data System (ADS)

    Kato, Cindy; Kurita, Hiroyuki; Izikson, Pavel; Robinson, John C.

    2009-03-01

    Overlay metrology and control have been critical for successful advanced microlithography for many years, and are taking on an even more important role as time goes on. Due to throughput constraints it is necessary to sample only a small subset of overlay metrology marks, and typical sample plans are static over time. Standard production monitoring and control involves measuring sufficient samples to calculate up to 6 linear correctables. As design rules shrink and processing becomes more complex, however, it is necessary to consider higher order models with additional degrees of freedom for control, fault detection, and disposition. This in turn, requires a higher level of sampling and a careful consideration of flyer removal. Due to throughput concerns, however, careful consideration is needed to establish a baseline sampling plan using rigorous statistical methods. This study focuses on establishing a 3x nm node immersion lithography production-worthy sampling plan for 3rd order modeling, verification of the accuracy, and proof of robustness of the sampling. In addition we discuss motivation for dynamic sampling for application to higher order modeling.

  9. Investigation of Iron Aluminide Weld Overlays

    SciTech Connect

    Banovic, S.W.; DuPont, J.B.; Levin, B.F.; Marder, A.R.

    1999-08-02

    Conventional fossil fired boilers have been retrofitted with low NO(sub)x burners in order for the power plants to comply with new clean air regulations. Due to the operating characteristics of these burners, boiler tube sulfidation corrosion typically has been enhanced resulting in premature tube failure. To protect the existing panels from accelerated attack, weld overlay coatings are typically being applied. By depositing an alloy that offers better corrosion resistance than the underlying tube material, the wastage rates can be reduced. While Ni-based and stainless steel compositions are presently providing protection, they are expensive and susceptible to failure via corrosion-fatigue due to microsegregation upon solidification. Another material system presently under consideration for use as a coating in the oxidation/sulfidation environments is iron-aluminum. These alloys are relatively inexpensive, exhibit little microsegregation, and show excellent corrosion resistance. However, their use is limited due to weldability issues and their lack of corrosion characterization in simulated low NO(sub)x gas compositions. Therefore a program was initiated in 1996 to evaluate the use of iron-aluminum weld overlay coatings for erosion/corrosion protection of boiler tubes in fossil fired boilers with low NO(sub)x burners. Investigated properties included weldability, corrosion behavior, erosion resistance, and erosion-corrosion performance.

  10. Selected elements in fly agaric Amanita muscaria.

    PubMed

    Falandysz, J; Kunito, T; Kubota, R; Lipka, K; Mazur, A; Falandysz, Justyna J; Tanabe, S

    2007-09-01

    Concentrations of Ag, Al, Ba, Ca, Cd, Co, Cu, Cr, Cs, Fe, Ga, Hg, K, Mg, Mn, Mo, Na, Pb, Rb, Se, Sb, Sr, V, Tl and Zn have been determined in the whole fruiting bodies, as well as separately in caps and stalks, of fly agaric collected from three geographically distant sites in northern part of Poland. The elements were determined using ICP-MS, ICP-OES, HG-AAS and CV-AAS, respectively. For elements such as Al, Ba, Cr, Fe, Ga, Mo, Mn, Pb, Sb, Sr, Tl, and V concentrations were similar in the caps and stalks, respectively, and for K, Zn, Ag, Ca, Cd, Cu, Hg, Mg, Rb and Se were greater in the caps, while for Co, Cs and Na in the stalks. For Ag, Al, Ba, Ca, Cd, Co, Cr, Cs, Fe, Ga, Hg, Mn, Mo, Pb, Rb, Sb, Sr, Tl and V concentration in the caps showed spatial variations (P<0.05), while for Cu, K, Mg, Na, Se and Zn was independent of the site. The elements such as K with median or mean in the caps between 37,000 and 43,000 microg/g.dm and Mg with 920 and 1,100 microg/g dm were most abundant. Next, within median values range from approximately 100 to 500 microg/g dm were such as Ca, Fe and Al, and in descending order they followed by Rb (100-400 microg/g dm); V, Na, Zn (50-200 microg/g dm); Cu, Mn (10-50 microg/g dm); Cd (10-20 microg/g dm); Se (5 microg/g dm); Ba (<1-3); Cr, Ag, Pb, Sr (<1-2 microg/g dm); Cs, Co, Hg (<1-1 microg/g dm); Ga (<0.5), Sb, Mo and Tl (<0.1 microg/g dm). PMID:17849303

  11. Real cell overlay measurement through design based metrology

    NASA Astrophysics Data System (ADS)

    Yoo, Gyun; Kim, Jungchan; Park, Chanha; Lee, Taehyeong; Ji, Sunkeun; Jo, Gyoyeon; Yang, Hyunjo; Yim, Donggyu; Yamamoto, Masahiro; Maruyama, Kotaro; Park, Byungjun

    2014-04-01

    Until recent device nodes, lithography has been struggling to improve its resolution limit. Even though next generation lithography technology is now facing various difficulties, several innovative resolution enhancement technologies, based on 193nm wavelength, were introduced and implemented to keep the trend of device scaling. Scanner makers keep developing state-of-the-art exposure system which guarantees higher productivity and meets a more aggressive overlay specification. "The scaling reduction of the overlay error has been a simple matter of the capability of exposure tools. However, it is clear that the scanner contributions may no longer be the majority component in total overlay performance. The ability to control correctable overlay components is paramount to achieve the desired performance.(2)" In a manufacturing fab, the overlay error, determined by a conventional overlay measurement: by using an overlay mark based on IBO and DBO, often does not represent the physical placement error in the cell area of a memory device. The mismatch may arise from the size or pitch difference between the overlay mark and the cell pattern. Pattern distortion, caused by etching or CMP, also can be a source of the mismatch. Therefore, the requirement of a direct overlay measurement in the cell pattern gradually increases in the manufacturing field, and also in the development level. In order to overcome the mismatch between conventional overlay measurement and the real placement error of layer to layer in the cell area of a memory device, we suggest an alternative overlay measurement method utilizing by design, based metrology tool. A basic concept of this method is shown in figure1. A CD-SEM measurement of the overlay error between layer 1 and 2 could be the ideal method but it takes too long time to extract a lot of data from wafer level. An E-beam based DBM tool provides high speed to cover the whole wafer with high repeatability. It is enabled by using the design as a

  12. A map overlay error model based on boundary geometry

    USGS Publications Warehouse

    Gaeuman, D.; Symanzik, J.; Schmidt, J.C.

    2005-01-01

    An error model for quantifying the magnitudes and variability of errors generated in the areas of polygons during spatial overlay of vector geographic information system layers is presented. Numerical simulation of polygon boundary displacements was used to propagate coordinate errors to spatial overlays. The model departs from most previous error models in that it incorporates spatial dependence of coordinate errors at the scale of the boundary segment. It can be readily adapted to match the scale of error-boundary interactions responsible for error generation on a given overlay. The area of error generated by overlay depends on the sinuosity of polygon boundaries, as well as the magnitude of the coordinate errors on the input layers. Asymmetry in boundary shape has relatively little effect on error generation. Overlay errors are affected by real differences in boundary positions on the input layers, as well as errors in the boundary positions. Real differences between input layers tend to compensate for much of the error generated by coordinate errors. Thus, the area of change measured on an overlay layer produced by the XOR overlay operation will be more accurate if the area of real change depicted on the overlay is large. The model presented here considers these interactions, making it especially useful for estimating errors studies of landscape change over time. ?? 2005 The Ohio State University.

  13. Improving text recognition by distinguishing scene and overlay text

    NASA Astrophysics Data System (ADS)

    Quehl, Bernhard; Yang, Haojin; Sack, Harald

    2015-02-01

    Video texts are closely related to the content of a video. They provide a valuable source for indexing and interpretation of video data. Text detection and recognition task in images or videos typically distinguished between overlay and scene text. Overlay text is artificially superimposed on the image at the time of editing and scene text is text captured by the recording system. Typically, OCR systems are specialized on one kind of text type. However, in video images both types of text can be found. In this paper, we propose a method to automatically distinguish between overlay and scene text to dynamically control and optimize post processing steps following text detection. Based on a feature combination a Support Vector Machine (SVM) is trained to classify scene and overlay text. We show how this distinction in overlay and scene text improves the word recognition rate. Accuracy of the proposed methods has been evaluated by using publicly available test data sets.

  14. Hyperspectral image reconstruction using RGB color for foodborne pathogen detection on agar plates

    NASA Astrophysics Data System (ADS)

    Yoon, Seung-Chul; Shin, Tae-Sung; Park, Bosoon; Lawrence, Kurt C.; Heitschmidt, Gerald W.

    2014-03-01

    This paper reports the latest development of a color vision technique for detecting colonies of foodborne pathogens grown on agar plates with a hyperspectral image classification model that was developed using full hyperspectral data. The hyperspectral classification model depended on reflectance spectra measured in the visible and near-infrared spectral range from 400 and 1,000 nm (473 narrow spectral bands). Multivariate regression methods were used to estimate and predict hyperspectral data from RGB color values. The six representative non-O157 Shiga-toxin producing Eschetichia coli (STEC) serogroups (O26, O45, O103, O111, O121, and O145) were grown on Rainbow agar plates. A line-scan pushbroom hyperspectral image sensor was used to scan 36 agar plates grown with pure STEC colonies at each plate. The 36 hyperspectral images of the agar plates were divided in half to create training and test sets. The mean Rsquared value for hyperspectral image estimation was about 0.98 in the spectral range between 400 and 700 nm for linear, quadratic and cubic polynomial regression models and the detection accuracy of the hyperspectral image classification model with the principal component analysis and k-nearest neighbors for the test set was up to 92% (99% with the original hyperspectral images). Thus, the results of the study suggested that color-based detection may be viable as a multispectral imaging solution without much loss of prediction accuracy compared to hyperspectral imaging.

  15. Prolonged use of coloured overlays for classroom reading.

    PubMed

    Jeanes, R; Busby, A; Martin, J; Lewis, E; Stevenson, N; Pointon, D; Wilkins, A

    1997-11-01

    Ninety-three children in a primary school and 59 children in two first-year classes of a secondary school were asked individually to observe a paragraph of random letters arranged to resemble text, and to compare the perceptual effects on its clarity of coloured plastic sheets overlaid on the text. A total of 29 colours were compared using 10 coloured plastic sheets and 19 pairwise combinations of sheets, one superimposed on another. The resulting colours sampled CIE 1976 hue angle (huv) and saturation (suv) systematically and efficiently. All the children who reported beneficial perceptual effects (53 per cent) were given their preferred overlay or combination of overlays to use as and when they wished. When the children were examined three months later the children tended to choose a colour similar to one they had chosen previously. Ten months later, 22 per cent of those offered the overlaps were still using them of their own volition. These children, but not those who had ceased to use their overlay(s), read randomly ordered simple words more quickly with their overlay than without. In a second independent group of children referred to the Norfolk Sensory Support Service, who used overlays routinely, the reading speed was similar with a grey or clear overlay; and slower than with the chosen coloured overlay, suggesting that reduction of contrast was not the critical factor. In a third independent group of children in a primary school in Kent, the increase in reading speed with the chosen overlay predicted the children who continued to use their overlay during the ensuing eight weeks. PMID:9415962

  16. Review of fluorescence guided surgery visualization and overlay techniques

    PubMed Central

    Elliott, Jonathan T.; Dsouza, Alisha V.; Davis, Scott C.; Olson, Jonathan D.; Paulsen, Keith D.; Roberts, David W.; Pogue, Brian W.

    2015-01-01

    In fluorescence guided surgery, data visualization represents a critical step between signal capture and display needed for clinical decisions informed by that signal. The diversity of methods for displaying surgical images are reviewed, and a particular focus is placed on electronically detected and visualized signals, as required for near-infrared or low concentration tracers. Factors driving the choices such as human perception, the need for rapid decision making in a surgical environment, and biases induced by display choices are outlined. Five practical suggestions are outlined for optimal display orientation, color map, transparency/alpha function, dynamic range compression, and color perception check. PMID:26504628

  17. Simplified 48-hour IMVic test: an agar plate method.

    PubMed

    Powers, E M; Latt, T G

    1977-09-01

    An agar plate method was developed for the performance of the IMVic (indole, methyl red, Voges-Proskauer, and citrate) tests in lieu of the conventional tubed liquid media. By modifying the composition of the media and adding agar, a single "X"-compartmented petri dish was prepared containing all four IMVic test media. Ease of performance and simplification of the test were achieved by inoculating all four media simultaneously from a single colony (single inoculum) on eosin-methylene blue agar. Tests with 87 cultures, representing 7 genera in the family Enterobacteriaceae, were completed with typical (correct) IMVic patterns for all cultures within 48 h. Parallel tests with conventional media showed that the agar plate method was superior, more sensitive, faster, and simpler to perform, and less time was required to identify Escherichia coli by 72 h. PMID:334074

  18. Thermal characterization of magnetically aligned carbonyl iron/agar composites.

    PubMed

    Diaz-Bleis, D; Vales-Pinzón, C; Freile-Pelegrín, Y; Alvarado-Gil, J J

    2014-01-01

    Composites of magnetic particles into polymeric matrices have received increasing research interest due to their capacity to respond to external magnetic or electromagnetic fields. In this study, agar from Gelidium robustum has been chosen as natural biocompatible polymer to build the matrix of the magnetic carbonyl iron particles (CIP) for their uses in biomedical fields. Heat transfer behavior of the CIP-agar composites containing different concentrations (5, 10, 15, 20, 25 and 30% w/w) of magnetically aligned and non-aligned CIP in the agar matrix was studied using photothermal radiometry (PTR) in the back-propagation emission configuration. The morphology of the CIP-agar composites with aligned and non-aligned CIP under magnetic field was also evaluated by scanning electron microscopy (SEM). The results revealed a dominant effect of CIP concentration over the alignment patterns induced by the magnetic field, which agrees with the behavior of the thermal diffusivity and thermal conductivity. Agar served as a perfect matrix to be used with CIP, and CIP-agar composites magnetically aligned at 20% CIP concentration can be considered as promising 'smart' material for hyperthermia treatments in the biomedical field. PMID:24274482

  19. Characterization of agar/soy protein biocomposite films: Effect of agar on the extruded pellets and compression moulded films.

    PubMed

    Garrido, T; Etxabide, A; Guerrero, P; de la Caba, K

    2016-10-20

    Agar/soy protein biocomposite films were successfully processed by extrusion and compression moulding, obtaining transparent and homogeneous films. The conformational changes occurred during the extrusion process and the effect of agar on the final properties were analyzed. As shown by differential scanning calorimetry (DSC) and specific mechanical energy (SME) values, during the extrusion process protein denatured and unfolded protein chains could interact with agar. These interactions were analyzed by Fourier transform infrared spectroscopy (FTIR) and the secondary structure was determined from the amide I band. Those interactions were supported by the decrease of film solubility. Furthermore, the good compatibility between agar and soy protein was confirmed by the images from scanning electron microscopy (SEM). PMID:27474583

  20. The Interplanetary Overlay Networking Protocol Accelerator

    NASA Technical Reports Server (NTRS)

    Pang, Jackson; Torgerson, Jordan L.; Clare, Loren P.

    2008-01-01

    A document describes the Interplanetary Overlay Networking Protocol Accelerator (IONAC) an electronic apparatus, now under development, for relaying data at high rates in spacecraft and interplanetary radio-communication systems utilizing a delay-tolerant networking protocol. The protocol includes provisions for transmission and reception of data in bundles (essentially, messages), transfer of custody of a bundle to a recipient relay station at each step of a relay, and return receipts. Because of limitations on energy resources available for such relays, data rates attainable in a conventional software implementation of the protocol are lower than those needed, at any given reasonable energy-consumption rate. Therefore, a main goal in developing the IONAC is to reduce the energy consumption by an order of magnitude and the data-throughput capability by two orders of magnitude. The IONAC prototype is a field-programmable gate array that serves as a reconfigurable hybrid (hardware/ firmware) system for implementation of the protocol. The prototype can decode 108,000 bundles per second and encode 100,000 bundles per second. It includes a bundle-cache static randomaccess memory that enables maintenance of a throughput of 2.7Gb/s, and an Ethernet convergence layer that supports a duplex throughput of 1Gb/s.

  1. Lithography aware overlay metrology target design method

    NASA Astrophysics Data System (ADS)

    Lee, Myungjun; Smith, Mark D.; Lee, Joonseuk; Jung, Mirim; Lee, Honggoo; Kim, Youngsik; Han, Sangjun; Adel, Michael E.; Lee, Kangsan; Lee, Dohwa; Choi, Dongsub; Liu, Zephyr; Itzkovich, Tal; Levinski, Vladimir; Levy, Ady

    2016-03-01

    We present a metrology target design (MTD) framework based on co-optimizing lithography and metrology performance. The overlay metrology performance is strongly related to the target design and optimizing the target under different process variations in a high NA optical lithography tool and measurement conditions in a metrology tool becomes critical for sub-20nm nodes. The lithography performance can be quantified by device matching and printability metrics, while accuracy and precision metrics are used to quantify the metrology performance. Based on using these metrics, we demonstrate how the optimized target can improve target printability while maintaining the good metrology performance for rotated dipole illumination used for printing a sub-100nm diagonal feature in a memory active layer. The remaining challenges and the existing tradeoff between metrology and lithography performance are explored with the metrology target designer's perspective. The proposed target design framework is completely general and can be used to optimize targets for different lithography conditions. The results from our analysis are both physically sensible and in good agreement with experimental results.

  2. Plastic (wire-combed) grooving of a slip-formed concrete runway overlay at Patrick Henry Airport: An initial evaluation

    NASA Technical Reports Server (NTRS)

    Marlin, E. C.; Horne, W. B.

    1977-01-01

    A wire-comb technique is described for transversely grooving the surface of a freshly laid (plastic state) slip-formed concrete overlay installed at Patrick Henry Airport. This method of surface texturing yields better water drainage and pavement skid resistance than that obtained with an older conventional burlap drag concrete surface treatment installed on an adjacent portion of the runway.

  3. Aseptic Laboratory Techniques: Plating Methods

    PubMed Central

    Sanders, Erin R.

    2012-01-01

    Microorganisms are present on all inanimate surfaces creating ubiquitous sources of possible contamination in the laboratory. Experimental success relies on the ability of a scientist to sterilize work surfaces and equipment as well as prevent contact of sterile instruments and solutions with non-sterile surfaces. Here we present the steps for several plating methods routinely used in the laboratory to isolate, propagate, or enumerate microorganisms such as bacteria and phage. All five methods incorporate aseptic technique, or procedures that maintain the sterility of experimental materials. Procedures described include (1) streak-plating bacterial cultures to isolate single colonies, (2) pour-plating and (3) spread-plating to enumerate viable bacterial colonies, (4) soft agar overlays to isolate phage and enumerate plaques, and (5) replica-plating to transfer cells from one plate to another in an identical spatial pattern. These procedures can be performed at the laboratory bench, provided they involve non-pathogenic strains of microorganisms (Biosafety Level 1, BSL-1). If working with BSL-2 organisms, then these manipulations must take place in a biosafety cabinet. Consult the most current edition of the Biosafety in Microbiological and Biomedical Laboratories (BMBL) as well as Material Safety Data Sheets (MSDS) for Infectious Substances to determine the biohazard classification as well as the safety precautions and containment facilities required for the microorganism in question. Bacterial strains and phage stocks can be obtained from research investigators, companies, and collections maintained by particular organizations such as the American Type Culture Collection (ATCC). It is recommended that non-pathogenic strains be used when learning the various plating methods. By following the procedures described in this protocol, students should be able to: ● Perform plating procedures without contaminating media. ● Isolate single bacterial colonies by the

  4. A portable image overlay projection device for computer-aided open liver surgery.

    PubMed

    Gavaghan, Kate A; Peterhans, Matthias; Oliveira-Santos, Thiago; Weber, Stefan

    2011-06-01

    Image overlay projection is a form of augmented reality that allows surgeons to view underlying anatomical structures directly on the patient surface. It improves intuitiveness of computer-aided surgery by removing the need for sight diversion between the patient and a display screen and has been reported to assist in 3-D understanding of anatomical structures and the identification of target and critical structures. Challenges in the development of image overlay technologies for surgery remain in the projection setup. Calibration, patient registration, view direction, and projection obstruction remain unsolved limitations to image overlay techniques. In this paper, we propose a novel, portable, and handheld-navigated image overlay device based on miniature laser projection technology that allows images of 3-D patient-specific models to be projected directly onto the organ surface intraoperatively without the need for intrusive hardware around the surgical site. The device can be integrated into a navigation system, thereby exploiting existing patient registration and model generation solutions. The position of the device is tracked by the navigation system's position sensor and used to project geometrically correct images from any position within the workspace of the navigation system. The projector was calibrated using modified camera calibration techniques and images for projection are rendered using a virtual camera defined by the projectors extrinsic parameters. Verification of the device's projection accuracy concluded a mean projection error of 1.3 mm. Visibility testing of the projection performed on pig liver tissue found the device suitable for the display of anatomical structures on the organ surface. The feasibility of use within the surgical workflow was assessed during open liver surgery. We show that the device could be quickly and unobtrusively deployed within the sterile environment. PMID:21411401

  5. Augmenting reality in Direct View Optical (DVO) overlay applications

    NASA Astrophysics Data System (ADS)

    Hogan, Tim; Edwards, Tim

    2014-06-01

    The integration of overlay displays into rifle scopes can transform precision Direct View Optical (DVO) sights into intelligent interactive fire-control systems. Overlay displays can provide ballistic solutions within the sight for dramatically improved targeting, can fuse sensor video to extend targeting into nighttime or dirty battlefield conditions, and can overlay complex situational awareness information over the real-world scene. High brightness overlay solutions for dismounted soldier applications have previously been hindered by excessive power consumption, weight and bulk making them unsuitable for man-portable, battery powered applications. This paper describes the advancements and capabilities of a high brightness, ultra-low power text and graphics overlay display module developed specifically for integration into DVO weapon sight applications. Central to the overlay display module was the development of a new general purpose low power graphics controller and dual-path display driver electronics. The graphics controller interface is a simple 2-wire RS-232 serial interface compatible with existing weapon systems such as the IBEAM ballistic computer and the RULR and STORM laser rangefinders (LRF). The module features include multiple graphics layers, user configurable fonts and icons, and parameterized vector rendering, making it suitable for general purpose DVO overlay applications. The module is configured for graphics-only operation for daytime use and overlays graphics with video for nighttime applications. The miniature footprint and ultra-low power consumption of the module enables a new generation of intelligent DVO systems and has been implemented for resolutions from VGA to SXGA, in monochrome and color, and in graphics applications with and without sensor video.

  6. Coloured overlays and their effects on reading speed: a review.

    PubMed

    Wilkins, Arnold

    2002-09-01

    Coloured overlays can reduce symptoms of visual stress and improve reading speed. These benefits are reliable and are not attributable simply to placebo effects. Five percent of children in mainstream education read at least 25% more quickly with an overlay, provided they have chosen the colour. The suboptimal design of children's text and the high level of classroom lighting may be partly responsible. PMID:12358317

  7. Overlay improvements using a real time machine learning algorithm

    NASA Astrophysics Data System (ADS)

    Schmitt-Weaver, Emil; Kubis, Michael; Henke, Wolfgang; Slotboom, Daan; Hoogenboom, Tom; Mulkens, Jan; Coogans, Martyn; ten Berge, Peter; Verkleij, Dick; van de Mast, Frank

    2014-04-01

    While semiconductor manufacturing is moving towards the 14nm node using immersion lithography, the overlay requirements are tightened to below 5nm. Next to improvements in the immersion scanner platform, enhancements in the overlay optimization and process control are needed to enable these low overlay numbers. Whereas conventional overlay control methods address wafer and lot variation autonomously with wafer pre exposure alignment metrology and post exposure overlay metrology, we see a need to reduce these variations by correlating more of the TWINSCAN system's sensor data directly to the post exposure YieldStar metrology in time. In this paper we will present the results of a study on applying a real time control algorithm based on machine learning technology. Machine learning methods use context and TWINSCAN system sensor data paired with post exposure YieldStar metrology to recognize generic behavior and train the control system to anticipate on this generic behavior. Specific for this study, the data concerns immersion scanner context, sensor data and on-wafer measured overlay data. By making the link between the scanner data and the wafer data we are able to establish a real time relationship. The result is an inline controller that accounts for small changes in scanner hardware performance in time while picking up subtle lot to lot and wafer to wafer deviations introduced by wafer processing.

  8. ``Electric growth`` of metal overlayers on semiconductor substrates

    SciTech Connect

    Zhang, Z.; Cho, J.H. |; Niu, Q.; Shih, C.K.; Suo, Z.

    1998-02-01

    In this article, the authors present the main results from their recent studies of metal overlayer growth on semiconductor substrates. They show that a variety of novel phenomena can exist in such systems, resulting from several competing interactions. The confined motion of the conduction electrons within the metal overlayer can mediate a surprisingly long-range repulsive force between the metal-semiconductor interface and the growth front, acting to stabilize the overlayer. Electron transfer from the overlayer to the substrate leads to an attractive force between the two interfaces, acting to destabilize the overlayer. Interface-induced Friedel oscillations in electron density can further impose an oscillatory modulation onto the two previous interactions. These three competing factors, of all electronic nature, can make a flat metal overlayer critically, marginally, or magically stable, or totally unstable against roughening. The authors further show that, for many systems, these electronic effects can easily win over the effect of stress. First-principles studies of a few representative systems support the main features of the present electronic growth concept.

  9. Interplanetary Overlay Network Bundle Protocol Implementation

    NASA Technical Reports Server (NTRS)

    Burleigh, Scott C.

    2011-01-01

    The Interplanetary Overlay Network (ION) system's BP package, an implementation of the Delay-Tolerant Networking (DTN) Bundle Protocol (BP) and supporting services, has been specifically designed to be suitable for use on deep-space robotic vehicles. Although the ION BP implementation is unique in its use of zero-copy objects for high performance, and in its use of resource-sensitive rate control, it is fully interoperable with other implementations of the BP specification (Internet RFC 5050). The ION BP implementation is built using the same software infrastructure that underlies the implementation of the CCSDS (Consultative Committee for Space Data Systems) File Delivery Protocol (CFDP) built into the flight software of Deep Impact. It is designed to minimize resource consumption, while maximizing operational robustness. For example, no dynamic allocation of system memory is required. Like all the other ION packages, ION's BP implementation is designed to port readily between Linux and Solaris (for easy development and for ground system operations) and VxWorks (for flight systems operations). The exact same source code is exercised in both environments. Initially included in the ION BP implementations are the following: libraries of functions used in constructing bundle forwarders and convergence-layer (CL) input and output adapters; a simple prototype bundle forwarder and associated CL adapters designed to run over an IPbased local area network; administrative tools for managing a simple DTN infrastructure built from these components; a background daemon process that silently destroys bundles whose time-to-live intervals have expired; a library of functions exposed to applications, enabling them to issue and receive data encapsulated in DTN bundles; and some simple applications that can be used for system checkout and benchmarking.

  10. Fly agaric (Amanita muscaria) poisoning, case report and review.

    PubMed

    Satora, Leszek; Pach, Dorota; Butryn, Beata; Hydzik, Piotr; Balicka-Slusarczyk, Barbara

    2005-06-01

    Gathering and eating mushrooms and other plants containing psychoactive substances has become increasingly popular among young people experimenting with drugs. Dried fly agaric Amanita muscaria fruiting bodies were eaten by five young persons (18-21 years of age) at a party in order to evoke hallucinations. Visual and auditory hallucinations occurred in four of them, whereas a 18-year-old girl lost consciousness. The following morning, she went to the Clinic of Toxicology. Due to the fact that not all the active substances present in the fly agaric have been identified, and some of them have an effect after a period of latency, the patient was admitted for several days of observation during which check-up examinations were performed. After four days without any problems, she was discharged. The poisoning regressed with no organ complications. The remaining persons who had eaten the fly agaric were free from any complaints. PMID:15904689

  11. IMPERMEABLE THIN AL2O3 OVERLAY FOR TBC PROTECTION FROM SULFATE AND VANADATE ATTACK IN GAS TURBINES

    SciTech Connect

    Scott X. Mao

    2002-01-31

    In order to improve the hot corrosion resistance of conventional YSZ TBC system, the overlay of Al{sub 2}O{sub 3} coating was deposited on the TBC by EB-PVD techniques. Hot corrosion tests were carried out on the TBC with and without Al{sub 2}O{sub 3} coating in molten salts mixtures (Na{sub 2}SO{sub 4} + 5%V{sub 2}O{sub 5}) at 950 C for 10h. The microstructures of TBC and overlay before and after exposure were examined by means of scanning electron microscopy (SEM), energy-dispersive X-ray spectrometer (EDX) and X-ray diffraction (XRD). It has been found that TBC will react with V{sub 2}O{sub 5} to form YVO{sub 4}. A substantial amount of M-phase was formed due to the leaching of Y{sub 2}O{sub 3} from YSZ. Al{sub 2}O{sub 3} overlay coating deposited by EB-PVD was dense, continues and adherent to the TBC. As a result, overlay Al{sub 2}O{sub 3} coating can prevent the YSZ from the attack by molten salts containing vanadium and arrest the penetration of salts into the YSZ along porous and cracks in the YSZ TBC, although there were some cracks in overlay Al{sub 2}O{sub 3} coating and at the interface between alumina and zirconia formed during hot corrosion tests due to the presence of tensile stress in the alumina coating. In the next reporting period, we will study the mechanisms of cracking of the overlay Al{sub 2}O{sub 3} layer and finish the hot corrosion tests of TBC with Al{sub 2}O{sub 3} coating deposited by high velocity oxy-fuel (HVOF) technique. The hot corrosion test of TBC with EB-PVD deposited Al{sub 2}O{sub 3} coating will be again performed. However before hot corrosion tests, a post-annealing will be carried out in vacuum (residual pressure 10{sup -3} Pa) at 1273K for 1h in order to transform the as-sputtered Al{sub 2}O{sub 3} overlay to crystalline {alpha}-Al{sub 2}O{sub 3} overlay.

  12. Infrared thermography analysis of thermal diffusion induced by RF magnetic field on agar phantoms loaded with magnetic nanoparticles

    NASA Astrophysics Data System (ADS)

    Bante-Guerra, Jose; Macías, J. D.; Caballero-Aguilar, L.; Vales-Pinzón, C.; Alvarado-Gil, J. J.

    2013-02-01

    Recently, several treatments for fighting malignant tumors have been designed. However these procedures have well known inconveniences, depending on their applicability, tumor size and side effects, among others. Magnetic hyperthermia is a safe, non-invasive method for cancer therapy. This treatment is applied via elevation of target tissue temperature by dissipation of heat from Magnetic Nanoparticles (MNPs), previously located within the tumor. The induction of heat causes cell death and therefore the removal of the tumor. In this work the thermal diffusion in phantoms of agar loaded with magnetic nanoparticles (MNPs) is studied using the infrared thermography technique, which is widely used in biology/medicine (e.g. skin temperature mapping). Agar is one of the materials used to simulate different types of body tissues, these samples are known as "phantoms". Agar is of natural origin, low cost and high degree of biocompatibility. In this work the agar gel was embedded with MNPs by coprecipitation and placed in an alternating magnetic field radiation. As a consequence, the energy from the radiation source is dissipated as heat and then transferred from the MNP to the gel, increasing its temperature. For the temperature analysis, the samples of agar gel were stimulated by RF magnetic field generated by coils. Heating was measured with infrared thermography using a Thermovision A20M infrared camera. Thermographic images allowed obtaining the dependence of thermal diffusion in the phantom as a function of the magnitude of the applied RF magnetic field and the load of magnetic particles.

  13. Effect of BiTek agar on lysostaphin susceptibility of staphylococci.

    PubMed Central

    Langlois, B E; Dawson, K; Akers, K

    1990-01-01

    Staphylococci which were considered to be lysostaphin susceptible on P agar containing Bacto-Agar showed different degrees of resistance to lysostaphin when tested on P agar made with BiTek agar. As a result, lysostaphin-susceptible strains were misidentified as lysostaphin-resistant strains. Images PMID:2254432

  14. Overlay progress in EUV lithography towards adoption for manufacturing

    NASA Astrophysics Data System (ADS)

    Hermans, Jan V.; Laidler, David; Pigneret, Charles; van Dijk, Andre; Voznyi, Oleg; Dusa, Mircea; Hendrickx, Eric

    2011-04-01

    Extreme Ultra-Violet (EUV) lithography is a candidate for semiconductor manufacturing for the 16nm technology node and beyond. Due to the very short wavelength of 13.5nm, EUV lithography provides the capability to continue single exposure scaling with improved resolution and higher pattern fidelity compared to 193nm immersion lithography. However, reducing the wavelength brings new equipment and process challenges. To enable EUV photon transmission through the optical system, the entire optical path of an EUV exposure tool operates under vacuum, and in addition reticle and optics are reflective. To obtain the required CD and overlay performance, both wafer and reticle front surfaces need to have near-perfect flatness, as non-flatness directly contributes to focus and image placement errors, in the case of the reticle due to non-telecentricity. Traditional vacuum chucks, both for reticle and wafer, cannot be used and are replaced by electrostatic chucks. Any contribution of this new clamping method on CD and overlay control therefore needs to be investigated, including avoidance of particle contamination over time. This work was performed on ASML's EUV Alpha Demo Tool (ADT). We investigated the different, non-conventional contributions to overlay control on the ADT, with particular attention to the wafer clamping performance of the exposure chuck. We demonstrate that we were able to improve the overlay performance by compensating for the wafer clamping error during the wafer alignment sequence. The impact of different wafer types on overlay was also evaluated. In addition to clamping effects, thermal effects have also been shown to impact overlay and were evaluated by monitoring the thermal behavior of a wafer during exposure on the ADT and correlating to the resulting overlay.

  15. An Agar-Based Method for Plating Marine Protozoan Parasites of the Genus Perkinsus

    PubMed Central

    Cold, Emma R.; Freyria, Nastasia J.; Martínez Martínez, Joaquín; Fernández Robledo, José A.

    2016-01-01

    The genus Perkinsus includes protozoan parasites of mollusks responsible for losses in the aquaculture industry and hampering the recovery of natural shellfish beds worldwide, and they are a key taxon for understanding intracellular parasitism adaptations. The ability to propagate the parasite in liquid media, in the absence of the host, has been crucial for improving understanding of its biology; however, alternative techniques to grow the parasite are needed to explore other basic aspects of the Perkinsus spp. biology. We optimized a DME: Ham’s F12–5% FBS- containing solid agar medium for plating Perkinsus marinus. This solid medium supported trophozoite propagation both by binary fission and schizogony. Colonies were visible to the naked eye 17 days after plating. We tested the suitability of this method for several applications, including the following: 1) Subcloning P. marinus isolates: single discrete P. marinus colonies were obtained from DME: Ham’s F12–5% FBS– 0.75% agar plates, which could be further propagated in liquid medium; 2) Subcloning engineered Perkinsus mediterraneus MOE[MOE]: GFP by streaking cultures on plates; 3) Chemical susceptibility: Infusing the DME: Ham’s F12–5% FBS– 0.75% agar plates with triclosan resulted in inhibition of the parasite propagation in a dose-dependent manner. Altogether, our plating method has the potential for becoming a key tool for investigating diverse aspects of Perkinsus spp. biology, developing new molecular tools, and for biotechnological applications. PMID:27149378

  16. An Agar-Based Method for Plating Marine Protozoan Parasites of the Genus Perkinsus.

    PubMed

    Cold, Emma R; Freyria, Nastasia J; Martínez Martínez, Joaquín; Fernández Robledo, José A

    2016-01-01

    The genus Perkinsus includes protozoan parasites of mollusks responsible for losses in the aquaculture industry and hampering the recovery of natural shellfish beds worldwide, and they are a key taxon for understanding intracellular parasitism adaptations. The ability to propagate the parasite in liquid media, in the absence of the host, has been crucial for improving understanding of its biology; however, alternative techniques to grow the parasite are needed to explore other basic aspects of the Perkinsus spp. biology. We optimized a DME: Ham's F12-5% FBS- containing solid agar medium for plating Perkinsus marinus. This solid medium supported trophozoite propagation both by binary fission and schizogony. Colonies were visible to the naked eye 17 days after plating. We tested the suitability of this method for several applications, including the following: 1) Subcloning P. marinus isolates: single discrete P. marinus colonies were obtained from DME: Ham's F12-5% FBS- 0.75% agar plates, which could be further propagated in liquid medium; 2) Subcloning engineered Perkinsus mediterraneus MOE[MOE]: GFP by streaking cultures on plates; 3) Chemical susceptibility: Infusing the DME: Ham's F12-5% FBS- 0.75% agar plates with triclosan resulted in inhibition of the parasite propagation in a dose-dependent manner. Altogether, our plating method has the potential for becoming a key tool for investigating diverse aspects of Perkinsus spp. biology, developing new molecular tools, and for biotechnological applications. PMID:27149378

  17. Co-precipitation with PVP and Agar to Improve Physicomechanical Properties of Ibuprofen

    PubMed Central

    Maghsoodi, Maryam; Kiafar, Farhad

    2013-01-01

    Objective(s) : Ibuprofen is a problematic drug in tableting due to its viscoelastic properties. Additionally its high cohesivity results in low flowability. In this study, co-precipitation of ibuprofen with varying concentration of agar and PVP to optimize properties of Ibuprofen was carried out. Materials and Methods: Co-precipitates of ibuprofen- PVP or agar were prepared by solvent evaporation technique under vacuum condition. Differential scanning calorimetry (DSC), X -ray diffraction of powder (XRDP) and FT-IR spectroscopy were used to investigate the solid state characteristics of the co-precipitates. The dissolution behavior, flowability, particle size and compaction properties of various batches were also studied. Results: Co-precipitation of drug with agar led to a change in habit from needle to plate shape crystals, while drug –PVP co-precipitates had agglomerated structure and consisted of numerous crystals which had been aggregated together. The co-precipitates showed improved flow properties compared with ibuprofen alone. Precipitation of ibuprofen with these additives led to modification in the dissolution of the drug. Agar in 1% w/w improved slightly the dissolution rate of drug while PVP had a negative impact and led to reduction in the dissolution rate of drug to less than that of pure drug. The all obtained co-precipitates exhibited significantly improved tableting behavior compared with drug crystals alone. This may be due to this fact that, the polymer covering the drug particles increases and changes the nature of the surface area available for interparticulate bonds between particles. DSC, XRDP and FT-IR experiments showed that drug particles, in co-precipitates samples, did not undergo polymorphic modifications. Conclusion: The study highlights the influence of polymeric additives on crystallization process leading to modified performance. PMID:24250942

  18. Co-precipitation with PVP and Agar to Improve Physicomechanical Properties of Ibuprofen

    PubMed Central

    Maghsoodi, Maryam; Kiafar, Farhad

    2013-01-01

    Objective(s) : Ibuprofen is a problematic drug in tableting due to its viscoelastic properties. Additionally its high cohesivity results in low flowability. In this study, co-precipitation of ibuprofen with varying concentration of agar and PVP to optimize properties of Ibuprofen was carried out. Materials and Methods: Co-precipitates of ibuprofen- PVP or agar were prepared by solvent evaporation technique under vacuum condition. Differential scanning calorimetry (DSC), X -ray diffraction of powder (XRDP) and FT-IR spectroscopy were used to investigate the solid state characteristics of the co-precipitates. The dissolution behavior, flowability, particle size and compaction properties of various batches were also studied. Results: Co-precipitation of drug with agar led to a change in habit from needle to plate shape crystals, while drug –PVP co-precipitates had agglomerated structure and consisted of numerous crystals which had been aggregated together. The co-precipitates showed improved flow properties compared with ibuprofen alone. Precipitation of ibuprofen with these additives led to modification in the dissolution of the drug. Agar in 1% w/w improved slightly the dissolution rate of drug while PVP had a negative impact and led to reduction in the dissolution rate of drug to less than that of pure drug. The all obtained co-precipitates exhibited significantly improved tableting behavior compared with drug crystals alone. This may be due to this fact that, the polymer covering the drug particles increases and changes the nature of the surface area available for interparticulate bonds between particles. DSC, XRDP and FT-IR experiments showed that drug particles, in co-precipitates samples, did not undergo polymorphic modifications. Conclusion: The study highlights the influence of polymeric additives on crystallization process leading to modified performance. PMID:24250936

  19. 21 CFR 866.4600 - Ouchterlony agar plate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Ouchterlony agar plate. 866.4600 Section 866.4600 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Immunology Laboratory Equipment and Reagents §...

  20. 21 CFR 866.4600 - Ouchterlony agar plate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Ouchterlony agar plate. 866.4600 Section 866.4600 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Immunology Laboratory Equipment and Reagents §...

  1. 21 CFR 866.4600 - Ouchterlony agar plate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Ouchterlony agar plate. 866.4600 Section 866.4600 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Immunology Laboratory Equipment and Reagents §...

  2. 21 CFR 866.4600 - Ouchterlony agar plate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ouchterlony agar plate. 866.4600 Section 866.4600 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Immunology Laboratory Equipment and Reagents §...

  3. 21 CFR 866.4600 - Ouchterlony agar plate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Ouchterlony agar plate. 866.4600 Section 866.4600 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Immunology Laboratory Equipment and Reagents §...

  4. Improving agar electrospinnability with choline-based deep eutectic solvents

    Technology Transfer Automated Retrieval System (TEKTRAN)

    One percent agar (% wt) was dissolved in the deep eutectic solvent (DES), (2-hydroxyethyl) trimethylammonium chloride/urea at a 1:2 molar ratio, and successfully electrospun into nanofibers. An existing electrospinning set-up, operated at 50 deg C, was adapted for use with an ethanol bath to collect...

  5. Fluorogenic Membrane Overlays to Enumerate Total and Fecal Escherichia coli and Total Vibrionaceae in Shellfish and Seawater.

    PubMed

    Richards, Gary P; Watson, Michael A

    2010-01-01

    Three assays were developed to enumerate total and fecal Escherichia coli and total Vibrionaceae in shellfish, seawater, and other foods and environmental samples. Assays involve membrane overlays of overnight colonies on nonselective agar plates to detect beta-glucuronidase and lysyl aminopeptidase activities for E. coli and Vibrionaceae, respectively. Cellulose membranes containing the substrates 4-methylumbeferyl-beta-D-glucuronide (MUG) produced a bright blue fluorescence when overlaid onto E. coli, while L-lysyl-7-amino-4-trifluoromethylcoumarin produced green fluorescent foci when overlaid onto Vibrionaceae family members. A multiplex assay was also developed for simultaneously enumerating total E. coli and total Vibrionaceae in oysters and seawater. Overall, 65% of overlaid E. coli (non-O157:H7) were MUG-positive, compared with 62% as determined by the most-probable-number-MUG assay. The overlays are rapid, simple, and cost effective for quantification purposes. This research provides practical alternatives for monitoring bacterial indicators and potential pathogens in complex samples, including molluscan shellfish. PMID:20396663

  6. Overlay metrology solutions in a triple patterning scheme

    NASA Astrophysics Data System (ADS)

    Leray, Philippe; Mao, Ming; Baudemprez, Bart; Amir, Nuriel

    2015-03-01

    Overlay metrology tool suppliers are offering today several options to their customers: Different hardware (Image Based Overlay or Diffraction Based Overlay), different target designs (with or without segmentation) or different target sizes (from 5 um to 30 um). All these variations are proposed to resolve issues like robustness of the target towards process variations, be more representative of the design or increase the density of measurements. In the frame of the development of a triple patterning BEOL scheme of 10 nm node layer, we compare IBO targets (standard AIM, AIMid and multilayer AIMid). The metrology tools used for the study are KLA-Tencor's nextgeneration Archer 500 system (scatterometry- and imaging-based measurement technologies on the same tool). The overlay response and fingerprint of these targets will be compared using a very dense sampling (up to 51 pts per field). The benefit of indie measurements compared to the traditional scribes is discussed. The contribution of process effects to overlay values are compared to the contribution of the performance of the target. Different targets are combined in one measurement set to benefit from their different strengths (performance vs size). The results are summarized and possible strategies for a triple patterning schemes are proposed.

  7. Large dynamic range Atomic Force Microscope for overlay improvements

    NASA Astrophysics Data System (ADS)

    Kuiper, Stefan; Fritz, Erik; Crowcombe, Will; Liebig, Thomas; Kramer, Geerten; Witvoet, Gert; Duivenvoorde, Tom; Overtoom, Ton; Rijnbeek, Ramon; van Zwet, Erwin; van Dijsseldonk, Anton; den Boef, Arie; Beems, Marcel; Levasier, Leon

    2016-03-01

    Nowadays most overlay metrology tools assess the overlay performance based on marker features which are deposited next to the functional device features within each layer of the semiconductor device. However, correct overlay of the relatively coarse marker features does not directly guarantee correct overlay of the much smaller device features. This paper presents the development of a tool that allows to measure the relative distance between the marker and device features within each layer of the semiconductor device, which can be used to improve the overlay at device feature level. In order to be effective, the marker to device feature distance should be measured with sub-nanometer measurement uncertainty over several millimeters range. Furthermore, the tool should be capable of profiling the marker features to allows prediction of the location interpretation of the optical diffraction based alignment sensors, which are sensitive for potential asymmetry of the marker features. To enable this, a highly stable Atomic Force Microscope system is being developed. The probe is positioned relative to the wafer with a 6DOF controlled hexapod stage, which has a relatively large positioning range of 8x8mm. The position and orientation of this stage is measured relative to the wafer using 6 interferometers via a highly stable metrology frame. A tilted probe concept is utilized to allow profiling of the high aspect ratio marker and device features. Current activities are aimed at demonstrating the measurement capabilities of the developed AFM system.

  8. IMPERMEABLE THIN AL2O3 OVERLAY FOR TBC PROTECTION FROM SULFATE AND VANADATE ATTACK IN GAS TURBINES

    SciTech Connect

    Scott X. Mao

    2002-08-31

    In order to improve the hot corrosion resistance of conventional YSZ TBC system, the overlay of Al{sub 2}O{sub 3} coating was deposited on the TBC by EB-PVD techniques. Hot corrosion tests were carried out on the TBC with and without Al{sub 2}O{sub 3} coating in molten salts mixtures (Na{sub 2}SO{sub 4} + 5%V{sub 2}O{sub 5}) at 950 C for different time up to 100h. The microstructures of TBC and overlay before and after exposure were examined by means of scanning electron microscopy (SEM), energy-dispersive X-ray spectrometer (EDX) and X-ray diffraction (XRD). It has been found that TBC will react with V{sub 2}O{sub 5} to form YVO{sub 4}. The amount of M-phase, which was formed due to the leaching of Y{sub 2}O{sub 3} from YSZ, was increased with corrosion time. Al{sub 2}O{sub 3} overlay coating deposited by EB-PVD was dense, continues and adherent to the TBC. As a result, overlay Al{sub 2}O{sub 3} coating can prevent the YSZ from the attack by molten salts containing vanadium and decrease the penetration of salts into the YSZ along porous and cracks in the YSZ TBC. The amount of M-phase formed in YSZ covered with an overlay Al{sub 2}O{sub 3} is substantially lower than that formed in conventional YSZ TBC, even after 100h exposure to the molten salts. In the next reporting period, the hot corrosion test of TBC with EB-PVD deposited Al{sub 2}O{sub 3} coating will be again performed. However before hot corrosion tests, the post-annealing will be carried out in vacuum (residual pressure 10 -3 Pa) at 1273K for 1h in order to transform the as-sputtered Al{sub 2}O{sub 3} overlay to crystalline {alpha}-Al{sub 2}O{sub 3} overlay. In addition, the effect of the thickness of overlay Al{sub 2}O{sub 3} on corrosion resistance will also be investigated.

  9. Development of a selective agar plate for the detection of Campylobacter spp. in fresh produce.

    PubMed

    Yoo, Jin-Hee; Choi, Na-Young; Bae, Young-Min; Lee, Jung-Su; Lee, Sun-Young

    2014-10-17

    This study was conducted to develop a selective medium for the detection of Campylobacter spp. in fresh produce. Campylobacter spp. (n=4), non-Campylobacter (showing positive results on Campylobacter selective agar) strains (n=49) isolated from fresh produce, indicator bacteria (n=13), and spoilage bacteria isolated from fresh produce (n=15) were plated on four Campylobacter selective media. Bolton agar and modified charcoal cefoperazone deoxycholate agar (mCCDA) exhibited higher sensitivity for Campylobacter spp. than did Preston agar and Hunt agar, although certain non-Campylobacter strains isolated from fresh produce by using a selective agar isolation method, were still able to grow on Bolton agar and mCCDA. To inhibit the growth of non-Campylobacter strains, Bolton agar and mCCDA were supplemented with 5 antibiotics (rifampicin, polymyxin B, sodium metabisulfite, sodium pyruvate, ferrous sulfate) and the growth of Campylobacter spp. (n=7) and non-Campylobacter strains (n=44) was evaluated. Although Bolton agar supplemented with rifampicin (BR agar) exhibited a higher selectivity for Campylobacter spp. than did mCCDA supplemented with antibiotics, certain non-Campylobacter strains were still able to grow on BR agar (18.8%). When BR agar with various concentrations of sulfamethoxazole-trimethoprim were tested with Campylobacter spp. (n=8) and non-Campylobacter (n=7), sulfamethoxazole-trimethoprim was inhibitory against 3 of 7 non-Campylobacter strains. Finally, we validated the use of BR agar containing 50mg/L sulfamethoxazole (BRS agar) or 0.5mg/L ciprofloxacin (BRCS agar) and other selective agars for the detection of Campylobacter spp. in chicken and fresh produce. All chicken samples were positive for Campylobacter spp. when tested on mCCDA, BR agar, and BRS agar. In fresh produce samples, BRS agar exhibited the highest selectivity for Campylobacter spp., demonstrating its suitability for the detection of Campylobacter spp. in fresh produce. PMID:25126968

  10. Thermal-induced ageing of agar solutions: impact on the structural and mechanical properties of agar gels

    NASA Astrophysics Data System (ADS)

    Mao, Bosi; Bentaleb, Ahmed; Louerat, Frédéric; Divoux, Thibaut; Snabre, Patrick

    Numerous hydrogels are prepared by cooling down to ambient temperature, aqueous polymer solutions brought to a boil. Although the incubation time of the polymer solution at such a high temperature could be used as a tuning parameter, its impact on the subsequent gelation has been poorly investigated. Here we study the effect of prolonged heating at 80°C on a 1.5% wt solution of agar, a natural polysaccharide. The incubation time is varied from a few hours up to five days. We show that the agar sol. continuously degrades as the result of both the hydrolysis and the intermolecular oxidation of the polymer chains. Furthermore, electronic microscopy and X-ray diffraction experiments reveal that gels formed from older agar sols display an increasingly coarser microstructure composed of micron-sized aggregated pieces of polysaccharides, in contrast with the fibrous-like structure of gels made from fresh sols. Along with structural changes prolonged incubation time leads to weaker gels of lower shear elastic modulus. Finally, macro-indentation experiments coupled to direct visualization show that increasing the incubation time of the agar sol. decreases the yield strain of the gel by a factor of three, while the rupture scenario turns continuously from brittle to ductile-like. Acknowledging funding from BioMérieux & CNRS.

  11. Total Antioxidant Capacity of Serum Determined Using the Potassium Permanganate Agar Method Based on Serum Diffusion in Agar.

    PubMed

    Zhou, Ying; Zhang, Meijuan; Liu, Hui

    2015-01-01

    Objectives. To develop a new method for determining total antioxidants in serum and to evaluate the total antioxidant capacity of organisms. Design and Methods. Sodium hyposulfite (Na2S2O3) and serum were used to evaluate the linearity and precision of the potassium permanganate agar method. The area of serum diffusion in samples from 30 intensive care unit (ICU) patients compared with 44 healthy subjects was determined by the potassium permanganate agar method. Results. The linearity (R (2) in the linear experiment of Na2S2O3 was 0.994; R (2) in the linear experiment of serum was 0.987) and precision (coefficient of variation of area of high level serum diffusion within-run, between-run, and between-day and coefficient of variation of area of low serum diffusion within-run, between-run, and between-day were all less than 10%) were acceptable using the potassium permanganate agar method. Total antioxidants of serum between the ICU group and the healthy group were different (p = 0.002, two tailed). Conclusions. Total antioxidants in serum can be determined by the potassium permanganate agar method. The total antioxidant capacity of an organism can be evaluated by the amount of total antioxidants in serum. PMID:26347595

  12. Total Antioxidant Capacity of Serum Determined Using the Potassium Permanganate Agar Method Based on Serum Diffusion in Agar

    PubMed Central

    Zhou, Ying; Zhang, Meijuan; Liu, Hui

    2015-01-01

    Objectives. To develop a new method for determining total antioxidants in serum and to evaluate the total antioxidant capacity of organisms. Design and Methods. Sodium hyposulfite (Na2S2O3) and serum were used to evaluate the linearity and precision of the potassium permanganate agar method. The area of serum diffusion in samples from 30 intensive care unit (ICU) patients compared with 44 healthy subjects was determined by the potassium permanganate agar method. Results. The linearity (R2 in the linear experiment of Na2S2O3 was 0.994; R2 in the linear experiment of serum was 0.987) and precision (coefficient of variation of area of high level serum diffusion within-run, between-run, and between-day and coefficient of variation of area of low serum diffusion within-run, between-run, and between-day were all less than 10%) were acceptable using the potassium permanganate agar method. Total antioxidants of serum between the ICU group and the healthy group were different (p = 0.002, two tailed). Conclusions. Total antioxidants in serum can be determined by the potassium permanganate agar method. The total antioxidant capacity of an organism can be evaluated by the amount of total antioxidants in serum. PMID:26347595

  13. Cooperative Resource Pricing in Service Overlay Networks for Mobile Agents

    NASA Astrophysics Data System (ADS)

    Nakano, Tadashi; Okaie, Yutaka

    The success of peer-to-peer overlay networks depends on cooperation among participating peers. In this paper, we investigate the degree of cooperation among individual peers required to induce globally favorable properties in an overlay network. Specifically, we consider a resource pricing problem in a market-oriented overlay network where participating peers sell own resources (e.g., CPU cycles) to earn energy which represents some money or rewards in the network. In the resource pricing model presented in this paper, each peer sets the price for own resource based on the degree of cooperation; non-cooperative peers attempt to maximize their own energy gains, while cooperative peers maximize the sum of own and neighbors' energy gains. Simulation results are presented to demonstrate that the network topology is an important factor influencing the minimum degree of cooperation required to increase the network-wide global energy gain.

