Characterization of Borosilicate Glass Through Confined Compression Testing with Numerical Validation

DTIC Science & Technology

2009-11-01

Characterization Data and Flyer-Plate Impact Data 7.1 Introduction Borosilicate and soda - lime glass have been the object of extensive plate impact...2 GPa as the strength of damaged soda - lime glass at pressures of 4 to 6 GPa. Bourne, et al. [9, 35], showed tests with strength values of 1.8 GPa...equation of state data for borosilicate and soda - lime glass . The flyer-plate impact data greatly extends the confining pressures that can be achieved with

A Space Imaging Concept Based on a 4-meter Spun-Cast Borosilicate Monolithic Primary Mirror

DTIC Science & Technology

2010-06-01

borosilicate monolithic primary mirror 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Steve West, S.H... Mirror Technology Days, Boulder, Colorado, USA, 7-9 June 2010. 14. ABSTRACT The goal of this effort is to produce the largest monolithic telescope...capable of being lifted by a Delta IV or Atlas V EELV to 500 km. A strategy using a 4 m borosilicate mirror is proposed. A preliminary architecture was

Antagonist effects of calcium on borosilicate glass alteration

NASA Astrophysics Data System (ADS)

Mercado-Depierre, S.; Angeli, F.; Frizon, F.; Gin, S.

2013-10-01

Numerous studies have been conducted on glass and cement durability in contact with water, but very little work to date has focused directly on interactions between the two materials. These interactions are mostly controlled by silicon-calcium reactivity. However, the physical and chemical processes involved remain insufficiently understood to predict the evolution of coupled glass-cement systems used in several industrial applications. Results are reported from borosilicate glass alteration in calcium-rich solutions. Our data show that four distinct behaviors can be expected according to the relative importance of three key parameters: the pH, the reaction progress (short- or long-term alteration) and the calcium concentration. Glass alteration is thus controlled by specific mechanisms depending on the solution chemistry: calcium complexation at the glass surface, precipitation of calcium silicate hydrates (C-S-H) or calcium incorporation in the altered layer. These findings highlight the impact of silicon-calcium interactions on glass durability and open the way for a better understanding of glass-cement mixing in civil engineering applications as well as in nuclear waste storage.

Modeling of Impact Properties of Auxetic Materials: Phase 1

DTIC Science & Technology

2013-08-01

avantages marqués comparativement aux matériaux techniques classiques. La présente étude avait pour objectifs de mieux comprendre le comportement des...possible benefits of incorporating auxetic materials into lightweight armour designs . New armour designs incorporating novel auxetic materials may...Poisson négatif et ils offriraient, pour certaines applications, des avantages marqués comparativement aux matériaux techniques classiques. La présente

TiO2 induced structural modifications in Cs containing borosilicate glasses: Raman and infrared studies

NASA Astrophysics Data System (ADS)

Pandey, M.; Banerjee, D.; Sudarsan, V.; Kshirsagar, R. J.

2018-04-01

Effect of TiO2 addition in Cs containing Sodium-borosilicate glasses is studied using Raman and infrared spectroscopic techniques. As revealed from infrared and Raman studies, TiO2 does not form segregated phase, but instead enters into the borosilicate network. It is further observed that TiO2 addition results in modifications of the borate and silicate structural units by transforming into tetraborates and metasilicate structural units. These structural modifications are responsible for Cs immobilization, leach rate and chemical durability of these glasses.

Magnetic Glass Ceramics by Sintering of Borosilicate Glass and Inorganic Waste.

PubMed

Ponsot, Inès M M M; Pontikes, Yiannis; Baldi, Giovanni; Chinnam, Rama K; Detsch, Rainer; Boccaccini, Aldo R; Bernardo, Enrico

2014-07-31

Ceramics and glass ceramics based on industrial waste have been widely recognized as competitive products for building applications; however, there is a great potential for such materials with novel functionalities. In this paper, we discuss the development of magnetic sintered glass ceramics based on two iron-rich slags, coming from non-ferrous metallurgy and recycled borosilicate glass. The substantial viscous flow of the glass led to dense products for rapid treatments at relatively low temperatures (900-1000 °C), whereas glass/slag interactions resulted in the formation of magnetite crystals, providing ferrimagnetism. Such behavior could be exploited for applying the obtained glass ceramics as induction heating plates, according to preliminary tests (showing the rapid heating of selected samples, even above 200 °C). The chemical durability and safety of the obtained glass ceramics were assessed by both leaching tests and cytotoxicity tests.

Application of atomic layer deposited microchannel plates to imaging photodetectors with high time resolution

DOE Office of Scientific and Technical Information (OSTI.GOV)

Siegmund, O. H. W.; McPhate, J. B.; Tremsin, A. S.

Novel microchannel plates have been constructed using borosilicate glass micro-capillary array substrates with 20 mu m and 10 mu m pores and coated with resistive, and secondary electron emissive, layers by atomic layer deposition. Microchannel plates in 33 mm, 50 mm and 20 cm square formats have been made and tested. Although their amplification, imaging, and timing properties are comparable to standard glass microchannel plates, the background rates and lifetime characteristics are considerably improved. Sealed tube detectors based on the Planacon tube, and a 25 mm cross delay line readout tube with a GaN(Mg) opaque photocathode deposited on borosilicate microchannelmore » plates have been fabricated. Considerable progress has also been made with 20 cm microchannel plates for a 20 cm format sealed tube sensor with strip-line readout that is being developed for Cherenkov light detection.« less

Magnetic Glass Ceramics by Sintering of Borosilicate Glass and Inorganic Waste

PubMed Central

Ponsot, Inès M. M. M.; Pontikes, Yiannis; Baldi, Giovanni; Chinnam, Rama K.; Detsch, Rainer; Boccaccini, Aldo R.; Bernardo, Enrico

2014-01-01

Ceramics and glass ceramics based on industrial waste have been widely recognized as competitive products for building applications; however, there is a great potential for such materials with novel functionalities. In this paper, we discuss the development of magnetic sintered glass ceramics based on two iron-rich slags, coming from non-ferrous metallurgy and recycled borosilicate glass. The substantial viscous flow of the glass led to dense products for rapid treatments at relatively low temperatures (900–1000 °C), whereas glass/slag interactions resulted in the formation of magnetite crystals, providing ferrimagnetism. Such behavior could be exploited for applying the obtained glass ceramics as induction heating plates, according to preliminary tests (showing the rapid heating of selected samples, even above 200 °C). The chemical durability and safety of the obtained glass ceramics were assessed by both leaching tests and cytotoxicity tests. PMID:28788146

Evaluation of alloy 690 process pot at the contact with borosilicate melt pool during vitrification of high-level nuclear waste

NASA Astrophysics Data System (ADS)

Sengupta, Pranesh; Kaushik, C. P.; Kale, G. B.; Das, D.; Raj, K.; Sharma, B. P.

2009-08-01

Understanding the material behaviour under service conditions is essential to enhance the life span of alloy 690 process pot used in vitrification of high-level nuclear waste. During vitrification process, interaction of alloy 690 with borosilicate melt takes place for substantial time period. Present experimental studies show that such interactions may result in Cr carbide precipitation along grain boundaries, Cr depletion in austenitic matrix and intergranular attack close to alloy 690/borosilicate melt pool interfaces. Widths of Cr depleted zone within alloy 690 is found to follow kinetics of the type x = 10.9 × 10 -6 + 1 × 10 -8t1/2 m. Based on the experimental results it is recommended that compositional modification of alloy 690 process pot adjacent to borosilicate melt pool need to be considered seriously for any efforts towards reduction and/or prevention of process pot failures.

Comprehensive studies of the Ag+ effect on borosilicate glass ceramics containing Ag nanoparticles and Er-doped hexagonal NaYF4 nanocrystals: morphology, structure, and 2.7 μm emission

NASA Astrophysics Data System (ADS)

Liu, Qunhuo; Tian, Ying; Tang, Wenhua; Jing, Xufeng; Zhang, Junjie; Xu, Shiqing

2018-05-01

In this work, we have performed a comprehensive investigation of the Ag+ concentration effect on the morphological, thermal, structural, and mid-infrared emission properties of novel oxyfluoride borosilicate glasses and glass ceramics containing both Ag nanoparticles and erbium-doped hexagonal NaYF4 nanocrystals. The effect of Ag+ ions on the glass forming and crystallization processes was discussed in detail by glass structural analysis. It was found that the Ag+ concentration can affect the distribution of Na+ ion and bridge oxygen in boron-rich and silicon-rich phases, which induced the transformation between BO3 triangles and BO4 tetrahedra during crystallization process. In addition, there was a turning point when the doped Ag+ ion concentration reached its solubility in the borosilicate glass. Furthermore, the enhancement of the 2.7 μm emission and the reduction of the lifetime of the 4I13/2 level were observed both in glasses and in glass ceramics, and its origin was revealed by qualitative and quantitative analyses of the Er3+-Ag nanoparticles (localized electric field enhancement) and Er3+-Er3+ (nonradiative resonance energy transfer) interactions within glasses and glass ceramics. Moreover, the high lifetime of the 4I11/2 level (2.12 ms) and the peak emission cross section in 2.7 μm (6.8×10-21 cm2) suggested that the prepared glass ceramics have promising mid-infrared laser applications.

Fabrication of Silicon Nitride Dental Core Ceramics with Borosilicate Veneering material

NASA Astrophysics Data System (ADS)

Wananuruksawong, R.; Jinawath, S.; Padipatvuthikul, P.; Wasanapiarnpong, T.

2011-10-01

Silicon nitride (Si3N4) ceramic is a great candidate for clinical applications due to its high fracture toughness, strength, hardness and bio-inertness. This study has focused on the Si3N4 ceramic as a dental core material. The white Si3N4 was prepared by pressureless sintering at relative low sintering temperature of 1650 °C in nitrogen atmosphere. The coefficient of thermal expansion (CTE) of Si3N4 ceramic is lower than that of Zirconia and Alumina ceramic which are popular in this field. The borosilicate glass veneering was employed due to its compatibility in thermal expansion. The sintered Si3N4 specimens represented the synthetic dental core were paintbrush coated by a veneer paste composed of borosilicate glass powder (<150 micrometer, Pyrex) with 5 wt% of zirconia powder (3 wt% Y2O3 - partial stabilized zirconia) and 30 wt% of polyvinyl alcohol (5 wt% solution). After coating the veneer on the Si3N4 specimens, the firing was performed in electric tube furnace between 1000-1200°C. The veneered specimens fired at 1100°C for 15 mins show good bonding, smooth and glossy without defect and crazing. The veneer has thermal expansion coefficient as 3.98×10-6 °C-1, rather white and semi opaque, due to zirconia addition, the Vickers hardness as 4.0 GPa which is closely to the human teeth.

Application of a novel new multispectral nanoparticle tracking technique

NASA Astrophysics Data System (ADS)

McElfresh, Cameron; Harrington, Tyler; Vecchio, Kenneth S.

2018-06-01

Fast, reliable, and accurate particle size analysis techniques must meet the demands of evolving industrial and academic research in areas of functionalized nanoparticle synthesis, advanced materials development, and other nanoscale enabled technologies. In this study a new multispectral particle tracking analysis (m-PTA) technique enabled by the ViewSizer™ 3000 (MANTA Instruments, USA) was evaluated using solutions of monomodal and multimodal gold and polystyrene latex nanoparticles, as well as a spark eroded polydisperse 316L stainless steel nanopowder, and large (non-Brownian) borosilicate particles. It was found that m-PTA performed comparably to the DLS in evaluation of monomodal particle size distributions. When measuring bimodal, trimodal and polydisperse solutions, the m-PTA technique overwhelmingly outperformed traditional dynamic light scattering (DLS) in both peak detection and relative particle concentration analysis. It was also observed that the m-PTA technique is less susceptible to large particle overexpression errors. The ViewSizer™ 3000 was also found to be successful in accurately evaluating sizes and concentrations of monomodal and bimodal sinking borosilicate particles.

Luminescence properties of Dy3+ doped lithium zinc borosilicate glasses for photonic applications.

PubMed

Jaidass, N; Krishna Moorthi, C; Mohan Babu, A; Reddi Babu, M

2018-03-01

Different concentrations of Dy 3+ ions doped lithium zinc borosilicate glasses of chemical composition (30-x) B 2 O 3 - 25 SiO 2 -10 Al 2 O 3 -30 LiF - 5 ZnO - x Dy 2 O 3 (x = 0, 0.1, 0.5, 1.0 and 2.0 mol%) were prepared by the melt quenching technique. The prepared glasses were investigated through X-ray diffraction, optical absorption, photoluminescence and decay measurements. Intensities of absorption bands expressed in terms of oscillator strengths (f) were used to determine the Judd-Ofelt (J-O) intensity parameters Ω λ (λ = 2, 4 and 6). The evaluated J-O parameters were used to determine the radiative parameters such as transition probabilities (A R ), total transition probability rate (A T ), radiative lifetime (τ R ) and branching ratios (β R ) for the excited 4 F 9/2 level of Dy 3+ ions. The chromaticity coordinates determined from the emission spectra were found to be located in the white light region of CIE chromaticity diagram.

High Pressure Response of Siliceous Materials

DTIC Science & Technology

2013-02-01

quartz, Starphire soda lime silicate glass, hydrated Starphire, BOROFLOAT borosilicate glass, an iron-containing soda lime silicate glass, opal (a hydrated... Opal (hydrated amorphous silica). .............................................................................. 10 2.7. ROBAX glass ceramic...spectrum as a function of stress for BOROFLOAT borosilicate glass. .......... 29 4.8. Raman spectrum as a function of stress for opal (hydrated

Effects of system size and cooling rate on the structure and properties of sodium borosilicate glasses from molecular dynamics simulations.

PubMed

Deng, Lu; Du, Jincheng

2018-01-14

Borosilicate glasses form an important glass forming system in both glass science and technologies. The structure and property changes of borosilicate glasses as a function of thermal history in terms of cooling rate during glass formation and simulation system sizes used in classical molecular dynamics (MD) simulation were investigated with recently developed composition dependent partial charge potentials. Short and medium range structural features such as boron coordination, Si and B Q n distributions, and ring size distributions were analyzed to elucidate the effects of cooling rate and simulation system size on these structure features and selected glass properties such as glass transition temperature, vibration density of states, and mechanical properties. Neutron structure factors, neutron broadened pair distribution functions, and vibrational density of states were calculated and compared with results from experiments as well as ab initio calculations to validate the structure models. The results clearly indicate that both cooling rate and system size play an important role on the structures of these glasses, mainly by affecting the 3 B and 4 B distributions and consequently properties of the glasses. It was also found that different structure features and properties converge at different sizes or cooling rates; thus convergence tests are needed in simulations of the borosilicate glasses depending on the targeted properties. The results also shed light on the complex thermal history dependence on structure and properties in borosilicate glasses and the protocols in MD simulations of these and other glass materials.

Effects of system size and cooling rate on the structure and properties of sodium borosilicate glasses from molecular dynamics simulations

NASA Astrophysics Data System (ADS)

Deng, Lu; Du, Jincheng

2018-01-01

Borosilicate glasses form an important glass forming system in both glass science and technologies. The structure and property changes of borosilicate glasses as a function of thermal history in terms of cooling rate during glass formation and simulation system sizes used in classical molecular dynamics (MD) simulation were investigated with recently developed composition dependent partial charge potentials. Short and medium range structural features such as boron coordination, Si and B Qn distributions, and ring size distributions were analyzed to elucidate the effects of cooling rate and simulation system size on these structure features and selected glass properties such as glass transition temperature, vibration density of states, and mechanical properties. Neutron structure factors, neutron broadened pair distribution functions, and vibrational density of states were calculated and compared with results from experiments as well as ab initio calculations to validate the structure models. The results clearly indicate that both cooling rate and system size play an important role on the structures of these glasses, mainly by affecting the 3B and 4B distributions and consequently properties of the glasses. It was also found that different structure features and properties converge at different sizes or cooling rates; thus convergence tests are needed in simulations of the borosilicate glasses depending on the targeted properties. The results also shed light on the complex thermal history dependence on structure and properties in borosilicate glasses and the protocols in MD simulations of these and other glass materials.

Refractive Surgery: New Techniques and Usability for Military Personnel (La chirurgie refractive: Nouvelles techniques et leur application pour le personnel militaire)

DTIC Science & Technology

2012-11-01

de loin sans correction, la chirurgie réfractive permet aux jeunes recrues ou militaires du rang de satisfaire aux normes de vision sans...correction exigées pour le métier militaire de leur choix, d’où une augmentation du nombre de candidats et la possibilité pour les individus...réfractive risquent d’engendrer des handicaps visuels et d’écourter des carrières militaires. Pour cette raison, la qualité du service fourni

Localized Iron Supply Triggers Lateral Root Elongation in Arabidopsis by Altering the AUX1-Mediated Auxin Distribution[C][W][OA

PubMed Central

Giehl, Ricardo F.H.; Lima, Joni E.; von Wirén, Nicolaus

2012-01-01

Root system architecture depends on nutrient availability, which shapes primary and lateral root development in a nutrient-specific manner. To better understand how nutrient signals are integrated into root developmental programs, we investigated the morphological response of Arabidopsis thaliana roots to iron (Fe). Relative to a homogeneous supply, localized Fe supply in horizontally separated agar plates doubled lateral root length without having a differential effect on lateral root number. In the Fe uptake-defective mutant iron-regulated transporter1 (irt1), lateral root development was severely repressed, but a requirement for IRT1 could be circumvented by Fe application to shoots, indicating that symplastic Fe triggered the local elongation of lateral roots. The Fe-stimulated emergence of lateral root primordia and root cell elongation depended on the rootward auxin stream and was accompanied by a higher activity of the auxin reporter DR5-β-glucuronidase in lateral root apices. A crucial role of the auxin transporter AUXIN RESISTANT1 (AUX1) in Fe-triggered lateral root elongation was indicated by Fe-responsive AUX1 promoter activities in lateral root apices and by the failure of the aux1-T mutant to elongate lateral roots into Fe-enriched agar patches. We conclude that a local symplastic Fe gradient in lateral roots upregulates AUX1 to accumulate auxin in lateral root apices as a prerequisite for lateral root elongation. PMID:22234997

Self-assembly of bimetallic AuxPd1-x alloy nanoparticles via dewetting of bilayers through the systematic control of temperature, thickness, composition and stacking sequence

NASA Astrophysics Data System (ADS)

Kunwar, Sundar; Pandey, Puran; Sui, Mao; Bastola, Sushil; Lee, Jihoon

2018-03-01

Bimetallic alloy nanoparticles (NPs) are attractive materials for various applications with their morphology and elemental composition dependent optical, electronic, magnetic and catalytic properties. This work demonstrates the evolution of AuxPd1-x alloy nanostructures by the solid-state dewetting of sequentially deposited bilayers of Au and Pd on sapphire (0001). Various shape, size and configuration of AuxPd1‑x alloy NPs are fabricated by the systematic control of annealing temperature, deposition thickness, composition as well as stacking sequence. The evolution of alloy nanostructures is attributed to the surface diffusion, interface diffusion between bilayers, surface and interface energy minimization, Volmer-Weber growth model and equilibrium configuration. Depending upon the temperature, the surface morphologies evolve with the formation of pits, grains and voids and gradually develop into isolated semi-spherical alloy NPs by the expansion of voids and agglomeration of Au and Pd adatoms. On the other hand, small isolated to enlarged elongated and over-grown layer-like alloy nanostructures are fabricated due to the coalescence, partial diffusion and inter-diffusion with the increased bilayer thickness. In addition, the composition and stacking sequence of bilayers remarkably affect the final geometry of AuxPd1‑x nanostructures due to the variation in the dewetting process. The optical analysis based on the UV–vis-NIR reflectance spectra reveals the surface morphology dependent plasmonic resonance, scattering, reflection and absorption properties of AuxPd1‑x alloy nanostructures.

Monte Carlo simulations of coupled diffusion and surface reactions during the aqueous corrosion of borosilicate glasses

DOE PAGES

Kerisit, Sebastien; Pierce, Eric M.; Ryan, Joseph V.

2014-09-19

Borosilicate nuclear waste glasses develop complex altered layers as a result of coupled processes such as hydrolysis of network species, condensation of Si species, and diffusion. However, diffusion has often been overlooked in Monte Carlo models of the aqueous corrosion of borosilicate glasses. Therefore, in this paper three different models for dissolved Si diffusion in the altered layer were implemented in a Monte Carlo model and evaluated for glasses in the compositional range (75 - x) mol% SiO 2 (12.5 + x/2) mol% B 2O 3 and (12.5 + x/2) mol% Na 2O, where 0 ≤ x ≤ 20%, andmore » corroded in static conditions at a surface-area-to-volume ratio of 1000 m -1. The three models considered instantaneous homogenization (M1), linear concentration gradients (M2), and concentration profiles determined by solving Fick's 2nd law using a finite difference method (M3). Model M3 revealed that concentration profiles in the altered layer are not linear and show changes in shape and magnitude as corrosion progresses, unlike those assumed in model M2. Furthermore, model M3 showed that, for borosilicate glasses with a high forward dissolution rate compared to the diffusion rate, the gradual polymerization and densification of the altered layer is significantly delayed compared to models M1 and M2. Finally, models M1 and M2 were found to be appropriate models only for glasses with high release rates such as simple borosilicate glasses with low ZrO 2 content.« less

Rhenium Solubility in Borosilicate Nuclear Waste Glass: Implications for the Processing and Immobilization of Technetium-99

DOE Office of Scientific and Technical Information (OSTI.GOV)

McCloy, John S.; Riley, Brian J.; Goel, Ashutosh

2012-10-26

The immobilization of 99Tc in a suitable host matrix has proved to be an arduous task for the researchers in nuclear waste community around the world. At the Hanford site in Washington State, the total amount of 99Tc in low-activity waste (LAW) is ~1300 kg and the current strategy is to immobilize the 99Tc in borosilicate glass with vitrification. In this context, the present article reports on the solubility/retention of rhenium, a nonradioactive surrogate for 99Tc, in a LAW borosilicate glass. Due to the radioactive nature of technetium, rhenium was chosen as a simulant because of the similarity between theirmore » ionic radii and other chemical aspects. The glasses containing Re (0 – 10,000 ppm by mass) were synthesized in vacuum-sealed quartz ampoules in order to minimize the loss of Re by volatilization during melting at 1000 °C. The rhenium was found to predominantly exist as Re (VII) in all the glasses as observed by X-ray absorption near-edge structure (XANES). The solubility of Re in borosilicate glasses was determined to be ~3000 ppm (by mass) with inductively coupled plasma-optical emission spectroscopy (ICP-OES). At higher rhenium concentrations, some additional material was retained in the glasses in the form of crystalline inclusions that were detected by X-ray diffraction (XRD) and laser ablation-ICP mass spectrometry (LA-ICP-MS). The implications of these results on the immobilization of 99Tc from radioactive wastes in borosilicate glasses have been discussed.« less

Continuous-wave laser-induced glass fiber generation

NASA Astrophysics Data System (ADS)

Nishioka, Nobuyasu; Hidai, Hirofumi; Matsusaka, Souta; Chiba, Akira; Morita, Noboru

2017-09-01

Pulsed-laser-induced glass fiber generation has been reported. We demonstrate a novel glass fiber generation technique by continuous-wave laser illumination and reveal the generation mechanism. In this technique, borosilicate glass, metal foil, and a heat insulator are stacked and clamped by a jig as the sample. Glass fibers are ejected from the side surface of the borosilicate glass by laser illumination of the sample from the borosilicate glass side. SEM observation shows that nanoparticles are attached on the glass fibers. High-speed imaging reveals that small bubbles are formed at the side surface of the borosilicate glass and the bursting of the bubble ejects the fibers. The temperature at the fiber ejection point is estimated to be 1220 K. The mechanism of the fiber ejection includes the following steps: the metal thin foil heated by the laser increases the temperature of the surrounding glass by heat conduction. Since the absorption coefficient of the glass is increased by increasing the temperature, the glass starts to absorb the laser irradiation. The heated glass softens and bubbles form. When the bubble bursts, molten glass and gas inside the bubble scatter into the air to generate the glass fibers.

Effect of barium on diffusion of sodium in borosilicate glass.

PubMed

Mishra, R K; Kumar, Sumit; Tomar, B S; Tyagi, A K; Kaushik, C P; Raj, Kanwar; Manchanda, V K

2008-08-15

Diffusion coefficients of sodium in barium borosilicate glasses having varying concentration of barium were determined by heterogeneous isotopic exchange method using (24)Na as the radiotracer for sodium. The measurements were carried out at various temperatures (748-798 K) to obtain the activation energy (E(a)) of diffusion. The E(a) values were found to increase with increasing barium content of the glass, indicating that introduction of barium in the borosilicate glass hinders the diffusion of alkali metal ions from the glass matrix. The results have been explained in terms of the electrostatic and structural factors, with the increasing barium concentration resulting in population of low energy sites by Na(+) ions and, plausibly, formation of more tight glass network. The leach rate measurements on the glass samples show similar trend.

AUX: a scripting language for auditory signal processing and software packages for psychoacoustic experiments and education.

PubMed

Kwon, Bomjun J

2012-06-01

This article introduces AUX (AUditory syntaX), a scripting syntax specifically designed to describe auditory signals and processing, to the members of the behavioral research community. The syntax is based on descriptive function names and intuitive operators suitable for researchers and students without substantial training in programming, who wish to generate and examine sound signals using a written script. In this article, the essence of AUX is discussed and practical examples of AUX scripts specifying various signals are illustrated. Additionally, two accompanying Windows-based programs and development libraries are described. AUX Viewer is a program that generates, visualizes, and plays sounds specified in AUX. AUX Viewer can also be used for class demonstrations or presentations. Another program, Psycon, allows a wide range of sound signals to be used as stimuli in common psychophysical testing paradigms, such as the adaptive procedure, the method of constant stimuli, and the method of adjustment. AUX Library is also provided, so that researchers can develop their own programs utilizing AUX. The philosophical basis of AUX is to separate signal generation from the user interface needed for experiments. AUX scripts are portable and reusable; they can be shared by other researchers, regardless of differences in actual AUX-based programs, and reused for future experiments. In short, the use of AUX can be potentially beneficial to all members of the research community-both those with programming backgrounds and those without.

Major Events Coordinated Security Solutions Technical Report Closeout (MECSS): The Application of Science and Technology to Reduce Risk for V2010 and G8/G20 Summits

DTIC Science & Technology

2010-12-01

CBRNE), aux infrastructures essentielles, à la surveillance, à la sécurité physique, à la cybernétique et à la socio- psychologie . Le présent rapport...la socio- psychologie . Dans le cadre du projet SCSGE, on a produit plus de 195 rapports scientifiques, fruit des efforts, du dévouement et du...aux infrastructures essentielles, à la surveillance, à la sécurité physique, à la cybernétique et à la socio- psychologie . Le présent rapport

Laser Fabrication and Characterization of Adhesive-Free Joints for Encapsulation of Biomedical Implant Devices

DTIC Science & Technology

2005-01-01

excitation sources should be helpful in overcoming this problem. CONCLUSIONS Biocompatible joints between polyimide and titanium-coated borosilicate...Technology, 46025 Port St., Plymouth, MI 48170, U.S.A. ABSTRACT Laser-fabricated joints of sub-millimeter widths between biocompatible , dissimilar materials...method of a very promising system, polyimide /titanium-coated borosilicate glass, and present and discuss results from characterization of such laser

Stress Wave and Damage Propagation in Transparent Laminates at Elevated Temperatures

DTIC Science & Technology

2010-03-01

materials like Starphire (a registered trademark of PPG Industries, Pittsburgh, PA) soda - lime glass , borosilicate glass , fused silica , and the...in transparent armor materials like Starphire soda - lime glass , borosilicate glass , fused silica , and the transparent ceramic AlON.1 Since...transparent ceramic AlON. Since transparent armor consists of glass laminates with polymer interlayer and backing, the influence of interlayer type and

Radiation response of cubic mesoporous silicate and borosilicate thin films

NASA Astrophysics Data System (ADS)

Manzini, Ayelén; Alurralde, Martín; Luca, Vittorio

2018-01-01

The radiation response has been studied of cubic mesoporous silicate and borosilicate thin films having different boron contents prepared using the block copolymer template Brij 58 and the dip coating technique. The degree of pore ordering of the films was analysed using low-angle X-ray diffraction and film thickness measured by X-ray reflectivity. For films calcined at 350 °C, the incorporation of boron resulted in a reproducible oscillatory variation in the d-spacing and intensity of the primary reflection as a function of boron content. A clear peak was observed in the d-spacing at 5-10 mol% boron incorporation. For borosilicate films of a given composition an overall suppression of d-spacing was observed as a function of aging time relative to films that did not contain boron. This was ascribed to a slow condensation process. The films were irradiated in pile with neutrons and with iodine ions at energies of 180 keV and 70 MeV. Neutron irradiation of the silicate thin films for periods up to 30 days and aged for 400 days resulted in little reduction in either d-spacing or intensity of the primary low-angle X-ray reflection indicating that the films retained their mesopore ordering. In contrast borosilicate films for which the B (n, α) reaction was expected to result in enhanced displacement damage showed much larger variations in X-ray parameters. For these films short irradiation times resulted in a reduction of the d-spacing and intensity of the primary reflections considerably beyond that observed through aging. It is concluded that prolonged neutron irradiation and internal α irradiation have only a small, although measurable, impact on mesoporous borosilicate thin films increasing the degree of condensation and increasing unit cell contraction. When these borosilicate films were irradiated with iodine ions, more profound changes occurred. The pore ordering of the films was significantly degraded when low energy ions were used. In some cases the degree of damage was such that no low-angle reflection could be observed. This degradation of pore ordering was confirmed in scanning electron microscopy images of the irradiated films.

Effect of Gd2O3 doping on structure and boron volatility of borosilicate glass sealants in solid oxide fuel cells-A study on the La0.6Sr0.4Co0.2Fe0.8O3-δ (LSCF) cathode

NASA Astrophysics Data System (ADS)

Zhang, Qi; Tan, Shengwei; Ren, Mengyuan; Yang, Hsiwen; Tang, Dian; Chen, Kongfa; Zhang, Teng; Jiang, San Ping

2018-04-01

Boron volatility is one of the most important properties of borosilicate-based glass sealants in solid oxide fuel cells (SOFCs), as boron contaminants react with lanthanum-containing cathodes, forming LaBO3 and degrading the activity of SOFCs. Here, we report that the reaction between the volatile boron and a La0.6Sr0.4Co0.2Fe0.8O3-δ (LSCF) cathode during polarization can be significantly reduced by doping aluminoborosilicate glass with Gd2O3. Specifically, the Gd cations in glass with 2 mol.% Gd2O3 dissolve preferentially in the borate-rich environment to form more Gd-metaborate structures and promote the formation of calcium metaborate (CaB2O4); they also condense the B-O network after heat treatment, which suppresses poisoning by boron contaminants on the LSCF cathode. The results provide insights into design and development of a reliable sealing glass for SOFC applications.

RHENIUM SOLUBILITY IN BOROSILICATE NUCLEAR WASTE GLASS IMPLICATIONS FOR THE PROCESSING AND IMMOBILIZATION OF TECHNETIUM-99 (AND SUPPORTING INFORMATION WITH GRAPHICAL ABSTRACT)

DOE Office of Scientific and Technical Information (OSTI.GOV)

AA KRUGER; A GOEL; CP RODRIGUEZ

2012-08-13

The immobilization of 99Tc in a suitable host matrix has proved a challenging task for researchers in the nuclear waste community around the world. At the Hanford site in Washington State in the U.S., the total amount of 99Tc in low-activity waste (LAW) is {approx} 1,300 kg and the current strategy is to immobilize the 99Tc in borosilicate glass with vitrification. In this context, the present article reports on the solubility and retention of rhenium, a nonradioactive surrogate for 99Tc, in a LAW sodium borosilicate glass. Due to the radioactive nature of technetium, rhenium was chosen as a simulant becausemore » of previously established similarities in ionic radii and other chemical aspects. The glasses containing target Re concentrations varying from 0 to10,000 ppm by mass were synthesized in vacuum-sealed quartz ampoules to minimize the loss of Re by volatilization during melting at 1000 DC. The rhenium was found to be present predominantly as Re7 + in all the glasses as observed by X-ray absorption near-edge structure (XANES). The solubility of Re in borosilicate glasses was determined to be {approx}3,000 ppm (by mass) using inductively coupled plasma-optical emission spectroscopy (ICP-OES). At higher rhenium concentrations, some additional material was retained in the glasses in the form of alkali perrhenate crystalline inclusions detected by X-ray diffraction (XRD) and laser ablation-ICP mass spectrometry (LA-ICP-MS). Assuming justifiably substantial similarities between Re7 + and Tc 7+ behavior in this glass system, these results implied that the processing and immobilization of 99Tc from radioactive wastes should not be limited by the solubility of 99Tc in borosilicate LAW glasses.« less

Silicate, borosilicate, and borate bioactive glass scaffolds with controllable degradation rate for bone tissue engineering applications. II. In vitro and in vivo biological evaluation.

PubMed

Fu, Qiang; Rahaman, Mohamed N; Bal, B Sonny; Bonewald, Lynda F; Kuroki, Keiichi; Brown, Roger F

2010-10-01

In Part I, the in vitro degradation of bioactivAR52115e glass scaffolds with a microstructure similar to that of human trabecular bone, but with three different compositions, was investigated as a function of immersion time in a simulated body fluid. The glasses consisted of a silicate (13-93) composition, a borosilicate composition (designated 13-93B1), and a borate composition (13-93B3), in which one-third or all of the SiO2 content of 13-93 was replaced by B2O3, respectively. This work is an extension of Part I, to investigate the effect of the glass composition on the in vitro response of osteogenic MLO-A5 cells to these scaffolds, and on the ability of the scaffolds to support tissue infiltration in a rat subcutaneous implantation model. The results of assays for cell viability and alkaline phosphatase activity showed that the slower degrading silicate 13-93 and borosilicate 13-93B1 scaffolds were far better than the borate 13-93B3 scaffolds in supporting cell proliferation and function. However, all three groups of scaffolds showed the ability to support tissue infiltration in vivo after implantation for 6 weeks. The results indicate that the required bioactivity and degradation rate may be achieved by substituting an appropriate amount of SiO2 in 13-93 glass with B2O3, and that these trabecular glass scaffolds could serve as substrates for the repair and regeneration of contained bone defects. Copyright 2010 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2010.

The ARF, AUX/IAA and GH3 gene families in citrus: genome-wide identification and expression analysis during fruitlet drop from abscission zone A.

PubMed

Xie, Rangjin; Pang, Shaoping; Ma, Yanyan; Deng, Lie; He, Shaolan; Yi, Shilai; Lv, Qiang; Zheng, Yongqiang

2015-12-01

Completion of the whole genome sequencing of citrus enabled us to perform genome-wide identification and functional analysis of the gene families involved in agronomic traits and morphological diversity of citrus. In this study, 22 CitARF, 11 CitGH3 and 26 CitAUX/IAA genes were identified in citrus, respectively. Phylogenetic analysis revealed that all the genes of each gene family could be subdivided into three groups and showed strong evolutionary conservation. The GH3 and AUX/IAA gene families shrank and ARF gene family was highly conserved in the citrus genome after speciation from Arabidopsis thaliana. Tissue-specific expression profiles revealed that 54 genes were expressed in at least one tissue while just 5 genes including CitARF07, CitARF20, CitGH3.04, CitAUX/IAA25 and CitAUX/IAA26 with very low expression level in all tissues tested, suggesting that the CitARF, CitGH3 and CitAUX/IAA gene families played important roles in the development of citrus organs. In addition, our data found that the expression of 2 CitARF, 4 CitGH3 and 4 AUX/IAA genes was affected by IAA treatment, and 7 genes including, CitGH3.04, CitGH3.07, CitAUX/IAA03, CitAUX/IAA04, CitAUX/IAA18, CitAUX/IAA19 and CitAUX/IAA23 were related to fruitlet abscission. This study provides a foundation for future studies on elucidating the precise role of citrus ARF, GH3 and AUX/IAA genes in early steps of auxin signal transduction and open up a new opportunity to uncover the molecular mechanism underlying citrus fruitlet abscission.

Understanding the structural drivers governing glass-water interactions in borosilicate based model bioactive glasses.

PubMed

Stone-Weiss, Nicholas; Pierce, Eric M; Youngman, Randall E; Gulbiten, Ozgur; Smith, Nicholas J; Du, Jincheng; Goel, Ashutosh

2018-01-01

The past decade has witnessed a significant upsurge in the development of borate and borosilicate based resorbable bioactive glasses owing to their faster degradation rate in comparison to their silicate counterparts. However, due to our lack of understanding about the fundamental science governing the aqueous corrosion of these glasses, most of the borate/borosilicate based bioactive glasses reported in the literature have been designed by "trial-and-error" approach. With an ever-increasing demand for their application in treating a broad spectrum of non-skeletal health problems, it is becoming increasingly difficult to design advanced glass formulations using the same conventional approach. Therefore, a paradigm shift from the "trial-and-error" approach to "materials-by-design" approach is required to develop new-generations of bioactive glasses with controlled release of functional ions tailored for specific patients and disease states, whereby material functions and properties can be predicted from first principles. Realizing this goal, however, requires a thorough understanding of the complex sequence of reactions that control the dissolution kinetics of bioactive glasses and the structural drivers that govern them. While there is a considerable amount of literature published on chemical dissolution behavior and apatite-forming ability of potentially bioactive glasses, the majority of this literature has been produced on silicate glass chemistries using different experimental and measurement protocols. It follows that inter-comparison of different datasets reveals inconsistencies between experimental groups. There are also some major experimental challenges or choices that need to be carefully navigated to unearth the mechanisms governing the chemical degradation behavior and kinetics of boron-containing bioactive glasses, and to accurately determine the composition-structure-property relationships. In order to address these challenges, a simplified borosilicate based model melt-quenched bioactive glass system has been studied to depict the impact of thermal history on its molecular structure and dissolution behavior in water. It has been shown that the methodology of quenching of the glass melt impacts the dissolution rate of the studied glasses by 1.5×-3× depending on the changes induced in their molecular structure due to variation in thermal history. Further, a recommendation has been made to study dissolution behavior of bioactive glasses using surface area of the sample - to - volume of solution (SA/V) approach instead of the currently followed mass of sample - to - volume of solution approach. The structural and chemical dissolution data obtained from bioactive glasses following the approach presented in this paper can be used to develop the structural descriptors and potential energy functions over a broad range of bioactive glass compositions. Realizing the goal of designing third generation bioactive glasses requires a thorough understanding of the complex sequence of reactions that control their rate of degradation (in physiological fluids) and the structural drivers that control them. In this article, we have highlighted some major experimental challenges and choices that need to be carefully navigated in order to unearth the mechanisms governing the chemical dissolution behavior of borosilicate based bioactive glasses. The proposed experimental approach allows us to gain a new level of conceptual understanding about the composition-structure-property relationships in these glass systems, which can be applied to attain a significant leap in designing borosilicate based bioactive glasses with controlled dissolution rates tailored for specific patient and disease states. Copyright © 2017 Acta Materialia Inc. All rights reserved.

Impact Experiments into Borosilicate Glass at Three Scale Sizes

DTIC Science & Technology

2009-11-01

DEDF and soda - lime glass during rod impact. Shock Compression in Condensed Matter–2005 (Furnish MD, Elert M, Russell TP, and White CT, Eds.) AIP Conf...in a float soda - lime silicate glass . Int. J. Appl. Glass Sci., to be submitted (2009). 18. Chocron S, Dannemann KA, Nicholls AE, and Anderson CE Jr...UNCLASSIFIED UNCLASSIFIED Impact Experiments into Borosilicate Glass at Three Scale Sizes Charles E. Anderson, Jr. Carl E. Weiss Sidney Chocron

Effect of Loading Rate and Surface Conditions on Flexural Strength of Borosilicate Glass

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nie, X; Chen, Wayne; Wereszczak, Andrew A

2009-01-01

This study evaluates the loading rate and surface condition dependence of the flexural strength of a borosilicate glass. The glass specimens are subjected to three different surface treatments before four-point bending tests to study the effect of surface flaws. Quasistatic (Material Test System 810) and dynamic (Kolsky bar) experiments are performed at loading rates ranging from 0.7 to 4 x 10{sup 6} MPa/s. The results show that the flexural strength of the borosilicate glass has a strong dependence on the loading rate. A chemically etched surface produces an enhanced flexural strength by about an order of magnitude. Scanning electron microscopymore » images on fracture surfaces indicate that the failure is governed by different types of flaws under different surface treatment conditions. Edge failure is also identified for samples possessing high flexural strength.« less

Alkali borosilicate glass by fly ash from a coal-fired power plant.

PubMed

Park, Jong Soo; Taniguchi, Shoji; Park, Young Jun

2009-01-01

The possibility of using coal fly ash as a silica source for alkali borosilicate glass was investigated. Alkali borosilicate glasses were prepared from the coal fly ash mixed with 30 wt.% reagents composed of Na(2)O and B(2)O(3) by susceptor-induction heating. Their densities ranged from 2.24 to 2.55 g cm(-3) and decreased as the amount of B(2)O(3) addition increased. However, the Vickers microhardness showed a different tendency with the density since the glass network connectivity improved by boron anomaly, which was identified by a nuclear magnetic resonance analysis. The Vickers microhardness of the glass product, with the addition of 15 wt.% B(2)O(3) and 15 wt.% Na(2)O, was about 4030 MPa. Furthermore, the changes in microstructure were consistent with those in the chemical stability by the toxicity characteristic leaching procedure (TCLP).

Sequence stratigraphy of the Aux Vases Sandstone: A major oil producer in the Illinois basin

USGS Publications Warehouse

Leetaru, H.E.

2000-01-01

The Aux Vases Sandstone (Mississippian) has contributed between 10 and 25% of all the oil produced in Illinois. The Aux Vases is not only an important oil reservoir but is also an important source of groundwater, quarrying stone, and fluorspar. Using sequence stratigraphy, a more accurate stratigraphic interpretation of this economically important formation can be discerned and thereby enable more effective exploration for the resources contained therein. Previous studies have assumed that the underlying Spar Mountain, Karnak, and Joppa formations interfingered with the Aux Vases, as did the overlying Renault Limestone. This study demonstrates that these formations instead are separated by sequence boundaries; therefore, they are not genetically related to each other. A result of this sequence stratigraphic approach is the identification of incised valleys, paleotopography, and potential new hydrocarbon reservoirs in the Spar Mountain and Aux Vases. In eastern Illinois, the Aux Vases is bounded by sequence boundaries with 20 ft (6 m) of relief. The Aux Vases oil reservoir facies was deposited as a tidally influenced siliciclastic wedge that prograded over underlying carbonate-rich sediments. The Aux Vases sedimentary succession consists of offshore sediment overlain by intertidal and supratidal sediments. Low-permeability shales and carbonates typically surround the Aux Vases reservoir sandstone and thereby form numerous bypassed compartments from which additional oil can be recovered. The potential for new significant oil fields within the Aux Vases is great, as is the potential for undrained reservoir compartments within existing Aux Vases fields.

Large Area and High Efficiency Photon Counting Imaging Detectors with High Time and Spatial Resolution for Night Time Sensing and Astronomy

NASA Astrophysics Data System (ADS)

Siegmund, O.; Vallerga, J.; Tremsin, A.; McPhate, J.; Frisch, H.; Elam, J.; Mane, A.; Wagner, R.; Varner, G.

2012-09-01

The development of large area photon counting, imaging, timing detectors with high performance has significance for applications in astronomy (such as our sensor on the SAAO SALT 10m telescope), night time remote reconnaissance, airborne/space situational awareness, and high-speed adaptive optics. Sealed tube configurations for optical/IR sensing also have applications in detection of Cherenkov light (RICH), biological single-molecule fluorescence lifetime imaging microscopy and neutron imaging applications. In open faced configurations these devices are important for UV and particle detection in space astrophysics, mass spectroscopy and many time-of flight applications. Currently available devices are limited to sizes of about 5 cm and use either conventional microchannel plates, or dynode multipliers for amplification, coupled coarse pad array readouts. Extension of these schemes to devices as large as 20 cm with high spatial resolution presents significant problems and potentially considerable cost. A collaboration (Large Area Picosecond Photon Detector) of the U. Chicago, Argonne National Laboratory, U.C. Berkeley, U. Hawaii and a number of other institutions has developed novel technologies to realize 20 cm format detectors in open face or sealed tube configurations. One critical component of this development is novel microchannel plates employing borosilicate micro-capillary arrays. The microchannel plates are based on a novel concept where the substrate is constructed from a borosilicate micro-capillary array that is made to function as a microchannel plate by deposition of resistive and secondary emissive layers using atomic layer deposition. The process is relatively inexpensive compared with conventional microchannel plates and allows very large microchannel plates to be produced with pore sizes as small as 10 microns. These provide many performance characteristics typical of conventional microchannel plates, but have been made in sizes up to 20 cm, have low intrinsic background (<0.1 events/sq-cm/sec) and high stability with no observed gain degradation behavior over at least 5 Coul/sq-cm of charge extraction. Initial tests in a 20 cm detector with a cross strip electronic readout have achieved 4k x 4k pixel imaging with single photon sub-ns timing and MHz event rates. In concert with this effort we have made stable, uniform 20 cm bialkali photocathodes with >20% quantum efficiency on borosilicate windows compatible with a large sealed tube device. Other related efforts have also produced small sealed tubes with 30% quantum efficiency GaAs sealed tubes with high resolution imaging and timing that are immediately applicable to current applications, and opaque GaN UV photocathodes directly deposited onto these novel microchannel plates. We will discuss the details and implications of these novel microchannel plates with respect to the realization of novel detectors up to 20 cm format with reasonable cost and performance, robust construction, high flexibility of format and readout, reduction of fabrication effort, dramatically increased lifetime and stability, and their potential applications.

There Is Still Room for Improvement: Presentation of a Neutral Borosilicate Glass with Improved Chemical Stability for Parenteral Packaging.

PubMed

Boltres, Bettine; Tratzky, Stephan; Kass, Christof; Eichholz, Rainer; Naß, Peter

2016-01-01

For pharmaceutical parenteral packaging the glass compositions have always been either Type I borosilicate or Type III soda-lime glass. As both the compositions and certain chemical and physical properties are mandated by international standards, there has not been room for any changes. However, by applying only minor adjustments, a borosilicate glass was developed that showed improved chemical stability. The chemical composition is still in the range of currently used borosilicate glasses, which makes it a Type I glass according to all current pharmacopeia. A study was performed on glass vials comparing the new glass with the standard FIOLAX(®) and two other publicly available glasses. In an extraction study with water at 121 °C the new glass showed the highest chemical stability with the lowest amount of extractables. In an accelerated ageing study, which was done with water, phosphate, and carbonate buffer at 40 °C for 12 months, the new glass also proved to have the lowest amount of leachables. In this article the new glass and the results from the studies are presented, showing the reader how much of an effect can be attained with only minor adjustments if the scientific fundamentals are clear. The pharmaceutical market has been quite constant and risk-oriented due to the high impact on the safety of the patient. As any change necessitates a complicated change process, this has, in consequence, lead the industry to resist changing the parenteral primary packaging material for decades. The main glasses have either been Type I borosilicate or Type III soda-lime glass. On the other hand, a combination of improved inspection systems and the development of more sensitive biologically based drugs has elevated the standards for parental packaging materials. For example, the measurement of extractables and leachables from the packaging material steadily came into focus. In this article, a new glass is presented that still belongs to the group of Type I borosilicate glasses according to all pharmacopeia. However, with some minor adjustments in the chemical composition it was possible to increase the chemical stability measurably. To prove this several studies were performed, of which the extraction study with water at 121 °C and the accelerated ageing study with water, phosphate, and carbonate buffer at 40 °C for 12 months are presented here. © PDA, Inc. 2016.

X-ray absorption and Raman spectroscopy studies of molybdenum environments in borosilicate waste glasses

NASA Astrophysics Data System (ADS)

McKeown, David A.; Gan, Hao; Pegg, Ian L.

2017-05-01

Mo-containing high-level nuclear waste borosilicate glasses were investigated as part of an effort to improve Mo loading while avoiding yellow phase crystallization. Previous work showed that additions of vanadium decrease yellow phase formation and increases Mo solubility. X-ray absorption spectroscopy (XAS) and Raman spectroscopy were used to characterize Mo environments in HLW borosilicate glasses and to investigate possible structural relationships between Mo and V. Mo XAS spectra for the glasses indicate isolated tetrahedral Mo6+O4 with Mo-O distances near 1.75 Å. V XANES indicate tetrahedral V5+O4 as the dominant species. Raman spectra show composition dependent trends, where Mo-O symmetrical stretch mode frequencies (ν1) are sensitive to the mix of alkali and alkaline earth cations, decreasing by up to 10 cm-1 for glasses that change from Li+ to Na+ as the dominant network-modifying species. This indicates that MoO4 tetrahedra are isolated from the borosilicate network and are surrounded, at least partly, by Na+ and Li+. Secondary ν1 frequency effects, with changes up to 7 cm-1, were also observed with increasing V2O5 and MoO3 content. These secondary trends may indicate MoO4-MoO4 and MoO4-VO4 clustering, suggesting that V additions may stabilize Mo in the matrix with respect to yellow phase formation.

Evolution Analysis of the Aux/IAA Gene Family in Plants Shows Dual Origins and Variable Nuclear Localization Signals.

PubMed

Wu, Wentao; Liu, Yaxue; Wang, Yuqian; Li, Huimin; Liu, Jiaxi; Tan, Jiaxin; He, Jiadai; Bai, Jingwen; Ma, Haoli

2017-10-08

The plant hormone auxin plays pivotal roles in many aspects of plant growth and development. The auxin/indole-3-acetic acid (Aux/IAA) gene family encodes short-lived nuclear proteins acting on auxin perception and signaling, but the evolutionary history of this gene family remains to be elucidated. In this study, the Aux/IAA gene family in 17 plant species covering all major lineages of plants is identified and analyzed by using multiple bioinformatics methods. A total of 434 Aux/IAA genes was found among these plant species, and the gene copy number ranges from three ( Physcomitrella patens ) to 63 ( Glycine max ). The phylogenetic analysis shows that the canonical Aux/IAA proteins can be generally divided into five major clades, and the origin of Aux/IAA proteins could be traced back to the common ancestor of land plants and green algae. Many truncated Aux/IAA proteins were found, and some of these truncated Aux/IAA proteins may be generated from the C-terminal truncation of auxin response factor (ARF) proteins. Our results indicate that tandem and segmental duplications play dominant roles for the expansion of the Aux/IAA gene family mainly under purifying selection. The putative nuclear localization signals (NLSs) in Aux/IAA proteins are conservative, and two kinds of new primordial bipartite NLSs in P. patens and Selaginella moellendorffii were discovered. Our findings not only give insights into the origin and expansion of the Aux/IAA gene family, but also provide a basis for understanding their functions during the course of evolution.

Evolution Analysis of the Aux/IAA Gene Family in Plants Shows Dual Origins and Variable Nuclear Localization Signals

PubMed Central

Wu, Wentao; Liu, Yaxue; Wang, Yuqian; Li, Huimin; Liu, Jiaxi; Tan, Jiaxin; He, Jiadai; Bai, Jingwen

2017-01-01

The plant hormone auxin plays pivotal roles in many aspects of plant growth and development. The auxin/indole-3-acetic acid (Aux/IAA) gene family encodes short-lived nuclear proteins acting on auxin perception and signaling, but the evolutionary history of this gene family remains to be elucidated. In this study, the Aux/IAA gene family in 17 plant species covering all major lineages of plants is identified and analyzed by using multiple bioinformatics methods. A total of 434 Aux/IAA genes was found among these plant species, and the gene copy number ranges from three (Physcomitrella patens) to 63 (Glycine max). The phylogenetic analysis shows that the canonical Aux/IAA proteins can be generally divided into five major clades, and the origin of Aux/IAA proteins could be traced back to the common ancestor of land plants and green algae. Many truncated Aux/IAA proteins were found, and some of these truncated Aux/IAA proteins may be generated from the C-terminal truncation of auxin response factor (ARF) proteins. Our results indicate that tandem and segmental duplications play dominant roles for the expansion of the Aux/IAA gene family mainly under purifying selection. The putative nuclear localization signals (NLSs) in Aux/IAA proteins are conservative, and two kinds of new primordial bipartite NLSs in P. patens and Selaginella moellendorffii were discovered. Our findings not only give insights into the origin and expansion of the Aux/IAA gene family, but also provide a basis for understanding their functions during the course of evolution. PMID:28991190

Note: Production of stable colloidal probes for high-temperature atomic force microscopy applications

NASA Astrophysics Data System (ADS)

Ditscherlein, L.; Peuker, U. A.

2017-04-01

For the application of colloidal probe atomic force microscopy at high temperatures (>500 K), stable colloidal probe cantilevers are essential. In this study, two new methods for gluing alumina particles onto temperature stable cantilevers are presented and compared with an existing method for borosilicate particles at elevated temperatures as well as with cp-cantilevers prepared with epoxy resin at room temperature. The durability of the fixing of the particle is quantified with a test method applying high shear forces. The force is calculated with a mechanical model considering both the bending as well as the torsion on the colloidal probe.

Ultrapure glass optical waveguide development in microgravity by the sol-gel process

NASA Technical Reports Server (NTRS)

Mukherjee, S. P.

1980-01-01

The alkali-borosilicate system was selected as the glass system for the preparation of ultrapure low loss glasses suitable for optical communication. The effect of different oxide contents on the absorption loss was critically reviewed. One composition was chosen to develop the gel preparation procedure in the alkali-borosilicate system. In addition, several procedures for the preparation of gels based on two different approaches were developed. The influence of different preparation parameters were investigated qualitatively. Several conclusions are drawn from the results.

SEM and AFM Studies of Two-Phase Magnetic Alkali Borosilicate Glasses

PubMed Central

Tomkovich, M.; Nacke, B.; Filimonov, A.; Alekseeva, O.; Vanina, P.; Nizhankovskii, V.

2017-01-01

The morphology and composition of four types of two-phase alkali borosilicate glasses with magnetic atoms prepared by inductive melting have been studied. The results of scanning electron microscopy point to uniform distribution of Na, Si, and O atoms in these samples while magnetic iron atoms form ball-shaped agglomerates. The magnetic properties of these agglomerates have been confirmed by magnetic force microscopy. Atomic force microscopy had shown that in these samples two different morphological structures, drop-like and dendrite net, are formed. The formation of dendrite-like structure is a necessary condition for production of porous magnetic glasses. The obtained results allow us to optimize the melting and heat treatment processes leading to production of porous alkali borosilicate glasses with magnetic properties. The first results for nanocomposite materials on the basis of magnetic glasses containing the embedded ferroelectrics KH2PO4 demonstrate the effect of applied magnetic field on the ferroelectric phase transition. PMID:28428976

Identification and Analyses of AUX-IAA target genes controlling multiple pathways in developing fiber cells of Gossypium hirsutum L

PubMed Central

Nigam, Deepti; Sawant, Samir V

2013-01-01

Technological development led to an increased interest in systems biological approaches in plants to characterize developmental mechanism and candidate genes relevant to specific tissue or cell morphology. AUX-IAA proteins are important plant-specific putative transcription factors. There are several reports on physiological response of this family in Arabidopsis but in cotton fiber the transcriptional network through which AUX-IAA regulated its target genes is still unknown. in-silico modelling of cotton fiber development specific gene expression data (108 microarrays and 22,737 genes) using Algorithm for the Reconstruction of Accurate Cellular Networks (ARACNe) reveals 3690 putative AUX-IAA target genes of which 139 genes were known to be AUX-IAA co-regulated within Arabidopsis. Further AUX-IAA targeted gene regulatory network (GRN) had substantial impact on the transcriptional dynamics of cotton fiber, as showed by, altered TF networks, and Gene Ontology (GO) biological processes and metabolic pathway associated with its target genes. Analysis of the AUX-IAA-correlated gene network reveals multiple functions for AUX-IAA target genes such as unidimensional cell growth, cellular nitrogen compound metabolic process, nucleosome organization, DNA-protein complex and process related to cell wall. These candidate networks/pathways have a variety of profound impacts on such cellular functions as stress response, cell proliferation, and cell differentiation. While these functions are fairly broad, their underlying TF networks may provide a global view of AUX-IAA regulated gene expression and a GRN that guides future studies in understanding role of AUX-IAA box protein and its targets regulating fiber development. PMID:24497725

X-ray absorption and Raman spectroscopy studies of molybdenum environments in borosilicate waste glasses

DOE Office of Scientific and Technical Information (OSTI.GOV)

McKeown, David A.; Gan, Hao; Pegg, Ian L.

