WorldWideScience

Sample records for single quartz vial

  1. Protect Patients by Using Single- and Multi-Dose Vials Correctly

    Centers for Disease Control (CDC) Podcasts

    2014-07-10

    CDC’s One & Only Campaign urges healthcare providers to recognize the differences between single-dose and multi-dose vials, and to understand appropriate use of each container type.  Created: 7/10/2014 by National Center for Emerging and Zoonotic Infectious Diseases (NCEZID).   Date Released: 7/10/2014.

  2. Quality of bevacizumab (Avastin®) repacked in single-use glass vials for intravitreal administration.

    Science.gov (United States)

    Sugimoto, Michelle A A; Toledo, Vicente de Paulo Coelho Peixoto de; Cunha, Mariem Rodrigues Ribeiro; Carregal, Virginia M; Jorge, Rodrigo; Leão, Pedro; Fialho, Sílvia Ligorio; Silva-Cunha, Armando

    2017-01-01

    Avastin® (bevacizumab) is an anti-vascular endothelial growth factor (VEGF) monoclonal antibody given as an off-label drug by intravitreal administration for treatment of ocular diseases. The drug's clinical application and its cost-benefit profile has generated demand for its division into single-use vials to meet the low volume and low-cost doses necessary for intraocular administration. However, the safety of compounding the drug in single-use vials is still under discussion. In this study, the stability and efficacy of Avastin® repacked in individual single-use glass vials and glass ampoules by external compounding pharmacies were evaluated. Polyacrylamide gel electrophoresis (PAGE), size-exclusion chromatography (SEC), dynamic light scattering (DLS), and turbidimetry were selected to detect the formation of aggregates of various sizes. Changes in bevacizumab biological efficacy were investigated by using an enzyme-linked immunosorbent assay (ELISA). Repacked and reference bevacizumab showed similar results when analyzed by PAGE. By SEC, a slight increase in high molecular weight aggregates and a reduction in bevacizumab monomers were observed in the products of the three compounding pharmacies relative to those in the reference bevacizumab. A comparison of repacked and reference SEC chromatograms showed that the mean monomer loss was ≤1% for all compounding pharmacies. Protein aggregates in the nanometer- and micrometer-size ranges were not detected by DLS and turbidimetry. In the efficacy assay, the biological function of repacked bevacizumab was preserved, with <3% loss of VEGF binding capacity relative to that of the reference. The results showed that bevacizumab remained stable after compounding in ampoules and single-use glass vials; no significant aggregation, fragmentation, or loss of biological activity was observed.

  3. Vial Memory

    OpenAIRE

    Grimes, Karl

    2005-01-01

    Vial Memory is the final part in the Collected trilogy. Following Still Life and Future Nature, the work marks a return to the medical archive and the body on display. The project is an art and science collaboration with the Mütter Museum and the College of Physicians of Philadelphia, U.S.A. Vial Memory explicitly invokes scientific process and human consciousness. On one level functioning as a form of memento mori with their intimations of mortality, yet the vivid spectacular of the images a...

  4. Fluid inclusions and microstructures in experimentally deformed quartz single crystals

    Science.gov (United States)

    Thust, A.; Tarantola, A.; Heilbronner, R.; Stünitz, H.

    2009-04-01

    The "H2O-weakening" effect that reduces the strength of quartz dramatically (e.g. Griggs & Blacic 1965) is still not understood. For example, Kronenberg & Tullis (1984) conclude that the weakening effect is pressure dependent while Paterson (1989) infers a glide and recovery control of water. Obviously, the spatial distribution and transport of H2O are important factors (Kronenberg et al. 1986, FitzGerald et al. 1991). We have carried out experiments on milky quartz in a Griggs deformation apparatus. Cylinders (6.5 mm in diameter, 12-13 mm in length) from a milky zone of a natural quartz single crystal have been cored in orientations (1) normal to one of the prism planes and (2) 45˚ to and 45˚ to (O+orientation). At 1 GPa confining pressure, 900˚ C and 10-6s-1, the flow strength is 150 MPa for samples with orientation (1). Further experiments are needed to establish the flow strength for orientation (2). FTIR measurements on double-polished thick sections (200-500 μm) in the undeformed quartz material yield an average H2O content of approximately 100 H/106Si. The water is heterogeneously distributed in the sample. Direct measurements on fluid inclusions yield a H2O content of more than 25 000 H/106Si. Thus, the H2O in the undeformed material is predominantly present in fluid inclusions of size from tens to hundred microns. Micro-thermometric measurements at low temperature indicate the presence of different salts in the fluid inclusions. The ice melting temperature, between -6.9 and -7.4˚ C, indicate an average salinity of 10.5 wt% NaCl. After deformation the distribution of H2O is more homogeneous throughout the sample. The majority of the big inclusions have disappeared and very small inclusions of several microns to sub-micron size have formed. FTIR measurements in zones of undulatory extinction and shear bands show an average H2O content of approximately 3000 H/106Si. Moreover, the larger fluid inclusions are characterized by a higher salinity (12 wt%) due

  5. Hydrothermal Synthesis of Monodisperse Single-Crystalline Alpha-Quartz Nanospheres

    Science.gov (United States)

    Jiang, Xingmao; Jiang, Ying-Bing

    2014-01-01

    Uniformly-sized, single-crystal alpha-quartz nanospheres have been synthesized at 200°C and 15atm under continuous stirring starting from uniform, amorphous Stöber silica colloids and using NaCl and alkali hydroxide as mineralizers. Quartz nanosphere size is controlled by the colloid particle size via direct devitrification. Uniform, high-purity nanocrystalline quartz is important for understanding nanoparticle toxicology and for advanced polishing and nanocomposite fabrication. PMID:21629887

  6. Assessment of infection control practices for interventional techniques: a best evidence synthesis of safe injection practices and use of single-dose medication vials.

    Science.gov (United States)

    Manchikanti, Laxmaiah; Falco, Frank J E; Benyamin, Ramsin M; Caraway, David L; Helm Ii, Standiford; Wargo, Bradley W; Hansen, Hans; Parr, Allan T; Singh, Vijay; Hirsch, Joshua A

    2012-01-01

    It is universally accepted that transmission of bloodborne pathogens during health care procedures continues to occur because of the use of unsafe and improper injection, infusion, and medication administration practices by health care professionals in various clinical settings. This resulted in development of multiple guidelines based on case reports; however, these case reports are confounded by multiple factors without causal relationship to a single factor. Even then, single-dose vials used for multiple patients have been singled out and became the focus of infection control policies resulting in inordinate expenses for practices without improving patient safety. The cost of implementation of single dose vial policy in interventional pain management for drugs alone may cost $750 million, whereas with single use radional gloves may exceed $1 billion per year. Best evidence synthesis. To critically appraise and synthesize the literature on infection control practices for interventional techniques, including safe injection and medication vial utilization. The available literature on infection control practices was reviewed. Due to the nature of the studies involved, with the majority being case reports, and a few prospective evaluations, quality assessment and clinical relevance criteria were not applied. Data sources included relevant literature identified through searches of PubMed and EMBASE from 1966 through June 2012, literature from the Centers for Disease Control and Prevention (CDC), the U.S. Food and Drug Administration (FDA), and manual searches of the bibliographies of known primary and review articles. The primary outcome measure was correlating infection to a breach of standards in infection control practices. The secondary objective was to assess the contribution of single-dose vials independently for infection. A total of 60 reports met inclusion criteria, with 16 reports related to pain management and other procedures, of which 9 reports were

  7. Identification of the volcanic quartz origins from dune sand using a single-grain RTL measurement

    Science.gov (United States)

    Yawata, Takashi; Hashimoto, Tetsuo

    2004-05-01

    In an earlier study, we found that quartz grains extracted from Niigata dune sand all contained red thermoluminescence (RTL) phenomena. This RTL could subsequently be attributed to the volcanic origin of the material. The Agano River is assumed to be the main source of the Niigata dune material. Using the single aliquot regenerative method, which involves the measurement of several hundreds of grains, the measured equivalent doses from the RTL-quartz grains were larger than expected. Consequently, a single-grain method combined with RTL-measurement was developed to determine the equivalent doses from each quartz grain. Placing a biotite plate with a central hole for the sample grain on the sample disk made a significant contribution to keeping background levels as low as possible. The histogram of the equivalent doses evaluated from 72 quartz grains revealed that the Niigata dune originates from at least four different volcanic sources around Agano River. One of them is the Numazawa volcano, because the minimum equivalent dose values from the single grain method are equal to those of quartz grains from the Numazawa pumice.

  8. Sources of variability in OSL dose measurements using single grains of quartz

    DEFF Research Database (Denmark)

    Thomsen, Kristina Jørkov; Murray, A.S.; Bøtter-Jensen, L.

    2005-01-01

    spread. In this preliminary study, dose distributions have been studied using single grains of heated and laboratory irradiated quartz. By heating the sample, the contribution from incomplete zeroing was excluded and at the same time the sample was sensitised. The laboratory gamma irradiation...

  9. Optical dating of quartz from young deposits : From single-aliquot to single-grain

    NARCIS (Netherlands)

    Ballarini, M.

    2006-01-01

    Optically Stimulated Luminescence (OSL) dating is a tool used in Quaternary Geology for assessing ages of depositional mineral grains such as quartz, feldspars and zircons. In particular, OSL showed to be exceptionally robust and reliable for dating quartz samples. Such a technique has been

  10. Optically stimulated luminescence techniques in retrospective dosimetry using single grains of quartz extracted from unheated materials

    International Nuclear Information System (INIS)

    Joerkov Thomsen, Kristina

    2004-02-01

    This work investigates the possibility of applying optically stimulated luminescence (OSL) in retrospective dose determinations using unheated materials. It focuses on identifying materials suitable for use in assessment of doses absorbed as a consequence of radiation accidents (i.e. accident dosimetry). Special attention has been paid to quartz extracted from unheated building materials such as concrete and mortar. The single-aliquot regeneration-dose (SAR) protocol has been used to determine absorbed doses in small aliquots as well as single grains of quartz. It is shown that OSL measurements of single grains of quartz extracted from poorly-bleached building materials can provide useful information on radiation accident doses, even when the luminescence sensitivity is low. Sources of variance in well-bleached single grain dose distributions have been investigated in detail and it is concluded that the observed variability in the data is consistent with the sum (in quadrature) of a component, which depends on the number of photons detected from each grain, and a fixed component independent of light level. Dose depth profiles through laboratory irradiated concrete bricks have successfully been measured and minimum detection limits of less than 100 mGy are derived. Measurements of thermal transfer in single grains of poorly-bleached quartz show that thermal transfer is variable on a grain-to-grain basis and that it can be a source of variance in single-grain dose distributions. Furthermore, the potential of using common household and workplace chemicals, such as table salt, washing powder and water softener, in retrospective dosimetry has been investigated. It is concluded that such materials should be considered as retrospective dosimeters in the event of a radiation accident. (au)

  11. Operational experience and validation of the triathlerTM model 425-034(1) single vial liquid scintillation counter for meeting department of energy release criteria

    International Nuclear Information System (INIS)

    Kanady, R. W.

    2008-01-01

    Triathler TM Model 425-034 single vial liquid scintillation counter (LSC) counters have been in use at the Safety and Tritium Applied Research Facility (STAR) for approximately three years. During facility setup and determination of instrumentation needs to support STAR facility operations, the Triathler was chose to assess smearable tritium contamination levels for operational conditions. The Triathler was selected due to the rapid turnaround time for obtaining tritium contamination levels versus other automated batch LSC counters currently in use at the Idaho National Laboratory (INL) and other Dept. of Energy (DOE) installations. Operational experience with the Triathler thus far has shown a high reliability for verifying removable contamination levels at a level of 2 when compared to the Packard TM Tri-Carb 1905 AB/LA Liquid Scintillation Analyzer used by the Reactor Technologies Complex (RTC) Radiochemistry Measurements Laboratory (RML). However, variances in the reported results for activity in DPM/vial from the Triathler versus the Packard Tri-Carb have been noted when operating in the range of 5,000 to 20,000 DPM. These variances make reliability and use of the Triathler suspect for verifying smearable contamination levels meet the release criteria identified in DOE Order 5400.5, Radiation Protection of the Public and Environment. Ensuring that removable tritium contamination levels on materials and equipment intended for free-release to the public are 2 is a requirement in the Idaho National Laboratory (INL) contract. Comprehensive cross-comparisons have been ongoing to ensure the Triathler LSC reported DPM values provide sufficient detection of smearable tritium contamination when cross-compared to other automated liquid scintillation counters available at the INL. (authors)

  12. Neutron diffraction in a quartz single crystal under the action of acoustic oscillations or a temperature gradient

    CERN Document Server

    Mkrtchyan, A R; Hunanyan, H A; Beglaryan, A G

    1986-01-01

    The paper deals with the problem of neutron diffraction in a quartz single crystal under the action of acoustic oscillations or a temperature gradient in the Laue geometry. Theoretical conclusions were compared with experimental results.

  13. Development of a Single Vial Kit Solution for Radiolabeling of 68Ga-DKFZ-PSMA-11 and Its Performance in Prostate Cancer Patients

    Directory of Open Access Journals (Sweden)

    Thomas Ebenhan

    2015-08-01

    Full Text Available Prostate-specific membrane antigen (PSMA, a type II glycoprotein, is highly expressed in almost all prostate cancers. By playing such a universal role in the disease, PSMA provides a target for diagnostic imaging of prostate cancer using positron emission tomography/computed tomography (PET/CT. The PSMA-targeting ligand Glu-NH-CO-NH-Lys-(Ahx-HBED-CC (DKFZ-PSMA-11 has superior imaging properties and allows for highly-specific complexation of the generator-based radioisotope Gallium-68 (68Ga. However, only module-based radiolabeling procedures are currently available. This study intended to develop a single vial kit solution to radiolabel buffered DKFZ-PSMA-11 with 68Ga. A 68Ge/68Ga-generator was utilized to yield 68GaCl3 and major aspects of the kit development were assessed, such as radiolabeling performance, quality assurance, and stability. The final product was injected into patients with prostate cancer for PET/CT imaging and the kit performance was evaluated on the basis of the expected biodistribution, lesion detection, and dose optimization. Kits containing 5 nmol DKFZ-PSMA-11 showed rapid, quantitative 68Ga-complexation and all quality measurements met the release criteria for human application. The increased precursor content did not compromise the ability of 68Ga-DKFZ-PSMA-11 PET/CT to detect primary prostate cancer and its advanced lymphatic- and metastatic lesions. The 68Ga-DKFZ-PSMA-11 kit is a robust, ready-to-use diagnostic agent in prostate cancer with high diagnostic performance.

  14. Optically stimulated luminescence sensitivity changes in quartz due to repeated use in single aliquot readout: Experiments and computer simulations

    DEFF Research Database (Denmark)

    McKeever, S.W.S.; Bøtter-Jensen, L.; Agersnap Larsen, N.

    1996-01-01

    As part of a study to examine sensitivity changes in single aliquot techniques using optically stimulated luminescence (OSL) a series of experiments has been conducted with single aliquots of natural quartz, and the data compared with the results of computer simulations of the type of processes...

  15. Dating ice shelf edge marine sediments: A new approach using single-grain quartz luminescence

    DEFF Research Database (Denmark)

    Berger, G.W.; Murray, A.S.; Thomsen, Kristina Jørkov

    2010-01-01

    the Antarctic Peninsula, sediment-water-interface (“zero-age” analogs), silt-rich short cores were collected in 2001–2003, originally only for fine silt dating tests. Later access to suitable instrumentation also permitted testing the potential of single-grain quartz (SGQ) dating of sand grains from these cores...... estimates (>20 ka), with the sixth sample yielding a multiple-aliquot short-bleach age estimate of 1.1 ± 0.6 ka. In contrast, five of seven sand samples yielded geologically reasonable last daylight exposure ages of 0.2–0.6 ka. These SGQ results are also remarkable when compared to published 14C ages of 1...

  16. Variation with depth of dose distributions in single grains of quartz extracted from an irradiated concrete block

    DEFF Research Database (Denmark)

    Thomsen, Kristina Jørkov; Jain, M.; Bøtter-Jensen, L.

    2003-01-01

    irradiated normal to one face in the laboratory using Cs-137 gamma photons. The OSL dose-depth profile for the irradiated block was determined by measuring the dose distributions from single quartz grains extracted from slices taken across the block and compared with that predicted using Monte Carlo...

  17. Temperature effect on phase states of quartz nano-crystals in silicon single crystal

    International Nuclear Information System (INIS)

    Kalanov, M.U.; Ibragimova, E.M.; Khamraeva, R.N.; Rustamova, V.M.; Ummatov, Kh.D.

    2006-01-01

    Full text: Oxygen penetrates into the silicon lattice up to the concentration of 2·10 18 cm -3 in the course of growing [1]. By the author's opinion at a low oxygen content the formation of solid solution is possible in the local defect places of the silicon single crystal lattice due to the difference in effective ion radius of oxygen and silicon (r O 0.176 and r Si = 0.065 nm). Upon reaching some critical content (∼ 10 17 cm -3 ), it becomes favorable energetically for oxygen ions to form precipitates (SiO x ) and finally a dielectric layer (stoichiometric inclusions of SiO 2 ). It was shown later that depending on the growth conditions, indeed the quartz crystal inclusions are formed in the silicon single crystals at an amount of 0.3 /0.5 wt. % [2]. However the authors did not study a phase state of the quartz inclusions. Therefore the aim of this work was to study a phase state of the quartz inclusions in silicon crystal at various temperatures. We examined the silicon single crystals grown by Czochralski technique, which were cut in (111) plane in the form of disk of 20 mm diameter and 1.5 thickness and had hole conductivity with the specific resistance ρ o ≅ 1/10 Ohm cm. The dislocation density was N D ≅ 10 1 /10 3 cm -2 , the concentrations of oxygen and boron were N 0 ≅ 2/ 4·10 17 cm -3 and N B ≅ 3*10 15 cm -3 . Structure was analyzed at the set-up DRON-UM1 with high temperature supply UVD-2000 ( CuK = 0.1542 nm) at the temperatures of 300, 1173 and 1573 K measured with platinum-platinum-rhodium thermocouple. The high temperature diffraction spectrum measured at 1573 K in the angle range (2Θ≅10/70 d egree ) there is only one main structure reflection (111) with a high intensity and d/n ≅ 0.3136 nm (2 Θ≅ 28.5 d egree ) from the matrix lattice of silicon single crystal. The weak line at 2 Θ≅ 25.5 d egree ( d/n≅0.3136 nm) is β component of the main reflection (111), and the weak structure peak at 2Θ≅59 d egree ( d/n≅ 0.1568 nm

  18. Optical dating of single sand-sized grains of quartz: Sources of variability

    DEFF Research Database (Denmark)

    Duller, G.A.T.; Bøtter-Jensen, L.; Murray, A.S.

    2000-01-01

    Optically stimulated luminescence (OSL) measurements have been made of over 3000 sand-sized grains of quartz. Analysis at this scale highlights the variability in the luminescence sensitivity and the dose saturation characteristics of individual quartz grains. Using a new instrument capable of me...... intensity, dose saturation characteristics and instrument uncertainty in equivalent dose calculation. (C) 2000 Elsevier Science Ltd. All rights reserved....

  19. The dose dependency of the over-dispersion of quartz OSL single grain dose distributions

    International Nuclear Information System (INIS)

    Thomsen, Kristina J.; Murray, Andrew; Jain, Mayank

    2012-01-01

    The use of single grain quartz OSL dating has become widespread over the past decade, particularly with application to samples likely to have been incompletely bleached before burial. By reducing the aliquot size to a single grain the probability of identifying the grain population most likely to have been well-bleached at deposition is maximised and thus the accuracy with which the equivalent dose can be determined is – at least in principle – improved. However, analysis of single grain dose distributions requires knowledge of the dispersion of the well-bleached part of the dose distribution. This can be estimated by measurement of a suitable analogue, e.g. a well-bleached aeolian sample, but this requires such an analogue to be available, and in addition the assumptions that the sample is in fact a) well-bleached, and b) has a similar dose rate heterogeneity to the fossil deposit. Finally, it is an implicit assumption in such analysis that any over-dispersion is not significantly dose dependent. In this study we have undertaken laboratory investigations of the dose dependency of over-dispersion using a well-bleached modern sample with an average measured dose of 36 ± 3 mGy. This sample was prepared as heated (750 °C for 1 h), bleached and untreated portions which were then given uniform gamma doses ranging from 100 mGy to 208 Gy. We show that for these samples the relative laboratory over-dispersion is not constant as a function of dose and that the over-dispersion is smaller in heated samples. We also show that the dim grains in the distributions have a greater over-dispersion than the bright grains, implying that insensitive samples will have greater values of over-dispersion than sensitive samples.

  20. Retrospective dosimetry: Estimation of the dose to quartz using the single-aliquot regenerative-dose protocol

    DEFF Research Database (Denmark)

    Banerjee, D.; Bøtter-Jensen, L.; Murray, A.S.

    2000-01-01

    We report on the application of the single-aliquot regenerative-dose protocol to retrospective dosimetry, using the optically stimulated luminescence (OSL) from quartz extracted from fired bricks. These bricks had previously been exposed to enhanced levels of ionising radiation while part...... meets the fundamental requirement of the single-aliquot regenerative-dose protocol, in that any change in the luminescence recombination probability can be corrected for by using the OSL response to a fixed test dose. The response of a particular aliquot is examined after three different treatments...

  1. Quartz crystal microbalance detection of DNA single-base mutation based on monobase-coded cadmium tellurium nanoprobe.

    Science.gov (United States)

    Zhang, Yuqin; Lin, Fanbo; Zhang, Youyu; Li, Haitao; Zeng, Yue; Tang, Hao; Yao, Shouzhuo

    2011-01-01

    A new method for the detection of point mutation in DNA based on the monobase-coded cadmium tellurium nanoprobes and the quartz crystal microbalance (QCM) technique was reported. A point mutation (single-base, adenine, thymine, cytosine, and guanine, namely, A, T, C and G, mutation in DNA strand, respectively) DNA QCM sensor was fabricated by immobilizing single-base mutation DNA modified magnetic beads onto the electrode surface with an external magnetic field near the electrode. The DNA-modified magnetic beads were obtained from the biotin-avidin affinity reaction of biotinylated DNA and streptavidin-functionalized core/shell Fe(3)O(4)/Au magnetic nanoparticles, followed by a DNA hybridization reaction. Single-base coded CdTe nanoprobes (A-CdTe, T-CdTe, C-CdTe and G-CdTe, respectively) were used as the detection probes. The mutation site in DNA was distinguished by detecting the decreases of the resonance frequency of the piezoelectric quartz crystal when the coded nanoprobe was added to the test system. This proposed detection strategy for point mutation in DNA is proved to be sensitive, simple, repeatable and low-cost, consequently, it has a great potential for single nucleotide polymorphism (SNP) detection. 2011 © The Japan Society for Analytical Chemistry

  2. Using the OSL single-aliquot regenerative-dose protocol with quartz extracted from building materials in retrospective dosimetry

    DEFF Research Database (Denmark)

    Bøtter-Jensen, L.; Solongo, S.; Murray, A.S.

    2000-01-01

    We report on the application of the single-aliquot regenerative-dose (SAR) protocol to the optically stimulated luminescence signal from quartz extracted from fired bricks acid unfired mortar in retrospective dosimetry. The samples came from a radioactive materials storage facility, with ambient...... dose rates of about 0.1 mGy/h. A detailed dose-depth profile was analysed from one brick, and compared with dose records from area TL dosemeters. Small-aliquot dose-distributions were analysed from the mortar samples; one associated with the exposed brick, and one from a remote site exposed only...

  3. Absence of single critical dose for the amorphization of quartz under ion irradiation

    Science.gov (United States)

    Zhang, S.; Pakarinen, O. H.; Backholm, M.; Djurabekova, F.; Nordlund, K.; Keinonen, J.; Wang, T. S.

    2018-01-01

    In this work, we first simulated the amorphization of crystalline quartz under 50 keV 23 Na ion irradiation with classical molecular dynamics (MD). We then used binary collision approximation algorithms to simulate the Rutherford backscattering spectrometry in channeling conditions (RBS-C) from these irradiated MD cells, and compared the RBS-C spectra with experiments. The simulated RBS-C results show an agreement with experiments in the evolution of amorphization as a function of dose, showing what appears to be (by this measure) full amorphization at about 2.2 eVṡatom-1 . We also applied other analysis methods, such as angular structure factor, Wigner–Seitz, coordination analysis and topological analysis, to analyze the structural evolution of the irradiated MD cells. The results show that the atomic-level structure of the sample keeps evolving after the RBS signal has saturated, until the dose of about 5 eVṡatom-1 . The continued evolution of the SiO2 structure makes the definition of what is, on the atomic level, an amorphized quartz ambiguous.

  4. Utility of Paired BACTEC MYCO/F LYTIC Blood Culture Vials for Detection of Bacteremia, Mycobacteremia, and Fungemia

    OpenAIRE

    Archibald, Lennox K.; Dobbie, Hamish; Kazembe, Peter; Nwanyanwu, Okey; McKnight, Celeste; Byrne, Terry; Addison, Rachel M.; Bell, Michael; Reller, L. Barth; Jarvis, William R.

    2001-01-01

    In previous bloodstream infection studies in Malawi, we inoculated blood from a single venesection into a single BACTEC MYCO/F LYTIC (MFL) vial. Inoculation of one vial, however, would be expected to reduce the sensitivity of bloodstream pathogen detection with MFL vials. To ascertain the degree of this loss of sensitivity, blood was drawn from each of 228 febrile, adult inpatients in Malawi and 5 ml of each blood sample was inoculated into each of two MFL vials. Of 228 paired vials, 51 (22%)...

  5. Characterization of Surface Properties of Glass Vials Used as Primary Packaging Material for Parenterals.

    Science.gov (United States)

    Ditter, Dominique; Mahler, Hanns-Christian; Roehl, Holger; Wahl, Michael; Huwyler, Joerg; Nieto, Alejandra; Allmendinger, Andrea

    2018-01-10

    The appropriate selection of adequate primary packaging, such as the glass vial, rubber stopper, and crimp cap for parenteral products is of high importance to ensure product stability, microbiological quality (integrity) during storage as well as patient safety. A number of issues can arise when inadequate vial material is chosen, and sole compliance to hydrolytic class I is sometimes not sufficient when choosing a glass vial. Using an appropriate pre-treatment, such as surface modification or coating of the inner vial surface after the vial forming process the glass container quality is often improved and interactions of the formulation with the surface of glass may be minimized. This study aimed to characterize the inner surface of different type I glass vials (Exp33, Exp51, Siliconized, TopLyo TM and Type I plus®) at the nanoscale level. All vials were investigated topographically by colorimetric staining and Scanning Electron Microscopy (SEM). Glass composition of the surface was studied by Time-of-Flight - Secondary Ion Mass Spectrometry (ToF-SIMS) and X-ray Photoelectron Spectroscopy (XPS), and hydrophobicity/hydrophilicity of the inner surface was assessed by dye tests and surface energy measurements. All containers were studied unprocessed, as received from the vendor, i.e. in unwashed and non-depyrogenized condition. Clear differences were found between the different vial types studied. Especially glass vials without further surface modifications, like Exp33 and Exp51 vials, showed significant (I) vial-to-vial variations within one vial lot as well as (II) variations along the vertical axis of a single vial when studying topography and chemical composition. In addition, differences and heterogeneity in surface energy were found within a given tranche (circumferential direction) of Exp51 as well as Type I plus® vials. Most consistent quality was achieved with TopLyo TM vials. The present comprehensive characterization of surface properties of the

  6. Tool wear of a single-crystal diamond tool in nano-groove machining of a quartz glass plate

    International Nuclear Information System (INIS)

    Yoshino, Masahiko; Nakajima, Satoshi; Terano, Motoki

    2015-01-01

    Tool wear characteristics of a diamond tool in ductile mode machining are presented in this paper. Nano-groove machining of a quartz glass plate was conducted to examine the tool wear rate of a single-crystal diamond tool. Effects of lubrication on the tool wear rate were also evaluated. A numerical simulation technique was developed to evaluate the tool temperature and normal stress acting on the wear surface. From the simulation results it was found that the tool temperature does not increase during the machining experiment. It is also demonstrated that tool wear is attributed to the abrasive wear mechanism, but the effect of the adhesion wear mechanism is minor in nano-groove machining. It is found that the tool wear rate is reduced by using water or kerosene as a lubricant. (paper)

  7. Testing single-grain quartz OSL methods using sediment samples with independent age control from the Bordes-Fitte rockshelter (Roches d'Abilly site, Central France)

    DEFF Research Database (Denmark)

    Thomsen, Kristina Jørkov; Murray, Andrew Sean; Buylaert, Jan-Pieter

    2016-01-01

    We present quartz single-grain dose distributions for four well-bleached and unmixed sediment samples with independent age control (22–48 ka), from the archaeologically important Bordes-Fitte rockshelter at Roches d'Abilly, France. This site has previously been dated using 14C AMS dating and stan......We present quartz single-grain dose distributions for four well-bleached and unmixed sediment samples with independent age control (22–48 ka), from the archaeologically important Bordes-Fitte rockshelter at Roches d'Abilly, France. This site has previously been dated using 14C AMS dating...

  8. Bioelectrical impedimetric sensor for single cell analysis based on nanoroughened quartz substrate; suitable for cancer therapeutic purposes.

    Science.gov (United States)

    Gharooni, Milad; Abdolahad, Mohammad

    2017-08-05

    Single cells analysis has been interested in recent decade. Apart from scientific benefits to achieve new biological phenomena in cell study, many diagnostic and therapeutic protocols in non-communicable diseases were introduced by single cell analysis. Moreover, non-invasive methods to maintain the investigated cell for time dependent monitoring has been widely studied because of its importance in some crucial cases such as drug resistance in cancer. Bioelectrical monitoring is one of such methods Although the procedures reported based on electrical probing might not induce cell disruption, indirect connection between recording electrodes and cell membrane (mostly in microfluidic approaches) reduced the quality of response and limited the precision of the results. Here, a bioelectronic sensor for monitoring the effect of anticancer drugs on single breast cancer cells was fabricated based on nano-roughened gold electrodes on a quartz substrate applied direct contacts to cell membrane. Whole of the surface except a microcircle surrounded the sensing region was passivated by overbaked photoresist layer. Cells were dropped on the sensor without the assistance of any micropipette or microfluidic systems and just individual regions for attachment of one cell has been opened on the sensing region arrays. MCF-7 cancer cells were time tracked under the effect of Paclitaxel and Mebendazole anti-tubulin drugs in low and high doses. Inducing non regulated depolymerization and polymerization in tubulin structures of the single cancer cells were monitored by the electrical signals recorded before and after drug treatment. Electrical responses of single cells to their incubation with drugs completely reflected their vitality and biological states which were confirmed by confocal imaging. This is one of the first investigation on bioelectrical monitoring of single cell's resistance to anticancer drugs. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. A single-aliquot regenerative-dose method based on IR (1.49 eV) bleaching of the fast OSL component in quartz

    DEFF Research Database (Denmark)

    Jain, M.; Murray, A.S.; Bøtter-Jensen, L.

    2005-01-01

    assistance energy required for IR stimulation (1.49 eV; 830 nm) of the fast component is calculated to be 0.41 +/- 0.02 eV. However, the elevated temperature IRSL of quartz has a poor signal-to-noise ratio; hence a single-aliquot regenerative-dose (SAR) protocol based on a differential-OSL signal (the...

  10. The dose dependency of the over-dispersion of quartz OSL single grain dose distributions

    DEFF Research Database (Denmark)

    Thomsen, Kristina Jørkov; Murray, Andrew S.; Jain, Mayank

    2012-01-01

    to have been well-bleached at deposition is maximised and thus the accuracy with which the equivalent dose can be determined is – at least in principle – improved. However, analysis of single grain dose distributions requires knowledge of the dispersion of the well-bleached part of the dose distribution....... This can be estimated by measurement of a suitable analogue, e.g. a well-bleached aeolian sample, but this requires such an analogue to be available, and in addition the assumptions that the sample is in fact a) well-bleached, and b) has a similar dose rate heterogeneity to the fossil deposit. Finally......, it is an implicit assumption in such analysis that any over-dispersion is not significantly dose dependent. In this study we have undertaken laboratory investigations of the dose dependency of over-dispersion using a well-bleached modern sample with an average measured dose of 36 ± 3 mGy. This sample was prepared...

  11. Infraestructura vial nacional asociada a la competitividad

    OpenAIRE

    Carrasco Osorio, Arturo Emilio

    2009-01-01

    El objetivo de esta investigación es dar a conocer la situación de nuestro sistema vial de carreteras evaluando la gestión que se realiza en la misma por parte del Gobierno Central. Para ello, se realiza un análisis de la situación de la infraestructura vial nacional, a fin de establecer criterios de aporte para mejorar las condiciones de competitividad del Perú respecto a otros países de la región Latinoamericana y el mundo. Finalmente, se puede concluir que el sistema de transporte vial, es...

  12. Measurement of light emission in scintillation vials

    International Nuclear Information System (INIS)

    Duran Ramiro, M. Teresa; Garcia-Torano, Eduardo

    2005-01-01

    The efficiency and energy resolution of liquid scintillation counting (LSC) systems are strongly dependent on the optical characteristics of scintillators, vials, and reflectors. This article presents the results of measurements of the light-emission profile of scintillation vials. Two measurement techniques, autoradiographs and direct measurements with a photomultiplier tube, have been used to obtain light-emission distribution for standard vials of glass, etched glass and polyethylene. Results obtained with both techniques are in good agreement. For the first time, the effect of the meniscus in terms of light contribution has been numerically estimated. These results can help design LSC systems that are more efficient in terms of light collection

  13. Drawing medicine out of a vial

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/patientinstructions/000530.htm Drawing medicine out of a vial To use the sharing ... a clean area. Wash your hands. Check Your Medicine Carefully check your medicine: Check the label. Make ...

  14. On the performances of the single-aliquot regenerative-dose (SAR) protocol for Chinese loess: fine quartz and polymineral grains

    International Nuclear Information System (INIS)

    Wang Xulong; Lu Yanchou; Zhao Hua

    2006-01-01

    This paper presents the results of a study which assesses the performances of the single-aliquot regenerative-dose (SAR) protocol in fine quartz and polymineral grains (4-11μm) obtained from the Luochuan loess-paleosol section on the central Loess Plateau, China. Fine quartz was isolated from polymineral grains, with the grain mineralogy confirmed by infrared (IR) stimulation detection. The fine quartz optically stimulated luminescence (OSL) results obtained yielded a stratigraphically consistent equivalent dose (D e ) distribution for the Luochuan loess-paleosol sequence deposited during the last glacial-interglacial. The performances of the infrared stimulated luminescence (IRSL) signal and the optically stimulated luminescence signal after infrared exposure ([post-IR] OSL) for polymineral grains were estimated by a comparison with that of fine quartz. Our results suggest that the IRSL D e value is underestimated in relatively old samples (about >50Gy) probably due to anomalous fading of the natural IRSL signal. We propose that the ratio of IRSL vs. [post-IR] OSL signal provides a measure of the degree of fading of the IRSL signal. It is confirmed that the [post-IR] OSL signal after sufficient IR exposure provides a better performance than that of the IRSL signal in Chinese loess, not only for the Holocene samples, but also for the last glacial samples. A suitable IR exposure time prior to measurement of the [post-IR] OSL signal can be obtained by determination of the plateau region of a plot of the [post-IR] OSL D e value vs. IR exposure duration. The results obtained suggest that both quartz OSL and polymineral [post-IR] OSL signal can produce consistent D e estimates for the loess-paleosol succession. The linear modulation technique was used to explain the good performance of [post-IR] OSL signal in D e determination

  15. Combining infrared- and green-laser stimulation sources in single-grain luminescence measurements of feldspar and quartz

    DEFF Research Database (Denmark)

    Duller, G.A.T.; Bøtter-Jensen, L.; Murray, A.S.

    2003-01-01

    possible to interchangeably use the two laser sources for optical stimulation. This is especially valuable for the measurement of feldspars. The power density using the IR laser at the grain is similar to500 W cm(-2), and stimulation for 1 s reduces the OSL signal to near background level. Initial results...... on grains from two feldspar samples are described. These show that the ratio of the OSL signal under green and IR stimulation is similar for all the feldspar grains. As expected, the ratio for quartz grains is very different, with a much weaker signal when using IR stimulation. For the two feldspars...

  16. INTEGRITY OF VOA-VIAL SEALS

    Science.gov (United States)

    Preservation of soil samples for the analysis of volatile organic compounds (VOCs) requires both the inhibition of VOC degradation and the restriction of vapor movement in or out of the sample container. Clear, 40,mL glass VOA vials manufactured by the four major U.S. glass manu...

  17. INTEGRITY OF VOA-VIAL SEALS | Science Inventory | US ...

    Science.gov (United States)

    Preservation of soil samples for the analysis of volatile organic compounds (VOCs) requires both the inhibition of VOC degradation and the restriction of vapor movement in or out of the sample container. Clear, 40,mL glass VOA vials manufactured by the four major U.S. glass manufacturers were tested for seal integrity. Visual inspection revealed a variety of imperfections ranging from small indentations, bumps, and scratches on vial threads or lips, through obvious defects, such as large indentations or grooves in the vial lips and chipped or broken glass. The aluminum plate vacuum test proved to be unreliable in identifying potentially leaky vials. The septa-seal vacuum test was conducted twice on the 80 selected vials.Mean VOC concentrations after 14 days storage generally were within +- 20% of the known concentration with a majority of the concentrations within +- 15% of their known values. There were no statistically significant differences in VOC concentrations between vials in the potentially leaky and control group for any of the manufacturers. Only 1 vial lost VOCs and that was due to a large chip in the vial's lip and neck. These findings indicate that the silicone septa are flexible enough to overcome most vial imperfections and form a complete seal against VOC loss. A careful inspection of the VOA vials prior to use to remove any vials with large and obvious imperfections should be sufficient to screen out vials that are subject to VOC losses.

  18. Quartz crystal growth

    Science.gov (United States)

    Baughman, Richard J.

    1992-01-01

    A process for growing single crystals from an amorphous substance that can undergo phase transformation to the crystalline state in an appropriate solvent. The process is carried out in an autoclave having a lower dissolution zone and an upper crystallization zone between which a temperature differential (.DELTA.T) is maintained at all times. The apparatus loaded with the substance, solvent, and seed crystals is heated slowly maintaining a very low .DELTA.T between the warmer lower zone and cooler upper zone until the amorphous substance is transformed to the crystalline state in the lower zone. The heating rate is then increased to maintain a large .DELTA.T sufficient to increase material transport between the zones and rapid crystallization. .alpha.-Quartz single crystal can thus be made from fused quartz in caustic solvent by heating to 350.degree. C. stepwise with a .DELTA.T of 0.25.degree.-3.degree. C., increasing the .DELTA.T to about 50.degree. C. after the fused quartz has crystallized, and maintaining these conditions until crystal growth in the upper zone is completed.

  19. Thermal transfer and apparent-dose distributions in poorly bleached mortar samples: Results from single grains and small aliquots of quartz

    DEFF Research Database (Denmark)

    Jain, M.; Thomsen, Kristina Jørkov; Bøtter-Jensen, L.

    2004-01-01

    -300 mum and compare the dose-distributions obtained from small aliquots and single-grain procedures. A comparison of three different methods viz. (a) first 5%, (b) probability plot and (c) comparison of internal and external uncertainties, is made for equivalent dose estimation. The results have......;, this process releases all the prior trapped charge and simultaneously sensitises the quartz. Unfortunately unheated materials such as mortar and concrete are more common in industrial sites and particularly in nuclear installations. These materials are usually exposed to daylight during quarrying...... and construction, but in general this exposure is insufficient to completely empty (bleach) any geological trapped charge. This leads to a distribution of apparent doses in the sample at the time of construction with only some (if any) grains exposed to sufficient light to be considered well bleached for OSL...

  20. Near-infrared spectroscopic determination of residual moisture in lyophilized sucrose through intact glass vials.

    Science.gov (United States)

    Kamat, M S; Lodder, R A; DeLuca, P P

    1989-11-01

    A rapid, noninvasive, and nondestructive method for determining moisture in sealed freeze-drying vials is described. The method, based on near-infrared spectrometry, used a novel fiber-optic diffuse-reflectance probe to make remote reflectance measurements from 1100 to 2500 nm through the bottom of glass vials. The correlation of the method to results obtained by Karl Fischer analysis was good (r2 = 0.97). The moisture content of sucrose, a common cryoprotectant, was determined with an error of 0.27% using a single sample scan.

  1. Drogas ilegales, alcohol y agresividad vial

    OpenAIRE

    Benavidez Rodríguez, Daniela; Gómez Talegón, María Trinidad; Fierro Lorenzo, Inmaculada; Álvarez González, Francisco Javier

    2011-01-01

    El consumo de alcohol, cocaína y cannabis se asocia a comportamientos agresivos, a ser víctima de lesiones de diversas causas, y a accidentes de tráfi co, pero existen pocos estudios acerca de cómo afecta el consumo de estas sustancias la experiencia de agresividad vial. El objetivo de este estudio es analizar la bibliografía existente sobre el tema y extraer conclusiones claras respecto de su verdadero impacto. Se analizaron cinco publicaciones. Más de un tercio de los conduct...

  2. Reproducibility of optically stimulated luminescence measurements from single grains of Al2O3: C and annealed quartz

    DEFF Research Database (Denmark)

    Truscott, A.J.; Duller, G.A.T.; Bøtter-Jensen, L.

    2000-01-01

    We have measured some aspects concerning the performance of a new instrument for the measurement of optically stimulated luminescence (OSL) from single sand-sized grains. The instrument uses a solid-state laser to stimulate OSL from each grain individually. These grains are placed in a regular grid...

  3. Can a Compact Pre-Filled Auto-Disable Injection System (cPAD) Save Costs for DTP-HepB-Hib Vaccine as Compared with Single-Dose (SDV) and Multi-Dose Vials (MDV)? Evidence from Cambodia, Ghana, and Peru.

    Science.gov (United States)

    Nogier, Cyril; Hanlon, Patrick; Wiedenmayer, Karin; Maire, Nicolas

    2015-03-01

    A compact pre-filled auto-disable injection (cPAD) presentation is being developed for the fully liquid pentavalent DTP-HepB-Hib vaccine. A cost analysis (CA) to compare this presentation with the presently used single-dose vial (SDV) and multi-dose vial (MDV) was conducted in Cambodia, Ghana, and Peru. The CA included the development of an excel-based costing model and considered the costs of vaccine, safe injection equipment, procurement, storage, transport and distribution, vaccine administration by health staff, medical waste management, start-up activities, as well as coverage, birth cohort, vaccine, and safe injection equipment wastage rates. The outcome was the change in cost per pentavalent fully immunized child (PFIC) for a switch to cPAD. Field visits to health facilities, and interviews with key informants from immunization services and regulatory authorities, were conducted to collect data and to test the costing model in country context. Cost data were also obtained from manufacturers, published price lists, and author estimates. A sensitivity analysis (SA) was conducted to explore possible variations in values of data collected. Based on vaccine price trends estimated for 2016, cPAD is less costly in Ghana [incremental cost per PFIC: $US-0.59 (-6.46 %)] than the current presentation (ten-dose MDV) and in Peru (SDV): $US-0.89 (-7.14 %). In Cambodia, cPAD is more costly than SDV: $US+0.33 (+3.90 %). The most significant cost item per PFIC is the vaccine (reflecting wastage rates) in all presentations. The dominance of the vaccine price per dose and, to a lesser extent, the wastage rates in the incremental cost per PFIC show potential to simplify future analyses. Other relevant considerations at country level for a change of presentation include the potential for improved safety with cPAD, planned introduction of other vaccines, environmental and safety issues, and financial sustainability.

  4. Single-scan measurement of conductance of a quartz crystal microbalance array coupled with resonant markers for biosensing in liquid phase

    International Nuclear Information System (INIS)

    Hsiao, Hsien-Yi; Chen, Richie L. C.; Cheng, Tzong-Jih

    2009-01-01

    This work presents a method for sensing the viscoelastic property of liquid/solid interface using a quartz crystal microbalance (QCM) array. Each sensor in a QCM array has a unique resonant frequency and can be identified by a single-scan measurement of admittance (or impedance). The resonant frequency encoding at each sensor in an array was realized by connecting a capacitor with a known capacitance, called a resonant marker, to the sensor in series. Changes in the resonant frequency of all sensors in an array can be determined using an impedance analyzer and a program that determines the frequencies at which the conductance is at a local maximum. The sensing method allows every sensor output (resonant frequency) to be obtained without the use of time-consuming multiplexed hardware and software. Adsorptions of biomolecules by multiple sensor are monitored in the liquid phase to demonstrate the feasibility of frequency encoding using resonant markers and the single-scan measurement of conductance of a QCM array.

  5. Modelling dose rate to single grains of quartz in well-sorted sand samples: The dispersion arising from the presence of potassium feldspars and implications for single grain OSL dating

    DEFF Research Database (Denmark)

    Guerin, Guillaume; Jain, Mayank; Thomsen, Kristina Jørkov

    2015-01-01

    Single grain OSL has become a widely used approach in Quaternary geochronology. However, the origins of De distributions and the sources of variation in individual dose estimates are still poorly understood. The amount of scatter in these distributions on top of the known uncertainties...... in measurement and analysis is defined by overdispersion and this quantity is generally used for weighting individual De values to calculate a central equivalent dose. In this study, we address the nature and amount of different sources of dispersion in quartz single grain De estimates, by (i) using appropriate...... statistical tools to characterize De populations and (ii) modelling, with a specifically designed GEANT4 code, dose rate distributions arising from the presence of potassium feldspar grains in well-sorted sands. The model uses Monte Carlo simulations of beta emissions and interactions in a random close...

  6. A vapor response mechanism study of surface-modified single-walled carbon nanotubes coated chemiresistors and quartz crystal microbalance sensor arrays.

    Science.gov (United States)

    Lu, Hung-Ling; Lu, Chia-Jung; Tian, Wei-Cheng; Sheen, Horn-Jiunn

    2015-01-01

    This paper compares the selectivity and discusses the response mechanisms of various surface-modified, single-walled carbon nanotube (SWCNT)-coated sensor arrays for the detection of volatile organic compounds (VOCs). Two types of sensor platforms, chemiresistor and quartz crystal microbalance (QCM), were used to probe the resistance changes and absorption masses during vapor sensing. Four sensing materials were used in this comparison study: pristine, acidified, esterified, and surfactant (sodium dodecyl sulfate, SDS)-coated SWCNTs. SWCNT-coated QCMs reached the response equilibrium faster than the chemiresistors did, which revealed a delay diffusion behavior at the inter-tube junction. In addition, the calibration lines for QCMs were all linear, but the chemiresistors showed curvature calibration lines which indicated less effectiveness of swelling at high concentrations. While the sorption of vapor molecules caused an increase in the resistance for most SWCNTs due to the swelling, the acidified SWCNTs showed no responses to nonpolar vapors and a negative response to hydrogen bond acceptors. This discovery provided insight into the inter-tube interlocks and conductivity modulation of acidified SWCNTs via a hydrogen bond. The results in this study provide a stepping-stone for further understanding of the mechanisms behind the vapor selectivity of surface-modified SWCNT sensor arrays. Copyright © 2014 Elsevier B.V. All rights reserved.

  7. A living cell quartz crystal microbalance biosensor for continuous monitoring of cytotoxic responses of macrophages to single-walled carbon nanotubes

    Directory of Open Access Journals (Sweden)

    Marx Kenneth A

    2011-01-01

    Full Text Available Abstract Background Numerous engineered nanomaterials (ENMs exist and new ENMs are being developed. A challenge to nanotoxicology and environmental health and safety is evaluating toxicity of ENMs before they become widely utilized. Cellular assays remain the predominant test platform yet these methods are limited by using discrete time endpoints and reliance on organic dyes, vulnerable to interference from ENMs. Label-free, continuous, rapid response systems with biologically meaningful endpoints are needed. We have developed a device to detect and monitor in real time responses of living cells to ENMs. The device, a living cell quartz crystal microbalance biosensor (QCMB, uses macrophages adherent to a quartz crystal. The communal response of macrophages to treatments is monitored continuously as changes in crystal oscillation frequency (Δf. We report the ability of this QCMB to distinguish benign from toxic exposures and reveal unique kinetic information about cellular responses to varying doses of single-walled carbon nanotubes (SWCNTs. Results We analyzed macrophage responses to additions of Zymosan A, polystyrene beads (PBs (benign substances or SWCNT (3-150 μg/ml in the QCMB over 18 hrs. In parallel, toxicity was monitored over 24/48 hrs using conventional viability assays and histological stains to detect apoptosis. In the QCMB, a stable unchanging oscillation frequency occurred when cells alone, Zymosan A alone, PBs alone or SWCNTs without cells at the highest dose alone were used. With living cells in the QCMB, when Zymosan A, PBs or SWCNTs were added, a significant decrease in frequency occurred from 1-6 hrs. For SWCNTs, this Δf was dose-dependent. From 6-18 hrs, benign substances or low dose SWCNT (3-30 μg/ml treatments showed a reversal of the decrease of oscillation frequency, returning to or exceeding pre-treatment levels. Cell recovery was confirmed in conventional assays. The lag time to see the Δf reversal in QCMB plots

  8. A living cell quartz crystal microbalance biosensor for continuous monitoring of cytotoxic responses of macrophages to single-walled carbon nanotubes

    Science.gov (United States)

    2011-01-01

    Background Numerous engineered nanomaterials (ENMs) exist and new ENMs are being developed. A challenge to nanotoxicology and environmental health and safety is evaluating toxicity of ENMs before they become widely utilized. Cellular assays remain the predominant test platform yet these methods are limited by using discrete time endpoints and reliance on organic dyes, vulnerable to interference from ENMs. Label-free, continuous, rapid response systems with biologically meaningful endpoints are needed. We have developed a device to detect and monitor in real time responses of living cells to ENMs. The device, a living cell quartz crystal microbalance biosensor (QCMB), uses macrophages adherent to a quartz crystal. The communal response of macrophages to treatments is monitored continuously as changes in crystal oscillation frequency (Δf). We report the ability of this QCMB to distinguish benign from toxic exposures and reveal unique kinetic information about cellular responses to varying doses of single-walled carbon nanotubes (SWCNTs). Results We analyzed macrophage responses to additions of Zymosan A, polystyrene beads (PBs) (benign substances) or SWCNT (3-150 μg/ml) in the QCMB over 18 hrs. In parallel, toxicity was monitored over 24/48 hrs using conventional viability assays and histological stains to detect apoptosis. In the QCMB, a stable unchanging oscillation frequency occurred when cells alone, Zymosan A alone, PBs alone or SWCNTs without cells at the highest dose alone were used. With living cells in the QCMB, when Zymosan A, PBs or SWCNTs were added, a significant decrease in frequency occurred from 1-6 hrs. For SWCNTs, this Δf was dose-dependent. From 6-18 hrs, benign substances or low dose SWCNT (3-30 μg/ml) treatments showed a reversal of the decrease of oscillation frequency, returning to or exceeding pre-treatment levels. Cell recovery was confirmed in conventional assays. The lag time to see the Δf reversal in QCMB plots was linearly SWCNT

  9. Characteristics of high-purity Teflon vial for 14C measurement in old tree rings

    International Nuclear Information System (INIS)

    Sakurai, H.; Saswaki, Y.; Matsumoto, T.; Aoki, T.; Kato, W.; Gandou, T.; Gunji, S.; Tokanai, F.

    2003-01-01

    14 C concentration in single-year tree rings of an old cedar of ca. 2500 years ago is measured to investigate the 11-yr periodicity of solar activity. Our highly accurate 14 C measuring system is composed of a benzene synthesizer capable of producing a large quantity (10 g) of benzene and a Quantulus 1220 TM liquid scintillation counting system. The accuracy is less than 0.2% for measurements of 14 C concentration. The benzene sample is contained in a high-purity Teflon/copper-counting vial (20 ml) manufactured by Wallac Oy Company. We found a vial with an irregular copper cap for the measurements of 11 tree rings. The behavior of the vial with the irregular cap was investigated. The Teflon sheet inside the cap plays an important role in achieving stable measurement. The rate of volatilization of the benzene was less than 0.35 mg/day for vials with ordinary caps. This results in the volatilization rate of 0.003% for 10.5 g of benzene and hence guarantees measurement at an accuracy of 0.2% for 70 days

  10. Quartz resonator processing system

    Science.gov (United States)

    Peters, Roswell D. M.

    1983-01-01

    Disclosed is a single chamber ultra-high vacuum processing system for the oduction of hermetically sealed quartz resonators wherein electrode metallization and sealing are carried out along with cleaning and bake-out without any air exposure between the processing steps. The system includes a common vacuum chamber in which is located a rotatable wheel-like member which is adapted to move a plurality of individual component sets of a flat pack resonator unit past discretely located processing stations in said chamber whereupon electrode deposition takes place followed by the placement of ceramic covers over a frame containing a resonator element and then to a sealing stage where a pair of hydraulic rams including heating elements effect a metallized bonding of the covers to the frame.

  11. Optimizing human semen cryopreservation by reducing test vial volume and repetitive test vial sampling

    DEFF Research Database (Denmark)

    Jensen, Christian F S; Ohl, Dana A; Parker, Walter R

    2015-01-01

    : Prospective clinical laboratory study. SETTING: University assisted reproductive technology (ART) laboratory. PATIENT(S): A total of 594 patients undergoing semen analysis and cryopreservation. INTERVENTION(S): Semen analysis, cryopreservation with different intermediate steps and in different volumes (50......-1,000 μL), and long-term storage in LN2 or VN2. MAIN OUTCOME MEASURE(S): Optimal TV volume, prediction of cryosurvival (CS) in ART procedure vials (ARTVs) with pre-freeze semen parameters and TV CS, post-thaw motility after two- or three-step semen cryopreservation and cryostorage in VN2 and LN2. RESULT......(S): Test vial volume of 50 μL yielded lower CS than other volumes tested. Cryosurvival of 100 μL was similar to that of larger volumes tested. An intermediate temperature exposure (-88°C to -93°C for 20 minutes) during cryopreservation did not affect post-thaw motility. Cryosurvival of TVs and ARTVs from...

  12. QUARTZ FIBER ELECTROSCOPES

    Science.gov (United States)

    Henderson, R.P.

    1957-09-17

    An instrument carried unobtrusively about the person such as in a finger ring to indicate when that person has been exposed to an unusual radiation hazard is described. A metallized quartz fiber is electrically charged to indicate a full scale reading on an etched glass background. The quartz fiber and the scale may be viewed through a magnifying lens for ease of reading. Incident radiation will ionize gaseous particles in the sealed structure thereby allowing the charge to leak off the quartz fiber with its resulting movement across the scale proportionally indicating the radiation exposure.

  13. Evaluation of the open vial method in the radon measurement

    International Nuclear Information System (INIS)

    Lopez del Rio, H.; Davila R, J. I.; Mireles G, F.

    2014-10-01

    The open vial method is a simple technique, under-utilized but that take advantage of the great radon solubility in organic solvents, therefore applies in the measurement of the radon concentration exhaled in soil. The method consists on the exposition to the gas radon of an open vial with scintillating solution. An integral mathematical model for indoors that describes the emanation processes and gas radon exhalation was developed, as well as the radon dissolution in the scintillation liquid, besides obtaining the characteristic parameters of the experimental system proposed for the radon concentration calculation exhaled by soils. Two experimental arrangements were designed with exposition cameras of 12 and 6 L and quantity of different soil. The open vial was prepared with a mixture of 8 ml of deionized water and 12 ml of scintillation liquid OptiPhase Hi Safe 3 in polyethylene vials; the measurements of the dissolved radon were carried out in scintillation liquid equipment. As a result, on average 2.0% of the exhaled radon is dissolved in the open vial and the dissolved fraction is independent of the experimental arrangement. Also was observed that the exposition time does not affect the radon dissolution significantly, in correspondence with the reported in the literature. (Author)

  14. Quartz-enhanced photoacoustic spectroscopy: a review.

    Science.gov (United States)

    Patimisco, Pietro; Scamarcio, Gaetano; Tittel, Frank K; Spagnolo, Vincenzo

    2014-03-28

    A detailed review on the development of quartz-enhanced photoacoustic sensors (QEPAS) for the sensitive and selective quantification of molecular trace gas species with resolved spectroscopic features is reported. The basis of the QEPAS technique, the technology available to support this field in terms of key components, such as light sources and quartz-tuning forks and the recent developments in detection methods and performance limitations will be discussed. Furthermore, different experimental QEPAS methods such as: on-beam and off-beam QEPAS, quartz-enhanced evanescent wave photoacoustic detection, modulation-cancellation approach and mid-IR single mode fiber-coupled sensor systems will be reviewed and analysed. A QEPAS sensor operating in the THz range, employing a custom-made quartz-tuning fork and a THz quantum cascade laser will be also described. Finally, we evaluated data reported during the past decade and draw relevant and useful conclusions from this analysis.

  15. Vacuum electrolysis of quartz

    Science.gov (United States)

    King, James Claude

    1976-01-13

    The disclosure is directed to a method for processing quartz used in fabricating crystal resonators such that transient frequency change of resonators exposed to pulse irradiation is virtually eliminated. The method involves heating the crystal quartz in a hydrogen-free atmosphere while simultaneously applying an electric field in the Z-axis direction of the crystal. The electric field is maintained during the cool-down phase of the process.

  16. A new method for charge trapping measurement during electron beam irradiation: application to glass containing alkali ions and single-crystalline quartz

    International Nuclear Information System (INIS)

    Fakhfakh, S; Ghorbel, N; Jbara, O; Rondot, S; Martin, D; Fakhfakh, Z; Kallel, A

    2004-01-01

    The aim of this work is to study the electron irradiation behaviour of an insulating material surface using a scanning electron microscope (SEM). The charging phenomena caused in two kinds of insulating materials (quartz and glass) by continuous electron irradiation have been observed. The discharging phenomena following switching off of irradiation have also been studied. The trapped charge density is determined by using the so-called electrostatic influence method based on the measurement, during and after the irradiation, of the influence and leakage currents using an arrangement adapted to the SEM. The experimental results reveal that the behaviour under irradiation of glass is entirely different from that of quartz. The trapped charges are found to be different, and the dependence of charging on the primary beam energy is discussed. The charging and discharging time constants have been determined accurately, and their evolution versus the mean electron penetration depth is qualitatively explained. Moreover, the role of secondary electron emission in the regulation mechanism of charging is underlined

  17. A new method for charge trapping measurement during electron beam irradiation: application to glass containing alkali ions and single-crystalline quartz

    Energy Technology Data Exchange (ETDEWEB)

    Fakhfakh, S [LASSI/DTI UMR CNRS 6107, Faculte des Sciences BP 1039, 51687 Reims CDX 2 (France); Ghorbel, N [LASSI/DTI UMR CNRS 6107, Faculte des Sciences BP 1039, 51687 Reims CDX 2 (France); Jbara, O [LASSI/DTI UMR CNRS 6107, Faculte des Sciences BP 1039, 51687 Reims CDX 2 (France); Rondot, S [LASSI/DTI UMR CNRS 6107, Faculte des Sciences BP 1039, 51687 Reims CDX 2 (France); Martin, D [Saint Gobain Recherche, 39 quai Lucien Lefranc, BP 135, 93303 Aubervilliers CDX (France); Fakhfakh, Z [LaMaCop, Faculte des Sciences de SFAX, Route Soukra km 3, BP 802, 3018 Sfax (Tunisia); Kallel, A [LaMaCop, Faculte des Sciences de SFAX, Route Soukra km 3, BP 802, 3018 Sfax (Tunisia)

    2004-08-07

    The aim of this work is to study the electron irradiation behaviour of an insulating material surface using a scanning electron microscope (SEM). The charging phenomena caused in two kinds of insulating materials (quartz and glass) by continuous electron irradiation have been observed. The discharging phenomena following switching off of irradiation have also been studied. The trapped charge density is determined by using the so-called electrostatic influence method based on the measurement, during and after the irradiation, of the influence and leakage currents using an arrangement adapted to the SEM. The experimental results reveal that the behaviour under irradiation of glass is entirely different from that of quartz. The trapped charges are found to be different, and the dependence of charging on the primary beam energy is discussed. The charging and discharging time constants have been determined accurately, and their evolution versus the mean electron penetration depth is qualitatively explained. Moreover, the role of secondary electron emission in the regulation mechanism of charging is underlined.

  18. Filtration of Glass Delamination Particles with West Pharmaceutical Vial Adapters.

    Science.gov (United States)

    Zarour-Shalev, Elinor H; Ovadia, Yaron; Tuchmay, Oren; Reynolds, Graham; Lev, Nimrod

    2015-01-01

    One major current challenge facing companies producing injectable drugs contained in glass vials is the phenomenon of delamination that results in drug contamination. Particulate contamination of parenteral fluids is a fact of life. Particulate infusion is unlikely to cause immediate or severe signs and symptoms, but adverse effects, tissue damage, and loss of function are likely in the long term. Since 2010, recalls due to glass delamination have increased, and recently the U.S. Food and Drug Administration exercised temporary regulatory flexibility by allowing filtration as means of removing glass particles. The vial adapter is a needle-free product from West Pharmaceuticals Services that provides a simple and cost-effective solution for the safe and rapid transfer reconstitution of drugs between vials and syringes. One variant of the vial adapter is integrated with a filter to address various types of particles. In the present study, the performance of the filter-integrated vial adapter is evaluated with respect to glass delamination particles. Silica particles of 0.5-10 μm are used to emulate glass delamination particles. High-filtration efficiency is demonstrated according to the severest criteria stated by the British Pharmacopoeia that allows up to 100 particles smaller than 5 μm for every 1 mL liquid of a large-volume parenteral. The study was conducted using environmental scanning electron microscopy and statistical analysis. One major current challenge facing companies producing injectable drugs contained in glass vials is the phenomenon of delamination that results in drug contamination. Glass delamination is defined as degradation of surface glass, as from a vial, that produces glass flakes. Contamination of injectable drugs due to glass delamination is a fact of life. Normally, this type of contamination does not involve immediate severe signs, but rather accumulative damage to tissues in the long run. Recently, the U.S. Food and Drug Administration

  19. Radiation Damage of Quartz Fibers

    OpenAIRE

    Hagopian, V

    1999-01-01

    Quartz fibers are used in high energy physics experiments as the active medium in high radiation area calorimetry. Quartz fibers are also used in the transmission of optical signals. Even though quartz does not damage by moderate amounts of irradiation, the clad of the fibers and the protective coating ( buffer) do damage reducing light transmission. Various types of quartz fibers have been irradiated and measured for light transmission. The most radiation hard quartz fibers are those with qu...

  20. Insulin vials vs. insulin cartridges: Further cost considerations.

    Science.gov (United States)

    Al-Sharayri, Mohammad G; Alsabrah, Tariq M; Aljbori, Tareq M; Abu-Rumman, Ala'a Eddeen K

    2013-04-01

    Many studies have provided evidence that favor the use of insulin pens over traditional insulin vials due to lower overall costs. The cost of insulin in the Royal Medical Services in Jordan is subject to other considerations due to the favorable tender prices and the process of dispensing of insulin within the Royal Medical Services. To highlight further cost considerations associated with the wastage in the use of insulin vials and cartridges in the Jordanian Royal Medical Services. Two random samples were selected from prescriptions dispensed for diabetic patients using insulin in January 2012 from the outpatient pharmacy in Al-Hussein Hospital, King Hussein Medical Center, Amman, Jordan. First sample was selected from prescriptions of patients using vials; second sample was selected from prescriptions of patients using pens and cartridges. Average costs for insulin and wastage were calculated per patient from the Royal Medical Services perspective. The average direct cost per patient using vials was JD 5.197 and for those using cartridges was JD 22.135. The average wasted quantity per patient in the first sample was more than ten times that of the second sample. The cost of the average wasted quantity per patient in the first sample (1.022 JD) was more than the double that in the second sample (0.441 JD). Although, the direct cost of insulin per patient by using vials was lower than cartridges, there was a substantial reduction in the cost of wastage by using the cartridges in the Jordanian Royal Medical Services outpatients.

  1. Microstructural development of quartz gouge at the brittle-to-viscous-transition in shear experiments

    Science.gov (United States)

    Richter, Bettina; Kilian, Rüdiger; Stünitz, Holger; Heilbronner, Renée

    2014-05-01

    We conducted a series of shear experiments on quartz gouge in a Griggs-type solid medium deformation apparatus to investigate the brittle-viscous transition. The starting material is obtained by crushing quartz single crystals (sieved grain size

  2. Diversity of primary CL textures in quartz from porphyry environments: implication for origin of quartz eyes

    Science.gov (United States)

    Vasyukova, O. V.; Kamenetsky, V. S.; Goemann, K.; Davidson, P.

    2013-10-01

    Porphyry-style mineralization is related to the intrusion and crystallization of small stocks, which can be of different compositions (from intermediate to felsic) and can intrude into different host rocks (from magmatic to sedimentary). We used cathodoluminescence and electron probe microanalysis to study the internal textures of more than 300 quartz eyes from six porphyry deposits, Panguna (Papua New Guinea), Far Southeast porphyry (Philippines), Batu Hijau (Indonesia), Antapaccay (Peru), Rio Blanco (Chile) and Climax (USA). Significant diversity of the internal textures in quartz eyes was revealed, sometimes even within a single sample. Quartz grains with Ti-rich cores surrounded by Ti-poor mantles were found next to the grains showing the opposite Ti distribution or only slight Ti fluctuations.We propose that diversity of the internal patterns in quartz eyes can actually reflect in situ crystallization history, and that prolonged crystallization after magma emplacement under conditions of continuous cooling can account for the observed features of internal textures. Formation of quartz eyes begins at high temperatures with crystallization of high titanium Quartz 1, which as the melt becomes more and more evolved and cooler, is overgrown by low Ti Quartz 2. Subsequent fluid exsolution brings about dramatic change in the melt composition: OH - , alkalis and other Cl-complexed elements partition into the fluid phase, whereas Ti stays in the melt, contributing to a rapid increase in Ti activity. Separation of the fluid and its further cooling causes disequilibrium in the system, and the Quartz 2 becomes partially resorbed. Exsolution of the fluid gradually builds up the pressure until it exceeds the yield strength of the host rocks and they then fracture. This pressure release most likely triggers crystallization of Quartz 3, which is higher in Ti than Quartz 2 because Ti activity in the melt is higher and pressure of crystallization is lower. As a result of the

  3. Electron irradiation damage effects in hydrothermal grown quartz ...

    African Journals Online (AJOL)

    Electron irradiation effects in synthetic quartz single crystals were investigated to determine the extent of damage of the crystals during transmission electron microscopy examination, as the rapid deterioration is of major concern. On exposure of the quartz crystals to electron flux of 3.0 x 108 e/cm2/s at 200 kV accelerating ...

  4. Residual volume in vials of antibiotics used in pediatrics.

    Science.gov (United States)

    Chaves, Caroline Magna Pessoa; Bezerra, Carolina Martins; Lima, Francisca Elisângela Teixeira; Cardoso, Maria Vera Lúcia Moreira Leitão; Fonseca, Said Gonçalves da Cruz; Silva, Viviane Martins da

    2017-06-12

    Quantifying residual volume contained in vials of antibiotics used in pediatrics. This is an experiment involving samples from vials of antibiotics used in a pediatric hospital. Residual volume was identified by calculating the difference in weight measurement before and after the vials were washed. Evaluation of the residual volume difference in the vials was determined by the Wilcoxon non-parametric test for a sample and established at a significance level of 5%. 105 samples of antibiotics were selected. The correct use of the antibiotics oxacillin (88.57%) and ceftriaxone (94.28%) predominated with low residual values. The same did not occur for procaine benzylpenicillin + potassium benzylpenicillin, since a greater residual volume was discarded in 74.28% of the vials. We highlight the need for improvements in managing antibiotics in the institution under study, so that the excess volume of the antibiotics in the vials is used within the acceptable stable time. It is also necessary that the disposal of the residual volume be adequately disposed, since it presents a risk to public health and the environment. Quantificar o volume residual contido em frascos-ampola de antibióticos utilizados na pediatria. Trata-se de um experimento com amostras de frascos-ampola de antibióticos utilizados em hospital pediátrico. O volume residual foi identificado calculando-se a diferença da aferição do peso antes e após a lavagem do frasco-ampola. A avaliação da diferença dos volumes residuais nos frascos-ampola foi determinada pelo teste não paramétrico de Wilcoxon para uma amostra e estabelecido o nível de significância de 5%. Foram selecionadas 105 amostras de antibióticos. Predominou o correto aproveitamento dos antibióticos oxacilina (88,57%) e ceftriaxona (94,28%), com baixos valores residuais. O mesmo não ocorreu com a benzilpenicilina procaína + potássica, pois em 74,28% dos frascos houve descarte de volume residual superior. Destaca-se a necessidade de

  5. Angular dependence of quartz fiber calorimeter response

    International Nuclear Information System (INIS)

    Anzivino, G.; Chamorovskii, Yu.; Contin, A.; Danilov, M.; Dellacasa, G.; DeSalvo, R.; Gavrilov, V.; Golutvin, A.; Gorodetzky, P.; Johnson, K.F.; Juillot, P.; Lacommare, G.; Lazic, D.; Litvintsev, D.; Lundin, M.; Marino, M.; Musso, A.; Ratnikov, F.; Rusinov, V.; Stolin, V.; Vinogradov, M.

    1995-01-01

    A small quartz fiber calorimeter prototype with copper absorber has been assembled and tested at ITEP as a first test of a ''0 degree'' component of the RD-40 R and D program. Calibration and monitoring of each tower response was performed using the positions of single photoelectron peaks as well as the response to minimum ionizing particles incident at an angle of 45 . The response of the prototype to 4 GeV electrons as a function of beam angle with respect to the quartz fibers was studied in the range from 0 to 90 . The test results are compared to the GEANT based Monte Carlo (MC) simulations. (orig.)