  14. Tensile Bond Strength of Latex-Modified Bonded Concrete Overlays

    NASA Astrophysics Data System (ADS)

    Dubois, Cameron; Ramseyer, Chris

    2010-10-01

    The tensile bond strength of bonded concrete overlays was tested using the in-situ pull-off method described in ASTM C 1583 with the goal of determining whether adding latex to the mix design increases bond strength. One slab of ductile concrete (f'c > 12,000 psi) was cast with one half tined, i.e. roughened, and one half steel-troweled, i.e. smooth. The slab surface was sectioned off and overlay mixtures containing different latex contents cast in each section. Partial cores were drilled perpendicular to the surface through the overlay into the substrate. A tensile loading device applied a direct tensile load to each specimen and the load was increased until failure occurred. The tensile bond strength was then calculated for comparison between the specimens.

  15. Tuning carrier density at complex oxide interface with metallic overlayer

    NASA Astrophysics Data System (ADS)

    Zhou, Y.; Shi, Y. J.; Jiang, S. W.; Yue, F. J.; Wang, P.; Ding, H. F.; Wu, D.

    2016-06-01

    We have systematically investigated the electronic transport properties of the LaAlO3/SrTiO3 interfaces with several different metal capping layers. The sheet carrier density can be tuned in a wide range by the metallic overlayer without changing the carrier mobility. The sheet carrier density variation is found to be linearly dependent on the size of metal work function. This behavior is explained by the mechanism of the charge transfer between the oxide interface and the metal overlayer across the LaAlO3 layer. Our results confirm the existence of a built-in electric field in LaAlO3 film with an estimated value of 67.7 eV/Å. Since the metallic overlayer is essential for devices, the present phenomena must be considered for future applications.

  16. Using Mobile Agents and Overlay Networks to Secure Electrical Netoworks

    SciTech Connect

    Dawes, Neal A.; Prosser, Bryan J.; Fulp, Errin W.; McKinnon, Archibald D.

    2013-04-01

    ABSTRACT The use of wandering, mobile agents can provide a robust approach for managing, monitoring, and securing electrical distribution networks. However, the topological structure of electrical networks can affect system performance. For example, if the multi-agent system relies on a regular inspection rate (on average, points of interest are inspected with equal frequency), then locations that are not well connected will on average be inspected less frequently. This paper discusses creation and use of overlay networks that create a virtual grid graph can provide faster coverage and a more uniform average agent sampling rate. Using overlays agents wander a virtual neighborhood consisting of only points of interest that are interconnected in a regular fashion (each point has the same number of neighbors). Experimental results will show that an overlay can often provide better network coverage and a more uniform inspection rate, which can improve cyber security by providing a faster detection of threats

  17. Impaction onto a Glass Slide or Agar versus Impingement into a Liquid for the Collection and Recovery of Airborne Microorganisms

    PubMed Central

    Juozaitis, Arvydas; Willeke, Klaus; Grinshpun, Sergey A.; Donnelly, Jean

    1994-01-01

    To study impaction versus impingement for the collection and recovery of viable airborne microorganisms, three new bioaerosol samplers have been designed and built. They differ from each other by the medium onto which the bioaerosol particles are collected (glass, agar, and liquid) but have the same inlet and collection geometries and the same sampling flow rate. The bioaerosol concentrations recorded by three different collection techniques have been compared with each other: impaction onto a glass slide, impaction onto an agar medium, and impingement into a liquid. It was found that the particle collection efficiency of agar slide impaction depends on the concentration of agar in the collection medium and on the sampling time, when samples are collected on a nonmoving agar slide. Impingement into a liquid showed anomalous behavior with respect to the sampling flow rate. Optimal sampling conditions in which all three new samplers exhibit the same overall sampling efficiency for nonbiological particles have been established. Inlet and collection efficiencies of about 100% have been achieved for all three devices at a sampling flow rate of 10 liters/min. The new agar slide impactor and the new impinger were then used to study the biological factors affecting the overall sampling efficiency. Laboratory experiments on the total recovery of a typical environmental microorganism, Pseudomonas fluorescens ATCC 13525, showed that both sampling methods, impaction and impingement, provided essentially the same total recovery when relatively nonstressed microorganisms were sampled under optimal sampling conditions. Comparison tests of the newly developed bioaerosol samplers with those commercially available showed that the incorporation of our research findings into the design of the new samplers yields better performance data than data from currently available samplers. PMID:16349217

  18. Measured residual stresses in overlay pipe weldments removed from service

    SciTech Connect

    Shack, W.J.

    1985-02-01

    Surface and throughwall residual stresses were measured on an elbow-to-pipe weldment that had been removed from the Hatch-2 reactor about a year after the application of a weld overlay. The results were compared with experimental measurements on three mock-up weldments and with finite-element calculations. The comparison shows that there are significant differences in the form and magnitude of the residual stress distributions. However, even after more than a year of service, the residual stresses over most of the inner surface of the actual plant weldment with an overlay were strongly compressive. 3 refs., 7 figs.

  19. Implementing a Trust Overlay Framework for Digital Ecosystems

    NASA Astrophysics Data System (ADS)

    Malone, Paul; McGibney, Jimmy; Botvich, Dmitri; McLaughlin, Mark

    Digital Ecosystems, being decentralised in nature, are inherently untrustworthy environments. This is due to the fact that these environments lack a centralised gatekeeper and identity provider. In order for businesses to operate in these environments there is a need for security measures to support accountability and traceability. This paper describes a trust overlay network developed in the OPAALS project to allow entities participating in digital ecosystems to share experience through the exchange of trust values and to leverage on this network to determine reputation based trustworthiness of unknown and initially untrusted entities. An overlay network is described together with sample algorithms and a discussion on implementation.

  20. High-frequency nonreciprocal reflection from magnetic films with overlayers

    SciTech Connect

    Wang, Ying; Nie, Yan; Camley, R. E.

    2013-11-14

    We perform a theoretical study of the nonreciprocal reflection of high-frequency microwave radiation from ferromagnetic films with thin overlayers. Reflection from metallic ferromagnetic films is always near unity and shows no nonreciprocity. In contrast, reflection from a structure which has a dielectric overlayer on top of a film composed of insulated ferromagnetic nanoparticles or nanostructures can show significant nonreciprocity in the 75–80 GHz frequency range, a very high value. This can be important for devices such as isolators or circulators.

  1. Flexible TWDM PON with WDM overlay for converged services

    NASA Astrophysics Data System (ADS)

    Cheng, Ning

    2015-12-01

    This paper reviews recent developments of flexible TWDM PON (time- and wavelength-division multiplexed passive optical network) with pluggable transceivers for pay-as-you-grow deployment, load balancing, channel protection and power saving. Different architectures for TWDM PON with WDM (wavelength division multiplexed) overlay for converged broadband services are discussed and experimental results are presented for WDM overlay using low-cost self-seeded RSOA (reflective semiconductor optical amplifiers). Challenging issues and possible solutions for future evolution toward software defined flexible PONs (FlexPONs) are also discussed with respect to dynamic lambda flow, elastic bandwidth and flexible reach.

  2. Advanced overlay: sampling and modeling for optimized run-to-run control

    NASA Astrophysics Data System (ADS)

    Subramany, Lokesh; Chung, WoongJae; Samudrala, Pavan; Gao, Haiyong; Aung, Nyan; Gomez, Juan Manuel; Gutjahr, Karsten; Park, DongSuk; Snow, Patrick; Garcia-Medina, Miguel; Yap, Lipkong; Demirer, Onur Nihat; Pierson, Bill; Robinson, John C.

    2016-03-01

    In recent years overlay (OVL) control schemes have become more complicated in order to meet the ever shrinking margins of advanced technology nodes. As a result, this brings up new challenges to be addressed for effective run-to- run OVL control. This work addresses two of these challenges by new advanced analysis techniques: (1) sampling optimization for run-to-run control and (2) bias-variance tradeoff in modeling. The first challenge in a high order OVL control strategy is to optimize the number of measurements and the locations on the wafer, so that the "sample plan" of measurements provides high quality information about the OVL signature on the wafer with acceptable metrology throughput. We solve this tradeoff between accuracy and throughput by using a smart sampling scheme which utilizes various design-based and data-based metrics to increase model accuracy and reduce model uncertainty while avoiding wafer to wafer and within wafer measurement noise caused by metrology, scanner or process. This sort of sampling scheme, combined with an advanced field by field extrapolated modeling algorithm helps to maximize model stability and minimize on product overlay (OPO). Second, the use of higher order overlay models means more degrees of freedom, which enables increased capability to correct for complicated overlay signatures, but also increases sensitivity to process or metrology induced noise. This is also known as the bias-variance trade-off. A high order model that minimizes the bias between the modeled and raw overlay signature on a single wafer will also have a higher variation from wafer to wafer or lot to lot, that is unless an advanced modeling approach is used. In this paper, we characterize the bias-variance trade off to find the optimal scheme. The sampling and modeling solutions proposed in this study are validated by advanced process control (APC) simulations to estimate run-to-run performance, lot-to-lot and wafer-to- wafer model term monitoring to

  3. Comparison of chromogenic Biolog Rainbow agar Shigella/Aeromonas with xylose lysine desoxycholate agar for isolation and detection of Shigella spp. from foods.

    PubMed

    Zhang, Guodong; Lampel, Keith A

    2010-08-01

    Shigella outbreaks are widely reported throughout the world. However, it remains a challenge to isolate Shigella spp. from foods by using conventional microbiological media. The main objective of this study was to determine the effectiveness of a novel chromogenic medium, Rainbow agar Shigella/Aeromonas (Rainbow agar), for the isolation and detection of Shigella spp. in foods. All four Shigella species, S. sonnei, S. flexneri, S. dysenteriae, and S. boydii, were studied. Rainbow agar was compared with tryptic soy agar, xylose lysine desoxycholate agar (XLD), and Salmonella Shigella agar (SSA) for enumeration of Shigella spp. in pure culture. This chromogenic agar and XLD were also used to isolate Shigella spp. in artificially contaminated foods (4.8 log CFU/g of food), including lettuce, parsley, cilantro, spinach, potato salad, and shrimp. The inhibitory effect on Shigella growth by Rainbow agar was between that of XLD and SSA. All vegetables studied showed a moderately high background microflora on XLD and Rainbow agar. With artificially inoculated produce, Rainbow agar recovered about 1 to 2 log CFU more S. sonnei, S. dysenteriae, and S. boydii per g of food than did XLD. For potato salad and shrimp, which had low background microflora on Rainbow agar, Rainbow agar was slightly better in recovering Shigella spp. than XLD was in most cases. However, we found that the addition of streptomycin (6.25 mg/liter) to Rainbow agar could facilitate the isolation of Shigella in vegetables tested. In conclusion, Rainbow agar was a much more effective medium than was XLD for the isolation of Shigella spp. from foods. PMID:20819355

  4. Impermeable thin AI2O3 overlay for TBC protection from sulfate and vanadate attack in gas turbines

    SciTech Connect

    Scott X. Mao

    2005-10-30

    In order to improve the hot corrosion resistance of conventional YSZ TBC system, a dense and continues overlay of Al{sub 2}O{sub 3} coating of about 0.1-25 {micro}m thick was deposited on the surface of TBC by EB-PVD, high velocity oxy-fuel (HVOF) spray and composite-sol-gel (CSG) techniques. Hot corrosion tests were carried out on the TBC with and without Al{sub 2}O{sub 3} coating in molten salts mixtures (Na{sub 2}SO{sub 4} + 5%V{sub 2}O{sub 5}) at 950 C for 10h. The microstructures of TBC and overlay before and after exposure were examined by means of scanning electron microscopy (SEM), energy-dispersive X-ray spectrometer (EDX), X-ray diffraction (XRD) and secondary ion mass spectrometry (SIMS). In order to investigate the effect of Al{sub 2}O{sub 3} overlay on degradation and spalling of the TBC, indentation test has been employed to study spallation behaviors of YSZ coating with and without Al{sub 2}O{sub 3} overlay. It has been found that TBC will react with V{sub 2}O5 to form YVO{sub 4} in hot corrosion tests. A substantial amount of M-phase of ZrO{sub 2} was formed due to the leaching of Y{sub 2}O{sub 3} from YSZ. During hot corrosion test, there were no significant interactions between overlay Al{sub 2}O{sub 3} coating and molten salts. After exposure, the alumina coating, especially produced by HVOF, was still very dense and cover the surface of YSZ, although they had been translated to {alpha} - Al{sub 2}O{sub 3} from original {gamma} - Al{sub 2}O{sub 3}. As a result, Al{sub 2}O{sub 3} overlay coating decreased the penetration of salts into the YSZ and prevented the YSZ from the attack by molten salts containing vanadium. Accordingly, only a few M-phase was formed in YSZ TBC, compared with TBC without overlay coating. The penetration of salts into alumina coating was thought to be through microcracks formed in overlay Al{sub 2}O{sub 3} coating and at the interface between alumina and zirconia due to the presence of tensile stress in the alumina coating

  5. Comparison of dosimetry gels prepared by agar and bovine gelatine

    NASA Astrophysics Data System (ADS)

    Sağsöz, M. E.; Korkut, Ö.; Alemdar, N.; Aktaş, S.; Çalı, E. B.; Kantarcı, M.

    2016-04-01

    Gel dosimeters are unique materials capable of showing three dimensional (3D) dose distributions of therapeutic or diagnostic exposures. Fricke gel dosimeters can be considered as chemical dosimeters that rely on a radiation-induced chemical reaction. Dose distribution of Fricke solutions containing Fe+2 ions determines the transformation of acidic, oxygen saturated Fe+2 ions to Fe+3 ions by the ionizing radiation in aqueous solutions. In this study we produced two different types of gel dosimeters using agar and bovine gelatin with similar fabrication methods. We compared the magnetic resonance (MR) T1 imaging responses of these two gel dosimeters to acquire a dose dependency of MR intensities. In conclusion agar gel dosimeters found to be produced easily and more consistent.

  6. Mupirocin-mucin agar for selective enumeration of Bifidobacterium bifidum.

    PubMed

    Pechar, Radko; Rada, Vojtech; Parafati, Lucia; Musilova, Sarka; Bunesova, Vera; Vlkova, Eva; Killer, Jiri; Mrazek, Jakub; Kmet, Vladimir; Svejstil, Roman

    2014-11-17

    Bifidobacterium bifidum is a bacterial species exclusively found in the human intestinal tract. This species is becoming increasingly popular as a probiotic organism added to lyophilized products. In this study, porcine mucin was used as the sole carbon source for the selective enumeration of B. bifidum in probiotic food additives. Thirty-six bifidobacterial strains were cultivated in broth with mucin. Only 13 strains of B. bifidum utilized the mucin to produce acids. B. bifidum was selectively enumerated in eight probiotic food supplements using agar (MM agar) containing mupirocin (100 mg/L) and mucin (20 g/L) as the sole carbon source. MM agar was fully selective if the B. bifidum species was presented together with Bifidobacterium animalis subsp. lactis, Bifidobacterium breve, and Bifidobacterium longum subsp. longum species and with lactic acid bacteria (lactobacilli, streptococci). Isolated strains of B. bifidum were identified using biochemical, PCR, MALDI-TOF procedures and 16S rRNA gene sequencing. The novel selective medium was also suitable for the isolation of B. bifidum strains from human fecal samples. PMID:25217723

  7. Individual based simulations of bacterial growth on agar plates

    NASA Astrophysics Data System (ADS)

    Ginovart, M.; López, D.; Valls, J.; Silbert, M.

    2002-03-01

    The individual based simulator, INDividual DIScrete SIMulations (INDISIM) has been used to study the behaviour of the growth of bacterial colonies on a finite dish. The simulations reproduce the qualitative trends of pattern formation that appear during the growth of Bacillus subtilis on an agar plate under different initial conditions of nutrient peptone concentration, the amount of agar on the plate, and the temperature. The simulations are carried out by imposing closed boundary conditions on a square lattice divided into square spatial cells. The simulator studies the temporal evolution of the bacterial population possible by setting rules of behaviour for each bacterium, such as its uptake, metabolism and reproduction, as well as rules for the medium in which the bacterial cells grow, such as concentration of nutrient particles and their diffusion. The determining factors that characterize the structure of the bacterial colony patterns in the presents simulations, are the initial concentrations of nutrient particles, that mimic the amount of peptone in the experiments, and the set of values for the microscopic diffusion parameter related, in the experiments, to the amount of the agar medium.

  8. Modeling development of inhibition zones in an agar diffusion bioassay.

    PubMed

    Chandrasekar, Vaishnavi; Knabel, Stephen J; Anantheswaran, Ramaswamy C

    2015-09-01

    A two-temperature agar diffusion bioassay is commonly used to quantify the concentration of nisin using Micrococcus luteus as the indicator microorganism. A finite element computational model based on Fick's second law of diffusion was used to predict the radius of the inhibition zone in this diffusion bioassay. The model developed was used to calculate nisin concentration profiles as a function of time and position within the agar. The minimum inhibitory concentration (MIC) of nisin against M. luteus was determined experimentally. The critical time (T c) for growth of M. luteus within the agar diffusion bioassay was experimentally determined using incubation studies with nisin. The radius of the inhibition zone was predicted from the computational model as the location where the predicted nisin concentration at T c was equal to MIC. The MIC was experimentally determined to be 0.156 μg mL(-1), and T c was determined to be 7 h. Good agreement (R (2) = 0.984) was obtained between model-predicted and experimentally determined inhibition zone radii. PMID:26405525

  9. Modeling development of inhibition zones in an agar diffusion bioassay

    PubMed Central

    Chandrasekar, Vaishnavi; Knabel, Stephen J; Anantheswaran, Ramaswamy C

    2015-01-01

    A two-temperature agar diffusion bioassay is commonly used to quantify the concentration of nisin using Micrococcus luteus as the indicator microorganism. A finite element computational model based on Fick's second law of diffusion was used to predict the radius of the inhibition zone in this diffusion bioassay. The model developed was used to calculate nisin concentration profiles as a function of time and position within the agar. The minimum inhibitory concentration (MIC) of nisin against M. luteus was determined experimentally. The critical time (Tc) for growth of M. luteus within the agar diffusion bioassay was experimentally determined using incubation studies with nisin. The radius of the inhibition zone was predicted from the computational model as the location where the predicted nisin concentration at Tc was equal to MIC. The MIC was experimentally determined to be 0.156 μg mL−1, and Tc was determined to be 7 h. Good agreement (R2 = 0.984) was obtained between model-predicted and experimentally determined inhibition zone radii. PMID:26405525

  10. Incidental Learning of Geospatial Concepts across Grade Levels: Map Overlay

    ERIC Educational Resources Information Center

    Battersby, Sarah E.; Golledge, Reginald G.; Marsh, Meredith J.

    2006-01-01

    In this paper, the authors evaluate map overlay, a concept central to geospatial thinking, to determine how it is naively and technically understood, as well as to identify when it is leaner innately. The evaluation is supported by results from studies at three grade levels to show the progression of incidentally learned geospatial knowledge as…

  11. 12. DETAIL INDICATING TRANSITION FROM ORIGINAL SURFACE TO GUNITE OVERLAY ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    12. DETAIL INDICATING TRANSITION FROM ORIGINAL SURFACE TO GUNITE OVERLAY ON UPSTREAM EMBANKMENT OF DAM (FROM REPAIRS COMPLETED IN 1977) - Upper Doughty Dam, 200 feet west of Garden State Parkway, 1.7 miles west of Absecon, Egg Harbor City, Atlantic County, NJ

  12. Semantic overlay network for large-scale spatial information indexing

    NASA Astrophysics Data System (ADS)

    Zou, Zhiqiang; Wang, Yue; Cao, Kai; Qu, Tianshan; Wang, Zhongmin

    2013-08-01

    The increased demand for online services of spatial information poses new challenges to the combined filed of Computer Science and Geographic Information Science. Amongst others, these include fast indexing of spatial data in distributed networks. In this paper we propose a novel semantic overlay network for large-scale multi-dimensional spatial information indexing, called SON_LSII, which has a hybrid structure integrating a semantic quad-tree and Chord ring. The SON_LSII is a small world overlay network that achieves a very competitive trade-off between indexing efficiency and maintenance overhead. To create SON_LSII, we use an effective semantic clustering strategy that considers two aspects, i.e., the semantic of spatial information that peer holds in overlay network and physical network performances. Based on SON_LSII, a mapping method is used to reduce the multi-dimensional features into a single dimension and an efficient indexing algorithm is presented to support complex range queries of the spatial information with a massive number of concurrent users. The results from extensive experiments demonstrate that SON_LSII is superior to existing overlay networks in various respects, including scalability, maintenance, rate of indexing hits, indexing logical hops, and adaptability. Thus, the proposed SON_LSII can be used for large-scale spatial information indexing.

  13. Factors affecting the erosion resistance of weld overlays

    SciTech Connect

    Levin, B.F.; Dupont, J.N.; Marder, A.R.

    1996-12-31

    Research was conducted to study factors affecting the solid particle erosion resistance of weld overlay coatings. Eleven weld overlay alloys were deposited on 1018 steel substrates using the plasma arc welding process and erosion tested at 400 C. Erosion resistance was evaluated by determining the steady state erosion rate. Ultimet, Inconel-625, and 316L SS coatings showed the best erosion resistance at 30 and 90{degree} impact angles. Microhardness tests were performed on the eroded samples below the erosion surface to determine the size of the plastically deformed zone and it was found that one group of coatings deformed plastically as a result of the particle impact while the others did not. No correlations were found between average microhardness at 400 C and volumetric erosion rates for plastically deformed weld overlays. For this group of overlays erosion resistance was correlated to the area under the curve of microhardness versus distance from the eroded surface. The physical significance of this parameter is discussed. For coatings that did not deform plastically, an increase in average microhardness at 400 C led to an increase in their volumetric erosion rates. The possible erosion mechanisms for these coating groups are discussed.

  14. Promoting Learning of Instructional Design via Overlay Design Tools

    ERIC Educational Resources Information Center

    Carle, Andrew Jacob

    2012-01-01

    I begin by introducing Virtual Design Apprenticeship (VDA), a learning model--built on a solid foundation of education principles and theories--that promotes learning of design skills via overlay design tools. In VDA, when an individual needs to learn a new design skill or paradigm she is provided accessible, concrete examples that have been…

  15. Crosslayer Survivability in Overlay-IP-WDM Networks

    ERIC Educational Resources Information Center

    Pacharintanakul, Peera

    2010-01-01

    As the Internet moves towards a three-layer architecture consisting of overlay networks on top of the IP network layer on top of WDM-based physical networks, incorporating the interaction between and among network layers is crucial for efficient and effective implementation of survivability. This dissertation has four major foci as follows:…

  16. IMPERMEABLE THIN Al2O3 OVERLAY FOR TBC PROTECTION FROM SULFATE AND VANADATE ATTACK IN GAS TURBINES

    SciTech Connect

    Scott X. Mao

    2002-06-30

    In order to improve the hot corrosion resistance of conventional YSZ TBC system (YSZ/CoNiCrAlY/Inconel 601), an overlay Al{sub 2}O{sub 3} was sprayed on the surface of TBC samples by high velocity oxy-fuel (HVOF) spray techniques. The TBC preparation in Japan was based on our technical requirement by plasma spray. Bond coat CoNiCrAlY and the YSZ was produced by low-pressure plasma spray and air plasma spray respectively. Hot corrosion tests were carried out on the TBC with and without Al{sub 2}O{sub 3} coating in molten salts mixtures (Na{sub 2}SO{sub 4} + 5%V{sub 2}O{sub 5}) at 950 C for 10h. The microstructures of TBC and overlay before and after exposure were examined by means of scanning electron microscopy (SEM), energy-dispersive X-ray spectrometer (EDX) and X-ray diffraction (XRD). It has been found that TBC reacted with V{sub 2}O{sub 5} to form YVO{sub 4}. A substantial amount of M-phase was formed due to the leaching of Y{sub 2}O{sub 3} from YSZ. Al{sub 2}O{sub 3} overlay coating sprayed by HVOF was dense, continues and adherent to the TBC even after exposure to the molten salts. As a result, overlay Al{sub 2}O{sub 3} coating can prevent the YSZ from the attack by molten salts containing vanadium and arrest the penetration of salts into the YSZ along porous and cracks in the YSZ TBC. Accordingly, the amount of M-phase formed in TBC with Al{sub 2}O{sub 3} overlay was significantly lower than that in conventional YSZ TBC system. In the next period, the hot corrosion tests of TBC with EB-PVD Al{sub 2}O{sub 3} coating under Na{sub 2}SO{sub 4} + 5%V{sub 2}O{sub 5} will be again performed at 950 C. However before hot corrosion tests, the post-annealing will be carried at 1273K for 1h in order to transform the as-sputtered {gamma}-Al{sub 2}O{sub 3} overlay to crystalline {alpha}-Al{sub 2}O{sub 3} overlay. In addition, the effect of coating thickness on corrosion resistance and the mechanisms of cracking of EB-PVD alumina layer during hot corrosion will be also

  17. A Facile Surface Passivation of Hematite Photoanodes with TiO2 Overlayers for Efficient Solar Water Splitting.

    PubMed

    Ahmed, Mahmoud G; Kretschmer, Imme E; Kandiel, Tarek A; Ahmed, Amira Y; Rashwan, Farouk A; Bahnemann, Detlef W

    2015-11-01

    The surface modification of semiconductor photoelectrodes with passivation overlayers has recently attracted great attention as an effective strategy to improve the charge-separation and charge-transfer processes across semiconductor-liquid interfaces. It is usually carried out by employing the sophisticated atomic layer deposition technique, which relies on reactive and expensive metalorganic compounds and vacuum processing, both of which are significant obstacles toward large-scale applications. In this paper, a facile water-based solution method has been developed for the modification of nanostructured hematite photoanode with TiO2 overlayers using a water-soluble titanium complex (i.e., titanium bis(ammonium lactate) dihydroxide, TALH). The thus-fabricated nanostructured hematite photoanodes have been characterized by X-ray diffraction, scanning electron microscopy, and X-ray photoelectron spectroscopy. Photoelectrochemical measurements indicated that a nanostructured hematite photoanodes modified with a TiO2 overlayer exhibited a photocurrent response ca. 4.5 times higher (i.e., 1.2 mA cm(-2) vs RHE) than that obtained on the bare hematite photoanode (i.e., 0.27 mA cm(-2) vs RHE) measured under standard illumination conditions. Moreover, a cathodic shift of ca. 190 mV in the water oxidation onset potential was achieved. These results are discussed and explored on the basis of steady-state polarization, transient photocurrent response, open-circuit potential, intensity-modulated photocurrent spectroscopy, and impedance spectroscopy measurements. It is concluded that the TiO2 overlayer passivates the surface states and suppresses the surface electron-hole recombination, thus increasing the generated photovoltage and the band bending. The present method for the hematite electrode modification with a TiO2 overlayer is effective and simple and might find broad applications in the development of stable and high-performance photoelectrodes. PMID:26488924

  18. Utilization of the Soft Agar Colony Formation Assay to Identify Inhibitors of Tumorigenicity in Breast Cancer Cells.

    PubMed

    Horibata, Sachi; Vo, Tommy V; Subramanian, Venkataraman; Thompson, Paul R; Coonrod, Scott A

    2015-01-01

    Given the inherent difficulties in investigating the mechanisms of tumor progression in vivo, cell-based assays such as the soft agar colony formation assay (hereafter called soft agar assay), which measures the ability of cells to proliferate in semi-solid matrices, remain a hallmark of cancer research. A key advantage of this technique over conventional 2D monolayer or 3D spheroid cell culture assays is the close mimicry of the 3D cellular environment to that seen in vivo. Importantly, the soft agar assay also provides an ideal tool to rigorously test the effects of novel compounds or treatment conditions on cell proliferation and migration. Additionally, this assay enables the quantitative assessment of cell transformation potential within the context of genetic perturbations. We recently identified peptidylarginine deiminase 2 (PADI2) as a potential breast cancer biomarker and therapeutic target. Here we highlight the utility of the soft agar assay for preclinical anti-cancer studies by testing the effects of the PADI inhibitor, BB-Cl-amidine (BB-CLA), on the tumorigenicity of human ductal carcinoma in situ (MCF10DCIS) cells. PMID:26067809

  19. Hydrogen-bond-mediated in situ fabrication of AgNPs/agar/PAN electrospun nanofibers as reproducible SERS substrates.

    PubMed

    Yang, Tong; Yang, Hui; Zhen, Shu Jun; Huang, Cheng Zhi

    2015-01-28

    Reproducibility in surface enhanced Raman scattering (SERS) measurements is a challenge. This work developed a facile way to make highly dispersed uniform silver nanoparticles (AgNPs) loaded in the agar/polyacrylonitrile (PAN) nanofibers by the coupling the electrospinning technology from metal complex-containing polymer solution and in situ photoreductive technique. Agar, as hydrophilic component, was introduced into the electrospinning solution considering that its abundant hydroxyl group sites could greatly improve the contents of silver ions in the polymers because of the rich silver ion chelated with the hydroxyl group, whereas hydrophilic agar was integrated with hydrophobic PAN by -OH···N≡C- hydrogen bonds as a bridge. Meanwhile, the in situ photoreductive reaction was made under different light irradiations such as desk lamp, 365 nm UV-lamp, and 254 nm UV-lamp. High yield of stable AgNPs with highly uniform and dispersion are available in the agar/PAN nanofibers after the in situ photoreductive reaction, supplying the possibility of reproducible SERS signals. To identify that concept of proof, a facile approach for the determination of malachite green (MG) in three environmental practical samples was demonstrated by using the composite nanofibrous material irradiated by 365 nm UV-lamp, giving the minimum detection concentration of MG as low as 0.1 μmol/L with a good linear response ranging from 0.1-100 μmol/L (R(2) = 0.9960). PMID:25546719

  20. Throughput and Packet Delay Analysis of the Intermittent DCF for Overlay Access Networks

    NASA Astrophysics Data System (ADS)

    Adamis, Athanassios V.; Maliatsos, Konstantinos N.; Constantinou, Philip

    Overlay Access Technology can compensate for the spectrum underutilization problem by exploiting Cognitive Radios capabilities. MAC design is an important aspect of Overlay Access research. In this paper we present the overlay access environment and the challenges it poses to MAC design. Then, we propose the use of a modified Distributed Coordination Function as the MAC protocol for distributed Overlay Access networks. The resulted Intermittent DCF performs with robustness in the demanding overlay access environment, which is characterized by frequent spectrum scan procedure interruptions and low achievable transmission rates. The most recent DCF Markov Chain Model is extended in order to include the overlay operation modifications. Our extension concerns the slot duration expectations calculation which, in the overlay environment, have not constant values but depend on overlay operation parameters. Using the analytical model we evaluate the performance of the DCF under the effect of certain overlay access parameters. The new analytical model predictions are validated with simulations, and are found to accurately capture many interesting features of the overlay operation. Our model can be used in feasibility studies of realistic overlay scenarios and in admission control algorithms of QoS enabled distributed overlay access networks that engage the Intermittent DCF.

  1. Differential recovery of Streptococcus mutans from various mitis-salivarius agar preparations.

    PubMed Central

    Liljemark, W F; Okrent, D H; Bloomquist, C G

    1976-01-01

    Recoveries of Streptococcus mutans from human dental plaque were lower when plated on mitis-salivarius agar obtained from Baltimore Biological Laboratories as compared with mitis-salivarius agar obtained from Difco Laboratories. However, no difference in recoveries of established laboratory strains of S. mutans was observed between these two agar preparations. PMID:956358

  2. [Tryptose sulphite cycloserine agar for the recovery of Clostridium perfringens in surface waters: a study of different modes of utilization].

    PubMed

    Nusca, A; Orefice, L; Paradiso, R

    2007-01-01

    In the recent European Drinking Water Directive, Clostridium perfringens has assumed increasing importance so as to be considered a primary contamination indicator. Therefore it emerged the necessity to make culture methods, aimed at its recovery, more specific and sensitive. In this study we have verified the ability of Tryptose Sulphite Cycloserine Agar plates (TSC Agar), prepared and stored before the use at refrigeration temperature (+4 degrees) for different times, to show typical colonies, using both, the single layer and double layer techniques. Results show that storage of the prepared medium, even for a few days, decrease the recovery of typical colonies although such negative effect is minimized by using the double layer technique. PMID:17405507

  3. Conjugate point determination for multitemporal data overlay

    NASA Technical Reports Server (NTRS)

    Emmert, R. A.; Mcgillem, C. D.

    1972-01-01

    The machine processing is discussed of spatially variant multitemporal data such as imagery obtained at different times which requires that these data be in geometrical registration so that the analysis processor may obtain the datum for a specified ground resolution element in each of the sets of imagery being utilized for analysis. Misregistration between corresponding subsets of imagery contains both a displacement and a geometrical distortion component. Search techniques utilizing the moduli of the Fourier Transforms are developed for estimating the coefficients of geometrical distortion components of this model. Following the correction of these distortion components, the displacement is located by the crosscorrelation of a template obtained from one set of data, termed the reference, with the second, or background data. This template, derived for the optimum discrimination of the reference data embedded in the background, is determined by the solution of a system of equations involving the reference data and the covariance matrix of these data.

  4. A soft agar colony assay for Lewis lung tumour and B16 melanoma taken directly from the mouse.

    PubMed Central

    Courtenay, V. D.

    1976-01-01

    A soft agar colony assay has been developed for the B16 mouse melanoma and the Lewis lung tumour. The special features of the technique are the use of a gas phase with 5% O2 instead of air and the addition of rat red blood cells. Single cell suspensions are prepared by trypsinization from the solid tumour and the cells are plated out in 0-3% agar over a layer of 0-5% agar in 30-mm Petri dishes. After 8 to 15 days' incubation in 5% O2, colonies of more than 50 cells are produced. Plating efficiencies of between 30 and 50% are usually obtained. The addition of up to 10(4) heavily irradiated tumour cells gives some further improvement in plating efficiency for the B16 melanoma but not for the Lewis lung tumour. Applications of the technique to measure cell survival in the two tumours after treatment with cytotoxic drugs and radiation are reported. The scatter of experimental points is relatively small, and in comparative experiments good agreement has been obtained with results using in vivo assay techniques. PMID:782495

  5. Chlorine adsorption on Au(111): chlorine overlayer or surface chloride?

    PubMed

    Gao, Weiwei; Baker, Thomas A; Zhou, Ling; Pinnaduwage, Dilini S; Kaxiras, Efthimios; Friend, Cynthia M

    2008-03-19

    We report the first scanning tunneling microscope (STM) investigation, combined with density functional theory calculations, to resolve controversy regarding the bonding and structure of chlorine adsorbed on Au(111). STM experiments are carried out at 120 K to overcome instability caused by mobile species upon chlorine adsorption at room temperature. Chlorine adsorption initially lifts the herringbone reconstruction. At low coverages (<0.33 ML), chlorine binds to the top of Au(111)-(1 x 1) surface and leads to formation of an overlayer with (square root(3) x square root(3))R30 degree structure at 0.33 ML. At higher coverages, packing chlorine into an overlayer structure is no longer favored. Gold atoms incorporate into a complex superlattice of a Au-Cl surface compound. PMID:18290645

  6. Modeling the dynamical interaction between epidemics on overlay networks

    NASA Astrophysics Data System (ADS)

    Marceau, Vincent; Noël, Pierre-André; Hébert-Dufresne, Laurent; Allard, Antoine; Dubé, Louis J.

    2011-08-01

    Epidemics seldom occur as isolated phenomena. Typically, two or more viral agents spread within the same host population and may interact dynamically with each other. We present a general model where two viral agents interact via an immunity mechanism as they propagate simultaneously on two networks connecting the same set of nodes. By exploiting a correspondence between the propagation dynamics and a dynamical process performing progressive network generation, we develop an analytical approach that accurately captures the dynamical interaction between epidemics on overlay networks. The formalism allows for overlay networks with arbitrary joint degree distribution and overlap. To illustrate the versatility of our approach, we consider a hypothetical delayed intervention scenario in which an immunizing agent is disseminated in a host population to hinder the propagation of an undesirable agent (e.g., the spread of preventive information in the context of an emerging infectious disease).

  7. On-demand Overlay Networks for Large Scientific Data Transfers

    SciTech Connect

    Ramakrishnan, Lavanya; Guok, Chin; Jackson, Keith; Kissel, Ezra; Swany, D. Martin; Agarwal, Deborah

    2009-10-12

    Large scale scientific data transfers are central to scientific processes. Data from large experimental facilities have to be moved to local institutions for analysis or often data needs to be moved between local clusters and large supercomputing centers. In this paper, we propose and evaluate a network overlay architecture to enable highthroughput, on-demand, coordinated data transfers over wide-area networks. Our work leverages Phoebus and On-demand Secure Circuits and AdvanceReservation System (OSCARS) to provide high performance wide-area network connections. OSCARS enables dynamic provisioning of network paths with guaranteed bandwidth and Phoebus enables the coordination and effective utilization of the OSCARS network paths. Our evaluation shows that this approach leads to improved end-to-end data transfer throughput with minimal overheads. The achievedthroughput using our overlay was limited only by the ability of the end hosts to sink the data.

  8. Modeling of Co overlayers on Pd (111) from first principles

    NASA Astrophysics Data System (ADS)

    Uba, S.; Uba, L.; Antonov, V. N.

    2007-04-01

    The electronic, magnetic and magneto-optical properties of Co overlayers on Pd (1 1 1) substrate have been investigated by ab initio band structure calculations within the spin-polarized relativistic linear muffin-thin orbitals (LMTO) method and supercell approach. The role of the Co-Pd interface structure, the number of the Co atomic layers ( n Co ), as well as the spin-orbit interaction and induced Pd spin polarization, in formation of magneto-optical response of the structures for [ n CoCo/Pd (1 1 1)] system is shown. The sign reversal of the polar Kerr rotation obtained theoretically with decreasing thickness of Co overlayers agrees well with experiment. We will demonstrate the effectiveness of the extended numeric modeling of magneto-optical properties from first principles.

  9. Flutter Analysis of the Shuttle Tile Overlay Repair Concept

    NASA Technical Reports Server (NTRS)

    Bey, Kim S.; Scott, Robert C.; Bartels, Robert E.; Waters, William A.; Chen, Roger

    2007-01-01

    The Space Shuttle tile overlay repair concept, developed at the NASA Johnson Space Center, is designed for on-orbit installation over an area of damaged tile to permit safe re-entry. The thin flexible plate is placed over the damaged area and secured to tile at discreet points around its perimeter. A series of flutter analyses were performed to determine if the onset of flutter met the required safety margins. Normal vibration modes of the panel, obtained from a simplified structural analysis of the installed concept, were combined with a series of aerodynamic analyses of increasing levels of fidelity in terms of modeling the flow physics to determine the onset of flutter. Results from these analyses indicate that it is unlikely that the overlay installed at body point 1800 will flutter during re-entry.

  10. Improved overlay metrology device correlation on 90-nm logic processes

    NASA Astrophysics Data System (ADS)

    Ueno, Atsushi; Tsujita, Kouichirou; Kurita, Hiroyuki; Iwata, Yasuhisa; Ghinovker, Mark; Poplawski, Jorge M.; Kassel, Elyakim; Adel, Mike E.

    2004-05-01

    Isolated and dense patterns were formed at process layers from gate through to back-end on wafers using a 90 nm logic device process utilizing ArF lithography under various lithography conditions. Pattern placement errors (PPE) between AIM grating and BiB marks were characterized for line widths varying from 1000nm to 140nm. As pattern size was reduced, overlay discrepancies became larger, a tendency which was confirmed by optical simulation with simple coma aberration. Furthermore, incorporating such small patterns into conventional marks resulted in significant degradation in metrology performance while performance on small pattern segmented grating marks was excellent. Finally, the data also show good correlation between the grating mark and specialized design rule feature SEM marks, with poorer correlation between conventional mark and SEM mark confirming that new grating mark significantly improves overlay metrology correlation with device patterns.

  11. Relative value of selective group A streptococcal agar incubated under different atmospheres.

    PubMed Central

    Pacifico, L; Ranucci, A; Ravagnan, G; Chiesa, C

    1995-01-01

    A commercially available selective group A streptococcal agar (ssA) was evaluated for the recovery of group A streptococci (GAS) in comparison with recovery from simultaneous cultures on conventional sheep blood agar (SBA). Both sets of plates were incubated in air, 5% CO2, and anaerobically for 48 h, with a first reading taken at 24 h. A total of 402 (67.0%) GAS were isolated from the 600 specimens that were submitted. Recovery of GAS was significantly greater after 48 h of incubation than after 24 h of incubation for each medium-atmosphere combination. After 48 h of incubation, the sensitivities of GAS detection obtained by each culture technique were as follows: ssA-anaerobic atmosphere, 98.5%; SBA-anaerobic atmosphere, 89.5%; ssA-CO2 atmosphere, 88.0%; SBA-air, 86.5%; SBA-CO2 atmosphere, 82.0%; and ssA-air, 74.6%. There were no cultures positive in air or CO2 which were not positive anaerobically on either medium. The increased sensitivity of detecting positive GAS cultures when incubation was done in an ssA-anaerobic atmosphere for 48 h uncovered patients truly infected with the organisms. PMID:7494053

  12. CLIO — A Cross-Layer Information Service for Overlay Network Optimization

    NASA Astrophysics Data System (ADS)

    Haage, Dirk; Holz, Ralph; Niedermayer, Heiko; Laskov, Pavel

    New overlay-based services aim to provide properties like resilience, availability or QoS. To achieve this, automatic organization and optimization is required, which again demands accurate information on the network. Collecting and exchanging this data has a significant impact on the network, especially if several overlays are used on the same host. In this paper, we provide a survey of the current state of the art and identify challenges which must be addressed in order for new overlay-based services to be successful. We present our own solution CLIO, a cross-layer information service for overlays. CLIO provides information for the automatic creation and optimization of overlays. The service supports multiple overlays on the same node, the provided information is overlay-independent, and collected information is reused.

  13. Borelli's lactritmel agar induces conidiation in rare-macroconidia producing dermatophytic fungi.

    PubMed

    Ilkit, Macit; Gümral, Ramazan; Döğen, Aylin

    2012-10-01

    Macroconidia are among the most important indicators used to identify dermatophytic fungi, but several do not usually sporulate and/or produce macroconidia on Sabouraud glucose agar. Specifically, Microsporum audouinii, M. ferrugineum, Trichophyton concentricum, T. schoenleinii, T. verrucosum, and T. violaceum (including T. soudanense and T. yaoundei) rarely form macroconidia and, therefore, cannot be easily identified. In this study, we investigated the production of macroconidia on nine common laboratory media, including Borelli's lactritmel agar (BLA), modified Borelli's lactritmel agar (MBLA), brain heart infusion agar (BHIA), Christensen's urease agar in Petri dishes (UPA), cornmeal dextrose agar (CMDA), Lowenstein-Jensen agar (LJA), malt extract agar (MEA), oatmeal agar (OA), and potato dextrose agar (PDA). The performance of these media was evaluated using 18 rare-macroconidia producing isolates, including representative of the six species mentioned above. All cultures in this study were incubated at 26°C on the bench, and conidia formation on each was investigated at 5, 10, 15, 20, 25, and 30 days of incubation. BLA apparently improved macroconidia production after 15 days and was the most useful nutrient agar medium to induce these phenotypic characters in daily practice, closely followed by OA, PDA, and MBLA. PMID:22563856

  14. Physicochemical properties of biodegradable polyvinyl alcohol-agar films from the red algae Hydropuntia cornea.

    PubMed

    Madera-Santana, Tomás J; Robledo, Daniel; Freile-Pelegrín, Yolanda

    2011-08-01

    Agar obtained from the red alga Hydropuntia cornea was blended with polyvinyl alcohol (PVOH) in order to produce biodegradable films. In this study, we compare the properties of biopolymeric films formulated with agars extracted from H. cornea collected at different seasons (rainy and dry) in the Gulf of Mexico coast and PVOH as synthetic matrix. The films were prepared at different agar contents (0%, 25%, 50%, 75%, and 100%) and their optical, mechanical, thermal, and morphological properties analyzed. The tensile strength of PVOH-agar films increased when agar content was augmented. The formulation with 50% agar from rainy season (RS) had a significant higher tensile strength when compared to those from dry season (DS; p < 0.05). Tensile modulus also displayed an increasing trend and likewise, for 50% and 75% agar blends from RS showed higher values than those from DS (p < 0.05). In contrast, elongation at break decreased as the agar content increased, independently of the season. Environmental scanning electron microscopy images of PVOH-agar 75% biofilms from RS showed a homogeneous structure with good interfacial adhesion between the two components. The changes evidenced in the FTIR spectrum of this blend suggest that hydrogen bonding is taking place between the agar ether linkages (C-O-C) and the hydroxyl groups (OH) of the PVOH. Based on the above mentioned results, blends of PVOH and 75% agar from H. cornea collected in rainy season showed good properties for applications in the biodegradable packaging industry. PMID:21207092

  15. Prepenetrant Etchant For Incology(R) 903 Weld Overlays

    NASA Technical Reports Server (NTRS)

    O'Tousa, Joseph E.; Thomas, Clark S.; Foster, Robert E.

    1990-01-01

    Etching solution developed for use prior to type-IVc penetrant inspection of Incology(R) 903 weld overlays. Formulated as follows: 80 g ferric chloride hexahydrate, 300 mL reagent-grade hydrochloric acid, 25 mL food- or reagent-grade phosphoric acid, and 100 mL ethylene glycol. Gives more reasonable range of etching time and reduces probability of overetching and resulting damage. Stored indefinitely.

  16. An Overlapping Structured P2P for REIK Overlay Network

    NASA Astrophysics Data System (ADS)

    Liu, Wenjun; Song, Jingjing; Yu, Jiguo

    REIK is based on a ring which embedded an inverse Kautz digraph, to enable multi-path P2P routing. It has the constant degree and the logarithmic diameter DHT scheme with constant congestion and Byzantine fault tolerance. However, REIK did not consider the interconnection of many independent smaller networks. In this paper, we propose a new approach to build overlay network, OLS-REIK which is an overlapping structured P2P for REIK overlay network. It is a more flexible interconnecting different REIK network. Peers can belong to several rings, allowing this interconnection. By connecting smaller structured overlay networks in an unstructured way, it provides a cost effective alternative to hierarchical structured P2P systems requiring costly merging. Routing of lookup messages is performed as in REIK within one ring, but a peer belonging to several rings forwards the request to the different rings it belongs to. Furthermore a small number of across point is enough to ensure a high exhaustiveness level.

  17. Diffusion Barriers to Increase the Oxidative Life of Overlay Coatings

    NASA Technical Reports Server (NTRS)

    Nesbitt, James A.; Lei, Jih-Fen

    1999-01-01

    Currently, most blades and vanes in the hottest section of aero gas turbine engines require some type of coating for oxidation protection. Newly developed single crystal superalloys have the mechanical potential to operate at increasingly higher component temperatures. However, at these elevated temperatures, coating/substrate interdiffusion can shorten the protective life of the coating. Diffusion barriers between overlay coatings and substrates are being examined to extend the protective life of the coating. A previously- developed finite-difference diffusion model has been modified to predict the oxidative life enhancement due to use of a diffusion barrier. The original diffusion model, designated COSIM, simulates Al diffusion in the coating to the growing oxide scale as well as Al diffusion into the substrate. The COSIM model incorporates an oxide growth and spalling model to provide the rate of Al consumption during cyclic oxidation. Coating failure is predicted when the Al concentration at the coating surface drops to a defined critical level. The modified COSIM model predicts the oxidative life of an overlay coating when a diffusion barrier is present eliminating diffusion of Al from the coating into the substrate. Both the original and the modified diffusion models have been used to predict the effectiveness of a diffusion barrier in extending the protective life of a NiCrAl overlay coating undergoing cyclic oxidation at 1100 C.

  18. Overlay mark optimization using the KTD signal simulation system

    NASA Astrophysics Data System (ADS)

    Marchelli, Anat; Gutjahr, Karsten; Kubis, Michael; Sparka, Christian; Ghinovker, Mark; Navarra, Alessandra; Widmann, Amir

    2009-03-01

    As the overlay performance and accuracy requirements become tighter, the impact of process parameters on the target signal becomes more significant. Traditionally, in order to choose the optimum overlay target, several candidates are placed in the kerf area. The candidate targets are tested under different process conditions, before the target to be used in mass production is selected. The varieties of targets are left on the mass production mask and although they will not be used for overlay measurements they still consume kerf real estate. To improve the efficiency of the process we are proposing the KTD (KLA-Tencor Target Designer). It is an easy to use system that enables the user to select the optimum target based on advanced signal simulation. Implementing the KTD in production is expected to save 30% of kerf real estate due to more efficient target design process as well as reduced engineering time. In this work we demonstrate the capability of the KTD to simulate the Archer signal in the context of advanced DRAM processes. For several stacks we are comparing simulated target signals with the Archer100 signals. We demonstrate the robustness feature in the KTD application that enables the user to test the target sensitivity to process changes. The results indicate the benefit of using KTD in the target optimization process.

  19. Multicast Routing in Structured Overlays and Hybrid Networks

    NASA Astrophysics Data System (ADS)

    Wählisch, Matthias; Schmidt, Thomas C.

    Key-based routing has enabled efficient group communication on the application or service middleware layer, stimulated by the need of applications to access multicast. These developments follow a continuous debate about network layer multicast that had lasted for about 30 years history of the Internet. The IP host group model today still faces a strongly divergent state of deployment. In this chapter, we first review the key concepts of multicast and broadcast data distribution on structured overlays. Second, we perform a comprehensive theoretical analysis examining the different distribution trees constructed on top of a key-based routing layer. Characteristic performance measures of the multicast approaches are compared in detail and major structural differences are identified. Overlay multicast overcomes deployment problems on the price of a performance penalty. Hybrid approaches, which dynamically combine multicast in overlay and underlay, adaptively optimize group communication. We discuss current schemes along with its integration in common multicast routing protocols in the third part of this chapter. Finally, we reconsider and enhance approaches to a common API for group communication, which serves the requirements of data distribution and maintenance for multicast and broadcast on a middleware abstraction layer, and in particular facilitates hybrid multicast schemes.

  20. Study of spread spectrum multiple access systems for satellite communications with overlay on current services

    NASA Technical Reports Server (NTRS)

    Ha, Tri T.; Pratt, Timothy

    1989-01-01

    The feasibility of using spread spectrum techniques to provide a low-cost multiple access system for a very large number of low data terminals was investigated. Two applications of spread spectrum technology to very small aperture terminal (VSAT) satellite communication networks are presented. Two spread spectrum multiple access systems which use a form of noncoherent M-ary FSK (MFSK) as the primary modulation are described and the throughput analyzed. The analysis considers such factors as satellite power constraints and adjacent satellite interference. Also considered is the effect of on-board processing on the multiple access efficiency and the feasibility of overlaying low data rate spread spectrum signals on existing satellite traffic as a form of frequency reuse is investigated. The use of chirp is examined for spread spectrum communications. In a chirp communication system, each data bit is converted into one or more up or down sweeps of frequency, which spread the RF energy across a broad range of frequencies. Several different forms of chirp communication systems are considered, and a multiple-chirp coded system is proposed for overlay service. The mutual interference problem is examined in detail and a performance analysis undertaken for the case of a chirp data channel overlaid on a video channel.

  1. A high-accuracy surgical augmented reality system using enhanced integral videography image overlay.

    PubMed

    Zhang, Xinran; Chen, Guowen; Liao, Hongen

    2015-08-01

    Image guided surgery has been used in clinic to improve the surgery safety and accuracy. Augmented reality (AR) technique, which can provide intuitive image guidance, has been greatly evolved these years. As one promising approach of surgical AR systems, integral videography (IV) autostereoscopic image overlay has achieved accurate fusion of full parallax guidance into surgical scene. This paper describes an image enhanced high-accuracy IV overlay system. A flexible optical image enhancement system (IES) is designed to increase the resolution and quality of IV image. Furthermore, we introduce a novel IV rendering algorithm to promote the spatial accuracy with the consideration of distortion introduced by micro lens array. Preliminary experiments validated that the image accuracy and resolution are improved with the proposed methods. The resolution of the IV image could be promoted to 1 mm for a micro lens array with pitch of 2.32 mm and IES magnification value of 0.5. The relative deviation of accuracy in depth and lateral directions are -4.68 ± 0.83% and -9.01 ± 0.42%. PMID:26737223

  2. IMPERMEABLE THIN AL2O3 OVERLAY FOR TBC PROTECTION FROM SULFATE AND VANADATE ATTACK IN GAS TURBINES

    SciTech Connect

    Scott X. Mao

    2002-08-31

    In order to improve the hot corrosion resistance of conventional YSZ TBC system, a dense and continues overlay of Al{sub 2}O{sub 3} coating of about 25 {micro}m thick was deposited on the surface of TBC by EB-PVD and high velocity oxy-fuel (HVOF) spray techniques. Hot corrosion tests were carried out on the TBC with and without Al{sub 2}O{sub 3} coating in molten salts mixtures (Na{sub 2}SO{sub 4} + 5% V{sub 2}O5) at 950 C for 10h. The microstructures of TBC and overlay before and after exposure were examined by means of scanning electron microscopy (SEM), energy-dispersive X-ray spectrometer (EDX), X-ray diffraction (XRD) and secondary ion mass spectrometry (SIMS). It has been found that TBC will react with V{sub 2}O{sub 5} to form YVO{sub 4}. A substantial amount of M-phase of ZrO{sub 2} was formed due to the leaching of Y{sub 2}O{sub 3} from YSZ. During hot corrosion test, there were no significant interactions between overlay Al{sub 2}O{sub 3} coating and molten salts. After exposure, the alumina coating, especially produced by HVOF, was still very dense and cover the surface of YSZ, although they had been translated to {alpha}-Al{sub 2}O{sub 3} from original {gamma}-Al{sub 2}O{sub 3}. As a result, Al{sub 2}O{sub 3} overlay coating decreased the penetration of salts into the YSZ and prevented the YSZ from the attack by molten salts containing vanadium. Accordingly, only a few M-phase was formed in YSZ TBC, compared with TBC without overlay coating. The penetration of salts into alumina coating was thought to be through microcracks formed in overlay Al{sub 2}O{sub 3} coating and at the interface between alumina and zirconia due to the presence of tensile stress in the alumina coating. In the next year, we will study the mechanisms of cracking of the overlay Al{sub 2}O{sub 3} layer. The hot corrosion test of TBC with EB-PVD deposited Al{sub 2}O{sub 3} coating will be again performed. However before hot corrosion tests, the post-annealing will be carried out in

  3. Effect of EDTA on Pb(II) Uptake and Translocation by Tumbleweed (Salsola Kali): Agar and Hydroponics Studies

    SciTech Connect

    de la Rosa, Guadalupe; Gardea-Torresdey, Jorge L.; Peralta-Videa, Jose R.; Aldrich, Mary

    2004-03-31

    Environmental accumulation of Pb represents a worldwide health hazard. While conventional cleanup techniques are generally expensive and soil disturbing, phytoremediation represents an inexpensive friendly option for the removal of contaminants from soil and water. In this research, tumbleweed (Salsola kali) plants exposed for 15 days to Pb(NO3)2 at 80 and 125 ppm in hydroponics and agar media, demonstrated a high capacity to uptake lead. The results showed that the plants cultivated in agar accumulated 25563, 5534 and 2185 mg Pb kg-1 DW in roots, stems and leaves, respectively. Moreover, Pb concentrations found in hydroponically grown tumbleweed plants tissues were 30744, 1511 and 1421 mg kg-1 DW in roots, stems and leaves, respectively. It was observed that EDTA enhanced Pb translocation. No Pb phytotoxic effects were observed during the experimental time period. Cellular structural features were also observed using TEM.