2017-05-01

Mo-containing high-level nuclear waste borosilicate glasses were investigated as part of an effort to improve Mo loading while avoiding yellow phase crystallization. Previous work showed that additions of vanadium decrease yellow phase formation and increases Mo solubility. X-ray absorption spectroscopy (XAS) and Raman spectroscopy were used to characterize Mo environments in HLW borosilicate glasses and to investigate possible structural relationships between Mo and V. Mo XAS spectra for the glasses indicate isolated tetrahedral Mo6+O4 with Mo-O distances near 1.75 Å. V XANES indicate tetrahedral V5+O4 as the dominant species. Raman spectra show composition dependent trends, where Mo-O symmetrical stretch modemore » frequencies (ν1) are sensitive to the mix of alkali and alkaline earth cations, decreasing by up to 10 cm-1 for glasses that change from Li+ to Na+ as the dominant network-modifying species. This indicates that MoO4 tetrahedra are isolated from the borosilicate network and are surrounded, at least partly, by Na+ and Li+. Secondary ν1 frequency effects, with changes up to 7 cm-1, were also observed with increasing V2O5 and MoO3 content. These secondary trends may indicate MoO4-MoO4 and MoO4-VO4 clustering, suggesting that V additions may stabilize Mo in the matrix with respect to yellow phase formation.« less

The magnetic properties of a magnetic detector using oxidized amorphous Co 95- xFe 5(BSi) x alloys

NASA Astrophysics Data System (ADS)

Ahn, S. J.; Kim, C. K.; Kim, S. J.; Choi, D. K.; O'Handley, R. C.

2000-07-01

A comparative oxidation study of several amorphous Co 75- xFe 5(BSi) 20+ x alloys was carried out. Reentrant magnetization behavior and field-induced anisotropy which are of a critical importance for a magnetic detector were obtained after oxidation of the amorphous Co-rich ribbons. During this oxidation, the ribbons develop surface oxides which are primarily nonmagnetic borosilicate or a combination of borosilicate and magnetic oxides such CoO or FeO. Beneath this lies a 100-1000 Å thick Co-rich magnetic alloy which may be either HCP or FCC in its crystal structure. The thickness of the Co-crystallized layer is determined by the type of the surface oxides. The oxidation products such as appear to affect the reentrant magnetization behavior of Co-rich amorphous alloys significantly. We have determined the amount of metalloids (a critical concentration of B and Si) which is necessary to form a continuous layer of the most thermodynamically stable oxide, in our case borosilicate, on the surface. We also observed that there is a good correlation between reentrant magnetization and the thickness of Co layer. The best reentrant M- H loop for the magnetic detector was obtained in ribbons with a surface borate-rich borosilicate since it ensures conditions such as (1) metalloid depletion in the substrate and (2) formation of oxygen impurity faults in Co grains that are required for strong reentrant magnetization behavior.

Molecular cloning and characterization of the genes encoding an auxin efflux carrier and the auxin influx carriers associated with the adventitious root formation in mango (Mangifera indica L.) cotyledon segments.

PubMed

Li, Yun-He; Zou, Ming-Hong; Feng, Bi-Hong; Huang, Xia; Zhang, Zhi; Sun, Guang-Ming

2012-06-01

Polar auxin transport (PAT) plays an important role in the adventitious root formation of mango cotyledon segments, but the molecular mechanism remains unclear. In this study, we cloned a gene encoding an auxin efflux carrier (designated as MiPIN1), and we cloned four genes encoding auxin influx carriers (designated as MiAUX1, MiAUX2, MiAUX3 and MiAUX4). The results of a phylogenetic tree analysis indicated that MiPIN1 and the MiAUXs belong to plant PIN and AUXs/LAXs groups. Quantitative real-time PCR indicated that the expression of MiPIN1 and the MiAUXs was lowest at 0 days but sharply increased on and after day 4. During the root formation in the mango cotyledon segments, the MiPIN1 expression in the distal cut surface (DCS) was always higher than the expression in the proximal cut surface (PCS) whereas the expression of the MiAUXs in the PCS was usually higher than in the DCS. This expression pattern might be result in the PAT from the DCS to the PCS, which is essential for the adventitious root formation in the PCS. Our previous study indicated that a pre-treatment of embryos with indole-3-butyric acid (IBA) significantly promoted adventitious rooting in PCS whereas a pre-treatment with 2,3,5-triiodobenzoic acid (TIBA) completely inhibited this rooting. In this study, however, IBA and TIBA pre-treatments slightly changed the expression of MiPIN1. In contrast, while the MiAUX3 and MiAUX4 expression levels were significantly up-regulated by the IBA pre-treatment, the expression levels were down-regulated by the TIBA pre-treatment. These findings imply that MiAUX3 and MiAUX4 are more sensitive to the IBA and TIBA treatments and that they might play important roles during adventitious root formation in mango cotyledon segments. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

The clathrin-binding motif and the J-domain of Drosophila Auxilin are essential for facilitating Notch ligand endocytosis

PubMed Central

Kandachar, Vasundhara; Bai, Ting; Chang, Henry C

2008-01-01

Background Ligand endocytosis plays a critical role in regulating the activity of the Notch pathway. The Drosophila homolog of auxilin (dAux), a J-domain-containing protein best known for its role in the disassembly of clathrin coats from clathrin-coated vesicles, has recently been implicated in Notch signaling, although its exact mechanism remains poorly understood. Results To understand the role of auxilin in Notch ligand endocytosis, we have analyzed several point mutations affecting specific domains of dAux. In agreement with previous work, analysis using these stronger dAux alleles shows that dAux is required for several Notch-dependent processes, and its function during Notch signaling is required in the signaling cells. In support of the genetic evidences, the level of Delta appears elevated in dAux deficient cells, suggesting that the endocytosis of Notch ligand is disrupted. Deletion analysis shows that the clathrin-binding motif and the J-domain, when over-expressed, are sufficient for rescuing dAux phenotypes, implying that the recruitment of Hsc70 to clathrin is a critical role for dAux. However, surface labeling experiment shows that, in dAux mutant cells, Delta accumulates at the cell surface. In dAux mutant cells, clathrin appears to form large aggregates, although Delta is not enriched in these aberrant clathrin-positive structures. Conclusion Our data suggest that dAux mutations inhibit Notch ligand internalization at an early step during clathrin-mediated endocytosis, before the disassembly of clathrin-coated vesicles. Further, the inhibition of ligand endocytosis in dAux mutant cells possibly occurs due to depletion of cytosolic pools of clathrin via the formation of clathrin aggregates. Together, our observations argue that ligand endocytosis is critical for Notch signaling and auxilin participates in Notch signaling by facilitating ligand internalization. PMID:18466624

An in vivo study of the biocompatibility of classic and novel device materials on the central nervous system

NASA Astrophysics Data System (ADS)

Jaboro, Claudine

2007-12-01

Investigation of novel biomaterials is an essential part of the development of electrical stimulation and chemical drug delivery for biomedical applications. In evaluating biocompatibility, the material's surface and the tissue should both be analyzed to determine their interaction during neural exposure. This includes a material investigation of bulk sapphire substrate, platinum (Pt) deposited on sapphire substrate using magnetron sputtering and aluminum nitride (AlN) which was deposited on sapphire substrate using plasma source molecular beam epitaxy (PSMBE). Zinc titania coverslip glass and borosilicate glass were used as control materials. The materials were implanted for periods of 10, 28 and 90 days on the cortical surface of the brain in a rat animal model. The chronic implants were analyzed both pre- and post- implantation for device structure/tissue interactions down to the atomic level. The characterization techniques used to explore structural and chemical changes on or within the material included optical microscopy, atomic force microscopy (AFM) and x-ray photoelectron spectroscopy (XPS). Magnetic Resonance Imaging (MRI) and histology were used to determine the effects of the implants in vivo. Biocompatibility is the ability of a material or device to be exposed to the dynamic environment of the body and elicit little or no adverse effects. The data suggests that the biocompatibility of a material may be directly associated with structure and topology. The sapphire, zinc titania coverslip glass and platinum all had signs of bio-incompatibility. The aluminum nitride and borosilicate glass materials were both biocompatible based on our studies. The borosilicate glass elicited no response from the tissue while the aluminum nitride had a positive affect on the tissue encouraging the attachment of proteins and tissue without glial scars instigation. The material characterization, MR imaging and histological data show that surface features such as roughness in addition to chemical stability may have a direct effect on the neurocompatibility of the chronic implants.

Characterization of Fast-Scan Cyclic Voltammetric Electrodes Using Paraffin as an Effective Sealant with In Vitro and In Vivo Applications.

PubMed

Ramsson, Eric S; Cholger, Daniel; Dionise, Albert; Poirier, Nicholas; Andrus, Avery; Curtiss, Randi

2015-01-01

Fast-scan cyclic voltammetry (FSCV) is a powerful technique for measuring sub-second changes in neurotransmitter levels. A great time-limiting factor in the use of FSCV is the production of high-quality recording electrodes; common recording electrodes consist of cylindrical carbon fiber encased in borosilicate glass. When the borosilicate is heated and pulled, the molten glass ideally forms a tight seal around the carbon fiber cylinder. It is often difficult, however, to guarantee a perfect seal between the glass and carbon. Indeed, much of the time spent creating electrodes is in an effort to find a good seal. Even though epoxy resins can be useful in this regard, they are irreversible (seals are permanent), wasteful (epoxy cannot be reused once hardener is added), hazardous (hardeners are often caustic), and require curing. Herein we characterize paraffin as an electrode sealant for FSCV microelectrodes. Paraffin boasts the advantages of near-immediate curing times, simplicity in use, long shelf-life and stable waterproof seals capable of withstanding extended cycling. Borosilicate electrode tips were left intact or broken and dipped in paraffin embedding wax. Excess wax was removed from the carbon surface with xyelenes or by repeated cycling at an extended waveform (-0.4 to 1.4V, 400 V/s, 60 Hz). Then, the waveform was switched to a standard waveform (-0.4 to 1.3V, 400 V/s, 10 Hz) and cycled until stable. Wax-sealing does not inhibit electrode sensitivity, as electrodes detected linear changes in dopamine before and after wax (then xylenes) exposure. Paraffin seals are intact after 11 days of implantation in the mouse, and still capable of measuring transient changes in in vivo dopamine. From this it is clear that paraffin wax is an effective sealant for FSCV electrodes that provides a convenient substitute to epoxy sealants.

Characterization of Fast-Scan Cyclic Voltammetric Electrodes Using Paraffin as an Effective Sealant with In Vitro and In Vivo Applications

PubMed Central

Ramsson, Eric S.; Cholger, Daniel; Dionise, Albert; Poirier, Nicholas; Andrus, Avery; Curtiss, Randi

2015-01-01

Fast-scan cyclic voltammetry (FSCV) is a powerful technique for measuring sub-second changes in neurotransmitter levels. A great time-limiting factor in the use of FSCV is the production of high-quality recording electrodes; common recording electrodes consist of cylindrical carbon fiber encased in borosilicate glass. When the borosilicate is heated and pulled, the molten glass ideally forms a tight seal around the carbon fiber cylinder. It is often difficult, however, to guarantee a perfect seal between the glass and carbon. Indeed, much of the time spent creating electrodes is in an effort to find a good seal. Even though epoxy resins can be useful in this regard, they are irreversible (seals are permanent), wasteful (epoxy cannot be reused once hardener is added), hazardous (hardeners are often caustic), and require curing. Herein we characterize paraffin as an electrode sealant for FSCV microelectrodes. Paraffin boasts the advantages of near-immediate curing times, simplicity in use, long shelf-life and stable waterproof seals capable of withstanding extended cycling. Borosilicate electrode tips were left intact or broken and dipped in paraffin embedding wax. Excess wax was removed from the carbon surface with xyelenes or by repeated cycling at an extended waveform (-0.4 to 1.4V, 400 V/s, 60 Hz). Then, the waveform was switched to a standard waveform (-0.4 to 1.3V, 400 V/s, 10 Hz) and cycled until stable. Wax-sealing does not inhibit electrode sensitivity, as electrodes detected linear changes in dopamine before and after wax (then xylenes) exposure. Paraffin seals are intact after 11 days of implantation in the mouse, and still capable of measuring transient changes in in vivo dopamine. From this it is clear that paraffin wax is an effective sealant for FSCV electrodes that provides a convenient substitute to epoxy sealants. PMID:26505195

Effect of X-ray irradiation on the optical absorption of СdSe1-xTex nanocrystals embedded in borosilicate glass

NASA Astrophysics Data System (ADS)

Prymak, M. V.; Azhniuk, Yu. M.; Solomon, A. M.; Krasilinets, V. M.; Lopushansky, V. V.; Bodnar, I. V.; Gomonnai, A. V.; Zahn, D. R. T.

2012-07-01

The effect of X-ray irradiation on the optical absorption spectra of CdSe1-xTex nanocrystals embedded in a borosilicate matrix is studied. The observed blue shift of the absorption edge and bleaching of the confinement-related features in the spectra are related to X-ray induced negative ionization of the nanocrystals with charge transfer across the nanocrystal/matrix interface. The radiation-induced changes are observed to recover after longer post-irradiation storage at room temperature.

Study of the Accelerating Channel Wall Property Influence on the Hall Thruster Discharge Characteristics

DTIC Science & Technology

2004-11-01

Hall thruster characteristics there was prepared Hall thruster model of the SPT-100 type for these experiments and there were manufactured the required discharge chamber parts (rings) made of the Russian BN-SiO2 (borosil) ceramics and of the Russian AIN-BN (ABN) and Western ABN ceramics having secondary electron emission yield (SEEY) different from that one for borosil. These parts were replaceable during experiments. Thruster model was equipped by set of the near wall probes mounted at external discharge chamber wall. There was made characterization

High-level waste borosilicate glass: A compendium of corrosion characteristics. Volume 3

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cunnane, J.C.; Bates, J.K.; Bradley, C.R.

1994-03-01

The objective of this document is to summarize scientific information pertinent to evaluating the extent to which high-level waste borosilicate glass corrosion and the associated radionuclide release processes are understood for the range of environmental conditions to which waste glass may be exposed in service. Alteration processes occurring within the bulk of the glass (e.g., devitrification and radiation-induced changes) are discussed insofar as they affect glass corrosion. Volume III contains a bibliography of glass corrosion studies, including studies that are not cited in Volumes I and II.

Low Velocity Sphere Impact of a Borosilicate Glass

DOE Office of Scientific and Technical Information (OSTI.GOV)

Morrissey, Timothy G; Ferber, Mattison K; Wereszczak, Andrew A

2012-05-01

This report summarizes US Army TARDEC sponsored work at Oak Ridge National Laboratory (ORNL) involving low velocity (< 30 m/s or < 65 mph) ball impact testing of Borofloat borosilicate glass, and is a follow-up to a similar study completed by the authors on Starphire soda-lime silicate glass last year. The response of the borosilicate glass to impact testing at different angles was also studied. The Borofloat glass was supplied by the US Army Research Laboratory and its tin-side was impacted or indented. The intent was to better understand low velocity impact response in the Borofloat. Seven sphere materials weremore » used whose densities bracket that of rock: borosilicate glass, soda-lime silicate glass, silicon nitride, aluminum oxide, zirconium oxide, carbon steel, and a chrome steel. A gas gun or a ball-drop test setup was used to produce controlled velocity delivery of the spheres against the glass tile targets. Minimum impact velocities to initiate fracture in the Borofloat were measured and interpreted in context to the kinetic energy of impact and the elastic property mismatch between the seven sphere-Borofloat-target combinations. The primary observations from this low velocity (< 30 m/s or < 65 mph) testing were: (1) BS glass responded similarly to soda-lime silicate glass when spherically indented but quite differently under sphere impact conditions; (2) Frictional effects contributed to fracture initiation in BS glass when it spherically indented. This effect was also observed with soda-lime silicate glass; (3) The force necessary to initiate fracture in BS glass under spherical impact decreases with increasing elastic modulus of the sphere material. This trend is opposite to what was observed with soda-lime silicate glass. Friction cannot explain this trend and the authors do not have a legitimate explanation for it yet; (4) The force necessary to initiate contact-induced fracture is higher under dynamic conditions than under quasi-static conditions. That difference decreases with increasing elastic modulus mismatch between the sphere material and borosilicate This trend was opposite in soda-lime silicate glass; (5) Fracture in borosilicate glass occurs at lower velocities (i.e., easier) at 24{sup o} than at 0{sup o} (orthogonal) and 46{sup o} of impact for the same probability of failure. Though not analyzed yet, this suggests that a convolution of kinetic energy and friction is contributing to that trend; (6) There is a subtle indication there was intra-tile differences in spherical indentation RCIF. This likely is not a material property nor exclusive to borosilicate glass, rather, it is a statistical response of a combination of local, surface-located flaw and imposed tensile stress. Understanding of the surface flaw population and flaw positioning can likely enable prediction of spherical indentation RCIF; and (7) Contact-induced fracture did not initiate in the Borofloat BS for impact kinetic energies up to {approx} 20 mJ. For kinetic energies between {approx} 20-150 mJ, fracture sometimes initiated. Contact-induced fracture would always occur for impact energies > 150 mJ. The energy values, and their boundaries, were much lower for BS glass than they were for soda-lime silicate glass.« less

Arabidopsis SHR and SCR transcription factors and AUX1 auxin influx carrier control the switch between adventitious rooting and xylogenesis in planta and in in vitro cultured thin cell layers.

PubMed

Della Rovere, F; Fattorini, L; D'Angeli, S; Veloccia, A; Del Duca, S; Cai, G; Falasca, G; Altamura, M M

2015-03-01

Adventitious roots (ARs) are essential for vegetative propagation. The Arabidopsis thaliana transcription factors SHORT ROOT (SHR) and SCARECROW (SCR) affect primary/lateral root development, but their involvement in AR formation is uncertain. LAX3 and AUX1 auxin influx carriers contribute to primary/lateral root development. LAX3 expression is regulated by SHR, and LAX3 contributes to AR tip auxin maximum. In contrast, AUX1 involvement in AR development is unknown. Xylogenesis is induced by auxin plus cytokinin as is AR formation, but the genes involved are largely unknown. Stem thin cell layers (TCLs) form ARs and undergo xylogenesis under the same auxin plus cytokinin input. The aim of this research was to investigate SHR, SCR, AUX1 and LAX3 involvement in AR formation and xylogenesis in intact hypocotyls and stem TCLs in arabidopsis. Hypocotyls of scr-1, shr-1, lax3, aux1-21 and lax3/aux1-21 Arabidopsis thaliana null mutant seedlings grown with or without auxin plus cytokinin were examined histologically, as were stem TCLs cultured with auxin plus cytokinin. SCR and AUX1 expression was monitored using pSCR::GFP and AUX1::GUS lines, and LAX3 expression and auxin localization during xylogenesis were monitored by using LAX3::GUS and DR5::GUS lines. AR formation was inhibited in all mutants, except lax3. SCR was expressed in pericycle anticlinally derived AR-forming cells of intact hypocotyls, and in cell clumps forming AR meristemoids of TCLs. The apex was anomalous in shr and scr ARs. In all mutant hypocotyls, the pericycle divided periclinally to produce xylogenesis. Xylary element maturation was favoured by auxin plus cytokinin in shr and aux1-21. Xylogenesis was enhanced in TCLs, and in aux1-21 and shr in particular. AUX1 was expressed before LAX3, i.e. in the early derivatives leading to either ARs or xylogenesis. AR formation and xylogenesis are developmental programmes that are inversely related, but they involve fine-tuning by the same proteins, namely SHR, SCR and AUX1. Pericycle activity is central for the equilibrium between xylary development and AR formation in the hypocotyl, with a role for AUX1 in switching between, and balancing of, the two developmental programmes. © The Author 2015. Published by Oxford University Press on behalf of the Annals of Botany Company.

Pilot production and advanced development of large-area picosecond photodetectors

NASA Astrophysics Data System (ADS)

Minot, Michael J.; Adams, Bernhard W.; Aviles, Melvin; Bond, Justin L.; Craven, Christopher A.; Cremer, Till; Foley, Michael R.; Lyashenko, Alexey; Popecki, Mark A.; Stochaj, Michael E.; Worstell, William A.; Mane, Anil U.; Elam, Jeffrey W.; Siegmund, Oswald H. W.; Ertley, Camden; Frisch, Henry; Elagin, Andrey

2016-09-01

We report pilot production and advanced development performance results achieved for Large Area Picosecond Photodetectors (LAPPD). The LAPPD is a microchannel plate (MCP) based photodetector, capable of imaging with single-photon sensitivity at high spatial and temporal resolutions in a hermetic package with an active area of 400 square centimeters. In December 2015, Incom Inc. completed installation of equipment and facilities for demonstration of early stage pilot production of LAPPD. Initial fabrication trials commenced in January 2016. The "baseline" LAPPD employs an all-glass hermetic package with top and bottom plates and sidewalls made of borosilicate float glass. Signals are generated by a bi-alkali Na2KSb photocathode and amplified with a stacked chevron pair of "next generation" MCPs produced by applying resistive and emissive atomic layer deposition coatings to borosilicate glass capillary array (GCA) substrates. Signals are collected on RF strip-line anodes applied to the bottom plates which exit the detector via pinfree hermetic seals under the side walls. Prior tests show that LAPPDs have electron gains greater than 107, submillimeter space resolution for large pulses and several mm for single photons, time resolutions of 50 picoseconds for single photons, predicted resolution of less than 5 picoseconds for large pulses, high stability versus charge extraction, and good uniformity. LAPPD performance results for product produced during the first half of 2016 will be reviewed. Recent advances in the development of LAPPD will also be reviewed, as the baseline design is adapted to meet the requirements for a wide range of emerging application. These include a novel ceramic package design, ALD coated MCPs optimized to have a low temperature coefficient of resistance (TCR) and further advances to adapt the LAPPD for cryogenic applications using Liquid Argon (LAr). These developments will meet the needs for DOE-supported RD for the Deep Underground Neutrino Experiment (DUNE), nuclear physics applications such as EIC, medical, homeland security and astronomical applications for direct and indirect photon detection.

The Bacillus subtilis Conjugative Plasmid pLS20 Encodes Two Ribbon-Helix-Helix Type Auxiliary Relaxosome Proteins That Are Essential for Conjugation.

PubMed

Miguel-Arribas, Andrés; Hao, Jian-An; Luque-Ortega, Juan R; Ramachandran, Gayetri; Val-Calvo, Jorge; Gago-Córdoba, César; González-Álvarez, Daniel; Abia, David; Alfonso, Carlos; Wu, Ling J; Meijer, Wilfried J J

2017-01-01

Bacterial conjugation is the process by which a conjugative element (CE) is transferred horizontally from a donor to a recipient cell via a connecting pore. One of the first steps in the conjugation process is the formation of a nucleoprotein complex at the origin of transfer ( oriT ), where one of the components of the nucleoprotein complex, the relaxase, introduces a site- and strand specific nick to initiate the transfer of a single DNA strand into the recipient cell. In most cases, the nucleoprotein complex involves, besides the relaxase, one or more additional proteins, named auxiliary proteins, which are encoded by the CE and/or the host. The conjugative plasmid pLS20 replicates in the Gram-positive Firmicute bacterium Bacillus subtilis . We have recently identified the relaxase gene and the oriT of pLS20, which are separated by a region of almost 1 kb. Here we show that this region contains two auxiliary genes that we name aux1 LS20 and aux2 LS20 , and which we show are essential for conjugation. Both Aux1 LS20 and Aux2 LS20 are predicted to contain a Ribbon-Helix-Helix DNA binding motif near their N-terminus. Analyses of the purified proteins show that Aux1 LS20 and Aux2 LS20 form tetramers and hexamers in solution, respectively, and that they both bind preferentially to oriT LS20 , although with different characteristics and specificities. In silico analyses revealed that genes encoding homologs of Aux1 LS20 and/or Aux2 LS20 are located upstream of almost 400 relaxase genes of the Rel LS20 family (MOB L ) of relaxases. Thus, Aux1 LS20 and Aux2 LS20 of pLS20 constitute the founding member of the first two families of auxiliary proteins described for CEs of Gram-positive origin.

U. S. Atlantic Fleet, Eighth Amphibious Force. Operation Plan Number 2-44

DTIC Science & Technology

1944-01-01

distributed with this Operation Order. (c) Panoramic Bench Sketches No. P-l for Boach 259 and No. P~3 for Loach 26l (South) givo viator level...To indicate tank or ID targets. (g) Green Cluster, White Cluster - Lift Artillery fire. Page 32 of 33. ANNEX KENS . GTMFIRS SUPPORT PLAN. TABLE VI...AURORA . SFCP 5 AUX GROUND SPOT - LIVERMORS SFCP 6 AUX GROUND SPOT - LA GLOIRE SFCP 7 AUX GROUND -SPOT ~ TERM- ERIC SFCP 8 AUX GROUND SPOT - ORION-KEAR

Morphology and Magnetic Properties of Ferriferous Two-Phase Sodium Borosilicate Glasses

PubMed Central

Naberezhnov, Alexander; Porechnaya, Nadezda; Nizhankovskii, Viktor; Filimonov, Alexey; Nacke, Bernard

2014-01-01

This contribution is devoted to the study of morphology and magnetic properties of sodium borosilicate glasses with different concentrations (15, 20, and 25 wt.%) of α-Fe2O3 in an initial furnace charge. These glasses were prepared by a melt-quenching method. For all glasses a coexistence of drop-like and two-phase interpenetrative structures is observed. The most part of a drop structure is formed by self-assembling iron oxides particles. All types of glasses demonstrate the magnetic properties and can be used for preparation of porous magnetic matrices with nanometer through dendrite channel structure. PMID:25162045

The Capability of Virtual Reality to Meet Military Requirements (la Capacite de la rea1ite virtuelle a repondre aux besoins militaires)

DTIC Science & Technology

2000-11-01

importance of the sensation of presence, and cybersickness . The third day reviewed assessment methods and applications research. Speakers reviewed...of the sensation of presence, and cybersickness . The third day reviewed assessment methods and applications research. Speakers reviewed existing or...Reality technology. Presentations discussed sensory interfaces, measures of effectiveness, importance of the sensation of presence, and cybersickness

The Maize (Zea mays L.) AUXIN/INDOLE-3-ACETIC ACID Gene Family: Phylogeny, Synteny, and Unique Root-Type and Tissue-Specific Expression Patterns during Development

PubMed Central

Ludwig, Yvonne; Zhang, Yanxiang; Hochholdinger, Frank

2013-01-01

The plant hormone auxin plays a key role in the coordination of many aspects of growth and development. AUXIN/INDOLE-3-ACETIC ACID (Aux/IAA) genes encode instable primary auxin responsive regulators of plant development that display a protein structure with four characteristic domains. In the present study, a comprehensive analysis of the 34 members of the maize Aux/IAA gene family was performed. Phylogenetic reconstructions revealed two classes of Aux/IAA proteins that can be distinguished by alterations in their domain III. Seven pairs of paralogous maize Aux/IAA proteins were discovered. Comprehensive root-type and tissue-specific expression profiling revealed unique expression patterns of the diverse members of the gene family. Remarkably, five of seven pairs of paralogous genes displayed highly correlated expression patterns in roots. All but one (ZmIAA23) tested maize Aux/IAA genes were auxin inducible, displaying two types of auxin induction within three hours of treatment. Moreover, 51 of 55 (93%) differential Aux/IAA expression patterns between different root-types followed the expression tendency: crown roots > seminal roots > primary roots > lateral roots. This pattern might imply root-type-specific regulation of Aux/IAA transcript abundance. In summary, the detailed analysis of the maize Aux/IAA gene family provides novel insights in the evolution and developmental regulation and thus the function of these genes in different root-types and tissues. PMID:24223858

OsAUX1 controls lateral root initiation in rice (Oryza sativa L.).

PubMed

Zhao, Heming; Ma, Tengfei; Wang, Xin; Deng, Yingtian; Ma, Haoli; Zhang, Rongsheng; Zhao, Jie

2015-11-01

Polar auxin transport, mediated by influx and efflux transporters, controls many aspects of plant growth and development. The auxin influx carriers in Arabidopsis have been shown to control lateral root development and gravitropism, but little is known about these proteins in rice. This paper reports on the functional characterization of OsAUX1. Three OsAUX1 T-DNA insertion mutants and RNAi knockdown transgenic plants reduced lateral root initiation compared with wild-type (WT) plants. OsAUX1 overexpression plants exhibited increased lateral root initiation and OsAUX1 was highly expressed in lateral roots and lateral root primordia. Similarly, the auxin reporter, DR5-GUS, was expressed at lower levels in osaux1 than in the WT plants, which indicated that the auxin levels in the mutant roots had decreased. Exogenous 1-naphthylacetic acid (NAA) treatment rescued the defective phenotype in osaux1-1 plants, whereas indole-3-acetic acid (IAA) and 2,4-D could not, which suggested that OsAUX1 was a putative auxin influx carrier. The transcript levels of several auxin signalling genes and cell cycle genes significantly declined in osaux1, hinting that the regulatory role of OsAUX1 may be mediated by auxin signalling and cell cycle genes. Overall, our results indicated that OsAUX1 was involved in polar auxin transport and functioned to control auxin-mediated lateral root initiation in rice. © 2014 John Wiley & Sons Ltd.

The maize (Zea mays L.) AUXIN/INDOLE-3-ACETIC ACID gene family: phylogeny, synteny, and unique root-type and tissue-specific expression patterns during development.

PubMed

Ludwig, Yvonne; Zhang, Yanxiang; Hochholdinger, Frank

2013-01-01

The plant hormone auxin plays a key role in the coordination of many aspects of growth and development. AUXIN/INDOLE-3-ACETIC ACID (Aux/IAA) genes encode instable primary auxin responsive regulators of plant development that display a protein structure with four characteristic domains. In the present study, a comprehensive analysis of the 34 members of the maize Aux/IAA gene family was performed. Phylogenetic reconstructions revealed two classes of Aux/IAA proteins that can be distinguished by alterations in their domain III. Seven pairs of paralogous maize Aux/IAA proteins were discovered. Comprehensive root-type and tissue-specific expression profiling revealed unique expression patterns of the diverse members of the gene family. Remarkably, five of seven pairs of paralogous genes displayed highly correlated expression patterns in roots. All but one (ZmIAA23) tested maize Aux/IAA genes were auxin inducible, displaying two types of auxin induction within three hours of treatment. Moreover, 51 of 55 (93%) differential Aux/IAA expression patterns between different root-types followed the expression tendency: crown roots > seminal roots > primary roots > lateral roots. This pattern might imply root-type-specific regulation of Aux/IAA transcript abundance. In summary, the detailed analysis of the maize Aux/IAA gene family provides novel insights in the evolution and developmental regulation and thus the function of these genes in different root-types and tissues.

Application of Mathematical Signal Processing Techniques to Mission Systems. (l’Application des techniques mathematiques du traitement du signal aux systemes de conduite des missions)

DTIC Science & Technology

1999-11-01

represents the linear time invariant (LTI) response of the combined analysis /synthesis system while the second repre- sents the aliasing introduced into...effectively to implement voice scrambling systems based on time - frequency permutation . The most general form of such a system is shown in Fig. 22 where...92201 NEUILLY-SUR-SEINE CEDEX, FRANCE RTO LECTURE SERIES 216 Application of Mathematical Signal Processing Techniques to Mission Systems (1

CFD Techniques for Propulsion Applications Panel Symposium (77th), Held in San Antonio, Texas on 27-31 May 1991 (Les Techniques de l’Aerodynamique Numerique pour les Applications aux Propulseurs)

DTIC Science & Technology

1992-02-01

CONCLUDING REMARKS secondary flow pattern. Probably both factors are influential. Unfortunately The present study has examined the the secondary...Panels which are compesed of experts appointed - by the National Delegates, the Consultant and Exchange Programme and the Aerospace Applications Studies ...CP 352. September 1983 /Combustion Problems in Turbine Engines AGARD CP 353, January 1984 (,rHazard Studies for Solid Propellant Rocket Motors AGARD CP

Emission analysis of Tb3+ -and Sm3+ -ion-doped (Li2 O/Na2 O/K2 O) and (Li2 O + Na2 O/Li2 O + K2 O/K2 O + Na2 O)-modified borosilicate glasses.

PubMed

Naveen Kumar Reddy, B; Sailaja, S; Thyagarajan, K; Jho, Young Dahl; Sudhakar Reddy, B

2018-05-01

Four series of borosilicate glasses modified by alkali oxides and doped with Tb 3+ and Sm 3+ ions were prepared using the conventional melt quenching technique, with the chemical composition 74.5B 2 O 3 + 10SiO 2 + 5MgO + R + 0.5(Tb 2 O 3 /Sm 2 O 3 ) [where R = 10(Li 2 O /Na 2 O/K 2 O) for series A and C, and R = 5(Li 2 O + Na 2 O/Li 2 O + K 2 O/K 2 O + Na 2 O) for series B and D]. The X-ray diffraction (XRD) patterns of all the prepared glasses indicate their amorphous nature. The spectroscopic properties of the prepared glasses were studied by optical absorption analysis, photoluminescence excitation (PLE) and photoluminescence (PL) analysis. A green emission corresponding to the 5 D 4 → 7 F 5 (543 nm) transition of the Tb 3+ ions was registered under excitation at 379 nm for series A and B glasses. The emission spectra of the Sm 3+ ions with the series C and D glasses showed strong reddish-orange emission at 600 nm ( 4 G 5/2 → 6 H 7/2 ) with an excitation wavelength λ exci = 404 nm ( 6 H 5/2 → 4 F 7/2 ). Furthermore, the change in the luminescence intensity with the addition of an alkali oxide and combinations of these alkali oxides to borosilicate glasses doped with Tb 3+ and Sm 3+ ions was studied to optimize the potential alkali-oxide-modified borosilicate glass. Copyright © 2017 John Wiley & Sons, Ltd.

A space imaging concept based on a 4m structured spun-cast borosilicate monolithic primary mirror

NASA Astrophysics Data System (ADS)

West, S. C.; Bailey, S. H.; Bauman, S.; Cuerden, B.; Granger, Z.; Olbert, B. H.

2010-07-01

Lockheed Martin Corporation (LMC) tasked The University of Arizona Steward Observatory (UASO) to conduct an engineering study to examine the feasibility of creating a 4m space telescope based on mature borosilicate technology developed at the UASO for ground-based telescopes. UASO has completed this study and concluded that existing launch vehicles can deliver a 4m monolithic telescope system to a 500 km circular orbit and provide reliable imagery at NIIRS 7-8. An analysis of such an imager based on a lightweight, high-performance, structured 4m primary mirror cast from borosilicate glass is described. The relatively high CTE of this glass is used to advantage by maintaining mirror shape quality with a thermal figuring method. Placed in a 290 K thermal shroud (similar to the Hubble Space Telescope), the orbit averaged figure surface error is 6nm rms when earth-looking. Space-looking optical performance shows that a similar thermal conditioning scheme combined with a 270 K shroud achieves primary mirror distortion of 10 nm rms surface. Analysis shows that a 3-point bipod mount will provide launch survivability with ample margin. The primary mirror naturally maintains its shape at 1g allowing excellent end-to-end pre-launch testing with e.g. the LOTIS 6.5m Collimator. The telescope includes simple systems to measure and correct mirror shape and alignment errors incorporating technologies already proven on the LOTIS Collimator. We have sketched a notional earth-looking 4m telescope concept combined with a wide field TMA concept into a DELTA IV or ATLAS 552 EELV fairing. We have combined an initial analysis of launch and space performance of a special light-weighted honeycomb borosilicate mirror (areal density 95 kg/m2) with public domain information on the existing launch vehicles.

Kinetics and mechanisms of the conversion of silicate (45S5), borate, and borosilicate glasses to hydroxyapatite in dilute phosphate solutions.

PubMed

Huang, Wenhai; Day, Delbert E; Kittiratanapiboon, Kanisa; Rahaman, Mohamed N

2006-07-01

Bioactive glasses with controllable conversion rates to hydroxyapatite (HA) may provide a novel class of scaffold materials for bone tissue engineering. The objective of the present work was to comprehensively characterize the conversion of a silicate bioactive glass (45S5), a borate glass, and two intermediate borosilicate glass compositions to HA in a dilute phosphate solution at 37 degrees Celsius. The borate glass and the borosilicate glasses were derived from the 45S5 glass by fully or partially replacing the SiO(2) with B(2)O(3). Higher B(2)O(3) content produced a more rapid conversion of the glass to HA and a lower pH value of the phosphate solution. Whereas the borate glass was fully converted to HA in less than 4 days, the silicate (45S5) and borosilicate compositions were only partially converted even after 70 days, and contained residual SiO(2) in a Na-depleted core. The concentration of Na(+) in the phosphate solution increased with reaction time whereas the PO(4) (3-) concentration decreased, both reaching final limiting values at a rate that increased with the B(2)O(3) content of the glass. However, the Ca(2+) concentration in the solution remained low, below the detection limit of atomic absorption, throughout the reaction. Immersion of the glasses in a mixed solution of K(2)HPO(4) and K(2)CO(3) produced a carbonate-substituted HA but the presence of the K(2)CO(3) had little effect on the kinetics of conversion to HA. The kinetics and mechanisms of the conversion process of the four glasses to HA are compared and used to develop a model for the process.

Large Area Flat Panel Imaging Detectors for Astronomy and Night Time Sensing

NASA Astrophysics Data System (ADS)

Siegmund, O.; McPhate, J.; Frisch, H.; Elam, J.; Mane, A.; Wagner, R.; Varner, G.

2013-09-01

Sealed tube photo-sensing detectors for optical/IR detection have applications in astronomy, nighttime remote reconnaissance, and airborne/space situational awareness. The potential development of large area photon counting, imaging, timing detectors has significance for these applications and a number of other areas (High energy particle detection (RICH), biological single-molecule fluorescence lifetime imaging microscopy, neutron imaging, time of flight mass spectroscopy, diffraction imaging). We will present details of progress towards the development of a 20 cm sealed tube optical detector with nanoengineered microchannel plates for photon counting, imaging and sub-ns event time stamping. In the operational scheme of the photodetector incoming light passes through an entrance window and interacts with a semitransparent photocathode on the inside of the window. The photoelectrons emitted are accelerated across a proximity gap and are detected by an MCP pair. The pair of novel borosilicate substrate MCPs are functionalized by atomic layer deposition (ALD), and amplify the signal and the resulting electron cloud is detected by a conductive strip line anode for determination of the event positions and the time of arrival. The physical package is ~ 25 x 25 cm but only 1.5 cm thick. Development of such a device in a square 20 cm format presents challenges: hermetic sealing to a large entrance window, a 20 cm semitransparent photocathode with good efficiency and uniformity, 20 cm MCPs with reasonable cost and performance, robust construction to preserve high vacuum and withstand an atmosphere pressure differential. We will discuss the schemes developed to address these issues and present the results for the first test devices. The novel microchannel plates employing borosilicate micro-capillary arrays provide many performance characteristics typical of conventional MCPs, but have been made in sizes up to 20 cm, have low intrinsic background (0.08 events cm2 s-1) and have very stable gain behavior over > 7 C cm2 of charge extracted. They are high temperature compatible and have minimal outgassing, which shortens and simplifies the sealed tube production process and should improve overall lifetimes. Bialkali (NaKSb) semitransparent photocathodes with > 20% quantum efficiency have also been made on 20 cm borosilicate windows compatible with the window seals for the large sealed tube device. The photocathodes have good response uniformity and have been stable for > 5 months in testing. Tests with a 20 cm detector with a cross delay line readout have achieved ~50µm FWHM imaging with single photon sub-ns timing and MHz event rates, and tests with a 10 x 10cm detector with cross strip readout has achieved ~20µm FWHM imaging with >4 MHz event rates with ~10% deadtime. We will discuss the details and implications of these novel detector implementations and their potential applications.

Molecular adsorption properties of CO and H2O on Au-, Cu-, and AuxCuy-doped MoS2 monolayer

NASA Astrophysics Data System (ADS)

Kadioglu, Yelda; Gökoğlu, Gökhan; Üzengi Aktürk, Olcay

2017-12-01

In this study, we investigate the adsorption properties of Au, Cu, and AuxCuy nanoclusters on MoS2 sheet and the interactions of the adsorbed systems with CO and H2O molecules by using first principles calculations. Results indicate that Au, Cu, or AuxCuy strongly binds to MoS2 monolayer resulting in enhanced chemical activity and sensitivity toward CO and H2O molecules compared to bare MoS2 monolayer. Although both CO and H2O molecules bind weakly to pristine MoS2 monolayer, CO strongly binds to MoS2 sheet in the presence of Au, Cu atoms or AuxCuy clusters. Semiconductor MoS2 monolayer turns into metal upon Au or Cu adsorption. AuxCuy nanocluster adsorption decreases the band gap of MoS2 monolayer acting as a n-type dopant. AuxCuy-doped MoS2 systems have improved adsorption properties for CO and H2O molecules, so the conclusions provided in this study can be useful as a guide for next generation device modeling.

AUX1 regulates root gravitropism in Arabidopsis by facilitating auxin uptake within root apical tissues.

PubMed Central

Marchant, A; Kargul, J; May, S T; Muller, P; Delbarre, A; Perrot-Rechenmann, C; Bennett, M J

1999-01-01

Plants employ a specialized transport system composed of separate influx and efflux carriers to mobilize the plant hormone auxin between its site(s) of synthesis and action. Mutations within the permease-like AUX1 protein significantly reduce the rate of carrier-mediated auxin uptake within Arabidopsis roots, conferring an agravitropic phenotype. We are able to bypass the defect within auxin uptake and restore the gravitropic root phenotype of aux1 by growing mutant seedlings in the presence of the membrane-permeable synthetic auxin, 1-naphthaleneacetic acid. We illustrate that AUX1 expression overlaps that previously described for the auxin efflux carrier, AtPIN2, using transgenic lines expressing an AUX1 promoter::uidA (GUS) gene. Finally, we demonstrate that AUX1 regulates gravitropic curvature by acting in unison with the auxin efflux carrier to co-ordinate the localized redistribution of auxin within the Arabidopsis root apex. Our results provide the first example of a developmental role for the auxin influx carrier within higher plants and supply new insight into the molecular basis of gravitropic signalling. PMID:10205161

Structural investigations of bismuth lead borosilicate glasses under the influence of gamma irradiation through ultrasonic studies

NASA Astrophysics Data System (ADS)

Bootjomchai, Cherdsak; Laopaiboon, Jintana; Laopaiboon, Raewat

2012-04-01

The ultrasonic velocity measurements for different compositions of irradiated bismuth lead borosilicate glasses xBi2O3-(50-x)PbO-20B2O3-30SiO2 (x=2, 4, 6, 8, and 10 mol.%) were performed at room temperature using pulse-echo technique. Densities of glass samples were measured by Archimedes' principle using n-hexane as the immersion liquid. The results from the studies show that ultrasonic velocity, elastic moduli, Poisson's ratio, microhardness, and the Debye temperature increase with increasing bismuth oxide content and increasing gamma-radiation dose (3-12 Gy).

Interaction of water vapor with silicate glass surfaces: Mass-spectrometric investigations

NASA Astrophysics Data System (ADS)

Kudriavtsev, Yu.; Asomoza-Palacio, R.; Manzanilla-Naim, L.

2017-05-01

The secondary ion mass-spectroscopy technique was used to study the results of hydration of borosilicate, aluminosilicate, and soda-lime silicate glasses in 1H2 18O water vapor containing 97% of the isotope 18O. It is shown that hydration of the surface of the soda-lime silicate glass occurs as a result of the ion-exchange reaction with alkali metals. In the case of borosilicate and aluminosilicate glasses, water molecules decompose on the glass surface, with the observed formation of hydrogenated layer in the glass being the result of a solid-state chemical reaction—presumably, with the formation of hydroxides from aluminum and boron oxides.

Liquidus temperature and chemical durability of selected glasses to immobilize rare earth oxides waste

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mohd Fadzil, Syazwani Binti; Hrma, Pavel R.; Schweiger, Michael J.

Pyroprocessing is a reprocessing method for managing and reusing used nuclear fuel (UNF) by dissolving it in an electrorefiner with a molten alkali or alkaline earth chloride salt mixture while avoiding wet reprocessing. Pyroprocessing UNF with a LiCl-KCl eutectic salt releases the fission products from the fuel and generates a variety of metallic and salt-based species, including rare earth (RE) chlorides. If the RE-chlorides are converted to oxides, borosilicate glass is a prime candidate for their immobilization because of its durability and ability to dissolve almost any RE waste component into the matrix at high loadings. Crystallization that occurs inmore » waste glasses as the waste loading increases may complicate glass processing and affect the product quality. This work compares three types of borosilicate glasses in terms of liquidus temperature (TL): the International Simple Glass designed by the International Working Group, sodium borosilicate glass developed by Korea Hydro and Nuclear Power, and the lanthanide aluminoborosilicate (LABS) glass established in the United States. The LABS glass allows the highest waste loadings (over 50 mass% RE2O3) while possessing an acceptable chemical durability.« less

Liquidus temperature and chemical durability of selected glasses to immobilize rare earth oxides waste

NASA Astrophysics Data System (ADS)

Mohd Fadzil, Syazwani; Hrma, Pavel; Schweiger, Michael J.; Riley, Brian J.

2015-10-01

Pyroprocessing is are processing method for managing and reusing used nuclear fuel (UNF) by dissolving it in an electrorefiner with a molten alkali or alkaline earth chloride salt mixture while avoiding wet reprocessing. Pyroprocessing UNF with a LiCl-KCl eutectic salt releases the fission products from the fuel and generates a variety of metallic and salt-based species, including rare earth (RE) chlorides. If the RE-chlorides are converted to oxides, borosilicate glass is a prime candidate for their immobilization because of its durability and ability to dissolve almost any RE waste component into the glass matrix at high loadings. Crystallization that occurs in waste glasses as the waste loading increases may complicate glass processing and affect the product quality. This work compares three types of borosilicate glasses in terms of liquidus temperature (TL): the International Simple Glass designed by the International Working Group, sodium borosilicate glass developed by Korea Hydro and Nuclear Power, and the lanthanide aluminoborosilicate (LABS) glass established in the United States. The LABS glass allows the highest waste loadings (over 50 mass% RE2O3) while possessing an acceptable chemical durability.

The thermal degradation of 5 alpha (H)-cholestane during closed-system pyrolysis

NASA Astrophysics Data System (ADS)

Abbott, Geoffrey D.; Bennett, Barry; Stuart Fetch, G.

1995-06-01

Involatile hydrocarbons were identified following the heating of 5α(H)-cholestane in water with reaction vessel walls composed of 316 grade stainless steel and borosilicate glass. These analyses were compared with the hydrocarbon product compositions from closed-system pyrolysis experiments with no added water. Unsaturated hydrocarbons dominate their saturated counterparts following hydrous pyrolysis in both stainless steel-316 and borosilicate glass. In the absence of added water the converse is true in that saturated components dominate the hydrocarbon mixture. Backbone rearrangement in the steroid nucleus leading to spirosterene formation was only observed under aqueous conditions in both borosilicate glass and stainless steel-316 vessels. These comparisons demonstrate that water, as opposed to reaction vessel surface catalytic effects, plays a central role in mediating hydrocarbon degradation during closed-system hydrous pyrolysis. 5α(H)-cholestane degradation under aqueous conditions is a complex composite of dissociative and rearrangement processes. These include (I) carbon-carbon bond cleavage in the sidechains as well as the ring system, (2) dehydrogenation, and (3) backbone rearrangement. These laboratory experiments provide a product description of the involatile hydrocarbons which will be the basis for a mechanistic study of 5α(H)-cholestane degradation in hot water.

A new potential for radiation studies of borosilicate glass

NASA Astrophysics Data System (ADS)

Alharbi, Amal F.; Jolley, Kenny; Smith, Roger; Archer, Andrew J.; Christie, Jamieson K.

2017-02-01

Borosilicate glass containing 70 mol% SiO2 and 30 mol% B2O3 is investigated theoretically using fixed charge potentials. An existing potential parameterisation for borosilicate glass is found to give good agreement for the bond angle and bond length distributions compared to experimental values but the optimal density is 30% higher than experiment. Therefore the potential parameters are refitted to give an optimal density of 2.1 g/cm3, in line with experiment. To determine the optimal density, a series of random initial structures are quenched at a rate of 5 × 1012 K/s using constant volume molecular dynamics. An average of 10 such quenches is carried out for each fixed volume. For each quenched structure, the bond angles, bond lengths, mechanical properties and melting points are determined. The new parameterisation is found to give the density, bond angles, bond lengths and Young's modulus comparable with experimental data, however, the melting points and Poisson's ratio are higher than the reported experimental values. The displacement energy thresholds are computed to be similar to those determined with the earlier parameterisation, which is lower than those for ionic crystalline materials.

Estimating rock and slag wool fiber dissolution rate from composition.

PubMed

Eastes, W; Potter, R M; Hadley, J G

2000-12-01

A method was tested for calculating the dissolution rate constant in the lung for a wide variety of synthetic vitreous silicate fibers from the oxide composition in weight percent. It is based upon expressing the logarithm of the dissolution rate as a linear function of the composition and using a different set of coefficients for different types of fibers. The method was applied to 29 fiber compositions including rock and slag fibers as well as refractory ceramic and special-purpose, thin E-glass fibers and borosilicate glass fibers for which in vivo measurements have been carried out. These fibers had dissolution rates that ranged over a factor of about 400, and the calculated dissolution rates agreed with the in vivo values typically within a factor of 4. The method presented here is similar to one developed previously for borosilicate glass fibers that was accurate to a factor of 1.25. The present coefficients work over a much broader range of composition than the borosilicate ones but with less accuracy. The dissolution rate constant of a fiber may be used to estimate whether disease would occur in animal inhalation or intraperitoneal injection studies of that fiber.

Computing the non-Markovian coarse-grained interactions derived from the Mori-Zwanzig formalism in molecular systems: Application to polymer melts

NASA Astrophysics Data System (ADS)

Li, Zhen; Lee, Hee Sun; Darve, Eric; Karniadakis, George Em

2017-01-01

Memory effects are often introduced during coarse-graining of a complex dynamical system. In particular, a generalized Langevin equation (GLE) for the coarse-grained (CG) system arises in the context of Mori-Zwanzig formalism. Upon a pairwise decomposition, GLE can be reformulated into its pairwise version, i.e., non-Markovian dissipative particle dynamics (DPD). GLE models the dynamics of a single coarse particle, while DPD considers the dynamics of many interacting CG particles, with both CG systems governed by non-Markovian interactions. We compare two different methods for the practical implementation of the non-Markovian interactions in GLE and DPD systems. More specifically, a direct evaluation of the non-Markovian (NM) terms is performed in LE-NM and DPD-NM models, which requires the storage of historical information that significantly increases computational complexity. Alternatively, we use a few auxiliary variables in LE-AUX and DPD-AUX models to replace the non-Markovian dynamics with a Markovian dynamics in a higher dimensional space, leading to a much reduced memory footprint and computational cost. In our numerical benchmarks, the GLE and non-Markovian DPD models are constructed from molecular dynamics (MD) simulations of star-polymer melts. Results show that a Markovian dynamics with auxiliary variables successfully generates equivalent non-Markovian dynamics consistent with the reference MD system, while maintaining a tractable computational cost. Also, transient subdiffusion of the star-polymers observed in the MD system can be reproduced by the coarse-grained models. The non-interacting particle models, LE-NM/AUX, are computationally much cheaper than the interacting particle models, DPD-NM/AUX. However, the pairwise models with momentum conservation are more appropriate for correctly reproducing the long-time hydrodynamics characterised by an algebraic decay in the velocity autocorrelation function.

The aux1 gene of the Ri plasmid is sufficient to confer auxin autotrophy in tobacco BY-2 cells.

PubMed

Nemoto, Keiichirou; Hara, Masamitsu; Goto, Shingo; Kasai, Kouji; Seki, Hikaru; Suzuki, Masashi; Oka, Atsuhiro; Muranaka, Toshiya; Mano, Yoshihiro

2009-05-01

Tobacco (Nicotiana tabacum) Bright Yellow-2 (BY-2) cells are rapidly proliferating meristematic cells that require auxin for culture in vitro. We have established several transgenic BY-2 cell lines that carry the T-DNA of Agrobacterium rhizogenes 15834, which harbors an agropine-type root-inducing (Ri) plasmid. Two of these lines, BYHR-3 and BYHR-7, were used to test the role of auxin in the proliferation of plant cells. The lines grew rapidly in Linsmaier-Skoog (LS) medium lacking auxin and other phytohormones. The TR-DNA, containing the aux1 (tryptophan monooxygenase) and aux2 (indoleacetamide hydrolase) genes, was present in the genomes of both transgenic lines, whereas the TL-DNA, containing the rolA, B, C and D genes, was present in the genome of BYHR-7 but not BYHR-3. Since the introduction of the rolABCD genes alone did not affect the auxin requirement of BY-2 cells, the aux1 and aux2 genes, but not the rolABCD genes, appear to be relevant to the auxin autotrophy of these transgenic lines. Furthermore, the overexpression of aux1 allowed BY-2 cells to grow rapidly in the absence of auxin, suggesting the existence in plant cells of an unidentified gene whose product is functionally equivalent or similar to that of aux2 of the Ri plasmid.

Silicate, borosilicate, and borate bioactive glass scaffolds with controllable degradation rate for bone tissue engineering applications. I. Preparation and in vitro degradation.

PubMed

Fu, Qiang; Rahaman, Mohamed N; Fu, Hailuo; Liu, Xin

2010-10-01

Bioactive glass scaffolds with a microstructure similar to that of dry human trabecular bone but with three different compositions were evaluated for potential applications in bone repair. The preparation of the scaffolds and the effect of the glass composition on the degradation and conversion of the scaffolds to a hydroxyapatite (HA)-type material in a simulated body fluid (SBF) are reported here (Part I). The in vitro response of osteogenic cells to the scaffolds and the in vivo evaluation of the scaffolds in a rat subcutaneous implantation model are described in Part II. Scaffolds (porosity = 78-82%; pore size = 100-500 microm) were prepared using a polymer foam replication technique. The glasses consisted of a silicate (13-93) composition, a borosilicate composition (designated 13-93B1), and a borate composition (13-93B3), in which one-third or all of the SiO2 content of 13-93 was replaced by B2O3, respectively. The conversion rate of the scaffolds to HA in the SBF increased markedly with the B2O3 content of the glass. Concurrently, the pH of the SBF also increased with the B2O3 content of the scaffolds. The compressive strengths of the as-prepared scaffolds (5-11 MPa) were in the upper range of values reported for trabecular bone, but they decreased markedly with immersion time in the SBF and with increasing B2O3 content of the glass. The results show that scaffolds with a wide range of bioactivity and degradation rate can be achieved by replacing varying amounts of SiO(2) in silicate bioactive glass with B2O3. Copyright 2010 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2010.

Structural basis for the auxin-induced transcriptional regulation by Aux/IAA17.

PubMed

Han, Mookyoung; Park, Yangshin; Kim, Iktae; Kim, Eun-Hee; Yu, Tae-Kyung; Rhee, Sangkee; Suh, Jeong-Yong

2014-12-30

Auxin is the central hormone that regulates plant growth and organ development. Transcriptional regulation by auxin is mediated by the auxin response factor (ARF) and the repressor, AUX/IAA. Aux/IAA associates with ARF via domain III-IV for transcriptional repression that is reversed by auxin-induced Aux/IAA degradation. It has been known that Aux/IAA and ARF form homo- and hetero-oligomers for the transcriptional regulation, but what determines their association states is poorly understood. Here we report, to our knowledge, the first solution structure of domain III-IV of Aux/IAA17 (IAA17), and characterize molecular interactions underlying the homotypic and heterotypic oligomerization. The structure exhibits a compact β-grasp fold with a highly dynamic insert helix that is unique in Aux/IAA family proteins. IAA17 associates to form a heterogeneous ensemble of front-to-back oligomers in a concentration-dependent manner. IAA17 and ARF5 associate to form homo- or hetero-oligomers using a common scaffold and binding interfaces, but their affinities vary significantly. The equilibrium dissociation constants (KD) for homo-oligomerization are 6.6 μM and 0.87 μM for IAA17 and ARF5, respectively, whereas hetero-oligomerization reveals a ∼ 10- to ∼ 100-fold greater affinity (KD = 73 nM). Thus, individual homo-oligomers of IAA17 and ARF5 spontaneously exchange their subunits to form alternating hetero-oligomers for transcriptional repression. Oligomerization is mainly driven by electrostatic interactions, so that charge complementarity at the interface determines the binding affinity. Variable binding affinity by surface charge modulation may effectively regulate the complex interaction network between Aux/IAA and ARF family proteins required for the transcriptional control of auxin-response genes.

L'application de l'appareil Suvaglingua de correction phonetique a l'enseignement de l'espagnol aux francophones (The Use of the Suvaglingua Synthesizer for Phonetic Correction in Spanish Courses for French Speakers)

ERIC Educational Resources Information Center

Sarmiento, Jose; And Others

1974-01-01

Describes the use of the verbo-tonal method of phonetic correction and the Suvaglingua synthesizer in Spanish courses at the International School of Interpreters at Mons, France. (Text is in French.) (PMP)

Manufacture of large glass honeycomb mirrors. [for astronomical telescopes

NASA Technical Reports Server (NTRS)

Angel, J. R. P.; Hill, J. M.