  6. Vial washers for the compounding pharmacy: ensuring preparation safety.

    Science.gov (United States)

    Johnson, Kain; Sully, Andrew; Anthenat, Bruce

    2014-01-01

    The safety and effectiveness of customized formulations have always been priorities for compounding pharmacists, perhaps even more so since a tragic outbreak of meningitis in 2012 was traced to preparations from the New England Compounding Center in Framingham, Massachusetts. Since that time, pharmaceutical compounding in the U.S. has been the focus of renewed interest from the public and from government organizations and regulatory bodies created to ensure patient safety. As a result, responsible compounders have responded to ensure--to even greater levels--the purity and safety of the formulations they prepare. One tool useful in doing so is the mechanical vial washer, which can produce cleaner vials (and/or ampules, syringes, and cartridges, depending on the washer model) more consistently than does washing vessels by hand. In this article, several such washers appropriate for use in a compounding pharmacy are profiled, and a pharmacist's experience in using one of those models is described.

  7. Choosing a Vial Processing Line for Aseptic Compounding: Part 1.

    Science.gov (United States)

    Noorian, Shaun; Vahedi, Navid

    2016-01-01

    Equipment systems that enable compliance with stringent state and federal compounding requirements are a topic of increasing interest to U.S. pharmacists. Of those equipment types, an aseptic vial processing line offers unique benefits (especially to 503B compounding pharmacies and small contract manufacturers of aseptic pilot-size batches) if the volume of sterile preparations dispensed offsets the cost of purchase, installation, and maintenance. In this article, the reasons for and the process of selecting an aseptic vial processing line for use in 2 independent 503B compounding pharmacies are presented, the operation of our choice of equipment is described, and specifications for the components of that line are listed. In part 2 of this series, the success of our choice and its effect on sterile compounding in our facilities will be reported. Copyright© by International Journal of Pharmaceutical Compounding, Inc.

  8. Proteja a sus seres queridos de las lesiones viales

    Centers for Disease Control (CDC) Podcasts

    2008-12-10

    Este podcast, que forma parte de la iniciativa Proteja a sus seres queridos, aborda las medidas que pueden tomar los padres de familia para ayudar a proteger a sus niños de las lesiones viales, una de las principales causas de lesiones infantiles.  Created: 12/10/2008 by National Center for Injury Prevention and Control (NCIPC).   Date Released: 4/1/2009.

  9. Gestión de conservación vial en la infraestructura regional

    OpenAIRE

    Aza Morales, Percy Donato

    2009-01-01

    El Deterioro de la red vial departamental en la infraestructura vial de la Región Puno, ha alcanzado un estado deficiente de transitabilidad, por una inadecuada atención en los programas de mantenimiento vial, ocasionado por una descoordinación entre las entidades responsables de la conservación vial en la jurisdicción regional, destinándose limitados recursos financieros con ausencia de proyectos de gestión vial lo que genera un creciente deterioro de las características físicas de las carre...

  10. Colorado quartz: occurrence and discovery

    Science.gov (United States)

    Kile, D.E.; Modreski, P.J.; Kile, D.L.

    1991-01-01

    The many varieties and associations of quartz found throughout the state rank it as one of the premier worldwide localities for that species. This paper briefly outlines the historical importance of the mineral, the mining history and the geological setting before discussing the varieties of quartz present, its crystallography and the geological enviroments in which it is found. The latter include volcanic rocks and near surface igneous rocks; pegmatites; metamorphic and plutonic rocks; hydrothermal veins; skarns and sedimentary deposits. Details of the localities and mode of occurrence of smoky quartz, amethyst, milky quartz, rock crystal, rose quartz, citrine, agate and jasper are then given. -S.J.Stone

  11. Measurement of the dose in quartz in the presence of feldspar contamination

    DEFF Research Database (Denmark)

    Wallinga, J.; Murray, A.S.; Bøtter-Jensen, L.

    2002-01-01

    , without seriously affecting the quartz OSL signal. A single-aliquot regenerative-dose protocol is proposed which, in our samples, allows accurate measurement of the dose in quartz in the presence of feldspar contamination. The protocol also has potential use for quartz dose determination in mixed...

  12. Inventario de deslizamientos en la red vial colombiana

    OpenAIRE

    Juan Montero O.; Lisandro Beltrán M.; Ricardo Cortés D.

    1988-01-01

    El Ministerio de Obres Públicas y Transporte solicitó en 1985 a la Facultad de Ingeniería de la Universidad Nacional de Colombia en Bogotá, la realización de una investigación piloto sobre los deslizamientos que afectan la red vial nacional, en desarrollo de la cual se efectuó un inventario de los deslizamientos y movimientos de masa más importantes. Con base en los resultados obtenidos se propone la división del territorio nacional en ocho regiones, cada una con características similares des...

  13. Edificio de oficinas. Viale di Trastevere – Roma

    Directory of Open Access Journals (Sweden)

    Lafuente, Julio G.

    1958-09-01

    Full Text Available El solar, largo y estrecho, en esquina a Viale di Trastevere y Via Carlo Porta, y con fachada posterior a amplio patio de manzana, ha permitido resolver el bloque de viviendas en tres unidades alineadas, cada una de cuyas escaleras da acceso a dos viviendas por planta. No obstante, al exterior, el conjunto ha sido concebido con gran unidad de composición, jugando un papel importante el ritmo vigoroso de terrazas y paños ciegos de fábrica de ladrillo de sus miradores.

  14. Safety and efficacy of multiuse botulinum toxin vials for intralaryngeal injection.

    Science.gov (United States)

    Barrow, Emily M; Rosen, Clark A; Hapner, Edie R; Smith, Sarah; Hatcher, Jeanne L; Simpson, Blake; Johns, Michael M

    2015-05-01

    Centers for Disease Control and Prevention guidelines maintain that single-use vials cannot be used for multiple patients. Botox product labeling states that the reconstituted toxin should be used within 4 hours on a single patient based on concerns of reduced potency, contamination, and consequent infections. The purpose of this study was to determine the safety and efficacy of using single-use vials in a multidose fashion. Prospective study and cohort chart review. A multi-institutional three-part study was performed between May 2013 and October 2013: 1) a summation of subjects' recall of their past experiences (symptoms/response) with previous multidose Botox injections, 2) a prospective study of intralaryngeal injections, and 3) a chart review of injection responses in a subset of the cohort. Seven hundred forty-three subjects receiving 6,216 injections demonstrated zero infection-related complications on retrospective chart review. One hundred seventy-nine subjects recalled 24.0% overall adverse events, 10.6% redness, 7.3% pain and swelling at the injection site, and 0% fever. One hundred seventy-four subjects prospectively reported 12.6% overall adverse events. The self-reported efficacy rate of Botox injection was 96.6%. The low rates of adverse events following the use of Botox in a multipatient fashion are consistent with other percutaneous injections. No evidence of infection was found with multidose Botox use. Given the low incidence of side effects and high success rate, Botox can be used both safely and effectively in a multipatient fashion. 4 © 2014 The American Laryngological, Rhinological and Otological Society, Inc.

  15. CRITERIOS E INDICADORES DE SOSTENIBILIDAD EN EL SUBSECTOR VIAL

    Directory of Open Access Journals (Sweden)

    Martha Melizza Ordoñez Díaz

    2015-01-01

    Full Text Available Actualmente en Colombia el desempeño de un contratista de obra se determina de acuerdo con los avances y resultados obtenidos en la construcción de la misma, mas no por su desempeño ambiental; sin embargo, cualquier tipo de obra civil se puede llevar a cabo con mayor o menor complejidad, dependiendo de la disponibilidad de recursos naturales en la zona y la visión que tenga la comunidad sobre el proyecto, de tal forma que la inversión económica y el tiempo de ejecución no solo dependerá de las actividades y costos netos de las obras civiles sino, además, de factores ambientales y sociales propios del lugar de ejecución. Con esta revisión bibliográfica sobre indicadores y guías ambientales internacionales, se pretende incentivar la sostenibilidad como eje transversal de los proyectos viales en Colombia, fortalecer las medidas de manejo socioambiental y mejorar el seguimiento y evaluación de los proyectos viales en el marco del equilibrio social, ambiental y económico que impulsa el desarrollo sostenible

  16. Inventario de deslizamientos en la red vial colombiana

    Directory of Open Access Journals (Sweden)

    Juan Montero O.

    1988-01-01

    Full Text Available El Ministerio de Obres Públicas y Transporte solicitó en 1985 a la Facultad de Ingeniería de la Universidad Nacional de Colombia en Bogotá, la realización de una investigación piloto sobre los deslizamientos que afectan la red vial nacional, en desarrollo de la cual se efectuó un inventario de los deslizamientos y movimientos de masa más importantes. Con base en los resultados obtenidos se propone la división del territorio nacional en ocho regiones, cada una con características similares desde el punto de vista de la estabilidad de los taludes, y se comentan los resultados y perspectivas de mayor interés.

  17. Seguridad vial en carreteras rurales de dos carriles

    Directory of Open Access Journals (Sweden)

    R García

    Full Text Available La presente investigación se realiza con el objetivo de evaluar la seguridad vial en carreteras rurales de dos carriles de interés nacional en la provincia de Sancti Spíritus, a partir del procedimiento desarrollado en la Universidad Central de Las Villas (UCLV, donde se realiza la caracterización de la accidentalidad, la identificación de los tramos de mayor peligrosidad y la identifican los factores de riesgos, en el tramos de mayor peligrosidad, para con esta información formular las posibles acciones a efectuar en el tramo, las cuales luego de su aprobación por los organismos rectores de la vialidad se implementan, y transcurrido un período de tiempo pueden ser evaluadas para comprobar su efectividad.

  18. Hydrogen speciation in synthetic quartz

    Science.gov (United States)

    Aines, R.D.; Kirby, S.H.; Rossman, G.R.

    1984-01-01

    The dominant hydrogen impurity in synthetic quartz is molecular H2O. H-OH groups also occur, but there is no direct evidence for the hydrolysis of Si-O-Si bonds to yield Si-OH HO-Si groups. Molecular H2O concentrations in the synthetic quartz crystals studied range from less than 10 to 3,300 ppm (H/Si), and decrease smoothly by up to an order of magnitude with distance away from the seed. OH- concentrations range from 96 to 715 ppm, and rise smoothly with distance away from the seed by up to a factor of three. The observed OH- is probably all associated with cationic impurities, as in natural quartz. Molecular H2O is the dominant initial hydrogen impurity in weak quartz. The hydrolytic weakening of quartz may be caused by the transformation H2O + Si-O-Si ??? 2SiOH, but this may be a transitory change with the SiOH groups recombining to form H2O, and the average SiOH concentration remaining very low. Synthetic quartz is strengthened when the H2O is accumulated into fluid inclusions and cannot react with the quartz framework. ?? 1984 Springer-Verlag.

  19. Analysis of pressurization of plutonium oxide storage vials during a postulated fire

    Energy Technology Data Exchange (ETDEWEB)

    Laurinat, J.; Kesterson, M.; Hensel, S.

    2015-02-10

    The documented safety analysis for the Savannah River Site evaluates the consequences of a postulated 1000 °C fire in a glovebox. The radiological dose consequences for a pressurized release of plutonium oxide powder during such a fire depend on the maximum pressure that is attained inside the oxide storage vial. To enable evaluation of the dose consequences, pressure transients and venting flow rates have been calculated for exposure of the storage vial to the fire. A standard B vial with a capacity of approximately 8 cc was selected for analysis. The analysis compares the pressurization rate from heating and evaporation of moisture adsorbed onto the plutonium oxide contents of the vial with the pressure loss due to venting of gas through the threaded connection between the vial cap and body. Tabulated results from the analysis include maximum pressures, maximum venting velocities, and cumulative vial volumes vented during the first 10 minutes of the fire transient. Results are obtained for various amounts of oxide in the vial, various amounts of adsorbed moisture, different vial orientations, and different surface fire exposures.

  20. The construction of permanent standards for scintillation counting involving the use of polyethylene mini-vials

    International Nuclear Information System (INIS)

    Noble, R.C.; Drummond, J.T.

    1977-01-01

    A method is described and evaluated of providing permanent and semi-permanent sets of standards for the routine counting of biological samples in polyethylene mini-vials by constructing sealed glass mini-vial standards within conventional polyethylene counting containers. Much time and labour can be saved by this method of providing sets of standards for quench correction of samples. (U.K.)

  1. RAPID DETECTION OF RESPIRATORY VIRUSES USING MIXTURES OF MONOCLONAL-ANTIBODIES ON SHELL VIAL CULTURES

    NARCIS (Netherlands)

    SCHIRM, J; LUIJT, DS; PASTOOR, GW; MANDEMA, JM; SCHRODER, FP

    1992-01-01

    Eleven hundred and thirty-three clinical specimens submitted to the laboratory for diagnosis of respiratory virus infections were tested by direct immunofluorescence (DIF) for respiratory syncytial virus (RSV), by shell vial culture, and by conventional cell culture. The shell vial cultures were

  2. Lack of clinical relevance in routine final subcultures of radiometrically negative BACTEC blood culture vials

    International Nuclear Information System (INIS)

    Plorde, J.J.; Carlson, L.G.; Dau, M.E.

    1982-01-01

    During a 38-month period, 10,106 blood specimens were received in the laboratory for culture. These were inoculated into 26,424 vials and processed using the BACTEC radiometric detection system. Of these vials, 1,914 were eventually found to be microbiologically positive. Isolates from 836 vials were judged to be contaminants. In the remaining 1,078 vials, growth was first detected visually or radiometrically in 1,062 and by final subculture in 16. Growth from these sixteen bottles represented 12 clinically significant bacteremic episodes in as many patients. In nine of these episodes, other culture vials from the same patient were positive radiometrically. Therefore, 358 of 361 (99.2%) bacteremic episodes were detected without the benefit of routine final subcultures. The three patients whose bacteremia was missed were diagnosed clinically and placed on appropriate therapy prior to the detection of the bacteremias by final subculture

  3. Influência do tamanho do frasco de tuberculina nos resultados da prova tuberculínica Influence of vial size on the results of the tuberculin test

    Directory of Open Access Journals (Sweden)

    Antonio Ruffino-Netto

    2005-04-01

    using the Mantoux technique. Patients were randomly allocated to receive two 0.1-ml injections, either one in the right forearm from a 1.5-ml vial and one in the left forearm from a 5-ml vial or vice versa. Induration was determined in a blinded fashion by a single, previously trained observer. Right arm-left arm differences of 2 mm or less were considered concordant results. RESULTS: Twenty-one patients presented no induration and were excluded from analysis. Among the 42 remaining patients, mean induration diameters obtained in tuberculin tests using the larger vials were greater than those obtained in tests using the smaller vials. Concordance was achieved in 40.5% (17/42. The difference was negative (large-vial indurations smaller than small-vial indurations in 16.7% (7/42 and positive in 42.9% (18/42. CONCLUSIONS: The size of the vial may influence tuberculin test results. Adsorption to the sides of the vial may explain this phenomenon. The authors caution others to be aware of the impact of these variations in epidemiological and operational studies.

  4. Effectiveness of Needles Vial Adaptors and Blunt Cannulas for Drug Administration in a Microgravity Environment

    Science.gov (United States)

    Hailey, Melinda; Bayuse, Tina

    2009-01-01

    The need for a new system of injectable medications aboard the International Space Station (ISS) was identified. It is desired that this system fly medications in their original manufacturer's packaging, allowing the system to comply with United States Pharmacopeia (USP) guidelines while minimizing the resupply frequency due to medication expiration. Pre-filled syringes are desired, however, the evolving nature of the healthcare marketplace requires flexibility in the redesign. If medications must be supplied in a vial, a system is required that allows for the safe withdrawal of medication from the vial into a syringe for administration in microgravity. During two reduced gravity flights, the effectiveness of two versions of a blunt cannula and needleless vial adaptors was evaluated to facilitate the withdrawal of liquid medication from a vial into a syringe for injection. Other parameters assessed included the ability to withdraw the required amount of medication and whether this is dependent on vial size, liquid, or the total volume of fluid within the vial. Injectable medications proposed for flight on ISS were used for this evaluation. Due to differing sizes of vials and the fluid properties of the medications, the needleless vial adaptors proved to be too cumbersome to recommend for use on the ISS. The blunt cannula, specifically the plastic version, proved to be more effective at removing medication from the various sizes of vials and are the recommended hardware for ISS. Fluid isolation within the vials and syringes is an important step in preparing medication for injection regardless of the hardware used. Although isolation is a challenge in the relatively short parabolas during flight, it is not an obstacle for sustained microgravity. This presentation will provide an overview of the products tested as well as the challenges identified during the microgravity flights.

  5. 78 FR 14095 - Determination That GEREF (Sermorelin Acetate) Injection, 0.5 Milligrams Base/Vial and 1.0...

    Science.gov (United States)

    2013-03-04

    ...] Determination That GEREF (Sermorelin Acetate) Injection, 0.5 Milligrams Base/Vial and 1.0 Milligrams Base/Vial, and GEREF (Sermorelin Acetate) Injection, 0.05 Milligrams Base/Amp, Were Not Withdrawn From Sale for...

  6. 76 FR 36576 - Certain Flip-Top Vials and Products Using the Same; Notice of Institution of Investigation...

    Science.gov (United States)

    2011-06-22

    ... INTERNATIONAL TRADE COMMISSION [Inv. No. 337-TA-779] Certain Flip-Top Vials and Products Using the... the sale within the United States after importation of certain flip-top vials and products using the... importation, or the sale within the United States after importation of certain flip-top vials and products...

  7. Valoraciones sobre la gestión del sistema de seguridad vial en Cuba.

    Directory of Open Access Journals (Sweden)

    Tania Ivón Sosa Ibarra

    2015-12-01

    Full Text Available El presente trabajo tiene como objetivo valorar con enfoque crítico el cumplimiento de la agenda del Observatorio Iberoamericano para la Seguridad Vial (OISEVI que evidencie los aciertos y desaciertos en esta actividad, se analiza en la literatura los enfoques de los autores Tony Bliss y Jeanne Breen que enfatizan en la concepción de sistema no solo a la seguridad vial sino también a la gestión de esta como sistema y se realiza una aplicación de los aspectos de la encuesta del OISEVI a la gestión de la seguridad vial en Cuba por el grupo de asesores de la Comisión Nacional de seguridad vial, pertenecientes a la Universidad de Sancti Spíritus, que durante los últimos años estudian esta problemática, detallando los argumentos que conciben para otorgar los valores en las respuestas al cuestionario. Con esta encuesta se obtiene una primera aproximación del estado de la gestión de la seguridad vial en el país, y se arriban a valoraciones acerca de cómo se encuentra Cuba respecto a los lineamientos básicos y generales que hacen exitosa a la gestión en seguridad vial, basada en los cinco pilares del Plan Mundial para el Decenio de Acción para la Seguridad Vial 2011-2020.

  8. Evaluation of the open vial method in the radon measurement; Evaluacion del metodo del vial abierto en la medicion de radon

    Energy Technology Data Exchange (ETDEWEB)

    Lopez del Rio, H.; Davila R, J. I.; Mireles G, F., E-mail: hlopezdelrio@hotmail.com [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Cipres No. 10, Fracc. La Penuela, 98068 Zacatecas (Mexico)

    2014-10-15

    The open vial method is a simple technique, under-utilized but that take advantage of the great radon solubility in organic solvents, therefore applies in the measurement of the radon concentration exhaled in soil. The method consists on the exposition to the gas radon of an open vial with scintillating solution. An integral mathematical model for indoors that describes the emanation processes and gas radon exhalation was developed, as well as the radon dissolution in the scintillation liquid, besides obtaining the characteristic parameters of the experimental system proposed for the radon concentration calculation exhaled by soils. Two experimental arrangements were designed with exposition cameras of 12 and 6 L and quantity of different soil. The open vial was prepared with a mixture of 8 ml of deionized water and 12 ml of scintillation liquid OptiPhase Hi Safe 3 in polyethylene vials; the measurements of the dissolved radon were carried out in scintillation liquid equipment. As a result, on average 2.0% of the exhaled radon is dissolved in the open vial and the dissolved fraction is independent of the experimental arrangement. Also was observed that the exposition time does not affect the radon dissolution significantly, in correspondence with the reported in the literature. (Author)

  9. Educación vial y movilidad en la Infancia

    Directory of Open Access Journals (Sweden)

    Fernando Martín Poó

    Full Text Available Resumen:La motorización creciente de los desplazamientos ha convertido al ambiente urbano en un lugar cada vez más hostil para los niños y niñas, quienes se encuentran entre los grupos humanos más vulnerables del tránsito. En esta etapa del desarrollo, la educación puede ser una herramienta clave para prevenir comportamientos de riesgo y promocionar hábitos de movilidad más saludables. El presente trabajo discute algunos aspectos relacionados con la educación vial en la infancia. Se destaca la importancia de considerar los patrones de movilidad típicos de cada edad, y de promover el uso de medios de transporte más saludables, equitativos y sustentables. Se señala además la necesidad de complementar las acciones educativas con intervenciones multi-sectoriales a diferente nivel.

  10. Inventarios viales y categorización de la red vial en estudios de Ingeniería de Tránsito y Transporte

    Directory of Open Access Journals (Sweden)

    Julián Rodrigo Quintero

    2011-03-01

    Full Text Available Se presentan las principales consideraciones y los aspectos técnicos fundamentales de la elaboración de Inventarios Viales y la Categorización de la Red Vial, aplicadas a la realización de estudios de ingeniería de tránsito y transporte. Se exponen los aspectos generales relacionados con la elaboración de los inventarios de infraestructura vial, de señalización y dispositivos de control, de estacionamientos, de paraderos y de rutas de transporte público colectivo urbano de pasajeros, como una herramienta práctica para complementar los procedimientos de campo y optimizar los procesos y análisis de resultados orientados a identificar, caracterizar y cuantificar las variables relacionadas con el desarrollo del fenómeno del tránsito y la actividad del transporte.

  11. Plan de Educación Vial de la Municipalidad Metropolitana de Lima en el desarrollo de la cultura vial en estudiantes de secundaria 2014

    OpenAIRE

    Manrique Malpica, José Wilder

    2015-01-01

    El Plan de Educación Vial de la Municipalidad Metropolitana de Lima en el desarrollo de la cultura vial en estudiantes de secundaria 2014. Se trata de una investigación tipo aplicada, de diseño no experimental, transversal – correlacionar. La muestra es probabilística; estuvo conformada por los alumnos de educación secundaria de lima cercado y magdalena del mar el instrumento de investigación cumplió con los requisitos de validez y la confiabilidad. El método que se utilizó ...

  12. Application of modified shell vial culture procedure for arbovirus detection.

    Directory of Open Access Journals (Sweden)

    Edna R Caceda

    Full Text Available The isolation of arboviruses from patient's low titer sera can be difficult. Here we compared the detection efficiency of Dengue (DEN, Yellow Fever (YF, Saint Louis Encephalitis (SLE, West Nile (WN, Ilheus (ILH, Group C (GC, Oropouche (ORO, Mayaro (MAY and Venezuela Encephalitis Equine (VEE viruses using a Modified Shell Vial Culture (MSVC protocol to a Standard Cell Culture (SCC protocol. First the MSVC and SCC protocols were compared using five dilutions for each of the following stock viruses: DEN-1, DEN-2, DEN-3, DEN-4, YF, SLE, WN, ILH, GC, ORO, MAY and VEE. Next, patients' original sera from which viruses (DEN-1, DEN-2, DEN-3, YF, GC, ORO, MAY and VEE had been previously isolated were compare by the two methods using five sera dilutions. In addition, seven sera that were positive for DEN-3 by RT-PCR and negative by SCC were processed by MSVC. The MSVC protocol was consistently 1-2 logs higher virus dilution more sensitive for virus detection than the SCC protocol for all stock Flaviviruses tested (DEN-1, DEN-2, DEN-3, DEN-4, YF, SLE, WN and ILH. MSVC was equal to or one log more sensitive for virus detection than SCC for the stock Bunyaviruses (GC and ORO. For the stock Alphavirus MAY, MSVC was equally or one log more sensitive for virus detection than SCC, while for VEE SCC was equally or one log more sensitive for virus detection than MSVC. MSVC was consistently one to two sera dilutions more sensitive than SCC for the detection of Flaviviruses from patients' sera. Both methods were approximately equally sensitive for the detection of Bunyaviruses from patients' sera and equal or one dilution less sensitive for the detection of Alphaviruses from patients' sera. Additionally, MSVC detected DEN virus in five of seven DEN-3 RT-PCR positive, SCC negative patients' sera.

  13. Laser welding of fused quartz

    Science.gov (United States)

    Piltch, Martin S.; Carpenter, Robert W.; Archer, III, McIlwaine

    2003-06-10

    Refractory materials, such as fused quartz plates and rods are welded using a heat source, such as a high power continuous wave carbon dioxide laser. The radiation is optimized through a process of varying the power, the focus, and the feed rates of the laser such that full penetration welds may be accomplished. The process of optimization varies the characteristic wavelengths of the laser until the radiation is almost completely absorbed by the refractory material, thereby leading to a very rapid heating of the material to the melting point. This optimization naturally occurs when a carbon dioxide laser is used to weld quartz. As such this method of quartz welding creates a minimum sized heat-affected zone. Furthermore, the welding apparatus and process requires a ventilation system to carry away the silicon oxides that are produced during the welding process to avoid the deposition of the silicon oxides on the surface of the quartz plates or the contamination of the welds with the silicon oxides.

  14. Modelling the thermal quenching mechanism in quartz based on time-resolved optically stimulated luminescence

    DEFF Research Database (Denmark)

    Pagonis, V.; Ankjærgaard, Christina; Murray, Andrew

    2010-01-01

    This paper presents a new numerical model for thermal quenching in quartz, based on the previously suggested Mott–Seitz mechanism. In the model electrons from a dosimetric trap are raised by optical or thermal stimulation into the conduction band, followed by an electronic transition from the con...... experimental data obtained using a single-aliquot procedure on a sedimentary quartz sample....

  15. Charge movement in grains of quartz studied using exo-electron emission

    DEFF Research Database (Denmark)

    Ankjærgaard, Christina; Denby, Phil M.; Murray, A.S.

    2008-01-01

    movement in luminescence phosphors. Here we show that OSE from natural quartz grains gives an easily detectable, reproducible and light sensitive signal, although it is not as intense as OSL. A single sample of natural quartz grains extracted from a sediment is used to investigate the thermal stability...

  16. Stability of 10 mg/mL cefuroxime solution for intracameral injection in commonly used polypropylene syringes and new ready-to-use cyclic olefin copolymer sterile vials using the LC-UV stability-indicating method.

    Science.gov (United States)

    Feutry, Frédéric; Simon, Nicolas; Genay, Stéphanie; Lannoy, Damien; Barthélémy, Christine; Décaudin, Bertrand; Labalette, Pierre; Odou, Pascal

    2016-01-01

    Injecting intracameral cefuroxime has been found beneficial in reducing the risk of postoperative endophthalmitis but its use has been limited through a lack of approved marketing and of ready-to-use single-units as well as the problem of aseptic compounding. Our aim was to assess a new automated primary packaging system which should ensure a higher level of sterility, thanks to its closed, sterile, ready-to-use polymer vial called "Crystal® vial". The chemical stability of a 10 mg/mL cefuroxime solution was compared in 1 mL Crystal® vials and 1 mL Luer-lock polypropylene syringes (actual reference) to eliminate any potential and specific interactions with its cyclic olefin copolymer (COC) body and elastomer stopper. Cefuroxime solution was introduced into vials and syringes and stored at -20 °C, +5 °C and +25°C/60% Relative Humidity. Cefuroxime concentration and the relative amount of the main degradation product (descarbamoyl-cefuroxime) were both determined by an HPLC/UV method indicating stability. Solutions were considered steady if the concentration remained at over 90% of the initial value. In the adapted storage conditions, the evolution of osmolality, pH and sterility was assessed. Stability profiles were identical between vials and syringes in all storage and temperature conditions. The solution was stable (cefuroxime concentration, pH and osmolality) and still sterile for 365 days at -20°C. The concentration fell below 90% after 21 days at +5 °C and after 16 h at +25°C/60%s relative humidity. The COC and thermoplastic elastomer of the vials had no impact on the degradation process confirming its possible use for a ready-to-use cefuroxime solution single-unit dose.

  17. Quartz red TL SAR equivalent dose overestimation for Chinese loess

    DEFF Research Database (Denmark)

    Lai, Z.P.; Murray, A.S.; Bailey, R.M.

    2006-01-01

    For the red TL of quartz extracted from Chinese loess, the single-aliquot regenerative-dose (SAR) procedure overestimates the known laboratory doses in dose recovery test. The overestimation is the result of the first heating during the measurement of natural TL signal causing a sensitivity...

  18. Dosimetric properties of natural quartz grains extracted from fired materials

    DEFF Research Database (Denmark)

    Bluszcz, A.; Bøtter-Jensen, L.

    1995-01-01

    were obtained showing the possibility of measuring the doses of around 10 mGy with 1% precision using GLSL or TL and using the single aliquot technique for natural quartz as a dosimeter. The lowest detectable dose was estimated to be lower than 500 mu Gy. The results obtained indicate that natural...

  19. Quartz crystal reinforced quartz glass by spark plasma sintering

    International Nuclear Information System (INIS)

    Torikai, D.; Barazani, B.; Ono, E.; Santos, M.F.M.; Suzuki, C.K.

    2011-01-01

    The Spark Plasma Sintering presents fast processing time when compared to conventional sintering techniques. This allows to control the grain growth during sintering as well as the diffusion rate of a multi-material compounds, and make possible obtainment of functionally graded materials and nanostructured compounds. Powders of high purity silica glass and crystalline silica were sintered in a SPS equipment at temperatures around 1350° C, i.e., above the softening temperature of silica glass and below the melting temperature of quartz crystal. As a result, glass ceramics with pure silica glass matrix reinforced with crystalline alpha-quartz grains were fabricated at almost any desired range of composition, as well as controlled size of the crystalline reinforcement. X-ray diffraction and density measurements showed the possibility to manufacture a well controlled density and crystallinity glass-ceramic materials. (author)

  20. Toroidal helical quartz forming machine

    International Nuclear Information System (INIS)

    Hanks, K.W.; Cole, T.R.

    1977-01-01

    The Scyllac fusion experimental machine used 10 cm diameter smooth bore discharge tubes formed into a simple toroidal shape prior to 1974. At about that time, it was discovered that a discharge tube was required to follow the convoluted shape of the load coil. A machine was designed and built to form a fused quartz tube with a toroidal shape. The machine will accommodate quartz tubes from 5 cm to 20 cm diameter forming it into a 4 m toroidal radius with a 1 to 5 cm helical displacement. The machine will also generate a helical shape on a linear tube. Two sets of tubes with different helical radii and wavelengths have been successfully fabricated. The problems encountered with the design and fabrication of this machine are discussed

  1. Agresividad vial en la población general Road-rage in the general population

    OpenAIRE

    Inmaculada Fierro; Trinidad Gómez-Talegón; Francisco Javier Álvarez

    2010-01-01

    Objetivos: Analizar la prevalencia y los factores sociodemográficos asociados con la agresividad vial en la población. Métodos: Se han realizado 2.500 entrevistas a la población de Castilla y León de entre 14 y 70 años de edad. Se evaluó la agresividad vial en el año previo a la realización de la encuesta utilizando un test de ocho preguntas. Resultados: El 31,1% refirió haber vivido alguna situación de agresividad vial en el último año, y el 26,8% en más de una ocasión. El 2,6% fueron agreso...

  2. Experiencia-modelo piloto de los talleres de seguridad vial, como alternativa a la pena privativa de libertad en los delitos contra la seguridad vial

    Directory of Open Access Journals (Sweden)

    Isabel Germán Mancebo

    2012-12-01

    Full Text Available Algunos de los delitos contra la seguridad vial en España tienen asignada la pena de trabajos en beneficio de la comunidad (TBC. Y en la práctica se han percibido problemas en su implementación, entre otros motivos por el aumento de la comisión de los delitos de tránsito y la escasez de puestos de trabajo social para poder llevar a cabo los trabajos comunitarios. Tanto la reciente modificación del Código Penal, como de la normativa reguladora de esta sanción, permite desarrollar los TBC por medio de la realización de talleres. En este artículo se presenta la experiencia-modelo piloto de los talleres de seguridad vial que dan contenido a la pena de TBC, como alternativa a la pena privativa de libertad, lo que resulta de especial interés al ser una de las primeras experiencias de esta naturaleza en España. Para ello se describen los talleres desarrollados, mensualmente, durante el año 2010, a saber: su primer año de funcionamiento en la provincia de Gipuzkoa (España, detallando su estructura, dinámica y tareas -tanto formativas como de utilidad pública- que realizaron los penados. La implementación de estos talleres ha paliado las deficiencias percibidas en la aplicación de la pena de TBC, dotándola de contenido, y superando así las críticas a las que esta sanción se había visto expuesta. Los talleres de seguridad vial responden de forma efectiva al papel preventivo que se le ha otorgado a este tipo de sanciones en el ámbito de la seguridad vial.

  3. Inventarios viales y categorización de la red vial en estudios de Ingeniería de Tránsito y Transporte

    Directory of Open Access Journals (Sweden)

    Julián Rodrigo Quintero

    2011-11-01

    Full Text Available Se presentan las principales consideraciones y los aspectos técnicos fundamentales de la elaboración de Inventarios Viales y la Categorización de la Red Vial, aplicadas a la realización de estudios de ingeniería de tránsito y transporte. Se exponen los aspectos generales relacionados con la elaboración de los inventarios de infraestructura vial, de señalización y dispositivos de control, de estacionamientos, de paraderos y de rutas de transporte público colectivo urbano de pasajeros, como una herramienta práctica para complementar los procedimientos de campo y optimizar los procesos y análisis de resultados orientados a identificar, caracterizar y cuantificar las variables relacionadas con el desarrollo del fenómeno del tránsito y la actividad del transporte.

  4. Valoraciones sobre la gestión del sistema de seguridad vial en Cuba.

    OpenAIRE

    Tania Ivón Sosa Ibarra; Suyen Rodríguez Álvarez; Anisley Pérez Silva

    2015-01-01

    El presente trabajo tiene como objetivo valorar con enfoque crítico el cumplimiento de la agenda del Observatorio Iberoamericano para la Seguridad Vial (OISEVI) que evidencie los aciertos y desaciertos en esta actividad, se analiza en la literatura los enfoques de los autores Tony Bliss y Jeanne Breen que enfatizan en la concepción de sistema no solo a la seguridad vial sino también a la gestión de esta como sistema y se realiza una aplicación de los aspectos de la encuesta del OISEVI a la ge...

  5. Characterisation of blue-light stimulated luminescence components in different quartz samples: Implications for dose measurement

    DEFF Research Database (Denmark)

    Jain, M.; Murray, A.S.; Bøtter-Jensen, L.

    2003-01-01

    Over the last few years, we have become increasingly confident that quartz is a reliable natural dosimeter for sediment dating. Nevertheless, there is only a limited understanding of the behaviour of the different components of optically stimulated luminescence (OSL) from quartz. Recent single-aliquot...... modulated (LM-OSL) components. We then discuss the implications of these characteristics for dose assessment using the single aliquot regeneration dose protocol. (C) 2003 Elsevier Science Ltd. All rights reserved....

  6. 76 FR 58841 - In the Matter of Certain Flip-Top Vials and Products Using the Same; Notice of Commission...

    Science.gov (United States)

    2011-09-22

    ... INTERNATIONAL TRADE COMMISSION [Investigation No. 337-TA-779] In the Matter of Certain Flip-Top Vials and Products Using the Same; Notice of Commission Decision Not To Review an Initial Determination... United States after importation of certain flip-top vials and products using the same by reason of...

  7. Radiation-Hard Quartz Cerenkov Calorimeters

    CERN Document Server

    Akgun, U

    2006-01-01

    New generation hadron colliders are going to reach unprecedented energies and radiation levels. Quartz has been identified as a radiation-hard material that can be used for Cerenkov calorimeters of the future experiments. We report from the radiation hardness tests performed on quartz fibers, as well as the characteristics of the quartz fiber and plate Cerenkov calorimeters that have been built, designed, and proposed for the CMS experiment.

  8. Hacia el desarrollo sostenible en la seguridad vial : el caso holandés.

    NARCIS (Netherlands)

    Wegman, F.C.M.

    1999-01-01

    En esta ponencia, se hace un estudio general sobre la Seguridad Vial en los Países Bajos, mostrando la evolución del indice de accidentes. Se indican cuales son los objetivos fijados por el Gobierno neerlandés y la estrategia a seguir desde el punto de vista político. Aparece el concepto de

  9. Aluminum elution and precipitation in glass vials: effect of pH and buffer species.

    Science.gov (United States)

    Ogawa, Toru; Miyajima, Makoto; Wakiyama, Naoki; Terada, Katsuhide

    2015-02-01

    Inorganic extractables from glass vials may cause particle formation in the drug solution. In this study, the ability of eluting Al ion from borosilicate glass vials, and tendencies of precipitation containing Al were investigated using various pHs of phosphate, citrate, acetate and histidine buffer. Through heating, all of the buffers showed that Si and Al were eluted from glass vials in ratios almost the same as the composition of borosilicate glass, and the amounts of Al and Si from various buffer solutions at pH 7 were in the following order: citrate > phosphate > acetate > histidine. In addition, during storage after heating, the Al concentration at certain pHs of phosphate and acetate buffer solution decreased, suggesting the formation of particles containing Al. In citrate buffer, Al did not decrease in spite of the high elution amount. Considering that the solubility profile of aluminum oxide and the Al eluting profile of borosilicate glass were different, it is speculated that Al ion may be forced to leach into the buffer solution according to Si elution on the surface of glass vials. When Al ions were added to the buffer solutions, phosphate, acetate and histidine buffer showed a decrease of Al concentration during storage at a neutral range of pHs, indicating the formation of particles containing Al. In conclusion, it is suggested that phosphate buffer solution has higher possibility of forming particles containing Al than other buffer solutions.

  10. On the use of aquasol in plastic mini-vials for liquid-scintillation counting

    International Nuclear Information System (INIS)

    Allen, H.J.

    1976-01-01

    The results of an investigation into the use of Aquasol in Mini-Vials, for tritium assay by liquid scintillation counting, are reported. It is shown that the drift in the automatic external-standardization (AES) ratio with time, which was studied upto 23 days after preparation, was always to lower values. However the count rate and hence the counting efficiency for the samples with and without 0.2N KOH added remained essentially constant and thus an AES curve derived from commercial quenched standards in glass vials could not be used to calculate the observed counting efficiency for samples in Mini-Vials. In order to calculate counting efficiencies for samples of unknown tritium concentrations, it is therefore necessary to prepare a set of quenched standards in Mini-Vials for use with each set of samples. The AES ratio may then be used for counting-efficiency determinations if the quenched standards are prepared at the same time as the samples. Alternatively, counting efficiencies of samples may be determined by the internal standardization technique. (U.K.)

  11. The contribution of the counting vial to variable quench in Cerenkov counting

    International Nuclear Information System (INIS)

    Smith, B.S.W.

    1981-01-01

    Evidence for significant variation in counting efficiency within and between batches of glass and plastic vials is presented. Effective corrections for the consequential potential errors can be made by means of appropriate quench curves using a sample channels ratio technique. (author)

  12. Development of quartz particulate reinforced AA6063 aluminum matrix composites via friction stir processing

    Directory of Open Access Journals (Sweden)

    S. Joyson Abraham

    2016-12-01

    Full Text Available Friction stir processing (FSP has been accepted as a potential method to produce aluminum matrix composites (AMCs without the drawbacks of liquid metallurgy methods. The present work focuses on the development of AMCs reinforced with quartz (SiO2 particles using FSP. Grooves with various dimensions were machined on AA6063 plates and compacted with quartz particles. A single pass FSP was carried out using a combination of optimized process parameters. The volume fraction of quartz particles in the AMCs was varied from 0 to 18 vol.% in steps of 6 vol.%. The developed AA6063/Quartz AMCs were characterized using optical, scanning and transmission electron microscopy. The quartz particles were distributed uniformly in the aluminum matrix irrespective of the location within the stir zone. The grains of the AA6063 were extensively refined by the combination of thermomechanical effect of FSP and the pinning effect of quartz particles. The dispersion of the quartz particles improved the microhardness and wear resistance of the AMCs. The role of quartz particles on the worn surface and wear debris is reported.

  13. Impact of changing the measles vaccine vial size on Niger's vaccine supply chain: a computational model

    Science.gov (United States)

    2011-01-01

    Background Many countries, such as Niger, are considering changing their vaccine vial size presentation and may want to evaluate the subsequent impact on their supply chains, the series of steps required to get vaccines from their manufacturers to patients. The measles vaccine is particularly important in Niger, a country prone to measles outbreaks. Methods We developed a detailed discrete event simulation model of the vaccine supply chain representing every vaccine, storage location, refrigerator, freezer, and transport device (e.g., cold trucks, 4 × 4 trucks, and vaccine carriers) in the Niger Expanded Programme on Immunization (EPI). Experiments simulated the impact of replacing the 10-dose measles vial size with 5-dose, 2-dose and 1-dose vial sizes. Results Switching from the 10-dose to the 5-dose, 2-dose and 1-dose vial sizes decreased the average availability of EPI vaccines for arriving patients from 83% to 82%, 81% and 78%, respectively for a 100% target population size. The switches also changed transport vehicle's utilization from a mean of 58% (range: 4-164%) to means of 59% (range: 4-164%), 62% (range: 4-175%), and 67% (range: 5-192%), respectively, between the regional and district stores, and from a mean of 160% (range: 83-300%) to means of 161% (range: 82-322%), 175% (range: 78-344%), and 198% (range: 88-402%), respectively, between the district to integrated health centres (IHC). The switch also changed district level storage utilization from a mean of 65% to means of 64%, 66% and 68% (range for all scenarios: 3-100%). Finally, accounting for vaccine administration, wastage, and disposal, replacing the 10-dose vial with the 5 or 1-dose vials would increase the cost per immunized patient from $0.47US to $0.71US and $1.26US, respectively. Conclusions The switch from the 10-dose measles vaccines to smaller vial sizes could overwhelm the capacities of many storage facilities and transport vehicles as well as increase the cost per vaccinated child. PMID

  14. Impact of changing the measles vaccine vial size on Niger's vaccine supply chain: a computational model

    Directory of Open Access Journals (Sweden)

    Kenea Hailu

    2011-06-01

    Full Text Available Abstract Background Many countries, such as Niger, are considering changing their vaccine vial size presentation and may want to evaluate the subsequent impact on their supply chains, the series of steps required to get vaccines from their manufacturers to patients. The measles vaccine is particularly important in Niger, a country prone to measles outbreaks. Methods We developed a detailed discrete event simulation model of the vaccine supply chain representing every vaccine, storage location, refrigerator, freezer, and transport device (e.g., cold trucks, 4 × 4 trucks, and vaccine carriers in the Niger Expanded Programme on Immunization (EPI. Experiments simulated the impact of replacing the 10-dose measles vial size with 5-dose, 2-dose and 1-dose vial sizes. Results Switching from the 10-dose to the 5-dose, 2-dose and 1-dose vial sizes decreased the average availability of EPI vaccines for arriving patients from 83% to 82%, 81% and 78%, respectively for a 100% target population size. The switches also changed transport vehicle's utilization from a mean of 58% (range: 4-164% to means of 59% (range: 4-164%, 62% (range: 4-175%, and 67% (range: 5-192%, respectively, between the regional and district stores, and from a mean of 160% (range: 83-300% to means of 161% (range: 82-322%, 175% (range: 78-344%, and 198% (range: 88-402%, respectively, between the district to integrated health centres (IHC. The switch also changed district level storage utilization from a mean of 65% to means of 64%, 66% and 68% (range for all scenarios: 3-100%. Finally, accounting for vaccine administration, wastage, and disposal, replacing the 10-dose vial with the 5 or 1-dose vials would increase the cost per immunized patient from $0.47US to $0.71US and $1.26US, respectively. Conclusions The switch from the 10-dose measles vaccines to smaller vial sizes could overwhelm the capacities of many storage facilities and transport vehicles as well as increase the cost per

  15. Impact of changing the measles vaccine vial size on Niger's vaccine supply chain: a computational model.

    Science.gov (United States)

    Assi, Tina-Marie; Brown, Shawn T; Djibo, Ali; Norman, Bryan A; Rajgopal, Jayant; Welling, Joel S; Chen, Sheng-I; Bailey, Rachel R; Kone, Souleymane; Kenea, Hailu; Connor, Diana L; Wateska, Angela R; Jana, Anirban; Wisniewski, Stephen R; Van Panhuis, Willem G; Burke, Donald S; Lee, Bruce Y

    2011-06-02

    Many countries, such as Niger, are considering changing their vaccine vial size presentation and may want to evaluate the subsequent impact on their supply chains, the series of steps required to get vaccines from their manufacturers to patients. The measles vaccine is particularly important in Niger, a country prone to measles outbreaks. We developed a detailed discrete event simulation model of the vaccine supply chain representing every vaccine, storage location, refrigerator, freezer, and transport device (e.g., cold trucks, 4 × 4 trucks, and vaccine carriers) in the Niger Expanded Programme on Immunization (EPI). Experiments simulated the impact of replacing the 10-dose measles vial size with 5-dose, 2-dose and 1-dose vial sizes. Switching from the 10-dose to the 5-dose, 2-dose and 1-dose vial sizes decreased the average availability of EPI vaccines for arriving patients from 83% to 82%, 81% and 78%, respectively for a 100% target population size. The switches also changed transport vehicle's utilization from a mean of 58% (range: 4-164%) to means of 59% (range: 4-164%), 62% (range: 4-175%), and 67% (range: 5-192%), respectively, between the regional and district stores, and from a mean of 160% (range: 83-300%) to means of 161% (range: 82-322%), 175% (range: 78-344%), and 198% (range: 88-402%), respectively, between the district to integrated health centres (IHC). The switch also changed district level storage utilization from a mean of 65% to means of 64%, 66% and 68% (range for all scenarios: 3-100%). Finally, accounting for vaccine administration, wastage, and disposal, replacing the 10-dose vial with the 5 or 1-dose vials would increase the cost per immunized patient from $0.47US to $0.71US and $1.26US, respectively. The switch from the 10-dose measles vaccines to smaller vial sizes could overwhelm the capacities of many storage facilities and transport vehicles as well as increase the cost per vaccinated child.

  16. Bench scale flotation of spodume/quartz and lepidolite/quartz synthetic mixtures

    International Nuclear Information System (INIS)

    Valadao, G.E.S.; Gontijo, C.F.; Peres, A.E.C.

    1985-01-01

    Based on results of zeta potential determinations and microflotation tests, bench scale flotation experiments were carried out using spodume/quartz and lepodolite/quartz synthetic mixtures. Pure natural samples, further purified in laboratory, and commercial reagents were employed. The minerals were characterized by X-ray diffraction technique. Selectivity between spodume and quartz was achieved through modification with corn starch and between lepidolite and quartz through pH control in the acidic range. (Author) [pt

  17. Development of Quartz Fiber Calorimetry

    CERN Multimedia

    2002-01-01

    % RD40 \\\\ \\\\ Very Forward Calorimeters (VFCs) in LHC detectors should cover the pseudorapidity range from $\\eta$~=~2.5 to at least $\\eta$~=~5 in order to compute missing transverse energy and for jet tagging. Operation at such high rapidity requires the use of a calorimetry technique that is very radiation resistant, fast and insensitive to radioactivity (especially to neutrons). This can be accomplished through the Quartz-Calorimeter~(Q-Cal) concept of embedding silica core fibers, that resist to the Gigarad radiation level, into an absorber. In this calorimeter the shower particles produce light through the Cherenkov effect generating a signal less than 10~ns in duration. Unique to this new technology the visible energy of hadronic showers has a transverse dimension nearly an order of magnitude smaller than that in conventional calorimeters, enabling precise spatial resolution, sharper isolation cuts and better jet recognition against the minimum bias events background. Last but not least, most radioactive ...

  18. Radiation-Induced Changes in Quartz, A Mineral Analog of Nuclear Power Plant Concrete Aggregates.

    Science.gov (United States)

    Silva, Chinthaka M; Rosseel, Thomas M; Kirkegaard, Marie C

    2018-03-19

    Quartz single-crystal samples consisting of α-quartz crystal structure were neutron irradiated to fluences of 5 × 10 18 , 4 × 10 19 , and 2 × 10 20 n/cm 2 (E > 0.1 MeV) at two temperatures (52 and 95 °C). The changes in the α-quartz phase as a function of these two conditions (temperature and fluence) were studied using X-ray powder diffraction (XRD), Raman spectroscopy, and transmission electron microscopy (TEM), and the results acquired using these complementary techniques are presented in a single place for the first time. XRD studies showed that the lattice parameters of α-quartz increased with increasing neutron flux. The lattice growth was larger for the samples that were neutron irradiated at 52 °C than at 95 °C. Moreover, an amorphous content was determined in the quartz samples neutron irradiated at 4 × 10 19 n/cm 2 , with the greater amount being in the 52 °C irradiated sample. Complete amorphization of quartz was observed at a fluence of 2 × 10 20 n/cm 2 (E > 0.1 MeV) using XRD and confirmed by TEM characterization and Raman spectroscopic studies. The cause for α-quartz lattice expansion and sample amorphization was also explored using XRD and Raman spectroscopic studies.

  19. The Quartz Analog Watch: A Wonder Machine.

    Science.gov (United States)

    Crane, H. Richard, Ed.

    1993-01-01

    Summarizes how a quartz watch works. Discusses the quartz crystal, its form, and how its frequency is set to a standard; the integrated circuit chip that drives the crystal in vibration, scales its frequency down, and forms pulses that turn the motor; and the motor that drives the gear train that turns the hands. (ZWH)

  20. Quartz gauge response in ion radiation

    International Nuclear Information System (INIS)

    Taylor, P.E.; Gilbert, P.H.; Kernthaler, C.; Anderson, M.U.

    1995-01-01

    This paper describes recent work to make high quality quartz gauge (temporal and spatial) shock wave measurements in a pulsed ion beam environment. Intense ion beam radiation, nominally 1 MeV protons, was deposited into material samples instrumented with shunted quartz gauges adjacent to the ion deposition zone. Fluence levels were chosen to excite three fundamentally different material response modes (1) strong vapor, (2) combined vapor and melt phase and (3) thermoelastic material response. A unique quartz gauge design was utilized that employed printed circuit board (PCB) technology to facilitate electrical shielding, ruggedness, and fabrication at sign e meeting the essential one dimensional requirements of the characterized Sandia shunted quartz gauge. Shock loading and unloading experiments were conducted to evaluate the piezoelectric response of the coupled quartz gauge/PCB transducer. High fidelity shock wave profiles were recorded at the three ion fluence levels providing dynamic material response data for vapor, melt and solid material phases

  1. Single vial kit formulation for preparation of PET radiopharmaceutical. 68Ga-DOTA-TOC

    International Nuclear Information System (INIS)

    Archana Mukherjee; Usha Pandey; Rubel Chakravarty; Ashutosh Dash; Haladhar Dev Sarma

    2014-01-01

    This paper describes the development of a lyophilized cold kit of DOTA-[Tyr 3 ]-Octreotide (DOTA-TOC) for instant compounding of 68 Ga-DOTA-TOC, suitable for diagnosis of neuroendocrine tumors. The work involved formulation of DOTA-TOC kits, optimization of radiolabeling, quality control of 68 Ga-DOTA-TOC and animal biodistribution studies. The prepared kits enable a reliable method for preparation of 68 Ga-DOTA-TOC of high radiochemical purity and excellent stability. Availability of such kits along with 68 Ge/ 68 Ga generators is expected to stimulate the widespread use of 68 Ga-DOTA-TOC in nuclear medicine practice in developing countries. (author)

  2. Electron microscopic investigations of tracks of Cf252 fission fragments in quartz glass

    International Nuclear Information System (INIS)

    Werba, T.; Granzer, F.

    1977-01-01

    Using a single stage carbon replication technique, track pits of Cf 252 -fission products in quartz glass could be revealed by transmission electron microscopy with a high degree of resolution. From the shape of the track pits the angles of incidence of the nuclear particles were determined down to extremely small angles. In addition track pits on the fracture surface of irradiated quartz glass samples have been investigated by scanning electron microscopy. (author)

  3. Afectación de la TIR por materialización de riesgos en proyectos de infraestructura vial

    OpenAIRE

    Caro Londoño, Diego León

    2015-01-01

    El presente trabajo de grado, tuvo como propósito identificar los riesgos presentes en la construcción de un proyecto de infraestructura vial y analizar cuál sería su impacto en la Tasa Interna de Retorno TIR, en caso de que estos se materialicen -- Para dar cumplimiento a estos objetivos se realizó el estudio de varios proyectos de infraestructura vial apoyado en visitas aprovechando las nuevas concesiones viales que surgen en el País como es el caso de las 4G o cuarta generación de concesio...

  4. Determination of geometry correction factors to different vials used to radiopharmaceutical activity measurements

    Energy Technology Data Exchange (ETDEWEB)

    Kuahara, Lilian T.; Correa, Eduardo L.; Potiens, Maria da Penha A., E-mail: lilian547@hotmail.com, E-mail: educorrea1905@gmail.com, E-mail: andmppalbu@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2015-07-01

    The aim of this study is to present the geometry correction factors and their respective uncertainties to P6 and 10R vials and 3 mL and 5 mL plastic syringes using the reference activity meters present at the Laboratorio de Calibracao de Instrumentos (LCI), IPEN the secondary standard system Capintec NPL-CRC radionuclide calibrator, with traceability to the National Physics Laboratory (NPL), England and the work standard Capintec CRC-15BT and the Capintec CRC-25R. The procedure was made using {sup 99m}Tc, which is responsible for about 80 % of the routine procedures in a nuclear medicine service. Variations of up to 40 % between different vials using the same radionuclide were found. (author)

  5. Effect of Air Space in Storage Vials on Motility of Spermatozoa in Chilled Buck Semen

    Directory of Open Access Journals (Sweden)

    Magnus Paul K and Lali F Anand 1

    Full Text Available This study was conducted in order to find out the effect of air space on the top of glass vial in which semen is stored, on the motility of spermatozoa. 45 samples collected from two bucks over a span of 6 months were used for experiment. Goat milk extender was the diluent used. Two ml each of diluted semen after noting their initial motility was stored in 2 ml and 5 ml vials. Samples were stored at 5°C and motility of spermatozoa noted at 24 and 48 hours. Semen without air space was found to preserve the motility better than semen with air space on 24 and 48 hours of incubation. This could be better attributed to reactive oxygen species production by the spermatozoa, but further investigation is needed in this aspect to confirm it. [Veterinary World 2010; 3(9.000: 421-423

  6. The mechanism of growth of quartz crystals into fused silica

    Science.gov (United States)

    Fratello, V. J.; Hays, J. F.; Spaepen, F.; Turnbull, D.

    1980-01-01

    It is proposed that the growth of quartz crystals into fused silica is effected by a mechanism involving the breaking of an Si-O bond and its association with an OH group, followed by cooperative motion of the nonbridging oxygen and the hydroxyl group which results in the crystallization of a row of several molecules along a crystalline-amorphous interfacial ledge. This mechanism explains, at least qualitatively, all the results of the earlier experimental study of the dependence of quartz crystal growth upon applied pressure: large negative activation volume; single activation enthalpy below Si-O bond energy; growth velocity constant in time, proportional to the hydroxyl and chlorine content, decreasing with increasing degree of reduction, and enhanced by nonhydrostatic stresses; lower pre-exponential for the synthetic than for the natural silica.

  7. Coesite as stress indicator in experimentally deformed quartz gouge

    Science.gov (United States)

    Richter, Bettina; Stünitz, Holger; Heilbronner, Reneé

    2015-04-01

    In shearing experiments conducted to study the behaviour of quartz gouge at the brittle - viscous transition, coesite was found in samples that were deformed at confining pressures of 1.0 GPa or 1.5 GPa, at temperatures between 600° C and 800° C, and at constant displacement rates of ~1.3 x 10-5 mms-1 or ~1.3 x 10-4 mms-1. The experiments were performed in a Griggs type deformation apparatus and the starting material was obtained from a hydrothermally grown single crystal. The crystal was crushed and sieved to a grain size solid medium deformation apparatus lies within the same error range as that of the quartz-coesite phase transitions determined with the piston cylinder apparatus.

  8. Equivalent dose determination using a quartz isothermal TL signal

    DEFF Research Database (Denmark)

    Vandenberghe, D.A.G.; Jain, Mayank; Murray, A.S.

    2009-01-01

    signal can be fully reset by sunlight, and grows with dose over at least the same range as the OSL signal. A single-aliquot regenerative-dose (SAR) protocol can be used with this ITL signal. Dose recovery experiments confirm the suitability of the measurement protocol; the De values are in acceptable...... agreement with the expected burial dose in samples from a variety of depositional environments and ages. Our results suggest that measurement of the ITL signal at 270 °C enables the quartz 325 °C TL peak to be used for accurate dose measurements on a single aliquot. The signal allows dating over at least...

  9. Ejecución del inventario vial georeferenciado de Piura y propuesta de optimización de metodologías existentes

    OpenAIRE

    Rojas Ugaz, Humberto Omar

    2005-01-01

    Tesis (Master en Ingeniería Civil con mención en Ingeniería Vial)--Universidad de Piura. Facultad de Ingeniería. Programa Académico de Ingeniería Civil, 2005. Introducción. Cap. 1: Marco conceptual. Cap. 2: Elaboración de documentos para el inventario vial. Cap. 3: Ejecución del inventario vial georeferenciado. Cap. 4: Descripción de la red vial de la región Piura. Cap. 5: Reportes del inventario vial georeferenciado. Conclusiones y recomendaciones. Referencias bibliográficos. Anexos....

  10. Influence of H2O Rich Fluid Inclusions on Quartz Deformation

    Science.gov (United States)

    Thust, Anja; Heilbronner, Renée.; Stünitz, Holger; Tarantola, Alexandre; Behrens, Harald

    2010-05-01

    The effect of H2O on the strength of quartz is well known and has been discussed many times in the literature (e.g. Griggs & Blacic 1965, Kronenberg 1994). In this project we study the H2O interactions between natural dry quartz and H2O rich fluid inclusions during deformation in the solid medium Griggs apparatus. High pressure and temperature experiments were carried out using a quartz single crystal containing a large number of H2O-rich fluid inclusions. Adjacent to the fluid inclusions the crystal is essentially dry (micro thermometry. They show a large range in size from 50 μm to 700 μm and their spatial distribution is extremely heterogeneous. After deformation the inclusions are more homogeneously distributed throughout the sample and dramatically reduced in size (water). After deformation, the absorption spectra display a discrete peak, indicating OH- bonding in the quartz lattice. The release of H2O from fluid inclusions is an important process for crystal plastic deformation. Fluid inclusion rupture, micro cracking and the fast crack healing at these temperatures promote the distribution of H2O through the quartz and influences the strength of the material. Reference: Griggs, D.T. & Blacic, J.D., 1965: Quartz: Anomalous weakness of synthetic crystals. Science 174, 293-295. Kronenberg A.K., (1994): Hydrogen specifications and chemical weakening of quartz, Rev. Mineral. Ser. 29 (1994), pp. 123-176.

  11. Use of soft sensors to monitor a pharmaceuticals freeze-drying process in vials.

    Science.gov (United States)

    Bosca, Serena; Barresi, Antonello A; Fissore, Davide

    2014-03-01

    This paper presents a soft sensor that can be effectively used for in-line monitoring of the primary drying step of a pharmaceuticals freeze-drying process in vials. Process modeling and product temperature measurements are used to estimate the residual amount of ice in the vial and the heat transfer coefficient from the shelf to the product in the vial. The resistance of the dried cake to vapor flow is determined through the heat balance equation at the interface of sublimation. Mathematical simulation and experimental tests have been carried out to validate the estimations provided by the soft sensor. Accurate estimations of the dynamics of the product until the end of primary drying are obtained, as well as of the heat and mass transfer coefficients, even in the case of a highly non-uniform batch. The reduction in the number of variables directly estimated by the soft sensor allows increasing the robustness of the tool with respect to other sensors presented in the literature. The proposed soft sensor is thus effective for process monitoring and it allows using model-based tools for cycle development in lab-scale units, where thermocouples are usually available, and for process monitoring in industrial-scale freeze-dryers, in case wireless sensors are used.

  12. Laser Scanner Como Sistema de Detección de Entornos Viales

    Directory of Open Access Journals (Sweden)

    F. García

    2011-01-01

    Full Text Available Resumen: Los últimos avances en seguridad vial, con sistemas cada vez más complejos, requieren de los más modernos sistemas de adquisición de información. La naturaleza misma del problema requiere sensores capaces de proveer información fiable para tareas complejas y exigentes. Los escáneres láser (LIDAR han demostrado ser una familia de sensores altamente fiable, por lo que durante los últimos años los esfuerzos dedicados a investigar posibles aplicaciones viales han ido en aumento. De esta forma, es cada vez más frecuente observar sistemas de ayuda a la conducción (ADAS con este tipo de dispositivos que proveen de información del entorno necesaria para realizar tareas complejas como deteccián y prediccián de situaciones peligrosas. En el presente trabajo, dos sistemas LIDAR han sido probados para comprobar sus capacidades reales en entornos viales. En segundo término, se propone una aplicación que hace uso de las capacidades de dichos sensores para la detección y clasificación de obstaculos en entornos viarios. Palabras clave: sensores, procesamiento de senales, sistemas reales, vehiculos, algoritmos de deteccion

  13. The pharmaceutical vial capping process: Container closure systems, capping equipment, regulatory framework, and seal quality tests.

    Science.gov (United States)

    Mathaes, Roman; Mahler, Hanns-Christian; Buettiker, Jean-Pierre; Roehl, Holger; Lam, Philippe; Brown, Helen; Luemkemann, Joerg; Adler, Michael; Huwyler, Joerg; Streubel, Alexander; Mohl, Silke

    2016-02-01

    Parenteral drug products are protected by appropriate primary packaging to protect against environmental factors, including potential microbial contamination during shelf life duration. The most commonly used CCS configuration for parenteral drug products is the glass vial, sealed with a rubber stopper and an aluminum crimp cap. In combination with an adequately designed and controlled aseptic fill/finish processes, a well-designed and characterized capping process is indispensable to ensure product quality and integrity and to minimize rejections during the manufacturing process. In this review, the health authority requirements and expectations related to container closure system quality and container closure integrity are summarized. The pharmaceutical vial, the rubber stopper, and the crimp cap are described. Different capping techniques are critically compared: The most common capping equipment with a rotating capping plate produces the lowest amount of particle. The strength and challenges of methods to control the capping process are discussed. The residual seal force method can characterize the capping process independent of the used capping equipment or CCS. We analyze the root causes of several cosmetic defects associated with the vial capping process. Copyright © 2015 Elsevier B.V. All rights reserved.

  14. The hydrolytic weakening effect in quartz

    Science.gov (United States)

    Hobbs, B. E.

    Experiments on single crystals of quartz have shown that an order of magnitude increase in the fugacity of H2O is associated with about an order of magnitude decrease in the flow strength at a given temperature and pressure. The classical interpretation of this hydrolytic weakening effect is that H2O groups are incorporated into the quartz structure as Si-OH.HO-Si groups. Then, in order to move a dislocation, OH.HO bonds need to be broken rather than Si-O bonds. The rate controlling process is envisaged as the diffusion of the (OH)-defect to or with the dislocation core. This paper discusses the manner in which charged hydrogen- or hydroxyl-defects alter the concentrations of other charged defects such as kinks and jogs on dislocations or vacancies and interstitials and so have an influence on the deformation rate. As an example, an increase in the concentration of negatively charged (OH)-defects leads to an increase in the concentration of positively charged kinks on dislocations thus increasing the strain rate. Other deformation mechanisms involving diffusion of oxygen and silicon with or without climb of dislocations or motion of kinks are also investigated and are shown to be capable of explaining the observed effect. This defect chemistry interpretation is consistent with the classical interpretation but also proposes other mechanisms where the direct diffusion of (OH)-defects plays no role in the process. As an example, an increase in the concentration of negatively charged (OH)-defects increases both the concentration of positively charged jogs and positively charged silicon interstitials in such a way as to explain the magnitude of the hydrolytic weakening effect. As such, the rate controlling process is the climb of dislocations controlled by silicon diffusion, not the diffusion of (OH)-defects. Although several different mechanisms are capable of explaining the hydrolytic weakening effect, many have different dependencies upon the activity of oxygen so

  15. Sample vial inserts: A better approach for sampling heterogeneous slurry samples in the SRS Defense Waste Processing Facility

    International Nuclear Information System (INIS)

    Coleman, C.J.; Goode, S.R.

    1996-01-01

    A convenient and effective new approach for analyzing DWPF samples involves the use of inserts with volumes of 1.5--3 ml placed in the neck of 14 ml sample vials. The inserts have rims that conform to the rim of the vials so that they sit straight and stable in the vial. The DWPF tank sampling system fills the pre-weighed insert rather than the entire vial, so the vial functions only as the insert holder. The shielded cell operator then removes the vial cap and decants the insert containing the sample into a plastic bottle, crucible, etc., for analysis. Inert materials such as Teflon, plastic, and zirconium are used for the insert so it is unnecessary to separate the insert from the sample for most analyses. The key technique advantage of using inserts to take DWPF samples versus filling sample vials is that it provides a convenient and almost foolproof way of obtaining and handling small volumes of slurry samples in a shielded cell without corrupting the sample. Since the insert allows the entire sample to be analyzed, this approach eliminates the errors inherent with subsampling heterogeneous slurries that comprise DWPF samples. Slurry samples can then be analyzed with confidence. Analysis times are dramatically reduced by eliminating the drying and vitrification steps normally used to produce a homogeneous solid sample. Direct dissolution and elemental analysis of slurry samples are achieved in 8 hours or less compared with 40 hours for analysis of vitrified slurry samples. Comparison of samples taken in inserts versus full vials indicate that the insert does not significantly affect sample composition

  16. Electronic dipole resonance in smoky quartz

    NARCIS (Netherlands)

    Kerssen, J.; Volger, J.

    1967-01-01

    Microwave absorption in smoky quartz mono-crystal is ascribed to resonance transitions of trapped electrons between initially configurational degenerated states, which are Stark-splitted by a polarizing electric field.

  17. Fabrication of a novel quartz micromachined gyroscope

    Directory of Open Access Journals (Sweden)

    Liqiang Xie

    2015-04-01

    Full Text Available A novel quartz micromachined gyroscope is proposed in this paper. The novel gyroscope is realized by quartz anisotropic wet etching and 3-dimensional electrodes deposition. In the quartz wet etching process, the quality of Cr/Au mask films affecting the process are studied by experiment. An excellent mask film with 100 Å Cr and 2000 Å Au is achieved by optimization of experimental parameters. Crystal facets after etching seriously affect the following sidewall electrodes deposition process and the structure’s mechanical behaviours. Removal of crystal facets is successfully implemented by increasing etching time based on etching rate ratios between facets and crystal planes. In the electrodes deposition process, an aperture mask evaporation method is employed to prepare electrodes on 3-dimensional surfaces of the gyroscope structure. The alignments among the aperture masks are realized by the ABM™ Mask Aligner System. Based on the processes described above, a z–axis quartz gyroscope is fabricated successfully.

  18. Quartz Mountain/Oklahoma Summer Arts Institute.

    Science.gov (United States)

    Frates, Mary Y.; Madeja, Stanley S.

    1982-01-01

    Describes the Quartz Mountain Oklahoma Summer Arts Institute program. It is designed to nurture artistic talent and to provide intensive arts experiences in music, dance, theater, and the visual arts for talented students aged 14-18. (AM)

  19. Properties and behavior of quartz for the silicon process

    Energy Technology Data Exchange (ETDEWEB)

    Aasly, Kurt

    2008-07-01

    This PhD-thesis is a result of the study on important properties of quartz as a raw material for the metallurgical production of ferrosilicon and silicon metal. This includes defining mechanical properties important for the size reduction experienced during transport and storage and thermo-mechanical properties of quartz that is important for how the quartz reacts to the high temperatures experienced as it is charged on the furnace. Additionally, softening properties of quartz have been briefly discussed in some of the papers. Another important goal has been to test analytical and experimental methods for investigating the various properties. The investigations of important factors for the mechanical properties of ores and industrial minerals have been carried out as a literature study. The mining operation and transport from mine to smelter has been discussed and several factors that are significant for achieving best possible mechanical properties of the quartz have been identified. The most important factors are related to production in the mine and processing plant, which should be carefully planned to minimize the amount of blast-induced damage in the rock and thus achieve the best possible mechanical strength of the raw material. The amount of fines can be minimized by controlling the handling of the raw materials during the transport and storage. It is especially important to avoid high drops, both high single drops and accumulated height of all the drops in total. Investigations of the thermo-mechanical properties of quartz have been carried out by using different experimental and characterization methods. The petrographic investigations of the raw materials by polarized light microscopy have been important. Thermo-mechanical investigations have been high-temperature microthermometry and shock heating of quartz samples in an induction furnace with subsequent investigations of the heated material. The subsequent investigation included polarized- and

  20. A quartz Cherenkov detector for polarimetry at the ILC

    International Nuclear Information System (INIS)

    Vauth, Annika

    2014-09-01

    At the proposed International Linear Collider (ILC), the use of polarised electron and positron beams is a key ingredient of the physics program. A measurement of the polarisation with a yet unprecedented precision of δP / P =0.25% is required. To achieve this, Compton polarimeter measurements in front of and behind the collision point are foreseen. In this thesis, a novel concept for a detector for ILC polarimetry is introduced to eliminate one of the dominating systematics limiting the previous best measurement of beam polarisation: a detector using quartz as Cherenkov medium could increase the tolerance against non-linear photodetector responses. The high refractive index of quartz results in a higher Cherenkov light yield compared to conventional Cherenkov gases. This could allow single-peak resolution in the Cherenkov photon spectra produced by the Compton electrons at the polarimeters. The detailed simulation studies presented in this work imply that such single-peak resolution is possible. Considerations for the choice of a suitable detector geometry are discussed. A four-channel prototype has been constructed and successfully operated in a first testbeam campaign at the DESY testbeam, confirming simulation predictions. Although further studies have to be considered to quantify all aspects of the detector response, the findings of the analysis of the data from the first testbeam are promising with regards to reaching the desired light yield. In the final part of this thesis, the application of a detector concept allowing single-peak resolution to the polarisation measurement at the ILC is examined. Two of the main sources of systematic uncertainties on the polarimeter measurements are detector non-linearities and misalignments. The performance of the suggested quartz detector concept in Monte Carlo studies promises a control of these systematics which meets the precision requirements for ILC polarimetry.