  4. Evaluation of eight agar media for the isolation of shiga toxin-Producing Escherichia coli.

    PubMed

    Gill, Alexander; Huszczynski, George; Gauthier, Martine; Blais, Burton

    2014-01-01

    The growth characteristics of 96 shiga toxin-producing Escherichia coli (STEC) strains representing 36 different O-types (including priority O types O26, O45, O103, O111, O121, O145 and O157) on commercial and in-house agar media were studied. The ability of the strains to grow on agar media with varying selective supplement formulations was evaluated using MacConkey Agar (MAC); Rainbow® Agar O157 (RBA); Rainbow® Agar O157 with manufacturer-recommended selective supplements (RBA-NT); Rainbow® Agar O157 with USDA-recommended selective supplements (RBA-USDA); CHROMagar STEC™ (CH STEC); Tryptone Bile agar containing cefixime and tellurite (TBA-CT); Tryptone Bile agar containing cefixime, tellurite, eosin and methylene blue (TBA-EM); and VTEC agar. All of the strains were able to grow on MAC, RBA and VTEC agar, whereas a number of strains (including some non-O157 priority O types) were unable to grow on the highly selective media CH STEC, RBA-NT, RBA-USDA, TBA-EM and TBA-CT. Only RBA-NT and CH STEC exhibited significant inhibition of background flora from ground beef enrichment. Significant inhibition of background flora from beef trim enrichment was observed with RBA-NT, RBA-USDA, CH STEC, TBA-EM and VTEC agar. With exception of E. coli O157, several different colony morphologies were observed on the differential plating media among strains of the same O type, indicating that this colony morphology is not a reliable means of identifying target STEC. These results suggest that an approach to maximize the recovery of target STEC from beef enrichment cultures is dual plating on lesser (RBA, MAC, VTEC agar) and more highly (RBA-NT, CH STEC) selective agars. PMID:24211606

  5. Study of correlation between overlay and displacement measured by Coherent Gradient Sensing (CGS) interferometry

    NASA Astrophysics Data System (ADS)

    Mileham, Jeffrey; Tanaka, Yasushi; Anberg, Doug; Owen, David M.; Lee, Byoung-Ho; Bouche, Eric

    2016-03-01

    Within the semiconductor lithographic process, alignment control is one of the most critical considerations. In order to realize high device performance, semiconductor technology is approaching the 10 nm design rule, which requires progressively smaller overlay budgets. Simultaneously, structures are expanding in the 3rd dimension, thereby increasing the potential for inter-layer distortion. For these reasons, device patterning is becoming increasingly difficult as the portion of the overlay budget attributed to process-induced variation increases. After lithography, overlay gives valuable feedback to the lithography tool; however overlay measurements typically have limited density, especially at the wafer edge, due to throughput considerations. Moreover, since overlay is measured after lithography, it can only react to, but not predict the process-induced overlay. This study is a joint investigation in a high-volume manufacturing environment of the portion of overlay associated with displacement induced by a single process across many chambers. Displacement measurements are measured by Coherent Gradient Sensing (CGS) interferometry, which generates high-density displacement maps (>3 million points on a 300 mm wafer) such that the stresses induced die-by-die and process-by-process can be tracked in detail. The results indicate the relationship between displacement and overlay shows the ability to forecast overlay values before the lithographic process. Details of the correlation including overlay/displacement range, and lot-to-lot displacement variability are considered.

  6. Characterization of Leptospiral Chemoreceptors Using a Microscopic Agar Drop Assay.

    PubMed

    Affroze, Samia; Islam, Md Shafiqul; Takabe, Kyosuke; Kudo, Seishi; Nakamura, Shuichi

    2016-08-01

    Bacterial chemotaxis is induced by sensing chemical stimuli via chemoreceptors embedded in the cytoplasmic membrane, enabling the cells to migrate toward nutrients or away from toxins. The chemoreceptors of Escherichia coli and Salmonella spp. have been well studied and are functionally classified on the basis of detectable substrates. The spirochete Leptospira possesses more than ten chemoreceptors and shows attractive or repellent responses against some sugars, amino acids, and fatty acids. However, the roles of these chemoreceptors have not been investigated. In this study, we conducted a chemotaxis assay called microscopic agar drop assay in combination with competition experiments, determining whether two kinds of attractants are recognized by the same type of chemoreceptor in the saprophytic Leptospira strain, Leptospira biflexa. Analyzing the competition effect observed between several pairs of chemicals, we found that L. biflexa senses sugars via chemoreceptors different from those that sense amino acids and fatty acids. PMID:27109059

  7. Co-optimization of RegC and TWINSCAN corrections to improve the intra-field on-product overlay performance

    NASA Astrophysics Data System (ADS)

    Gorhad, Kujan; Sharoni, Ofir; Dmitriev, Vladimir; Cohen, Avi; van Haren, Richard; Roelofs, Christian; Cekli, Hakki Ergun; Gallagher, Emily; Leray, Philippe; Beyer, Dirk; Trautzsch, Thomas; Steinert, Steffen

    2016-03-01

    Improving wafer On Product Overlay (OPO) is becoming a major challenge in lithography, especially for multipatterning techniques like N-repetitive Litho-Etch steps (LEN, N >= 2). When using different scanner settings and litho processes between inter-layer overlays, intra-field overlay control becomes more complicated. In addition to the Image Placement Error (IPE) contribution, the TWINSCANTM lens fingerprint in combination with the exposure settings is playing a significant role as well. Furthermore the scanner needs to deal with dynamic fingerprints caused by for instance lens and/or reticle heating. This paper will demonstrate the complementary RegC® and TWINSCANTM solution for improving the OPO by cooptimizing the correction capabilities of the individual tools, respectively. As a consequence, the systematic intra-field fingerprints can be decreased along with the overlay (OVL) error at wafer level. Furthermore, the application could be utilized for extending some of the scanner actuators ranges by inducing a pre-determined signatures. These solutions perfectly fit into the ASML Litho InSight (LIS) product in which feedforward and feedback corrections based on YieldStar overlay and other measurements are used to improve the OPO. While the TWINSCANTM scanner corrects for global distortions (up to third order) - scanner Correctable Errors ( CE), the RegC® application can correct for the None Correctable Errors (NCE) by making the high frequency NCE into a CE with low frequency nature. The RegC® induces predictable deformation elements inside the quartz (Qz) material of the reticle, and by doing so it can induce a desired pre-defined signature into the reticle. The deformation introduced by the RegC® is optimized for the actual wafer print taking into account the scale and ortho compensation by the scanner, to correct for the systematic fingerprints and the wafer overlay. These two applications might be very powerful and could contribute to achieve a better

  8. The effect of mold materials on the overlay accuracy of a roll-to-roll imprinting system using UV LED illumination within a transparent mold

    NASA Astrophysics Data System (ADS)

    Choi, Sungwoo; Kook, YunHo; Kim, ChulHo; Yoo, SoonSung; Park, Kwon-Shik; Kim, Seok-min; Kang, Shinill

    2016-06-01

    Although several studies on the roll-to-roll (R2R) imprinting process have reported achieving flexible electronics, improving the alignment accuracy in the overlay process of R2R imprinting is recognized as the biggest problem for the commercialization of this technology. For an overlay technique with high alignment accuracy, it is essential to develop a roll mold with high positional accuracy. In this study, a method for fabricating a roll mold with high positional accuracy is proposed by wrapping a thin glass substrate flexible mold around the transparent roll base, because it can provide higher mechanical strength and thermal stability than a conventional polymer substrate. To confirm the usability of the proposed process, the prepared roll mold was used to fabricate a test pattern of thin-film transistor backplane for a rollable display. The positional and overlay accuracy of the roll mold with the proposed thin glass substrate flexible mold were compared with the roll mold with a conventional polymer substrate flexible mold. Large-area transparent flexible molds with a size of 470  ×  370 mm were fabricated by an ultraviolet (UV) imprinting process on thin glass and polyethylene terephthalate substrates, and these flexible molds were wrapped around a roll base of 125 mm radius through a precision alignment process. After an anti-adhesion treatment and the wrapping process, the roll mold with the polymer substrate showed a ~180 μm positional error, whereas the thin glass substrate showed a ~30 μm positional error. After the overlay process using the R2R imprinting system with the alignment system, an average overlay error of ~3 μm was obtained when the thin glass flexible wrapped roll mold was used, whereas a ~22 μm overlay error was obtained when the polymer substrate flexible wrapped roll mold was used.

  9. Atomistic simulation study of short pulse laser interactions with a metal target under conditions of spatial confinement by a transparent overlayer

    SciTech Connect

    Karim, Eaman T.; Shugaev, Maxim; Wu, Chengping; Zhigilei, Leonid V.; Lin, Zhibin; Hainsey, Robert F.

    2014-05-14

    The distinct characteristics of short pulse laser interactions with a metal target under conditions of spatial confinement by a solid transparent overlayer are investigated in a series of atomistic simulations. The simulations are performed with a computational model combining classical molecular dynamics (MD) technique with a continuum description of the laser excitation, electron-phonon equilibration, and electronic heat transfer based on two-temperature model (TTM). Two methods for incorporation of the description of a transparent overlayer into the TTM-MD model are designed and parameterized for Ag-silica system. The material response to the laser energy deposition is studied for a range of laser fluences that, in the absence of the transparent overlayer, covers the regimes of melting and resolidification, photomechanical spallation, and phase explosion of the overheated surface region. In contrast to the irradiation in vacuum, the spatial confinement by the overlayer facilitates generation of sustained high-temperature and high-pressure conditions near the metal-overlayer interface, suppresses the generation of unloading tensile wave, decreases the maximum depth of melting, and prevents the spallation and explosive disintegration of the surface region of the metal target. At high laser fluences, when the laser excitation brings the surface region of the metal target to supercritical conditions, the confinement prevents the expansion and phase decomposition characteristic for the vacuum conditions leading to a gradual cooling of the hot compressed supercritical fluid down to the liquid phase and eventual solidification. The target modification in this case is limited to the generation of crystal defects and the detachment of the metal target from the overlayer.

  10. Comparison of ChromID Agar and Clostridium difficile Selective Agar for Effective Isolation of C. difficile from Stool Specimens

    PubMed Central

    Lee, Eun Joo

    2014-01-01

    Background ChromID Clostridium difficile agar (IDCd; bioMérieux SA, France) is a recently developed chromogenic medium for rapid and specific isolation of C. difficile. We compared the performance of IDCd with that of Clostridium difficile Selective Agar (CDSA). Methods A total of 530 fresh stool specimens were collected from patients with clinical signs compatible with C. difficile infection, and cultures for C. difficile were performed on IDCd and CDSA. C. difficile colonies were identified by spore staining, odor, use of an ANI identification test kit (bioMérieux SA), and multiplex PCR for tcdA, tcdB, and tpi. Results The concordance rate between IDCd and CDSA was 90.6% (480/530). The positivity rates on IDCd on days 1 and 2 (55.6% and 85.0%, respectively) were significantly higher than those on CDSA (19.4% and 75.6%, respectively) (P<0.001 for day 1 and P=0.02 for day 2), but the detection rates on IDCd and CDSA on day 3 were not different (89.4% vs. 82.8%, P=0.0914). On day 3, the recovery rates for non-C. difficile isolates on IDCd and CDSA were 30.2% (160/530) and 22.1% (117/530), respectively (P=0.0075). Clostridium spp. other than C. difficile were the most prevalent non-C. difficile isolates on both media. Conclusions The culture positivity rates on IDCd and CDSA were not different on day 3 but IDCd may allow for rapid and sensitive detection of C. difficile within 2 days of cultivation. PMID:24422190

  11. A basic guide to overlay design using nondestructive testing equipment data

    NASA Astrophysics Data System (ADS)

    Turner, Vernon R.

    1990-08-01

    The purpose of this paper is to provide a basic and concise guide to designing asphalt concrete (AC) overlays over existing AC pavements. The basis for these designs is deflection data obtained from nondestructive testing (NDT) equipment. This data is used in design procedures which produce required overlay thickness or an estimate of remaining pavement life. This guide enables one to design overlays or better monitor the designs being performed by others. This paper will discuss three types of NDT equipment, the Asphalt Institute Overlay Designs by Deflection Analysis and by the effective thickness method as well as a method of estimating remaining pavement life, correlations between NDT equipment and recent correlations in Washington State. Asphalt overlays provide one of the most cost effective methods of improving existing pavements. Asphalt overlays can be used to strengthen existing pavements, to reduce maintenance costs, to increase pavement life, to provide a smoother ride, and to improve skid resistance.

  12. Evaluation of Free-Riding Traffic Problem in Overlay Routing and Its Mitigation Method

    NASA Astrophysics Data System (ADS)

    Hasegawa, Go; Hiraoka, Yuichiro; Murata, Masayuki

    Recent research on overlay networks has revealed that user-perceived network performance could be improved by an overlay routing mechanism. The effectiveness of overlay routing is mainly a result of the policy mismatch between the overlay routing and the underlay IP routing operated by ISPs. However, this policy mismatch causes a “free-riding” traffic problem, which may become harmful to the cost structure of Internet Service Providers. In the present paper, we define the free-riding problem in the overlay routing and evaluate the degree of free-riding traffic to reveal the effect of the problem on ISPs. We introduce a numerical metric to evaluate the degree of the free-riding problem and confirm that most multihop overlay paths that have better performance than the direct path brings the free-riding problem. We also discuss the guidelines for selecting paths that are more effective than the direct path and that mitigate the free-riding problem.

  13. Effect of Perovskite Overlayers on TiO2 Electrodes in Perovskite-Sensitized Solar Cells.

    PubMed

    Kim, Kang-Pil; Kim, Jeong-Hwa; Hwang, Dae-Kue

    2016-05-01

    In this paper, we have studied the effect of the thickness of a CH3NH3PbI3 perovskite overlayer on mesoporous TiO2 electrodes in perovskite solar cells. The overlayers were prepared by spin coating PbI2 films on the electrodes, which were subsequently exposed to a CH3NH3I/2-propanol solution. We controlled the thickness of the perovskite overlayer by changing the PbI2 solution concentration. The thicknesses of the overlayers spin-coated from 0.5, 0.75, 0.9, and 1 M PbI2 solutions were approximately 179, 262, 316, and 341 nm, respectively. Perovskite solar cells with an approximately 316-nm-thick overlayer showed the highest efficiency of 9.11%. We conclude that optimization of the perovskite overlayer thickness in the solar cell structure is necessary to improve the cell efficiency. PMID:27483921

  14. Bandwidth auction for SVC streaming in dynamic multi-overlay

    NASA Astrophysics Data System (ADS)

    Xiong, Yanting; Zou, Junni; Xiong, Hongkai

    2010-07-01

    In this paper, we study the optimal bandwidth allocation for scalable video coding (SVC) streaming in multiple overlays. We model the whole bandwidth request and distribution process as a set of decentralized auction games between the competing peers. For the upstream peer, a bandwidth allocation mechanism is introduced to maximize the aggregate revenue. For the downstream peer, a dynamic bidding strategy is proposed. It achieves maximum utility and efficient resource usage by collaborating with a content-aware layer dropping/adding strategy. Also, the convergence of the proposed auction games is theoretically proved. Experimental results show that the auction strategies can adapt to dynamic join of competing peers and video layers.

  15. Secret Forwarding of Events over Distributed Publish/Subscribe Overlay Network

    PubMed Central

    Kim, Beom Heyn

    2016-01-01

    Publish/subscribe is a communication paradigm where loosely-coupled clients communicate in an asynchronous fashion. Publish/subscribe supports the flexible development of large-scale, event-driven and ubiquitous systems. Publish/subscribe is prevalent in a number of application domains such as social networking, distributed business processes and real-time mission-critical systems. Many publish/subscribe applications are sensitive to message loss and violation of privacy. To overcome such issues, we propose a novel method of using secret sharing and replication techniques. This is to reliably and confidentially deliver decryption keys along with encrypted publications even under the presence of several Byzantine brokers across publish/subscribe overlay networks. We also propose a framework for dynamically and strategically allocating broker replicas based on flexibly definable criteria for reliability and performance. Moreover, a thorough evaluation is done through a case study on social networks using the real trace of interactions among Facebook users. PMID:27367610

  16. Secret Forwarding of Events over Distributed Publish/Subscribe Overlay Network.

    PubMed

    Yoon, Young; Kim, Beom Heyn

    2016-01-01

    Publish/subscribe is a communication paradigm where loosely-coupled clients communicate in an asynchronous fashion. Publish/subscribe supports the flexible development of large-scale, event-driven and ubiquitous systems. Publish/subscribe is prevalent in a number of application domains such as social networking, distributed business processes and real-time mission-critical systems. Many publish/subscribe applications are sensitive to message loss and violation of privacy. To overcome such issues, we propose a novel method of using secret sharing and replication techniques. This is to reliably and confidentially deliver decryption keys along with encrypted publications even under the presence of several Byzantine brokers across publish/subscribe overlay networks. We also propose a framework for dynamically and strategically allocating broker replicas based on flexibly definable criteria for reliability and performance. Moreover, a thorough evaluation is done through a case study on social networks using the real trace of interactions among Facebook users. PMID:27367610

  17. Digital overlay of cartographic information on Landsat MSS data for soil surveys

    NASA Technical Reports Server (NTRS)

    Imhoff, M. L.; Irons, J. R.; Petersen, G. W.; Sykes, S. G.

    1982-01-01

    Cartographic soils data were digitized, spatially registered, and merged with processed Landsat image data. The Landsat Multispectral Scanner Subsystem (MSS) image data were used to generate a thematic map representing different soil surface characteristics and an enhanced image. The thematic map was generated using supervised and unsupervised classification procedures. The enhanced image was generated by performing a linear contrast stretch on data altered by a principal components transformation. Although both procedures yielded images useful for soil unit delineation, image enhancement was determined to be more suitable because it was more expedient and inexpensive. Enhanced images cost $0.06 per hectare, spectral classifications cost $0.08 per hectare. The overlay of cartographic data on Landsat data facilitates comparisons between the various processing methods used for soil unit boundary determination, delineation, and verification. This technique also provides for accurate and expedient spatial referencing for field observations and cartographic correlation.

  18. Effect of a Dielectric Overlay on a Linearly Tapered Slot Antenna Excited by a Coplanar Waveguide

    NASA Technical Reports Server (NTRS)

    Simons, Rainee N.; Lee, Richard Q.; Perl, Thomas D.; Silvestro, John

    1993-01-01

    The effect of a dielectric overlay on a linearly tapered slot antenna (LTSA) is studied. The LTSA under study has very wide bandwidth and excellent radiation patterns. A dielectric overlay improves the patterns and directivity of the antenna by increasing the electrical length and effective aperture of the antenna. A dielectric overlay can also be used to reduce the physical length of the antenna without compromising the pattern quality.

  19. Residual Agar Determination in Bacterial Spores by Electrospray Ionization Mass Spectrometry

    SciTech Connect

    Wahl, Karen L.; Colburn, Heather A.; Wunschel, David S.; Petersen, Catherine E.; Jarman, Kristin H.; Valentine, Nancy B.

    2010-02-15

    Presented here is an analytical method to detect residual agar from a bacterial spore sample as an indication of culturing on an agar plate. This method is based on the resolubilization of agar polysaccharide from a bacterial spore sample, enzymatic digestion, followed by electrospray ionization tandem mass spectrometry (ESI-MSn) analysis for detection of a specific agar fragment ion. A range of Bacillus species and strains were selected to demonstrate the effectiveness of this approach. The characteristic agar fragment ion was detected in the spores grown on agar that were washed from 1 to 5 times, irradiated or non-irradiated and not in the spores grown in broth. A sample containing approximately 108 spores is currently needed for confident detection of residual agar from culture on agar plates in the presence of bacterial spores with a limit of detection of approximately 1 ppm agar spiked into a broth-grown spore sample. The results of a proficiency test with 42 blinded samples are presented demonstrating the utility of this method with no false positives and only 3 false negatives for samples that were below the detection level of the method as documented.

  20. Examination of overlay pipe weldments removed from the Hatch-2 reactor

    SciTech Connect

    Park, J.Y.; Kupperman, D.S.; Shack, W.J.

    1985-02-01

    Laboratory ultrasonic examination (UT), dye penetrant examination (PT), metallography, and sensitization measurements were performed on Type 304 stainless steel overlay pipe weldments from the Hatch-2 BWR to determine the effectiveness of UT through overlays and the effects of the overlays on crack propagation in the weldments. Little correlation was observed between the results of earlier in-service ultrasonic inspection and the results of PT and destructive examination. Considerable difficulty was encountered in correctly detecting the presence of cracks by UT in the laboratory. Blunting of the crack tip by the weld overlay was observed, but there was no evidence of tearing or throughwall extension of the crack beyond the blunted region.

  1. Green synthesis of gold nanoparticles of different sizes and shapes using agar-agar water solution and femtosecond pulse laser irradiation

    NASA Astrophysics Data System (ADS)

    Almeida de Matos, Ricardo; da Silva Cordeiro, Thiago; Elgul Samad, Ricardo; Dias Vieira, Nilson; Coronato Courrol, Lilia

    2012-11-01

    We report a method to create gold nanoparticles of different sizes and shapes using agar-agar water solution and irradiation with light from a xenon lamp, followed by ultrashort laser pulses. No additives, such as solvents, surfactants or reducing agents, were used in the procedure. Laser irradiation (laser ablation) was important to the reduction of the nanoparticles diameter and formation of another shapes. Distilled water was used as solvent and agar-agar (hydrophilic colloid extracted from certain seaweeds) was important for the stabilization of gold nanoparticles, avoiding their agglomeration. The formation of gold nanoparticles was confirmed with ultraviolet-visible absorption and TEM microscopy. The gold nanoparticles acquired spherical, prism, and rod shapes depending on the laser parameters. Variation of laser irradiation parameters as pulse energy, irradiation time and repetition rate was assessed. The relevant mechanisms contributing for the gold nanoparticles production are discussed.

  2. Glucose-sucrose-potassium tellurite-bacitracin agar, an alternative to mitis salivarius-bacitracin agar for enumeration of Streptococcus mutans.

    PubMed Central

    Tanzer, J M; Börjesson, A C; Laskowski, L; Kurasz, A B; Testa, M

    1984-01-01

    An agar medium for selective recovery and enumeration of Streptococcus mutans was developed as an alternative to mitis salivarius-bacitracin (MSB) agar. Combinations of dyes, antibiotics, and tellurite were added to a nonselective medium which, because of its sucrose content, allowed easy recognition of S. mutans colonies. Candle jar incubation for 2 days, by comparison with anaerobic incubation, reduced background flora but did not diminish S. mutans recoveries from clinical samples. Quantitative comparisons were made of the simultaneous recoveries of a number of authentic S. mutans serotype representatives and fresh clinical isolates, using various glucose-sucrose-potassium tellurite-bacitracin (GSTB) formulations and mitis salivarius, MSB, and blood agars. Mitis salivarius counts were not detectably different from blood counts, but counts on MSB were distinctly lower. A formulation of the new medium containing 5% glucose 5% sucrose, 0.001% potassium tellurite, 0.3 U of bacitracin per ml (hence GSTB), and 2% agar gave recoveries nearly equal to those on mitis salivarius agar and much greater than those on MSB. The medium yielded readily recognized S. mutans colonies and facilitated detection of intracellular polysaccharide formers upon flooding with I2 reagent. Freshly isolated serotype c, E, and f colonies could often be distinguished from serotype d and g colonies, a distinction made reliable by testing for intracellular polysaccharide. A study of 300 salivary samples revealed GSTB to give significantly higher recoveries than MSB. About 72% of all samples were substantially underestimated for S. mutans with MSB, and 6.7% of samples were falsely negative for S. mutans with MSB. Recovery of background flora on GSTB was as low or lower than on MSB, and both types of agar could be stored for at least 9 weeks without notable change of selectivity. Thus, GSTB agar appears to be simple and reliable to use and requires no anaerobic incubation. Caution is voiced about

  3. Lightweight storage and overlay networks for fault tolerance.

    SciTech Connect

    Oldfield, Ron A.

    2010-01-01

    The next generation of capability-class, massively parallel processing (MPP) systems is expected to have hundreds of thousands to millions of processors, In such environments, it is critical to have fault-tolerance mechanisms, including checkpoint/restart, that scale with the size of applications and the percentage of the system on which the applications execute. For application-driven, periodic checkpoint operations, the state-of-the-art does not provide a scalable solution. For example, on today's massive-scale systems that execute applications which consume most of the memory of the employed compute nodes, checkpoint operations generate I/O that consumes nearly 80% of the total I/O usage. Motivated by this observation, this project aims to improve I/O performance for application-directed checkpoints through the use of lightweight storage architectures and overlay networks. Lightweight storage provide direct access to underlying storage devices. Overlay networks provide caching and processing capabilities in the compute-node fabric. The combination has potential to signifcantly reduce I/O overhead for large-scale applications. This report describes our combined efforts to model and understand overheads for application-directed checkpoints, as well as implementation and performance analysis of a checkpoint service that uses available compute nodes as a network cache for checkpoint operations.

  4. Dynamic bi-overlay rotation for streaming with heterogeneous devices

    NASA Astrophysics Data System (ADS)

    Liu, Dongyu; Chen, Songqing; Shen, Bo

    2008-01-01

    Recently Internet P2P/overlay streaming has gained increasing popularity. While plenty of research has focused on streaming performance study, it is not quite known yet on how to efficiently serve heterogeneous devices that have different limitations on display size, color depth, bandwidth capacities, CPU and battery power, than desktop computers. Although previous work1 proposes to reuse intermediate information (metadata) produced during transcoding to facilitate runtime content adaption to serve heterogeneous clients by reducing total computing load, unbalanced resource contribution may pre-maturely exhaust the limited power of mobile devices, and adversely affect the performance of participating nodes and subsequently threaten the robustness of the whole system. In this work, we propose a Dynamic Bi-Overlay Rotation (DOOR) scheme, in which, we further consider resource consumption of participating nodes to design a dynamic rotation scheme that reacts to dynamic situations and balances across multiple types of resources on individual nodes. Based on the computing load and transcoding quality parameters obtained through real transcoding sessions, we drive large scale simulations to evaluate DOOR. The results show clear improvement of DOOR over earlier work.

  5. Pulsed photothermal temperature profiling of agar tissue phantoms.

    PubMed

    Milanic, Matija; Majaron, Boris; Nelson, J Stuart

    2007-11-01

    We determine experimentally the accuracy of pulsed photothermal radiometric (PPTR) temperature depth profiling in water-based samples. We use custom tissue phantoms composed of agar gel layers separated by very thin absorbing layers. Two configurations of the acquisition system are compared, one using the customary spectral band of the InSb radiation detector (3.0-5.5 microm) and the other with a spectrally narrowed acquisition band (4.5-5.5 microm). The laser-induced temperature depth profiles are reconstructed from measured radiometric signals using a custom minimization algorithm. The results correlate very well with phantom geometry as determined by optical coherence tomography (OCT) and histology in all evaluated samples. Determination of the absorbing layer depth shows good repeatability with spatial resolution decreasing with depth. Spectral filtering improves the accuracy and resolution, especially for shallow absorption layers (~120 microm) and more complex structures (e.g., with two absorbing layers). The average full width at half maximum (FWHM) of the temperature peaks equals 23% of the layer depth. PMID:17522951

  6. Lithographic overlay measurement precision and calibration and their effect on pattern registration optimization

    NASA Astrophysics Data System (ADS)

    Zavecz, Terrence E.

    1992-06-01

    Overlay of pattern registration is considered by some to be the most yield critical metrology element monitored in the semiconductor manufacturing process. Over the years, the aggressive demands of competitive chip design have constantly maintained these specifications at the process capability limit. This has driven the lithographer from somewhat simple process control techniques like optically read verniers, to computer automated overlay measurement systems whose outputs are applied to the estimation and correction of full field systematic error sources primarily as modeled wafer and lens pattern distortions. When modeled pattern distortions are used to optimize the lithographic overlay process, the point measurement of registration error is no longer the parameter of interest. Instead the lithographer wishes to measure and minimize the surface modeled pattern distortions such as translation, rotation, and magnification. Yet, often neglected is the fact that estimates of these parameters are influenced by measurement system errors resulting in a loss of precision in the estimate of the distortions and the false introduction of otherwise nonexistent distortions leading to improper determination of the true values for the lens. This paper describes the results of a screening simulation designed to determine the relative effects of measurement system errors on the distortion coefficient estimates produced by a pattern distortion model. The simulation confirms the somewhat obvious result that tool induced shift (TIS) translates directly into the estimate of the offset term of the model. In addition, the simulation indicates that errors in the measurement system pixel scale calibration directly scale all distortion estimates by the same factor. The variance of the measurement system sums with the variance of the stepper and inflates the standard error of the regression as well as the uncertainty of each lens parameter's estimate. Higher order nonlinearities or

  7. Physicochemical and morphological properties of plasticized poly(vinyl alcohol)-agar biodegradable films.

    PubMed

    Madera-Santana, T J; Freile-Pelegrín, Y; Azamar-Barrios, J A

    2014-08-01

    The effects of the addition of glycerol (GLY) on the physicochemical and morphological properties of poly(vinyl alcohol) (PVA)-agar films were reported. PVA-agar films were prepared by solution cast method, and the addition of GLY in PVA-agar films altered the optical properties, resulting in a decrease in opacity values and in the color difference (ΔE) of the films. Structural characterization using Fourier transformation infrared (FTIR) spectroscopy and X-ray diffraction (XRD) indicated that the presence of GLY altered the intensity of the bands (from 1200 to 800cm(-1)) and crystallinity. The characterization of the thermal properties indicated that an increase in the agar content produces a decrease in the melting temperature and augments the heat of fusion. Similar tendencies were observed in plasticized films, but at different magnification. The formulation that demonstrated the lowest mechanical properties contained 25wt.% agar, whereas the formulation that contained 75wt.% agar demonstrated a significant improvement. The water vapor transmission rate (WVTR) and surface morphology analysis demonstrated that the structure of PVA-agar films is reorganized upon GLY addition. The physicochemical properties of PVA-agar films using GLY as a plasticizer provide information for the application of this formulation as packaging material for specific food applications. PMID:24875313

  8. Inhibition of Streptococcus mutans strains by different mitis-salivarius agar preparations.

    PubMed Central

    Staat, R H

    1976-01-01

    Several Streptococcus mutans strains were markedly inhibited by mitis-salivarius agar manufactured by Baltimore Biological Laboratories, but little, if any, inhibition was noted using Difco Laboratories' mitis-salivarius agar. Supplementation of the basic medium with sucrose and bacitracin for specific selection of S. mutans resulted in suppression of representative S. mutans type a strains regardless of manufacturer. PMID:1270597

  9. Effects of season on the yield and quality of agar from Gracilaria species (Gracilariaceae, Rhodophyta).

    PubMed

    Marinho-Soriano, E; Bourret, E

    2003-12-01

    The effect of season on yield and physical properties of agars extracted from Gracia gracilis and G. bursa-pastoris were determined. The agar yield from G. gracilis was maximum during spring (30%) and minimum during autumn (19%). In G. bursa-pastoris, the agar yield was greatest in summer (36%) and lowest in winter (23%). Agar yield from G. bursa-pastoris was positively correlated with temperature (r=0.94; P<0.01) and salinity (r=0.97; P<0.01) and negatively with nitrogen content (r=-0.93; P<0.01). Agar gel strengths fluctuated from 229 to 828 gcm(-2) and 23 to 168 gcm(-2) for G. gracilis and G. bursa-pastoris, respectively. The gelling temperature showed significant seasonal variation for both species. Chemical analysis of agar from the two seaweeds indicated variation in 3,6-anhydrogalactose and sulfate content (P<0.01). Furthermore, there was an inverse correlation between the two chemical variables. In general, agar extracted from G. gracilis possessed better qualities than agar extracted from G. bursa-pastoris and can be considered a candidate for industrial use. PMID:14575957

  10. Agar composition affects in vitro screening of biocontrol activity of antagonistic microorganisms.

    PubMed

    Bosmans, L; De Bruijn, I; De Mot, R; Rediers, H; Lievens, B

    2016-08-01

    Agar-based screening assays are the method of choice when evaluating antagonistic potential of bacterial biocontrol-candidates against pathogens. We showed that when using the same medium, but different agar compositions, the activity of a bacterial antagonist against Agrobacterium was strongly affected. Consequently, results from in vitro screenings should be interpreted cautiously. PMID:27166668

  11. Characteristics of thermoplastic sugar palm Starch/Agar blend: Thermal, tensile, and physical properties.

    PubMed

    Jumaidin, R; Sapuan, S M; Jawaid, M; Ishak, M R; Sahari, J

    2016-08-01

    The aim of this work is to study the behavior of biodegradable sugar palm starch (SPS) based thermoplastic containing agar in the range of 10-40wt%. The thermoplastics were melt-mixed and then hot pressed at 140°C for 10min. SEM investigation showed good miscibility between SPS and agar. FT-IR analysis confirmed that SPS and agar were compatible and inter-molecular hydrogen bonds existed between them. Incorporation of agar increased the thermoplastic starch tensile properties (Young's modulus and tensile strength). The thermal stability and moisture uptake increased with increasing agar content. The present work shows that starch-based thermoplastics with 30wt% agar content have the highest tensile strength. Higher content of agar (40wt%) resulted to more rough cleavage fracture and slight decrease in the tensile strength. In conclusion, the addition of agar improved the thermal and tensile properties of thermoplastic SPS which widened the potential application of this eco-friendly material. The most promising applications for this eco-friendly material are short-life products such as packaging, container, tray, etc. PMID:27177458

  12. Efficacy of agar-plate culture in detection of Strongyloides stercoralis infection.

    PubMed

    Arakaki, T; Iwanaga, M; Kinjo, F; Saito, A; Asato, R; Ikeshiro, T

    1990-06-01

    Agar-plate culture of feces using a modified petri dish proved to be highly efficient in the detection of Strongyloides stercoralis infection. Furrows left by S. stercoralis on the agar plate were distinguished readily in size from those left by Necator americanus. PMID:2352073

  13. [Evaluation of a new medium, eggplant (Solanum melongena) agar as a screening medium for Cryptococcus neoformans in environmental samples].

    PubMed

    Sengul, Mustafa; Ergin, Cağrı; Kartal, Tuğba

    2014-04-01

    Cryptococcus neofomans is an encapsulated yeast-like fungus that causes life-threatening infections, especially in immunosuppresive patients. C.neoformans infection is believed to be acquired via inhalation of aerosolized particles from the environment. Avian guano, decaying tree hollows and soil are the related known environmental niches. Brown pigmented yeast growth from the precursors in growth media is an important step for the identification and isolation of C.neoformans. Seeds of plants in nature are preferred owing to easy accessibility and low costs for the preparation of such media. Guizotia abysinicca (Niger seed) as Staib agar, Helianthus annus (Sunflower) as Pal's medium, Brassica nigra (Mustard) agar, tobacco agar, Mucuna pruriens (Velvet bean) seed agar, Perilla frutescens (Beefsteak plant) seed agar, Rubus fruticosus (Blackberry) agar and ground red hot pepper agar are pigment-based selective media for the differentiation of C.neoformans. The aim of this study was to observe the pigment production of C.neoformans in a new medium based on eggplant (Solanum melongena) and also to compare its performance with the simplified Staib, Pal's and tobacco agar for isolation from the environment. Three different eggplant-based medium (S.melongena Melanzaza viserba, S.melongena Pinstripe F1 and S.ovigerum Ivory F1) were included in the study. Pigment-forming eggplant medium, simplified Staib agar, Pal's agar and tobacco agar were used for the cultivation of the environmental swabbed samples from 19 Eucalyptus camaldulensis trunk hollows in continuous colonization region. While pigment formation were observed with S.melongena Melanzaza viserba and S.melongena Pinstripe F1 containing media, S.ovigerum Ivory F1 medium was found to be non-reactive. In colonization area (Gökova-Akyaka, Turkey), 11 (57.9%) out of 19 E.camaldulensis samples were positive with simplified Staib agar, Pal's agar and eggplant agar while 10 (52.6%) of them are positive with tobacco agar. C

  14. Adsorptive removal of methylene blue by agar: effects of NaCl and ethanol

    PubMed Central

    2012-01-01

    Adsorption of methylene blue (MB) on agar was investigated as a function of temperature (308-328 K), different concentrations of NaCl and HCl and various weight percentages of binary mixtures of ethanol with water. It was observed that the maximum experimental adsorption capacity, qm, exp, in water is up to 50 mg g-1 and decreases with increase in weight percentage of ethanol and NaCl and HCl concentration compared to that of water. Analysis of data using ARIAN model showed that MB adsorbs as monomer and dimer on the surface of agar. Binding constants of MB to agar were calculated using the Temkin isotherm. The process is exothermic in water and other solutions. The mean adsorption energy (E) value indicated binding of MB to agar is chemical adsorption. Kinetics of this interaction obeys from the pseudo-second-order model and diffusion of the MB molecules into the agar is the main rate-controlling step. PMID:22339759

  15. An Efficient, Scalable and Robust P2P Overlay for Autonomic Communication

    NASA Astrophysics Data System (ADS)

    Li, Deng; Liu, Hui; Vasilakos, Athanasios

    The term Autonomic Communication (AC) refers to self-managing systems which are capable of supporting self-configuration, self-healing and self-optimization. However, information reflection and collection, lack of centralized control, non-cooperation and so on are just some of the challenges within AC systems. Since many self-* properties (e.g. selfconfiguration, self-optimization, self-healing, and self-protecting) are achieved by a group of autonomous entities that coordinate in a peer-to-peer (P2P) fashion, it has opened the door to migrating research techniques from P2P systems. P2P's meaning can be better understood with a set of key characteristics similar to AC: Decentralized organization, Self-organizing nature (i.e. adaptability), Resource sharing and aggregation, and Fault-tolerance. However, not all P2P systems are compatible with AC. Unstructured systems are designed more specifically than structured systems for the heterogeneous Internet environment, where the nodes' persistence and availability are not guaranteed. Motivated by the challenges in AC and based on comprehensive analysis of popular P2P applications, three correlative standards for evaluating the compatibility of a P2P system with AC are presented in this chapter. According to these standards, a novel Efficient, Scalable and Robust (ESR) P2P overlay is proposed. Differing from current structured and unstructured, or meshed and tree-like P2P overlay, the ESR is a whole new three dimensional structure to improve the efficiency of routing, while information exchanges take in immediate neighbors with local information to make the system scalable and fault-tolerant. Furthermore, rather than a complex game theory or incentive mechanism, asimple but effective punish mechanism has been presented based on a new ID structure which can guarantee the continuity of each node's record in order to discourage negative behavior on an autonomous environment as AC.

  16. Toward 7nm target on product overlay for C028 FDSOI technology

    NASA Astrophysics Data System (ADS)

    Gatefait, Maxime; Le-Gratiet, Bertrand; Goirand, Pierre Jerome; Lam, Auguste; Van Haren, Richard; Pastol, Anne; Doytcheva, Maya; Liu, Xing Lan; Beltman, Jan

    2013-04-01

    The continuous need for lithography overlay performance improvement is a key point for advanced integrated circuit manufacturing. Overlay control is more and more challenging in the 2x nm process nodes regarding functionality margin of the chip and tool capability. Transistor architecture rules which are set, confirm poly to contact space as the most critical one for 28nm technology node. Critical Dimension variability of these layers, even with best in class process stability, in addition to design constraint lead to on product overlay specifications of around 7nm. In order to ensure that the target is met in production environment and to identify potential ways for improvement, identification of the contributors to overlay errors is essential. We have introduced a novel budget breakdown methodology using both bottom-up and top-down overlay data. For the bottom up part, we have performed extensive testing with very high sampling scheme so as to quantify the main effects. In-line overlay metrology data has been used for top down approach to verify the overall performance in production. In this paper we focused on the 28nm contact to gate overlay in a FDSOI process. The initial inconsistency between bottom up and top down results led us to further exploration of the root cause of these inconsistencies. We have been able to highlight key figures to focus on, like reticle heating, wafer table contamination and etch processing effects. Finally, we conclude on 7nm overlay target achievement feasibility in high volume manufacturing environment.

  17. Questioning the Benefits That Coloured Overlays Can Have for Reading in Students with and without Dyslexia

    ERIC Educational Resources Information Center

    Henderson, Lisa M.; Tsogka, Natassa; Snowling, Margaret J.

    2013-01-01

    Visual stress (the experience of visual distortions and discomfort during prolonged reading) is frequently identified and alleviated with coloured overlays or lenses. Previous studies have associated visual stress with dyslexia and as a consequence, coloured overlays are widely distributed to children and adults with reading difficulty. However,…

  18. Overlay improvement by exposure map based mask registration optimization

    NASA Astrophysics Data System (ADS)

    Shi, Irene; Guo, Eric; Chen, Ming; Lu, Max; Li, Gordon; Li, Rivan; Tian, Eric

    2015-03-01

    Along with the increased miniaturization of semiconductor electronic devices, the design rules of advanced semiconductor devices shrink dramatically. [1] One of the main challenges of lithography step is the layer-to-layer overlay control. Furthermore, DPT (Double Patterning Technology) has been adapted for the advanced technology node like 28nm and 14nm, corresponding overlay budget becomes even tighter. [2][3] After the in-die mask registration (pattern placement) measurement is introduced, with the model analysis of a KLA SOV (sources of variation) tool, it's observed that registration difference between masks is a significant error source of wafer layer-to-layer overlay at 28nm process. [4][5] Mask registration optimization would highly improve wafer overlay performance accordingly. It was reported that a laser based registration control (RegC) process could be applied after the pattern generation or after pellicle mounting and allowed fine tuning of the mask registration. [6] In this paper we propose a novel method of mask registration correction, which can be applied before mask writing based on mask exposure map, considering the factors of mask chip layout, writing sequence, and pattern density distribution. Our experiment data show if pattern density on the mask keeps at a low level, in-die mask registration residue error in 3sigma could be always under 5nm whatever blank type and related writer POSCOR (position correction) file was applied; it proves random error induced by material or equipment would occupy relatively fixed error budget as an error source of mask registration. On the real production, comparing the mask registration difference through critical production layers, it could be revealed that registration residue error of line space layers with higher pattern density is always much larger than the one of contact hole layers with lower pattern density. Additionally, the mask registration difference between layers with similar pattern density

  19. Extremely fast hydrogen absorption/desorption through platinum overlayers

    NASA Astrophysics Data System (ADS)

    Połczyński, Piotr; Jurczakowski, Rafał

    2016-02-01

    The hydrogen electrosorption in thin palladium films (50-1000 nm) was investigated at palladium electrodes covered with platinum overlayers. The results for this model system show that the rates of the hydrogen sorption/desorption are orders of magnitude higher for platinized samples with respect to pure palladium. The highest absorption kinetics have been observed for Pd electrodes fully covered with 1-3 platinum monolayers. By means of electrochemical impedance spectroscopy (EIS) we have shown that the process is diffusion limited at platinized Pd layers. Diffusion coefficient, DH, determined in EIS, is two orders of magnitude higher than that previously reported for thin palladium films and approaches DH for bulk palladium. The system stability after hydrogen absorption was assessed and the sorption mechanism was discussed. Surprisingly high durability of the platinized palladium enables its use in a variety of applications where fast and selective response in the presence of hydrogen is required.

  20. Decentralized Service Allocation in a Broker Overlay Based Grid

    NASA Astrophysics Data System (ADS)

    Azab, Abdulrahman; Meling, Hein

    Grid computing is based on coordinated resource sharing in a dynamic environment of multi-institutional virtual organizations. Data exchanges, and service allocation, are challenging problems in the field of Grid computing. This is due to the decentralization of Grid systems. Building decentralized Grid systems with efficient resource management and software component mechanisms is a need for achieving the required efficiency and usability of Grid systems. In this work, a decentralized Grid system model is presented in which, the system is divided into virtual organizations each controlled by a broker. An overlay network of brokers is responsible for global resource management and managing allocation of services. Experimental results show that, the system achieves dependable performance with various loads of services, and broker failures.

  1. Integrated production overlay field-by-field control for leading edge technology nodes

    NASA Astrophysics Data System (ADS)

    Chung, Woong Jae; Tristan, John; Gutjahr, Karsten; Subramany, Lokesh; Li, Chen; Sun, Yulei; Yelverton, Mark; Kim, Young Ki; Kim, Jeong Soo; Huang, Chin-Chou Kevin; Pierson, William; Karur-Shanmugam, Ramkumar; Riggs, Brent; Jug, Sven; Robinson, John C.; Yap, Lipkong; Ramanathan, Vidya

    2014-04-01

    As photolithography will continue with 193nm immersion multiple patterning technologies for the leading edge HVM process node, the production overlay requirement for critical layers in logic devices has almost reached the scanner hardware performance limit. To meet the extreme overlay requirements in HVM production environment, this study investigates a new integrated overlay control concept for leading edge technology nodes that combines the run-to-run (R2R) linear or high order control loop, the periodic field-by-field or correction per exposure (CPE) wafer process signature control loop, and the scanner baseline control loop into a single integrated overlay control path through the fab host APC system. The goal is to meet the fab requirements for overlay performance, lower the cost of ownership, and provide freedom of control methodology. In this paper, a detailed implementation of this concept will be discussed, along with some preliminary results.

  2. Exact and reliable overlay metrology in nanoscale semiconductor devices using an image processing method

    NASA Astrophysics Data System (ADS)

    Park, Jinkook; Shin, ChaeHo; Kim, Minkook; Kim, Junghwan; Park, JeongKyun; Kim, JungSoo; Jun, ChungSam; Yim, Yeny; Lee, Janghee

    2014-10-01

    As semiconductor processing becomes more complicated and pattern sizes shrink, the overlay metrology has become one of the most important issues in the semiconductor industry. Therefore, in order to obtain correct, reliable overlay values in semiconductor fabrication facilities (fab), quantization methods for the efficient management and implementation of a measurement algorithm are required, as well as an understanding of the target structures in the semiconductor device. We implemented correct, reliable overlay values in the pattern using the image processing method. The quantization method, through correlation analysis and a new algorithm for target structures, were able to improve the sensitivity to misalignment in the pattern and enable more stable and credible in-line measurement by decreasing the distribution of the residuals in overlay values. Since overlay values of the pattern in the fab were measured and managed more reliably and quickly, it is expected that our study will be able to contribute to the yield enhancement of semiconductor companies.

  3. Fundamentals of overlay measurement and inspection using scanning electron-microscope

    NASA Astrophysics Data System (ADS)

    Kato, T.; Okagawa, Y.; Inoue, O.; Arai, K.; Yamaguchi, S.

    2013-04-01

    Scanning electron-microscope (SEM) has been successfully applied to CD measurement as promising tools for qualifying and controlling quality of semiconductor devices in in-line manufacturing process since 1985. Furthermore SEM is proposed to be applied to in-die overlay monitor in the local area which is too small to be measured by optical overlay measurement tools any more, when the overlay control limit is going to be stringent and have un-ignorable dependence on device pattern layout, in-die location, and singular locations in wafer edge, etc. In this paper, we proposed new overlay measurement and inspection system to make an effective use of in-line SEM image, in consideration of trade-off between measurement uncertainty and measurement pattern density in each SEM conditions. In parallel, we make it clear that the best hybrid overlay metrology is in considering each tool's technology portfolio.

  4. Detection of Agar, by Analysis of Sugar Markers, Associated with Bacillus Anthracis Spores, After Culture

    SciTech Connect

    Wunschel, David S.; Colburn, Heather A.; Fox, Alvin; Fox, Karen F.; Harley, William M.; Wahl, Jon H.; Wahl, Karen L.

    2008-08-01

    Detection of small quantities of agar associated with spores of Bacillus anthracis could provide key information regarding its source or growth characteristics. Agar, widely used in growth of bacteria on solid surfaces, consists primarily of repeating polysaccharide units of 3,6-anhydro-L-galactose (AGal) and galactose (Gal) with sulfated and O-methylated galactoses present as minor constituents. Two variants of the alditol acetate procedure were evaluated for detection of potential agar markers associated with spores. The first method employed a reductive hydrolysis step, to stabilize labile anhydrogalactose, by converting to anhydrogalactitol. The second eliminated the reductive hydrolysis step simplifying the procedure. Anhydrogalactitol, derived from agar, was detected using both derivatization methods followed by gas chromatography-mass spectrometry (GC-MS) analysis. However, challenges with artefactual background (reductive hydrolysis) or marker destruction (hydrolysis) lead to the search for alternative sugar markers. A minor agar component, 6-O-methyl galactose (6-O-M gal), was readily detected in agar-grown but not broth-grown bacteria. Detection was optimized by the use of gas chromatography-tandem mass spectrometry (GC-MS-MS). With appropriate choice of sugar marker and analytical procedure, detection of sugar markers for agar has considerable potential in microbial forensics.

  5. Factors Affecting Selectivity of Brilliant Green-Phenol Red Agar for Salmonellae

    PubMed Central

    Moats, W. A.; Kinner, J. A.

    1974-01-01

    Commercial brilliant green (BG)-sulfa agar was found to be nonselective toward a test series of Enterobacteriaceae. Various formulations of BG were prepared by using Trypticase soy agar (BBL) as a base. Results were more reproducible when BG dye was added after sterilization than before. Sulfonamides improved selectivity as compared with brilliant green alone. Sulfanilamide (SN) was slightly more selective for salmonellae than other sulfonamides tested. Bile salts and sodium dodecyl sulfate markedly reduced the toxicity of BG to all the test bacteria. Enterobacter strains were most difficult to inhibit. A combination of 5 mg of BG and 1 g of SN/liter prevented growth of Proteus mirabilis and Escherichia coli and retarded growth of Enterobacter strains. The BG-SN agars were superior in selectivity to a series of commercial agars tested, and numbers of salmonellae recovered on BG-SN agar and Trypticase soy agar (BBL) were the same. Brilliant green agars with various degrees of selectivity are described. PMID:4589120

  6. Polymer film deposition on agar using a dielectric barrier discharge jet and its bacterial growth inhibition

    NASA Astrophysics Data System (ADS)

    Tsai, T.-C.; Cho, J.; Mcintyre, K.; Jo, Y.-K.; Staack, D.

    2012-08-01

    Polymer film deposition on agar in ambient air was achieved using the helium dielectric barrier discharge jet (DBD jet) fed with polymer precursors, and the bacterial growth inhibition due to the deposited film was observed. The DBD jet with precursor addition was more efficient at sterilization than a helium-only DBD jet. On the areas where polymer films cover the agar the bacterial growth was significantly inhibited. The inhibition efficacy showed dependence on the film thickness. The DBD jet without precursor also created a modified agar layer, which may slow the growth of some bacterial strains.

  7. Modeling of the Bacillus subtilis Bacterial Biofilm Growing on an Agar Substrate.

    PubMed

    Wang, Xiaoling; Wang, Guoqing; Hao, Mudong

    2015-01-01

    Bacterial biofilms are organized communities composed of millions of microorganisms that accumulate on almost any kinds of surfaces. In this paper, a biofilm growth model on an agar substrate is developed based on mass conservation principles, Fick's first law, and Monod's kinetic reaction, by considering nutrient diffusion between biofilm and agar substrate. Our results show biofilm growth evolution characteristics such as biofilm thickness, active biomass, and nutrient concentration in the agar substrate. We quantitatively obtain biofilm growth dependence on different parameters. We provide an alternative mathematical method to describe other kinds of biofilm growth such as multiple bacterial species biofilm and also biofilm growth on various complex substrates. PMID:26355542

  8. Modeling of the Bacillus subtilis Bacterial Biofilm Growing on an Agar Substrate

    PubMed Central

    Wang, Xiaoling; Wang, Guoqing; Hao, Mudong

    2015-01-01

    Bacterial biofilms are organized communities composed of millions of microorganisms that accumulate on almost any kinds of surfaces. In this paper, a biofilm growth model on an agar substrate is developed based on mass conservation principles, Fick's first law, and Monod's kinetic reaction, by considering nutrient diffusion between biofilm and agar substrate. Our results show biofilm growth evolution characteristics such as biofilm thickness, active biomass, and nutrient concentration in the agar substrate. We quantitatively obtain biofilm growth dependence on different parameters. We provide an alternative mathematical method to describe other kinds of biofilm growth such as multiple bacterial species biofilm and also biofilm growth on various complex substrates. PMID:26355542

  9. Effect of heat treatment on the performance of tryptose-sulfite-cycloserine agar for enumeration of Clostridium perfringens.

    PubMed

    Brodsky, M H; Ciebin, B W

    1979-05-01

    Dissolving dehydrated tryptose-sulfite-cycloserine agar by only boiling or microwaving was found to inhibit Clostridium perfringens colony development in pour plates when compared with C. perfringens recovery in tryptose-sulfite-cycloserine agar prepared by autoclaving. PMID:225988

  10. Diffraction based overlay metrology: accuracy and performance on front end stack

    NASA Astrophysics Data System (ADS)

    Leray, Philippe; Cheng, Shaunee; Kandel, Daniel; Adel, Michael; Marchelli, Anat; Vakshtein, Irina; Vasconi, Mauro; Salski, Bartlomiej

    2008-03-01

    The overlay metrology budget is typically 1/10 of the overlay control budget resulting in overlay metrology total measurement uncertainty requirements of 0.57 nm for the most challenging use cases of the 32nm technology generation. Theoretical considerations show that overlay technology based on differential signal scatterometry (SCOL TM) has inherent advantages, which will allow it to achieve the 32nm technology generation requirements and go beyond it. In this work we present results of an experimental and theoretical study of SCOL. We present experimental results, comparing this technology with the standard imaging overlay metrology. In particular, we present performance results, such as precision and tool induced shift, for different target designs. The response to a large range of induced misalignment is also shown. SCOL performance on these targets for a real stack is reported. We also show results of simulations of the expected accuracy and performance associated with a variety of scatterometry overlay target designs. The simulations were carried out on several stacks including FEOL and BEOL materials. The inherent limitations and possible improvements of the SCOL technology are discussed. We show that with the appropriate target design and algorithms, scatterometry overlay achieves the accuracy required for future technology generations.