1982-01-01

The problem of making very large glass mirrors for astronomical telescopes is examined, and the advantages of honeycomb mirrors made of borosilicate glass are discussed. Thermal gradients in the glass that degrade the figure of thick borosilicate mirrors during use can be largely eliminated in a honeycomb structure by internal ventilation (in air) or careful control of the radiation environment (in space). It is expected that ground-based telescopes with honeycomb mirrors will give better images than those with solid mirrors. Materials, techniques, and the experience that has been gained making trial mirrors and test castings as part of a program to develop 8-10-m-diameter lightweight mirrors are discussed.

Investigating the effect of V2O5 addition on sodium barium borosilicate glasses

NASA Astrophysics Data System (ADS)

Halder, Rumu; Sengupta, Pranesh; Sudarsan, V.; Kaushik, C. P.; Dey, G. K.

2016-05-01

V2O5 doped sodium barium borosilicate glasses were characterized by photoluminescence spectroscopy and electron probe microanalyzer (EPMA). The glass remains homogeneous for lower concentration of V2O5 but a phase separation is observed when V2O5 doping is increased beyond 5 mol%. Detailed microanalysis reveals that the phase separated glass consists of a phase containing V, Ba and Si and a separate Si rich phase within the glass matrix. The luminescence study demonstrated that at low concentration the vanadium mainly interacts with the structural units of B/Si while at higher concentrations, V-O-V/ V-O- Na+/Ba2+ linkages are formed.

Color centers of a borosilicate glass induced by 10 MeV proton, 1.85 MeV electron and 60Co-γ ray

NASA Astrophysics Data System (ADS)

Du, Jishi; Wu, Jiehua; Zhao, Lili; Song, Lixin

2013-05-01

Optical absorption spectra, electron paramagnetic resonance (EPR) spectra, Raman spectra of a borosilicate glass after irradiation by 10 MeV proton, 1.85 MeV electron and 60Co-γ ray were studied. The process of irradiation inducing color centers in the glass was discussed. The band gap of the glass before and after 60Co-γ ray irradiation was studied using Mott and Davis's theory, and it was found that calculated change of the band gap introduced a paradox, because Mott and Davis's theory on the band gap cannot be adopted in the study on the irradiated glass.

Electron irradiation induced phase separation in a sodium borosilicate glass

NASA Astrophysics Data System (ADS)

Sun, K.; Wang, L. M.; Ewing, R. C.; Weber, W. J.

2004-06-01

Electron irradiation induced phase separation in a sodium borosilicate glass was studied in situ by analytical electron microscopy. Distinctly separate phases that are rich in boron and silicon formed at electron doses higher than 4.0 × 10 11 Gy during irradiation. The separated phases are still in amorphous states even at a much high dose (2.1 × 10 12 Gy). It indicates that most silicon atoms remain tetrahedrally coordinated in the glass during the entire irradiation period, except some possible reduction to amorphous silicon. The particulate B-rich phase that formed at high dose was identified as amorphous boron that may contain some oxygen. Both ballistic and ionization processes may contribute to the phase separation.

High efficiency tantalum-based ceramic composite structures

NASA Technical Reports Server (NTRS)

Stewart, David A. (Inventor); Leiser, Daniel B. (Inventor); DiFiore, Robert R. (Inventor); Katvala, Victor W. (Inventor)

2010-01-01

Tantalum-based ceramics are suitable for use in thermal protection systems. These composite structures have high efficiency surfaces (low catalytic efficiency and high emittance), thereby reducing heat flux to a spacecraft during planetary re-entry. These ceramics contain tantalum disilicide, molybdenum disilicide and borosilicate glass. The components are milled, along with a processing aid, then applied to a surface of a porous substrate, such as a fibrous silica or carbon substrate. Following application, the coating is then sintered on the substrate. The composite structure is substantially impervious to hot gas penetration and capable of surviving high heat fluxes at temperatures approaching 3000.degree. F. and above.

Rationale for windshield glass system specification requirements for shuttle orbiter

NASA Technical Reports Server (NTRS)

Hayashida, K.; King, G. L.; Tesinsiky, J.; Wittenburg, D. R.

1972-01-01

A preliminary procurement specification for the space shuttle orbiter windshield pane, and some of the design considerations and rationale leading to its development are presented. The windshield designer is given the necessary methods and procedures for assuring glass pane structural integrity by proof test. These methods and procedures are fully developed for annealed and thermally tempered aluminosilicate, borosilicate, and soda lime glass and for annealed fused silica. Application of the method to chemically tempered glass is considered. Other considerations are vision requirements, protection against bird impact, hail, frost, rain, and meteoroids. The functional requirements of the windshield system during landing, ferrying, boost, space flight, and entry are included.

Tilt and strain deformation induced by hydrologically active natural fractures: application to the tiltmeters installed in Sainte-Croix-aux-Mines observatory (France)

NASA Astrophysics Data System (ADS)

Longuevergne, Laurent; Florsch, Nicolas; Boudin, Frédéric; Oudin, Ludovic; Camerlynck, Christian

2009-08-01

We investigate the deformation induced by water pressure variations in hydrologically active natural fractures, and recorded by tiltmeters and strainmeters. The deformation associated with a single fracture is derived using finite-element modelling (FEM). A range in fracture geometries is explored, first to highlight the sensitivity of each geometrical parameter to the deformation, and secondly to allow transfer to observation sites. Water level variations in the fracture are then derived from a hydrological model, driven by observed rainfall, and calibrated on fracture water flow measurements. The modelling results are explicitly applied to constrain the local hydrological contribution to observations with the 100-m-long hydrostatic tiltmeter installed at Sainte-Croix-aux-Mines (France). Our study shows that well-founded physical modelling of local hydrological effect allows a substantial correction of records in observatories.

Mineralogical textural and compositional data on the alteration of basaltic glass from Kilauea, Hawaii to 300 degrees C: Insights to the corrosion of a borosilicate glass waste-form. [Yucca Mountain Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Smith, D.K.

1990-01-01

Mineralogical, textural and compositional data accompanying greenschist facies metamorphism (to 300{degrees}C) of basalts of the East Rift Zone (ERZ), Kilauea, Hawaii may be evaluated relative to published and experimental results for the surface corrosion of borosilicate glass. The ERZ alteration sequence is dominated by intermittent palagonite, interlayered smectite-chlorite, chlorite, and actinolite-epidote-anhydrite. Alteration is best developed in fractures and vesicles where surface reaction layers root on the glass matrix forming rinds in excess of 100 microns thick. Fractures control fluid circulation and the alteration sequence. Proximal to the glass surface, palagonite, Fe-Ti oxides and clays replace fresh glass as the surfacemore » reaction layer migrates inwards; away from the surface, amphibole, anhydrite, quartz and calcite crystallize from hydrothermal fluids in contact with the glass. The texture and composition of basaltic glass surfaces are similar to those of a SRL-165 glass leached statically for sixty days at 150 {degrees}C. While the ERZ reservoir is a complex open system, conservative comparisons between the alteration of ERZ and synthetic borosilicate glass are warranted. 31 refs., 2 figs.« less

Glass viscosity calculation based on a global statistical modelling approach

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fluegel, Alex

2007-02-01

A global statistical glass viscosity model was developed for predicting the complete viscosity curve, based on more than 2200 composition-property data of silicate glasses from the scientific literature, including soda-lime-silica container and float glasses, TV panel glasses, borosilicate fiber wool and E type glasses, low expansion borosilicate glasses, glasses for nuclear waste vitrification, lead crystal glasses, binary alkali silicates, and various further compositions from over half a century. It is shown that within a measurement series from a specific laboratory the reported viscosity values are often over-estimated at higher temperatures due to alkali and boron oxide evaporation during the measurementmore » and glass preparation, including data by Lakatos et al. (1972) and the recently published High temperature glass melt property database for process modeling by Seward et al. (2005). Similarly, in the glass transition range many experimental data of borosilicate glasses are reported too high due to phase separation effects. The developed global model corrects those errors. The model standard error was 9-17°C, with R^2 = 0.985-0.989. The prediction 95% confidence interval for glass in mass production largely depends on the glass composition of interest, the composition uncertainty, and the viscosity level. New insights in the mixed-alkali effect are provided.« less

Optical and structural investigation on sodium borosilicate glasses doped with Cr2O3

NASA Astrophysics Data System (ADS)

Ebrahimi, E.; Rezvani, M.

2018-02-01

In this work, Sodium borosilicate glasses with chemical composition of 60% SiO2-20% B2O3-20%Na2O doped with different contents of Cr2O3 were prepared by melting-quenching method. Physical, structural and optical properties of glasses were investigated by studying density and molar volume, Fourier Transform Infrared (FT-IR) Spectra and UV-visible absorption spectroscopy. The results showed an increase in density of glasses with the increase of Cr2O3 that can be due to addition of oxide with high molar mass. The optical absorption spectra of un-doped glass reveals UV absorption due to trace iron impurities with no visible band however Cr2O3 doped glasses shows absorption in visible range that are characteristic. Increasing of Cr3 + ions in the glassy microstructure of samples provides a semiconducting character to Sodium borosilicate glass by reducing the direct and indirect optical band gaps of glass samples from 3.79 to 2.59 (ev) and 3.36 to 2.09 (ev), respectively. These changes could be attributed to the role of Cr3 + ions as the network former which asserts improvement of semiconducting behavior in presence of Cr2O3.

Optical and structural investigation on sodium borosilicate glasses doped with Cr2O3.

PubMed

Ebrahimi, E; Rezvani, M

2018-02-05

In this work, Sodium borosilicate glasses with chemical composition of 60% SiO 2 -20% B 2 O 3 -20%Na 2 O doped with different contents of Cr 2 O 3 were prepared by melting-quenching method. Physical, structural and optical properties of glasses were investigated by studying density and molar volume, Fourier Transform Infrared (FT-IR) Spectra and UV-visible absorption spectroscopy. The results showed an increase in density of glasses with the increase of Cr 2 O 3 that can be due to addition of oxide with high molar mass. The optical absorption spectra of un-doped glass reveals UV absorption due to trace iron impurities with no visible band however Cr 2 O 3 doped glasses shows absorption in visible range that are characteristic. Increasing of Cr 3+ ions in the glassy microstructure of samples provides a semiconducting character to Sodium borosilicate glass by reducing the direct and indirect optical band gaps of glass samples from 3.79 to 2.59 (ev) and 3.36 to 2.09 (ev), respectively. These changes could be attributed to the role of Cr 3+ ions as the network former which asserts improvement of semiconducting behavior in presence of Cr 2 O 3 . Copyright © 2017. Published by Elsevier B.V.

Rhenium solubility in borosilicate nuclear waste glass: implications for the processing and immobilization of technetium-99.

PubMed

McCloy, John S; Riley, Brian J; Goel, Ashutosh; Liezers, Martin; Schweiger, Michael J; Rodriguez, Carmen P; Hrma, Pavel; Kim, Dong-Sang; Lukens, Wayne W; Kruger, Albert A

2012-11-20

The immobilization of technetium-99 ((99)Tc) in a suitable host matrix has proven to be a challenging task for researchers in the nuclear waste community around the world. In this context, the present work reports on the solubility and retention of rhenium, a nonradioactive surrogate for (99)Tc, in a sodium borosilicate glass. Glasses containing target Re concentrations from 0 to 10,000 ppm [by mass, added as KReO(4) (Re(7+))] were synthesized in vacuum-sealed quartz ampules to minimize the loss of Re from volatilization during melting at 1000 °C. The rhenium was found as Re(7+) in all of the glasses as observed by X-ray absorption near-edge structure. The solubility of Re in borosilicate glasses was determined to be ~3000 ppm (by mass) using inductively coupled plasma optical emission spectroscopy. At higher rhenium concentrations, additional rhenium was retained in the glasses as crystalline inclusions of alkali perrhenates detected with X-ray diffraction. Since (99)Tc concentrations in a glass waste form are predicted to be <10 ppm (by mass), these Re results implied that the solubility should not be a limiting factor in processing radioactive wastes, assuming Tc as Tc(7+) and similarities between Re(7+) and Tc(7+) behavior in this glass system.

Imagerie polarimétrique active : des applications militaires et duales

NASA Astrophysics Data System (ADS)

Goudail, François; Boffety, Matthieu; Leviandier, Luc; Vannier, Nicolas

2017-12-01

L'imagerie polarimétrique active permet de révéler des contrastes invisibles à l'oeil humain et aux caméras classiques. Elle peut étendre les capacités de décamouflage des systèmes d'imagerie active et améliorer la détection d'objets dangereux sur des pistes. Elle possède également de nombreuses applications duales dans des domaines tels que l'imagerie biomédicale ou la vision industrielle.

CONCLUSIONS ET RECOMMANDATIONS À L’ISSUE DE LA CONSULTATION DE L’OMS SUR LA LUTTE CONTRE LA CARENCE MARTIALE CHEZ LE NOURRISSON ET LE JEUNE ENFANT DANS LES PAYS D’ENDÉMIE PALUSTRE

PubMed Central

Allen, L.; Black, R.E.; Brandes, N.; Brittenham, G.; Chazot, G.; Chunming, C.; Crawley, J.; de Benoist, B.; Dalmiya, N.; Darnton-Hill, I.; Dewey, K.; El-Arifeen, S.; Fontaine, O.; Geissler, C.; Haberle, H.; Harvey, P.; Hasler, J.; Hershko, C.; Hurrell, R.; Juma, M.A.; Lönnerdal, B.; Lozoff, B.; Lynch, S.; Salgado, H. Martines; McLean, E.; Metz, J.; Oppenheimer, S.; Premji, Z.; Prentice, A.; Ramsan, M.; Ratledge, C.; Stoltzfus, R.; Tielsch, J.; Winachagoon, P.

2011-01-01

Cet article présentent les résultats d'une Consultation d'Experts dont l'objectif était d'évaluer l'efficacité et l'innocuité des suppléments de fer administrés aux nourrissons et aux jeunes enfants dans les zones d’endémie palustre, ainsi que les conséquences d’une telle mesure pour la santé publique. Les participants à cette Consultation, qui s’est déroulée à Lyon (France) les 12–14 juin 2006, se sont entendus sur plusieurs questions importantes concernant l’administration d’une supplémentation martiale aux nourrissons et aux jeunes enfants dans les zones d’endémie palustre. Les conclusions du présent rapport s’appliquent plus particulièrement aux pays où le paludisme est endémique. PMID:18630054

Laser printed glass planar lightwave circuits with integrated fiber alignment structures

NASA Astrophysics Data System (ADS)

Desmet, A.; Radosavljevic, A.; Missinne, J.; Van Thourhout, D.; Van Steenberge, G.

2018-02-01

Femtosecond laser inscription allows straightforward manufacturing of glass planar lightwave circuits such as waveguides, interferometers, directional couplers, resonators and more complex structures. Fiber alignment structures are needed to facilitate communication with the glass planar lightwave circuit. In this study, a technique is described to create optical waveguides and alignment structures in the same laser exposure step. Using an industrial ytterbium-doped 1030 nm fiber laser pulses of 400 fs were focused into glass with a 0.4 NA objective causing permanent alteration of the material. Depending on laser parameters this modification allows direct writing of waveguides or the creation of channels after exposing the irradiated volumes to an etchant such as KOH. Writing of channels and waveguides with different laser powers, frequencies, polarisations, stage translation speeds and scan densities were investigated in fused silica and borosilicate glass. Waveguides with controlled dimensions were created, as well as etched U-grooves with a diameter of 126 μm and a sidewall roughness Ra of 255 nm. Cut back measurements were performed giving a waveguide propagation loss of 1.1 dB/cm in borosilicate glass. A coupling loss of 0.7 dB was measured for a transition between the waveguide and standard single mode fiber at 1550 nm, using index matching liquid. The described technique eliminates active alignment requirements and is useful for many applications such as microfluidic sensing, PLCs, fan-out connectors for multicore fibers and quantum optical networks.

Borosilicate Glass Fiber-Optic Biosensor for the Detection of Escherichia coli.

PubMed

Maas, Michael B; Maybery, Giles H C; Perold, Willem J; Neveling, Deon P; Dicks, Leon M T

2018-02-01

Polyclonal antibodies against Escherichia coli and fluorescent, secondary, antibodies were immobilized on borosilicate glass fibers pre-treated with 3-glycidyloxypropyl trimethoxysilane (GPS). Light with an average wavelength of 627 nm, emitted by a diode placed at one end of the glass fiber, was detected by an ultrasensitive photodiode with peak sensitivity at 640 nm. Changes in fluorescence, caused by binding of E. coli to the antibodies, changed the net refractive index of the glass fiber and thus the internal reflection of light. These evanescent changes in photon energy were recorded by an ultrasensitive photodiode. Signals were amplified and changes in voltage recorded with a digital multimeter. A linear increase in voltage readings was recorded over 2 h when 3.0 × 10 7 CFU/ml and 2.77 × 10 9 CFU/ml E. coli were adhered to the antibodies. Voltage readings were recorded with E. coli cell numbers from 2 × 10 3 CFU/ml to 2 × 10 6 CFU/ml, but readings remained unchanged for 2 h, indicating that the limit of detection is 3.0 × 10 7 CFU/ml. This simple technology may be used to develop a low-cost, portable, fiber-optic biosensor to detect E. coli in infections and may have applications in the medical field. Research is in progress to optimize the sensitivity of the fiber-optic biosensor and determine its specificity.

Gravistimulation changes expression of genes encoding putative carrier proteins of auxin polar transport in etiolated pea epicotyls

NASA Astrophysics Data System (ADS)

Hoshino, T.; Hitotsubashi, R.; Miyamoto, K.; Tanimoto, E.; Ueda, J.

STS-95 space experiment has showed that auxin polar transport in etiolated epicotyls of pea (Pisum sativum L. cv. Alaska) seedlings is controlled by gravistimulation. In Arabidopsis thaliana auxin polar transport has considered to be regulated by efflux and influx carrier proteins in plasma membranes, AtPIN1 and AtAUX1, respectively. In order to know how gravistimuli control auxin polar transport in etiolated pea epicotyls at molecular levels, strenuous efforts have been made, resulting in successful isolation of full-length cDNAs of a putative auxin efflux and influx carriers, PsPIN2 and PsAUX1, respectively. Significantly high levels in homology were found on nucleotide and deduced amino acid sequences among PsPIN2, PsPIN1 (accession no. AY222857, Chawla and DeMason, 2003) and AtPINs, and also among PsAUX1, AtAUX1 and their related genes. Phylogenetic analyses based on the deduced amino acid sequences revealed that PsPIN2 belonged to a subclade including AtPIN3, AtPIN4 relating to lateral transport of auxin, while PsPIN1 belonged to the same clade as AtPIN1 relating to auxin polar transport. In the present study, we examined the effects of gravistimuli on the expression of PsPINs and PsAUX1 in etiolated pea seedlings by northern blot analysis. Expression of PsPIN1, PsPIN2 and PsAUX1 in hook region of 3.5-d-old etiolated pea seedlings grown under simulated microgravity conditions on a 3-D clinostat increased as compared with that of the seedlings grown under 1 g conditions. On the other hand, that of PsPIN1 and PsAUX1 in the 1st internode region under simulated microgravity conditions on a 3-D clinostat also increased, while that of PsPIN2 was affected little. These results suggest that expression of PsPIN1, PsPIN2 and PsAUX1 regulating polar/lateral transport of auxin is substantially under the control of gravity. A possible role of PsPINs and PsAUX1 of auxin polar transport in etiolated pea seedlings will also be discussed.

Genome-wide survey of Aux/IAA gene family members in potato (Solanum tuberosum): Identification, expression analysis, and evaluation of their roles in tuber development.

PubMed

Gao, Junpeng; Cao, Xiaoli; Shi, Shandang; Ma, Yuling; Wang, Kai; Liu, Shengjie; Chen, Dan; Chen, Qin; Ma, Haoli

2016-03-04

The Auxin/indole-3-acetic acid (Aux/IAA) genes encode short-lived nuclear proteins that are known to be involved in the primary cellular responses to auxin. To date, systematic analysis of the Aux/IAA genes in potato (Solanum tuberosum) has not been conducted. In this study, a total of 26 potato Aux/IAA genes were identified (designated from StIAA1 to StIAA26), and the distribution of four conserved domains shared by the StIAAs were analyzed based on multiple sequence alignment and a motif-based sequence analysis. A phylogenetic analysis of the Aux/IAA gene families of potato and Arabidopsis was also conducted. In order to assess the roles of StIAA genes in tuber development, the results of RNA-seq studies were reformatted to analyze the expression patterns of StIAA genes, and then verified by quantitative real-time PCR. A large number of StIAA genes (12 genes) were highly expressed in stolon organs and in during the tuber initiation and expansion developmental stages, and most of these genes were responsive to indoleacetic acid treatment. Our results suggested that StIAA genes were involved in the process of tuber development and provided insights into functional roles of potato Aux/IAA genes. Copyright © 2016 Elsevier Inc. All rights reserved.

Wetting of single crystal mullite by borosilicate and yttrium-aluminosilicate glasses and wetting phenomena of steels containing aluminum and titanium

NASA Astrophysics Data System (ADS)

Eldred, Benjamin Todd

This dissertation consists of two major sections. The first section concerns the wetting of single crystal mullite by borosilicate and yttrium-aluminosilicate glasses. The borosilicate glass showed poor wetting and interacted only moderately with the substrate. The yttrium-aluminosilicate glass interacted strongly with mullite and showed very good wetting. Balanced chemical equations between each glass and mullite were derived from EDS data. Wetting was found to be dependent on the crystallographic orientation of the substrate, in agreement with previous studies of the surface energy of mullite. The second section concerns the wetting phenomena of steels containing aluminum and titanium. A modified sessile drop technique was used to investigate the wetting of steels containing aluminum and/or titanium as a function of furnace atmosphere. It was found that the steel chemistry and furnace atmosphere had little effect on wetting except in the case of a particular ultra-low carbon steel containing both aluminum and titanium. This steel was found to show significantly lower contact angles than any other steel tested when it was in an atmosphere of pure hydrogen. As nitrogen was added to the atmosphere, the contact angle increased monotonically and irreversibly. The interaction between aluminum, titanium, and nitrogen is explained in terms of first-order interaction coefficients available in thermodynamic literature.

An Experimental Investigation of the Long-Term Stability of Triple-Point-of-Water Cells

NASA Astrophysics Data System (ADS)

Hill, K. D.

2014-04-01

Contamination of triple-point-of-water (TPW) cells by the chemical components of the borosilicate glass that contains the water is now widely recognized as the principal contributor to long-term drift of the cell temperature. To add to the available experimental data, a comparison of 24 TPW cells of various ages (from 10 years to 59 years), manufacturers (NRC, Jarrett, Isotech), and materials (borosilicate glass and fused quartz) was undertaken in 2013. Twelve cells from this group were compared to one another in 1997. By comparing the current inter-cell temperature differences to those determined 16 years earlier, it was found that some cells have remained stable, others have become colder (as might be expected from ongoing dissolution of the glass), and one or two show an apparent increase in temperature that seems anomalous. Also included among the 24 cells are five cells of borosilicate glass and five of fused quartz that were purchased 10 years ago. By comparing the relative temperature differences among this group of borosilcate and fused-quartz-encapsulated cells to the values obtained when they were last compared 6 years ago, it was found that the average temperature of the borosilcate group of cells decreases by , in reasonable agreement with an average drift of suggested 12 years ago. It was concluded that fused quartz is the superior container for TPW cells.

Analytical Solutions for Predicting Underwater Explosion Gas Bubble Behaviour

DTIC Science & Technology

2010-11-01

donne les meilleures prévisions comparativement aux ajustements avec les données expérimentales. Le modèle à fluide incompressible exige d’utiliser une...couplage des mouvements radial et migratoire. L’étude montre que, comparativement aux résultats d’expérience, la réduction du rayon de la bulle... comparativement aux ajustements avec les données expérimentales. Le modèle à fluide incompressible exige d’utiliser une fonction empirique de perte d’énergie

Spectral properties of molecular iodine in absorption cells filled to specified saturation pressure.

PubMed

Hrabina, Jan; Šarbort, Martin; Acef, Ouali; Burck, Frédéric Du; Chiodo, Nicola; Holá, Miroslava; Číp, Ondřej; Lazar, Josef

2014-11-01

We present the results of measurement and evaluation of spectral properties of iodine absorption cells filled at certain saturation pressure. A set of cells made of borosilicate glass instead of common fused silica was tested for their spectral properties in greater detail with special care for the long-term development of the absorption media purity. The results were compared with standard fused silica cells and the high quality of iodine was verified. A measurement method based on an approach relying on measurement of linewidth of the hyperfine transitions is proposed as a novel technique for iodine cell absorption media purity evaluation. A potential application in laser metrology of length is also discussed.

Admission Requirements to Canadian Faculties of Medicine and Their Selection Policies = Conditions d'Admission aux Facultes de Medecine Canadiennes et Leurs Politiques de Selection.

ERIC Educational Resources Information Center

Association of Canadian Medical Colleges, Ottawa (Ontario).

Information is presented to help applicants to Canadian medical colleges realistically assess their chances for gaining admission. The guide is also intended for career counselors in high schools and higher education. One section provides statistics on the following characteristics that are associated with being selected: sex, age, Medical College…

Granger Causality and National Procurement Spending: Applications to the CC130 Hercules Fleet Performance

DTIC Science & Technology

2011-09-01

intentionally left blank. ii DRDC CORA TM 2011-154 Dr aft Co py Executive summary Granger Causality and National Procurement Spending David W...à croire que la chaîne d’approvisionnement sous jacente est optimale - la résistance aux chocs de dépenses peut simplement s’expliquer par des stocks...i Executive summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . iii Sommaire

Evaluation of Diffuse Reflection Infrared Spectrometry for End-of-Shift Measurement of α-quartz in Coal Dust Samples

PubMed Central

Miller, Arthur L.; Murphy, Nathaniel C.; Bayman, Sean J.; Briggs, Zachary P.; Kilpatrick, Andrew D.; Quinn, Courtney A.; Wadas, Mackenzie R.; Cauda, Emanuele G.; Griffiths, Peter R.

2015-01-01

The inhalation of toxic substances is a major threat to the health of miners, and dust containing respirable crystalline silica (α-quartz) is of particular concern, due to the recent rise in cases of coal workers’ pneumoconiosis and silicosis in some U.S. mining regions. Currently, there is no field-portable instrument that can measure airborne α-quartz and give miners timely feedback on their exposure. The U.S. National Institute for Occupational Safety and Health (NIOSH) is therefore conducting studies to investigate technologies capable of end-of-shift or real-time measurement of airborne quartz. The present study focuses on the potential application of Fourier transform infrared (FT-IR) spectrometry conducted in the diffuse reflection (DR) mode as a technique for measuring α-quartz in respirable mine dust. A DR accessory was used to analyze lab-generated respirable samples of Min-U-Sil 5 (which contains more than 90% α-quartz) and coal dust, at mass loadings in the ranges of 100–600 μg and 600–5300 μg, respectively. The dust samples were deposited onto three different types of filters, borosilicate fiberglass, nylon, and polyvinyl chloride (PVC). The reflectance, R, was calculated by the ratio of a blank filter and a filter with deposited mine dust. Results suggest that for coal and pure quartz dusts deposited on 37 mm PVC filters, measurements of −log R correlate linearly with known amounts of quartz on filters, with R2 values of approximately 0.99 and 0.94, respectively, for samples loaded up to ~4000 μg. Additional tests were conducted to measure quartz in coal dusts deposited onto the borosilicate fiberglass and nylon filter media used in the NIOSH-developed Personal Dust Monitor (PDM). The nylon filter was shown to be amenable to DR analysis, but quantification of quartz is more accurate when the filter is “free,” as opposed to being mounted in the PDM filter holder. The borosilicate fiberglass filters were shown to produce excessive interference, making quartz quantification impossible. It was concluded that, while the DR/FT-IR method is potentially useful for on-filter measurement of quartz in dust samples, the use of PVC filters produced the most accurate results. PMID:25636081

Evaluation of Diffuse Reflection Infrared Spectrometry for End-of-Shift Measurement of α-quartz in Coal Dust Samples.

PubMed

Miller, Arthur L; Murphy, Nathaniel C; Bayman, Sean J; Briggs, Zachary P; Kilpatrick, Andrew D; Quinn, Courtney A; Wadas, Mackenzie R; Cauda, Emanuele G; Griffiths, Peter R

2015-01-01

The inhalation of toxic substances is a major threat to the health of miners, and dust containing respirable crystalline silica (α-quartz) is of particular concern, due to the recent rise in cases of coal workers' pneumoconiosis and silicosis in some U.S. mining regions. Currently, there is no field-portable instrument that can measure airborne α-quartz and give miners timely feedback on their exposure. The U.S. National Institute for Occupational Safety and Health (NIOSH) is therefore conducting studies to investigate technologies capable of end-of-shift or real-time measurement of airborne quartz. The present study focuses on the potential application of Fourier transform infrared (FT-IR) spectrometry conducted in the diffuse reflection (DR) mode as a technique for measuring α-quartz in respirable mine dust. A DR accessory was used to analyze lab-generated respirable samples of Min-U-Sil 5 (which contains more than 90% α-quartz) and coal dust, at mass loadings in the ranges of 100-600 μg and 600-5300 μg, respectively. The dust samples were deposited onto three different types of filters, borosilicate fiberglass, nylon, and polyvinyl chloride (PVC). The reflectance, R, was calculated by the ratio of a blank filter and a filter with deposited mine dust. Results suggest that for coal and pure quartz dusts deposited on 37 mm PVC filters, measurements of -log R correlate linearly with known amounts of quartz on filters, with R(2) values of approximately 0.99 and 0.94, respectively, for samples loaded up to ∼4000 μg. Additional tests were conducted to measure quartz in coal dusts deposited onto the borosilicate fiberglass and nylon filter media used in the NIOSH-developed Personal Dust Monitor (PDM). The nylon filter was shown to be amenable to DR analysis, but quantification of quartz is more accurate when the filter is "free," as opposed to being mounted in the PDM filter holder. The borosilicate fiberglass filters were shown to produce excessive interference, making quartz quantification impossible. It was concluded that, while the DR/FT-IR method is potentially useful for on-filter measurement of quartz in dust samples, the use of PVC filters produced the most accurate results.

A Literature Survey of Reverberation Modeling: With Emphasis on Bellhop Compatibility for Operational Applications

DTIC Science & Technology

2010-09-01

modèles à orientation opérationnelle ( comparativement à ceux orientés vers la recherche) qui pourraient être compatibles avec le modèle de propagation...concentre sur les modèles à orientation opérationnelle (en sacrifiant un certain degré d’exactitude pour accroître la réactivité, comparativement aux modèles...these modeling efforts are not applicable to Bellhop because they are designed specifically to take advantage of the normal mode decomposition

Commercial Ion Exchange Resin Vitrification in Borosilicate Glass

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cicero-Herman, C.A.; Workman, P.; Poole, K.

1998-05-01

Bench-scale studies were performed to determine the feasibility of vitrification treatment of six resins representative of those used in the commercial nuclear industry. Each resin was successfully immobilized using the same proprietary borosilicate glass formulation. Waste loadings varied from 38 to 70 g of resin/100 g of glass produced depending on the particular resin, with volume reductions of 28 percent to 68 percent. The bench-scale results were used to perform a melter demonstration with one of the resins at the Clemson Environmental Technologies Laboratory (CETL). The resin used was a weakly acidic meth acrylic cation exchange resin. The vitrification processmore » utilized represented a approximately 64 percent volume reduction. Glass characterization, radionuclide retention, offgas analyses, and system compatibility results will be discussed in this paper.« less

Investigating the effect of V{sub 2}O{sub 5} addition on sodium barium borosilicate glasses

DOE Office of Scientific and Technical Information (OSTI.GOV)

Halder, Rumu, E-mail: rumuhalder24feb@gmail.com; Sengupta, Pranesh; Dey, G. K.

2016-05-23

V{sub 2}O{sub 5} doped sodium barium borosilicate glasses were characterized by photoluminescence spectroscopy and electron probe microanalyzer (EPMA). The glass remains homogeneous for lower concentration of V{sub 2}O{sub 5} but a phase separation is observed when V{sub 2}O{sub 5} doping is increased beyond 5 mol%. Detailed microanalysis reveals that the phase separated glass consists of a phase containing V, Ba and Si and a separate Si rich phase within the glass matrix. The luminescence study demonstrated that at low concentration the vanadium mainly interacts with the structural units of B/Si while at higher concentrations, V-O-V/ V-O{sup −} Na{sup +}/Ba{sup 2+} linkagesmore » are formed.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gao, Junpeng; Innovation Experimental College, Northwest A&F University, Yangling, Shaanxi 712100; Cao, Xiaoli

The Auxin/indole-3-acetic acid (Aux/IAA) genes encode short-lived nuclear proteins that are known to be involved in the primary cellular responses to auxin. To date, systematic analysis of the Aux/IAA genes in potato (Solanum tuberosum) has not been conducted. In this study, a total of 26 potato Aux/IAA genes were identified (designated from StIAA1 to StIAA26), and the distribution of four conserved domains shared by the StIAAs were analyzed based on multiple sequence alignment and a motif-based sequence analysis. A phylogenetic analysis of the Aux/IAA gene families of potato and Arabidopsis was also conducted. In order to assess the roles ofmore » StIAA genes in tuber development, the results of RNA-seq studies were reformatted to analyze the expression patterns of StIAA genes, and then verified by quantitative real-time PCR. A large number of StIAA genes (12 genes) were highly expressed in stolon organs and in during the tuber initiation and expansion developmental stages, and most of these genes were responsive to indoleacetic acid treatment. Our results suggested that StIAA genes were involved in the process of tuber development and provided insights into functional roles of potato Aux/IAA genes. - Highlights: • A systematic analysis of the potato AUX/IAA gene family were performed. • StIAA genes were related to auxin perception and signal transduction. • Candidate StIAA genes likely related to tuber initiation and expansion were screened.« less

DPSSL for direct dicing and drilling of dielectrics

NASA Astrophysics Data System (ADS)

Ashkenasi, David; Schwagmeier, M.

2007-02-01

New strategies in laser micro processing of glasses and other optically transparent materials are being developed with increasing interest and intensity using diode pumped solid state laser (DPSSL) systems generating short or ultra-short pulses in the optical spectra at good beam quality. Utilizing non-linear absorption channels, it can be demonstrated that ns green (532 nm) laser light can scribe, dice, full body cut and drill (flat) borofloat and borosilicate glasses at good quality. Outside of the correct choice in laser parameters, an intelligent laser beam management plays an important role in successful micro processing of glass. This application characterizes a very interesting alternative where standard methods demonstrate severe limitations such as diamond dicing, CO2 laser treatment or water jet cutting, especially for certain type of optical materials and/or geometric conditions. Application near processing examples using different DPSSL systems generating ns pulsed light at 532 nm in TEM 00 at average powers up to 10 W are presented and discussed in respect to potential applications in display technology, micro electronics and optics.

Comparison of Three Commercial Systems for Identification of Yeasts Commonly Isolated in the Clinical Microbiology Laboratory

PubMed Central

Wadlin, Jill K.; Hanko, Gayle; Stewart, Rebecca; Pape, John; Nachamkin, Irving

1999-01-01

We evaluated three commercial systems (RapID Yeast Plus System; Innovative Diagnostic Systems, Norcross, Ga.; API 20C Aux; bioMerieux-Vitek, Hazelwood, Mo.; and Vitek Yeast Biochemical Card, bioMerieux-Vitek) against an auxinographic and microscopic morphologic reference method for the ability to identify yeasts commonly isolated in our clinical microbiology laboratory. Two-hundred one yeast isolates were compared in the study. The RapID Yeast Plus System was significantly better than either API 20C Aux (193 versus 167 correct identifications; P < 0.0001) or the Vitek Yeast Biochemical Card (193 versus 173 correct identifications; P = 0.003) for obtaining correct identifications to the species level without additional testing. There was no significant difference between results obtained with API 20C Aux and the Vitek Yeast Biochemical Card system (P = 0.39). The API 20C Aux system did not correctly identify any of the Candida krusei isolates (n = 23) without supplemental testing and accounted for the major differences between the API 20C Aux and RapID Yeast Plus systems. Overall, the RapID Yeast Plus System was easy to use and is a good system for the routine identification of clinically relevant yeasts. PMID:10325356

Les soins aux enfants et aux adolescents des familles des militaires canadiens : les considérations particulières

PubMed Central

Rowan-Legg, Anne

2017-01-01

Résumé Les familles des militaires font face à de nombreux facteurs de stress, tels que les réinstallations fréquentes, les longues pério des de séparation familiale, l’isolement géographique du réseau de soutien de la famille élargie et le déploiement en zones très dangereuses. Les enfants et les adolescents des familles des militaires vivent les mêmes trajectoires développementales et motivationnelles que leurs homologues civils, mais ils sont également aux prises avec des pressions et des facteurs de stress liés à leur développement qui sont inhabituels et qui leur sont imposés par les exigences de la vie militaire. Les effets de la vie militaire sur les familles et les enfants commencent à être admis et mieux caractérisés. Il est essentiel de comprendre les préoccupations propres aux enfants et aux adolescents des familles des militaires et de mobiliser les ressources nécessaires pour les soutenir afin de répondre à leurs besoins en matière de santé.

Nondestructive evaluation of a ceramic matrix composite material

NASA Technical Reports Server (NTRS)

Grosskopf, Paul P.; Duke, John C., Jr.

1992-01-01

Monolithic ceramic materials have proven their usefulness in many applications, yet, their potential for critical structural applications is limited because of their sensitivity to small imperfections. To overcome this extreme sensitivity to small imperfections, ceramic matrix composite materials have been developed that have the ability to withstand some distributed damage. A borosilicate glass reinforced with several layers of silicon-carbide fiber mat has been studied. Four-point flexure and tension tests were performed not only to determine some of the material properties, but also to initiate a controlled amount of damage within each specimen. Acousto-ultrasonic (AU) measurements were performed periodically during mechanical testing. This paper will compare the AU results to the mechanical test results and data from other nondestructive methods including acoustic emission monitoring and X-ray radiography. It was found that the AU measurements were sensitive to the damage that had developed within the material.

Extended electron energy loss fine structure simulation of the local boron environment in sodium aluminoborosilicate glasses containing gadolinium

DOE Office of Scientific and Technical Information (OSTI.GOV)

Qian, Morris; Li, Hong; Li, Liyu

Gadolinium can be dissolved in sodium-alumino-borosilicate glasses up to 47 wt% in a baseline borosilicate glass (mol%) 20 B2O3, 5 Al2O3, 60 SiO2,and 20 Na2O. Understanding of Gd dissolution in borosilicate melts is important in glass formulation optimization. Electron energy loss fine structure (ELFS) spectroscopy is chosen, which provides well resolved local atomic structure information for both amorphous and crystalline materials with high sensitivity to low Z elements such as Al, B, Na, O, and Si where the x-ray absorption fine structure (XAFS) technique faces experimental difficulty. In this study, we report our results of boron K-edge ELFS study. Twomore » borosilicate glass samples with 30 and 47 mass% Gd2O3, B20Gd30 and B20Gd47were chosen for B K-edge ELFS study. EEL spectra were acquired on a Philips 430 TEM equipped with Gatan PEELS system 666 and EL/P 2.1 software with Custom function AcqLong. The ELFS data analysis was performed using UWELFS, UWXAFS and FEFF software. From our Gd solubility study, the local structure of Gd in the borate environment possibly resembles double chain structure found in crystalline Gd(BO2)3 as proposed by Chakraborty et al. The B/Gd ratio's in both glasses are smaller then 3, which means the excess Gd atoms in the Si-sites would be 17 and 60 mol% of the total Gd atoms, respectively according to the model, yet the local environment of borate sites saturated with Gd should be remained. To verity above hypothesis, the double chain structure model was applied to fit boron K-edge. The model was shown to well fit experimental boron K-edge EELS spectra for both glasses with some degree of distance distortion which is understandable in amorphous structure. Therefore, it is very likely that Gd stabilized in borate sites has a local structure resembling the double chain Gd(BO2)3 structure as proposed by our solubility study and literature.« less

Helium High Pressure Tanks at EADS Space Transportation New Technology with Thermoplastic Liner

DTIC Science & Technology

2005-07-13

l’art actuel pour l’application d’un liner thermoplastique sur le réservoir hélium 300 litres pour le lanceur ARIANE 5, réservoir actuellement réalisé à...L à liner thermoplastique ont complètement démontré le respect aux exigences majeures demandées pour le lanceur A5. Ces travaux finalisent la phase

Negative phototropism is seen in Arabidopsis inflorescences when auxin signaling is reduced to a minimal level by an Aux/IAA dominant mutation, axr2.

PubMed

Sato, Atsuko; Sasaki, Shu; Matsuzaki, Jun; Yamamoto, Kotaro T

2015-01-01

Inflorescences of a dominant mutant of Arabidopsis Aux/IAA7, axr2, showed negative phototropism with a similar fluence response curve to the positive phototropism of wild-type stems. Application of a synthetic auxin, NAA, and an inhibitor of polar auxin transport, NPA, increased and decreased respectively the magnitude of the phototropic response in the wild type, while in axr2 application of NAA reduced the negative phototropic response and NPA had no effect. Decapitation of the apex induced a small negative phototropism in wild-type stems, and had no effect in axr2 plants. Inflorescences of the double mutants of auxin transporters, pgp1 pgp19, showed no phototropic response, while decapitation resulted in a negative phototropic response. These results suggest that negative phototropism can occur when the level of auxin or of auxin signaling is reduced to a minimal level, and that in plant axial organs the default phototropic response to unilateral blue light may be negative. Expression of axr2 protein by an endodermis-specific promoter resulted in agravitropism of inflorescences in a similar way to that of axr2, but phototropism was normal, confirming that the endodermis does not play a critical role in phototropism.

Negative phototropism is seen in Arabidopsis inflorescences when auxin signaling is reduced to a minimal level by an Aux/IAA dominant mutation, axr2

PubMed Central

Sato, Atsuko; Sasaki, Shu; Matsuzaki, Jun; Yamamoto, Kotaro T.

2015-01-01

Inflorescences of a dominant mutant of Arabidopsis Aux/IAA7, axr2, showed negative phototropism with a similar fluence response curve to the positive phototropism of wild-type stems. Application of a synthetic auxin, NAA, and an inhibitor of polar auxin transport, NPA, increased and decreased respectively the magnitude of the phototropic response in the wild type, while in axr2 application of NAA reduced the negative phototropic response and NPA had no effect. Decapitation of the apex induced a small negative phototropism in wild-type stems, and had no effect in axr2 plants. Inflorescences of the double mutants of auxin transporters, pgp1 pgp19, showed no phototropic response, while decapitation resulted in a negative phototropic response. These results suggest that negative phototropism can occur when the level of auxin or of auxin signaling is reduced to a minimal level, and that in plant axial organs the default phototropic response to unilateral blue light may be negative. Expression of axr2 protein by an endodermis-specific promoter resulted in agravitropism of inflorescences in a similar way to that of axr2, but phototropism was normal, confirming that the endodermis does not play a critical role in phototropism. PMID:25738325

Visit CD

ScienceCinema

None

2017-12-09

Le DG H.Schopper souhaite la bienvenue aux ambassadeurs des pays membres et aux représentants des pays avec lesquels le Cern entretient des relations proches et fait un exposé sur les activités au Cern

Evidence supporting an intentional Neandertal burial at La Chapelle-aux-Saints.

PubMed

Rendu, William; Beauval, Cédric; Crevecoeur, Isabelle; Bayle, Priscilla; Balzeau, Antoine; Bismuth, Thierry; Bourguignon, Laurence; Delfour, Géraldine; Faivre, Jean-Philippe; Lacrampe-Cuyaubère, François; Tavormina, Carlotta; Todisco, Dominique; Turq, Alain; Maureille, Bruno

2014-01-07

The bouffia Bonneval at La Chapelle-aux-Saints is well known for the discovery of the first secure Neandertal burial in the early 20th century. However, the intentionality of the burial remains an issue of some debate. Here, we present the results of a 12-y fieldwork project, along with a taphonomic analysis of the human remains, designed to assess the funerary context of the La Chapelle-aux-Saints Neandertal. We have established the anthropogenic nature of the burial pit and underlined the taphonomic evidence of a rapid burial of the body. These multiple lines of evidence support the hypothesis of an intentional burial. Finally, the discovery of skeletal elements belonging to the original La Chapelle aux Saints 1 individual, two additional young individuals, and a second adult in the bouffia Bonneval highlights a more complex site-formation history than previously proposed.

ULTRASONIC NEUTRON DOSIMETER

DOEpatents

Truell, R.; de Klerk, J.; Levy, P.W.

1960-02-23

A neutron dosimeter is described which utilizes ultrasonic waves in the megacycle region for determination of the extent of neutron damage in a borosilicate glass through ultrasonic wave velocity and attenuation measurements before and after damage.

Caracterisation environnementale des emissions atmospheriques d'une source fixe et creation d'un outil de gestion dynamique =

NASA Astrophysics Data System (ADS)

Fournier, Marie-Claude

Une caracterisation des emissions atmospheriques provenant des sources fixes en operation, alimentees au gaz et a l'huile legere, a ete conduite aux installations visees des sites no.1 et no.2. La caracterisation et les calculs theoriques des emissions atmospheriques aux installations des sites no.1 et no.2 presentent des resultats qui sont en dessous des valeurs reglementaires pour des conditions d'operation normales en periode hivernale et par consequent, a de plus fortes demandes energetiques. Ainsi, pour une demande energetique plus basse, le taux de contaminants dans les emissions atmospheriques pourrait egalement etre en dessous des reglementations municipales et provinciales en vigueur. Dans la perspective d'une nouvelle reglementation provinciale, dont les termes sont discutes depuis 2005, il serait souhaitable que le proprietaire des infrastructures visees participe aux echanges avec le Ministere du Developpement Durable, de l'Environnement et des Parcs (MDDEP) du Quebec. En effet, meme si le principe de droit acquis permettrait d'eviter d'etre assujetti a la nouvelle reglementation, l'application de ce type de principe ne s'inscrit pas dans ceux d'un developpement durable. L'âge avance des installations etudiees implique la planification d'un entretien rigoureux afin d'assurer les conditions optimales de combustion en fonction du type de combustible. Des tests de combustion sur une base reguliere sont donc recommandes. Afin de supporter le processus de suivi et d'evaluation de la performance environnementale des sources fixes, un outil d'aide a la gestion de l'information environnementale a ete developpe. Dans ce contexte, la poursuite du developpement d'un outil d'aide a la gestion de l'information environnementale faciliterait non seulement le travail des personnes affectees aux inventaires annuels mais egalement le processus de communication entre les differents acteurs concernes tant intra- qu'inter-etablissement. Cet outil serait egalement un bon moyen pour sensibiliser le personnel a leur consommation energetique ainsi qu'a leur role dans la lutte contre les emissions polluantes et les gaz a effets de serre. En outre, ce type d'outil a pour principale fonction de generer des rapports dynamiques pouvant s'adapter a des besoins precis. Le decoupage coherent de l'information associe a un developpement par modules offre la perspective d'application de l'outil pour d'autres types d'activites. Dans ce cas, il s'agit de definir la part commune avec les modules existants et planifier les activites de developpement specifiques selon la meme demarche que celle presentee dans le present document.

Genome-wide analysis and characterization of Aux/IAA family genes related to fruit ripening in papaya (Carica papaya L.).

PubMed

Liu, Kaidong; Yuan, Changchun; Feng, Shaoxian; Zhong, Shuting; Li, Haili; Zhong, Jundi; Shen, Chenjia; Liu, Jinxiang

2017-05-05

Auxin/indole-3-acetic acid (Aux/IAA) family genes encode short-lived nuclear proteins that mediate the responses of auxin-related genes and are involved in several plant developmental and growth processes. However, how Aux/IAA genes function in the fruit development and ripening of papaya (Carica papaya L.) is largely unknown. In this study, a comprehensive identification and a distinctive expression analysis of 18 C. papaya Aux/IAA (CpIAA) genes were performed using newly updated papaya reference genome data. The Aux/IAA gene family in papaya is slightly smaller than that in Arabidopsis, but all of the phylogenetic subfamilies are represented. Most of the CpIAA genes are responsive to various phytohormones and expressed in a tissues-specific manner. To understand the putative biological functions of the CpIAA genes involved in fruit development and ripening, quantitative real-time PCR was used to test the expression profiling of CpIAA genes at different stages. Furthermore, an IAA treatment significantly delayed the ripening process in papaya fruit at the early stages. The expression changes of CpIAA genes in ACC and 1-MCP treatments suggested a crosstalk between auxin and ethylene during the fruit ripening process of papaya. Our study provided comprehensive information on the Aux/IAA family in papaya, including gene structures, phylogenetic relationships and expression profiles. The involvement of CpIAA gene expression changes in fruit development and ripening gives us an opportunity to understand the roles of auxin signaling in the maturation of papaya reproductive organs.

Research on graphite reinforced glass matrix composites

NASA Technical Reports Server (NTRS)

Bacon, J. F.; Prewo, K. M.; Thompson, E. R.

1978-01-01

A composite that can be used at temperatures up to 875 K with mechanical properties equal or superior to graphite fiber reinforced epoxy composites is presented. The composite system consist of graphite fiber, uniaxially or biaxially, reinforced borosilicate glass. The mechanical and thermal properties of such a graphite fiber reinforced glass composite are described, and the system is shown to offer promise as a high performance structural material. Specific properties that were measured were: a modified borosilicate glass uniaxially reinforced by Hercules HMS graphite fiber has a three-point flexural strength of 1030 MPa, a four-point flexural strength of 964 MPa, an elastic modulus of 199 GPa and a failure strain of 0.0052. The preparation and properties of similar composites with Hercules HTS, Celanese DG-102, Thornel 300 and Thornel Pitch graphite fibers are also described.

Optical waveguides in magneto-optical glasses fabricated by proton implantation

NASA Astrophysics Data System (ADS)

Liu, Chun-Xiao; Li, Yu-Wen; Zheng, Rui-Lin; Fu, Li-Li; Zhang, Liao-Lin; Guo, Hai-Tao; Zhou, Zhi-Guang; Li, Wei-Nan; Lin, She-Bao; Wei, Wei

2016-11-01

Planar waveguides in magneto-optical glasses (Tb3+-doped aluminum borosilicate glasses) have been produced by a 550-keV proton implantation at a dose of 4.0×1016 ions/cm2 for the first time to our knowledge. After annealing at 260 °C for 1.0 h, the dark-mode spectra and near-field intensity distributions are measured by the prism-coupling and end-face coupling methods. The damage profile, refractive index distribution and light propagation mode of the planar waveguide are numerically calculated by SRIM 2010, RCM and FD-BPM, respectively. The effects of implantation on the structural and optical properties are investigated by Raman and absorption spectra. It suggests that the proton-implanted Tb3+-doped aluminum borosilicate glass waveguide is a good candidate for a waveguide isolator in optical fiber communication and all-optical communication.

Incorporation and distribution of rhenium in a borosilicate glass melt heat treated in a sealed ampoule

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, Dong-Sang; Schweiger, Michael J.

2013-07-25

We investigated a mass balance of rhenium (used as a surrogate for technetium-99) in a borosilicate glass that was mixed with excess Re source (KReO4) beyond its solubility and heat treated in a vacuum-sealed fused silica ampoule. Distribution of Re in the bulk of the glass, in a salt phase formed on the melt surface, and in condensate material deposited on the ampoule wall was evaluated to understand the Re migration into different phases during the reaction between the molten glass and KReO4. The information gained from this study will contribute to an effort to understand the mechanism of technetiummore » retention in or escape from glass melt during early stages of glass batch melting, which is a goal of the present series of studies.« less

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

PubMed

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.

Effects of optical dopants and laser wavelength on atom probe tomography analyses of borosilicate glasses

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lu, Xiaonan; Schreiber, Daniel K.; Neeway, James J.

Atom probe tomography (APT) is a novel analytical microscopy method that provides three dimensional elemental mapping with sub-nanometer spatial resolution and has only recently been applied to insulating glass and ceramic samples. In this paper, we have studied the influence of the optical absorption in glass samples on APT characterization by introducing different transition metal optical dopants to a model borosilicate nuclear waste glass (international simple glass). A systematic comparison is presented of the glass optical properties and the resulting APT data quality in terms of compositional accuracy and the mass spectra quality for two APT systems: one with amore » green laser (532 nm, LEAP 3000X HR) and one with a UV laser (355 nm, LEAP 4000X HR). These data were also compared to the study of a more complex borosilicate glass (SON68). The results show that the analysis data quality such as compositional accuracy and total ions collected, was clearly linked to optical absorption when using a green laser, while for the UV laser optical doping aided in improving data yield but did not have a significant effect on compositional accuracy. Comparisons of data between the LEAP systems suggest that the smaller laser spot size of the LEAP 4000X HR played a more critical role for optimum performance than the optical dopants themselves. The smaller spot size resulted in more accurate composition measurements due to a reduced background level independent of the material’s optical properties.« less

Possible quantum valence criticality in CeCu6-xAux

NASA Astrophysics Data System (ADS)

Shiino, Takayuki; Nobe, Kohei; Imura, Keiichiro; Deguchi, Kazuhiko; Sato, Noriaki K.

2018-05-01

CeCu6-xAux is known as a heavy fermion compound that exhibits antiferromagnetism for x ≳ 0 . 1 and non-Fermi-liquid (NFL) behavior around the critical concentration xc ≈ 0 . 1. Although this material has been studied by means of a lot of experiments, the origin of its NFL is still veiled in mystery. In this study, we examine the magnetic properties of CeCu6-xAux for various values of x (0 ≤ x ≤ 0.8), and discuss the possibility that the quantum valence criticality might be responsible for the low-temperature magnetic properties.

Historical Review of Glasses Used for Parenteral Packaging.

PubMed

Schaut, Robert A; Weeks, W Porter

2017-01-01

Glass has long been used for packaging precious liquids, in particular pharmaceuticals. Its unique combination of hermeticity, transparency, strength, and chemical durability make it the optimal material for such an important role. Today's life-saving drugs are stored in borosilicate glasses, which evolved from applications in microscope optics and thermometers. As the glass compositions improved, so did the methods used to shape them and the tests used to characterize them. While all of these advances improved the quality of the glass container and its ability to protect the contents, problems still exist such as delamination, cracks, and glass particulates. In addition to these issues, we review new developments in glass composition development, performance, and testing in the 21 st century. © PDA, Inc. 2017.

Spent fuel canister for geological repository: Inner material requirements and candidates evaluation

NASA Astrophysics Data System (ADS)

Puig, Francesc; Dies, Javier; Pablo, Joan de; Martínez-Esparza, Aurora

2008-05-01

One of the key aspects in designing Spanish spent nuclear fuel canister for geological repository is selecting the inner material to be placed between the steel walls and the fuel assemblies. This material has to primarily avoid the possibility of a criticality event once the canister gets breached by corrosion and flooded by groundwater. A detailed set of requirements for a material to fulfil this role in that environment have been devised and presented in this paper. With these requirements in view, eight potentially interesting candidates were evaluated: cast iron or steel, borosilicate glass, spinel, depleted uranium, dehydrated zeolites, haematite, phosphates, and olivine. Among these, the first four materials or their families are found promising for this application.

Novel online security system based on rare-earth-doped glass microbeads

NASA Astrophysics Data System (ADS)

Officer, Simon; Prabhu, G. R.; Pollard, Pat; Hunter, Catherine; Ross, Gary A.

2004-06-01

A novel fluorescent security label has been produced that could replace numerous conventional fluorescent dyes in document security. This label utilizes rare earth ions doped in a borosilicate glass matrix to produce sharp spectral fluorescence peaks with characteristic long lifetimes due to the rare earth ions. These are subsequently detected by an online detection system based on fluorescence and the long lifetimes to avoid any interference from other fluorophores present in the background. Security is further enhanced by the interaction of the rare earth ions with each other and the effect of the host on the emission spectra and therefore the number of permutations that could be produced. This creates a very secure label with various applications for the security market.

Spectroscopie par transformee de fourier des spectres etroits: application aux interferometres statiques

NASA Astrophysics Data System (ADS)

Vermande, P.; Gilard, O.; Rosak, A.

2017-11-01

The Fourier transform spectrometry is useful to obtain optical spectra with high resolution. But in case of narrow band spectra, the number of sample become very important, related to the useful information (the sampling is proportional to the higher wavelength). By changing the sampling, it is possible to obtain narrow band spectra with far less samples. With fewer samples, static interferometers become possible to use. So with these two ideas (a better sampling and static interferometer) we can build a very simple, compact, and static instrument. We will show several possible application of this instrument.