  1. Agresividad vial en la población general Road-rage in the general population

    Directory of Open Access Journals (Sweden)

    Inmaculada Fierro

    2010-10-01

    Full Text Available Objetivos: Analizar la prevalencia y los factores sociodemográficos asociados con la agresividad vial en la población. Métodos: Se han realizado 2.500 entrevistas a la población de Castilla y León de entre 14 y 70 años de edad. Se evaluó la agresividad vial en el año previo a la realización de la encuesta utilizando un test de ocho preguntas. Resultados: El 31,1% refirió haber vivido alguna situación de agresividad vial en el último año, y el 26,8% en más de una ocasión. El 2,6% fueron agresores viales «graves». Entre los conductores, la probabilidad de experimentar agresividad vial aumenta a medida que aumentan los miles de kilómetros conducidos a la semana (odds ratio [OR]=1,52, es menor cuanto mayor es la edad del entrevistado (OR=0,975 y es mayor en los hombres (OR=1,287, en los que tienen estudios universitarios (OR=1,408 y en los que viven en localidades de más de 10.000 habitantes (OR=1,25. Conclusiones: Los datos del presente estudio muestran que la agresividad vial afecta a casi un tercio de la población general de Castilla y León, lo que justificaría la adopción de medidas para su prevención y reducción.Objective: To analyze the prevalence of road rage in the general population and the sociodemographic factors associated with this phenomenon. Methods: A total of 2,500 interviews were carried out in the population of Castile and Leon aged 14-70 years. Road rage was evaluated in the year prior to the survey using a test with eight questions. Results: One-third (31.1% of the interviewees reported they had experienced a situation involving road rage during the previous 12 months (26.8% on more than one occasion. Among these episodes, 2.6% involved "serious" aggressors. In drivers, the probability of experiencing road rage increased in line with the number of kilometers driven per week (odds ratio [OR]=1.52, decreased as the age of the driver increased (OR=0.975, and was highest in men (OR=1.287, university

  2. PROPUESTA DE PROCEDIMIENTOS DE AUTOCONTROL EN CONTRATOS DE CONSERVACIÓN DE UNA RED VIAL

    Directory of Open Access Journals (Sweden)

    R. F. Herrera

    2016-12-01

    Full Text Available Con un contrato global mixto se lleva a cabo la mantención de una red vial, a través de la ejecución simultánea de conservación bajo la modalidad a serie de precios unitarios, y bajo suma alzada por nivel de servicio. En estos últimos se evidencia una mayor precariedad en los procedimientos, debido a fallas en la visión de la empresa contratista en asumir la gestión de la conservación, carencia en la asignación de responsabilidades a los miembros del equipo, y el deficiente control de la calidad de las obras y documentación del contrato. Por este motivo, en este trabajo se realiza una propuesta de gestión definiendo cada una de las etapas que la componen, con la finalidad de asegurar una correcta conservación de los elementos que conforman la infraestructura vial. Los objetivos propuestos son: especificar la metodología a usar para gestionar la mantención de la red contratada bajo la modalidad global mixto, especificar el manejo y control de la documentación que deben mantener en el contrato, y definir las aptitudes y responsabilidades del equipo de trabajo. Para cumplir con los mismos se realizó una revisión bibliográfica de la normativa nacional acerca de la mantención de caminos, y se tomó conocimiento de la diversidad de contratos que utiliza la Dirección de Vialidad para la conservación vial. Además, a través de la experiencia en contratos de conservación global mixto se definen las aptitudes y responsabilidades que se recomienda que tengan los miembros del equipo de trabajo.

  3. Stability of Procainamide Injection in Clear Glass Vials and Polyvinyl Chloride Bags.

    Science.gov (United States)

    Donnelly, Ronald F

    2017-11-01

    The objective of this study was to evaluate the chemical stability of procainamide hydrochloride, 100 mg/mL, when repackaged in clear glass vials or diluted to 3 mg/mL with normal saline and packaged in polyvinyl chloride (PVC) bags when stored at either 23°C and exposed to light (ETL) or 5°C and protected from light (PFL). Solutions were assayed using a stability-indicating high-performance liquid chromatography method. Samples (5 mL) were collected from triplicate containers on days 0, 7, 14, 21, 28, 56, 91, and 193. Color/clarity and pH changes were also monitored at each time interval. During the study, all samples remained clear and there was only a slight pH change. The color of the solutions stored at 23°C intensified but did not correlate with a significant decrease in concentration, while solutions stored at 5°C remained unchanged. Solutions repackaged in glass vials were stable for 193 days when stored at 23ºC and ETL or 5ºC and PFL. When further diluted to 3 mg/mL with normal saline and packaged in PVC bags, procainamide was also stable for 193 days at either 23ºC and ETL or 5°C and PFL. The stability of procainamide, 100 mg/mL, repackaged in clear glass vials was 193 days when stored at either 23ºC and ETL or 5ºC or PFL. If diluted further to 3 mg/mL with normal saline and packaged in PVC bags, the drug was also stable for 193 days at either 23ºC and ETL or 5°C and PFL.

  4. MALDI-TOF MS based carbapenemase detection from culture isolates and from positive blood culture vials.

    Science.gov (United States)

    Ghebremedhin, B; Halstenbach, A; Smiljanic, M; Kaase, M; Ahmad-Nejad, P

    2016-02-02

    Antibiotic resistance in bacteria leads to massive health problems. Incidence of carbapenem and multidrug resistance in Gram-negative bacteria are increasing globally and turn out to be a very urgent challenge in health care. Resistant bacteria play an important clinical role during hospital outbreaks as well as in sepsis. Rapid diagnostic tests are necessary to provide immediate information for antimicrobial treatment and infection control measures. Our mass spectrometry-based assay was validated with 63 carbapenemase-producing Gram-negative bacterial isolates, and 35 carbapenem-resistant Gram-negative species with no carbapenemase production. These were analyzed from solid culture media and positive blood culture vials. After 4 h of incubation the carbapenemase products were analyzed with the MALDI-TOF MS. All the isolates were genotyped for carbapenemase genes by PCR and sequencing. For culture isolates the concordance of hydrolysis assay to genetic results was 98 % for OXA variants, KPC, VIM, IMP, GIM, and NDM. In contrast, only 14 of 29 Acinetobacter baumannii isolates carrying the OXA and NDM genes could be identified from blood culture. However, from blood culture vials our method allowed the detection of carbapenemases in 98 % of Pseudomonas and Enterobacteriaceae isolates harboring different genes. This MALDI-TOF MS-based assay permitted the detection of carbapenemases either from solid culture media (98-100 %) or blood culture vials (96 %) for all non-A. baumannii isolates within 4 h. In case of A. baumannii isolates the assay was highly sensitive for the detection of carbapenemases directly from solid culture media.

  5. Vaccine Wastage Assessment After Introduction of Open Vial Policy in Surat Municipal Corporation Area of India.

    Science.gov (United States)

    Patel, Prakash B; Rana, Jayesh J; Jangid, Sunil G; Bavarva, Neha R; Patel, Manan J; Bansal, Raj Kumar

    2015-12-08

    As per the vaccine management policy of the Government of India all vaccine vials opened for an immunization session were discarded at the end of that session, irrespective of the type of vaccine or the number of doses remaining in the vial prior to 2013. Subsequently, open vial policy (OVP) was introduced in 2013 and should reduce both vaccine wastage as well as governmental healthcare costs for immunization. This study evaluates the vaccine wastage after introduction of the OVP and its comparison with the previous study of vaccine wastage in Surat city before implementation of OVP. It needs to mention that the vaccine policy for this period under comparison was uniform except for the OVP. Information regarding vaccine doses consumed and children vaccinated during immunization sessions of 24 urban health centers (UHCs) of Surat city were retrieved for the period of January 1st, 2014 to March 31st, 2014. The data were analyzed to estimate vaccine wastage rate (WR) and vaccine wastage factor (WF). In order to assess the impact of OVP, vaccine WR of this study was compared with that of previous study conducted in Surat city during January 1st, 2012 to March 31st, 2012. The vaccine WR for oral polio vaccine (OPV) has decreased from 25% to 13.62%, while the WRs for DPT, hepatitis B virus (HBV) and the pentavalent vaccine combinedly have decreased from 17.94% to 8.05%. Thus, by implementation of OVP, an estimated 747 727 doses of OPV and 343 725 doses of diphtheria, pertussis and tetanus toxoid vaccine (DPT), HBV and the pentavalent vaccines combinedly have been saved in Surat city of India in a year. The implementation of the OVP in Surat city has led to a significant lowering in the vaccine wastage, leading to savings due to lower vaccine requirements. © 2016 by Kerman University of Medical Sciences.

  6. Quartz as a natural luminescence dosimeter

    Science.gov (United States)

    Preusser, Frank; Chithambo, Makaiko L.; Götte, Thomas; Martini, Marco; Ramseyer, Karl; Sendezera, Emmanuel J.; Susino, George J.; Wintle, Ann G.

    2009-12-01

    Luminescence from quartz is commonly used in retrospective dosimetry, in particular for the dating of archaeological materials and sediments from the Quaternary period. The phenomenon of luminescence is related to the interaction of natural radiation with mineral grains, by the activation of and subsequent trapping of electrons at defects within the quartz lattice. The latent luminescence signal (i.e. the trapped electrons) is released when the grains are exposed to stimulation energy in the form of light or heat. Despite the fact that quartz is most nominally pure SiO 2, the mineral forms in several different geological settings, i.e. under different pressure and temperature conditions. The luminescence emitted from quartz is complex and shows a variety of different components with diverse physical properties. This complexity is explained by the variety of defects in quartz that are either intrinsic (e.g., Si and O vacancies) or related to impurity atoms (e.g., Al or Ti). The concentration of impurity-related defects is dependent on the conditions of mineral formation or subsequent alteration. Experimental data have shown that the luminescence properties of quartz are highly variable with geological source and vary even at a grain-to-grain level within a sediment. As a consequence, caution is needed when making any general statements about the luminescence properties of quartz. When using luminescence measurements as a dating technique, it is necessary to adjust the measurement procedures for each geological provenance. Furthermore, some quartz has luminescence properties that make it problematic, or even unsuitable, for certain applications. These problems can arise from low and changing luminescence sensitivity, thermal transfer of trapped electrons, thermal instability of the trapped electrons and low saturation dose. Reviewing the present knowledge reveals that insufficient information is available either to unambiguously link distinctive lattice defects with

  7. Classification of glass particles in parenteral product vials by visual, microscopic, and spectroscopic methods.

    Science.gov (United States)

    Li, Gary Guiyang; Cao, Shawn; Jiao, Nancy; Wen, Zai-Qing

    2014-01-01

    Glass vials have been used as primary containers for parenteral drugs including biopharmaceuticals. Different types of glass-related particles, although in low occurrence rate, may be adventitiously introduced in these parenterals. Proper classification and investigations of these glass-related particles may help to understand their formation, improve process control, reduce glass-related particles, and deliver safe parenteral drugs to patients. In this article, we introduced a classification scheme, and identification procedures and methods, for the glass-related particles. We propose to classify them as glass chip, glass lamella/flake, and silica gel. Eight characteristics for each glass particle type have been identified and described for the visual inspection method. The limitations of the visual method and the need to correlate visual results with forensic analysis are discussed. Using representative examples from each type of glass particle, this study summarized their forensic differentiations based on microscopic methods of optical microscopy, scanning electron microscopy, micro-flow imaging, and spectroscopic methods of dnergy-dispersive spectroscopy and Fourier transform infrared spectroscopy. The mechanisms of glass particle formation are listed as references for drug development scientists to investigate the root causes and improve process control on visible glass particles in parenteral vials. Glass vials have been used as primary containers for parenteral drugs including biopharmaceuticals. Different types of glass-related particles, although in low occurrence rate, may be adventitiously introduced in these parenterals. Proper classification and investigations of these glass-related particles may help to understand their formation, improve process control, reduce glass-related particles, and deliver safe parenteral drugs to patients. In this article, we introduced a classification scheme, and identification procedures and methods, for the glass

  8. Thermal activation of OSL as a geothermometer for quartz grain heating during fault movements

    CERN Document Server

    Rink, W J; Rees-Jones, J; Schwarcz, H P

    1999-01-01

    In discussions of ESR dating of fault movements, there has been much debate whether zeroing of ESR signals is a mechanical shearing effect or caused by frictional heating. The OSL (optically stimulated luminescence) sensitivity of quartz is known to increase after heating. This thermal activation of dose response of the OSL in quartz should be useful as a geothermometer to test whether quartz particles in fault gouge had been heated. We tested the OSL sensitivities of quartz from fault gouge, and from a control (quartz grains from sandstone) and were able to show heat-induced enhancement of OSL sensitivity to a test dose. We observed that relative enhancement of OSL dose response (ratio of heated to unheated single aliquots) is significantly less for the finest grains (45-75 and 100-150 mu m) compared with coarser grains (150-250 mu m). These data are consistent with a model of zeroing of the quartz grains during faulting, by frictional heating localized to the grain boundaries, which would be expected to aff...

  9. Correct interpretation of diffraction properties of quartz crystals for X-ray optics applications

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Xian-Rong; Gog, Thomas; Kim, Jungho; Kasman, Elina; Said, Ayman H.; Casa, Diego M.; Wieczorek, Michael; Hönnicke, Marcelo G.; Assoufid, Lahsen

    2018-02-01

    Quartz has hundreds of strong Bragg reflections that may offer a great number of choices for making fixed-angle X-ray analyzers and polarizers at virtually any hard X-ray energies with selectable resolution. However, quartz crystals, unlike silicon and germanium, are chiral and may thus appear in two different forms of handedness that are mirror images. Furthermore, because of the threefold rotational symmetry along thecaxis, the {h1h2h3L} and {h2h1h3L} Bragg reflections may have quite different Darwin bandwidth, reflectivity and angular acceptance, although they have the same Bragg angle. The design of X-ray optics from quartz crystals therefore requires unambiguous determination of the orientation, handedness and polarity of the crystals. The Laue method and single-axis diffraction technique can provide such information, but the variety of conventions used in the literature to describe quartz structures has caused widespread confusion. The current studies give detailed guidelines for design and fabrication of quartz X-ray optics, with special emphasis on the correct interpretation of Laue patterns in terms of the crystallography and diffraction properties of quartz. Meanwhile, the quartz crystals examined were confirmed by X-ray topography to have acceptably low densities of dislocations and other defects, which is the foundation for developing high-resolution quartz-based X-ray optics.

  10. Thermal activation of OSL as a geothermometer for quartz grain heating during fault movements

    International Nuclear Information System (INIS)

    Rink, W.J.; Toyoda, S.; Rees-Jones, J.; Schwarcz, H.P.

    1999-01-01

    In discussions of ESR dating of fault movements, there has been much debate whether zeroing of ESR signals is a mechanical shearing effect or caused by frictional heating. The OSL (optically stimulated luminescence) sensitivity of quartz is known to increase after heating. This thermal activation of dose response of the OSL in quartz should be useful as a geothermometer to test whether quartz particles in fault gouge had been heated. We tested the OSL sensitivities of quartz from fault gouge, and from a control (quartz grains from sandstone) and were able to show heat-induced enhancement of OSL sensitivity to a test dose. We observed that relative enhancement of OSL dose response (ratio of heated to unheated single aliquots) is significantly less for the finest grains (45-75 and 100-150 μm) compared with coarser grains (150-250 μm). These data are consistent with a model of zeroing of the quartz grains during faulting, by frictional heating localized to the grain boundaries, which would be expected to affect smaller grains more than large ones. This argues against a zeroing model in which the entire fault gouge is heated by friction. Higher laboratory preheating of sandstone quartz reduces between-aliquot variability of OSL dose response in the unheated grains to nearly zero. Unheated coarsest fault gouge grains displayed virtually no among-aliquot variability, whereas fine grains showed much larger between-aliquot variability; as with the quartz sand, variability dropped to near zero after laboratory heating, suggesting that fine grains in fault gouge have experienced a wide range of natural thermal histories during faulting. This may present a problem for ESR dating of fault gouge using the plateau method

  11. A STUDY OF THE PRESSURE SOLUTION AND DEFORMATION OF QUARTZ CRYSTALS AT HIGH pH AND UNDER HIGH STRESS

    Directory of Open Access Journals (Sweden)

    JUNG-HAE CHOI

    2013-02-01

    Full Text Available Bentonite is generally used as a buffer material in high-level radioactive waste disposal facilities and consists of 50% quartz by weight. Quartz strongly affects the behavior of bentonite over very long periods. For this reason, quartz dissolution experiment was performed under high-pressure and high-alkalinity conditions based on the conditions found in a high-level radioactive waste disposal facility located deep underground. In this study, two quartz dissolution experiments were conducted on 1 quartz beads under low-pressure and high-alkalinity conditions and 2 a single quartz crystal under high-pressure and high-alkalinity conditions. Following the experiments, a confocal laser scanning microscope (CLSM was used to observe the surfaces of experimental samples. Numerical analyses using the finite element method (FEM were also performed to quantify the deformation of contact area. Quartz dissolution was observed in both experiments. This deformation was due to a concentrated compressive stress field, as indicated by the quartz deformation of the contact area through the FEM analysis. According to the numerical results, a high compressive stress field acted upon the neighboring contact area, which showed a rapid dissolution rate compared to other areas of the sample.

  12. Formation of cogenetic quartz and nepheline syenites

    Science.gov (United States)

    Foland, K. A.; Landoll, J. D.; Henderson, C. M. B.; Chen, Jiangfeng

    1993-02-01

    Understanding the processes involved in the formation of cogenetic silica-undersaturated and silica-saturated felsic rocks in alkaline igneous complexes has been a long-standing enigma because of constraints imposed by phase equilibria relationships. This problem is discussed in general drawing upon relationships at two magmatic centers: Marangudzi in Zimbabwe and Mt. Brome in Quebec, Canada. At each locality, cogenetic quartz and nepheline syenites appear to be derived from common critically undersaturated magmas. Strontium and neodymium isotope results indicate that quartz syenites bear the signatures of substantial amounts of crustal assimilation whereas nepheline syenites lack or display lesser effects. In the model outlined, quartz syenite melts develop from felsic silica undersaturated magmas by assimilation of granitic crust coupled with fractional crystallization whereas nepheline syenites form without large amounts of contamination. This model is compatible with the constraints imposed by phase equilibria.

  13. Study and determination of the influence factors of the radiopharmaceutical vials dimensions used for actimeter calibration at IPEN

    International Nuclear Information System (INIS)

    Martins, Elaine Wirney

    2010-01-01

    The efficiency and safety of the nuclear medicine practice depend, among others factors, of a quality control programme, mainly related to the use of the nuclide activity meters (activimeter). One of the most important sources of errors in the activimeter measurements is the thickness, size and volume of the vial that contains the radiopharmaceutical considering that a typical activimeter has its response dependent of the vial used. The objective of this work was to establish a quality control programme and the correction factors for the geometry of the vials used for distribution of radiopharmaceutical and activimeters calibration, considering that the Calibration Laboratory of Instruments (LCI) of the Instituto de Pesquisas Energeticas e Nucleares (IPEN) has a NPL-CRC Secondary Standard Radionuclide Calibrator System, manufactured for the Southern Scientific plc, compound by an ionization chamber well type and a current measurement system, with traceability to National Physical Laboratory (NPL) and calibrated with a P6 vial type with different dimensions of the one used for the IPEN. The radiopharmaceutical produced by IPEN 67 Ga, '1 31 I, 201 Tl and 99 mTc, had been tested using the two different vials. The results shown a maximum variation of 22% for 201 Tl, and the minimum variation was 2.98% for 131 I. The correction factors must be incorporated in the routine calibration of the activimeters. (author)

  14. Estimating Quartz Reserves Using Compositional Kriging

    Directory of Open Access Journals (Sweden)

    J. Taboada

    2013-01-01

    Full Text Available The aim of this study was to determine spatial distribution and volume of four commercial quartz grades, namely, silicon metal, ferrosilicon, aggregate, and kaolin (depending on content in impurities in a quartz seam. The chemical and mineralogical composition of the reserves in the seam were determined from samples collected from outcrops, blasting operations, and exploratory drilling, and compositional kriging was used to calculate the volume and distribution of the reserves. A more accurate knowledge of the deposit ensures better mine planning, leading to higher profitability and an improved relationship with the environment.

  15. Elementos del impacto ambiental producido por los deslizamientos de taludes viales colombianos

    Directory of Open Access Journals (Sweden)

    Lisandro Beltrán Moreno

    1992-05-01

    Full Text Available Las características orográficas; climáticas y geotécnices, junto con las condiciones impuestas por el tipo y el nivel de desarrollo en el territorio colombiano favorecen la ocurrencia de los deslizamientos. Durante las épocas de invierno se producen numerosos y a veces grandes movimiento en masa en los taludes viales causando notables pérdidas físicas y económicas. Para reducirlas se pueden mejorar los procedimientos seguidos durante el diseño, la interventorie, y la construcción. En este artículo se describen aquellos factores y condiciones que favorecen la ocurrencia de los movimientos en masa, se mencionan las características de estos últimos determinadas mediante un inventario reciente, se indican las deficiencias actuales más notorias qce se encuentran en el diseño y en la construcción de carreteras, y se incluyen informaciones sobre costos parciales de los daños ocasionados por  los derrumbes de los taludes viales. Este trabajo fue publicado en las memorias del lV Congreso Colombiano de Geotecnia, que se realizó en Bogotá, entre el 20 y 23 de agosto de 1991.

  16. Water in quartz? - A comparison of naturally and experimentally deformed crystals

    Science.gov (United States)

    Thust, A.; Kilian, R.; Heilbronner, R.; Stunitz, H.; Holyoke, C. W.; Kronenberg, A. K.

    2011-12-01

    In order to study the influence of water on the deformation of quartz, a series of high PT experiments (Pc up to 1500 MPa and T up to 900°C ) were carried out in a solid medium Griggs apparatus using a quartz single crystal containing a large number of fluid inclusions. FTIR spectroscopy was used to determine water contents. In the undeformed material, the H2O rich fluid inclusions show a large range in size (50 μm water). When samples were being brought up to experimental conditions, P and T remained close to the fluid inclusion isochore. After deformation, the inclusions are homogeneously distributed throughout the sample and dramatically reduced in size (d water contents comparable to Brazil quartz (plastic deformation. Fluid inclusion rupture, micro cracking and the fast crack healing promote the distribution of H2O in the quartz crystal and thus influence the strength of the material The comparison of both situations, - experimental deformation of wetted, single crystal quartz by dislocation glide and natural deformation of dry quartz with wet grain boundaries by dislocation creep - raises a number of questions. (1) Assuming that wet grain boundaries control the mechanical behavior of quartz (recovery) implies that the presence of intra-crystalline water is not critical. (2) Assuming that intra-crystalline water is crucial and - at the same time - measuring very low intra-crystalline water content in nature implies that either the water is lost (i.e. was transient) or else even the low contents of 200 H/10^6Si are sufficient to enable intra-crystalline plasticity.

  17. Evaluación vial y plan de rehabilitación y mantenimiento de la vía Azogues- Cojitambo- Déleg- La Raya

    OpenAIRE

    Garcés Velecela, Diana Patricia

    2017-01-01

    Contar con una infraestructura vial adecuada permite el desarrollo de cualquier región. De ahí que el mantenimiento de la infraestructura vial es importante para garantizar el buen funcionamiento de la misma. Considerando que en nuestro país durante los últimos años se ha tenido una gran inversión en proyectos viales y muchos de ellos al no tener un adecuado mantenimiento presentan daños prematuros, es necesario, por lo tanto, realizar la evaluación vial y establecer un plan de rehabilitación...

  18. Identifying well-bleached quartz using the different bleaching rates of quartz and feldspar luminescence signals

    DEFF Research Database (Denmark)

    Murray, A.S.; Thomsen, Kristina Jørkov; Masuda, N.

    2012-01-01

    the likely significance of the difficult-to-bleach residual feldspar signals in non-aeolian samples. For a set of mainly Late Pleistocene non-aeolian sediments, large aliquot quartz doses are then used to predict feldspar doses (based on a knowledge of the sample dose rates). The differences between observed...... that the large aliquot data are more likely to be correct. We conclude that a comparison of quartz and feldspar doses provides a useful independent method for identifying well-bleached quartz samples, and that it is unwise to apply statistical models to dose distributions without clear evidence for the physical...

  19. Geology and geochemistry of giant quartz veins

    Indian Academy of Sciences (India)

    They show imprints of strong brittle to ductile–brittle deformation, and in places are associated with base metal and gold incidences, and pyrophyllite-diaspore mineralization. The geochemistry of giant quartz veins were studied. Apart from presenting new data on the geology and geochemistry of these veins, an attempt has ...

  20. On the internal radioactivity in quartz

    Czech Academy of Sciences Publication Activity Database

    Vandenberghe, D.; De Corte, F.; Buylaert, J.P.; Kučera, Jan; Van den haute, P.

    2008-01-01

    Roč. 43, 2-6 (2008), s. 771-775 ISSN 1350-4487 Institutional research plan: CEZ:AV0Z10480505 Keywords : neutron activation * k0-method * quartz, dose rate Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 1.267, year: 2008

  1. Sistema de Gestión Vial: aplicación en la ciudad de Mar del Plata

    OpenAIRE

    Daguerre, Lisandro; Capra, Bernardino; Frígoli Albert, Elisa; Larsen, Diego Omar; Williams, Eduardo A.; Tidone, Leda; Faiella, Pablo; Bolgeri, Fernando; Schvartzer, Fabián

    2013-01-01

    Un Sistema de Gestión Vial es una herramienta de apoyo, que sobre la base del conocimiento integral del estado de situación en que se encuentran las diferentes arterias de la ciudad, posibilita la toma de decisiones de intervención con fundamento técnicoeconómico. El objetivo principal ha sido determinar planes de intervención a mediano y largo plazo, tanto en tareas de construcción, rehabilitación como de mantenimiento vial de acuerdo al grado de deterioro encontrado en las calles urbanas...

  2. Componentes descriptivos y explicativos de la accidentalidad vial en Colombia: Incidencia del factor humano

    Directory of Open Access Journals (Sweden)

    Ervyn H. Norza Céspedes

    2016-03-01

    Full Text Available Problema: Se analizó la incidencia del factor humano en la accidentalidad vial en el territorio colombiano, y se identificó evidencia empírica para la formulación de política pública del tránsito. Metodología: El diseño es descriptivo-correlacional. Instrumentos: cuestionario de comportamiento para conductores y motociclistas (D.B.Q. y encuesta tipo Likert. Muestra no probabilística intencional: 16.322 personas (8.631 conductores de automotores, 5.133 motociclistas y 2.558 peatones, pasajeros y acompañantes. Resultados: a conductores con nivel educativo superior inciden en menos accidentes; b peatones con menor nivel educativo inciden en mayores conductas riesgosas; c las mujeres tienen actitud positiva y perciben eficacia de campañas en prevencion; d estilos de conducción iracundo, ansioso, riesgoso y de alta velocidad cometen más infracciones y accidentes; e desobedecer señales de tránsito, la principal causa de accidentalidad; f agresividad, hostilidad y estrés en el tránsito son factores que aumentan la probabilidad de accidente; g campañas de prevención no están siendo captadas por la población más afectada. Conclusiones y recomendaciones: Los factores de accidentalidad vial guardan correspondencia con el Triángulo de Seguridad Vial establecido por la Organización de las Naciones Unidas -factor humano preponderante en la accidentalidad-. Lineamientos de política pública fundamentados en procesos educativos y corporativos tendientes a disminuir la accidentalidad por lo general no se concibe aplicada a la seguridad pública. Por ello, se presenta la inteligencia criminal como una disciplina que se ocupa de anticipar los riesgos criminales contra la seguridad pública. Esto permitiría disminuir la incertidumbre durante la toma de decisiones y calcular los daños contra la seguridad pública, que se pretende prevenir.

  3. Impact of Vial Capping on Residual Seal Force and Container Closure Integrity.

    Science.gov (United States)

    Mathaes, Roman; Mahler, Hanns-Christian; Roggo, Yves; Ovadia, Robert; Lam, Philippe; Stauch, Oliver; Vogt, Martin; Roehl, Holger; Huwyler, Joerg; Mohl, Silke; Streubel, Alexander

    2016-01-01

    The vial capping process is a critical unit operation during drug product manufacturing, as it could possibly generate cosmetic defects or even affect container closure integrity. Yet there is significant variability in capping equipment and processes, and their relation to potential defects or container closure integrity has not been thoroughly studied. In this study we applied several methods-residual seal force tester, a self-developed system of a piezo force sensor measurement, and computed tomography-to characterize different container closure system combinations that had been sealed using different capping process parameter settings. Additionally, container closure integrity of these samples was measured using helium leakage (physical container closure integrity) and compared to characterization data. The different capping equipment settings lead to residual seal force values from 7 to 115 N. High residual seal force values were achieved with high capping pre-compression force and a short distance between the capping plate and plunge. The choice of container closure system influenced the obtained residual seal force values. The residual seal force tester and piezoelectric measurements showed similar trends. All vials passed physical container closure integrity testing, and no stopper rupture was seen with any of the settings applied, suggesting that container closure integrity was warranted for the studied container closure system with the chosen capping setting ranges. The vial capping process is a critical unit operation during drug product manufacturing, as it could possibly generate cosmetic defects or even affect container closure integrity. Yet there is significant variability in capping equipment and processes, and their relation to potential defects or container closure integrity has not been thoroughly studied. In this study we applied several methods-residual seal force tester, a self-developed system of a piezo force sensor measurement, and

  4. Towards dating Quaternary sediments using the quartz Violet Stimulated Luminescence (VSL) signal

    DEFF Research Database (Denmark)

    Ankjærgaard, C.; Jain, Mayank; Wallinga, J.

    2013-01-01

    Quaternary sediments using the violet (402 nm) stimulated luminescence (VSL) signal of quartz.We develop and test a new post-blue VSL single aliquot regenerative dose dating protocol, and demonstrate that the VSL signal originates from a deep trap at about 1.9 eV with a thermal lifetime of 1011 years at 10...

  5. Quartz OSL dating of late Holocene beach ridges from the Magdalen Islands (Quebec, Canada)

    DEFF Research Database (Denmark)

    Remillard, A.M.; Buylaert, Jan-Pieter; Murray, Andrew

    2015-01-01

    different sites throughout the archipelago were investigated. At one of the sites, samples were taken at 9 m and 7.5 m depth using a vibracore. The quartz is dominated by the fast OSL component and a single-aliquot regenerative-dose (SAR) protocol was used to measure the equivalent doses; a low preheat (180...

  6. Electrochemical Quartz Crystal Microbalance Monitoring of the Cyclic Voltammetric Deposition of Polyaniline

    Science.gov (United States)

    Xie, Qingji; Li, Zhili; Deng, Chunyan; Liu, Meiling; Zhang, Youyu; Ma, Ming; Xia, Shaoxi; Xiao, Xiaoming; Yin, Dulin; Yao, Shouzhuo

    2007-01-01

    A real-time, labeled-free and nanogram-sensitive mass sensor, electrochemical quartz crystal microbalance (EQCM) is used to monitor a cyclic voltammetric deposition of polyaniline (PANI). The results determined that the efficiency for PANI deposition and the anion-doping ratio is calculated in one single cyclic voltammetric.

  7. Acute and subchronic airway inflammation after intratracheal instillation of quartz and titanium dioxide agglomerates in mice

    DEFF Research Database (Denmark)

    Roursgaard, Martin; Jensen, Keld A; Poulsen, Steen Seier

    2011-01-01

    compounds were the two micro-size reference quartzes, SRM1878a and DQ12, a micro- and nano-size rutile titanium dioxide (TiO2), a nano-size anatase, and an amorphous TiO2. Particles were administered by a single i.t. instillation in mice at a fixed dose of 5, 50, and 500 micrograms, respectively...

  8. Geology of the Quartz Creek Pegmatite District, Gunnison County Colorado

    Science.gov (United States)

    Staatz, Mortimer H.; Trites, A.F.

    1952-01-01

    The Quartz Creek pegmatite district includes an area about 29 square miles in the vicinity of Quartz Creek in Gunnison County,. Colo. This area contains 1,803 pegmatites that are intruded into pre-Cambrian rocks.

  9. Sulphide Microchemistry and Hydrothermal Fluid Evolution in Quartz ...

    African Journals Online (AJOL)

    2008-06-14

    bearing quartz veins of the Batouri gold district, southeast Cameroon. ...... (2008) in Carajas province, Brazil; Pollard (2006) for intrusion-related gold deposits around the world; Urban et al. (2006) in quartz-stibnite veins and Tsige ...

  10. Shocked quartz and more: Impact signatures in K-T boundary clays and claystones

    Science.gov (United States)

    Bohor, Bruce F.

    1988-01-01

    Quartz grains displaying multiple sets of planar features are described from numerous Cretaceous-Tertiary (K-T) boundary clays and claystones at both marine and nonmarine depositional sites around the world. All these sites also show anomalously high amounts of iridium and enrichments of other siderophile elements in cosmic ratios within these boundary units. This combination of mineralogical and geochemical features are used in support of an impact hypothesis for the end-Cretaceous event. Recently, it was suggested that some combination of explosive and nonexplosive volcanism associated with the formation of the Deccan traps in India could be responsible for the mineralogy and geochemistry seen in the K-T boundary units. Besides the obvious contradition of simultaneous explosive and nonexplosive volcanism from one locality during an instant of geologic time, there remains the difficulty of spreading both iridium (and trace elements in cosmic proportions) and quartz grains around the world by volcanic (atmospheric) transport. In addition, the ability of volcanism to produce the type of shock metamorphism seen in minerals at the K-T boundary was not demonstrated. Multiple sets of shock lamellae in quartz are considered characteristic of shock metamorphism in rocks at the sites of known impact craters and are the type of deformation seen in quartz from K-T boundary clays and claystones. Single sets of poorly defined lamellae described from rare quartz grains in certain volcanic deposits are characteristic of tectonic deformation and do not correspond to the shock lamellae in quartz from K-T sediments and impact structures. So-called shock mosaicism in quartz and feldspar grains described from volcanic deposits can result from many processes other than shock metamorphism, and therefore is not considered to be an effect characteristic solely of shock. The mineralogy of shock-metamorphosed grains at the K-T boundary also argues against a volcanic origin.

  11. Cryoprotectant-free ultra-rapid freezing of human spermatozoa in cryogenic vials.

    Science.gov (United States)

    Zhu, J; Jin, R-T; Wu, L-M; Johansson, L; Guo, T-H; Liu, Y-S; Tong, X-H

    2014-08-01

    The objective of this study was to investigate the effect of ultra-rapid freezing (direct immersion in liquid nitrogen) on human spermatozoa in cryogenic vials (≥0.5 ml) at different concentrations of sucrose. After swim-up, the sperm suspensions (N = 58) were diluted with sperm preparation medium and divided into six aliquots: swim-up (fresh), conventional freezing group (slow freezing) and four ultra-rapid freezing groups containing sucrose at different concentrations (0.15 m, 0.20 m, 0.25 m and 0.30 m). Sperm motility, progressive motility, plasma membrane integrity, DNA stability and acrosome integrity of fresh and cooled-warmed spermatozoa were analysed. The progressive motility, plasma membrane and acrosome integrity of spermatozoa in the 0.20 m sucrose group were significantly higher than those of the slow freezing group (47.5 ± 6.8% versus 36.4 ± 8.7%, 73.2 ± 6.9% versus 63.9 ± 6.3%, 53.7 ± 10.0% versus 35.9 ± 9.7% respectively, P 0.05 respectively) between the 0.20 m sucrose and the slow freezing group. No differences were found between the ultra-rapid and slow freezing group at the other concentrations of sucrose. Our findings suggest that the method of ultra-rapid freezing of human spermatozoa in cryogenic vials with a solution containing 0.20 m sucrose results in recovery of spermatozoon of superior qualities. In contrast to slow freezing, the ultra-rapid freezing technique of human spermatozoa seems to reduce cryoinjuries and maintain important physiological characteristics of the spermatozoa after warming. © 2013 Blackwell Verlag GmbH.

  12. Quartz exposure and increased respiratory symptoms among coal ...

    African Journals Online (AJOL)

    Quartz has been an inevitable composition of different type of coal mined. The quartz exposures among coalmine workers has been attributed to activities such as cutting the adjacent rock, the roof, the floor and the intrusions. Objective: The aim of the study is to determine the associations between quartz exposures and ...

  13. High-Precision Hysteresis Sensing of the Quartz Crystal Inductance-to-Frequency Converter.

    Science.gov (United States)

    Matko, Vojko; Milanović, Miro

    2016-06-28

    A new method for the automated measurement of the hysteresis of the temperature-compensated inductance-to-frequency converter with a single quartz crystal is proposed. The new idea behind this method is a converter with two programmable analog switches enabling the automated measurement of the converter hysteresis, as well as the temperature compensation of the quartz crystal and any other circuit element. Also used is the programmable timing control device that allows the selection of different oscillating frequencies. In the proposed programmable method two different inductances connected in series to the quartz crystal are switched in a short time sequence, compensating the crystal's natural temperature characteristics (in the temperature range between 0 and 50 °C). The procedure allows for the measurement of the converter hysteresis at various values of capacitance connected in parallel with the quartz crystal for the converter sensitivity setting at selected inductance. It, furthermore, enables the measurement of hysteresis at various values of inductance at selected parallel capacitance (sensitivity) connected to the quartz crystal. The article shows that the proposed hysteresis measurement of the converter, which converts the inductance in the range between 95 and 100 μH to a frequency in the range between 1 and 200 kHz, has only 7 × 10(-13) frequency instability (during the temperature change between 0 and 50 °C) with a maximum 1 × 10(-11) hysteresis frequency difference.

  14. High-Precision Hysteresis Sensing of the Quartz Crystal Inductance-to-Frequency Converter

    Directory of Open Access Journals (Sweden)

    Vojko Matko

    2016-06-01

    Full Text Available A new method for the automated measurement of the hysteresis of the temperature-compensated inductance-to-frequency converter with a single quartz crystal is proposed. The new idea behind this method is a converter with two programmable analog switches enabling the automated measurement of the converter hysteresis, as well as the temperature compensation of the quartz crystal and any other circuit element. Also used is the programmable timing control device that allows the selection of different oscillating frequencies. In the proposed programmable method two different inductances connected in series to the quartz crystal are switched in a short time sequence, compensating the crystal’s natural temperature characteristics (in the temperature range between 0 and 50 °C. The procedure allows for the measurement of the converter hysteresis at various values of capacitance connected in parallel with the quartz crystal for the converter sensitivity setting at selected inductance. It, furthermore, enables the measurement of hysteresis at various values of inductance at selected parallel capacitance (sensitivity connected to the quartz crystal. The article shows that the proposed hysteresis measurement of the converter, which converts the inductance in the range between 95 and 100 μH to a frequency in the range between 1 and 200 kHz, has only 7 × 10−13 frequency instability (during the temperature change between 0 and 50 °C with a maximum 1 × 10−11 hysteresis frequency difference.

  15. El Sistema Vial Inca y los desafíos para su conservación en tiempos modernos

    OpenAIRE

    Ríos Canales, Moisés

    2013-01-01

    El Estado peruano, a través del Ministerio de Cultura, desarrolla dentro de su política cultural una estrategia para la identificación, protección, conservación y puesta en uso social del Sistema Vial Inca, el mayor monumento de la historia americana construida por el Estado Inca en el Siglo XV.

  16. Historical review of quartz crystal growth

    Science.gov (United States)

    Iwasaki, Fumiko; Iwasaki, Hideo

    2002-04-01

    The history of quartz crystal growth is reviewed from the origin to the industrialization. The developing process of growth techniques is divided into the following three stages: (1) The fundamental work based on the mineralogical genetic view point, which was performed in Italy during the end of the 19th to the beginning of the 20th centuries. (2) The works to attempt the industrial application made in Germany and in England during World War II. (3) The industrialization of quartz growth after World War II. These were initiated in England, in USA and independently in Russia. The highest mass production process was developed in Japan. The historical flow is traced by the interview of several persons based on the original references.

  17. Diagenetic Quartz Morphologies and Zeolite formation

    DEFF Research Database (Denmark)

    Kazerouni, Afsoon Moatari; Hansen, Rikke Weibel; Friis, Henrik

    sands in these wells all contain authigenic silica/quartz of various morphologies identified with a combination of traditional optical microscopy and scanning electron microscopy. Late Paleocene–early Eocene volcanic ash layers are recognized throughout most of the North Sea and also recorded from......, the precipitation of zeolite may later facilitate further quartz cementation, which might otherwise be retarded by the presence of disordered microquartz. The silica activity of pore fluids can influence zeolite precipitation.  Although zeolite formation is clearly related to volcanic ash, zeolite has also formed...... are abundant in some of associated shales; and 2) volcanic ash. The dissolution of biogenic silica may result in a rapid release of silica thereby promoting the formation of diagenetic opal/microquartz, but there may be a limited release of Al. A limited release of Al may result in precipitation of Si...

  18. Emission polarization study on quartz and calcite.

    Science.gov (United States)

    Vincent, R. K.

    1972-01-01

    Calculation of the spectral emission polarization of quartz and calcite polished plates for observation angles of 20 and 70 deg by the substitution of complex index of refraction values for each mineral into Fresnel's equations. The emission polarization is shown to be quite wavelength-dependent, demonstrating that selected narrow or medium-width spectral bands exhibit a significantly higher percentage of polarization than a broad spectral band for these two minerals. Field measurements with a broadband infrared radiometer yield polarizations on the order of 2% for a coarse-grained granite rock and beach sand (both quartz-rich). This implies that a more sensitive detector with a selected medium-width filter may be capable of measuring emission polarization accurately enough to make this parameter useful as a remote sensing tool for discrimination among rocks on the basis of texture.

  19. The CMS forward calorimeter with quartz fibres

    CERN Multimedia

    Laurent Guiraud

    1999-01-01

    Part of the forward hadron calorimeter for the CMS experiment at the LHC is seen here. The calorimeter will be placed at the ends of the experiment barrel to measure the energy of particles produced in the 14 TeV proton-proton collisions. In consists of an iron absorber and specially designed radiation-hard quartz so that it survives the high radiation levels produced by collisions.

  20. Anisotropic electrical conductivity in quartz during γ-irradiation

    International Nuclear Information System (INIS)

    Miyazaki, T.; Kato, N.; Fueki, K.; Ohshima, N.

    1989-01-01

    Electrical conductivity of quartz during γ-irradiation has been studied at 295Κ. A significant electric current was observed in z-cut quartz, but it could not be measured at all in x-cut quartz, y-cut quartz, and amorphous silica. The mobile ionic species produced during γ-irradiation migrate efficiently along the c axis of a quartz crystal. The G value (i.e., the number of product molecules (or ions) formed on irradiations per 100 eV of energy absorbed) of the mobile free ions was determined to be 0.018 from the field dependence of current at low dose rates

  1. Deposits of gold-quartz formation in the Priamur province

    OpenAIRE

    В. А. Степанов; А. В. Мельников

    2017-01-01

    A description of gold-quartz formation deposits in the Priamur gold province is presented. Prevalence of gold-quartz deposits defines metallogenic profile of the province and presence of numerous rich placers. Deposits are attributed to frontal, middle and near-bottom parts of the ore pipe. Frontal part of the ore pipe contains a major part of the deposits. They are small and consist of scattered quartz, feldspar-quartz and carbonate-quartz veins. The ore is characterized by erratic perce...

  2. Characterization of color centers in quartz induced by gamma irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Guttler, Rainer A.S., E-mail: rainersg@usp.b [Universidade de Sao Paulo (USP), SP (Brazil). Inst. de Geociencias; Enokihara, Cyro T.; Rela, Paulo R., E-mail: prela@ipen.b, E-mail: cteiti@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2009-07-01

    The availability of gamma ray irradiators in Brazil increased the possibilities of treatments of gemstones for color enhancements. One of the minerals with a very high potential of these treatments is quartz, a very widespread mineral with much colored commercial varieties. Quartz occurs in Brazil mainly in two geological environments, called pegmatitic and hydrothermal. The detailed mechanism of color center formation of these two types of quartz will be investigated by spectroscopic and chemical analysis. Until yet, it can be shown that due to chemical differences of the nature of mineral forming fluids, the two types behave differently. All quartzes contain mainly traces of Iron, Aluminum, Lithium and some amounts of Water. The quartz of hydrothermal origin incorporated much structurally bound water, and despite some similarities with the chemical composition of pegmatitic quartz, this high water content is the reason for the formation of Silanol radicals, giving the green color to the quartz. The main difference in chemical composition of pegmatitic quartz is the presence of higher amounts of Al and Li , responsible for the brownish and yellowish colors formed by irradiation. Since each pegmatite is different, the quartz will behave differently. This explains the formation of the famous 'Green Gold' of quartz from Sao Jose da Safira , and the more yellowish, Citrine type, color of quartz from the Coluna deposit, near Itamarandiba, Minas Gerais. (author)

  3. Characterization of color centers in quartz induced by gamma irradiation

    International Nuclear Information System (INIS)

    Guttler, Rainer A.S.

    2009-01-01

    The availability of gamma ray irradiators in Brazil increased the possibilities of treatments of gemstones for color enhancements. One of the minerals with a very high potential of these treatments is quartz, a very widespread mineral with much colored commercial varieties. Quartz occurs in Brazil mainly in two geological environments, called pegmatitic and hydrothermal. The detailed mechanism of color center formation of these two types of quartz will be investigated by spectroscopic and chemical analysis. Until yet, it can be shown that due to chemical differences of the nature of mineral forming fluids, the two types behave differently. All quartzes contain mainly traces of Iron, Aluminum, Lithium and some amounts of Water. The quartz of hydrothermal origin incorporated much structurally bound water, and despite some similarities with the chemical composition of pegmatitic quartz, this high water content is the reason for the formation of Silanol radicals, giving the green color to the quartz. The main difference in chemical composition of pegmatitic quartz is the presence of higher amounts of Al and Li , responsible for the brownish and yellowish colors formed by irradiation. Since each pegmatite is different, the quartz will behave differently. This explains the formation of the famous 'Green Gold' of quartz from Sao Jose da Safira , and the more yellowish, Citrine type, color of quartz from the Coluna deposit, near Itamarandiba, Minas Gerais. (author)

  4. Bi-axial quartz as a stress indicator

    Science.gov (United States)

    Starkey, John

    2000-03-01

    Experiments confirm that stress causes quartz to become biaxial with the optical axial plane parallel to the direction of maximum applied stress. Five tectonites were studied for which published data indicate strong patterns of preferred orientation of quartz. Conoscopic investigation, using an optical universal stage, reveals that the quartz in these rocks is biaxial with the 2V as large as 22°. The optic axial planes display strong patterns of preferred orientation. In the natural tectonites the maximum stress directions deduced from the orientations of the optical axial planes cannot be correlated with the supposed tectonic framework responsible for the quartz orientation fabric. The ease with which quartz can be made biaxial experimentally suggests that the orientation of the optic axial planes may be sensitive to tectonic events which affected the rocks subsequent to the development of the quartz orientation fabrics. The analysis of the orientation of optic axial planes in biaxial quartz may provide a tool for the investigation of neotectonics.

  5. Container/Closure Integrity Testing and the Identification of a Suitable Vial/Stopper Combination for Low-Temperature Storage at -80 {degrees}C.

    Science.gov (United States)

    Zuleger, Brigitte; Werner, Uwe; Kort, Alexander; Glowienka, Rene; Wehnes, Engelbert; Duncan, Derek

    2012-01-01

    It was recently found that after storage of a live viral vaccine at -80 °C in glass vials closed with rubber stoppers, a phenomenon was revealed which had not been observed before with other viral products stored at -20 °C: overpressure in the vials. As this phenomenon poses a serious safety problem for medical personnel as well as for the product itself, an investigation was initiated to identify the root cause of the overpressure. After exclusion of possible root causes (differences in air temperature or atmospheric air pressure during filling and quality control testing, outgassing from the formulation buffer) the remaining hypothesis involved a possible container closure integrity issue at low temperature. The glass transition temperatures (T(g)) of many rubber stopper formulations are in the range -55 to -70 °C. At storage temperatures below T(g), the rubber stopper loses its elastic properties and there is a risk that the seal integrity of the vial could be compromised. Loss of seal integrity of the vials near storage temperatures of -80 °C would result in an ingress of cold dense gas into the vial headspace. After removal of the vials from storage at -80 °C, the rubber stoppers could regain their elastic properties and the vials would quickly reseal, thereby trapping the ingressed gas, which leads to overpressure in the vial headspace. Nondestructive laser-based headspace analysis was used to investigate the maintenance of container closure integrity as a function of the filling and capping/crimping process, storage and transport conditions, and vial/stopper designs. This analytical method is based on frequency modulation spectroscopy (FMS) and can be used for noninvasive headspace measurements of headspace pressure and headspace gas composition. Changes in the vial headspace composition and/or pressure are a clear marker for vials that have lost container closure integrity. After storage of a live viral vaccine at -80 °C in glass vials closed with

  6. Coating Characterization with the Quartz Crystal Microbalance

    Science.gov (United States)

    Sturdy, Lauren F.

    The quartz crystal microbalance is a sensitive tool that can be used to measure the mass, modulus and phase angle of films of appropriate thicknesses. It is can be applied to systems with very varied properties, from liquid to solid, and under many different conditions. In this thesis its capabilities have been used to study the properties of several different systems of relevance to the coatings, art conservation, and rubber communities, in the process of which new techniques and tools were developed to analyze data and improve QCM data collection and experimental design. Alkyd resins, which have been used in artists' paints since the twentieth century, are the subject of the first studies. Alkyds are oil-modified polyesters. These resins are of interest because of their relatively recent use in art and how little is known of the mechanical properties in the early stages of cure. The QCM was shown to be sensitive to the curing process, changes in temperature, and mass change due to exposure to water. Kinetic studies during the first days of curing showed that the curing process can be divided into three regions. The first is dominated by solvent evaporation. In the second, oxygen absorption dominates and the mechanical properties change rapidly. The final stage extends from when the film is touch dry after about a day to years and is characterized by mass loss and continued increases in the modulus. Studying the curing at different temperatures revealed that the reactions do proceed much more rapidly at higher temperatures and an overall energy of activation was calculated for the curing process. The mechanical properties of alkyd resins containing zinc oxide, a white pigment, were studied with the QCM, nanoindentation and dynamic mechanical analysis. These measurements showed increases in the modulus with the inclusion of zinc oxide, and the QCM data showed that the second region started at earlier times as the pigment concentration was increased. Linseed oil is

  7. Experimental diagenesis of quartz with petroleum; Diagenese experimentale du quartz en presence d'hydrocarbures

    Energy Technology Data Exchange (ETDEWEB)

    Teinturier, St.

    2002-11-01

    Quartz cementation has a great impact on petroleum reservoir quality by controlling the porosity and thus the gas or oil storage. However, the possible cementation of quartz during petroleum emplacement is still debated. In most cases, the reconstitution and the understanding of diagenetic processes is based on fluid inclusions studies. However, many questions concerning the representativeness and the reading of the fluid inclusions still remains misunderstood. The experiments were carried out in a silica{+-}water{+-}salts{+-}oil{+-}gas system with the objective to simulate the siliceous diagenesis of natural petroleum reservoirs and to better understand the mechanisms of fluid inclusions formation and quartz cementation in a water and/or petroleum system. Calibration curves have been established using Raman micro-spectroscopy and synthetic reference inclusions to calculate the methane content of aqueous inclusions in the H{sub 2}O-CH{sub 4}-NaCl system. A quantitative procedure for FT-IR micro-spectrometry has been developed to obtain, from individual petroleum fluid inclusions, mole % concentrations of methane, alkanes and carbon dioxide as constraints to thermodynamic modelling. Synthetic aqueous inclusions were created within quartz micro-fractures, with methane (from 150 deg C-200 bar), with petroleum (from 184 deg C-163 bar) and inside quartz overgrowth with the presence of hydrocarbons (from 277 deg C-300 bar). Synthetic petroleum inclusions were created with different water/oil ratios (W/O) within quartz micro-fractures (0quartz overgrowth (10

  8. Banco de ensayos para materiales piezoeléctricos en aplicaciones viales

    Directory of Open Access Journals (Sweden)

    de Frutos, J.

    2011-04-01

    Full Text Available The test bench system described in this paper performs experiments on piezoelectric materials used in road traffic applications, covering a range between 14 and 170 km/h, which is considered enough for testing under standard traffic conditions. A software has been developed to control the three phase induction motor driver and to acquire all the measurement data of the piezoelectric materials. The mass over each system’s axis can be selected, with a limit of 60 kg over each wheel. The test bench is used to simulate the real behaviour of buried piezoelectric cables in road traffic applications for both light and heavy vehicles. This new test bed system is a powerful research tool and can be applied to determine the optimal installation and configuration of the piezoelectric cable sensors and opens a new field of research: the study of energy harvesting techniques based on piezoelectric materials.

    En este trabajo se define y propone un banco de ensayos que permite testar materiales piezoeléctricos para aplicaciones viales en sus diferentes configuraciones en un rango de velocidad entre los 14 y los 170 km/h, lo que cubre sobradamente las condiciones de tráfico real. Tanto el control del variador de velocidad del motor trifásico que realiza el accionamiento del banco, como la recogida de resultados de medida en las pruebas de excitación y de fatiga de los compuestos piezoeléctricos, se realiza de forma automatizada mediante código informatico. El peso que soporta cada eje del banco es configurable, permitiendo reproducir las señales obtenidas en aplicaciones donde los materiales piezoeléctricos actúan de sensores enterrados en la calzada para vehículos tanto pesados como ligeros. Gracias a esta nueva herramienta se facilita la investigación con materiales de este tipo en aplicaciones viales optimizando tanto el tipo como la disposición e instalación de los mismos, además de abrir el camino a la novedosa investigación sobre

  9. Orientation of quartz nanocrystallites in the silicon lattice

    International Nuclear Information System (INIS)

    Kalanov, M.U.; Ibragimova, E.M.; Khamraeva, R.N.; Rustamova, V.M.; Ummatov, Kh.D.

    2006-01-01

    Full text: Basing on the study of medium angle diffuse X-ray scattering from silicon single crystals, it was supposed to be due to rod like oxygen precipitates. It was shown by us later, that depending on the growth conditions, as-grown silicon single crystals contain quartz crystal inclusions at an amount of 0.3 / 0.5 wt. % . Since it has not been done before, the aim of this work was to study the shape and orientation of quartz inclusions relative to a chosen axis of the silicon crystal lattice. We studied p-Si single crystals of one crucible origin with the specific resistance ρ 0 ≅ 1/10 Ohm· cm with different cut surfaces parallel to the crystal planes (100), (110) and (111). All the samples were cut and polished in the bar form with the sizes of 20x12x1.5 mm 3 . The dislocation density was N D ≅ 10 1 /10 3 cm -2 , the concentrations of oxygen and boron were N O ≅ 2/ 4 x10 17 cm -3 and N B ≅ 3· 10 1 5 c m -3 . Structure was analyzed at the set-up DRON-3M ( λ Cu K∝ = 0.1542 nm) at the room temperature in the angle range of angles 2Θ = 10/70 deg. The diffraction spectrum of the sample cut in (111) includes 5 selective reflections and the only diffuse one at 2Θ≅ 20 deg (d/n≅ 0.3136 nm), having a large width 0.1032 rad, which is due to presence of amorphous SiO x precipitate in the surface layer of silicon single crystal. The dominative selective line with d/n≅ 0.3136 nm at 2Θ≅ 28.5 deg belongs to reflection from (111) planes of the silicon lattice and the second less intensive one comes from the same planes with Cu K β radiation. Another selective reflection of a medium intensity at 2Θ≅ 59 deg with d/n≅ 0.1568 nm is its second order (222) and forbidden by the weakening laws. The rest narrow but weak lines with d/n≅ 0.3345 nm at 2Θ≅ 26.6 deg and 0.2468 nm at≅36.6 deg correspond to the diffraction reflections (101) and (110) from the crystal quartz lattice SiO 2 . It means that they are caused by optimally oriented quartz

  10. Comparison of a modified shell vial culture procedure with conventional mouse inoculation for rabies virus isolation.

    Science.gov (United States)

    Ribas Antúnez, María de los Angeles; Girón, Blanca; Monsalvez, Iraima; Morier, Luis; Acosta, Gretel; Tejero, Yahisel; Cordero, Yanislet; Piedra, Dainelyd

    2013-04-01

    Rabies is a neurotropic disease that is often lethal. The early diagnosis of rabies infection is important and requires methods that allow for the isolation of the virus from animals and humans. The present study compared a modified shell vial (MSV) procedure using 24-well tissue culture plates with the mouse inoculation test (MIT), which is considered the gold standard for rabies virus isolation. Thirty brain samples (25 positive and 5 negative by the fluorescent antibody test) obtained from different animal species at the National Institute of Hygiene Rafael Rangel in Caracas, Venezuela, were studied by the MIT and MSV assays. Nine samples (36%) were positive at 24 h, 10 (40%) were positive at 48 h and six (24%) were positive at 72 h by the MSV assay. With the MIT assay, 76% were positive at six days post inoculation and 12% were positive at 12 and 18 days post inoculation. One sample that was negative according to the MSV assay was positive with MIT on the 12th day. The MSV procedure exhibited a sensitivity of 96.2%, a specificity of 100%, a positive predictive value of 100% and a negative predictive value 80%. This procedure allowed for rapid rabies virus detection. MIT can be employed as an alternative method in laboratories without tissue culture facilities.

  11. Development of Conductivity Method as an Alternative to Titration for Hydrolytic Resistance Testing Used for Evaluation of Glass Vials Used in Pharmaceutical Industry.

    Science.gov (United States)

    Fujimori, Kiyoshi; Lee, Hans; Phillips, Joseph; Nashed-Samuel, Yasser

    The European Pharmacopeia surface test to analyze the hydrolytic resistance is a common industrial method to understand and ensure the quality of produced glass vials. Hydrolytic resistance is evaluated by calculating the alkalinity of water extract from autoclaved vials by titration. As an alternative to this titration technique, a conductivity technique was assessed, which directly measures the ions in the water extract. A conductivity meter with a 12 mm diameter electrode was calibrated with a 100 μS/cm conductivity standard and carryover minimized by rinsing the probe in a water beaker per analysis. The limit of quantification at 1 μS/cm was determined as having a signal-to-noise ratio of 3 compared with the water blank. The conductivity method was selective for glass-composing elements (boron, sodium, aluminum, silicon, potassium, and calcium) within the vial extract. Accuracies of spiked conductivity standard within the range of 1 to 100 μS/cm were ±7% and had linearity with coefficient of determination (R 2 ) of ≥0.9999. Intraday precision had a relative standard deviation (RSD) (n = 5) of ≤6% for spiked conductivity standard within the range of 1 to 100 μS/cm. Interday precision had a RSD (n = 4) of ≤6% for 10 vials from three glass vial lots. Conductivity of water extracts from nine sets of seven lots of glass vials had a precise linear relationship [R 2 = 0.9876, RSD = 1% (n = 9)] with titration volumes of the same lots. Conductivity results in μS/cm could be converted to titration volumes in milliliters by a conversion factor of 0.0275. The simplicity, sample stability, and individual vial analysis of the conductivity technique were more advantageous than the current titration technique. The quality of glass vials used as primary containers in the pharmaceutical industry is of concern due to recent observations of glass flake-like delamination, or lamellae, under specific storage conditions. The current European Pharmacopoeia method to assess

  12. Petrogenesis of low-δ18O quartz porphyry dykes, Koegel Fontein complex, South Africa

    Science.gov (United States)

    Harris, Chris; Mulder, Kwenidyn; Sarkar, Saheli; Whitehead, Benjamin; Roopnarain, Sherissa

    2018-04-01

    18O values in the same dyke can be explained by vertical emplacement, at variable rates of ascent along the dyke. The lateral variation in quartz, and hence magma δ18O value at a particular point along a single dyke would depend on the rate of ascent of magma at that point along the dyke, and the `age' of the particular magma batch.

  13. La Eficacia Publicitaria en las Campañas de Prevención para la Seguridad Vial

    OpenAIRE

    Serrano Cordero, Julia Catalina; Arévalo Peña, José David

    2017-01-01

    Este artículo aborda la importancia de los procesos de evaluación de los resultados en las campañas de educación y seguridad vial, éstos, si bien, han alcanzado notables progresos en la praxis, evidencian una falta de información en cuanto a la pertinencia e idoneidad de las herramientas de comunicación en prevención. El objetivo fue validar una campaña de educación y seguridad vial implementada por la Empresa Municipal de Tránsito y Transporte de la ciudad de Cuenca (Ecuador), en el año 2014...

  14. LA IMPORTANCIA DE LOS EJES DE FIJACIÓN DEL PAISAJE URBANO EN LA EDUCACIÓN VIAL

    OpenAIRE

    Nina, Mónica Marianela; Filippeti, Rosana; Pauletto, Selva del Valle

    2012-01-01

    La enseñanza de los ejes de fijación en el espacio urbano son elementos que deben ser vinculados con la educación vial ya que la misma no forma parte del diseño curricular en la educación formal. El propósito del presente trabajo es que a través de la enseñanza de las funciones de las arterias de circulación como calles, avenidas, rutas, autopistas se busca la toma de conciencia de los jóvenes de la importancia de conocer los principios de la educación vial para prevenir los accidentes de trá...

  15. Production of quartz plates for CMS-CASTOR Experiment

    CERN Document Server

    Adiguzel, Aytul; Ayhan, Aydin; Bakirci, Mustafa Numan; Basegmez, Suzan; Beaumont, Willem; Borras, Kerstin; Campbell, Alan; De Paula Carvalho, W; Çerçi, Salim; De Jesus Damiao, Dilson; Dogangün, O; Dumanoglu, Isa; d'Enterria, David; Erchov, Y; Eskut, Eda; Figueiredo, D; Girgis, Semiray; Göttlicher, P; Gouskos, Loukas; Gurpinar, Emine; Hos, Ilknur; Katkov, Igor; Katsas, Panagiotis; Khein, Lev; Knutsson, Albert; Kuznetsov, Andrey; Lebeau, Michel; Van Mechelen, Pierre; Muhl, Carsten; Musienko, Yuri; Ochesanu, Silvia; Onengüt, G; Onengut, G Jr; Ozdemir, Kadri; Panagiotou, Apostolos; Polatoz, A; Ripert, Marion; Shileev, K; Sogut, Kenan; Tiflov, B TaliV; Kayis-Topaksu, A; Uzun, Dilber

    2008-01-01

    Light transmission rate performance of $102$ irradiated quartz samples was measured to select the best quartz plates for CMS-CASTOR calorimeter. All the produced quartz plates were originally used in a previous CERN experiment, DELPHI. Three different doses of $^{60}$Co source were used with the collaboration of PSI (Paul Scherrer Institute, Villigen PSI, Switzerland.) to study the transmission rate performance of the quartz samples after irradiation for different incident light, ranging from $250$ to $700$ nm in $5$ nm increasing steps. All samples show different decrease in the rate with wavelength for different doses. Three different steps were followed before irradiation to find out the best way of cleaning the original DELPHI Cu/Cr tracks on the samples. Results of these measurements presented here correspond to the quartz plates that will be used in one hadronic sector of CASTOR calorimeter until end of 2008. For the full calorimeter new quartz plates will be installed. We also present the light transmi...

  16. Shock pressure estimation in basement rocks of the Chicxulub impact crater using cathodoluminescence spectroscopy of quartz

    Science.gov (United States)

    Tomioka, N.; Tani, R.; Kayama, M.; Chang, Y.; Nishido, H.; Kaushik, D.; Rae, A.; Ferrière, L.; Gulick, S. P. S.; Morgan, J. V.

    2017-12-01

    The Chicxulub impact structure, located in the northern Yucatan Peninsula, Mexico, was drilled by the joint IODP-ICDP Expedition 364 in April-May 2016. This expedition is the first attempt to obtain materials from the topographic peak ring within the crater previously identified by seismic imaging. A continuous core was successfully recovered from the peak ring at depths between 505.7 and 1334.7 mbsf. Uplifted, fractured, and shocked granitic basement rocks forming the peak ring were found below, in the impact breccia and impact melt rock unit (747.0-1334.7 mbsf; Morgan et al. 2016). In order to constrain impact crater formation, we investigated shock pressure distribution in the peak-ring basement rocks. Thin sections of the granitic rocks were prepared at intervals of 60 m. All the samples contains shocked minerals, with quartz grains frequently showing planar deformation features (PDFs). We determined shock pressures based on the cathodoluminescence (CL) spectroscopy of quartz. The strong advantage of the CL method is its applicability to shock pressure estimation for individual grains for both quartz and diaplectic SiO2 glass with high-spatial resolution ( 1 μm) (Chang et al. 2016). CL spectra of quartz shows a blue emission band caused by shock-induced defect centers, where its intensity increases with shock pressure. A total of 108 quartz grains in ten thin sections were analyzed using a scanning electron microscope with a CL spectrometer attached (an acceleration voltage of 15 kV and a beam current of 2 nA were used). Natural quartz single crystals, which were experimentally shocked at 0-30 GPa, were used for pressure calibration. CL spectra of all the quartz grains in the basement rocks showed broad blue emission band at the wavelength range of 300-500 nm and estimated shock pressures were in the range of 15-20 GPa. The result is consistent with values obtained from PDFs analysis in quartz using the universal stage (Ferrière et al. 2017; Rae et al. 2017

  17. Genomic instability in quartz dust exposed rat lungs: Is inflammation responsible?

    Energy Technology Data Exchange (ETDEWEB)

    Albrecht, C; Schins, R P F [Institut fuer Umweltmedizinische Forschung (IUF) at the Heinrich Heine University Duesseldorf (Germany); Demircigil, G Cakmak; Coskun, Erdem [Gazi University, Faculty of Pharmacy, Department of Toxicology, Ankara (Turkey); Schooten, F J van [Nutrition and Toxicology Research Institute Maastricht (NUTRIM), Department of Health Risk Analysis and Toxicology, University of Maastricht (Netherlands); Borm, P J A [Centre of Expertise in Life Sciences (Cel), Hogeschool Zuyd, Heerlen (Netherlands); Knaapen, A M, E-mail: catrin.albrecht@uni-duesseldorf.d

    2009-02-01

    Exposure to quartz dusts has been associated with lung cancer and fibrosis. Although the responsible mechanisms are not completely understood, progressive inflammation with associated induction of persistent oxidative stress has been discussed as a key event for these diseases. Previously we have evaluated the kinetics of pulmonary inflammation in the rat model following a single intratracheal instillation of 2mg DQ12 quartz, either in its native form or upon its surface modification with polyvinylpyridine-N-oxide or aluminium lactate. This model has been applied now to evaluate the role of inflammation in the kinetics of induction of DNA damage and response at 3, 7, 28, and 90 days after treatment. Bronchoalveolar lavage (BAL) cell counts and differentials as well as BAL fluid myeloperoxidase activity were used as markers of inflammation. Whole lung homogenate was investigated to determine the induction of the oxidative and pre-mutagenic DNA lesion 8-hydroxy-2-deoxy-guanosine (8-OHdG) by HPLC/ECD, while mRNA and protein expression of oxidative stress and DNA damage response genes including hemeoxygenase-1 (HO-1) and apurinic/apyrimidinic endonuclease (APE/Ref-1) were evaluated using Western blotting and real time PCR. Isolated lung epithelial cells from the treated rats were used for DNA strand breakage analysis using the alkaline comet assay as well as for micronucleus scoring in May-Gruenwald-Giemsa stained cytospin preparations. In the rats that were treated with quartz, no increased 8-OHdG levels were observed, despite the presence of a marked and persistent inflammation. However, DNA strand breakage in the lung epithelial cells of the quartz treated rats was significantly enhanced at 3 days, but not at 28 days. Moreover, significantly enhanced micronucleus frequencies were observed for all four time points investigated. In the animals that were treated with the PVNO modified quartz, micronuclei scores did not differ from controls, while in those treated with

  18. Phase transitions in shocked porous quartz

    Science.gov (United States)

    Akin, M. C.; Crum, R. S.; Lind, J.; Pagan, D. C.; Homel, M. A.; Hurley, R. C.; Herbold, E. B.

    2017-06-01

    The presence of porosity in granular media provides the means to probe regions of the phase diagram that do not coincide with the principal Hugoniot. In particular, the potential for increased heating is likely to lead to observable changes in phase boundaries. 55% dense quartz and forsterite were prepared by tap filling. These samples were shock compressed using the two stage light gas gun at DCS-APS to examine the impact of the increased porosity on the phase boundary. Here we discuss the observed changes to phase in quartz and forsterite compared to the fully dense materials, the effects of porosity upon compaction and phase transitions, and the implications for constructing the phase diagram. This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344. Work was supported by LLNL's LDRD program under Grant 16-ERD-010. The Dynamic Compression Sector (35) is supported by Department of Energy / National Nuclear Security Administration under Award Number DE-NA0002442. This research used resources of the Advanced Photon Source, a U.S. Department of Energy (DOE) Office of Science User Facility operated for the DOE Office of Science by Argonne National Laboratory under Contract No. DE-AC02-06CH11357.