  11. A fresh liver agar substrate for rearing small numbers of forensically important blow flies (Diptera: Calliphoridae)

    USGS Publications Warehouse

    Gruner, Susan V.; Slone, Daniel H.

    2014-01-01

    Forensically important calliphorids can be reared on a mixture of beef liver and agar. Small pieces of meat, especially fresh or frozen beef liver, will desiccate in 2–6 h, but this simple-to-make feeding substrate remains moist for at least 12 h at 25 and 30°C without desiccation, even in small (5 g) amounts. We determined the survivorship of small numbers of Chrysomya megacephala (F.) (first-instar larvae to adult eclosion) raised on 5 g of liver agar and fresh beef liver. We found that all larvae raised on 5 g of liver died due to desiccation, but survivorship on 5 g of liver agar was equivalent to that on larger (50 g) pieces of either liver agar or beef liver.

  12. Genome Sequence of the Agar-Degrading Marine Bacterium Alteromonadaceae sp. Strain G7

    PubMed Central

    Kwak, Min-Jung; Song, Ju Yeon; Kim, Byung Kwon; Chi, Won-Jae; Kwon, Soon-Kyeong; Choi, Soobeom; Chang, Yong-Keun

    2012-01-01

    Here, we present the high-quality draft genome sequence of the agar-degrading marine gammaproteobacterium Alteromonadaceae sp. strain G7, which was isolated from coastal seawater to be utilized as a bioresource for production of agar-derived biofuels. The 3.91-Mb genome contains a number of genes encoding algal polysaccharide-degrading enzymes such as agarases and sulfatases. PMID:23209220

  13. Low density, microcellular, dopable, agar/gelatin foams for pulsed power experiments

    SciTech Connect

    McNamara, W.F.; Aubert, J.H.

    1997-04-01

    Low-density, microcellular foams prepared from the natural polymers agar and gelatin have been developed for pulsed-power physics experiments. Numerous experiments were supported with foams having densities at or below 10 mg/cm{sup 3}. For some of the experiments, the agar/gelatin foam was uniformly doped with metallic elements using soluble salts. Depending on the method of preparation, cell sizes were typically below 10 microns and for one process were below 1.0 micron.

  14. Augmented Endoscopic Images Overlaying Shape Changes in Bone Cutting Procedures.

    PubMed

    Nakao, Megumi; Endo, Shota; Nakao, Shinichi; Yoshida, Munehito; Matsuda, Tetsuya

    2016-01-01

    In microendoscopic discectomy for spinal disorders, bone cutting procedures are performed in tight spaces while observing a small portion of the target structures. Although optical tracking systems are able to measure the tip of the surgical tool during surgery, the poor shape information available during surgery makes accurate cutting difficult, even if preoperative computed tomography and magnetic resonance images are used for reference. Shape estimation and visualization of the target structures are essential for accurate cutting. However, time-varying shape changes during cutting procedures are still challenging issues for intraoperative navigation. This paper introduces a concept of endoscopic image augmentation that overlays shape changes to support bone cutting procedures. This framework handles the history of the location of the measured drill tip as a volume label and visualizes the remains to be cut overlaid on the endoscopic image in real time. A cutting experiment was performed with volunteers, and the feasibility of this concept was examined using a clinical navigation system. The efficacy of the cutting aid was evaluated with respect to the shape similarity, total moved distance of a cutting tool, and required cutting time. The results of the experiments showed that cutting performance was significantly improved by the proposed framework. PMID:27584732

  15. Deployable Overlay Network for Defense against Distributed SYN Flood Attacks

    NASA Astrophysics Data System (ADS)

    Ohsita, Yuichi; Ata, Shingo; Murata, Masayuki

    Distributed denial-of-service attacks on public servers have recently become more serious. Most of them are SYN flood attacks, since the malicious attackers can easily exploit the TCP specification to generate traffic making public servers unavailable. We need a defense method which can protect legitimate traffic so that end users can connect the target servers during such attacks. In this paper, we propose a new framework, in which all of the TCP connections to the victim servers from a domain are maintained at the gateways of the domain (i. e., near the clients). We call the nodes maintaining the TCP connection defense nodes. The defense nodes check whether arriving packets are legitimate or not by maintaining the TCP connection. That is, the defense nodes delegate reply packets to the received connection request packets and identify the legitimate packets by checking whether the clients reply to the reply packets. Then, only identified traffic are relayed via overlay networks. As a result, by deploying the defense nodes at the gateways of a domain, the legitimate packets from the domain are relayed apart from other packets including attack packets and protected. Our simulation results show that our method can protect legitimate traffic from the domain deploying our method. We also describe the deployment scenario of our defense mechanism.

  16. Ultrasonic Evaluation of Two Dissimilar Metal Weld Overlay Specimens

    SciTech Connect

    Crawford, Susan L.; Cinson, Anthony D.; Prowant, Matthew S.; Moran, Traci L.; Anderson, Michael T.

    2012-06-30

    Two dissimilar metal weld (DMW) pipe-to-nozzle specimens were implanted with thermal fatigue cracks in the 13% to 90% through-wall depth range. The specimens were ultrasonically evaluated with phased-array probes having center frequencies of 0.8, 1.0, 1.5, and 2.0 megahertz (MHz). An Alloy 82/182 weld overlay (WOL) was applied and the specimens were ultrasonically re-evaluated for flaw detection and characterization. The Post-WOL flaw depths were approximately 10% to 56% through-wall. This study has shown the effectiveness of ultrasonic examinations of Alloy 82/182 overlaid DMW specimens. Phased-array probes with center frequency in the 0.8- to 1.0-MHz range provide a strong coherent signal but the greater ultrasonic wavelength and larger beam spot size prevent the reliable detection of small flaws. These small flaws had nominal through-wall depths of less than 15% and length in the 50-60 mm (2-2.4 in.) range. Flaws in the 19% and greater through-wall depth range were readily detected with all four probes. At the higher frequencies, the reflected signals are less coherent but still provide adequate signal for flaw detection and characterization. A single inspection at 2.0 MHz could provide adequate detection and sizing information but a supplemental inspection at 1.0 or 1.5 MHz is recommended.

  17. Quality metric for accurate overlay control in <20nm nodes

    NASA Astrophysics Data System (ADS)

    Klein, Dana; Amit, Eran; Cohen, Guy; Amir, Nuriel; Har-Zvi, Michael; Huang, Chin-Chou Kevin; Karur-Shanmugam, Ramkumar; Pierson, Bill; Kato, Cindy; Kurita, Hiroyuki

    2013-04-01

    The semiconductor industry is moving toward 20nm nodes and below. As the Overlay (OVL) budget is getting tighter at these advanced nodes, the importance in the accuracy in each nanometer of OVL error is critical. When process owners select OVL targets and methods for their process, they must do it wisely; otherwise the reported OVL could be inaccurate, resulting in yield loss. The same problem can occur when the target sampling map is chosen incorrectly, consisting of asymmetric targets that will cause biased correctable terms and a corrupted wafer. Total measurement uncertainty (TMU) is the main parameter that process owners use when choosing an OVL target per layer. Going towards the 20nm nodes and below, TMU will not be enough for accurate OVL control. KLA-Tencor has introduced a quality score named `Qmerit' for its imaging based OVL (IBO) targets, which is obtained on the-fly for each OVL measurement point in X & Y. This Qmerit score will enable the process owners to select compatible targets which provide accurate OVL values for their process and thereby improve their yield. Together with K-T Analyzer's ability to detect the symmetric targets across the wafer and within the field, the Archer tools will continue to provide an independent, reliable measurement of OVL error into the next advanced nodes, enabling fabs to manufacture devices that meet their tight OVL error budgets.

  18. Entrapment of α-Amylase in Agar Beads for Biocatalysis of Macromolecular Substrate

    PubMed Central

    Sharma, Manu; Sharma, Vinay; Majumdar, Dipak K.

    2014-01-01

    Attempts have been made to optimize immobilization parameters, catalytic property, and stability of immobilized α-amylase in agar. The work compares natural entrapment efficiency of agar with the ionotropically cross-linked agar hydrogel, with the advantage of easy scale-up and cost and time effectiveness. Beads prepared with 3% (w/v) agar and 75 mM calcium chloride and hardened for 20 minutes were selected for further studies on the basis of entrapment efficiency (80%) and physical stability. Following entrapment, pH and temperature optima of enzyme were shifted from 6 to 6.5 and 50 to 55°C, respectively. Michaelis constant (Km) for both free and entrapped enzymes remained the same (0.83%) suggesting no change in substrate affinity. However, Vmax⁡ of entrapped enzyme decreased ~37.5-fold. The midpoint of thermal inactivation for entrapped enzyme increased by 8 ± 1°C implying its higher thermal stability. The entrapped enzyme in calcium agar bead had an Ea value of 27.49 kcal/mol compared to 17.6 kcal/mol for free enzyme indicating increased stability on entrapment. Half-life of enzyme increased ~2.2 times after entrapment in calcium agar at 60°C indicating stabilization of enzyme. The reusability of beads was size dependent. Beads with diameter <710 μm were stable and could be reused for 6 cycles with ~22% loss in activity.

  19. Rapid detection of Clostridium perfringens: comparison of lactose sulfite broth with tryptose-sulfite-cycloserine agar.

    PubMed

    Neut, C; Pathak, J; Romond, C; Beerens, H

    1985-01-01

    The lactose sulfite (LS) medium recommended for the detection and identification of Clostridium perfringens in foods was compared with a reference method using tryptose-sulfite-cycloserine (TSC) agar for the enumeration of this organism in a variety of foods and food ingredients. C. perfringens was detected and enumerated in 17 of the 54 samples examined with LS broth, but its presence could be confirmed in only 9 of the samples with TSC agar. In only 2 instances, C. perfringens was detected on TSC agar but not in LS broth. A positive response (FeS + and gas +) in LS broth incubated at 46 degrees C always corresponded to the presence of C. perfringens; whereas the black colonies formed on TSC agar incubated at 37 degrees C were frequently found to be Clostridium species other than C. perfringens. Thus, because of its highly selective nature, LS broth was superior to TSC agar for enumerating and confirming the small numbers of C. perfringens that were present in a majority of the samples. This was especially true when other clostridia were also present. Besides its greater selectivity and sensitivity, LS broth had the additional advantages of requiring less work and giving confirmed results within 24-48 h compared with 3 days for the TSC agar method. PMID:2865247

  20. [GROWTH OF MICROMYCETES FROM DIFFERENT ECOLOGICAL NICHES ON AGAR NUTRIENT MEDIA].

    PubMed

    Kurchenko, I M; Yurieva, E M; Voychuk, S I

    2015-01-01

    Radial growth rate of (K(r)) 153 strains 6 species of micromycetes from different ecological niches was studied on 7 agar media: three standard (malt extract agar, potato-dextrose agar, Czapek's agar), and on agar media with plant polymers (carboxymethylcellulose, xylan, soluble starch and apple pectin). Endophytic and plant pathogenic strains (biotrophs) of all studied species did not differ significantly in their ability to grow on nutrient media of different composition--average values of K(r) for these two groups were the same (0,200 and 0,199 mm/h, respectively). Soil micromycetes (saprophytes) characterized by the lowest average growth rate (0,169 mm/h) and significantly differed from the endophytic and plant pathogenic ones. Average of the radial growth rates of studied microscopic fungi were higher on standard nutrient media than with plant polymers ones. Growth parameters of endophytes and plant pathogens of all studied species on various agar media differed from the soil strains. High growth rate of endophytic and plant pathogenic strains of Fusarium poae, Alternaria alternata and Ceratocystis sp. provides them the rapid colonization of plants. Penicillium funiculosum strains equally can exist as saprophytes in soil and as endophytic plant symbionts. A wide range of K(r) variation of endophytic dark pigmented Mycelia sterilia indicates the presence in this group of different species of micromycetes, which have no sporulation. PMID:26638483

  1. Growth of coagulase-negative staphylococci on colistin-nalidixic acid agar and susceptibility to polymyxins.

    PubMed

    Fung, J C; McKinley, G; Tyburski, M B; Berman, M; Goldstein, J

    1984-05-01

    Colistin-nalidixic acid agar, although recently recommended as a replacement for blood agar for primary plating of urine specimens ( Fung et al., J. Clin. Microbiol. 16:632-636, 1982), has also been reported to suppress the growth of some strains of staphylococci that are susceptible to colistin (polymyxin E). The susceptibility of 11 species of staphylococci to polymyxins was determined, and the ability of these species to grow on colistin-nalidixic acid agar was examined. Although the MICs for most of the strains tested were 8 micrograms/ml or less, only a few coagulase-negative staphylococci grew on or were inhibited by colistin-nalidixic acid agar. This descrepancy was explained by the antagonistic effects that medium components, such as physiological concentrations of magnesium and calcium and 5% sheep blood, had on the activity of polymyxin. Colistin-nalidixic acid agar is still recommended for routine urine processing; however, the poor growth of 13% of the Staphylococcus saprophyticus strains tested suggests that blood agar should be included in the primary plating battery of urine specimens obtained from female outpatients. PMID:6330170

  2. 64nm pitch metal1 double patterning metrology: CD and OVL control by SEMCD, image based overlay and diffraction based overlay

    NASA Astrophysics Data System (ADS)

    Ducoté, Julien; Dettoni, Florent; Bouyssou, Régis; Le-Gratiet, Bertrand; Carau, Damien; Dezauzier, Christophe

    2015-03-01

    Patterning process control of advanced nodes has required major changes over the last few years. Process control needs of critical patterning levels since 28nm technology node is extremely aggressive showing that metrology accuracy/sensitivity must be finely tuned. The introduction of pitch splitting (Litho-Etch-Litho-Etch) at 14FDSOInm node requires the development of specific metrologies to adopt advanced process control (for CD, overlay and focus corrections). The pitch splitting process leads to final line CD uniformities that are a combination of the CD uniformities of the two exposures, while the space CD uniformities are depending on both CD and OVL variability. In this paper, investigations of CD and OVL process control of 64nm minimum pitch at Metal1 level of 14FDSOI technology, within the double patterning process flow (Litho, hard mask etch, line etch) are presented. Various measurements with SEMCD tools (Hitachi), and overlay tools (KT for Image Based Overlay - IBO, and ASML for Diffraction Based Overlay - DBO) are compared. Metrology targets are embedded within a block instanced several times within the field to perform intra-field process variations characterizations. Specific SEMCD targets were designed for independent measurement of both line CD (A and B) and space CD (A to B and B to A) for each exposure within a single measurement during the DP flow. Based on those measurements correlation between overlay determined with SEMCD and with standard overlay tools can be evaluated. Such correlation at different steps through the DP flow is investigated regarding the metrology type. Process correction models are evaluated with respect to the measurement type and the intra-field sampling.

  3. Growth of Piscirickettsia salmonis on Enriched Blood Agar

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Piscirickettsia salmonis is the etiologic agent of piscirickettsiosis, an economically significant disease of fish. Isolation of P. salmonis by culturing on fish cell lines has been the standard technique since the initial isolation of the organism. The ability to grow P. salmonis on artificial medi...

  4. Characterisation of hydrocarbonaceous overlayers important in metal-catalysed selective hydrogenation reactions

    NASA Astrophysics Data System (ADS)

    Lennon, David; Warringham, Robbie; Guidi, Tatiana; Parker, Stewart F.

    2013-12-01

    The hydrogenation of alkynes to alkenes over supported metal catalysts is an important industrial process and it has been shown that hydrocarbonaceous overlayers are important in controlling selectivity profiles of metal-catalysed hydrogenation reactions. As a model system, we have selected propyne hydrogenation over a commercial Pd(5%)/Al2O3 catalyst. Inelastic neutron scattering studies show that the C-H stretching mode ranges from 2850 to 3063 cm-1, indicating the mostly aliphatic nature of the overlayer and this is supported by the quantification of the carbon and hydrogen on the surface. There is also a population of strongly hydrogen-bonded hydroxyls, their presence would indicate that the overlayer probably contains some oxygen functionality. There is little evidence for any olefinic or aromatic species. This is distinctly different from the hydrogen-poor overlayers that are deposited on Ni/Al2O3 catalysts during methane reforming.

  5. Computerized polar plots by a cathode ray tube/grid overlay method

    NASA Technical Reports Server (NTRS)

    Freeman, J. M.; Shoup, E. L.

    1970-01-01

    Overlay is aligned with four calibration dots so it is not affected by CRT drift or changes in vertical or horizontal gain when producing Nyquist /frequency-response phase/amplitude/ plots. Method produces over 50 plots per hour.

  6. Effect of an absorbent overlay on the residual stress field induced by laser shock processing on aluminum samples

    NASA Astrophysics Data System (ADS)

    Rubio-González, C.; Gomez-Rosas, G.; Ocaña, J. L.; Molpeceres, C.; Banderas, A.; Porro, J.; Morales, M.

    2006-07-01

    Laser shock processing (LSP) or laser shock peening is a new technique for strengthening metals. This process induces a compressive residual stress field, which increases fatigue crack initiation life and reduces fatigue crack growth rate. Specimens of 6061-T6 aluminum alloy are used in this investigation. A convergent lens is used to deliver 2.5 J, 8 ns laser pulses by a Q-switch Nd:YAG laser, operating at 10 Hz. The pulses are focused to a diameter of 1.5 mm onto aluminum samples. Density of 2500 pulses/cm 2 with infrared (1064 nm) radiation was used. The effect of an absorbent overlay on the residual stress field using this LSP setup and this energy level is evaluated. Residual stress distribution as a function of depth is assessed by the hole drilling method. It is observed that the overlay makes the compressive residual stress profile move to the surface. This effect is explained on the basis of the vaporization of the coat layer suppressing thermal effects on the metallic substrate. The effect of coating the specimen surface before LSP treatment may have advantages on improving wear and contact fatigue properties of this aluminum alloy.

  7. Focused-ion-beam overlay-patterning of three-dimensional diamond structures for advanced single-photon properties

    SciTech Connect

    Jiang, Qianqing; Liu, Dongqi; Liu, Gangqin; Chang, Yanchun; Li, Wuxia E-mail: czgu@aphy.iphy.ac.cn; Pan, Xinyu; Gu, Changzhi E-mail: czgu@aphy.iphy.ac.cn

    2014-07-28

    Sources of single photons are of fundamental importance in many applications as to provide quantum states for quantum communication and quantum information processing. Color centers in diamond are prominent candidates to generate and manipulate quantum states of light, even at room temperature. However, the efficiency of photon collection of the color centers in bulk diamond is greatly reduced by refraction at the diamond/air interface. To address this issue, diamond structuring has been investigated by various methods. Among them, focused-ion-beam (FIB) direct patterning has been recognized as the most favorable technique. But it has been noted that diamond tends to present significant challenges in FIB milling, e.g., the susceptibility of forming charging related artifacts and topographical features. In this work, periodically-positioned-rings and overlay patterning with stagger-superimposed-rings were proposed to alleviate some problems encountered in FIB milling of diamond, for improved surface morphology and shape control. Cross-scale network and uniform nanostructure arrays have been achieved in single crystalline diamond substrates. High quality diamond solid immersion lens and nanopillars were sculptured with a nitrogen-vacancy center buried at the desired position. Compared with the film counterpart, an enhancement of about ten folds in single photon collection efficiency was achieved with greatly improved signal to noise ratio. All these results indicate that FIB milling through over-lay patterning could be an effective approach to fabricate diamond structures, potentially for quantum information studies.

  8. Focused-ion-beam overlay-patterning of three-dimensional diamond structures for advanced single-photon properties

    NASA Astrophysics Data System (ADS)

    Jiang, Qianqing; Liu, Dongqi; Liu, Gangqin; Chang, Yanchun; Li, Wuxia; Pan, Xinyu; Gu, Changzhi

    2014-07-01

    Sources of single photons are of fundamental importance in many applications as to provide quantum states for quantum communication and quantum information processing. Color centers in diamond are prominent candidates to generate and manipulate quantum states of light, even at room temperature. However, the efficiency of photon collection of the color centers in bulk diamond is greatly reduced by refraction at the diamond/air interface. To address this issue, diamond structuring has been investigated by various methods. Among them, focused-ion-beam (FIB) direct patterning has been recognized as the most favorable technique. But it has been noted that diamond tends to present significant challenges in FIB milling, e.g., the susceptibility of forming charging related artifacts and topographical features. In this work, periodically-positioned-rings and overlay patterning with stagger-superimposed-rings were proposed to alleviate some problems encountered in FIB milling of diamond, for improved surface morphology and shape control. Cross-scale network and uniform nanostructure arrays have been achieved in single crystalline diamond substrates. High quality diamond solid immersion lens and nanopillars were sculptured with a nitrogen-vacancy center buried at the desired position. Compared with the film counterpart, an enhancement of about ten folds in single photon collection efficiency was achieved with greatly improved signal to noise ratio. All these results indicate that FIB milling through over-lay patterning could be an effective approach to fabricate diamond structures, potentially for quantum information studies.

  9. Sol-Gel-Based Titania-Silica Thin Film Overlay for Long Period Fiber Grating-Based Biosensors.

    PubMed

    Chiavaioli, Francesco; Biswas, Palas; Trono, Cosimo; Jana, Sunirmal; Bandyopadhyay, Somnath; Basumallick, Nandini; Giannetti, Ambra; Tombelli, Sara; Bera, Susanta; Mallick, Aparajita; Baldini, Francesco

    2015-12-15

    An evanescent wave optical fiber biosensor based on titania-silica-coated long period grating (LPG) is presented. The chemical overlay, which increases the refractive index (RI) sensitivity of the sensor, consists of a sol-gel-based titania-silica thin film, deposited along the sensing portion of the fiber by means of the dip-coating technique. Changing both the sol viscosity and the withdrawal speed during the dip-coating made it possible to adjust the thickness of the film overlay, which is a crucial parameter for the sensor performance. After the functionalization of the fiber surface using a methacrylic acid/methacrylate copolymer, an antibody/antigen (IgG/anti-IgG) assay was carried out to assess the performance of sol-gel based titania-silica-coated LPGs as biosensors. The analyte concentration was determined from the wavelength shift at the end of the binding process and from the initial binding rate. This is the first time that a sol-gel based titania-silica-coated LPG is proposed as an effective and feasible label-free biosensor. The specificity of the sensor was validated by performing the same model assay after spiking anti-IgG into human serum. With this structured LPG, detection limits of the order of tens of micrograms per liter (10(-11) M) are attained. PMID:26548589

  10. IMPERMEABLE THIN AL2O3 OVERLAY FOR TBC PROTECTION FROM SULFATE AND VANADATE ATTACK IN GAS TURBINES

    SciTech Connect

    Scott X. Mao

    2002-01-31

    The project started on September 1, 2001. During last 4 months, one post-doctor has been hired for this project. We have received TBC samples (YSZ/CoNiCrAlY/ Inconel 601) from Tohoku University, Japan, while processing of the TBC samples was delayed in GE Corp. Research and Development. The TBC preparation in Japan was based on our technical requirement by plasma spray. Bond coat CoNiCrAlY and the YSZ was produced by low-pressure plasma spray and air plasma spray respectively. The morphology of the surface and the microstructure of cross-section of the sample was observed and analyzed by SEM and EDX. XRD was also used to detect the phases in the YSZ. Currently we are processing the overlay Al{sub 2}O{sub 3} on the TBC samples by EB-PVD and high velocity oxy-fuel (HVOF) spray techniques in collaboration with Penn State University and State University of New York at Stony Brook. We will finish comparing the hot corrosion behavior of the Al{sub 2}O{sub 3}/YSZ/CoNiCrAlY/superalloy system with the YSZ/CoNiCrAlY/superalloy system. The mechanism of hot corrosion will be investigated. The processing-structure-properties relationship of the overlays will be determined.

  11. Biological and chemical detection of fumonisins produced on agar medium by Fusarium verticillioides isolates collected from corn in Sohag, Egypt.

    PubMed

    Aboul-Nasr, M B; Obied-Allah, M R A

    2013-08-01

    Fusarium verticillioides (Sacc.) Nirenberg is among the most common Fusarium species corn pathogens worldwide, and has been recognized as a fumonisin B1 (FB1) and fumonisin B2 (FB2) producer. In the present work, extracts of 58 F. verticillioides isolates from corn samples collected from Sohag Governorate, Egypt, were tested for their biotoxicity and production of fumonisin toxins. Forty-four Fusarium verticillioides isolates out of 58 tested produced FB1 or FB1 and FB2 (15 and 29 isolates, respectively) on potato-sucrose agar medium, detected by TLC, whereas the other 14 isolates did not produce fumonisin toxins. HPLC crude extract analysis confirmed the results from TLC plates. Brine shrimp larvae as well as the Gram-negative bacteria Pseudomonas aeuroginosa showed low bio-sensitivity towards the F. verticillioides crude extract toxicity, whereas the Gram-positive bacteria Bacillus cereus and Bacillus subtilis, especially B. subtilis, showed higher sensitivity towards the tested Fusarium crude extracts. These results enabled us to bio-evaluate and chemically detect fumonisin mycotoxins using a simple agar medium technique. PMID:23760819

  12. Application of overlay modeling and control with Zernike polynomials in an HVM environment

    NASA Astrophysics Data System (ADS)

    Ju, JaeWuk; Kim, MinGyu; Lee, JuHan; Nabeth, Jeremy; Jeon, Sanghuck; Heo, Hoyoung; Robinson, John C.; Pierson, Bill

    2016-03-01

    Shrinking technology nodes and smaller process margins require improved photolithography overlay control. Generally, overlay measurement results are modeled with Cartesian polynomial functions for both intra-field and inter-field models and the model coefficients are sent to an advanced process control (APC) system operating in an XY Cartesian basis. Dampened overlay corrections, typically via exponentially or linearly weighted moving average in time, are then retrieved from the APC system to apply on the scanner in XY Cartesian form for subsequent lot exposure. The goal of the above method is to process lots with corrections that target the least possible overlay misregistration in steady state as well as in change point situations. In this study, we model overlay errors on product using Zernike polynomials with same fitting capability as the process of reference (POR) to represent the wafer-level terms, and use the standard Cartesian polynomials to represent the field-level terms. APC calculations for wafer-level correction are performed in Zernike basis while field-level calculations use standard XY Cartesian basis. Finally, weighted wafer-level correction terms are converted to XY Cartesian space in order to be applied on the scanner, along with field-level corrections, for future wafer exposures. Since Zernike polynomials have the property of being orthogonal in the unit disk we are able to reduce the amount of collinearity between terms and improve overlay stability. Our real time Zernike modeling and feedback evaluation was performed on a 20-lot dataset in a high volume manufacturing (HVM) environment. The measured on-product results were compared to POR and showed a 7% reduction in overlay variation including a 22% terms variation. This led to an on-product raw overlay Mean + 3Sigma X&Y improvement of 5% and resulted in 0.1% yield improvement.

  13. Live 3D image overlay for arterial duct closure with Amplatzer Duct Occluder II additional size.

    PubMed

    Goreczny, Sebstian; Morgan, Gareth J; Dryzek, Pawel

    2016-03-01

    Despite several reports describing echocardiography for the guidance of ductal closure, two-dimensional angiography remains the mainstay imaging tool; three-dimensional rotational angiography has the potential to overcome some of the drawbacks of standard angiography, and reconstructed image overlay provides reliable guidance for device placement. We describe arterial duct closure solely from venous approach guided by live three-dimensional image overlay. PMID:26358032

  14. Selective agars for the isolation of Streptococcus iniae from Japanese flounder, Paralichthys olivaceus, and its cultural environment.

    PubMed

    Nguyen, H T; Kanai, K

    1999-05-01

    Two kinds of selective agar were developed for the isolation of Streptococcus iniae, the causal agent of streptococcosis, from Japanese flounder (Paralichthys olivaceus) and from culture tanks in flounder farms. The selective agars were heart infusion agar with added thallium acetate and oxlinic acid (TAOA), and colistin sulphate and oxolinic acid (CSOA). For samples containing various bacterial flora, selective agars were supplemented with defibrinated horse blood in order to distinguish beta-haemolytic colonies of Strep. iniae. Streptococcus iniae was quantitatively isolated from the brain and kidney of diseased flounders in pure culture. Two-thirds of isolates picked up from selective blood agars inoculated with intestinal samples were identified as Strep. iniae. The bacterial colony numbers of deposits and water from culture tanks on selective blood agars were about 10-10(5) times smaller than those on control heart infusion agar; Strep. iniae was isolated from few deposit and water samples. PMID:10347871

  15. Assessment and prediction of drying shrinkage cracking in bonded mortar overlays

    SciTech Connect

    Beushausen, Hans Chilwesa, Masuzyo

    2013-11-15

    Restrained drying shrinkage cracking was investigated on composite beams consisting of substrate concrete and bonded mortar overlays, and compared to the performance of the same mortars when subjected to the ring test. Stress development and cracking in the composite specimens were analytically modeled and predicted based on the measurement of relevant time-dependent material properties such as drying shrinkage, elastic modulus, tensile relaxation and tensile strength. Overlay cracking in the composite beams could be very well predicted with the analytical model. The ring test provided a useful qualitative comparison of the cracking performance of the mortars. The duration of curing was found to only have a minor influence on crack development. This was ascribed to the fact that prolonged curing has a beneficial effect on tensile strength at the onset of stress development, but is in the same time not beneficial to the values of tensile relaxation and elastic modulus. -- Highlights: •Parameter study on material characteristics influencing overlay cracking. •Analytical model gives good quantitative indication of overlay cracking. •Ring test presents good qualitative indication of overlay cracking. •Curing duration has little effect on overlay cracking.

  16. VMCast: A VM-Assisted Stability Enhancing Solution for Tree-Based Overlay Multicast

    PubMed Central

    Gu, Weidong; Zhang, Xinchang; Gong, Bin; Zhang, Wei; Wang, Lu

    2015-01-01

    Tree-based overlay multicast is an effective group communication method for media streaming applications. However, a group member’s departure causes all of its descendants to be disconnected from the multicast tree for some time, which results in poor performance. The above problem is difficult to be addressed because overlay multicast tree is intrinsically instable. In this paper, we proposed a novel stability enhancing solution, VMCast, for tree-based overlay multicast. This solution uses two types of on-demand cloud virtual machines (VMs), i.e., multicast VMs (MVMs) and compensation VMs (CVMs). MVMs are used to disseminate the multicast data, whereas CVMs are used to offer streaming compensation. The used VMs in the same cloud datacenter constitute a VM cluster. Each VM cluster is responsible for a service domain (VMSD), and each group member belongs to a specific VMSD. The data source delivers the multicast data to MVMs through a reliable path, and MVMs further disseminate the data to group members along domain overlay multicast trees. The above approach structurally improves the stability of the overlay multicast tree. We further utilized CVM-based streaming compensation to enhance the stability of the data distribution in the VMSDs. VMCast can be used as an extension to existing tree-based overlay multicast solutions, to provide better services for media streaming applications. We applied VMCast to two application instances (i.e., HMTP and HCcast). The results show that it can obviously enhance the stability of the data distribution. PMID:26562152

  17. Mix-and-match overlay performance of the NSR-S622D immersion scanner

    NASA Astrophysics Data System (ADS)

    Makino, Katsushi; Kikuchi, Takahisa; Sasamoto, Satoru; Hongki, Park; Mori, Akiko; Takahashi, Nobuyuki; Wakamoto, Shinji

    2013-04-01

    Current technology nodes, as well as subsequent generations necessitate ongoing improvements to the mix-and-match overlay (MMO) capabilities of lithography scanners. This work will introduce newly developed scanner solutions to address this requirement, and performance data from the latest generation immersion scanner, the NSR-S622D, will be introduced. Enhanced MMO accuracy is imperative for the 22 nm half-pitch and future technology nodes. In order for the matched overlay accuracy to approach single machine overlay (SMO) capabilities, MMO errors must be reduced further. The dominant MMO error sources can be divided into three main areas: SMO, lens distortion matching and wafer grid matching. Nikon continues to decrease these matching error contributors over time, and the latest generation NSRS622D immersion scanner provides a number of innovative solutions to satisfy the most demanding overlay matching requirements ; as a result MMO performance within 3nm is achieved on S622D. Moreover, overlay master system is developed for further product overlay accuracy and stability improvement.

  18. VMCast: A VM-Assisted Stability Enhancing Solution for Tree-Based Overlay Multicast.

    PubMed

    Gu, Weidong; Zhang, Xinchang; Gong, Bin; Zhang, Wei; Wang, Lu

    2015-01-01

    Tree-based overlay multicast is an effective group communication method for media streaming applications. However, a group member's departure causes all of its descendants to be disconnected from the multicast tree for some time, which results in poor performance. The above problem is difficult to be addressed because overlay multicast tree is intrinsically instable. In this paper, we proposed a novel stability enhancing solution, VMCast, for tree-based overlay multicast. This solution uses two types of on-demand cloud virtual machines (VMs), i.e., multicast VMs (MVMs) and compensation VMs (CVMs). MVMs are used to disseminate the multicast data, whereas CVMs are used to offer streaming compensation. The used VMs in the same cloud datacenter constitute a VM cluster. Each VM cluster is responsible for a service domain (VMSD), and each group member belongs to a specific VMSD. The data source delivers the multicast data to MVMs through a reliable path, and MVMs further disseminate the data to group members along domain overlay multicast trees. The above approach structurally improves the stability of the overlay multicast tree. We further utilized CVM-based streaming compensation to enhance the stability of the data distribution in the VMSDs. VMCast can be used as an extension to existing tree-based overlay multicast solutions, to provide better services for media streaming applications. We applied VMCast to two application instances (i.e., HMTP and HCcast). The results show that it can obviously enhance the stability of the data distribution. PMID:26562152

  19. Application Oriented Flow Routing Algorithm for VoIP Overlay Networks

    NASA Astrophysics Data System (ADS)

    Wipusitwarakun, Komwut; Chimmanee, Sanon

    Overlay networks which are dynamically created over underlying IP networks are becoming widely used for delivering multimedia contents since they can provide several additional user-definable services. Multiple overlay paths between a source-destination overlay node pair are designed to improve service robustness against failures and bandwidth fluctuation of the underlying networks. Multimedia traffic can be distributed over those multiple paths in order to maximize paths' utilization and to increase application throughputs. Most of flow-based routing algorithms consider only common metrics such as paths' bandwidth or delay, which may be effective for data applications but not for real-time applications such as Voice over IP (VoIP), in which different levels of such performance metrics may give the same level of the performance experienced by end users. This paper focuses on such VoIP overlay networks and proposes a novel alternative path based flow routing algorithm using an application-specific traffic metric, i.e. “VoIP Path Capacity (VPCap), ” to calculate the maximum number of QoS satisfied VoIP flows which may be distributed over each available overlay path at a moment. The simulation results proved that more QoS-satisfied VoIP sessions can be established over the same multiple overlay paths, comparing to traditional approaches.

  20. Mass production of spores of lactic acid-producing Rhizopus oryzae NBRC 5384 on agar plate.

    PubMed

    Yamane, Tsuneo; Tanaka, Ryosuke

    2013-01-01

    Mass production of sporangiospores (spores) of Rhizopus oryzae NBRC 5384 (identical to NRRL 395 and ATCC 9363) on potato-dextrose-agar medium was studied aiming at starting its L(+)-lactic acid fermentation directly from spore inoculation. Various parameters including harvest time, sowed spore density, size of agar plate, height of air space, and incubation mode of plate (agar-on-bottom or agar-on-top) were studied. Ordinarily used shallow Petri dishes were found out to be unsuitable for the full growth of R. oryzae sporangiophores. In a very wide range of the sowed spore density, the smaller it was, the greater the number of the harvested spores was. It was also interesting to find out that R. oryzae grown downward vertically with a deep air space in an agar-on-top mode gave larger amount of spores than in an agar-on-bottom mode at 30°C for 7-day cultivation. Scale-up of the agar plate culture from 26.4 to 292 cm(2) was studied, resulting in the proportional relationship between the number of the harvested spores/plate and the plate area in the deep Petri dishes. The number of plates of 50 cm in diameter needed for 100 m(3) industrial submerged fermentation started directly from 2 × 10(5) spores/mL inoculum size was estimated as about 6, from which it was inferred that such a fermentation would be feasible. Designing a 50 cm plate and a method of spreading and collecting the spores were suggested. Bioprocess technological significance of the "full-scale industrial submerged fermentation started directly from spore inoculation omitting pre-culture" has been discussed. PMID:23658025

  1. Performance of CHROMAGAR candida and BIGGY agar for identification of yeast species

    PubMed Central

    Yücesoy, Mine; Marol, Serhat

    2003-01-01

    Background The importance of identifying the pathogenic fungi rapidly has encouraged the development of differential media for the presumptive identification of yeasts. In this study two differential media, CHROMagar Candida and bismuth sulphite glucose glycine yeast agar, were evaluated for the presumptive identification of yeast species. Methods A total number of 270 yeast strains including 169 Candida albicans, 33 C. tropicalis, 24 C. glabrata, 18 C. parapsilosis, 12 C. krusei, 5 Trichosporon spp., 4 C. kefyr, 2 C. lusitaniae, 1 Saccharomyces cerevisiae and 1 Geotrichum candidum were included. The strains were first identified by germ tube test, morphological characteristics on cornmeal tween 80 agar and Vitek 32 and API 20 C AUX systems. In parallel, they were also streaked onto CHROMagar Candida and bismuth sulphite glucose glycine yeast agar plates. The results were read according to the color, morphology of the colonies and the existance of halo around them after 48 hours of incubation at 37°C. Results The sensitivity and specificity values for C. albicans strains were found to be 99.4, 100% for CHROMagar Candida and 87.0, 75.2% for BiGGY agar, respectively. The sensitivity of CHROMagar Candida to identify C. tropicalis, C. glabrata and C. krusei ranged between 90.9 and 100% while the specificity was 100%. The sensitivity rates for BiGGY agar were 66.6 and 100% while the specificity values were found to be 95.4 and 100% for C. tropicalis and C. krusei, respectively. Conclusions It can be concluded that the use of CHROMagar Candida is an easy and reliable method for the presumptive identification of most commonly isolated Candida species especially C. albicans, C. tropicalis and C. krusei. The lower sensitivity and specificity of BiGGY agar to identify commonly isolated Candida species potentially limits the clinical usefulness of this agar. PMID:14613587

  2. Improving overlay control through proper use of multilevel query APC

    NASA Astrophysics Data System (ADS)

    Conway, Timothy H.; Carlson, Alan; Crow, David A.

    2003-06-01

    Many state-of-the-art fabs are operating with increasingly diversified product mixes. For example, at Cypress Semiconductor, it is not unusual to be concurrently running multiple technologies and many devices within each technology. This diverse product mix significantly increases the difficulty of manually controlling overlay process corrections. As a result, automated run-to-run feedforward-feedback control has become a necessary and vital component of manufacturing. However, traditional run-to-run controllers rely on highly correlated historical events to forecast process corrections. For example, the historical process events typically are constrained to match the current event for exposure tool, device, process level and reticle ID. This narrowly defined process stream can result in insufficient data when applied to lowvolume or new-release devices. The run-to-run controller implemented at Cypress utilizes a multi-level query (Level-N) correlation algorithm, where each subsequent level widens the search criteria for available historical data. The paper discusses how best to widen the search criteria and how to determine and apply a known bias to account for tool-to-tool and device-to-device differences. Specific applications include offloading lots from one tool to another when the first tool is down for preventive maintenance, utilizing related devices to determine a default feedback vector for new-release devices, and applying bias values to account for known reticle-to-reticle differences. In this study, we will show how historical data can be leveraged from related devices or tools to overcome the limitations of narrow process streams. In particular, this paper discusses how effectively handling narrow process streams allows Cypress to offload lots from a baseline tool to an alternate tool.

  3. Synchrotron radiation photoemission study of metal overlayers on hydrogenated amorphous silicon at room temperature

    SciTech Connect

    Pi, J.

    1990-09-21

    In this dissertation, metals deposited on a hydrogenated amorphous silicon (a-Si:H) film at room temperature are studied. The purpose of this work is mainly understanding the electronic properties of the interface, using high-resolution synchrotron radiation photoemission techniques as a probe. Atomic hydrogen plays an important role in passivating dangling bonds of a-Si:H films, thus reducing the gap-state distribution. In addition, singly bonded hydrogen also reduces states at the top of the valence band which are now replaced by deeper Si-H bonding states. The interface is formed by evaporating metal on an a-Si:H film in successive accumulations at room temperature. Au, Ag, and Cr were chosen as the deposited metals. Undoped films were used as substrates. Since some unique features can be found in a-Si:H, such as surface enrichment of hydrogen diffused from the bulk and instability of the free surface, we do not expect the metals/a-Si:H interface to behave exactly as its crystalline counterpart. Metal deposits, at low coverages, are found to gather preferentially around regions deficient in hydrogen. As the thickness is increased, some Si atoms in those regions are likely to leave their sites to intermix with metal overlayers like Au and Cr. 129 refs., 30 figs.

  4. Role of molecular orientational anisotropy in the chiral resolution of enantiomers in adsorbed overlayers.

    PubMed

    Szabelski, Paweł; Woszczyk, Aleksandra

    2012-07-31

    Separation of chiral molecules using achiral inputs is an interesting alternative to traditional techniques based on the chiral recognition mechanism. In this article we propose a lattice gas Monte Carlo model of two-dimensional chiral segregation induced by breaking of molecular orientational symmetry. Simulations were performed on a square lattice for rigid chain molecules composed of four and five identical segments. Mirror-image flat chain conformations resulting in different enantiomeric pairs were considered for each probe molecule. The enantiomers were assumed to interact via short-ranged segment-segment interaction potential limited to nearest neighbors on the lattice. We considered two qualitatively different situations in which (1) the molecules were allowed to rotate on the surface and adopt any of the four planar orientations and (2) the rotation was blocked, so that only one planar orientation was possible. The results obtained for the racemic overlayers showed clearly that the orientational symmetry breaking can induce spontaneous segregation of the enantiomers into large enantiopure domains. However, this effect was observed only for molecules with sufficiently long linear fragment. In the case of kinked bulky molecules a mixed assembly was formed, demonstrating the role of molecular shape in the orientationally biased segregation of enantiomers in adsorbed films. The insights from this study can be useful in developing strategies for 2D chiral separations in which external directional fields are used. PMID:22747234

  5. Preparation and characterization of bio-nanocomposite films of agar and silver nanoparticles: laser ablation method.

    PubMed

    Rhim, Jong-Whan; Wang, Long-Feng; Lee, Yonghoon; Hong, Seok-In

    2014-03-15

    Silver nanoparticles (AgNPs) were prepared by a laser ablation method and composite films with the AgNPs and agar were prepared by solvent casting method. UV-vis absorbance test and transmission electron microscopy (TEM) analysis results revealed that non-agglomerated spherical AgNPs were formed by the laser ablation method. The surface color of the resulting agar/AgNPs films exhibited the characteristic plasmonic effect of the AgNPs with the maximum absorption peaks of 400-407 nm. X-ray diffraction (XRD) test results also exhibited characteristic AgNPs crystals with diffraction peaks observed at 2θ values of 38.39°, 44.49°, and 64.45°, which were corresponding to (111), (200), and (220) crystallographic planes of face-centered cubic (fcc) silver crystals, respectively. Thermogravimetric analysis (TGA) results showed that thermal stability of the agar/AgNPs composite films was increased by the inclusion of metallic silver. Water vapor barrier properties and surface hydrophobicity of the agar/AgNPs films increased slightly with the increase in AgNPs content but they were not statistically significant (p>0.05), while mechanical strength and stiffness of the composite films decreased slightly (p<0.05). The agar/AgNPs films exhibited distinctive antimicrobial activity against both Gram-positive (Listeria monocytogenes) and Gram-negative (Escherichia coli O157:H7) bacterial pathogens. PMID:24528754

  6. Antimicrobial and physical-mechanical properties of agar-based films incorporated with grapefruit seed extract.

    PubMed

    Kanmani, Paulraj; Rhim, Jong-Whan

    2014-02-15

    The use of synthetic petroleum based packaging films caused serious environmental problems due to their difficulty in recycling and poor biodegradability. Therefore, present study was aimed to develop natural biopolymer-based antimicrobial packaging films as an alternative for the synthetic packaging films. As a natural antimicrobial agent, grapefruit seed extract (GSE) has been incorporated into agar to prepare antimicrobial packaging film. The films with different concentrations of GSE were prepared by a solvent casting method and the resulting composite films were examined physically and mechanically. In addition, the films were characterized by FE-SEM, XRD, FT-IR and TGA. The incorporation of GSE caused increase in color, UV barrier, moisture content, water solubility and water vapor permeability, while decrease in surface hydrophobicity, tensile strength and elastic modulus of the films. As the concentration of GSE increased from 0.6 to 13.3 μg/mL, the physical and mechanical properties of the films were affected significantly. The addition of GSE changed film microstructure of the film, but did not influence the crystallinity of agar and thermal stability of the agar-based films. The agar/GSE films exhibited distinctive antimicrobial activity against three test food pathogens, such as Listeria monocytogenes, Bacillus cereus and Escherichia coli. These results suggest that agar/GSE films have potential to be used in an active food packaging systems for maintaining food safety and extending the shelf-life of the packaged food. PMID:24507339

  7. Characterization of bionanocomposite films prepared with agar and paper-mulberry pulp nanocellulose.

    PubMed

    Reddy, Jeevan Prasad; Rhim, Jong-Whan

    2014-09-22

    Crystallized nanocellulose (CNC) was separated from paper-mulberry (Broussonetia kazinoki Siebold) bast pulp by sulfuric acid hydrolysis method and they were blended with agar to prepare bionanocomposite films. The effect of CNC content (1, 3, 5 and 10 wt% based on agar) on the mechanical, water vapor permeability (WVP), and thermal properties of the nanocomposites were studied. Changes of the cellulose fibers in structure, morphology, crystallinity, and thermal properties of the films were evaluated using FT-IR, TEM, SEM, XRD, and TGA analysis methods. The CNC was composed of fibrous and spherical or elliptic granules of nano-cellulose with sizes of 50-60 nm. Properties of agar film such as mechanical and water vapor barrier properties were improved significantly (p<0.05) by blending with the CNC. The tensile modulus and tensile strength of agar film increased by 40% and 25%, respectively, in the composite film with 5 wt% of CNC, and the WVP of agar film decreased by 25% after formation of nanocomposite with 3 wt% of CNC. The CNC obtained from the paper-mulberry bast pulp can be used as a reinforcing agent for the preparation of bio-nanocomposites, and they have a high potential for the development of completely biodegradable food packaging materials. PMID:24906782

  8. Novel grafted agar disks for the covalent immobilization of β-D-galactosidase.

    PubMed

    Wahba, Marwa I; Hassan, Mohamed E

    2015-12-01

    Novel grafted agar disks were prepared for the covalent immobilization of β-D-galactosidase (β-gal). The agar disks were activated through reacting with ethylenediamine or different molecular weights of Polyethyleneimine (PEI), followed by glutaraldehyde (GA). The modification of the agar gel and the binding of the enzyme were verified by Fourier Transform Infrared (FTIR) and elemental analysis. Moreover, the agar's activation process was optimized, and the amount of immobilized enzyme increased 3.44 folds, from 38.1 to 131.2 U/g gel, during the course of the optimization process. The immobilization of β-gal onto the activated agar disks caused its optimum temperature to increase from 45°C to 45-55°C. The optimum pH of the enzyme was also shifted towards the acidic side (3.6-4.6) after its immobilization. Additionally, the Michaelis-Menten constant (Km ) increased for the immobilized β-gal as compared to its free counterpart whereas the maximum reaction rate (Vmax ) decreased. The immobilized enzyme was also shown to retain 92.99% of its initial activity after being used for 15 consecutive times. PMID:26043937

  9. Strategies to improve the mechanical strength and water resistance of agar films for food packaging applications.

    PubMed

    Sousa, Ana M M; Gonçalves, Maria P

    2015-11-01

    Agar films possess several properties adequate for food packaging applications. However, their high cost-production and quality variations caused by physiological and environmental factors affecting wild seaweeds make them less attractive for industries. In this work, native (NA) and alkali-modified (AA) agars obtained from sustainably grown seaweeds (integrated multi-trophic aquaculture) were mixed with locust bean gum (LBG) to make 'knife-coated' films with fixed final concentration (1 wt%) and variable agar/LBG ratios. Agar films were easier to process upon LBG addition (viscosity increase and gelling character decrease of the film-forming solutions observed by dynamic oscillatory and steady shear measurements). The mechanical properties and water resistance were optimal for films with 50 and/or 75% LBG contents and best in the case of NA (cheaper to extract). These findings can help reduce the cost-production of agar packaging films. Moreover, the controlled cultivation of seaweeds can provide continuous and reliable feedstock for transformation industries. PMID:26256341

  10. Effects of shape and size of agar gels on heating uniformity during pulsed microwave treatment.

    PubMed

    Soto-Reyes, Nohemí; Temis-Pérez, Ana L; López-Malo, Aurelio; Rojas-Laguna, Roberto; Sosa-Morales, María Elena

    2015-05-01

    Model gel systems with different shape (sphere, cylinder, and slab) and size (180 and 290 g) were prepared with agar (5%) and sucrose (5%). Dielectric constant (ε'), loss factor (ε"), thermophysical properties, and temperature distribution of the model system were measured. Each agar model system was immersed and suspended in water, and then, heated in a microwave oven with intermittent heating until the core temperature reached 50 °C. The ε' and ε" of agar gels decreased when frequency increased. The density and thermal conductivity values of the agar gels were 1033 kg/m(3) and 0.55 W/m °C, respectively. The temperature distribution of sphere, cylinder, and slab was different when similar power doses were applied. The slab reached 50 °C in less time (10 min) and showed a more uniform heating than spheres and cylinders in both sizes. Agar model systems of 180 g heated faster than those of 290 g. The coldest point was the center of the model systems in all studied cases. Shape and size are critical food factors that affect the heating uniformity during microwave heating processes. PMID:25827444

  11. Cost-effective nanoporous Agar-Agar polymer/Nickel powder composite particle for effective bio-products adsorption by expanded bed chromatography.

    PubMed

    Asgari, Setareh; Jahanshahi, Mohsen; Rahimpour, Ahmad

    2014-09-26

    In the present work a novel kind of dense nanoporous composite matrix for expanded bed application has been successfully first prepared with Nickel powder as a densifier and was covered with Agar-Agar layer as a skeleton, through the method of water-in-oil emulsification. Agar-Agar is a porous and inexpensive polymer. In order to fabricate cost-effective adsorbent with favorable qualities Agar-Agar polymer was used. Thereafter, the customized composite particle was modified by pseudo-affinity dye-ligand, Reactive Blue 4 (RB4), aimed at preparing a pseudo-affinity adsorbent (RB4-Agar-Ni) for bioprodut adsorption from aqueous solution. Bovine Serum Albumin (BSA) was selected as a model protein to investigate the adsorption behavior in batchwise and expanded bed chromatography, and the obtained results were evaluated with that of Streamline™ (Amersham-Pharmacia Biotech, Sweden). Spherical appearance and porous structure of composite particles were observed by the optical microscope (OM) and scanning electronic microscope (SEM). The results suggested that the matrices followed the logarithmic normal size distribution with the range of 65-300 μm and average diameter of 126.81-151.47 μm, proper wet density of 1.64-2.78 g/ml, water content of 62.74-34%, porosity of 98-90% and pore size of about 38-130 nm. For better comprehension of the impact of solid phase properties on the performance of the expanded bed, the expansion and hydrodynamic properties of a composite matrix with a series of densities was evaluated and estimated by the retention time distribution method (RTD) in an expanded bed and was compared with that of other matrices. According to obtained results the expansion factors under the same fluid velocity decreased by increasing the matrix density. Moreover, the axial dispersion coefficient (Dax) is the most appropriate parameter for evaluating the stability of expanded bed, on various operating conditions, such as different flow velocity, bed expansion

  12. Simple protocol for secondary school hands-on activity: Electrophoresis of pre-stained nucleic acids on agar-agar borate gels.

    PubMed

    Britos, Leticia; Goyenola, Guillermo; Oroño, Silvia Umpiérrez

    2004-09-01

    An extremely simple, inexpensive, and safe method is presented, which emulates nucleic acids isolation and electrophoretic analysis as performed in a research environment, in the context of a secondary school hands-on activity. The protocol is amenable to an interdisciplinary approach, taking into consideration the electrical and chemical parameters of the electrophoretic system. Furthermore, the laboratory is framed in a more comprehensive pedagogical setting, which addresses the methodological aspects of a pivotal scientific enterprise such as the Human Genome Project. In this setting, the hands-on activity is complemented with animations, paper models, and discussions. Additionally, our results indicate that the use of borate buffer and agar-agar gels suits many of the experiments included in college-level laboratory activities, which currently make use of more expensive agarose gels and TBE or TAE buffers. PMID:21706751

  13. Robotic weld overlay coatings for erosion control. Quarterly technical progress report, July--September, 1994

    SciTech Connect

    Levin, B.F.; Dupont, J.N.; Marder, A.R.

    1994-10-26

    Research is presently being conducted to develop a criteria for selecting weld overlay coatings for erosion mitigation in Circulated Fluidized Beds. Initially, eleven weld overlay alloys were selected for erosion testing based upon a literature review. All eleven coatings were deposited on 1018 steel substrates using the plasma arc welding process. Ten samples from each coating were prepared for erosion testing. All selected coatings were erosion tested at 400 C and their erosion resistance was evaluated by determining the steady state erosion rate. In addition, the microstructure of each coating was characterized before and after the erosion tests. No correlations were found between room temperature hardness of the weld overlay coatings and their erosion resistance at elevated temperature. It was suggested that weld overlays mechanical properties such as fracture strength, toughness and work hardening rates may contributed to their erosion resistance. During the previous two quarters the microhardness tests were performed on the eroded samples in order to determine the size of the work hardened zone and the change in the coatings hardness due to erosion. As a result of these measurements it was established that one group of coatings deformed plastically, while another did not. In addition, the measurements of the weld overlays microhardness at 400 C were made. The coatings microhardness at 400 C was plotted versus their volume erosion rates. During the last quarter, erosion tests were performed for Inconel-625, 316L SS, and Iron-Aluminide wrought alloys in order to compare their erosion behavior with similar weld overlays. The results of microhardness profile measurements for all weld overlay coatings were analyzed. The factors that contribute to the erosion resistance of the coatings that deformed plastically are discussed in this progress report.