40 CFR 60.296 - Test methods and procedures.

Code of Federal Regulations, 2010 CFR

2010-07-01

..., g/kg. cs=concentration of particulate matter, g/dsm. Qsd=volumetric flow rate, dscm/hr. A=zero... (borosilicate) glass, wool fiberglass, and flat glass. P=glass production rate, kg/hr. (2) Method 5 shall be...

Guidance, Control and Positioning of Future Precision Guided Stand-off Weapons Systems

DTIC Science & Technology

1986-06-01

environment tests. The programme consists of approximately ten fl ights, the firsts having a passive nature . These are followed by progressive...Limited _. .. , 40 Chigwell Lane, Loughton, Essex IGIO 3TZ PREFACE The environment in which tactical air forces must be able to operate is becoming...GUIDANCE SYSTEM CONCEPT FOR HIGH-DYNAMIC ENVIRONMENT * by U.K.Krogmann 17 APPLICATIONS DES CENTRALES A COMPOSANTS LIES AUX MISSILES TACTIQUES: CAS DES

Issues in Intelligence Production: Summary of Interviews with Canadian Managers of Intelligence Analysts

DTIC Science & Technology

2010-12-01

la Reine (en droit du Canada), telle que représentée par le ministre de ...organisationnelles, ainsi qu’aux préjugés des analystes et des organismes du renseignement. Un tel constat exige la tenue d’un examen en profondeur de la ...processus de production du renseignement que l’on pourrait expliquer par la mise en application des connaissances et des méthodes acquises dans

Dual DNA binding property of ABA insensitive 3 like factors targeted to promoters responsive to ABA and auxin.

PubMed

Nag, Ronita; Maity, Manas Kanti; Dasgupta, Maitrayee

2005-11-01

The ABA responsive ABI3 and the auxin responsive ARF family of transcription factors bind the CATGCATG (Sph) and TGTCTC core motifs in ABA and auxin response elements (ABRE and AuxRE), respectively. Several evidences indicate ABI3s to act downstream to auxin too. Because DNA binding domain of ABI3s shows significant overlap with ARFs we enquired whether auxin responsiveness through ABI3s could be mediated by their binding to canonical AuxREs. Investigations were undertaken through in vitro gel mobility shift assays (GMSA) using the DNA binding domain B3 of PvAlf (Phaseolus vulgaris ABI3 like factor) and upstream regions of auxin responsive gene GH3 (-267 to -141) and ABA responsive gene Em (-316 to -146) harboring AuxRE and ABRE, respectively. We demonstrate that B3 domain of PvAlf could bind AuxRE only when B3 was associated with its flanking domain B2 (B2B3). Such strict requirement of B2 domain was not observed with ABRE, where B3 could bind with or without being associated with B2. This dual specificity in DNA binding of ABI3s was also demonstrated with nuclear extracts of cultured cells of Arachis hypogea. Supershift analysis of ABRE and AuxRE bound nuclear proteins with antibodies raised against B2B3 domains of PvAlf revealed that ABI3 associated complexes were detectable in association with both cis elements. Competition GMSA confirmed the same complexes to bind ABRE and AuxRE. This dual specificity of ABI3 like factors in DNA binding targeted to natural promoters responsive to ABA and auxin suggests them to have a potential role in conferring crosstalk between these two phytohormones.

The auxin transporter, OsAUX1, is involved in primary root and root hair elongation and in Cd stress responses in rice (Oryza sativa L.).

PubMed

Yu, ChenLiang; Sun, ChenDong; Shen, Chenjia; Wang, Suikang; Liu, Fang; Liu, Yan; Chen, YunLong; Li, Chuanyou; Qian, Qian; Aryal, Bibek; Geisler, Markus; Jiang, De An; Qi, YanHua

2015-09-01

Auxin and cadmium (Cd) stress play critical roles during root development. There are only a few reports on the mechanisms by which Cd stress influences auxin homeostasis and affects primary root (PR) and lateral root (LR) development, and almost nothing is known about how auxin and Cd interfere with root hair (RH) development. Here, we characterize rice osaux1 mutants that have a longer PR and shorter RHs in hydroponic culture, and that are more sensitive to Cd stress compared to wild-type (Dongjin). OsAUX1 expression in root hair cells is different from that of its paralogous gene, AtAUX1, which is expressed in non-hair cells. However, OsAUX1, like AtAUX1, localizes at the plasma membrane and appears to function as an auxin tranporter. Decreased auxin distribution and contents in the osaux1 mutant result in reduction of OsCyCB1;1 expression and shortened PRs, LRs and RHs under Cd stress, but may be rescued by treatment with the membrane-permeable auxin 1-naphthalene acetic acid. Treatment with the auxin transport inhibitors 1-naphthoxyacetic acid and N-1-naphthylphthalamic acid increased the Cd sensitivity of WT rice. Cd contents in the osaux1 mutant were not altered, but reactive oxygen species-mediated damage was enhanced, further increasing the sensitivity of the osaux1 mutant to Cd stress. Taken together, our results indicate that OsAUX1 plays an important role in root development and in responses to Cd stress. © 2015 The Authors The Plant Journal © 2015 John Wiley & Sons Ltd.

AGARD Flight Test Techniques Series. Volume 3. Identification of Dynamic Systems-Applications to Aircraft. Part 2. Nonlinear Analysis and Manoeuvre Design. (L’Identification des Systemes Dynamiques-Applications aux Aeronefs Titre 2; L’analyse non-lineaire et la Conception de la Manoeuvre)

DTIC Science & Technology

1994-05-01

matrix K(i+1) is calculated from the vector can be reconstructed by simple integration. covariance matrix P(i+1 Ii) by: In reality not all components...is preferable to use a symbolic algebra favorable wheather conditions, for flight tests with package such as Maple or Mathematica, which will large...proved to be virtually A A identical. IZX(r, + (Pro + kp)(q%, + kq)) The actual application of the extended Kalman M AxrPq filter and smoother to

Chemical composition and mineralogy of borate from Rio Grande deposit, Uyuni (Bolivia) as raw materials for industrial applications

NASA Astrophysics Data System (ADS)

Guillen Vargas, Julio; Arancibia, Jony Roger Hans; Alfonso, Pura; Garcia-Valles, Maite; Parcerisa, David; Martinez, Salvador

2014-05-01

Bolivia has large tailings as a result of the historic and present-day Sn mining activity developed extensively in that country. Tailings produced in these mining activities have an appropriate composition to reprocess them and make silicate glass and glass-ceramics, obtaining the valorization of wastes and reducing the visual and chemical impact. Reprocessing the wastes to make glass and glass-ceramics prevents the leaching of heavy metals from those wastes because they are retained in the structure of the glass. Furthermore, an option to increase the economic value of these glasses is the introduction of boron and other additives to produce borosilicate glass. In this study a characterization of the Rio Grande borate deposit for its use in the manufacture of borosilicate glass is presented. Mineralogy was determined by X-ray diffraction (XRD), and Fourier transforms infrared spectroscopy (FTIR); textures were observed by scanning electron microscopy (SEM) and chemical composition was determined by inductively coupled plasma mass spectrometry (ICP-MS). The Rio Grande borate deposit is located in an area of about 50 km2 close to the south of the Salar of Uyuni, in the Río Grande de Lípez Delta. Borates occur in the contact between fluvio-deltaic and lacustrine sediments from water raising the surface by capillarity. The borates crop out in an extent area but towards the west they are covered by fluvio-deltaic sediments, which can be up to 2 m thick. These borates occur as lenses 50-100 m in diameter and layers up to 1 m thick. They usually form brittle nodules with a cotton-ball texture. Chemical composition of the Rio Grande borates is CaO, 11.82-13.83 wt%; Na2O, 13.50-19.35 wt%; K2O, 0.05- 1.04 wt%; MgO, 0.42-1.46 wt%; B2O3, 36.21-42.60 wt%; SiO2, up to 0.53 wt% and SO2, up to 0.60 wt%. Trace elements are low: Sr content is between 151-786 ppm, Al 12-676 ppm, Mn between 1-17 ppm, As 2-10 ppm and Fe between 9-376 ppm. The most abundant borate mineral in this deposit is ulexite (NaCaB5.5H20), halite can reach up to 17 wt% and gypsum up to 1.2 wt.%. Calcite occurs in minor contents. Ulexite exhibits a fibrous morphology with fibers oriented parallel each other. Purity of borates from the Rio Grande deposits makes them suitable for the most restrictive applications. Chemistry of these borates is in accordance with the necessary composition for obtaining borosilicate glasses. Acknowledgements: This work was partly financed by the project AECID: A3/042750/11, and the SGR 2009SGR-00444.

Inhibiting the oxidation of diamond during preparing the vitrified dental grinding tools by depositing a ZnO coating using direct urea precipitation method.

PubMed

Wang, Yanhui; Yuan, Yungang; Cheng, Xiaozhe; Li, Xiaohu; Zang, Jianbing; Lu, Jing; Yu, Yiqing; Xu, Xipeng

2015-08-01

Oxidation of diamond during the manufacturing of vitrified dental grinding tools would reduce the strength and sharpness of tools. Zinc oxide (ZnO) coating was deposited on diamond particles by urea precipitation method to protect diamond in borosilicate glass. The FESEM results showed that the ZnO coating was formed by plate-shaped particles. According to the TG results, the onset oxidation temperature of the ZnO-coated diamond was about 70 °C higher than the pristine diamond. The EDS results showed that ZnO diffused into the borosilicate glass during sintering. As the result, the bending strength of the composites containing ZnO-coated diamond was increased by 24% compared to that of the composites containing pristine diamond. Copyright © 2015 Elsevier B.V. All rights reserved.

Evaluations of candidate encapsulation designs and materials for low-cost silicon photovoltaic arrays

NASA Technical Reports Server (NTRS)

Gaines, G. B.; Carmichael, D. C.; Sliemers, F. A.; Brockway, M. C.; Bunk, A. R.; Nance, G. P.

1978-01-01

Three encapsulation designs for silicon photovoltaic arrays based on cells with silk-screened Ag metallization have been evaluated: transparent polymeric coatings over cells laminated between two films or sheets of polymeric materials; cells adhesively bonded to a glass cover with a polymer pottant and a glass or other substrate component. Silicone and acrylic coatings were assessed, together with acrylic sheet, 0.635 mm fiberglass-reinforced polyester sheet, 0.102 mm polycarbonate/acrylic dual-layer film, 0.127 mm fluorocarbon film, soda-lime glass, borosilicate glass, low-iron glass, and several adhesives. The encapsulation materials were characterized by light transmittance measurements, determination of moisture barrier properties and bond strengths, and by the performance of cells before and after encapsulation. Silicon and acrylic coatings provided inadequate protection. Acrylic and fluorocarbon films displayed good weatherability and acceptable optical transmittance. Borosilicate, low-iron and soda-lime-float glasses were found to be acceptable candidate encapsulants for most environments.

Extraction of heavy metal ions from waste colored glass through phase separation.

PubMed

Chen, Danping; Masui, Hirotsugu; Miyoshi, Hiroshi; Akai, Tomoko; Yazawa, Tetsuo

2006-01-01

A new method utilizing phase separation phenomena for the extraction of heavy metal ions used as colorants in colored glass is proposed. Colored soda-lime-silica glass containing Co or Cr as a colorant was remelted with B2O3 to yield soda-lime-borosilicate glass. The soda-lime-borosilicate glass thus obtained was leached in 1M nitric acid at 90 degrees C to dissolve the borate phase. All cations (Na, Ca, Cr and Co) concentrated in the borate phase are successfully leached out with the dissolution of the borate phase, when the amount of the B2O3 added to the glass and heat treatment conditions are properly chosen. Porous silicate glass powders with high SiO2 purity are obtained as the result of the leaching. Porous glass can also be formed as bulk material by controlling the composition of additives during the remelting.

Washing and caustic leaching of Hanford tank sludges: results of FY 1996 studies. Revision

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lumetta, G.J.; Rapko, B.M.; Wagner, M.J.

During the past few years, the primary mission at the US Department of Energy`s Hanford Site has changed from producing plutonium to restoring the environment. Large volumes of high-level radioactive wastes (HLW), generated during past Pu production and other operations, are stored in underground tanks on site. The current plan for remediating the Hanford tank farms consists of waste retrieval, pretreatment, treatment (immobilization), and disposal. The HLW will be immobilized in a borosilicate glass matrix and then disposed of in a geologic repository. Because of the expected high cost of HLW vitrification and geologic disposal, pretreatment processes will be implementedmore » to reduce the volume of borosilicate glass produced in disposing of the tank wastes. On this basis, a pretreatment plan is being developed. This report describes the sludge washing and caustic leaching test conducted to create a Hanford tank sludge pretreatment flowsheet.« less

Program For Generating Interactive Displays

NASA Technical Reports Server (NTRS)

Costenbader, Jay; Moleski, Walt; Szczur, Martha; Howell, David; Engelberg, Norm; Li, Tin P.; Misra, Dharitri; Miller, Philip; Neve, Leif; Wolf, Karl;

Another Program For Generating Interactive Graphics

NASA Technical Reports Server (NTRS)

Costenbader, Jay; Moleski, Walt; Szczur, Martha; Howell, David; Engelberg, Norm; Li, Tin P.; Misra, Dharitri; Miller, Philip; Neve, Leif; Wolf, Karl;

Water Triple-Point Comparisons: Plateau Averaging or Peak Value?

NASA Astrophysics Data System (ADS)

Steur, P. P. M.; Dematteis, R.

2014-04-01

With a certain regularity, national metrology institutes conduct comparisons of water triple-point (WTP) cells. The WTP is the most important fixed point for the International Temperature Scale of 1990 (ITS-90). In such comparisons, it is common practice to simply average all the single measured temperature points obtained on a single ice mantle. This practice is quite reasonable whenever the measurements show no time dependence in the results. Ever since the first Supplementary Information for the International Temperature Scale of 1990, published by the Bureau International des Poids et Mesures in Sèvres, it was strongly suggested to wait at least 1 day before taking measurements (now up to 10 days), in order for a newly created ice mantle to stabilize. This stabilization is accompanied by a change in temperature with time. A recent improvement in the sensitivity of resistance measurement enabled the Istituto Nazionale di Ricerca Metrologica to detect more clearly the (possible) change in temperature with time of the WTP on a single ice mantle, as for old borosilicate cells. A limited investigation was performed where the temperature of two cells was monitored day-by-day, from the moment of mantle creation, where it was found that with (old) borosilicate cells it may be counterproductive to wait the usual week before starting measurements. The results are presented and discussed, and it is suggested to adapt the standard procedure for comparisons of WTP cells allowing for a different data treatment with (old) borosilicate cells, because taking the temperature dependence into account will surely reduce the reported differences between cells.

Corrosion of inconel in high-temperature borosilicate glass melts containing simulant nuclear waste

NASA Astrophysics Data System (ADS)

Mao, Xianhe; Yuan, Xiaoning; Brigden, Clive T.; Tao, Jun; Hyatt, Neil C.; Miekina, Michal

2017-10-01

The corrosion behaviors of Inconel 601 in the borosilicate glass (MW glass) containing 25 wt.% of simulant Magnox waste, and in ZnO, Mn2O3 and Fe2O3 modified Mg/Ca borosilicate glasses (MZMF and CZMF glasses) containing 15 wt.% of simulant POCO waste, were evaluated by dimensional changes, the formation of internal defects and changes in alloy composition near corrosion surfaces. In all three kinds of glass melts, Cr at the inconel surface forms a protective Cr2O3 scale between the metal surface and the glass, and alumina precipitates penetrate from the metal surface or formed in-situ. The corrosion depths of inconel 601 in MW waste glass melt are greater than those in the other two glass melts. In MW glass, the Cr2O3 layer between inconel and glass is fragmented because of the reaction between MgO and Cr2O3, which forms the crystal phase MgCr2O4. In MZMF and CZMF waste glasses the layers are continuous and a thin (Zn, Fe, Ni, B)-containing layer forms on the surface of the chromium oxide layer and prevents Cr2O3 from reacting with MgO or other constituents. MgCr2O4 was observed in the XRD analysis of the bulk MW waste glass after the corrosion test, and ZrSiO4 in the MZMF waste glass, and ZrSiO4 and CaMoO4 in the CZMF waste glass.

Aircraft Trajectories Computation-Prediction-Control (La Trajectoire de l’Avion Calcul-Prediction-Controle). Volume 2

DTIC Science & Technology

1990-05-01

faire atterrir las a~ronefs sans recourir de faqon systimatique aux attentes habituelles; un de leurs coll~gues ayant contribu6 At la recherche de la...applicable to or usable for the management of the flows of aircraft and the control of individual flights, the integration of control phases over...February 1976. AIR TRAFFIC MANAGEMENT : Civil/Military Systems and Technologies Guidance and Control Symposium, Copenhagen, Denmark, 9-12 October 1979. AGARD

Light, Strong Insulating Tiles

NASA Technical Reports Server (NTRS)

Cordia, E.; Schirle, J.

1987-01-01

Improved lightweight insulating silica/aluminum borosilicate/silicon carbide tiles combine increased tensile strength with low thermal conductivity. Changes in composition substantially improve heat-insulating properties of silica-based refractory tile. Silicon carbide particles act as high-emissivity radiation scatterers in tile material.

Bioactive glass/polymer composites for bone and nerve repair and regeneration

NASA Astrophysics Data System (ADS)

Mohammadkhah, Ali

Bioactive glasses have several attractive properties in hard and soft tissue repair but their brittleness limited their use, as scaffolding materials, for applications in load-bearing hard tissue repair. At the same time, because of their bioactive properties, they are being studied more often for soft tissue repair. In the present work, a new glass/polymer composite scaffold was developed for the repair of load-bearing bones with high flexural strength and without brittle behavior. The new composites have 2.5 times higher flexural strength and ˜100 times higher work of fracture (without catastrophic failure) compared to a similar bare glass scaffold. Also the use of two known bioactive glasses (13-93-B3 and 45S5) was investigated in developing glass/Poly(epsilon-caprolactone) (PCL) composite films for peripheral nerve repair. It was found that a layer of globular hydroxyapatite (HA) formed on both sides of the composites. The borate glass in the composites was fully reacted in SBF and different ions were released into the solution. The addition of bioactive glass particles to the PCL lowered its elastic modulus and yield strength, but the composites remained intact after the 14 day period in SBF at 37°C. Finally, in an effort to design a better bioactive glass, new borosilicate glass compositions were developed that possess advantages of borate and silicate bioactive glasses at the same time. It was found that replacing small amounts of B2O3 with SiO2 improved glass formation, resistance to nucleation and crystallization, and increased the release rate of boron and silicon in vitro. This new borosilicate glass could be a good alternative to existing silicate and borate bioactive glasses.

Boron

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cozen, L.F.

1991-05-01

This paper reports that borate minerals and refined borates are used extensively for the manufacture of vitreous materials such as insulation and textile fiberglasses, borosilicate glass, and porcelain enamels and frits. In North America, these applications are estimated to account for over 54% of the borate consumption. Other substantial uses are in soaps and detergents, metallurgy, fire retardants, industrial biocides, agriculture, and various miscellaneous applications. Reported domestic borate consumption in 1990 was estimated by the U.S. Bureau of Mines to be 320 000 metric tons B{sub 2}O{sub 3} versus 354 000 metric tons B{sub 2}O{sub 3} in 1989. Consumption ismore » projected to remain essentially static in 1991. Imports were estimated by the Bureau to be 50 000 metric tons B{sub 2}O{sub 3} in 1990. Exports of boric acid and refined borates were approximately 650 000 metric tons of product, a 15 000 metric ton increase from the 1989 level. This increase partially offsets the drop in the 1990 consumption level.« less

Trust Restoration in International Military Missions

DTIC Science & Technology

2010-11-01

confiance comparativement aux scénarios sans bris de confiance (groupe témoin). ii DRDC Toronto TR 2010-151 This page intentionally left...restauration de la confiance comparativement aux scénarios sans bris de confiance (groupe témoin). Nos observations concordent avec celles d’études...11 Figure 2: Design Overview

L’évaluation et le traitement du nourrisson exposé au virus d’immunodéficience humaine de type 1

PubMed Central

2004-01-01

RÉSUMÉ Dans les pays industrialisés, des soins et un traitement sont offerts aux femmes enceintes et aux nourrissons, afin de faire chuter à 2 % ou moins le taux d’infection périnatale au virus d’immunodéficience humaine de type 1 (VIH-1). Le pédiatre joue un rôle de premier plan dans la prévention de la transmission du VIH-1 de la mère à l’enfant par le dépistage des nourrissons exposés au VIH dont l’infection au VIH de la mère n’a pas été diagnostiquée avant l’accouchement. Il prescrit une prophylaxie antirétrovirale à ces nourrissons, afin de réduire le risque d’acquisition de l’infection au VIH-1 et d’en éviter le plus possible la transmission par le lait maternel. De plus, le pédiatre peut soigner les nourrissons exposés au VIH-1 en les surveillant pour obtenir un dépistage précoce de l’infection au VIH-1 et évaluer les toxicités à court et à long terme de l’exposition aux antirétroviraux, assurer une chimioprophylaxie de la pneumonie à Pneumocystis et soutenir les familles qui vivent avec une infection au VIH-1, grâce à des conseils thérapeutiques aux parents ou aux soignants.

Interdire aux enfants et aux adolescents de moins de 18 ans l’accès aux établissements commerciaux de bronzage

PubMed Central

Taddeo, Danielle; Stanwick, Richard

2012-01-01

RÉSUMÉ Le nombre de mélanomes cutanés malins a plus que triplé depuis 35 ans. Puisque les dommages sont cumulatifs, l’exposition aux rayonnements ultraviolets tôt dans la vie accroît le risque, qui augmente davantage avec l’utilisation de sources artificielles de rayonnements ultraviolets. Il peut falloir des années pour évaluer les répercussions et l’étendue complètes des dommages causés par le bronzage artificiel à longueur d’année, compte tenu de la longue période de latence de la plupart des cancers de la peau. Les adolescents fréquentent souvent les salons de bronzage, les filles s’y rendant davantage et de manière soutenue. L’industrie du bronzage conteste la classification de cancérigène physique de groupe 1 qu’attribuent au bronzage artificiel l’Organisation mondiale de la santé et le Centre international de recherche sur le cancer. Les salons de bronzage cherchent à établir et à maintenir une clientèle chez les adolescents. Par conséquent, la Société canadienne de pédiatrie s’ajoute à d’autres organismes de santé réputés pour appuyer l’interdiction des établissements commerciaux de bronzage aux enfants et adolescents de moins de 18 ans.

Disordered porous solids : from chord distributions to small angle scattering

NASA Astrophysics Data System (ADS)

Levitz, P.; Tchoubar, D.

1992-06-01

Disordered biphasic porous solids are examples of complex interfacial media. Small angle scattering strongly depends on the geometrical properties of the internal surface partitioning a porous system. Properties of the second derivative of the bulk autocorrelation function quantitatively defines the level of connection between the small angle scattering and the statistical properties of this interface. A tractable expression of this second derivative, involving the pore and the mass chord distribution functions, was proposed by Mering and Tchoubar (MT). Based on the present possibility to make a quantitative connection between imaging techniques and the small angle scattering, this paper tries to complete and to extend the MT approach. We first discuss how chord distribution functions can be used as fingerprints of the structural disorder. An explicit relation between the small angle scattering and these chord distributions is then proposed. In a third part, the application to different types of disorder is critically discussed and predictions are compared to available experimental data. Using image processing, we will consider three types of disorder : the long-range Debye randomness, the “ correlated " disorder with a special emphasis on the structure of a porous glass (the vycor), and, finally, complex structures where length scale invariance properties can be observed. Les solides poreux biphasiques sont des exemples de milieux interfaciaux complexes. La diffusion aux petits angles (SAS) dépend fortement des propriétés géométriques de l'interface partitionant le milieu poreux. Les propriétés de la dérivée seconde de la fonction d'autocorrélation de densité définit quantitativement le niveau de connection entre la diffusion aux petits angles et les caractéristiques statistiques de cette interface. Une expression utilisable de cette seconde dérivée, impliquant les distributions de cordes associées à la phase massique et au réseau de pores, fut proposée par Mering et Tchoubar (MT). Mettant à profit la possibilité actuelle d'une comparaison quantitative entre les techniques d'imagerie et la diffusion aux petits angles, ce papier tente de compléter et d'étendre l'approche MT. Dans un premier temps, nous montrons en quoi la connaissance de ces distributions de cordes permet de distinguer certains types de désordres structuraux. Une relation explicite entre le spectre de diffusion aux petits angles et les distributions de cordes est alors proposée. Dans une troisième partie, l'application à différents types de désordre est discutée et les prédictions du modèle comparées aux résultats expérimentaux disponibles. Par utilisation du traitement d'images, nous nous intéressons à trois types de désordre : le milieu aléatoire de Debye, pour ses propriétés à grandes distances, le désordre “ corrélé " avec une attention particulière pour le cas d'un verre poreux (le Vycor) et enfin des organisations complexes où des propriétés d'invariance d'échelle de longueur peuvent être observées.

[Graviresponse in higher plants and its regulation in molecular bases: relevance to growth and development, and auxin polar transport in etiolated pea seedlings].

PubMed

Ueda, Junichi; Miyamoto, Kensuke

2003-08-01

We review the graviresponse under true and simulated microgravity conditions on a clinostat in higher plants, and its regulation in molecular bases, especially on the aspect of auxin polar transport in etiolated pea (Pisum sativum L. cv. Alaska) seedlings which were the plant materials subjected to STS-95 space experiments. True and simulated microgravity conditions substantially affected growth and development in etiolated pea seedlings, especially the direction of growth of stems and roots, resulting in automorphosis. In etiolated pea seedlings grown in space, epicotyls were the most oriented toward the direction far from the cotyledons, and roots grew toward the aerial space of Plant Growth Chamber. Automorphosis observed in space were well simulated by a clinorotation on a 3-dimensional clinostat and also phenocopied by the application of auxin polar transport inhibitors of 2,3,5-triiodobenzoic acid, N-(1-naphtyl)phthalamic acid and 9-hydroxyfluorene-9-carboxylic acid. Judging from the results described above together with the fact that activities of auxin polar transport in epicotyls of etiolated pea seedlings grown in space substantially were reduced, auxin polar transport seems to be closely related to automorphosis. Strenuous efforts to learn in molecular levels how gravity contributes to the auxin polar transport in etiolated pea epicotyls resulted in successful identification of PsPIN2 and PsAUX1 genes located in plasma membrane which products are considered to be putative efflux and influx carriers of auxin, respectively. Based on the results of expression of PsPIN2 and PsAUX1 genes under various gravistimulations, a possible role of PsPIN2 and PsAUX1 genes for auxin polar transport in etiolated pea seedlings will be discussed.

Strategies facilitant les tests en pre-certification pour la robustesse a l'egard des radiations =

NASA Astrophysics Data System (ADS)

Souari, Anis

Les effets des radiations cosmiques sur l'electronique embarquee preoccupent depuis. quelques decennies les chercheurs interesses par la robustesse des circuits integres. Plusieurs. recherches ont ete menees dans cette direction, principalement pour les applications spatiales. ou l’environnement de leur deploiement est hostile. En effet, ces environnements sont denses. en termes de particules qui, lorsqu’elles interagissent avec les circuits integres, peuvent. mener a leur dysfonctionnement, voir meme a leur destruction. De plus, les effets des. radiations s’accentuent pour les nouvelles generations des circuits integres ou la diminution. de la taille des transistors et l’augmentation de la complexite de ces circuits augmentent la. probabilite d’apparition des anomalies et par consequence la croissance des besoins de test. L’expansion de l’electronique grand public (commercial off-the-shelf, COTS) et l’adoption. de ces composants pour des applications critiques comme les applications avioniques et. spatiales incitent egalement les chercheurs a doubler les efforts de verification de la fiabilite. de ces circuits. Les COTS, malgre leurs meilleures caracteristiques en comparaison avec les. circuits durcis tolerants aux radiations qui sont couteux et en retard en termes de technologie. utilisee, sont vulnerables aux radiations. Afin d’ameliorer la fiabilite de ces circuits, une evaluation de leur vulnerabilite dans les. differents niveaux d’abstraction du flot de conception est recommandee. Ceci aide les. concepteurs a prendre les mesures de mitigation necessaires sur le design au niveau. d’abstraction en question. Enfin, afin de satisfaire les exigences de tolerance aux pannes, des. tests tres couteux de certification, obtenus a l’aide de bombardement de particules (protons, neutrons, etc.), sont necessaires. Dans cette these, nous nous interessons principalement a definir une strategie de precertification. permettant d’evaluer d’une facon realiste la sensibilite des circuits integres face. aux effets des radiations afin d’eviter d’envoyer des circuits non robustes a la phase tres. couteuse de la certification. Les circuits cibles par nos travaux sont les circuits integres. programmables par l’usager (FPGA) a base de memoire SRAM et le type de pannes ciblees, causees par les radiations, est les SEU (single event upset) consistant a un basculement de. l’etat logique d’un element de memoire a son complementaire. En effet, les FPGA a base de. memoire SRAM sont de plus en plus demandes par la communaute de l’aerospatial grace a. leurs caracteristiques de prototypage rapide et de reconfiguration sur site mais ils sont. vulnerables face aux radiations ou les SEU sont les pannes les plus frequentes dans les. elements de memoire de type SRAM. Nous proposons une nouvelle approche d’injection de. pannes par emulation permettant de mimer les effets des radiations sur la memoire de. configuration des FPGA et de generer des resultats les plus fideles possibles des resultats des. tests de certification. Cette approche est basee sur la consideration de la difference de. sensibilite des elements de memoire de configuration lorsqu’ils sont a l’etat '1' et a l’etat '0', observee sous des tests acceleres sous faisceaux de protons au renomme laboratoire. TRIUMF, dans la procedure de generation des sequences de test dans le but de mimer la. distribution des pannes dans la memoire de configuration. Les resultats des experimentations. de validation montrent que la strategie proposee est efficace et genere des resultats realistes. Ces resultats revelent que ne pas considerer la difference de sensibilite peut mener a une. sous-estimation de la sensibilite des circuits face aux radiations. Dans la meme optique d’optimisation de la procedure d’injection des pannes par emulation, a. savoir le test de pre-certification, nous proposons une methodologie permettant de maximiser. la detection des bits critiques (bits provoquant une defaillance fonctionnelle s’ils changent. d’etat) pour un nombre bien determine de SEU (qui est le modele de pannes adopte) ou de. maximiser la precision de l’estimation de nombre des bits critiques. Pour ce faire, une. classification des bits de configuration en differents ensembles est tout d’abord mise en. oeuvre, selon leur contenu, les ressources qu’ils configurent et leur criticite. Ensuite, une. evaluation de la sensibilite de chaque ensemble est accomplie. Enfin, la priorisation. d’injection des pannes dans les ensembles les plus sensibles est recommandee. Plusieurs. scenarios d’optimisation d’injection des pannes sont proposes et les resultats sont compares. avec ceux donnes par la methode conventionnelle d’injection aleatoire des pannes. La. methodologie d’optimisation proposee assure une amelioration de plus de deux ordres de. grandeur. Une derniere approche facilitant l’evaluation de la sensibilite des bits configurant les LUT. (look up table) de FPGA, les plus petites entites configurables du FPGA permettant. d’implementer des fonctions combinatoires, utilises par un design est presentee. Elle permet. l’identification facile et sans cout en termes d’utilisation du materiel ou d’outils externes des. bits des LUT. L’approche proposee est simple et efficace, offrant une couverture de pannes. de 100 % et applicable aux nouvelles generations des FPGA de Xilinx. Les approches proposees contribuent a repondre aux exigences du cahier des charges de cette. these et a achever les objectifs definis. Le realisme et la maximisation de l’estimation de la. vulnerabilite des circuits sous test offerts par les nouvelles approches assurent le. developpement d’une strategie de test en pre-certification efficace. En effet, la premiere. approche d’injection de pannes considerant la difference de sensibilite relative des elements. de memoire selon leur contenu genere des resultats donnant une erreur relative atteignant. 3.1 % quand compares aux resultats obtenus a TRIUMF alors que l’erreur relative donnee. par la comparaison des resultats d’une injection conventionnelle aleatoire de pannes avec. ceux de TRIUMF peut atteindre la valeur de 75 %. De plus, l’application de cette approche a. des circuits plus conventionnels montre que 2.3 fois plus d’erreurs sont detectees en. comparaison avec l’injection aleatoire des pannes. Ceci suggere que ne pas considerer la. difference de sensibilite relative dans la procedure d’emulation peut mener a une sousestimation. de la sensibilite du design face aux radiations. Les resultats de la deuxieme. approche proposee ont ete aussi compares aux resultats d’une injection aleatoire de pannes. L’approche proposee, maximisant le nombre des bits critiques inverses, permet d’atteindre. un facteur d’acceleration de 108 de la procedure d’injection des pannes en comparaison a. l’approche aleatoire. Elle permet aussi de minimiser l’erreur d’estimation du nombre des bits. critiques pour atteindre une valeur de ±1.1 % calculee pour un intervalle de confiance de. 95 % tandis que la valeur d’erreur d’estimation des bits critiques generee par l’approche. aleatoire d’injection des pannes pour le meme intervalle de confiance peut atteindre ±8.6 %. Enfin, la derniere approche proposee d’injection de pannes dans les LUT se distingue des. autres approches disponibles dans la litterature par sa simplicite tout en assurant une. couverture maximale de pannes de 100 %. En effet, l’approche proposee est independante. des outils externes permettant d’identifier les bits configurant les LUT qui sont obsoletes ou. ne supportent pas les nouvelles generations des FPGA. Elle agit directement sur les fichiers. generes par l’outil de synthese adopte.

Application of Fiber Optic Instrumentation (Validation des systemes d’instrumentation a fibres optiques)

DTIC Science & Technology

2012-07-01

SCI-228) Executive Summary This AGARDograph presents an introduction to fiber optic systems and is intended to provide a basic understanding of...22 / SCI-228) Synthèse Cette AGARDograph présente une introduction aux systèmes à fibres optiques et a pour objet d’expliquer l’utilisation de ces...l’instrumentation des essais en vol dans l’ensemble des pays membres de l’OTAN, entraînant la disparition progressive des jauges extensométriques et des

A Novel Detector of Broadband Transient Signals

DTIC Science & Technology

2006-11-01

accroissement soudain de l’énergie spectrale observé pendant une courte période sur une vaste gamme de fréquences. Contrairement aux autres méthodes de...nombre d’applications différentes dans lesquelles les transitoires se manifestent sous forme d’un accroissement soudain de l’énergie spectrale observé...torpedo bearing error of 20 degrees (θ = θ1 + 20) was introduced (equation (16)). Al - though, in this case r2 was reduced, the two transients were

Second-order non-linear optical studies on CdS microcrystallite-doped alkali borosilicate glasses

NASA Astrophysics Data System (ADS)

Liu, Hao; Liu, Qiming; Wang, Mingliang; Zhao, Xiujian

2007-05-01

CdS microcrystal-doped alkali borosilicate glasses were prepared by conventional fusion and heat-treatment method. Utilizing Maker fringe method, second-harmonic generation (SHG) was both observed from CdS-doped glasses before and after certain thermal/electrical poling. While because the direction of polarization axes of CdS crystals formed in the samples is random or insufficient interferences of generated SH waves occur, the fringe patterns obtained in samples without poling treatments showed no fine structures. For the poled samples, larger SH intensity has been obtained than that of the samples without any poling treatments. It was considered that the increase of an amount of hexagonal CdS in the anode surface layer caused by the applied dc field increased the SH intensity. The second-order non-linearity χ(2) was estimated to be 1.23 pm/V for the sample poled with 2.5 kV at 360 °C for 30 min.

Release of Gd-ions from peralkaline borosilicate glass in pure water for neutrino detection in Water-Cherenkov Detectors

NASA Astrophysics Data System (ADS)

Dongol, R.; Sundaram, S. K.

2017-09-01

The addition of Gadolinium (Gd)-based salt, specially GdCl3, in the Water Cherenkov Detectors (WCDs) enhances the sensitivity to neutrino detection. However, the unwanted Cl-based byproducts, significantly reduces the transparency of water and sensitivity of WCDs. An alternative method, to introduce Gd-ions in the WCDs, is through Gd-release from a custom designed Gd-doped glass, when in contact with water. This can potentially eliminate the use of Gd-based salts and byproducts. In this work, we report the Gd-ions release for a Gd-doped peralkaline (Na/Al > 1) borosilicate glass, which closely represents photomultiplier tube (PMT) glass composition used in WCDs. The purpose of the paper is to show that the Gd-ion release from a custom designed glass in the form of beads or powders is feasible and could be used as a controlled Gd-source in future WCDs to enhance neutrino detection. In addition, we present our results of Gd-solubility in the base glass composition.

Failure kinetics in borosilicate glass during rod impact

DOE Office of Scientific and Technical Information (OSTI.GOV)

Orphal, Dennis L.; Anderson, Charles E. Jr.; Behner, Thilo

2007-12-12

Failure front (FF) and penetration velocity have been measured for long gold rods impacting and penetrating borosilicate (BS) glass. Data are obtained by visualizing simultaneously FF propagation with a high speed camera and rod penetration with flash X-rays. Results for BS glass are qualitatively similar to those of DEDF (PbO) glass. FF velocity rapidly decreases from an initial value to a lower, approximately constant value. FF velocity increases with impact velocity, v{sub p}. The FF velocity remains significantly lower than the shear velocity, even at the highest impact velocity tested, about 2.5 km/s. The ratio of the FF velocity tomore » the rod penetration velocity, v{sub F}/u, decreases with increasing v{sub p} and appears to be approaching v{sub F}/u = 1 asymptotically, as observed previously for DEDF glass. The separation of the FF and the tip of the rod decreases with increasing impact velocity. Importantly, since v{sub F}/u{>=}1, the gold rod is always penetrating glass behind the FF.« less

Failure and penetration response of borosilicate glass during short-rod impact

DOE Office of Scientific and Technical Information (OSTI.GOV)

Anderson, C. E. Jr.; Orphal, D. L.; Behner, Th.

2007-12-12

The failure characterization of brittle materials like glass is of fundamental importance in describing the penetration resistance against projectiles. A critical question is whether this failure front remains 'steady' after the driving stress is removed. A test series with short gold rods (D = 1 mm, L/D{approx_equal}5-11) impacting borosilicate glass at {approx}1 to 2 km/s was carried out to investigate this question. The reverse ballistic method was used for the experiments, and the impact and penetration process was observed simultaneously with five flash X-rays and a 16-frame high-speed optical camera. Very high measurement accuracy was established to ensure reliable results.more » Results show that the failure front induced by rod impact and penetration does arrest (ceases to propagate) after the rod is totally eroded inside the glass. The impact of a second rod after a short time delay reinitiates the failure front at about the same speed.« less

Experimental and computed results investigating time-dependent failure in a borosilicate glass

NASA Astrophysics Data System (ADS)

Chocron, Sidney; Barnette, Darrel; Holmquist, Timothy; Anderson, Charles E.; Bigger, Rory; Moore, Thomas

2017-01-01

Symmetric plate-impact tests of borosilicate glass were performed from low (116 m/s) to higher (351 m/s) velocities. The tests were recorded with an ultra-high-speed camera to see the shock and failure propagation. The velocity of the back of the target was also recorded with a PDV (Photon Doppler Velocimeter). The images show failure nucleation sites that trail the shock wave. Interestingly, even though the failure wave is clearly seen, the PDV never detected the expected recompression wave. The reason might be that at these low impact velocities the recompression wave is too small to be seen and is lost in the noise. This work also presents a new way to interpret the signals from the PDV. By letting part of the signal travel through the target and reflect on the impact side, it is possible to see the PDV decrease in intensity with time, probably due to the damage growth behind the shock wave.

Process parameter effects on material removal in magnetorheological finishing of borosilicate glass.

PubMed

Miao, Chunlin; Lambropoulos, John C; Jacobs, Stephen D

2010-04-01

We investigate the effects of processing parameters on material removal for borosilicate glass. Data are collected on a magnetorheological finishing (MRF) spot taking machine (STM) with a standard aqueous magnetorheological (MR) fluid. Normal and shear forces are measured simultaneously, in situ, with a dynamic dual load cell. Shear stress is found to be independent of nanodiamond concentration, penetration depth, magnetic field strength, and the relative velocity between the part and the rotating MR fluid ribbon. Shear stress, determined primarily by the material mechanical properties, dominates removal in MRF. The addition of nanodiamond abrasives greatly enhances the material removal efficiency, with the removal rate saturating at a high abrasive concentration. The volumetric removal rate (VRR) increases with penetration depth but is insensitive to magnetic field strength. The VRR is strongly correlated with the relative velocity between the ribbon and the part, as expected by the Preston equation. A modified removal rate model for MRF offers a better estimation of MRF removal capability by including nanodiamond concentration and penetration depth.

The role of troublesome components in plutonium vitrification

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Hong; Vienna, J.D.; Peeler, D.K.

1996-05-01

One option for immobilizing surplus plutonium is vitrification in a borosilicate glass. Two advantages of the glass form are (1) high tolerance to feed variability and, (2) high solubility of some impurity components. The types of plutonium-containing materials in the United States inventory include: pits, metals, oxides, residues, scrap, compounds, and fuel. Many of them also contain high concentrations of carbon, chloride, fluoride, phosphate, sulfate, and chromium oxide. To vitrify plutonium-containing scrap and residues, it is critical to understand the impact of each component on glass processing and chemical durability of the final product. This paper addresses glass processing issuesmore » associated with these troublesome components. It covers solubility limits of chlorine, fluorine, phosphate, sulfate, and chromium oxide in several borosilicate based glasses, and the effect of each component on vitrification (volatility, phase segregation, crystallization, and melt viscosity). Techniques (formulation, pretreatment, removal, and/or dilution) to mitigate the effect of these troublesome components are suggested.« less

Size determination of gold nanoparticles in silicate glasses by UV-Vis spectroscopy

NASA Astrophysics Data System (ADS)

Ali, Shahid; Khan, Younas; Iqbal, Yaseen; Hayat, Khizar; Ali, Muhammad

2017-01-01

A relatively easier and more accurate method for the determination of average size of metal nanoparticles/aggregates in silicate glasses based on ultraviolet visible (UV-Vis) spectra fitted with the Mie and Mie-Gans models was reported. Gold ions were diffused into sodalime silicate and borosilicate glasses by field-assisted solid-state ion-exchange technique using the same experimental parameters for both glasses. Transmission electron microscopy was performed to directly investigate the morphology and distribution of the dopant nanoparticles. UV-Vis spectra of the doped glasses showed broad surface plasmon resonance peaks in their fingerprint regions, i.e., at 525 and 500 nm for sodalime silicate and borosilicate glass matrices, respectively. These spectra were fitted with the Mie model for spherical nanoparticles and the Mie-Gans model for spheroidal nanoparticles. Although both the models were developed for colloidal nanoparticles, the size of the nanoparticles/aggregates calculated was accurate to within ˜10% in both the glass matrices in comparison to the size measured directly from the transmission electron microscope images.

Cerium doped glasses: search for a new scintillator

NASA Astrophysics Data System (ADS)

Kielty, Matthew William

Single crystals have been the standard material when it comes to scintillators, but with the ability to easily be produced at a considerably lower cost and fabricated into tailored sizes and shapes there is increasing interest in the development of glass scintillators as an alternative. Ce-doped borosilicate and phosphate glasses were investigated focusing on the effect of different modifiers on their optical properties and luminescence. The borosilicate glasses were prepared aiming at the detection of thermal neutrons, utilizing B-10, while the phosphate glasses were targeting the detection of gamma-rays taking advantage of high Z elements such as, Ba, Bi, Ta, Pb and W. Structural characteristics determined by Raman spectroscopy were coupled with results from photoluminescence and UV-visible transmission measurements, while the index of refraction was estimated using the Gladstone-Dale relation using experimentally obtained density values. This work revealed barium, with its superior optical transmission and luminescent properties, to be the best high Z element for inclusion in the phosphate glasses studied.

Conception, elaboration et mise a l'essai d'un simulateur interactif permettant une approche modelisante: Application aux lois de la genetique mendelienne

NASA Astrophysics Data System (ADS)

Lasri, Abdel-Halim

Dans cette recherche-developpement, nous avons concu, developpe et mis a l'essai un simulateur interactif pour favoriser l'apprentissage des lois probabilistes impliqees dans la genetique mendelienne. Cet environnement informatise devra permettre aux etudiants de mener des experiences simulees, utilisant les statistiques et les probebilites comme outils mathematiques pour modeliser le phenomene de la transmission des caracteres hereditaires. L'approche didactique est essentiellement orientee vers l'utilisation des methodes quantitatives impliquees dans l'experimentation des facteurs hereditaires. En incorporant au simulateur le principe de la "Lunette cognitive" de Nonnon (1986), l'etudiant fut place dans une situation ou il a pu synchroniser la perception de la representation iconique (concrete) et symbolique (abstraite) des lois probabilistes de Mendel. A l'aide de cet environnement, nous avons amene l'etudiant a identifier le(s) caractere(s) hereditaire(s) des parents a croiser, a predire les frequences phenotypiques probables de la descendance issue du croisement, a observer les resultats statistiques et leur fluctuation au niveau de l'histogramme des frequences, a comparer ces resultats aux predictions anticipees, a interpreter les donnees et a selectionner en consequence d'autres experiences a realiser. Les etapes de l'approche inductive sont privilegiees du debut a la fin des activites proposees. L'elaboration, du simulateur et des documents d'accompagnement, a ete concue a partir d'une vingtaine de principes directeurs et d'un modele d'action. Ces principes directeurs et le modele d'action decoulent de considerations theoriques psychologiques, didactiques et technologiques. La recherche decrit la structure des differentes parties composant le simulateur. L'architecture de celui-ci est construite autour d'une unite centrale, la "Principale", dont les liens et les ramifications avec les autres unites confere a l'ensemble du simulateur sa souplesse et sa facilite d'utilisation. Le simulateur "Genetique", a l'etat de prototype, et la documentation qui lui est afferente ont ete soumis a deux mises a l'essai: l'une fonctionnelle, l'autre empirique. La mise a l'essai fonctionnelle, menee aupres d'un groupe d'enseignants experts, a permis d'identifier les lacunes du materiel elabore afin de lui apporter les reajustements qui s'imposaient. La mise a l'essai empirique, conduite par un groupe de onze (11) etudiants de niveau secondaire, avait pour but, d'une part, de tester la facilite d'utilisation du simulateur "Genetique" ainsi que les documents d'accompagnement et, d'autre part, de verifier si les participants retiraient des avantages pedagogiques de cet environnement. Trois techniques furent exploitees pour recolter les donnees de la mise a l'essai empirique. L'analyse des resultats a permis de faire un retour critique sur les productions concretes de cette recherche et d'apporter les modifications necessaires tant au simulateur qu'aux documents d'accompagnement. Cette analyse a permis egalement de conclure que notre simulateur interactif favorise une approche inductive permettant aux etudiants de s'approprier les lois probabilistes de Mendel. Enfin, la conclusion degage des pistes de recherches destinees aux etudes ulterieures, plus particulierement celles qui s'interessent a developper des simulateurs, afin d'integrer a ceux-ci des representations concretes et abstraites presentees en temps reel. Les disquettes du simulateur "Genetique" et les documents d'accompagnement sont annexes a la presente recherche.

X-ray and EPR Characterization of the Auxiliary Fe-S Clusters in the Radical SAM Enzyme PqqE.

PubMed

Barr, Ian; Stich, Troy A; Gizzi, Anthony S; Grove, Tyler L; Bonanno, Jeffrey B; Latham, John A; Chung, Tyler; Wilmot, Carrie M; Britt, R David; Almo, Steven C; Klinman, Judith P

2018-02-27

The Radical SAM (RS) enzyme PqqE catalyzes the first step in the biosynthesis of the bacterial cofactor pyrroloquinoline quinone, forming a new carbon-carbon bond between two side chains within the ribosomally synthesized peptide substrate PqqA. In addition to the active site RS 4Fe-4S cluster, PqqE is predicted to have two auxiliary Fe-S clusters, like the other members of the SPASM domain family. Here we identify these sites and examine their structure using a combination of X-ray crystallography and Mössbauer and electron paramagnetic resonance (EPR) spectroscopies. X-ray crystallography allows us to identify the ligands to each of the two auxiliary clusters at the C-terminal region of the protein. The auxiliary cluster nearest the RS site (AuxI) is in the form of a 2Fe-2S cluster ligated by four cysteines, an Fe-S center not seen previously in other SPASM domain proteins; this assignment is further supported by Mössbauer and EPR spectroscopies. The second, more remote cluster (AuxII) is a 4Fe-4S center that is ligated by three cysteine residues and one aspartate residue. In addition, we examined the roles these ligands play in catalysis by the RS and AuxII clusters using site-directed mutagenesis coupled with EPR spectroscopy. Lastly, we discuss the possible functional consequences that these unique AuxI and AuxII clusters may have in catalysis for PqqE and how these may extend to additional RS enzymes catalyzing the post-translational modification of ribosomally encoded peptides.

Enzyme-Linked Immunosorbant Assays for Identification of Biological Agents in Sample Unknowns: NATO SIBCA. Exercise 5

DTIC Science & Technology

2004-12-01

avantage comme Brucella spp par ex. De plus, chaque ELISA d’agent devrait &tre test~e avec un agent vivant pour confirmer la sensibilit6 du biotest aux...materiaux vivants . A plus long terme, i1 serait souhaitable d𔄀tudier des solutions de rechange qui seraient plus sensibles aux techniques

Glutathione-capped gold nanoclusters as photosensitizers. Visible light-induced hydrogen generation in neutral water.

PubMed

Chen, Yong-Siou; Kamat, Prashant V

2014-04-23

Glutathione-capped metal nanoclusters (Aux-GSH NCs) which exhibit molecular-like properties are employed as a photosensitizer for hydrogen generation in a photoelectrochemical cell (PEC) and a photocatalytic slurry reactor. The reversible reduction (E(0) = -0.63 V vs RHE) and oxidation (E(0) = 0.97 and 1.51 V vs RHE) potentials of these metal nanoclusters make them suitable for driving the water-splitting reaction. When a mesoscopic TiO2 film sensitized by Aux-GSH NCs is used as the photoanode with a Pt counter electrode in aqueous buffer solution (pH = 7), we observe significant photocurrent activity under visible light (400-500 nm) excitation. Additionally, sensitizing Pt/TiO2 nanoparticles with Aux-GSH NCs in an aqueous slurry system and irradiating with visible light produce H2 at a rate of 0.3 mmol of hydrogen/h/g of Aux-GSH NCs. The rate of H2 evolution is significantly enhanced (∼5 times) when a sacrificial donor, such as EDTA, is introduced into the system. Using metal nanoclusters as a photosensitizer for hydrogen generation lays the foundation for the future exploration of other metal nanoclusters with well-controlled numbers of metal atoms and capping ligands.

Auxin Influx Carriers Control Vascular Patterning and Xylem Differentiation in Arabidopsis thaliana

PubMed Central

Siligato, Riccardo; Alonso, Jose M.; Swarup, Ranjan; Bennett, Malcolm J.; Mähönen, Ari Pekka; Caño-Delgado, Ana I.; Ibañes, Marta

2015-01-01

Auxin is an essential hormone for plant growth and development. Auxin influx carriers AUX1/LAX transport auxin into the cell, while auxin efflux carriers PIN pump it out of the cell. It is well established that efflux carriers play an important role in the shoot vascular patterning, yet the contribution of influx carriers to the shoot vasculature remains unknown. Here, we combined theoretical and experimental approaches to decipher the role of auxin influx carriers in the patterning and differentiation of vascular tissues in the Arabidopsis inflorescence stem. Our theoretical analysis predicts that influx carriers facilitate periodic patterning and modulate the periodicity of auxin maxima. In agreement, we observed fewer and more spaced vascular bundles in quadruple mutants plants of the auxin influx carriers aux1lax1lax2lax3. Furthermore, we show AUX1/LAX carriers promote xylem differentiation in both the shoot and the root tissues. Influx carriers increase cytoplasmic auxin signaling, and thereby differentiation. In addition to this cytoplasmic role of auxin, our computational simulations propose a role for extracellular auxin as an inhibitor of xylem differentiation. Altogether, our study shows that auxin influx carriers AUX1/LAX regulate vascular patterning and differentiation in plants. PMID:25922946

Stabilité et pertes des conducteurs pour régime alternatif

NASA Astrophysics Data System (ADS)

Estop, P.; Lacaze, A.

1994-04-01

Recent progresses obtained on low-T_c superconductors usable at industrial frequencies allow to envisage a new and innovating application as the current limiter. The device conception determines a cryogenic cost due to the dissipated energy in superconducting wires. In order to reduce the losses sufficiently, fine wires with submicromic filaments must be used. In relation to the need to obtain an infaillible protection during the quench, a new type of conductor, has been worked out, tested and validated. The main technical aspects concerning the losses of low-T_c superconductors have been developed on this paper. Les récents progrès obtenus sur les conducteurs supraconducteurs basse température critique utilisables aux fréquences industrielles permettent d'entrevoir une application nouvelle et innovante comme le limiteur de courant. De la conception d'un tel système résulte un coût cryogénique lié à l'énergie dissipée dans les brins supraconducteurs. La réduction des pertes nécessite l'utilisation de brins suffisamment fins et disposant de filaments submicromiques. Concernant le besoin d'obtenir une protection infaillible au moment de la transition, un conducteur d'un concept nouveau a été élaboré, testé et validé. L'article passe en revue les principaux aspects techniques liés à la stabilité et aux pertes dans les conducteurs supraconducteurs basse température critique.

Study of the Retention of Fission Products by a Few Common Minerals. Application to the Treatment of Medium Activity Effluents; ETUDE DE LA RETENTION DES PRODUITS DE FISSION PAR QUELQUES MINERAUX USUELS. (APPLICATION AUX TRAITEMENTS D'EFFLUENTS DE MOYENNE ACTIVITE SPECIFIQUE)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Auchapt, J.M.

1962-01-01

The conditions in which Sr is fixed on calcite (the object of Geneva report P/395-USA-- 1958) are more closely studied and the work is extended to five fission products in the effluerts and to 17 common rocks and minerals. Although this fixation is not suitsble as a method of treating STE effluents (i.e., those from the effluent treatment plant at MIarcoule), the study shows that all the crystals considered are strongly contaminated by simple contact. (auth)

Fiber pigtailed thin wall capillary coupler for excitation of microsphere WGM resonator.

PubMed

Wang, Hanzheng; Lan, Xinwei; Huang, Jie; Yuan, Lei; Kim, Cheol-Woon; Xiao, Hai

2013-07-01

In this paper, we demonstrate a fiber pigtailed thin wall capillary coupler for excitation of Whispering Gallery Modes (WGMs) of microsphere resonators. The coupler is made by fusion-splicing an optical fiber with a capillary tube and consequently etching the capillary wall to a thickness of a few microns. Light is coupled through the peripheral contact between inserted microsphere and the etched capillary wall. The coupling efficiency as a function of the wall thickness was studied experimentally. WGM resonance with a Q-factor of 1.14 × 10(4) was observed using a borosilicate glass microsphere with a diameter of 71 μm. The coupler operates in the reflection mode and provides a robust mechanical support to the microsphere resonator. It is expected that the new coupler may find broad applications in sensors, optical filters and lasers.

Measurement System of Surface Electrostatic Potential on Insulation Board in Vacuum and its Application

NASA Astrophysics Data System (ADS)

Morita, Hiroshi; Hatanaka, Ayumu; Yokosuka, Toshiyuki; Seki, Yoshitaka; Tsumuraya, Yoshiaki; Doi, Motomichi

The measurement system of the surface electrostatic potential on a solid insulation board in vacuum has been developed. We used this system to measure the electrostatic potential distribution of the surface of a borosilicate glass plate applied a high voltage. A local increase in the electric field was observed. It is considered that this phenomenon is caused by a positive electrostatic charge generated by a secondary emission of field emission electrons from an electrode. On the other hand, a local increase in the electric field was not observed on a glass plate coated with silica particles and a glass plate roughened by sandblast. We reasoned that this could be because the electrons were trapped by the roughness of the surface. It is considered that these phenomena make many types of equipment using the vacuum insulation more reliable.

Grand canonical electronic density-functional theory: Algorithms and applications to electrochemistry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sundararaman, Ravishankar; Goddard, III, William A.; Arias, Tomas A.