  19. Aqueous Wetting Films on Fused Quartz.

    Science.gov (United States)

    Mazzoco; Wayner

    1999-06-15

    Using an image analyzing interferometer, IAI, the interfacial characteristics of an isothermal constrained vapor bubble, CVB, in a quartz cuvette were studied as a precursor to heat transfer research. The effects of pH and electrolyte concentration on the meniscus properties (curvature and adsorbed film thickness) and the stability of the aqueous wetting films were evaluated. The surface potential in the electric double layer was a function of the cleaning and hydroxylation of the quartz surface. The disjoining pressure isotherm for pure water was very close to that predicted by the Langmuir equation. For aqueous solutions of moderate electrolyte concentration, the Gouy-Chapman theory provided a good representation of the electrostatic effects in the film. The effect of temperature on the film properties of aqueous solutions and pure water was also evaluated: The meniscus curvature decreased with increasing temperature, while Marangoni effects, intermolecular forces, and local evaporation and condensation enhanced waves on the adsorbed film layer. Pure water wetting films were mechanically metastable, breaking into droplets and very thin films (less than 10 nm) after a few hours. Aqueous wetting films with pH 12.4 proved to be stable during a test of several months, even when subjected to temperature and mechanical perturbations. The mechanical stability of wetting films can explain the reported differences between the critical heat fluxes of pure water and aqueous solutions. The IAI-CVB technique is a simple and versatile experimental technique for studying the characteristics of interfacial systems. Copyright 1999 Academic Press.

  20. La Webquest como innovación educativa en el ámbito de la educación vial

    Directory of Open Access Journals (Sweden)

    Rosa María GOIG MARTÍNEZ

    2013-01-01

    Full Text Available La Educación Vial en las edades tempranas se puede implementar a través de cuentos, talleres, rincones de juego, patios de recreo, salidas extraescolares, actividades de psicomotricidad. Sin embargo, es importante destacar el papel de las Tecnologías de la Información y la Comunicación en el enriquecimiento de las propuestas de aula en relación a la Educación Vial, tomándolas como recurso complementario, en nuestro contexto, la Webquest. Sin olvidar la necesidad de seguir trabajando con los niños y las niñas situaciones reales ligadas a sus experiencias vitales en materia de Educación Vial, pues el mundo real nunca debiera ser desplazado por el mundo virtual en ningún caso, máxime si tenemos en cuenta que se trata de la etapa de Educación Infantil. El objetivo general de este artículo es corroborar que la Webquest constituye una auténtica oportunidad para innovar en el ámbito de la Educación Vial, ofreciendo al alumnado experiencias didácticas coherentes y complementarias desde la etapa de Educación Infantil. La metodología, de carácter cuantitativo y cualitativo, se desarrolló a través de la aplicación de un cuestionario, de una entrevista, del análisis documental y su triangulación, finalizando con el análisis de los datos obtenidos. Una de las conclusiones obtenidas expone que la Webquest es un recurso que nos facilita el proceso de enseñanza-aprendizaje y aumenta la motivación tanto en alumnos como en agentes educativos.

  1. DIAGNÓSTICO DE CONECTIVIDAD Y ACCESIBILIDAD DE LA RED VIAL DEL CANTÓN DE SAN CARLOS, COSTA RICA

    Directory of Open Access Journals (Sweden)

    Diego Armando Cespedes Alvarez

    2016-09-01

    Full Text Available El presente estudio fue realizado con el fin de dar a conocer el nivel de accesibilidad y conectividad de la red vial, constituye una herramienta importante para la coordinación de las labores de atención y gestión sobre la infraestructura vial. Por medio del presente trabajo, se plantea el diagnostico respectivo de conectividad y accesibilidad dentro de la red vial del cantón de San Carlos, Costa Rica; aplicando la Teoría de Grafos y analizando cada una de las variables que el modelo conlleva,  complementando con la aplicación de los Sistemas de Información Geográfica (SIG y el trabajo de campo. Los resultados muestran que los sectores periféricos al cantón, presentan las situaciones más difíciles en conectividad y accesibilidad, mientras que los sectores ubicados hacia el centro del cantón, presentan los mejores niveles en conectividad y accesibilidad.

  2. EMBRYONIC DEVELOPMENTAL ANOMALY IDENTIFICATION OF GIANT MIMI-MINTUNO (Tachupleus gigas DURING ARTIFICIAL INCUBATION PERIOD IN THE VIAL BOTTLES

    Directory of Open Access Journals (Sweden)

    Ciptono Ciptono

    2016-04-01

    Full Text Available This study aims to reveal the phenomenon of presence / absence of anomalies in the early development of Mimi-giant mintuno (Tachypleus gigas during artificial incubation in the vial bottles. Samples 5 eggs are fertilized incorporated into transparent 50 bottles and vials each filled with clear sea water medium. Embryonic stages (instars hatch, bottles marked, then dumped seawater medium was replaced with 4% formalin solution and glycerin amount of 5% by volume, up to ¾ of the total volume of the vial bottles. Standard stages of giant Mimi-mintuno embryonic normal development Mimi-mintuno according to Itow (1988. The description type of anomalies contained in the post-hatching embryo development. The observations are documented in the form of stereo-microphotograph. The results showed that there are forms anomalies: (a. Delayed development, the structure of the body is not perfect; (b. In observation of the embryo hatches, open shell and egg perivitelline membrane has been opened but delayed development, the structure of the body is not perfect; (c. Embryos after hatched perfectly, abnormalities of morphologic structure such as abnormal protrusion on the dorsal carapace part found.   Keywords: Tachypleus gigas, artificially, incubation

  3. Rat strain differences in levels and effects of chronic inflammation due to intratracheal instillation of quartz on lung tumorigenesis induced by DHPN.

    Science.gov (United States)

    Nakano, Yuko; Yokohira, Masanao; Hashimoto, Nozomi; Yamakawa, Keiko; Kishi, Sosuke; Ninomiya, Fumiko; Kanie, Shohei; Saoo, Kousuke; Imaida, Katsumi

    2014-10-01

    Chronic inflammatory effects of single intratracheal instillation (i.t.) of quartz on rat lung tumorigenesis were examined using 4 different animal models. At first, in order to determine an appropriate dose of quartz i.t. to promote lung tumorigenesis, F344 male rats were administrated single 0, 0.5, 1, 2 or 4 mg quartz/rat after initiation by N-bis(2-hydroxypropyl) nitrosamine (DHPN). Further studies were performed to examine strain differences of the effects of chronic inflammation caused by quartz i.t. in 3 strains of rat, i.e. F344, Wistar-Hannover and SD. Each was instilled with 2mg quartz/rat after DHPN administration and sacrificed in week 24. In addition, strain differences in generation of inflammation were determined at days 1 and 28. Finally, for determination of long-term effects period, F344 and Wistar-Hannover rats were similarly treated, but the experiment was terminated at week 52. In F344 rats, the tumor areas in DHPN treated groups showed a tendency to increase along with the dose of quartz. F344 rats demonstrated the highest and Wistar-Hannover rats the lowest sensitivity to quartz in acute and chronic phases in the 3 strains. In 52 week, in F344 rats, the multiplicity of tumors and the serum concentration of IL-6 in the group treated with DHPN and quartz were significantly increased. The present experiments indicated that chronic inflammation due to quartz instillation exerted promoting effects on lung carcinogenesis in F344, SD and Wistar-Hannover rats. The strain differences in tumor promotion appeared to correlate with inflammatory reactions to quartz and increase of IL-6. Copyright © 2014 Elsevier GmbH. All rights reserved.

  4. Analysis of Excitation and Dead Vibration Modes of Quartz Resonators

    Directory of Open Access Journals (Sweden)

    Zi-Gui Huang

    2014-01-01

    Full Text Available This study uses the finite element method (FEM to analyze the excitation and dead vibration modes of two-dimensional quartz plates. We first simplify three-dimensional quartz plates with plane strain simplification and then compare the modes of the simplified three-dimensional plates to those of two-dimensional plates. We then analyze quartz vibrating elements of AT-cut plates and SC-cut plates. To understand the regularity of the resonance frequency of plates that are excitable by voltage loading, we compare the natural vibrations of quartz plates with the excitation frequency generated after the plates are excited by voltage loading.

  5. Note: sensitivity multiplication module for quartz crystal microbalance applications.

    Science.gov (United States)

    Burda, Ioan; Silaghi, Andreea; Tunyagi, Arthur; Simon, Simion; Popescu, Octavian

    2014-02-01

    In this Note, a novel sensitivity multiplication module was added to classical quartz crystal microbalance (QCM). The purpose is to increase QCM frequency shift without changing nominal frequency of the quartz crystal resonator or nominal frequency value delivered to the frequency counter. Allan deviance measurement confirms that the multiplication of the frequency shift is limited by the quartz crystal loads with direct effect in quartz crystal quality factor and oscillator stability. An experimental implementation of this new sensitivity multiplication module that can increase up to six times the frequency shift of the QCM was experimentally investigated using different load conditions.

  6. Effects of quartz on crystallization behavior of mold fluxes and microstructural characteristics of flux film.

    Science.gov (United States)

    Lei, Liu; Xiuli, Han; Mingduo, Li; Di, Zhang

    2018-01-01

    Mold fluxes are mainly prepared using cement clinker, quartz, wollastonite, borax, fluorite, soda ash and other mineral materials. Quartz, as one of the most common and essential materials, was chosen for this study to analyze itseffects on crystallization temperature, critical cooling rate, crystal incubation time, crystallization ratio and phases of flux film. We used the research methods of process mineralogy with the application of the single hot thermocouple technique, heat flux simulator, polarizing microscope, X-ray diffraction, etc. Results: By increasing the quartz content from 16 mass% to 24 mass%, the crystallization temperature, critical cooling rate and crystallization ratio of flux film decreased, and the crystal incubation time was extended. Meanwhile, the mineralogical structure of the flux film changed, with a large amount of wollastonite precipitation and a significant decrease in the cuspidine content until it reached zero. This showed a steady decline in the heat transfer control capacity of the flux film. The reason for the results above is that, by increasing the quartz content, the silicon-oxygen tetrahedron network structure promoted a rise in viscosity and restrained ion migration, inhibiting crystal nucleation and growth, leading to the weakening of the crystallization and a decline in the crystallization ratio.

  7. Effects of pressure and temperature on the thermal properties of a salt and a quartz monzonite

    Energy Technology Data Exchange (ETDEWEB)

    Durham, W.B.; Abey, A.E.

    1981-03-27

    Measurements have been made of thermal conductivity, diffusivity, and linear expansion as a function of temperature (to 573 K) and hydrostatic pressure (to 50 MPa) on two rocks, Avery Island domal salt and Climax Stock quartz monzonite. For Avery Island salt the thermal properties do not show any pressure dependence and are approximately the same values as for single crystal halite at 0.1 MPa. The lack of pressure dependence is attributed to the high symmetry of halite (cubic) and to its low strength, both of which inhibit brittle fracturing. For Climax Stock quartz monzonite no pressure dependence of thermal diffusivity has been resolved, but conductivity does show a drop of approximately 10% with decreasing pressure from 50 to 3 MPa. The pressure dependence is not measurably altered by heating the rock to as high as 473 K under 50 MPa. Our measurements so far on the thermal conductivity of quartz monzonite vs temperature and pressure are in agreement with predictions of the Walsh and Decker (1966) model of thermal conductivity vs crack porosity based on independent measurements of crack porosity vs temperature and pressure for the same quartz monzonite. Heating to temperatures greater than 473 K at 50 MPa, or heating to lower temperatures at lower pressures, should substantially reduce thermal conductivity of the quart monzonite.

  8. Criterios de cuantificación indemnizatoria en accidentalidad vial: una ítica judicial

    Directory of Open Access Journals (Sweden)

    Marcela Pantoja Echeverri

    2010-12-01

    Full Text Available La accidentalidad vial, es la segunda causa de muerte violenta en Colombia, fuente de daños materiales y morales en las personas. Las normas de responsabilidad civil obligan al propietario o conductor a responder civil y penalmente por sus consecuencias. El problema de accidentalidad y de la cuantificación de indemnizaciones, reviste gran interés por el alto número de procesos que por homicidios en accidentes de tránsito cursan en el Distrito Judicial de Cali. En la investigación realizada en la Escuela de Ingeniería Estadística de la Universidad del Valle, se efectuó recolección de expedientes y se aplicó una encuesta de tipo cuestionario para indagar sobre la política judicial que se usó en el cálculo de indemnizaciones en Juzgados Penales del Circuito de Cali, donde se observa gran disparidad en los criterios de reparación. Tampoco se contempla un modelo estándar para cuantificar los perjuicios tanto materiales como morales y no hay evidencia de una política baremada; por tanto, el estudio intenta brindar un marco de referencia para proponer a Jueces y Fiscales, un modelo de regresión múltiple en el cual se consideran características socioeconómicas de víctimas, perjudicados y procesados, con el fin de unificar criterios de cuantificación que fijen el monto de la reparación económica a los perjudicados, sus herederos. El modelo resultante propone criterios utilizados por las compañías de seguros para fijar las primas de seguro de vida, tales como: el tiempo de vida y el nivel de ingresos del occiso, y responsabilidades con su grupo familiar.

  9. Comparison of tau-fluvalinate, acrinathrin, and amitraz effects on susceptible and resistant populations of Varroa destructor in a vial test.

    Science.gov (United States)

    Kamler, Martin; Nesvorna, Marta; Stara, Jitka; Erban, Tomas; Hubert, Jan

    2016-05-01

    The parasitic mite Varroa destructor is a major pest of the western honeybee, Apis mellifera. The development of acaricide resistance in Varroa populations is a global issue. Discriminating concentrations of acaricides are widely used to detect pest resistance. Two methods, using either glass vials or paraffin capsules, are used to screen for Varroa resistance to various acaricides. We found the glass vial method to be useless for testing Varroa resistance to acaridices, so we developed a polypropylene vial bioassay. This method was tested on tau-fluvalinate-, acrinathrin-, and amitraz-resistant mite populations from three apiaries in Czechia. Acetone was used as a control and technical grade acaricide compounds diluted in acetone were applied to the polypropylene vials. The solutions were spread on the vial surface by rolling the vial, and were then evaporated. Freshly collected Varroa females were placed in the vials and the mortality of the exposed mites was measured after 24 h. The Varroa populations differed in mortality between the apiaries and the tested compounds. Mites from the Kyvalka site were resistant to acrinathrin, tau-fluvalinate, and amitraz, while mites from the Postrizin site were susceptible to all three acaricides. In Prelovice apiary, the mites were susceptible to acrinathrin and amitraz, but not to tau-fluvalinate. The calculated discriminating concentrations for tau-fluvalinate, acrinathrin, and amitraz were 0.66, 0.26 and 0.19 µg/mL, respectively. These results indicate that polyproplyne vial tests can be used to determine discriminating concentrations for the early detection of acaricide resistant Varroa. Finally, multiple-resistance in Kyvalka may indicate metabolic resistance.

  10. Development of a magnetic quartz crystal microbalance

    International Nuclear Information System (INIS)

    Yu, George Y.; Hunt, William D.; Josowicz, Mira; Janata, Jiri

    2007-01-01

    A new technique for measurement of magnetic properties of materials is demonstrated. It can be used for the measurement of thin magnetic films during their chemical modification. The resonance frequency of a quartz crystal microbalance (QCM) with conducting polymer (polyaniline) suspension in poly(ethylene glycol) was observed to increase with increasing the externally applied uniform dc magnetic field. Slowly sweeping the magnetic field between 0 and 3.1 T results in a frequency-field response curve. Chemical doping was done by exposing the polyaniline-emeraldine base film to HCl vapor. The change in population of free spins is reflected in increased frequency-field curve magnitude after HCl doping. Two working hypotheses explaining this observation are offered to explain how frequency of QCM with deposited magnetic film shifts with increasing intensity of the magnetic field

  11. Mechanism of thermoluminescence in Vietnam natural quartz

    International Nuclear Information System (INIS)

    Tran Ngoc; Nguyen Manh Son; Phan Tien Dung; Trinh The Cuong; Nguyen Trong Thanh; Vu Xuan Quang

    2006-01-01

    Thermoluminescence properties of the Vietnam's natural quartz showed a number of peaks in the glow curve at 100 o C and 325 o C. the TL emission spectrum mainly consisted of three broad emission bands located at around 380 nm (3.26 eV), 470 nm (2.64 eV) and 610 nm (2.03 eV). These peaks were attributed to the [H 3 O 4 ] 0 hole centres, [AlO 4 ] 0 centres and E ' centres (oxygen vacancy), respectively. The main effect of blue light (450 nm) exposure was the appearance of the distinctive 110 o C TL peak and a reduction of the 325 o C TL peak. The observed relationship between TL intensity and illumination wavelength was consistent with those reported in the work of Botter-Jensen et al. (1994b) who suggested a linear relationship between logarithm of intensity and the photon energy. (author)

  12. Quartz enhanced photoacoustic spectroscopy based trace gas sensors using different quartz tuning forks.

    Science.gov (United States)

    Ma, Yufei; Yu, Guang; Zhang, Jingbo; Yu, Xin; Sun, Rui; Tittel, Frank K

    2015-03-27

    A sensitive trace gas sensor platform based on quartz-enhanced photoacoustic spectroscopy (QEPAS) is reported. A 1.395 μm continuous wave (CW), distributed feedback pigtailed diode laser was used as the excitation source and H2O was selected as the target analyte. Two kinds of quartz tuning forks (QTFs) with a resonant frequency (f0) of 30.72 kHz and 38 kHz were employed for the first time as an acoustic wave transducer, respectively for QEPAS instead of a standard QTF with a f0 of 32.768 kHz. The QEPAS sensor performance using the three different QTFs was experimentally investigated and theoretically analyzed. A minimum detection limit of 5.9 ppmv and 4.3 ppmv was achieved for f0 of 32.768 kHz and 30.72 kHz, respectively.

  13. Quartz exposure in agriculture: literature review and South African survey.

    NARCIS (Netherlands)

    Swanepoel, A.J.; Rees, D.; Renton, K.; Swanepoel, C.; Kromhout, H.; Gardiner, K.

    2010-01-01

    OBJECTIVES: To review the published literature on respirable quartz exposure and associated disease in agricultural related settings systematically and to describe personal respirable dust and quartz measurements collected on a sandy soil farm in the Free State province of South Africa. METHODS: The

  14. Recent developments of OSL techniques for dating quartz and feldspars

    DEFF Research Database (Denmark)

    Bøtter-Jensen, L.; Jungner, H.; Mejdahl, V.

    1993-01-01

    The construction of a unit for measuring optically stimulated luminescence from quartz and feldspar is described. The light sources used for stimulation are infrared diodes for feldspar and green light from a halogen lamp (obtained with a system of filters) for both quartz and feldspar. The unit...... in feldspar....

  15. Refractometry characteristics of α-quartz after neutron irradiation

    International Nuclear Information System (INIS)

    Abdkadyrova, I.Kh.

    1997-01-01

    Lattice structure distortions in irradiated crystalline quartz were studied by refractometry methods. The refractometry constants of α-quartz for the flux of fast neutrons 10 18 - 10 21 neutron/cm 2 were calculated. The critical kinetics of this constants at the phase transformation is observed.(author). 5 refs., 1 fig

  16. Luminescence sensitivity changes in quartz as a result of annealing

    DEFF Research Database (Denmark)

    Bøtter-Jensen, L.; Agersnap Larsen, N.; Mejdahl, V.

    1995-01-01

    Retrospective dosimetry using optically stimulated luminescence (OSL) on quartz extracted from (for example) bricks needs to account for strong OSL sensitivity changes that are known to occur depending on the previous thermal treatment of the sample. Non-heated quartz exhibits OSL orders of magni...

  17. Removal of Ozone by Carbon Nanotubes/Quartz Fiber Film.

    Science.gov (United States)

    Yang, Shen; Nie, Jingqi; Wei, Fei; Yang, Xudong

    2016-09-06

    Ozone is recognized as a harmful gaseous pollutant, which can lead to severe human health problems. In this study, carbon nanotubes (CNTs) were tested as a new approach for ozone removal. The CNTs/quartz fiber film was fabricated through growth of CNTs upon pure quartz fiber using chemical vapor deposition method. Ozone conversion efficiency of the CNTs/quartz fiber film was tested for 10 h and compared with that of quartz film, activated carbon (AC), and a potassium iodide (KI) solution under the same conditions. The pressure resistance of these materials under different airflow rates was also measured. The results showed that the CNTs/quartz fiber film had better ozone conversion efficiency but also higher pressure resistance than AC and the KI solution of the same weight. The ozone removal performance of the CNTs/quartz fiber film was comparable with AC at 20 times more weight. The CNTs played a dominant role in ozone removal by the CNTs/quartz fiber film. Its high ozone conversion efficiency, lightweight and free-standing properties make the CNTs/quartz fiber film applicable to ozone removal. Further investigation should be focused on reducing pressure resistance and studying the CNT mechanism for removing ozone.

  18. A nanocell for quartz crystal microbalance and quartz crystal microbalance with dissipation-monitoring sensing

    Science.gov (United States)

    Ohlsson, Gabriel; Langhammer, Christoph; Zorić, Igor; Kasemo, Bengt

    2009-08-01

    A novel device for nanometer-confinement of soft matter in one dimension (1D) is presented. This nanocell, with very large (up to 106:1) cell-radius to cell-height ratio, is tailored as an accessory for quartz crystal microbalance (QCM) and QCM with dissipation-monitoring (QCM-D) sensing to study internal and interfacial energy dissipation phenomena in highly confined (in 1D) soft matter and fluid films (patent pending). The cell consists of two macroscopic plates (diameter of 9 mm), a top (the "lid") and a bottom (the QCM-D sensor), separated by appropriate spacers with heights ranging from below 100 nm up to 10 μm. The surfaces of both the lid and the bottom plate can be mechanically or/and chemically modified, prior to cell assembly, in order to tailor desired interfacial properties for the experiment. The cell is mounted on a standard QCM-D sensor, an AT-cut quartz crystal (the quartz crystal is cut at an angle of 35° from its ZX-plane), forming the bottom plate. We illustrate theoretically and experimentally, as application examples, the use of this device for studies of dynamic mass loading and internal energy dissipation processes in thin films of ethylene glycol respective thin liquid crystal films around the nematic-isotropic phase transition.

  19. Activation analysis of high pure quartz used as packing materials

    International Nuclear Information System (INIS)

    Luknitskij, V.A.; Morozov, B.A.

    1979-01-01

    A γ-spectrometric technique of neutron activation determination of microelements in quartz tubes used as a packing material for irradiation in reactors is reported. The analysis of 29 micro-admixtures in quartz tubes of USSR brands ''spectrtosil'' and ''KV'' was carried out. The γ-spectra of ''KV'' quartz irradiated by thermal and epithermal neutrons are presented. The activation by epithermal neutrons provides an activity gain for the nuclei whose resonance integral is high enough as compared to the activation cross-section with regard to thermal neutrons. The activation by epithermal neutrons permits additional determination of W, Cd, V, Th, Mn and Ni and provides for a substantial decrease in the activity of 24 Na, 42 K, 140 La, 46 Sc, 141 Ce, 51 Cr, and 59 Fe, which hinder the determination of the above-mentioned elements. The microelement composition of Soviet-made quartz varieties is compared to that of foreign-made quartz brands

  20. Aspects of pre-dose and other luminescence phenomena in quartz absorbed dose estimation

    International Nuclear Information System (INIS)

    Adamiec, G.

    2000-01-01

    The understanding of all luminescence processes occurring in quartz is of paramount importance in the further development of robust absorbed dose estimation techniques (for the purpose of dating and retrospective dosimetry). The findings presented in this thesis, aid future improvements of absorbed dose estimation techniques using quartz by presenting investigations in the following areas: 1) interpretation of measurement results, 2) numerical modelling of luminescence in quartz, 3) phenomena needing inclusion in future physical models of luminescence. In the first part, the variability of properties of single quartz grains is examined. Through empirical and theoretical considerations, investigations are made of various problems of measurements of luminescence using multi-grain aliquots, and specifically areas where the heterogeneity of the sample at the inter-grain level may be misinterpreted at the multi-grain-aliquot level. The results obtained suggest that the heterogeneity of samples is often overlooked, and that such differences can have a profound influence on the interpretation of measurement results. Discussed are the shape of TL glow curves, OSL decay curves, dose response curves (including consequences for using certain signals as proxies for others), normalisation procedures and D E estimation techniques. Further, a numerical model of luminescence is proposed, which includes multiple R-centres and is used to describe the pre-dose sensitisation in quartz. The numerical model exhibits a broad-scale behaviour observed experimentally in a sample of annealed quartz. The shapes of TAC for lower (20 Gy) and higher doses (1 kGy) and the evolution with temperature of the isothermal sensitisation curves are qualitatively matched for the empirical and numerical systems. In the third area, a preliminary investigation of the properties of the '110 deg. C peak' in the 550 nm emission band, in annealed quartz is presented. These properties are in sharp contrast with

  1. Vaccine vial monitor availability and use in low- and middle-income countries: A systematic review.

    Science.gov (United States)

    Eriksson, Pär; Gessner, Bradford D; Jaillard, Philippe; Morgan, Christopher; Le Gargasson, Jean Bernard

    2017-04-19

    The vaccine vial monitor (VVM) registers cumulative heat exposure on vaccines over time. As low- and lower-middle-income countries transition beyond support from the Global Alliance for Vaccines and Immunization (Gavi), they will assume full responsibility for vaccine financing and procurement. It is unclear to what extent countries transitioning out of Gavi support will continue to include VVMs on their vaccines. This paper aims to systematically review evidence on VVM availability and use in low- and middle-income countries to document factors behind global access to and country demand for VVMs. Such results could help identify actions needed to ensure continued use of VVMs in countries that transition out of Gavi support. We performed a systematic review of electronic databases, reference lists, and grey literature in English and French languages with publication dates from 2005 onwards. The studies included were analyzed for the following outcomes: (1) availability and deployment of VVM-labeled vaccines; (2) VVM practices and perceptions in the immunization system; (3) vaccine introduction and decision-making processes; (4) Gavi graduation and vaccine program sustainability. The study found that VVM availability and use was affected by multiple sourcing of vaccines and the extent to which VVM was included in the vaccine specification in the tendering documents when procuring vaccines. Knowledge about VVM and its impact on the EPI program was found to be high among health workers as well as decision-makers. However, the study also found that weak capacity in key national institutions such as NRA and NPA might impact on demand for VVM. As countries take decisions regarding the adoption of new vaccines, factors such as disease burden and vaccine price may assume greater importance than vaccine characteristics and presentation. Finally, the study found that countries rely largely on the advice and recommendations from technical partners such as WHO and PAHO. The

  2. Determination of moisture content in lyophilized mannitol through intact glass vials using NIR micro-spectrometers

    Directory of Open Access Journals (Sweden)

    Cristian Rodrigo Muzzio

    2011-06-01

    Full Text Available Determination of moisture content in lyophilized solids is fundamental to predict quality and stability of freeze-dried products, but conventional methods are time-consuming, invasive and destructive. The aim of this study was to develop and optimize a fast, inexpensive, noninvasive and nondestructive method for determination of moisture content in lyophilized mannitol, based on an NIR micro-spectrometer instead of a conventional NIR spectrometer. Measurements of lyophilized mannitol were performed through the bottom of rotating glass vials by means of a reflectance probe. The root mean standard error of prediction (RMSEP and the correlation coefficient (R²pred, yielded by the pre-treatments and calibration method proposed, was 0.233% (w/w and 0.994, respectively.A determinação do conteúdo de umidade em sólidos liofilizados é fundamental para se prever a qualidade e a estabilidade de produtos liofilizados, mas os métodos convencionais consomem muito tempo, são invasivos e destrutivos. O objetivo desse estudo foi desenvolver e otimizar um método rápido, econômico, não invasivo e não destrutivo para a determinação do conteúdo de umidade em manitol liofilizado, com base em microespectrômetro de infravermelho próximo ao invés de um espectrômetro de infravermelho próximo convencional. As medidas de manitol liofilizado foram realizadas através do fundo de recipiente de vidro em rotação por meio de sonda de reflectância. A raíz do erro médio padrão de predição (RMSEP e o coeficiente de correlação (R²pred obtidos pelo prétratamento e pelo método de calibração proposto foram, respectivamente, 0,233% (p/p e 0,994.

  3. EXTRA PURE QUARTZ OF THE UFALEYSKY QUARTZIFEROUS DISTRICT (SOUTHERN URALS

    Directory of Open Access Journals (Sweden)

    V. N. Ogorodnikov

    2018-03-01

    Full Text Available The urgency of the problem is conditioned by the necessity for a considerable specification of the notion “extra pure quartz” which is used to mean a sort of mineral raw materials. The purpose of the work: to study in detail the genesis of the ufaley and yegustin types, which are of great interest as a raw material for obtaining quartz concentrates of a high quality. This should be taken into account while developing the rational systems of working the quartz objects through and the application of the concentration schemes. Methodology of the research: the detailed study of geochemical, geological and age-specific parameters of the quartz bodies, which are composed with the vein quartz of ufaley type, yegustin type and other types as well. Results. The quartz-vein formations of the Ufaley quartz-bearing region are the result of long and complex processes of the Ufaley gneissamphibolite complex formation. Multistage formation of complexes causes the combination of different types of quartz veins, which belong to different age families, in the same zone. We have identified quartz-vein formation of the following genetic types: metamorphic differentiation, slyudyanogorsky, ufaley, yegustinsky, kyshtym, pugachevsky and shcherbakovsky. The quartz-vein formations, which are made up of fine-grained metasomatic vein quartz of the Ufaley type with the superimposed yegustinsky type are confined to the Slyudyanogorskaya-Teplogorskaya suture zone. Their metasomatic genesis is associated with albitites, rare-earth carbonatites and nelsonite of the Precambrian age. Summary. For the vein quartz of the ufaley and yegustinsky types, it is impossible to apply the term “granular quartz”. The quartz of the kyshtym type can be called such since the mechanism of the granules formation is initially metasomatic with the subsequent metamorphic and metasomatic transformation. High-pressure and high-temperature conditions of formation of quartz have led to a high

  4. El presupuesto por resultados y la gestión de la infraestructura vial de Provias Nacional 2015

    OpenAIRE

    Gallardo de la Cruz, Julio Manuel

    2016-01-01

    El objetivo de la investigación fue determinar la relación que existe entre el presupuesto por resultados y la gestión de la infraestructura vial de Provias Nacional 201 5. Metodológicamente, la investigación fue de tipo básica, de nivel correlacional de diseño descriptivo-correlacional, pues se describió la relación entre variables. La muestra fue de 38 trabajadores de Provias Nacional durante el 201 5. Para la recolección de datos se utilizó la técnica de la encuesta, cuyo in...

  5. Comparative analysis of ampoules and vials in sterile and conventional packaging as to microbial load and sterility test.

    Science.gov (United States)

    Freitas, Raphael Ribeiro de Aquino; Tardelli, Maria Angela

    2016-05-24

    To compare sterility and microbial (bacteria and fungi) load in the outer part of hyperbaric bupivacaine (Neocaína®) in ampoule and bupivacaine in vial, in conventional and sterile pack formulations. The sterile packs were divided into two groups: G1 (n=16) with ampoules and G2 (n=16) with vials. Conventional formulations were divided into two groups, being G3 (n=16) with ampoules and G4 (n=16) with vials. The ampoules and vials were opened and had their content drawn. The empty bottles were then placed in sterile plastic bags and sent for analysis of microbial load (bacteria and fungi) and sterility testing. Data were analyzed using the χ2 test with Yates correction, and 95% confidence interval. G1 and G2 showed no bacterial growth when compared to conventional groups (pcontamination of the anesthetic solution. Comparar a esterilidade e a carga microbiana (bactérias e fungos) da parte externa dos frascos de envasamento de bupivacaína hiperbárica (Neocaína®) em ampola e bupivacaína em frasco-ampola das apresentações convencional e estéril (sterile pack). As apresentações estéreis (sterile pack) foram distribuídas em dois grupos, sendo que o G1 (n=16) continha as ampolas e o G2 (n=16), os frascos-ampola. As apresentações convencionais foram distribuídas em dois grupos, a saber G3 (n=16) com as ampolas e G4 (n=16) com os frascos-ampola. As ampolas e os frascos-ampolas eram abertos e tinham seu conteúdo aspirado. Os frascos vazios eram, então, acondicionados em sacos plásticos estéreis e enviados para análise quanto à carga microbiana (bactérias e fungos), bem como para o teste de esterilidade. Os dados foram analisados por meio do teste χ2 com correção Yates com intervalo de confiança de 95%. Os grupos G1 e G2 não apresentaram crescimento bacteriano quando comparado aos grupos convencionais (p<0,001). O microbiano mais comum nas amostras convencionais foi o Staphylococcus aureus. Não houve crescimento de fungos em nenhum dos grupos. O

  6. Optimización de la oferta vial para el transporte privado de la ciudad de Azogues

    OpenAIRE

    Cabrera Vélez, Sonia Lucía

    2017-01-01

    La optimización de la oferta vial para el transporte privado en la ciudad de Azogues, se obtiene a través de la implementación de los Sistemas Inteligentes de Transporte, que son un conjunto de soluciones diseñadas para mejorar la operación y seguridad del transporte. Enmarcados en este concepto, dentro de la Ciudad de Azogues, se estudió este tema debido al crecimiento de la flota vehicular, en gran parte, producto del aumento económico de los ingresos familiares por el fenómeno migratorio, ...

  7. Charge movement in grains of quartz studied using exo-electron emission

    International Nuclear Information System (INIS)

    Ankjaergaard, C.; Denby, P.M.; Murray, A.S.; Jain, M.

    2008-01-01

    A flow-through Geiger-Mueller pancake electron detector attachment has been fitted to the Riso TL/OSL reader, enabling optically stimulated electrons (OSE) to be measured simultaneously with optically stimulated luminescence (OSL). This detector has been used to provide new insights into charge movement in luminescence phosphors. Here we show that OSE from natural quartz grains gives an easily detectable, reproducible and light sensitive signal, although it is not as intense as OSL. A single sample of natural quartz grains extracted from a sediment is used to investigate the thermal stability and dependence on stimulation temperature of the OSE and OSL signals. The response to dose of these signals is also investigated, and conclusions drawn on the movement of electrons in this natural phosphor

  8. Interlaboratory beta source calibration using TL and OSL on natural quartz

    DEFF Research Database (Denmark)

    Goksu. H.Y.; Bailiff, I.K.; Bøtter-Jensen, L.

    1995-01-01

    Laboratories using luminescence methods for dose reconstruction have to make interlaboratory source calibrations-initially this will be a single isotope beta or gamma source using one particular reference material. The procedure requires not only the administration of exact doses to the material...... difficulties finding sufficient suitable quartz. Five different batches were obtained from the Merck company and tested for sensitivity, linearity and stability of the 340 degrees C peak, the 1992 batch was found to be the most appropriate. The irradiations were performed at the Secondary Standard Dosimetry...... Laboratory at GSF using a Go-60 source as well as the in situ measurements with an ionization chamber, calibrated to the primary standards of PTB Braunschweig. Irradiated and unirradiated quartz was distributed to the five laboratories and although different procedures were used for thermoluminescence...

  9. On the importance of grain size in luminescence dating using quartz

    DEFF Research Database (Denmark)

    Timar-Gabor, A.; Buylaert, Jan-Pieter; Guralnik, B.

    2017-01-01

    -grain (63-90 μm) quartz single aliquot regeneration protocol (SAR) ages has been reported previously for Romanian and Serbian loess >40 ka (De of ∼100 Gy), generally with fine-grain ages underestimating the depositional age. In this paper, we show a similar age pattern for two grain size fractions from...... the dose response curves of quartz from different sedimentary contexts around the world, using a range of grain sizes (diameters of 4-11 μm, 11-30 μm, 35-50 μm, 63-90μm, 90-125μm, 125-180 μm, and 180-250 μm). All dose response curves can be adequately described by a sum of two saturating exponential...

  10. Identification of color development potential of quartz by Raman spectroscopy

    International Nuclear Information System (INIS)

    Alkmim, Danielle G.; Lameiras, Fernando S.; Almeida, Frederico O.T.

    2013-01-01

    Colorless quartz is usually exposed to ionizing radiation (gamma rays or high energy electron beams) to acquire different colors for jewelry. Color development is due to the presence of traces of some elements such as aluminum, iron, hydrogen, lithium, or sodium. Most quartz crystals are extracted colorless from nature and it is necessary to separate those that can develop colors from those that cannot. Irradiation tests can be used to accomplish this separation, but they take a long time. Infrared signature of colorless quartz can also be used. However, infrared spectroscopy is quite expensive, especially when using portable devices. Raman spectroscopy is now available as an inexpensive and portable technique that could provide identification of the samples of colorless quartz still in the field, facilitating the prediction for their economic exploitation. In addition, Raman spectroscopy usually requires a minimum or no sample preparation. This paper presents an investigation of the feasibility of using Raman spectroscopy as a substitute for infrared spectroscopy to predict the potential for color development of quartz. A band at 3595 cm -1 in the Raman shift spectrum was observed only along the c axis of a prasiolite excited by a high power 514 nm laser. This band was not observed in quartz samples that do not develop color after irradiation. Further studies are required to identify the potential for color development by Raman spectroscopy of other types of colorless quartz. (author)

  11. Gamma irradiation of quartz from Pannier basin, South America

    International Nuclear Information System (INIS)

    Enokihara, Cyro T.; Rela, Paulo R.; Guttler, Rainer A.S.

    2007-01-01

    The use of gamma radiation to induce or enhance color centers in gemstones is a widespread technique and applied worldwide on a industrial scale since at least 1970. The presence of defects and defect structures in quartz from a border region of southern Brazil and Uruguay are the reason for the creation of a new color variety of quartz called 'Prasiolite' in the gem trade. This quartz has a pleasant green color produced by gamma irradiation. The procedures of irradiation at IPEN show that the activation of these color producing defects can be monitored by detailed chemical and spectroscopic analysis. For the first time UV-VIS-NIR spectra of this new color variety of quartz are shown. They revealed special features of these quartz crystals coming from basaltic terranes of the Parana Basin. Contrary to most specimen of quartz from other parts of Brazil, they have such a high water and OH content that they resemble more chalcedony or opal, but not highly crystalline quartz specimens. The cause of the color are broken bonds of Si-OH defining the so-called dangling bonds. (author)

  12. Gamma irradiation of quartz from Pannier basin, South America

    Energy Technology Data Exchange (ETDEWEB)

    Enokihara, Cyro T.; Rela, Paulo R. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)], E-mail: cteiti@ipen.br, E-mail: prela@ipen.br; Guttler, Rainer A.S. [Universidade de Sao Paulo (USP), SP (Brazil). Inst. de Geociencias

    2007-07-01

    The use of gamma radiation to induce or enhance color centers in gemstones is a widespread technique and applied worldwide on a industrial scale since at least 1970. The presence of defects and defect structures in quartz from a border region of southern Brazil and Uruguay are the reason for the creation of a new color variety of quartz called 'Prasiolite' in the gem trade. This quartz has a pleasant green color produced by gamma irradiation. The procedures of irradiation at IPEN show that the activation of these color producing defects can be monitored by detailed chemical and spectroscopic analysis. For the first time UV-VIS-NIR spectra of this new color variety of quartz are shown. They revealed special features of these quartz crystals coming from basaltic terranes of the Parana Basin. Contrary to most specimen of quartz from other parts of Brazil, they have such a high water and OH content that they resemble more chalcedony or opal, but not highly crystalline quartz specimens. The cause of the color are broken bonds of Si-OH defining the so-called dangling bonds. (author)

  13. Fluid Inclusion Study of Quartz Xenocrysts in Mafic Dykes from Kawant Area, Chhota Udaipur District, Gujarat, India

    Directory of Open Access Journals (Sweden)

    Randive Kirtikumar

    2015-09-01

    Full Text Available Unusual mafic dykes occur in the proximity of the Ambadongar Carbonatite Complex, Lower Narmada Valley, Gujarat, India. The dykes contain dense population of quartz xenocrysts within the basaltic matrix metasomatised by carbonate-rich fluids. Plagioclase feldspars, relict pyroxenes, chlorite, barite, rutile, magnetite, Fe-Ti oxides and glass were identified in the basaltic matrix. Quartz xenocrysts occur in various shapes and sizes and form an intricate growth pattern with carbonates. The xenocrysts are fractured and contain several types of primary and secondary, single phase and two-phase fluid inclusions. The two-phase inclusions are dominated by aqueous liquid, whereas the monophase inclusions are composed of carbonic gas and the aqueous inclusions homogenize to liquid between 226°C and 361°C. Majority of the inclusions are secondary in origin and are therefore unrelated to the crystallization of quartz. Moreover, the inclusions have mixed carbonic-aqueous compositions that inhibit their direct correlation with the crustal or mantle fluids. The composition of dilute CO2-rich fluids observed in the quartz xenocrysts appear similar to those exsolved during the final stages of evolution of the Amba Dongar carbonatites. However, the carbonates are devoid of fluid inclusions and therefore their genetic relation with the quartz xenocrysts cannot be established.

  14. Progresses on the theory and application of quartz crystal microbalance

    Science.gov (United States)

    Qiao, Xiaoxi; Zhang, Xiangjun; Tian, Yu; Meng, Yonggang

    2016-09-01

    Quartz crystal microbalance (QCM) is a nondestructive technique in investigating the physical properties of solid-liquid interfacial layer in situ. It has the capability of quantifying the extremely tiny force change occurring on the interface by measuring the frequency shift Δ f and the energy dissipation change Δ D (or the half-bandwidth variation Δ Γ ). The quantitative analysis of QCM results greatly depends on the theoretical models, whose development could generally expand the comprehension of the properties at the interfaces and the application of QCM. In the paper, the progresses on the theory and applications of QCM are reviewed. The commonly used theoretical models for a single layer in the gas/liquid phase are essential for QCM in the fields of biosensor application, surface chemistry study, and interfacial rheology, such as the adsorption of proteins, the polymer and surfactants, and the viscoelastic properties of the interfacial liquid layer. The advanced models, incorporating the effects of boundary slip, surface roughness, microstructure, and micro/nanoscale confinement, are helpful for a better understanding and description of how these factors influence the various interfacial processes occurring on the solid-liquid interface, e.g., interfacial rheology and adsorption. The establishments of nanocell and the corresponding theoretical model make QCM a potential technique in studying the dynamic behavior of micro/nanoscale flow coupling with various surface effects by connecting a micro/nanofluidic channel to the nanocell.

  15. Anisotropic annealing of fission fragments in synthetic quartz

    CERN Document Server

    Sawamura, T; Narita, M

    1999-01-01

    A study on the thermal annealing behavior of fission fragments in synthetic quartz crystals was performed for application of synthetic quartz to track detectors under high temperature circumstances: x-, y-, and z-cut quartz plates were exposed to fission fragments from sup 2 sup 5 sup 2 Cf and were annealed up to 750 deg. C. It was found that track retention depended on the crystallographic structure: the annealing temperature, where the number of etched tracks was sharply reduced, was 550 deg. C for the x- and y-cut plates and 750 deg. C for z-cut plates. Track sizes decrease and disperse with reductions in the track retention.

  16. El impacto de las nuevas políticas de seguridad vial sobre la conducta de los conductores

    Directory of Open Access Journals (Sweden)

    Jordi Tena-Sánchez

    2013-04-01

    Full Text Available La evidencia empírica disponible señala de manera unánime que las nuevas políticas de tráfico y seguridad vial aplicadas en España desde 2004, y en particular la introducción del carné por puntos y la reforma del Código Penal, han tenido una fuerte incidencia positiva en la reducción de la siniestralidad. De dichos resultados se deriva que las nuevas políticas han tenido también un efecto positivo sobre la conducta de los conductores, de modo que ha sido esa mejora en la conducta al volante la que finalmente se ha traducido en una reducción de la siniestralidad. No obstante, hasta el momento, los investigadores han descuidado el análisis directo de los datos sobre cumplimiento. En el presente trabajo se analizan todos los datos disponibles que ofrecen información sobre el cumplimiento de la normativa de tráfico y seguridad vial.

  17. Hyperfine interactions of muonium in alpha-quartz

    International Nuclear Information System (INIS)

    Barsov, S.G.; Gordeev, V.A.; Baryshevsky, V.G.; Kuten, S.A.; Rapoport, V.I.

    1990-01-01

    We present the properties of muonium which are connected with the presence of the muonium quadrupole moment and discuss the results of experimental studies of the quadrupole interactions of muonium with the alpha-quartz lattice. (orig.)

  18. Petrographic and optical cathodoluminescence study of detrital quartz

    African Journals Online (AJOL)

    Basange Formation had been investigated using integrated optical Cathodoluminescence and Petrographic characteristics approach. Results showed the presence, in abundance, of detrital quartz with characteristic dull red to violet CL colour and ...

  19. Structure optimization and simulation analysis of the quartz micromachined gyroscope

    Directory of Open Access Journals (Sweden)

    Xuezhong Wu

    2014-02-01

    Full Text Available Structure optimization and simulation analysis of the quartz micromachined gyroscope are reported in this paper. The relationships between the structure parameters and the frequencies of work mode were analysed by finite element analysis. The structure parameters of the quartz micromachined gyroscope were optimized to reduce the difference between the frequencies of the drive mode and the sense mode. The simulation results were proved by testing the prototype gyroscope, which was fabricated by micro-electromechanical systems (MEMS technology. Therefore, the frequencies of the drive mode and the sense mode can match each other by the structure optimization and simulation analysis of the quartz micromachined gyroscope, which is helpful in the design of the high sensitivity quartz micromachined gyroscope.

  20. Subsolidus segregation of quartz in metamorphic differentiation of metasedimentary rocks

    Science.gov (United States)

    Artimenko, M. V.

    2017-08-01

    Thermodynamic modeling of the SiO2-TiO2-Al2O3-Fe2O3-MnO-MgO-CaO-Na2O-K2O-P2O5-H2O (STAFMMCNKPOH) system at 600°C, 5 kbar has been applied to investigate dissolution and re-precipitation of quartz. Comparing silica molality in the STAFMMCNKPOH and SiO2-H2O systems, there is seen to be no effect of mineral assemblage on quartz solubility. From quantitatively estimated water/rock ratio required to dissolve quartz completely, one can deduce that the segregation of quartz appears to be due to diffusive transport of silica in inner pore fluid rather than to advective transport (in fluid flow).

  1. The TL and age determination of the impacted quartz sandstone

    International Nuclear Information System (INIS)

    Liu Jingfa; Hu Suimin; Li Dahong

    1999-01-01

    When a quartz sandstone target was shocked by a steel ball (6 mm in diameter) accelerated to 7 km/s by using a two-stage light gas gun, the crystal structure and physical characteristics of the quartz was changed. By measuring the TL of the quartz sandstone before and after shocking it was found that the TL of the quartz sandstone decreased with the increasing shocking pressure and there was a TL gradient from outside to inside around the shocked point. The induced TL test was made for the sample taken from the shocked point at the same time, and an induced TL gradient from outside to inside was also found, though it was less than natural TL gradient. A sample with TL gradient is often valuable for meteoric crater determination

  2. Degradation of glycine and alanine on irradiated quartz.

    Science.gov (United States)

    Pawlikowski, Maciej; Benko, Aleksandra; Wróbel, Tomasz P

    2013-04-01

    Recent researches suggest participation of minerals in the formation of life under primordial conditions. Among all of the minerals, quartz seems to be one of the most probable to take part in such processes. However, an external source of energy is needed, e.g. electric discharge. A device simulating the proposed conditions was designed and was used to simulate prebiotic conditions. Investigation of processes occurring during the stimulation of quartz with electric discharge was studied by means of Ultraviolet-visible (UV-VIS) spectroscopy, in order to monitor the generation kinetics of free radicals. Additionally, infrared spectroscopy was applied to identify chemical reaction products created in a solution of alanine or glycine, in the presence of quartz treated with electric discharge. Formation of increased amounts of free radicals, compared to experiments performed without quartz and/or amino acid, is reported, along with identification of possible degradation products of alanine. No synthetic reactions were observed.

  3. Miniature Quartz Crystal Microbalance for Spacecraft and Missile Applications

    National Research Council Canada - National Science Library

    Uy, O

    1999-01-01

    Quartz crystal microbalances (QCMs) have been used for over 20 years as contamination monitors in spacecraft to measure film deposition on sensitive surfaces such as optical mirrors, thermal radiators, and solar arrays...

  4. Anisotropic viscoelastic properties of quartz and quartzite in the vicinity of the α- β phase transition

    Science.gov (United States)

    Klumbach, Steffen; Schilling, Frank R.

    2017-10-01

    In this study we performed high-temperature, dynamic (i.e. sinusoidal), three-point bending experiments of quartz single crystals and quartzite samples within the frequency range of seismic surveys (i.e. 0.1-20 Hz). At constant temperature close to the α- β phase transition we observed a unique complex elastic behaviour of both quartz and quartzite. We find a frequency dependence of the complex Young's modulus of α-quartz, including a dissipation maximum at ≈1 Hz supposedly related to the formation and variation of Dauphiné twin domains. Based on our experimental results for different crystallographic directions and additional modelling, we are able to describe the complex Young's modulus of quartz at its α- β phase transition in a 3D diagram. We derive a frequency-dependent elasticity tensor, using a three-element equivalent circuit, composed of two springs E 1 and E 2 as well as a dashpot η. E 1 and η are connected parallel to each other, E 2 is added in series. Compliance coefficients yield ( S 11) E 1 = 572 GPa, E 2 = 70.0 GPa, η = 64.6 GPa·s, ( S 33) E 1 = 127 GPa, E 2 = 52.1 GPa, η = 22.9 GPa·s, ( S 44) E 1 = 204 GPa, E 2 = 37.5 GPa, η = 26.4 GPa·s, ( S 12) E 1 = 612 GPa, E 2 = 106.7 GPa, η = 78.5 GPa·s, ( S 13) E 1 = 1546 GPa, E 2 = 284 GPa, η = 200 GPa·s; S 14 ≈-0.0024 GPa-1. We use the derived direction-dependent coefficients to predict the frequency-dependent complex elastic properties of isotropic polycrystalline quartz. These predictions agree well with the experimental results of the investigated quartzite. Finally, we explore the potential of using the anomalous frequency-dependent complex elastic properties of quartz at the α- β phase transition that we observed as an in situ temperature probe for seismic studies of the Earth's continental crust.

  5. Deposits of gold-quartz formation in the Priamur province

    Directory of Open Access Journals (Sweden)

    В. А. Степанов

    2017-03-01

    Small deposits of near-bottom ore pipe are quite rare. Ore bodies are represented by quartz veins and zones of metasomatites. Gold is mostly free, of fine and super fine grain size. The prevailing trace element is mercury. Attribution of gold-quartz deposits to a certain part of ore pipe can facilitate more precise estimation of their prospects. In its own turn, this will allow to choose more favorable objects for further evaluation.

  6. The association between use of mealtime insulin pens versus vials and healthcare charges and resource utilization in patients with type 2 diabetes: a retrospective cohort study.

    Science.gov (United States)

    Eby, Elizabeth L; Boye, Kristina S; Lage, Maureen J

    2013-10-01

    To compare all-cause and diabetes-related resource utilization and healthcare charges among adults with type 2 diabetes mellitus who initiated therapy with mealtime insulin disposable pens or vials. Data were obtained from the Innovus inVision database from January 1, 2006 through June 30, 2010. Generalized linear models with a gamma distribution and log link estimated the association between medical charges and use of mealtime insulin pens vs vials in the 1 year post-index date, while generalized linear models with a negative binomial distribution estimated resource utilization. Controlling for patient characteristics, general health, and patient copayments, insulin therapy initiation with disposable pens, compared to vials, was associated with significantly fewer all-cause hospitalizations (1.45 vs. 1.66; p charges ($3593 vs. $2755; p charges ($42,150 vs. $53,340; p charges ($12,722 vs. $14,540; p charges.

  7. Use of a vial equilibration technique to measure the change in fugacity capacity of avian food and feces samples for 1,2,3,4-tetrachlorobenzene.

    Science.gov (United States)

    Drouillard, Ken G; Norstrom, R J

    2014-11-01

    A vial equilibration technique was used to estimate the fugacity capacities of food and feces samples for 1,2,3,4-tetrachlorobenzene (TCB). The method was calibrated using different volumes of n-octanol and by comparing the measured and predicted fugacity capacity (Zoct) of n-octanol for TCB. The vial equilibration technique showed linearity with increasing amounts of n-octanol added to the vial. However, the measured Zoct was on average 8.5 times lower than the literature estimate and interpreted to be influenced by co-solvent effects. The ratio of fugacity capacities of food/feces was 2.9 and was consistent with the ratio estimated using Zt calculation methods (4.3) which considers partitioning capacity of both lipids and non-lipid organic matter. These results provide experimental support to the use of lipid equivalent approaches as opposed to lipid normalization when estimating the partition capacity of biological samples containing low lipid contents.

  8. Basic characteristics of quartz crystal sensor with interdigitated electrodes

    Directory of Open Access Journals (Sweden)

    Hiroshi Muramatsu

    2016-03-01

    Full Text Available This paper describes basic characteristics of the quartz crystal sensor with interdigitated electrodes (IDE quartz crystal sensor which is for simultaneous monitoring of mass, viscosity, conductivity and dielectric changes of liquids or thin films. As the IDE quartz crystal sensor has three terminals for a pair of IDEs on the one side and a counter electrode on the other side, the resonance properties have been analyzed using the electrical equivalent circuit models and measured experimentally for all connecting types of electrode pairs. The IDE quartz crystal has shown clear resonance curves for calculating the resonance frequency and resonance resistance values as well as normal quartz crystal in the air and in contact with liquid. Small shifts in the resonance frequency and resonance resistance depending on the connecting types have been obtained and analyzed using the equivalent circuit models. We have found the integrated quartz crystal and IDE sensors could be monitored simultaneously by only one impedance analyzer. Finally, two types of measuring systems have been demonstrated for continuous measuring methods.

  9. Interaction Between Graphene Oxide Nanoparticles and Quartz Sand.

    Science.gov (United States)

    Sotirelis, Nikolaos P; Chrysikopoulos, Constantinos V

    2015-11-17

    In this study, the influence of pH, ionic strength (IS), and temperature on graphene oxide (GO) nanoparticles attachment onto quartz sand were investigated. Batch experiments were conducted at three controlled temperatures (4, 12, and 25 °C) in solutions with different pH values (pH 4, 7, and 10), and ionic strengths (IS = 1.4, 6.4, and 21.4 mM), under static and dynamic conditions. The surface properties of GO nanoparticles and quartz sand were evaluated by electrophoretic mobility measurements. Derjaguin-Landau-Verwey-Overbeek (DLVO) potential energy profiles were constructed for the experimental conditions, using measured zeta potentials. The experimental results showed that GO nanoparticles were very stable under the experimental conditions. Both temperature and pH did not play a significant role in the attachment of GO nanoparticles onto quartz sand. In contrast, IS was shown to influence attachment. The attachment of GO particles onto quartz sand increased significantly with increasing IS. The experimental data were fitted nicely with a Freundlich isotherm, and the attachment kinetics were satisfactorily described with a pseudo-second-order model, which implies that the quartz sand exhibited substantial surface heterogeneity and that GO retention was governed by chemisorption. Furthermore, thermodynamic analysis revealed that the attachment process was nonspontaneous and endothermic, which may be associated with structural changes of the sand surfaces due to chemisorption. Therefore, secondary minimum interaction may not be the dominant mechanism for GO attachment onto the quartz sand under the experimental conditions.

  10. Trace element characterisation and purification of quartz powder of Indian origin

    International Nuclear Information System (INIS)

    Dash, K.; Thangavel, S.; Dhavile, S.M.; Sahayam, A.C.; Chaurasia, S.C.

    2002-11-01

    Analytical methodologies for the trace element characterisation and purification of quartz powder of Indian origin have been described. Metallic impurities (11 elements) in ∼700 quartz samples have been analysed using different instrumental techniques. The values are cross-validated by American and British analytical laboratories. A special multi channel vapour phase digestion (MCVPD) chamber has been designed to reduce the process blank levels for the determination of ultra trace impurities in high purity silicon matrix. In this vessel 21 samples can be digested at a time in a period of 8 hrs. at normal pressure and low temperature (∼ 80 degC). Analytical methodologies for the determination of non-metals (phosphorus, boron and chloride) at very low levels <1 ppm) have also been described. A highly cost effective, single step, room temperature purification procedure is developed based on chemical leaching. Around 300 raw quartz powders (3-4N) from various mines have been purified to 5N pure ( optical grade ). (author)

  11. Flux-Grown Piezoelectric Materials: Application to α-Quartz Analogues

    Directory of Open Access Journals (Sweden)

    Pascale Armand

    2014-06-01

    Full Text Available Using the slow-cooling method in selected MoO3-based fluxes, single-crystals of GeO2 and GaPO4 materials with an α-quartz-like structure were grown at high temperatures (T ≥ 950 °C. These piezoelectric materials were obtained in millimeter-size as well-faceted, visually colorless and transparent crystals. Compared to crystals grown by hydrothermal methods, infrared and Raman measurements revealed flux-grown samples without significant hydroxyl group contamination and thermal analyses demonstrated a total reversibility of the α-quartz ↔ β-cristobalite phase transition for GaPO4 and an absence of phase transition before melting for α-GeO2. The elastic constants CIJ (with I, J indices from 1 to 6 of these flux-grown piezoelectric crystals were experimentally determined at room and high temperatures. The ambient results for as-grown α-GaPO4 were in good agreement with those obtained from hydrothermally-grown samples and the two longitudinal elastic constants measured versus temperature up to 850 °C showed a monotonous evolution. The extraction of the ambient piezoelectric stress contribution e11 from the CD11 to CE11 difference gave for the piezoelectric strain coefficient d11 of flux-grown α-GeO2 crystal a value of 5.7(2 pC/N, which is more than twice that of α-quartz. As the α-quartz structure of GeO2 remained stable up to melting, a piezoelectric activity was observed up to 1000 °C.

  12. Efectividad de las campañas de publicidad para reducir la siniestralidad vial en España: un análisis econométrico

    OpenAIRE

    Castillo Manzano, José I.; Castro Nuño, Mercedes; Pedregal Tercero, Diego José

    2011-01-01

    A principios del siglo XXI, hemos asistido a un endurecimiento considerable de las estrategias de prevención y sanción aplicadas por la Administración española en materia de seguridad vial, con objeto de lograr una reducción en los accidentes de tráfico. Este endurecimiento puede apreciarse de manera particular, en las campañas públicas de publicidad vial dirigidas a los diferentes medios de comunicación, a través de un cambio profundo en el diseño de los mensajes emitidos, pas...

  13. definición de rangos para la clasificación estructural y funcional de la red vial nacional de costa rica

    OpenAIRE

    Barrantes Jiménez, Roy; Badilla Vargas, Gustavo; Sibaja Obando, Denia

    2011-01-01

    Se presenta una propuesta para la clasificación de rangos que permiten clasificar los resultados de la evaluación dela Red Vial Nacional de Costa Rica (RVN), de acuerdo con su capacidad estructural y funcional.Debido a que las rutas que componen la Red Vial Nacional de Costa Rica difieren entre sí, tanto por su importanciacomo por la cantidad de vehículos y la estructura, se reconoce la necesidad de agruparlas y definir rangos de deflexionesque se ajusten a las características de cada subgrup...

  14. Synthesis and deformation of a Ti doped quartz aggregate

    Science.gov (United States)

    Nachlas, William O.; Hirth, Greg; Teyssier, Christian; Whitney, Donna L.; Zimmerman, Mark

    2013-04-01

    A primary advantage of studying mylonites for thermobarometric reconstructions of tectonic events is that it enables direct comparison of P-T estimates with the mechanics of quartz deformation. Quartz is a common phase in crustal mylonites and is a particularly sensitive recorder of metamorphic and rheologic conditions in shear zones, owing to its responsiveness to dynamic recrystallization, involvement in metamorphic reaction, and propensity for dissolution and precipitation. The signature of its trace element chemistry, particularly Ti, can reflect involvement from each of these processes. The concentration of Ti in mylonites is typically heterogeneous at the thin section scale, providing a rich record of the different factors that influence the incorporation of Ti in quartz. Observations of quartz in deformed mylonite and undeformed protolith from an extensional shear zone in the North American Cordillera (Shuswap Complex, Canada) show that an originally uniform Ti distribution was modified during deformation to form zoned crystals in which the core preserves a higher Ti concentration than the rim. The zoned Ti concentration likely records a continuum of deformation conditions during extension-related exhumation, and this presents a challenge in resolving the effect of deformation on the equilibrium solubility of Ti in quartz in natural settings. By conducting deformation experiments on synthetic quartz aggregates with known Ti concentration at a constant, elevated temperature and pressure under high strain conditions, we investigate the influence of progressive dynamic recrystallization on Ti solubility in quartz. This study applies a novel doping technique that enables the synthesis of a large population of quartz crystals with a precisely controlled Ti concentration and distribution. This produces a sample that most closely replicates the protolith of extensional shear zones that typically develop under retrograde conditions. This strategy can be used to

  15. Soil chemistry in lithologically diverse datasets: the quartz dilution effect

    Science.gov (United States)

    Bern, Carleton R.

    2009-01-01

    National- and continental-scale soil geochemical datasets are likely to move our understanding of broad soil geochemistry patterns forward significantly. Patterns of chemistry and mineralogy delineated from these datasets are strongly influenced by the composition of the soil parent material, which itself is largely a function of lithology and particle size sorting. Such controls present a challenge by obscuring subtler patterns arising from subsequent pedogenic processes. Here the effect of quartz concentration is examined in moist-climate soils from a pilot dataset of the North American Soil Geochemical Landscapes Project. Due to variable and high quartz contents (6.2–81.7 wt.%), and its residual and inert nature in soil, quartz is demonstrated to influence broad patterns in soil chemistry. A dilution effect is observed whereby concentrations of various elements are significantly and strongly negatively correlated with quartz. Quartz content drives artificial positive correlations between concentrations of some elements and obscures negative correlations between others. Unadjusted soil data show the highly mobile base cations Ca, Mg, and Na to be often strongly positively correlated with intermediately mobile Al or Fe, and generally uncorrelated with the relatively immobile high-field-strength elements (HFS) Ti and Nb. Both patterns are contrary to broad expectations for soils being weathered and leached. After transforming bulk soil chemistry to a quartz-free basis, the base cations are generally uncorrelated with Al and Fe, and negative correlations generally emerge with the HFS elements. Quartz-free element data may be a useful tool for elucidating patterns of weathering or parent-material chemistry in large soil datasets.

  16. Quartz concentration trends in metal and nonmetal mining.

    Science.gov (United States)

    Watts, Winthrop F; Huynh, Tran B; Ramachandran, Gurumurthy

    2012-01-01

    From 1974 through 2010, the Mine Safety and Health Administration (MSHA) collected nearly 147,000 respirable dust samples with a mass of at least 0.1 mg and a minimum of 1% quartz. These samples represent about 50% of all respirable dust compliance samples collected by MSHA. Analysis of these data shows that pockets of high concentrations and overexposure continue to exist. At underground mines, from 2005 to 2010, occupations with >20% of the samples exceeding the permissible exposure limit (PEL) and geometric mean quartz concentrations exceeding the ACGIH threshold limit value of 25 μg/m(3) included mucking, crusher operator, general laborer/utility, and front-end loader operator. During the same period, stone and rock saw operators and bagger and packers working at surface mines and mills also had >20% of the samples exceeding the PEL and geometric mean quartz concentrations >25 μg/m(3). Regardless of mine type or location, slow but steady improvement in exposure levels is seen in jobs involving crushing operations, which are widespread in the mining industry. Crusher operators are more likely to work in an enclosed area where it is easier to apply dust controls and air conditioning. A downward trend is also observed for vehicle equipment operators who drive load-haul-dumps, front-end loaders, trucks, and similar equipment. Crusher operators and vehicle equipment operators represent occupational categories that are widely sampled by MSHA inspectors. A small but statistically significant reduction in the overall mean respirable quartz dust and quartz concentrations from 1993 to 2010 was observed in most commodity groups. Variability from year to year and between commodities is high. Reduction in respirable quartz dust concentration does not necessarily correspond to a reduction in quartz concentration within the same commodity group. These trends are consistent with those reported in previous studies.

  17. Evaluación del estado de los puentes de acero de la red vial de Colombia

    OpenAIRE

    Muñoz, Edgard; Valbuena, Edgar

    2004-01-01

    Este artículo pretende estudiar en detalle el estado y los daños típicos de los puentes en acero y en estructura mixta (acero y concreto) de la Red Vial Nacional de Colombia. El estudio está basado en la evaluación del inventario y las inspecciones realizadas por el Instituto Nacional de Vías (Invias) desde el año de 1996, a través del Sistema de Administración de Puentes de Colombia (Sipucol). El artículo se divide en dos (2) partes: en la primera se presenta una descripción de las diferente...

  18. Environmental Testing of Tritium-Phosphor Glass Vials for Use in Long-Life Radioisotope Power Conversion Units

    Science.gov (United States)

    Zemcov, Michael; Cardona, Pedro; Parkus, James; Patru, Dorin; Yost, Valerie

    2017-01-01

    Power generation in extreme environments, such as the outer solar system, the night side of planets, or other low-illumination environments, currently presents a technology gap that challenges NASA's ambitious scientific goals. We are developing a radioisotope power cell (RPC) that utilizes commercially available tritium light sources and standard 1.85 eV InGaP2 photovoltaic cells to convert beta particle energy to electric energy. In the test program described here, we perform environmental tests on commercially available borosilicate glass vials internally coated with a ZnS luminescent phosphor that are designed to contain gaseous tritium in our proposed power source. Such testing is necessary to ensure that the glass containing the radioactive tritium is capable of withstanding the extreme environments of launch and space for extended periods of time.

  19. Note: Wide band amplifier for quartz tuning fork sensors with digitally controlled stray capacitance compensation.

    Science.gov (United States)

    Peng, Ping; Hao, Lifeng; Ding, Ning; Jiao, Weicheng; Wang, Qi; Zhang, Jian; Wang, Rongguo

    2015-11-01

    We presented a preamplifier design for quartz tuning fork (QTF) sensors in which the stray capacitance is digitally compensated. In this design, the manually controlled variable capacitor is replaced by a pair of varicap diodes, whose capacitance could be accurately tuned by a bias voltage. A tuning circuit including a single side low power operational amplifier, a digital-to-analog converter, and a microprocessor is also described, and the tuning process can be conveniently carried out on a personal computer. For the design, the noise level was investigated experimentally.

  20. In-vial liquid-liquid microextraction-capillary electrophoresis method for the determination of phenolic acids in vegetable oils.

    Science.gov (United States)

    Abu Bakar, Nur Bahiyah; Makahleh, Ahmad; Saad, Bahruddin

    2012-09-12

    An in-vial liquid-liquid microextraction method was developed for the selective extraction of the phenolic acids (caffeic, gallic, cinnamic, ferulic, chlorogenic, syringic, vanillic, benzoic, p-hydroxybenzoic, 2,4-dihydroxybenzoic, o-coumaric, m-coumaric and p-coumaric) in vegetable oil samples. The optimised extraction conditions for 20 g sample were: volume of diluent (n-hexane), 2 mL; extractant, methanol: 5 mM sodium hydroxide (60:40; v/v); volume of extractant, 300 μL (twice); vortex, 1 min; centrifugation, 5 min. Recoveries for the studied phenolic acids were 80.1-119.5%. The simultaneous determination of the phenolic acid extracts was investigated by capillary electrophoresis (CE). Separations were carried out on a bare fused-silica capillary (50 μm i.d.× 40 cm length) involving 25 mM sodium tetraborate (pH 9.15) and 5% methanol as CE background electrolyte in the normal polarity mode, voltage of 30 kV, temperature of 25°C, injection time of 4s (50 mbar) and electropherograms were recorded at 200 nm. The phenolic acids were successfully separated in less than 10 min. The validated in-vial LLME-CE method was applied to the determination of phenolic acids in vegetable oil samples (extra virgin olive oil, virgin olive oil, pure olive oil, walnut oil and grapeseed oil). The developed method shows significant advantages over the current methods as lengthy evaporation step is not required. Copyright © 2012 Elsevier B.V. All rights reserved.

  1. Quartz roughness affect on WO3 coated QCM

    International Nuclear Information System (INIS)

    Georgieva, V; Raicheva, Z; Grechnikov, A; Gadjanova, V; Atanassov, M; Lazarov, J; Manolov, E

    2010-01-01

    The influence of the initial quartz roughness on the WO 3 -QCM (Quartz Crystal Microbalance) parameters and sorption properties was investigated. Experiments were carried out using AT-cut quartz crystal with different surface roughness obtained after treatment with SiC abrasive having grain size of 3 μm, 7 μm, 14 μm and 20 μm respectively. The QCMs were covered with thin WO 3 films. The equivalent dynamic parameters of the WO 3 - QCM were measured and a correlation with the surface roughness was determined. The equivalent dynamic resistance of the as-created QCM increases from 15.42 Ω to 117 Ω and the quality factor decreases as a result of the roughness changes. The surface morphology was observed by a Scanning Electron Microscopy (SEM), which showed higher increase of the WO 3 surface roughness compared to those of the initial quartz surface. The cross-section profiles of the investigated structures show different overlay of Au-electrodes. The sorption properties of WO 3 -QCM system to NH 3 were studied in the range from 10 ppm to 1000 ppm. The response and recovering times were determined. The experimental results show an increase of the sorption ability with the increase of the initial quartz roughness. By increasing the roughness the mass-loading is improved.