  14. Evaluation of Tizian overlays by means of a swept source optical coherence tomography system

    NASA Astrophysics Data System (ADS)

    Marcauteanu, Corina; Sinescu, Cosmin; Negrutiu, Meda Lavinia; Stoica, Eniko Tunde; Topala, Florin; Duma, Virgil Florin; Bradu, Adrian; Podoleanu, Adrian Gh.

    2016-03-01

    The teeth affected by pathologic attrition can be restored by a minimally invasive approach, using Tizian overlays. In this study we prove the advantages of a fast swept source (SS) OCT system in the evaluation of Tizian overlays placed in an environment characterized by high occlusal forces. 12 maxillary first premolars were extracted and prepared for overlays. The Tizian overlays were subjected to 3000 alternating cycles of thermo-cycling (from -10°C to +50°C) and to mechanical occlusal overloads (at 800 N). A fast SS OCT system was used to evaluate the Tizian overlays before and after the mechanical and thermal straining. The SS (Axsun Technologies, Billerica, MA) has a central wavelength of 1060 nm, sweeping range of 106 nm (quoted at 10 dB) and a 100 kHz line rate. The depth resolution of the system, measured experimentally in air was 10 μm. The imaging system used for this study offers high spatial resolutions in both directions, transversal and longitudinal of around 10 μm, a high sensitivity, and it is also able to acquire entire tridimensional (3D)/volume reconstructions as fast as 2.5 s. Once the full dataset was acquired, rendered high resolutions en-face projections could be produced. Using them, the overlay (i.e., cement) abutment tooth interfaces were remarked both on B-scans/two-dimensional (2D) sections and in the 3D reconstructions. Using the system several open interfaces were possible to detect. The fast SS OCT system thus proves useful in the evaluation of zirconia reinforced composite overlays, placed in an environment characterized by high occlusal forces.

  15. Effect of Diethylaminoethyl Dextran on the Growth of Mycoplasma in Agar

    PubMed Central

    Tauraso, Nicola M.

    1967-01-01

    The growth of certain strains of Mycoplasma is inhibited by substances present in commercial agar preparations. The addition of diethylaminoethyl (DEAE) dextran (10 mg per 100 ml) to agar media appears to enhance the growth of some strains. Of eight strains initially tested, the presence of DEAE dextran grossly enhanced the growth of three strains. One strain appeared not to be affected, and a clearly enhancing effect was not evident with four strains. Quantitative studies revealed that growth enhancement varied from 10 colony-forming units (CFU) for M. hominis type II (strain Campo) to 103.3 CFU for M. pulmonis (strain 880). The growth-enhancing effect is probably due to the ability of DEAE dextran to bind the sulfated polysaccharide moieties in agar and not to the DEAE dextran, per se. Images PMID:6025444

  16. An agar diffusion study comparing the antimicrobial activity of Nanoseal with some other endodontic sealers.

    PubMed

    Aal-Saraj, Ali Burak; Ariffin, Zaihan; Masudi, Sam'an Malik

    2012-08-01

    The aim of this study was to evaluate the antimicrobial activity of a new experimental nano-hydroxyapatite epoxy resin-based sealer (Nanoseal) with several other commercially available sealers; AH26, Tubliseal, Sealapex and Roekoseal against Enterococcus faecalis, Pseudomonas aeruginosa, Streptococcus mutans, Streptococcus sobrinus and Escherichia coli for up to 7 days. Agar diffusion was used in this study. Fifty Muller-Hinton agar plates were prepared and divided into five experimental groups (n = 10), for each micro-organism. Another 10 agar plates were used as positive and negative controls. Endodontic sealers were tested against each micro-organism. Inhibition zones produced were recorded. The results of this study showed that all test materials exhibited inhibition zones towards the tested micro-organisms for 7 days except for Roekoseal, which showed no inhibition zones. Nanoseal and AH26 exhibited similar zones of inhibition. Significant difference was found between Nanoseal and the other tested sealers (P < 0.001). PMID:22827817

  17. Blood agar to detect virulence factors in tap water heterotrophic bacteria.

    PubMed Central

    Payment, P; Coffin, E; Paquette, G

    1994-01-01

    Cytolytic colonies were found in 57% of tap water samples, and up to 6% of samples were found to contain bacteria having three or more virulence factors. The factors evaluated were cytotoxicity, hemolysis, cell adherence, and cell invasiveness. Overall, 17% of the samples contained cytolytic colonies that were adherent and hemolytic. Among the media tested, tryptic soy agar with sheep blood (incubated at 35 degrees C for 48 h) was the best medium for the detection of cytolytic colonies. Of the colonies growing on this medium, 13% were cytolytic, whereas on medium R2A, less than 3% were cytolytic. Furthermore, when tryptic soy agar with blood was used, 24% of the samples contained colonies with at least three virulence factors whereas only 5% were positive with R2A. Routine monitoring by using tryptic soy agar with sheep blood is suggested as an appropriate procedure for the detection of bacteria with pathogenic potential in drinking water. PMID:8017913

  18. [DNA and chemical analyses of commercial fly agaric-related products].

    PubMed

    Maruyama, Takuro; Kawahara, Nobuo; Fukiharu, Toshimitsu; Yokoyama, Kazumasa; Makino, Yukiko; Goda, Yukihiro

    2005-04-01

    Since June 6, 2002, psilocin and psilocybin-containing fungi (commonly called "magic mushrooms") have been regulated by the Narcotics and Psychotropics Control Law in Japan. However, various fly agaric-related products are now entering the Japanese market via the internet. In this study, fly agaric-related products available in this way were investigated for raw materials by DNA analysis and for additives by chemical analysis. Nucleotide sequence analysis of the mitochondrial 12S rDNA region suggested that these fly agaric-related products originate from A. muscaria or A. muscaria var. persicina. Furthermore, they were classified into three strains based on the ITS2-LSU nucleotide sequence. Harmine derivatives and/or tryptamine derivatives were detected in some of these products by LC/MS analysis. In accordance with this, the matK gene of Peganum harmala was found in all of the harmine derivative-containing samples. PMID:16018591

  19. Growth kinetics of Salmonella enterica in Hajna tetrathionate broth, Rappaport broth and modified semisolid Rappaport agar

    PubMed Central

    FUJIHARA, Masatoshi; TABUCHI, Hiroyuki; UEGAKI, Kaho

    2015-01-01

    To determine the appropriate method for isolating Salmonella enterica, we compared the growth of S. enterica serovars using three selective enrichment media. S. enterica was more successfully isolated from artificially contaminated fecal samples after enrichment in Hajna tetrathionate broth or modified semisolid Rappaport agar than in Rappaport broth. Since most bacteria (other than motile S. enterica) do not migrate on modified semisolid Rappaport agar, the growth characteristics of S. enterica can be interpreted easily and quickly. Two S. enterica isolates did not migrate on modified semisolid Rappaport agar, but did grow in Hajna tetrathionate broth, which suggests that the combined use of these selective enrichment media is appropriate for isolating S. enterica. PMID:26498402

  20. Asphalt overlay design methods for rigid pavements considering rutting, reflection cracking, and fatigue cracking. Research report September 1996--August 1997

    SciTech Connect

    Cho, Y.H.; Liu, C.; Dossey, T.; McCullough, B.F.

    1998-10-01

    An asphalt concrete pavement (ACP) overlay over a rigid pavement represents a viable rehabilitation strategy. It can provide good serviceability at an initial construction cost that is substantially less than that of a rigid overlay rehabilitation. In addition, ACP overlays require less construction time, which can reduce user costs during construction. However, it may not be the most economical solution for long-term rehabilitation. Because of their relatively short service life, ACP overlays may require maintenance sooner than rigid overlays. And one of the more critical distresses that effectively determine the life span of the structure is reflection cracking. This report investigates alternative strategies that seek to prevent reflection cracking on ACP overlays.

  1. Assessment of Etest as an alternative to agar dilution for antimicrobial susceptibility testing of Neisseria gonorrhoeae.

    PubMed

    Liu, Hsi; Taylor, Thomas H; Pettus, Kevin; Trees, David

    2014-05-01

    We studied whether the Etest can be used as an alternative to agar dilution to determine antimicrobial susceptibilities of ceftriaxone, cefixime, and cefpodoxime in Neisseria gonorrhoeae surveillance. One hundred fifteen clinical and laboratory isolates of N. gonorrhoeae were tested following the Clinical Laboratory Improvement Amendments (CLIA)-approved CLSI standard agar dilution method and, separately, by the Etest according to the manufacturer's recommendations. The MICs were determined and compared. Ten laboratory-generated mutants were used to simulate substantially nonsusceptible specimens. The Etest and agar dilution methods were well correlated. Statistical tests produced regression R2 values of 88%, 82%, and 85% and Pearson correlation coefficients of 92%, 91%, and 92% for ceftriaxone, cefixime, and cefpodoxime, respectively. When paired comparisons were made, the two tests were 88.7%, 80%, and 87% within 1 log2 dilution from each other for ceftriaxone, cefixime, and cefpodoxime, respectively. The within-2-log2 agreements were 99.1%, 98.3%, and 94.8% for ceftriaxone, cefixime, and cefpodoxime, respectively. Notwithstanding the good correlations and the within-2-log2 general agreement, the Etest results produced slightly lower MICs than the agar dilution results. In conclusion, we found that the Etest can be effectively used as an alternative to agar dilution testing to determine the susceptibility of N. gonorrhoeae to ceftriaxone, cefixime, and cefpodoxime, although we recommend further research into extremely resistant isolates. For isolates within the typical range of clinical MICs, reexamination of the Etest interpretation of susceptible and nonsusceptible categories would likely allow for successful transition from agar dilution to the Etest. PMID:24554750

  2. Assessment of Etest as an Alternative to Agar Dilution for Antimicrobial Susceptibility Testing of Neisseria gonorrhoeae

    PubMed Central

    Taylor, Thomas H.; Pettus, Kevin; Trees, David

    2014-01-01

    We studied whether the Etest can be used as an alternative to agar dilution to determine antimicrobial susceptibilities of ceftriaxone, cefixime, and cefpodoxime in Neisseria gonorrhoeae surveillance. One hundred fifteen clinical and laboratory isolates of N. gonorrhoeae were tested following the Clinical Laboratory Improvement Amendments (CLIA)-approved CLSI standard agar dilution method and, separately, by the Etest according to the manufacturer's recommendations. The MICs were determined and compared. Ten laboratory-generated mutants were used to simulate substantially nonsusceptible specimens. The Etest and agar dilution methods were well correlated. Statistical tests produced regression R2 values of 88%, 82%, and 85% and Pearson correlation coefficients of 92%, 91%, and 92% for ceftriaxone, cefixime, and cefpodoxime, respectively. When paired comparisons were made, the two tests were 88.7%, 80%, and 87% within 1 log2 dilution from each other for ceftriaxone, cefixime, and cefpodoxime, respectively. The within-2-log2 agreements were 99.1%, 98.3%, and 94.8% for ceftriaxone, cefixime, and cefpodoxime, respectively. Notwithstanding the good correlations and the within-2-log2 general agreement, the Etest results produced slightly lower MICs than the agar dilution results. In conclusion, we found that the Etest can be effectively used as an alternative to agar dilution testing to determine the susceptibility of N. gonorrhoeae to ceftriaxone, cefixime, and cefpodoxime, although we recommend further research into extremely resistant isolates. For isolates within the typical range of clinical MICs, reexamination of the Etest interpretation of susceptible and nonsusceptible categories would likely allow for successful transition from agar dilution to the Etest. PMID:24554750

  3. Interactive multimodality display environment with photographic overlay enhancement for epilepsy surgical planning

    NASA Astrophysics Data System (ADS)

    Wang, An; Mirsattari, Seyed; Gobbi, David G.; Bihari, Frank; Das, Piali; Zhang, Qi; Peters, Terry M.

    2008-03-01

    We describe an interactive multimodality display environment, which combines anatomic CT, MRI, functional MRI images and photographs taken during surgical procedures, to provide comprehensive localization information regarding epilepsy seizure foci and the context of their surroundings. Our environment incorporates several unique features, including GPU-accelerated volume rendering and image fusion, versatile GPU-based clipping of volumetric images, and the ability to enhance the information delivered to the surgeon by fusing a direct (photographic) view of the surgical field with the volumetric image. We employ direct volume rendering for the fusion of multiple volumes using GPU-accelerated ray-casting. In addition, to expose the internal structures during volume fusion, we have developed user interaction tools that enable the surgeon to explore the fused volume using clipping-cube and cutaway clipping schemes. The fusion of intraoperative images onto the image volume allows enhanced visualization of the surgical procedure sites within the surgical planning environment. These techniques have been implemented as Visualization Toolkit (VTK) classes using the OpenGL fragment shading program and Python modules, and have been successfully implemented within our surgical planning environment "EpilepsyViewer". The results and performance of our GPU-based approach are compared with similar techniques in VTK, demonstrating that the use of the GPU can greatly accelerate visualization and enable increased flexibility of the system in the operating room. The result of photographic overlay shows good correspondence between the intraoperative photograph images and the preoperative image model. This environment can also be extended for use in other neurosurgical planning tasks.

  4. Serogroup identification of Neisseria meningitidis: comparison of an antiserum agar method with bacterial slide agglutination.

    PubMed Central

    Craven, D E; Frasch, C E; Robbins, J B; Feldman, H A

    1978-01-01

    A serum agar method for serogrouping Neisseria meningitidis is described and compared with conventional bacterial slide agglutination. There was 93% agreement for 300 strains examined individually by each method. Among strains from serogroups A, B, C, Y, and W135, there was 100% correlation, whereas strains from serogroup 29E (Z') had only 67% correlation. The serum agar method was rapid, as well as easy to perform and interpret. The potential benefits of this method for epidemiological studies and reference laboratories processing large numbers of meningococcal isolates are emphasized. Images PMID:96123

  5. Casein Agar: a Useful Medium for Differentiating Candida dubliniensis from Candida albicans

    PubMed Central

    Mosca, Christian O.; Moragues, María D.; Llovo, José; Al Mosaid, Asmaa; Coleman, David C.; Pontón, José

    2003-01-01

    Production of chlamydospores on casein agar at 24°C for 48 h provides a simple means for differentiating Candida dubliniensis from Candida albicans based on chlamydospore production. Of 109 C. dubliniensis isolates tested on this medium, 106 (97.2%) produced abundant chlamydospores and three produced few chlamydospores. In contrast, of the 120 C. albicans isolates tested, 111 (92.5%) failed to produce any chlamydospores, whereas the remaining nine isolates produced few chlamydospores. These findings indicate that abundant chlamydospore production on casein agar is a useful test for discriminating between C. dubliniensis and C. albicans. PMID:12624062

  6. Compensation of overlay errors due to mask bending and non-flatness for EUV masks

    NASA Astrophysics Data System (ADS)

    Chandhok, Manish; Goyal, Sanjay; Carson, Steven; Park, Seh-Jin; Zhang, Guojing; Myers, Alan M.; Leeson, Michael L.; Kamna, Marilyn; Martinez, Fabian C.; Stivers, Alan R.; Lorusso, Gian F.; Hermans, Jan; Hendrickx, Eric; Govindjee, Sanjay; Brandstetter, Gerd; Laursen, Tod

    2009-03-01

    EUV blank non-flatness results in both out of plane distortion (OPD) and in-plane distortion (IPD) [3-5]. Even for extremely flat masks (~50 nm peak to valley (PV)), the overlay error is estimated to be greater than the allocation in the overlay budget. In addition, due to multilayer and other thin film induced stresses, EUV masks have severe bow (~1 um PV). Since there is no electrostatic chuck to flatten the mask during the e-beam write step, EUV masks are written in a bent state that can result in ~15 nm of overlay error. In this article we present the use of physically-based models of mask bending and non-flatness induced overlay errors, to compensate for pattern placement of EUV masks during the e-beam write step in a process we refer to as E-beam Writer based Overlay error Correction (EWOC). This work could result in less restrictive tolerances for the mask blank non-flatness specs which in turn would result in less blank defects.

  7. Image-based overlay (IBO) target segment design on self-aligned patterning process

    NASA Astrophysics Data System (ADS)

    Ye, Lei; Hu, Huayong; He, Weiming

    2016-03-01

    Self-Aligned Double Patterning (SADP) is widely applied in advanced sub-4X patterning technology, especially for the 1D resolution shrinkage of memory technology. As the application of SADP makes lithography minimum pitch down to half of design pitch with the remaining spacer aside core, its alignment mark and overlay (OVL) mark have to be well-segmented to ensure enough mark contrast. In this paper, we designed two types of image-based overlay (IBO) bar in bar (BIB) OVL target: bar-segmentation and background-segmentation with different duty ratio. Based on these two designed types of marks, we focus on the OVL of 2nd photo layer to 1st SADP layer with the core removed (which means spacer grating structure remained). We studied the effect of the overlay target segmentation on the precision and robustness of wafer-level overlay performance. Different lithography processes were also studied, including single layer lithography and tri-layer lithography with planarized spacer grating structures. We found there are strong correlations between overlay measurement accuracy and background segmentation rules. The results of our study will be presented and discussed in this paper.

  8. Robotic weld overlay coatings for erosion control. Quarterly technical progress report, January 1994--March 1994

    SciTech Connect

    Levin, B.F.; Dupont, J.N.; Marder, A.R.

    1994-04-21

    The erosion of materials by the impact of solid particles has received increasing attention during the past twenty years. Recently, research has been initiated with the event of advanced coal conversion processes in which erosion plays an important role. The resulting damage, termed Solid Particle Erosion (SPE), is of concern primarily because of the significantly increased operating costs which result in material failures. Reduced power plant efficiency due to solid particle erosion of boiler tubes and waterwalls has led to various methods to combat SPE. One method is to apply coatings to the components subjected to erosive environments. Protective weld overlay coatings are particularly advantageous in terms of coating quality. The weld overlay coatings are essentially immune to spallation due to a strong metallurgical bond with the substrate material. By using powder mixtures, multiple alloys can be mixed in order to achieve the best performance in an erosive environment. However, a review of the literature revealed a lack of information on weld overlay coating performance in erosive environments which makes the selection of weld overlay alloys a difficult task. The objective of this project is to determine the effects of weld overlay coating composition and microstructure on erosion resistance. These results will lead to a better understanding of erosion mitigation in circulated fluidized beds.

  9. Implementation and benefits of advanced process control for lithography CD and overlay

    NASA Astrophysics Data System (ADS)

    Zavyalova, Lena; Fu, Chong-Cheng; Seligman, Gary S.; Tapp, Perry A.; Pol, Victor

    2003-05-01

    Due to the rapidly reduced imaging process windows and increasingly stingent device overlay requirements, sub-130 nm lithography processes are more severely impacted than ever by systamic fault. Limits on critical dimensions (CD) and overlay capability further challenge the operational effectiveness of a mix-and-match environment using multiple lithography tools, as such mode additionally consumes the available error budgets. Therefore, a focus on advanced process control (APC) methodologies is key to gaining control in the lithographic modules for critical device levels, which in turn translates to accelerated yield learning, achieving time-to-market lead, and ultimately a higher return on investment. This paper describes the implementation and unique challenges of a closed-loop CD and overlay control solution in high voume manufacturing of leading edge devices. A particular emphasis has been placed on developing a flexible APC application capable of managing a wide range of control aspects such as process and tool drifts, single and multiple lot excursions, referential overlay control, 'special lot' handling, advanced model hierarchy, and automatic model seeding. Specific integration cases, including the multiple-reticle complementary phase shift lithography process, are discussed. A continuous improvement in the overlay and CD Cpk performance as well as the rework rate has been observed through the implementation of this system, and the results are studied.

  10. Design and development of a mobile image overlay system for needle interventions.

    PubMed

    Anand, M; King, F; Ungi, T; Lasso, A; Rudan, J; Jayender, J; Fritz, J; Carrino, J A; Jolesz, F A; Fichtinger, G

    2014-01-01

    Previously, a static and adjustable image overlay systems were proposed for aiding needle interventions. The system was either fixed to a scanner or mounted over a large articulated counterbalanced arm. Certain drawbacks associated with these systems limited the clinical translation. In order to minimize these limitations, we present the mobile image overlay system with the objective of reduced system weight, smaller dimension, and increased tracking accuracy. The design study includes optimal workspace definition, selection of display device, mirror, and laser source. The laser plane alignment, phantom design, image overlay plane calibration, and system accuracy validation methods are discussed. The virtual image is generated by a tablet device and projected into the patient by using a beamsplitter mirror. The viewbox weight (1.0 kg) was reduced by 8.2 times and image overlay plane tracking precision (0.21 mm, STD = 0.05) was improved by 5 times compared to previous system. The automatic self-calibration of the image overlay plane was achieved in two simple steps and can be done away from patient table. The fiducial registration error of the physical phantom to scanned image volume registration was 1.35 mm (STD = 0.11). The reduced system weight and increased accuracy of optical tracking should enable the system to be hand held by the physician and explore the image volume over the patient for needle interventions. PMID:25571403

  11. Diffraction-based overlay measurement on dedicated mark using rigorous modeling method

    NASA Astrophysics Data System (ADS)

    Lu, Hailiang; Wang, Fan; Zhang, Qingyun; Chen, Yonghui; Zhou, Chang

    2012-03-01

    Diffraction Based Overlay (DBO) is widely evaluated by numerous authors, results show DBO can provide better performance than Imaging Based Overlay (IBO). However, DBO has its own problems. As well known, Modeling based DBO (mDBO) faces challenges of low measurement sensitivity and crosstalk between various structure parameters, which may result in poor accuracy and precision. Meanwhile, main obstacle encountered by empirical DBO (eDBO) is that a few pads must be employed to gain sufficient information on overlay-induced diffraction signature variations, which consumes more wafer space and costs more measuring time. Also, eDBO may suffer from mark profile asymmetry caused by processes. In this paper, we propose an alternative DBO technology that employs a dedicated overlay mark and takes a rigorous modeling approach. This technology needs only two or three pads for each direction, which is economic and time saving. While overlay measurement error induced by mark profile asymmetry being reduced, this technology is expected to be as accurate and precise as scatterometry technologies.

  12. Interaction of nanostructured metal overlayers with oxide surfaces

    NASA Astrophysics Data System (ADS)

    Fu, Qiang; Wagner, Thomas

    2007-11-01

    Interactions between metals and oxides are key factors to determine the performance of metal/oxide heterojunctions, particularly in nanotechnology, where the miniaturization of devices down to the nanoregime leads to an enormous increase in the density of interfaces. One central issue of concern in engineering metal/oxide interfaces is to understand and control the interactions which consist of two fundamental aspects: (i) interfacial charge redistribution — electronic interaction, and (ii) interfacial atom transport — chemical interaction. The present paper focuses on recent advances in both electronic and atomic level understanding of the metal-oxide interactions at temperatures below 1000 ∘C, with special emphasis on model systems like ultrathin metal overlayers or metal nanoclusters supported on well-defined oxide surfaces. The important factors determining the metal-oxide interactions are provided. Guidelines are given in order to predict the interactions in such systems, and methods to desirably tune them are suggested. The review starts with a brief summary of the physics and chemistry of heterophase interface contacts. Basic concepts for quantifying the electronic interaction at metal/oxide interfaces are compared to well-developed contact theories and calculation methods. The chemical interaction between metals and oxides, i.e., the interface chemical reaction, is described in terms of its thermodynamics and kinetics. We review the different chemical driving forces and the influence of kinetics on interface reactions, proposing a strong interplay between the chemical interaction and electronic interaction, which is decisive for the final interfacial reactivity. In addition, a brief review of solid-gas interface reactions (oxidation of metal surfaces and etching of semiconductor surfaces) is given, in addition to a comparison of a similar mechanism dominating in solid-solid and solid-gas interface reactions. The main body of the paper reviews

  13. Effects of indium and tin overlayers on the photoluminescence spectrum of mercuric iodide

    NASA Astrophysics Data System (ADS)

    James, R. B.; Bao, X. J.; Schlesinger, T. E.; Ortale, C.; Cheng, A. Y.

    1990-03-01

    Mercuric iodide (HgI2 ) crystals with semitransparent metal overlayers of indium and tin were characterized using low-temperature photoluminescence (PL) spectroscopy. The PL spectra were found to differ for points beneath the thin metal overlayers and points that were masked off during each deposition. The photoluminescence data were compared with PL measurements taken on HgI2 photodetectors with indium-tin-oxide (ITO) entrance electrodes. The similarities of the spectra for the HgI2 samples with In, Sn, and ITO conducting overlayers indicate that the regions in the ITO-contacted photodetectors with relatively poor photoresponses are associated with the interaction of indium or tin with the mercuric iodide substrate.

  14. Characterizing the Global Impact of P2P Overlays on the AS-Level Underlay

    NASA Astrophysics Data System (ADS)

    Rasti, Amir Hassan; Rejaie, Reza; Willinger, Walter

    This paper examines the problem of characterizing and assessing the global impact of the load imposed by a Peer-to-Peer (P2P) overlay on the AS-level underlay. In particular, we capture Gnutella snapshots for four consecutive years, obtain the corresponding AS-level topology snapshots of the Internet and infer the AS-paths associated with each overlay connection. Assuming a simple model of overlay traffic, we analyze the observed load imposed by these Gnutella snapshots on the AS-level underlay using metrics that characterize the load seen on individual AS-paths and by the transit ASes, illustrate the churn among the top transit ASes during this 4-year period, and describe the propagation of traffic within the AS-level hierarchy.

  15. 40-Gb/s FSK modulated WDM-PON with variable-rate multicast overlay.

    PubMed

    Xin, Xiangjun; Liu, Bo; Zhang, Lijia; Yu, Jianjun

    2011-06-20

    This paper proposes a novel conjugate-driven frequency shift keying (FSK) modulated wavelength division multiplexing passive network (WDM-PON) with variable-rate multicast services. Optical orthogonal frequency division multiplexing (OFDM) is adopted for multicast overlay services with different rate requirements. A differential detection is used for the demodulation of FSK signal, which can eliminate the crosstalk from the OFDM signal. A total 40-Gb/s FSK point to point (P2P) signal and 6.3-Gb/s OFDM overlay with three kinds of variable-rate multicast services are experimentally demonstrated. A physical-layer adaptive identification is proposed for the variable-rate multicast services. After 25 km single mode fiber (SMF) transmission, the power penalties of FSK P2P signal and OFDM multicast overlay are 1.3 dB and 1.7 dB respectively. PMID:21716492

  16. High strength and corrosion resistant alloys weld overlays for oil patch applications

    SciTech Connect

    Hibner, E.L.; Maligas, M.N.; Vicic, J.C.

    1995-10-01

    Corrosion resistant alloys (CRAs) are specified for oilfield applications where severe environments cause general corrosion, pitting, crevice corrosion, chloride stress corrosion cracking and more importantly sulfide stress cracking. Historically, alloy 625 (UNS N06625) weld overlay has successfully been used in severely corrosive environments. Alloy 686 (UNS N06686) and alloy 725 (UNS N07725) have recently been evaluated as replacement materials for alloy 625. Alloy 686, because of it`s high alloying content, exhibits superior corrosion resistance to alloy 625. And, alloy 725 is a highly corrosion resistant alloy capable of being age hardened to 0.2% yield strengths of above 827 MPa (120 ksi) Mechanical properties and Slow Strain Rate test results for the alloy 686 and alloy 725 weld overlays are discussed relative to alloy 625, alloy C-22 (UNS N06622) and alloy 59 (UNS N06059) weld overlays.

  17. Threshold analysis of the susceptible-infected-susceptible model on overlay networks

    NASA Astrophysics Data System (ADS)

    Wu, Qingchu; Zhang, Haifeng; Small, Michael; Fu, Xinchu

    2014-07-01

    In this paper, we study epidemic spreading on overlay networks in which n multiple sets of links interconnect among the same nodes. By using the microscopic Markov-chain approximation (MMA) approach, we establish the conditions of epidemic outbreak for two kinds of spreading mechanisms in such an overlay network: the concatenation case and the switching case. When a uniform infection rate is set in all the subnetworks, we find the epidemic threshold for the switching case is just n times as large as that of concatenation case. We also find that the overlay network with a uniform infection rate can be considered as an equivalent (in the sense of epidemic dynamics and epidemic threshold) weighted network. To be specific, the concatenation case corresponds to the integer weighted network, while the switching case corresponds to the fractional weighted network. Interestingly, the time-varying unweighted network can be mapped into the static weighted network. Our analytic results exhibit good agreement with numerical simulations.

  18. Weld overlay coatings for erosion control. Task A: Literature review, progress report

    SciTech Connect

    Levin, B.; DuPont, J.N.; Marder, A.R.

    1993-03-03

    A literature review was made. In spite of similarities between abrasive wear and solid particle erosion, weld overlay hardfacing alloys that exhibit high abrasion resistance may not necessarily have good erosion resistance. The performance of weld overlay hardfacing alloys in erosive environments has not been studied in detail. It is believed that primary-solidified hard phases such as carbides and intermetallic compounds have a strong influence on erosion resistance of weld overlay hardfacing alloys. However, relationships between size, shape, and volume fraction of hard phases in a hardfacing alloys and erosion resistance were not established. Almost all hardfacing alloys can be separated into two major groups based upon chemical compositions of the primary solidified hard phases: (a) carbide hardening alloys (Co-base/carbide, WC-Co and some Fe base superalloys); and (b) intermetallic hardening alloys (Ni-base alloys, austenitic steels, iron-aluminides).

  19. Applying Agar's Concept of "Languaculture" to Explain Asian Students' Experiences in the Australian Tertiary Context

    ERIC Educational Resources Information Center

    Norris, Lindy; Tsedendamba, Nara

    2015-01-01

    This paper reports part of a broader qualitative case study of Asian students "translation" (Agar, 2006) to study in an Australian university. The paper is concerned with the experiences of eight participants and their involvement in a training programme in the use of language learning strategies (LLS) to support their engagement with…

  20. THE MICROGARDENING COOKBOOK, DIRECTIONS FOR PREPARING DISHES AND TUBES OF STERILE NUTRIENT AGAR.

    ERIC Educational Resources Information Center

    CHANDLER, MARION N.

    THIS BOOKLET WAS PREPARED FOR TEACHER USE IN ASSOCIATION WITH THE ELEMENTARY SCIENCE STUDY UNIT "MICROGARDENING." IT CONTAINS DIRECTIONS FOR PREPARING CULTURE DISHES AND TUBES OF NUTRIENT STERILE AGAR FOR FUNGAL AND/OR BACTERIAL GROWTH. IT INCLUDES (1) LISTS OF NEEDED SUPPLIES AND EQUIPMENT, (2) DIRECTIONS FOR THE PREPARATION AND STERILIZATION OF…

  1. Comparison of the antibacterial activity of chelating agents using the agar diffusion method

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The agar diffusion assay was used to examine antibacterial activity of 2 metal chelators. Concentrations of 0 to 40 mM of ethylenediaminetetraacetic acid (EDTA) and ethylenediamine-N,N’-disuccinic acid (EDDS) were prepared in 1.0 M potassium hydroxide (KOH). The pH of the solutions was adjusted to 1...

  2. Mercury in fruiting bodies of Fly Agaric Amanita muscaria (L.: Fr.) Pers. collected from Poland

    NASA Astrophysics Data System (ADS)

    Falandysz, J.; Lipka, K.

    2003-05-01

    Total mercury concentrations were determined in the fruiting bodies of Fly Agaric Amanita muscaria (L.: FL) Pers. and underlying soil substrate collected from several sites in Poland in 1993-2000 to evaluate mercury status as contaminant and bioindicating features of this species. The samples were collected from the spatially distant sites such as: Zaborski Landscape Park, Mierzeja Wiślana Landscape Park, Wdzydzki Landscape Park, Borecka Forest, Tucholskie Forest, Wieluńska Upland, the communities of Gubin, Manowo, Lubiana and Morag. Total mercury content of caps and stalks of Fly agaric varied widely depending on the sites examined. The range of the mean mercury concentrations for all 17 sites was between 96±10 and 1900±1400 ng/g dry wt for the caps and between 6l±32 and 920±760 ng/g dry wt for the stalks, while between 4.4±3.1 and 150±20 ng/g were noted for soil substrate samples from 9 sites examined. Fly agaric independently of the site examined showed relatively good capacity to accumulate total mercury and BCF values varied between 16±10 and 74±15 for the caps and between 11±8 and 42±10 for the stalks. Nevertheless, relatively high bioconcentration potential of mercury by Fly agaric seems to be specific for that species and under soil mercury concentrations noted no bioindication properties of this mushroom could be observed.

  3. Seasonal variation in the biomass and agar yield from Gracilaria cervicornis and Hydropuntia cornea from Brazil.

    PubMed

    Marinho-Soriano, E; Silva, T S; Moreira, W S

    2001-04-01

    Seasonality of biomass and agar yield from two agarophytes (G. cervicornis and H. cornea) was determined. The biomass from G. cervicornis was higher (390 g m-2) during the dry season and lower during the rainy season (129 g m-2). The data analysis for G. cervicornis revealed a significant seasonal variation (P < 0.05). H. cornea did not show a clear seasonal variation and was present only from March to August. The peak in biomass for this species was recorded in April (383 g m-2) and was significantly different from the other months (P < 0.05). The agar yield for G. cervicornis varied from 11% to 20%, with generally higher values recorded during the dry season. The agar yield showed a highly significant variation (P < 0.001). Agar yield from H. cornea ranged from 29% to 41%, with a peak recorded in June. The results above indicate that H. cornea can be considered a good candidate for commercial use. PMID:11272017

  4. Radiation survival of murine and human melanoma cells utilizing two assay systems: monolayer and soft agar.

    PubMed Central

    Yohem, K. H.; Slymen, D. J.; Bregman, M. D.; Meyskens, F. L.

    1988-01-01

    The radiation response of murine and human melanoma cells assayed in bilayer soft agar and monolayer was examined. Cells from the murine melanoma Cloudman S91 CCL 53.1 cell line and three human melanoma cell strains (C8146C, C8161, and R83-4) developed in our laboratory were irradiated by single dose X-rays and plated either in agar or on plastic. D0 values were the same within 95% confidence intervals for cells from the human melanoma cell strains C8146C, C8161, and R83-4 but were dissimilar for the murine cell line CCL 53.1 Dq values were different for all cells studied. The shape of the survival curve for all four melanomas was not identical for cells assayed in soft agar versus cells grown on plastic. This would indicate that apparent radiosensitivity was influenced by the method of assay although there were no apparent consistent differences between the curves generated by monolayer or bilayer soft agar assays. PMID:3348949

  5. EFFECT OF IMPACT STRESS ON MICROBIAL RECOVERY ON AN AGAR SURFACE

    EPA Science Inventory

    Microbial stress due to the impaction of microorganisms onto an agar collection surface was studied experimentally. he relative recovery rates of aerosolized Pseudomonas fluorescens and Micrococcus luteus were determined as a function of the impaction velocity by using a moving a...

  6. A Method for Cell Culture and Maintenance of Ammonia-Oxidizing Archaea in Agar Stab.

    PubMed

    Chu, Yeon-Jin; Lee, Jin-Young; Shin, So-Ra; Kim, Geun-Joong

    2015-12-01

    Ammonia oxidizing archaea (AOA) are predominantly found and closely linked with geochemical cycling of nitrogen in non-extreme habitats. However, these strains have mainly been investigated using liquid cultures of enriched cells. Here, we provide an agar stab as a simple and reliable means of cultivating and maintaining AOA. PMID:26543273

  7. Evolutionary consequences of putative intra- and interspecific hybridization in agaric fungi

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Agaric fungi of the southern Appalachians including the Great Smoky Mountains National Park are often heterozygous for the rDNA internal transcribed spacer region (ITS) with >42% of collections showing some level of heterozygosity for indels and/or base-pair substitutions. For these collections, int...

  8. Fishmeal extract bile salt lactose agar--a differential medium for enteric bacteria.

    PubMed

    Subbannayya, K; Udayalaxmi, J; Anugraha, M

    2006-08-01

    Fishmeal extract bile salt lactose agar (FEBLA), a new differential medium for enteric bacteria was developed and evaluated for its ability to grow and differentiate lactose fermenters (LF) from non-lactose fermenters (NLF) in comparison with MacConkeys agar. Performance of FEBLA was at par with the latter. On FEBLA medium, the contrast between LF and NLF colonies was pronounced and Klebsiella pneumoniae produced more mucoid colonies than on MacConkeys agar (Hi Media). Unlike MacConkeys agar, a 24 h culture of K. pneumoniae cells on FEBLA were longer and thicker with abundant capsular material around the bacilli. Escherichia coli produced long and thick cells but only after 48h. No change in cell morphology was evident with regard to Salmonella typhi, S. paratyphi A, Shigella flexneri, Pseudomonas aeruginosa, Proteus mirabilis, Proteus vulgaris, Citrobacter koseri and Acinetobacter baumannii. Performance of the medium was controlled using E. coli and S. flexneri. FEBLA is simple, cost effective and may be a suitable alternative in the preliminary identification of enteric bacteria. PMID:16924840

  9. MODIFIED AGAR MEDIUM FOR DETECTING ENVIRONMENTAL SALMONELLAE BY THE MOST-PROBABLE-NUMBER METHOD

    EPA Science Inventory

    Salmonellae in the environment remain a potential source of disease. Low numbers of salmonellae have been detected and enumerated from environmental samples by most probable number methods that require careful colony selection from plated agar medium. A modified xylose lysine bri...

  10. Alternative plasticizers for the production of thermo-compressed agar films

    Technology Transfer Automated Retrieval System (TEKTRAN)

    One percent agar (% wt) was dissolved in the deep eutectic solvent (DES), (2-hydroxyethyl) trimethylammonium chloride/urea at a 1:2 molar ratio, and successfully Electrospun into nanofibers. An existing electrospinning set-up, operated at 50 deg C, was adapted for use with an ethanol bath to collect...

  11. Investigation of dental alginate and agar impression materials as a brain simulant for ballistic testing.

    PubMed

    Falland-Cheung, Lisa; Piccione, Neil; Zhao, Tianqi; Lazarjan, Milad Soltanipour; Hanlin, Suzanne; Jermy, Mark; Waddell, J Neil

    2016-06-01

    Routine forensic research into in vitro skin/skull/brain ballistic blood backspatter behavior has traditionally used gelatin at a 1:10 Water:Powder (W:P) ratio by volume as a brain simulant. A limitation of gelatin is its high elasticity compared to brain tissue. Therefore this study investigated the use of dental alginate and agar impression materials as a brain simulant for ballistic testing. Fresh deer brain, alginate (W:P ratio 91.5:8.5) and agar (W:P ratio 81:19) specimens (n=10) (11×22×33mm) were placed in transparent Perspex boxes of the same internal dimensions prior to shooting with a 0.22inch caliber high velocity air gun. Quantitative analysis to establish kinetic energy loss, vertical displacement elastic behavior and qualitative analysis to establish elasticity behavior was done via high-speed camera footage (SA5, Photron, Japan) using Photron Fastcam Viewer software (Version 3.5.1, Photron, Japan) and visual observation. Damage mechanisms and behavior were qualitatively established by observation of the materials during and after shooting. The qualitative analysis found that of the two simulant materials tested, agar behaved more like brain in terms of damage and showed similar mechanical response to brain during the passage of the projectile, in terms of energy absorption and vertical velocity displacement. In conclusion agar showed a mechanical and subsequent damage response that was similar to brain compared to alginate. PMID:27131216

  12. Production of microbial medium from defatted brebra (Milletia ferruginea) seed flour to substitute commercial peptone agar

    PubMed Central

    Andualem, Berhanu; Gessesse, Amare

    2013-01-01

    Objective To investigate and optimize microbial media that substitute peptone agar using brebra seed defatted flour. Methods 'Defatted process, inoculums preparation, evaluation of bacterial growth, preparation of cooked and hydrolyzed media and growth turbidity of tested bacteria were determined. Results Two percent defatted flour was found to be suitable concentration for the growth of pathogenic bacteria: Escherichia coli (ATCC 25922) (E. coli), Pseudomonas aeruginosa (ATCC 27853), Salmonella (NCTC 8385) and Shigella flexneri (ATCC 12022) (S. flexneri), while 3% defatted flour was suitable for Staphylococcus aureus (ATCC 25923) (S. aureus). E. coli (93±1) and S. flexneri (524±1) colony count were significantly (P≤0.05) greater in defatted flour without supplement than in supplemented medium. E. coli [(3.72×109±2) CFU/mL], S. aureus [(7.4×109±2) CFU/mL], S. flexneri [(4.03×109±2) CFU/mL] and Salmonella [(2.37×109±1) CFU/mL] in non-hydrolyzed sample were statistically (P≤0.05) greater than hydrolyzed one and commercial peptone agar. Colony count of Salmonella [(4.55×109±3) CFU/mL], S. flexneri [(5.40×109±3) CFU/mL] and Lyesria moncytogenes (ATCC 19116) [(5.4×109±3) CFU/mL] on raw defatted flour agar was significantly (P≤0.05) greater than cooked defatted flour and commercial peptone agar. Biomass of E. coli, S. aureus, Salmonella and Enterococcus faecalis in non-hydrolyzed defatted flour is highly increased over hydrolyzed defatted flour and commercial peptone broth. Conclusions The defatted flour agar was found to be better microbial media or comparable with peptone agar. The substances in it can serve as sources of carbon, nitrogen, vitamins and minerals that are essential to support the growth of microorganisms without any supplements. Currently, all supplements of peptone agar are very expensive in the market. PMID:24075344

  13. Full chip two-layer CD and overlay process window analysis

    NASA Astrophysics Data System (ADS)

    Gupta, Rachit; Shang, Shumay; Sturtevant, John

    2015-03-01

    In-line CD and overlay metrology specifications are typically established by starting with design rules and making certain assumptions about error distributions which might be encountered in manufacturing. Lot disposition criteria in photo metrology (rework or pass to etch) are set assuming worst case assumptions for CD and overlay respectively. For example poly to active overlay specs start with poly endcap design rules and make assumptions about active and poly lot average and across lot CDs, and incorporate general knowledge about poly line end rounding to ensure that leakage current is maintained within specification. There is an opportunity to go beyond generalized guard band design rules to full-chip, design-specific, model-based exploration of worst case layout locations. Such an approach can leverage not only the above mentioned coupling of CD and overlay errors, but can interrogate all layout configurations for both layers to help determine lot-specific, design-specific CD and overlay dispositioning criteria for the fab. Such an approach can elucidate whether for a specific design layout there exist asymmetries in the response to misalignment which might be exploited in manufacturing. This paper will investigate an example of two-layer model-based analysis of CD and overlay errors. It is shown, somewhat non-intuitively, that there can be small preferred misalignment asymmetries which should be respected to protect yield. We will show this relationship for via-metal overlap. We additionally present a new method of displaying edge placement process window variability, akin to traditional CD process window analysis.

  14. Diffraction order control in overlay metrology: a review of the roadmap options

    NASA Astrophysics Data System (ADS)

    Adel, Mike; Kandel, Daniel; Levinski, Vladimir; Seligson, Joel; Kuniavsky, Alex

    2008-03-01

    Resolution enhancement in advanced optical lithography will reach a new plateau of complexity at the 32 nm design rule manufacturing node. In order to circumvent the fundamental optical resolution limitations, ultra low k I printing processes are being adopted, which typically involve multiple exposure steps. Since alignment performance is not fundamentally limited by resolution, it is expected to yield a greater contribution to the effort to tighten lithographic error budgets. In the worst case, the positioning budget usually allocated to a single patterning step is divided between two. A concurrent emerging reality is that of high order overlay modeling and control. In tandem with multiple exposures, this trend creates great pressure to reduce scribeline target real estate per exposure. As the industry migrates away from metrology targets formed from large isolated features, the adoption of dense periodic array proxies brings improved process compatibility and information density as epitomized by the AIM target1. These periodic structures enable a whole range of new metrology sensor architectures, both imaging and scatterometry based, that rely on the principle of diffraction order control and which are no longer aberration limited. Advanced imaging techniques remain compatible with side-by-side targets while scatterometry methods require grating-over-grating targets. In this paper, a number of different imaging and scatterometry architectures are presented and compared in terms of random errors, systematic errors and scribespace requirements. It is asserted that an optimal solution must combine the TMU peak performance capabilities of scatterometry with the cost of ownership advantages of target size and multi-layer capabilities of imaging.

  15. A safety evaluation for overlay disbonding of high-temperature and pressure vessels

    SciTech Connect

    Horita, Ryuichi; Nakajima; Hiroyuki; Tanaka, Kazunori; Murakami, Shunzo; Fujii, Tadaomi

    1995-11-01

    Hydrogen induced disbonding test (autoclave test) of stainless weld-overlaid 2-1/4Cr-1Mo and 2-1/4Cr-1Mo-1/4V steel, and the calculations of residual hydrogen contents at the fusion boundary in the specimens and actual vessels, were performed. The effects of microstructure of weld overlay near the fusion boundary and postweld heat treatment on disbonding resistance were clarified, and critical hydrogen content values in weld overlay to prevent disbonding were obtained. A simple evaluation method for disbonding in actual vessels using Tempering Parameter was established.

  16. Robotic weld overlay coatings for erosion control. Quarterly technical progress report, January 1993--March 1993

    SciTech Connect

    Levin, B.F.; Dupont, J.N.; Marder, A.R.

    1993-04-18

    Twelve weld overlay hardfacing alloys have been selected for preliminary erosion testing based on a literature review These alloys have been separated into three major groups: (1) Cobalt containing alloys, (2) Nickel-base alloys, (3) Iron base alloys. These alloys are being applied to carbon steel substrates and will undergo preliminary erosion testing to identify candidates weld overlay alloys for erosion control in CFB boilers. The candidate alloys selected from the preliminary erosion tests will then undergo more detailed evaluations in future research.

  17. Scalable Tool Infrastructure for the Cray XT Using Tree-Based Overlay Networks

    SciTech Connect

    Roth, Philip C; Vetter, Jeffrey S

    2009-01-01

    Performance, debugging, and administration tools are critical for the effective use of parallel computing platforms, but traditional tools have failed to overcome several problems that limit their scalability, such as communication between a large number of tool processes and the management and processing of the volume of data generated on a large number of compute nodes. A tree-based overlay network has proven effective for overcoming these challenges. In this paper, we present our experiences in bringing our MRNet tree-based overlay network infrastructure to the Cray XT platform, including a description of proof-of-concept tools that use MRNet on the Cray XT.

  18. Effect of impact stress on microbial recovery on an agar surface.

    PubMed

    Stewart, S L; Grinshpun, S A; Willeke, K; Terzieva, S; Ulevicius, V; Donnelly, J

    1995-04-01

    Microbial stress due to the impaction of microorganisms onto an agar collection surface was studied experimentally. The relative recovery rates of aerosolized Pseudomonas fluorescens and Micrococcus luteus were determined as a function of the impaction velocity by using a moving agar slide impactor operating over a flow rate range from 3.8 to 40 liters/min yielding impaction velocities from 24 to 250 m/s. As a reference, the sixth stage of the Andersen Six-Stage Viable Particle Sizing Sampler was used at its operating flow rate of 28.3 liters/min (24 m/s). At a collection efficiency of close to 100% for the agar slide impactor, an increase in sampling flow rate and, therefore, in impaction velocity produced a significant decline in the percentage of microorganisms recovered. Conversely, when the collection efficiency was less than 100%, greater recovery and lower injury rates occurred. The highest relative rate of recovery (approximately 51% for P. fluorescens and approximately 62% for M. luteus) was obtained on the complete (Trypticase soy agar) medium at 40 and 24 m/s (6.4 and 3.8 liters/min), respectively. M. luteus demonstrated less damage than P. fluorescens, suggesting the hardy nature of the gram-positive strain versus that of the gram-negative microorganism. Comparison of results from the agar slide and Andersen impactors at the same sampling velocity showed that recovery and injury due to collection depends not only on the magnitude of the impaction velocity but also on the degree to which the microorganisms may be embedded in the collection medium.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7747946

  19. Effect of impact stress on microbial recovery on an agar surface.

    PubMed Central

    Stewart, S L; Grinshpun, S A; Willeke, K; Terzieva, S; Ulevicius, V; Donnelly, J

    1995-01-01

    Microbial stress due to the impaction of microorganisms onto an agar collection surface was studied experimentally. The relative recovery rates of aerosolized Pseudomonas fluorescens and Micrococcus luteus were determined as a function of the impaction velocity by using a moving agar slide impactor operating over a flow rate range from 3.8 to 40 liters/min yielding impaction velocities from 24 to 250 m/s. As a reference, the sixth stage of the Andersen Six-Stage Viable Particle Sizing Sampler was used at its operating flow rate of 28.3 liters/min (24 m/s). At a collection efficiency of close to 100% for the agar slide impactor, an increase in sampling flow rate and, therefore, in impaction velocity produced a significant decline in the percentage of microorganisms recovered. Conversely, when the collection efficiency was less than 100%, greater recovery and lower injury rates occurred. The highest relative rate of recovery (approximately 51% for P. fluorescens and approximately 62% for M. luteus) was obtained on the complete (Trypticase soy agar) medium at 40 and 24 m/s (6.4 and 3.8 liters/min), respectively. M. luteus demonstrated less damage than P. fluorescens, suggesting the hardy nature of the gram-positive strain versus that of the gram-negative microorganism. Comparison of results from the agar slide and Andersen impactors at the same sampling velocity showed that recovery and injury due to collection depends not only on the magnitude of the impaction velocity but also on the degree to which the microorganisms may be embedded in the collection medium.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7747946

  20. Use of Dehydrated Agar to Estimate Microbial Water Quality for Horticulture Irrigation.

    PubMed

    Meador, Dustin P; Fisher, Paul R; Guy, Charles L; Harmon, Philip F; Peres, Natalia A; Teplitski, Max

    2016-07-01

    Petrifilms are dehydrated agar culture plates that have been used to quantify colony forming units (CFU) mL of either aerobic bacteria (Petrifilm-AC) or fungus (Petrifilm-YM), depending on substrate composition. Microbes in irrigation systems can indicate biofilm risk and potential clogging of irrigation emitters. The research objective was to compare counts on Petrifilms versus traditional, hydrated-agar plates using samples collected from recirculated irrigation waters and cultures of isolated known species. The estimated count (in CFU mL) from a recirculated irrigation sample after 7 d of incubation on Petrifilm-YM was only 5.5% of the count quantified using sabouraud dextrose agar (SDA) with chloramphenicol after 14 d. In a separate experiment with a known species, Petrifilm-YM did not successfully culture zoospores of . Isolates of viable zoospores were cultured successfully on potato-dextrose agar (PDA), with comparable counts with a vegetable juice medium supplemented with the antibiotics pimaricin, ampicillin, rifamycin, pentochloronitrobenzene and hymexazol (PARP-H). The quantification of pv. Begoniaceae on Petrifilm-AC was not significantly different ( < 0.05) than on PDA, but was lower than on Reasoner and Goldrich agar (R2A) or with a hemocytometer. The current formulation of Petrifilm-YM is unlikely to be a useful monitoring method for plant pathogens in irrigation water because of the inability to successfully culture oomycetes. However, Petrifilm-AC was an effective method to quantify bacteria and can provide an easy-to-use on-farm tool to monitor biofilm risk and microbial density. PMID:27380096

  1. Evaluation of Iron Aluminide Weld Overlays for Erosion-Corrosion Resistant Boiler Tube Coatings in Low NOx Boilers

    SciTech Connect

    Regina, J.R.; Lim, M.; Barbosa, N., DuPont, J.N.; Marder, A.R.

    2000-04-28

    Iron aluminide weld overlays containing ternary additions and thermal spray coatings are being investigated for corrosion protection of boiler tubes in Low NO{sub x} burners. The primary objective of the research is to identify overlay and thermal spray compositions that provide corrosion protection of waterwall boiler tubes.

  2. Effect of heat treatment on the performance of tryptose-sulfite-cycloserine agar for enumeration of Clostridium perfringens.

    PubMed Central

    Brodsky, M H; Ciebin, B W

    1979-01-01

    Dissolving dehydrated tryptose-sulfite-cycloserine agar by only boiling or microwaving was found to inhibit Clostridium perfringens colony development in pour plates when compared with C. perfringens recovery in tryptose-sulfite-cycloserine agar prepared by autoclaving. Images PMID:225988

  3. Effect of lignin on water vapor barrier, mechanical, and structural properties of agar/lignin composite films.

    PubMed

    Shankar, Shiv; Reddy, Jeevan Prasad; Rhim, Jong-Whan

    2015-11-01

    Biodegradable composite films were prepared using two renewable resources based biopolymers, agar and lignin alkali. The lignin was used as a reinforcing material and agar as a biopolymer matrix. The effect of lignin concentration (1, 3, 5, and 10wt%) on the performance of the composite films was studied. In addition, the mechanical, water vapor barrier, UV light barrier properties, FE-SEM, and TGA of the films were analyzed. The agar/lignin films exhibited higher mechanical and UV barrier properties along with lower water vapor permeability compared to the neat agar film. The FTIR and SEM results showed the compatibility of lignin with agar polymer. The swelling ratio and moisture content of agar/lignin composite films were decreased with increase in lignin content. The thermostability and char content of agar/lignin composite films increased with increased lignin content. The results suggested that agar/lignin films have a potential to be used as a UV barrier food packaging material for maintaining food safety and extending the shelf-life of the packaged food. PMID:26271435

  4. Differentiating non-0157:H7 STEC serogroups from ground beef plated on agar media by hyperspetral imaging

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Introduction: The development of an assay to detect and confirm a positive non-O157:H7 isolate is challenging when mixed morphologically results are obtained from the serogroups growing on Rainbow agar. Rainbow agar is only claimed by the manufacturer to be very specific for E.coli O157:H7 strain...

  5. Novel Single-Tube Agar-Based Test System for Motility Enhancement and Immunocapture of Escherichia coli O157:H7 by H7 Flagellar Antigen-Specific Antibodies

    PubMed Central

    Murinda, Shelton E.; Nguyen, Lien T.; Ivey, Susan J.; Almeida, Raul A.; Oliver, Stephen P.