First-principles calculations combining density-functional theory and continuum solvation models enable realistic theoretical modeling and design of electrochemical systems. When a reaction proceeds in such systems, the number of electrons in the portion of the system treated quantum mechanically changes continuously, with a balancing charge appearing in the continuum electrolyte. A grand-canonical ensemble of electrons at a chemical potential set by the electrode potential is therefore the ideal description of such systems that directly mimics the experimental condition. We present two distinct algorithms: a self-consistent field method and a direct variational free energy minimization method using auxiliary Hamiltonians (GC-AuxH), to solvemore » the Kohn-Sham equations of electronic density-functional theory directly in the grand canonical ensemble at fixed potential. Both methods substantially improve performance compared to a sequence of conventional fixed-number calculations targeting the desired potential, with the GC-AuxH method additionally exhibiting reliable and smooth exponential convergence of the grand free energy. Lastly, we apply grand-canonical density-functional theory to the under-potential deposition of copper on platinum from chloride-containing electrolytes and show that chloride desorption, not partial copper monolayer formation, is responsible for the second voltammetric peak.« less

Grand canonical electronic density-functional theory: Algorithms and applications to electrochemistry.

PubMed

Sundararaman, Ravishankar; Goddard, William A; Arias, Tomas A

2017-03-21

First-principles calculations combining density-functional theory and continuum solvation models enable realistic theoretical modeling and design of electrochemical systems. When a reaction proceeds in such systems, the number of electrons in the portion of the system treated quantum mechanically changes continuously, with a balancing charge appearing in the continuum electrolyte. A grand-canonical ensemble of electrons at a chemical potential set by the electrode potential is therefore the ideal description of such systems that directly mimics the experimental condition. We present two distinct algorithms: a self-consistent field method and a direct variational free energy minimization method using auxiliary Hamiltonians (GC-AuxH), to solve the Kohn-Sham equations of electronic density-functional theory directly in the grand canonical ensemble at fixed potential. Both methods substantially improve performance compared to a sequence of conventional fixed-number calculations targeting the desired potential, with the GC-AuxH method additionally exhibiting reliable and smooth exponential convergence of the grand free energy. Finally, we apply grand-canonical density-functional theory to the under-potential deposition of copper on platinum from chloride-containing electrolytes and show that chloride desorption, not partial copper monolayer formation, is responsible for the second voltammetric peak.

Croissance des couches minces et des multicouches de matériaux supraconducteurs H Tboldmath_c : bilan et perspective

NASA Astrophysics Data System (ADS)

Contour, J. P.

1994-11-01

The main physical and chemical techniques of epitaxial growth of High T_c superconductor thin films are described together with their in situ analysis facilities and discussed with respect to their cost, sophistication and results (T_c, J_c growth defects, thickness and composition uniformity, crystallinity, electronic applications...). The future trends of the growth machines are then examined in connection with the present results and the development of superconductor electronics. Après la présentation des principales techniques de croissance physique et physicochimique de couches minces d'oxydes supraconducteurs à haute température critique, un bilan des résultats sera dressé par rapport aux différentes propriétés des films (transition résistive, courant critique, défauts de croissance, uniformité d'épaisseur et de composition, cristallinité...), aux difficultés de mise en œuvre et au coût de l'expérience. Les perspectives des différentes techniques seront ensuite examinées dans le cadre du développement potentiel d'une électronique utilisant les matériaux supraconducteurs H T_c.

Grand canonical electronic density-functional theory: Algorithms and applications to electrochemistry

DOE PAGES

Sundararaman, Ravishankar; Goddard, III, William A.; Arias, Tomas A.

2017-03-16

First-principles calculations combining density-functional theory and continuum solvation models enable realistic theoretical modeling and design of electrochemical systems. When a reaction proceeds in such systems, the number of electrons in the portion of the system treated quantum mechanically changes continuously, with a balancing charge appearing in the continuum electrolyte. A grand-canonical ensemble of electrons at a chemical potential set by the electrode potential is therefore the ideal description of such systems that directly mimics the experimental condition. We present two distinct algorithms: a self-consistent field method and a direct variational free energy minimization method using auxiliary Hamiltonians (GC-AuxH), to solvemore » the Kohn-Sham equations of electronic density-functional theory directly in the grand canonical ensemble at fixed potential. Both methods substantially improve performance compared to a sequence of conventional fixed-number calculations targeting the desired potential, with the GC-AuxH method additionally exhibiting reliable and smooth exponential convergence of the grand free energy. Lastly, we apply grand-canonical density-functional theory to the under-potential deposition of copper on platinum from chloride-containing electrolytes and show that chloride desorption, not partial copper monolayer formation, is responsible for the second voltammetric peak.« less

Development of a High Ionization Efficiency Molten Glass Ion Emitter for TIMS

NASA Astrophysics Data System (ADS)

Cheversia, M. B.; Farmer, G.; Koval, C.; David, D.

2006-12-01

Thermal ionization mass spectrometry (TIMS) remains the method of choice for many high precision isotope ratio determinations but is handicapped by the use of low efficiency ion emitters. For example, ionization efficiencies from molten glass emitters (Si-gel) used for such elements as Pb, Cr, Ru, and Ag are in the range of 0.05-2%, which limits the sample size and the precision to which isotope ratio determinations for these elements can be made. Our aim is to improve the ionization efficiency of the molten glass ion emitter using electrochemical methods. This work builds on recent observations indicating that many metals doped in borosilicate glasses (eg. Bi, Ag), are emitted from the liquid glass (in vacuo) primarily as the neutral metal atom. Our goal is to increase the proportion of singly charged metal atoms in metal-doped molten glasses via oxidation induced by electrochemical methods and to assess whether such in situ oxidation of metal atoms leads to an increase in emitted metal ions. Our experiments are performed in a vacuum chamber that mimics conditions in the sample chamber of the TIMS. A borosilicate glass sample is placed in a miniature ceramic crucible. The crucible contains working and reference Pt electrodes, and a Pt thermocouple. The entire apparatus is wrapped with a resistively heated Ta wire until temperatures in the glass reach approximately 1400°C, to ensure that the glass is molten. By this method, we have produced simple cyclic voltammograms that suggest that over a 100°C temperature range, the borosilicate glass undergoes a transition from resistive behavior as a solid, to a conductive electrolyte, as a molten liquid glass, as expected. The change is evident as an order of magnitude decrease in resistivity of the glass, as interpreted from the voltammograms. The voltammograms produced for the pure borosilicate glasses represent the baseline against which we will compare the electrochemical characteristics of Pb doped glasses. These experiments are currently underway and are designed to determine the speciation of lead in the glass, and to determine the voltages required to induce cathodic currents in the glass corresponding to ionization to Pb+ and Pb2+. By generating a cathodic current and an increased concentration of the oxidized species, we hope to ultimately generate a higher intensity ion beam, higher ionization efficiency for low efficiency elements, and higher precision analyses on small sample sizes for the TIMS.

Evaluation d'un scenario d'apprentissage favorisant la mobilisation des habiletes reliees au processus d'enquete

NASA Astrophysics Data System (ADS)

Blanchard, Samuel F. J.

Les resultats au Programme international pour le suivi des acquis des eleves (PISA) demontrent que les jeunes neobrunswickois francophones se classent b un niveau significativement inferieur comparaiivement aux eleves anglophones du Nouveau-Brunswick, aux eleves des autres provinces canadiennes et se classent sous la moyenne internationale de tous les pays participants quant b la culture scientifique. L'evaluation de cette culture scientifique est basee sur une serie de savoirs, de savoir-faire et de savoir-etre reliee au processus d'enquete scolaire. Le processus d'enquete scolaire est une approche b l'apprentissage ou les eleves effectuent des recherches d'informations, discutent d'idees et entreprennent des investigations pour augmenter leur comprehension d'un probleme ou d'un sujet. Les recherches demontrent que le processus d'enquete scolaire est rarement une composante pedagogique importante de la salle de classe et les recherches portant sur l'implantation du processus d'enquete scolaire recommandent de rendre ce dernier plus accessible aux enseignantes et aux enseignants. Afin de rendre le processus d'enquete plus accessible aux enseignantes et aux enseignants, notre recherche porte sur l'evaluation de la valeur pedagogique d'un scenario d'apprentissage (PhaRoboS) concu specialement pour creer un environnement dans lequel les eleves auront plusieurs occasions a mobiliser les habiletes reliees au processus d'enquete. Les retombees de cette evaluation nous permettront d'offrir des pistes de remediations afin d'aider plus d'enseignantes et d'enseignants b creer un environnement dans lequel les eleves auront plusieurs occasions b mobiliser les habiletes reliees au processus d'enquete. Cette evaluation s'est faite a partir d'une methodologie inspiree de l'evaluation pour fin d'amelioration d'un objet pedagogique. L'analyse des donnees qualitatives recueillies aupres des eleves et de leur enseignante d'une ecole francophone du Nouveau-Brunswick semble montrer que le scenario d'apprentissage a cree un environnement dans lequel les eleves ont eu plusieurs occasions b mobiliser les habiletes reliees aux processus d'enquete. Entres autres, les eleves ont emis et ont confronte des hypotheses, ont choisi des strategies de resolutions de probleme, ont communique leurs observations et ont analyse et interprete des donnees lors de leur investigation. Cependant, comme suite a cette analyse, quelques petites ameliorations seront apportees a une version subsequente du scenario d'apprentissage PhaRoboS afin de favoriser davantage la mobilisation des habiletes reliees au processus d'enquete.

Et pourquoi pas une education aux sciences qui aborde la participation des acteurs sociaux aux controverses sociotechniques?

ERIC Educational Resources Information Center

Pouliot, Chantal

2012-01-01

In this article we discuss research that was conducted as part of a project on citizen science education. We present the research and some of the results, and then take a position on the pertinence of examining, in science classes, questions on citizen participation in socio-technical debates and the roles and capacities of the social actors…

Earth Observations taken by Expedition 30 crewmember

NASA Image and Video Library

2012-03-25

ISS030-E-193144 (25 March 2012) --- Wave clouds near Ile aux Cochons are featured in this image photographed by an Expedition 30 crew member on the International Space Station. This photograph illustrates the formation of wave clouds in the wake—or downwind side—of Ile aux Cochons (“Isle of Pigs”) located in the Southern Indian Ocean. The island is approximately located 3,000 kilometers southeast of the southern tip of the African continent and 2,300 kilometers northwest of Antarctica. The island itself, of which only a part of the eastern coastline is visible at center, is volcanic in origin with a summit elevation of 775 meters above sea level. According to scientists, the Ile aux Cochons stratovolcano is thought to have erupted within the last 12,000 years; however no historical activity has been recorded. The summit elevation is high enough for the land surface to interact with cloud layers and winds flowing past the island. Two major cloud layers are visible; a lower, more uniform layer consists of roughly parallel cloud “streets” that suggest a westerly flow pattern of air. When the air mass encounters the Ile aux Cochons, moisture-laden air rises and cools, causing more water vapor to condense into clouds. As the air mass passes over the summit of Ile aux Cochons and descends, it may encounter alternating moist and dry air layers, enabling the formation of the discontinuous chevron-shaped wave clouds in the wake of the island. While their appearance suggests that the clouds are forming in the wake of the island and moving eastwards, in fact it is the air mass that is moving, with clouds forming in regions of moist air and dissipating in dry regions. Ile aux Cochons is the westernmost of the islands that form the subantarctic Crozet Archipelago (part of the French Southern and Antarctic Lands). Accept for occasional research visits, the island is uninhabited. The island is an important breeding site for seabirds, including the world’s largest King Penguin colony.

Improved Blackbody Simulator

DTIC Science & Technology

1974-06-01

28 - ABS Resins ................... 012 0.02 Carbon & Free-Cutting Steels%,. . . . . 27 - Acrylics ......................... 0.12 0.10 Alloy...Borosilicate Glasses................. 0.7 - Zinc At Its Alloys ................. 65.3 60.5 Alkyds .... .... .............. 010 0.20 Tungsten Carbide Cermet...cast).............47.6 25 ABS Resins ............ .. IS 3 FlowbnFie ........... 7 - Cellulose Acetate ............ &. 1.9 Pajadafi CW

Initial Examination of Low Velocity Sphere Impact of Glass Ceramics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Morrissey, Timothy G; Fox, Ethan E; Wereszczak, Andrew A

This report summarizes US Army TARDEC sponsored work at Oak Ridge National Laboratory (ORNL) involving low velocity (< 30 m/s or < 65 mph) sphere impact testing of two materials from the lithium aluminosilicate family reinforced with different amounts of ceramic particulate, i.e., glass-ceramic materials, SCHOTT Resistan{trademark}-G1 and SCHOTT Resistan{trademark}-L. Both materials are provided by SCHOTT Glass (Duryea, PA). This work is a follow-up to similar sphere impact studies completed by the authors on PPG's Starphire{reg_sign} soda-lime silicate glass and SCHOTT BOROFLOAT{reg_sign} borosilicate glass. A gas gun or a sphere-drop test setup was used to produce controlled velocity delivery ofmore » silicon nitride (Si{sub 3}N{sub 4}) spheres against the glass ceramic tile targets. Minimum impact velocities to initiate fracture in the glass-ceramics were measured and interpreted in context to the kinetic energy of impact and the elastic property mismatch between sphere and target material. Quasistatic spherical indentation was also performed on both glass ceramics and their contact damage responses were compared to those of soda-lime silicate and borosilicate glasses. Lastly, variability of contact damage response was assessed by performing spherical indentation testing across the area of an entire glass ceramic tile. The primary observations from this low velocity (< 30 m/s or < 65 mph) testing were: (1) Resistan{trademark}-L glass ceramic required the highest velocity of sphere impact for damage to initiate. Starphire{reg_sign} soda-lime silicate glass was second best, then Resistan{trademark}-G1 glass ceramic, and then BOROFLOAT{reg_sign} borosilicate glass. (2) Glass-ceramic Resistan{trademark}-L also required the largest force to initiate ring crack from quasi-static indentation. That ranking was followed, in descending order, by Starphire{reg_sign} soda-lime silicate glass, Resistan{trademark}-G1 glass ceramic, and BOROFLOAT{reg_sign} borosilicate glass. (3) Spheres with a lower elastic modulus require less force to initiate fracture in Resistan{trademark}-G1 from quasi-static spherical indentation. This indicates that friction is affecting ring crack initiation in Resistan{trademark}-G1. Friction also affected ring crack initiation in Starphire{reg_sign} soda-lime silicate and BOROFLOAT{reg_sign} borosilicate glasses. Among these three materials, friction was the most pronounced (largest slope in the RCIF-elastic modulus graph) in the Starphire{reg_sign} and least pronounced in the BOROFLOAT{reg_sign}. The reason for this is not understood, but differences in deformation behavior under high contact stresses could be a cause or contributor to this. (4) The force necessary to initiate contact-induced fracture is higher under dynamic conditions than it is under quasi-static conditions in Resistan{trademark}-L and Resistan{trademark}-G1 glass ceramics. This is a trend observed too in Starphire{reg_sign} and BOROFLOAT{reg_sign}. (5) There is a subtle indication there was intra-tile differences in spherical indentation-induced ring crack initiation forces. This is not a material property nor is it exclusive to glass-ceramic Resistan{trademark}-G1 glass ceramic, rather, it is a statistical mechanical response to an accumulated history of processing and handling of that specific tile.« less

Disruptions in AUX1-dependent auxin influx alter hypocotyl phototropism in Arabidopsis.

PubMed

Stone, Bethany B; Stowe-Evans, Emily L; Harper, Reneé M; Celaya, R Brandon; Ljung, Karin; Sandberg, Göran; Liscum, Emmanuel

2008-01-01

Phototropism represents a differential growth response by which plant organs can respond adaptively to changes in the direction of incident light to optimize leaf/stem positioning for photosynthetic light capture and root growth orientation for water/nutrient acquisition. Studies over the past few years have identified a number of components in the signaling pathway(s) leading to development of phototropic curvatures in hypocotyls. These include the phototropin photoreceptors (phot1 and phot2) that perceive directional blue-light (BL) cues and then stimulate signaling, leading to relocalization of the plant hormone auxin, as well as the auxin response factor NPH4/ARF7 that responds to changes in local auxin concentrations to directly mediate expression of genes likely encoding proteins necessary for development of phototropic curvatures. While null mutations in NPH4/ARF7 condition an aphototropic response to unidirectional BL, seedlings carrying the same mutations recover BL-dependent phototropic responsiveness if co-irradiated with red light (RL) or pre-treated with either ethylene. In the present study, we identify second-site enhancer mutations in the nph4 background that abrogate these recovery responses. One of these mutations--map1 (modifier of arf7 phenotypes 1)--was found to represent a missense allele of AUX1--a gene encoding a high-affinity auxin influx carrier previously associated with a number of root responses. Pharmacological studies and analyses of additional aux1 mutants confirmed that AUX1 functions as a modulator of hypocotyl phototropism. Moreover, we have found that the strength of dependence of hypocotyl phototropism on AUX1-mediated auxin influx is directly related to the auxin responsiveness of the seedling in question.

Comparison of Vitek Matrix-assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry Versus Conventional Methods in Candida Identification.

PubMed

Keçeli, Sema Aşkın; Dündar, Devrim; Tamer, Gülden Sönmez

2016-02-01

Candida species are generally identified by conventional methods such as germ tube or morphological appearance on corn meal agar, biochemical methods using API kits and molecular biological methods. Alternative to these methods, rapid and accurate identification methods of microorganisms called matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDİ-TOF MS) has recently been described. In this study, Candida identification results by API Candida kit, API 20C AUX kit and identifications on corn meal agar (CMA) are compared with the results obtained on Vitek-MS. All results were confirmed by sequencing internal transcribed spacer (ITS) regions of rDNA. Totally, 97 Candida strains were identified by germ tube test, CMA, API and Vitek-MS. Vitek-MS results were compatible with 74.2 % of API 20C AUX and 81.4 % of CMA results. The difference between the results of API Candida and API 20C AUX was detected. The ratio of discrepancy between Vitek-MS and API 20C AUX was 25.8 %. Candida species mostly identified as C. famata or C. tropicalis by and not compatible with API kits were identified as C. albicans by Vitek-MS. Sixteen Candida species having discrepant results with Vitek-MS, API or CMA were randomly chosen, and ITS sequence analysis was performed. The results of sequencing were compatible 56.2 % with API 20C AUX, 50 % with CMA and 93.7 % with Vitek-MS. When compared with conventional identification methods, MS results are more reliable and rapid for Candida identification. MS system may be used as routine identification method in clinical microbiology laboratories.

Urban Traffic Signal Control for Fuel Economy. Part 2. Extension to Small Cars (Economie D’Essence Grace a la Commande des Feux de Circulation en Zone Urbaine. Partie 2. Application aux Vehicules de Petite Cylindree)

DTIC Science & Technology

1981-11-01

d’essence comparativement au plan en vigueur. Le rapport mentionne 6galement que la consommation d’un gros v"hicule a6t calcul6e a l’aide d’un module...most of the submitted data was not readily enterable into the Vehicle Simulation program. Because of the design of the table look-ups in the program

Les recommandations relatives aux vaccins antigrippaux administrés aux enfants et aux adolescents pour la saison 2017-2018.

PubMed

Moore, Dorothy L

2018-02-01

La Société canadienne de pédiatrie continue d'encourager la vaccination antigrippale annuelle de TOUS les enfants et les adolescents, dès l'âge de six mois. Les recommandations du Comité consultatif national de l'immunisation (CCNI) pour la saison 2017-2018 n'ont pas subi de changements importants par rapport à la saison précédente. Le CCNI a analysé toutes les données sur l'efficacité du vaccin vivant atténué contre l'influenza (VVAI) sur le marché et conclut qu'elles en appuient l'utilisation au Canada, même si les États-Unis ne le recommandent pas en raison de doutes quant à son efficacité.

A review of bioactive glasses: Their structure, properties, fabrication and apatite formation.

PubMed

Kaur, Gurbinder; Pandey, Om P; Singh, Kulvir; Homa, Dan; Scott, Brian; Pickrell, Gary

2014-01-01

Bioactive glass and glass-ceramics are used in bone repair applications and are being developed for tissue engineering applications. Bioactive glasses/Bioglass are very attractive materials for producing scaffolds devoted to bone regeneration due to their versatile properties, which can be properly designed depending on their composition. An important feature of bioactive glasses, which enables them to work for applications in bone tissue engineering, is their ability to enhance revascularization, osteoblast adhesion, enzyme activity and differentiation of mesenchymal stem cells as well as osteoprogenitor cells. An extensive amount of research work has been carried out to develop silicate, borate/borosilicate bioactive glasses and phosphate glasses. Along with this, some metallic glasses have also been investigated for biomedical and technological applications in tissue engineering. Many trace elements have also been incorporated in the glass network to obtain the desired properties, which have beneficial effects on bone remodeling and/or associated angiogenesis. The motivation of this review is to provide an overview of the general requirements, composition, structure-property relationship with hydroxyapatite formation and future perspectives of bioglasses.Attention has also been given to developments of metallic glasses and doped bioglasses along with the techniques used for their fabrication. Copyright © 2013 Wiley Periodicals, Inc., a Wiley Company.

First-principles study of the structural and elastic properties of AuxV1-x and AuxNb1-x alloys

NASA Astrophysics Data System (ADS)

Al-Zoubi, N.

2018-04-01

Ab initio total energy calculations, based on the Exact Muffin-Tin Orbitals (EMTO) method in combination with the coherent potential approximation (CPA), are used to calculate the total energy of AuxV1-x and AuxNb1-x random alloys along the Bain path that connects the body-centred cubic (bcc) and face-centred cubic (fcc) structures as a function of composition x (0 ≤ x ≤ 1). The equilibrium Wigner-Seitz radius and the elastic properties of both systems are determined as a function of composition. Our theoretical prediction in case of pure elements (x = 0 or x = 1) are in good agreement with the available experimental data. For the Au-V system, the equilibrium Wigner-Seitz radius increase as x increases, while for the Au-Nb system, the equilibrium Wigner-Seitz radius is almost constant. The bulk modulus B and C44 for both alloys exhibit nearly parabolic trend. On the other hand, the tetragonal shear elastic constant C‧ decreases as x increases and correlates reasonably well with the structural energy difference between fcc and bcc structures. Our results offer a consistent starting point for further theoretical and experimental studies of the elastic and micromechanical properties of Au-V and Au-Nb systems.

La santé des Premières nations, des Inuits et des Métis: les facteurs que doivent envisager les leaders en santé canadiens dans la foulée du rapport de la Commission de vérité et réconciliation du Canada.

PubMed

McNally, Mary; Martin, Debbie

2017-03-01

Les peuples des Premières nations, inuits et métis qui habitent au Canada sont aux prises avec de profondes disparités en matière de santé par rapport aux Canadiens non autochtones, et ce, dans presque toutes les mesures liées à la santé et au bien-être. Pour faire progresser les services de santé auprès des peuples autochtones, il faut passer à l'action dans tous les ordres de prestation des soins et des politiques en santé. Il est donc essentiel que les leaders et les prestataires des établissements, des systèmes et des installations de santé du Canada comprennent et prennent en main les déterminants de la santé propres aux peuples autochtones, y compris l'héritage du colonialisme et le racisme ancien et actuel. La Commission de vérité et réconciliation du Canada est le point de départ pour réagir de manière positive aux injustices.

75 FR 41850 - Amended Notice of Intent to Modify the Scope of the Surplus Plutonium Disposition Supplemental...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-07-19

... immobilization). Also, DOE had identified a glass can-in-canister immobilization approach as its preferred... allow immobilization of some or all of the surplus plutonium in glass or ceramic material for disposal... in canisters to be filled with borosilicate glass containing intensely radioactive high-level waste...

Production Process for Strong, Light Ceramic Tiles

NASA Technical Reports Server (NTRS)

Holmquist, G. R.; Cordia, E. R.; Tomer, R. S.

1985-01-01

Proportions of ingredients and sintering time/temperature schedule changed. Production process for lightweight, high-strength ceramic insulating tiles for Space Shuttle more than just scaled-up version of laboratory process for making small tiles. Boron in aluminum borosilicate fibers allows fusion at points where fibers contact each other during sintering, thereby greatly strengthening tiles structure.

Nanoparticle Solutions for Printed Electronics

DTIC Science & Technology

2013-09-19

the printed semiconductor materials and their nanoparticle and colloidal precursors. Without this basic knowledge, further development and the...titania, silica ) were investigated in the production of complementary inks for complex devices. These were either obtained commercially in...layers were also deposited on borosilicate glass and silicon wafers. In the photovoltaic program, hybrid inorganic-organic semiconductor combinations

Electrodeless discharge lamp is easily started, has high stability

NASA Technical Reports Server (NTRS)

Bell, W. E.; Bloom, A. L.

1966-01-01

Electrodeless discharge borosilicate glass lamp is used in various high-resolution optical systems. It is partially charged with krypton, contains small amounts of rubidium, and is enclosed in a hermetically sealed envelope that maintains the lamp at an optimum temperature during discharge. The lamp is quickly started by its excitation coil.

Iodine Solubility in Low-Activity Waste Borosilicate Glass at 1000 °C

DOE Office of Scientific and Technical Information (OSTI.GOV)

Riley, Brian J.; Schweiger, Michael J.; Kim, Dong-Sang

2014-04-30

The purpose of this study was to determine the solubility of iodine in a low-activity waste borosilicate glass when heated inside an evacuated and sealed fused quartz ampoule. The iodine was added to glass frit as KI in quantities of 100–24000 ppm iodine (by mass), each mixture was added to an ampoule, the ampoule was heated at 1000 °C for 2 h and then air quenched. In samples with ≥12000 ppm iodine, low viscosity salt phases were observed on the surface of the melts during cooling that solidified into a white coating upon cooling. These salts were identified as mixturesmore » of KI, NaI, and Na2SO4 with X-ray diffraction (XRD). The iodine concentrations in glass specimens were analyzed with inductively-coupled plasma mass spectrometry and the overall iodine solubility was determined to be 10000 ppm by mass. Several crystalline inclusions of iodine sodalite, Na8(AlSiO4)6I2, were observed in the 24000 ppm specimen and were verified with micro-XRD and wavelength dispersive spectroscopy.« less

Mesoscale Phase Field Modeling of Glass Strengthening Under Triaxial Compression

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Yulan; Sun, Xin

2015-09-28

Recent hydraulic bomb and confined sleeve tests on transparent armor glass materials such as borosilicate glass and soda-lime glass showed that the glass strength was a function of confinement pressure. The measured stress-strain relation is not a straight line as most brittle materials behave under little or no confinement. Moreover, borosilicate glass exhibited a stronger compressive strength when compared to soda-lime glass, even though soda-lime has higher bulk and shear moduli as well as apparent yield strength. To better understand these experimental findings, a mesoscale phase field model is developed to simulate the nonlinear stress versus strain behaviors under confinementmore » by considering heterogeneity formation under triaxial compression and the energy barrier of a micro shear banding event (referred to as pseudo-slip hereafter) in the amorphous glass. With calibrated modeling parameters, the simulation results demonstrate that the developed phase field model can quantitatively predict the pressure-dependent strength, and it can also explain the difference between the two types of glasses from the perspective of energy barrier associated with a pseudo-slip event.« less

Physical and optical properties of lithium borosilicate glasses doped with Dy3+ ions

NASA Astrophysics Data System (ADS)

Ramteke, D. D.; Gedam, R. S.; Swart, H. C.

2018-04-01

The borosilicate glasses with Dy3+ ions were prepared by the melt quench technique with varying concentration of Dy2O3. The glasses were characterized by the density calculation, absorbance and photoluminescence (PL) spectroscopy measurements. Density and molar volume of the glasses increases with increase in Dy3+ ions in the glass matrix. This behavior is correlated with the higher molecular weight and larger ionic radius of Dy3+ ion compared to the other constituents of glass matrix. Emission of Dy3+ doped glasses showed three bands at 482, 573 and at 665 nm which correspond to 6H15/2 (blue), 6H13/2 (yellow) and 6H11/2 (red) transitions. The emission spectra of glasses with different concentration of Dy3+ ions shows that, glasses with 0.5 mol% of Dy2O3 shows highest emission and decreases with further doping. CIE 1931 chromaticity diagram showed that the emission of these glasses was in the white region. Photographs of these glasses under 349 nm Light emitting diode excitation also confirmed the white light emission from these glasses.

Chemical durability of alkali-borosilicate glasses studied by analytical SEM, IBA, isotopic-tracing and SIMS

NASA Astrophysics Data System (ADS)

Trocellier, P.; Djanarthany, S.; Chêne, J.; Haddi, A.; Brass, A. M.; Poissonnet, S.; Farges, F.

2005-10-01

Simple and complex alkali-borosilicate glasses were submitted to aqueous corrosion at room temperature, 60 and 90 °C in solutions with pH ranging between 0 and 12. Analytical scanning electron microscopy (SEM), ion beam analysis (IBA) techniques, isotopic tracing and secondary ion mass-depth profiling (SIMS) have been used to investigate the variations of the surface composition of glass. In acidic medium, the glass surface is generally covered by a thick hydrated silica layer, mobile elements like Li, Na and B and transition elements (Fe, Zr, Mo, etc.) are strongly depleted. Near pH 7, relative enrichments of aluminium, iron and rare earths are shown together with strong Li, Na and B depletions. In basic medium, the glass surface exhibits relative enrichments of the major part of transition metals (from Cr to U) whereas mobile elements seem to be kept close to their nominal concentration level at the glass surface and Si is severely impoverished. Hydrogen incorporated at the glass surface after leaching is much more immobile in neutral and basic media than in acid medium.

Process Parameter Effects on Material Removal in Magnetorheological Finishing of Borosilicate Glass

DOE Office of Scientific and Technical Information (OSTI.GOV)

Miao, C.; Lambroopulos, J.C.; Jacobs, S.D.

2010-04-14

We investigate the effects of processing parameters on material removal for borosilicate glass. Data are collected on a magnetorheological finishing (MRF) spot taking machine (STM) with a standard aqueous magnetorheological (MR) fluid. Normal and shear forces are measured simultaneously, in situ, with a dynamic dual load cell. Shear stress is found to be independent of nanodiamond concentration, penetration depth, magnetic field strength, and the relative velocity between the part and the rotating MR fluid ribbon. Shear stress, determined primarily by the material mechanical properties, dominates removal in MRF. The addition of nanodiamond abrasives greatly enhances the material removal efficiency, withmore » the removal rate saturating at a high abrasive concentration. The volumetric removal rate (VRR) increases with penetration depth but is insensitive to magnetic field strength. The VRR is strongly correlated with the relative velocity between the ribbon and the part, as expected by the Preston equation. A modified removal rate model for MRF offers a better estimation of MRF removal capability by including nanodiamond concentration and penetration depth.« less

Influence of zeolite precipitation on borosilicate glass alteration under hyperalkaline conditions

NASA Astrophysics Data System (ADS)

Mercado-Depierre, S.; Fournier, M.; Gin, S.; Angeli, F.

2017-08-01

This study enables a better understanding of how nucleation-growth of zeolites affects glass dissolution kinetics in hyperalkaline solutions characteristic of cement waters. A 20-oxide borosilicate glass, an inactive surrogate of a typical intermediate level waste glass, was altered in static mode at 50 °C in a hyperalkaline solution rich in Na+, K+ and Ca2+ and at an initial pH50°C of 12.6. Experiments were performed at four glass-surface-area-to-solution-volume (S/V) ratios to investigate various reaction progresses. Two types of glass alteration kinetics were obtained: (i) at low S/V, a sharp alteration resumption occurred after a rate drop regime, (ii) at high S/V, a high dissolution rate was maintained throughout the test duration with a slight progressive slow-down. In all the experiments, zeolites precipitated but the time taken to form stable zeolite nuclei varied dramatically depending on the S/V. Resulting changes in pH affected zeolite composition, morphology, solubility and growth rate. A change in a critical parameter such as S/V affected all the processes controlling glass dissolution.

Iodine solubility in a low-activity waste borosilicate glass at 1000°C

DOE PAGES

Riley, Brian J.; Schweiger, Michael J.; Kim, Dong-Sang; ...

2014-04-30

The purpose of this study was to determine the solubility of iodine in a low-activity waste borosilicate glass when heated inside an evacuated and sealed fused quartz ampoule. The iodine was added to glass frit as KI in quantities of 100–24000 ppm iodine (by mass), each mixture was added to an ampoule, the ampoules were heated at 1000 °C for 2h, and then air quenched. In samples with ≥12000 ppm iodine, low viscosity salt phases were observed on the surface of the melts during cooling that solidified into a white coating upon cooling. These salts were identified as mixtures ofmore » KI, NaI, and Na 2SO 4 with X-ray diffraction (XRD). The iodine concentrations in glass specimens were analyzed with inductively-coupled plasma mass spectrometry and the overall iodine solubility was determined to be 10000 ppm by mass. Several crystalline inclusions of iodine sodalite, Na 8(AlSiO 4) 6I 2, were observed in the 24000 ppm specimen as determined by micro-XRD and wavelength dispersive spectroscopy.« less

High-level waste borosilicate glass: A compendium of corrosion characteristics. Volume 2

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cunnane, J.C.; Bates, J.K.; Bradley, C.R.

The objective of this document is to summarize scientific information pertinent to evaluating the extent to which high-level waste borosilicate glass corrosion and the associated radionuclide release processes are understood for the range of environmental conditions to which waste glass may be exposed in service. Alteration processes occurring within the bulk of the glass (e.g., devitrification and radiation-induced changes) are discussed insofar as they affect glass corrosion.This document is organized into three volumes. Volumes I and II represent a tiered set of information intended for somewhat different audiences. Volume I is intended to provide an overview of waste glass corrosion,more » and Volume 11 is intended to provide additional experimental details on experimental factors that influence waste glass corrosion. Volume III contains a bibliography of glass corrosion studies, including studies that are not cited in Volumes I and II. Volume I is intended for managers, decision makers, and modelers, the combined set of Volumes I, II, and III is intended for scientists and engineers working in the field of high-level waste.« less

DISCOURS QUI RÉSISTENT À L’OBJECTIVATION : QUE PEUT-ON EN TIRER POUR L’ÉVALUATION?

PubMed Central

Brousselle, Astrid

2013-01-01

Résumé L’évaluateur doit porter attention aux distorsions qu’il contribue à créer lorsqu’il utilise l’entrevue comme méthode de collecte de données. L’évaluation est un exercice politique qui, placé dans un contexte politique, peut favoriser l’émergence de discours de résistance à l’objectivation. À partir des entrevues que nous avons effectuées lors de l’évaluation du processus d’implantation de l’initiative ONUSIDA d’accès aux médicaments au Chili, nous illustrons différentes tactiques que les acteurs utilisent et qui peuvent soit attirer la sympathie de l’évaluateur, soit faire obstacle à son besoin d’information. Nous présentons une méthode d’analyse que l’évaluateur peut utiliser pour redonner du sens aux discours de résistance. PMID:23997421

Teaching resources. Model of the TIR1 pathway for auxin-mediated gene expression.

PubMed

Laskowski, Marta

2006-02-14

Auxin mediates numerous plant responses, some of which have been shown to require transcriptional regulation. One auxin response pathway, which depends on the relief of transcriptional repression, is mediated by TIR1 (transport inhibitor response protein 1). TIR1 is an auxin receptor and also a subunit of an SCF-type ubiquitin ligase. In the presence of a low concentration of auxin in the nucleus, members of the Aux/IAA family of transcriptional repressors bind to ARF proteins and inhibit the transcription of specific auxin response genes. Increased nuclear concentrations of auxin promote auxin binding to TIR1, causing the Aux/IAA proteins to associate with TIR1 and leading to their degradation by a proteasome-mediated pathway. This decreases the concentration of Aux/IAA proteins in the nucleus and thereby enables the expression of certain auxin response genes.

Invisibility Cloak Printed on a Photonic Chip

PubMed Central

Feng, Zhen; Wu, Bing-Hong; Zhao, Yu-Xi; Gao, Jun; Qiao, Lu-Feng; Yang, Ai-Lin; Lin, Xiao-Feng; Jin, Xian-Min

2016-01-01

Invisibility cloak capable of hiding an object can be achieved by properly manipulating electromagnetic field. Such a remarkable ability has been shown in transformation and ray optics. Alternatively, it may be realistic to create a spatial cloak by means of confining electromagnetic field in three-dimensional arrayed waveguides and introducing appropriate collective curvature surrounding an object. We realize the artificial structure in borosilicate by femtosecond laser direct writing, where we prototype up to 5,000 waveguides to conceal millimeter-scale volume. We characterize the performance of the cloak by normalized cross correlation, tomography analysis and continuous three-dimensional viewing angle scan. Our results show invisibility cloak can be achieved in waveguide optics. Furthermore, directly printed invisibility cloak on a photonic chip may enable controllable study and novel applications in classical and quantum integrated photonics, such as invisualising a coupling or swapping operation with on-chip circuits of their own. PMID:27329510

Time-resolved microscopy of fs-laser-induced heat flows in glasses

NASA Astrophysics Data System (ADS)

Bonse, Jörn; Seuthe, Thomas; Grehn, Moritz; Eberstein, Markus; Rosenfeld, Arkadi; Mermillod-Blondin, Alexandre

2018-01-01

Time-resolved phase-contrast microscopy is employed to visualize spatio-temporal thermal transients induced by tight focusing of a single Ti:sapphire fs-laser pulse into a solid dielectric sample. This method relies on the coupling of the refractive index change and the sample temperature through the thermo-optic coefficient d n/d T. The thermal transients are studied on a timescale ranging from 10 ns up to 0.1 ms after laser excitation. Beyond providing direct insights into the laser-matter interaction, analyzing the results obtained also enables quantifying the local thermal diffusivity of the sample on a micrometer scale. Studies conducted in different solid dielectrics, namely amorphous fused silica (a-SiO2), a commercial borosilicate glass (BO33, Schott), and a custom alkaline earth silicate glass (NaSi66), illustrate the applicability of this approach to the investigation of various glassy materials.

Synthesis, characterization and properties of Dy3+-activated single host borosilicate phosphors

NASA Astrophysics Data System (ADS)

Yu, Hong; Chen, Shanyong; Chen, Jinlei

2017-12-01

New phosphors Sr3B2SiO8: Dy3+ have been successfully synthesized via solid-state reaction process. Emission/excitation spectra, photoluminescence decay behaviors were investigated in detail. Under the excitation of 351 nm, the emission spectrum consisting of the characteristic transitions of Dy3+ which mainly peaking at 480, 487 nm and 574 nm corresponding to the4F9/2→6H15/2 and4F9/2→6H13/2, respectively, the intensity of the blue emission stronger than the yellow one which indicated that Dy3+ ions take the site without inversion symmetry. The chromaticity coordinates of Sr3-xB2SiO8: x Dy3+ fixed in the white region. The results showed the kind of phosphor may be act potential applications in the fields of UV-excited white LEDs.

Invisibility Cloak Printed on a Photonic Chip

NASA Astrophysics Data System (ADS)

Feng, Zhen; Wu, Bing-Hong; Zhao, Yu-Xi; Gao, Jun; Qiao, Lu-Feng; Yang, Ai-Lin; Lin, Xiao-Feng; Jin, Xian-Min

2016-06-01

Invisibility cloak capable of hiding an object can be achieved by properly manipulating electromagnetic field. Such a remarkable ability has been shown in transformation and ray optics. Alternatively, it may be realistic to create a spatial cloak by means of confining electromagnetic field in three-dimensional arrayed waveguides and introducing appropriate collective curvature surrounding an object. We realize the artificial structure in borosilicate by femtosecond laser direct writing, where we prototype up to 5,000 waveguides to conceal millimeter-scale volume. We characterize the performance of the cloak by normalized cross correlation, tomography analysis and continuous three-dimensional viewing angle scan. Our results show invisibility cloak can be achieved in waveguide optics. Furthermore, directly printed invisibility cloak on a photonic chip may enable controllable study and novel applications in classical and quantum integrated photonics, such as invisualising a coupling or swapping operation with on-chip circuits of their own.

Caracterisation des proprietes dielectriques de materiaux composites a base de polyethylene terephtalate recycle =

NASA Astrophysics Data System (ADS)

Mebarki, Fouzia

Cette etude vise a etudier la possibilite d'utiliser des materiaux composites a matrice thermoplastique pour des applications electriques comme les supports des systemes d'allumage dans les moteurs d'automobile. Nous nous interessons plus particulierement aux composites a base de polyethylene terephtalate (PET) recycle. Les isolants classiques comme le PET ne peuvent pas satisfaire toutes les exigences. L'introduction des renforts comme les fibres de verre et le mica peuvent ameliorer les caracteristiques mecaniques de ces materiaux. Toutefois, cette amelioration peut etre accompagnee d'une diminution des proprietes electriques surtout que ces materiaux doivent operer sous contraintes thermiques et electriques tres severes. Afin d'estimer la duree de vie de ces isolants, des essais de vieillissement accelere ont ete effectues a une frequence de 300Hz dans une plage de temperature allant de la temperature ambiante a 140°C. L'etude a haute temperature permettra de determiner la temperature de service des materiaux candidats. Des essais de la rupture dielectrique ont ete realises sur un grand nombre d'echantillon selon la norme ASTM D-149 relative aux mesures de rigidite dielectrique des isolants solides. Ces tests ont permis de deceler les echantillons problematiques et de verifier la qualite de ces isolants solides. Les differentes connaissances acquises lors de cette analyse ont servi a predire les performances des materiaux en service et vont permettre a la compagnie Groupe Lavergne d'apporter des ameliorations au niveau des formulations existantes et par la suite developper un materiau ayant les proprietes electriques et thermiques adequates pour ce type d'application. None None None None

Evaluation of a High-Throughput Peptide Reactivity Format Assay for Assessment of the Skin Sensitization Potential of Chemicals

PubMed Central

Wong, Chin Lin; Lam, Ai-Leen; Smith, Maree T.; Ghassabian, Sussan

2016-01-01

The direct peptide reactivity assay (DPRA) is a validated method for in vitro assessment of the skin sensitization potential of chemicals. In the present work, we describe a peptide reactivity assay using 96-well plate format and systematically identified the optimal assay conditions for accurate and reproducible classification of chemicals with known sensitizing capacity. The aim of the research is to ensure that the analytical component of the peptide reactivity assay is robust, accurate, and reproducible in accordance with criteria that are used for the validation of bioanalytical methods. Analytical performance was evaluated using quality control samples (QCs; heptapeptides at low, medium, and high concentrations) and incubation of control chemicals (chemicals with known sensitization capacity, weak, moderate, strong, extreme, and non-sensitizers) with each of three synthetic heptapeptides, viz Cor1-C420 (Ac-NKKCDLF), cysteine- (Ac-RFAACAA), and lysine- (Ac-RFAAKAA) containing heptapeptides. The optimal incubation temperature for all three heptapeptides was 25°C. Apparent heptapeptide depletion was affected by vial material composition. Incubation of test chemicals with Cor1-C420, showed that peptide depletion was unchanged in polypropylene vials over 3-days storage in an autosampler but this was not the case for borosilicate glass vials. For cysteine-containing heptapeptide, the concentration was not stable by day 3 post-incubation in borosilicate glass vials. Although the lysine-containing heptapeptide concentration was unchanged in both polypropylene and borosilicate glass vials, the apparent extent of lysine-containing heptapeptide depletion by ethyl acrylate, differed between polypropylene (24.7%) and glass (47.3%) vials. Additionally, the peptide-chemical complexes for Cor1-C420-cinnamaldehyde and cysteine-containing heptapeptide-2, 4-dinitrochlorobenzene were partially reversible during 3-days of autosampler storage. These observations further highlight the difficulty in adapting in vitro methods to high-throughput format for screening the skin sensitization potential of large numbers of chemicals whilst ensuring that the data produced are both accurate and reproducible. PMID:27014067

Erbium-doped borosilicate glasses containing various amounts of P{sub 2}O{sub 5} and Al{sub 2}O{sub 3}: Influence of the silica content on the structure and thermal, physical, optical and luminescence properties

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bourhis, Kevin; Massera, Jonathan; BioMediTech, Tampere

2015-10-15

Highlights: • Er{sup 3+} doped borosilicate glasses were processed with different compositions and characterizations. • An increase in the SiO{sub 2} content leads to a silicate-rich environment around the Er{sup 3+} site. • An increase in the SiO{sub 2} content decreases the Er{sup 3+} absorption cross-section at 980 nm. • Glasses with 60 mol% of SiO{sub 2} exhibit a stronger emission intensity at 1530 nm than glasses with x = 50. • Highest 1.5 μm emission intensity was achieved for the Al and P containing glass with 60 mol% of SiO{sub 2}. - Abstract: The influence of the silica contentmore » on several properties of Er-doped borosilicate glasses in the presence of various amounts of P{sub 2}O{sub 5} and Al{sub 2}O{sub 3} has been investigated. The introduction of P{sub 2}O{sub 5} and/or Al{sub 2}O{sub 3} are responsible for structural modifications in the glass network through a charge-compensation mechanism related to the formation of negatively-charged PO{sub 4} and AlO{sub 4} groups or through the formation of AlPO{sub 4}-like structural units. In this paper, we show that an increase in the SiO{sub 2} content leads to a silicate-rich environment around the Er{sup 3+} site, resulting in an increased dependence of the Er{sup 3+} ions optical and luminescence properties on the P{sub 2}O{sub 5} and/or Al{sub 2}O{sub 3} concentration. The highest emission intensity at 1.5 μm was achieved for the glass with an equal proportion of P and Al in the glass system with 60 mol% of SiO{sub 2}.« less

Lignes directrices canadiennes sur l’utilisation sécuritaire et efficace des opioïdes pour la douleur chronique non cancéreuse

PubMed Central

Kahan, Meldon; Wilson, Lynn; Mailis-Gagnon, Angela; Srivastava, Anita

2011-01-01

Résumé Objectif Présenter aux médecins de famille un résumé clinique pratique sur la prescription d’opioïdes à des populations particulières en se fondant sur les recommandations faites dans les lignes directrices canadiennes sur l’utilisation sécuritaire et efficace des opioïdes pour la douleur chronique non cancéreuse. Qualité des données Pour produire les lignes directrices, les chercheurs ont effectué une synthèse critique de la littérature médicale en insistant plus précisément sur les études de l’efficacité et de la sécurité des opioïdes dans des populations particulières. Message principal Les médecins de famille peuvent atténuer les risques de surdose, de sédation, d’usage abusif et de dépendance grâce à des stratégies adaptées à l’âge et à l’état de santé des patients. Dans le cas de patients à risque de dépendance, on devrait réserver les opioïdes aux douleurs nociceptives ou neuropathiques bien définies qui n’ont pas répondu aux traitements de première intention. Il faut procéder lentement au titrage des opioïdes, avec des dispensations fréquentes et une étroite surveillance pour dépister tout signe d’usage abusif. Une dépendance aux opioïdes suspectée est prise en charge au moyen d’une thérapie structurée aux opioïdes, d’un traitement à la méthadone ou à la buprénorphine ou encore d’un traitement fondé sur l’abstinence. Les patients souffrant de troubles de l’humeur ou d’anxiété ont tendance à avoir une réponse analgésique atténuée aux opioïdes, sont à risque plus élevé d’usage abusif et prennent souvent des sédatifs qui interagissent défavorablement avec les opioïdes. Il faut prendre des précautions semblables à celles utilisées avec d’autres patients à risque élevé. Il faut faire un sevrage progressif si la douleur du patient demeure sévère même avec un essai adéquat de thérapie aux opioïdes. Chez les personnes âgées, la sédation, les chutes et la surdose peuvent être minimisées en utilisant des doses initiales faibles, un titrage plus lent, un sevrage des benzodiazépines et une bonne éducation des patients. Dans le cas des femmes enceintes qui prennent des opioïdes chaque jour, il faut faire un sevrage progressif et cesser complètement. Si ce n’est pas possible, il faut administrer la dose efficace la plus faible. Les femmes enceintes qui ont une dépendance aux opioïdes devraient recevoir un traitement à la méthadone. Les adolescents sont à risque élevé de surdose d’opioïdes, d’usage abusif et de dépendance. Les patients qui ont des adolescents qui vivent à la maison devraient entreposer leurs opioïdes dans un lieu sûr. Les adolescents ont rarement besoin d’une thérapie à long terme aux opioïdes. Conclusion Les médecins de famille doivent tenir compte de l’âge, de la condition psychiatrique, du degré de risque de dépendance du patient et d’autres facteurs quand ils prescrivent des opioïdes pour la douleur chronique.

Comparaison des effets des irradiations γ, X et UV dans les fibres optiques

NASA Astrophysics Data System (ADS)

Girard, S.; Ouerdane, Y.; Baggio, J.; Boukenter, A.; Meunier, J.-P.; Leray, J.-L.

2005-06-01

Les fibres optiques présentent de nombreux avantages incitant à les intégrer dans des applications devant résister aux environnements radiatifs associés aux domaines civil, spatial ou militaire. Cependant, leur exposition à un rayonnement entraîne la création de défauts ponctuels dans la silice amorphe pure ou dopée qui constitue les différentes parties de la fibre optique. Ces défauts causent, en particulier, une augmentation transitoire de l'atténuation linéique des fibres optiques responsable de la dégradation voire de la perte du signal propagé dans celles-ci. Dans cet article, nous comparons les effets de deux types d'irradiation: une impulsion X et une dose γ cumulée. Les effets de ces irradiations sont ensuite comparés avec ceux induits par une insolation ultraviolette (244 nm) sur les propriétés d'absorption des fibres optiques. Nous montrons qu'il existe des similitudes entre ces différentes excitations et qu'il est possible, sous certaines conditions, d'utiliser celles-ci afin d'évaluer la capacité de certaines fibres optiques à fonctionner dans un environnement nucléaire donné.

AGARD/SMP Review Damage Tolerance for Engine Structures. 3. Component Behaviour and Life Management

DTIC Science & Technology

1990-06-01

Life Management (Revue AGARD/SMP - ToIrance aux Dommages pour les Composants de Moteurs 3. Le Comportement des Composants et la Gestion %𔄀 de Leur Dur...Structures 3. Component Behaviour and Life Management . (Revue AGARD/SMP - ToI~rance aux Dommages pour les Compos ants de Moteurs 3. Le Comportement...engine parts. The present report includes the papers presented during Workshop Ill which was devoted to Component Behaviour and Life Management . It also

High-Level Operations in Nonprocedural Programming Languages.

DTIC Science & Technology

1983-12-01

defining type specific operators. Abstract data type has been applied to the nonprocedural language NOPAL [Sang8O]. It was primarily used as a tool...level operation is transformed using the integral operation MATINV as follows: 1 GA IS GROUP, 2 GRA(*) IS GROUP, 3 AUX(*) IS FIELD (DEC FLOAT); I GI...IS GROUP, 2 GRI(*) IS GROUP, 3 INV(*) IS FIELD (DEC FLOAT); AUX = A; GI = MATINV( GA ); C = INV; In code generation, the assertion GI=MATINV( GA ) is

L'Anse Aux Meadows, Newfoundland

NASA Technical Reports Server (NTRS)

2008-01-01

L'Anse aux Meadows is a site on the northernmost tip of the island of Newfoundland, located in the Province of Newfoundland and Labrador, Canada, where the remains of a Viking village were discovered in 1960 by the Norwegians Helge and Anne Ingstad. The only authenticated Viking settlement in North America outside Greenland, it was the site of a multi-year archaeological dig that found dwellings, tools and implements that verified its time frame. The settlement, dating more than five hundred years before Christopher Columbus, contains the earliest European structures in North America. Named a World Heritage site by UNESCO, it is thought by many to be the semi-legendary 'Vinland' settlement of explorer Leif Ericson around AD 1000. The settlement at L'Anse aux Meadows consisted of at least eight buildings, including a forge and smelter, and a lumber yard that supported a shipyard. The largest house measured 28.8 by 15.6 m and consisted of several rooms. Sewing and knitting tools found at the site indicate women were present at L'Anse aux Meadows

The image was acquired on September 14, 2007, covers an area of 14.2 x 14.6 km, and is located at 51.5 degrees north latitude, 55.6 degrees west longitude.

The U.S. science team is located at NASA's Jet Propulsion Laboratory, Pasadena, Calif. The Terra mission is part of NASA's Science Mission Directorate.

Pathology and the posture of the La Chapelle-aux-Saints Neandertal.

PubMed

Trinkaus, E

1985-05-01

The depiction of the Neandertals as incompletely erect was based primarily on Boule's (1911, 1912a, 1913) analysis of the La Chapelle-aux-Saints 1 partial skeleton. The inaccurate aspects of Boule's postural reconstruction were corrected during the 1950s. However, it has come to be believed, following Straus and Cave (1957), that Boule's errors of reconstruction were due to the diseased condition of the La Chapelle-aux-Saints 1 remains, rather than to Boule's misinterpretation of morphology. The abnormalities on the La Chapelle-aux-Saints 1 postcranium include: lower cervical, upper thoracic, and lower thoracic intervertebral degenerative joint disease (DJD), a distal fracture of a mid-thoracic rib, extensive DJD of the left hip, DJD of the right fifth proximal interphalangeal articulation, bilateral humeral head eburnation, and minor exostosis formation on the right humerus, ulna, and radius. These were associated with extensive alveolar inflammation including apical abscesses and antemortem tooth loss, some temporomandibular DJD, bilateral auditory exostoses, and minimal occipital condyle DJD. None of these abnormalities significantly affected Boule's Neandertal postural reconstruction, and a review of his analysis indicates that early twentieth century interpretations of skeletal morphology (primarily of the cranium, cervical vertebrae, lumbar and sacral vertebrae, proximal femora and tibiae, posterior tarsals, and hallucial tarsometatarsal joint), combined with Boule's evolutionary preconceptions, were responsible for his mistaken view of Neandertal posture.

Design for Maintainability with Modified Petri Nets (MPNs): Shipboard Propulsion System Application.

DTIC Science & Technology

1984-11-01

hazard (in acco- Fance with current environmental protection requirements). P20 YES T20 T2 1 EOOW report to 000, "Fire hazards removed from No engine room...8217-..! AARCA: GAS TURBINE MAIN ENGINE - GENERATOR Room NO 2 , .’ .- " SE7 NO. 2 \\ N 2 GEN MRGA GTM ,RZT 4o i .. .E rAF- _....Pr AJ*~ IAMR...GA Z0GYM GEN "-- ~ ~ P LL-L GIM. I I - GT MAIN ENGINE/ \\ t I . ROOM NO. I GAS 7RBINE ALIX MCHRY AUX MCHRY O OROO NO OOM NO. GENEU.ATOF ROOM NO 2 R

Le recours aux modeles dans l'enseignement de la biologie au secondaire : Conceptions d'enseignantes et d'enseignants et modes d'utilisation

NASA Astrophysics Data System (ADS)

Varlet, Madeleine

Le recours aux modeles et a la modelisation est mentionne dans la documentation scientifique comme un moyen de favoriser la mise en oeuvre de pratiques d'enseignement-apprentissage constructivistes pour pallier les difficultes d'apprentissage en sciences. L'etude prealable du rapport des enseignantes et des enseignants aux modeles et a la modelisation est alors pertinente pour comprendre leurs pratiques d'enseignement et identifier des elements dont la prise en compte dans les formations initiale et disciplinaire peut contribuer au developpement d'un enseignement constructiviste des sciences. Plusieurs recherches ont porte sur ces conceptions sans faire de distinction selon les matieres enseignees, telles la physique, la chimie ou la biologie, alors que les modeles ne sont pas forcement utilises ou compris de la meme maniere dans ces differentes disciplines. Notre recherche s'est interessee aux conceptions d'enseignantes et d'enseignants de biologie au secondaire au sujet des modeles scientifiques, de quelques formes de representations de ces modeles ainsi que de leurs modes d'utilisation en classe. Les resultats, que nous avons obtenus au moyen d'une serie d'entrevues semi-dirigees, indiquent que globalement leurs conceptions au sujet des modeles sont compatibles avec celle scientifiquement admise, mais varient quant aux formes de representations des modeles. L'examen de ces conceptions temoigne d'une connaissance limitee des modeles et variable selon la matiere enseignee. Le niveau d'etudes, la formation prealable, l'experience en enseignement et un possible cloisonnement des matieres pourraient expliquer les differentes conceptions identifiees. En outre, des difficultes temporelles, conceptuelles et techniques peuvent freiner leurs tentatives de modelisation avec les eleves. Toutefois, nos resultats accreditent l'hypothese que les conceptions des enseignantes et des enseignants eux-memes au sujet des modeles, de leurs formes de representation et de leur approche constructiviste en enseignement representent les plus grands obstacles a la construction des modeles en classe. Mots-cles : Modeles et modelisation, biologie, conceptions, modes d'utilisation, constructivisme, enseignement, secondaire.