  2. Influence of the sample volume and the position of the electrode and the capillary-end in the sample vial on the electrokinetic injection in capillary electrophoresis

    NARCIS (Netherlands)

    Ensing, K

    1997-01-01

    The influence of the positions of the electrode and the capillary-end and volume in the sample vials on the electrokinetically injected amount of the analytes in capillary electrophoresis was studied. The influence may be reduced by using a more or less fixed position of the electrode and the

  3. Carbothermal Reduction of Quartz and Carbon Pellets at Elevated Temperatures

    Science.gov (United States)

    Li, Fei; Tangstad, Merete; Ringdalen, Eli

    2018-02-01

    In this study, the carbothermal reduction of pellets composed of quartz and carbon at temperatures between 1898 K and 1948 K (1625 °C and 1675 °C) are investigated. The main product from this reaction is silicon carbide (SiC). The reduction of quartz with carbon black, charcoal, coke, coal, and pre-heated coal in the pellet were compared to investigate the different carbon resources used in silicon production. Charcoal and coke have high SiO reactivity, while carbon black and coal (pre-heated coal) have low SiO reactivity. Charcoal and carbon black show better matching between quartz/carbon reactivity and SiO reactivity, and will lose less SiO gas than coke and pre-heated coal. Coal has a high volatile content and is thus not recommended as a raw material for the pellets.

  4. Sorption and distribution of asphaltene, resin, aromatic and saturate fractions of heavy crude oil on quartz surface: molecular dynamic simulation.

    Science.gov (United States)

    Wu, Guozhong; He, Lin; Chen, Daoyi

    2013-09-01

    The molecular scale sorption, diffusion and distribution of asphaltene, resin, aromatic and saturate fractions of heavy crude oil on quartz surface were studied using molecular dynamic simulation. Sorption of saturates on quartz decreased by 31% when temperature increased from 298 to 398K while opposite trend was observed for resins, but insignificant changes were found in asphaltenes and aromatics. Despite of this variety, the main contribution of interactions was van der Waals energy (>90%) irrespective of molecular components and temperatures. The diffusion coefficient of saturates was predicted as 10.8×10(-10)m(2)s(-1) while that of the remaining fractions was about 4×10(-10)m(2)s(-1) at 298K. The most likely oil distribution on quartz surface was that aromatics and saturates transported randomly into and out of the complex consisting of asphaltenes surrounded by resins, which was influenced by temperature. Overall, the knowledge on quartz-oil and oil-oil interactions gained in this study is essential for future risk assessment and remediation activities as previous studies on soil remediation either limited to light oil fractions with <40 carbons or treated the heavy crude oil as a single pseudo entity ignoring the interactions between oil fractions. Copyright © 2013 Elsevier Ltd. All rights reserved.

  5. Risk of Injection-Site Abscess among Infants Receiving a Preservative-Free, Two-Dose Vial Formulation of Pneumococcal Conjugate Vaccine in Kenya

    Science.gov (United States)

    Burton, Deron C.; Bigogo, Godfrey M.; Audi, Allan O.; Williamson, John; Munge, Kenneth; Wafula, Jackline; Ouma, Dominic; Khagayi, Sammy; Mugoya, Isaac; Mburu, James; Muema, Shadrack; Bauni, Evasius; Bwanaali, Tahreni; Feikin, Daniel R.; Ochieng, Peter M.; Mogeni, Ondari D.; Otieno, George A.; Olack, Beatrice; Kamau, Tatu; Van Dyke, Melissa K.; Chen, Robert; Farrington, Paddy; Montgomery, Joel M.; Breiman, Robert F.; Scott, J. Anthony G.; Laserson, Kayla F.

    2015-01-01

    There is a theoretical risk of adverse events following immunization with a preservative-free, 2-dose vial formulation of 10-valent-pneumococcal conjugate vaccine (PCV10). We set out to measure this risk. Four population-based surveillance sites in Kenya (total annual birth cohort of 11,500 infants) were used to conduct a 2-year post-introduction vaccine safety study of PCV10. Injection-site abscesses occurring within 7 days following vaccine administration were clinically diagnosed in all study sites (passive facility-based surveillance) and, also, detected by caregiver-reported symptoms of swelling plus discharge in two sites (active household-based surveillance). Abscess risk was expressed as the number of abscesses per 100,000 injections and was compared for the second vs first vial dose of PCV10 and for PCV10 vs pentavalent vaccine (comparator). A total of 58,288 PCV10 injections were recorded, including 24,054 and 19,702 identified as first and second vial doses, respectively (14,532 unknown vial dose). The risk ratio for abscess following injection with the second (41 per 100,000) vs first (33 per 100,000) vial dose of PCV10 was 1.22 (95% confidence interval [CI] 0.37–4.06). The comparator vaccine was changed from a 2-dose to 10-dose presentation midway through the study. The matched odds ratios for abscess following PCV10 were 1.00 (95% CI 0.12–8.56) and 0.27 (95% CI 0.14–0.54) when compared to the 2-dose and 10-dose pentavalent vaccine presentations, respectively. In Kenya immunization with PCV10 was not associated with an increased risk of injection site abscess, providing confidence that the vaccine may be safely used in Africa. The relatively higher risk of abscess following the 10-dose presentation of pentavalent vaccine merits further study. PMID:26509274

  6. Pressure effect on the sensitivity of quartz Bourdon tube gauges.

    Science.gov (United States)

    Szaniszlo, A. J.

    1972-01-01

    The sensitivity change for a commercial fused quartz Bourdon tube precision pressure gauge, due to a change in absolute pressure level, has been analytically computed and experimentally confirmed. The computed differential pressure error is 2.5% of full scale at a 100 atm absolute pressure level. The experimental method compared the fused quartz Bourdon tube gauge digital output to the results obtained from a nitrogen gas pressure system which had a high pressure, well-type mercury manometer as the differential pressure reference.

  7. ST Quartz Acoustic Wave Sensors with Sectional Guiding Layers

    Directory of Open Access Journals (Sweden)

    Glen McHale

    2008-07-01

    Full Text Available We report the effect of removing a section of guiding layer from the propagation paths of ST-quartz Love wave sensors; this offers the ease of fabrication of a polymer guiding layer whilst retaining the native surface of the quartz which may then be used for the attachment of a sensitizing layer. Data is presented for the rigid and viscous loading, which indicates a small reduction in mass sensitivity compared to a Love wave device. Biosensing capabilities of these discontinuous ‘sectional’ guiding layer devices are demonstrated using protein adsorption from solution.

  8. Chiral habit selection on nanostructured epitaxial quartz films.

    Science.gov (United States)

    Carretero-Genevrier, Adrián; Gich, Martí; Picas, Laura; Sanchez, Clément; Rodriguez-Carvajal, Juan

    2015-01-01

    Understanding the crystallization of enantiomorphically pure systems can be relevant to diverse fields such as the study of the origins of life or the purification of racemates. Here we report on polycrystalline epitaxial thin films of quartz on Si substrates displaying two distinct types of chiral habits that never coexist in the same film. We combine Atomic Force Microscopy (AFM) analysis and computer-assisted crystallographic calculations to make a detailed study of these habits of quartz. By estimating the surface energies of the observed crystallites we argue that the films are enantiomorphically pure and we briefly outline a possible mechanism to explain the habit and chiral selection in this system.

  9. A Naturally-Calibrated Flow Law for Quartz

    Science.gov (United States)

    Lusk, A. D.; Platt, J. P.

    2017-12-01

    Flow laws for power-law behavior of quartz deforming by crystal-plastic processes with grain size sensitive creep included take the general form: ė = A σn f(H2O) exp(-Q/RT) dmWhere A - prefactor; σ - differential stress; n - stress exponent; f(H2O) - water fugacity; Q - activation energy; R - gas constant; T - temperature (K); d - grain size sensitivity raised to power m. Assuming the dynamically recrystallized grain size for quartz follows the peizometric relationship, substitute dm = (K σ-p)m, where K - piezometric constant; σ - differential stress; p - piezometric exponent. Rearranging the above flow law: ė = A K σ(n-pm) f(H2O) exp(-Q/RT)We use deformation temperatures, paleo-stresses, and strain rates calculated from rocks deformed in the Caledonian Orogeny, NW Scotland, along with existing experimental data, to compare naturally-calibrated values of stress exponent (n-pm) and activation energy (Q) to those determined experimentally. Microstructures preserved in the naturally-strained rocks closely resemble those produced by experimental work, indicating that quartz was deformed by the same mechanism(s). These observations validate the use of predetermined values for A as well as the addition of experimental data to calculate Q. Values for f(H2O) are based on calculated pressure and temperature conditions. Using the abovementioned constraints, we compare results, discuss challenges, and explore implications of naturally- vs. experimentally-derived flow laws for dislocation creep in quartz. Rocks used for this study include quartzite and quartz-rich psammite of the Cambrian-Ordovician shelf sequence and tectonically overlying Moine Supergroup. In both cases, quartz is likely the primary phase that controlled rheological behavior. We use the empirically derived piezometer for the dynamically recrystallized grain size of quartz to calculate the magnitude of differential stress, along with the Ti-in-quartz thermobarometer and the c-axis opening angle

  10. Dose evaluation using multiple-aliquot quartz OSL: Test of methods and a new protocol for improved accuracy and precision

    DEFF Research Database (Denmark)

    Jain, M.; Bøtter-Jensen, L.; Singhvi, A.K.

    2003-01-01

    Multiple-aliquot quartz OSL dose-response curves often suffer from substantial variability in the luminescence output from identically treated aliquots (scatter) that leads to large uncertainties in the equivalent-dose estimates. In this study, normalisation and its bearing on the accuracy...... from the single-aliquot-regeneration protocol (SAR) gave similar accuracy and precision, (C) 2002 Elsevier Science Ltd. All rights reserved....

  11. Quartz exposure levels in the underground and surface coal mining industry

    Energy Technology Data Exchange (ETDEWEB)

    Ainsworth, S.M.; Gero, A.J.; Parobeck, P.S; Tomb, T.F. [US Mine Safety and Health Administration, Pittsburgh, PA (United States)

    1995-10-01

    Occupational quartz exposure data gathered from the Mine Safety and Health Adminsitration`s respirable dust enforcement program and a program to monitor quartz exposure in several mining occupations were compiled and analyzed to assess the status of quartz exposures in the coal mining industry. The analysis showed that, in underground mines, a substantial number of samples contained greater than 5% quartz. Occupations that showed a high frequency of excessive quartz exposure included the roof bolter, continuous miner operator, and continuous miner operator helper. In surface coal mines the highwall drill operator and helper, bulldozer operator, scraper operator, and truck driver were frequently exposed to high quartz concentrations.

  12. Evaluation of trapping parameters of annealed natural quartz

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Rui [College of Resources, Environment & Tourism, Capital Normal University, 100048 Beijing (China); Shisanling Seismic Station, Institute of Earthquake Science, CEA, 102200 Beijing (China); Wei, Ming-Jian, E-mail: weimj@cnu.edu.cn [College of Resources, Environment & Tourism, Capital Normal University, 100048 Beijing (China); Song, Bo [College of Resources, Environment & Tourism, Capital Normal University, 100048 Beijing (China); Beijing Jing Yuan School, 100040 Beijing (China); Zhang, Yan [College of Resources, Environment & Tourism, Capital Normal University, 100048 Beijing (China); School of TaiPingqiao, Nan Lu of West Railway Station, 100073 Beijing (China); Zhao, Qiu-Yue [Key Laboratory of Tourism and Resources Environment in Universities of Shandong, Taishan University, 271000 Tai’an (China); Pan, Bao-Lin; Li, Teng-Fei [College of Resources, Environment & Tourism, Capital Normal University, 100048 Beijing (China)

    2016-05-15

    The thermoluminescence (TL) trapping parameters of annealed quartz have been investigated. The apparent TL peaks observed at temperatures of 133 °C, 211 °C, 266 °C and 405 °C, respectively, were named Peak I, Peak II, Peak III and Peak IV. The T{sub m} − T{sub stop} method is applied to investigate the number of peaks and their positions, and to obtain the trap distributions in the quartz. Peak shape (PS), Hoogenstraaten method (Various Heating Rates Method, VHR), and Computerized Glow Curve Deconvolution (CGCD) are used to evaluate the trapping parameters of the annealed quartz. The glow curve can be considered as a superposition of at least nine overlapping peaks. These peaks show up at 133 °C, 211 °C, 266 °C, 308 °C, 333 °C, 384 °C, 441 °C, 466 °C and 484 °C. The PS method can be only used in evaluating the parameters for Peaks I. The VHR method can be used in evaluating the trapping parameters for the first three peaks. CGCD method is complementary to obtaining parameters for the sub-peaks, and the thermal quenching correction with the Urbach’s method is necessary. The Urbach’s coefficient for the quartz is 30.03 kT{sub m}.

  13. Triplet states at an O vacancy in alpha-quartz

    DEFF Research Database (Denmark)

    Lægsgaard, Jesper

    2002-01-01

    The energy landscape of an alpha-quartz O vacancy in the lowest triplet state is investigated. Four local minima are identified and geometries, total energies, and electron paramagnetic resonance (EPR) parameters are obtained. On the basis of calculated values for the magnetic dipole interaction...

  14. A new equation of state for α-quartz

    Science.gov (United States)

    Magyar, Rudolph; Carpenter, John

    2015-06-01

    Quartz (SiO2) is often used as an optically transparent window for visar signals in shock experiments and is itself an active component of the experiments. Therefore, the shock response of quartz is an important input that must be known to high fidelity for precise measurement of other materials. We describe on-going work to develop a wide-range equation of state table that includes multiple phases and incorporates the latest high quality experimental and density functional theory (DFT) calculations. The emphasis in this work is the proper description of α-quartz along its principal Hugoniot through Stishovite and liquid phases. While molecular dissociation occurs at high pressures and temperatures, we find that an additional dissociation model is unnecessary. Although SiO2 possesses a number of solid phases, we restrict our focus to α-quartz and Stishovite as these two provide the density change along the Hugoniot path. We compare the model to recently measured data on Sandia's Z-machine. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE.

  15. Evaluation of trapping parameters of annealed natural quartz

    International Nuclear Information System (INIS)

    Zhou, Rui; Wei, Ming-Jian; Song, Bo; Zhang, Yan; Zhao, Qiu-Yue; Pan, Bao-Lin; Li, Teng-Fei

    2016-01-01

    The thermoluminescence (TL) trapping parameters of annealed quartz have been investigated. The apparent TL peaks observed at temperatures of 133 °C, 211 °C, 266 °C and 405 °C, respectively, were named Peak I, Peak II, Peak III and Peak IV. The T m  − T stop method is applied to investigate the number of peaks and their positions, and to obtain the trap distributions in the quartz. Peak shape (PS), Hoogenstraaten method (Various Heating Rates Method, VHR), and Computerized Glow Curve Deconvolution (CGCD) are used to evaluate the trapping parameters of the annealed quartz. The glow curve can be considered as a superposition of at least nine overlapping peaks. These peaks show up at 133 °C, 211 °C, 266 °C, 308 °C, 333 °C, 384 °C, 441 °C, 466 °C and 484 °C. The PS method can be only used in evaluating the parameters for Peaks I. The VHR method can be used in evaluating the trapping parameters for the first three peaks. CGCD method is complementary to obtaining parameters for the sub-peaks, and the thermal quenching correction with the Urbach’s method is necessary. The Urbach’s coefficient for the quartz is 30.03 kT m .

  16. Quartz crystal microbalance gas sensor with nanocrystalline diamond sensitive layer

    Czech Academy of Sciences Publication Activity Database

    Varga, Marián; Laposa, A.; Kulha, Pavel; Kroutil, J.; Husák, M.; Kromka, Alexander

    2015-01-01

    Roč. 252, č. 11 (2015), s. 2591-2597 ISSN 0370-1972 R&D Projects: GA ČR(CZ) GBP108/12/G108 Institutional support: RVO:68378271 Keywords : gas sensor * nanocrystalline diamond * quartz resonator * thickness shear mode Subject RIV: JB - Sensors, Measurment, Regulation Impact factor: 1.522, year: 2015

  17. Electron spin resonance of Fe4+ in amethyst quartz

    International Nuclear Information System (INIS)

    Cox, R.T.

    1975-01-01

    The ESR spectrum of Fe 4+ was looked for in amethyst quartz. Besides saturated Fe 3+ lines, ESR lines of a new paramagnetic center whose spin-lattice relaxation time is relatively short were observed. They could be attributed to Fe 4+ [fr

  18. Influence of Quartz Fillers in Dielectric Composites on Electrostrictive Sensors

    Directory of Open Access Journals (Sweden)

    B.Shivamurthy

    2008-05-01

    Full Text Available In this investigation E-glass epoxy composite filled with different amount of quartz powder were prepared by compression moulding and hot curing. Plain waived E-glass cloth with density 200gm / meter square was used as reinforcement. Epoxy resin LY556 mixed with Hardener HT907 and accelerator DY063 in the ratio 100:80:2 was used as matrix. The quartz powder of 30 microns particle size was used as fillers. Four types of composites were prepared with different amount of quartz fillers like 0%, 3%, 6% and 9% with unchanged reinforcement. For all the samples, dielectric dissipation factor (tan δ, dielectric constant and a. c. conductivity and electrostriction have been measured by using a LCR meter at 1 KHz frequency. The phenomenon of electrostriction was examined for all samples (of different percentage of quartz filled composites. It is observed that the percentage of filler influences the electrostriction phenomena in the composites. The 6 % filler content composites samples exhibits the improved electrostriction phenomenon required for sensors compared to other types of composites.

  19. Geology and geochemistry of giant quartz veins from the ...

    Indian Academy of Sciences (India)

    They show imprints of strong brittle to ductile–brittle deformation, and in places are associated with base metal and gold incidences, and pyrophyllite-diaspore mineralization. The geochemistry of giant quartz veins were studied. Apart from presenting new data on the geology and geochemistry of these veins, an attempt has ...

  20. Significant step in ultra-high stability quartz crystal oscillators

    Czech Academy of Sciences Publication Activity Database

    Salzenstein, P.; Kuna, Alexander; Šojdr, Ludvík; Chauvin, J.

    2010-01-01

    Roč. 46, č. 21 (2010), s. 1433-1434 ISSN 0013-5194 Institutional research plan: CEZ:AV0Z20670512 Keywords : ultrahigh stability quartz crystal oscillators * flicker frequency modulation floor * frequency 5 MHz Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 1.001, year: 2010

  1. Characterization of silica quartz as raw material in photovoltaic applications

    Science.gov (United States)

    Boussaa, S. Anas; Kheloufi, A.; Zaourar, N. Boutarek; Kefaifi, A.; Kerkar, F.

    2016-07-01

    Raw materials are essential for the functioning of modern societies, and access to these raw materials is vital to the world economy. Sustainable development, both globally level, raises important new challenges associated with access and efficient use of raw materials. High purity quartz, is consider as a critical raw material and it is a rare commodity that only forms under geological conditions where a narrow set of chemical and physical parameters is fulfilled. When identified and following special beneficiation techniques, high purity quartz obtains very attractive prices and is applied in high technology sectors that currently are under rapid expansion such as photovoltaic solar cells, silicon metal - oxide wafers in the semiconductor industry and long distance optical fibers that are used in communication networks. Crystalline silicon remains the principal material for photovoltaic technology. Metallurgical silicon is produced industrially by the reduction of silica with carbon in an electric arc furnace at temperatures higher than 2000 °C in the hottest parts, by a reaction that can be written ideally as: SiO2 + 2C = Si + 2CO. The aim of this study has been to test experimental methods for investigating the various physical and chemical proprieties of Hoggar quartz with different techniques: X Ray Fluorescence, infra-red spectroscopy, Scanning Electron Microscopy, Optic Microscopy, Carbon Analyzer and Vickers Hardness. The results show finally that the quartz has got good result in purity but need enrichment for the photovoltaic application.

  2. Application of quartz crystal microbalance technology in tribological investigation

    Science.gov (United States)

    The last fifteen years have seen considerable growth in the application of quartz crystal microbalance (QCM) to explore the tribological characteristics of materials. This article reviews some of the advances made in characterizing frictional properties of materials using the QCM, especially with di...

  3. Quartz-like Crystals Found in Planetary Disks

    Science.gov (United States)

    2008-01-01

    NASA's Spitzer Space Telescope has, for the first time, detected tiny quartz-like crystals sprinkled in young planetary systems. The crystals, which are types of silica minerals called cristobalite and tridymite, can be seen close-up in the black-and-white insets (cristobalite is on the left, and tridymite on the right). The main picture is an artist's concept of a young star and its swirling disk of planet-forming materials. Cristobalite and tridymite are thought to be two of many planet ingredients. On Earth, they are normally found as tiny crystals in volcanic lava flows and meteorites from space. These minerals are both related to quartz. For example, if you were to heat the familiar quartz crystals often sold as mystical tokens, the quartz would transform into cristobalite and tridymite. Because cristobalite and tridymite require rapid heating and cooling to form, astronomers say they were most likely generated by shock waves traveling through the planetary disks. The insets are Scanning Electron Microscope pictures courtesy of George Rossman of the California Institute of Technology, Pasadena, Calif.

  4. Food irradiation dosimetry using thermoluminescence of quartz sand

    International Nuclear Information System (INIS)

    Khan, H.M.; Ehlermann, D.A.E.

    1993-01-01

    Thermoluminescence of quartz sand, which is inert and concomitant to several food materials, has been investigated for applications in food irradiation dosimetry and detection of irradiated foods. The glow curves consist of at least three overlapping peaks from 100 to 420 C. The peak at lower temperature is not stable and decays quickly at room temperature. However, the peaks at higher temperature are stable and more useful for dosimetry work. The intensity of the peak at 360 C, measured using different optical filters, shows a linear response in the range of 0.05 to 23 kGy. Stability of these signals at different annealing temperatures has been investigated. Thermoluminescence from adhering minerals and contaminating dust in different food materials has been found useful for the detection of irradiation treatment. Since quartz is frequently one of these minerals, further computerized deconvolution of individual glow peaks from the complex glow curves of quartz sand was carried out which improves the dosimetric results. Possible applications of thermoluminescence of quartz sand in food irradiation dosimetry and detection of irradiated foods have been discussed. (orig.)

  5. Effect of room temperature transport vials on DNA quality and phylogenetic composition of faecal microbiota of elderly adults and infants.

    Science.gov (United States)

    Hill, Cian J; Brown, Jillian R M; Lynch, Denise B; Jeffery, Ian B; Ryan, C Anthony; Ross, R Paul; Stanton, Catherine; O'Toole, Paul W

    2016-05-10

    Alterations in intestinal microbiota have been correlated with a growing number of diseases. Investigating the faecal microbiota is widely used as a non-invasive and ethically simple proxy for intestinal biopsies. There is an urgent need for collection and transport media that would allow faecal sampling at distance from the processing laboratory, obviating the need for same-day DNA extraction recommended by previous studies of freezing and processing methods for stool. We compared the faecal bacterial DNA quality and apparent phylogenetic composition derived using a commercial kit for stool storage and transport (DNA Genotek OMNIgene GUT) with that of freshly extracted samples, 22 from infants and 20 from older adults. Use of the storage vials increased the quality of extracted bacterial DNA by reduction of DNA shearing. When infant and elderly datasets were examined separately, no differences in microbiota composition were observed due to storage. When the two datasets were combined, there was a difference according to a Wilcoxon test in the relative proportions of Faecalibacterium, Sporobacter, Clostridium XVIII, and Clostridium XlVa after 1 week's storage compared to immediately extracted samples. After 2 weeks' storage, Bacteroides abundance was also significantly different, showing an apparent increase from week 1 to week 2. The microbiota composition of infant samples was more affected than that of elderly samples by storage, with significantly higher Spearman distances between paired freshly extracted and stored samples (p < 0.001). When the microbiota profiles were analysed at the operational taxonomic unit (OTU) level, three infant datasets in the study did not cluster together, while only one elderly dataset did not. The lower microbiota diversity of the infant gut microbiota compared to the elderly gut microbiota (p < 0.001) means that any alteration in the infant datasets has a proportionally larger effect. The commercial storage vials appear

  6. Pressure-induced drastic collapse of a high oxygen coordination shell in quartz-like α-GeO2

    International Nuclear Information System (INIS)

    Dong, Juncai; Zhang, Xiaoli; Wu, Ziyu; Chen, Dongliang; Zhang, Qian; Wu, Ye; Wu, Xiang

    2014-01-01

    With the combination of a single crystal diamond anvil cell and a polycapillary half-lens, the local structural evolution around germanium in tetrahedrally networked quartz-like α-GeO 2 has been investigated using extended x-ray absorption fine structure spectroscopy of up to 14 GPa by multiple-scattering analysis method. While the first shell Ge–O bond distances show a slight contraction with increasing pressure, the third shell Ge–O bond distances are found to decrease dramatically. The sluggish lengthening of the first shell Ge–O bond distances, initiated by coordination increase from fourfold to sixfold, occurs in the 7–14 GPa range just when the third shell Ge–O bond distances fall in the region of the second shell Ge–Ge bond distances. Moreover, these features are accompanied by the closing of intertetrahedral Ge–O–Ge angles and the opening of two intratetrahedral O–Ge–O angles, whose topological configuration surprisingly exhibits a helical chirality along the c axis that is opposite to the double helices of the corner-linked GeO 4 tetrahedra. These results suggest that the high-pressure phase transitions in quartz and quartz-like materials could be associated with a structural instability that is driven by the drastic collapse of the next-nearest-neighbour anion shell, which is consistent with the emergence of high-symmetry anion sublattice. Our findings provide crucial insights into the densification mechanisms of quartz-like oxides, which would have broad implications for our understanding of the metastability of various post-quartz crystalline phases and pressure-induced amorphization. (paper)

  7. A natural example of crystal-plastic deformation enhancing the incorporation of water into quartz

    Science.gov (United States)

    Gleason, Gayle C.; DeSisto, Stephanie

    2008-01-01

    Water content of quartz in and around a greenschist facies mylonitic shear zone located in the western Adirondacks was analyzed by micro-FTIR spectroscopy. The shear zone is within a pegmatitic dike, which cuts across a granitic gneiss. The thickness of the shear zone varies along strike from 15 cm wide and encompassing all of the pegmatite dike at its northern most exposure to 5 cm wide approximately 10 m south, along strike. Microstructures, including quartz ribbons and recrystallized grains, indicate quartz and feldspar within the mylonite underwent dislocation creep. Infrared spectral analysis was carried out using a Nicolet micro-FTIR on mylonitic quartz ribbons, pegmatitic quartz and gneissic quartz. A small aperture size (56 μm by 50 μm) for the IR beam allowed optically clear regions of the quartz grains to be analyzed without any contribution from grain boundaries. The smallest dimension of the quartz ribbons is 0.3 mm, whereas the pegmatitic quartz has a grain size of 3 to 5 cm. Results show mylonitic quartz ribbons contain the most water (320 H:10 6 Si average, range of 50 to 1120 H:10 6 Si); pegmatite quartz contains much less water (30 H:10 6 Si average, range of 20-40 H:10 6 Si) and the gneissic quartz contained an intermediate amount (200 H:10 6 Si average, range of 20 to 870 H:10 6 Si). These data indicate that water was preferentially incorporated into the deformed quartz ribbons.

  8. Titanium zoning and diffusion chronometry reveal dynamic and late-stage quartz growth in the Youngest Toba Tuff, Indonesia

    Science.gov (United States)

    Tierney, C. R.; Reid, M. R.; Burns, D. H.; Costa Rodriguez, F.; Chesner, C. A.

    2017-12-01

    The enormous 74 ka Youngest Toba Tuff (YTT) ejected 2800 km3 of compositionally zoned (68-77 wt.% SiO2) ignimbrite and co-ignimbrite ash. Titanium zoning within YTT quartz records a dynamic growth history, and sometimes concludes with a final growth stage under different conditions. We investigated the timescales of quartz growth using diffusion chronometry, and determined whether the last stage of crystallization was the result of a discrete and chamber-wide magmatic event. This work offers insight into the dynamics and timescales of storage and remobilization of voluminous silicic magmas - an important consideration for hazards assessment. High-resolution (1 µm steps) hyperspectral CL was mapped from 5-20 quartz crystals from each of five pumices spanning the YTT compositional spectrum. CL intensity was calibrated to Ti concentration via EPMA, and numerically modeled time-dependent diffusional relaxation curves where fit to concentration profiles across zone boundaries. CL-bright/high-Ti rims are found in quartz from all samples, but become less common and have lower Ti concentrations with increasing host pumice silica content (e.g., 70 ppm vs 50 ppm). Some large crystals contain distinct CL-bright interior zones with similar Ti concentration to the rims. Onset of growth of CL-bright rims commenced between 15 and 100 years before eruption, and interior bands between 30 and 1500 years. Neither rim nor interior ages correlate significantly with host pumice silica. Rim growth on quartz evidently occurred closer to eruption than a previous estimate of several decades to centuries for quartz from a single YTT pumice (Matthews et al., 2012). The similar timing for the onset of high-Ti quartz rim growth across all samples suggests a marked and temporally discrete magmatic event in the years to decades prior to eruption and may be recording the chamber-wide influence of magmatic recharge or remobilization. High-Ti interior zones likely record older recharge events that

  9. Fracture flow due to hydrothermally induced quartz growth

    Science.gov (United States)

    Kling, Tobias; Schwarz, Jens-Oliver; Wendler, Frank; Enzmann, Frieder; Blum, Philipp

    2017-09-01

    Mineral precipitations are a common feature and limitation of initially open, permeable rock fractures by forming sealing structures or secondary roughness in open voids. Hence, the objective of this numerical study is the evaluation of hydraulic properties of fractures sealed by hydrothermally induced needle and compact quartz growth. Phase-field models of progressive syntaxial and idiomorphic quartz growth are implemented into a fluid flow simulation solving the Navier-Stokes equation. Flow simulations for both quartz types indicate an obvious correlation between changes in permeability, fracture properties (e.g. aperture, relative roughness and porosity) and crystal growth behavior, which also forms distinct flow paths. Thus, at lower sealing stages initial fracture permeability significantly drops down for the 'needle fracture' forming highly tortuous flow paths, while the 'compact fracture' records a considerably smaller loss. Fluid flow in both sealing fractures most widely is governed by a ;parallel plate;-like cubic law behavior. However, the 'needle fracture' also reveals flow characteristics of a porous media. A semi-theoretical equation is introduced that links geometrical (am) with hydraulically effective apertures (ah) and the relative fracture roughness. For this purpose, a geometry factor α is introduced being α = 2.5 for needle quartz and α = 1.0 for compact quartz growth. In contrast to most common ah-am-relationships this novel formulation not only reveals more precise predictions for the needle (RMSE = 1.5) and the compact fractures (RMSE = 3.2), but also exhibit a larger range of validity concerning the roughness of the 'needle' (σ/am = 0-2.4) and the 'compact fractures' (σ/am = 0-1.8).

  10. Note: A dual-channel sensor for dew point measurement based on quartz crystal microbalance

    Science.gov (United States)

    Li, Ning; Meng, Xiaofeng; Nie, Jing

    2017-05-01

    A new sensor with dual-channel was designed for eliminating the temperature effect on the frequency measurement of the quartz crystal microbalance (QCM) in dew point detection. The sensor uses active temperature control, produces condensation on the surface of QCM, and then detects the dew point. Both the single-channel and the dual-channel methods were conducted based on the device. The measurement error of the single-channel method was less than 0.5 °C at the dew point range of -2 °C-10 °C while the dual-channel was 0.3 °C. The results showed that the dual-channel method was able to eliminate the temperature effect and yield better measurement accuracy.

  11. Spatial Distribution of Oxygen Isotope of Quartz from Major Asian Dust Sources and Its Application in Source Tracing of Aeolian Dust

    Science.gov (United States)

    Yan, Y.; Sun, Y.

    2015-12-01

    Provenance studies of aeolian dust in East Asia had made much progress. The interpretations of the provenance of modern aeolian dust and paleo-dust (loess) sequences, however, still suffer disputes. To provide more scientific evidence, we present a provenance study using oxygen isotope (δ18O) of quartz as a tracer. We studied the quartz δ18O of both fine (Asia, including the Taklimakan desert, Mongolian Gobi, Badain Juran desert, Tengger desert, Mu Us desert, and Qaidam Basin. Among them, quartz δ18O of both fractions shows consonant increasing trend from the Mongolian Gobi, to the northern Chinese deserts (i.e. Badain Juran, Tennger, and Mu Us deserts), Qaidam Basin, and then to the Taklimakan desert, indicating a decreasing igneous rock coverage in the sources. The coverage ratio survey of the igneous rocks in different sources corroborated this inference. Using quartz δ18O of both fractions can differentiate dust from the Mongolian Gobi, Taklimakan desert and the northern Chinese deserts. Combination of quartz δ18O and quartz Electronic Spinning Resonance signal intensity (ESR) - Crystalinity Index (CI) from previous studies helps further the differentiation. The bivariate plot of quartz δ18O and CI of fine fraction can make clear separation of dust from different sources, regardless of single-sourced or mixed dust, while the trivariate plot of quartz δ18O, ESR, and CI of fine fraction can further increase the differentiability. Applying quartz δ18O-CI, we found that the four natural dust storm events happening in Xi'an in the spring of 2012 mainly originated from the northern Chinese deserts. Dust entrainment monitoring by MODIS images and air mass transport route simulation by back trajectory modeling show that the dust plumes or dust-containing air parcels originating from the northern Chinese deserts reached Xi'an on those dust storm days, thus confirmed the source tracer comparison results. Our study supports the previous proximal

  12. Effect of ferrule preparation on fatigue resistance of teeth restored with quartz-fiber posts

    Directory of Open Access Journals (Sweden)

    Nasermostofi Sh.

    2009-08-01

    Full Text Available "nBackground and Aim: A key factor in restoring the endodontically treated teeth is ferrule preparation. When the ferrule is absent, occlusal loads may cause the post or root to fracture. The purpose of this in vitro study was to evaluate the effect of ferrule preparation on fatigue resistance of teeth restored with quartz-fiber posts. "nMaterials and Methods: Twenty single-rooted lower premolars having similar dimentions were randomly devided into two groups of 10. In control group the teeth were prepared with 3-mm of remaining coronal tooth structure and in test group teeth were prepared with 1-mm of remaining coronal tooth structure. The teeth were endodontically treated. 9-mm long Post holes were prepared, and D.T. light quartz-fiber(RTD,France posts were cemented with Panavia F2(Kuraray,Japan.Then the core build up was done with Bisco core build up composite(Bisco,USA and full metal crowns were cemented with Zinc phosphate(Harvard cement, Germany. All specimens were mounted in acrylic resin blocks and intermittently loaded (180 N at an angulation of 45- degree to the long axis of the teeth at a frequency of 4 loads per second, until failure occurred. "nResults: There was significant difference between the loads cycles of two groups studied. (p<0.0001. "nConclusion: The results of this study showed that an increased amount of coronal dentin significantly increases the fracture resistance of teeth restored with quartz-fiber posts.

  13. WIP: A Web-based program for indexing planar features in quartz grains and its usage

    Science.gov (United States)

    Losiak, Anna; Golebiowska, Izabela; FerrièRe, Ludovic; Wojciechowski, Jacek; Huber, Matthew S.; Koeberl, Christian

    2016-04-01

    Planar deformation features (PDFs) in quartz are the most important diagnostic features that allow the unambiguous identification of impact structures on Earth. In order to confirm that these features (that are characterized by planar character and form along specific crystallographic planes) are indeed PDFs, they need to be properly investigated and indexed. Following universal-stage measurements, the process of indexing is usually performed manually, using a Wulff stereonet and following a strict procedure, which is time consuming and error prone. In this article, we present WIP, a new Web-based program for indexing planar deformation features in quartz. The correctness of our program is shown by its application to measurements that had previously been indexed manually. The observed minor differences, especially in the absolute frequency percentage of PDFs, are negligible and not significant enough to influence the estimation of shock pressure that could be calculated from the indexed results. Usability of this program is shown using the spatial relationships between a statistically significant number of 278 quartz grains with 409 sets of PDFs analyzed within the area ( 35 mm2) of a single thin section of a meta-greywacke from the Bosumtwi impact structure. Our program is not only more accurate and faster than the manual (graphical) method but also removes the human error from the plotting process and allows control of several parameters, such as the value of estimated measurement error used in the indexing calculation or method of aggregated error handling. The program also provides information about the angles between the planes of the measured PDF sets present in a grain, which allows determination of the angles between (for example) indexed {10accent="true">1¯3} and {10accent="true">1¯1} sets.

  14. Stibine preconcentration in a quartz trap with subsequent atomization in the quartz multiatomizer for atomic absorption spectrometry

    Czech Academy of Sciences Publication Activity Database

    Korkmaz, D.; Dědina, Jiří; Ataman, O. Y.

    2004-01-01

    Roč. 19, č. 2 (2004), s. 255-259 ISSN 0267-9477 R&D Projects: GA ČR GA203/01/0453 Institutional research plan: CEZ:AV0Z4031919 Keywords : stibine preconcentration * quartz multiatomizer * efficiency Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 3.926, year: 2004

  15. La valoración monetaria de los costes humanos de la siniestralidad vial en España

    Directory of Open Access Journals (Sweden)

    Jorge Eduardo Martínez Pérez

    2015-09-01

    Full Text Available Los análisis coste-beneficio en el ámbito de la seguridad vial han de computar la totalidad de los costes, y dentro de ellos ocupan un lugar clave los costes humanos. En esta nota se da cuenta de dos estudios promovidos por la Dirección General de Tráfico orientados a la obtención de valores oficiales para España de los costes asociados a las víctimas mortales y no mortales de los accidentes de tráfico. Mediante la combinación del enfoque de la valoración contingente con la técnica de la lotería estándar (modificada, y con muestras amplias (n1 = 2020, n2 = 2000 representativas de la población española, se estimó en 1,4 millones de euros el valor monetario de prevenir un fallecido por accidente de tráfico. Para las lesiones graves y leves, los valores estimados fueron de 219.000 y 6100 euros, respectivamente. Las cifras obtenidas tienen un orden de magnitud similar al de los países de nuestro entorno.

  16. A critical assessment of the occurrence and extend of oxygen contamination during anaerobic incubations utilizing commercially available vials

    DEFF Research Database (Denmark)

    De Brabandere, Loreto; Thamdrup, Bo; Revsbech, Niels Peter

    2012-01-01

    For rate determinations of anaerobic metabolism it is essential to maintain strictly anoxic conditions throughout the experiment. However, even if oxygen contamination can be avoided while preparing the incubation containers, it is still possible that the incubation containers themselves contamin......For rate determinations of anaerobic metabolism it is essential to maintain strictly anoxic conditions throughout the experiment. However, even if oxygen contamination can be avoided while preparing the incubation containers, it is still possible that the incubation containers themselves...... contaminate the samples by oxygen diffusing from or through their plastic or rubber components. In this study, we investigated the sources and extent of oxygen contamination during anoxic incubations, and present solutions to minimize oxygen contamination. In particular, we investigated oxygen contamination...... in Labco® Exetainers, glass vials with a butyl rubber septum in the screw cap, which are frequently used in microbiological experiments. Our results show that significant oxygen contamination occurred at different stages during the incubation. Contamination occurred when Exetainers were either filled...

  17. Nivel y cambio de la mortalidad vial en Argentina, Chile, Colombia y México, 2000-2011

    Directory of Open Access Journals (Sweden)

    Gabriel Escanés

    2015-01-01

    Full Text Available El objetivo de este trabajo es estimar el efecto de las muertes por atropellos y colisiones de tránsito en la esperanza de vida en Argentina, Chile, Colombia y México, entre 2000 y 2011. Se calcularon los años de esperanza de vida perdidos (AEVP para los trienios 2000-2002 y 2009-2011. Los resultados indican que los decesos ocurridos por el tránsito representaron entre el 1% y el 4% del total para cada país. En el primer trienio, el mayor nivel de mortalidad ocurrió en Colombia (AEVP=0,96, mientras que el más bajo se registró en Argentina (AEVP=0,59. A excepción de este último país, hacia el segundo trienio, se redujo el impacto de estos fallecimientos sobre la esperanza de vida. El principal cambio tuvo lugar en Colombia que pasó a 0,72 AEVP. Se concluye que las muertes asociadas con el tránsito impactan de manera negativa en los sistemas de salud, las víctimas, el sector productivo y la sociedad en general. Desde esta perspectiva, la situación vial representa un problema de salud pública que requiere la intervención multisectorial en el diseño de políticas de alcance nacional y regional.

  18. Metal pollution (Pb, Zn, Ni and Cr) in air, road and soil sediment in a high traffic area; Contaminacion por metales (Pb, Zn, Ni y Cr) en aire, sedimentos viales y suelo en una zona de alto trafico vehicular

    Energy Technology Data Exchange (ETDEWEB)

    Manchado, Anali; Garcia, Neyma; Garcia, Cezar; Acosta, Lorena; Cordova, Alberto; Linares, Maria; Giraldoth, Debora [Centro de Investigaciones CEDEGAS, Facultad de Ingenieria, Universidad del Zulia, Maracaibo (Venezuela)]. E-mail: analimachado@yahoo.com; amachadop@luz.edu.ve; Velasquez, Harvi [Facultad Experimental de Ciencias, Universidad del Zulia, Maracaibo (Venezuela)

    2008-11-15

    Due to the important health effects of inhalable particles (PM10) and its associated metals, levels of four trace metals (Pb, Ni, Zn, Cr) generated by mobile sources with variable toxicity incorporated to PM10 atmospheric samples in a high density traffic area were evaluated. Samples were collected at two different sites (being considered as emission and dispersion areas) during a dry-wet season period, using a low volume air sampler equipped with quartz fiber filters; after an acid extraction, samples were analyzed by atomic absorption spectrometry. PM10 concentrations were two times higher in the emission area than in the dispersion area for both climatic regimens, but exhibited a better correlation between sites during the dry season. All the elements showed statistically significant differences between monitoring sites. On the other hand, when the total sampling period for PM10 is compared for all the tested metals, significant differences between sites and between meteorological seasons can be appreciated. The Venezuelan air quality standard for Pb was not exceeded, but a mean concentration of 1.13 {mu}g/m{sup 3} -very close to Venezuelan and USEPA standard- was obtained at the emission site. Nevertheless, Pb and Ni reported levels for both locations were above the Organizacion Mundial de la Salud (OMS) allowed limit during the whole sampling period. Further, the statistical analysis demonstrated the selection of the monitoring areas was adequate, confirming that motor vehicles are the main emission source of these atmospheric pollutants. [Spanish] Debido a la importancia del efecto sobre la salud de las particulas inhalables PM10 y los metales asociados a ellas, se evaluaron los niveles de cuatro metales traza (Pb, Ni, Zn y Cr) generados por fuentes moviles de dichas particulas, en sedimentos viales y suelo en una zona de alta densidad vehicular. Las muestras fueron colectadas en los sitios considerados como de emision y dispersion durante las epocas de

  19. EXTRACTION OF CRISTOBALITE FROM MILKY-WHITE FORMS OF QUARTZ STUFF1

    OpenAIRE

    Issaev, V.; Oreshnikova, N.

    1997-01-01

    Natural quartz is one of die main sources of getting a unique material - quartz glass. Wide application of quartz glass in chemical and electronic industry, aviation and cosmonautics, fibre optics and computer techniques makes it absolutely indispensable. However, industrial reserves of rock-chrystal lodes, that is die most pure source of quartz stuff with minimal mineral admixturer, are practically exhausted everywhere. All this results in usage of.low quality stuff and, thus, to significant...

  20. Deteksi Gelatin Babi Menggunakan Emas Termodifikasi Ni(oh)2 Nanopartikel dengan Quartz Crystal Microbalance (Qcm)

    OpenAIRE

    Kurniawan, Fredy; Candle, Lourentia

    2015-01-01

    Sensor Quartz emas dari QCM (Quartz Crystal Microbalance) yang terlapis senyawa Nanopartikel Ni(OH)2 telah berhasil dibuat. Senyawa Nanopartikel Ni(OH)2 disintesis dengan menggunakan metode pengendapan. Pada pelapisan senyawa Nanopartikel Ni(OH)2 pada Quartz emas dari QCM dilakukan bantuan Polimer Konduktif Polianilin dengan metode voltametri siklik. Pelapisan senyawa Nanopartikel Ni(OH)2 pada Quartz emas dari QCM dengan metode layer by layer. Pengujian dilakukan dengan variasi konsentrasi (...

  1. Métodos para la mejora de la seguridad de las carreteras en Europa. Auditorías de seguridad vial

    OpenAIRE

    Pardillo Mayora, José M.

    2008-01-01

    El Programa de acción europeo de seguridad vial 2003-2010 tiene como objetivo adoptar las medidas necesarias para conseguir que el número de víctimas mortales en accidentes de circulación en los países de la Unión Europea sea inferior a 25.000 en 2010. En lo que se refiere a las actuaciones sobre la infraestructura, los métodos de actuación que se proponen para las distintas fases de desarrollo de la red viaria son: la evaluación del impacto de seguridad vial en la etapa de planificación; la ...

  2. Cancer morbidity and quartz exposure in Swedish iron foundries.

    Science.gov (United States)

    Westberg, Håkan; Andersson, Lena; Bryngelsson, Ing-Liss; Ngo, Yen; Ohlson, Carl-Göran

    2013-07-01

    The aim of this study was to determine cancer morbidity amongst Swedish iron foundry workers with special reference to quartz exposure. In addition to respirable dust and quartz, phenol, formaldehyde, furfuryl alcohols, polycyclic aromatic hydrocarbons (PAHs), carbon black, isocyanates and asbestos are used or generated by foundry production techniques and exposure to any of these substances could have potentially carcinogenic effects. Cancer morbidity between 1958 and 2004 was evaluated in a cohort of 3,045 male foundry workers employed for >1 year between 1913 and 2005. Standardised incidence ratios (SIRs) with 95 % confidence intervals (95 % CI) were determined by comparing observed numbers of incident cancers with frequencies in the Swedish cancer register. Exposure measures were assessed using information from the personal files of employees and modelling quartz measurement based on a database of 1,667 quartz measurements. Dose responses for lung cancer were determined for duration of employment and cumulative quartz exposure for latency periods >20 years. Overall cancer morbidity was not increased amongst the foundry workers (SIR 1.00; 95 % CI, 0.90-1.11), but the incidence of lung cancer was significantly elevated (SIR 1.61; 95 % CI, 1.20-2.12). A non-significant negative dose response was determined using external comparison with a latency period of >20 years (SIR 2.05, 1.72 1.26 for the low, medium and high exposure groups), supported by internal comparison data (hazard ratios 1, 1.01, 0.78) for the corresponding groups. For cancers at sites with at least five observed cases and a SIR > 1.25, non-significant risks with SIRs > 1.5 were determined for cancers of the liver, larynx, testis, connective muscle tissue, multiple myeloma plasmacytoma and lymphatic leukaemia. A significant overall risk of lung cancer was determined, but using external and internal comparison groups could not confirm any dose response at our cumulative quartz dose levels.

  3. Off-axis quartz-enhanced photoacoustic spectroscopy using a pulsed nanosecond mid-infrared optical parametric oscillator.

    Science.gov (United States)

    Lassen, Mikael; Lamard, Laurent; Feng, Yuyang; Peremans, Andre; Petersen, Jan C

    2016-09-01

    A trace-gas sensor, based on quartz-enhanced photoacoustic spectroscopy (QEPAS), consisting of two acoustically coupled micro-resonators (mR) with an off-axis 20 kHz quartz tuning fork (QTF) is demonstrated. The complete acoustically coupled mR system is optimized based on finite-element simulations and is experimentally verified. The QEPAS sensor is pumped resonantly by a nanosecond pulsed single-mode mid-infrared optical parametric oscillator. The sensor is used for spectroscopic measurements on methane in the 3.1-3.5 μm wavelength region with a resolution bandwidth of 1  cm-1 and a detection limit of 0.8 ppm. An Allan deviation analysis shows that the detection limit at the optimum integration time for the QEPAS sensor is 32 ppbv at 190 s, and that the background noise is due solely to the thermal noise of the QTF.

  4. 30 CFR 71.101 - Respirable dust standard when quartz is present.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Respirable dust standard when quartz is present... UNDERGROUND COAL MINES Dust Standards § 71.101 Respirable dust standard when quartz is present. When the respirable dust in the mine atmosphere of the active workings contains more than 5 percent quartz, the...

  5. 30 CFR 90.101 - Respirable dust standard when quartz is present.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Respirable dust standard when quartz is present... quartz is present. When the respirable dust in the mine atmosphere of the active workings to which a Part 90 miner is exposed contains more than 5 percent quartz, the operator shall continuously maintain the...

  6. 30 CFR 70.101 - Respirable dust standard when quartz is present.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Respirable dust standard when quartz is present... Respirable dust standard when quartz is present. When the respirable dust in the mine atmosphere of the active workings contains more than 5 percent quartz, the operator shall continuously maintain the average...

  7. Activation energies from blue- and red-thermoluminescence (TL) of quartz grains and mean lives of trapped electrons related to natural red-TL

    International Nuclear Information System (INIS)

    Hashimoto, T.; Kojima, M.; Shirai, N.; Ichino, M.

    1993-01-01

    A three-dimensional representation of thermoluminescence (TL) spectra has been established by employing an image intensifier unit combined with a simple spectrophotometer and a microcomputer. By means of this TL spectrometric system, natural quartz grains could be distinguished as either blue-and/or red-TL ones. In these blue- and red-TL wavelength regions, activation energies from artificially irradiated quartz grains are evaluated using a repeated initial rise method. An apparent difference of activation energies in the two colorations was observed for dune sands presumably originating from different quartz sources. On the other hand, quartz grains extracted from a volcanic ash sediment showed completely similar activation energies in both TL color regions over all temperatures. Subsequently, the kinetic parameters were derived for the naturally occurring red-TL, possessing an apparent single peak around 340 o C, from volcanically originating quartz grains by fitting a theoretical equation to the glow curves, after evaluating activation energies. On the basis of the empirical kinetic parameters, the mean life of trapped electrons relating to a main 340 o C peak has been proved to be 1 million years, and a secondary weak peak around 280 o C in the natural red-TL glow curve has been confirmed. (author)

  8. Real-time multianalyte biosensors based on interference-free multichannel monolithic quartz crystal microbalance.

    Science.gov (United States)

    Jaruwongrungsee, Kata; Waiwijit, Uraiwan; Wisitsoraat, Anurat; Sangworasil, Manas; Pintavirooj, Chuchart; Tuantranont, Adisorn

    2015-05-15

    In this work, we design, fabricate and characterize a new interference-free multichannel monolithic quartz crystal microbalance (MQCM) platform for bio-sensing applications. Firstly, interference due to thickness-shear vibration mode coupling between channels in MQCM array is effectively suppressed by interposing a polydimethylsiloxane wall between adjacent QCM electrodes on a quartz substrate to form inverted-mesa-like structure. In addition, the electrical coupling due to the electrical impedance of solution is diminished by extending the flow path between them with an extended-design flow channel. The electrical testing results show that individual QCM signal is unaffected by those of adjacent channels under liquid loading, signifying the achievement of interference-free MQCM. The MQCM is applied for multi-analyte biosensing of IgG and HSA. The anti-IgG and anti-HSA are separately immobilized on two adjacent QCM electrodes, which are subsequently blocked with BSA to avoid unspecific binding. The MQCM biosensors are tested with single- and double-analyte solutions under continuous flow of buffer. The IgG and HSA QCM sensors only show frequency shift responses to their corresponding analytes and there are very small cross frequency shifts due to remnant unspecific binding. Moreover, MQCM sensors show approximately linear frequency shift response with analyte concentration. Therefore, the developed MQCM platform is promising for real-time interference-free label-free detection and quantification of multiple bio-analytes. Copyright © 2014 Elsevier B.V. All rights reserved.

  9. TL dosimetry of natural quartz sensitized by heat-treatment and high dose irradiation

    International Nuclear Information System (INIS)

    Khoury, H.J.; Guzzo, P.L.; Souza, L.B.F.; Farias, T.M.B.; Watanabe, S.

    2008-01-01

    The aim of this paper is to report the sensitization of the TL peak appearing at 270 deg. C in the glow curve of natural quartz by using the combined effect of heat-treatments and irradiation with high γ doses. For this, thirty discs with 6x1mm 2 were prepared from plates parallell to a rhombohedral crystal face. The specimens were separated into four lots according to its TL read out between 160 and 320 deg. C. One lot was submitted to γ doses of 60 Co radiation starting at 2 kGy and going up until a cumulative dose of 25 kGy. The other three lots were initially heat-treated at 500, 800 and 1000 deg. C and then irradiated with a single dose of 25 kGy. The TL response of each lot was determined as a function of test-doses ranging from 0.1 to 30 mGy. As a result, it was observed that heat-treatments themselves did not produce the strong peak at 270 deg. C that was observed after the administration of high γ doses. This peak is associated with the optical absorption band appearing at 470 nm which is due to the formation of [AlO 4 ] o acting as electron-hole recombination centers. The formation of the 270 deg. C peak was preliminary analyzed in relation to aluminum- and oxygen-vacancy-related centers found in crystalline quartz

  10. Non-monotonic dose dependence of the Ge- and Ti-centres in quartz

    Energy Technology Data Exchange (ETDEWEB)

    Woda, C. [Forschungsstelle Archaeometrie der Heidelberger Akademie der Wissenschaften, Max-Planck-Institut fuer Kernphysik, Saupfercheckweg 1, 69117 Heidelberg (Germany)], E-mail: clemens.woda@gsf.de; Wagner, G.A. [Forschungsstelle Archaeometrie der Heidelberger Akademie der Wissenschaften, Max-Planck-Institut fuer Kernphysik, Saupfercheckweg 1, 69117 Heidelberg (Germany)

    2007-10-15

    The dose response of the Ge- and Ti-centres in quartz is studied over a large dose range. After an initial signal increase in the low dose range, both defects show a pronounced decrease in signal intensities for high doses. The model by Euler and Kahan [1987. Radiation effects and anelastic loss in germanium-doped quartz. Phys. Rev. B 35 (9), 4351-4359], in which the signal drop is explained by an enhanced trapping of holes at the electron trapping site, is critically discussed. A generalization of the model is then developed, following similar considerations by Lawless et al. [2005. A model for non-monotonic dose dependence of thermoluminescence (TL). J. Phys. Condens. Matter 17, 737-753], who explained a signal drop in TL by an enhanced recombination rate with electrons at the recombination centre. Finally, an alternative model for the signal decay is given, based on the competition between single and double electron capture at the electron trapping site. From the critical discussion of the different models it is concluded that the double electron capture mechanism is the most probable effect for the dose response.

  11. A quartz crystal microbalance characterization of metal-oil interfaces and interactions with wax molecules

    Energy Technology Data Exchange (ETDEWEB)

    Paso, K.; Kompalla, T.; Braathen, B.; Sjoblom, J. [Norwegian Univ. of Science and Technology, Trondheim (Norway). Dept. of Chemical Engineering, Ugelstad Laboratory; Aske, N.; Ronningsen, H.P. [StatoilHydro, Stavanger (Norway); Viitala, T. [KSV Instruments, Helsinki (Finland)

    2008-07-01

    This study investigated the solid-liquid interface between stainless steel and model petroleum fluids at isothermal conditions using a quartz crystal microbalance. AISI 316 (Fe/Cr18/Ni10/Mo3) stainless steel was chosen to represent the metal surface, while paraffin components dissolved in dodecane constituted the petroleum model fluid. Commercial macro-crystalline and micro-crystalline waxes provided linear and branched paraffin components, respectively. A van't Hoff relationship was used to establish the paraffin solubility conditions. The well-defined solubility conditions were provided by model fluids prepared with the single-component alkanes n-C36 or n-C30 paraffin. According to the monitored changes in resonance frequency and dissipation factor of the quartz crystal resonator immersed in the model fluids, there was no continual deposition of paraffin components at isothermal conditions. Moreover, solid paraffin crystals dispersed in solution did not adhere to the stainless steel surface. The absence of attractive interactions between the stainless steel surface and dispersed paraffin crystals suggests that an axial transport mechanism exists for incipient wax deposit formation, where gelation kinetics play a key role. These conclusions were supported by QCM measurements performed under a thermal gradient.

  12. Stability of ipilimumab in its original vial after opening allows its use for at least 4 weeks and facilitates pooling of residues.

    Science.gov (United States)

    Bardo-Brouard, Pascale; Vieillard, Victoire; Shekarian, Tala; Marabelle, Aurélien; Astier, Alain; Paul, Muriel

    2016-05-01

    Well-documented stability data of monoclonal antibodies are generally missing. That is why we studied the physicochemical and biological stability of undiluted ipilimumab (IPI) in glass vial (5 mg/ml) over 28 d after opening, stored at 4 °C and 25 °C. A stressed study (60 °C) was performed to validate our analytical methods as 'stability indicating'. The different methods used were turbidimetry, dynamic light scattering (DLS), second-derivative ultraviolet and chromatographic methods as size-exclusion chromatography (SEC) and cation-exchange (CEX). Biological characterisation was performed by an in vitro functional binding inhibition bioassay. We demonstrated that ipilimumab in opened vials stored at 4 °C and 25 °C remained stable for at least 28 d. No physical, chemical or structural instability was found. No aggregation was observed by turbidimetry, SEC and DLS. Hydrodynamic diameters remained unchanged, as chromatographic profiles in CEX and thermal aggregation curves. Functionally, the ability of IPI to antagonise CTLA-4/B7.2 binding remained stable over 1 month at 4 °C. These results indicate that unused residues of IPI in their original vials can be safely kept up to 28 d, following good manufacturing procedures, allowing re-use for another patient or in case of cold-chain rupture. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. Un lazo ausente: política vial y condiciones de vida en ámbitos rurales de la provincia de Buenos Aires (Argentina, 1940-1950

    Directory of Open Access Journals (Sweden)

    Alejandra Laura Salomón

    2017-12-01

    Full Text Available Desde la década de 1920, en la Argentina cobró fuerza una acción pública orientada al diagnóstico y a la búsqueda de soluciones en materia vial, delineándose un consenso en torno a su importancia para el progreso material y moral de la nación. En las décadas de 1940 y 1950, la planificación de la política nacional adquirió mayores bríos, aunque fuentes de época destacan desequilibrios territoriales, manifestando la escasez y malas condiciones de los caminos en ámbitos rurales, y su impacto decisivo no sólo en la dinámica productiva sino también en la calidad de vida. Frente a estas expresiones, nos preguntamos en qué medida los gobiernos asumieron dichas falencias y las incorporaron a la agenda pública. ¿Qué argumentos eran empleados para impulsar la red vial y qué intereses eran priorizados? Para responder estos interrogantes, examinamos representaciones sociales gubernamentales -en especial de la provincia de Buenos Aires- alrededor de la red vial en las décadas de 1940 y 1950.

  14. Japanese FITEL quartz fibrescope stands up to radiation

    International Nuclear Information System (INIS)

    Anon.

    1990-01-01

    The FITEL scope is an image guide made up of tens of thousands of optical fibres bundled together with an objective lens at one end and an ocular lens at the other. The arrangement of optical fibres is identical at the two ends of the image guide, so images are clear. The quartz fibre in the FITEL scope makes use of optical fibre technology developed by the Furukawa Electric Co of Japan. This fibre enables the FITEL scope to be used over a wide range of wavelengths, from ultraviolet to almost infrared. Furthermore, thanks to high transmission efficiency, the scope can be up to 100m long. The quartz fibre has excellent radiation resistance, heat resistance and durability, so it is well suited for use in nuclear power plants. Examples of the fibrescope's application to remote visual inspection in reactors are given. (author)

  15. Establishment of gold-quartz standard GQS-1

    Science.gov (United States)

    Millard, Hugh T.; Marinenko, John; McLane, John E.

    1969-01-01

    A homogeneous gold-quartz standard, GQS-1, was prepared from a heterogeneous gold-bearing quartz by chemical treatment. The concentration of gold in GQS-1 was determined by both instrumental neutron activation analysis and radioisotope dilution analysis to be 2.61?0.10 parts per million. Analysis of 10 samples of the standard by both instrumental neutron activation analysis and radioisotope dilution analysis failed to reveal heterogeneity within the standard. The precision of the analytical methods, expressed as standard error, was approximately 0.1 part per million. The analytical data were also used to estimate the average size of gold particles. The chemical treatment apparently reduced the average diameter of the gold particles by at least an order of magnitude and increased the concentration of gold grains by a factor of at least 4,000.

  16. Increased Acid Dissociation at the Quartz/Water Interface.

    Science.gov (United States)

    Parashar, Shivam; Lesnicki, Dominika; Sulpizi, Marialore

    2018-04-16

    As shown by a quite significant amount of literature, acids at the water surface tend to be "less" acid, meaning that their associated form is favored over the conjugated base. What happens at the solid/liquid interface? In the case of the silica/water interface, we show how the acidity of adsorbed molecules can instead increase. Using a free energy perturbation approach in combination with electronic structure-based molecular dynamics simulations, we show how the acidity of pyruvic acid at the quartz/water interface is increased by almost two units. Such increased acidity is the result of the specific microsolvation at the interface and, in particular, of the stabilization of the deprotonated form by the silanols on the quartz surface and the special interfacial water layer.

  17. Present status of CMS HF quartz fiber calorimetry

    CERN Document Server

    Önel, Y M

    2002-01-01

    The experiments at the Large Hadron Collider will have to deal with unprecedented radiation levels. The design of the CMS forward calorimetry detector (HF) is now finalized. The present design of CMS calls for the HF calorimeter to be based on quartz fiber technology. It consists of two modules, located symmetrically at about 11 meters from either side of interaction point. They cover the pseudorapidity range 3-5. The length along the beam is 1.65 m or 10 nuclear interaction lengths. Each calorimeter consists of a large steel block that serves as the absorber. Embedded quartz fibers in the steel absorber run parallel to the beam and constitute the active component of the detector. In order to optimize energy resolution for E and E /sup T/ flows and forward jets, the calorimeter is effectively segmented longitudinally by using two different fiber lengths. The present status will be discussed. (6 refs).

  18. Spectrographic analysis of metallic silicium and natural quartz

    International Nuclear Information System (INIS)

    Grigoletto, T.; Lordello, A.R.

    1985-01-01

    A method has been developed for the spectrographic determination of B, Mg, Al, Ca, Ti, Mn, Fe, Ni, Cu and Ag in silicon metal and other for Al, Ca, Mg, Ti, Cr, Mn, and Fe in natural quartz. A mixture of the matrix with a proper buffer is excited directly in a dc-arc. High-current (25A) and argon atmosphere are used for both the methods. Silicon metal is blended with 8% NaF and after 1:1 (w/w) with graphite. For natural quartz 20% NaF and 30% graphite by weight is the buffer mixture employed. The lower values in the determinations varies from 0.5 to 40 μg/g and the precision of the analysis from 7% to 45%. (Author) [pt

  19. A Multi-Fork Z-Axis Quartz Micromachined Gyroscope

    Science.gov (United States)

    Feng, Lihui; Zhao, Ke; Sun, Yunan; Cui, Jianmin; Cui, Fang; Yang, Aiying

    2013-01-01

    A novel multi-fork z-axis gyroscope is presented in this paper. Different from traditional quartz gyroscopes, the lateral electrodes of the sense beam can be arranged in simple patterns; as a result, the fabrication is simplified. High sensitivity is achieved by the multi-fork design. The working principles are introduced, while the finite element method (FEM) is used to simulate the modal and sensitivity. A quartz fork is fabricated, and a prototype is assembled. Impedance testing shows that the drive frequency and sense frequency are similar to the simulations, and the quality factor is approximately 10,000 in air. The scale factor is measured to be 18.134 mV/(°/s) and the nonlinearity is 0.40% in a full-scale input range of ±250 °/s. PMID:24048339

  20. Deposition and alignment of cells on laser-patterned quartz

    International Nuclear Information System (INIS)

    George, Sajan D.; Ladiwala, Uma; Thomas, John; Bankapur, Aseefhali; Chidangil, Santhosh; Mathur, Deepak

    2014-01-01

    Linear grooves have been laser-written on quartz surfaces using ultrashort (50 fs) pulses of 800 nm light. Measurements of water contact angle indicate that laser patterning makes the quartz surface more hydrophilic. Fibroblast cells were cultured on such laser-written surfaces; they were observed to align preferentially along the direction of the laser written grooves (width ∼2 μm. Raman spectroscopy results indicate that there are no chemical changes induced in the surface upon our laser writing. Most unexpectedly, there are also no chemical changes induced in the cells that are spatially aligned along the laser-written grooves. Atomic force microscopy measurements confirm that our laser-writing induces dramatic enhancement of surface roughness along the grooves, and the cells appear to respond to this. Thus, cell alignment seems to be in response to physical cues rather than chemical signals.

  1. Structural analysis of simulated swift heavy ion tracks in quartz

    International Nuclear Information System (INIS)

    Leino, Aleksi A.; Daraszewicz, Szymon L.; Pakarinen, Olli H.; Djurabekova, Flyura; Nordlund, Kai; Afra, Boshra; Kluth, Patrick

    2014-01-01

    Swift heavy ions (SHI), of specific kinetic energies in the excess of 1 MeV/u, can create cylindrical regions of structural transformation in SiO 2 targets, also known as SHI tracks. Recent measurements of the track cross-sections in α-quartz show significant and consistent discrepancies across different experimental techniques used. In particular, the track radii obtained from channelling experiments based on the Rutherford Backscattering Spectrometry (RBS-c) method increase monotonically with the electronic stopping power, whereas the track radii obtained from the Small Angle X-ray scattering (SAXS) saturate past a certain stopping power threshold. We perform a systematic study of the structure of the α-quartz tracks obtained from the molecular dynamics (MD) simulations incorporating a time-dependent energy deposition based on the inelastic thermal spike model, which allows us to discuss the possible origins of these experimental discrepancies

  2. Evaluation of the approach to respirable quartz exposure control in U.S. coal mines.

    Science.gov (United States)

    Joy, Gerald J

    2012-01-01

    Occupational exposure to high levels of respirable quartz can result in respiratory and other diseases in humans. The Mine Safety and Health Adminstration (MSHA) regulates exposure to respirable quartz in coal mines indirectly through reductions in the respirable coal mine dust exposure limit based on the content of quartz in the airborne respirable dust. This reduction is implemented when the quartz content of airborne respirable dust exceeds 5% by weight. The intent of this dust standard reduction is to restrict miners' exposure to respirable quartz to a time-weighted average concentration of 100 μg/m(3). The effectiveness of this indirect approach to control quartz exposure was evaluated by analyzing respirable dust samples collected by MSHA inspectors from 1995 through 2008. The performance of the current regulatory approach was found to be lacking due to the use of a variable property-quartz content in airborne dust-to establish a standard for subsequent exposures. In one situation, 11.7% (4370/37,346) of samples that were below the applicable respirable coal mine dust exposure limit exceeded 100 μg/m(3) quartz. In a second situation, 4.4% (895/20,560) of samples with 5% or less quartz content in the airborne respirable dust exceeded 100 μg/m(3) quartz. In these two situations, the samples exceeding 100 μg/m(3) quartz were not subject to any potential compliance action. Therefore, the current respirable quartz exposure control approach does not reliably maintain miner exposure below 100 μg/m(3) quartz. A separate and specific respirable quartz exposure standard may improve control of coal miners' occupational exposure to respirable quartz.

  3. Symmetry and piezoelectricity: evaluation of α-quartz coefficients

    Science.gov (United States)

    Tannous, C.

    2017-11-01

    Piezoelectric coefficients of α-quartz are derived from symmetry arguments based on Neumann’s principle using three different methods: Fumi, Landau-Lifshitz and Royer-Dieulesaint. While the Fumi method is tedious and the Landau-Lifshitz method requires additional physical principles to evaluate the piezoelectric coefficients, the Royer-Dieulesaint method is the most elegant and most efficient of the three techniques.

  4. Influence of quartz particles on wear in vertical roller mills

    DEFF Research Database (Denmark)

    Jensen, Lucas R.D.; Friis, Henrik; Fundal, Erling

    2010-01-01

    The standard closed circuit comminution process commonly employed in industrial vertical roller mills has been analyzed to determine the influence of typical abrasive minerals on wear rates. With the main focus on raw mixes used in cement plants, synthetic mixtures imitating were prepared. Using...... in an increased concentration of abrasive particles in the grinding bed ðR2 > 0:99Þ. The present study shows that the quartz concentration in the grinding bed is determining the wear rate....

  5. A vibrating quartz fork - a tool for cryogenic helium research

    Czech Academy of Sciences Publication Activity Database

    Blažková, Michaela; Člověčko, M.; Eltsov, V. B.; Gažo, E.; de Graaf, R.; Hosio, J.J.; Krusius, M.; Schmoranzer, D.; Schoepe, W.; Skrbek, Ladislav; Skyba, P.; Solntsev, R.E.; Vinen, W. F.

    2008-01-01

    Roč. 150, - (2008), s. 525-535 ISSN 0022-2291 R&D Projects: GA ČR GA202/05/0218 Grant - others:GAUK(CZ) 7953/2007; Transnational Access Programme(XE) RITA-CT-2003-505313 Institutional research plan: CEZ:AV0Z10100520 Keywords : normal 3He * superfluid 3He * superfluid 4He * turbulence, * cavitation * quartz tuning fork Subject RIV: BK - Fluid Dynamics Impact factor: 1.034, year: 2008

  6. Effects of surface slope on erosion rates of quartz particles

    OpenAIRE

    Lodge, Phillip.

    2006-01-01

    Modeling sediment erosion is important in a wide range of environmental problems. The effects of various environmental factors on erosion rates have been studied, but the effects of surface slope on erosion rates of a wide range of sediments have not been quantified. The effects of surface slope, both in the direction of flow (pitch) and perpendicular to the flow (roll), on erosion rates of quartz particles were investigated using the Sediment Erosion at Depth Flume (Sedflume). US Navy (US...