    2002-01-01

    This paper describes a novel single-tube agar-based technique for motility enhancement and immunoimmobilization of Escherichia coli O157:H7. Motility indole ornithine medium and agar (0.4%, wt/vol) media containing either nutrient broth, tryptone broth, or tryptic soy broth (TSBA) were evaluated for their abilities to enhance bacterial motility. Twenty-six E. coli strains, including 19 O157:H7 strains, 1 O157:H− strain, and 6 generic E. coli strains, were evaluated. Test bacteria were stab inoculated in the center of the agar column, and tubes were incubated at 37°C for 18 to 96 h. Nineteen to 24 of the 26 test strains (73.1 to 92.3%) were motile in the different media. TSBA medium performed best and was employed in subsequent studies of motility enhancement and H7 flagellar immunocapture. H7 flagellar antiserum (30 and 60 μl) mixed with TSBA was placed as a band (1 ml) in the middle of an agar column separating the top (3-ml) and bottom (3-ml) agar layers. The top agar layer was inoculated with the test bacterial strains. The tubes were incubated at 37°C for 12 to 18 h and for 18 to 96 h. The specificity and sensitivity of the H7 flagellar immunocapture tests were 75 and 100%, respectively. The procedure described is simple and sensitive and could be adapted easily for routine use in laboratories that do not have sophisticated equipment and resources for confirming the presence of H7 flagellar antigens. Accurate and rapid identification of H7 flagellar antigen is critical for the complete characterization of E. coli O157:H7, owing to the immense clinical, public health, and economic significance of this food-borne pathogen. PMID:12454173

  6. Agar Sediment Test for Assessing the Suitability of Organic Waste Streams for Recovering Nutrients by the Aquatic Worm Lumbriculus variegatus.

    PubMed

    Laarhoven, Bob; Elissen, H J H; Temmink, H; Buisman, C J N

    2016-01-01

    An agar sediment test was developed to evaluate the suitability of organic waste streams from the food industry for recovering nutrients by the aquatic worm Lumbriculus variegatus (Lv). The effects of agar gel, sand, and food quantities in the sediment test on worm growth, reproduction, and water quality were studied. Agar gel addition ameliorated growth conditions by reducing food hydrolysis and altering sediment structure. Best results for combined reproduction and growth were obtained with 0.6% agar-gel (20 ml), 10 g. fine sand, 40 g. coarse sand, and 105 mg fish food (Tetramin). With agar gel, ingestion and growth is more the result of addition of food in its original quality. Final tests with secondary potato starch sludge and wheat bran demonstrated that this test is appropriate for the comparison of solid feedstuffs and suspended organic waste streams. This test method is expected to be suitable for organic waste studies using other sediment dwelling invertebrates. PMID:26937632

  7. Agar Sediment Test for Assessing the Suitability of Organic Waste Streams for Recovering Nutrients by the Aquatic Worm Lumbriculus variegatus

    PubMed Central

    Laarhoven, Bob; Elissen, H. J. H.; Temmink, H.; Buisman, C. J. N.

    2016-01-01

    An agar sediment test was developed to evaluate the suitability of organic waste streams from the food industry for recovering nutrients by the aquatic worm Lumbriculus variegatus (Lv). The effects of agar gel, sand, and food quantities in the sediment test on worm growth, reproduction, and water quality were studied. Agar gel addition ameliorated growth conditions by reducing food hydrolysis and altering sediment structure. Best results for combined reproduction and growth were obtained with 0.6% agar-gel (20 ml), 10 g. fine sand, 40 g. coarse sand, and 105 mg fish food (Tetramin). With agar gel, ingestion and growth is more the result of addition of food in its original quality. Final tests with secondary potato starch sludge and wheat bran demonstrated that this test is appropriate for the comparison of solid feedstuffs and suspended organic waste streams. This test method is expected to be suitable for organic waste studies using other sediment dwelling invertebrates. PMID:26937632

  8. An abbreviated scheme for identification of Yersinia enterocolitica isolated from food enrichments on CIN (cefsulodin-irgasan-novobiocin) agar.

    PubMed

    Devenish, J A; Schiemann, D A

    1981-09-01

    An abbreviated procedure for the biochemical identification of Yersinia enterocolitica isolated from food enrichments on CIN (cefsulodin-irgasan-novobiocin) agar was investigated. A total of 170 colonies resembling Y. enterocolitica in colonial morphology and appearance on CIN agar were selected for identification using API strips. Ninety-three of these isolates were examined with the PathoTec ornithine decarboxylase, Voges-Proskauer, and urease test strips. The PathoTec urease strip alone was adequate for identification of all isolates of Y. enterocolitica. Christensen's urea agar was applied to the remaining 77 isolates and found less specific in the 1 isolate of Enterobacter agglomerans was urease positive along with 10 isolates of Y. enterocolitica. CIN agar is a highly specific medium for isolation of Y. enterocolitica, requiring only Kligler iron agar and urea slants for confirmation of presumptive colonies. PMID:7306881

  9. Use of fabrics and other measures for retarding reflective cracking of asphaltic concrete overlays

    NASA Astrophysics Data System (ADS)

    Jackson, R. D.

    1980-03-01

    Prevention or control of reflection cracks in asphaltic concrete overlays has been a problem from the inception of this type of construction. The many different treatments that have been tried in an effort to solve this problem are: (1) reinforcement within and below the overlay, (2) bond breakers, (3) stress relieving layers, (4) asphalt-mix additives, and (5) placement of fabrics between the existing pavement and the overlay. At the present time, no treatment has been tried that will completely prevent the formation of reflection cracks. Some treatments do delay the formation of cracks, while others do not appear to help at all. Indications are that fabrics do have some beneficial effects, such as a moisture barrier, even though the overlays develop reflection cracks. The fabrics that have been tried for the control of reflection cracks included: (1) Petromat, (2) Bidim, (3) Typar, (4) Cerex, (5) Mirafi, (6) Structofors, (7) Bituthene, (8) Protecto-Wrap, and (9) Fiberglass. Asphalt-rubber interlayers, as formulated by the Arizona Refining Company and the Sahuaro Petroleum Company, show promise in retarding reflection cracks.

  10. Assessing the Crossdisciplinarity of Technology-Enhanced Learning with Science Overlay Maps and Diversity Measures

    ERIC Educational Resources Information Center

    Kalz, Marco; Specht, Marcus

    2014-01-01

    This paper deals with the assessment of the crossdisciplinarity of technology-enhanced learning (TEL). Based on a general discussion of the concept interdisciplinarity and a summary of the discussion in the field, two empirical methods from scientometrics are introduced and applied. Science overlay maps and the Rao-Stirling diversity index are…

  11. Passivation of hematite nanorod photoanodes with a phosphorus overlayer for enhanced photoelectrochemical water oxidation

    NASA Astrophysics Data System (ADS)

    Xiong, Dehua; Li, Wei; Wang, Xiaoguang; Liu, Lifeng

    2016-09-01

    Hematite (i.e., α-Fe2O3) nanorod photoanodes passivated with a phosphorus overlayer have been fabricated by decomposing sodium hypophosphite (NaH2PO2) at a low temperature over the hematite nanorod surface. Extensive scanning electron microscopy, transmission electron microscopy, x-ray diffractometry and UV–vis spectroscopy characterizations confirm that conformal deposition of an amorphous phosphorus overlayer does not change the crystal structure, morphology, and optical absorption properties of hematite photoanodes. X-ray photoelectron spectroscopy reveals that phosphorus in the deposited overlayer exists in an oxidized state. Comprehensive steady-state polarization, transient photocurrent response, and impedance spectroscopy measurements as well as Mott–Schottky analysis manifest that the phosphorus overlayer is able to effectively passivate surface states and suppress electron–hole recombination, substantially enhancing the photocurrent for water oxidation. Combining the phosphorization treatment with two-step thermal activation, a photocurrent density of 1.1 mA cm‑2 is achieved at 1.23 V versus reversible hydrogen electrode under illumination of 100 mW cm‑2, ca 55 times higher than that of the non-activated pristine hematite photoanode measured under the same conditions. The simple and fast phosphorization strategy we present here can be readily applied to passivate surfaces of other semiconductor photoelectrodes to improve their photoelectrochemical performance.

  12. Robotic weld overlay coatings for erosion control. Quarterly progress report, October 1993--December 1993

    SciTech Connect

    Levin, B.F.; DuPont, J.N.; Marder, A.R.

    1994-01-20

    Research is being conducted to develop criteria for selecting weld overlay coatings for erosion mitigation in Circulated Fluidized Beds. Twelve weld overlay alloys were deposited on 1018 steel substrates using plasma arc welding. Ten samples from each coating were prepared for erosion testing. All selected coatings were erosion tested at 400C and their erosion resistance and microstructure evaluated. Steady state erosion rates were similar for several weld overlay coatings (Ultimet, Inconel-625, Iron-Aluminide, 316L SS, and High Chromium Cast Iron) and were considerably lower than the remaining coating evaluated. These coatings had different base (Co, Fe, Ni-base). No correlations were found between room temperature microhardness of the weld overlay coatings and their erosion resistance at elevated temperature, although this criteria is often thought to be an indicator of erosion resistance. It was suggested that the coatings that showed similar erosion rates may have similar mechanical properties such as fracture strength, toughness and work hardening rates at this temperature. During the past quarter, Iron-Aluminide, Inconel-625, and 316L SS coatings were selected for more detailed investigations based upon the preliminary erosion test results. Microhardness tests were performed on eroded samples to determine the size of the work hardened zone and change in coatings hardness due to erosion. The work hardened zone was to correlated with erosion resistance of the coatings. Additional Iron-Aluminide, Inconel-625, and 316L SS coatings were deposited on 1018 steel substrates.

  13. A new approach to plane-sweep overlay: topological structuring and line-segment classification

    USGS Publications Warehouse

    van Roessel, Jan W.

    1991-01-01

    An integrated approach to spatial overlay was developed with the objective of creating a single function that can perform most of the tasks now assigned to discrete functions in current systems. Two important components of this system are a unique method for topological structuring, and a method for attribute propagation and line-segment classification. -Author

  14. Arbitration Intervention Worker (AIW) Services: Case Management Overlay in a Juvenile Diversion Program

    ERIC Educational Resources Information Center

    Poythress, Norman G.; Dembo, Richard; DuDell, Gary; Wareham, Jennifer

    2006-01-01

    In this issue we describe a clinical trials study of the impact of adding specific case manager overlay services to "treatment as usual" services for youths in a Juvenile Arbitration Program. In this first article we describe the experimental intervention, the Arbitration Intervention Worker (AIW) service, which was provided to a randomly selected…

  15. Disbond detection with piezoelectric wafer active sensors in RC structures strengthened with FRP composite overlays

    NASA Astrophysics Data System (ADS)

    Giurgiutiu, Victor; Harries, Kent; Petrou, Michael; Bost, Joel; Quattlebaum, Josh B.

    2003-12-01

    The capability of embedded piezoelectric wafer active sensors (PWAS) to perform in-situ nondestructive evaluation (NDE) for structural health monitoring (SHM) of reinforced concrete (RC) structures strengthened with fiber reinforced polymer (FRP) composite overlays is explored. First, the disbond detection method were developed on coupon specimens consisting of concrete blocks covered with an FRP composite layer. It was found that the presence of a disbond crack drastically changes the electromechanical (E/M) impedance spectrum measured at the PWAS terminals. The spectral changes depend on the distance between the PWAS and the crack tip. Second, large scale experiments were conducted on a RC beam strengthened with carbon fiber reinforced polymer (CFRP) composite overlay. The beam was subject to an accelerated fatigue load regime in a three-point bending configuration up to a total of 807,415 cycles. During these fatigue tests, the CFRP overlay experienced disbonding beginning at about 500,000 cycles. The PWAS were able to detect the disbonding before it could be reliably seen by visual inspection. Good correlation between the PWAS readings and the position and extent of disbond damage was observed. These preliminary results demonstrate the potential of PWAS technology for SHM of RC structures strengthened with FRP composite overlays.

  16. Robotic weld overlay coatings for erosion control. Final technical progress report, July 1992--July 1995

    SciTech Connect

    Levin, B.F.; DuPont, J.N.; Marder, A.R.

    1995-10-15

    The erosion behavior of weld overlay coatings has been studied. Eleven weld overlay alloys were deposited on 1018 steel substrates using the plasma arc welding process and erosion tested at 400{degrees}C at 90{degrees} and 30{degrees} particle impact angles. The microstructure of each coating was characterized before erosion testing. A relative ranking of the coatings erosion resistance was developed by determining the steady state erosion rates. Ultimet, Inconel-625, and 316L SS coatings showed the best erosion resistance at both impact angles. It was found that weld overlays that exhibit good abrasion resistance did not show good erosion resistance. Erosion tests were also performed for selected wrought materials with chemical composition similar to weld overlays. Eroded surfaces of the wrought and weld alloys were examined by Scanning Electron Microscopy (SEM). Microhardness tests were performed on the eroded samples below the erosion surface to determine size of the plastically deformed region. It was found that one group of coatings experienced significant plastic deformation as a result of erosion while the other did not. It was also established that, in the steady state erosion regime, the size of the plastically deformed region is constant.

  17. Semantic Overlays in Educational Content Networks--The hylOs Approach

    ERIC Educational Resources Information Center

    Engelhardt, Michael; Hildebrand, Arne; Lange, Dagmar; Schmidt, Thomas C.

    2006-01-01

    Purpose: The paper aims to introduce an educational content management system, Hypermedia Learning Objects System (hylOs), which is fully compliant to the IEEE LOM eLearning object metadata standard. Enabled through an advanced authoring toolset, hylOs allows the definition of instructional overlays of a given eLearning object mesh.…

  18. Scalable P2P Overlays of Very Small Constant Degree: An Emerging Security Threat

    NASA Astrophysics Data System (ADS)

    Jelasity, Márk; Bilicki, Vilmos

    In recent years peer-to-peer (P2P) technology has been adopted by Internet-based malware as a fault tolerant and scalable communication medium for self-organization and survival. It has been shown that malicious P2P networks would be nearly impossible to uncover if they operated in a stealth mode, that is, using only a small constant number of fixed overlay connections per node for communication. While overlay networks of a small constant maximal degree are generally considered to be unscalable, we argue in this paper that it is possible to design them to be scalable, efficient and robust. This is an important finding from a security point of view: we show that stealth mode P2P malware that is very difficult to discover with state-of-the-art methods is a plausible threat. In this paper we discuss algorithms and theoretical results that support the scalability of stealth mode overlays, and we present realistic simulations using an event based implementation of a proof-of-concept system. Besides P2P botnets, our results are also applicable in scenarios where relying on a large number of overlay connections per node is not feasible because of cost or the limited number of communication channels available.

  19. Impact of the back side flatness of a mask on the panel overlay

    NASA Astrophysics Data System (ADS)

    Kemmochi, Daisuke; Yoshikawa, Yutaka; Iwanaga, Yoshinori; Hirano, Termusa; Kinoshita, Hiroshi

    2015-07-01

    Recently, the annual increase in the definition of high-function panels for mobile devices such as smartphones or tablets has led to TFT-LCD and TFT-OLED (Organic Light Emitting Diode) circuits becoming increasingly miniaturized and densified. TFT circuits are comprised of a superposition of layers such as gates, acts and contact holes, with a certain amount of allowance between each layer. However, that allowance has now disappeared due to the high density of the circuit. Therefore, a high-precision mask overlay is essential in order to realize circuits with even higher density. In the mask manufacturing process, the mask is placed on a writer tool, during which the back side surface of the mask makes contact with the stage. This contact alters the front side flatness of the mask. Moreover, once the circuit pattern has been drawn on the mask, it is removed from the writer tool, thus altering the front side flatness and coordinates of the mask. In this paper, we evaluated the overlay of a panel that underwent exposure using a number of masks with different back side flatness. As a result, we confirmed that deviations in the back side flatness of each mask manifest themselves in the panel overlay. Therefore, we need to improve the flatness of the back side of masks hereafter in order to further enhance the panel overlay.

  20. Enumeration of fecal Clostridium perfringens spores in egg yolk-free tryptose-sulfite-cycloserine agar.

    PubMed

    Hauschild, A H; Hilsheimer, R; Griffith, D W

    1974-03-01

    The Shahidi-Ferguson perfringens, tryptose-sulfite-cycloserine (TSC), and egg yolk-free TSC agars have been tested for their suitability to enumerate fecal spores of Clostridium perfringens. When these spores comprised at least 20% of the total anaerobe spores, equally accurate counts were obtained in the three media. With lower ratios of C. perfringens spores, the most accurate counts were obtained in egg yolk-free TSC agar. The median C. perfringens spore count of 60 normal fecal specimens was log 3.4/g. A nonmotile, sulfite- and nitrate-reducing Clostridium, not identifiable with any known clostridial species, was isolated from 14 out of 60 fecal specimans. It was not differentiated from C. perfringens in the nitrite motility test, but could be distinguished by its inability to liquefy gelatin. PMID:4363369

  1. Enumeration of Fecal Clostridium perfringens Spores in Egg Yolk-Free Tryptose-Sulfite-Cycloserine Agar

    PubMed Central

    Hauschild, A. H. W.; Hilsheimer, R.; Griffith, D. W.

    1974-01-01

    The Shahidi-Ferguson perfringens, tryptose-sulfite-cycloserine (TSC), and egg yolk-free TSC agars have been tested for their suitability to enumerate fecal spores of Clostridium perfringens. When these spores comprised at least 20% of the total anaerobe spores, equally accurate counts were obtained in the three media. With lower ratios of C. perfringens spores, the most accurate counts were obtained in egg yolk-free TSC agar. The median C. perfringens spore count of 60 normal fecal specimens was log 3.4/g. A nonmotile, sulfite- and nitrate-reducing Clostridium, not identifiable with any known clostridial species, was isolated from 14 out of 60 fecal specimans. It was not differentiated from C. perfringens in the nitrite motility test, but could be distinguished by its inability to liquefy gelatin. PMID:4363369

  2. Characterization of gelatin-agar based phase separated hydrogel, emulgel and bigel: a comparative study.

    PubMed

    Wakhet, Senggam; Singh, Vinay K; Sahoo, Saikat; Sagiri, Sai Sateesh; Kulanthaivel, Senthilguru; Bhattacharya, Mrinal K; Kumar, Naresh; Banerjee, Indranil; Pal, Kunal

    2015-02-01

    The current study describes the in-depth characterization of agar-gelatin based co-hydrogels, emulgels and bigels to have an insight about the differences in the properties of the formulations. Hydrogels have been extensively studied as vehicle for controlled drug release, whereas, the concept of emulgels and bigels is relatively new. The formulations were characterized by scanning electron microscopy, FTIR spectroscopy, XRD and mechanical properties. The biocompatibility and the ability of the formulations to be used as drug delivery vehicle were also studied. The scanning electron micrographs suggested the presence of internal phases within the agar-gelatin composite matrices of co-hydrogel, emulgel and bigel. FTIR and XRD studies suggested higher crystallinity of emulgels and bigels. Electrical impedance and mechanical stability of the emulgel and the bigel was higher than the hydrogel. The prepared formulations were found to be biocompatible and suitable for drug delivery applications. PMID:25672596

  3. Effect of Soybean Casein Digest Agar Lot on Number of Bacillus stearothermophilus Spores Recovered †

    PubMed Central

    Pflug, I. J.; Smith, Geraldine M.; Christensen, Ronald

    1981-01-01

    In recent years it has become increasingly apparent that Bacillus stearothermophilus spores are affected by various environmental factors that influence the performance of the spores as biological indicators. One environmental factor is the recovery medium. The effect of different lots of commercial soybean casein digest agar on the number of colony-forming units per plate was examined in two series of experiments: (i) several lots of medium from two manufacturers were compared in single experiments, and (ii) paired media experiments with four lots of medium were carried out and yielded three-point survivor curves. The results demonstrate that commercial soybean casein digest agar is variable on a lot-to-lot basis. The variation was lowest when recovering unheated or minimally heated spores and increased greatly with the severity of heating. PMID:16345822

  4. Effect of Soybean Casein Digest Agar Lot on Number of Bacillus stearothermophilus Spores Recovered.

    PubMed

    Pflug, I J; Smith, G M; Christensen, R

    1981-08-01

    In recent years it has become increasingly apparent that Bacillus stearothermophilus spores are affected by various environmental factors that influence the performance of the spores as biological indicators. One environmental factor is the recovery medium. The effect of different lots of commercial soybean casein digest agar on the number of colony-forming units per plate was examined in two series of experiments: (i) several lots of medium from two manufacturers were compared in single experiments, and (ii) paired media experiments with four lots of medium were carried out and yielded three-point survivor curves. The results demonstrate that commercial soybean casein digest agar is variable on a lot-to-lot basis. The variation was lowest when recovering unheated or minimally heated spores and increased greatly with the severity of heating. PMID:16345822

  5. The Resazurin-Agar Method - a Quick Test to Determine Water Quality

    NASA Astrophysics Data System (ADS)

    Huckfeldt, J.; Westphal, B.; Claußen, L.

    2015-12-01

    Rezasurin has been used as a smart tracer in stream ecosystems to indicate metabolic activity, specifically aerobic respiration by heterotrophic bacteria. Resazurin is a blue compound which is irreversibly reduced to the pink resorufin in the presence of aerobic bacteria. The degree and speed of colour change from blue to pink is a measure of the degree of oxygen consumption and thus an indirect indication of the concentration of aerobic bacteria in a given medium. A high concentration of bacteria in water indicates a bad water quality. In our work a method was developed using resazurin agar plates to find a quick and easy way for testing water quality and comparing concentrations of bacteria in freshwater and seawater samples. The theory was to concentrate bacteria from a defined volume of water sample onto polycarbonate filters (0.2 μm), which are then placed onto the resazurin agar plate. The presence of aerobic bacteria on the filter will reduce the resazurin in the agar and the compound changes its colour. First tests conducted with different dilutions of a pure culture of yoghurt bacteria showed promising results and confirmed the feasibility of the method. In a further assay, we used water samples from different water layers and different temperatures and were also able to observe differences in the concentration of bacteria, depending on these different environmental conditions.The assay was also successfully used with seawater samples, collected from 2 different stations at 3 different depths in the Baltic Sea (salinity=15). The discolouration of the plates showed good correlation with the oxygen concentrations in the water. The resazurin-agar plate method is economical and fast. Several samples could be investigated at the same time without sacrificing the reliability of the results. Thus it is a good pre-screening test for a quantitative evaluation of bacteria in a water sample.

  6. Cytotoxicity of ferrite particles by MTT and agar diffusion methods for hyperthermic application

    NASA Astrophysics Data System (ADS)

    Kim, Dong-Hyun; Lee, Se-Ho; Kim, Kyoung-Nam; Kim, Kwang-Mahn; Shim, In-Bo; Lee, Yong-Keun

    2005-05-01

    We investigated the cytotoxicity of the prepared various ferrites (Fe-, Li-, Ni/Zn/Cu-, Ba-, Sr-, Co-, Co/Ni-ferrites) using MTT assay as well as agar diffusion method. Their cytotoxicity was compared with that of alginate-encapsulated ferrites. In the MTT assay, Fe 3O 4 and SrFe 12O 19 ferrite showed the highest cell viability of 90%. Alginate-encapsulated Ba-ferrite was ranked mildly cytotoxic, whereas their ferrite particles were ranked cytotoxic.

  7. Alternative plasticizers for the production of thermo-compressed agar films.

    PubMed

    Sousa, Ana M M; Souza, Hiléia K S; Liu, LinShu; Gonçalves, Maria P

    2015-05-01

    Agar films were produced by thermo-compression using choline chloride (ChCl) as a plasticizer with urea. The three solid components were mixed together with the salt and urea (minor components) added to agar (main component) according to a fixed mass ratio of, respectively, 1.16:1:5. A central composite rotatable design (CCRD) with three parameters, 2(3), was used to evaluate the effects of temperature (X1; °C), time (X2; min) and applied load (X3; kN) of heat-pressing on the maximum tensile strength (TS) of the films (Y; MPa). Mixtures of urea and agar prepared at a mass ratio of 1:5 did not form homogeneous films suggesting the important plasticizing role of the salt. Heat-pressing the mixtures at more draconian conditions led to much darker and opaque films, with better mechanical resistance (higher values of TS). The most resistant film (∼ 15 MPa) was obtained at 140°C, 20 min and 176 kN. Selected films, including the optimal, showed similar water sorption profiles and close values of water vapor permeability (∼ 2.5-3.7 × 10(-9)gm(-1)s(-1)Pa(-1)). The fracture behavior and mechanical properties of the films were greatly affected by additional water plasticization when the films were stored at different conditions of relative humidity. PMID:25727746

  8. Simulation of Bacillus subtilis biofilm growth on agar plate by diffusion–reaction based continuum model

    NASA Astrophysics Data System (ADS)

    Zhang, Xianlong; Wang, Xiaoling; Nie, Kai; Li, Mingpeng; Sun, Qingping

    2016-08-01

    Various species of bacteria form highly organized spatially-structured aggregates known as biofilms. To understand how microenvironments impact biofilm growth dynamics, we propose a diffusion–reaction continuum model to simulate the formation of Bacillus subtilis biofilm on an agar plate. The extended finite element method combined with level set method are employed to perform the simulation, numerical results show the quantitative relationship between colony morphologies and nutrient depletion over time. Considering that the production of polysaccharide in wild-type cells may enhance biofilm spreading on the agar plate, we inoculate mutant colony incapable of producing polysaccharide to verify our results. Predictions of the glutamate source biofilm’s shape parameters agree with the experimental mutant colony better than that of glycerol source biofilm, suggesting that glutamate is rate limiting nutrient for Bacillus subtilis biofilm growth on agar plate, and the diffusion-limited is a better description to the experiment. In addition, we find that the diffusion time scale is of the same magnitude as growth process, and the common-employed quasi-steady approximation is not applicable here.

  9. Susceptibility testing of Propionibacterium acnes comparing agar dilution with E test.

    PubMed Central

    Smith, M A; Alperstein, P; France, K; Vellozzi, E M; Isenberg, H D

    1996-01-01

    Propionibacterium acnes has been identified as a significant agent of nosocomial infections, including endophthalmitis. Data concerning susceptibility of P. acnes to newer beta-lactam antibiotics and fluoroquinolones are limited. Recent reports suggest that quinolones have activity against these organisms sufficient to warrant further study. We undertook a study to select appropriate antimicrobial agents for use in a rabbit model of P. acnes endophthalmitis. We compared the antibiotic susceptibilities of P. acnes by using the National Committee for Clinical Laboratory Standards method of agar dilution with the E test. Thirteen clinical isolates obtained from eye specimens and three American Type Culture Collection control strains were tested against 14 antibiotics. All the clinical isolates were susceptible by both methods to piperacillin, piperacillin-tazobactam, ampicillin-sulbactam, ticarcillin-clavulanate, cefotaxime, cefotetan, ceftriaxone, cefoxitin, and imipenem in addition to clindamycin but were resistant to metronidazole. The clinical P. acnes isolates also displayed high-level susceptibility to ciprofloxacin, sparfloxacin, and ofloxacin. Almost all the P. acnes strains demonstrated E-test MICs within 2 dilutions of the MICs observed by the agar dilution method. Those few strains for which discrepancies were noted exhibited E-test susceptibilities three- to fivefold dilutions lower than the agar dilution method susceptibilities but only with ampicillin-sulbactam, ticarcillin-clavulanate, and/or clindamycin. On the basis of our study, all of clinical eye isolates were susceptible to these newer antimicrobial agents and the two methods demonstrated similar susceptibility patterns. PMID:8815076

  10. Evaluation of cephamycins as supplements to selective agar for detecting Campylobacter spp. in chicken carcass rinses.

    PubMed

    Chon, Jung-Whan; Kim, Young-Ji; Kim, Hong-Seok; Kim, Dong-Hyeon; Kim, Hyunsook; Song, Kwang-Young; Sung, Kidon; Seo, Kun-Ho

    2016-04-16

    Although cefoperazone is the most commonly used antibiotic in Campylobacter-selective media, the distribution of cefoperazone-resistant bacteria such as extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli is increasing. Here we evaluated the potential of cephamycins for use as supplements to improve modified charcoal-cefoperazone-deoxycholate agar (mCCDA) by replacing cefoperazone with the same concentrations (32 mg/L) of cefotetan (modified charcoal-cefotetan-deoxycholate agar, mCCtDA) and cefoxitin (modified charcoal-cefoxitin-deoxycholate agar, mCCxDA). In chicken carcass rinse samples, the number of mCCDA plates detecting for Campylobacter (18/70, 26%) was significantly lower than that of mCCtDA (42/70, 60%) or mCCxDA plates (40/70, 57%). The number of mCCDA plates (70/70, 100%) that were contaminated with non-Campylobacter species was significantly higher than that of mCCtDA (20/70, 29%) or mCCxDA plates (21/70, 30%). The most common competing species identified using mCCDA was ESBL-producing E. coli, while Pseudomonas species frequently appeared on mCCtDA and mCCxDA. PMID:26915052

  11. Simulation of Bacillus subtilis biofilm growth on agar plate by diffusion-reaction based continuum model.

    PubMed

    Zhang, Xianlong; Wang, Xiaoling; Nie, Kai; Li, Mingpeng; Sun, Qingping

    2016-01-01

    Various species of bacteria form highly organized spatially-structured aggregates known as biofilms. To understand how microenvironments impact biofilm growth dynamics, we propose a diffusion-reaction continuum model to simulate the formation of Bacillus subtilis biofilm on an agar plate. The extended finite element method combined with level set method are employed to perform the simulation, numerical results show the quantitative relationship between colony morphologies and nutrient depletion over time. Considering that the production of polysaccharide in wild-type cells may enhance biofilm spreading on the agar plate, we inoculate mutant colony incapable of producing polysaccharide to verify our results. Predictions of the glutamate source biofilm's shape parameters agree with the experimental mutant colony better than that of glycerol source biofilm, suggesting that glutamate is rate limiting nutrient for Bacillus subtilis biofilm growth on agar plate, and the diffusion-limited is a better description to the experiment. In addition, we find that the diffusion time scale is of the same magnitude as growth process, and the common-employed quasi-steady approximation is not applicable here. PMID:27434099

  12. Agar Plate Method for Detection and Enumeration of Alkylbenzenesulfonate-Degrading Microorganisms

    PubMed Central

    Ohwada, Kouichi

    1975-01-01

    A simple method for detection and enumeration of alkylbenzenesulfonate (ABS)-degrading microorganisms by using agar plates was developed and used in microbiological studies of coastal marine and polluted river waters. The method depends upon the color responses of neutral red in alkaline medium. Neutral red changes from pink, when it enters into ABS micelles, to yellow, when the ABS is degraded, and does not form micelles. When neutral red-tris(hydroxymethyl)-aminomethane buffer solution and then cationic surfactant solution were sprayed onto the agar surface of ABS-nutrient agar cultures, transparent haloes appeared around the colonies of ABS-degrading microorganisms against a pink background. Viable counts of ABS-degrading bacteria isolated from both seawater and freshwater environments were considerably higher in polluted waters than in less polluted areas. Viable counts of ABS-degrading bacteria averaged 1.5 × 105/ml in samples from the surface water of polluted Tokyo Bay and 3.0 × 104/ml in samples from the surface water of polluted Tamagawa River but were fewer in number in samples from less polluted waters. Images PMID:234155

  13. A supplemented soft agar chemotaxis assay demonstrates the Helicobacter pylori chemotactic response to zinc and nickel

    PubMed Central

    Sanders, Lisa; Andermann, Tessa M.

    2013-01-01

    Directed motility, or chemotaxis, is required for Helicobacter pylori to establish infection in the stomach, although the full repertoire of this bacterium’s chemotactic responses is not yet known. Here we report that H. pylori responds to zinc as an attractant and nickel as a repellent. To reach this conclusion, we employed both a temporal chemotaxis assay based on bacterial reversals and a supplemented soft agar spatial assay. We refined the temporal assay using a previously described chemorepellent, acid, and found that H. pylori requires rich media with serum to maintain optimal swimming motility. Surprisingly, we found that some strains respond to acid as an attractant, and that the TlpC chemoreceptor correlated with whether acid was sensed as an attractant or repellent. Using this same assay, we detected weak repellent responses to nickel and copper, and a varied response to zinc. We thus developed an alternative spatial chemotactic assay called the supplemented soft agar assay, which utilizes soft agar medium supplemented with the test compound. With Escherichia coli, the attractant serine slowed overall bacterial migration, while the repellent nickel increased the speed of overall migration. In H. pylori we detected slowed migration with doubled tryptone media, as well as zinc, consistent with an attractant response. In contrast, nickel increased migration, consistent with repulsion. PMID:23139399

  14. How do microorganisms influence trace element uptake by plants? Screening in an agar model rhizosphere.

    NASA Astrophysics Data System (ADS)

    Marchetti, M.; Robinson, B. H.; Evangelou, M. W. H.; Vachey, A.; Schwitzguebel, J. P.; Bernier-Latmani, R.; Schulin, R.

    2009-04-01

    Trace elements (TE) are essential for humans and plants, but they may be toxic if their concentration is too high. For this reason, the management of TE in soils is very important. In some cases it may be necessary to increase the uptake of nutrients or TE by plants, for example in a biofortification perspective. Conversely, in some other cases TE uptake by plants should be decreased, for instance to avoid heavy metals entering the food chain via edible crops. Microorganisms living in the rhizosphere affect trace element (TE) uptake by plants. However, due to the complexity of this space and the variety of microorganisms that occur there, it is difficult to isolate the effect of any particular strain. To overcome this hurdle, we developed a system in which we grew plants under sterile conditions in agar and inoculated their rhizosphere with a single, well-defined microbial strain. For many years, agar has been used as a growth substrate for microorganisms and plant tissues. It is cheap, easy to use, and can be autoclaved to ensure its sterility. Because of its widespread use, an experiment conducted using this substrate can be reproduced under the same conditions in any laboratory. In contrast to soil, there is little interaction between the trace elements and the agar matrix. There are many studies investigating the influence of microorganisms on TE uptake by plants. However, so far only a small variety of microorganisms has been tested on few plant species. Therefore, the first objective of our research was to develop a method to rapidly screen a large variety of microorganisms on various plant species. Once this goal was achieved, we sought to study the effect of single, well-defined microbial strains on TE uptake by sunflower and wheat. The substrate for plants growth was a 10% agar solution prepared with modified Hoagland's solution and a TE solution containing 1 mg/kg Pb and molar equivalents of Cu, Ni and Zn. The agar solution was autoclaved and poured into

  15. Development and characterisation of an agar--polyvinyl alcohol blend hydrogel.

    PubMed

    Lyons, John G; Geever, Luke M; Nugent, Michael J D; Kennedy, James E; Higginbotham, Clement L

    2009-10-01

    Numerous authors have reported on hydrogel technologies providing products suitable for applications in biomedical, personal care as well as in nano-sensor applications. Hydrogels fabricated from single polymers have been extensively investigated. However, in many cases a single polymer alone cannot meet divergent demands in terms of both properties and performance. In this work, hydrogels were prepared by physically blending the natural polymer agar with polyvinyl alcohol in varying ratios to produce a new biosynthetic polymer applicable for a variety of purposes. Hydrogen bonding was observed to take place between the polyvinyl alcohol and the agar molecules in the composite materials leading to changes in the thermal, mechanical and swelling characteristics of the composite hydrogels. The composite hydrogels exhibited a slightly higher melting temperature than pure agar (116.81 degrees C). Irreversible compressive damage was found to occur at lower strain levels during compression testing of the dehydrated samples consisting of higher PVOH concentrations. Rheological analysis of hydrated sample revealed G' values of between 5000 and 10,000 Pa for the composite blends, with gels containing higher PVOH percentages exhibiting poorer mechanical strength. PMID:19627855

  16. Isolation of Clostridium difficile from faecal specimens--a comparison of chromID C. difficile agar and cycloserine-cefoxitin-fructose agar.

    PubMed

    Carson, Kerry C; Boseiwaqa, Lusiana V; Thean, Sara K; Foster, Niki F; Riley, Thomas V

    2013-09-01

    The culture of toxigenic Clostridium difficile from stool specimens is still seen as the gold standard for the laboratory diagnosis of C. difficile infection (CDI). bioMérieux have released ChromID Cdiff chromogenic agar (CDIF) for the isolation and identification of C. difficile in 24 h. In this study, we compared CDIF to pre-reduced cycloserine-cefoxitin-fructose agar with sodium taurocholate (TCCFA) in the examination of glutamate dehydrogenase-positive faecal specimens that were either GeneOhm positive or negative, using direct culture or culture following alcohol shock. Direct culture on CDIF had a sensitivity of 100 % and recovery of 94 % while for TCCFA these were 87 % and 82 %, respectively. For GeneOhm-positive alcohol-shocked faecal samples, sensitivity and recovery on CDIF was similar to direct culture while on TCCFA they were about 10 % higher. For direct culture, there was a significant difference between growth on CDIF at 24 h and TCCFA at 48 h (P = 0.001) and between the two media at 48 h (P<0.001). A total of 142 strains of C. difficile were recovered in pure culture from all GeneOhm-positive samples used in this study and 11 (7.7 %) of these were A(-)B(-)CDT(-) and may represent mixed infections of toxigenic and non-toxigenic C. difficile. The most dominant ribotype was UK 014 (14.7 %) followed by 002 (11.9 %) and 020 (11.9 %), and 36 % of toxigenic isolates, including an A(-)B(+)CDT(-) strain, could not be assigned a UK ribotype. CDIF outperformed pre-reduced TCCFA by negating the need for alcohol shock treatment and by giving a time saving of 24 h in the isolation of C. difficile. CDIF plates were also more selective than TCCFA and C. difficile colonies were easy to identify and subculture prior to strain typing. PMID:23579394

  17. Agar disk elution method for susceptibility testing of Mycobacterium marinum and Mycobacterium fortuitum complex to sulfonamides and antibiotics.

    PubMed Central

    Stone, M S; Wallace, R J; Swenson, J M; Thornsberry, C; Christensen, L A

    1983-01-01

    An agar disk elution method using round well plates, supplemented Mueller-Hinton agar, and commercial drug disks is described for susceptibility testing of Mycobacterium marinum and the rapidly growing mycobacteria to antibiotics and sulfonamides. By this method, 14 of 14 strains of M. marinum were susceptible to rifampin, doxycycline, minocycline, and trimethoprim-sulfamethoxazole. Identical results were obtained with Middlebrook 7H10 agar and drugs prepared from standard powders. With 58 isolates of Mycobacterium fortuitum and Mycobacterium chelonei, this method had a 92% correlation with broth minimal inhibitory concentration determinations for cefoxitin and greater than 98% for doxycycline, kanamycin, amikacin, and the sulfonamides. Sixty-nine percent of isolates of M. chelonei susceptible to amikacin on supplemented Mueller-Hinton agar were resistant on 7H10 agar, and 15 of 16 M. chelonei isolates susceptible to erythromycin in broth were resistant by disk elution when an endpoint of no growth was used with either agar. The agar disk elution method offers a practical method for testing of most antibacterial agents against these mycobacterial species. Images PMID:6651277

  18. IMPERMEABLE THIN AL2O3 OVERLAY FOR TBC PROTECTION FROM SULFATE AND VANADATE ATTACK IN GAS TURBINES

    SciTech Connect

    Scott X. Mao

    2003-12-16

    To improve the hot corrosion resistance of YSZ thermal barrier coatings, a 25 {micro}m and a 2 {micro}m thick Al{sub 2}O{sub 3} overlay were deposited by HVOF thermal spray and by sol-gel coating method, respectively, onto to the surface of YSZ coating. Indenter test was employed to investigate the spalling of YSZ with and without Al{sub 2}O{sub 3} overlay after hot corrosion. The results showed that Al{sub 2}O{sub 3} overlay acted as a barrier against the infiltration of the molten salt into the YSZ coating during exposure, thus significantly reduced the amount of M-phase of ZrO{sub 2} in YSZ coating. However, a thick Al{sub 2}O{sub 3} overlay was harmful for TBC by increasing compressive stress which causes crack and spalling of YSZ coating. As a result, a dense and thin Al{sub 2}O{sub 3} overlay is critical for simultaneously preventing YSZ from hot corrosion and spalling. In the next reporting period, we will measure or calculate the residue stress within Al{sub 2}O{sub 3} overlay and YSZ coating to study the mechanism of effect of Al{sub 2}O{sub 3} overlay on spalling of YSZ coating.

  19. Heterogeneous sensor networks: a bio-inspired overlay architecture

    NASA Astrophysics Data System (ADS)

    Burman, Jerry; Hespanha, Joao; Madhow, Upamanyu; Klein, Daniel; Isaacs, Jason; Venkateswaran, Sriram; Pham, Tien

    2010-04-01

    Teledyne Scientific Company, the University of California at Santa Barbara (UCSB) and the Army Research Lab are developing technologies for automated data exfiltration from heterogeneous sensor networks through the Institute for Collaborative Biotechnologies (ICB). Unmanned air vehicles (UAV) provide an effective means to autonomously collect data from unattended ground sensors (UGSs) that cannot communicate with each other. UAVs are used to reduce the system reaction time by generating autonomous data-driven collection routes. Bio-inspired techniques for search provide a novel strategy to detect, capture and fuse data across heterogeneous sensors. A fast and accurate method has been developed for routing UAVs and localizing an event by fusing data from a sparse number of UGSs; it leverages a bio-inspired technique based on chemotaxis or the motion of bacteria seeking nutrients in their environment. The system was implemented and successfully tested using a high level simulation environment using a flight simulator to emulate a UAV. A field test was also conducted in November 2009 at Camp Roberts, CA using a UAV provided by AeroMech Engineering. The field test results showed that the system can detect and locate the source of an acoustic event with an accuracy of about 3 meters average circular error.

  20. Comparative evaluation of chromogenic agar medium and conventional culture system for isolation and presumptive identification of uropathogens

    PubMed Central

    Akter, Laila; Haque, Rezwana; Salam, Md. Abdus

    2014-01-01

    Objective: Urine is the most frequent specimen received for culture/sensitivity by clinical laboratories. The microbiological performance of HiCrome UTI agar medium was compared with Blood agar and MacConkey agar for isolation and presumptive identification of bacteria from urine culture. Methods: A total of 443 consecutively collected midstream and/or catheter-catch urine samples from patients attending the Islami Bank Medical College Hospital, Rajshahi, Bangladesh during January to December, 2012 were cultured. Urine samples showing pus cells ≥ 5/HPF were inoculated on to Blood agar (BA), MacConkey agar (MAC) and HiCrome UTI agar (CA) media simultaneously and incubated overnight aerobically at 370C. Rate of isolation and presumptive identification of bacterial species were compared for different media. Results: Culture yielded a total of 199 bacterial isolates from 189 (42.67%) positive plates including 179 (40.40%) unimicrobial and 10 (2.26%) polymicrobial (mixed growth of pair of bacteria) growths. Both HiCrome UTI agar and Blood agar media supported 100% growths while 151 (75.88%) growths were observed on MacConkey agar. The rate of presumptive identification was found significantly higher on HiCrome UTI agar (97.49%) than MAC agar (67.34%) (P<0.001) as primary urine culture medium. Of 199 isolates, E. coli was found to be the leading uropathogen isolated from 118 (59.30%) samples with its presumptive identification rate of 95.76%, 93.22% and 5.93% on CA, MAC and BA respectively. All 10 (100%) polymicrobial growths were demonstrated distinctly on CA against only 01(10%) on each BA and MAC. Conclusion: HiCrome UTI agar was found to be more useful as primary urine culture medium in both higher rate of isolation and presumptive identification of uropathogens in comparison to conventional media. Its inherent characteristics in demonstrating polymicrobial growth and ease of rapid identification by distinct colony colour are unique. PMID:25225521

  1. IMPERMEABLE THIN Al2O3 OVERLAY FOR TBC PROTECTION FROM SULFATE AND VANADATE ATTACK IN GAS TURBINES

    SciTech Connect

    Scott X. Mao

    2002-11-30

    In order to improve the hot corrosion resistance of conventional YSZ TBC system, the Al{sub 2}O{sub 3} overlay coating has been successfully produced on the surface of YSZ by the Sol-gel route. The YSZ substrates were coated with boehmite sol by dip coating process, dried to form a gel film and calcined at 1200 C to form {alpha}-Al{sub 2}O{sub 3} overlay. The microstructures of TBC and Al{sub 2}O{sub 3} overlay were examined by scanning electron microscopy (SEM). The results showed that micro-pores ranged from 3 {micro}m to 20 {micro}m and micro-cracks could be clearly seen on the surface of APS YSZ coating. The thickness of alumina overlay increased with increasing the number of dip coating circles. The small microcracks (0.5-1.0 {micro}m width) on the YSZ surface could be filled and blocked by calcined alumina particles, whereas large pores remained empty and the alumina overlay was un-continuous after one time dip coating circle. Alumina overlay thicker than 5 m m obtained by five times dip coating circles largely cracked after calcinations. As a result, multiple dip coatings up to three times were ideal for getting high quality, crack- free and continuous overlay. The optimal thickness of alumina overlay was in the range of 2.5-3.5 {micro}m. In the next reporting period, we will study the hot corrosion behaviors of YSZ TBC with Al{sub 2}O{sub 3} overlay coating produced by sol gel route by exposure the samples to molten salts mixtures (Na{sub 2}SO{sub 4} + 5%V{sub 2}O{sub 5}) at 950 C.

  2. A novel approach for latent print identification using accurate overlays to prioritize reference prints.

    PubMed

    Gantz, Daniel T; Gantz, Donald T; Walch, Mark A; Roberts, Maria Antonia; Buscaglia, JoAnn

    2014-12-01

    A novel approach to automated fingerprint matching and scoring that produces accurate locally and nonlinearly adjusted overlays of a latent print onto each reference print in a corpus is described. The technology, which addresses challenges inherent to latent prints, provides the latent print examiner with a prioritized ranking of candidate reference prints based on the overlays of the latent onto each candidate print. In addition to supporting current latent print comparison practices, this approach can make it possible to return a greater number of AFIS candidate prints because the ranked overlays provide a substantial starting point for latent-to-reference print comparison. To provide the image information required to create an accurate overlay of a latent print onto a reference print, "Ridge-Specific Markers" (RSMs), which correspond to short continuous segments of a ridge or furrow, are introduced. RSMs are reliably associated with any specific local section of a ridge or a furrow using the geometric information available from the image. Latent prints are commonly fragmentary, with reduced clarity and limited minutiae (i.e., ridge endings and bifurcations). Even in the absence of traditional minutiae, latent prints contain very important information in their ridges that permit automated matching using RSMs. No print orientation or information beyond the RSMs is required to generate the overlays. This automated process is applied to the 88 good quality latent prints in the NIST Special Database (SD) 27. Nonlinear overlays of each latent were produced onto all of the 88 reference prints in the NIST SD27. With fully automated processing, the true mate reference prints were ranked in the first candidate position for 80.7% of the latents tested, and 89.8% of the true mate reference prints ranked in the top ten positions. After manual post-processing of those latents for which the true mate reference print was not ranked first, these frequencies increased to 90

  3. The effect of oxide overlayers on secondary electron dopant mapping.

    PubMed

    Dapor, Maurizio; Jepson, Mark A E; Inkson, Beverley J; Rodenburg, Cornelia

    2009-06-01

    The International Technology Roadmap for Semiconductors ranks dopant profiling as one of the most difficult challenges for analysis of semiconductors. Dopant mapping in the scanning electron microscope (SEM) has the potential to provide a solution. This technique has not yet found widespread application, however, mainly due to the lack of a comprehensive theoretical model, uncertain quantification, and its inability to differentiate doping levels in n-type silicon. Although a Monte Carlo model was recently published that closely matched experimental data obtained in p-doped silicon to data obtained from the theoretical model, a large discrepancy between experimental data obtained for n-type silicon was found. Here we present a Monte Carlo model that provides close matches between experimental and calculated data in both n- and p-type silicon, paving the way for a widespread application of SEM dopant contrast. PMID:19460180

  4. Holistic overlay control for multi-patterning process layers at the 10nm and 7nm nodes

    NASA Astrophysics Data System (ADS)

    Verstappen, Leon; Mos, Evert; Wardenier, Peter; Megens, Henry; Schmitt-Weaver, Emil; Bhattacharyya, Kaustuve; Adam, Omer; Grzela, Grzegorz; van Heijst, Joost; Willems, Lotte; Wildenberg, Jochem; Ignatova, Velislava; Chen, Albert; Elich, Frank; Rajasekharan, Bijoy; Vergaij-Huizer, Lydia; Lewis, Brian; Kea, Marc; Mulkens, Jan

    2016-03-01

    Multi-patterning lithography at the 10-nm and 7-nm nodes is driving the allowed overlay error down to extreme low values. Advanced high order overlay correction schemes are needed to control the process variability. Additionally the increase of the number of split layers results in an exponential increase of metrology complexity of the total overlay and alignment tree. At the same time, the process stack includes more hard-mask steps and becomes more and more complex, with as consequence that the setup and verification of the overlay metrology recipe becomes more critical. All of the above require a holistic approach that addresses total overlay optimization from process design to process setup and control in volume manufacturing. In this paper we will present the holistic overlay control flow designed for 10-nm and 7-nm nodes and illustrate the achievable ultimate overlay performance for a logic and DRAM use case. As figure 1 illustrates we will explain the details of the steps in the holistic flow. Overlay accuracy is the driver for target design and metrology tool optimization like wavelength and polarization. We will show that it is essential to include processing effects like etching and CMP which can result in a physical asymmetry of the bottom grating of diffraction based overlay targets. We will introduce a new method to create a reference overlay map, based on metrology data using multiple wavelengths and polarization settings. A similar approach is developed for the wafer alignment step. The overlay fingerprint correction using linear or high order correction per exposure (CPE) has a large amount of parameters. It is critical to balance the metrology noise with the ultimate correction model and the related metrology sampling scheme. Similar approach is needed for the wafer align step. Both for overlay control as well as alignment we have developed methods which include efficient use of metrology time, available for an in the litho-cluster integrated

  5. How do microorganisms influence trace element uptake by plants? Screening in an agar model rhizosphere.

    NASA Astrophysics Data System (ADS)

    Marchetti, M.; Robinson, B. H.; Evangelou, M. W. H.; Vachey, A.; Schwitzguebel, J. P.; Bernier-Latmani, R.; Schulin, R.

    2009-04-01

    Trace elements (TE) are essential for humans and plants, but they may be toxic if their concentration is too high. For this reason, the management of TE in soils is very important. In some cases it may be necessary to increase the uptake of nutrients or TE by plants, for example in a biofortification perspective. Conversely, in some other cases TE uptake by plants should be decreased, for instance to avoid heavy metals entering the food chain via edible crops. Microorganisms living in the rhizosphere affect trace element (TE) uptake by plants. However, due to the complexity of this space and the variety of microorganisms that occur there, it is difficult to isolate the effect of any particular strain. To overcome this hurdle, we developed a system in which we grew plants under sterile conditions in agar and inoculated their rhizosphere with a single, well-defined microbial strain. For many years, agar has been used as a growth substrate for microorganisms and plant tissues. It is cheap, easy to use, and can be autoclaved to ensure its sterility. Because of its widespread use, an experiment conducted using this substrate can be reproduced under the same conditions in any laboratory. In contrast to soil, there is little interaction between the trace elements and the agar matrix. There are many studies investigating the influence of microorganisms on TE uptake by plants. However, so far only a small variety of microorganisms has been tested on few plant species. Therefore, the first objective of our research was to develop a method to rapidly screen a large variety of microorganisms on various plant species. Once this goal was achieved, we sought to study the effect of single, well-defined microbial strains on TE uptake by sunflower and wheat. The substrate for plants growth was a 10% agar solution prepared with modified Hoagland's solution and a TE solution containing 1 mg/kg Pb and molar equivalents of Cu, Ni and Zn. The agar solution was autoclaved and poured into

  6. New clear-out scheme to improve the overlay performance for a CMP process

    NASA Astrophysics Data System (ADS)

    Guo, Yao-Wen; Kao, Han-Pin; Chien, Tsung-Chih; Chang, Chiafu; Lin, Hsin-Sung; Chen, Yen-Fen; Ku, Chin-Yu

    2002-07-01

    To obtain good overlay performance, the quality of the wafer marks should be well designed. Although different brands of steppers and scanners use unique mark pattern design and alignment system, these exposure tools determine the position of marks through the signal obtaining from the height difference within the mark region. The largest problem of the marks is that the quality of the marks is influenced by the process conditions, such as film deposition, chemical mechanical polishing, and etching conditions, etc. In this work, we studied the impact of the CMP on the quality of the ASML alignment mark. The film structure and process flow are also investigated to understand the deformation of marks for different clear-out scheme. The lot-to-lot overlay variation can be prevented when the new clear-out scheme is employed.

  7. A hierarchical P2P overlay network for interest-based media contents lookup

    NASA Astrophysics Data System (ADS)

    Lee, HyunRyong; Kim, JongWon

    2006-10-01

    We propose a P2P (peer-to-peer) overlay architecture, called IGN (interest grouping network), for contents lookup in the DHC (digital home community), which aims to provide a formalized home-network-extended construction of current P2P file sharing community. The IGN utilizes the Chord and de Bruijn graph for its hierarchical overlay network construction. By combining two schemes and by inheriting its features, the IGN efficiently supports contents lookup. More specifically, by introducing metadata-based lookup keyword, the IGN offers detailed contents lookup that can reflect the user interests. Moreover, the IGN tries to reflect home network environments of DHC by utilizing HG (home gateway) of each home network as a participating node of the IGN. Through experimental and analysis results, we show that the IGN is more efficient than Chord, a well-known DHT (distributed hash table)-based lookup protocol.

  8. Overlay metrology for dark hard mask process: simulation and experiment study

    NASA Astrophysics Data System (ADS)

    Shin, Jangho; Chalykh, Roman; Kang, Hyunjae; Kim, SeongSue; Lee, SukJoo; Cho, Han-Ku

    2007-03-01

    Simulation and experimental study results are reported to solve align/overlay problem in dark hard mask process in lithography. For simulation part, an in-house simulator, which is based on rigorous coupled wave analysis and Fourier optics method of high NA imaging, is used. According to the simulation and experiment study, image quality of alignment and overlay marks can be optimized by choosing hard mask and sub-film thickness carefully for a given process condition. In addition, it is important to keep the specification of film thickness uniformity within a certain limit. Simulation results are confirmed by experiment using the state of art memory process in Samsung semiconductor R&D facility.

  9. Robotic weld overlay coatings for erosion control. [Quarterly report, July--September 1993

    SciTech Connect

    Levin, B.F.; DuPont, J.N.; Marder, A.R.

    1993-10-20

    In the previous period of work, twelve overlay hardfacing alloys were selected for erosion testing based upon a literature review. All twelve coatings were deposited on 1018 steel substrates using the plasma arc welding process. Ten samples from each coating were prepared for erosion testing. The coating deposition and sample preparation procedures were described in the previous quarterly report. During the past quarter, all the coatings were erosion tested at 400 C. The erosion resistance of each coating was evaluated by determining the steady state erosion rate. In addition, the microstructure of each coating was characterized before and after the erosion tests. This progress report describes the erosion test results and coating microstructures. Also, a preliminary analysis on the relationships, between weld overlay coating hardness, microstructure, and erosion resistance will be discussed.

  10. Automatic Generation of Overlays and Offset Values Based on Visiting Vehicle Telemetry and RWS Visuals

    NASA Technical Reports Server (NTRS)

    Dunne, Matthew J.