Recommandations pour le dépistage de l’hypertension chez les adultes canadiens

PubMed Central

Lindsay, Patrice; Gorber, Sarah Connor; Joffres, Michel; Birtwhistle, Richard; McKay, Donald; Cloutier, Lyne

2013-01-01

Résumé Objectif Présenter des recommandations concernant le dépistage de l’hypertension chez les adultes de 18 ans et plus qui n’ont pas reçu antérieurement de diagnostic d’hypertension. Qualité des données Les données probantes sont tirées d’une recension systématique dans MEDLINE, EMBASE et la base de données des synthèses systématiques de la Collaboration Cochrane (EBM Reviews), de janvier 1985 à septembre 2011. Les types d’études retenues se limitaient aux études randomisées contrôlées, aux synthèses systématiques et aux études observationnelles avec groupes témoins. Message principal Trois fortes recommandations se sont dégagées de données probantes de qualité modérée. Il est recommandé de mesurer la pression artérielle à toutes les consultations appropriées en soins primaires, conformément aux techniques actuelles décrites dans les recommandations du Programme éducatif canadien sur l’hypertension pour la mesure de la pression artérielle en cabinet et en soins ambulatoires. Les critères du Programme éducatif canadien sur l’hypertension pour l’évaluation et le diagnostic de l’hypertension devraient s’appliquer aux personnes chez qui on observe une pression artérielle élevée. Conclusion À la suite d’un examen des plus récentes données probantes, le Groupe d’étude canadien sur les soins de santé préventifs continue de recommander la mesure de la pression artérielle lors des consultations périodiques auprès du médecin.

Phase Stability Determinations of DWPF Waste Glasses

DOE Office of Scientific and Technical Information (OSTI.GOV)

Marra, S.L.

1999-10-22

Liquid high-level nuclear waste will be immobilized at the Savannah River Site (SRS) by vitrification in borosilicate glass. To fulfill this requirement, glass samples were heat treated at various times and temperatures. These results will provide guidance to the repository program about conditions to be avoided during shipping, handling and storage of DWPF canistered waste forms.

Alternatives to Anti-Personnel Landmines (Solutions de remplacement aux mines antipersonnel)

DTIC Science & Technology

2003-05-01

remplacement ont un prix : elles sont plus pesantes sur le plan logistique et impliquent des risques opérationnels pour les forces de l’OTAN. En...très importante, de l’interopérabilité dans le transfert de secteurs qui ont été minés par un pays non-signataire de la Convention d’Ottawa. Le...SEINE CEDEX, FRANCE RTO TECHNICAL REPORT 40(I) Alternatives to Anti-Personnel Landmines (Solutions de remplacement aux mines antipersonnel) Military

The Resin-in-pulp Process and Its Application to Ores from Brosses "BRS 10"; LE PROCEDE "RESIN IN PULP" ET SON APPLICATION AUX MINERAIS DES BROSSES "BRS 10"

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kremer, M.

1959-03-01

The resin-in-pulp process is a technical variant of the recovery process of uranium in dilute solution by means of ion exchange resins. An anion resin, XE 123, of a welldefined grain size is placed in direct contact with the pulp produced by sulfuric acid attack on ore with a low uranium content. This process is of particular value in the treatment of pulps that cannot be filtered or decanted, such as those obtained with ore from Brosses. The preparation of the pulp, the elution of the uranium, and its fixation, as well as the various factors encountered in these operations,more » are discussed. (auth)« less

Down-regulation of SlIAA15 in tomato altered stem xylem development and production of volatile compounds in leaf exudates.

PubMed

Deng, Wei; Yan, Fang; Liu, Minchun; Wang, Xinyu; Li, Zhengguo

2012-08-01

The Aux/IAA family genes encode short-lived nuclear proteins that function as transcriptional regulators in auxin signal transduction. Aux/IAA genes have been reported to control many processes of plant development. Our recent study showed that down-regulation of SlIAA15 in tomato reduced apical dominance, altered pattern of axillary shoot development, increased lateral root formation and leaves thickness. The SlIAA15 suppressed lines display strong reduction of trichome density, suggesting that SlIAA15 is involved in trichome formation. Here, we reported that SlIAA15-suppressed transgenic lines display increased number of xylem cells compared to wild-type plants. Moreover, the monoterpene content in trichome exudates are significantly reduced in SlIAA15 down-regulated leaves. The results provide the roles of SlIAA15 in production of volatile compounds in leaf exudates and xylem development, clearly indicating that members of the Aux/IAA gene family can play distinct and specific functions. 

Periodicity, Electronic Structures, and Bonding of Gold Tetrahalides [AuX4](-) (X = F, CI, Br, I, At, Uus)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Wan-Lu; Li, Yong; Xu, Congqiao

2015-12-07

Systematic theoretical and experimental investigations have been performed to understand the periodicity and electronic structures of trivalent-gold halides using gold tetrahalides [AuX4]⁻ anions (X = F, Cl, Br, I, At, Uus). The [AuX4]⁻ (X = Cl, Br, I) anions were produced in gas phase and their negative-ion photoelectron spectra were obtained, which exhibited rich and well-resolved spectral peaks. We calculated the adiabatic as well as vertical electron detachment energies using density functional methods with scalar and spin-orbit coupling relativistic effects. The simulated photoelectron spectra based on these calculations are in good agreement with the experimental spectra. Our results show thatmore » the trivalent Au(III) oxidation state becomes progressively less stable while Au(I) is preferred when the halides become heavier along the Period Table. This trend reveals that the oxidation state of metals in complexes can be manipulated through ligand design« less

Decrease in artificial tanning by French teenagers: 2011-2016.

PubMed

Say, Matthieu; Beauchet, Alain; Vouldoukis, Ioannis; Beauchet, Pascale; Boudet, Monique; Tella, Emilie; Mahé, Emmanuel

2018-03-13

The major risk factor for skin cancers is exposure to solar and artificial ultraviolet radiation, in particular during childhood and adolescence. In France, a law was restricted for tanning-bed access to adults (≥18 years) since 1997. To evaluate teenagers' artificial tanning behaviour in 2016 and to compare results with those obtained in a similar survey performed in 2011. The SOLADO 2011 and 2016 surveys were conducted in a general school in Antony and a technical school in Fontenay-aux-Roses (Paris suburb). In 2016, 630 teenagers (mean age: 14.2 ± 1.9 y: Males/Females: 301/329) completed the questionnaire, 1.3% of teenagers reported using tanning beds, 1.1% tanning pills and 8.9% tanning creams. Between 2011 and 2016, the use of tanning beds decreased from 1.4% to 0.7% in Antony (P = .26) and from 9.5% to 4.8% in Fontenay-aux-Roses (P = .01), and the use of tanning creams from 39.8% to 17.6% in Fontenay-aux-Rose (P = .0007). The incidence of sunburn decreased from 60.5% to 54.0% in Antony (P = .02) and from 55.4% to 42.4% in Fontenay-aux-Roses (P = .05). As compared to 2011, teenagers used artificial tanning methods less frequently in 2016. In particular, they used tanning beds less frequently, suggesting that the new stricter legislation has been effective. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Failure Behavior of Glass and Aluminum Oxynitride (AlON) Tiles Under Spherical Indenters

DTIC Science & Technology

2010-05-01

soda - lime - silica glass are the result of intersections of shear flow lines...commercial glass manufacturers. The glasses were soda - lime - silica float glass (Starphire*), borosilicate float glass (BOROFLOAT†), and vitreous silica . The...ensued. For example, Swain and Hagan (47) observed plastic yielding and the formation of ring-cone, radial, and lateral cracks in soda - lime - silica

Review of waste package verification tests. Semiannual report, October 1982-March 1983

DOE Office of Scientific and Technical Information (OSTI.GOV)

Soo, P.

1983-08-01

The current study is part of an ongoing task to specify tests that may be used to verify that engineered waste package/repository systems comply with NRC radionuclide containment and controlled release performance objectives. Work covered in this report analyzes verification tests for borosilicate glass waste forms and bentonite- and zeolite-based packing mateials (discrete backfills). 76 references.

LASER DESORPTION-IONIZATION OF POLYCYCLIC AROMATIC HYDROCARBONS FROM GLASS SURFACES WITH ION MOBILITY SPECTROMETRY ANALYSIS. (R826769)

EPA Science Inventory

Polycyclic aromatic hydrocarbons (PAHs) were analyzed as adsorbates on borosilicate glass at levels from 40 pg (5.5 pg mm^-2) to 7 g (1 

Nepheline structural and chemical dependence on melt composition

DOE Office of Scientific and Technical Information (OSTI.GOV)

Marcial, José; Crum, Jarrod; Neill, Owen

Nepheline crystallizes upon slow-cooling in some melts concentrated in Na2O and Al2O3, which can result in a residual glass phase of low chemical durability. Nepheline can incorporate many components often found in high-level waste radioactive borosilicate glass, including glass network ions (e.g., Si, Al, Fe), alkali metals (e.g., Cs, K, Na, and possibly Li), alkaline-earth metals (e.g., Ba, Sr, Ca, Mg), and transition metals (e.g., Mn, and possibly Cr, Zn, Ni). When crystallized from melts of different compositions, nepheline chemistry varies as a function of starting glass composition. Five simulated high level nuclear waste borosilicate glasses shown to crystallize largemore » fractions of nepheline on slow cooling, were selected for study. These melts constituted a range of Al2O3, B2O3, CaO, Na2O, K2O, Fe2O3, and SiO2 compositions. Compositional analyses of nepheline crystals in glass by electron probe micro-analysis (EPMA) indicate that boron is unlikely to be present in any significant concentration, if at all, in nepheline. Also, several models are presented for calculating the fraction of vacancies in the nepheline structure.« less

Epsilon Metal Waste Form for Immobilization of Noble Metals from Used Nuclear Fuel

DOE Office of Scientific and Technical Information (OSTI.GOV)

Crum, Jarrod V.; Strachan, Denis M.; Rohatgi, Aashish

2013-10-01

Epsilon metal (ε-metal), an alloy of Mo, Pd, Rh, Ru, and Tc, is being developed as a waste form to treat and immobilize the undissolved solids and dissolved noble metals from aqueous reprocessing of commercial used nuclear fuel. Epsilon metal is an attractive waste form for several reasons: increased durability relative to borosilicate glass, it can be fabricated without additives (100% waste loading), and in addition it also benefits borosilicate glass waste loading by eliminating noble metals from the glass and thus the processing problems related there insolubility in glass. This work focused on the processing aspects of the epsilonmore » metal waste form development. Epsilon metal is comprised of refractory metals resulting in high reaction temperatures to form the alloy, expected to be 1500 - 2000°C making it a non-trivial phase to fabricate by traditional methods. Three commercially available advanced technologies were identified: spark-plasma sintering, microwave sintering, and hot isostatic pressing, and investigated as potential methods to fabricate this waste form. Results of these investigations are reported and compared in terms of bulk density, phase assemblage (X-ray diffraction and elemental analysis), and microstructure (scanning electron microscopy).« less

Development of graded Ni-YSZ composite coating on Alloy 690 by Pulsed Laser Deposition technique to reduce hazardous metallic nuclear waste inventory.

PubMed

Sengupta, Pranesh; Rogalla, Detlef; Becker, Hans Werner; Dey, Gautam Kumar; Chakraborty, Sumit

2011-08-15

Alloy 690 based 'nuclear waste vitrification furnace' components degrade prematurely due to molten glass-alloy interactions at high temperatures and thereby increase the volume of metallic nuclear waste. In order to reduce the waste inventory, compositionally graded Ni-YSZ (Y(2)O(3) stabilized ZrO(2)) composite coating has been developed on Alloy 690 using Pulsed Laser Deposition technique. Five different thin-films starting with Ni80YSZ20 (Ni 80 wt%+YSZ 20 wt%), through Ni60YSZ40 (Ni 60 wt%+YSZ 40 wt%), Ni40YSZ60 (Ni 40 wt%+YSZ 60 wt%), Ni20YSZ80 (Ni 20 wt%+YSZ 80 wt%) and Ni0YSZ100 (Ni 0 wt%+YSZ 100 wt%), were deposited successively on Alloy 690 coupons. Detailed analyses of the thin-films identify them as homogeneous, uniform, pore free and crystalline in nature. A comparative study of coated and uncoated Alloy 690 coupons, exposed to sodium borosilicate melt at 1000°C for 1-6h suggests that the graded composite coating could substantially reduced the chemical interactions between Alloy 690 and borosilicate melt. Copyright © 2011 Elsevier B.V. All rights reserved.

White-beam X-ray diffraction and radiography studies on high-boron-containing borosilicate glass at high pressures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ham, Kathryn J.; Vohra, Yogesh K.; Kono, Yoshio

Multi-angle energy-dispersive X-ray diffraction studies and white-beam X-ray radiography were conducted with a cylindrically shaped (1 mm diameter and 0.7 mm high) high-boron-content borosilicate glass sample (17.6% B 2O 3) to a pressure of 13.7 GPa using a Paris-Edinburgh (PE) press at Beamline 16-BM-B, HPCAT of the Advanced Photon Source. The measured structure factor S(q) to large q = 19 Å –1 is used to determine information about the internuclear bond distances between various species of atoms within the glass sample. Sample pressure was determined with gold as a pressure standard. The sample height as measured by radiography showed anmore » overall uniaxial compression of 22.5% at 13.7 GPa with 10.6% permanent compaction after decompression to ambient conditions. The reduced pair distribution function G(r) was extracted and Si–O, O–O and Si–Si bond distances were measured as a function of pressure. Lastly, Raman spectroscopy of the pressure recovered sample as compared to starting material showed blue-shift and changes in intensity and widths of Raman bands associated with silicate and four-coordinated boron.« less

White-beam X-ray diffraction and radiography studies on high-boron-containing borosilicate glass at high pressures

DOE PAGES

Ham, Kathryn J.; Vohra, Yogesh K.; Kono, Yoshio; ...

2017-02-06

Multi-angle energy-dispersive X-ray diffraction studies and white-beam X-ray radiography were conducted with a cylindrically shaped (1 mm diameter and 0.7 mm high) high-boron-content borosilicate glass sample (17.6% B 2O 3) to a pressure of 13.7 GPa using a Paris-Edinburgh (PE) press at Beamline 16-BM-B, HPCAT of the Advanced Photon Source. The measured structure factor S(q) to large q = 19 Å –1 is used to determine information about the internuclear bond distances between various species of atoms within the glass sample. Sample pressure was determined with gold as a pressure standard. The sample height as measured by radiography showed anmore » overall uniaxial compression of 22.5% at 13.7 GPa with 10.6% permanent compaction after decompression to ambient conditions. The reduced pair distribution function G(r) was extracted and Si–O, O–O and Si–Si bond distances were measured as a function of pressure. Lastly, Raman spectroscopy of the pressure recovered sample as compared to starting material showed blue-shift and changes in intensity and widths of Raman bands associated with silicate and four-coordinated boron.« less

Epsilon metal waste form for immobilization of noble metals from used nuclear fuel

NASA Astrophysics Data System (ADS)

Crum, Jarrod V.; Strachan, Denis; Rohatgi, Aashish; Zumhoff, Mac

2013-10-01

Epsilon metal (ɛ-metal), an alloy of Mo, Pd, Rh, Ru, and Tc, is being developed as a waste form to treat and immobilize the undissolved solids and dissolved noble metals from aqueous reprocessing of commercial used nuclear fuel. Epsilon metal is an attractive waste form for several reasons: increased durability relative to borosilicate glass, it can be fabricated without additives (100% waste loading), and in addition it also benefits borosilicate glass waste loading by eliminating noble metals from the glass, thus the processing problems related to their insolubility in glass. This work focused on the processing aspects of the epsilon metal waste form development. Epsilon metal is comprised of refractory metals resulting in high alloying temperatures, expected to be 1500-2000 °C, making it a non-trivial phase to fabricate by traditional methods. Three commercially available advanced technologies were identified: spark-plasma sintering, microwave sintering, and hot isostatic pressing, and investigated as potential methods to fabricate this waste form. Results of these investigations are reported and compared in terms of bulk density, phase assemblage (X-ray diffraction and elemental analysis), and microstructure (scanning electron microscopy).

Dispositifs semi-conducteurs pour biodetection photonique et imagerie hyperspectrale

NASA Astrophysics Data System (ADS)

Lepage, Dominic

La creation d'un microsysteme d'analyse biochimique, capable de livrer des diagnostics preliminaires sur la quantification d'elements pathogenes, est un defi multidisciplinaire ayant un impact potentiel important sur la majorite des activites humaines en sante et securite. En effet, un dispositif integre, peu dispendieux et livrant des resultats facilement interpretables, permettrait une vulgarisation des capacites de biodetection a travers differents domaines d'applications societaires et industriels. Le present document se concentre sur l'integration monolithique d'une methode de biocaracterisation dans le but de generer un transducteur miniaturise et efficace, element central d'un microsysteme de detection. Le projet de recherche ici presente vise l'etude de l'applicabilite d'un capteur plasmonique integre par l'entremise de nanostructures semi-conductrices aux proprietes quantiques et luminescentes. L'approche presentee est globale; c'est-a-dire qu'on vise a repondre aux questions fondamentales impliquant la comprehension des phenomenes photoniques, le developpement et la fabrication des dispositifs, les methodes de caracterisations possibles ainsi que l'application d'un transducteur SPR integre a la biodetection. En d'autres termes : dans quelles circonstances et comment un transducteur plasmonique integre doit-il etre realise pour l'application a la detection delocalisee d'elements pathogenes? Dans le but d'engendrer un instrument simple a l'echelle de l'usager, l'integration de la connaissance a l'echelle du design est donc effectuee. Ainsi, des capteurs plasmoniques monolithiques sont concus a l'aide de modeles theoriques ici presentes. Un instrument de mesure hyperspectrale conjuguee permettant de cartographier directement la relation de dispersion des plasmons diffractes a ete construit et teste. Cet instrument est employe a la cartographie d'elements de diffusion. Finalement, une demonstration du fonctionnement du dispositif, appliquee a la biocaracterisation d'evenements simples, tels que l'albumine de serum bovin et la detection d'une souche specifique d'influenza A, est livree. Ceci repond donc a la question de faisabilite d'un nanosysteme plasmonique applicable a la detection de pathogenes. Mots-Clefs: Biocapteur; Plasmons de surface; Diffusion lumineuse; Semi-conducteur quantique; Microscopie conjuguee; Virus Influenza A

Zinc Oxide-Based Self-Powered Potentiometric Chemical Sensors for Biomolecules and Metal Ions.

PubMed

Israr-Qadir, Muhammad; Jamil-Rana, Sadaf; Nur, Omer; Willander, Magnus

2017-07-19

Advances in the miniaturization and portability of the chemical sensing devices have always been hindered by the external power supply problem, which has focused new interest in the fabrication of self-powered sensing devices for disease diagnosis and the monitoring of analytes. This review describes the fabrication of ZnO nanomaterial-based sensors synthesized on different conducting substrates for extracellular detection, and the use of a sharp borosilicate glass capillary (diameter, d = 700 nm) to grow ZnO nanostructures for intracellular detection purposes in individual human and frog cells. The electrocatalytic activity and fast electron transfer properties of the ZnO materials provide the necessary energy to operate as well as a quick sensing device output response, where the role of the nanomorphology utilized for the fabrication of the sensor is crucial for the production of the operational energy. Simplicity, design, cost, sensitivity, selectivity and a quick and stable response are the most important features of a reliable sensor for routine applications. The review details the extra- and intra-cellular applications of the biosensors for the detection and monitoring of different metallic ions present in biological matrices, along with the biomolecules glucose and cholesterol.

Zinc Oxide-Based Self-Powered Potentiometric Chemical Sensors for Biomolecules and Metal Ions

PubMed Central

Israr-Qadir, Muhammad; Jamil-Rana, Sadaf; Nur, Omer; Willander, Magnus

2017-01-01

Advances in the miniaturization and portability of the chemical sensing devices have always been hindered by the external power supply problem, which has focused new interest in the fabrication of self-powered sensing devices for disease diagnosis and the monitoring of analytes. This review describes the fabrication of ZnO nanomaterial-based sensors synthesized on different conducting substrates for extracellular detection, and the use of a sharp borosilicate glass capillary (diameter, d = 700 nm) to grow ZnO nanostructures for intracellular detection purposes in individual human and frog cells. The electrocatalytic activity and fast electron transfer properties of the ZnO materials provide the necessary energy to operate as well as a quick sensing device output response, where the role of the nanomorphology utilized for the fabrication of the sensor is crucial for the production of the operational energy. Simplicity, design, cost, sensitivity, selectivity and a quick and stable response are the most important features of a reliable sensor for routine applications. The review details the extra- and intra-cellular applications of the biosensors for the detection and monitoring of different metallic ions present in biological matrices, along with the biomolecules glucose and cholesterol. PMID:28753916

Swell Across the Continental Shelf

DTIC Science & Technology

2001-09-01

Arlington, VA The views expressed in this thesis are those of the author and do not reflect the official policy or position of the Department of Defense ...le terme de source, tandis que les effets de la réfraction et du levage causés par les variations de profondeur aux échelles sous-maille sont...précisement pris en compte grâce aux rayons pré- calculés. Ainsi ce modèle peut être appliqué à de vastes zones côtières avec des maillages

The Evolution of Minehunting in France (L’Evolution de la Chasse aux Mines en France),

DTIC Science & Technology

1983-07-13

The Necessity of Minehunting in France And why are the French , Ohl such a small number of experts, interested in minehunting? The coasts of France are...AD-A132 532 THE EVOLUTION OF MINEHUNTING IN FRANCE IL’EVOLUTION DE I/1 LA CHASSE AUX MINES EN FRANCE )(U) NAVAL INTELLIGENCE SUPPORT CENTER WASHINGTON...MINEHUNTING IN FRANCE AUTHOR: DE DREZIGUE TRANSLATEO gY: LCDR ROBERT AUGELLI, USNR-R NISC TRANSLATION UNIT 0166 eei o DTIC MI’S OR&I DfIC T ELECTE Ja~tinoati

Fundamentals and Special Problems of Synthetic Aperture Radar (SAR) (Les Aspects Fondamentaux et les Problemes Specifiques aux Radars a Ouverture Synthetique (SAR)

DTIC Science & Technology

1992-08-01

limits of these topics will be included. Digital SAR processing is for SAR indispensible. Theories and special algorithms will be given along with basic...traitement num~rique est indispensable aux SAP,. Des theories et des algorithmes sp~cifiques; seront proposes, ainsi que des configurations de processeur...equation If N independent pixel values are added than fol- lows from the laws of probability theory that the ra mean value of the sum is identical with

Unsteady Aerodynamics - Fundamentals and Applications of Aircraft Dynamics. Conference Proceedings of the Joint Symposium of the Fluid Dynamics and Flight Mechanics Panels Held in Goettingen, Federal Republic of Germany on 6-9 May 1985.

DTIC Science & Technology

1985-11-01

tourbillons daxe perpendicu-V laire A l’fcoulement principal) issu d’un profil occillant en Tamis dan;, do,, condition,, dn dorochagp dynamique. 5_10...a~rodyna- - mique sur R. A partir de cette analyse experimentale, une tentative de modelisation th~sorique des effets non *lin~ laires observes aux...cisaillement A la paroi d’un profil d’aile anim6 d’un mouvament harmonique parall~le ou parpandicu- laire A 1𔄀coulement non perturb~s", EUROMECH

Identification des risques professionnels dans l'industrie textile en République Démocratique du Congo

PubMed Central

Kitronza, Panda Lukongo

2014-01-01

Introduction Le but de cette étude est de mettre en évidence les facteurs de risques professionnels liés aux conditions de travail. Méthodes Cette étude qualitative basée sur les entretiens de groupe a été réalisée par une équipe pluridisciplinaire dans l'industrie textile de la région du Est de la RDC; comprenant un médecin de travail, un médecin de santé publique, un toxicologue, deux infirmiers du centre hospitalier de l'usine, un représentant du comité d'hygiène et un technicien de prévention. La démarche méthodologique a consisté en des entretiens en groupe, des observations et visites guidées de lieux de travail de l'entreprise. Résultats Dans la culture du coton, les effets d'une forte exposition aux pesticides peuvent entraîner des intoxications aiguës, chroniques et voire le décès. Les autres risques sont les accidents de travail, les maladies professionnelles, les troubles psychologiques. Dans l'industrie, les travailleurs sont exposés aux risques liés à l'empoussiérage des fibres de coton, aux facteurs des risques traumatiques, physiques (bruits, vibration) et chimiques (acides forts, bases fortes, solvants et colorants minéraux), ainsi qu'aux risques psychosociaux. La pollution de l'environnement et l’écotoxicité inhérente à ces activités restent l'effet de l'usage des grandes quantités d'intrants agricoles, engrais et produits phytosanitaires. Conclusion Cette étude a permis de mettre en évidence les différents facteurs de risques auxquelles sont soumis les travailleurs textiles; ainsi que les risques environnementaux liés à cette activité. Cela est de nature à permettre la mise sur pied d'une stratégie efficace de prévention et de protection des travailleurs. PMID:25977736

Reconnaissance invariante d'objets 3-D et correlation SONG

NASA Astrophysics Data System (ADS)

Roy, Sebastien

Cette these propose des solutions a deux problemes de la reconnaissance automatique de formes: la reconnaissance invariante d'objets tridimensionnels a partir d'images d'intensite et la reconnaissance robuste a la presence de bruit disjoint. Un systeme utilisant le balayage angulaire des images et un classificateur par trajectoires d'espace des caracteristiques permet d'obtenir la reconnaissance invariante d'objets tridimensionnels. La reconnaissance robuste a la presence de bruit disjoint est realisee au moyen de la correlation SONG. Nous avons realise la reconnaissance invariante aux translations, rotations et changements d'echelle d'objets tridimensionnels a partir d'images d'intensite segmentees. Nous utilisons le balayage angulaire et un classificateur a trajectoires d'espace des caracteris tiques. Afin d'obtenir l'invariance aux translations, le centre de balayage angulaire coincide avec le centre geometrique de l'image. Le balayage angulaire produit un vecteur de caracteristiques invariant aux changements d'echelle de l'image et il transforme en translations du signal les rotations autour d'un axe parallele a la ligne de visee. Le classificateur par trajectoires d'espace des caracteristiques represente une rotation autour d'un axe perpendiculaire a la ligne de visee par une courbe dans l'espace. La classification se fait par la mesure de la distance du vecteur de caracteristiques de l'image a reconnaitre aux trajectoires stockees dans l'espace. Nos resultats numeriques montrent un taux de classement atteignant 98% sur une banque d'images composee de 5 vehicules militaires. La correlation non-lineaire generalisee en tranches orthogonales (SONG) traite independamment les niveaux de gris presents dans une image. Elle somme les correlations lineaires des images binaires ayant le meme niveau de gris. Cette correlation est equivalente a compter le nombre de pixels situes aux memes positions relatives et ayant les memes intensites sur deux images. Nous presentons une realisation opto-electronique de la correlation SONG. Cette realisation utilise le correlateur a transformees conjointes. Les resultats des experiences numeriques et optiques montrent que le bruit disjoint ne nuit pas a la correlation SONG.

Maladie des vibrations

PubMed Central

Shen, Shixin (Cindy); House, Ronald A.

2017-01-01

Résumé Objectif Permettre aux médecins de famille de comprendre l’épidémiologie, la pathogenèse, les symptômes, le diagnostic et la prise en charge de la maladie des vibrations, une maladie professionnelle importante et courante au Canada. Sources d’information Une recherche a été effectuée sur MEDLINE afin de relever les recherches et comptes rendus portant sur la maladie des vibrations. Une recherche a été effectuée sur Google dans le but d’obtenir la littérature grise qui convient au contexte canadien. D’autres références ont été tirées des articles relevés. Message principal La maladie des vibrations est une maladie professionnelle répandue touchant les travailleurs de diverses industries qui utilisent des outils vibrants. La maladie est cependant sous-diagnostiquée au Canada. Elle compte 3 éléments : vasculaire, sous la forme d’un phénomène de Raynaud secondaire; neurosensoriel; et musculosquelettique. Aux stades les plus avancés, la maladie des vibrations entraîne une invalidité importante et une piètre qualité de vie. Son diagnostic exige une anamnèse minutieuse, en particulier des antécédents professionnels, un examen physique, des analyses de laboratoire afin d’éliminer les autres diagnostics, et la recommandation en médecine du travail aux fins d’investigations plus poussées. La prise en charge consiste à réduire l’exposition aux vibrations, éviter les températures froides, abandonner le tabac et administrer des médicaments. Conclusion Pour assurer un diagnostic rapide de la maladie des vibrations et améliorer le pronostic et la qualité de vie, les médecins de famille devraient connaître cette maladie professionnelle courante, et pouvoir obtenir les détails pertinents durant l’anamnèse, recommander les patients aux cliniques de médecine du travail et débuter les demandes d’indemnisation de manière appropriée. PMID:28292812

Complex facies relationships and regional stratigraphy of the Mississippian Ste. Genevieve, Paoli, and Aux Vases Formations, Illinois basin: A major hydrocarbon-producing interval

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cole, R.D.; Nelson, W.J.

1993-03-01

The Mississippian Ste. Genevieve and Paoli Limestones and sandstones of the Aux Vases Formation are lateral facies of one another. This interpretation is based on comprehensive investigations of outcrops, and selected cores, samples of well cuttings, and geophysical logs conducted over a period of four years. Both units exhibit similar sedimentological characteristics and represent open marine, shallow subtidal, and intertidal environments. The presence of low-angle cross-laminae, ripple- and plane-laminae, climbing ripples, and ooid shoals suggest most deposition occurred under low energy conditions. Lenticular, channel-like scour and fill structures that contain both fine-grained quartz sand and abraded, disarticulated fossil fragments indicatemore » localized higher energy deposition. The authors studies indicate that siliciclastic vs. carbonate deposition was controlled strictly by available sediment, and not by regressive (siliciclastic) and transgressive (carbonate) events, as inferred by previous workers. This conclusion is based on lateral facies relationships, and the supplanting of carbonates by clastics occurring in the upper part of the Ste. Genevieve through the middle part of the Paoli. The Aux Vases is thickest, coarsest, and least mature in the northwestern part of the Illinois Basin, and pinches out to the southeast. This implies a northwesterly source for clastics, perhaps the Transcontinental Arch. After early Chesterian time, the Transcontinental Arch apparently supplied little or no sediment to any flanking basin. The Ste. Genevieve, Paoli, and Aux Vases are major oil-producing units in the Illinois Basin. New understanding of regional relationships should enhance exploratory success and improve recovery from established fields.« less

Identification of ARF and AUX/IAA gene families in Rafflesia cantleyi

NASA Astrophysics Data System (ADS)

Elias, Nur Atiqah Mohd; Goh, Hoe-Han; Isa, Nurulhikma Md; Wan, Kiew-Lian

2016-11-01

Rafflesia is a unique plant that produces the largest flowers in the world. It has a short blooming period of 6 to 7 days. Due to its rarity and limited accessibility, little is known about the growth and developmental process in the Rafflesia plant. In all plant species, auxin is the key hormone that is involved in growth and development. The auxin signal transduction involves members of the ARF transcription factor and AUX/IAA regulator families, which activate or inhibit the regulation of auxin response genes, thereby control the developmental process in plants. To gain a better understanding of molecular regulations in the Rafflesia plant development during flowering, members of the ARF and AUX/IAA gene families were identified from the transcriptome data of flower blooming stages in Rafflesia cantleyi. Based on Rafflesia unique transcripts (UTs) against the Arabidopsis TAIR database using BLASTX search, a total of nine UTs were identified as ARF transcription factors, while another seven UTs were identified as AUX/IAA regulators. These genes were found to be expressed in all three R. cantleyi flower stages i.e. days 1 (F1), 3 (F2), and 5 (F3). Gene expression analysis identified three genes that are differentially expressed in stage F1 vs. F2 i.e. IAA4 is upregulated while IAA8 and ARF3 are downregulated. These genes may be involved in the activation and/or inhibition of the auxin signal transduction pathway. Further analysis of these genes may unravel their function in the phenotypic development of the Rafflesia plant.

Chemical composition and geologic history of saline waters in Aux Vases and Cypress Formations, Illinois Basin

USGS Publications Warehouse

Demir, I.; Seyler, B.

1999-01-01

Seventy-six samples of formation waters were collected from oil wells producing from the Aux Vases or Cypress Formations in the Illinois Basin. Forty core samples of the reservoir rocks were also collected from the two formations. Analyses of the samples indicated that the total dissolved solids content (TDS) of the waters ranged from 43,300 to 151,400 mg/L, far exceeding the 35,400 mg/mL of TDS found in typical seawater. Cl-Br relations suggested that high salinities in the Aux Vases and Cypress formation waters resulted from the evaporation of original seawater and subsequent mixing of the evaporated seawater with concentrated halite solutions. Mixing with the halite solutions increased Na and Cl concentrations and diluted the concentration of other ions in the formation waters. The elemental concentrations were influenced further by diagenetic reactions with silicate and carbonate minerals. Diagenetic signatures revealed by fluid chemistry and rock mineralogy delineated the water-rock interactions that took place in the Aux Vases and Cypress sandstones. Dissolution of K-feldspar released K into the solution, leading to the formation of authigenic illite and mixed-layered illite/smectite. Some Mg was removed from the solution by the formation of authigenic chlorite and dolomite. Dolomitization, calcite recrystallization, and contribution from clay minerals raised Sr levels significantly in the formation waters. The trend of increasing TDS of the saline formation waters with depth can be explained with density stratification. But, it is difficult to explain the combination of the increasing TDS and increasing Ca/Na ratio with depth without invoking the controversial 'ion filtration' mechanism.

Vitrification of ion exchange resins

DOEpatents

Cicero-Herman, Connie A.; Workman, Rhonda Jackson

2001-01-01

The present invention relates to vitrification of ion exchange resins that have become loaded with hazardous or radioactive wastes, in a way that produces a homogenous and durable waste form and reduces the disposal volume of the resin. The methods of the present invention involve directly adding borosilicate glass formers and an oxidizer to the ion exchange resin and heating the mixture at sufficient temperature to produce homogeneous glass.

Monolithic microcircuit techniques and processes

NASA Technical Reports Server (NTRS)

Kennedy, B. W.

1972-01-01

Brief discussions of the techniques used to make dielectric and metal thin film depositions for monolithic circuits are presented. Silicon nitride deposition and the properties of silicon nitride films are discussed. Deposition of dichlorosilane and thermally grown silicon dioxide are reported. The deposition and thermal densification of borosilicate, aluminosilicate, and phosphosilicate glasses are discussed. Metallization for monolithic circuits and the characteristics of thin films are also included.

Successful Capture, Extraction and Identification of Hypervelocity CM2 Meteorite Fragments Shot by Light-Gas Gun

NASA Technical Reports Server (NTRS)

Snead, C.; Westphal, A. J.; Dominguez, G.; Zolensky, M. E.

2003-01-01

Here we report the successful capture, extraction and identification of two fragments of a CM2 meteorite (ALH83100) into lowdensity aerogel. The shot was carried out at the AVGR at NASAARC. A mixture of powdered ALH83100 and borosilicate glass microspheres was shot at 4.55.0 km/sec into 50 mg cm silicate aerogel.

The Dissolution Behavior of Borosilicate Glasses in Far-From Equilibrium Conditions

DOE PAGES

Neeway, James J.; Rieke, Peter C.; Parruzot, Benjamin P.; ...

2018-02-10

An area of agreement in the waste glass corrosion community is that, at far-from-equilibrium conditions, the dissolution of borosilicate glasses used to immobilize nuclear waste is known to be a function of both temperature and pH. The aim of this work is to study the effects of temperature and pH on the dissolution rate of three model nuclear waste glasses (SON68, ISG, AFCI). The dissolution rate data are then used to parameterize a kinetic rate model based on Transition State Theory that has been developed to model glass corrosion behavior in dilute conditions. To do this, experiments were conducted atmore » temperatures of 23, 40, 70, and 90 °C and pH(22 °C) values of 9, 10, 11, and 12 with the single-pass flow-through (SPFT) test method. Both the absolute dissolution rates and the rate model parameters are compared with previous results. Rate model parameters for the three glasses studied here are nearly equivalent within error and in relative agreement with previous studies though quantifiable differences exist. The glass dissolution rates were analyzed with a linear multivariate regression (LMR) and a nonlinear multivariate regression performed with the use of the Glass Corrosion Modeling Tool (GCMT), with which a robust uncertainty analysis is performed. This robust analysis highlights the high degree of correlation of various parameters in the kinetic rate model. As more data are obtained on borosilicate glasses with varying compositions, a mathematical description of the effect of glass composition on the rate parameter values should be possible. This would allow for the possibility of calculating the forward dissolution rate of glass based solely on composition. In addition, the method of determination of parameter uncertainty and correlation provides a framework for other rate models that describe the dissolution rates of other amorphous and crystalline materials in a wide range of chemical conditions. As a result, the higher level of uncertainty analysis would provide a basis for comparison of different rate models and allow for a better means of quantifiably comparing the various models.« less

The dissolution behavior of borosilicate glasses in far-from equilibrium conditions

NASA Astrophysics Data System (ADS)

Neeway, James J.; Rieke, Peter C.; Parruzot, Benjamin P.; Ryan, Joseph V.; Asmussen, R. Matthew

2018-04-01

An area of agreement in the waste glass corrosion community is that, at far-from-equilibrium conditions, the dissolution of borosilicate glasses used to immobilize nuclear waste is known to be a function of both temperature and pH. The aim of this work is to study the effects of temperature and pH on the dissolution rate of three model nuclear waste glasses (SON68, ISG, AFCI). The dissolution rate data are then used to parameterize a kinetic rate model based on Transition State Theory that has been developed to model glass corrosion behavior in dilute conditions. To do this, experiments were conducted at temperatures of 23, 40, 70, and 90 °C and pH (22 °C) values of 9, 10, 11, and 12 with the single-pass flow-through (SPFT) test method. Both the absolute dissolution rates and the rate model parameters are compared with previous results. Rate model parameters for the three glasses studied here are nearly equivalent within error and in relative agreement with previous studies though quantifiable differences exist. The glass dissolution rates were analyzed with a linear multivariate regression (LMR) and a nonlinear multivariate regression performed with the use of the Glass Corrosion Modeling Tool (GCMT), with which a robust uncertainty analysis is performed. This robust analysis highlights the high degree of correlation of various parameters in the kinetic rate model. As more data are obtained on borosilicate glasses with varying compositions, a mathematical description of the effect of glass composition on the rate parameter values should be possible. This would allow for the possibility of calculating the forward dissolution rate of glass based solely on composition. In addition, the method of determination of parameter uncertainty and correlation provides a framework for other rate models that describe the dissolution rates of other amorphous and crystalline materials in a wide range of chemical conditions. The higher level of uncertainty analysis would provide a basis for comparison of different rate models and allow for a better means of quantifiably comparing the various models.

Reinforcement of poly-l-lactic acid electrospun membranes with strontium borosilicate bioactive glasses for bone tissue engineering.

PubMed

Fernandes, João S; Gentile, Piergiorgio; Martins, Margarida; Neves, Nuno M; Miller, Cheryl; Crawford, Aileen; Pires, Ricardo A; Hatton, Paul; Reis, Rui L

2016-10-15

Herein, for the first time, we combined poly-l-lactic acid (PLLA) with a strontium borosilicate bioactive glass (BBG-Sr) using electrospinning to fabricate a composite bioactive PLLA membrane loaded with 10% (w/w) of BBG-Sr glass particles (PLLA-BBG-Sr). The composites were characterised by scanning electron microscopy (SEM) and microcomputer tomography (μ-CT), and the results showed that we successfully fabricated smooth and uniform fibres (1-3μm in width) with a homogeneous distribution of BBG-Sr microparticles (<45μm). Degradation studies (in phosphate buffered saline) demonstrated that the incorporation of BBG-Sr glass particles into the PLLA membranes increased their degradability and water uptake with a continuous release of cations. The addition of BBG-Sr glass particles enhanced the membrane's mechanical properties (69% higher Young modulus and 36% higher tensile strength). Furthermore, cellular in vitro evaluation using bone marrow-derived mesenchymal stem cells (BM-MSCs) demonstrated that PLLA-BBG-Sr membranes promoted the osteogenic differentiation of the cells as demonstrated by increased alkaline phosphatase activity and up-regulated osteogenic gene expression (Alpl, Sp7 and Bglap) in relation to PLLA alone. These results strongly suggest that the composite PLLA membranes reinforced with the BBG-Sr glass particles have potential as an effective biomaterial capable of promoting bone regeneration. PLLA membranes were reinforced with 10% (w/w) of strontium-bioactive borosilicate glass microparticles, and their capacity to induce the osteogenic differentiation of bone marrow mesenchymal stem cells (BM-MSCs) was evaluated. These membranes presented an increased: degradability, water uptake, Young modulus and tensile strength. We also demonstrated that these membranes are non-cytotoxic and promote the attachment of BM-MSCs. The addition of the glass microparticles into the PLLA membranes promoted the increase of ALP activity (under osteogenic conditions), as well as the BM-MSCs osteogenic differentiation as shown by the upregulation of Alpl, Sp7 and Bglap gene expression. Overall, we demonstrated that the reinforcement of PLLA with glass microparticles results in a biomaterial with the appropriate properties for the regeneration of bone tissue. Copyright © 2016 Acta Materialia Inc. All rights reserved.

The Dissolution Behavior of Borosilicate Glasses in Far-From Equilibrium Conditions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Neeway, James J.; Rieke, Peter C.; Parruzot, Benjamin P.

An area of agreement in the waste glass corrosion community is that, at far-from-equilibrium conditions, the dissolution of borosilicate glasses used to immobilize nuclear waste is known to be a function of both temperature and pH. The aim of this work is to study the effects of temperature and pH on the dissolution rate of three model nuclear waste glasses (SON68, ISG, AFCI). The dissolution rate data are then used to parameterize a kinetic rate model based on Transition State Theory that has been developed to model glass corrosion behavior in dilute conditions. To do this, experiments were conducted atmore » temperatures of 23, 40, 70, and 90 °C and pH(22 °C) values of 9, 10, 11, and 12 with the single-pass flow-through (SPFT) test method. Both the absolute dissolution rates and the rate model parameters are compared with previous results. Rate model parameters for the three glasses studied here are nearly equivalent within error and in relative agreement with previous studies though quantifiable differences exist. The glass dissolution rates were analyzed with a linear multivariate regression (LMR) and a nonlinear multivariate regression performed with the use of the Glass Corrosion Modeling Tool (GCMT), with which a robust uncertainty analysis is performed. This robust analysis highlights the high degree of correlation of various parameters in the kinetic rate model. As more data are obtained on borosilicate glasses with varying compositions, a mathematical description of the effect of glass composition on the rate parameter values should be possible. This would allow for the possibility of calculating the forward dissolution rate of glass based solely on composition. In addition, the method of determination of parameter uncertainty and correlation provides a framework for other rate models that describe the dissolution rates of other amorphous and crystalline materials in a wide range of chemical conditions. As a result, the higher level of uncertainty analysis would provide a basis for comparison of different rate models and allow for a better means of quantifiably comparing the various models.« less

Boron environments in Pyrex® glass--a high resolution, Double-Rotation NMR and thermodynamic modelling study.

PubMed

Howes, A P; Vedishcheva, N M; Samoson, A; Hanna, J V; Smith, M E; Holland, D; Dupree, R

2011-07-07

It is shown, using the important technological glass Pyrex® as an example, that 1D and 2D (11)B Double-Rotation (DOR) NMR experiments, in combination with thermodynamic modelling, are able to provide unique structural information about complex glasses. (11)B DOR NMR has been applied to Pyrex® glass in order to remove both dipolar and quadrupolar broadening of the NMR lines, leading to high resolution spectra that allow unambiguous, accurate peak fitting to be carried out, of particular importance in the case of the 3-coordinated [BO(3)] (B3) trigonal planar environments. The data obtained are of sufficient quality that they can be used to test the distributions of borate and borosilicate superstructural units predicted by the thermodynamics-based Model of Associated Solutions. The model predicts the dominant boron-containing chemical groupings in Pyrex® glass to be those associated with B(2)O(3) and sodium tetraborate (with smaller amounts of sodium triborate, sodium diborate, sodium pentaborate, danburite and reedmergnerite). Excellent agreement is found between model and experiment provided the (11)B peaks with isotropic chemical shifts of -1.4 ppm and 0.5 ppm are assigned to B4 species from borosilicate units ([B(OSi)(4)] and [B(OSi)(3)(OB)]) and borate superstructural units (mainly triborate rings with some pentaborate and diborate) respectively. The peaks with isotropic shifts of 14 ppm and 18.1 ppm are then assigned to B3 in borate superstructural units (mainly triborate and pentaborate along with connecting B3) and boroxol rings respectively. The assignments of the DOR NMR peaks, are supported by the presence of cross-peaks in (11)B spin-diffusion DOR NMR spectra which can be used to develop a structural model in which B(2)O(3)-like regions are linked, via borate and borosilicate superstructural units, to the majority silica network. Pyrex® is thus shown to have a heterogeneous structure, with distinct molecular groupings that are far removed from a random distribution of network polyhedra with only short-range order. This journal is © the Owner Societies 2011

Clinical practice guideline: management of acute pancreatitis

PubMed Central

Greenberg, Joshua A.; Hsu, Jonathan; Bawazeer, Mohammad; Marshall, John; Friedrich, Jan O.; Nathens, Avery; Coburn, Natalie; May, Gary R.; Pearsall, Emily; McLeod, Robin S.

2016-01-01

There has been an increase in the incidence of acute pancreatitis reported worldwide. Despite improvements in access to care, imaging and interventional techniques, acute pancreatitis continues to be associated with significant morbidity and mortality. Despite the availability of clinical practice guidelines for the management of acute pancreatitis, recent studies auditing the clinical management of the condition have shown important areas of noncompliance with evidence-based recommendations. This underscores the importance of creating understandable and implementable recommendations for the diagnosis and management of acute pancreatitis. The purpose of the present guideline is to provide evidence-based recommendations for the management of both mild and severe acute pancreatitis as well as the management of complications of acute pancreatitis and of gall stone–induced pancreatitis. Une hausse de l’incidence de pancréatite aiguë a été constatée à l’échelle mondiale. Malgré l’amélioration de l’accès aux soins et aux techniques d’imagerie et d’intervention, la pancréatite aiguë est toujours associée à une morbidité et une mortalité importantes. Bien qu’il existe des guides de pratique clinique pour la prise en charge de la pancréatite aiguë, des études récentes sur la vérification de la prise en charge clinique de cette affection révèlent des lacunes importantes dans la conformité aux recommandations fondées sur des données probantes. Ces résultats mettent en relief l’importance de formuler des recommandations compréhensibles et applicables pour le diagnostic et la prise en charge de la pancréatite aiguë. La présente ligne directrice vise à fournir des recommandations fondées sur des données probantes pour la prise en charge de la pancréatite aiguë, qu’elle soit bénigne ou grave, ainsi que de ses complications et de celles de la pancréatite causée par un calcul biliaire. PMID:27007094

Caracterisation de la propagation sans-fil dans les avions commerciaux pour une transmission dediee aux services aux passagers et aux systemes avioniques

NASA Astrophysics Data System (ADS)

Saghir, Hassane

Aircraft systems are interconnected by cable bundles that may represent a hundred kilometres. Those wirings penalize the aircraft weight. Cable bundles favour electromagnetic interference on board aircraft and routing a new cable for integrating new equipment boxes in a sustained aircraft requires a lot of retrofit work. Consequently, the aviation industry and aerospace community are working in the scope of different projects on new alternatives that will better fit to the future generation of aircrafts and help to reduce interconnecting wires on board. Wireless technologies represent a coveted solution that could make significant improvements and benefits to new generations of aircrafts. This research work focuses on the study of the wireless propagation over some frequency bands inside commercial aircrafts. The main objective is to provide conclusions and recommendations on criteria that may help optimizing the wireless communication without impacting the existent systems. Targeted applications are the inflight entertainment (IFE) service and wireless sensing systems. This work was conducted in collaboration with Bombardier-Aerospace based in Montreal (QC) in the frame of AVIO-402 project under the grant of CRIAQ (http://www.criaq.aero/). In this study, an experimental characterization of the propagation channel in the ISM band around 2.4 GHz frequency 5.8 GHz has been performed in a CRJ700 aircraft from Bombardier Aerospace. This characterization allowed to extract the parameters needed to analyze the channel behavior. The measurements results have shown that the propagation characteristics are close to those of both typical indoor medium in terms of the delay spread and a tunnel in terms of path loss. Then, a 3D channel modeling and simulation have been achieved with an RF prediction software (Wireless Insite Remcom). The simulations also consider the millimeter band around 60 GHz. The simulations yielded to analytical models of radio coverage which were subsequently used to evaluate wireless link interference scenarios and performance metrics. Finally, these models were used to design a TDL (Tapped Delay Line) channel model with the goal of an implementation under Matlab in a wireless transmission chain.

Dynamic-SERS Optophysiology: A Nanosensor for Monitoring Cell Secretion Events.

PubMed

Lussier, Félix; Brulé, Thibault; Vishwakarma, Medhavi; Das, Tamal; Spatz, Joachim P; Masson, Jean-François

2016-06-08

We monitored metabolite secretion near living cells using a plasmonic nanosensor. The nanosensor created from borosilicate nanopipettes analogous to the patch clamp was decorated with Au nanoparticles and served as a surface-enhanced Raman scattering (SERS) substrate with addressable location. With this nanosensor, we acquired SERS locally near Madin-Darby canine kidney (MDCKII) epithelial cells, and we detected multiple metabolites, such as pyruvate, lactate, ATP, and urea simultaneously. These plasmonic nanosensors were capable of monitoring metabolites in the extracellular medium with enough sensitivity to detect an increase in metabolite concentration following the lyses of MDCKII cells with a nonionic surfactant. The plasmonic nanosensors also allowed a relative quantification of a chemical gradient for a metabolite near cells, as demonstrated with a decrease in relative lactate to pyruvate concentration further away from the MDCKII cells. This SERS optophysiology technique for the sensitive and nondestructive monitoring of extracellular metabolites near living cells is broadly applicable to different cellular and tissue models and should therefore provide a powerful tool for cellular studies.

An investigation of Au/Ti multilayer thin-films: surface morphology, structure and interfacial/surface migration of constituents under applied thermal stress

NASA Astrophysics Data System (ADS)

Senevirathne, Indrajith; Kemble, Eric; Lavoie, John

2014-03-01

Multilayer thin films are ubiquitous in industry. Au/Ti/substrate is unique due to possible biological applications in proof of concept devices. Material used for substrates include borosilicate glass, and quartz. Typical Ti depositions on substrates give rise to Stanski-Krastonov (SK) like growth while Frank-van der Merwe (FM) like growth is preferred. Ti films with thickness of ~ 100nm were deposited onto varying substrates using a thermal evaporator. The additional Au layer is then deposited via magnetron sputter deposition at 100mtorr at low deposition rates (~ 1ML/min) onto the Ti thin film. These systems were annealed at varying temperatures and at different durations. Systems were investigated via AFM (Atomic Force Microscopy) probes to examine the surface morphology, and structure. Further, the ambient contamination and elemental distribution/diffusion at annealing was investigated via Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray spectroscopy (EDX). PASSHE FPDC Annual Grant (LOU # 2010-LHU-03)

Optical properties modification induced by laser radiation in noble-metal-doped glasses

NASA Astrophysics Data System (ADS)

Nedyalkov, N.; Stankova, N. E.; Koleva, M. E.; Nikov, R.; Atanasov, P.; Grozeva, M.; Iordanova, E.; Yankov, G.; Aleksandrov, L.; Iordanova, R.; Karashanova, D.

2018-03-01

We present results on laser-induced color changes in gold- and silver-doped glass. The doped borosilicate glass was prepared by conventional melt quenching. The study was focused on the change of the optical properties after irradiation of the glass by femtosecond laser pulses. Under certain conditions, the laser radiation induces defects associated with formation of color centers in the material. We studied this process in a broad range of laser radiation wavelengths – from UV to IR, and observed changes in the color of the irradiated areas after annealing of the processed glass samples, the color being red for the gold-doped glass red and yellow for the silver-doped glass. The structural and morphological analyses performed indicated that this effect is related to formation of metal nanoparticles inside the material. The results obtained show that femtosecond laser processing of noble-metal-doped glasses can be used for fabrication of 3D-nanoparticles systems in transparent materials with application as novel optical components.

Polyglycerol coatings of glass vials for protein resistance.

PubMed

Höger, Kerstin; Becherer, Tobias; Qiang, Wei; Haag, Rainer; Friess, Wolfgang; Küchler, Sarah

2013-11-01

Proteins are surface active molecules which undergo non-specific adsorption when getting in contact with surfaces such as the primary packaging material. This process is critical as it may cause a loss of protein content or protein aggregation. To prevent unspecific adsorption, protein repellent coatings are of high interest. We describe the coating of industrial relevant borosilicate glass vials with linear methoxylated polyglycerol, hyperbranched polyglycerol, and hyperbranched methoxylated polyglycerol. All coatings provide excellent protein repellent effects. The hyperbranched, non-methoxylated coating performed best. The protein repellent properties were maintained also after applying industrial relevant sterilization methods (≥200 °C). Marginal differences in antibody stability between formulations stored in bare glass vials and coated vials were detected after 3 months storage; the protein repellent effect remained largely stable. Here, we describe a new material suitable for the coating of primary packaging material of proteins which significantly reduces the protein adsorption and thus could present an interesting new possibility for biomedical applications. Copyright © 2013 Elsevier B.V. All rights reserved.

Improved Miniaturized Linear Ion Trap Mass Spectrometer Using Lithographically Patterned Plates and Tapered Ejection Slit

NASA Astrophysics Data System (ADS)

Tian, Yuan; Decker, Trevor K.; McClellan, Joshua S.; Bennett, Linsey; Li, Ailin; De la Cruz, Abraham; Andrews, Derek; Lammert, Stephen A.; Hawkins, Aaron R.; Austin, Daniel E.

2018-02-01

We present a new two-plate linear ion trap mass spectrometer that overcomes both performance-based and miniaturization-related issues with prior designs. Borosilicate glass substrates are patterned with aluminum electrodes on one side and wire-bonded to printed circuit boards. Ions are trapped in the space between two such plates. Tapered ejection slits in each glass plate eliminate issues with charge build-up within the ejection slit and with blocking of ions that are ejected at off-nominal angles. The tapered slit allows miniaturization of the trap features (electrode size, slit width) needed for further reduction of trap size while allowing the use of substrates that are still thick enough to provide ruggedness during handling, assembly, and in-field applications. Plate spacing was optimized during operation using a motorized translation stage. A scan rate of 2300 Th/s with a sample mixture of toluene and deuterated toluene (D8) and xylenes (a mixture of o-, m-, p-) showed narrowest peak widths of 0.33 Th (FWHM).

Engine Fluid Leakage Detection: A Feasibility Study

DTIC Science & Technology

2011-07-01

2011 © Sa Majesté la Reine (en droit du Canada), telle que représentée par le ministre de la Défense nationale, 2011 DRDC Atlantic TM 2011-050 i... de détecter tout problème possible lié à la sécurité ou aux performances des moteurs à turbine à gaz d’aéronefs. Le signalement immédiat d’une fuite...carburant ou d’huile moteur nuisent non seulement aux performances d’un moteur, mais elles représentent également une menace réelle pour la sécurité de

Post-Deployment Reintegration Experiences of AF Personnel: Implications for Scale Development

DTIC Science & Technology

2006-09-01

peuvent également présenter des avantages, notamment une amélioration aux points de vue suivants : confiance en soi , tolérance à l’égard de soi...notamment une amélioration aux points de vue suivants : confiance en soi , tolérance à l’égard de soi, compréhension politique et compétence militaire... confiance en soi , tolérance à l’égard de soi, compréhension politique et compétence militaire. À ce jour, les études sur l’expérience de réinsertion

Approche aux soins en milieu communautaire à des adultes ayant une déficience développementale

PubMed Central

Osmun, W.E.; Chan, Nelson; Solomon, Robert

2015-01-01

Résumé Objectif Passer en revue les obligations d’ordre médical, éthique et juridique dans les soins aux adultes ayant une déficience développementale (DD) qui vivent dans la communauté. Sources des données Des recherches ont été faites dans Google et MEDLINE à l’aide des mots disabled, disability, vulnerable et community. Les lois pertinentes ont fait l’objet d’un examen. Message principal Le traitement d’un patient ayant une DD varie en fonction de facteurs comme la pathogenèse du problème actuel du patient, ses affections concomitantes, la gravité de ses déficiences et ses soutiens sociaux habituels. Bien que l’on s’entende sur les bienfaits du transfert des soins institutionnels vers des soins communautaires pour les patients ayant une DD, il s’est révélé difficile de leur dispenser des soins de grande qualité en milieu communautaire. Par ailleurs, il existe peu de travaux de recherche sur les façons d’offrir efficacement des soins aux adultes ayant une DD. En tant que professionnels des soins primaires, les médecins de famille sont souvent le premier point de contact pour les patients et sont à la fois responsables de la coordination et de la continuité des soins. Compte tenu de l’importance accrue accordée aux soins préventifs et à la détection précoce des maladies, la participation active du patient revêt aussi une grande importance. Les valeurs et les objectifs du patient sont des éléments essentiels à prendre en compte, même s’ils vont à l’encontre de la bonne santé du patient ou des propres valeurs du clinicien. Les lois s’appliquant aux personnes vulnérables varient d’une province à l’autre. Par conséquent, l’obligation de signaler des mauvais traitements suspectés pourrait différer selon que la personne vulnérable habite dans un centre de soins ou la communauté, que la personne qui soupçonne le comportement abusif est un fournisseur de services ou un professionnel de la santé ou encore que les circonstances spécifiques répondent à la définition légale de mauvais traitement ou de négligence. Conclusion Les professionnels des soins primaires doivent dispenser aux adultes ayant une DD des soins empreints de compassion qui respectent les souhaits du patient.