  7. Next Generation AT-Cut Quartz Crystal Sensing Devices

    Science.gov (United States)

    Matko, Vojko

    2011-01-01

    Generally, AT-cut quartz crystals have a limited scope of use when it comes to high-precision measurement of very small impedance changes due to their nonlinear frequency-temperature characteristics in the range between 0 °C and 50 °C. The new method improving quartz oscillator frequency-temperature characteristic compensation is switching between two impedance loads. By modifying the oscillator circuit with two logic switches and two impedance loads, the oscillator can switch oscillation between two resonance frequencies. The difference in resonance frequencies compensates the frequency-temperature characteristics influence as well as the influence of offset and quartz crystal ageing. The experimental results show that the new approach using the switching method highly improves second-to-second frequency stability from ±0.125 Hz to ±0.00001 Hz and minute-to-minute frequency stability from 0.1 Hz to 0.0001 Hz, which makes the high-precision measurement of aF and fH changes possible. PMID:22163858

  8. Characterization of hydrothermal green quartz produced by gamma radiation

    International Nuclear Information System (INIS)

    Enokihara, Cyro T.; Rela, Paulo R.; Schultz-Güttler, Rainer A.

    2015-01-01

    A specific variety of quartz showing a green color in nature or induced artificially by radiation gamma ( 60 Co) is quite rare. Only two occurrences are known today, where this type of quartz can be found: Canada, at the Thunder Bay Amethyst Mine, Ontario and Brazil, at widely scattered geode occurrences along a 600 km stretch from Quarai at Brazils southern most tip to Uberlandia in Minas Gerais. These two occurrences have been formed by strong hydrothermal activities.That way much quartz crystals showed a very fast growth history facilitating the formation of growth defects (twinning, small angle tilting, mosaic growth, striations) and the uptake of water in form of micro inclusions, molecular water, silanol (Si-OH) and OH. In the present work the material analyzed is from hydrothermal regimes found in intrusions of basaltic rocks located in the Rio Grande do Sul state. To characterize these materials, colored green by gamma rays, analyses by ICP, electron microscopy, water loss techniques and UV-VIS or NIR-FTIR spectroscopic measurements have been made. Silanol complexes are formed, which by radiation due to gamma rays form the color center NBOHC (Non-bonding Oxygen Hole Center), showing absorption between 590 to 620 nm, responsible for the green color. The water content with up to 3200 ppm by weight exceeds the amount of charge balancing cations (Fe, Al, Li). There is no correlation between water content and cations as in other color varieties. (author)

  9. Characterization of hydrothermal green quartz produced by gamma radiation

    Energy Technology Data Exchange (ETDEWEB)

    Enokihara, Cyro T.; Rela, Paulo R., E-mail: cteiti@ipen.br, E-mail: prela06@yahoo.com.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Schultz-Güttler, Rainer A., E-mail: rainersgut@gmail.com [Universidade de Sao Paulo (USP), Sao Paulo, SP (Brazil). Instituto de Geociencias

    2015-07-01

    A specific variety of quartz showing a green color in nature or induced artificially by radiation gamma ({sup 60}Co) is quite rare. Only two occurrences are known today, where this type of quartz can be found: Canada, at the Thunder Bay Amethyst Mine, Ontario and Brazil, at widely scattered geode occurrences along a 600 km stretch from Quarai at Brazils southern most tip to Uberlandia in Minas Gerais. These two occurrences have been formed by strong hydrothermal activities.That way much quartz crystals showed a very fast growth history facilitating the formation of growth defects (twinning, small angle tilting, mosaic growth, striations) and the uptake of water in form of micro inclusions, molecular water, silanol (Si-OH) and OH. In the present work the material analyzed is from hydrothermal regimes found in intrusions of basaltic rocks located in the Rio Grande do Sul state. To characterize these materials, colored green by gamma rays, analyses by ICP, electron microscopy, water loss techniques and UV-VIS or NIR-FTIR spectroscopic measurements have been made. Silanol complexes are formed, which by radiation due to gamma rays form the color center NBOHC (Non-bonding Oxygen Hole Center), showing absorption between 590 to 620 nm, responsible for the green color. The water content with up to 3200 ppm by weight exceeds the amount of charge balancing cations (Fe, Al, Li). There is no correlation between water content and cations as in other color varieties. (author)

  10. Road safety legislation in the Americas Legislación sobre seguridad vial en las Américas

    Directory of Open Access Journals (Sweden)

    Martha Híjar

    2012-07-01

    Full Text Available Legislating five of the main risk factors for road traffic injuries (RTIs, as much as enforcing the law, is essential in forging an integral culture of road safety. Analysis of the level of progression in law enforcement allows for an evaluation of the state of world regions. A secondary analysis of the 2009 Global status report on road safety: time for action survey was undertaken to evaluate legislation on five risk factors (speed management, drinking and driving, motorcycle helmet use, seatbelt use, and use of child restraints in the Americas. Laws were classified depending on their level of progression: the existence of legislation, whether the legislation is adequate, a level of law enforcement > 6 (on a scale of 0-10, and whether the law is considered comprehensive. A descriptive analysis was performed. The totality of the countries has national or subnational legislation for at least one of the five risk factors. However, 63% have laws on the five risk factors studied, and none of them has comprehensive laws for all five. Seatbelt use appears to be the most extended enforced legislation, while speeding laws appear to be the least enforced. There are positive efforts that should be recognized in the region. However, the region stands in different stages of progression. Law enforcement remains the main issue to be tackled. Laws should be based on evidence about what is already known to be effective.La legislación sobre cinco de los principales factores de riesgo de sufrir lesiones causadas por el tránsito, así como el cumplimiento de la ley, son esenciales para forjar una cultura integral de seguridad vial. El análisis del nivel de progresión en el cumplimiento de la ley permite evaluar el estado de las regiones del mundo. Se llevó a cabo un análisis secundario de la encuesta Informe sobre la situación mundial de la seguridad vial: es hora de pasar a la acción, de 2009, para evaluar la legislación sobre cinco factores de riesgo

  11. Voltage-controlled narrowband and wide, variable-range four-segment quartz crystal oscillator.

    Science.gov (United States)

    Ruslan, Ruzaini; Satoh, Tomio; Akitsu, Tetsuya

    2012-03-01

    In this work, our goal is to develop a voltage-controlled variable-frequency quartz crystal oscillator with narrowband response, wide, variable frequency range and the capacity to oscillate across the series resonance frequency using a four-segment configuration of a quartz crystal oscillator. In conventional quartz oscillators, the quartz resonator is inserted in the feedback loop between the input and the output of the active circuit, providing sufficient gain and the phase relation. In the oscillator developed here, the quartz crystal resonator is inserted between the loop circuit and the ground potential. The performance of the voltage-controlled variable-frequency oscillator is demonstrated across the series resonance frequency.

  12. Dating quartz: Ar/Ar analyses of coexisting muscovite and fluid inclusion - rich quartz from paleocene amorphic aureole

    International Nuclear Information System (INIS)

    Matthews, S.J.; Perez de Arce, C.; Cornejo, P.; Cuitino, L; Klein, J

    2001-01-01

    We present Ar/Ar total fusion and step-heating data for coexisting muscovite and white quartz from the metamorphic aureole of the Lower Paleocene La Copiapina Pluton, 6 km south of Inca de Oro, III Region, Chile. The pluton intrudes the upper clastic sedimentary member of the Punta del Cobre Group (Upper Jurassic - Lower Cretaceous) and the calcareous sedimentary rocks of the Chanarcillo Group (Neocomian), and comprises fine to coarse grained pyroxene-hornblende-biotite quartz diorites and monzodiorites. Its emplacement was controlled on its north-western side by a subvertical NE-trending fault, along which were developed vertically banded skarns (skarn mylonite), suggesting syntectonic intrusion. Biotite K-Ar ages for the pluton fall in the range 61-63 Ma, relating it to a latest Cretaceous to Lowest Paleocene syn-compressional intrusive belt which is present in the area (Matthews and Cornejo, 2000). A metamorphic / metasomatic aureole is developed within the sandstones of the Punta del Cobre Group, on the extreme northern limit of the pluton. In this area, the sedimentary rocks have been replaced by quartz-sericite and quartz-muscovite assemblages, with minor hematite and tourmaline, and late supergene kaolinite and pyrophyllite. A coarse muscovite-quartz-tourmaline-hematite assemblage is developed in and around older (early Upper Cretaceous) andesitic dykes, in the form of replacement / fracture fill veins and replacement zones. Further from the contact with the pluton, fine-grained quartz-sericite rock with coarser muscovite-rich replacement veins represents the dominant lithology. Quartz in the coarse replacement rock is very rich in fluid inclusions. Primary inclusions are mainly of two coexisting types; bi-phase (liquid and gas bubble) and tri-phase (liquid, gas bubble and halite crystal), indicating that the quartz formed in the presence of a boiling fluid. Some inclusions also contain sylvite and occasional hematite daughter crystals. Secondary inclusions

  13. Carbon in intimate contact with quartz reduces the biological activity of crystalline silica dusts.

    Science.gov (United States)

    Ghiazza, Mara; Tomatis, Maura; Doublier, Sophie; Grendene, Francesca; Gazzano, Elena; Ghigo, Dario; Fubini, Bice

    2013-01-18

    To evaluate the effect of carbonaceous materials on the pathogenic activity of quartz dusts, mixtures of carbon soot (1 and 10%) and quartz (Min-U-Sil) were prepared and then milled so to attain an intimate association of carbon and the quartz surface. Both cellular and cell-free tests show that carbon associated to quartz completely inhibits the typical free radical generation of quartz dusts (through Fenton activity and homolytic cleavage of a C-H bond) and suppresses the oxidative stress and inflammation induced by quartz alone on MH-S murine macrophage cells (lipid peroxidation, nitric oxide release, and tumor necrosis factor-α synthesis). The cytotoxic response to quartz is also largely reduced. An extremely pure quartz milled with 10% of soot showed inactivating effects on the adverse reactions to quartz similar to Min-U-Sil quartz. None of these effects takes place when the same experiments are carried out with mechanically mixed samples, which suggests that carbon acts not just as a radical quencher but because of its association to the quartz surface.

  14. Microstructural analysis of quartz crystals in an andalusite-cordierite schist using electron backscatter diffraction

    International Nuclear Information System (INIS)

    Rahimi-Chakdel, A.; Boyle, A. P.

    2012-01-01

    The present study investigates the shape preferred orientation and crystal preferred orientation of quartz crystals using electron backscatter diffraction in andalusite-cordierite schist from the Ythan Valley, Aberdeenshire, in the Scottish Dalradian block. Quartz crystals in the matrix and andalusite pophyroblasts have inequant to slightly equant shapes. Quartz crystals show weak shape preferred orientation in the matrix and andalusite pophyroblasts, which are sub-parallel to each other. The weak shape preferred orientation in quartz crystals of the studied sample can be related to (1) Grain boundary migration of quartz crystals and (2) non-quartz crystals (e.g. mica) at junction of quartz crystals. Also, quartz crystals show random crystal preferred orientation in the matrix and inclusion. The lack of crystal preferred orientation of quartz crystals in the matrix can be explained by (i) absence, or low amounts of strain in the rock that is experienced only low temperature and pressure and (ii) diffusion creep. The random crystallographic orientation of quartz inclusions may confirm non-selective orientations of the matrix quartz crystals by andalusite pophyroblast during growth.

  15. Experimental deformation in sandstone, carbonates and quartz aggregate

    Energy Technology Data Exchange (ETDEWEB)

    Cheung, Cecilia See Nga [Stony Brook Univ., NY (United States)

    2015-05-01

    The first part of my thesis is mainly focused on the effect of grain size distribution on compaction localization in porous sandstone. To identify the microstructural parameters that influence compaction band formation, I conducted a systematic study of mechanical deformation, failure mode and microstructural evolution in Bleurswiller and Boise sandstones, of similar porosity (~25%) and mineralogy but different sorting. Discrete compaction bands were observed to develop over a wide range of pressure in the Bleurswiller sandstone that has a relatively uniform grain size distribution. In contrast, compaction localization was not observed in the poorly sorted Boise sandstone. My results demonstrate that grain size distribution exerts important influence on compaction band development, in agreement with recently published data from Valley of Fire and Buckskin Gulch, as well as numerical studies. The second part aimed to improve current knowledge on inelastic behavior, failure mode and brittle-ductile transition in another sedimentary rock, porous carbonates. A micritic Tavel (porosity of ~13%) and an allochemical Indiana (~18%) limestones were deformed under compaction in wet and dry conditions. At lower confining pressures, shear localization occurred in brittle faulting regime. Through transitional regime, the deformation switched to cataclastic flow regime at higher confining pressure. Specifically in the cataclastic regime, the (dry and wet) Tavel and dry Indiana failed by distributed cataclastic flow, while in contrast, wet Indiana failed as compaction localization. My results demonstrate that different failure modes and mechanical behaviors under different deformation regimes and water saturation are fundamental prior to any geophysical application in porous carbonates. The third part aimed to focus on investigating compaction on quartz aggregate starting at low (MPa) using X-ray diffraction. We report the diffraction peak evolution of quartz with increasing

  16. Amplifier Module for 260-GHz Band Using Quartz Waveguide Transitions

    Science.gov (United States)

    Padmanabhan, Sharmila; Fung, King Man; Kangaslahti, Pekka P.; Peralta, Alejandro; Soria, Mary M.; Pukala, David M.; Sin, Seth; Samoska, Lorene A.; Sarkozy, Stephen; Lai, Richard

    2012-01-01

    Packaging of MMIC LNA (monolithic microwave integrated circuit low-noise amplifier) chips at frequencies over 200 GHz has always been problematic due to the high loss in the transition between the MMIC chip and the waveguide medium in which the chip will typically be used. In addition, above 200 GHz, wire-bond inductance between the LNA and the waveguide can severely limit the RF matching and bandwidth of the final waveguide amplifier module. This work resulted in the development of a low-loss quartz waveguide transition that includes a capacitive transmission line between the MMIC and the waveguide probe element. This capacitive transmission line tunes out the wirebond inductance (where the wire-bond is required to bond between the MMIC and the probe element). This inductance can severely limit the RF matching and bandwidth of the final waveguide amplifier module. The amplifier module consists of a quartz E-plane waveguide probe transition, a short capacitive tuning element, a short wire-bond to the MMIC, and the MMIC LNA. The output structure is similar, with a short wire-bond at the output of the MMIC, a quartz E-plane waveguide probe transition, and the output waveguide. The quartz probe element is made of 3-mil quartz, which is the thinnest commercially available material. The waveguide band used is WR4, from 170 to 260 GHz. This new transition and block design is an improvement over prior art because it provides for better RF matching, and will likely yield lower loss and better noise figure. The development of high-performance, low-noise amplifiers in the 180-to- 700-GHz range has applications for future earth science and planetary instruments with low power and volume, and astrophysics array instruments for molecular spectroscopy. This frequency band, while suitable for homeland security and commercial applications (such as millimeter-wave imaging, hidden weapons detection, crowd scanning, airport security, and communications), also has applications to

  17. Mineralogy, morphology, and textural relationships in coatings on quartz grains in sediments in a quartz-sand aquifer

    Science.gov (United States)

    Zhang, Shouliang; Kent, Douglas B.; Elbert, David C.; Shi, Zhi; Davis, James A.; Veblen, David R.

    2011-01-01

    Mineralogical studies of coatings on quartz grains and bulk sediments from an aquifer on Western Cape Cod, Massachusetts, USA were carried out using a variety of transmission electron microscopy (TEM) techniques. Previous studies demonstrated that coatings on quartz grains control the adsorption properties of these sediments. Samples for TEM characterization were made by a gentle mechanical grinding method and focused ion beam (FIB) milling. The former method can make abundant electron-transparent coating assemblages for comprehensive and quantitative X-ray analysis and the latter technique protects the coating texture from being destroyed. Characterization of the samples from both a pristine area and an area heavily impacted by wastewater discharge shows similar coating textures and chemical compositions. Major constituents of the coating include Al-substituted goethite and illite/chlorite clays. Goethite is aggregated into well-crystallized domains through oriented attachment resulting in increased porosity. Illite/chlorite clays with various chemical compositions were observed to be mixed with goethite aggregates and aligned sub-parallel to the associated quartz surface. The uniform spatial distribution of wastewater-derived phosphorus throughout the coating from the wastewater-contaminated site suggests that all of the coating constituents, including those adjacent to the quartz surface, are accessible to groundwater solutes. Both TEM characterization and chemical extraction results indicate there is a significantly greater amount of amorphous iron oxide in samples from wastewater discharge area compared to those from the pristine region, which might reflect the impact of redox cycling of iron under the wastewater-discharge area. Coating compositions are consistent with the moderate metal and oxy-metalloid adsorption capacities, low but significant cation exchange capacities, and control of iron(III) solubility by goethite observed in reactive transport

  18. Accurate measurements of the acoustical physical constants of synthetic alpha-quartz for SAW devices.

    Science.gov (United States)

    Kushibiki, Juin-ichi; Takanaga, Izumi; Nishiyama, Shouichi

    2002-01-01

    Accurate measurements of the acoustical physical constants (elastic constants, piezoelectric constants, dielectric constants, and density) of commercially available and widely used surface acoustic wave (SAW)-grade synthetic a-quartz are reported. The propagation directions and modes of bulk waves optimal for accurately determining the constants were selected through numerical calculations, and three principal X-, Y-, and Z-cut specimens and several rotated Y-cut specimens were prepared from a single crystal ingot to determine the constants and to confirm their accuracy. All of the constants were determined through highly accurate measurements of the longitudinal velocities, shear velocities, dielectric constants, and density. The velocity values measured for the specimens that were not used to determine the constants agreed well with those calculated from the determined constants, within a difference of +/- 0.20 m/s (+/- 0.004%).

  19. Separate density and viscosity measurements of unknown liquid using quartz crystal microbalance

    Directory of Open Access Journals (Sweden)

    Feng Tan

    2016-09-01

    Full Text Available Aqueous liquids have a wide range of applications in many fields. Basic physical properties like the density and the viscosity have great impacts on the functionalities of a given ionic liquid. For the millions kinds of existing liquids, only a few have been systematically measured with the density and the viscosity using traditional methods. However, these methods are limited to measure the density and the viscosity of an ionic liquid simultaneously especially in processing micro sample volumes. To meet this challenge, we present a new theoretical model and a novel method to separate density and viscosity measurements with single quartz crystal microbalance (QCM in this work. The agreement of experimental results and theocratical calculations shows that the QCM is capable to measure the density and the viscosity of ionic liquids.

  20. Retrospective dosimetry using Japanese brick quartz: A way forward despite an unstable fast decaying OSL signal

    DEFF Research Database (Denmark)

    Fujita, Hiroki; Jain, Mayank; Murray, A.S.

    2011-01-01

    peak, which necessitates a prior heat treatment. A single-aliquot regenerative-dose (SAR) protocol is developed and tested using thermal treatments intended to isolate a stable dosimetric signal. A minimum detection limit of 65 mGy is then estimated using this protocol. Following irradiation using 60Co......) characteristics of quartz extracted from a Japanese commercial red brick produced by Mishima – Renga – Seizoujyo Co. are studied. These companies are based in the Aichi Prefecture (capital Nagoya), which accounts for about half of the red brick production in Japan. A comparison of TL (thermoluminescence) and OSL...... and 137Cs, dose–depth profiles were measured on two different commercial brick types (Mishima – Renga – Seizoujyo Co. and Hase – Renga Co.) with 5 Gy and 10 Gy surface doses. The profiles derived from the two sources were readily distinguishable. It is concluded that the OSL signals from the two types...

  1. Using optically stimulated electrons from quartz for the estimation of natural doses

    DEFF Research Database (Denmark)

    Ankjærgaard, Christina; Murray, A.S.; Denby, Phil M.

    2009-01-01

    A flow-through Geiger-Müller pancake electron detector attachment has been fitted to a standard Risø TL/OSL reader enabling optically stimulated electrons (OSE) to be measured simultaneously with optically stimulated luminescence (OSL). Using this detector, OSE and OSL measurements from natural......, a dose recovery test shows that OSE can successfully recover a laboratory dose of 300 Gy given before any laboratory thermal treatment, for preheating temperatures between 160 and 260 °C. Furthermore, for the first time natural OSE decay curves are detected and these signals are used to estimate a burial...... dose using the single-aliquot regenerative-dose (SAR) procedure. Finally, a comparative study of the equivalent doses estimated using both OSE and OSL from 10 quartz samples are presented, and it is shown that OSE has a significant potential in retrospective dosimetry....

  2. Piezoelectric characterization and thermal stability of a high-performance α-quartz-type material, gallium arsenate

    International Nuclear Information System (INIS)

    Cambon, Olivier; Haines, Julien; Fraysse, Guillaume; Detaint, Jacques; Capelle, Bernard; Lee, Arie van der

    2005-01-01

    Piezoelectric measurements were performed on large single crystals (8 mm along the c direction) of an α-quartz-type piezoelectric material, gallium arsenate, GaAsO 4 , which allow us to extend the structure-property relationships in the α-quartz-type materials. These first measurements on Y-rotated-cut plates have shown that gallium arsenate is the highest-performance piezoelectric material of this group. As compared to the coupling coefficients of the other materials with the same structure (k SiO 2 =8%, k AlPO 4 =11%, and k GaPO 4 =16%), gallium arsenate exhibits the highest piezoelectric coupling coefficient of about 22%, as has been predicted by the structure-property relationships. Moreover, from these piezoelectric measurements, the C 66 ' elastic constant was determined and compared with elastic constants in quartz-type materials. The proposed value for the cut angle of the AT plane in GaAsO 4 is -6.3 deg. . In order to extend the previous thermal stability results, thermal gravimetric analysis (TGA) and x-ray diffraction have been carried out on GaAsO 4 powder at high temperatures. It has been shown that GaAsO 4 is stable up to 1030 deg. C. The thermal-expansion coefficient of GaAsO 4 is 4.0x10 -5 K -1 . The thermal expansion of the predicted AT plane (Y-6.3 deg. ) in GaAsO 4 is shown to be similar to that of the other materials. Finally, it is demonstrated that the intertetrahedral bridging angle θ (A-O-B) of GaAsO 4 is the most stable in α-quartz materials, which enables one to predict that GaAsO 4 should retain high piezoelectric performances up to 925 deg. C

  3. Evaluating flow laws for dynamically recrystallized quartz based on field data

    Science.gov (United States)

    Peters, Max; Herwegh, Marco

    2013-04-01

    deformation rates between different calibrations for one corresponding grain size. The calibrations of Paterson & Luan (1990) and Hirth et al. (2001) yield most reliable results for peak metamorphic conditions, which are in line with the geological framework. Strain rates range between 10E-13 and 10E-10 s-1 (Paterson & Luan, 1990) with corresponding flow stresses between ca. 200 MPa (BLG) to ca. 20 MPa (SGR and transition SGR-GBM). Nevertheless, the applicability of single flow laws shall be discussed in greater detail. REFERENCES Herwegh, M., de Bresser, J.H.P. and ter Heege, J.H. 2005: Combining natural microstructures with composite flow laws: an improved approach for the extrapolation of lab data to nature. Journal of Structural Geology, 27. Hirth, G., Teyssier, C. and Dunlap, W.J. 2011: An evaluation of quartzite flow laws based on comparisons between experimentally and naturally deformed rocks. International Journal of Earth Sciences, 90. Luan, F.C. and Paterson, S.R. 1992: Perparation and deformation of synthetic aggregates of quartz. Journal of Geophysical Research, 97. Paterson, S.R. and Luan, F.C. 1990: Quartzite rheology under geological conditions. In: de Meer, S., Drury, M.R., de Bresser, J.H.P., Pennock, G.M Deformation mechanisms, rheology and tectonics: from minerals to the lithosphere. Geological Society of Lonodn Special Publications, 54. Rutter, E.H. and Brodie, K.H. 2004: Experimental grain size-sensitive flow of hot-pressed Brazilian quartz aggregates. Journal of Structural Geology, 26. Stipp, M. and Tullis, J. 2003: The recrystallized grain size piezometer for quartz. Geophysical Research Letters, 30.

  4. Thermal dependence of luminescence lifetimes and radioluminescence in quartz

    Energy Technology Data Exchange (ETDEWEB)

    Pagonis, V., E-mail: vpagonis@mcdaniel.edu [McDaniel College, Physics Department, Westminster, MD 21157 (United States); Chithambo, M.L. [Department of Physics and Electronics, Rhodes University, PO BOX 94, Grahamstown 6140 (South Africa); Chen, R. [Raymond and Beverly Sackler School of Physics and Astronomy, Tel-Aviv University, Tel-Aviv 69978 (Israel); Chruścińska, A. [Institute of Physics, Nicholas Copernicus University, 87-100 Toruń (Poland); Fasoli, M. [Department of Materials Science, University of Milano-Bicocca, Via Cozzi 53, 20125 Milano (Italy); Li, S.H. [Department of Earth Sciences, The University of Hong Kong (Hong Kong); Martini, M. [Department of Materials Science, University of Milano-Bicocca, Via Cozzi 53, 20125 Milano (Italy); Ramseyer, K. [Institut für Geologie, Baltzerstrasse 1-3, 3012 Bern (Switzerland)

    2014-01-15

    During time-resolved optical stimulation experiments (TR-OSL), one uses short light pulses to separate the stimulation and emission of luminescence in time. Experimental TR-OSL results show that the luminescence lifetime in quartz of sedimentary origin is independent of annealing temperature below 500 °C, but decreases monotonically thereafter. These results have been interpreted previously empirically on the basis of the existence of two separate luminescence centers L{sub H} and L{sub L} in quartz, each with its own distinct luminescence lifetime. Additional experimental evidence also supports the presence of a non-luminescent hole reservoir R, which plays a critical role in the predose effect in this material. This paper extends a recently published analytical model for thermal quenching in quartz, to include the two luminescence centers L{sub H} and L{sub L}, as well as the hole reservoir R. The new extended model involves localized electronic transitions between energy states within the two luminescence centers, and is described by a system of differential equations based on the Mott–Seitz mechanism of thermal quenching. It is shown that by using simplifying physical assumptions, one can obtain analytical solutions for the intensity of the light during a TR-OSL experiment carried out with previously annealed samples. These analytical expressions are found to be in good agreement with the numerical solutions of the equations. The results from the model are shown to be in quantitative agreement with published experimental data for commercially available quartz samples. Specifically the model describes the variation of the luminescence lifetimes with (a) annealing temperatures between room temperature and 900 °C, and (b) with stimulation temperatures between 20 and 200 °C. This paper also reports new radioluminescence (RL) measurements carried out using the same commercially available quartz samples. Gaussian deconvolution of the RL emission spectra was

  5. Quartz dustiness: A key factor in controlling exposure to crystalline silica in the workplace.

    Science.gov (United States)

    López-Lilao, A; Escrig, A; Orts, M J; Mallol, Gustavo; Monfort, E

    2016-11-01

    The classification of Respirable Crystalline Silica (RCS) as carcinogenic for humans has drawn greater attention to crystalline silica exposure in the workplace in recent years, leading to recommendations by safety and health bodies in Europe and the U.S. for lower occupational exposure limits. In view of this new scenario, the present study examined quartz dustiness, as quartz handling is a major source of crystalline silica in the workplace. The study was conducted on test samples with different mean particle sizes, prepared from several commercial quartzes. The quartz particle samples were characterised and the influence of certain quartz particle parameters on quartz dustiness was determined. The results indicate that quartz dustiness may be significantly affected by mean particle size, specific surface area, the Hausner ratio, and fine particle content. The study shows that, in order to minimise the adverse health effects associated with the inhalation of crystalline silica, quartz dustiness may be deemed a key factor in controlling the generation of fugitive quartz emissions during quartz processing, both into the outside atmosphere (air pollution) and inside the facilities (occupational health).

  6. Quartz exsolution topotaxy in clinopyroxene from the UHP eclogite of Weihai, China

    Science.gov (United States)

    Xu, Haijun; Zhang, Junfeng; Zong, Keqing; Liu, Liang

    2015-06-01

    Abundant oriented silica precipitates of α-quartz (4.0 ± 1.0 vol.%), in part coexisting with calcic amphiboles (topotactic relationships with their host clinopyroxenes. Three types of crystallographic topotactic relationship have been identified between quartz and host clinopyroxene: (1) 52% quartz precipitates share the same orientation for the c-axes with [0001]qz//[001]cpx; (2) 34% quartz precipitates share the same orientation for the a-axes with [11 2 bar0]qz//[001]cpx; and (3) 11% quartz precipitates share the same orientation for the s-planes with (11 2 bar1)qz//(100)cpx. Other quartz axes and planes disperse in large or small girdles around the shared axes or planes. Many quartz rods/needles are elongated parallel to the [001]cpx with the long axes of quartz being either [0001]qz or [11 2 bar0]qz. Amphibole precipitates have also a strong crystallographic relationship with host clinopyroxene, i.e., (100)amp//(100)cpx, [010]amp//[010]cpx, and [001]amp//[001]cpx. These results provide quantitative microstructural evidence supporting an exsolution origin for oriented quartz needles/rods in clinopyroxene and demonstrate that the exsolution of quartz from clinopyroxene occurred within the stability field of α-quartz rather than coesite. The oriented precipitates of α-quartz, in part coexisting with calcic amphiboles, in host clinopyroxene are probably promoted by supercritical fluid or partial melting during the early exhumation of eclogites. Our results suggest that oriented quartz precipitates in clinopyroxene cannot be used as an indisputable UHP-indicator.

  7. Synchrotron FTIR imaging of OH in quartz mylonites

    Directory of Open Access Journals (Sweden)

    A. K. Kronenberg

    2017-10-01

    Full Text Available Previous measurements of water in deformed quartzites using conventional Fourier transform infrared spectroscopy (FTIR instruments have shown that water contents of larger grains vary from one grain to another. However, the non-equilibrium variations in water content between neighboring grains and within quartz grains cannot be interrogated further without greater measurement resolution, nor can water contents be measured in finely recrystallized grains without including absorption bands due to fluid inclusions, films, and secondary minerals at grain boundaries.Synchrotron infrared (IR radiation coupled to a FTIR spectrometer has allowed us to distinguish and measure OH bands due to fluid inclusions, hydrogen point defects, and secondary hydrous mineral inclusions through an aperture of 10 µm for specimens > 40 µm thick. Doubly polished infrared (IR plates can be prepared with thicknesses down to 4–8 µm, but measurement of small OH bands is currently limited by strong interference fringes for samples < 25 µm thick, precluding measurements of water within individual, finely recrystallized grains. By translating specimens under the 10 µm IR beam by steps of 10 to 50 µm, using a software-controlled x − y stage, spectra have been collected over specimen areas of nearly 4.5 mm2. This technique allowed us to separate and quantify broad OH bands due to fluid inclusions in quartz and OH bands due to micas and map their distributions in quartzites from the Moine Thrust (Scotland and Main Central Thrust (Himalayas.Mylonitic quartzites deformed under greenschist facies conditions in the footwall to the Moine Thrust (MT exhibit a large and variable 3400 cm−1 OH absorption band due to molecular water, and maps of water content corresponding to fluid inclusions show that inclusion densities correlate with deformation and recrystallization microstructures. Quartz grains of mylonitic orthogneisses and paragneisses deformed

  8. Calculations on the stress compensated (SC-cut) quartz resonator

    International Nuclear Information System (INIS)

    EerNisse, E.P.

    1976-01-01

    Theoretical calculations have been carried out on the doubly-rotated SC-cut quartz resonator. The resonant frequency of this resonator is free from the third-order elastic constant effects of static mechanical stress bias. Calculations show that this stress compensation can be adjusted independently from the temperature compensation during fabrication. Angular tolerances necessary to attain the stress compensation are investigated. The theoretical results are shown to agree quantitatively with recently published thermal shock measurements. Gneral expressions for the SC-cut and AT-cut are provided to allow simple calculation of the frequency shifts due to any static mechanical stress bias

  9. Synchrotron FTIR imaging of OH in quartz mylonites

    Energy Technology Data Exchange (ETDEWEB)

    Kronenberg, Andreas K.; Hasnan, Hasnor F. B.; Holyoke III, Caleb W.; Law, Richard D.; Liu, Zhenxian; Thomas, Jay B.

    2017-01-01

    Previous measurements of water in deformed quartzites using conventional Fourier transform infrared spectroscopy (FTIR) instruments have shown that water contents of larger grains vary from one grain to another. However, the non-equilibrium variations in water content between neighboring grains and within quartz grains cannot be interrogated further without greater measurement resolution, nor can water contents be measured in finely recrystallized grains without including absorption bands due to fluid inclusions, films, and secondary minerals at grain boundaries.

    Synchrotron infrared (IR) radiation coupled to a FTIR spectrometer has allowed us to distinguish and measure OH bands due to fluid inclusions, hydrogen point defects, and secondary hydrous mineral inclusions through an aperture of 10 µm for specimens > 40 µm thick. Doubly polished infrared (IR) plates can be prepared with thicknesses down to 4–8 µm, but measurement of small OH bands is currently limited by strong interference fringes for samples < 25 µm thick, precluding measurements of water within individual, finely recrystallized grains. By translating specimens under the 10 µm IR beam by steps of 10 to 50 µm, using a software-controlled x-y stage, spectra have been collected over specimen areas of nearly 4.5 mm2. This technique allowed us to separate and quantify broad OH bands due to fluid inclusions in quartz and OH bands due to micas and map their distributions in quartzites from the Moine Thrust (Scotland) and Main Central Thrust (Himalayas).

    Mylonitic quartzites deformed under greenschist facies conditions in the footwall to the Moine Thrust (MT) exhibit a large and variable 3400 cm-1 OH absorption band due to molecular water, and maps of water content corresponding to fluid inclusions show that inclusion densities correlate with deformation and recrystallization microstructures. Quartz grains of mylonitic orthogneisses and

  10. Quartz Crystal Microbalance Operation and In Situ Calibration

    Science.gov (United States)

    Albyn, K. C.

    2004-01-01

    Quartz crystal microbalances (QCMs) are commonly used to measure the rate of deposition of molecular species on a surface. The measurement is often used to select materials with a low outgassing rate for applications where the material has a line of sight to a contamination-sensitive surface. A quantitative, in situ calibration of the balance, or balances, using a pure material for which the enthalpy of sublimation is known, is described in this Technical Memorandum. Supporting calculations for surface dwell times of deposited materials and the effusion cell Clausing factor are presented along with examples of multiple QCM measurements of outgassing from a common source.

  11. Sputtering measurements using a quartz crystal microbalance as a catcher

    Science.gov (United States)

    Berger, Bernhard M.; Szabo, Paul S.; Stadlmayr, Reinhard; Aumayr, Friedrich

    2017-09-01

    A quartz crystal microbalance (QCM) catcher setup for sputter yield measurements is described. In this setup a QCM is placed next to the sputter target and acts as a catcher for sputtered material. The sputter yield evaluation relies on assumptions about the angular distribution of sputtered particles and reflected primary projectiles taken from simulations as well as on the knowledge of the sticking coefficient. To test this new setup a second QCM with a Au layer was used as a sputter target. The measured ratio between target and catcher signal is well reproduced in the simulations demonstrating the feasibility of reconstructing the sputtering yield from the catcher signal.

  12. Monolithic Micromachined Quartz Resonator based Infrared Focal Plane Arrays

    Science.gov (United States)

    2012-05-05

    prototypes of integrated micromachined IR detectors consisting of 200 μm diameter QCM resonators, 241 MHz (6.9 μm) thick 5 x 5 resonator arrays from Y-cut...of small QCM devices. • A novel measurement method for the real-time tracking of the resonance frequency based on impedance measurement around the...miniaturize QCM ? • Micromachining Quartz • Evaluation of QCM MicroArrays • Adsorption Experiments – Human Serum Albumin, IgG, and Human Fibrinogen Adsorption

  13. BARRINGER AWARD ADDRESS: Shock Metamorphism of Quartz in Nature and Experiment: A Review

    Science.gov (United States)

    Stoffler, D.

    1993-07-01

    Quartz as a widespread rock-forming mineral of the Earth's crust represents the most sensitive indicator of impact-induced shock waves and therefore provides an outstanding tool for the recognition of terrestrial impact formations and for the pressure calibration of shock metamorphosed rocks. This paper attempts to summarize the current knowledge in this field. Shocked quartz has been observed in quite variable spatial relations to impact craters: (1) in the crater basement, (2) in rock and mineral clasts of polymict breccias, and (3) in distal ejecta such as tektites and global air- fall beds (e.g., K/T boundary). Quartz displays a wide variety of shock- induced mechanical deformations and transformations [1,2]. Microscopically observable effects are multiple sets of planar fractures (PF) and planar deformation features (PDF) parallel to low indices crystallographic planes; mosaickism; reduced refractivity and birefringence; partial transformation to stishovite; increased optic axial angle; amorphization (diaplectic glass), partial transformation to coesite; and melting (lechatelierite). Additional effects at the atomic scale are well documented by TEM, X-ray diffraction and spectroscopy [3-7]. All types of shock effects observed so far in natural quartz have been reproduced by experimental shock waves in the laboratory and in large scale TNT and nuclear explosions. By means of sophisticated techniques the pressure dependence of shock effects has been calibrated with high precision. Threshold pressures at room temperature (given in GPa) for the onset of certain effects in single crystals and in nonporous quartzofeldpathic rocks are: 7.5 +- 2, 10 +- 2, 20 +- 2 (various PFs and PDFs), 12 +- 1 (stishovite), 25 +- 1 (reduced refractive index and density), ~30 (coesite), 34 +- 1 (total transformation to diaplectic glass), 50 +- 2 (melting and formation of lechatelierite) [8-12]. The type of shock effects, their paragenetic combination, and their formation pressure are

  14. Evaluación de factores camión de los vehículos comerciales de carga que circulan por la red vial principal colombiana

    Directory of Open Access Journals (Sweden)

    Luis F. Macea

    2013-01-01

    Full Text Available La estimación del tránsito es uno de los aspectos más importantes en el análisis y diseño estructural de pavimentos y para su adecuada determinación se hace necesario disponer de valores de factor camión actualizados. En el presente estudio se evaluaron los factores camión de los vehículos comerciales de carga de la red vial primaria de Colombia. Con este objetivo, en el año 2011 se realizaron treinta y ocho operativos móviles de pesaje de ejes en carretera, localizados en distintos puntos estratégicos de la red vial nacional. Como resultado se obtuvo, a través de procedimientos estadísticos, factores camión actualizados y representativos para cada tipo de camión que circula en las vías analizadas. Estos factores camión podrían ser utilizados en el diseño de tramos carreteros con características socioeconómicas similares a aquellas de las vías evaluadas. De igual forma, se encontró que a nivel nacional la flota vehicular de carga está compuesta por los camiones tipo C3-S3, C2, C3-S2, C3 y C2-S2 con una distribución del 36%, 35%, 13%, 11% y 5%, respectivamente. Adicionalmente, se observó que los camiones C3 y C3-S3 son los que mayor daño le causan a la infraestructura vial colombiana, ya que se encuentran circulando excesivamente sobrecargados en algunos tramos departamentales del país.

  15. Inestabilidad de laderas e infraestructura vial: análisis de susceptibilidad en la Sierra Nororiental de Puebla, México

    OpenAIRE

    José Alejandro Galindo Serrano; Irasema Alcántara-Ayala

    2015-01-01

    En México y diversas partes del mundo los desastres asociados a la inestabilidad de laderas generan impactos negativos en el ámbito socio-económico y ambiental. Además de las pérdidas de vida, y el daño a la cubierta vegetal, las afectaciones a las viviendas y la infraestructura son frecuentes; en los últimos años, la destrucción y deterioro en la infraestructura vial ha sido de particular importancia. Entre las diferentes áreas del país que de manera recurrente suelen ser afectadas por inest...

  16. Implementación de un sistema integral de seguridad y Salud Ocupacional en Construcción de obras Viales para la Región Puno

    OpenAIRE

    Sardón Rojas, Freddy Antonio

    2015-01-01

    El presente trabajo brinda criterios y herramientas para la elaboración e implementación de un sistema integral de seguridad y salud ocupacional en construcción de obras viales para la Región Puno, tomando como referencia el Sistema Internacional de Gestión de Seguridad y Salud OHSAS 18001 y la normativa peruana vigente en materia de seguridad y salud en el trabajo para el sector construcción; entre las más importantes la nueva Ley 29783 ” Ley de seguridad y salud en e...

  17. Análisis de sostenibilidad socio – ambiental en el proyecto de infraestructura vial, tramo carreteable Neiva – Campoalegre, en el departamento del Huila

    OpenAIRE

    Gómez Galindo, Nury Xiomara

    2017-01-01

    Tesis (Maestría en Desarrollo Sostenible y Medio Ambiente). Universidad de Manizales. Facultad de Ciencias Contables, Económicas y Administrativas. CIMAD, 2017 El objetivo general se enmarca en realizar un análisis de los factores de sostenibilidad socio – ambiental en el proyecto de infraestructura vial, tramo carreteable Neiva – Campoalegre, en el departamento del Huila, haciendo uso de una metodología de enfoque mixto, que además de conocer cuantitativamente el grado de aceptación, la s...

  18. Estudio de ahorro energético del alumbrado público de viales y bulevar de la Alameda de San Antón, Cartagena

    OpenAIRE

    Olmos Avilés, Javier

    2015-01-01

    El objetivo principal del trabajo reside en el estudio de un entorno iluminado artificialmente y proponer la mejor alternativa para reducir el consumo energético, y por tanto, disminuir las emisiones de CO2 a la atmósfera en un municipio. La elaboración de este Trabajo se llevará a cabo en dos fases: • Primera fase: estudio del estado actual de los viales y bulevar. Los objetivos de esta fase son: o Adquisición de todos los datos posibles sobre el consumo energético actual. ...

  19. Aplicación de la Teoría de la Conducta Planificada en la Seguridad Vial: velocidad, alcohol y drogas.

    OpenAIRE

    Pintado Giménez, Mª del Mar

    2017-01-01

    El estudio de las actitudes sigue siendo una de las investigaciones principales de los psicólogos sociales. Las actitudes son objeto de estudio en diferentes disciplinas como la salud, la política, la economía o la publicidad. Las actitudes adquieren una especial relevancia en el ámbito de la seguridad vial ya que desempeñan un papel fundamental en el cambio social. En esta tesis se atiende a las relaciones que se establecen entre la actitud y la conducta. Interesa conocer no só...

  20. Cambios en las concesiones viales en Uruguay: un análisis basado en la teoría de subastas

    Directory of Open Access Journals (Sweden)

    Andrés Pereyra

    2010-06-01

    Full Text Available Este trabajo analiza el impacto de la privatización de un concesionario vial de propiedad estatal sobre el valor de las inversiones futuras, considerando que el gobierno puede manejar la asimetría de información con el concesionario. Mediante un modelo basado en la teoría de subastas se estima el impacto, para el gobierno, de privatizar al concesionario sin modificar el contrato vigente. Si se decidiera privatizar al concesionario, se requerían modificaciones significativas en el contrato, especialmente si no hay cambios institucionales que mejoren la capacidad de supervisión y control del gobierno.

  1. Auditorías de seguridad vial como políticas para mejorar la seguridad del transporte en la provincia de Chimborazo-Ecuador

    OpenAIRE

    Paredes García, Angel

    2016-01-01

    [ES] La provincia de Chimborazo localizada en el centro del país se encuentra atravesada por una de las principales carreteras denominadas Troncal de la Sierra, la misma que conecta Colombia, Ecuador y Perú. Una auditoría de seguridad vial es un análisis formal que pretende garantizar que un camino, en nuestro caso existente, cumpla con criterios óptimos de seguridad. Dichas auditorías deben ser llevadas a cabo por un equipo de profesionales, cuyos miembros sean independientes ...

  2. Outbreak of silicosis in Spanish quartz conglomerate workers

    Science.gov (United States)

    Pérez-Alonso, Aránzazu; Córdoba-Doña, Juan Antonio; Millares-Lorenzo, José Luis; Figueroa-Murillo, Estrella; García-Vadillo, Cristina; Romero-Morillo, José

    2014-01-01

    Objectives: To describe the epidemiological and clinical characteristics of an outbreak of occupational silicosis and the associated working conditions. Methods: Cases were defined as men working in the stone cutting, shaping, and finishing industry in the province of Cádiz, diagnosed with silicosis between July 2009 and May 2012, and were identified and diagnosed by the department of pulmonology of the University Hospital of Puerto Real (Cádiz). A census of workplaces using quartz conglomerates was carried out to determine total numbers of potentially exposed workers. A patient telephone survey on occupational exposures and a review of medical records for all participants were conducted. Results: Silicosis was diagnosed in 46 men with a median age of 33 years and a median of 11 years working in the manufacturing of countertops. Of these cases, 91.3% were diagnosed with simple chronic silicosis, with an abnormal high-resolution computerized tomography (HRCT) scan. One patient died during the study period. Employer non-compliance in prevention and control measures was frequently reported, as were environmental and individual protection failures. Conclusions: The use of new construction materials such as quartz conglomerates has increased silicosis incidence due to intensive occupational exposures, in the context of high demand fuelled by the housing boom. This widespread exposure poses a risk if appropriate preventive measures are not undertaken. PMID:24804337

  3. Assessing rare earth elements in quartz rich geological samples.

    Science.gov (United States)

    Santoro, A; Thoss, V; Ribeiro Guevara, S; Urgast, D; Raab, A; Mastrolitti, S; Feldmann, J

    2016-01-01

    Sodium peroxide (Na2O2) fusion coupled to Inductively Coupled Plasma Tandem Mass Spectrometry (ICP-MS/MS) measurements was used to rapidly screen quartz-rich geological samples for rare earth element (REE) content. The method accuracy was checked with a geological reference material and Instrumental Neutron Activation Analysis (INAA) measurements. The used mass-mode combinations presented accurate results (only exception being (157)Gd in He gas mode) with recovery of the geological reference material QLO-1 between 80% and 98% (lower values for Lu, Nd and Sm) and in general comparable to INAA measurements. Low limits of detection for all elements were achieved, generally below 10 pg g(-1), as well as measurement repeatability below 15%. Overall, the Na2O2/ICP-MS/MS method proved to be a suitable lab-based method to quickly and accurately screen rock samples originating from quartz-rich geological areas for rare earth element content; particularly useful if checking commercial viability. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. Inferring origin of mercury inclusions in quartz by multifractal analysis

    Science.gov (United States)

    Shibata, T.; Maruoka, T.; Echigo, T.

    2015-01-01

    In order to refine our understanding of how fluid inclusions were trapped in the host minerals, we non-destructively observed mercury inclusions (liquid Hg0) in quartz samples using X-ray computed tomography (CT) technique. The X-ray CT apparatus can observe internal structures of the samples and give cross-sectional images from the transmission of the X-rays through the samples. From the cross-sectional images, we obtained three-dimensional spatial distributions of mercury inclusions, and quantitatively analyzed them using fractal and multifractal methods. Although the samples were from different geological settings, the resultant fractal dimensions were 1.70 and 1.71 for the San Benito and Itomuka samples, respectively. The fractal dimensions were also close to those predicted by diffusion-limited aggregation models and percolation theory, which are controlled by the irreversible kinetics. Given the fractal dimension and its implied mechanism, we conclude that the mercury-bearing fluids were not primary fluid inclusions, but migrated into the pre-existing cracks of quartz crystals by diffusion processes.

  5. Electronic Nose using Gas Chromatography Column and Quartz Crystal Microbalance

    Directory of Open Access Journals (Sweden)

    Hari Agus Sujono

    2011-08-01

    Full Text Available The conventional electronic nose usually consists of an array of dissimilar chemical sensors such as quartz crystal microbalance (QCM combined with pattern recognition algorithm such as Neural network. Because of parallel processing, the system needs a huge number of sensors and circuits which may emerge complexity and inter-channel crosstalk problems. In this research, a new type of odor identification which combines between gas chromatography (GC and electronic nose methods has been developed. The system consists of a GC column and a 10-MHz quartz crystal microbalance sensor producing a unique pattern for an odor in time domain. This method offers advantages of substantially reduced size, interferences and power consumption in comparison to existing odor identification system. Several odors of organic compounds were introduced to evaluate the selectivity of the system. Principle component analysis method was used to visualize the classification of each odor in two-dimensional space. This system could resolve common organic solvents, including molecules of different classes (aromatic from alcohols as well as those within a particular class (methanol from ethanol and also fuels (premium from pertamax. The neural network can be taught to recognize the odors tested in the experiment with identification rate of 85 %. It is therefore the system may take the place of human nose, especially for poisonous odor evaluations.

  6. Respirable quartz hazard associated with coal mine roof bolter dust

    International Nuclear Information System (INIS)

    Joy, G.J.; Beck, T.W.; Listak, J.M.

    2010-01-01

    Pneumoconiosis has been reported to be increasing among underground coal miners in the Southern Appalachian Region. The National Institute for Occupational Safety and Health conducted a study to examine the particle size distribution and quartz content of dust generated by the installation of roof bolts in mines. Forty-six bulk samples of roof bolting machine pre-cleaner cyclone dump dust and collector box dust were collected from 26 underground coal mines. Real-time and integrated airborne respirable dust concentrations were measured on 3 mining sections in 2 mines. The real-time airborne dust concentrations profiles were examined to identify any concentration changes that might be associated with pre-cleaner cyclone dust discharge events. The study showed that bolter dust is a potential inhalation hazard due to the fraction of dust less than 10 μm in size, and the quartz content of the dust. The pre-cleaner cyclone dust was significantly larger than the collector box dust, indicating that the pre-cleaner functioned properly in removing the larger dust size fraction from the airstream. However, the pre-cleaner dust still contained a substantial amount of respirable dust. It was concluded that in order to maintain the effectiveness of a roof bolter dust collector, periodic removal of dust is required. Appropriate work procedures and equipment are necessary to minimize exposure during this cleaning task. 13 refs., 3 tabs., 2 figs.

  7. A combined nanoplasmonic and electrodeless quartz crystal microbalance setup

    International Nuclear Information System (INIS)

    Larsson, Elin M.; Langhammer, Christoph; Zoric, Igor; Kasemo, Bengt; Edvardsson, Malin E. M.

    2009-01-01

    We have developed an instrument combining localized surface plasmon resonance (LSPR) sensing with electrodeless quartz crystal microbalance with dissipation monitoring (QCM-D). The two techniques can be run simultaneously, on the same sensor surface, and with the same time resolution and sensitivity as for the individual techniques. The electrodeless QCM eliminates the need to fabricate electrodes on the quartz crystal and gives a large flexibility in choosing the surface structure and coating for both QCM-D and LSPR. The performance is demonstrated for liquid phase measurements of lipid bilayer formation and biorecognition events, and for gas phase measurements of hydrogen uptake/release by palladium nanoparticles. Advantages of using the combined equipment for biomolecular adsorption studies include synchronized information about structural transformations and extraction of molecular (dry) mass and degree of hydration of the adlayer, which cannot be obtained with the individual techniques. In hydrogen storage studies the combined equipment, allows for synchronized measurements of uptake/release kinetics and quantification of stored hydrogen amounts in nanoparticles and films at practically interesting hydrogen pressures and temperatures.

  8. A combined nanoplasmonic and electrodeless quartz crystal microbalance setup

    Science.gov (United States)

    Larsson, Elin M.; Edvardsson, Malin E. M.; Langhammer, Christoph; Zorić, Igor; Kasemo, Bengt

    2009-12-01

    We have developed an instrument combining localized surface plasmon resonance (LSPR) sensing with electrodeless quartz crystal microbalance with dissipation monitoring (QCM-D). The two techniques can be run simultaneously, on the same sensor surface, and with the same time resolution and sensitivity as for the individual techniques. The electrodeless QCM eliminates the need to fabricate electrodes on the quartz crystal and gives a large flexibility in choosing the surface structure and coating for both QCM-D and LSPR. The performance is demonstrated for liquid phase measurements of lipid bilayer formation and biorecognition events, and for gas phase measurements of hydrogen uptake/release by palladium nanoparticles. Advantages of using the combined equipment for biomolecular adsorption studies include synchronized information about structural transformations and extraction of molecular (dry) mass and degree of hydration of the adlayer, which cannot be obtained with the individual techniques. In hydrogen storage studies the combined equipment, allows for synchronized measurements of uptake/release kinetics and quantification of stored hydrogen amounts in nanoparticles and films at practically interesting hydrogen pressures and temperatures.

  9. A combined nanoplasmonic and electrodeless quartz crystal microbalance setup

    Energy Technology Data Exchange (ETDEWEB)

    Larsson, Elin M.; Langhammer, Christoph; Zoric, Igor; Kasemo, Bengt [Department of Applied Physics, Chemical Physics Group, Chalmers University of Technology, SE-41296 Gothenburg (Sweden); Edvardsson, Malin E. M. [Department of Applied Physics, Biological Physics Group, Chalmers University of Technology, SE-41296 Gothenburg (Sweden)

    2009-12-15

    We have developed an instrument combining localized surface plasmon resonance (LSPR) sensing with electrodeless quartz crystal microbalance with dissipation monitoring (QCM-D). The two techniques can be run simultaneously, on the same sensor surface, and with the same time resolution and sensitivity as for the individual techniques. The electrodeless QCM eliminates the need to fabricate electrodes on the quartz crystal and gives a large flexibility in choosing the surface structure and coating for both QCM-D and LSPR. The performance is demonstrated for liquid phase measurements of lipid bilayer formation and biorecognition events, and for gas phase measurements of hydrogen uptake/release by palladium nanoparticles. Advantages of using the combined equipment for biomolecular adsorption studies include synchronized information about structural transformations and extraction of molecular (dry) mass and degree of hydration of the adlayer, which cannot be obtained with the individual techniques. In hydrogen storage studies the combined equipment, allows for synchronized measurements of uptake/release kinetics and quantification of stored hydrogen amounts in nanoparticles and films at practically interesting hydrogen pressures and temperatures.

  10. Pulsed ESR measurements of oxygen deficient type centers in various quartz

    International Nuclear Information System (INIS)

    Yamanaka, C.; Kohno, H.; Ikeya, M.

    1996-01-01

    Phase-memory times T M for E'-centers in various quartz samples were measured by pulse-ESR. Manually ground quartz followed by γ-irradiation, α-irradiated quartz and that from a natural uranium deposit showed T M M of 15-18μs. Natural SiO 2 with dense spins, (∼ 3.96 Ga) and sandstone from an impact crater were also examined. (author)

  11. Three-dimensional thermoluminescence spectra of different origin quartz from Altay Orogenic belt, Xinjiang, China

    International Nuclear Information System (INIS)

    Tan Kaixuan; Liu Zehua; Zeng Sheng; Liu Yan; Xie Yanshi; Rieser, Uwe

    2009-01-01

    Three-dimensional thermoluminescence spectra are measured for different types of geological origin quartz from the Altay orogenic belt, northern Xinjiang, China. The results show striking differences which appear to be characteristic of their geological origin. Granitic quartz is dominated by emission bands at 420-430 nm, 550-560 nm, at a temperature of 170 deg. C. Pegmatite quartz is characterized by an intense 480 nm emission band at 170 deg. C. Volcanic quartz has exclusive UV (340-360 nm) and violet (410-430 nm) emission bands. Hydrothermal quartz exhibits very different TL spectral characteristics because of different hydrothermal activity and mineralization. Only one TL peaks at 485 nm/170 deg. C was observed in sedimentary quartz. An intense 730 nm emission band observed at 170 deg. C considered generally to be characteristics of feldspar was observed in quartz from granite and hydrothermal Au-bearing quartz. This TL peak is probably related to the centre of [FeO 4 ] 0 on an Si site. All samples show an intense 990-1000 nm emission band at 330 deg. C. Identical types of quartz formed in different regions or different geological and tectonic settings can also exhibit striking differences in TL spectra.

  12. Ionic diffusion in quartz studied by transport measurements, SIMS and atomistic simulations

    International Nuclear Information System (INIS)

    Sartbaeva, Asel; Wells, Stephen A; Redfern, Simon A T; Hinton, Richard W; Reed, Stephen J B

    2005-01-01

    Ionic diffusion in the quartz-β-eucryptite system is studied by DC transport measurements, SIMS and atomistic simulations. Transport data show a large transient increase in ionic current at the α-β phase transition of quartz (the Hedvall effect). The SIMS data indicate two diffusion processes, one involving rapid Li + motion and the other involving penetration of Al and Li atoms into quartz at the phase transition. Atomistic simulations explain why the fine microstructure of twin domain walls in quartz near the transition does not hinder Li + diffusion

  13. Planificación urbana, modernización vial y cambios en la vida cotidiana de Quito: el caso del barrio San Blas, 1967-1973

    Directory of Open Access Journals (Sweden)

    María Ángela Cifuentes Guerra

    2016-11-01

    Full Text Available La investigación analiza el impacto que la planicación urbana desarrollada por el Municipio de Quito tuvo sobre el centro histórico de la ciudad, en los años sesenta y setenta. Se examinan las políticas de modernización de la ciudad expresadas en una visión de ordenamiento territorial, interconexión zonal y desarrollo vial. Al mismo tiempo, se evalúan las consecuencias de estas intervenciones en la vida social. El análisis se centra en el caso del barrio de San Blas, escenario en el que se construyó el proyecto vial de conexión norte-sur, sobre la base de lo previsto en el Plan Director de Urbanismo de 1967. Se describen las consecuencias de estas intervenciones urbanas especialmente en el ámbito de la vida barrial y en el derrocamiento del emblemático edicio de la Biblioteca Nacional, en 1973.

  14. Beneficios económicos de Transmetro sobre la reducción de la accidentalidad vial en el área metropolitana de Barranquilla, Colombia

    Directory of Open Access Journals (Sweden)

    José Andrés Perdomo Calvo

    2015-01-01

    Full Text Available El principal objetivo de este documento es examinar la reducción de la accidentalidad vial en el área metropolitana de Barranquilla (AMBAQ, Colombia, a partir de la implementación del bus de tránsito rápido (BTR Transmetro, y estimar económicamente los beneficios sociales debidos a la disminución de muertes y heridos por accidentes de tránsito en esta área entre 2010 y 2011. Con este propósito, se emplearon los lineamientos teóricos sobre externalidades en economía del transporte y un análisis cuantitativo, mediante información secundaria, a través de modelos de series de tiempo ARIMAX con cambio estructural y el valor estadístico de la vida por accidentalidad vial en Colombia. De este modo, se determinó que el beneficio agregado anual por disminución de muertes en accidentes de tránsito en el AMBAQ en 2011 fue de $3.553’216.056, y para heridos graves fue de $13.732’882.320 aproximadamente.

  15. A Shandon PapSpin liquid-based gynecological test: A split-sample and direct-to-vial test with histology follow-up study

    Directory of Open Access Journals (Sweden)

    Rimiene J

    2010-01-01

    Full Text Available Background: Studies for liquid-based Papanicolaou (Pap tests reveal that liquid-based cytology (LBC is a safe and effective alternative to the conventional Pap smear. Although there is research on ThinPrep and SurePath systems, information is lacking to evaluate the efficiency and effectiveness of systems based on cytocentrifugation. This study is designed to determine the sensitivity and specificity of the Shandon PapSpin (ThermoShandon, Pittsburgh, Pennsylvania, USA liquid-based gynecological system. We used split-sample and direct-to-vial study design. Materials and Methods: 2,945 women referred to prophylactic check-up were enrolled in this study. Split sample design was used in 1,500 women and residual cervical cytology specimen from all these cases was placed in fluid for PapSpin preparation after performing conventional smear. The direct-to-vial study was carried out in another cohort of 1,445 women in whom the entire cervical material was investigated using only the PapSpin technique. Follow up histological diagnoses for 141 women were obtained from both study arms following 189 abnormal cytology cases. 80 LBC cases from the split sample group and 61 LBC cases in the direct-to-vial group were correlated with the histology results. The sensitivity and secificity of the conventional smear and PapSpin tests in both study arms were compared. Results: In the split sample group, conventional smears showed a higher proportion of ASC-US (atypical cells undetermined significance: 31 (2.1% vs 10 (0.7% in PapSpin (P = 0.001. A higher proportion of unsatisfactory samples was found in the conventional smear group: 25 (1.7% vs 6 (0.4% cases (P = 0.001. In the split sample group, the sensitivity of the conventional and PapSpin tests was 68.7% vs 78.1%, and the specificity 93.8% vs 91.8%, respectively. In the direct to vial group PapSpin sensitivity was 75.9% and specificity 96.5%. The differences in sensitivity and specificity were not significant. The

  16. Clinical utility of indigenously formulated single-vial lyophilized HYNIC-TOC kit in evaluating Gastro-entero Pancreatic neuro endocrine tumours

    Directory of Open Access Journals (Sweden)

    Ajit S Shinto

    2014-05-01

    Results: 99mTc HYNIC TOC showed sensitivity and specificity of 87.5% and 85.7%, respectively, for primary tumor and 100% and 86% for metastases. It was better than conventional imaging modalities for the detection of both primary tumor (P

  17. Clinical utility of indigenously formulated single-vial lyophilized HYNIC-TOC kit in evaluating Gastro-entero Pancreatic neuro endocrine tumours

    International Nuclear Information System (INIS)

    Shinto, Ajit S; Kamaleshwaran, K; Vyshak, K; Sudhakar, Natarajan; Banerjee, Sharmila; Korde, Aruna; Samuel, Grace; Mallia, Madhav

    2014-01-01

    The objective of this study was to evaluate the performance and utility of 99m Tc HYNIC-TOC planar scintigraphy and SPECT/CT in the diagnosis, staging and management of gastroenteropancreatic neuroendocrine tumors (GPNETs). 22 patients (median age, 46 years) with histologically proven gastro- entero- pancreatic NETs underwent 99m Tc HYNIC-TOC whole body scintigraphy and regional SPECT/CT as indicated. Scanning was performed after injection of 370-550 MBq (10-15 mCi) of 99m Tc HYNIC-TOC intravenously. Images were evaluated by two experienced nuclear medicine physicians both qualitatively as well as semi quantitatively (tumor to background and tumor to normal liver ratios on SPECT -CT images). Results of SPECT/CT were compared with the results of conventional imaging. Histopathology results and follow-up somatostatin receptor scintigraphy with 99m Tc HYNIC TOC or conventional imaging with biochemical markers were considered to be the reference standards. 99m Tc HYNIC TOC showed sensitivity and specificity of 87.5% and 85.7%, respectively, for primary tumor and 100% and 86% for metastases. It was better than conventional imaging modalities for the detection of both primary tumor (P<0.001) and metastases (P<0.0001). It changed the management strategy in 6 patients (31.8%) and supported management decisions in 8 patients (36.3%). 99m Tc HYNIC TOC SPECT/CT appears to be a highly sensitive and specific modality for the detection and staging of GPNETs. It is better than conventional imaging for the evaluation of GPNETs and can have a significant impact on patient management and planning further therapeutic options

  18. Clinical utility of indigenously formulated single-vial lyophilized HYNIC-TOC kit in evaluating Gastro-entero Pancreatic neuro endocrine tumours.

    Science.gov (United States)

    Shinto, Ajit S; Kamaleshwaran, K; Vyshak, K; Sudhakar, Natarajan; Banerjee, Sharmila; Korde, Aruna; Samuel, Grace; Mallia, Madhav

    2014-01-01

    The objective of this study was to evaluate the performance and utility of (99m)Tc HYNIC-TOC planar scintigraphy and SPECT/CT in the diagnosis, staging and management of gastroenteropancreatic neuroendocrine tumors (GPNETs). 22 patients (median age, 46 years) with histologically proven gastro- entero- pancreatic NETs underwent (99m)Tc HYNIC-TOC whole body scintigraphy and regional SPECT/CT as indicated. Scanning was performed after injection of 370-550 MBq (10-15 mCi) of (99m)Tc HYNIC-TOC intravenously. Images were evaluated by two experienced nuclear medicine physicians both qualitatively as well as semi quantitatively (tumor to background and tumor to normal liver ratios on SPECT -CT images). Results of SPECT/CT were compared with the results of conventional imaging. Histopathology results and follow-up somatostatin receptor scintigraphy with (99m)Tc HYNIC TOC or conventional imaging with biochemical markers were considered to be the reference standards. (99m)Tc HYNIC TOC showed sensitivity and specificity of 87.5% and 85.7%, respectively, for primary tumor and 100% and 86% for metastases. It was better than conventional imaging modalities for the detection of both primary tumor (PTOC SPECT/CT appears to be a highly sensitive and specific modality for the detection and staging of GPNETs. It is better than conventional imaging for the evaluation of GPNETs and can have a significant impact on patient management and planning further therapeutic options.

  19. Quartz crystal microbalance and photoacoustic measurements in dental photocuring

    Science.gov (United States)

    Lima, Marcenilda A.; Bastos, Ivan N.; Cella, Norberto

    2016-09-01

    Photocured dental resins are used extensively in restorative procedures in dentistry. Inadequate curing reduces the lifetime of the dental restoration, and consequently it is essential to precisely measure the polymerisation kinetics. In this study, two techniques, Quartz Crystal Microbalance (QCM) and Photoacoustic Spectroscopy (PAS), were used to monitor the real-time cure and to obtain the optical absorption spectra of resins, respectively. From the PAS measurements, the precise peaks of absorption were identified, and were used as the appropriate wavelength of the photocuring light in the QCM monitoring. The combined use of these techniques allows reliable determination of the duration of the phases of physical and chemical changes that occur during photocuring. Two commercial dental resins were tested, and the results confirmed the advantages of using PAS and QCM to study polymerisation kinetics.

  20. Using Quartz Crystal Microbalance for Field Measurement of Liquid Viscosities

    Directory of Open Access Journals (Sweden)

    Qingsong Bai

    2016-01-01

    Full Text Available The field measurement of liquid viscosities, especially the high viscous liquids, is challenging and often requires expensive equipment, long processing time, and lots of reagent. We use quartz crystal microbalances (QCMs operating in solution which are also sensitive to the viscosity and density of the contacting solution. QCMs are typically investigated for sensor applications in which one surface of QCM completely immersed in Newtonian liquid, but the viscous damping in liquids would cause not only large frequency shifts but also large losses in the quality factor Q leading to instability and even cessation of oscillation. A novel mass-sensitivity-based method for field measurement of liquid viscosities using a QCM is demonstrated in this paper and a model describing the influence of the liquid properties on the oscillation frequency is established as well. Two groups of verified experiments were performed and the experimental results show that the presented method is effective and possesses potential applications.

  1. Uranium deposits in Proterozoic quartz-pebble conglomerates

    International Nuclear Information System (INIS)

    1987-09-01

    This report is the result of an effort to gather together the most important information on uranium deposits in Proterozoic quartz-pebble conglomerates in the United States of America, Canada, Finland, Ghana, South Africa and Australia. The paper discusses the uranium potential (and in some cases also the gold potential in South Africa, Western Australia and Ghana) in terms of ores, sedimentation, mineralization, metamorphism, placers, geologic formations, stratigraphy, petrology, exploration, tectonics and distribution. Geologic history and application of geologic models are also discussed. Glacial outwash and water influx is also mentioned. The uranium deposits in a number of States in the USA are covered. The Witwatersrand placers are discussed in several papers. Refs, figs, tabs

  2. Finite Element Analysis of Electrically Excited Quartz Tuning Fork Devices

    Science.gov (United States)

    Oria, Roger; Otero, Jorge; González, Laura; Botaya, Luis; Carmona, Manuel; Puig-Vidal, Manel

    2013-01-01

    Quartz Tuning Fork (QTF)-based Scanning Probe Microscopy (SPM) is an important field of research. A suitable model for the QTF is important to obtain quantitative measurements with these devices. Analytical models have the limitation of being based on the double cantilever configuration. In this paper, we present an electromechanical finite element model of the QTF electrically excited with two free prongs. The model goes beyond the state-of-the-art of numerical simulations currently found in the literature for this QTF configuration. We present the first numerical analysis of both the electrical and mechanical behavior of QTF devices. Experimental measurements obtained with 10 units of the same model of QTF validate the finite element model with a good agreement. PMID:23722828

  3. Finite Element Analysis of Electrically Excited Quartz Tuning Fork Devices

    Directory of Open Access Journals (Sweden)

    Manel Puig-Vidal

    2013-05-01

    Full Text Available Quartz Tuning Fork (QTF-based Scanning Probe Microscopy (SPM is an important field of research. A suitable model for the QTF is important to obtain quantitative measurements with these devices. Analytical models have the limitation of being based on the double cantilever configuration. In this paper, we present an electromechanical finite element model of the QTF electrically excited with two free prongs. The model goes beyond the state-of-the-art of numerical simulations currently found in the literature for this QTF configuration. We present the first numerical analysis of both the electrical and mechanical behavior of QTF devices. Experimental measurements obtained with 10 units of the same model of QTF validate the finite element model with a good agreement.

  4. Respiratory Monitoring by Porphyrin Modified Quartz Crystal Microbalance Sensors

    Directory of Open Access Journals (Sweden)

    Seung-Woo Lee

    2011-01-01

    Full Text Available A respiratory monitoring system based on a quartz crystal microbalance (QCM sensor with a functional film was designed and investigated. Porphyrins 5,10,15,20-tetrakis-(4-sulfophenyl-21H,23H-porphine (TSPP and 5,10,15,20-tetrakis-(4-sulfophenyl-21H, 23H-porphine manganese (III chloride (MnTSPP used as sensitive elements were assembled with a poly(diallyldimethyl ammonium chloride (PDDA. Films were deposited on the QCM resonators using layer-by-layer method in order to develop the sensor. The developed system, in which the sensor response reflects lung movements, was able to track human respiration providing respiratory rate (RR and respiratory pattern (RP. The sensor system was tested on healthy volunteers to compare RPs and calculate RRs. The operation principle of the proposed system is based on the fast adsorption/desorption behavior of water originated from human breath into the sensor films deposited on the QCM electrode.

  5. Quartz crystal microbalance based on torsional piezoelectric resonators

    International Nuclear Information System (INIS)

    Buecking, W.; Du, B.; Turshatov, A.; Koenig, A. M.; Reviakine, I.; Bode, B.; Johannsmann, D.