    2011-01-01

    The development of computer software as a tool to generate visual displays has led to an overall expansion of automated computer generated images in the aerospace industry. These visual overlays are generated by combining raw data with pre-existing data on the object or objects being analyzed on the screen. The National Aeronautics and Space Administration (NASA) uses this computer software to generate on-screen overlays when a Visiting Vehicle (VV) is berthing with the International Space Station (ISS). In order for Mission Control Center personnel to be a contributing factor in the VV berthing process, computer software similar to that on the ISS must be readily available on the ground to be used for analysis. In addition, this software must perform engineering calculations and save data for further analysis.

  11. Detection and characterization of heparin-binding proteins with a gel overlay procedure

    SciTech Connect

    Mehlman, T.; Burgess, W.H. )

    1990-07-01

    The binding of {sup 125}I-labeled derivatives of heparin has been used by several investigators to identify heparin-binding fragments of different heparin-binding proteins. In this report we utilize the procedure described by J.W. Smith and D.J. Knauer (1987, Anal. Biochem. 160, 105-114) to produce {sup 125}I-fluorescein-heparin. Using this derivative, we compare the use of gel overlay procedures with Western blot procedures for the detection of heparin-binding proteins following polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate. We show that the gel overlay procedure is a relatively simple and sensitive method for visualizing heparin-binding proteins. In addition, we use the procedure to characterize the heparin-binding properties of heparin-binding growth factor 1 (acidic fibroblast growth factor) with synthetic peptide competitors and site-directed mutants of the growth factor.

  12. A bi-overlayer type plasmonic photocatalyst consisting of mesoporous Au/TiO2 and CuO/SnO2 films separately coated on FTO.

    PubMed

    Naya, Shin-ichi; Kume, Takahiro; Okumura, Nozomi; Tada, Hiroaki

    2015-07-21

    The principal purpose of this study is to present a new design for preparing highly active immobilized gold nanoparticle-based plasmonic photocatalysts. Gold nanoparticles were loaded on rutile TiO2 particles with a mean size of 80 nm (Au/TiO2) by the deposition precipitation method. The surface of SnO2 particles with a mean size of 100 nm was modified by copper(ii) oxide clusters (CuO/SnO2) with the loading amount (Γ/Cu ions nm(-2)) precisely controlled by the chemisorption-calcination cycle technique. Two mesoporous overlayers of Au/TiO2 and CuO/SnO2 were coated side by side on glass substrates with a fluorine-doped tin oxide film (FTO) using the doctor blade method (Au/mp-TiO2|FTO|CuO/mp-SnO2). As test reactions for assessing the visible-light activity, we carried out gas-phase decomposition of acetaldehyde and liquid-phase oxidation of alcohol. In each reaction, this bi-overlayer type catalyst shows a high level of visible-light activity much exceeding those of Au/TiO2 particles and a Au/mp-TiO2|FTO mono-overlayer type catalyst [J. Phys. Chem. C, 2014, 118, 26887]. To confirm the origin of the striking visible-light activity, we studied the electrocatalytic activity of CuO/mp-SnO2|FTO electrodes for the oxygen reduction reaction (ORR). Both the visible-light activity of Au/mp-TiO2|FTO|CuO/mp-SnO2 and the electrocatalytic activity of CuO/mp-SnO2|FTO for ORR strongly depend on the Γ value. A good positive correlation has been found between the visible-light activities and the electrocatalytic activity for ORR. The striking activity of the present bi-overlayer type catalyst can be attributed to the efficient and long-range charge separation by the vectorial electron transport (Au(oxidation sites) → TiO2→ FTO, SnO2→ CuO(reduction sites)) and the excellent electrocatalytic activity of the CuO clusters. PMID:26094620

  13. ACINETOBACTER SPP.: DISTINCT MORPHOLOGY ON EOSIN METHYLENE BLUE AGAR AS AN AID TO IDENTIFICATION IN DRINKING WATER

    EPA Science Inventory

    'Acinetobacter calcoaceticus', frequently found in drinking waters and implicated in nosocomial infections, was presumptively identified by its tiny, blue colonial appearance on Levine eosin methylene blue agar. All of the 33 isolates from drinking water showing this distinctive ...

  14. Preparation of an agar-silver nanoparticles (A-AgNp) film for increasing the shelf-life of fruits.

    PubMed

    Gudadhe, Janhavi A; Yadav, Alka; Gade, Aniket; Marcato, Priscyla D; Durán, Nelson; Rai, Mahendra

    2014-12-01

    Preparation of protective coating possessing antimicrobial properties is present day need as they increase the shelf life of fruits and vegetables. In the present study, preparation of agar-silver nanoparticle film for increasing the shelf life of fruits is reported. Silver nanoparticles (Ag-NPs) biosynthesised using an extract of Ocimum sanctum leaves, were mixed with agar-agar to prepare an agar-silver nanoparticles (A-AgNp) film. This film was surface-coated over the fruits, Citrus aurantifolium (Thornless lime) and Pyrus malus (Apple), and evaluated for the determination of antimicrobial activity of A-AgNp films using disc diffusion method, weight loss and shelf life of fruits. This study demonstrates that these A-AgNp films possess antimicrobial activity and also increase the shelf life of fruits. PMID:25429496

  15. Atom-probe and field emission electron spectroscopy studies of ordered structures and electronic properties of Ge overlayers on Ir-tips

    NASA Astrophysics Data System (ADS)

    Ashino, Makoto; Tomitori, Masahiko; Nishikawa, Osamu

    1994-03-01

    The combined instrument of an atom probe (AP) and a field emission electron spectroscope (FEES) was employed to investigate the crystallinity and the surface electronic state of Ge overlayers deposited on Ir tips. The crystallinity of Ge overlayers deposited at 300 and 420 K, and those annealed after the deposition, is better than that of the overlayers deposited at 50 K. The surface electronic state of the well-crystallized Ge overlayer is semiconductive at the thickness of ≈4 ML. When the degree of crystallinity is rather low or Ir atoms exist in the Ge overlayer, even a thick overlayer exhibits metallic surface electronic states. When an Ir atom exists on the overlayer surface, a small peak appears at ≈ 0.3 eV below the Fermi level in the field emission electron distribution (FEED), indicating a local state of the Ir atom.

  16. Microeconomics-based resource allocation in overlay networks by using non-strategic behavior modeling

    NASA Astrophysics Data System (ADS)

    Analoui, Morteza; Rezvani, Mohammad Hossein

    2011-01-01

    Behavior modeling has recently been investigated for designing self-organizing mechanisms in the context of communication networks in order to exploit the natural selfishness of the users with the goal of maximizing the overall utility. In strategic behavior modeling, the users of the network are assumed to be game players who seek to maximize their utility with taking into account the decisions that the other players might make. The essential difference between the aforementioned researches and this work is that it incorporates the non-strategic decisions in order to design the mechanism for the overlay network. In this solution concept, the decisions that a peer might make does not affect the actions of the other peers at all. The theory of consumer-firm developed in microeconomics is a model of the non-strategic behavior that we have adopted in our research. Based on it, we have presented distributed algorithms for peers' "joining" and "leaving" operations. We have modeled the overlay network as a competitive economy in which the content provided by an origin server can be viewed as commodity and the origin server and the peers who multicast the content to their downside are considered as the firms. On the other hand, due to the dual role of the peers in the overlay network, they can be considered as the consumers as well. On joining to the overlay economy, each peer is provided with an income and tries to get hold of the service regardless to the behavior of the other peers. We have designed the scalable algorithms in such a way that the existence of equilibrium price (known as Walrasian equilibrium price) is guaranteed.

  17. The Corrosion and Corrosion Fatigue Behavior of Nickel Based Alloy Weld Overlay and Coextruded Claddings

    NASA Astrophysics Data System (ADS)

    Stockdale, Andrew

    The use of low NOx boilers in coal fired power plants has resulted in sulfidizing corrosive conditions within the boilers and a reduction in the service lifetime of the waterwall tubes. As a solution to this problem, Ni-based weld overlays are used to provide the necessary corrosion resistance however; they are susceptible to corrosion fatigue. There are several metallurgical factors which give rise to corrosion fatigue that are associated with the localized melting and solidification of the weld overlay process. Coextruded coatings offer the potential for improved corrosion fatigue resistance since coextrusion is a solid state coating process. The corrosion and corrosion fatigue behavior of alloy 622 weld overlays and coextruded claddings was investigated using a Gleeble thermo-mechanical simulator retrofitted with a retort. The experiments were conducted at a constant temperature of 600°C using a simulated combustion gas of N2-10%CO-5%CO2-0.12%H 2S. An alternating stress profile was used with a minimum tensile stress of 0 MPa and a maximum tensile stress of 300 MPa (ten minute fatigue cycles). The results have demonstrated that the Gleeble can be used to successfully simulate the known corrosion fatigue cracking mechanism of Ni-based weld overlays in service. Multilayer corrosion scales developed on each of the claddings that consisted of inner and outer corrosion layers. The scales formed by the outward diffusion of cations and the inward diffusion of sulfur and oxygen anions. The corrosion fatigue behavior was influenced by the surface finish and the crack interactions. The initiation of a large number of corrosion fatigue cracks was not necessarily detrimental to the corrosion fatigue resistance. Finally, the as-received coextruded cladding exhibited the best corrosion fatigue resistance.

  18. RESTORING A DAMAGED 16-YEAR -OLD INSULATING POLYMER CONCRETE DIKE OVERLAY: REPAIR MATERIALS AND TECHNOLOGIES.

    SciTech Connect

    SUGAMA,T.

    2007-01-01

    The objective of this program was to design and formulate organic polymer-based material systems suitable for repairing and restoring the overlay panels of insulating lightweight polymer concrete (ILPC) from the concrete floor and slope wall of a dike at KeySpan liquefied natural gas (LNG) facility in Greenpoint, Brooklyn, NY, just over sixteen years ago. It also included undertaking a small-scale field demonstration to ensure that the commercial repairing technologies were applicable to the designed and formulated materials.

  19. Trace Amounts of Furan-2-Carboxylic Acids Determine the Quality of Solid Agar Plates for Bacterial Culture

    PubMed Central

    Hara, Shintaro; Isoda, Reika; Tahvanainen, Teemu; Hashidoko, Yasuyuki

    2012-01-01

    Background Many investigators have recognised that a significant proportion of environmental bacteria exist in a viable but non-culturable state on agar plates, and some researchers have also noticed that some of such bacteria clearly recover their growth on matrices other than agar. However, the reason why agar is unsuitable for the growth of some bacteria has not been addressed. Methodology/Principal Findings According to the guide of a bioassay for swarming inhibition, we identified 5-hydroxymethylfuran-2-carboxylic acid (5-HMFA) and furan-2-carboxylic acid (FA) as factors that inhibit bacterial swarming and likely inhibit extracellular polysaccharide production on agar. The furan-2-carboxylic acids 5-HMFA and FA effectively inhibited the swarming and swimming of several environmental bacteria at concentrations of 1.8 and 2.3 µg L−1 (13 and 21 nmol L−1), respectively, which are equivalent to the concentrations of these compounds in 0.3% agar. On Luria-Bertani (LB) plates containing 1.0% agar that had been previously washed with MeOH, a mixture of 5-HMFA and FA in amounts equivalent to their original concentrations in the unwashed agar repressed the swarming of Escherichia coli K12 strain W3110, a representative swarming bacterium. Conclusions/Significance Agar that contains trace amounts of 5-HMFA and FA inhibits the proliferation of some slow-growing or difficult-to-culture bacteria on the plates, but it is useful for single colony isolation due to the ease of identification of swarmable bacteria as the non-swarmed colonies. PMID:22848437

  20. In vitro/in vivo evaluation of agar nanospheres for pulmonary delivery of bupropion HCl.

    PubMed

    Varshosaz, Jaleh; Minaiyan, Mohsen; Zaki, Mohammad Reza; Fathi, Milad; Jaleh, Hossein

    2016-07-01

    Bupropion HCl is an atypical antidepressant drug with rapid and high first-pass metabolism. Sustained release dosage form of this drug is suggested for reducing its side effects which are mainly seizures. The aim of the present study was to design pulmonary agar nanospheres of bupropion HCl with effective systemic absorption and extended release properties. Bupropion HCl was encapsulated in agar nanospheres by ionic gelation, and characterized for physical and release properties. Pharmacokinetic studies on nanospheres were performed on rats by intratracheal spraying of 5 mg/kg of drug in form of nanospheres compared to intravenous and pulmonary delivery of the same dose as simple solution of the drug. The optimized nanoparticles showed particle size of 320 ± 90 nm with polydispersity index of 0.85, the zeta potential of -29.6 mV, drug loading efficiency of 43.1 ± 0.28% and release efficiency of 66.7 ± 2%. The area under the serum concentration-time profile for the pulmonary nanospheres versus simple solution was 10 237.84 versus 28.8 µg/ml min, Tmax of 360 versus 60 min and the Cmax of 1927.93 versus9.93 ng/ml, respectively. The absolute bioavailability of the drug was 86.69% for nanospheres and 0.25% for pulmonary simple solution. Our results indicate that pulmonary delivery of bupropion loaded agar nanospheres achieves systemic exposure and extends serum levels of the drug. PMID:25835223

  1. Cavitation-enhanced delivery of insulin in agar and porcine models of human skin

    NASA Astrophysics Data System (ADS)

    Feiszthuber, Helga; Bhatnagar, Sunali; Gyöngy, Miklós; Coussios, Constantin-C.

    2015-03-01

    Ultrasound-assisted transdermal insulin delivery offers a less painful and less invasive alternative to subcutaneous insulin injections. However, ultrasound-based drug delivery, otherwise known as sonophoresis, is a highly variable phenomenon, in part dependent on cavitation. The aim of the current work is to investigate the role of cavitation in transdermal insulin delivery. Fluorescently stained, soluble Actrapid insulin was placed on the surface of human skin-mimicking materials subjected to 265 kHz, 10% duty cycle focused ultrasound. A confocally and coaxially aligned 5 MHz broadband ultrasound transducer was used to detect cavitation. Two different skin models were used. The first model, 3% agar hydrogel, was insonated with a range of pressures (0.25-1.40 MPa peak rarefactional focal pressure—PRFP), with and without cavitation nuclei embedded within the agar at a concentration of 0.05% w/v. The second, porcine skin was insonated at 1.00 and 1.40 MPa PRFP. In both models, fluorescence measurements were used to determine penetration depth and concentration of delivered insulin. Results show that in agar gel, both insulin penetration depth and concentration only increased significantly in the presence of inertial cavitation, with up to a 40% enhancement. In porcine skin the amount of fluorescent insulin was higher in the epidermis of those samples that were exposed to ultrasound compared to the control samples, but there was no significant increase in penetration distance. The results underline the importance of instigating and monitoring inertial cavitation during transdermal insulin delivery.

  2. Cavitation-enhanced delivery of insulin in agar and porcine models of human skin.

    PubMed

    Feiszthuber, Helga; Bhatnagar, Sunali; Gyöngy, Miklós; Coussios, Constantin-C

    2015-03-21

    Ultrasound-assisted transdermal insulin delivery offers a less painful and less invasive alternative to subcutaneous insulin injections. However, ultrasound-based drug delivery, otherwise known as sonophoresis, is a highly variable phenomenon, in part dependent on cavitation. The aim of the current work is to investigate the role of cavitation in transdermal insulin delivery. Fluorescently stained, soluble Actrapid insulin was placed on the surface of human skin-mimicking materials subjected to 265 kHz, 10% duty cycle focused ultrasound. A confocally and coaxially aligned 5 MHz broadband ultrasound transducer was used to detect cavitation. Two different skin models were used. The first model, 3% agar hydrogel, was insonated with a range of pressures (0.25-1.40 MPa peak rarefactional focal pressure-PRFP), with and without cavitation nuclei embedded within the agar at a concentration of 0.05% w/v. The second, porcine skin was insonated at 1.00 and 1.40 MPa PRFP. In both models, fluorescence measurements were used to determine penetration depth and concentration of delivered insulin. Results show that in agar gel, both insulin penetration depth and concentration only increased significantly in the presence of inertial cavitation, with up to a 40% enhancement. In porcine skin the amount of fluorescent insulin was higher in the epidermis of those samples that were exposed to ultrasound compared to the control samples, but there was no significant increase in penetration distance. The results underline the importance of instigating and monitoring inertial cavitation during transdermal insulin delivery. PMID:25716689

  3. Factors controlling the CO intercalation of h-BN overlayers on Ru(0001).

    PubMed

    Dong, Aiyi; Fu, Qiang; Wu, Hao; Wei, Mingming; Bao, Xinhe

    2016-09-21

    The space between a two-dimensional (2D) material overlayer and a metal surface can be regarded as a nanoreactor, in which molecule adsorption and surface reaction may occur. In this work, we present CO intercalation under a hexagonal boron nitride (h-BN) overlayer on Ru(0001) at room temperature, observed using X-ray photoelectron spectroscopy, ultraviolet photoelectron spectroscopy, and scanning tunneling microscopy. Critical factors influencing the interfacial process have been investigated, including CO partial pressure, h-BN coverage, and oxygen pre-adsorption on the Ru surface. It has been identified that CO adsorption on the bare Ru surface region plays an important role in CO intercalation. Comparative studies of CO intercalation at h-BN/Ru(0001) and graphene/Ru(0001) interfaces indicate that CO starts to intercalate h-BN overlayers more easily than graphene. Temperature-programmed CO desorption experiments from h-BN/CO/Ru(0001) and graphene/CO/Ru(0001) surfaces reveal a similar confinement effect of the 2D cover on CO adsorption, which results in a more abrupt and quick CO desorption in comparison with the CO/Ru(0001) surface. PMID:27530273

  4. An Area-Based Overlay Architecture for Scalable Integration of Sensor Networks

    NASA Astrophysics Data System (ADS)

    Pappas, Lampros; Lalis, Spyros

    With many different sensor networks being deployed, there will be an increased need to facilitate their uniform and efficient access at a large, perhaps even global, scale. To this end, we present an overlay-based architecture for organizing and querying multiple sensor networks based on their geographical area. The nodes of the system, representing query processors and individual sensor network gateways, are organized in a hierarchy which is used for query forwarding and result delivery. The key features of our system are: (i) support for the dynamic addition and removal of query processors and sensor network gateways; (ii) automatic hierarchy construction and awareness of sensing capabilities based on explicit metadata information; and (iii) efficient query multiplexing and result de-multiplexing within the overlay. We present a first evaluation of the proposed architecture. Results indicate that our design considerably reduces the communication between the nodes of the overlay as well as the actual sensing load at the edges (sensor networks) of the system.

  5. Enhancement of electron-phonon coupling in Cs-overlayered intercalated bilayer graphene.

    PubMed

    Kleeman, J; Sugawara, K; Sato, T; Takahashi, T

    2016-05-25

    We have performed high-resolution angle-resolved photoemission spectroscopy (ARPES) on cesium (Cs) intercalated bilayer graphene with a Cs overlayer (Cs-C8CsC8). Low-energy electron diffraction shows a (2  ×  2) pattern consistent with intercalation of a Cs layer similar to bulk C8Cs, in addition to the signature of a nearly commensurate superstructure created by the Cs overlayer. ARPES results reveal folding of the π bands due to the periodic (2  ×  2) potential of the intercalated Cs atoms, together with a free-electron-like state at the [Formula: see text] point. Significant mass renormalization is observed in the band dispersion near the Fermi level, indicative of strong electron-phonon coupling. Based on analysis of the self-energy, we find anisotropic electron-phonon coupling with an estimated strength of [Formula: see text]  ±  0.02 in the K-[Formula: see text] direction, and [Formula: see text] in the K-M direction. This coupling is much larger than that of other doped graphenes, and comparable to superconducting bulk GICs. We attribute this large electron-phonon coupling constant to the presence of the Cs overlayer, which highly dopes [Formula: see text] bands, and creates a structure similar to stage-I graphite intercalation compounds. PMID:27094681

  6. Image overlay solution based on threshold detection for a compact near infrared fluorescence goggle system.

    PubMed

    Gao, Shengkui; Mondal, Suman B; Zhu, Nan; Liang, RongGuang; Achilefu, Samuel; Gruev, Viktor

    2015-01-01

    Near infrared (NIR) fluorescence imaging has shown great potential for various clinical procedures, including intraoperative image guidance. However, existing NIR fluorescence imaging systems either have a large footprint or are handheld, which limits their usage in intraoperative applications. We present a compact NIR fluorescence imaging system (NFIS) with an image overlay solution based on threshold detection, which can be easily integrated with a goggle display system for intraoperative guidance. The proposed NFIS achieves compactness, light weight, hands-free operation, high-precision superimposition, and a real-time frame rate. In addition, the miniature and ultra-lightweight light-emitting diode tracking pod is easy to incorporate with NIR fluorescence imaging. Based on experimental evaluation, the proposed NFIS solution has a lower detection limit of 25 nM of indocyanine green at 27 fps and realizes a highly precise image overlay of NIR and visible images of mice in vivo. The overlay error is limited within a 2-mm scale at a 65-cm working distance, which is highly reliable for clinical study and surgical use. PMID:25607724

  7. Image overlay solution based on threshold detection for a compact near infrared fluorescence goggle system

    NASA Astrophysics Data System (ADS)

    Gao, Shengkui; Mondal, Suman B.; Zhu, Nan; Liang, RongGuang; Achilefu, Samuel; Gruev, Viktor

    2015-01-01

    Near infrared (NIR) fluorescence imaging has shown great potential for various clinical procedures, including intraoperative image guidance. However, existing NIR fluorescence imaging systems either have a large footprint or are handheld, which limits their usage in intraoperative applications. We present a compact NIR fluorescence imaging system (NFIS) with an image overlay solution based on threshold detection, which can be easily integrated with a goggle display system for intraoperative guidance. The proposed NFIS achieves compactness, light weight, hands-free operation, high-precision superimposition, and a real-time frame rate. In addition, the miniature and ultra-lightweight light-emitting diode tracking pod is easy to incorporate with NIR fluorescence imaging. Based on experimental evaluation, the proposed NFIS solution has a lower detection limit of 25 nM of indocyanine green at 27 fps and realizes a highly precise image overlay of NIR and visible images of mice in vivo. The overlay error is limited within a 2-mm scale at a 65-cm working distance, which is highly reliable for clinical study and surgical use.

  8. Image overlay solution based on threshold detection for a compact near infrared fluorescence goggle system

    PubMed Central

    Gao, Shengkui; Mondal, Suman B.; Zhu, Nan; Liang, RongGuang; Achilefu, Samuel; Gruev, Viktor

    2015-01-01

    Abstract. Near infrared (NIR) fluorescence imaging has shown great potential for various clinical procedures, including intraoperative image guidance. However, existing NIR fluorescence imaging systems either have a large footprint or are handheld, which limits their usage in intraoperative applications. We present a compact NIR fluorescence imaging system (NFIS) with an image overlay solution based on threshold detection, which can be easily integrated with a goggle display system for intraoperative guidance. The proposed NFIS achieves compactness, light weight, hands-free operation, high-precision superimposition, and a real-time frame rate. In addition, the miniature and ultra-lightweight light-emitting diode tracking pod is easy to incorporate with NIR fluorescence imaging. Based on experimental evaluation, the proposed NFIS solution has a lower detection limit of 25 nM of indocyanine green at 27 fps and realizes a highly precise image overlay of NIR and visible images of mice in vivo. The overlay error is limited within a 2-mm scale at a 65-cm working distance, which is highly reliable for clinical study and surgical use. PMID:25607724

  9. Solar-reflective coating as a cooling overlay for asphalt pavement

    NASA Astrophysics Data System (ADS)

    Wang, He; Xu, Geng; Feng, Decheng; Zhong, Jing; Xie, Ning

    2011-11-01

    Rutting is one of the most serious problems on asphalt pavements. Decrease the surface temperature of the asphalt pavement is an effective method to solve the rutting problem on asphalt pavements. In this study, nano sized particles filled polymer composite was developed as an overlay to reflect the solar energy and decrease the surface temperature of asphalt pavements. The overlay was composed of acrylic or epoxy resin filled with nano TiO2 or nano TiNO2. The solar reflection of the nano particle filled polymers was tested and the results showed that solar reflection effectiveness of the epoxy/TiO2 composite reached the highest value. The results of outdoor temperature test indicate that the solar-reflective overlay could decrease the surface temperature of asphalt pavements about 10 °C when the pavement temperature is about 60 °C. Pavement skid resistance was also tested, which expressed by micro/macrotexture depth and the results of which showed that both matrix was qualified after coated with aggregates on the surface.

  10. Solar-reflective coating as a cooling overlay for asphalt pavement

    NASA Astrophysics Data System (ADS)

    Wang, He; Xu, Geng; Feng, Decheng; Zhong, Jing; Xie, Ning

    2012-04-01

    Rutting is one of the most serious problems on asphalt pavements. Decrease the surface temperature of the asphalt pavement is an effective method to solve the rutting problem on asphalt pavements. In this study, nano sized particles filled polymer composite was developed as an overlay to reflect the solar energy and decrease the surface temperature of asphalt pavements. The overlay was composed of acrylic or epoxy resin filled with nano TiO2 or nano TiNO2. The solar reflection of the nano particle filled polymers was tested and the results showed that solar reflection effectiveness of the epoxy/TiO2 composite reached the highest value. The results of outdoor temperature test indicate that the solar-reflective overlay could decrease the surface temperature of asphalt pavements about 10 °C when the pavement temperature is about 60 °C. Pavement skid resistance was also tested, which expressed by micro/macrotexture depth and the results of which showed that both matrix was qualified after coated with aggregates on the surface.

  11. Structural evolution of the Pb/Si(111) interface with metal overlayer thickness

    NASA Astrophysics Data System (ADS)

    Souto-Casares, Jaime; Chan, Tzu-Liang; Chelikowsky, James R.; Ho, Kai-Ming; Wang, Cai-Zhuang; Zhang, S. B.

    2015-09-01

    We employ a real-space pseudopotential method to compute the structural energies of a prototypical metal-semiconductor interface. Specifically, we examine a Pb(111) film overlaid on a Si(111) substrate as a function of the metal thickness. For each layer of Pb, we fully relax the atomic coordinates and determine the lowest-energy structure. Owing to the lattice mismatch between the Pb and Si crystal structures, we consider a large supercell containing up to 1505 atoms for the largest system. Systems of this size remain challenging for most current computational approaches and require algorithms specifically designed for highly parallel computational platforms. We examine the structural properties of the interface with respect to the thickness of the metal overlayer, e.g., the corrugation of the profile of the Pb overlayer. The combined influence of the Si substrate and quantum confinement results in a rich profile for a transition between a thin overlayer (less than a few monolayers), where the corrugation is strong, and the bulk region (more than a half-dozen layers), where the overlaid Pb film is atomically flat. This work proves the feasibility of handling systems with such a level of complexity.

  12. Enhancement of electron–phonon coupling in Cs-overlayered intercalated bilayer graphene

    NASA Astrophysics Data System (ADS)

    Kleeman, J.; Sugawara, K.; Sato, T.; Takahashi, T.

    2016-05-01

    We have performed high-resolution angle-resolved photoemission spectroscopy (ARPES) on cesium (Cs) intercalated bilayer graphene with a Cs overlayer (Cs-C8CsC8). Low-energy electron diffraction shows a (2  ×  2) pattern consistent with intercalation of a Cs layer similar to bulk C8Cs, in addition to the signature of a nearly commensurate superstructure created by the Cs overlayer. ARPES results reveal folding of the π bands due to the periodic (2  ×  2) potential of the intercalated Cs atoms, together with a free-electron-like state at the Γ point. Significant mass renormalization is observed in the band dispersion near the Fermi level, indicative of strong electron–phonon coupling. Based on analysis of the self-energy, we find anisotropic electron–phonon coupling with an estimated strength of λ =0.38   ±  0.02 in the K-Γ direction, and λ =0.60+/- 0.02 in the K-M direction. This coupling is much larger than that of other doped graphenes, and comparable to superconducting bulk GICs. We attribute this large electron–phonon coupling constant to the presence of the Cs overlayer, which highly dopes {π\\ast} bands, and creates a structure similar to stage-I graphite intercalation compounds.

  13. Iron aluminide weld overlay coatings for boiler tube protection in coal-fired low NOx boilers

    SciTech Connect

    Banovic, S.W.; DuPont, J.N.; Marder, A.R.

    1997-12-01

    Iron aluminide weld overlay coatings are currently being considered for enhanced sulfidation resistance in coal-fired low NO{sub x} boilers. The use of these materials is currently limited due to hydrogen cracking susceptibility, which generally increases with an increase in aluminum concentration of the deposit. The overall objective of this program is to attain an optimum aluminum content with good weldability and improved sulfidation resistance with respect to conventional materials presently in use. Research has been initiated using Gas Tungsten Arc Welding (GTAW) in order to achieve this end. Under different sets of GTAW parameters (wire feed speed, current), both single and multiple pass overlays were produced. Characterization of all weldments was conducted using light optical microscopy, scanning electron microscopy, and electron probe microanalysis. Resultant deposits exhibited a wide range of aluminum contents (5--43 wt%). It was found that the GTAW overlays with aluminum contents above {approximately}10 wt% resulted in cracked coatings. Preliminary corrosion experiments of 5 to 10 wt% Al cast alloys in relatively simple H{sub 2}/H{sub 2}S gas mixtures exhibited corrosion rates lower than 304 stainless steel.

  14. Ellipsometric study of ambient-produced overlayer growth rate on YBa2Cu3O(7-x) films

    NASA Technical Reports Server (NTRS)

    Sieg, Robert M.; Alterovitz, Samuel A.; Warner, Joseph D.

    1993-01-01

    An ellipsometric study of ambient-reaction-produced BaCO3 overlayer growth on laser-ablated YBCO is presented as a function of time. The effects of the anisotropy of YBCO on the ellipsometric data inversion process are discussed, and it is concluded that with certain restrictions on the data acquisition method, the anisotropic substrate can be adequately modeled by its isotropic pseudodielectric function for the purpose of overlayer thickness estimation. It is found that after an initial period of rapid growth attributed to the chemical reaction of the exposed surface bonds, the BaCO3 overlayer growth is linear at 1-2 A per day. This slow growth rate is attributed to the complexity of the BaCO3-forming reaction, together with the need for ambient reactants to diffuse through the overlayer.

  15. Study of spread spectrum multiple access systems for satellite communications with overlay on current services: Executive summary

    NASA Technical Reports Server (NTRS)

    Ha, Tri T.; Pratt, Timothy

    1987-01-01

    Two different methods of generating spread spectrum signals for an overlay service are discussed, and the data rate and efficiency which can be achieved while maintaining low interference with existing traffic are examined.

  16. [Change of leukocytic phagocytosis during repeat hemoperfusion with cross-linked agar beads entrapped attapulgite clay].

    PubMed

    Huang, Wei; Ma, Yu; Yang, Xiaolan; Tang, Xianjue; Shu, Changda

    2003-06-01

    The leukocytic phagocytosis rate and the index of phagocytosis of rats on cross-linked agar beads entrapped attapulgite clay (CAA) hemoperfusion were studied. The results revealed that the leukocytic phagocytosis rate and the index of phagocytosis descended significantly after 1 hour and rose gradually after 6 hours. Finally it reached the normal level after 48 hours. Hemoperfusion repeated two times gave similar results. In conclusion, the function of leukocytic phagocytosis declined temporarily during CAA hemoperfusion. Many times hemoperfusion will not notably affect the body's defense system of rats. PMID:12856604

  17. Coma in the course of severe poisoning after consumption of red fly agaric (Amanita muscaria).

    PubMed

    Mikaszewska-Sokolewicz, Małgorzata A; Pankowska, Sylwestra; Janiak, Marek; Pruszczyk, Piotr; Łazowski, Tomasz; Jankowski, Krzysztof

    2016-01-01

    Red fly agaric poisoning is rare. It can be consumed for suicidal purposes or its psychedelic effect. The paper describes the case of a young men, who fell into a coma after ingestion of the red toadstools. Quick identification of the poison, early use of gastric lavage and symptomatic treatment resulted in regression of symptoms and lead to the patient's discharge from the hospital on the third day after intoxication. Authors discussing the poisonous alkaloids contained in the red toadtools: ibotenic acid, muscimol, muscasone and muscarine and theirs properties, responsible for the symptoms of intoxication. PMID:26828668

  18. CHROMagar Yersinia, a New Chromogenic Agar for Screening of Potentially Pathogenic Yersinia enterocolitica Isolates in Stools

    PubMed Central

    Renaud, Nicolas; Lecci, Laetitia; Courcol, René J.; Simonet, Michel

    2013-01-01

    CHROMagar Yersinia (CAY) is a new chromogenic medium for the presumptive detection of virulent Yersinia enterocolitica in stools. Based on a comparative analysis of 1,494 consecutive stools from hospitalized patients, CAY was found to be just as sensitive as the reference medium (cefsulodin-irgasan-novobiocin agar) but was significantly more specific and had a very low false-positive rate. CAY reduces the workload (and thus costs) for stool analysis and can therefore be recommended for routine laboratory use. PMID:23363840

  19. Comparative study of 6-APA production by free and agar immobilized bacteria in nutrient broth culture.

    PubMed

    Dolui, A K; Das, S

    2011-04-01

    In the present study different bacterial samples were isolated from soil of different places of Dibrugarh and screened for biotransformation ability to produce 6-Aminopenicillanic acid. Among ten isolated bacterial samples, three gram positive bacterial samples designated as AKDD-2, AKDD-4 and AKDD-6 showed the production of 6-APA from penicillin G. Assessment of production of 6-APA after incubation in penicillin G (2 mg/ml) by three different samples separately in free and agar immobilization state was done by HPLC analysis. Reusability of immobilized cells was found successful up to 14 days. PMID:21614893

  20. Three-dimensional characterization of bacterial microcolonies on solid agar-based culture media.

    PubMed

    Drazek, Laurent; Tournoud, Maud; Derepas, Frédéric; Guicherd, Maryse; Mahé, Pierre; Pinston, Frédéric; Veyrieras, Jean-Baptiste; Chatellier, Sonia

    2015-02-01

    For the last century, in vitro diagnostic process in microbiology has mainly relied on the growth of bacteria on the surface of a solid agar medium. Nevertheless, few studies focused in the past on the dynamics of microcolonies growth on agar surface before 8 to 10h of incubation. In this article, chromatic confocal microscopy has been applied to characterize the early development of a bacterial colony. This technology relies on a differential focusing depth of the white light. It allows one to fully measure the tridimensional shape of microcolonies more quickly than classical confocal microscopy but with the same spatial resolution. Placing the device in an incubator, the method was able to individually track colonies growing on an agar plate, and to follow the evolution of their surface or volume. Using an appropriate statistical modeling framework, for a given microorganism, the doubling time has been estimated for each individual colony, as well as its variability between colonies, both within and between agar plates. A proof of concept led on four bacterial strains of four distinct species demonstrated the feasibility and the interest of the approach. It showed in particular that doubling times derived from early tri-dimensional measurements on microcolonies differed from classical measurements in micro-dilutions based on optical diffusion. Such a precise characterization of the tri-dimensional shape of microcolonies in their late-lag to early-exponential phase could be beneficial in terms of in vitro diagnostics. Indeed, real-time monitoring of the biomass available in a colony could allow to run well established microbial identification workflows like, for instance, MALDI-TOF mass-spectrometry, as soon as a sufficient quantity of material is available, thereby reducing the time needed to provide a diagnostic. Moreover, as done for pre-identification of macro-colonies, morphological indicators such as three-dimensional growth profiles derived from

  1. Amino acid mediated synthesis of silver nanoparticles and preparation of antimicrobial agar/silver nanoparticles composite films.

    PubMed

    Shankar, Shiv; Rhim, Jong-Whan

    2015-10-01

    Silver nanoparticles (AgNPs) were synthesized using amino acids (tyrosine and tryptophan) as reducing and capping agents, and they were incorporated into the agar to prepare antimicrobial composite films. The AgNPs solutions exhibited characteristic absorption peak at 420 nm that showed a red shift to ∼434 nm after forming composite with agar. XRD data demonstrated the crystalline structure of AgNPs with dominant (111) facet. Apparent surface color and transmittance of agar films were greatly influenced by the AgNPs. The incorporation of AgNPs into agar did not exhibit any change in chemical structure, thermal stability, moisture content, and water vapor permeability. The water contact angle, tensile strength, and modulus decreased slightly, but elongation at break increased after AgNPs incorporation. The agar/AgNPs nanocomposite films possessed strong antibacterial activity against Listeria monocytogenes and Escherichia coli. The agar/AgNPs film could be applied to the active food packaging by controlling the food-borne pathogens. PMID:26076636

  2. Capability for Fine Tuning of the Refractive Index Sensing Properties of Long-Period Gratings by Atomic Layer Deposited Al2O3 Overlays

    PubMed Central

    Śmietana, Mateusz; Myśliwiec, Marcin; Mikulic, Predrag; Witkowski, Bartłomiej S.; Bock, Wojtek J.

    2013-01-01

    This work presents an application of thin aluminum oxide (Al2O3) films obtained using atomic layer deposition (ALD) for fine tuning the spectral response and refractive-index (RI) sensitivity of long-period gratings (LPGs) induced in optical fibers. The technique allows for an efficient and well controlled deposition at monolayer level (resolution ∼ 0.12 nm) of excellent quality nano-films as required for optical sensors. The effect of Al2O3 deposition on the spectral properties of the LPGs is demonstrated experimentally and numerically. We correlated both the increase in Al2O3 thickness and changes in optical properties of the film with the shift of the LPG resonance wavelength and proved that similar films are deposited on fibers and oxidized silicon reference samples in the same process run. Since the thin overlay effectively changes the distribution of the cladding modes and thus also tunes the device's RI sensitivity, the tuning can be simply realized by varying number of cycles, which is proportional to thickness of the high-refractive-index (n > 1.6 in infrared spectral range) Al2O3 film. The advantage of this approach is the precision in determining the film properties resulting in RI sensitivity of the LPGs. To the best of our knowledge, this is the first time that an ultra-precise method for overlay deposition has been applied on LPGs for RI tuning purposes and the results have been compared with numerical simulations based on LP mode approximation.

  3. IMPERMEABLE THIN Al2O3 OVERLAY FOR TBC PROTECTION FROM SULFATE AND VANADATE ATTACK IN GAS TURBINES

    SciTech Connect

    Scott X. Mao

    2003-03-10

    In order to improve the hot corrosion resistance of conventional YSZ TBC system, a thin and dense {alpha}-Al{sub 2}O{sub 3} overlay has been deposited on the YSZ surface by the composite-sol-gel route (CSG). The YSZ substrates were dipped with boehmite sol containing calcined {alpha}-Al{sub 2}O{sub 3} particles, dried to form a gel film and calcined at 1200 C to form {alpha}-Al{sub 2}O{sub 3} overlay. Hot corrosion tests were carried out on the TBCs with and without Al{sub 2}O{sub 3} coating in molten salt mixtures (Na{sub 2}SO{sub 4} + 5% V{sub 2}O{sub 5}) at 950 C for 10 hours. The results showed that besides a thin and dense alumina overlay with the thickness of about 100-500 nm formed on the YSZ surface, the microcracks and porous near the surface in YSZ was also occupied by alumina because of penetration of the low viscosity precursor. As a result, the Al{sub 2}O{sub 3} overlay remarkably refrained the infiltration of the molten salt into the YSZ coating. The amount of M-phase in the TBC coating with Al{sub 2}O{sub 3} overlay was substantially reduced comparing to that without alumina overlay. In the next reporting period, we will prepare the alumina overlay by CSG route with different thickness and study the hot corrosion mechanism of YSZ TBC with thin Al{sub 2}O{sub 3} overlay coating produced by CSG.

  4. Detection by hyperspectral imaging of shiga toxin-producing Escherichia coli serogroups O26, O45, O103, O111, O121, and O145 on rainbow agar.

    PubMed

    Windham, William R; Yoon, Seung-Chul; Ladely, Scott R; Haley, Jennifer A; Heitschmidt, Jerry W; Lawrence, Kurt C; Park, Bosoon; Narrang, Neelam; Cray, William C

    2013-07-01

    The U.S. Department of Agriculture, Food Safety Inspection Service has determined that six non-O157 Shiga toxin-producing Escherichia coli (STEC) serogroups (O26, O45, O103, O111, O121, and O145) are adulterants in raw beef. Isolate and phenotypic discrimination of non-O157 STEC is problematic due to the lack of suitable agar media. The lack of distinct phenotypic color variation among non-O157serogroups cultured on chromogenic agar poses a challenge in selecting colonies for confirmation. In this study, visible and near-infrared hyperspectral imaging and chemometrics were used to detect and classify non-O157 STEC serogroups grown on Rainbow agar O157. The method was first developed by building spectral libraries for each serogroup obtained from ground-truth regions of interest representing the true identity of each pixel and thus each pure culture colony in the hyperspectral agar-plate image. The spectral library for the pure-culture non-O157 STEC consisted of 2,171 colonies, with spectra derived from 124,347 of pixels. The classification models for each serogroup were developed with a k nearest-neighbor classifier. The overall classification training accuracy at the colony level was 99%. The classifier was validated with ground beef enrichments artificially inoculated with 10, 50, and 100 CFU/ml STEC. The validation ground-truth regions of interest of the STEC target colonies consisted of 606 colonies, with 3,030 pixels of spectra. The overall classification accuracy was 98%. The average specificity of the method was 98% due to the low false-positive rate of 1.2%. The sensitivity ranged from 78 to 100% due to the false-negative rates of 22, 7, and 8% for O145, O45, and O26, respectively. This study showed the potential of visible and near-infrared hyperspectral imaging for detecting and classifying colonies of the six non-O157 STEC serogroups. The technique needs to be validated with bacterial cultures directly extracted from meat products and positive

  5. Effects of neutron irradiation on microstructures and hardness of stainless steel weld-overlay cladding of nuclear reactor pressure vessels

    NASA Astrophysics Data System (ADS)

    Takeuchi, T.; Kakubo, Y.; Matsukawa, Y.; Nozawa, Y.; Toyama, T.; Nagai, Y.; Nishiyama, Y.; Katsuyama, J.; Yamaguchi, Y.; Onizawa, K.

    2014-06-01

    The microstructures and the hardness of stainless steel weld overlay cladding of reactor pressure vessels subjected to neutron irradiation at a dose of 7.2 × 1019 n cm-2 (E > 1 MeV) and a flux of 1.1 × 1013 n cm-2 s-1 at 290 °C were investigated by atom probe tomography and by a nanoindentation technique. To isolate the effects of the neutron irradiation, we compared the results of the measurements of the neutron-irradiated samples with those from a sample aged at 300 °C for a duration equivalent to that of the irradiation. The Cr concentration fluctuation was enhanced in the δ-ferrite phase of the irradiated sample. In addition, enhancement of the concentration fluctuation of Si, which was not observed in the aged sample, was observed. The hardening in the δ-ferrite phase occurred due to both irradiation and aging; however, the hardening of the irradiated sample was more than that expected from the Cr concentration fluctuation, which suggested that the Si concentration fluctuation and irradiation-induced defects were possible origins of the additional hardening.

  6. Mechanical and water barrier properties of agar/κ-carrageenan/konjac glucomannan ternary blend biohydrogel films.

    PubMed

    Rhim, Jong-Whan; Wang, Long-Feng

    2013-07-01

    Multicomponent hydrogel films composed of agar, κ-carrageenan, konjac glucomannan powder, and nanoclay (Cloisite(®) 30B) were prepared and their mechanical and water barrier properties such as water vapor permeability (WVP), water contact angle (CA), water solubility (WS), water uptake ratio (WUR), water vapor uptake ratio (WVUR) were determined. Mechanical, water vapor barrier, and water resistance properties of the ternary blend film exhibited middle range of individual component films, however, they increased significantly after formation of nanocomposite with the clay. Especially, the water holding capacity of the ternary blend biopolymer films increased tremendously, from 800% to 1681% of WUR for agar and κ-carrageenan films up to 5118% and 5488% of WUR for the ternary blend and ternary blend nanocomposite films, respectively. Water vapor adsorption behavior of films was also tested by water vapor adsorption kinetics and water vapor adsorption isotherms test. Preliminary test result for fresh spinach packaging revealed that the ternary blend biohydrogel films had a high potential for the use as an antifogging film for packaging highly respiring agricultural produce. In addition, the ternary blend nanocomposite film showed an antimicrobial activity against Gram-positive bacteria, Listeria monocytogenes. PMID:23688456

  7. Visualization of Biosurfactant Film Flow in a Bacillus subtilis Swarm Colony on an Agar Plate

    PubMed Central

    Kim, Kyunghoon; Kim, Jung Kyung

    2015-01-01

    Collective bacterial dynamics plays a crucial role in colony development. Although many research groups have studied the behavior of fluidic swarm colonies, the detailed mechanics of its motion remains elusive. Here, we developed a visualization method using submicron fluorescent beads for investigating the flow field in a thin layer of fluid that covers a Bacillus subtilis swarm colony growing on an agar plate. The beads were initially embedded in the agar plate and subsequently distributed spontaneously at the upper surface of the expanding colony. We conducted long-term live cell imaging of the B. subtilis colony using the fluorescent tracers, and obtained high-resolution velocity maps of microscale vortices in the swarm colony using particle image velocimetry. A distinct periodic fluctuation in the average speed and vorticity of flow in swarm colony was observed at the inner region of the colony, and correlated with the switch between bacterial swarming and growth phases. At the advancing edge of the colony, both the magnitudes of velocity and vorticity of flow in swarm colony were inversely correlated with the spreading speed of the swarm edge. The advanced imaging tool developed in this study would facilitate further understanding of the effect of micro vortices in swarm colony on the collective dynamics of bacteria. PMID:26343634

  8. Evaluation of a Modified Cefsulodin-Irgasan-Novobiocin Agar for Isolation of Yersinia spp

    PubMed Central

    Tan, Lai Kuan; Ooi, Peck Toung; Carniel, Elisabeth; Thong, Kwai Lin

    2014-01-01

    Y. enterocolitica and Y. pseudotuberculosis are important food borne pathogens. However, the presence of competitive microbiota makes the isolation of Y. enterocolitica and Y. pseudotuberculosis from naturally contaminated foods difficult. We attempted to evaluate the performance of a modified Cefsulodin-Irgasan-Novobiocin (CIN) agar in the differentiation of Y. enterocolitica from non-Yersinia species, particularly the natural intestinal microbiota. The modified CIN enabled the growth of Y. enterocolitica colonies with the same efficiency as CIN and Luria-Bertani agar. The detection limits of the modified CIN for Y. enterocolitica in culture medium (10 cfu/ml) and in artificially contaminated pork (104 cfu/ml) were also comparable to those of CIN. However, the modified CIN provided a better discrimination of Yersinia colonies from other bacteria exhibiting Yersinia-like colonies on CIN (H2S-producing Citrobacter freundii, C. braakii, Enterobacter cloacae, Aeromonas hydrophila, Providencia rettgeri, and Morganella morganii). The modified CIN exhibited a higher recovery rate of Y. enterocolitica from artificially prepared bacterial cultures and naturally contaminated samples compared with CIN. Our results thus demonstrated that the use of modified CIN may be a valuable means to increase the recovery rate of food borne Yersinia from natural samples, which are usually contaminated by multiple types of bacteria. PMID:25170941

  9. Visualization of Biosurfactant Film Flow in a Bacillus subtilis Swarm Colony on an Agar Plate.

    PubMed

    Kim, Kyunghoon; Kim, Jung Kyung

    2015-01-01

    Collective bacterial dynamics plays a crucial role in colony development. Although many research groups have studied the behavior of fluidic swarm colonies, the detailed mechanics of its motion remains elusive. Here, we developed a visualization method using submicron fluorescent beads for investigating the flow field in a thin layer of fluid that covers a Bacillus subtilis swarm colony growing on an agar plate. The beads were initially embedded in the agar plate and subsequently distributed spontaneously at the upper surface of the expanding colony. We conducted long-term live cell imaging of the B. subtilis colony using the fluorescent tracers, and obtained high-resolution velocity maps of microscale vortices in the swarm colony using particle image velocimetry. A distinct periodic fluctuation in the average speed and vorticity of flow in swarm colony was observed at the inner region of the colony, and correlated with the switch between bacterial swarming and growth phases. At the advancing edge of the colony, both the magnitudes of velocity and vorticity of flow in swarm colony were inversely correlated with the spreading speed of the swarm edge. The advanced imaging tool developed in this study would facilitate further understanding of the effect of micro vortices in swarm colony on the collective dynamics of bacteria. PMID:26343634

  10. Evaluation of a modified Cefsulodin-Irgasan-Novobiocin agar for isolation of Yersinia spp.

    PubMed

    Tan, Lai Kuan; Ooi, Peck Toung; Carniel, Elisabeth; Thong, Kwai Lin

    2014-01-01

    Y. enterocolitica and Y. pseudotuberculosis are important food borne pathogens. However, the presence of competitive microbiota makes the isolation of Y. enterocolitica and Y. pseudotuberculosis from naturally contaminated foods difficult. We attempted to evaluate the performance of a modified Cefsulodin-Irgasan-Novobiocin (CIN) agar in the differentiation of Y. enterocolitica from non-Yersinia species, particularly the natural intestinal microbiota. The modified CIN enabled the growth of Y. enterocolitica colonies with the same efficiency as CIN and Luria-Bertani agar. The detection limits of the modified CIN for Y. enterocolitica in culture medium (10 cfu/ml) and in artificially contaminated pork (10(4) cfu/ml) were also comparable to those of CIN. However, the modified CIN provided a better discrimination of Yersinia colonies from other bacteria exhibiting Yersinia-like colonies on CIN (H2S-producing Citrobacter freundii, C. braakii, Enterobacter cloacae, Aeromonas hydrophila, Providencia rettgeri, and Morganella morganii). The modified CIN exhibited a higher recovery rate of Y. enterocolitica from artificially prepared bacterial cultures and naturally contaminated samples compared with CIN. Our results thus demonstrated that the use of modified CIN may be a valuable means to increase the recovery rate of food borne Yersinia from natural samples, which are usually contaminated by multiple types of bacteria. PMID:25170941

  11. An agar gel enzyme assay (AGEA) for simple detection of Salmonella enteritidis antibodies in chicken sera.

    PubMed

    Kim, C J; Nagaraja, K V

    1991-01-01

    An agar gel enzyme assay (AGEA) was developed for the detection of antibodies to Salmonella enteritidis (SE). The assay was based on the ability of antibodies to diffuse through an agar gel and react with antigen coated on a polystyrene surface. The antigen-antibody reaction was then made visible by applying an enzyme-conjugated anti-immunoglobulin and the addition, subsequently, of a substrate-containing gel. The color change in circular zones was taken as the indication for the presence of antibodies. The present investigation reports identification of an antigen specific for SE and its use in the development of a relatively simple AGEA procedure. The results of AGEA were compared with those of conventional microagglutination (MA) test and serum plate (SP) test. The percentage agreement between MA and AGEA in positive serum sample was found to be 94.4%, and in negative serum samples it was found to be 88.8%. The present results suggest that the AGEA could be a very useful screening test for the detection of SE antibodies because the assay is inexpensive, specific and simple to perform without much equipment, and give results within a 3-hr period. PMID:1832368

  12. Inactivation of Listeria monocytogenes on agar and processed meat surfaces by atmospheric pressure plasma jets.

    PubMed

    Lee, Hyun Jung; Jung, Heesoo; Choe, Wonho; Ham, Jun Sang; Lee, Jun Heon; Jo, Cheorun

    2011-12-01

    An apparatus for generating atmospheric pressure plasma (APP) jet was used to investigate the inactivation of Listeria monocytogenes on the surface of agar plates and slices of cooked chicken breast and ham. He, N₂ (both 7 L/min), and mixtures of each with O₂ (0.07 L/min) were used to produce the plasma jets. After treatment for 2 min with APP jets of He, He + O₂, N₂, or N₂ + O₂, the numbers of L. monocytogenes on agar plates were reduced by 0.87, 4.19, 4.26, and 7.59 log units, respectively. Similar treatments reduced the L. monocytogenes inoculated onto sliced chicken breast and ham by 1.37 to 4.73 and 1.94 to 6.52 log units, respectively, according to the input gas used with the N₂ + O₂ mixture being the most effective. Most APP jets reduced the numbers of aerobic bacteria on the meat surfaces to <10² CFU/g, and the numbers remained below that level of detection after storage at 10 °C for 7 days. The results indicate that APP jets are effective for the inactivation of L. monocytogenes on sliced meats and for prolonging the shelf-life of such foods. PMID:21925030

  13. Abolition of Swarming of Proteus by p-Nitrophenyl Glycerin: Application to Blood Agar Media

    PubMed Central

    Williams, Fred D.

    1973-01-01

    Comparative plate counts were made of Staphylococcus aureus and Streptococcus pyogenes growing on blood agar supplemented with individual chemicals to abolish the swarming of Proteus. B-phenylethanol, sodium azide, and p-nitrophenyl glycerin (PNPG) were used as anti-swarm agents. Each anti-swarm agent effectively abolished swarming for 24 h, but azide failed to control swarming for longer periods of incubation. In addition, azide displayed growth inhibition towards the staphylococci and streptococci resulting in no hemolysis and reduced viable cell numbers with the streptococci. Phenylethanol showed reduced viable cell numbers with the streptococci and unreliable hemolytic reactions. At 0.1 to 0.3 mM, PNPG proved to be a superior anti-swarm agent in that it showed no growth inhibition and allowed normal hemolysis, but abolished swarming for extended periods of time. When laboratory strains of Streptococcus pneumoniae, Klebsiella pneumoniae, Pseudomonas aeruginosa. Listeria monocytogenes, and Vibrio cholerae were screened on a blood agar medium containing 0.1 mm PNPG, they displayed similar growth and hemolytic characteristics to the identical medium without PNPG. PMID:4715553

  14. Colonic cell growth and mucin degradation in rats fed diets containing various levels of beta-carotene with and without dietary agar.