Gestion des ressources hydriques adaptee aux changements climatiques pour la production optimale d'hydroelectricite. Etude de cas: Bassin versant de la riviere Manicouagan

NASA Astrophysics Data System (ADS)

Haguma, Didier

Il est dorenavant etabli que les changements climatiques auront des repercussions sur les ressources en eau. La situation est preoccupante pour le secteur de production d'energie hydroelectrique, car l'eau constitue le moteur pour generer cette forme d'energie. Il sera important d'adapter les regles de gestion et/ou les installations des systemes hydriques, afin de minimiser les impacts negatifs et/ou pour capitaliser sur les retombees positives que les changements climatiques pourront apporter. Les travaux de la presente recherche s'interessent au developpement d'une methode de gestion des systemes hydriques qui tient compte des projections climatiques pour mieux anticiper les impacts de l'evolution du climat sur la production d'hydroelectricite et d'etablir des strategies d'adaptation aux changements climatiques. Le domaine d'etude est le bassin versant de la riviere Manicouagan situe dans la partie centrale du Quebec. Une nouvelle approche d'optimisation des ressources hydriques dans le contexte des changements climatiques est proposee. L'approche traite le probleme de la saisonnalite et de la non-stationnarite du climat d'une maniere explicite pour representer l'incertitude rattachee a un ensemble des projections climatiques. Cette approche permet d'integrer les projections climatiques dans le probleme d'optimisation des ressources en eau pour une gestion a long terme des systemes hydriques et de developper des strategies d'adaptation de ces systemes aux changements climatiques. Les resultats montrent que les impacts des changements climatiques sur le regime hydrologique du bassin de la riviere Manicouagan seraient le devancement et l'attenuation de la crue printaniere et l'augmentation du volume annuel d'apports. L'adaptation des regles de gestion du systeme hydrique engendrerait une hausse de la production hydroelectrique. Neanmoins, une perte de la performance des installations existantes du systeme hydrique serait observee a cause de l'augmentation des deversements non productibles dans le climat futur. Des strategies d'adaptation structurale ont ete analysees pour augmenter la capacite de production et la capacite d'ecoulement de certaines centrales hydroelectriques afin d'ameliorer la performance du systeme. Une analyse economique a permis de choisir les meilleures mesures d'adaptation et de determiner le moment opportun pour la mise en oeuvre de ces mesures. Les resultats de la recherche offrent aux gestionnaires des systemes hydriques un outil qui permet de mieux anticiper les consequences des changements climatiques sur la production hydroelectrique, incluant le rendement de centrales, les deversements non productibles et le moment le plus opportun pour inclure des modifications aux systemes hydriques. Mots-cles : systemes hydriques, adaptation aux changements climatiques, riviere Manicouagan

Design, Development and Operational Experience of Demonstration Facility for Cs-137 Source Pencil Production at Trombay - 13283

DOE Office of Scientific and Technical Information (OSTI.GOV)

Patil, S.B.; Srivastava, P.; Mishra, S.K.

2013-07-01

Radioactive waste management is a vital aspect of any nuclear program. The commercial feasibility of the nuclear program largely depends on the efficiency of the waste management techniques. One of such techniques is the separation of high yield radio-nuclides from the waste and making it suitable for medical and industrial applications. This will give societal benefit in addition to revenue generation. Co-60, the isotope presently being used for medical applications, needs frequent replacement because of its short half life. Cs-137, the major constituent of the nuclear waste, is a suitable substitute for Co-60 as a radioactive source because of itsmore » longer half life (28 years). Indian nuclear waste management program has given special emphasis on utilization of Cs-137 for such applications. In view of this a demonstration facility has been designed for vitrification of Cs-137 in borosilicate glass, cast in stainless steel pencils, to be used as source pencils of 300 Ci strength for blood irradiation. An induction heated metallic melter of suitable capacity has been custom designed for the application and employed for the Cs-137 pencil fabrication facility. This article describes various systems, design features, experiments and resulting modifications, observations and remote handling features necessary for the actual operation of such facility. The layout of the facility has been planned in such a way that the same can be adopted in a hot cell for commercial production of source pencils. (authors)« less

A glass capillary based microfluidic electromembrane extraction of basic degradation products of nitrogen mustard and VX from water.

PubMed

Tak, Vijay; Kabra, Ankur; Pardasani, Deepak; Goud, D Raghavender; Jain, Rajeev; Dubey, D K

2015-12-24

In this work, a glass capillary based microfluidic electromembrane extraction (μ-EME) was demonstrated for the first time. The device was made by connecting an auxillary borosilicate glass tubing (O.D. 3mm, I.D. 2mm) perpendicular to main borosilicate glass capillary just below one end of the capillary (O.D. 8mm, I.D. 1.2mm). It generated the distorted T-shaped device with inlet '1' and inlet '2' for the introduction of sample and acceptor solutions, respectively. At one end of this device (inlet '2'), a microsyringe containing acceptor solution along with hollow fiber (O.D. 1000μm) was introduced. This configuration creates the micro-channel between inner wall of glass capillary and outer surface of hollow fiber. Sample solution was pumped into the system through another end of glass capillary (inlet '1'), with a micro-syringe pump. The sample was in direct contact with the supported liquid membrane (SLM), consisted of 20% (w/w) di-(2-ethylhexyl)phosphate in 2-nitrophenyl octyl ether immobilized in the pores of the hollow fiber. In the lumen of the hollow fiber, the acceptor phase was present. The driving force for extraction was direct current (DC) electrical potential sustained over the SLM. Highly polar (logP=-2.5 to 1.4) basic degradation products of nitrogen mustard and VX were selected as model analytes. The influence of chemical composition of SLM, extraction time, voltage and pH of donor and acceptor phase were investigated. The model analytes were extracted from 10μL of pure water with recoveries ranging from 15.7 to 99.7% just after 3min of operation time. Under optimized conditions, good limits of detection (2-50ngmL(-1)), linearity (from 5-1000 to 100-1000ngmL(-1)), and repeatability (RSDs below 11.9%, n=3) were achieved. Applicability of the proposed μ-EME was proved by recovering triethanolamine (31.3%) from 10μL of five times diluted original water sample provided by the Organization for the Prohibition of Chemical Weapons during 28th official proficiency test. Copyright © 2015 Elsevier B.V. All rights reserved.

Fabrication of polycrystalline solar cells on low-cost substrates

NASA Technical Reports Server (NTRS)

Chu, T. L. (Inventor)

1976-01-01

A new method of producing p-n junction semiconductors for solar cells was described; the principal objective of this investigation is to reduce production costs significantly by depositing polycrystalline silicon on a relatively cheap substrate such as metallurgical-grade silicon, graphite, or steel. The silicon layer contains appropriate dopants, and the substrates are coated with a diffusion barrier of silica, borosilicate, phosphosilicate, or mixtures of these compounds.

Polyurethane Self-Priming Topcoats

DTIC Science & Technology

1992-06-23

of a combination of metal salts or pigments which consist essentially of calcium borosilicate, zinc salts of benzoic acids , and an alkaline earth...essentially of calcium borosilkate. zinc salts of benzoic acids , and an alkaline earth metal phos- phate such as zinc-barium phosphate. In addition, the...purpose* without the ">ic acids or substituted benzo.c acids , and c.lcium pavment of any royalties thereon or therefor. boros.hcate. All three of

Quantum-dot temperature profiles during laser irradiation for semiconductor-doped glasses

NASA Astrophysics Data System (ADS)

Nagpal, Swati

2002-12-01

Temperature profiles around laser irradiated CdX (X=S, Se, and Te) quantum dots in borosilicate glasses were theoretically modeled. Initially the quantum dots heat up rapidly, followed by a gradual increase of temperature. Also it is found that larger dots reach higher temperatures for the same pulse characteristics. After the pulse is turned off, the dots initially cool rapidly, followed by a gradual decrease in temperature.

International Collaboration Program on Innovative Chemical Processing of Superior Electronic and Optical Materials

DTIC Science & Technology

1994-07-01

Chem. Phys. Lett., 153 (1988) 351 . l -11- AFOSR 91-0317 Dense Sodium Borosilicate New Organically-Modified Glass as Matrix Silicate (Ormosil) as Matrix... GelI Oxidation in 02 (450’C, 24 hrs) SCdO-doped Gel Sulphuration in H2S (1 10"C, 24 hrs) CdS-doped Gel I Densification (540’C, 6 hrs) CdS in Sodium

Oxidation of SiC/BN/SiC Composites in Reduced Oxygen Partial Pressures

NASA Technical Reports Server (NTRS)

Opila, Elizabeth J.; Boyd, Meredith

2010-01-01

SiC fiber-reinforced SiC composites with a BN interphase are proposed for use as leading edge structures of hypersonic vehicles. The durability of these materials under hypersonic flight conditions is therefore of interest. Thermogravimetric analysis was used to characterize the oxidation kinetics of both the constituent fibers and composite coupons at four temperatures: 816, 1149, 1343, and 1538 C (1500, 2100, 2450, and 2800 F) and in oxygen partial pressures between 5% and 0.1% (balance argon) at 1 atm total pressure. One edge of the coupons was ground off so the effects of oxygen ingress into the composite could be monitored by post-test SEM and EDS. Additional characterization of the oxidation products was conducted by XPS and TOF-SIMS. Under most conditions, the BN oxidized rapidly, leading to the formation of borosilicate glass. Rapid initial oxidation followed by volatilization of boria lead to protective oxide formation and further oxidation was slow. At 1538C in 5% oxygen, both the fibers and coupons exhibited borosilicate glass formation and bubbling. At 1538C in 0.1% oxygen, active oxidation of both the fibers and the composites was observed leading to rapid SiC degradation. BN oxidation at 1538C in 0.1% oxygen was not significant.

Ce3+/Yb3+/Er3+ triply doped bismuth borosilicate glass: a potential fiber material for broadband near-infrared fiber amplifiers

PubMed Central

Chu, Yushi; Ren, Jing; Zhang, Jianzhong; Peng, Gangding; Yang, Jun; Wang, Pengfei; Yuan, Libo

2016-01-01

Erbium doped bismuth borosilicate (BBS) glasses, possessing the broadest 1.55 μm near infrared (NIR) emission band among oxide glasses, stand out as excellent fiber material for optical fiber amplifiers. In this work, we demonstrate that both broadened and enhanced NIR emission of Er3+ can be obtained by sensibly combining the effects such as mixed glass former effect, phonon-assisted energy transfer (PAET) and de-excitation effect induced by codopant. Specially, by codoping CeO2 in a controlled manner, it leads to not only much improved optical quality of the glasses, enhanced NIR emission, but also significantly suppressed energy transfer up-conversion (ETU) luminescence which is detrimental to the NIR emission. Cerium incorporated in the glasses exists overwhelmingly as the trivalent oxidation state Ce3+ and its effects on the luminescence properties of Er3+ are discussed. Judd-Ofelt analysis is used to evaluate gain amplification of the glasses. The result indicates that Ce3+/Yb3+/Er3+ triply doped BBS glasses are promising candidate for erbium doped fiber amplifiers. The strategy described here can be readily extended to other rare-earth ions (REs) to improve the performance of REs doped fiber lasers and amplifiers. PMID:27646191

Processing and optical characterization of lead calcium titanate borosilicate glass doped with germanium

NASA Astrophysics Data System (ADS)

Gautam, C. R.; Das, Sangeeta; Gautam, S. S.; Madheshiya, Abhishek; Singh, Anod Kumar

2018-04-01

In this study, various compositions of lead calcium titanate borosilicate glass doped with a fixed amount of germanium were synthesized using the rapid melt quench technique. The amorphous nature of the synthesized glass was confirmed by X-ray diffraction and scanning electron microscopy analyses. The structural and optical properties were deduced using Raman, Fourier transform infrared (FTIR), and ultraviolet-visible (UV-Vis) spectroscopy. FTIR spectroscopy confirmed the presence of borate groups in triangular and tetrahedral coordination. Infrared and Raman analyses detected the vibrational bonds of Gesbnd Osbnd Ge, Bsbnd Osbnd Ge, Sisbnd Osbnd Ge, Sisbnd Osbnd Si, and Pbsbnd Osbnd Ge. The energy band gaps were evaluated for the prepared glass samples based on Tauc plots of the UV-Vis spectra. The calculated values of the optical band gap decreased from 2.91 to 2.85 eV as the PbO content increased from x = 0.0 to x = 0.7. Furthermore, the Urbach energy was studied based on the UV-Vis results to confirm the disordered structure of the glass. The calculated densities of the glass samples (1.5835 g/cm3 to 3.9184 g/cm3) increased as the concentration of PbO increased, whereas they decreased with the molar volume.

White-Beam X-ray Diffraction and Radiography Studies on High-Boron Containing Borosilicate Glass at High Pressures

NASA Astrophysics Data System (ADS)

Ham, Kathryn; Vohra, Yogesh; Kono, Yoshio; Wereszczak, Andrew; Patel, Parimal

Multi-angle energy-dispersive x-ray diffraction studies and white-beam x-ray radiography were conducted with a cylindrically shaped (1 mm diameter and 0.7 mm high) high-boron content borosilicate glass sample (17.6% B2O3) to a pressure of 13.7 GPa using a Paris-Edinburgh (PE) press at Beamline 16-BM-B, HPCAT of the Advanced Photon Source. The measured structure factor S(q) to large q = 19 Å-1, is used to determine information about the internuclear bond distances between various species of atoms within the glass sample. Sample pressure was determined with gold as a pressure standard. The sample height as measured by radiography showed an overall uniaxial compression of 22.5 % at 13.7 GPa with 10.6% permanent compaction after decompression to ambient conditions. The reduced pair distribution function G(r) was extracted and Si-O, O-O, and Si-Si bond distances were measured as a function of pressure. Raman spectroscopy of pressure recovered sample as compared to starting material showed blue-shift and changes in intensity and widths of Raman bands associated with silicate and B3O6 boroxol rings. US Army Research Office under Grant No. W911NF-15-1-0614.

Investigation of gamma radiation induced changes in local structure of borosilicate glass by TDPAC and EXAFS

NASA Astrophysics Data System (ADS)

Kumar, Ashwani; Nayak, C.; Rajput, P.; Mishra, R. K.; Bhattacharyya, D.; Kaushik, C. P.; Tomar, B. S.

2016-12-01

Gamma radiation induced changes in local structure around the probe atom (Hafnium) were investigated in sodium barium borosilicate (NBS) glass, used for immobilization of high level liquid waste generated from the reprocessing plant at Trombay, Mumbai. The (NBS) glass was doped with 181Hf as a probe for time differential perturbed angular correlation (TDPAC) spectroscopy studies, while for studies using extended X-ray absorption fine structure (EXAFS) spectroscopy, the same was doped with 0.5 and 2 % (mole %) hafnium oxide. The irradiated as well as un-irradiated glass samples were studied by TDPAC and EXAFS techniques to obtain information about the changes (if any) around the probe atom due to gamma irradiation. TDPAC spectra of unirradiated and irradiated glasses were similar and reminescent of amorphous materials, indicating negligible effect of gamma radiation on the microstructure around Hafnium probe atom, though the quaqdrupole interaction frequency ( ω Q) and asymmetry parameter ( η) did show a marginal decrease in the irradiated glass compared to that in the unirradiated glass. EXAFS measurements showed a slight decrease in the Hf-O bond distance upon gamma irradiation of Hf doped NBS glass indicating densification of the glass matrix, while the cordination number around hafnium remains unchanged.

Deformation mechanisms during nanoindentation of sodium borosilicate glasses of nuclear interest.

PubMed

Kilymis, D A; Delaye, J-M

2014-07-07

In this paper we analyze results of Molecular Dynamics simulations of Vickers nanoindentation, performed for sodium borosilicate glasses of interest in the nuclear industry. Three glasses have been studied in their pristine form, as well as a disordered one that is analogous to the real irradiated glass. We focused in the behavior of the glass during the nanoindentation in order to reveal the mechanisms of deformation and how they are affected by microstructural characteristics. Results have shown a strong dependence on the SiO2 content of the glass, which promotes densification due to the open structure of SiO4 tetrahedra and also due to the strength of Si-O bonds. Densification for the glasses is primarily expressed by the relative decrease of the Si-O-Si and Si-O-B angles, indicating rotation of the structural units and decrease of free volume. The increase of alkali content on the other hand results to higher plasticity of the matrix and increased shear flow. The most important effect on the deformation mechanism of the disordered glasses is that of the highly depolymerized network that will also induce shear flow and, in combination with the increased free volume, will result in the decreased hardness of these glasses, as has been previously observed.

Gamma radiation induced changes in nuclear waste glass containing Eu

NASA Astrophysics Data System (ADS)

Mohapatra, M.; Kadam, R. M.; Mishra, R. K.; Kaushik, C. P.; Tomar, B. S.; Godbole, S. V.

2011-10-01

Gamma radiation induced changes were investigated in sodium-barium borosilicate glasses containing Eu. The glass composition was similar to that of nuclear waste glasses used for vitrifying Trombay research reactor nuclear waste at Bhabha Atomic Research Centre, India. Photoluminescence (PL) and electron paramagnetic resonance (EPR) techniques were used to study the speciation of the rare earth (RE) ion in the matrix before and after gamma irradiation. Judd-Ofelt ( J- O) analyses of the emission spectra were done before and after irradiation. The spin counting technique was employed to quantify the number of defect centres formed in the glass at the highest gamma dose studied. PL data suggested the stabilisation of the trivalent RE ion in the borosilicate glass matrix both before and after irradiation. It was also observed that, the RE ion distributes itself in two different environments in the irradiated glass. From the EPR data it was observed that, boron oxygen hole centre based radicals are the predominant defect centres produced in the glass after irradiation along with small amount of E’ centres. From the spin counting studies the concentration of defect centres in the glass was calculated to be 350 ppm at 900 kGy. This indicated the fact that bulk of the glass remained unaffected after gamma irradiation up to 900 kGy.

Lead iron phosphate glass as a containment medium for disposal of high-level nuclear waste

DOEpatents

Boatner, Lynn A.; Sales, Brian C.

1989-01-01

Lead-iron phosphate glasses containing a high level of Fe.sub.2 O.sub.3 for use as a storage medium for high-level radioactive nuclear waste. By combining lead-iron phosphate glass with various types of simulated high-level nuclear waste, a highly corrosion resistant, homogeneous, easily processed glass can be formed. For corroding solutions at 90.degree. C., with solution pH values in the range between 5 and 9, the corrosion rate of the lead-iron phosphate nuclear waste glass is at least 10.sup.2 to 10.sup.3 times lower than the corrosion rate of a comparable borosilicate nuclear waste glass. The presence of Fe.sub.2 O.sub.3 in forming the lead-iron phosphate glass is critical. Lead-iron phosphate nuclear waste glass can be prepared at temperatures as low as 800.degree. C., since they exhibit very low melt viscosities in the 800.degree. to 1050.degree. C. temperature range. These waste-loaded glasses do not readily devitrify at temperatures as high as 550.degree. C. and are not adversely affected by large doses of gamma radiation in H.sub.2 O at 135.degree. C. The lead-iron phosphate waste glasses can be prepared with minimal modification of the technology developed for processing borosilicate glass nuclear wasteforms.

In Vitro Degradation of Borosilicate Bioactive Glass and Poly(l-lactide-co-ε-caprolactone) Composite Scaffolds

PubMed Central

Tainio, Jenna; Paakinaho, Kaarlo; Ahola, Niina; Hannula, Markus; Hyttinen, Jari; Kellomäki, Minna

2017-01-01

Composite scaffolds were obtained by mixing various amounts (10, 30 and 50 weight % [wt %]) of borosilicate bioactive glass and poly(l-lactide-co-ε-caprolactone) (PLCL) copolymer. The composites were foamed using supercritical CO2. An increase in the glass content led to a decrease in the pore size and density. In vitro dissolution/reaction test was performed in simulated body fluid. As a function of immersion time, the solution pH increased due to the glass dissolution. This was further supported by the increasing amount of Ca in the immersing solution with increasing immersion time and glass content. Furthermore, the change in scaffold mass was significantly greater with increasing the glass content in the scaffold. However, only the scaffolds containing 30 and 50 wt % of glasses exhibited significant hydroxyapatite (HA) formation at 72 h of immersion. The compression strength of the samples was also measured. The Young’s modulus was similar for the 10 and 30 wt % glass-containing scaffolds whereas it increased to 90 MPa for the 50 wt % glass containing scaffold. Upon immersion up to 72 h, the Young’s modulus increased and then remained constant for longer immersion times. The scaffold prepared could have great potential for bone and cartilage regeneration. PMID:29113141

Préface

NASA Astrophysics Data System (ADS)

Jörgen Stevefelt, Henri Bachau Et

2003-06-01

UVX 2002, sixième édition du “Colloque sur les Sources Cohérentes et Incohérentes UV, VUV, et X : Applications et Développements Récents" s'est tenu du 11 au 14 juin 2002 au Centre CAES du CNRS “La Vieille, Perrotine", à Saint-Pierre d'Oléron. Le colloque a réunni une centaine de chercheurs et d'industriels et a permis de faire le point sur la production, la caractérisation et l'utilisation de rayonnement dans un domaine spectral s'étendant de l'ultraviolet aux rayons X. Les participants ont pu assister a trente conférences et une table ronde autour des problèmes locaux de pollution, une cinquantaine d'affiches ont été présentées au travers de deux sessions. Une douzaine d'industriels ont exposé leurs produits durant les séances d'affiches.Conformément aux éditions précédentes, les domaines couverts par le colloque UVX 2002 sont très variés et il est impossible de les résumer en quelques lignes. Parmi les activités en développement rapide on notera les lasers femtosecondes dont les applications se multiplient dans les laboratoires (propriétés des molécules, agrégats et solides), dans l'industrie (usinage, ablation...) et en médecine. L'absence de thermalisation ou de diffusion thermique ouvre aussi des perspectives pour la réalisation de films minces par ablation laser, un domaine où les lasers excimères sont traditionnellement utilisés, avec des applications importantes dans le secteur des télécommunications. Dans le domaine de l'extrème UV, des progrès significatifs ont été réalisés par plusieurs groupes dans la gamme de longueur d'onde de 5 à 20 nm, ouvrant ainsi la voie au développement industriel de la lithographie EUV. On note les progrès dans la réalisation des sources UV et X (laser X, génération d'harmoniques, laser a électrons libres) et la nécessité de développer des optiques adaptées. Une perspective intéressante, ouverte par la génération d'harmoniques, est la production d'impulsions attosecondes qui permettra d'explorer la matière à l'echelle de temps atomique. En même temps la caractérisation de ces impulsions nécessite la conception de techniques nouvelles d'analyse du signal aux temps ultra brefs.L'intéret particulier du colloque UVX est de réunir les communautés de scientifiques qui vont des chercheurs s'intéressant aux processus fondamentaux à ceux travaillant dans les domaines les plus appliqués, voire industriels. Une caractéristique marquante de notre discipline est la rapidité avec laquelle les progrès réalisés dans les laboratoires de recherche sont diffusés vers les applications industrielles. Il est donc important de maintenir un bon équilibre entre les recherches a caractères fondamental et appliqué dans les laboratoires.Nous tenons remercier les membres du comité d'organisation, le comité scientifique et les différents partenaires, institutionnels et industriels, qui par leur soutien ont permis que le colloque UVX puisse se dérouler. Ce colloque a été parrainé par les départements des Sciences Physiques et Mathématiques (SPM) et des Sciences pour l'Ingénieur (SPI) du CNRS, la Délégation Générale de l'Armement (DGA), le CEA DRECAM, le CEA DAM, le Conseil Géneral de Charente Maritime, l'Université de Bordeaux I, la Société Française d'optique, le Groupement de Recherche “SAXO" du CNRS et la société Air Liquide.

SlLAX1 is Required for Normal Leaf Development Mediated by Balanced Adaxial and Abaxial Pavement Cell Growth in Tomato.

PubMed

Pulungan, Sri Imriani; Yano, Ryoichi; Okabe, Yoshihiro; Ichino, Takuji; Kojima, Mikiko; Takebayashi, Yumiko; Sakakibara, Hitoshi; Ariizumi, Tohru; Ezura, Hiroshi

2018-06-01

Leaves are the major plant organs with a primary function for photosynthesis. Auxin controls various aspects of plant growth and development, including leaf initiation, expansion and differentiation. Unique and intriguing auxin features include its polar transport, which is mainly controlled by the AUX1/LAX and PIN gene families as influx and efflux carriers, respectively. The role of AUX1/LAX genes in root development is well documented, but the role of these genes in leaf morphogenesis remains unclear. Moreover, most studies have been conducted in the plant model Arabidopsis thaliana, while studies in tomato are still scarce. In this study, we isolated six lines of the allelic curly leaf phenotype 'curl' mutants from a γ-ray and EMS (ethyl methanesulfonate) mutagenized population. Using a map-based cloning strategy combined with exome sequencing, we observed that a mutation occurred in the SlLAX1 gene (Solyc09g014380), which is homologous to an Arabidopsis auxin influx carrier gene, AUX1 (AtAUX1). Characterization of six alleles of single curl mutants revealed the pivotal role of SlLAX1 in controlling tomato leaf flatness by balancing adaxial and abaxial pavement cell growth, which has not been reported in tomato. Using TILLING (Targeting Induced Local Lesions IN Genome) technology, we isolated an additional mutant allele of the SlLAX1 gene and this mutant showed a curled leaf phenotype similar to other curl mutants, suggesting that Solyc09g014380 is responsible for the curl phenotype. These results showed that SlLAX1 is required for normal leaf development mediated by balanced adaxial and abaxial pavement cell growth in tomato.

Comprendre. La diffusion Raman exaltée de surface

NASA Astrophysics Data System (ADS)

Boubekeur-Lecaque, Leïla; Felidj, Nordin; Lamy de la Chapelle, Marc

2018-02-01

La spectroscopie Raman est une spectroscopie vibrationnelle très peu sensible qui limite l'analyse d'espèces chimiques aux fortes concentrations. Néanmoins, lorsque des molécules sont placées au voisinage d'une surface métallique nanostructurée, il est possible d'exalter considérablement leur signature Raman. On parle alors de diffusion Raman exaltée de surface. Les remarquables potentialités de cette technique ont nourri de nombreux champs d'étude tant pour le design de substrats dits SERS-actifs, que pour l'exploration d'applications en médecine, pharmacologie, défense ou le monde de l'art.

A Random Matrix Theory Approach to National Procurement Spending: Applications to the CC130 Hercules Fleet Performance

DTIC Science & Technology

2010-08-01

indicateurs de rendement de haut niveau, ce qui donne à penser que la flotte a une réaction inélastique aux chocs de dépenses. Ces résultats révèlent...corrélations entre les données. DRDC CORA TM 2010-168 i Dr aft Co py This page intentionally left blank. ii DRDC CORA TM 2010-168 Dr aft Co py Executive ...celles qui sont observées dans les données ont peu d’effet sur le rendement. Nous pouvons conclure que l’entretien est très robuste ; les chocs de

Absolute NMR shielding scales and nuclear spin–rotation constants in {sup 175}LuX and {sup 197}AuX (X = {sup 19}F, {sup 35}Cl, {sup 79}Br and {sup 127}I)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Demissie, Taye B., E-mail: taye.b.demissie@uit.no; Komorovsky, Stanislav; Repisky, Michal

2015-10-28

We present nuclear spin–rotation constants, absolute nuclear magnetic resonance (NMR) shielding constants, and shielding spans of all the nuclei in {sup 175}LuX and {sup 197}AuX (X = {sup 19}F, {sup 35}Cl, {sup 79}Br, {sup 127}I), calculated using coupled-cluster singles-and-doubles with a perturbative triples (CCSD(T)) correction theory, four-component relativistic density functional theory (relativistic DFT), and non-relativistic DFT. The total nuclear spin–rotation constants determined by adding the relativistic corrections obtained from DFT calculations to the CCSD(T) values are in general in agreement with available experimental data, indicating that the computational approach followed in this study allows us to predict reliable results formore » the unknown spin–rotation constants in these molecules. The total NMR absolute shielding constants are determined for all the nuclei following the same approach as that applied for the nuclear spin–rotation constants. In most of the molecules, relativistic effects significantly change the computed shielding constants, demonstrating that straightforward application of the non-relativistic formula relating the electronic contribution to the nuclear spin–rotation constants and the paramagnetic contribution to the shielding constants does not yield correct results. We also analyze the origin of the unusually large absolute shielding constant and its relativistic correction of gold in AuF compared to the other gold monohalides.« less

Largely enhanced photocatalytic activity of Au/XS2/Au (X = Re, Mo) antenna-reactor hybrids: charge and energy transfer.

PubMed

Chen, Kai; Ding, Si-Jing; Luo, Zhi-Jun; Pan, Gui-Ming; Wang, Jia-Hong; Liu, Jia; Zhou, Li; Wang, Qu-Quan

2018-02-22

An antenna-reactor hybrid coupling plasmonic antenna with catalytic nanoparticles is a new strategy to optimize photocatalytic activity. Herein, we have rationally proposed a Au/XS 2 /Au (X = Re, Mo) antenna reactor, which has a large Au core as the antenna and small satellite Au nanoparticles as the reactor separated by an ultrathin two-dimensional transition-metal dichalcogenide XS 2 shell (∼2.6 nm). Due to efficient charge transfer across the XS 2 shell as well as energy transfer via coupling of the Au antenna and Au reactor, the photocatalytic activity has been largely enhanced: Au/ReS 2 /Au exhibits a 3.59-fold enhancement, whereas Au/MoS 2 /Au exhibits a 2.66-fold enhancement as compared to that of the sum of the three individual components. The different enhancement in the Au/ReS 2 /Au and Au/MoS 2 /Au antenna-reactor hybrid is related to the competition and cooperation of charge and energy transfer. These results indicate the great potential of the Au/XS 2 /Au antenna-reactor hybrid for the development of highly efficient plasmonic photocatalysts.

Exotic species with explicit noble metal-noble gas-noble metal linkages.

PubMed

Moreno, Norberto; Restrepo, Albeiro; Hadad, C Z

2018-02-14

We present a study of the isoelectronic Pt 2 Ng 2 F 4 and [Au 2 Ng 2 F 4 ] 2+ species with noble gas atoms (Ng = Kr, Xe, Rn) acting as links bridging the two noble metal atoms. The stability of the species is investigated using several thermodynamic, kinetic and reactivity indicators. The results are compared against [AuXe 4 ] 2+ , which is thermodynamically unstable in the gas phase but is stabilized in the solid state to the point that it has been experimentally detected as [AuXe 4 ](Sb 2 F 11 ) 2 (S. Seidel and K. Seppelt, Science, 2000, 290, 117-118). Our results indicate that improving upon [AuXe 4 ] 2+ , these exotic combinations between the a priori non-reactive noble metals and noble gases lead to metastable species, and, therefore, they have the possibility of existing in the solid state under adequate conditions. Our calculations include accurate energies and geometries at both the CCSD/SDDALL and MP2/SDDALL levels. We offer a detailed description of the nature of the bonding interactions using orbital and density-based analyses. The computational evidence suggests partially covalent and ionic interactions as the stabilization factors.

Consensus formalisé: recommandations de pratiques cliniques pour la prise en charge de la lombalgie aiguë du patient africain

PubMed Central

Elleuch, Mohamed; El Maghraoui, Abdellah; Griene, Brahim; Nejmi, Mati; Ndongo, Souhaibou; Serrie, Alain

2015-01-01

La lombalgie aiguë est la pathologie rhumatismale la plus fréquente en Afrique. L’épidémiologie et la présentation clinique ne diffèrent pas de celles observées sur les autres continents. En revanche, les aspects psycho-sociaux, la disponibilité des traitements, l'accès aux soins et le poids culturel des médecines traditionnelles sont autant de spécificités qui ont conduit à la réalisation du 1er consensus d'experts en rhumatologie pour la prise en charge du patient africain. Destiné aux praticiens, ce travail collaboratif multinational a pour objectif de fournir 11 recommandations de pratiques cliniques simples, fondées sur les preuves, et adaptées aux conditions de l'exercice médical en Afrique. Leur ambition est d'améliorer la prise en charge de la lombalgie aigue par une évaluation initiale clinique pertinente, une diminution des examens radiologiques inutiles, une prescription médicamenteuse adéquate et l'abandon de procédures invasives inappropriées. PMID:26955427

Evaluation des indicateurs d’alerte précoce de la résistance du VIH aux ARV en Côte d’Ivoire en 2011

PubMed Central

Yao, Kouadio Jean; Damey, Néto Florence; Konan, Diby Jean Paul; Aka, Joseph; Aka-Konan, Sandrine; Ani, Alex; Bonle, Marguerite Te; Kouassi, Dinard

2016-01-01

Introduction En 2001, l'Organisation des Nations Unies recommandait de rendre disponible les médicaments antirétroviraux dans les pays à ressources limitées. Cependant, l'utilisation de ces médicaments à grande échelle s'accompagne du développement de résistance du virus. En Côte d'Ivoire, plusieurs sites prescrivent les antirétroviraux. Cette étude avait pour objectif d'évaluer les facteurs programmatiques associés à un risque élevé d'émergence de résistance du VIH aux antirétroviraux. Méthodes Il s'agit d'une cohorte rétrospective sur 20 sites de prise en charge des personnes vivant avec le VIH. La population d'étude était constituée des personnes ayant initié leur traitement antirétroviral sur les sites en 2008-2009. L'estimation de la taille de l'échantillon a été faite à partir de la stratégie d'échantillonnage de l'OMS. Résultats Sur 20 sites, 98% des prescriptions initiales étaient conformes aux directives nationales et 20% des sites avaient 100% de prescriptions conformes. Au total, 33% des patients étaient perdus de vue au cours des 12 premiers mois de traitement antirétroviral et 20% des sites avaient moins de 20% de perdus de vue. A 12 mois, 51% des patients demeuraient sous traitement de première intention approprié et 11% des sites ont atteint le seuil d'au moins 70% de patients sous traitement de première intention approprié. Un seul site n'a pas connu de rupture d'antirétroviraux sur les 12 mois. Conclusion Des insuffisances relevées dans la prise en charge des personnes vivant avec le VIH traduisent l'existence d'un risque important de résistance du virus aux antirétroviraux en 2008-2009. Pour minimiser ce risque les pratiques de prescription devraient être améliorées, un système de recherche des absents aux rendez-vous devrait être mis en place et la disponibilité constante des antirétroviraux devraient être assurée. PMID:28250876

Luminescence of powdered uranium glasses

NASA Technical Reports Server (NTRS)

Eubanks, A. G.; Mcgarrity, J. M.; Silverman, J.

1974-01-01

Measurement of cathodoluminescence and photoluminescence efficiencies in powdered borosilicate glasses having different particle size and different uranium content. Excitation with 100 to 350 keV electrons and with 253.7 nm light was found to produce identical absolute radiant exitance spectra in powdered samples. The most efficient glass was one containing 29.4 wt% B2O3, 58.8 wt% SiO2, 9.8 wt% Na2O and 2.0 wt% UO2.

Basic Research on Plasma Cathode for HPM Sources (NE - Luginsland)

DTIC Science & Technology

2011-11-30

to NEPP Vacuum Pump for Mock Magnetron 12 (b) Borosilicate glass (Insulator)  Anode Cathode Vacuum chamber Ion gauge controller Charge...channeling may be one physical mechanism that can explain the stability of the pinch in the discharge. (a) Scroll Pump High Voltage Power Supply DC... vacuum and/or low vacuum slow wave devices and cross field devices) in burst mode? Here, burst mode effectively implies an impulse-like (short pulse

Development of Improved and Novel Thermal Control Coatings (Preprint)

DTIC Science & Technology

2007-05-01

a ZnO-based coating (Figure 5). A product offered by the 3M Corporation composed of hollow soda - lime borosilicate spheres with diameters ranging...as well as the current zinc oxide based coatings. In addition, a novel pigment concept based on hollow silica particles is continuing to be explored...coatings. In addition, a novel pigment concept based on hollow silica particles is continuing to be explored as an extremely space durable and

Visualization and Analysis of Impact Damage in Sapphire

DTIC Science & Technology

2011-11-01

transparent armor materials like Starphire soda - lime and borosilicate glass [8], fused silica [9] and the transparent polycrystalline ceramic AlON...conventional glass -based armor when a transparent ceramic is used as strike face on a glass -polymer laminate [1, 2, 3]. Sapphire, i.e. single crystal aluminum...materials. Since part of transparent armor consists of brittle materials, the fragmentation of the ceramic and glass layers plays a key role in the

Toughened uni-piece fibrous insulation

NASA Technical Reports Server (NTRS)

Leiser, Daniel B (Inventor); Smith, Marnell (Inventor); Churchward, Rex A. (Inventor); Katvala, Victor W. (Inventor)

1992-01-01

A porous body of fibrous, low density silica-based insulation material is at least in part impregnated with a reactive boron oxide containing borosilicate glass frit, a silicon tetraboride fluxing agent and a molybdenum silicide emittance agent. The glass frit, fluxing agent and emittance agent are separately milled to reduce their particle size, then mixed together to produce a slurry in ethanol. The slurry is then applied to the insulation material and sintered to produce the porous body.

Consortium for Bone and Tissue Repair and Regeneration

DTIC Science & Technology

2009-10-01

visualization of angiogenic responses to the test scaffolds. Silicate 13-93 Borosilicate 13-93B1 Borate 13-93B3 H&E Toluidine blue Goldner’s...bringing together life scientists and materials engineers in the development and testing of new biomaterials. The Consortium focuses on the...chambers in rats to assess possible angiogenic responses; • Initiated in vitro tests of covalently bonding a bioadhesive peptide to 13-93 glass scaffolds as

N° 341-Diagnostic et prise en charge de la torsion annexielle chez les filles, les adolescentes et les femmes adultes.

PubMed

Kives, Sari; Gascon, Suzy; Dubuc, Élise; Van Eyk, Nancy

2017-02-01

Passer en revue les connaissances scientifiques actuelles et formuler des recommandations relatives au diagnostic et à la prise en charge de la torsion annexielle chez les filles, les adolescentes et les femmes adultes. L'étude porte sur les facteurs de risque, la précision diagnostique, les options de prise en charge et les issues de la torsion annexielle. RéSULTATS: Nous avons examiné les études publiées en faisant des recherches dans MEDLINE, Embase, CINAHL et la Bibliothèque Cochrane à l'aide d'une terminologie contrôlée et de mots-clés appropriés (« adnexal torsion », « ovarian torsion »). Nous avons limité les résultats aux revues systématiques, aux essais contrôlés aléatoires, aux essais cliniques contrôlés et aux études d'observation. Nous avons refait les recherches de façon régulière et intégré de nouvelles données à la directive jusqu'en décembre 2014. Nous avons également étudié la littérature grise (non publiée) trouvée sur les sites Web d'organismes d'évaluation des technologies de la santé et d'autres organismes connexes, dans des collections de directives cliniques et dans des registres d'essais cliniques, et obtenue auprès d'associations nationales et internationales de médecins spécialistes. Les résultats ont été examinés et évalués par le comité CANPAGO de la Société des obstétriciens et gynécologues du Canada (SOGC), sous la direction des auteures principales. Les recommandations ont été classées selon les critères établis par le Groupe d'étude canadien sur les soins de santé préventifs. AVANTAGES, DéSAVANTAGES ET COûTS: L'application de la directive devrait aider les praticiens à adopter une approche de diagnostic et de prise en charge optimale en matière de torsion annexielle, à réduire au minimum les effets néfastes et à améliorer l'issue qui attend les patientes. La présente directive a été évaluée et approuvée par le Comité de pratique - gynécologie de la SOGC, et approuvée par le Conseil de la SOGC. Parrainé par la Société des obstétriciens et gynécologues du Canada. DéCLARATIONS SOMMAIRES: RECOMMANDATIONS. Copyright © 2017. Published by Elsevier Inc.

Crystallization of rhenium salts in a simulated low-activity waste borosilicate glass

DOE Office of Scientific and Technical Information (OSTI.GOV)

Riley, Brian J.; McCloy, John S.; Goel, Ashutosh

2013-04-01

This study presents a new method for looking at the solubility of volatile species in simulated low-activity waste glass. The present study looking at rhenium salts is also applicable to real applications involving radioactive technetium salts. In this synthesis method, oxide glass powder is mixed with the volatiles species, vacuum-sealed in a fused quartz ampoule, and then heat-treated under vacuum in a furnace. This technique restricts the volatile species to the headspace above the melt but still within the sealed ampoule, thus maximizing the volatile concentration in contact with the glass. Various techniques were used to measure the solubility ofmore » rhenium in glass and include energy dispersive spectroscopy, wavelength dispersive spectroscopy, laser ablation inductively-coupled plasma mass spectroscopy, and inductively-coupled plasma optical emission spectroscopy. The Re-solubility in this glass was determined to be ~3004 parts per million Re atoms. Above this concentration, the salts separated out of the melt as inclusions and as a low viscosity molten salt phase on top of the melt observed during and after cooling. This salt phase was analyzed with X-ray diffraction, scanning electron microscopy as well as some of the other aforementioned techniques and identified to be composed of alkali perrhenate and alkali sulfate.« less

Révision systématique des effets de la fréquence des repas en famille sur les résultats psychosociaux chez les jeunes

PubMed Central

Harrison, Megan E.; Norris, Mark L.; Obeid, Nicole; Fu, Maeghan; Weinstangel, Hannah; Sampson, Margaret

2015-01-01

Résumé Objectif Effectuer une révision systématique des effets de repas en famille fréquents sur les résultats psychosociaux chez les enfants et les adolescents et examiner s’il existe des différences dans les résultats selon le sexe. Sources des données Des études ont été cernées à la suite d’une recherche dans MEDLINE (de 1948 à la dernière semaine de juin 2011) et dans PsycINFO (de 1806 à la première semaine de juillet 2011) à l’aide de l’interface Ovide. Les expressions et mots clés MeSH utilisés seuls ou en combinaisons étaient les suivants : family, meal, food intake, nutrition, diets, body weight, adolescent attitudes, eating behaviour, feeding behaviour et eating disorders. Les bibliographies des articles jugés pertinents ont aussi été passées en revus. Sélection des études La recherche initiale a produit 1783 articles. Pour être incluses dans l’analyse, les études devaient répondre aux critères suivants : être publiées en anglais dans une revue révisée par des pairs; porter sur des enfants ou des adolescents; traiter de l’influence des repas en famille sur les paramètres psychosociaux (p. ex. consommation de drogues et autres substances, troubles de l’alimentation, dépression) chez les enfants ou les adolescents; avoir une conception d’étude appropriée, notamment des méthodes statistiques acceptables pour l’analyse des paramètres. Quatorze articles satisfaisaient aux critères d’inclusion. Deux examinateurs indépendants ont étudié et analysé les articles. Synthèse Dans l’ensemble, les résultats font valoir que la fréquence des repas en famille est inversement proportionnelle aux troubles de l’alimentation, à la consommation d’alcool et de drogues, aux comportements violents, aux sentiments de dépression ou aux pensées suicidaires chez les adolescents. Il existe une relation positive entre de fréquents repas en famille, une bonne estime de soi et la réussite scolaire. Les études révèlent des différences considérables dans les résultats chez les enfants et adolescents masculins et féminins, les sujets féminins ayant des résultats plus positifs. Conclusion Cette révision systématique vient confirmer davantage qu’il convient de préconiser de fréquents repas en famille. Tous les professionnels de la santé devraient renseigner les familles concernant les bienfaits de prendre régulièrement ensemble des repas.

Particulate Study on NeoProfen, a Neonatal Injectable Product.

PubMed

Krishna, Aravind; Rice, Michael; Kester, Tom; Waters, Michael; Wilson, Terry

2016-01-01

NeoProfen or sterile ibuprofen L-lysine at 10 mg/mL ibuprofen, in 2 mL single-use Type I glass vials is often a first choice medication used to close a patent ductus arteriosus in neonatal patients from 500 to 1500 g body weight. Visible particulate matter was found in vials that were placed on a commercial stability program prior to the approved expiration date of 2 years. A combination of instrumental techniques including inductively coupled plasma-mass spectrometry, x-ray photoelectron spectroscopy, scanning electron microscopy energy dispersive x-ray spectrometry, and Raman and Fourier transform infrared microspectroscopy was used to evaluate stability, pilot batch and packaging samples in a root cause investigation. The particulate matter was shown to consist largely of ibuprofen aluminum salts of various stoichiometries. It developed over time by a substitution mechanism, in which the ibuprofen anion in solution reacts with the aluminum oxide network of the borosilicate glass giving the ibuprofen aluminum salt with =Al-OH remaining in the network. For corrective action an alternate Type I borosilicate glass vial with interior coating, not found in the original vial, was chosen for the product to prevent this occurrence. NeoProfen (sterile preservative-free ibuprofin L-lysine at 17 mg/mL in a single-use glass vial) is used to close a clinically significant patent ductus arteriosus in premature infants no more than 32 weeks gestational age. The neonatal population is especially sensitive to outside chemical, physical and environmental conditions because of incompletely developed organ systems, low birth weight and other underlying conditions. Two batches of this product were voluntarily recalled by the manufacturer, Lundbeck, and investigated for the source of particulate matter observed during a commercial stability testing program. This was found to result from an interaction between the product and the Type I borosilicate glass vial where ibuprofen substitutes for the aluminum oxide network in the glass, forming an ibuprofen aluminum hydroxide salt as particulate. In order to prevent this salt formation an alternate glass vial was chosen which had interiors treated using a chemical vapor deposition technique. These vials were found to preserve NeoProfen quality properties during short term stress and medium term stability studies. © PDA, Inc. 2016.

Des furoncles résistants aux antibiotiques: penser à la myiase !!

PubMed Central

Ajili, Faida; Abid, Rim; Bousseta, Najeh; Mrabet, Ali; Karoui, Ghazi; Louzir, Bassem; Battikh, Riadh; Othmani, Salah

2013-01-01

Les myiases sont des infections parasitaires par des larves de mouches. La localisation cutanée doit être évoquée de retour d'un pays tropical devant une évolution inhabituelle de lésions cutanées. Nous rapportons une observation d'un militaire tunisien, ayant séjourné en République Démocratique du Congo. Il était atteint de myiase cutanée simulatrice d'une furonculose résistante aux antibiotiques. L'intérêt de cette observation est de souligner l'importance d’évoquer la myiase dont le traitement est simple et rapide chez un patient de retour de zone d'endémie. PMID:24106569

Bioactive glass in tissue engineering

PubMed Central

Rahaman, Mohamed N.; Day, Delbert E.; Bal, B. Sonny; Fu, Qiang; Jung, Steven B.; Bonewald, Lynda F.; Tomsia, Antoni P.

2011-01-01

This review focuses on recent advances in the development and use of bioactive glass for tissue engineering applications. Despite its inherent brittleness, bioactive glass has several appealing characteristics as a scaffold material for bone tissue engineering. New bioactive glasses based on borate and borosilicate compositions have shown the ability to enhance new bone formation when compared to silicate bioactive glass. Borate-based bioactive glasses also have controllable degradation rates, so the degradation of the bioactive glass implant can be more closely matched to the rate of new bone formation. Bioactive glasses can be doped with trace quantities of elements such as Cu, Zn and Sr, which are known to be beneficial for healthy bone growth. In addition to the new bioactive glasses, recent advances in biomaterials processing have resulted in the creation of scaffold architectures with a range of mechanical properties suitable for the substitution of loaded as well as non-loaded bone. While bioactive glass has been extensively investigated for bone repair, there has been relatively little research on the application of bioactive glass to the repair of soft tissues. However, recent work has shown the ability of bioactive glass to promote angiogenesis, which is critical to numerous applications in tissue regeneration, such as neovascularization for bone regeneration and the healing of soft tissue wounds. Bioactive glass has also been shown to enhance neocartilage formation during in vitro culture of chondrocyte-seeded hydrogels, and to serve as a subchondral substrate for tissue-engineered osteochondral constructs. Methods used to manipulate the structure and performance of bioactive glass in these tissue engineering applications are analyzed. PMID:21421084

The Kinetics and Dynamics of Elementary Gas-Phase Reactions

DTIC Science & Technology

2002-09-01

We report CRDS measurements of thin films of oxazine 1, oxazine 170 and malachite green dyes deposited on borosilicate substrates. The method...measure monolayer and sub-monolayer quantities of dye. The minimum observed concentration of malachite green in the present work was calculated to be...the dyes: at surface coverages of ~ 2.8 × 10-7 mol m-2, the ratio of malachite green dimers to monomers was estimated as Cd/Cm = 0.22. The Kinetics

High-Level Waste System Process Interface Description

DOE Office of Scientific and Technical Information (OSTI.GOV)

d'Entremont, P.D.

1999-01-14

The High-Level Waste System is a set of six different processes interconnected by pipelines. These processes function as one large treatment plant that receives, stores, and treats high-level wastes from various generators at SRS and converts them into forms suitable for final disposal. The three major forms are borosilicate glass, which will be eventually disposed of in a Federal Repository, Saltstone to be buried on site, and treated water effluent that is released to the environment.

Crystalline phase, microstructure, and aqueous stability of zirconolite-barium borosilicate glass-ceramics for immobilization of simulated sulfate bearing high-level liquid waste

NASA Astrophysics Data System (ADS)

Wu, Lang; Xiao, Jizong; Wang, Xin; Teng, Yuancheng; Li, Yuxiang; Liao, Qilong

2018-01-01

The crystalline phase, microstructure, and aqueous stability of zirconolite-barium borosilicate glass-ceramics with different content (0-30 wt %) of simulated sulfate bearing high-level liquid waste (HLLW) were evaluated. The sulfate phase segregation in vitrification process was also investigated. The results show that the glass-ceramics with 0-20 wt% of HLLW possess mainly zirconolite phase along with a small amount baddeleyite phase. The amount of perovskite crystals increases while the amount of zirconolite crystals decreases when the HLLW content increases from 20 to 30 wt%. For the samples with 20-30 wt% HLLW, yellow phase was observed during the vitrification process and it disappeared after melting at 1150 °C for 2 h. The viscosity of the sample with 16 wt% HLLW (HLLW-16) is about 27 dPa·s at 1150 °C. The addition of a certain amount (≤20 wt %) of HLLW has no significant change on the aqueous stability of glass-ceramic waste forms. After 28 days, the 90 °C PCT-type normalized leaching rates of Na, B, Si, and La of the sample HLLW-16 are 7.23 × 10-3, 1.57 × 10-3, 8.06 × 10-4, and 1.23 × 10-4 g·m-2·d-1, respectively.

Photolysis of oxyfluorfen in aqueous methanol.

PubMed

Chakraborty, Subhasish K; Chakraborty, Savitri; Bhattacharyya, Anjan; Chowdhury, Ashim

2013-01-01

Photolysis of oxyfluorfen, an herbicide of the nitrodiphenyl ether class, was studied in aqueous methanol under UV and sunlight. UV irradiation was carried out in a borosilicate glass photoreactor (containing 250 ppm oxyfluorfen in 50% aqueous methanol) equipped with a quartz filter and 125 watt mercury lamp (maximum output 254 nm) at 25 ± 1°C. Sunlight irradiation was conducted at 28 ± 1°C in borosilicate Erlenmeyer flasks containing 250 ppm oxyfluorfen in 50% aqueous methanol. The samples from both the irradiated conditions were withdrawn at a definite time interval and extracted to measure oxyfluorfen content by gas chromatography-flame ionization detector for rate study. The half-life values were 20 hours and 2.7 days under UV and sunlight exposure, respectively. Photolysis of oxyfluorfen yielded 13 photoproducts of which three were characterized by infrared spectrophotometer and (1)H NMR and (13)C NMR spectroscopy. The rest of the photoproducts were identified by gas chromatography-mass spectrometry (GC-MS) and thin layer chromatography (TLC). An ionization potential 70 eV was used for electron impact-mass spectrometry (EI-MS) and methane was used as reagent gas for chemical ionization-mass spectrometry (CI-MS). Two of the photoproducts were also synthesized for comparison. The main phototransformation pathways of oxyfluorfen involved nitro reduction, dechlorination, and hydrolysis as well as nucleophiles displacement reaction.

Element speciation during nuclear glass alteration

NASA Astrophysics Data System (ADS)

Galoisy, L.; Calas, G.; Bergeron, B.; Jollivet, P.; Pelegrin, E.

2011-12-01

Assessing the long-term behavior of nuclear glasses implies the prediction of their long-term performance. An important controlling parameter is their evolution during interaction with water under conditions simulating geological repositories. After briefly recalling the major characteristics of the local and medium-range structure of borosilicate glasses of nuclear interest, we will present some structural features of this evolution. Specific structural tools used to determine the local structure of glass surfaces include synchrotron-radiation x-ray absorption spectroscopy with total electron yield detection. The evolution of the structure of glass surface has been determined at the Zr-, Fe-, Si- and Al-K edges and U-LIII edge. During alteration in near- or under-saturated conditions, some elements such as Fe change coordination, as other elements such as Zr only suffer structural modifications in under-saturated conditions. Uranium exhibits a modification of its speciation from an hexa-coordinated U(VI) in the borosilicate glass to an uranyl group in the gel. These structural modifications may explain the chemical dependence of the initial alteration rate and the transition to the residual regime. They also illustrate the molecular-scale origin of the processes at the origin of the glass-to-gel transformation. Eventually, they explain the provisional trapping of U by the alteration gel: the uranium retention factors in the gel depend on the alteration conditions, and thus on the nature of the resulting gel and on the trapping conditions.

Wetspun poly-L-(lactic acid)-borosilicate bioactive glass scaffolds for guided bone regeneration.

PubMed

Fernandes, João S; Reis, Rui L; Pires, Ricardo A

2017-02-01

We developed a porous poly-L-lactic acid (PLLA) scaffold compounded with borosilicate bioactive glasses (BBGs) endowing it with bioactive properties. Porous PLLA-BBG fibre mesh scaffolds were successfully prepared by the combination of wet spinning and fibre bonding techniques. Micro-computed tomography (μCT) confirmed that the PLLA-BBG scaffolds containing ≈25% of BBGs (w/w) exhibited randomly interconnected porous (58 to 62% of interconnectivity and 53 to 67% of porosity) with mean pore diameters higher that 100μm. Bioactivity and degradation studies were performed by immersing the scaffolds in simulated body fluid (SBF) and ultrapure water, respectively. The PLLA-BBG scaffolds presented a faster degradation rate with a constant release of inorganic species, which are capable to produce calcium phosphate structures at the surface of the material after 7days of immersion in SBF (Ca/P ratio of ~1.7). Cellular in vitro studies with human osteosarcoma cell line (Saos-2) and human adipose-derived stem cells (hASCs) showed that PLLA-BBGs are not cytotoxic to cells, while demonstrating their capacity to promote cell adhesion and proliferation. Overall, we showed that the proposed scaffolds present a tailored kinetics on the release of inorganic species and controlled biological response under conditions that mimic the bone physiological environment. Copyright © 2016 Elsevier B.V. All rights reserved.

Three-dimensional zinc incorporated borosilicate bioactive glass scaffolds for rodent critical-sized calvarial defects repair and regeneration.

PubMed

Wang, Hui; Zhao, Shichang; Xiao, Wei; Cui, Xu; Huang, Wenhai; Rahaman, Mohamed N; Zhang, Changqing; Wang, Deping

2015-06-01

The biomaterials with high osteogenic ability are being intensively investigated. In this study, we evaluated the bioactivity and osteogenesis of BG-Zn scaffolds in vitro and in vivo with a rodent calvarial defects model. Zinc containing borosilicate bioactive glass was prepared by doping glass with 1.5, 5 and 10 wt.% ZnO (denoted as BG-1.5Zn, BG-5Zn and BG-10Zn, respectively). When immersed in simulated body fluid, dopant ZnO retarded the degradation process, but did not affect the formation of hydroxyapatite (HA) after long-period soaking. BG-Zn scaffolds showed controlled release of Zn ions into the medium for over 8 weeks. Human bone marrow derived stem cells (hBMSCs) attached well on the BG-1.5Zn and BG-5Zn scaffolds, which exhibited no cytotoxicity to hBMSCs. In addition, the alkaline phosphatase activity of the hBMSCs increased with increasing dopant amount in the glass, while the BG-10Zn group showed over-dose of Zn. Furthermore, when implanted in rat calvarial defects for 8 weeks, the BG-5Zn scaffolds showed a significantly better capacity to regenerate bone tissue compared to the non-doping scaffolds. Generally, these results showed the BG-Zn scaffolds with high osteogenic capacity will be promising candidates using in bone tissue repair and regeneration. Copyright © 2015. Published by Elsevier B.V.