    2007-01-01

    A quartz crystal microbalance (QCM) is described, which is based on a torsional resonator, rather than a conventional thickness-shear resonator. Typical applications are measurements of film thickness in the coating industry and monitoring of biofouling. The torsional QCM is about a factor of 100 less sensitive than the conventional QCM. On the other hand, it can probe film thicknesses in the range of hundreds of microns, which is impossible with the conventional QCM due to viscoelastic artifacts. Data acquisition and data analysis proceed in analogy to the conventional QCM. An indicator of the material's softness can be extracted from the bandwidth of the resonance. Within the small-load approximation, the frequency shift is independent of whether the sample is applied to the face or to the side of the cylinder. Details of the geometry matter if the viscoelastic properties of the sample are of interest

  6. Quartz crystal microbalance based on passive frequency to voltage converter

    International Nuclear Information System (INIS)

    Burda, Ioan; Tunyagi, Arthur

    2012-01-01

    In dynamics of evaporation or drying of microdrops from a solid surface, a faster and precise quartz crystal microbalance (QCM) is needed. The fast QCM based on frequency to voltage converter is an attractive and powerful tool in the investigation of the dynamic regime of evaporation to translate the frequency shift in terms of a continuous voltage change. The frequency shift monitoring in fast QCM applications is a real challenge for electronic processing interface. Originally developed as a frequency shift processing interface, this novel passive frequency to voltage converter can produce faster, stable, and accurate results in regard to the QCM sensor behavior. In this article, the concept and circuit of passive frequency to voltage converter will be explained followed by static and dynamic characterization. Experimental results of microdrops evaporation will be given.

  7. Measuring the diffraction properties of an imaging quartz(211) crystal

    Energy Technology Data Exchange (ETDEWEB)

    Haugh, M. J.; Jacoby, K. D.; Koch, J. A. [National Security Technologies, LLC, Livermore, California 94550 (United States); Chen, H.; Schneider, M. B. [Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550 (United States); Hill, K. W. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States)

    2016-06-15

    A dual goniometer X-ray system was used to measure the reflectivity curve for a spherically bent quartz(211) crystal. An analysis of the dual goniometer instrument response function for the rocking curve width measurement was developed and tested against the actual measurements. The rocking curve was measured at 4510.8 eV using the Ti Kα1 characteristic spectral line. The crystal is the dispersion element for a high resolution spectrometer used for plasma studies. It was expected to have a very narrow rocking curve width. The analysis showed that we could measure the upper bound for the rocking curve width of the Qz(211) crystal. The upper bound was 58 μrad giving a lower bound for the instrument resolving power E/ΔE = 34 000. Greatly improved insight into the dual goniometer operation and its limitations was achieved.

  8. Carbothermal Reduction of Quartz with Carbon from Natural Gas

    Science.gov (United States)

    Li, Fei; Tangstad, Merete

    2017-04-01

    Carbothermal reaction between quartz and two different carbons originating from natural gas were investigated in this paper. One of two carbons is the commercial carbon black produced from natural gas in a medium thermal production process. The other carbon is obtained from natural gas cracking at 1273 K (1000 °C) deposited directly on the quartz pellet. At the 1923 K (1650 °C) and CO atmosphere, the impact of carbon content, pellet structure, gas transfer, and heating rate are investigated in a thermo-gravimetric furnace. The reaction process can be divided into two steps: an initial SiC-producing step followed by a SiO-producing step. Higher carbon content and increased gas transfer improves the reaction rate of SiC-producing step, while the thicker carbon coating in carbon-deposited pellet hinders reaction rate. Better gas transfer of sample holder improves reaction rate but causes more SiO loss. Heating rate has almost no influence on reaction. Mass balance analysis shows that mole ratios between SiO2, free carbon, and SiC in the SiC-producing step and SiO-producing step in CO and Ar fit the reaction SiO2(s) + 3 C(s) = SiC(s) + 2 CO(g). SiC-particle and SiC-coating formation process in mixed pellet and carbon-deposited pellet are proposed. SiC whiskers formed in the voids of these two types of pellets.

  9. Deliquescence phase transition measurements by quartz crystal microbalance frequency shifts.

    Science.gov (United States)

    Arenas, Kathleen Jane L; Schill, Steven R; Malla, Ammaji; Hudson, Paula K

    2012-07-26

    Measurements of the hygroscopic properties of aerosols are needed to better understand the role of aerosols as cloud condensation nuclei. Several techniques have been used to measure deliquescence (solid to liquid) phase transitions in particular. In this study, we have measured the deliquescence relative humidity (DRH) of organic and inorganic salts, organic acids (glutaric and succinic acid), and mixtures of organic acids with ammonium sulfate using a quartz crystal microbalance (QCM). The QCM allows for measurement of the deliquescence phase transition due to inherent measurement differences between solids and liquids in the oscillation frequency of a quartz crystal. The relative humidity dependent frequency measurements can be used to identify compounds that adsorb monolayer amounts of water or form hydrates prior to deliquescence (e.g., lithium chloride, potassium and sodium acetate). Although the amount of water uptake by a deliquescing material cannot be quantified with this technique, deliquescence measurements of mixtures of hygroscopic and nonhygroscopic components (e.g., ammonium sulfate and succinic acid (DRH > 95%)) show that the mass fraction of the deliquescing portion of the sample can be quantitatively determined from the relative change in oscillation frequency at deliquescence. The results demonstrate the use of this technique as an alternative method for phase transition measurements and as a direct measurement of the mass fraction of a sample that undergoes deliquescence. Further, deliquescence measurements by the QCM may provide improved understanding of discrepancies in atmospheric particle mass measurements between filter samples and the tapered element oscillating microbalance given the similar measurement principle employed by the QCM.

  10. Aplicación de los Sistemas de Información Geográfica para la gestión de la malla vial de la ciudad de Medellín

    Directory of Open Access Journals (Sweden)

    Jaime A. Zapata Duque

    2012-12-01

    Full Text Available El estado de la malla vial depende fundamentalmente de factores tales como el tráfico, características estructurales y funcionales del pavimento y condiciones climatológicas locales, y su mantenimiento tiene importantes implicaciones espaciales. Este documento describe el proceso de implementación del sistema de gestión de pavimentos de la ciudad de Medellín, desarrollado en una plataforma SIG. El sistema está soportado en una geodatabase corporativa de inventario y diagnóstico, el cual alimenta un software de modelación del deterioro del pavimento y arroja recomendaciones de intervención en cada segmento vial. Este sistema sirve como apoyo a las autoridades encargadas a la toma de decisiones, con el fin de realizar la planeación del mantenimiento de la malla vial, optimizar los recursos disponibles y ofrecer un mejor servicio a la comunidad.

  11. The Effect of Quartz on the Flotation of Fine Wolframite with Octyl Hydroxamic Acid

    Directory of Open Access Journals (Sweden)

    Qingyou Meng

    2017-09-01

    Full Text Available The influence of quartz on the flotation of fine wolframite using octyl hydroxamic acid (OHA as the collector was investigated by micro-flotation tests, inductively coupled plasma (ICP measurements, adsorption experiments, zeta potential, and Fourier transform infrared spectroscopy (FT-IR analysis. Micro-flotation tests showed that a large difference in floatability existed between fine wolframite and quartz in the pH range of 7.0 to 10.0. However, in a synthetic mixture, the flotation separation of fine wolframite from quartz became more difficult as the particle size of the latter decreased. When a dissolved solution of wolframite was used as the flotation medium, quartz floatability improved significantly. Zeta potentials of quartz particles shifted positively in the dissolved solution of wolframite compared to distilled water, especially at a pH level of 7.0–10.0, which was attributed to the metal ions dissolved from the wolframite being adsorbed onto the quartz surface. The surface activation of quartz led to an increase in the OHA adsorption and made the surface hydrophobic. FT-IR analysis further demonstrated that OHA could adsorb onto the activated quartz surface through a dominantly chemical process.

  12. Effect of substitution of sand stone dust for quartz and clay in triaxial ...

    Indian Academy of Sciences (India)

    SEM photomicrographs of the 1115◦C heated specimen show presence of quartz grain and glassy matrix. Few quartz grains (20–40μm) are associated with circumferential cracks around them. Keywords. Environmental pollutant; sand stone dust; ceramic tiles; pavement block; vitrification; triaxial porcelain. 1. Introduction.

  13. Dose recovery and residual dose of quartz ESR signals using modern sediments

    NARCIS (Netherlands)

    Tsukamoto, Sumiko; Porat, Naomi; Ankjærgaard, Christina

    2017-01-01

    Electron spin resonance (ESR) dating is a promising method for dating sedimentary quartz beyond a million years. Here we investigate the use of modern quartz samples with well bleached optically stimulated luminescence (OSL) signals to study the bleachability of the ESR signals, and to further

  14. A comparative study of the thermoluminescence properties of several varieties of Brazilian natural quartz

    International Nuclear Information System (INIS)

    Brito Farias, Thiago Michel de; Watanabe, Shigueo

    2012-01-01

    The following varieties of natural quartz, as the blue, the green, the red, the pink, the black, the sulphurous and the milky quartz, have been investigated concerning their thermoluminescence properties. For comparison sake natural colorless alpha quartz has been include. Since X-rays diffraction analysis has shown that all of them have the same crystal structure as the alpha quartz, it is expected that no great change in the TL property should be found, however, that was not the case. The TL peaks at 110, 175, 220, 325 and 375 °C observed in the alpha quartz are not found in all the varieties of quartz, for instance, the sulphurous quartz presented only 110° and 245° peaks, the pink one presented just 110, 220 and 375 °C peaks and so on. In respect to TL response as function of gamma ray dose a quite varied behavior has been observed and discussed. - Highlights: ► We evaluated seven varieties of natural quartz. ► Thermoluminescence properties were compared. ► Their properties are different. ► The models proposed for the TL emission cannot be applied.

  15. Wettability of quartz surface as observed by NMR transverse relaxation time (T2)

    DEFF Research Database (Denmark)

    Alam, Mohammad Monzurul; Katika, Konstantina; Fabricius, Ida Lykke

    the wettability property of quartz surface by using Nuclear Magnetic Resonance (NMR) method. The principle of this method is that protons in water relax faster when it comes close to solid surface. We observed that quart is highly water wet. A layer of water (bound water) forms on the quartz surface when...

  16. 75 FR 12468 - Airworthiness Directives; Quartz Mountain Aerospace, Inc. Model 11E Airplanes

    Science.gov (United States)

    2010-03-16

    ... Aerospace, Inc. Model 11E Airplanes AGENCY: Federal Aviation Administration (FAA), Department of... airworthiness directive (AD) for all Quartz Mountain Aerospace, Inc. Model 11E airplanes. This proposed AD would... 5 p.m., Monday through Friday, except Federal holidays. Quartz Mountain Aerospace, Inc. is in...

  17. 75 FR 30282 - Airworthiness Directives; Quartz Mountain Aerospace, Inc. Model 11E Airplanes

    Science.gov (United States)

    2010-06-01

    ... Aerospace, Inc. Model 11E Airplanes AGENCY: Federal Aviation Administration (FAA), Department of... Quartz Mountain Aerospace, Inc. Model 11E airplanes. This AD requires you to clean and lubricate the... publications listed in this AD. ADDRESSES: Quartz Mountain Aerospace, Inc. is in liquidation. For service/or...

  18. The Suitability Of Local Quartz Sand In The Production Of Bath Crucibles.

    Directory of Open Access Journals (Sweden)

    C. O. Okpanachi

    2017-03-01

    Full Text Available The suitability of local quartz sand in the production of bath crucibles is a study that was carried out in order to impart overall strength on bath crucibles hence reduce breakages during fettling. Therefore this research constitutes a study to enhance the efficiency of production of bath crucibles by addition of quartz sand in slip preparation. The steps taken in the beneficiation of quartz sand for the production of bath crucibles are comminution which entails crushing and milling classification washing liquid dispersion sizing and reduction of iron content by magnetic separation. The slip contains materials like plastic clay feldspar kaolin talc sodium silicate water quartz sand etc. These were all milled in the ball mill for slip production casting and fettling glazing and sintering to get final bath crucibles as the end products. Quartz sand is used in a variety of products essentially as raw material for the foundry casting and glass industries and also in chemicals water filtration and ceramics the heat resistance nature of quartz sand makes it an excellent refractory substance for these industrial processes. Slip can be prepared for production of bath crucibles without the inclusion of quartz sand however the addition of quartz sand is needed to improve the mechanical performance of the slip in the production of bath crucibles.

  19. The Cherenkov correlated timing detector: beam test results from quartz and acrylic bars

    International Nuclear Information System (INIS)

    Kichimi, H.; Sugaya, Y.; Yamaguchi, H.; Yoshimura, Y.; Kanda, S.; Olsen, S.; Ueno, K.; Varner, G.; Bergfeld, T.; Bialek, J.; Lorenc, J.; Palmer, M.; Rudnick, G.; Selen, M.; Auran, T.; Boyer, V.; Honscheid, K.; Tamura, N.; Yoshimura, K.; Lu, C.; Marlow, D.; Mindas, C.; Prebys, E.; Asai, M.; Kimura, A.; Hayashi, S.

    1996-01-01

    Several prototypes of a Cherenkov correlated timing (CCT) detector have been tested at the KEK-PS test beam line. We describe the results for Cherenkov light yields and timing characteristics from quartz and acrylic bar prototypes. A Cherenkov angle resolution is found to be 15 mrad at a propagation distance of 100 cm with a 2 cm thick quartz bar prototype. (orig.)

  20. Determination of burial dose in incompletely bleached fluvial samples using single grains of quartz

    DEFF Research Database (Denmark)

    Thomsen, Kristina Jørkov; Murray, A.S.; Bøtter-Jensen, Lars

    2007-01-01

    -bleached and gamma-irradiated samples. We show that there is a linear relationship between the over-dispersion and the mean dose. Knowing this uncertainty relationship enables us to estimate the burial dose by comparing the predicted uncertainty on the running mean with that calculated from actual dispersion. (c...

  1. Investigation of the polarization anisotropy in a single-mode quartz fiber

    Science.gov (United States)

    Kozel, S. M.; Listvin, V. N.; Shatalin, S. V.

    A method is presented for investigating the fiber-length dependence of optical activity, linear birefringence and the azimuth of the major axis of linear birefringence on the basis of the evolution of two states of light polarization in a fiber with arbitrary polarization anisotropy. Linear and circular birefringent properties of the fiber are determined, and, it is shown that the fiber is irregular.

  2. Optically stimulated luminescence techniques in retrospective dosimetry using single grains of quartz extracted from unheated materials

    DEFF Research Database (Denmark)

    Thomsen, Kristina Jørkov

    This work investigates the possibility of applying optically stimulated luminescence (OSL) in retrospective dose determinations using unheated materials. It focuses on identifying materials suitable for use in assessment of doses absorbed as a consequenceof radiation accidents (i.e. accident...... that the observed variability in the data is consistent with the sum (in quadrature) of a component,which depends on the number of photons detected from each grain, and a fixed component independent of light level. Dose depth profiles through laboratory irradiated concrete bricks have successfully been measured...... of using common household and workplace chemicals, such as table salt, washing powder and water softener, in retrospective dosimetry has been investigated. It is concluded that such materials should be considered as retrospective dosimeters inthe event of a radiation accident....

  3. Aequorin as a bioluminescent indicator for use in the determination of biomolecules in single cells. Final technical report

    Energy Technology Data Exchange (ETDEWEB)

    Sylvia Daunert

    2000-02-17

    During this funding period, the laboratories of Drs. Anderson and Daunert have performed a considerable amount of work toward addressing the issues associated with small volume analysis necessary for single cell studies. In that respect, their research has been focused on (1) developing new assays that can be miniaturized and are suitable for small volume and single cell analysis; (2) fabricating pL-vials that simulate the volume of single cells and setting up instrumentation capable of low-volume detection; (3) developing reproducible and reliable microinjection techniques; (4) developing methods of analysis for biomolecules in the pL-vials and employing these assays in the detection of biomolecules in single cells. The accomplishments attained in all these areas are described below. A total of 24 publications and 35 presentations have resulted from this work.

  4. The red, white and blue of quartz luminescence: A comparison of D{sub e} values derived for sediments from Australia and Indonesia using thermoluminescence and optically stimulated luminescence emissions

    Energy Technology Data Exchange (ETDEWEB)

    Westaway, K.E. [Department of Environment and Geography, Faculty of Science, Macquarie University, NSW 2109 (Australia)], E-mail: kira@els.mq.edu.au

    2009-05-15

    Heated quartz, including quartz from volcanic provinces, commonly displays different luminescence characteristics compared with the same mineral in non-volcanic contexts. These differing properties demand thorough investigations into the most suitable dating techniques for samples composed of quartz grains with different origins. In cave settings, independent techniques such as radiocarbon and U-series can prove useful for validating results, but further insights may be gained by comparing the results obtained for quartz using different luminescence emissions. Twenty-two quartz samples have been selected from five areas (Australia, Timor, Flores, Java and Sulawesi) for comparison of the red and blue emissions. The dual-aliquot regenerative-dose protocol was used to estimate the equivalent dose (D{sub e}) associated with the light-sensitive red thermoluminescence while the single aliquot regenerative-dose protocol was used to measure the D{sub e} values for single grains and single aliquots, which were optically stimulated by green or blue light, respectively. The results obtained from the red thermoluminescence and optically stimulated luminescence measurements display good agreement with independent dating techniques (within {approx}20%). However, the blue emissions exhibit a thermally unstable component, which causes a large underestimation in palaeodoses (on average {approx}80%) and an age limit of {approx}25 ka, while the red emissions are more thermally stable over geological timescales but produce an overestimation in red TL ages (by {approx}13 ka) and low precision (typically {approx}24%). These results can be correlated to three different quartz groups, which have been divided according to their luminescence emissions.

  5. Ultraviolet Transmission Studies on Proton Irradiated KU1 Quartz Glass

    International Nuclear Information System (INIS)

    Constantinescu, B.

    2006-01-01

    The optical transmission components of the future thermonuclear reactor will be expected to maintain their transmission properties under high levels of ionizing radiation (>> 5 Gy/s) during hundreds of hours. For such applications, radiation-induced optical absorption imposes a severe limitation. It is therefore necessary to study the optical degradation of suitable candidate materials, to assess the system lifetimes. KU1 quartz glass is known to be radiation-resistant, so, KU1 pellets (approx. 5 mm diameter) samples prepared in CIEMAT, Madrid, in the frame of Romania - EURATOM co-operation, and a CARY 4 VARIAN spectrophotometer have been used. The irradiation was performed using 12.6 MeV protons at Bucharest TANDEM accelerator, in the following conditions: 0.8 mm thick KU1 samples at a total dose of 2 x 10 14 protons, in air and in vacuum irradiation at temperatures between 20 and 50 C on the target. The presence of a 215 nm peak (due to both electron and nuclear collisions stopping) and a big reduction (as compare to a similar gamma irradiation) of the 270 nm peak (due only to nuclear collisions) were observed. Using the data from AEA Harwell FUS86 EURATOM report, the dose rate of our 12.6 MeV proton irradiations (1 nA beam intensity on a 3 x 3 mm 2 area during 15 hours) was evaluated at 200 Gy/s and the total irradiation dose at 10 MGy. Comparing our spectra (mainly the intensity of 215 nm peak) with the results for gamma and high energy electron irradiations, we can conclude for the 12.6 MeV proton irradiation at 50 C that the saturation effect in absorption is obtained after a 10 MGy dose, as compared with 4-5 MGy for gamma and with 11-12 MGy for electrons, suggesting the ionization process is essential for defect absorption centers in all the cases. Preliminary studies using high energy proton irradiations for a new type of quartz glass - KS-4V (dose and temperature dependence of absorption behavior in Ultraviolet and Visible regions) as a part of the efforts

  6. MODELO DE EVALUACIÓN DINÁMICA DE LA CALIDAD EN LA INFRAESTRUCTURA VIAL DE CORREDORES LOGÍSTICOS EN COLOMBIA

    Directory of Open Access Journals (Sweden)

    Jairo Alberto Gómez Lizarazo

    Full Text Available En el presente artículo se modeliza el comportamiento de la infraestructura vial de los corredores logísticos de Colombia, utilizando dinámica de sistemas para evaluar los efectos de las políticas de inversión que se realizan en la red pavimentada. Para ello, se consideran cinco categorías que permiten evaluar la calidad de la red pavimentada definidas por el Instituto Nacional de Vías y Transporte - INVIAS. El modelo contiene la parametrización para evaluar el desgaste de las vías en función de tráfico promedio y de las inversiones que se realizan para la rehabilitación y el mantenimiento de las vías.

  7. Aproximación neuro-fuzzy para identificación de señales viales mediante tecnología infrarroja

    Directory of Open Access Journals (Sweden)

    G.N. Marichal

    2007-04-01

    Full Text Available Resumen: En este artículo se presenta un sistema basado en tecnología infrarroja para la clasificación de marcas viales empleando un sistema Neuro-Fuzzy como herramienta de clasificación. El sistema se ha testeado a partir de los datos suministrados cuando se ha instalado un prototipo en un robot móvil. Los resultados obtenidos son explicados en este artículo, haciendo hincapié en el diseño de nuevas reglas y la mejoría lograda mediante los métodos propuestos. Palabras clave: Control Inteligente, Robótica, Navegación de robots, Sistemas Neuro-Fuzzy

  8. Artificial Leaks in Container Closure Integrity Testing: Nonlinear Finite Element Simulation of Aperture Size Originated by a Copper Wire Sandwiched between the Stopper and the Glass Vial.

    Science.gov (United States)

    Nieto, Alejandra; Roehl, Holger; Brown, Helen; Adler, Michael; Chalus, Pascal; Mahler, Hanns-Christian

    2016-01-01

    Container closure integrity (CCI) testing is required by different regulatory authorities in order to provide assurance of tightness of the container closure system against possible contamination, for example, by microorganisms. Microbial ingress CCI testing is performed by incubation of the container closure system with microorganisms under specified testing conditions. Physical CCI uses surrogate endpoints, such as coloration by dye solution ingress or gas flow (helium leakage testing). In order to correlate microbial CCI and physical CCI test methods and to evaluate the methods' capability to detect a given leak, artificial leaks are being introduced into the container closure system in a variety of different ways. In our study, artificial leaks were generated using inserted copper wires between the glass vial opening and rubber stopper. However, the insertion of copper wires introduces leaks of unknown size and shape. With nonlinear finite element simulations, the aperture size between the rubber stopper and the glass vial was calculated, depending on wire diameter and capping force. The dependency of the aperture size on the copper wire diameter was quadratic. With the data obtained, we were able to calculate the leak size and model leak shape. Our results suggest that the size as well as the shape of the artificial leaks should be taken into account when evaluating critical leak sizes, as flow rate does not, independently, correlate to hole size. Capping force also affected leak size. An increase in the capping force from 30 to 70 N resulted in a reduction of the aperture (leak size) by approximately 50% for all wire diameters. From 30 to 50 N, the reduction was approximately 33%. Container closure integrity (CCI) testing is required by different regulatory authorities in order to provide assurance of tightness of the container closure system against contamination, for example, by microorganisms. Microbial ingress CCI testing is performed by incubation of the

  9. Deformation assisted by fluids in quartz veins of shear zones: an example from Iron Formations of Quadrilátero Ferrífero, Brazil.

    Science.gov (United States)

    Barbosa, Paola; Lagoeiro, Leonardo

    2013-04-01

    exhibit any kind of fibrous structures that can indicate a sense of growth of the quartz crystals inside the vein. The less deformed veins are composed of tabular crystals of quartz, with the optical axes oriented sub-parallel to the foliation. Mechanical Dauphiné twinning of quartz may also be observed in the single crystals. On the other hand, the deformed veins are represented by polycrystalline layers of quartz, with two distinct CPOs of c-axes: 1) oblique to the foliation and 2) parallel to the Y axis. We suppose that the veins are the result of a concurrence between transformation, recrystallization and recovery of quartz assisted by fluid activity at low temperature and confining pressure. In the related deformation conditions, slip on basal planes and mechanical twinning are consistent with a strong c-axis CPO of quartz sub-parallel to the foliation, but it is not acceptable to the c-axis CPO around Y. To achieve this distinct crystallographic orientation, it is necessary a slip system on prismatic planes followed by grain boundary migration. At low temperatures, one possible situation to explain the CPO under theses conditions is the progressive deformation assisted by fluid activity. A posterior static recrystallization by discontinuous grain growth of quartz may be responsible for the concentration of the c-axis around the Y, intensifying the CPO.

  10. Streamlined sample cleanup using combined dispersive solid-phase extraction and in-vial filtration for analysis of pesticides and environmental pollutants in shrimp

    Energy Technology Data Exchange (ETDEWEB)

    Han, Lijun [College of Science, China Agricultural University, Beijing (China); Sapozhnikova, Yelena [U.S. Dept. of Agriculture, Agricultural Research Service, Eastern Regional Research Center, 600 East Mermaid Lane, Wyndmoor, PA 19038 (United States); Lehotay, Steven J., E-mail: Steven.Lehotay@ars.usda.gov [U.S. Dept. of Agriculture, Agricultural Research Service, Eastern Regional Research Center, 600 East Mermaid Lane, Wyndmoor, PA 19038 (United States)

    2014-05-01

    Highlights: • The first report that combines in-vial filtration and dispersive-SPE for sample cleanup. • The unique application of ammonium formate for salting-out partitioning in QuEChERS. • Evaluations of a new zirconium-based and a non-friable GCB sorbent for d-SPE cleanup. • A new analytical method for 59 pesticides and environmental pollutants in shrimp. Abstract: A new method of sample preparation was developed and is reported for the first time. The approach combines in-vial filtration with dispersive solid-phase extraction (d-SPE) in a fast and convenient cleanup of QuEChERS (quick, easy, cheap, effective, rugged, and safe) extracts. The method was applied to simultaneous analysis of 42 diverse pesticides and 17 environmental contaminants, including polycyclic aromatic hydrocarbons, polychlorinated biphenyls (PCBs), and flame retardants, in shrimp as the sample matrix. Final extracts were analyzed by both low-pressure gas chromatography – triple quadrupole tandem mass spectrometry (LPGC-MS/MS), and high-performance liquid chromatography – triple quadrupole tandem mass spectrometry (HPLC-MS/MS) to provide a wide scope of analysis for targeted analytes. During method development, several different commercial sorbents for d-SPE were investigated and compared with respect to analyte recoveries. The method was validated at 10, 50, and 100 ng g⁻¹ spiking levels (10-fold lower for PCBs), and the results for nearly all analytes were between 70 and 115% recoveries with ≤17% relative standard deviations. The method was shown to be simple, fast, and effective for multi-application analysis of chemical residues in the representative food and environmental marker matrix.

  11. Diseño de un plan estratégico de seguridad vial departamental (Modelo piloto para el departamento de Boyacá

    Directory of Open Access Journals (Sweden)

    Flor Ángela Cerquera Escobar Julio Andrés Pabón Cachope Ricardo Andrés Fajardo

    2010-11-01

    Full Text Available Sintetiza  una  serie  de  consideraciones  que  sirvencomo marco  de  referencia  para  definir  un  plan  deacción en seguridad vial, cuyo desarrollo y ejecuciónestán  encaminados  a  reducir  los  accidentes  en  lasvías del departamento de Boyacá, y que sirve comomodelo guía para cualquier otra región del país. Losresultados  que  se  presentan  fueron  obtenidos  en  eldesarrollo  del  proyecto  de  grado  en  Ingeniería  deTransporte  y  Vías  t itulado  “Diseño  del  PlanEstratégico de Seguridad Vial para el departamentode Boyacá”;  además,  se  consideran  varios  tópicosplanteados en documentos que sobre Seguridad Vialha  desarrollado  el  Grupo  de  Invest igación  yDesarrollo en Operación del Tránsito, GIDOT. Esteproyecto  se  adelantó  como  un  direccionamiento  alPlan  de  Desarrollo  del  departamento,   en  lo

  12. Stability of tranexamic acid in 0.9% sodium chloride, stored in type 1 glass vials and ethylene/propylene copolymer plastic containers.

    Science.gov (United States)

    McCluskey, Susan V; Sztajnkrycer, Matthew D; Jenkins, Donald A; Zietlow, Scott P; Berns, Kathleen S; Park, Myung S

    2014-01-01

    Tranexamic acid has recently been demonstrated to decrease all-cause mortality and deaths due to hemorrhage in trauma patients. The optimal administration of tranexamic acid is within one hour of injury, but not more than three hours from the time of injury. To aid with timely administration, a premixed solution of 1 gram tranexamic acid and 0.9% sodium chloride was proposed to be stocked as a medication in both the aeromedical transport helicopters and Emergency Department at Mayo Clinic Hospital--Rochester Saint Marys Campus. Since no published stability data exists for tranexamic acid diluted with 0.9% sodium chloride, this study was undertaken to determine the stability of tranexamic acid diluted with 0.9% sodium chloride while being stored in two types of containers. Stability was determined through the use of a stability-indicating high-performance liquid reverse phase chromatography assay, pH, and visual tests. Tranexamic acid solutions of 1 gram in 0.9% sodium chloride 65 mL were studied at predetermined intervals for 90 days in ethylene/propylene copolymer plastic containers, protected from light, and at both controlled room and refrigerated temperatures. Tranexamic acid solutions of 1 gram in 0.9% sodium chloride 50 mL were studied at predetermined intervals for 180 days in clear Type 1 borosilicate glass vials sealed with intact elastomeric, Flourotec-coated stoppers, stored protected from light at controlled room temperature. Solutions stored in the ethylene/propylene copolymer plastic containers at both storage temperatures maintained at least 98% of initial potency throughout the 90-day study period. Solutions stored in glass vials at controlled room temperature maintained at least 92% of initial potency throughout the 180-day study period. Visual and pH tests revealed stable, clear, colorless, and particulate-free solutions throughout the respective study periods.

  13. Quartz in ash, and air in a high lung cancer incidence area in China.

    Science.gov (United States)

    Downward, George S; Hu, Wei; Rothman, Nat; Reiss, Boris; Tromp, Peter; Wu, Guoping; Wei, Fusheng; Xu, Jun; Seow, Wei Jie; Chapman, Robert S; Lan, Qing; Vermeulen, Roel

    2017-02-01

    Exposure to crystalline silica (quartz) has been implicated as a potential cause of the high lung cancer rates in the neighbouring counties of Xuanwei and Fuyuan, China, where the domestic combustion of locally sourced "smoky" coal (a bituminous coal) is responsible for some of the highest lung cancer rates in the nation, irrespective of gender or smoking status. Previous studies have shown that smoky coal contains approximately twice as much quartz when compared to alternative fuels in the area, although it is unclear how the quartz in coal relates to household air pollution. Samples of ash and fine particulate matter (PM 2.5 ) were collected from 163 households and analysed for quartz content by Fourier transformed infrared spectroscopy (FT-IR). Additionally, air samples from 12 further households, were analysed by scanning electron microscopy (SEM) to evaluate particle structure and silica content. The majority (89%) of household air samples had undetectable quartz levels (quartz in smoky coal went on to form part of the ash. These findings indicate that the quartz within smoky coal does not become adequately airborne during the combustion process to cause significant lung cancer risk, instead going on to form part of the ash. The identification of fibre-like particles in air samples is an interesting finding, although the clinical relevance of this finding remains unclear. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Additive surface complexation modeling of uranium(VI) adsorption onto quartz-sand dominated sediments.

    Science.gov (United States)

    Dong, Wenming; Wan, Jiamin

    2014-06-17

    Many aquifers contaminated by U(VI)-containing acidic plumes are composed predominantly of quartz-sand sediments. The F-Area of the Savannah River Site (SRS) in South Carolina (USA) is an example. To predict U(VI) mobility and natural attenuation, we conducted U(VI) adsorption experiments using the F-Area plume sediments and reference quartz, goethite, and kaolinite. The sediments are composed of ∼96% quartz-sand and 3-4% fine fractions of kaolinite and goethite. We developed a new humic acid adsorption method for determining the relative surface area abundances of goethite and kaolinite in the fine fractions. This method is expected to be applicable to many other binary mineral pairs, and allows successful application of the component additivity (CA) approach based surface complexation modeling (SCM) at the SRS F-Area and other similar aquifers. Our experimental results indicate that quartz has stronger U(VI) adsorption ability per unit surface area than goethite and kaolinite at pH ≤ 4.0. Our modeling results indicate that the binary (goethite/kaolinite) CA-SCM under-predicts U(VI) adsorption to the quartz-sand dominated sediments at pH ≤ 4.0. The new ternary (quartz/goethite/kaolinite) CA-SCM provides excellent predictions. The contributions of quartz-sand, kaolinite, and goethite to U(VI) adsorption and the potential influences of dissolved Al, Si, and Fe are also discussed.

  15. Respirable quartz exposure on two medium-sized farms in southern Mozambique.

    Science.gov (United States)

    Franque Mirembo, José C; Swanepoel, Andrew J; Rees, David

    2013-01-01

    Little is known about the potential for overexposure to respirable quartz in farming, in most parts of the world. To measure respirable dust and quartz exposure of tractor operators on two medium-sized dry climate farms. This is a descriptive cross-sectional study of dust exposure of four tractor operators. Farms were selected by convenience sampling. The MDHS 14/3 and FTIR MDHS 101 HSE methods were used to measure dust and to analyze the mass of quartz in dust, respectively. Seventy respirable dust measurements were done. Respirable dust and quartz ranged from 0·01 to 2·88 and 0·001 to 0·30 mg/m(3), respectively. All operators had at least one respirable quartz exposure above 0·1 mg/m(3). Only 17% of respirable quartz concentrations were lower than the ACGIH TLV of 0·025 mg/m(3). The potential for overexposure to respirable quartz was demonstrated. There was a great deal of exposure variability on these farms which has implications for sampling strategies for dust in farming.

  16. Microscopy and Cathodoluminescence Spectroscopy Characterization of Quartz Exhibiting Different Alkali-Silica Reaction Potential.

    Science.gov (United States)

    Kuchařová, Aneta; Götze, Jens; Šachlová, Šárka; Pertold, Zdeněk; Přikryl, Richard

    2016-02-01

    Different quartz types from several localities in the Czech Republic and Sweden were examined by polarizing microscopy combined with cathodoluminescence (CL) microscopy, spectroscopy, and petrographic image analysis, and tested by use of an accelerated mortar bar test (following ASTM C1260). The highest alkali-silica reaction potential was indicated by very fine-grained chert, containing significant amounts of fine-grained to cryptocrystalline matrix. The chert exhibited a dark red CL emission band at ~640 nm with a low intensity. Fine-grained orthoquartzites, as well as fine-grained metamorphic vein quartz, separated from phyllite exhibited medium expansion values. The orthoquartzites showed various CL of quartz grains, from blue through violet, red, and brown. Two CL spectral bands at ~450 and ~630 nm, with various intensities, were detected. The quartz from phyllite displayed an inhomogeneous dark red CL with two CL spectral bands of low intensities at ~460 and ~640 nm. The massive coarse-grained pegmatite quartz from pegmatite was assessed to be nonreactive and displayed a typical short-lived blue CL (~480 nm). The higher reactivity of the fine-grained hydrothermal quartz may be connected with high concentrations of defect centers, and probably with amorphized micro-regions in the quartz, respectively; indicated by a yellow CL emission (~570 nm).

  17. Evaluation of the sterility of single-dose medications used in a multiple-dose fashion.

    Science.gov (United States)

    Martin, Elizabeth P; Mukherjee, Jean; Sharp, Claire R; Sinnott-Stutzman, Virginia B

    2017-11-01

    Bacterial proliferation was evaluated in single-dose medications used in a multi-dose fashion and when medications were intentionally inoculated with bacteria. Of 5 experimentally punctured medications, 1 of 75 vials (50% dextrose) became contaminated. When intentionally inoculated, hydroxyethyl starch and heparinized saline supported microbial growth. Based on these findings, it is recommended that hydroxyethyl starch and heparinized saline not be used in a multi-dose fashion.

  18. COMMENT: Comment on `Inhomogeneities and birefringence in quartz'

    Science.gov (United States)

    Saint-Grégoire, P.; Luk'yanchuk, I.

    1999-10-01

    We comment on the role of the novel incommensurate elongated-triangle (ELT) phase in the huge light scattering in quartz at small angles that was observed more than 40 years ago at the icons/Journals/Common/alpha" ALT="alpha" ALIGN="TOP"/>-icons/Journals/Common/beta" ALT="beta" ALIGN="TOP"/> phase transition and was associated with optical inhomogeneities of unknown nature. The relation of these inhomogeneities with the differently oriented ferroelastic blocks of the ELT phase proposed by us and co-workers in a previous publication was misinterpreted and criticized in a recent article by Aslanyan et al (Aslanyan T E, Shigenari T and Abe K 1998 J. Phys.: Condens. Matter 10 4577), who claimed also that the lock-in occurs at qicons/Journals/Common/neq" ALT="neq" ALIGN="TOP"/>0. Responding to their criticism, we claim that the ELT blocks do have ferroelastic properties which induce the inhomogeneities of optical indices and that the lock-in occurs at q = 0.

  19. Dedicated finite elements for electrode thin films on quartz resonators.

    Science.gov (United States)

    Srivastava, Sonal A; Yong, Yook-Kong; Tanaka, Masako; Imai, Tsutomu

    2008-08-01

    The accuracy of the finite element analysis for thickness shear quartz resonators is a function of the mesh resolution; the finer the mesh resolution, the more accurate the finite element solution. A certain minimum number of elements are required in each direction for the solution to converge. This places a high demand on memory for computation, and often the available memory is insufficient. Typically the thickness of the electrode films is very small compared with the thickness of the resonator itself; as a result, electrode elements have very poor aspect ratios, and this is detrimental to the accuracy of the result. In this paper, we propose special methods to model the electrodes at the crystal interface of an AT cut crystal. This reduces the overall problem size and eliminates electrode elements having poor aspect ratios. First, experimental data are presented to demonstrate the effects of electrode film boundary conditions on the frequency-temperature curves of an AT cut plate. Finite element analysis is performed on a mesh representing the resonator, and the results are compared for testing the accuracy of the analysis itself and thus validating the results of analysis. Approximations such as lumping and Guyan reduction are then used to model the electrode thin films at the electrode interface and their results are studied. In addition, a new approximation called merging is proposed to model electrodes at the electrode interface.

  20. Sputtered type s thermocouples on quartz glass substrates

    International Nuclear Information System (INIS)

    Sopko, B.; Vlk, J.; Chren, D.; Sopko, V.; Dammer, J.; Mengler, J.; Hynek, V.

    2011-01-01

    The work deals with the development of thin film thermocouples and their practical use. The principle of measuring planar thin film thermocouples is the same as for conventional thermocouples and is based on the thermoelectric effect, which named after its discoverer, Seebeck. Seebeck effect is direct conversion of temperature differences to electric voltage. In different applications it is necessary to use temperature sensors with high spatial resolution (with the placement of several measured points on the segment of length 1 mm) and short response time. For this application are currently used planar thermocouples with important advantage in production price and reproducible production. The innovative potential of thin-film thermocouples are to be found mainly in: 1 st use of technology in thin layers, unlike the already mature technologies applied in the production of conventional thermocouple probes are capable of further improvement with the usage of new substrate materials, modified methods for creating electrical contacts to the new thermocouple configuration and adhesive and protective layers, 2 nd in saving precious and rare metals, 3 rd decreasing the thickness of the layers and reducing the overall size of thermo probe. Measuring the temperature of molten steel, leading to a general loss of strength and the subsequent destruction of the probe. Here exhibited the highest resistance of quartz plates used in thin film substrates thermocouples. (authors)

  1. Molecular Imprinting Technology in Quartz Crystal Microbalance (QCM Sensors

    Directory of Open Access Journals (Sweden)

    Sibel Emir Diltemiz

    2017-02-01

    Full Text Available Molecularly imprinted polymers (MIPs as artificial antibodies have received considerable scientific attention in the past years in the field of (biosensors since they have unique features that distinguish them from natural antibodies such as robustness, multiple binding sites, low cost, facile preparation and high stability under extreme operation conditions (higher pH and temperature values, etc.. On the other hand, the Quartz Crystal Microbalance (QCM is an analytical tool based on the measurement of small mass changes on the sensor surface. QCM sensors are practical and convenient monitoring tools because of their specificity, sensitivity, high accuracy, stability and reproducibility. QCM devices are highly suitable for converting the recognition process achieved using MIP-based memories into a sensor signal. Therefore, the combination of a QCM and MIPs as synthetic receptors enhances the sensitivity through MIP process-based multiplexed binding sites using size, 3D-shape and chemical function having molecular memories of the prepared sensor system toward the target compound to be detected. This review aims to highlight and summarize the recent progress and studies in the field of (biosensor systems based on QCMs combined with molecular imprinting technology.

  2. Molecular Imprinting Technology in Quartz Crystal Microbalance (QCM) Sensors.

    Science.gov (United States)

    Emir Diltemiz, Sibel; Keçili, Rüstem; Ersöz, Arzu; Say, Rıdvan

    2017-02-24

    Molecularly imprinted polymers (MIPs) as artificial antibodies have received considerable scientific attention in the past years in the field of (bio)sensors since they have unique features that distinguish them from natural antibodies such as robustness, multiple binding sites, low cost, facile preparation and high stability under extreme operation conditions (higher pH and temperature values, etc.). On the other hand, the Quartz Crystal Microbalance (QCM) is an analytical tool based on the measurement of small mass changes on the sensor surface. QCM sensors are practical and convenient monitoring tools because of their specificity, sensitivity, high accuracy, stability and reproducibility. QCM devices are highly suitable for converting the recognition process achieved using MIP-based memories into a sensor signal. Therefore, the combination of a QCM and MIPs as synthetic receptors enhances the sensitivity through MIP process-based multiplexed binding sites using size, 3D-shape and chemical function having molecular memories of the prepared sensor system toward the target compound to be detected. This review aims to highlight and summarize the recent progress and studies in the field of (bio)sensor systems based on QCMs combined with molecular imprinting technology.

  3. Quartz Crystal Microbalance Electronic Interfacing Systems: A Review

    Directory of Open Access Journals (Sweden)

    Abdulrahman Alassi

    2017-12-01

    Full Text Available Quartz Crystal Microbalance (QCM sensors are actively being implemented in various fields due to their compatibility with different operating conditions in gaseous/liquid mediums for a wide range of measurements. This trend has been matched by the parallel advancement in tailored electronic interfacing systems for QCM sensors. That is, selecting the appropriate electronic circuit is vital for accurate sensor measurements. Many techniques were developed over time to cover the expanding measurement requirements (e.g., accommodating highly-damping environments. This paper presents a comprehensive review of the various existing QCM electronic interfacing systems. Namely, impedance-based analysis, oscillators (conventional and lock-in based techniques, exponential decay methods and the emerging phase-mass based characterization. The aforementioned methods are discussed in detail and qualitatively compared in terms of their performance for various applications. In addition, some theoretical improvements and recommendations are introduced for adequate systems implementation. Finally, specific design considerations of high-temperature microbalance systems (e.g., GaPO4 crystals (GCM and Langasite crystals (LCM are introduced, while assessing their overall system performance, stability and quality compared to conventional low-temperature applications.

  4. Quartz Crystal Microbalance Electronic Interfacing Systems: A Review

    Science.gov (United States)

    Benammar, Mohieddine; Brett, Dan

    2017-01-01

    Quartz Crystal Microbalance (QCM) sensors are actively being implemented in various fields due to their compatibility with different operating conditions in gaseous/liquid mediums for a wide range of measurements. This trend has been matched by the parallel advancement in tailored electronic interfacing systems for QCM sensors. That is, selecting the appropriate electronic circuit is vital for accurate sensor measurements. Many techniques were developed over time to cover the expanding measurement requirements (e.g., accommodating highly-damping environments). This paper presents a comprehensive review of the various existing QCM electronic interfacing systems. Namely, impedance-based analysis, oscillators (conventional and lock-in based techniques), exponential decay methods and the emerging phase-mass based characterization. The aforementioned methods are discussed in detail and qualitatively compared in terms of their performance for various applications. In addition, some theoretical improvements and recommendations are introduced for adequate systems implementation. Finally, specific design considerations of high-temperature microbalance systems (e.g., GaPO4 crystals (GCM) and Langasite crystals (LCM)) are introduced, while assessing their overall system performance, stability and quality compared to conventional low-temperature applications. PMID:29206212

  5. Quartz Microbalance Sensor for the Detection of Acrylamide

    Directory of Open Access Journals (Sweden)

    Christoph A. Schalley

    2004-10-01

    Full Text Available Abstract: Several macrocycles of the Hunter-Vögtle type have been identified as superior host compounds for the detection of small amounts of acrylamide. When coated onto the surface of a quartz microbalance, these compounds serve as highly sensitive and selective sensor-active layers for their use in electronic noses. In this study, differently substituted macrocycles were investigated including an open-chain analogue and a catenane. Their structure and functional groups are correlated with their observed affinities to acrylamide and related acids and amides. The much smaller response of the open-chain compound and the almost absent sensor response of the catenane suggest that binding occurs within the cavity of the macrocycle. Theoretical calculations agree well with the experimental data even though they do not yet take into account the arrangement of the macrocycles in the sensor-active layer. The lower detection limit of acrylamide is 10 parts per billion (ppb, which is impressively low for this type of sensor. Other related compounds such as acrylic acid, propionamide, or propionic acid show no or significantly lower affinities to the macrocycles in these concentration ranges.

  6. Some experiments on the high-low transition of quartz

    International Nuclear Information System (INIS)

    Mayer, G.

    1959-12-01

    First section. - We expose on the one hand a theory of specific heat, thermal expansion and variations of elastic constants as functions of temperature, which is applicable only in the absence of transformation phenomena affecting symmetry or periodicity of the crystal lattice. On the other hand, we discuss some theories relative to the phenomena which accompany phase transformations. Second section. - We have gathered together numerical results concerning elastic, piezoelectric and optical properties of quartz. Some have been collected from the literature, other have been obtained in our laboratories with the help of experimental methods which we describe. As a result, we are able to present a complete picture of the evolution of these constants in a large temperature range containing the critical temperature of 574 deg. C at which these constants exhibit discontinuities. New phenomena have been observed, in the course of these studies. Third section. - We show that the evolution of the two piezoelectric and elastic constants which cancel out in the high temperature form is described by the same function. With the inclusion of one other function, it is possible to explain quantitatively the behaviour in the transformation range of all the other constants under study. With the help of crystallographic considerations and of hypotheses concerning the nature of the transformation entropy, we finally try to account for the experimental values of these two functions. (author) [fr

  7. Manipulated wettability of a superhydrophobic quartz crystal microbalance through electrowetting

    International Nuclear Information System (INIS)

    Esmeryan, K D; McHale, G; Trabi, C L; Geraldi, N R; Newton, M I

    2013-01-01

    The liquid phase response of quartz crystal microbalances (QCMs) with a thin coating (∼9 µm) of epoxy resin with and without a carbon nanoparticles top layer is reported. The nanoparticles convert the epoxy surface to a superhydrophobic one with a high static contact angle (∼151°–155°) and low contact angle hysteresis (∼1°–3.7°) where droplets of water are in the suspended Cassie–Baxter state. The frequency decrease of the fully immersed QCM with the superhydrophobic surface is less than with only epoxy layer, thus indicating a decoupling of the QCM response. A wettability transition to a liquid penetrating into the surface roughness state (for droplets a high contact angle hysteresis Wenzel state) was triggered using a molarity-of-ethanol droplet test (MED) and electrowetting; the MED approach caused some surface damage. The electrowetting-induced transition caused a frequency decrease of 739 Hz at a critical voltage of ∼100 V compared to the QCM in air. This critical voltage correlates to a contact angle decrease of 26° and a high contact angle hysteresis state in droplet experiments. These experiments provide a proof-of-concept that QCMs can be used to sense wetting state transitions and not only mass attachments or changes in viscosity–density products of liquids. (paper)

  8. Single transverse mode protein laser

    Science.gov (United States)

    Dogru, Itir Bakis; Min, Kyungtaek; Umar, Muhammad; Bahmani Jalali, Houman; Begar, Efe; Conkar, Deniz; Firat Karalar, Elif Nur; Kim, Sunghwan; Nizamoglu, Sedat

    2017-12-01

    Here, we report a single transverse mode distributed feedback (DFB) protein laser. The gain medium that is composed of enhanced green fluorescent protein in a silk fibroin matrix yields a waveguiding gain layer on a DFB resonator. The thin TiO2 layer on the quartz grating improves optical feedback due to the increased effective refractive index. The protein laser shows a single transverse mode lasing at the wavelength of 520 nm with the threshold level of 92.1 μJ/ mm2.

  9. Analytical procedure for the in-vial derivatization-extraction of phenolic acids and flavonoids in methanolic and aqueous plant extracts followed by gas chromatography with mass selective detection.

    NARCIS (Netherlands)

    Fiamegos, Y.C.; Nanos, C.G.; Vervoort, J.J.M.; Stalikas, C.D.

    2004-01-01

    An in-vial simple method for the combined derivatization and extraction of phenolic acids and flavonoids from plant extracts and their direct determination with GC-MS, is described. The method is taking advantage of the beneficial potentials of phase transfer catalysis (PTC). Catalysts in soluble

  10. A resonant sensor composed of quartz double ended tuning fork and silicon substrate for digital acceleration measurement

    Energy Technology Data Exchange (ETDEWEB)

    Li, Cun; Zhao, Yulong, E-mail: zhaoyulong@mail.xjtu.edu.cn; Cheng, Rongjun; Yu, Zhongliang; Liu, Yan [State Key Laboratory for Manufacturing System Engineering, Xi' an Jiaotong University, Xi' an, Shannxi 710049 (China)

    2014-03-15

    Presented in this paper is a micro-resonant acceleration sensor based on the frequency shift of quartz double ended tuning fork (DETF). The structure is silicon substrate having a proof mass supported by two parallel flexure hinges as doubly sustained cantilever, with a resonating DETF located between the hinges. The acceleration normal to the chip plane induces an axial stress in the DETF beam and, in turn, a proportional shift in the beam resonant frequency. Substrate is manufactured by single-crystal silicon for stable mechanical properties and batch-fabrication processes. Electrodes on the four surfaces of DETF beam excite anti-phase vibration model, to balance inner stress and torque and imply a high quality factor. The sensor is simply packaged and operates unsealed in atmosphere for measurements. The tested natural frequency is 36.9 kHz and the sensitivity is 21 Hz/g on a nominally ±100 g device, which is in good agreement with analytical calculation and finite element simulation. The output frequency drifting is less than 0.5 Hz (0.0014% of steady output) within 1 h. The nonlinearity is 0.0019%FS and hysteresis is 0.0026%FS. The testing results confirm the feasibility of combining quartz DETF and silicon substrate to achieve a micro-resonant sensor based on simple processing for digital acceleration measurements.

  11. Stresses and pressures at the quartz-coesite transition in shear experiments

    Science.gov (United States)

    Richter, B.; Stunitz, H.; Heilbronner, R.

    2015-12-01

    Experiments on quartz (qtz) gouge were performed in a Griggs-type deformation apparatus at displacement rates of ~1.3 x 10-5 mms-1 or ~1.3 x 10-4 mms-1, at Pc= 1.0 GPa or 1.5 GPa and T = 600°C to 800°C. The starting material is a natural hydrothermally grown single crystal that was crushed to a powder with grain size d clasts. At high stresses, where Pm is also above the QCT, coe often forms radiating aggregates. At lower stresses, where only σ1 lies in the stability field of coe, and at low strain the coe grains have a preferred orientation of the b-axes (sub-) parallel to σ1. With increasing strain, the rigid coe grains rotate and align with the preferred qtz fabric. For coe to be found, it is sufficient that σ1 reaches values above the transformation pressure. If σ1 drops back into the qtz stability field during an experiment, a back-reaction from coe to qtz is observed. It appears therefore that the pressure that defines the QCT is not Pc or Pm, but σ1.

  12. Impact of firing on the OSL luminescence properties of natural quartz: A case study

    International Nuclear Information System (INIS)

    Koul, D.K.; Polymeris, G.S.; Soni, A.; Kulkarni, M.S.

    2016-01-01

    A comprehensive study was carried out to observe the impact of firing on the behavior of different features of the optically stimulated luminescence (OSL) signal of geological quartz. The different features which could influence its use in different applications were studied. A comparison of nature of (i) thermoluminescence (TL) glow curves, (ii) OSL decay curves, (iii) pulse annealing curves, (iv) fast and slow components and (v) thermally transferred OSL (TT-OSL) emission of unfired and fired samples suggested a profound influence of thermal firing on the OSL signal. The composition of the OSL signal was seen to get altered by firing treatment; the magnitude of slow component losing its dominance to the fast component. This was true of pulse annealing also, the fired curve looked different from the unfired one. TT-OSL was observed to be larger in unfired sample as compared to the fired sample. Finally, firing was seen to enable reliable dose recovery using single aliquot regenerative (SAR) method, which has not been the case with the unfired sample studied here.

  13. Evaluating endoglucanase Cel7B-lignin interaction mechanisms and kinetics using quartz crystal microgravimetry.

    Science.gov (United States)

    Pfeiffer, Katherine A; Sorek, Hagit; Roche, Christine M; Strobel, Kathryn L; Blanch, Harvey W; Clark, Douglas S

    2015-11-01

    The kinetics and mechanisms of protein interactions with solid surfaces are important to fields as diverse as industrial biocatalysis, biomedical engineering, food science, and cell biology. The nonproductive adsorption of cellulase enzymes to lignin, a plant cell wall polymer, reduces their effectiveness in saccharifying biomass. Cellulase has been shown to interact with lignin, but the heterogeneity of lignin surfaces, challenges in measuring irreversible components of these interactions, and fast adsorption rates make quantifying the reaction kinetics difficult. This work employs quartz crystal microgravimetry with dissipation monitoring (QCM-D) for real-time measurement of adsorbed mass on a flat lignin surface. We have developed a method for casting homogeneous lignin films that are chemically similar to lignin found in pretreated biomass, and used QCM-D to compare three models of reversible-irreversible binding behavior: a single-site transition model, a transition model with changing adsorbate footprint, and a two-site transition model. Of the three models tested, the two-site transition model provides the only kinetic mechanism able to describe the behavior of Cel7B binding to lignin. While the direct implications of lignin-cellulase interactions may be limited to biomass deconstruction for renewable energy and green chemistry, the analytical and experimental methods demonstrated in this work are relevant to any system in which the kinetics and reaction mechanism of reversible and irreversible protein adsorption at a solid-liquid interface are important. © 2015 Wiley Periodicals, Inc.

  14. Development of a Flow Injection Based High Frequency Dual Channel Quartz Crystal Microbalance

    Directory of Open Access Journals (Sweden)

    Jinxing Liang

    2017-05-01

    Full Text Available When the quartz crystal microbalance (QCM is used in liquid for adsorption or desorption monitoring based bio- or chemical sensing applications, the frequency shift is not only determined by the surface mass change, but also by the change of liquid characteristics, such as density and viscosity, which are greatly affected by the liquid environmental temperature. A monolithic dual-channel QCM is designed and fabricated by arranging two QCM resonators on one single chip for cancelling the fluctuation induced by environmental factors. In actual applications, one QCM works as a specific sensor by modifying with functional membranes and the other acts as a reference, only measuring the liquid property. The dual-channel QCM is designed with an inverted-mesa structure, aiming to realize a high frequency miniaturized chip and suppress the frequency interference between the neighbored QCM resonators. The key problem of dual-channel QCMs is the interference between two channels, which is influenced by the distance of adjacent resonators. The diameter of the reference electrode has been designed into several values in order to find the optimal parameter. Experimental results demonstrated that the two QCMs could vibrate individually and the output frequency stability and drift can be greatly improved with the aid of the reference QCM.

  15. Theoretical modelling of experimental diagnostic procedures employed during pre-dose dosimetry of quartz

    International Nuclear Information System (INIS)

    Pagonis, V.; Chen, R.; Kitis, G.

    2006-01-01

    The pre-dose technique in thermoluminescence (TL) is used for dating archaeological ceramics and for accident dosimetry. During routine applications of this technique, the sensitisation of the quartz samples is measured as a function of the annealing temperature, yielding the so-called thermal activation characteristic (TAC). The measurement of multiple TACs and the study of the effect of UV-radiation on the TL sensitivity of quartz are important analytical and diagnostic tools. In this paper, it is shown that a modified Zimmerman model for quartz can successfully model the experimental steps undertaken during a measurement of multiple TACs. (authors)

  16. Corroded hydrothermal quartz in Ordovician altered volcanic ash beds of the Baltoscandian Region

    Directory of Open Access Journals (Sweden)

    Kiipli, Tarmo

    2009-12-01

    Full Text Available Partly dissolved prismatic quartz crystals have been found in an Upper Ordovician volcanic ash bed of the Vasagård section on Bornholm, Denmark. Similar crystals occur also in a volcanic ash in the Adze Formation of the Aizpute core, Latvia. Although biostratigraphic data are insufficient for the correlation of these findings, the abundant occurrence of this rare form of quartz at Vasagård indicates that it can be reliably used as a correlation criterion in future studies. Partly dissolved prismatic quartz crystals were most likely formed during hydrothermal processes in the volcanic source area.

  17. Quartz Crystal Microbalance (QCM) monitor of contamination for LES-8/9

    Science.gov (United States)

    Lynch, J. T.

    1977-01-01

    A Quartz Crystal Microbalance (QCM) was used to monitor condensable contamination during the launching of two Lincoln Laboratory Experimental Satellites--LES-8 and LES-9. The QCM was installed on the dispenser truss and measured contamination by means of a frequency shift of a quartz crystal oscillator. By using a special crystal cut and a second reference quartz crystal, the sensor had extreme sensitivity and remarkable temperature independence. A 1-Hz frequency shift, which corresponds to 3.5 x 10 to the -9th power g/sq cm was resolved by the flight instrumentation.

  18. Fluoride retardation from quartz sand-packed column tests

    Directory of Open Access Journals (Sweden)

    Eduardo Usunoff

    2009-06-01

    Full Text Available Inasmuch as both low and high concentrations of F- in groundwater have different detrimental effects on human health (increased dental caries, and mottled enamel or even severe structural bone deformations, respectively, many efforts have focused on the movement of such anion in aqueous systems. It is so because water drinking is the main intake of F- by humans. This paper presents the results of seven dynamic experiments in which solutions of varying [F-], pH, and flow velocities circulated through columns packed with clean quartz sand. The breakthrough data were analyzed by means of a computer code adapted to the estimation of equilibrium and non-equilibrium solute transport parameters from miscible displacement experiments in a steady-state, uniform flow field using a pulse-type or continuous source. It was found that larger retardation factors (R are associated with low pH, low [F-] in the feed solutions, and larger flow velocities. Such results appear to be related to the form of the F species, the rather weak bond between the adsorbate and the quartz sand, and stronger anion repulsion at low pore velocities. The estimated values for R vary between 1,22 and 1,50, whereas the distribution coefficients were in the range of 0,1 to 0,05 L kg-1. It should be said that the breakthrough curves display hysteresis, leading to a desorption behavior that proceeds faster than the adsorption process.Puesto que tanto valores bajos como altos de F- en las aguas subterráneas tienen efectos adversos en la salud de los humanos (mayor cantidad de caries, y manchas del esmalte dental e incluso deformaciones óseas, respectivamente, han sido muchos los esfuerzos destinados a dilucidar el movimiento de especies fluoradas en ambientes acuosos. Ello es así porque el consumo de agua por parte de seres humanos representa la mayor fuente de ingreso de F-. Este trabajo presenta los resultados de siete experimentos dinámicos en los que soluciones de diferentes [F

  19. Selection of ligands for affinity chromatography using quartz crystal biosensor.

    Science.gov (United States)

    Liu, Yang; Tang, Xiaoling; Liu, Feng; Li, Ke'an

    2005-07-01

    This paper described a new strategy for rapid selecting ligands for application in affinity chromatography using a quartz crystal microbalance (QCM) biosensor. An aminoglycoside antibiotic drug, kanamycin (KM), was immobilized on the gold electrodes of the QCM sensor chip. The binding interactions of the immobilized KM with various proteins in solution were monitored as the variations of the resonant frequency of the modified sensor. Such a rapid screen analysis of interactions indicated clearly that KM-immobilized sensor showed strong specific interaction only with lysozyme (LZM). The resultant sensorgrams were rapidly analyzed by using a kinetic analysis software based on a genetic algorithm to derive both the kinetic rate constants (k(ass) and k(diss)) and equilibrium dissociation constants (K(D)) for LZM-KM interactions. The immobilized KM showed higher affinity to LZM with a dissociation constant on the order of 10(-5) M, which is within the range of 10(-4)-10(-8) M and suitable for an affinity ligand. Therefore, KM was demonstrated for the first time as a novel affinity ligand for purification of LZM and immobilized onto the epoxy-activated silica in the presence of a high potassium phosphate concentration. The KM immobilized affinity column has proved useful for a very convenient purification of LZM from chicken egg white. The purity of LZM obtained was higher than 90%, as determined by densitometric scanning of sodium dodecyl sulfate-polyacrylamide gel electrophoresis of purified fraction. These results confirmed that the selected KM ligand is indeed a valuable affinity ligand for purification of LZM. The new screening strategy based on a QCM biosensor is expected to be a promising way for rapid selecting specific ligands for purifying other valuable proteins.

  20. Arsenic Sulfide Nanowire Formation on Fused Quartz Surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Olmstead, J.; Riley, B.J.; Johnson, B.R.; Sundaram, S.K.

    2005-01-01

    Arsenic sulfide (AsxSy) nanowires were synthesized by an evaporation-condensation process in evacuated fused quartz ampoules. During the deposition process, a thin, colored film of AsxSy was deposited along the upper, cooler portion of the ampoule. The ampoule was sectioned and the deposited film analyzed using scanning electron microscopy (SEM) to characterize and semi-quantitatively evaluate the microstructural features of the deposited film. A variety of microstructures were observed that ranged from a continuous thin film (warmer portion of the ampoule), to isolated micron- and nano-scale droplets (in the intermediate portion), as well as nanowires (colder portion of the ampoule). Experiments were conducted to evaluate the effects of ampoule cleaning methods (e.g. modify surface chemistry) and quantity of source material on nanowire formation. The evolution of these microstructures in the thin film was determined to be a function of initial pressure, substrate temperature, substrate surface treatment, and initial volume of As2S3 glass. In a set of two experiments where the initial pressure, substrate thermal gradient, and surface treatment were the same, the initial quantity of As2S3 glass per internal ampoule volume was doubled from one test to the other. The results showed that AsxSy nanowires were only formed in the test with the greater initial quantity of As2S3 per internal ampoule volume. The growth data for variation in diameter (e.g. nanowire or droplet) as a function of substrate temperature was fit to an exponential trendline with the form y = Aekx, where y is the structure diameter, A = 1.25×10-3, k = 3.96×10-2, and x is the temperature with correlation coefficient, R2 = 0.979, indicating a thermally-activated process.

  1. Microcontact imprinted quartz crystal microbalance nanosensor for protein C recognition.

    Science.gov (United States)

    Bakhshpour, Monireh; Özgür, Erdoğan; Bereli, Nilay; Denizli, Adil

    2017-03-01

    Detection of protein C (PC) in human serum was performed by quartz crystal microbalance (QCM) based on molecular imprinting technique (MIP). The high-resolution and mass-sensitive QCM based sensor was integrated with high sensitivity and selectivity of the MIP technique. The PC microcontact imprinted (PC-μCIP) nanofilm was prepared on the glass surface. Then, the PC-μCIP/QCM sensor was prepared with 2-hydroxyethyl methacrylate (HEMA), ethylene glycol dimethacrylate (EGDMA) and N-methacryloyl l-histidine methylester (MAH) as the functional monomer with copper(II) ions. The polymerization was performed under UV light (100W and 365nm) for 20-25min under nitrogen atmosphere. The characterization studies of QCM sensor were done by observation using atomic force microscopy (AFM), contact angle measurements, ellipsometry and fourier transform infrared spectroscopy (FTIR). Detection of PC was investigated in a concentration range of 0.1-30μg/mL. Selectivity of PC-μCIP and PC non-imprinted/QCM (PC-non-μCIP) sensors for PC determination was investigated by using proteins namely hemoglobin (Hb), human serum albumin (HSA) and fibrinogen solutions. QCM sensor was also used for detection of PC molecules in aqueous solutions and human plasma. The detection limit was determined as 0.01μg/mL for PC analysis. The PC-μCIP/QCM sensor was used for five consecutive adsorption-desorption cycles. According to the results, the PC-μCIP/QCM sensor had obtained high selectivity and sensitivity for detection of PC molecules. Copyright © 2016 Elsevier B.V. All rights reserved.

  2. Structures and growth textures of Japanese twin boundaries in quartz

    Science.gov (United States)

    Momma, K.; Nagase, T.; Kudoh, Y.; Kuribayashi, T.

    2008-12-01

    Growth textures and atomic configurations of Japanese twin boundaries in quartz were studied by the observation of natural samples and by computational simulations. Samples used in this study are collected from Narushima, Nagasaki Prefecture, Japan. The samples were first polished, and then etched by hydrofluoric acid for several minutes. The etched figures were observed by phase-contrast reflection microscopy and scanning electron microscopy. From these observations, high concentration of Brazil twin lamellae is found near the composition plane of Japanese twin. Observations of cathode luminescence images reveal that the development of Brazil twin lamellae at {112×2} composition plane of Japanese twin is directly related to the preferential growth of Japanese twin along the composition plane. Atomic configurations at {112×2} composition planes of Japanese twin were simulated by using molecular dynamics simulations and the energy minimization method. The simulated structures proved that {112×2} or {1×1×22} composition planes are the only composition planes that do not introduce unsatisfied bonding between Si and O atoms. When the composition plane is different from these planes, some kind of defect structures, like dislocations, are inevitably introduced. In the case of Brazil twin, screw dislocations are also known to be incorporated where orientation of Brazil twin boundary changes from one orientation to another. On the other hand, in the case where Brazil twin boundaries intersect with {112×2} composition planes of Japanese twin, we found that structures are kept coherently without any unsatisfied bonding. This result means that {112×2} composition planes of Japanese twin are the crystallographic sites having more than one possible stacking structures. Observations in this study indicate that {112×2} composition plane of Japanese twin serves as a source of Brazil twin during the course of crystal growth.

  3. The interpretation of quartz optically stimulated luminescence equivalent dose versus time plots

    International Nuclear Information System (INIS)

    Bailey, R.M.

    2000-01-01

    Numerical modelling has shown that the form of the quartz OSL shine plateau (hereafter 'D e (t)-plot') is influenced by the effects of phototransferred TL in the ∼110 deg. C region. It is suggested also that the presence of multiple OSL components (as described by Partial bleaching and the decay form characteristics of quartz OSL. Radiat. Meas., 27, 123-136. The form of the optically stimulated luminescence signal of quartz: implications of dating. Unpublished PhD thesis, University of London) affects the form of the D e (t)-plot. Laboratory measurements of a fully reset and artificially dosed sample yielded non-flat D e (t)-plots, the deviation being greater for the larger of the two simulated palaeodoses, in accordance with theoretical predictions. It is suggested that the so-called 'shine plateau' test is of limited use in assessing the bleaching history of quartz sediments

  4. Vibration characteristic analysis method for the quartz microgyroscope based on the admittance circle

    Science.gov (United States)

    Wang, Haoxu; Dong, Peitao; Xie, Liqiang; Wu, Xuezhong

    2014-03-01

    The vibration characteristic analysis method for a quartz microgyroscope based on the admittance circle is reported in this paper. Admittance theory is introduced and the admittance circle principle is analysed to study the vibration characteristics of the quartz microgyroscope. The prototype gyroscope was fabricated by micro-electromechanical systems (MEMS) technology. The admittance and phase diagram of the work mode were obtained by vibration mode test systems. Then the admittance circle of the work mode was drawn, and the parameter identification of the transfer function between the voltage and current was completed to analyse the vibration characteristics. Therefore, the vibration characteristic analysis method based on the admittance circle can be used to build the transfer function of the quartz microgyroscope, which is helpful for the design of a high performance quartz microgyroscope.

  5. Optically stimulated luminescence from quartz measured using the linear modulation technique

    DEFF Research Database (Denmark)

    Bulur, E.; Bøtter-Jensen, L.; Murray, A.S.

    2000-01-01

    The optically stimulated luminescence (OSL) from heated natural quartz has been investigated using the linear modulation technique (LMT), in which the excitation light intensity is increased linearly during stimulation. In contrast to conventional stimulation, which usually produces a monotonical...

  6. Measurement of temperature fields in specimens of quartz ceramic during surface ablation

    Science.gov (United States)

    Frolov, G. A.; Pasichnyi, V. V.; Suzdal'Tsev, E. I.; Tsyganenko, V. S.

    1989-08-01

    The authors propose a method of mounting thermocouples and have obtained temperature fields within specimens of pure and doped quartz ceramic. The linearity of the dependenceΔ * = fleft( {sqrt tau } right) for deep isotherms has been proved experimentally.

  7. Cathodoluminescence investigations on quartz cement in sandstones of Khabour Formation from Iraqi Kurdistan region, northern Iraq

    DEFF Research Database (Denmark)

    Omer, Muhamed Fakhri; Friis, Henrik

    The Ordovician deltaic to shallow marine Khabour Formation in Northern Iraq consists mainly of sandstone with minor siltstone and interbedded shale. The sandstones are pervasively cemented by quartz that resulted in very little preserved primary porosity. Cathodoluminescence and petrographic stud...

  8. EPR investigation into the structure of boron-containing quartz glasses

    International Nuclear Information System (INIS)

    Amosov, A.V.; Bushmarin, D.B.; Prokhorova, T.I.; Yudin, D.M.