    PubMed

    Hwa, S H; Shiau, S Y

    1993-06-01

    1. To either an agar-containing diet or an agar-free diet, 0, 0.3 and 2.0 mg/100 g of beta-carotene were incorporated and fed to groups of five rats for 28 days. 2. Weight gain and food consumption of rats fed different dietary groups did not show a significant difference (P > 0.05). 3. Colon weight, colonic mucosal DNA and RNA were generally higher in rats fed agar diets than rats fed agar-free diets at either beta-carotene supplementation level. 4. Mucinase activity was higher (P < 0.05) in rats fed the agar diet than in rats fed an agar-free diet without beta-carotene. However, the difference was not observed (P > 0.05) when beta-carotene was incorporated. 5. These data suggest that colonic mucin degradation in rats fed an agar diet decreased when the dietary beta-carotene inclusion level increased. PMID:7687211

  15. Susceptibility of a polycaprolactone-based root canal filling material to degradation using an agar-well diffusion assay

    PubMed Central

    Hiraishi, Noriko; Sadek, Fernanda T.; King, Nigel M.; Ferrari, Marco; Pashley, David H.; Tay, Franklin R

    2013-01-01

    Purpose Cholesterol esterase is both a component of salivary hydrolases as well as an inflammatory cell-derived enzyme and has been shown to cause biodegradation of methacrylate-based resin composites. This study examined whether Resilon, a polycaprolactone-based thermoplastic root filling material is susceptible to biodegradation by cholesterol esterase using agar-well diffusion assay of serially-diluted aqueous Resilon emulsions that were dispersed in agar. Materials and methods Emulsions of Resilon and polycaprolactone were prepared and dispersed in agar on culture plates. Two different concentrations of a cholesterol esterase (0.3 and 1.2 U/mL) were prepared and fed to wells prepared in the agar plates using an agar-well diffusion assay for examination the degradation of polymeric materials. Results Degradation of the emulsified Resilon was manifested as the formation of clear zones of different sizes around the agar wells. No clear zones were observed in agar wells that contain sterile distilled water as the negative control. Clinical significance Although dispersion Resilon into an emulsion is not the way in which this material is employed as a root filling material, the potential for Resilon to be degraded by cholesterol esterase is of potential concern as one cannot limit the degradation of extruded Resilon from a root apex by monocyte-derived macrophages to just the anatomical root apex. As the present study employed a high concentration of cholesterol esterase, further studies should be directed to examining the degradation of Resilon using macrophage cell cultures. PMID:18578181

  16. IMPERMEABLE THIN Al{sub 2}O{sub 3} OVERLAY FOR TBC PROTECTION FROM SULFATE AND VANADATE ATTACK IN GAS TURBINES

    SciTech Connect

    Scott X. Mao

    2004-06-30

    In order to further improve the hot corrosion resistance of yttria-stabilized zirconia (YSZ), an Al{sub 2}O{sub 3} overlay of 58 {micro}m thick was deposited on the surface of YSZ by electron-beam physical vapor deposition. Hot corrosion tests were performed on the YSZ coatings with {gamma}-Al{sub 2}O{sub 3} overlay and {alpha}-Al{sub 2}O{sub 3} overlay in molten salt mixture (Na2SO4 + 5wt%V2O5) at 950 C. The {alpha}-Al{sub 2}O{sub 3} overlay was obtained by the post-annealing of g-Al{sub 2}O{sub 3} overlay at 1200 C for 1h. The results showed that compared with the hot corrosion resistance of YSZ coating with 25 {micro}m thick {gamma}-Al{sub 2}O{sub 3} overlay, either thickening {gamma}-Al{sub 2}O{sub 3} overlay or employing {alpha}-Al{sub 2}O{sub 3} overlay could impair the hot corrosion resistance of YSZ coating, because the tensile stresses developed in the alumina overlay in both cases due to the mismatch in thermal expansion coefficient (TEC) between alumina and zirconia resulted in cracking of Al{sub 2}O{sub 3} overlay. The formation of cracks increased contact area between molten salt and Al{sub 2}O{sub 3} overlay, and also the penetration rate of molten salt into Al{sub 2}O{sub 3} overlay and YSZ coating, leading a faster and greater degradation of YSZ coating upon exposure. In the next reporting period, we will study the effect of Al{sub 2}O{sub 3} overlay thickness on hot corrosion and spalling of YSZ coatings.

  17. An International Randomized Multicenter Comparison of Nasal Potential Difference Techniques

    PubMed Central

    Solomon, George M.; Konstan, Michael W.; Wilschanski, Michael; Billings, Joanne; Sermet-Gaudelus, Isabelle; Accurso, Frank; Vermeulen, François; Levin, Elina; Hathorne, Heather; Reeves, Ginger; Sabbatini, Gina; Hill, Aubrey; Mayer-Hamblett, Nicole; Ashlock, Melissa; Clancy, John Paul

    2010-01-01

    Background: The transepithelial nasal potential difference (NPD) is used to assess cystic fibrosis transmembrane conductance regulator (CFTR) activity. Unreliability, excessive artifacts, and lack of standardization of current testing systems can compromise its use as a diagnostic test and outcome measure for clinical trials. Methods: To determine whether a nonperfusing (agar gel) nasal catheter for NPD measurement is more reliable and less susceptible to artifacts than a continuously perfusing nasal catheter, we performed a multicenter, randomized, crossover trial comparing a standardized NPD protocol using an agar nasal catheter with the same protocol using a continuously perfusing catheter. The data capture technique was identical in both protocols. A total of 26 normal adult subjects underwent NPD testing at six different centers. Results: Artifact frequency was reduced by 75% (P < .001), and duration was less pronounced using the agar catheter. The measurement of sodium conductance was similar between the two catheter methods, but the agar catheter demonstrated significantly greater CFTR-dependent hyperpolarization, because Δ zero Cl- + isoproterenol measurements were significantly more hyperpolarized with the agar catheter (224.2 ± 12.9 mV with agar vs 18.2 ± 9.1 mV with perfusion, P < .05). Conclusions: The agar nasal catheter approach demonstrates superior reliability compared with the perfusion nasal catheter method for measurement of NPD. This nonperfusion catheter method should be considered for adoption as a standardized protocol to monitor CFTR activity in clinical trials. PMID:20472865

  18. Isolation and characterization of agar-digesting Vibrio species from the rotten thallus of Gracilariopsis heteroclada Zhang et Xia.

    PubMed

    Martinez, Joval N; Padilla, Philip Ian P

    2016-08-01

    Gracilariopsis heteroclada Zhang et Xia (Gracilariaceae, Rhodophyta) is one of the most studied marine seaweeds due to its economic importance. This has been cultivated extensively on commercial scale in the Philippines and other Asian countries. However, sustainable production of G. heteroclada in the Philippines could not be maximized due to the occurrence of rotten thallus disease. Thus, isolation and characterization of agar-digesting bacteria from the rotten thalli of G. heteroclada was conducted. A total of seven representative bacterial isolates were randomly selected based on their ability to digest agar as evidenced by the formation of depressions around the bacterial colonies on nutrient agar plates supplemented with 1.5% NaCl and liquefaction of agar. Gram-staining and biochemical characterization revealed that isolates tested were gram-negative rods and taxonomically identified as Vibrio parahaemolyticus (86-99.5%) and Vibrio alginolyticus (94.2-97.7%), respectively. It is yet to be confirmed whether these agar-digesting vibrios are involved in the induction and development of rotten thallus disease in G. heteroclada in concomitance with other opportunistic bacterial pathogens coupled with adverse environmental conditions. PMID:27285614

  19. Robotic weld overlay coatings for erosion control. Quarterly technical progress report, October 1994--December 1994

    SciTech Connect

    Levin, B.F.; Dupont, J.N.; Marder, A.R.

    1995-01-25

    Research is presently being conducted to develop a criteria for selecting weld overlay coatings for erosion mitigation in Circulated Fluidized Beds. Initially, eleven weld overlay alloys were selected for erosion testing based upon a literature review. All eleven coatings were deposited on 1018 steel substrates using the plasma arc welding process. Ten samples from each coating were prepared for erosion testing. The coating deposition and sample preparation procedures were described in the second quarterly report. All selected coatings were erosion tested at 400{degree}C and their erosion resistance was evaluated by determining the steady state erosion rate. In addition, the microstructure of each coating was characterized before and after the erosion tests. The results of the tests are discussed in the third quarterly report. No correlations were found between room temperature hardness of the weld overlay coatings and their erosion resistance at elevated temperature. During the last quarter tensile tests were performed at 400{degree}C for the Ultimet, Inconel-625, 316L SS, C-22, and Stellite-6 wrought alloys. The erosion tests for these materials at 400{degree}C are in progress. The results of mechanical and erosion tests will be used to correlate mechanical properties of selected wrought alloys such as tensile toughness, ductility, strain hardening coefficient and yield strength to their erosion resistance at 400{degree}C. Also, the erosion behavior of the wrought alloys compared with similar weld alloys will be analyzed. The experimental procedure and results of the tensile tests are presented in this progress report.

  20. Improving mask registration and wafer overlay control using an ultrashort pulsed laser

    NASA Astrophysics Data System (ADS)

    Avizemer, Dan; Dmitriev, Vladimir; Hibbs, Michael

    2016-04-01

    Requirements for control of mask registration errors and wafer overlay errors become more demanding as the integrated circuit (IC) feature size specifications become tighter and tighter. Registration control, also known as RegC, is a well-known laser-based process in the IC industry that has proven to be robust, repeatable, and efficient in adjusting mask registration and wafer overlay. Using an ultrashort pulsed laser, microscopic deformation elements, strain centers, which are also known as pixels, are generated deep inside the fused silica mask substrate causing strain. The induced strain moves the mask pattern in predicted calculated directions to reduce the measured image placement error (IPE). RegC corrections can be applied in two different ways: as a periphery-mask correction, which places the strain centers in the mask frame area outside the exposure field, or as a full-mask correction, that places the strain centers across the entire mask, including the exposure field. Relative pattern displacements up to 1 nm can be achieved between sites located at a distance of 1 mm, reducing the magnitude of the residual IPE by an average of 20% (10% to 25% range) for a periphery correction or 40% (20% to 50% range) for a full-mask correction. The input data for the RegC process are typically taken from mask registration information, which is measured by registration metrology tools or measured from wafer overlay (the latter is not within the scope of this paper). This paper reviews the RegC process flow for improving mask registration in mask shops.

  1. Characteristics of rat megakaryocyte colonies and their progenitors in agar culture

    SciTech Connect

    Kellar, K.L.; Rolovic, Z.; Evatt, B.L.; Sewell, E.T.

    1985-11-01

    The characteristics of megakaryocyte colonies that develop from megakaryocyte progenitors of rat bone marrow stimulated by rat spleen-conditioned medium (SCM) in agar culture were investigated. Colony frequency was optimal on day 7 and increased relative to both the number of cells plated and the concentration of SCM used. Colonies were categorized as small cell and big cell. Small-cell colonies had a greater proliferative potential, with a mean of 25 cells/colony. Big-cell colonies averaged 15 cells/colony. The ratio of big-cell to small-cell colonies was 0.69 +/- 0.29. Granulocyte-macrophage colonies, which were also stimulated by SCM, accounted for 70% +/- 15% of the total colonies in the cultures. Cytocidal experiments with tritiated thymidine reduced megakaryocyte colony formation by 45% and granulocyte-macrophage colony formation by 21%. The properties of rat, mouse, and human megakaryocyte progenitors as assayed in vitro are compared.

  2. Comparison of four commercial brucella agar media for growth of anaerobic organisms.

    PubMed Central

    Mangels, J I; Douglas, B P

    1989-01-01

    Four different commercial brucella blood agar plating media (Anaerobe Systems, BBL Microbiology Systems, Remel, and Scott Laboratories) were compared for the abilities to recover anaerobic organisms from clinical specimens and to support the growth of American Type Culture Collection anaerobic stock cultures. Following 24 h of incubation in an anaerobe chamber, Anaerobe Systems prereduced, anaerobically sterilized brucella plates yielded 63% of the total clinical anaerobe isolates, the Scott medium yielded 51%, the Remel medium yielded 42%, and the BBL medium yielded 37%. Poor growth of Peptostreptococcus magnus, P. anaerobius, Fusobacterium necrophorum, F. nucleatum, and pigmented Bacteroides spp. was observed on brucella media obtained from BBL, Remel, and Scott. Data obtained with stock anaerobic cultures showed that Anaerobe Systems plates yielded good growth and produced a larger colony size with all of the strains tested in 1 day, whereas poor growth of Peptostreptococcus spp., B. melaninogenicus, and Fusobacterium spp. was noted on brucella media from BBL, Remel, and Scott. PMID:2584378

  3. Nocardia pigrifrangens sp. nov., a novel actinomycete isolated from a contaminated agar plate.

    PubMed

    Wang, Liming; Zhang, Yamei; Huang, Ying; Maldonado, Luis A; Liu, Zhiheng; Goodfellow, Michael

    2004-09-01

    A polyphasic study was undertaken to establish the taxonomic position of an actinomycete strain isolated from a contaminated agar plate. The strain, designated 7031T, had morphological and chemotaxonomic properties typical of the genus Nocardia. An almost-complete 16S rRNA gene sequence determined for the strain was aligned with available sequences for nocardiae, and phylogenetic trees were inferred using three tree-generating algorithms. Strain 7031T clustered with the type strains of Nocardia carnea and Nocardia flavorosea, showing low 16S rRNA gene sequence similarities to these species (97.2 and 97.5 %, respectively). The strain was also distinguished from the closest species by a range of phenotypic properties. It is proposed that the strain be recognized as a novel species of Nocardia, Nocardia pigrifrangens sp. nov., the type strain of which is 7031T (= AS 4.1808T = JCM 11884T). PMID:15388728

  4. Antimicrobial Disk Susceptibility Testing of Leptospira spp. Using Leptospira Vanaporn Wuthiekanun (LVW) Agar.

    PubMed

    Wuthiekanun, Vanaporn; Amornchai, Premjit; Langla, Sayan; White, Nicholas J; Day, Nicholas P J; Limmathurotsakul, Direk; Peacock, Sharon J

    2015-08-01

    Leptospira Vanaporn Wuthiekanun (LVW) agar was used to develop a disk diffusion assay for Leptospira spp. Ten pathogenic Leptospira isolates were tested, all of which were susceptible to 17 antimicrobial agents (amoxicillin/clavulanic acid, amoxicillin, azithromycin, cefoxitin, ceftazidime, ceftriaxone, chloramphenicol, ciprofloxacin, clindamycin, doripenem, doxycycline, gentamicin, linezolid, nitrofurantoin, penicillin, piperacillin/tazobactam, and tetracycline). All 10 isolates had no zone of growth inhibition for four antimicrobials (fosfomycin, nalidixic acid, rifampicin, and trimethoprim/sulfamethoxazole). Of the ten Leptospira, seven had a growth inhibition zone of ≤ 21 mm for aztreonam, the zone diameter susceptibility break point for Enterobacteriaceae. This assay could find utility as a simple screening method during the epidemiological surveillance of antimicrobial resistance in Leptospira spp. PMID:26055750

  5. Serotyping reanalysis of unserotypable Actinobacillus pleuropneumoniae isolates by agar gel diffusion test.

    PubMed

    Morioka, Ayako; Shimazaki, Yoko; Uchiyama, Mariko; Suzuki, Shoko

    2016-05-01

    We observed increasing unserotypable (UT) Actinobacillus pleuropneumoniae isolates using agar gel diffusion (AGD) test. To reanalyze their serovar, we performed rapid slide agglutination (RSA) test and multiplex PCR for 47 UT isolates. Of these, 25 were serovar 1 (UT-serovar 1), 20 were serovar 2 (UT-serovar 2) and 2 were serovar 15 (UT-serovar 15). We examined serotyping antigen extraction temperature to determine heat influence. UT-serovar 1 and 15 were influenced by heat, because their precipitation lines were observed in the case of low antigen extraction temperature. To investigate the relationship between antigenicity and genotype, we performed pulsed-field gel electrophoresis (PFGE) analysis using UT-serovar 2 and 15. The predominant PFGE pattern of UT-serovar 2 was identical to that of serovar 2. PMID:26726101

  6. Injection of Acanthaster planci with thiosulfate-citrate-bile-sucrose agar (TCBS). I. Disease induction.

    PubMed

    Rivera-Posada, J A; Pratchett, M; Cano-Gómez, A; Arango-Gómez, J D; Owens, L

    2011-12-01

    This is the first report of the successful induction of a transmissible disease in the coral-eating crown-of-thorns starfish Acanthaster planci (COTS). Injection of thiosulfate-citrate-bile-sucrose agar (TCBS) culture medium into COTS induced a disease characterized by discoloured and necrotic skin, ulcerations, loss of body turgor, accumulation of colourless mucus on many spines especially at their tip, and loss of spines. Blisters on the dorsal integument broke through the skin surface and resulted in large, open sores that exposed the internal organs. Oedema and reddened digestive tissues and destruction of connective fibers were common. Moreover, healthy COTS in contact with these infected animals also displayed signs of disease and died within 24 h. TCBS induced 100% mortality in injected starfish. There was no introduction of new pathogens into the marine environment. TCBS promoted the growth of COTS' naturally occurring Vibrionales to high densities with subsequent symbiont imbalance followed by disease and death. PMID:22303625

  7. [Cryofractographic study of intercellular junctions in the populations of agar-cultivated Bordetella pertussis].

    PubMed

    Vysotskiĭ, V V; Vaisman, I Sh; Efimova, O G; Chemurzieva, N V

    1985-09-01

    The characteristic feature of replicas obtained from the freeze-fractures of B. pertussis unfixed cultures developing on casein charcoal agar for 1-7 days is the associative growth of highly polymorphic cells, ensured by the ramified system of intercellular connections (IC) formed by the derivatives of the outer layers of the cell wall. This proves that the associative location of bacterial cells, linked by numerous IC, in the preparation is not the artefact appearing in the process of their chemical fixation. In replicas obtained from the freeze-fractures of B. pertussis cultures, previously fixed with glutaraldehyde, osmic acid and uranyl acetate, oval cells with the cytoplasm having a relatively homogeneous structure and with the smoothed-out three-layer cell wall prevail. As a rule, IC are limited to the sites of direct contacts between individual cells. PMID:2866645

  8. Agar gel immunodiffusion assay to detect antibodies to Type A influenza virus.

    PubMed

    Jenson, Terra A

    2014-01-01

    The agar gel immunodiffusion (AGID) test is used to detect antibodies to Type A influenza group-specific antigens, i.e., the ribonucleoprotein (RNP) and matrix (M) proteins. Therefore, this test will detect antibodies to all influenza A virus subtypes. AGID is commonly used to screen poultry flocks for avian influenza virus infection. The AGID is a simple and economical serological test. All serological testing has its advantages and disadvantages which should be considered before choosing the optimal test for the laboratory needs. Each laboratory must evaluate the laboratory's resources, the volume of testing, the goal of testing, how the test results are used and what types of samples are being tested in order to select the optimal test. PMID:24899427

  9. Growth of Bacillus cereus on solid media as affected by agar, sodium chloride, and potassium sorbate.

    PubMed

    Stecchini, M L; Del Torre, M; Donda, S; Maltini, E

    2000-07-01

    The effect of two independent variables: microstructure, as modified by the agar content (1.0, 4.0, 7.0%), and water activity (a(w)), as modified by the NaCl content (0.5, 2.5, 4.5%), in the absence or in the presence of potassium sorbate (0.0; 2,000 ppm) on Bacillus cereus growth on solid media was studied. The time to visible growth (TVG) and the radial growth rate (RGR) of colonies were evaluated. TVG was not affected by microstructure and K-sorbate, although when a(w) was reduced, TVG tended to increase. RGR depended on linear effects of microstructure and a(w) variables and their interaction. When K-sorbate was added to cultural media, RGR was reduced significantly. However, in the presence of K-sorbate, RGR was found to change only when a(w) vas varied. PMID:10914662

  10. Nutrient Requirements of Renibacterium salmoninarum on Agar and in Broth Media.

    PubMed

    Daly, J G; Stevenson, R M

    1993-07-01

    In well-aerated broth cultures, good growth of Renibacterium salmoninarum was obtained in a serum-free medium consisting of 1% peptone, 1% yeast extract, and 0.1% l-cysteine (PYC broth). In contrast, serum or charcoal is required for growth on agar medium. Charcoal treatment of broth media, either before bacterial inoculation or during growth, increased the growth of R. salmoninarum, whereas the surfactants Tween 20 and Tween 80 inhibited growth. l-Cysteine was essential for optimal growth. Other organic sulfur compounds, such as d-cysteine, l-methionine, homocysteine, homocysteine thiolactone, and reduced glutathione, supported only lower levels of growth, while cystine and dithiothreitol did not allow growth. PMID:16348993

  11. Nutrient Requirements of Renibacterium salmoninarum on Agar and in Broth Media

    PubMed Central

    Daly, J. G.; Stevenson, R. M. W.

    1993-01-01

    In well-aerated broth cultures, good growth of Renibacterium salmoninarum was obtained in a serum-free medium consisting of 1% peptone, 1% yeast extract, and 0.1% l-cysteine (PYC broth). In contrast, serum or charcoal is required for growth on agar medium. Charcoal treatment of broth media, either before bacterial inoculation or during growth, increased the growth of R. salmoninarum, whereas the surfactants Tween 20 and Tween 80 inhibited growth. l-Cysteine was essential for optimal growth. Other organic sulfur compounds, such as d-cysteine, l-methionine, homocysteine, homocysteine thiolactone, and reduced glutathione, supported only lower levels of growth, while cystine and dithiothreitol did not allow growth. PMID:16348993

  12. Charcoal agar, a new growth medium for the fish disease bacterium Renibacterium salmoninarum.

    PubMed Central

    Daly, J G; Stevenson, R M

    1985-01-01

    Charcoal is an effective replacement for serum in media for the isolation and culture of Renibacterium salmoninarum, the causative agent of bacterial kidney disease in salmonid fish. The medium, KDM-C, contains 10 g of peptone, 0.5 g of yeast extract, 1 g of L-cysteine hydrochloride, 1 g of activated charcoal, and 15 g of agar per liter and is adjusted to pH 6.8 with NaOH before autoclaving. Eight strains of R. salmoninarum grew from dilute inocula as well on KDM-C as on a standard serum-containing medium (KDM-2). The medium was effective for both primary isolations from fish and repeated transfers and has potential value for antigen preparation and physiological studies. Images PMID:4083882

  13. Serotyping reanalysis of unserotypable Actinobacillus pleuropneumoniae isolates by agar gel diffusion test

    PubMed Central

    MORIOKA, Ayako; SHIMAZAKI, Yoko; UCHIYAMA, Mariko; SUZUKI, Shoko

    2016-01-01

    We observed increasing unserotypable (UT) Actinobacillus pleuropneumoniae isolates using agar gel diffusion (AGD) test. To reanalyze their serovar, we performed rapid slide agglutination (RSA) test and multiplex PCR for 47 UT isolates. Of these, 25 were serovar 1 (UT-serovar 1), 20 were serovar 2 (UT-serovar 2) and 2 were serovar 15 (UT-serovar 15). We examined serotyping antigen extraction temperature to determine heat influence. UT-serovar 1 and 15 were influenced by heat, because their precipitation lines were observed in the case of low antigen extraction temperature. To investigate the relationship between antigenicity and genotype, we performed pulsed-field gel electrophoresis (PFGE) analysis using UT-serovar 2 and 15. The predominant PFGE pattern of UT-serovar 2 was identical to that of serovar 2. PMID:26726101

  14. Robotic weld overlay coatings for erosion control. Quarterly technical progress report, April 1993--June 1993

    SciTech Connect

    Levin, B.F.; Dupont, J.N.; Marder, A.R.

    1993-07-20

    Twelve weld overlay hardfacing alloys have been selected for preliminary erosion testing based upon a literature review. Four of the selected coatings were deposited on a 1018 steel substrate using plasma arc welding process. During the past quarter, the remaining eight coatings were deposited in the same manner. Ten samples from each coatings were prepared for erosion testing. Microstructural characterization of each coating is in progress. This progress report describes coating deposition and sample preparation procedures. Relation between coatings hardness and formation of cracks in coatings is discussed.

  15. Two-dimensional Ostwald ripening on a patterned support and in a mixed overlayer

    NASA Astrophysics Data System (ADS)

    Zhdanov, Vladimir P.

    2016-02-01

    The author presents lattice Monte Carlo simulations of Ostwald ripening of islands formed of monomers with attractive nearest-neighbor interaction in two situations. The first one implies that monomers of one kind are located on a heterogeneous support which itself includes embedded frozen patterns of the Ostwald type. This feature is demonstrated to be able to terminate the island ripening. In the second case, the support is considered to be uniform while the overlayer is assumed to contain monomers of two kinds. This complicating factor is found to nearly not modify the ripening kinetics or make it somewhat slower despite appreciable correlations in the arrangement of different monomers.

  16. The structure of Na overlayers on Cu(111) at room temperature

    NASA Astrophysics Data System (ADS)

    Tang, D.; McIlroy, D.; Shi, X.; Su, C.; Heskett, D.

    1991-09-01

    Thermal desorption spectroscopy (TDS), low energy electron diffraction (LEED), and work function change measurements have been carried out to study the adsorption of sodium on Cu(111) at room temperature. The first layer develops from a disordered phase at low coverage to an evenly spaced incommensurate structure then to a commensurate hexagonal overlayer structure at the completion of the first layer. The work function change passes through a minimum at intermediate coverage, levels off by the completion of the first monolayer, then decreases slightly with increasing Na coverage in the second layer. The measurements will be discussed in relation to other investigations of this and related systems.

  17. The structure of Na overlayers on Cu(111) at room temperature

    NASA Astrophysics Data System (ADS)

    Tang, D.; McIlroy, D.; Shi, X.; Su, C.; Heskett, D.

    Thermal desorption spectroscopy (TDS), low energy electron diffraction (LEED), and work function change measurements have been carried out to study the adsorption of sodium on Cu(111) at room temperature. The first layer develops from a disordered phase at low coverage to an evenly spaced incommensurate structure then to a commensurate hexagonal overlayer structure at the completion of the first layer. The work function change passes through a minimum at intermediate coverage, levels off by the completion of the first monolayer, then decreases slightly with increasing Na coverage in the second layer. The measurements will be discussed in relation to other investigations of this and related systems.

  18. Modeling degradation and failure of Ni-Cr-Al overlay coatings

    NASA Technical Reports Server (NTRS)

    Nesbitt, J. A.; Heckel, R. W.

    1984-01-01

    Degradation of a Ni-16Cr-25Al-0.06Zr overlay coating on a Ni-22Cr substrate was examined after oxidation accompanied by thermal cycling. Concentration/distance profiles were measured in the coating and substrate after various one-hour cycles at 1150 C. A numerical model was developed to simulate coating degradation by simultaneous oxidation and coating/substrate interdiffusion. The validity of the model was confirmed by comparison of predicted and measured concentration/distance profiles. The ability of the model to identify critical system parameters was demonstrated for the case of the initial Al and Cr content of the coating and substrate.

  19. Residual stress distribution in FeAl weld overlay on steel

    SciTech Connect

    Wang, X.L.; Spooner, S.; Hubbard, C.R.; Maziasz, P.J.; Goodwin, G.M.; Feng, Z.; Zacharia, T.

    1994-12-31

    Neutron diffraction was used to measure the residual stress distribution in an FeAl weld overlay on steel. It was found that the residual stresses accumulated during welding were essentially removed by the post-weld heat treatment that was applied to the specimen; most residual stresses in the specimen developed during cooling following the post-weld heat treatment. The experimental data were compared with a plasto-elastic finite element analysis. While some disagreement exists in absolute strain values, there is satisfactory agreement in strain spatial distribution between the experimental data and the finite element analysis.

  20. Evaluation of agar dilution and broth microdilution methods to determine the disinfectant susceptibility.

    PubMed

    Wu, Guoyan; Yang, Qianru; Long, Mei; Guo, Lijuan; Li, Bei; Meng, Yue; Zhang, Anyun; Wang, Hongning; Liu, Shuliang; Zou, Likou

    2015-11-01

    A variety of disinfectants have been widely used in veterinary hygiene, food industries and environments, which could induce the development of bacterial resistance to disinfectants. The methods used to investigate antimicrobial effects of disinfectant vary considerably among studies, making comparisons difficult. In this study, agar dilution and broth microdilution methods were used to compare the antimicrobial activities of four quaternary ammonium compounds (QACs) against foodborne and zoonotic pathogens. The potential relationship between the presence of QACs resistance genes and phenotypic resistance to QACs was also investigated. Our results indicated that the minimum inhibitory concentrations (MICs) determined by two methods might be different depended upon different QACs and bacteria applied. Regardless of the testing methods, Klebsiella pneumoniae was more tolerant among Gram-negative strains to four QACs, followed by Salmonella and Escherichia coli. The agreement between MICs obtained by the two methods was good, for benzalkonium chloride (78.15%), didecyldimethylammonium chloride (DDAC) (82.35%), cetylpyridinium chloride (CTPC) (97.48%) and cetyltrimethylammonium bromide (CTAB) (99.16%), respectively. Among all Gram-negative bacteria, 94.55% (n=52) of qacEΔ1-positive strains showed higher MICs (512 mg l(-1)) to CTAB. The qacEΔ1 gene was highly associated (P<0.05) with the high MICs of QACs (⩾512 mg l(-1)). In addition, DDAC remained as the most effective disinfectant against both Gram-positive and Gram-negative bacteria. This is the first study that compared the agar dilution and broth microdilution methods to assess the antimicrobial activity of QACs. The study demonstrated the need to standardize method that would be used in evaluating QACs antimicrobial properties in the future. PMID:25944532

  1. Evolutionary consequences of putative intra-and interspecific hybridization in agaric fungi.

    PubMed

    Hughes, Karen W; Petersen, Ronald H; Lodge, D Jean; Bergemann, Sarah E; Baumgartner, Kendra; Tulloss, Rodham E; Lickey, Edgar; Cifuentes, Joaquin

    2013-01-01

    Agaric fungi of the southern Appalachian Mountains including Great Smoky Mountains National Park are often heterozygous for the rDNA internal transcribed spacer region (ITS) with >42% of collections showing some heterozygosity for indels and/or base-pair substitutions. For these collections, intra-individual haplotype divergence is typically less than 2%, but for 3% of these collections intra-individual haplotype divergence exceeds that figure. We hypothesize that high intra-individual haplotype divergence is due to hybridization between agaric fungi with divergent haplotypes, possibly migrants from geographically isolated glacial refugia. Four species with relatively high haplotype divergence were examined: Armillaria mellea, Amanita citrina f. lavendula, Gymnopus dichrous and the Hygrocybe flavescens/chlorophana complex. The ITS region was sequenced, haplotypes of heterozygotes were resolved through cloning, and phylogenetic analyses were used to determine the outcome of hybridization events. Within Armillaria mellea and Amanita citrina f. lavendula, we found evidence of interbreeding and recombination. Within G. dichrous and H. flavescens/chlorophana, hybrids were identified but there was no evidence for F2 or higher progeny in natural populations suggesting that the hybrid fruitbodies might be an evolutionary dead end and that the genetically divergent Mendelian populations from which they were derived are, in fact, different species. The association between ITS haplotype divergence of less than 5% (Armillaria mellea = 2.6% excluding gaps; Amanita citrina f. lavendula = 3.3%) with the presence of putative recombinants and greater than 5% (Gymnopus dichrous = 5.7%; Hygrocybe flavescens/chlorophana = 14.1%) with apparent failure of F1 hybrids to produce F2 or higher progeny in populations may suggest a correlation between genetic distance and reproductive isolation. PMID:23928423

  2. Evaluation of use of a new chromogenic agar in detection of urinary tract pathogens.

    PubMed

    Samra, Z; Heifetz, M; Talmor, J; Bain, E; Bahar, J

    1998-04-01

    CHROMagar Orientation, a new chromogenic medium, was evaluated for the detection and differentiation of gram-positive and gram-negative pathogenic microorganisms in 900 urine samples from hospitalized patients. Performance characteristics of the medium were evaluated in comparison to those of 5% sheep blood and MacConkey agars by direct inoculation of the urine samples on the three media. Four gram-negative and two gram-positive strains as well as one yeast control strain from the American Type Culture Collection were used to ensure quality control. CHROMagar Orientation succeeded in detecting all the urine pathogens that were detected by the reference media, including gram-negative bacilli, staphylococci, streptococci, and yeasts. Colony color and morphology on CHROMagar Orientation accurately differentiated Escherichia coli, Proteus mirabilis, Proteus vulgaris, Pseudomonas aeruginosa, and Acinetobacter spp. Owing to the similarity in the pigmentation produced by Klebsiella, Enterobacter, and Citrobacter isolates, the medium failed to distinguish among them; however, these isolates were easily recognized as coliforms because of their metallic blue coloration. Staphylococci were clearly perceptible: S. aureus and S. epidermidis grow in regular-size colonies that range from opaque white to yellowish, and S. saprophyticus produces opaque pink colonies. All streptococcus strains, including those from groups B and C, were detected. They grow as undifferentiated flat dry diffused colonies, and additional tests were required for identification. Enterococci were easily discriminated by their strong turquoise pigmentation and their typical growth on the agar's surface. Yeast grow in typical creamy wet convex colonies. The accuracy of antibiotic susceptibility determinations according to standard methods was also tested by picking isolates directly from CHROMagar Orientation. The results showed excellent correlation with those obtained with microorganisms picked from

  3. Detection of Ca(2+)-binding proteins by electrophoretic migration in the presence of Ca2+ combined with 45Ca2+ overlay of protein blots

    SciTech Connect

    Garrigos, M.; Deschamps, S.; Viel, A.; Lund, S.; Champeil, P.; Moller, J.V.; le Maire, M. , Gif-sur-Yvette )

    1991-04-01

    When high affinity Ca(2+)-binding proteins like calmodulin, or proteins with a high Ca(2+)-binding capacity like calsequestrin, underwent sodium dodecyl sulfate-gel electrophoresis in Laemmli systems, their electrophoretic migration rates were much higher in gels containing 1 mM Ca2+ than in gels containing ethylene glycol bis(beta-aminoethyl ether) N,N{prime}-tetraacetic acid (EGTA). Replacement of EGTA by Ca2+ in the gel, combined with the blotting of electrophoretically separated proteins on polyvinylidene difluoride membranes and subsequent 45Ca2+ overlay, proved a very effective means of detecting Ca(2+)-binding proteins. This combined approach is important since artifacts occur in both techniques when used separately. We found that the usual procedure of adding Ca2+ to the sample before electrophoresis without including it in the gel itself permitted the detection of only very high affinity Ca(2+)-binding proteins.

  4. Reducing overlay sampling for APC-based correction per exposure by replacing measured data with computational prediction

    NASA Astrophysics Data System (ADS)

    Noyes, Ben F.; Mokaberi, Babak; Oh, Jong Hun; Kim, Hyun Sik; Sung, Jun Ha; Kea, Marc

    2016-03-01

    One of the keys to successful mass production of sub-20nm nodes in the semiconductor industry is the development of an overlay correction strategy that can meet specifications, reduce the number of layers that require dedicated chuck overlay, and minimize measurement time. Three important aspects of this strategy are: correction per exposure (CPE), integrated metrology (IM), and the prioritization of automated correction over manual subrecipes. The first and third aspects are accomplished through an APC system that uses measurements from production lots to generate CPE corrections that are dynamically applied to future lots. The drawback of this method is that production overlay sampling must be extremely high in order to provide the system with enough data to generate CPE. That drawback makes IM particularly difficult because of the throughput impact that can be created on expensive bottleneck photolithography process tools. The goal is to realize the cycle time and feedback benefits of IM coupled with the enhanced overlay correction capability of automated CPE without impacting process tool throughput. This paper will discuss the development of a system that sends measured data with reduced sampling via an optimized layout to the exposure tool's computational modelling platform to predict and create "upsampled" overlay data in a customizable output layout that is compatible with the fab user CPE APC system. The result is dynamic CPE without the burden of extensive measurement time, which leads to increased utilization of IM.

  5. A nanometric Rh overlayer on a metal foil surface as a highly efficient three-way catalyst

    PubMed Central

    Misumi, Satoshi; Yoshida, Hiroshi; Hinokuma, Satoshi; Sato, Tetsuya; Machida, Masato

    2016-01-01

    Pulsed arc-plasma (AP) deposition of an Rh overlayer on an Fe–Cr–Al stainless steel foil produced a composite material that exhibited high activity for automotive three-way catalysis (TWC). The AP pulses deposited metallic Rh nanoparticles 1–3 nm in size, whose density on the surface increased with the number of pulses. This led to coalescence and grain growth on the foil surface and the eventual formation of a uniform two-dimensional Rh overlayer. Full coverage of the 51 μm-thick flat foil by a 3.2 nm-thick Rh overlayer was achieved after 1,000 pulses. A simulated TWC reaction using a miniature honeycomb fabricated using flat and corrugated foils with the Rh overlayers exhibited successful light-off at a practical gaseous hourly space velocity of 1.2 × 105 h−1. The turnover frequency for the NO–CO reaction over the metallic honeycomb catalyst was ca. 80-fold greater than that achieved with a reference Rh/ZrO2-coated cordierite honeycomb prepared using a conventional wet impregnation and slurry coating procedure. Despite the nonporosity and low surface area of the foil-supported Rh overlayer compared with conventional powder catalysts (Rh/ZrO2), it is a promising alternative design for more efficient automotive catalysts that use less Rh loading. PMID:27388976

  6. IMPERMEABLE THIN Al2O3 OVERLAY FOR TBC PROTECTION FROM SULFATE AND VANADATE ATTACK IN GAS TURBINES

    SciTech Connect

    Scott X. Mao

    2003-06-10

    In order to improve the hot corrosion resistance of yttria-stabilized zirconia (YSZ), an Al{sub 2}O{sub 3} overlay has been deposited on the surface of YSZ by electron-beam physical vapor deposition. Currently, hot corrosion tests were performed on the YSZ coatings with and without Al{sub 2}O{sub 3} overlay in molten salt mixture (Na{sub 2}SO{sub 4} + 0 {approx} 15wt%V{sub 2}O{sub 5}) at 950 C in order to investigate the effect of amount of vanadate on the hot corrosion behaviors. The results showed that the presence of in V{sub 2}O{sub 5} the molten salt exacerbates the degradation of both the monolithic YSZ coating and the composite YSZ/Al{sub 2}O{sub 3} system. The formation of low-melting Na{sub 2}O-V{sub 2}O{sub 5}-Al{sub 2}O{sub 3} liquid phase is responsible for degradation of the Al{sub 2}O{sub 3} overlay. The Al{sub 2}O{sub 3} overlay acts as a barrier against the infiltration of the molten salt into the YSZ coating during exposure to the molten salt mixture with <5wt% vanadate. In the next reporting period, we will use XPS and SIMS to study the interactions between alumina overlay and molten salt containing vanadate.

  7. A nanometric Rh overlayer on a metal foil surface as a highly efficient three-way catalyst.

    PubMed

    Misumi, Satoshi; Yoshida, Hiroshi; Hinokuma, Satoshi; Sato, Tetsuya; Machida, Masato

    2016-01-01

    Pulsed arc-plasma (AP) deposition of an Rh overlayer on an Fe-Cr-Al stainless steel foil produced a composite material that exhibited high activity for automotive three-way catalysis (TWC). The AP pulses deposited metallic Rh nanoparticles 1-3 nm in size, whose density on the surface increased with the number of pulses. This led to coalescence and grain growth on the foil surface and the eventual formation of a uniform two-dimensional Rh overlayer. Full coverage of the 51 μm-thick flat foil by a 3.2 nm-thick Rh overlayer was achieved after 1,000 pulses. A simulated TWC reaction using a miniature honeycomb fabricated using flat and corrugated foils with the Rh overlayers exhibited successful light-off at a practical gaseous hourly space velocity of 1.2 × 10(5) h(-1). The turnover frequency for the NO-CO reaction over the metallic honeycomb catalyst was ca. 80-fold greater than that achieved with a reference Rh/ZrO2-coated cordierite honeycomb prepared using a conventional wet impregnation and slurry coating procedure. Despite the nonporosity and low surface area of the foil-supported Rh overlayer compared with conventional powder catalysts (Rh/ZrO2), it is a promising alternative design for more efficient automotive catalysts that use less Rh loading. PMID:27388976

  8. A nanometric Rh overlayer on a metal foil surface as a highly efficient three-way catalyst

    NASA Astrophysics Data System (ADS)

    Misumi, Satoshi; Yoshida, Hiroshi; Hinokuma, Satoshi; Sato, Tetsuya; Machida, Masato

    2016-07-01

    Pulsed arc-plasma (AP) deposition of an Rh overlayer on an Fe–Cr–Al stainless steel foil produced a composite material that exhibited high activity for automotive three-way catalysis (TWC). The AP pulses deposited metallic Rh nanoparticles 1–3 nm in size, whose density on the surface increased with the number of pulses. This led to coalescence and grain growth on the foil surface and the eventual formation of a uniform two-dimensional Rh overlayer. Full coverage of the 51 μm-thick flat foil by a 3.2 nm-thick Rh overlayer was achieved after 1,000 pulses. A simulated TWC reaction using a miniature honeycomb fabricated using flat and corrugated foils with the Rh overlayers exhibited successful light-off at a practical gaseous hourly space velocity of 1.2 × 105 h‑1. The turnover frequency for the NO–CO reaction over the metallic honeycomb catalyst was ca. 80-fold greater than that achieved with a reference Rh/ZrO2-coated cordierite honeycomb prepared using a conventional wet impregnation and slurry coating procedure. Despite the nonporosity and low surface area of the foil-supported Rh overlayer compared with conventional powder catalysts (Rh/ZrO2), it is a promising alternative design for more efficient automotive catalysts that use less Rh loading.

  9. Assessment of Potential Location of High Arsenic Contamination Using Fuzzy Overlay and Spatial Anisotropy Approach in Iron Mine Surrounding Area

    PubMed Central

    Wirojanagud, Wanpen; Srisatit, Thares

    2014-01-01

    Fuzzy overlay approach on three raster maps including land slope, soil type, and distance to stream can be used to identify the most potential locations of high arsenic contamination in soils. Verification of high arsenic contamination was made by collection samples and analysis of arsenic content and interpolation surface by spatial anisotropic method. A total of 51 soil samples were collected at the potential contaminated location clarified by fuzzy overlay approach. At each location, soil samples were taken at the depth of 0.00-1.00 m from the surface ground level. Interpolation surface of the analysed arsenic content using spatial anisotropic would verify the potential arsenic contamination location obtained from fuzzy overlay outputs. Both outputs of the spatial surface anisotropic and the fuzzy overlay mapping were significantly spatially conformed. Three contaminated areas with arsenic concentrations of 7.19 ± 2.86, 6.60 ± 3.04, and 4.90 ± 2.67 mg/kg exceeded the arsenic content of 3.9 mg/kg, the maximum concentration level (MCL) for agricultural soils as designated by Office of National Environment Board of Thailand. It is concluded that fuzzy overlay mapping could be employed for identification of potential contamination area with the verification by surface anisotropic approach including intensive sampling and analysis of the substances of interest. PMID:25110751

  10. Impermeable thin AI2O3 overlay for TBC protection from sulfate and vanadate attack in gas turbines

    SciTech Connect

    Scott X. Mao

    2005-01-31

    25 {micro}m and a 2 {micro}m thick Al{sub 2}O{sub 3} overlay were deposited by HVOF thermal spray and by sol-gel coating method, respectively, onto to the surface of YSZ coating. Indenter test was employed to investigate the spalling of YSZ with and without Al{sub 2}O{sub 3} overlay after hot corrosion. The results showed that Al{sub 2}O{sub 3} overlay acted as a barrier against the infiltration of the molten salt into the YSZ coating during exposure, thus significantly reduced the amount of M-phase of ZrO{sub 2} in YSZ coating. Thick Al{sub 2}O{sub 3} overlay will increase compressive stress and failure in TBC. During next reporting time, Al{sub 2}O{sub 3} overlay will be deposited on the YSZ surface by the composite-sol-gel route (CSG). Hot corrosion tests will be carried out on the TBC.

  11. Variation in the excitability of developed D. discoideum cells as a function of agar concentration in the substrate

    NASA Astrophysics Data System (ADS)

    Oikawa, Noriko; Bae, Albert; Amselem, Gabriel; Bodenschatz, Eberhard

    2010-03-01

    In the absence of nutrients, Dictyostelium discoideum cells enter a developmental cycle--they signal each other, aggregate, and ultimately form fruiting bodies. During the signaling stage, the cells relay waves of cyclic adenosine 3',5' monophosphate (cAMP). We observed a transition from spiral to circular patterns in the signaling wave, depending on the agar concentration of the substrate. In this talk we will present the changes in the times for the onset of signaling and synchronization versus agar concentration, as measured by spectral entropy. We also will discuss the origin of these effects.

  12. Modified agar dilution susceptibility testing method for determining in vitro activities of antifungal agents, including azole compounds.

    PubMed Central

    Yoshida, T; Jono, K; Okonogi, K

    1997-01-01

    In vitro activities of antifungal agents, including azole compounds, against yeasts were easily determined by using RPMI-1640 agar medium and by incubating the plates in the presence of 20% CO2. The end point of inhibition was clear by this method, even in the case of azole compounds, because of the almost complete inhibition of yeast growth at high concentrations which permitted weak growth of some Candida strains by traditional methods. MICs obtained by the agar dilution method were similar to those obtained by the broth dilution method proposed by the National Committee for Clinical Laboratory Standards. PMID:9174197

  13. Growth of clinical isolates of anaerobic bacteria on agar media: effects of media composition, storage conditions, and reduction under anaerobic conditions.

    PubMed Central

    Murray, P R

    1978-01-01

    The quantitative growth, the colony size, and the rate of growth of 47 clinical anaerobic isolates were compared on five different media, namely Brucella agar, brain heart infusion agar, Columbia agar, Schaedler agar, and tryptic soy agar. There was no significant difference in the quantitative growth of the anaerobes inoculated onto the five media. Although no single medium was superior for the growth of all isolates, 12 of 22 isolates, inoculated onto media stored for 4 weeks or less, grew best on Schaedler agar. The effects of supplementation of the media with reducing agents and reduction of the media before use were also analyzed and were found to be affected by the composition and length of storage of the media, as well as the bacteria tested. PMID:744801

  14. Platinum and Palladium Overlayers Dramatically Enhance the Activity of Ruthenium Nanotubes for Alkaline Hydrogen Oxidation

    DOE PAGESBeta

    St. John, Samuel; Atkinson, Robert W.; Unocic, Kinga A.; Unocic, Raymond R.; Zawodzinski, Thomas A.; Papandrew, Alexander B.

    2015-10-18

    Templated vapor synthesis and thermal annealing were used to synthesize unsupported metallic Ru nanotubes with Pt or Pd overlayers. By controlling the elemental composition and thickness of these overlayers, we obtain nanostructures with very high alkaline hydrogen oxidation activity. For nanotubes with a nominal atomic composition of Ru0.90Pt0.10 display a surface-specific activity (2.4 mA/cm2) that is 35 times greater than that of pure Ru nanotubes at a 50 mV overpotential and 2.5 times greater than that of pure Pt nanotubes (0.98 mA/cm2). The surface-segregated structure also confers dramatically increased Pt utilization efficiency. We find a platinum-mass-specific activity of 1240 A/gPtmore » for the optimized nanotube versus 280 A/gPt for carbon-supported Pt nanoparticles and 109 A/gPt for monometallic Pt nanotubes. Here, we attribute the enhancement of both area- and platinum-mass-specific activity to the atomic-scale homeomorphism of the nanotube form factor with adlayer-modified polycrystals. Subsurface ligand and bifunctional effects previously observed on segregated, adlayer-modified polycrystals are translated to nanoscale catalysts.« less

  15. Optical fibre long period grating spectral actuators utilizing ferrofluids as outclading overlayers

    NASA Astrophysics Data System (ADS)

    Konstantaki, M.; Candiani, A.; Pissadakis, S.

    2011-03-01

    Results are presented on the spectral tuning of optical fibre long period gratings utilizing water and oil based ferrofluids as outclading overlayers, under static magnetic field stimulus. Two approaches are adopted for modifying the ambient refractive index at the position of the long period grating. In the first approach, a water based ferrofluid is controllably translated along the length of the grating via a magnetic field. Changes as high as 7.5nm and 6.5dB are monitored in the wavelength and strength, respectively, of the attenuation bands of the grating. The repeatable performance of this device for repetitive forward and backward translation verifies that no ferrofluidic residue is left on the fibre, due to silanization cladding functionalisation. In the second approach, the refractive index of an oil based ferrofluidic overlayer is modified through the magneto-optical effect. For an applied static magnetic field in the order of 400 Gauss the strength of the attenuation band of the grating is modified by more than 10% while its spectral position remains unaffected. Accordingly for the implementation of the last approach, the magnetically induced refractive index changes of ferrofluids of different solution concentrations are studied by employing diffraction efficiency measurements.

  16. Hot Corrosion of Inconel 625 Overlay Weld Cladding in Smelting Off-Gas Environment

    NASA Astrophysics Data System (ADS)

    Mohammadi Zahrani, E.; Alfantazi, A. M.

    2013-10-01

    Degradation mechanisms and hot corrosion behavior of weld overlay alloy 625 were studied. Phase structure, morphology, thermal behavior, and chemical composition of deposited salt mixture on the weld overlay were characterized utilizing XRD, SEM/EDX, DTA, and ICP/OES, respectively. Dilution level of Fe in the weldment, dendritic structure, and degradation mechanisms of the weld were investigated. A molten phase formed on the weld layer at the operating temperature range of the boiler, which led to the hot corrosion attack in the water wall and the ultimate failure. Open circuit potential and weight-loss measurements and potentiodynamic polarization were carried out to study the hot corrosion behavior of the weld in the simulated molten salt medium at 873 K, 973 K, and 1073 K (600 °C, 700 °C, and 800 °C). Internal oxidation and sulfidation plus pitting corrosion were identified as the main hot corrosion mechanisms in the weld and boiler tubes. The presence of a significant amount of Fe made the dendritic structure of the weld susceptible to preferential corrosion. Preferentially corroded (Mo, Nb)-depleted dendrite cores acted as potential sites for crack initiation from the surface layer. The penetration of the molten phase into the cracks accelerated the cracks' propagation mainly through the dendrite cores and further crack branching/widening.

  17. Improving Management Performance of P2PSIP for Mobile Sensing in Wireless Overlays

    PubMed Central

    Sendín-Raña, Pablo; González-Castaño, Francisco Javier; Gómez-Cuba, Felipe; Asorey-Cacheda, Rafael; Pousada-Carballo, José María

    2013-01-01

    Future wireless communications are heading towards an all-Internet Protocol (all-IP) design, and will rely on the Session Initiation Protocol (SIP) to manage services, such as voice over IP (VoIP). The centralized architecture of traditional SIP has numerous disadvantages for mobile ad hoc services that may be possibly overcome by advanced peer-to-peer (P2P) technologies initially developed for the Internet. In the context of mobile sensing, P2PSIP protocols facilitate decentralized and fast communications with sensor-enabled terminals. Nevertheless, in order to make P2PSIP protocols feasible in mobile sensing networks, it is necessary to minimize overhead transmissions for signaling purposes, which reduces the battery lifetime. In this paper, we present a solution to improve the management of wireless overlay networks by defining an adaptive algorithm for the calculation of refresh time. The main advantage of the proposed algorithm is that it takes into account new parameters, such as the delay between nodes, and provides satisfactory performance and reliability levels at a much lower management overhead than previous approaches. The proposed solution can be applied to many structured P2P overlays or P2PSIP protocols. We evaluate it with Kademlia-based distributed hash tables (DHT) and dSIP PMID:24217358

  18. Platinum and Palladium Overlayers Dramatically Enhance the Activity of Ruthenium Nanotubes for Alkaline Hydrogen Oxidation

    SciTech Connect

    St. John, Samuel; Atkinson, Robert W.; Unocic, Kinga A.; Unocic, Raymond R.; Zawodzinski, Thomas A.; Papandrew, Alexander B.

    2015-10-18

    Templated vapor synthesis and thermal annealing were used to synthesize unsupported metallic Ru nanotubes with Pt or Pd overlayers. By controlling the elemental composition and thickness of these overlayers, we obtain nanostructures with very high alkaline hydrogen oxidation activity. For nanotubes with a nominal atomic composition of Ru0.90Pt0.10 display a surface-specific activity (2.4 mA/cm2) that is 35 times greater than that of pure Ru nanotubes at a 50 mV overpotential and 2.5 times greater than that of pure Pt nanotubes (0.98 mA/cm2). The surface-segregated structure also confers dramatically increased Pt utilization efficiency. We find a platinum-mass-specific activity of 1240 A/gPt for the optimized nanotube versus 280 A/gPt for carbon-supported Pt nanoparticles and 109 A/gPt for monometallic Pt nanotubes. Here, we attribute the enhancement of both area- and platinum-mass-specific activity to the atomic-scale homeomorphism of the nanotube form factor with adlayer-modified polycrystals. Subsurface ligand and bifunctional effects previously observed on segregated, adlayer-modified polycrystals are translated to nanoscale catalysts.

  19. Development of dengue virus plaques under serum-free overlay medium.

    PubMed Central

    Malewicz, B; Jenkin, H M

    1979-01-01

    An improved plaque assay for dengue virus was developed utilizing baby hamster kidney (BHK-21) cells initially grown in shaker culture. Different media preparations were tested for uniform and fast formation of BHK-21 cell sheets. Several overlay formulas were tested to develop a rapid plaque assay in 6- and 24-well plastic plates. The best results were obtained utilizing Eagle minimal essential medium (pH 7.2 to 7.4) supplemented with 1 mg of NaHCO3 per ml and 5% newborn calf serum for the formation of cell monolayers after 8 to 24 h of incubation at 37 degrees C. Serum-free Eagle minimal essential medium supplemented with 1% methylcellulose and buffered with 10 mM N-2-hydroxyethyl piperazine-N'-2-ethanesulfonic acid (pH 7.4 to 7.6) was used as an overlay medium. This system allowed for plaque formation after 3 days of incubation of dengue type 2 virus and after 4 days for dengue type 1 and 4 viruses. Images PMID:39085

  20. The Effects of a Dynamic Spectrum Access Overlay in LTE-Advanced Networks

    SciTech Connect

    Juan D. Deaton; Ryan E. lrwin; Luiz A. DaSilva

    2011-05-01

    As early as 2014, wireless network operators spectral capacity will be overwhelmed by a data tsunami brought on by new devices and applications. To augment spectral capacity, operators could deploy a Dynamic Spectrum Access (DSA) overlay. In the light of the many planned Long Term Evolution (LTE) network deployments, the affects of a DSA overlay have not been fully considered into the existing LTE standards. Coalescing many different aspects of DSA, this paper develops the Spectrum Accountability (SA) framework. The SA framework defines specific network element functionality, protocol interfaces, and signaling flow diagrams for LTE to support service requests and enforce rights of responsibilities of primary and secondary users, respectively. We also include a network simulation to quantify the benefits of using DSA channels to augment capacity. Based on our simulation we show that, network operators can benefit up to %40 increase in operating capacity when sharing DSA bands to augment spectral capacity. With our framework, this paper could serve as an guide in developing future LTE network standards that include DSA.