    1975-01-01

    Certain properties of boron-containing quartz glasses and the nature of occurrence of boron in the glass lattice are studied as functions of the method of alloying. The formation of three types of borate structural nodes (BO 4 , BO 3 and BO 4 -BO 3 ) in the lattice of quartz glasses is established. Alloying by boron oxide up to 3% (weight) increases the crystallization stability of quartz glasses, lowers down tsub(g) from 1220 to 950 deg C and does not affect the coefficient of thermal expansion. Low symmetry of borate structural nodes, following from the analysis of EPR spectra, confirms the literature data concerning the low symmetry of glass-forming polyhedrons in a quartz glass

  9. Surface textures of quartz grains from Goa coast - An application of the scanning electron microscope

    Digital Repository Service at National Institute of Oceanography (India)

    Ambre, N.V.; Gujar, A.R.; Mislankar, P.G.

    The scanning electron microscopy of quartz grains along the Goa beaches reveals 10 microfeatures. Three types of process response environments viz. Beach (Littoral), subaqueous and low to high-energy chemical environments appears to be active...

  10. Cathodoluminescence investigations on quartz cement in sandstones of Khabour Formation from Iraqi Kurdistan region, northern Iraq

    DEFF Research Database (Denmark)

    Omer, Muhamed Fakhri; Friis, Henrik

    The Ordovician deltaic to shallow marine Khabour Formation in Northern Iraq consists mainly of sandstone with minor siltstone and interbedded shale. The sandstones are pervasively cemented by quartz that resulted in very little preserved primary porosity. Cathodoluminescence and petrographic...

  11. Study of the α and β phases of quartz by neutron multiple diffraction

    International Nuclear Information System (INIS)

    Mazzocchi, V.L.

    1984-01-01

    Crystal structures of α and β phases of quartz are studied, employing neutron multiple diffraction as a method of analysis. Theoretical multiple diffraction patterns in a many-beam case were determined by a computer program which calculates intensities of beams as sums of Taylor's series expansions, retaining terms up to a order n. Experimental 'umweg' and transmitted beam patterns were obtained for the 00.1 primary reflection of α and β phases of quartz. To calculate α - quartz multiple diffraction intensities it was necessary to determine the Dauphine twinning fraction for the crystal after having passed by the β-phase. For the two models of β-quartz a better agreement between experimental and calculated integrated intensities was found for the disordered structure model based on split-half-oxigen positions. (Author) [pt

  12. Vibration characteristic analysis method for the quartz microgyroscope based on the admittance circle

    Directory of Open Access Journals (Sweden)

    Haoxu Wang

    2014-02-01

    Full Text Available The vibration characteristic analysis method for a quartz microgyroscope based on the admittance circle is reported in this paper. Admittance theory is introduced and the admittance circle principle is analysed to study the vibration characteristics of the quartz microgyroscope. The prototype gyroscope was fabricated by micro-electromechanical systems (MEMS technology. The admittance and phase diagram of the work mode were obtained by vibration mode test systems. Then the admittance circle of the work mode was drawn, and the parameter identification of the transfer function between the voltage and current was completed to analyse the vibration characteristics. Therefore, the vibration characteristic analysis method based on the admittance circle can be used to build the transfer function of the quartz microgyroscope, which is helpful for the design of a high performance quartz microgyroscope.

  13. Effect of pre-dose irradiation in the quartz and its use for archaelogical dating

    International Nuclear Information System (INIS)

    Yukimitu, K.

    1985-01-01

    The technique of pre-dose for dating ceramics, using the thermoluminescent properties of quartz is presented. The behavior of thermoluminescent (TL) sensitivity of the 110 0 C peak of Brazilian quartz, in its geologic state, submitted to thermal treatments from 600 to 900 0 C, is studied. The samples were tritured for separating the quartz crystals from clay. The quartz grains were submitted to leaching with chloric acid solution followed by leaching with running water. The samples were irradiated in laboratory, with gamma radiation using Co-60 and Cs-137 sources, for calibration. A sensitivity enhancement rate of 2% per rad was observed for samples annealed at 900 0 C, was observed. (M.C.K.) [pt

  14. The Quartz-Crystal Microbalance in an Undergraduate Laboratory Experiment: I. Fundamentals and Instrumentation

    Science.gov (United States)

    Tsionsky, Vladimir

    2007-01-01

    The fundamentals, as well as the instrumentation of the quartz-crystal microbalance (QCM) technique that is used in an undergraduate laboratory experiment are being described. The QCM response can be easily used to change the properties of any system.

  15. Installation and evaluation of weigh-in-motion utilizing quartz-piezo sensor technology.

    Science.gov (United States)

    2016-06-28

    The objective of the research study was: to install a quartz-piezo based WIM system, and to : determine sensor survivability, accuracy and reliability under actual traffic conditions in : Connecticuts environment. If the systems prove dependable a...

  16. Imperfections study of the smoky quartz from Bahia by X-ray diffraction

    International Nuclear Information System (INIS)

    D'Aguiar Neto, M.M.F.

    1974-01-01

    X-ray diffraction techniques were used to study the type of point defects in Smoky quartz from Itambe and Vitoria da Conquista in Bahia. The power method, using the Seemann Bohlin camara (back refletion), was utilized in the analysis of the policrystals, while the monocrystals were studied by means of the precession camara. The positions occupied by the defects in the crystal net were calculated. The results show that while the defects of substitutional impurities predominate in the quartz from Itambe, in the quartz from Vitoria da Conquista the substitutional defects exist in comparable proportions that the interstital ones. Isochronous annealing curves, for both type of smoky quartz indicate an increase in the net parameter to temperature values above the annealing temperatures. Was formulated the hypothesis that providing a thermal energy greater than that of annealing is used, new interstitial defects would be created as a result of a thermic diffusion mechanism. (C.D.G.) [pt

  17. ANIE: A Mathematical Algorithm for Automated Indexing of Planar Deformation Features in Shocked Quartz

    Science.gov (United States)

    Huber, M. S.; Ferrière, L.; Losiak, A.; Koeberl, C.

    2011-03-01

    A mathematical method of indexing planar deformation features in quartz and a Microsoft Excel macro for automated indexing is presented, allowing for more rapid and accurate results than the previously used manual method.

  18. Direct measurement of asperity contact growth in quartz at hydrothermal conditions

    Science.gov (United States)

    Beeler, Nicholas M.; Hickman, Stephen H.

    2015-01-01

    Earthquake recurrence requires interseismic fault restrengthening which results from solid state deformation in room-temperature friction and indentation experiments. In contrast exhumed fault zones show solution-transport processes such as pressure solution and contact overgrowths influence fault zone properties . In the absence of fluid flow, overgrowths are driven by gradients in surface curvature where material is dissolved, diffuses, and precipitates at the contact without convergence normal to the contact. To determine the rate of overgrowth for quartz, we conducted single contact experiments in an externally heated pressure vessel. Convergence was continuously monitored using reflected-light interferometry through a long-working-distance microscope. Contact normal force was constant with an initial effective normal stress of 1.7 MPa, temperature was between 350 and 530{degree sign}C, and water pressure was constant at 150 MPa. Two control experiments were conducted: one dry at 425{degree sign}C and one bi-material (sapphire) at 425{degree sign}C and 150 MPa water pressure. No contact growth or convergence was observed in the controls. For wet single-phase contacts, growth was initially rapid and then decreased with time. No convergence was observed. Fluid inclusions indicate that the contact is not uniformly wetted. The contact is bounded by small regions of high aperture, reflecting local free-face dissolution as the source for the overgrowth. The apparent activation energy is ~125 kJ/mol. Extrapolation predicts rates of contact area increase orders of magnitude faster than in dry, room-temperature and hydrothermal friction experiments, suggesting that natural strength recovery near the base of the seismogenic zone could be dominated by contact overgrowth.

  19. SIMS Investigations on Growth and Sector Zoning in Natural Hydrothermal Quartz: Isotopic and Trace Element Analyses

    Science.gov (United States)

    May, E.; Vennemann, T. W.; Baumgartner, L. P.; Meisser, N.

    2014-12-01

    Quartz is the most abundant mineral in the Earth's crust and is found in virtually every geological context. Despite its ubiquity and the detailed studies on the conditions of quartz crystallization, some questions concerning its growth and sector zoning with regard to trace element incorporation and oxygen isotope fractionations and the implications thereof for interpretations on the conditions of formation remain (e.g., Jourdan et al., 2009). This study presents new in-situ measurements of trace element and oxygen isotope ratios on natural hydrothermal quartz from an extensional gold-bearing quartz vein in the western Swiss Alps. The temperature of formation of the veins is estimated by quartz-hematite oxygen isotope thermometry to be about 360°C. A detailed SEM-CL study of this sample shows cyclic lamellar growth, alternating with phases of dissolution that are directly followed by macro-mosaic growth of the quartz, before returning to a cyclic lamellar growth again. Trace element concentrations (measured for Na, K, Li, Al, and Ti) notably showed Al/Si variations of three orders of magnitude and coupled Al and Li variations, likely substituting for Si in different growth zones with lower values in macro-mosaic zones precipitating after the period of dissolution. The oxygen isotope composition of the crystal, in contrast, is homogeneous through all growth zones (δ18O values between 15.6‰ and 16.2‰) indicating that the fluid must have been buffered by the host-rock and/or the source of the fluid remained the same despite the period of quartz dissolution. Furthermore, the temperature during crystallization of the quartz crystal has likely also remained similar. The fact that no variations are measured in oxygen isotope compositions but some variations in trace element contents may suggest that changes in pressure were important during the formation of this quartz crystal. Give the pressure effects on the solubility of quartz (Fournier and Potter, 1982), both

  20. OSL and IRSL characteristics of quartz and feldspar from southern California, USA

    International Nuclear Information System (INIS)

    Lawson, Michael J.; Roder, Belinda J.; Stang, Dallon M.; Rhodes, Edward J.

    2012-01-01

    Southern California comprises of a wide range of diverse landscapes and environments, from high mountains with glacial and periglacial sediments to deserts with large sand dunes, extensive alluvial fans and ephemeral playas. Highly active tectonic processes has exposed ancient (c. 2 Ga) plutonic and metamorphic basement from deep within the crust, while similar Palaeozoic, Mesozoic and Cenozoic rocks are also common. A rich array of volcanic lithologies extending into the late Quaternary complement many thick sedimentary sequences that formed in equally diverse ancient environments typical of an accreting active continental margin. In some locations, notably in the Coachella Valley close to Palm Springs and the Salton Sea, low OSL sensitivity and poor characteristics restrict the application of the quartz SAR protocol to date late Pleistocene and Holocene fluvial sediments. In other locations such as the Malibu coastline, high sensitivity of the quartz OSL signal is observed, despite local source rocks being dominated by volcanic lithologies. Problems of poor quartz characteristics, along with uncertainty in predicting quartz OSL behavior for future dating campaigns poses a significant problem for projects, in particular for neotectonic contexts. While K-feldspar has been used extensively to date eolian and fluvial sediments in southern California, little information regarding signal stability is available. We explore the characteristics of both quartz and feldspar sub-samples from eolian, fluvial, lacustrine environments, in order to help develop mineral selection criteria for optical dating applications and clarify these issues. The importance of radiation quenching in quartz grains recently eroded from bedrock and the role of fires in enhancing OSL sensitivity are considered. The relative bleachability of quartz and feldspar fractions, along with thermal stability considerations is discussed. A simple test for quartz OSL signal contamination based on thermal

  1. FTIR measurements of OH in deformed quartz and feldspars of the South Tibetan Detachment, Greater Himalaya

    Science.gov (United States)

    Jezek, L.; Law, R. D.; Jessup, M. J.; Searle, M. P.; Kronenberg, A. K.

    2017-12-01

    OH absorption bands due to water in deformed quartz and feldspar grains of mylonites from the low-angle Lhotse Detachment (of the South Tibetan Detachment System, Rongbuk Valley north of Mount Everest) have been measured by Fourier Transform Infrared (FTIR) Spectroscopy. Previous microstructural studies have shown that these rocks deformed by dislocation creep at high temperature conditions in the middle crust (lower - middle amphibolite facies), and oxygen isotope studies suggest significant influx of meteoric water. OH absorption bands at 3400 cm-1 of quartz mylonites from the footwall of the Lhotse Detachment Fault are large, with the character of the molecular water band due to fluid inclusions in milky quartz. Mean water contents depend on structural position relative to the core of the Lhotse Detachment, from 1000 ppm (OH/106 Si) at 420 m below the fault to 11,350 (+/-1095) ppm near its center. The gradient in OH content shown by quartz grains implies influx of meteoric water along the Lhotse Detachment from the Tibetan Plateau ground surface to middle crustal depths, and significant fluid penetration into the extruding Himalayan slab by intergranular, permeable fluid flow processes. Feldspars of individual samples have comparable water contents to those of quartz and some are wetter. Large water contents of quartz and feldspar may have contributed to continued deformation and strain localization on the South Tibetan Detachment System. Dislocation creep in quartz is facilitated by water in laboratory experiments, and the water contents of the Lhotse fault rocks are similar to (and even larger than) water contents of quartz experimentally deformed during water weakening. Water contents of feldspars are comparable to those of plagioclase aggregates deformed experimentally by dislocation and diffusion creep under wet conditions.

  2. Oxygen isotopic ratios in quartz as an indicator of provenance of dust

    International Nuclear Information System (INIS)

    Jackson, M.L.

    1977-01-01

    Quartz was isolated in the long range aerosol size range (fine silt, 1-10 μm in diameter) from atmospheric aerosols, wind-erosive soils, soil silts, shales, and Pacific pelagic sediments of the Northern and Southern Hemispheres, to trace their provenance or origin, as part of a study of dust mineral sequestering of 137 Cs and other products of nuclear fission. The oxygen isotopic ratio ( 18 O/ 16 O) was determined by mass spectrometry. The provenance has been established for this fine silt fraction which reflects the relative proportion of two classes of quartz source: (a) weathering of igneous and metamorphic rocks (high temperature origin and low 18 O/ 16 O ratio) and (b) of quartz crystallized in cherts and overgrowths (low temperature origin and high 18 O/ 16 O ratio). This quartz mixing ratio is a basic model or paradigm. Analyses of present day atmospheric aerosols and eolian-derived soils, Pacific pelagic sediments, and now-raised Phanerozoic marine sediments show that the Northern and Southern Hemispheres have separate large-scale reservoirs of the fine grain sizes that contribute to aerosol dusts. These can be identified by distinctive values of 18 O/ 16 O ratios of the quartz therein. The difference in quartz delta 18 O value in parts per thousand per ml ( 0 / 00 of about 12 +- 2 0 / 00 in Southern Hemisphere mixed detrital sediments and about 19 +- 2 0 / 00 in those of the Northern Hemisphere (for constant size, the 1-10 μm size fraction) results from the presence of a considerably larger proportion of quartz having low-temperature origin and higher delta 18 O values (chert, silica overgrowths, etc.) in the Northern Hemisphere reservoirs. The early paleoclimatic and paleogeochemical differences remain the control of the North-South Hemisphere difference in delta 18 O values in long-range aerosol sized quartz

  3. Optically stimulated exoelectron emission processes in quartz: comparison of experiment and theory

    DEFF Research Database (Denmark)

    Pagonis, V.; Ankjærgaard, Christina; Murray, A.S.

    2009-01-01

    Recent experiments have demonstrated that it is possible to measure optically stimulated exoelectron emission (OSE) signals simultaneously with optically stimulated luminescence (OSL) from quartz samples. These experiments provide valuable information on the charge movement in quartz grains. Two ...... at W(0.29±0.02) eV. Good quantitative agreement is obtained between theory and experiment by assuming a thermal broadening of the thermal depletion factor for the OSL traps, described by a Gaussian distribution of energies....

  4. Saturation spectroscopy of calcium atomic vapor in hot quartz cells with cold windows

    Science.gov (United States)

    Vilshanskaya, E. V.; Saakyan, S. A.; Sautenkov, V. A.; Murashkin, D. A.; Zelener, B. B.; Zelener, B. V.

    2018-01-01

    Saturation spectroscopy of calcium atomic vapor was performed in hot quartz cells with cold windows. The Doppler-free absorption resonances with spectral width near 50 MHz were observed. For these experiments and future applications long-lived quartz cells with buffer gas were designed and made. A cooling laser for calcium magneto-optical trap will be frequency locked to the saturation resonances in the long-lived cells.

  5. [Influence of spectral interferences on the results of quartz determination by infrared spectrometry].

    Science.gov (United States)

    Maciejewska, Aleksandra

    2015-01-01

    Determination of quartz by Fourier transform infrared spectrometry (FTIR) is not specific: the obtained results are influenced by matrix components, some of which cause spectral interference. The aim of the study was to evaluate the effect of dust components responsible for spectral interference with quartz on the results of its determinations, and to develop methods to minimize the effects of interferences. Investigation of interferent effects were conducted using respirable dusts: quartz SRM 1878a, cristobalite SRM 1879a, synthetic amorphous silica (Zeosil) and feldspar, albite and kaolinite. For the study 17 mixtures with quartz and interferents at concentrations from 10 to 90% were prepared. Determinations of quartz were carried out by the KBr disc method. In mixtures of quartz with interferents, the results based on bands 798-779 cm-1 were overestimated by 10-55%, while those based on band 695 cm-1 were closer to the true content of quartz. It was found that the best methods able to decrease the impact of spectral interference are: scaled subtraction of IR spectra of feldspar or kaolinite analysed in nonashed samples, correction curve for kaolinite also investigated in nonashed samples with quartz-content calculation based on band 695 cm-1 in mixtures with cristobalite, amorphous silica or kaolinite in ashed samples. The study indicates the need to identify spectral interferences in dust when determining crystalline silica by FT-IR and to take actions to minimize their impact on the obtained results. This work is available in Open Access model and licensed under a CC BY-NC 3.0 PL license.

  6. Influence of spectral interferences on the results of quartz determination by infrared spectrometry

    Directory of Open Access Journals (Sweden)

    Aleksandra Maciejewska

    2015-07-01

    Full Text Available Background: Determination of quartz by Fourier transform infrared spectrometry (FTIR is not specific: the obtained results are influenced by matrix components, some of which cause spectral interference. The aim of the study was to evaluate the effect of dust components responsible for spectral interference with quartz on the results of its determinations, and to develop methods to minimize the effects of interferences. Material and Methods: Investigation of interferent effects were conducted using respirable dusts: quartz SRM 1878a, cristobalite SRM 1879a, synthetic amorphous silica (Zeosil and feldspar, albite and kaolinite. For the study 17 mixtures with quartz and interferents at concentrations from 10 to 90% were prepared. Determinations of quartz were carried out by the KBr disc method. Results: In mixtures of quartz with interferents, the results based on bands 798–779 cm–1 were overestimated by 10–55%, while those based on band 695 cm–1 were closer to the true content of quartz. It was found that the best methods able to decrease the impact of spectral interference are: scaled subtraction of IR spectra of feldspar or kaolinite analysed in nonashed samples, correction curve for kaolinite also investigated in nonashed samples with quartz-content calculation based on band 695 cm–1 in mixtures with cristobalite, amorphous silica or kaolinite in ashed samples. Conclusions: The study indicates the need to identify spectral interferences in dust when determining crystalline silica by FT-IR and to take actions to minimize their impact on the obtained results. Med Pr 2015;66(4:497–509

  7. Evaluating the influence of stress on the dislocation creep flow law for quartz

    Science.gov (United States)

    Tokle, L.; Hirth, G.

    2017-12-01

    Due to the abundance of quartz in the continental crust, quartz rheology is fundamental to our understanding of many geodynamic processes. Microstructures in many naturally deformed quartzites deformed at ductile conditions, indicate that dislocation creep is a common deformation mechanism in quartz at crustal conditions. The dislocation creep flow laws for quartz were constructed based on deformation experiments on aggregates at temperatures from 900 to 1100°C and strain rates of 10-5-10-6 s-1. Hirth et al. (2001) point out that these flow laws underestimate sample strengths for experiments conducted below 900°C; yet samples deformed as low as 700°C exhibit dislocation creep microstructures. To address this discrepancy, we compared 14 different studies on experimentally deformed wet quartzite aggregates ranging in temperature from 700 to 1100°C. Our analysis shows that two clear trends develop, one with a power-law stress exponent of n = 4 and the other, at a higher stress, with a stress exponent of n = 3. This change suggests a transition in the rate-limiting process; further, the conditions where the transition in stress exponent occurs correlate well with changes in quartz c-axis fabrics in general shear experiments. At low stresses, quartz fabrics are defined by a Y-max, indicating prism slip, while at higher stresses quartz fabrics are defined by basal slip. Our interpretation is that the c-axis fabrics represent the easy slip system in quartz and hypothesize that basal slip is rate-limiting at low stresses while prism is rate-limiting at high stresses. A change in the stress exponent has significant consequences for our understanding of high stress tectonic environments, such as the brittle-ductile transition and sediment rheology in a subducting slab.

  8. The response of quartz crystals coated with thin fatty acid film to organic gases

    CERN Document Server

    Jin, C N; Kim, K H; Kwon, Y S

    1999-01-01

    We tried to apply a quartz crystal as a sensor by using the resonant frequency and the resistance properties of quartz crystals. Four kinds of fatty acids that have the same head groups were coated on the surfaces of the quartz crystals, and the shift of the resonant frequency and the resistance were observed based on the lengths of the tail groups. Myristic acid (C sub 1 sub 4), palmitic acid (C sub 1 sub 6), stearic acid (C sub 1 sub 8), and arachidic acid (C sub 2 sub 0) were deposited on the surfaces of quartz crystals by using the Langmuir-Blodgett (LB) method. As a result, the resonant frequency change was more sensitive to high molecular-weight fatty acids than to low molecular-weight ones. We also observed the effect of temperature on stearic acid LB films, and the response properties of quartz crystals coated with stearic-acid LB films to organic gases were investigated. As a result, the sensitivity of quartz crystals to organic gases was higher for higher molecular-weight gas, and we found that quar...

  9. BENTONITE-QUARTZ SAND AS THE BACKFILL MATERIALS ON THE RADIOACTIVE WASTE REPOSITORY

    Directory of Open Access Journals (Sweden)

    Raharjo Raharjo

    2010-06-01

    Full Text Available An investigation of the contribution of quartz sand in the bentonite mixture as the backfill materials on the shallow land burial of radioactive waste has been done. The experiment objective is to determine the effect of quartz sand in a bentonite mixture with bentonite particle sizes of -20+40, -40+60, and -60+80 mesh on the retardation factor and the uranium dispersion in the simulation of uranium migration in the backfill materials. The experiment was carried out by the fixed bed method in the column filled by the bentonite mixture with a bentonite-to-quartz sand weight percent ratio of 0/100, 25/75, 50/50, 75/25, and 100/0 on the water saturated condition flown by uranyl nitrate solution at concentration (Co of 500 ppm. The concentration of uranium in the effluents in interval 15 minutes represented as Ct was analyzed by spectrophotometer, then using Co and Ct, retardation factor (R and dispersivity ( were determined. The experiment data showed that the bentonite of -60+80 mesh and the quartz sand of -20+40 mesh on bentonite-to-quartz sand with weight percent ratio of 50/50 gave the highest retardation factor and dispersivity of 18.37 and 0.0363 cm, respectively.   Keywords: bentonite, quartz sand, backfill materials, radioactive waste

  10. Quartz luminescence response to a mixed alpha-beta field: Investigations on Romanian loess

    DEFF Research Database (Denmark)

    Constantin, Daniela; Jain, Mayank; Murray, Andrew S.

    2015-01-01

    Previous SAR-OSL dating studies using quartz extracted from Romanian and Serbian loess samples report SAR-OSL dose-response curves on fine grained (4-11μm) quartz that grow to much higher doses compared to those of coarse-grained (63-90, 90-125, 125-180μm) quartz. Furthermore, quartz SAR......-OSL laboratory dose response curves do not reflect the growth of the OSL signal in nature. A main difference in coarse- and fine-grained quartz dating lies in the alpha irradiation history, but the effect of mixed alpha-beta fields has so far received little attention. In the present study we investigate whether...... the alpha dose experienced by fine grains over geological cycles of irradiation and bleaching may have an effect on the saturation characteristics of the laboratory dose response. By applying time resolved optically stimulated luminescence we confirm that the OSL signals induced in quartz by alpha and beta...

  11. Molecular modeling of interactions between heavy crude oil and the soil organic matter coated quartz surface.

    Science.gov (United States)

    Wu, Guozhong; Zhu, Xinzhe; Ji, Haoqing; Chen, Daoyi

    2015-01-01

    Molecular dynamic (MD) simulation was applied to evaluate the mobility, diffusivity and partitioning of SARA (saturates, aromatics, resins, asphaltenes) fractions of heavy crude oil on soil organic matter (SOM) coated quartz surface. Four types of SOM were investigated including Leonardite humic acid, Temple-Northeastern-Birmingham humic acid, Chelsea soil humic acid and Suwannee river fulvic acid. The SOM aggregation at oil-quartz interface decreased the adsorption of SARA on the quartz surface by 13-83%. Although the SOM tended to promote asphaltenes aggregation, the overall mobility of SARA was significantly greater on SOM-quartz complex than on pure quartz. Particularly, the diffusion coefficient of asphaltenes and resins increased by up to one-order of magnitude after SOM addition. The SOM increased the overall oil adsorption capacity but also mobilized SARA by driving them from the viscous oil phase and rigid quartz to the elastic SOM. This highlighted the potential of SOM addition for increasing the bioavailability of heavy crude oil without necessarily increasing the environmental risks. The MD simulation was demonstrated to be helpful for interpreting the role of SOM and the host oil phase for the adsorption and partitioning of SARA molecules, which is the key for developing more realistic remediation appraisal for heavy crude oil in soils. Copyright © 2014 Elsevier Ltd. All rights reserved.

  12. Ultrasensitive quartz crystal microbalance sensors for detection of M13-Phages in liquids.

    Science.gov (United States)

    Uttenthaler, E; Schräml, M; Mandel, J; Drost, S

    2001-12-01

    Quartz crystal microbalance (QCM) sensors are widely used for determining liquid properties or probing interfacial processes. For some applications the sensitivity of the QCM sensors typically used (5-20 MHz) is limited compared with other biosensor methods. In this study ultrasensitive QCM sensors with resonant frequencies from 39 to 110 MHz for measurements in the liquid phase are presented. The fundamental sensor effect of a QCM is the decrease of the resonant frequency of an oscillating quartz crystal due to the binding of mass on a coated surface during the measurement. The sensitivity of QCM sensors increases strongly with an increasing resonant frequency and, therefore, with a decreasing thickness of the sensitive area. The new kind of ultrasensitive QCM sensors used in this study is based on chemically milled shear mode quartz crystals which are etched only in the center of the blank, forming a thin quartz membrane with a thick, mechanically stable outer ring. An immunoassay using a virus specific monoclonal antibody and a M13-Phage showed an increase in the signal to noise ratio by a factor of more than 6 for 56 MHz quartz crystals compared with standard 19 MHz quartz crystals, the detection limit was improved by a factor of 200. Probing of acoustic properties of glycerol/water mixtures resulted in an increase in sensitivity, which is in very good agreement with theory. Chemically milled QCM sensors strongly improve the sensitivity in biosensing and probing of acoustic properties and, therefore, offer interesting new application fields for QCM sensors.

  13. Importance of surface characteristics of QUARTZ DQ 12 for acute inflammation

    Energy Technology Data Exchange (ETDEWEB)

    Albrecht, C.; Becher, A.; Scins, R.P.F.; Hoehr, D.; Unfried, K.; Knaapen, A.M.; Borm, P.J.A. [Institut fuer medizinische Forschung (IUF), Duesseldorf (Germany)

    2004-07-01

    Although quartz is known to induce inflammation in rat lungs, mechanisms are not yet fully understood. The importance of particle surface characteristics was investigated in vivo after intratracheal instillation of different preparations of quartz in rat lungs. Three days after instillation of 2 mg DQ12 quartz, or DQ12 coated with polyvinylpyridine-N-oxide (PVNO) or Aluminium lactate (AL), lungs of female Wistar rats were lavaged in situ to determine markers of inflammation. Control rats received saline or the coating substances alone. DQ12 induced a marked inflammatory response, as indicated by a significant increase in the number of neutrophils and macrophages, as well as in the levels of b-glucuronidase and myeloperoxidase. None of these inflammatory markers was increased for both coated quartz preparations, with the exception of neutrophil influx which was also increased after treatment with AL quartz. Our results indicate that surface characteristics are important in the onset of quartz-induced lung inflammation which could imply a different development of persistent inflammation. This will be investigated in later follow-up time points of the same animal study. (orig.)

  14. Some experiments on the high-low transition of quartz; Recherches experimentales sur une transformation du quartz

    Energy Technology Data Exchange (ETDEWEB)

    Mayer, G. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1959-12-15

    First section. - We expose on the one hand a theory of specific heat, thermal expansion and variations of elastic constants as functions of temperature, which is applicable only in the absence of transformation phenomena affecting symmetry or periodicity of the crystal lattice. On the other hand, we discuss some theories relative to the phenomena which accompany phase transformations. Second section. - We have gathered together numerical results concerning elastic, piezoelectric and optical properties of quartz. Some have been collected from the literature, other have been obtained in our laboratories with the help of experimental methods which we describe. As a result, we are able to present a complete picture of the evolution of these constants in a large temperature range containing the critical temperature of 574 deg. C at which these constants exhibit discontinuities. New phenomena have been observed, in the course of these studies. Third section. - We show that the evolution of the two piezoelectric and elastic constants which cancel out in the high temperature form is described by the same function. With the inclusion of one other function, it is possible to explain quantitatively the behaviour in the transformation range of all the other constants under study. With the help of crystallographic considerations and of hypotheses concerning the nature of the transformation entropy, we finally try to account for the experimental values of these two functions. (author) [French] Dans une premiere partie, nous exposons d'une part une theorie de la chaleur specifique, de la dilatation thermique et des variations des constantes elastiques des solides avec la temperature qui n'est valable qu'en l'absence de phenomenes de transformation affectant la symetrie ou la periodicite de l'edifice cristallin, et nous rappelons d'autre part quelques theories relatives aux phenomenes qui accompagnent les changements de phase. Dans une seconde partie

  15. Compact 84 GHz passive mode-locked fiber laser using dual-fiber coupled fused-quartz microresonator

    Science.gov (United States)

    Liu, Tze-An; Hsu, Yung; Chow, Chi-Wai; Chuang, Yi-Chen; Ting, Wei-Jo; Wang, Bo-Chun; Peng, Jin-Long; Chen, Guan-Hong; Chang, Yuan-Chia

    2017-10-01

    We propose and demonstrate a compact and portable-size 84-GHz passive mode-locked fiber laser, in which a dual-fiber coupled fused-quartz microresonator is employed as the intracavity optical comb filter as well as the optical nonlinear material for optical frequency comb generation. About eight coherent optical tones can be generated in the proposed fiber laser. The 20-dB bandwidth is larger than 588 GHz. The full-width half-maximum pulse-width of the proposed laser is 2.5 ps. We also demonstrate the feasibility of using the proposed passive mode-locked fiber laser to carry a 5-Gbit/s on-off-keying signal and transmit over 20-km standard single mode fiber. A 7% forward error correction requirement can be achieved, showing the proposed fiber laser can be a potential candidate for fiber-wireless applications.

  16. Geologic history of quartz-normative and olivine-normative basalts in the vicinity of Hadley Rille (Apollo 15)

    International Nuclear Information System (INIS)

    Grove, T.L.

    1985-01-01

    The geologic history of the quartz normative (QNB) and olivine normative (ONB) basalt types at Hadley Rille are discussed. A model for the geology of the mare basalts was constructed from a combination of field observations, sample chemistry, sample petrology and personal bias from terrestrial experience. The model proposes that the QNBs are the only mare lava type that is present as outcrop in the area traversed by the astronauts during the Apollo 15 mission. The returned QNB samples formed during a single eruptive phase of the Hadley Rille lava tube system. The ONB lavas are an exotic component transported to the site by a cratering event, or the ONBs are samples excavated from older are bedrock that was partly covered by the QNB lavas

  17. Diaplectic quartz glass and SiO2 melt experimentally generated at only 5 GPa shock pressure in porous sandstone: Laboratory observations and meso-scale numerical modeling

    Science.gov (United States)

    Kowitz, A.; Güldemeister, N.; Reimold, W. U.; Schmitt, R. T.; Wünnemann, K.

    2013-12-01

    A combination of shock recovery experiments and numerical modeling of shock deformation in the low pressure range from 2.5 to 17.5 GPa in dry, porous Seeberger sandstone provides new, significant insights with respect to the heterogeneous nature of shock distribution in such important, upper crustal material, for which to date no pressure-calibrated scheme for shock metamorphism exists. We found that pores are already completely closed at 2.5 GPa shock pressure. Whole quartz grains or parts of them are transformed to diaplectic quartz glass and/or SiO2 melt starting already at 5 GPa, whereas these effects are not observed below shock pressures of 30-35 and ˜45 GPa, respectively, in shock experiments with quartz single crystals. The appearance of diaplectic glass or melt is not restricted to the zone directly below the impacted surface but is related to the occurrence of pores in a much broader zone. The combined amount of these phases increases distinctly with increasing shock pressure from 0.03 vol.% at 5 GPa to ˜80 vol.% at 17.5 GPa. In accordance with a previous shock classification for silica phases in naturally shocked Coconino sandstone from Meteor Crater that was based on varied slopes of the Coconino sandstone Hugoniot curve, our observations allow us to construct a shock pressure classification for porous sandstone consistent with shock stages 1b-4 of the progressive shock metamorphism classification of Kieffer (1971).

  18. Development of an instrument to assess expectations of and preference for an insulin injection pen compared with the vial and syringe.

    Science.gov (United States)

    Szeinbach, Sheryl L; Barnes, James H; Summers, Kent H; Lenox, Sheila M

    2004-04-01

    Before using a product, patients form expectations regarding the extent of a product's desirable attributes. These expectations can be used to understand their preference and anticipate potential satisfaction with the product. The aim of this study was to produce a valid and reliable data collection instrument (the Insulin Injection Preference questionnaire [IIP-q]) to measure expectations of and preference for the insulin injection pen compared with the vial and syringe. This study was initiated at the University of Mississippi (University, Mississippi). The IIP-q was developed to determine the extent to which respondents' prepurchase expectations of a product's attributes relate to preference for an insulin injection pen compared with the vial and syringe. Instrument development began with item generation related to product attributes important to patients who inject insulin. Items originated from an extensive search of the peer-reviewed Internet-based literature, marketing reports, clinical studies, and existing instruments. Content validity also was assessed using expert panel and focus group review. The resultant instrument (the IIP-q) was mailed to 1200 patients known to have type 1 or type 2 diabetes mellitus who either did or did not use insulin. Subscales were identified through exploratory factor analysis. Reliability and validity were assessed using Cronbach alpha for subscale items. Product-moment correlations between subscale dimensions and 2 global measures of preference were used to test the relationship between attribute expectations and preference. Seventeen of the questionnaires were returned as undeliverable, leaving 1183 in the sample population. Questionnaires were received from 302 individuals, 55 of whom failed to complete > or = 85% of the items and thus were not included in the final analysis. Of the 247 respondents (135 women, 112 men; mean [SD] age, 52.4 [13.2] years (range, 18-83 years]), 99 (40.1%) were current insulin users and 143 (57

  19. Stress distribution during cold compression of a quartz aggregate using synchrotron X-ray diffraction: Observed yielding, damage, and grain crushing: STRESS DISTRIBUTION OF QUARTZ AGGREGATE

    Energy Technology Data Exchange (ETDEWEB)

    Cheung, C. S. N. [Mineral Physics Institute, Stony Brook University, Stony Brook New York USA; Geological Engineering, University of Wisconsin-Madison, Madison Wisconsin USA; Weidner, D. J. [Mineral Physics Institute, Stony Brook University, Stony Brook New York USA; Li, L. [Mineral Physics Institute, Stony Brook University, Stony Brook New York USA; Meredith, P. G. [Rock and Ice Physics Laboratory, Department of Earth Sciences, University College London, London UK; Chen, H. [Mineral Physics Institute, Stony Brook University, Stony Brook New York USA; Whitaker, M. L. [Mineral Physics Institute, Stony Brook University, Stony Brook New York USA; Chen, X. [Chemistry Department, Stony Brook University, Stony Brook New York USA

    2017-04-01

    We report new experimental results that quantify the stress distribution within a quartz aggregate during pore collapse and grain crushing. The samples were probed with synchrotron X-ray diffraction as they were compressed in a multianvil deformation apparatus at room temperature from low pressure (tens of megapascal) to pressures of a few gigapascal. In such a material, stress is likely to concentrate at grain-to-grain contacts and vanish where grains are bounded by open porosity. Therefore, internal stress is likely to vary significantly from point to point in such an aggregate, and hence, it is important to understand both the heterogeneity and anisotropy of such variation with respect to the externally applied stress. In our quartz aggregate (grain size of ~4 μm), the measured diffraction peaks broaden asymmetrically at low pressure (tens of megapascal), suggesting that open pores are still a dominant characteristic of grain boundaries. In contrast, a reference sample of novaculite (a highly dense quartz polycrystal, grain size of ~6–9 μm) showed virtually no peak broadening with increasing pressure. In the quartz aggregate, we observed significant deviation in the pressure-volume curves in the range of P = 400–600 MPa. We suggest that this marks the onset of grain crushing (generally denoted as P* in the rock mechanic literature), which is commonly reported to occur in sandstones at pressures of this order, in general agreement with a Hertzian analysis of fracturing at grain contacts.

  20. Photoluminescence and optical absorption in neutron-irradiated crystalline quartz

    Energy Technology Data Exchange (ETDEWEB)

    Corazza, A.; Crivelli, B.; Martini, M.; Spinolo, G.; Vedda, A. [Istituto Nazionale Di Fisica Della Materia, Dipartimento di Fisica, Universita di Milano, Via Celoria 16, I-20133 Milano (Italy)

    1996-04-01

    Optical absorption measurements in the 3.5{endash}6.5 eV spectral range and photoluminescence spectra, excited in the 4{endash}8 eV range have been performed on neutron irradiated synthetic crystalline quartz as a function of temperature and of neutron fluence. The Gaussian deconvolution of the radiation-induced absorption spectrum in the 4.5{endash}6 eV region reveals a complex structure: five distinct components, peaking at 4.85, 5.06, 5.35, 5.62, and 5.96 eV are detected. The complexity of the absorption pattern finds a correspondence in photoluminescence spectra excited in the 5 eV region: a detailed analysis of the emission spectra as a function of excitation energy indicates the presence of three emission bands centered at 3.91, 4.23, and 4.46 eV, excited at 5.25, 4.83, and 5.03 eV respectively. Excitation in the 5.62 and 5.96 eV absorption peaks does not produce emission. The features of the 4.23 eV and of the 4.46 eV bands are very similar to those of the {alpha}{sub intrinsic} emission, already well studied in amorphous SiO{sub 2}: this suggests a possible correlation between these bands and the {alpha}{sub intrinsic} center. The 3.91 eV band does not find a correspondence in amorphous SiO{sub 2}, and so the responsible defect appears specifically related to the crystalline structure. The emission spectra excited in the E absorption band ({approx_equal}7.6 eV) present a weak band centered at 4.83 eV: its dependence on neutron irradiation dose suggests the attribution to an intrinsic center different from those responsible for the emission in the 3.8 {endash} 4.5 eV region. {copyright} {ital 1996 The American Physical Society.}

  1. Photoluminescence and optical absorption in neutron-irradiated crystalline quartz

    International Nuclear Information System (INIS)

    Corazza, A.; Crivelli, B.; Martini, M.; Spinolo, G.; Vedda, A.

    1996-01-01

    Optical absorption measurements in the 3.5 endash 6.5 eV spectral range and photoluminescence spectra, excited in the 4 endash 8 eV range have been performed on neutron irradiated synthetic crystalline quartz as a function of temperature and of neutron fluence. The Gaussian deconvolution of the radiation-induced absorption spectrum in the 4.5 endash 6 eV region reveals a complex structure: five distinct components, peaking at 4.85, 5.06, 5.35, 5.62, and 5.96 eV are detected. The complexity of the absorption pattern finds a correspondence in photoluminescence spectra excited in the 5 eV region: a detailed analysis of the emission spectra as a function of excitation energy indicates the presence of three emission bands centered at 3.91, 4.23, and 4.46 eV, excited at 5.25, 4.83, and 5.03 eV respectively. Excitation in the 5.62 and 5.96 eV absorption peaks does not produce emission. The features of the 4.23 eV and of the 4.46 eV bands are very similar to those of the α intrinsic emission, already well studied in amorphous SiO 2 : this suggests a possible correlation between these bands and the α intrinsic center. The 3.91 eV band does not find a correspondence in amorphous SiO 2 , and so the responsible defect appears specifically related to the crystalline structure. The emission spectra excited in the E absorption band (≅7.6 eV) present a weak band centered at 4.83 eV: its dependence on neutron irradiation dose suggests the attribution to an intrinsic center different from those responsible for the emission in the 3.8 endash 4.5 eV region. copyright 1996 The American Physical Society

  2. Dose response on the 110 °C thermoluminescence peak of un-heated, synthetic Merck quartz

    Energy Technology Data Exchange (ETDEWEB)

    Kaya Keleş, Şule, E-mail: sule.kaya@ankara.edu.tr; Meriç, Niyazi; Polymeris, George S.

    2016-07-15

    Studies on 110 °C TL peak have been carried out using natural quartz from different origins and synthetic quartz produced by different suppliers. The interest in quartz is due to its usage in dating and retrospective dosimetry as a main material; both synthetic and natural types of quartz yield the 110 °C TL peak in their glow curve. In most studies to understand the physical mechanism behind the TL system, synthetic quartz samples are used and there are many investigations about dose response, in both low and high radiation dose region. In these studies generally synthetic quartz samples produced by Sawyer Research Products are used and the studies showed that both heated and un-heated synthetic quartz samples have intense supra-linear responses. Supra-linearity was enhanced by applying a pre-irradiation while several models have been developed towards an explanation to these supra-linearity effects. In this study commercially available synthetic Merck quartz was used. Different combinations of optical filters were used to obtain dose response curves upto 266 Gy and the effect of pre-dose to these dose response curves was studied. Un-pre-dosed Merck quartz samples dose supra-linearity index is below 1 independently on the optical filters; so Merck quartz showed linear or sub-linear dose response.

  3. Oxygen isotope exchange with quartz during pyrolysis of silver sulfate and silver nitrate.

    Science.gov (United States)

    Schauer, Andrew J; Kunasek, Shelley A; Sofen, Eric D; Erbland, Joseph; Savarino, Joel; Johnson, Ben W; Amos, Helen M; Shaheen, Robina; Abaunza, Mariana; Jackson, Terri L; Thiemens, Mark H; Alexander, Becky

    2012-09-30

    Triple oxygen isotopes of sulfate and nitrate are useful metrics for the chemistry of their formation. Existing measurement methods, however, do not account for oxygen atom exchange with quartz during the thermal decomposition of sulfate. We present evidence for oxygen atom exchange, a simple modification to prevent exchange, and a correction for previous measurements. Silver sulfates and silver nitrates with excess (17)O were thermally decomposed in quartz and gold (for sulfate) and quartz and silver (for nitrate) sample containers to O(2) and byproducts in a modified Temperature Conversion/Elemental Analyzer (TC/EA). Helium carries O(2) through purification for isotope-ratio analysis of the three isotopes of oxygen in a Finnigan MAT253 isotope ratio mass spectrometer. The Δ(17)O results show clear oxygen atom exchange from non-zero (17)O-excess reference materials to zero (17)O-excess quartz cup sample containers. Quartz sample containers lower the Δ(17)O values of designer sulfate reference materials and USGS35 nitrate by 15% relative to gold or silver sample containers for quantities of 2-10 µmol O(2). Previous Δ(17)O measurements of sulfate that rely on pyrolysis in a quartz cup have been affected by oxygen exchange. These previous results can be corrected using a simple linear equation (Δ(17)O(gold) = Δ(17)O(quartz) * 1.14 + 0.06). Future pyrolysis of silver sulfate should be conducted in gold capsules or corrected to data obtained from gold capsules to avoid obtaining oxygen isotope exchange-affected data. Copyright © 2012 John Wiley & Sons, Ltd.

  4. Fission track dating of authigenic quartz in red weathering crusts of carbonate rocks in Guizhou province

    International Nuclear Information System (INIS)

    Liu Xiuming; Wang Shijie; Zhang Feng

    2004-01-01

    The Cenozoic evolution history of Guizhou Province, which is located on the southeastern flank of the Qinghai-Tibet Plateau, is unclear because of the lack of sedimentation records. The red weathering crusts widespread on the Yunnan-Guizhou Plateau may bear critical information about their evolution history. This work firstly determined the ages of four red weathering crusts in eastern, central and northern Guizhou. The material used in fission track dating is well-crystallized quartz occurring in many in-situ weathering crusts of carbonate rocks. The results showed that the fission track ages of quartz vary over a wide range from 1 Ma to 25 Ma in the four profiles, significantly younger than the ages of Triassic and Cambrian parent rocks. In combination with the regionally geological evolution history during the period from 25 Ma to 1 Ma, the ages of quartz can exclude the possibility that the origin of quartz has nothing to do with primary clastic minerals in parent rocks, authigenesis during diagenesis and hydrothermal precipitation or replacement by volcanic activities. It is deduced that the well-crystallized quartz was precipitated from Si-rich weathering fluids during weathering processes of carbonate rocks. The recorded ages of quartz from the four profiles are consistent with the episodes of planation surfaces on the Qinghai-Tibet Plateau, the stages of red soil in the tropics of South China, the tectonically stable periods in Guizhou, and the ages of weathering in other parts of the world during the Cenozoic era. That is to say, the ages of authigenic quartz dated by the fission track method are well feasible and credible. (authors)

  5. Consideration of kaolinite interference correction for quartz measurements in coal mine dust.

    Science.gov (United States)

    Lee, Taekhee; Chisholm, William P; Kashon, Michael; Key-Schwartz, Rosa J; Harper, Martin

    2013-01-01

    Kaolinite interferes with the infrared analysis of quartz. Improper correction can cause over- or underestimation of silica concentration. The standard sampling method for quartz in coal mine dust is size selective, and, since infrared spectrometry is sensitive to particle size, it is intuitively better to use the same size fractions for quantification of quartz and kaolinite. Standard infrared spectrometric methods for quartz measurement in coal mine dust correct interference from the kaolinite, but they do not specify a particle size for the material used for correction. This study compares calibration curves using as-received and respirable size fractions of nine different examples of kaolinite in the different correction methods from the National Institute for Occupational Safety and Health Manual of Analytical Methods (NMAM) 7603 and the Mine Safety and Health Administration (MSHA) P-7. Four kaolinites showed significant differences between calibration curves with as-received and respirable size fractions for NMAM 7603 and seven for MSHA P-7. The quartz mass measured in 48 samples spiked with respirable fraction silica and kaolinite ranged between 0.28 and 23% (NMAM 7603) and 0.18 and 26% (MSHA P-7) of the expected applied mass when the kaolinite interference was corrected with respirable size fraction kaolinite. This is termed "deviation," not bias, because the applied mass is also subject to unknown variance. Generally, the deviations in the spiked samples are larger when corrected with the as-received size fraction of kaolinite than with the respirable size fraction. Results indicate that if a kaolinite correction with reference material of respirable size fraction is applied in current standard methods for quartz measurement in coal mine dust, the quartz result would be somewhat closer to the true exposure, although the actual mass difference would be small. Most kinds of kaolinite can be used for laboratory calibration, but preferably, the size fraction

  6. Improvement of sensor sensitivity of quartz crystal microbalance by mechanical and chemical treatment

    International Nuclear Information System (INIS)

    Raicheva, Z.; Georgieva, V.; Gadjanova, V.; Vergov, L.; Angelov, Ts.; Lazarov, Y.

    2013-01-01

    The influence of quartz plate roughening on the dynamic parameters of quartz resonators has been studied. For this aim AT-cut quartz plates with a diameter of 8~mm, after a standard technological cleaning, are subjected to treatment with abrasive of varying grain sizes: 3, 7, 14 and 20 μm. Piezoquartz resonators are fabricated on these plates with 4 mm Au electrodes. The alterations of resonators' dynamic parameters are followed after mass loading with a sensitive magnetron sputtered WO 3 layer, 200 nm thick. Quartz Crystal Microbalance (QCM) sorption properties are evaluated for 100 ppm NH 3 concentration; the frequency shift from 20 to 120 Hz, are obtained when the grain sizes change from 3 to 20 μm. The measured average roughness by Atomic Force Microscopy (AFM) was 179 nm, 288 nm, 763 nm for 7 μm, 14 μm and 20 μm, respectively. The influence of the etching process of AT-cut quartz plates on the QCM parameters has been studied. Quartz wafers (100 μm thick, with a diameter of 8 mm), have been etched in [NH 4 ]2 F 2 : H 2 O = 1:1 solution at temperature range from 70°C to 90°C. The influence of etch treatment on the quartz surface morphology has been estimated by AFM. Sorption properties of QCM-MoO 3 are evaluated at NH 3 concentrations in the interval from 100 ppm to 500 ppm. The increase of effective sorption surface, obtained by mechanical and chemical treatment, can be successfully used to realize high sensitive QCM-thin film structure

  7. Streamlined sample cleanup using combined dispersive solid-phase extraction and in-vial filtration for analysis of pesticides and environmental pollutants in shrimp.

    Science.gov (United States)

    Han, Lijun; Sapozhnikova, Yelena; Lehotay, Steven J

    2014-05-27

    A new method of sample preparation was developed and is reported for the first time. The approach combines in-vial filtration with dispersive solid-phase extraction (d-SPE) in a fast and convenient cleanup of QuEChERS (quick, easy, cheap, effective, rugged, and safe) extracts. The method was applied to simultaneous analysis of 42 diverse pesticides and 17 environmental contaminants, including polycyclic aromatic hydrocarbons, polychlorinated biphenyls (PCBs), and flame retardants, in shrimp as the sample matrix. Final extracts were analyzed by both low-pressure gas chromatography - triple quadrupole tandem mass spectrometry (LPGC-MS/MS), and high-performance liquid chromatography - triple quadrupole tandem mass spectrometry (HPLC-MS/MS) to provide a wide scope of analysis for targeted analytes. During method development, several different commercial sorbents for d-SPE were investigated and compared with respect to analyte recoveries. The method was validated at 10, 50, and 100 ng g(-1) spiking levels (10-fold lower for PCBs), and the results for nearly all analytes were between 70 and 115% recoveries with ≤17% relative standard deviations. The method was shown to be simple, fast, and effective for multi-application analysis of chemical residues in the representative food and environmental marker matrix. Copyright © 2014. Published by Elsevier B.V.

  8. In-Vial Micro-Matrix-Solid Phase Dispersion for the Analysis of Fragrance Allergens, Preservatives, Plasticizers, and Musks in Cosmetics

    Directory of Open Access Journals (Sweden)

    Maria Celeiro

    2014-07-01

    Full Text Available Fragrance allergens, preservatives, plasticizers, and synthetic musks are usually present in cosmetic and personal care products formulations and many of them are subjected to use restrictions or labeling requirements. Matrix solid-phase dispersion (MSPD is a very suitable analytical technique for the extraction of these compounds providing a simple, low cost sample preparation, and the possibility of performing both extraction and clean-up in one step, reducing possible contamination and analyte losses. This extraction technique has been successfully applied to many cosmetics ingredients allowing obtaining quantitative recoveries. A new very simple micro-MSPD procedure performing the disruption step in a vial is proposed for the gas chromatography-mass spectrometry (GC-MS analysis of 66 chemicals usually present in cosmetics and personal care products. The method was validated showing general recoveries between 80% and 110%, relative standard deviation (RSD values lower than 15%, and limits of detection (LODs below 30 ng·g−1. The validated method was applied to a broad range of cosmetics and personal care products, including several products intended for baby care.

  9. Simultaneous in-vial acetylation solid-phase microextraction followed by gas chromatography tandem mass spectrometry for the analysis of multiclass organic UV filters in water.

    Science.gov (United States)

    Vila, Marlene; Celeiro, Maria; Lamas, J Pablo; Garcia-Jares, Carmen; Dagnac, Thierry; Llompart, Maria

    2017-02-05

    UV filters are a class of emerging contaminants that are widely used in personal care products (PCPs) and that can be detected at low concentrations in the aquatic environment (ngL -1 ). Sensitive modern analytical methods are then mandatory to accurately analyze them. A methodology based on solid-phase-microextraction (SPME), considered as a 'Green Chemistry' technique, followed by gas chromatography-tandem mass spectrometry (GC-MS/MS) has been developed for the simultaneous analysis of 14 UV filters of different chemical nature in environmental and recreational waters. In-vial low-cost derivatization was carried out to improve chromatographic performance of phenolic compounds. The extraction parameters (fiber coating, extraction mode, and salt addition) were optimized by means of experimental designs in order to achieve reliable conditions. Finally, the SPME-GC-MS/MS method was validated in terms of linearity, accuracy and precision with LODs in the low ngL -1 level. Its application to the analysis of 28 different samples including sea, river, spa, swimming pool, and aquapark waters, enabled the detection of 11 target UV filters at concentration levels up to 540μgL -1 , highlighting the presence of OCR in all analyzed samples and of 2EHMC (proposed to be considered as priority pollutant) in 79% of them. Copyright © 2016 Elsevier B.V. All rights reserved.

  10. Metabolomic method: UPLC-q-ToF polar and non-polar metabolites in the healthy rat cerebellum using an in-vial dual extraction.

    Directory of Open Access Journals (Sweden)

    Amera A Ebshiana

    Full Text Available Unbiased metabolomic analysis of biological samples is a powerful and increasingly commonly utilised tool, especially for the analysis of bio-fluids to identify candidate biomarkers. To date however only a small number of metabolomic studies have been applied to studying the metabolite composition of tissue samples, this is due, in part to a number of technical challenges including scarcity of material and difficulty in extracting metabolites. The aim of this study was to develop a method for maximising the biological information obtained from small tissue samples by optimising sample preparation, LC-MS analysis and metabolite identification. Here we describe an in-vial dual extraction (IVDE method, with reversed phase and hydrophilic liquid interaction chromatography (HILIC which reproducibly measured over 4,000 metabolite features from as little as 3mg of brain tissue. The aqueous phase was analysed in positive and negative modes following HILIC separation in which 2,838 metabolite features were consistently measured including amino acids, sugars and purine bases. The non-aqueous phase was also analysed in positive and negative modes following reversed phase separation gradients respectively from which 1,183 metabolite features were consistently measured representing metabolites such as phosphatidylcholines, sphingolipids and triacylglycerides. The described metabolomics method includes a database for 200 metabolites, retention time, mass and relative intensity, and presents the basal metabolite composition for brain tissue in the healthy rat cerebellum.

  11. Brittle-to-viscous behaviour of quartz gouge in shear experiments

    Science.gov (United States)

    Richter, Bettina; Stunitz, Holger; Heilbronner, Renée

    2016-04-01

    In order to study the microstructure development across the brittle-viscous transition and to derive the corresponding flow laws, we performed shear experiments on quartz gouge in a Griggs-type deformation apparatus. The starting material is a crushed quartz single crystal (sieved grain size strain-rate-stepping experiments were conducted at strain rates between ˜2.5 x 10-6 s-1 and ˜2.5 x 10-4 s-1. Other experiments were conducted at constant strain rates of ˜2.5 x 10-6 s-1, ˜2.5 x 10-5 s-1, ˜2.5 x 10-4 s-1 and ˜2.5 x 10-3 s-1. At high confining pressure, the strength of the samples decreases with increasing temperature for all strain rates. The largest decrease occurred between 650 ° C and 700 ° C at shear strain rates of ˜2.5 x 10-5 s-1. At the same time, the pressure dependence of strength is positive for T ≤ 650 ° C while an inverse pressure dependence is observed at T > 650 ° C. For T strain rates of ˜2.5 x 10-5 s-1 a change in the deformation process occurs from one dominated by cataclastic flow to one dominated by crystal plasticity. The microstructure reveals a less abrupt transition in terms of operating processes, because brittle and viscous processes are equally active around 650 ° C. With increasing temperature the volume fraction of recrystallised grains increases, and at 900 ° C - 1000 ° C recrystallisation is nearly complete at strains of γ ˜ 3. The crystallographic preferred orientation of the c-axis evolves from a random distribution at low temperatures towards two peripheral maxima at intermediate temperatures. At high temperatures the c-axis show a single Y-maximum. At high temperature, the stress exponent is n = 2.1 ± 0.2. The activation energy Q is 193 ± 12 kJ/mol at strain rates of 10-5 s-1, at faster strain rates the activation energy drops down to Q = 119 ± 12 kJ/mol. This small stress exponent at high temperatures indicates a combination of deformation processes (diffusion in very fine grained material and dislocation

  12. Correlating the TL response of γ-irradiated natural quartz to aluminum and hydroxyl point defects

    International Nuclear Information System (INIS)

    Ferreira de Souza, Leonardo B.; Guzzo, Pedro L.; Khoury, Helen J.

    2010-01-01

    This paper investigates the relationship between Al- and OH-related point defects with the thermoluminescent (TL) response of natural quartz sensitized with high doses of γ radiation and heat-treatments. For this, specimens from a single crystal were progressively irradiated with doses of 60 Co from 2 to 50 kGy. After each step of sensitization, the absorption bands related to [AlO 4 ] 0 , [AlO 4 /H] 0 , [H 4 O 4 ] 0 and Li-dependent OH point defects were measured by optical absorption and infrared (IR) spectroscopy. The sensitization of the 280 o C TL peak increased up to 15 kGy and then its intensity remained constant. The absorption intensity at 470 nm increased with γ doses suggesting a progressive creation of [AlO 4 ] 0 acting as recombination centers for the sensitized peak. At the same time, the TL intensity of the 90 o C peak decreased with the accumulated dose. This effect was not related to the saturation in the number of recombination centers because both [H 4 O 4 ] 0 and [AlO 4 ] 0 bands were increasing after 50 kGy. Compared to the as-received condition, it was found that IR bands associated with [AlO 4 /H] 0 and Li-dependent OH decreased with the effect of heat-treatments. The precursor for [AlO 4 ] 0 is [AlO 4 /Li] 0 and the Li species dislodged from [AlO 4 /Li] 0 and Li-dependent OH centers play an important role in the sensitization process.

  13. Characterization of the QUartz Photon Intensifying Detector (QUPID) for noble liquid detectors

    Science.gov (United States)

    Teymourian, A.; Aharoni, D.; Baudis, L.; Beltrame, P.; Brown, E.; Cline, D.; Ferella, A. D.; Fukasawa, A.; Lam, C. W.; Lim, T.; Lung, K.; Meng, Y.; Muramatsu, S.; Pantic, E.; Suyama, M.; Wang, H.; Arisaka, K.

    2011-10-01

    Dark matter and double beta decay experiments require extremely low radioactivity within the detector materials. For this purpose, the University of California, Los Angeles and Hamamatsu Photonics have developed the QUartz Photon Intensifying Detector (QUPID), an ultra-low background photodetector based on the Hybrid Avalanche Photo Diode (HAPD) and entirely made of ultraclean synthetic fused silica. In this work we present the basic concept of the QUPID and the testing measurements on QUPIDs from the first production line.Screening of radioactivity at the Gator facility in the Laboratori Nazionali del Gran Sasso has shown that the QUPIDs safely fulfill the low radioactive contamination requirements for the next generation zero background experiments set by Monte Carlo simulations.The quantum efficiency of the QUPID at room temperature is >30% at the xenon scintillation wavelength. At -100 °C, the QUPID shows a leakage current smaller than 1 nA and a global gain of 105. In these conditions, the photocathode and the anode show >95% linearity up to 1μA for the cathode and 3 mA for the anode. The photocathode and collection efficiency are uniform to 80% over the entire surface. In parallel with single photon counting capabilities, the QUPIDs have a good timing response: 1.8 ±0.1 ns rise time, 2.5 ±0.2 ns fall time, 4.20 ±0.05 ns (FWHM) pulse width, and 160 ±30 ps (FWHM) transit time spread.The QUPIDs have also been tested in a liquid xenon environment, and scintillation light from 57Co and 210Po radioactive sources was observed.

  14. Analysis of Fracture Pattern of Pulverized Quartz Formed by Stick Slip Experiment

    Science.gov (United States)

    Nishikawa, Osamu; Muto, Jun; Otsuki, Kenshiro; Kano, Harumasa; Sasaki, Osamu

    2013-04-01

    In order to clarify how wall rocks of faults are damaged, fracture pattern analysis was performed imaging experimentally pulverized rocks by a micro-focus X-ray CT. Analyzed samples are core (diameter of 2cm) of single crystals of synthetic quartz and natural quartzites, which were pre-cut 50° to the core axis and mirror-polished. Experiments were conducted with axial strain rate of 10-3/s under the confining pressure of 180 MPa and room temperature using gas apparatus. Intense fracturing of the core occurred during the stick-slip with very large stress drop. Although thin melt layer is formed on the slip plane, the core is pulverized overall by tensile fracturing characterized by apparent lack of shear deformation. X-ray CT images demonstrate the fracture pattern being strongly controlled by slip direction and shear sense. Cracks are exponentially increased toward the slip plane and concentrated in the central portion rather than outer margin of core. Cracks tend to develop parallel to core axis and at high to moderate angles (90° ~ ±50°) with the plane including both core axis and slip direction, and lean to be higher angle to the surface near the slip plane. Due to this fracture pattern, the pulverized fragments show polygonal column or needle in shape with sharp and curving edges irrespective of their sizes, and the intensely fractured slip surface exhibit distinct rugged topography of an array of ridges developed perpendicular to slip direction. Mode and distribution pattern of fractures indicate that the stress concentration at the rupture front during dynamic rupture propagation or the constructive interference of reflected seismic waves focused at the center of core are possible mechanisms of pulverization.

  15. Absorbed dose evaluations in retrospective dosimetry: Methodological developments using quartz

    DEFF Research Database (Denmark)

    Bailiff, I.K.; Bøtter-Jensen, L.; Correcher, V.

    2000-01-01

    -300 mGy were obtained using TL (210 degreesC TL and pre-dose) and OSL (single and multiple aliquot) procedures. Overall, good inter-laboratory concordance of dose evaluations was achieved, with a variance (1 sigma) of similar to+/-10 mGy for the samples examined. (C) 2000 Elsevier Science Ltd. All...

  16. Oxygen isotopic ratios in fine quartz silt from sediments and soils of southern Africa

    International Nuclear Information System (INIS)

    Le Roux, J.; Jackson, M.L.; Clayton, R.N.

    1980-01-01

    Fine quartz silt (1 to 10 μm dia, important in aerosol dust) isolated from a large number of soils, as well as Phanerozoic shales, sandstones and recent sands of the southern African stratigraphic column (Carboniferous, Permian and Triassic) exhibits a mean delta 18 O of 12.2 +- 2.1 parts per thousand. These values are similar to those reported for South Pacific pelagic sediments and adjacent land areas of similar latitude but are lower than those reported for this size fraction of 30 Mesozoic and Paleozoic shales (20.7 +- 1.8 parts per thousand) and soils from mid-continental U.S.A., for aerosol quartz in the North Pacific pelagic sediments, and for eolian caps in high-elevation soils of Hawaii. The lower oxygen isotopic ratios in fine quartz silt of southern Africa reinforces the earlier indication that Southern Hemisphere detrital sedimentary reservoirs contain a higher proportion of igneous and metamorphic quartz (lower delta 18 O) and less low-temperature authigenic quartz (higher delta 18 O) than Northern Hemisphere detrital sediments. The difference reflects climates, as continents drifted in latitude. (author)

  17. Timescales of Quartz Crystallization and the Longevity of the Bishop Giant Magma Body

    Energy Technology Data Exchange (ETDEWEB)

    Gualda, Guilherme A.R.; Pamukcu, Ayla S.; Ghiorso, Mark S.; Anderson, Jr. , Alfred T.; Sutton, Stephen R.; Rivers, Mark L. (OFM Res.); (Vanderbilt); (UC)

    2013-04-08

    Supereruptions violently transfer huge amounts (100 s-1000 s km{sup 3}) of magma to the surface in a matter of days and testify to the existence of giant pools of magma at depth. The longevity of these giant magma bodies is of significant scientific and societal interest. Radiometric data on whole rocks, glasses, feldspar and zircon crystals have been used to suggest that the Bishop Tuff giant magma body, which erupted {approx}760,000 years ago and created the Long Valley caldera (California), was long-lived (>100,000 years) and evolved rather slowly. In this work, we present four lines of evidence to constrain the timescales of crystallization of the Bishop magma body: (1) quartz residence times based on diffusional relaxation of Ti profiles, (2) quartz residence times based on the kinetics of faceting of melt inclusions, (3) quartz and feldspar crystallization times derived using quartz+feldspar crystal size distributions, and (4) timescales of cooling and crystallization based on thermodynamic and heat flow modeling. All of our estimates suggest quartz crystallization on timescales of <10,000 years, more typically within 500-3,000 years before eruption. We conclude that large-volume, crystal-poor magma bodies are ephemeral features that, once established, evolve on millennial timescales. We also suggest that zircon crystals, rather than recording the timescales of crystallization of a large pool of crystal-poor magma, record the extended periods of time necessary for maturation of the crust and establishment of these giant magma bodies.

  18. Autocrine abscisic acid plays a key role in quartz-induced macrophage activation.

    Science.gov (United States)

    Magnone, Mirko; Sturla, Laura; Jacchetti, Emanuela; Scarfì, Sonia; Bruzzone, Santina; Usai, Cesare; Guida, Lucrezia; Salis, Annalisa; Damonte, Gianluca; De Flora, Antonio; Zocchi, Elena

    2012-03-01

    Inhalation of quartz induces silicosis, a lung disease where alveolar macrophages release inflammatory mediators, including prostaglandin-E(2) (PGE(2)) and tumor necrosis factor α (TNF-α). Here we report the pivotal role of abscisic acid (ABA), a recently discovered human inflammatory hormone, in silica-induced activation of murine RAW264.7 macrophages and of rat alveolar macrophages (AMs). Stimulation of both RAW264.7 cells and AMs with quartz induced a significant increase of ABA release (5- and 10-fold, respectively), compared to untreated cells. In RAW264.7 cells, autocrine ABA released after quartz stimulation sequentially activates the plasma membrane receptor LANCL2 and NADPH oxidase, generating a Ca(2+) influx resulting in NFκ B nuclear translocation and PGE(2) and TNF-α release (3-, 2-, and 3.5-fold increase, respectively, compared to control, unstimulated cells). Quartz-stimulated RAW264.7 cells silenced for LANCL2 or preincubated with a monoclonal antibody against ABA show an almost complete inhibition of NFκ B nuclear translocation and PGE(2) and TNF-α release compared to controls electroporated with a scramble oligonucleotide or preincubated with an unrelated antibody. AMs showed similar early and late ABA-induced responses as RAW264.7 cells. These findings identify ABA and LANCL2 as key mediators in quartz-induced inflammation, providing possible new targets for antisilicotic therapy.

  19. Time-resolved luminescence from quartz: An overview of contemporary developments and applications

    Science.gov (United States)

    Chithambo, M. L.; Ankjærgaard, C.; Pagonis, V.

    2016-01-01

    Time-resolved optical stimulation of luminescence has become established as a key method for measurement of optically stimulated luminescence from quartz, feldspar and α-Al2O3:C, all materials of interest in dosimetry. The aim of time-resolved optical stimulation is to separate in time the stimulation and emission of luminescence. The luminescence is stimulated from a sample using a brief light pulse and the emission monitored during stimulation in the presence of scattered stimulating light or after pulsing, over photomultiplier noise only. Although the use of the method in retrospective dosimetry has been somewhat limited, the technique has been successfully applied to study mechanisms in the processes leading up to luminescence emission. The main means for this has been the temperature dependence of the luminescence intensity as well as the luminescence lifetimes determined from time-resolved luminescence spectra. In this paper we review some key developments in theory and applications to quartz including methods of evaluating lifetimes, techniques of evaluating kinetic parameters using both the dependence of luminescence intensity and lifetime on measurement temperature, and of lifetimes on annealing temperature. We then provide an overview of some notable applications such as separation of quartz signals from a quartz-feldspar admixture and the utility of the dynamic throughput, a measure of luminescence measured as a function of the pulse width. The paper concludes with some suggestions of areas where further exploration would advance understanding of dynamics of luminescence in quartz and help address some outstanding problems in its application.

  20. Effectiveness of a Multidimensional Randomized Control Intervention to Reduce Quartz Exposure Among Construction Workers.

    Science.gov (United States)

    van Deurssen, Erik; Meijster, Tim; Oude Hengel, Karen M; Boessen, Ruud; Spaan, Suzanne; Tielemans, Erik; Heederik, Dick; Pronk, Anjoeka

    2015-10-01

    There is little evidence with respect to the effectiveness of intervention programs that focus on the reduction of occupational quartz exposure in the construction industry. This article evaluates the effectiveness of a multidimensional intervention which was aimed at reducing occupational quartz exposure among construction workers by increasing the use of technical control measures. Eight companies participating in the cluster randomized controlled trial were randomly allocated to the intervention (four companies) or control condition (four companies). The multidimensional intervention included engineering, organizational, and behavioural elements at both organizational and individual level. Full-shift personal quartz exposure measurements and detailed observations were conducted before and after the intervention among bricklayers, carpenters, concrete drillers, demolishers, and tuck pointers (n = 282). About 59% of these workers measured at baseline were reassessed during follow-up. Bayesian hierarchical models were used to evaluate the intervention effect on exposure levels. Concrete drillers in the intervention group used technical control measures, particularly water suppression, for a significantly greater proportion of the time spent on abrasive tasks during follow-up compared to baseline (93 versus 62%; P quartz exposure (73 versus 40% in the intervention and control group respectively; P quartz exposure among high exposed construction workers. © The Author 2015. Published by Oxford University Press on behalf of the British Occupational Hygiene Society.