Borosilicate glass structure: An investigation of high resolution B K-edge XANES

NASA Astrophysics Data System (ADS)

Dong, S.; Henderson, G. S.; Galoisy, L.; Calas, G.

2009-05-01

The Alkali-borosilicate glasses in the systems Na2O-B2O3-SiO2 and K2O- B2O3-SiO2 have been prepared by melting/quenching in air and studied using synchrotron radiation B K-edge XANES to estimate the evolution of boron coordination as a function of composition. The ratio of alkali/B2O3 (R) and SiO2/B2O3 (K) in the glasses are respectively between 0.5 to 2.0 and 0.5 to 7.0. The edge features of trigonal B ([3]B) and tetrahedral B ([4]B) in B K-edge XANES spectra have been interpreted carefully from B standards such as (B2O3 and BPO4), as well as, a wide range of borate minerals. We find that the proportion of tetrahedral B in glass is increasing as a function of both R and K, similar to previous studies. Contributions of the [3]B and [4]B features to the B K-edge XANES is complex with 6-7 individual transitions contributing to the overall spectral envelope. Many of these transitions are common to both B coordination states making extraction of quantitative [4]B numbers difficult. However, we can calculate the proportion of tetrahedral B accurately by appropriate curve- fitting.

Modelling the local atomic structure of molybdenum in nuclear waste glasses with ab initio molecular dynamics simulations.

PubMed

Konstantinou, Konstantinos; Sushko, Peter V; Duffy, Dorothy M

2016-09-21

The nature of chemical bonding of molybdenum in high level nuclear waste glasses has been elucidated by ab initio molecular dynamics simulations. Two compositions, (SiO 2 ) 57.5 -(B 2 O 3 ) 10 -(Na 2 O) 15 -(CaO) 15 -(MoO 3 ) 2.5 and (SiO 2 ) 57.3 -(B 2 O 3 ) 20 -(Na 2 O) 6.8 -(Li 2 O) 13.4 -(MoO 3 ) 2.5 , were considered in order to investigate the effect of ionic and covalent components on the glass structure and the formation of the crystallisation precursors (Na 2 MoO 4 and CaMoO 4 ). The coordination environments of Mo cations and the corresponding bond lengths calculated from our model are in excellent agreement with experimental observations. The analysis of the first coordination shell reveals two different types of molybdenum host matrix bonds in the lithium sodium borosilicate glass. Based on the structural data and the bond valence model, we demonstrate that the Mo cation can be found in a redox state and the molybdate tetrahedron can be connected with the borosilicate network in a way that inhibits the formation of crystalline molybdates. These results significantly extend our understanding of bonding in Mo-containing nuclear waste glasses and demonstrate that tailoring the glass composition to specific heavy metal constituents can facilitate incorporation of heavy metals at high concentrations.

Effect of temperature and thermal history on borosilicate glass structure

NASA Astrophysics Data System (ADS)

Angeli, Frédéric; Villain, Olivier; Schuller, Sophie; Charpentier, Thibault; de Ligny, Dominique; Bressel, Lena; Wondraczek, Lothar

2012-02-01

The influence of the temperature and quenching rate on the structure of a borosilicate glass was studied by high-resolution solid-state 11B, 23Na, 29Si nuclear magnetic resonance (NMR) and high-temperature Raman spectroscopy. Data were obtained for glass in the solid state after annealing and quenching at cooling rates covering four orders of magnitude as well as in the liquid state from Raman experiments and from calorimetry and rheological data. Nuclear magnetic resonance measurements were used to calibrate the Raman spectra in order to quantify the change in boron coordination with temperature. This result can then be used to determine the fictive temperature of the glass directly from the boron coordination. The fictive temperature, heat capacity, and configurational entropy are extracted from calorimetry and viscosity measurements. Changes in the boron coordination account for only 25% of the configurational heat capacity of the liquid. The structural parameters capable of accounting for the remaining quantity are discussed on the basis of structural data, both local (inhomogeneity of the sodium distribution) and medium-range (from NMR parameter distribution). It has thus been shown that, although the B-O-B angular distributions of the boroxol rings (and probably the Si-O-Si distributions) are not affected by temperature, a structural disorder is identified through the angular distributions of the bonds linking borate and silicate groups.

Corrosion Testing of Monofrax K-3 Refractory in Defense Waste Processing Facility (DWPF) Alternate Reductant Feeds

DOE Office of Scientific and Technical Information (OSTI.GOV)

Williams, M.; Jantzen, C.; Burket, P.

The Defense Waste Processing Facility (DWPF) at the Savannah River Site (SRS) uses a combination of reductants and oxidants while converting high level waste (HLW) to a borosilicate waste form. A reducing flowsheet is maintained to retain radionuclides in their reduced oxidation states which promotes their incorporation into borosilicate glass. For the last 20 years of processing, the DWPF has used formic acid as the main reductant and nitric acid as the main oxidant. During reaction in the Chemical Process Cell (CPC), formate and formic acid release measurably significant H 2 gas which requires monitoring of certain vessel’s vapor spaces.more » A switch to a nitric acid-glycolic acid (NG) flowsheet from the nitric-formic (NF) flowsheet is desired as the NG flowsheet releases considerably less H 2 gas upon decomposition. This would greatly simplify DWPF processing from a safety standpoint as close monitoring of the H 2 gas concentration could become less critical. In terms of the waste glass melter vapor space flammability, the switch from the NF flowsheet to the NG flowsheet showed a reduction of H 2 gas production from the vitrification process as well. Due to the positive impact of the switch to glycolic acid determined on the flammability issues, evaluation of the other impacts of glycolic acid on the facility must be examined.« less

Structure of rhenium-containing sodium borosilicate glass

DOE Office of Scientific and Technical Information (OSTI.GOV)

Goel, Ashutosh; McCloy, John S.; Windisch, Charles F.

2013-03-01

A series of sodium borosilicate glasses were synthesized with increasing fractions of KReO4 or Re2O7, to 10000 ppm (1 mass%) target Re in glass, to assess the effects of large concentrations of rhenium on glass structure and to estimate the solubility of technetium, a radioactive component in typical low active waste nuclear waste glasses. Magic angle spinning nuclear magnetic resonance (MAS-NMR), Fourier transform infrared (FTIR) spectroscopy, and Raman spectroscopy were performed to characterize the glasses as a function of Re source additions. In general, silicon was found coordinated in a mixture of Q2 and Q3 structural units, while Al wasmore » 4-coordinated and B was largely 3-coordinate and partially 4-coordinated. The rhenium source did not appear to have significant effects on the glass structure. Thus, at the up to the concentrations that remain in dissolved in glass, ~3000 ppm Re by mass maximum. , the Re appeared to be neither a glass-former nor a strong glass modifier., Rhenium likely exists in isolated ReO4- anions in the interstices of the glass network, as evidenced by the polarized Raman spectrum of the Re glass in the absence of sulfate. Analogous to SO42-¬ in similar glasses, ReO4- is likely a network modifier and forms alkali salt phases on the surface and in the bulk glass above solubility.« less

Laser femtoseconde, filamentation, nuage et orage

NASA Astrophysics Data System (ADS)

Courvoisier, F.; Boutou, V.; Kasparian, J.; Salmon, E.; Méjean, G.; Yu, J.; Wolf, J.-P.

2005-06-01

Les applications telles que le contrôle de foudre grâce aux filaments autoguidés générés par un laser femtoseconde nécessitent de propager un tel filament à travers des aérosols de gouttes d'eau. Nous montrons qu'un filament survit à son interaction avec une goutte de diamètre comparable au sien (95 μ m), ainsi qu'à des nuages d'épaisseur optique 3,2, soit 5% de transmission. Cette transmission est permise par la présence d'un “bain de photons” autour du filament. Ce bain forme un réservoir contenant une part importante de l'énergie du faisceau, en équilibre avec le filament, et favorisant son alimentation.

A simple pendulum borehole tiltmeter based on a triaxial optical-fibre displacement sensor

NASA Astrophysics Data System (ADS)

Chawah, P.; Chéry, J.; Boudin, F.; Cattoen, M.; Seat, H. C.; Plantier, G.; Lizion, F.; Sourice, A.; Bernard, P.; Brunet, C.; Boyer, D.; Gaffet, S.

2015-11-01

Sensitive instruments like strainmeters and tiltmeters are necessary for measuring slowly varying low amplitude Earth deformations. Nonetheless, laser and fibre interferometers are particularly suitable for interrogating such instruments due to their extreme precision and accuracy. In this paper, a practical design of a simple pendulum borehole tiltmeter based on laser fibre interferometric displacement sensors is presented. A prototype instrument has been constructed using welded borosilicate with a pendulum length of 0.85 m resulting in a main resonance frequency of 0.6 Hz. By implementing three coplanar extrinsic fibre Fabry-Perot interferometric probes and appropriate signal filtering, our instrument provides tilt measurements that are insensitive to parasitic deformations caused by temperature and pressure variations. This prototype has been installed in an underground facility (Rustrel, France) where results show accurate measurements of Earth strains derived from Earth and ocean tides, local hydrologic effects, as well as local and remote earthquakes. The large dynamic range and the high sensitivity of this tiltmeter render it an invaluable tool for numerous geophysical applications such as transient fault motion, volcanic strain and reservoir monitoring.

Strontium borate glass: potential biomaterial for bone regeneration

PubMed Central

Pan, H. B.; Zhao, X. L.; Zhang, X.; Zhang, K. B.; Li, L. C.; Li, Z. Y.; Lam, W. M.; Lu, W. W.; Wang, D. P.; Huang, W. H.; Lin, K. L.; Chang, J.

2010-01-01

Boron plays important roles in many life processes including embryogenesis, bone growth and maintenance, immune function and psychomotor skills. Thus, the delivery of boron by the degradation of borate glass is of special interest in biomedical applications. However, the cytotoxicity of borate glass which arises with the rapid release of boron has to be carefully considered. In this study, it was found that the incorporation of strontium into borate glass can not only moderate the rapid release of boron, but also induce the adhesion of osteoblast-like cells, SaOS-2, thus significantly increasing the cyto-compatibility of borate glass. The formation of multilayers of apatite with porous structure indicates that complete degradation is optimistic, and the spread of SaOS-2 covered by apatite to form a sandwich structure may induce bone-like tissue formation at earlier stages. Therefore, such novel strontium-incorporated borosilicate may act as a new generation of biomaterial for bone regeneration, which not only renders boron as a nutritious element for bone health, but also delivers strontium to stimulate formation of new bones. PMID:20031984

Design and construction of a home-made and cheaper argon arc lamp

NASA Astrophysics Data System (ADS)

Sabaeian, Mohammad; Nazari-Tarkarani, Zeinab; Ebrahimzadeh, Azadeh

2018-05-01

The authors report on the design and construction of an argon arc lamp which provides noticeably a cheaper instrument for laser and medical applications. Cesium-doped tungsten and pure tungsten rods were used, respectively, for the lamp cathode and anode. To seal the glassy tube, a 50-50 Fe-Ni alloy was successfully used as a medium to attach the tungsten electrodes to the borosilicate glass tube. Starting voltage of the lamp versus the gas pressure, operation voltage-current diagram at various gas pressures, and lamp spectrum in the various pressures were measured. A comparison was made with krypton arc lamp. The lamp operation was satisfactory without any crack or fracture during lightening operation. The results showed that the lamp-lightening threshold voltage depends linearly on the pressure and arc length in such a way that there is an increase in the voltage by raising these two parameters. We have also observed that by increasing the argon pressure, there is a shifting in emission spectrum from the ultraviolet to the visible region. Comparison with krypton arc lamp indicated that argon lamp needs a higher threshold lightening voltage.

Strontium borate glass: potential biomaterial for bone regeneration.

PubMed

Pan, H B; Zhao, X L; Zhang, X; Zhang, K B; Li, L C; Li, Z Y; Lam, W M; Lu, W W; Wang, D P; Huang, W H; Lin, K L; Chang, J

2010-07-06

Boron plays important roles in many life processes including embryogenesis, bone growth and maintenance, immune function and psychomotor skills. Thus, the delivery of boron by the degradation of borate glass is of special interest in biomedical applications. However, the cytotoxicity of borate glass which arises with the rapid release of boron has to be carefully considered. In this study, it was found that the incorporation of strontium into borate glass can not only moderate the rapid release of boron, but also induce the adhesion of osteoblast-like cells, SaOS-2, thus significantly increasing the cyto-compatibility of borate glass. The formation of multilayers of apatite with porous structure indicates that complete degradation is optimistic, and the spread of SaOS-2 covered by apatite to form a sandwich structure may induce bone-like tissue formation at earlier stages. Therefore, such novel strontium-incorporated borosilicate may act as a new generation of biomaterial for bone regeneration, which not only renders boron as a nutritious element for bone health, but also delivers strontium to stimulate formation of new bones.

Free volume of mixed cation borosilicate glass sealants elucidated by positron annihilation lifetime spectroscopy and its correlation with glass properties

NASA Astrophysics Data System (ADS)

Ojha, Prasanta K.; Rath, Sangram K.; Sharma, Sandeep K.; Sudarshan, Kathi; Pujari, Pradeep K.; Chongdar, Tapas K.; Gokhale, Nitin M.

2015-01-01

The role of La+3/Sr+2 ratios, which is varied from 0.08 to 5.09, on density, molar volume, packing fraction, free volume, thermal and electrical properties in strontium lanthanum aluminoborosilicate based glass sealants intended for solid oxide fuel cell (SOFC) applications is evaluated. The studies reveal expansion of the glass network evident from increasing molar volume and decreasing packing fraction of glasses with progressive La+3 substitutions. The molecular origin of these macroscopic structural features can be accounted for by the free volume parameters measured from positron annihilation lifetime spectroscopy (PALS). The La+3 induced expanded glass networks show increased number of subnanoscopic voids with larger sizes, as revealed from the ortho-positronium (o-Ps) lifetime and its intensity. A remarkably direct correspondence between the molar volume and fractional free volume trend is established with progressive La2O3 substitution in the glasses. The effect of these structural changes on the glass transition temperature, softening temperature, coefficient of thermal expansion, thermal stability as well as electrical conductivity has been studied.

Formation and Properties of Laser-Induced Periodic Surface Structures on Different Glasses.

PubMed

Gräf, Stephan; Kunz, Clemens; Müller, Frank A

2017-08-10

The formation and properties of laser-induced periodic surface structures (LIPSS) was investigated on different technically relevant glasses including fused silica, borosilicate glass, and soda-lime-silicate glass under irradiation of fs-laser pulses characterized by a pulse duration τ = 300 fs and a laser wavelength λ = 1025 nm. For this purpose, LIPSS were fabricated in an air environment at normal incidence with different laser peak fluence, pulse number, and repetition frequency. The generated structures were characterized by using optical microscopy, scanning electron microscopy, focused ion beam preparation and Fast-Fourier transformation. The results reveal the formation of LIPSS on all investigated glasses. LIPSS formation on soda-lime-silicate glass is determined by remarkable melt-formation as an intra-pulse effect. Differences between the different glasses concerning the appearing structures, their spatial period and their morphology were discussed based on the non-linear absorption behavior and the temperature-dependent viscosity. The findings facilitate the fabrication of tailored LIPSS-based surface structures on different technically relevant glasses that could be of particular interest for various applications.

Formation and Properties of Laser-Induced Periodic Surface Structures on Different Glasses

PubMed Central

Kunz, Clemens; Müller, Frank A.

2017-01-01

The formation and properties of laser-induced periodic surface structures (LIPSS) was investigated on different technically relevant glasses including fused silica, borosilicate glass, and soda-lime-silicate glass under irradiation of fs-laser pulses characterized by a pulse duration τ = 300 fs and a laser wavelength λ = 1025 nm. For this purpose, LIPSS were fabricated in an air environment at normal incidence with different laser peak fluence, pulse number, and repetition frequency. The generated structures were characterized by using optical microscopy, scanning electron microscopy, focused ion beam preparation and Fast-Fourier transformation. The results reveal the formation of LIPSS on all investigated glasses. LIPSS formation on soda-lime-silicate glass is determined by remarkable melt-formation as an intra-pulse effect. Differences between the different glasses concerning the appearing structures, their spatial period and their morphology were discussed based on the non-linear absorption behavior and the temperature-dependent viscosity. The findings facilitate the fabrication of tailored LIPSS-based surface structures on different technically relevant glasses that could be of particular interest for various applications. PMID:28796180

Role of auxin during intercellular infection of Discaria trinervis by Frankia

PubMed Central

Imanishi, Leandro; Perrine-Walker, Francine M.; Ndour, Adama; Vayssières, Alice; Conejero, Genevieve; Lucas, Mikaël; Champion, Antony; Laplaze, Laurent; Wall, Luis; Svistoonoff, Sergio

2014-01-01

Nitrogen-fixing nodules induced by Frankia in the actinorhizal plant Discaria trinervis result from a primitive intercellular root invasion pathway that does not involve root hair deformation and infection threads. Here, we analyzed the role of auxin in this intercellular infection pathway at the molecular level and compared it with our previous work in the intracellular infected actinorhizal plant Casuarina glauca. Immunolocalisation experiments showed that auxin accumulated in Frankia-infected cells in both systems. We then characterized the expression of auxin transporters in D. trinervis nodules. No activation of the heterologous CgAUX1 promoter was detected in infected cells in D. trinervis. These results were confirmed with the endogenous D. trinervis gene, DtAUX1. However, DtAUX1 was expressed in the nodule meristem. Consistently, transgenic D. trinervis plants containing the auxin response marker DR5:VENUS showed expression of the reporter gene in the meristem. Immunolocalisation experiments using an antibody against the auxin efflux carrier PIN1, revealed the presence of this transporter in the plasma membrane of infected cells. Finally, we used in silico cellular models to analyse auxin fluxes in D. trinervis nodules. Our results point to the existence of divergent roles of auxin in intercellularly- and intracellularly-infected actinorhizal plants, an ancestral infection pathways leading to root nodule symbioses. PMID:25191330

Consensus formalisé: recommandations de pratiques cliniques pour la prise en charge de la migraine du patient adulte africain

PubMed Central

Ahmed, Mahmoud Ait Kaci; Haddad, Monia; Kouassi, Beugré; Ouhabi, Hamid; Serrie, Alain

2016-01-01

La migraine est une céphalée primaire (selon les derniers critères de l'International Headache Society) qui affecte environ 8% de la population africaine. Les femmes sont plus fréquemment touchées que les hommes et les crises apparaissent le plus souvent avant l’âge de 40 ans. Bien qu'un certain nombre de traitements, de mesure hygiéno-diététiques, et d'autres méthodes non pharmacologiques permettent de limiter l'intensité et la fréquence des crises, la prise en charge médicamenteuse de la crise de migraine est très souvent nécessaire. La disponibilité des traitements et l'accès aux soins diffèrent sur le continent africain et ont conduit à la réalisation du 1er consensus d'experts pour la prise en charge du patient adulte africain. Destiné aux praticiens, ce travail collaboratif multinational a pour objectif de fournir 16 recommandations de pratiques cliniques simples, fondées sur les preuves, et adaptées aux conditions de l'exercice médical en Afrique. PMID:27642420

Complexing Agents and pH Influence on Chemical Durability of Type I Molded Glass Containers.

PubMed

Biavati, Alberto; Poncini, Michele; Ferrarini, Arianna; Favaro, Nicola; Scarpa, Martina; Vallotto, Marta

2017-01-01

Among the factors that affect the glass surface chemical durability, pH and complexing agents present in aqueous solution have the main role. Glass surface attack can be also related to the delamination issue causing glass particles' appearance in the pharmaceutical preparation. A few methods to check for glass containers delamination propensity and some control guidelines have been proposed. The present study emphasizes the possible synergy between a few complexing agents with pH on borosilicate glass chemical durability.Hydrolytic attack was performed in small-volume 23 mL type I glass containers autoclaved according to the European Pharmacopoeia or United States Pharmacopeia for 1 h at 121 °C, in order to enhance the chemical attack due to time, temperature, and the unfavorable surface/volume ratio. Solutions of 0.048 M or 0.024 M (M/L) of the acids citric, glutaric, acetic, EDTA (ethylenediaminetetraacetic acid), together with sodium phosphate with water for comparison, were used for the trials. The pH was adjusted ±0.05 units at fixed values 5.5, 6.6, 7, 7.4, 8, and 9 by LiOH diluted solution.Because silicon is the main glass network former, silicon release into the attack solutions was chosen as the main index of the glass surface attack and analysed by inductively coupled plasma atomic emission spectrophotometry. The work was completed by the analysis of the silicon release in the worst attack conditions of molded glass, soda lime type II glass, and tubing borosilicate glass vials to compare different glass compositions and forming technologies. Surface analysis by scanning electron microscopy was finally performed to check for the surface status after the worst chemical attack condition by citric acid. LAY ABSTRACT: Glass, like every packaging material, can have some usage limits, mainly in basic pH solutions. The issue of glass surface degradation particles that appear in vials (delamination) has forced a number of drug product recalls in recent years. To prevent such situations, pharmaceutical and biopharmaceutical manufacturers need to understand the reasons for accelerate surface glass corrosion mainly in the case of injectables.Some drugs can contain active components with known ability to corrode glass silica networks. Sometimes these ingredients are dissolved in an alkaline medium that dramatically increases the glass corrosion and potentially causes the issue. As this action is strongly affected by time and temperature, flaking may become visible only after a long storage time. The purpose of this investigation is to verify the borosilicate glass chemical durability during controlled conditions of time and temperature when in contact with testing solutions containing different complexing agents by varying the pH. Si concentration in the extract solution is taken as an index of glass dissolution during constant autoclaving conditions for 1 h at 121 °C, which simulates approximately five years of contact at room temperature.Acetate, citrate, ethylenediaminetetraacetic acid (EDTA), phosphate, and glutarate 0.048 M or 0.024 M solutions were used at increasing pH from 5.5 to 9.0. The chemical durability of two borosilicate tubing glass vials of different glass compositions were compared with the molded one in the worst attack conditions by citric acid. Even if no delamination issue has been experienced by this study in type I molded and tubing containers, the conclusions developed can provide pharmaceutical manufacturers with useful information to prevent glass delamination risk in their processes. © PDA, Inc. 2017.

Anthocyanin biosynthesis is differentially regulated by light in the skin and flesh of white-fleshed and teinturier grape berries.

PubMed

Guan, Le; Dai, Zhanwu; Wu, Ben-Hong; Wu, Jing; Merlin, Isabelle; Hilbert, Ghislaine; Renaud, Christel; Gomès, Eric; Edwards, Everard; Li, Shao-Hua; Delrot, Serge

2016-01-01

Light exclusion reduces the concentration and modifies the composition of grape anthocyanins, by altering the expression of genes involved in anthocyanin biosynthesis and transport, in a cultivar- and tissue-specific manner. Unlike most grapes, teinturier grapes accumulate anthocyanins both in skin and flesh. However, the concentration and composition of anthocyanins in both tissues differ, providing a valuable system to study tissue-specific regulation of anthocyanin synthesis. Furthermore, little is known about the mechanisms controlling the sensitivity of anthocyanin accumulation to light. Here, light was excluded from Gamay (white-fleshed) and Gamay Fréaux (teinturier mutant) berries throughout berry development. Under light-exposed conditions, the skin of Gamay Fréaux accumulated the highest level of anthocyanins, followed by the skin of Gamay, while the pulp of Gamay Fréaux had much lower anthocyanins than the skins. Network analysis revealed the same order on the number of significant correlations among metabolites and transcripts in the three colored tissues, indicating a higher connectivity that reflects a higher efficiency of the anthocyanin pathway. Compared to light conditions, light exclusion reduced the total amount of anthocyanins, most severely in the skin of Gamay and to a lesser extent in the flesh and skin of Gamay Fréaux. Coordinated decrease in the transcript abundance of structural, regulatory and transporter genes by light exclusion correlated with the reduced anthocyanin concentration in a cultivar- and tissue-specific manner. Moreover, light exclusion increased the ratio of dihydroxylated to trihydroxylated anthocyanins, in parallel with F3'H and F3'5'H transcript amounts. Sugars and ABA only play a limited role in the control of anthocyanin synthesis in the berries, in contrast with what has been described in cell suspensions. This study provides novel insights into the regulation of anthocyanin in wild type and teinturier cultivars.

Effets de la pollution de l’air sur la santé

PubMed Central

Abelsohn, Alan; Stieb, Dave M.

2011-01-01

Résumé Objectif Faire connaître aux médecins de famille les effets de la pollution atmosphérique sur la santé et indiquer quels conseils donner aux patients vulnérables pour qu’ils soient moins exposés. Sources de l’information On a consulté MEDLINE à l’aide des termes relatifs à la pollution atmosphérique et à ses effets indésirables. On a révisé les articles en anglais publiés entre janvier 2008 et décembre 2009. La plupart des études contenaient des preuves de niveau II. Principal message Au Canada, la pollution de l’air extérieur cause une morbidité et une mortalité importantes. Elle peut affecter le système respiratoire (exacerbation de l’asthme et de la maladie pulmonaire obstructive chronique) et le système cardiovasculaire (déclencher l’arythmie, l’insuffisance cardiaque et les AVC). La cote air santé (CAS) est un nouvel outil de communication mis au point par Santé Canada et Environnement Canada qui indique sur une échelle de 1 à 10, le risque pour la santé causé par la pollution atmosphérique. La CAS est largement diffusée dans les médias et cet outil pourrait être utile au médecin de famille pour inciter les patients à haut risque (comme ceux qui souffrent d’asthme, de maladie pulmonaire obstructive chronique ou d’insuffisance cardiaque) à réduire leur exposition à la pollution atmosphérique. Conclusion Le médecin de famille peut se servir de la CAS et de ses messages sur la santé pour enseigner aux asthmatiques et aux autres patients à risque élevé la façon de réduire les risques pour la santé causés par la pollution atmosphérique.

Suivi après le traitement du cancer du sein

PubMed Central

Sisler, Jeffrey; Chaput, Geneviève; Sussman, Jonathan; Ozokwelu, Emmanuel

2016-01-01

Résumé Objectif Offrir aux médecins de famille un résumé des recommandations fondées sur les données probantes pour guider les soins aux survivantes traitées pour le cancer du sein. Qualité des données Une recherche documentaire a été effectuée dans MEDLINE entre 2000 et 2016 à l’aide des mots-clés anglais suivants : breast cancer, survivorship, follow-up care, aftercare, guidelines et survivorship care plans, en se concentrant sur la revue des lignes directrices publiées récemment par les organismes nationaux de cancérologie. Les données étaient de niveaux I à III. Message principal Les soins aux survivantes comportent 4 facettes : surveillance et dépistage, prise en charge des effets à long terme, promotion de la santé et coordination des soins. La surveillance des récidives ne se traduit que par une mammographie annuelle, et le dépistage d’autres cancers doit suivre les lignes directrices basées sur la population. La prise en charge des effets à long terme du cancer et de son traitement aborde des problèmes courants tels la douleur, la fatigue, le lymphœdème, la détresse et les effets indésirables des médicaments, de même que les préoccupations à long terme comme la santé du cœur et des os. La promotion de la santé met en relief les bienfaits de l’activité chez les survivantes du cancer, avec l’accent mis sur l’activité physique. Les soins aux survivantes sont de meilleure qualité lorsque divers services et professionnels de la santé participent aux soins, et le médecin de famille joue un rôle important dans la coordination des soins. Conclusion Les médecins de famille sont de plus en plus souvent les principaux fournisseurs de soins de suivi après le traitement du cancer du sein. Le cancer du sein doit être considéré comme une affection médicale chronique, même chez les femmes en rémission, et les patientes profitent de la même approche que celle utilisée pour les autres affections chroniques en soins de première ligne. PMID:27737992

Cyclic GMP is involved in auxin signalling during Arabidopsis root growth and development.

PubMed

Nan, Wenbin; Wang, Xiaomin; Yang, Lei; Hu, Yanfeng; Wei, Yuantao; Liang, Xiaolei; Mao, Lina; Bi, Yurong

2014-04-01

The second messenger cyclic guanosine 3',5'-monophosphate (cGMP) plays an important role in plant development and responses to stress. Recent studies indicated that cGMP is a secondary signal generated in response to auxin stimulation. cGMP also mediates auxin-induced adventitious root formation in mung bean and gravitropic bending in soybean. Nonetheless, the mechanism of the participation of cGMP in auxin signalling to affect these growth and developmental processes is largely unknown. In this report we provide evidence that indole-3-acetic acid (IAA) induces cGMP accumulation in Arabidopsis roots through modulation of the guanylate cyclase activity. Application of 8-bromo-cGMP (a cell-permeable cGMP derivative) increases auxin-dependent lateral root formation, root hair development, primary root growth, and gene expression. In contrast, inhibitors of endogenous cGMP synthesis block these processes induced by auxin. Data also showed that 8-bromo-cGMP enhances auxin-induced degradation of Aux/IAA protein modulated by the SCF(TIR1) ubiquitin-proteasome pathway. Furthermore, it was found that 8-bromo-cGMP is unable to directly influence the auxin-dependent TIR1-Aux/IAA interaction as evidenced by pull-down and yeast two-hybrid assays. In addition, we provide evidence for cGMP-mediated modulation of auxin signalling through cGMP-dependent protein kinase (PKG). Our results suggest that cGMP acts as a mediator to participate in auxin signalling and may govern this process by PKG activity via its influence on auxin-regulated gene expression and auxin/IAA degradation.

Development of a finite volume two-dimensional model and its application in a bay with two inlets: Mobile Bay, Alabama

NASA Astrophysics Data System (ADS)

Lee, Jun; Lee, Jungwoo; Yun, Sang-Leen; Oh, Hye-Cheol

2017-08-01

The purpose of this study was to develop a two-dimensional shallow water flow model using the finite volume method on a combined unstructured triangular and quadrilateral grid system to simulate coastal, estuarine and river flows. The intercell numerical fluxes were calculated using the classical Osher-Solomon's approximate Riemann solver for the governing conservation laws to be able to handle wetting and drying processes and to capture a tidal bore like phenomenon. The developed model was validated with several benchmark test problems including the two-dimensional dam-break problem. The model results were well agreed with results of other models and experimental results in literature. The unstructured triangular and quadrilateral combined grid system was successfully implemented in the model, thus the developed model would be more flexible when applying in an estuarine system, which includes narrow channels. Then, the model was tested in Mobile Bay, Alabama, USA. The developed model reproduced water surface elevation well as having overall Predictive Skill of 0.98. We found that the primary inlet, Main Pass, only covered 35% of the fresh water exchange while it covered 89% of the total water exchange between the ocean and Mobile Bay. There were also discharge phase difference between MP and the secondary inlet, Pass aux Herons, and this phase difference in flows would act as a critical role in substances' exchange between the eastern Mississippi Sound and the northern Gulf of Mexico through Main Pass and Pass aux Herons in Mobile Bay.

Micro-Biocidal Activity of Yeast Cells by Needle Plasma Irradiation at Atmospheric Pressure

NASA Astrophysics Data System (ADS)

Kurumi, Satoshi; Takahashi, Hideyuki; Taima, Tomohito; Suzuki, Kaoru; Hirose, Hideharu; Masutani, Shigeyuki

In this study, we report on the biocidal activity technique by needle helium plasma irradiation at atmospheric pressure using borosilicate capillary nozzle to apply for the oral surgery. The diameter of needle plasma was less than 50 µm, and temperature of plasma irradiated area was less than body temperature. Needle plasma showed emission due to OH and O radical. Raman spectra and methylene blue stain showed yeast cells were inactivated by needle plasma irradiation.

Optical Super-Resolution by High-Index Liquid-Immersed Microspheres

DTIC Science & Technology

2012-01-01

the BD without liquid can be achieved using microspheres with small-to-moderate index of refraction such as borosilicate glass (n 1.47), soda lime ...titanate glass microspheres with diameters (D) in the range 2–220 lm and with high refractive index (n 1.9–2.1) can be used for super-resolution...achieving optical super-resolution. It has been demonstrated10 that silica spheres with refractive index (n) about 1.46 and with diame- ters (D) in the

Medium-Range Structural Organization of Phosphorus-Bearing Borosilicate Glasses Revealed by Advanced Solid-State NMR Experiments and MD Simulations: Consequences of B/Si Substitutions.

PubMed

Yu, Yang; Stevensson, Baltzar; Edén, Mattias

2017-10-19

The short and intermediate range structures of a large series of bioactive borophosphosilicate (BPS) glasses were probed by solid-state nuclear magnetic resonance (NMR) spectroscopy and atomistic molecular dynamics (MD) simulations. Two BPS glass series were designed by gradually substituting SiO 2 by B 2 O 3 in the respective phosphosilicate base compositions 24.1Na 2 O-23.3CaO-48.6SiO 2 -4.0P 2 O 5 ("S49") and 24.6Na 2 O-26.7CaO-46.1SiO 2 -2.6P 2 O 5 ("S46"), the latter constituting the "45S5 Bioglass" utilized for bone grafting applications. The BPS glass networks are built by interconnected SiO 4 , BO 4 , and BO 3 moieties, whereas P exists mainly as orthophosphate anions, except for a minor network-associated portion involving P-O-Si and P-O-B [4] motifs, whose populations were estimated by heteronuclear 31 P{ 11 B} NMR experimentation. The high Na + /Ca 2+ contents give fragmented glass networks with large amounts of nonbridging oxygen (NBO) anions. The MD-generated glass models reveal an increasing propensity for NBO accommodation among the network units according to BO 4 < SiO 4 < BO 3 ≪ PO 4 . The BO 4 /BO 3 intermixing was examined by double-quantum-single-quantum correlation 11 B NMR experiments, which evidenced the presence of all three BO 3 -BO 3 , BO 3 -BO 4 , and BO 4 -BO 4 connectivities, with B [3] -O-B [4] bridges dominating. Notwithstanding that B [4] -O-B [4] linkages are disfavored, both NMR spectroscopy and MD simulations established their presence in these modifier-rich BPS glasses, along with non-negligible B [4] -NBO contacts, at odds with the conventional structural view of borosilicate glasses. We discuss the relative propensities for intermixing of the Si/B/P network formers. Despite the absence of pronounced preferences for Si-O-Si bond formation, the glass models manifest subtle subnanometer-sized structural inhomogeneities, where SiO 4 tetrahedra tend to self-associate into small chain/ring motifs embedded in BO 3 /BO 4 -dominated domains.

Microgenerateurs electriques a base d'oscillateurs thermiques

NASA Astrophysics Data System (ADS)

Leveille, Etienne

Dans un contexte de developpement durable et d'automatisation de notre environnement, l'utilisation de capteurs sans-fil distribues est croissante. Hors l'usage et le remplacement de piles s'avere couteux. La consommation energetique de plus en plus faible de l'electronique rend l'extraction energetique de l'energie ambiante envisageable. La chaleur residuelle est une source d'energie interessante puisqu'elle est la forme finale de la majeure partie de l'energie utilisee par l'humain. Cependant, a petite echelle, seuls les elements thermoelectriques sont disponibles. Les presents travaux s'interessent donc a explorer et comparer des mecanismes de generation alternatifs. Puisque la majorite des mecanismes de transduction alternatifs sont dynamiques, leur utilisation requiert une transformation de l'energie thermique continue en oscillations. Les mecanismes etudies ont donc tous en commun de posseder un oscillateur thermique en plus d'un mecanisme de transduction vers la forme d'energie electrique. Parmi les divers mecanismes identifies, deux sont etudies en details pour comprendre leurs comportements ainsi que connaitre leur efficacite et leur puissance potentielle. Le premier generateur etudie theoriquement est base sur le changement de ferromagnetisme d'une masse suspendue par des ressorts au-dessus d'un aimant. Les comportements du modele developpe correspondent aux comportements reportes dans la litterature. Deux parametres de conception principaux ont ete identifies, permettant un controle de la frequence, de la plage de temperatures d'operation. De plus le mecanisme peut operer avec de faibles differences de temperature et des temperatures proches de l'ambiant, ouvrant la porte a des applications utilisant la chaleur du corps humain. L'utilisation de materiau pyroelectrique comme mecanisme de transduction pourrait offrir des densites de puissance electrique envisageables de l'ordre de 1mW/cm3. Le second generateur etudie experimentalement est base sur l'evaporation explosive d'un liquide surchauffe en absence de sites de nucleation. Un premier prototype a permis de demontrer, pour la premiere fois, le fonctionnement d'un tel cycle. Une etude de l'effet de la temperature de la source de chaleur et de l'effet du debit de liquide montre qu'une zone d'operation ideale est presente. La puissance de sortie maximale mesuree est de l'ordre de 1.6muW. Des ameliorations sont proposees pour faire croitre cette puissance de deux ordres de grandeur. Finalement, l'utilisation du pompage capillaire pour rendre le systeme autonome est demontre, mais reste sensible aux variations de conditions. Finalement, l'etude des dispositifs montre que les microgenerateurs a base d'oscillateurs thermiques peuvent presenter un interet, par rapport aux elements thermoelectriques, dans les applications ou les temperatures sont faibles ou incertaines. Cependant, ces mecanismes souffrent d'une tres faible efficacite causee par les multiples transformations energetiques a faible couplage. Mots-cles : microgenerateur, oscillateur thermique, cycle thermodynamique, thermoelectricite, microsystemes electromecaniques, MEMS

L'astronomie des Anciens

NASA Astrophysics Data System (ADS)

Nazé, Yaël

2009-04-01

Quelle que soit la civilisation à laquelle il appartient, l'être humain cherche dans le ciel des réponses aux questions qu'il se pose sur son origine, son avenir et sa finalité. Le premier mérite de ce livre est de nous rappeler que l'astronomie a commencé ainsi à travers les mythes célestes imaginés par les Anciens pour expliquer l'ordre du monde et la place qu'ils y occupaient. Mais les savoirs astronomiques passés étaient loin d'être négligeables et certainement pas limités aux seuls travaux des Grecs : c'est ce que l'auteur montre à travers une passionnante enquête, de Stonehenge à Gizeh en passant par Pékin et Mexico, fondée sur l'étude des monuments anciens et des sources écrites encore accessibles. Les tablettes mésopotamiennes, les annales chinoises, les chroniques médiévales, etc. sont en outre d'une singulière utilité pour les astronomes modernes : comment sinon remonter aux variations de la durée du jour au cours des siècles, ou percer la nature de l'explosion qui a frappé tant d'observateurs en 1054 ? Ce livre offre un voyage magnifiquement illustré à travers les âges, entre astronomie et archéologie.

La prise en charge des morsures de chien chez les enfants

PubMed Central

Sabhaney, Vikram; Goldman, Ran D.

2012-01-01

Résumé Question Une fillette de 4 ans jouait avec le chien de ses voisins. Le chien s’est excité et a mordu la jeune fille à l’avant-bras, y laissant une plaie punctiforme. À cause cette blessure, elle s’est présentée à mon bureau. Devrais-je la traiter avec des antibiotiques? Quel antibiotique faut-il utiliser et pendant combien de temps? Réponse L’administration d’antibiotiques prophylactiques est indiquée lorsqu’on a procédé à une suture primitive de la morsure, que la plaie est de gravité modérée à sévère, qu’elle est punctiforme (particulièrement s’il y a eu pénétration de l’os, de la gaine tendineuse ou de l’articulation), pour les morsures au visage, aux mains, aux pieds ou aux parties génitales ou lorsque les victimes sont immunodéprimées ou souffrent d’asplénisme. L’antibiotique de première intention est l’amoxicilline-clavulanate. La prophylaxie appropriée antitétanique et contre la rage devrait faire partie des soins chez un patient qui a été mordu par un chien, tout comme le débridement local et le nettoyage complet de la plaie.

Les agressions sexuelles des jeunes ayant une incapacité ou une maladie chronique

PubMed Central

Kaufman, M

2011-01-01

Pour diverses raisons, les enfants et les adolescents ayant une incapacité ou une maladie chronique sont plus vulnérables aux agressions sexuelles. Les dispensateurs de soins, de même que les parents et les éducateurs, doivent se méfier davantage de la possibilité d’agression sexuelle au sein de cette population. Les médecins, tout particulièrement, doivent prôner des politiques pour prévenir ou déceler les agressions dans les hôpitaux, les écoles et autres établissements. Ces politiques incluent le dépistage détaillé et la surveillance étroite des employés et des bénévoles, la présence d’un chaperon aux examens physiques et aux interventions thérapeutiques, la supervision des sorties et une culture qui favorise la vie privée du patient en établissement. De plus, les médecins doivent favoriser la conscience de soi et l’habilitation des patients et leur donner très tôt des conseils préventifs au sujet de la sexualité, de l’habilitation personnelle et des risques d’agression. Le présent document de principes remplace celui que la Société canadienne de pédiatrie a publié en 1997.

Clathrin-Mediated Auxin Efflux and Maxima Regulate Hypocotyl Hook Formation and Light-Stimulated Hook Opening in Arabidopsis.

PubMed

Yu, Qinqin; Zhang, Ying; Wang, Juan; Yan, Xu; Wang, Chao; Xu, Jian; Pan, Jianwei

2016-01-04

The establishment of auxin maxima by PIN-FORMED 3 (PIN3)- and AUXIN RESISTANT 1/LIKE AUX1 (LAX) 3 (AUX1/LAX3)-mediated auxin transport is essential for hook formation in Arabidopsis hypocotyls. Until now, however, the underlying regulatory mechanism has remained poorly understood. Here, we show that loss of function of clathrin light chain CLC2 and CLC3 genes enhanced auxin maxima and thereby hook curvature, alleviated the inhibitory effect of auxin overproduction on auxin maxima and hook curvature, and delayed blue light-stimulated auxin maxima reduction and hook opening. Moreover, pharmacological experiments revealed that auxin maxima formation and hook curvature in clc2 clc3 were sensitive to auxin efflux inhibitors 1-naphthylphthalamic acid and 2,3,5-triiodobenzoic acid but not to the auxin influx inhibitor 1-naphthoxyacetic acid. Live-cell imaging analysis further uncovered that loss of CLC2 and CLC3 function impaired PIN3 endocytosis and promoted its lateralization in the cortical cells but did not affect AUX1 localization. Taken together, these results suggest that clathrin regulates auxin maxima and thereby hook formation through modulating PIN3 localization and auxin efflux, providing a novel mechanism that integrates developmental signals and environmental cues to regulate plant skotomorphogenesis and photomorphogenesis. Copyright © 2016 The Author. Published by Elsevier Inc. All rights reserved.

Molecular and Functional Characterization of GR2-R1 Event Based Backcross Derived Lines of Golden Rice in the Genetic Background of a Mega Rice Variety Swarna

PubMed Central

Bollinedi, Haritha; S., Gopala Krishnan; Prabhu, Kumble Vinod; Singh, Nagendra Kumar; Mishra, Sushma; Khurana, Jitendra P.; Singh, Ashok Kumar

2017-01-01

Homozygous Golden Rice lines developed in the background of Swarna through marker assisted backcross breeding (MABB) using transgenic GR2-R1 event as a donor for the provitamin A trait have high levels of provitamin A (up to 20 ppm) but are dwarf with pale green leaves and drastically reduced panicle size, grain number and yield as compared to the recurrent parent, Swarna. In this study, we carried out detailed morphological, biochemical and molecular characterization of these lines in a quest to identify the probable reasons for their abnormal phenotype. Nucleotide blast analysis with the primer sequences used to amplify the transgene revealed that the integration of transgene disrupted the native OsAux1 gene, which codes for an auxin transmembrane transporter protein. Real time expression analysis of the transgenes (ZmPsy and CrtI) driven by endosperm-specific promoter revealed the leaky expression of the transgene in the vegetative tissues. We propose that the disruption of OsAux1 disturbed the fine balance of plant growth regulators viz., auxins, gibberellic acid and abscisic acid, leading to the abnormalities in the growth and development of the lines homozygous for the transgene. The study demonstrates the conserved roles of OsAux1 gene in rice and Arabidopsis. PMID:28068433

Molecular and Functional Characterization of GR2-R1 Event Based Backcross Derived Lines of Golden Rice in the Genetic Background of a Mega Rice Variety Swarna.

PubMed

Bollinedi, Haritha; S, Gopala Krishnan; Prabhu, Kumble Vinod; Singh, Nagendra Kumar; Mishra, Sushma; Khurana, Jitendra P; Singh, Ashok Kumar

2017-01-01

Homozygous Golden Rice lines developed in the background of Swarna through marker assisted backcross breeding (MABB) using transgenic GR2-R1 event as a donor for the provitamin A trait have high levels of provitamin A (up to 20 ppm) but are dwarf with pale green leaves and drastically reduced panicle size, grain number and yield as compared to the recurrent parent, Swarna. In this study, we carried out detailed morphological, biochemical and molecular characterization of these lines in a quest to identify the probable reasons for their abnormal phenotype. Nucleotide blast analysis with the primer sequences used to amplify the transgene revealed that the integration of transgene disrupted the native OsAux1 gene, which codes for an auxin transmembrane transporter protein. Real time expression analysis of the transgenes (ZmPsy and CrtI) driven by endosperm-specific promoter revealed the leaky expression of the transgene in the vegetative tissues. We propose that the disruption of OsAux1 disturbed the fine balance of plant growth regulators viz., auxins, gibberellic acid and abscisic acid, leading to the abnormalities in the growth and development of the lines homozygous for the transgene. The study demonstrates the conserved roles of OsAux1 gene in rice and Arabidopsis.

Occurrence des traumatismes alvéolo-dentaires aux cliniques universitaires de Kinshasa: deuxième partie, étude préliminaire de 93 cas

PubMed Central

Foche, Adelin Nzudjom; Bushabu, Fidele Nyimi; Mana, Charles Mfutu; Haruna, Ramazani; Masin, Steve Sekele; Nsudila, Monique; Alifi, Paul Bobe; Muinamiyi, Pierre Muyembi; Burley, Jean Paul Sekele Isourady

2018-01-01

Introduction L'objectif de cette étude était d'analyser les caractéristiques épidémiologiques cliniques des fractures alvéolo-dentaires aux cliniques universitaires de Kinshasa/RDC. Méthodes Étude transversale de 7 ans, réalisée dans le département d'odontostomatologie, service de stomatologie et de chirurgie maxillo-faciale/cliniques universitaires de Kinshasa de Janvier 2007 à Décembre 2014. Résultats Sur les 93 dossiers colligés, le sexe masculin était prédominant (66,7%) et l'âge le plus prévalent se situait entre 20 ans et 29 ans. Les causes les plus fréquentes ont été les agressions/rixes (52,7%) et la luxation dentaire a été le type des lésions la plus fréquente avec 52,7%. La RX retro-alvéolaire été réalisée dans 75,7%, et le blocage mono-maxillaire fut le type de traitement le plus réalisé (60,2%). Conclusion L'analyse de profil clinique des traumatismes alvéolo-dentaires aux cliniques universitaires de Kinshasa est celui d'un adulte jeune de sexe masculin, présentant des luxations dentaires des maxillaires dont les causes sont les agressions/rixes. PMID:29875931

DOE Office of Scientific and Technical Information (OSTI.GOV)

Neeway, James J.; Rieke, Peter C.; Parruzot, Benjamin P.

In far-from-equilibrium conditions, the dissolution of borosilicate glasses used to immobilize nuclear waste is known to be a function of both temperature and pH. The aim of this paper is to study effects of these variables on three model waste glasses (SON68, ISG, AFCI). To do this, experiments were conducted at temperatures of 23, 40, 70, and 90 °C and pH(RT) values of 9, 10, 11, and 12 with the single-pass flow-through (SPFT) test method. The results from these tests were then used to parameterize a kinetic rate model based on transition state theory. Both the absolute dissolution rates andmore » the rate model parameters are compared with previous results. Discrepancies in the absolute dissolution rates as compared to those obtained using other test methods are discussed. Rate model parameters for the three glasses studied here are nearly equivalent within error and in relative agreement with previous studies. The results were analyzed with a linear multivariate regression (LMR) and a nonlinear multivariate regression performed with the use of the Glass Corrosion Modeling Tool (GCMT), which is capable of providing a robust uncertainty analysis. This robust analysis highlights the high degree of correlation of various parameters in the kinetic rate model. As more data are obtained on borosilicate glasses with varying compositions, the effect of glass composition on the rate parameter values could possibly be obtained. This would allow for the possibility of predicting the forward dissolution rate of glass based solely on composition« less

Free-solution electrophoretic separations of DNA–drag-tag conjugates on glass microchips with no polymer network and no loss of resolution at increased electric field strength

PubMed Central

Albrecht, Jennifer Coyne; Kerby, Matthew B.; Niedringhaus, Thomas P.; Lin, Jennifer S.; Wang, Xiaoxiao; Barron, Annelise E.

2012-01-01

Here, we demonstrate the potential for high-resolution electrophoretic separations of ssDNA-protein conjugates in borosilicate glass microfluidic chips, with no sieving media and excellent repeatability. Using polynucleotides of two different lengths conjugated to moderately cationic protein polymer drag-tags, we measured separation efficiency as a function of applied electric field. In excellent agreement with prior theoretical predictions of Slater et al., resolution is found to remain constant as applied field is increased up to 700 V/cm, the highest field we were able to apply. This remarkable result illustrates the fundamentally different physical limitations of Free-Solution Conjugate Electrophoresis (FSCE)-based DNA separations relative to matrix-based DNA electrophoresis. Single-stranded DNA separations in “gels” have always shown rapidly declining resolution as the field strength is increased; this is especially true for ssDNA > 400 bases in length. FSCE’s ability to decouple DNA peak resolution from applied electric field suggests the future possibility of ultra-rapid FSCE sequencing on chips. We investigated sources of peak broadening for FSCE separations on borosilicate glass microchips, using six different protein polymer drag-tags. For drag-tags with four or more positive charges, electrostatic and adsorptive interactions with pHEA-coated microchannel walls led to appreciable band-broadening, while much sharper peaks were seen for bioconjugates with nearly charge-neutral protein drag-tags. PMID:21500207

The influence of ZnO incorporation on the aqueous leaching characteristics of a borosilicate glass

NASA Astrophysics Data System (ADS)

Vance, E. R.; Gregg, D. J.; Karatchevtseva, I.; Griffiths, G. J.; Olufson, K.; Rees, Gregory J.; Hanna, John V.

2017-10-01

With increasing ZnO content, short term aqueous durability enhancement of all elements in borosilicate glasses containing 1.0 and 3.85 wt% ZnO was evident in 7-day PCT-B tests. In 14-day MCC-1 type leach tests conducted at 90 °C, surface alteration was very clear in the undoped glass via the formation of strongly altered amorphous material which tended to spall off the surface. No sign of crystallinity was detected by grazing incidence X-ray diffraction or electron microscopy of the surface layers and the surface material was very rich in silica. For the ZnO-bearing glasses, significant growth of particles following PCT leaching for 7 days was observed, due to a build-up of surface ZnO-containing Si-rich material and possible agglomeration. This alteration layer was also observed in MCC-1 type experiments in which cross-section SEM-EDS data were obtained. Raman, infrared and 11B and 29Si MAS NMR spectroscopy showed only slight changes in boron speciation on the addition of up to 9.1 wt% ZnO. Bulk positron annihilation lifetime spectra (PALS) of glasses containing 0-3.85 wt% ZnO could be analysed with three distinct lifetimes and also showed only slight differences. These results indicate that the basic glass structure was essentially not influenced by the ZnO content and that the passivation of the alteration layer is promoted by ZnO content.

Synthesis, electrical and magnetic properties of sodium borosilicate glasses containing Co-ferrites nanoparticles

NASA Astrophysics Data System (ADS)

Othman, H. A.; Eltabey, M. M.; Ibrahim, Samia. E.; El-Deen, L. M. Sharaf; Elkholy, M. M.

2017-02-01

Co-ferrites nanoparticles that have been prepared by the co-precipitation method were added to sodium borosilicate (Na2O-B2O3-SiO2) glass matrix by the solid solution method and they were characterized using X-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared (FTIR) and magnetization measurements. (XRD) revealed the formation of the Co-ferrite magnetic crystalline phase embedded in an amorphous matrix in all the samples. The investigated samples by (TEM) showed the formation of the cobalt ferrite nanoparticles with a spherical shape and highly monodispersed with an average size about 13 nm. IR data revealed that the BO3 and BO4 are the main structural units of these samples network. IR spectra of the investigated samples showed the characteristic vibration bands of Co-ferrite. Composition and frequency dependent dielectric properties of the prepared samples were measured at room temperature in the frequency range 100-100 kHz. The conductivity was found to increase with increasing cobalt ferrite content. The variations of conductivity and dielectric properties with frequency and composition were discussed. Magnetic hysteresis loops were traced at room temperature using VSM and values of saturation magnetization MS and coercive field HC were determined. The obtained results revealed that a ferrimagnetic behavior were observed and as Co-ferrite concentration increases the values of MS and HC increase from 2.84 to 8.79 (emu/g) and from 88.4 to 736.3 Oe, respectively.

L'Apport de la Greffe de Peau Totale dans le Traitement des Sequelles des Brulures de la Main: a Propos de 14 Cas

PubMed Central

Ettalbi, S.; Ibnouzahir, M.; Rachid, M.; Bahaichar, N.; Boukind, H.

2007-01-01

Summary La main est fréquemment exposée aux brûlures, ce qui entraîne des séquelles cutanées. A partir d'une série de 14 patients suivis dans notre service sur une année, nous avons essayé d'établir la simplicité, l'efficacité et le rôle de la greffe de peau totale dans le traitement de ces séquelles (les organes nobles ne sont pas mis à nu). La greffe de peau totale associée à une rééducation efficace permet aux patients de reprendre la mobilité des mains dans les brefs délais. PMID:21991094

Conference B.Bettelheim

ScienceCinema

None

2017-12-09

Le Dr.Bruno Bettelheim, psychologue américain, d'origine viennoise, a passé son doctorat en psychologie à l'université de Vienne. Il émigra aux Etats-Unis et enseigna la psychologie au Rockford College en Illinois et la psychologie de l'éducation à L'université de Chicago, où il dirigea également l'institut orthogénique Sonia-Shankman pour le traitement des enfants psychotiques. Cet homme a bouleversé la compréhension des relations parents et enfants en y introduisant la psychanalyse. Basé sur ses expériences aux Etats-Unis,il nous parle des changements dans la structure de la famille et ses conséquences pour la relation entre enfants et parents.

Supplémentation préconceptionnelle en acide folique / multivitamines pour la prévention primaire et secondaire des anomalies du tube neural et d'autres anomalies congénitales sensibles à l'acide folique.

PubMed

Wilson, R Douglas

2016-12-01

Offrir des renseignements à jour sur l'utilisation pré et postconceptionnelle d'acide folique par voie orale, avec ou sans supplément de multivitamines / micronutriments, aux fins de la prévention des anomalies du tube neural et d'autres anomalies congénitales. Ces renseignements aideront les médecins, les sages-femmes, les infirmières et les autres professionnels de la santé à contribuer aux efforts de sensibilisation des femmes quant à l'utilisation et aux posologies adéquates de la supplémentation en acide folique / multivitamines, avant et pendant la grossesse. RéSULTATS: La littérature publiée a été récupérée par l'intermédiaire de recherches menées dans PubMed, Medline, CINAHL et la Cochrane Library en janvier 2011 au moyen d'un vocabulaire contrôlé et de mots clés appropriés (p. ex. « folic acid », « prenatal multivitamins », « folate sensitive birth defects », « congenital anomaly risk reduction », « pre-conception counselling »). Les résultats ont été restreints aux analyses systématiques, aux études observationnelles et aux essais comparatifs randomisés / essais cliniques comparatifs publiés en anglais entre 1985 et juin 2014. Les recherches ont été mises à jour de façon régulière et intégrées à la directive clinique jusqu'en juin 2014. La littérature grise (non publiée) a été identifiée par l'intermédiaire de recherches menées dans les sites Web d'organismes s'intéressant à l'évaluation des technologies dans le domaine de la santé et d'organismes connexes, dans des collections de directives cliniques, dans des registres d'essais cliniques, et auprès de sociétés de spécialité médicale nationales et internationales. COûTS, RISQUES ET AVANTAGES: Les coûts financiers sont ceux de la supplémentation quotidienne en vitamines et de la consommation d'un régime alimentaire santé enrichi en folate. Les risques sont ceux qui sont liés à une association signalée entre la supplémentation alimentaire en acide folique et des modifications épigénétiques fœtales / la probabilité accrue d'obtenir une grossesse gémellaire. Ces associations pourraient devoir être prises en considération avant la mise en œuvre d'une supplémentation en acide folique. La supplémentation en acide folique par voie orale (ou l'apport alimentaire en folate combiné à un supplément de multivitamines / micronutriments) a pour avantage de mener à une baisse connexe du taux d'anomalies du tube neural et peut-être même des taux d'autres complications obstétricales et anomalies congénitales particulières. La qualité des résultats est évaluée au moyen des critères décrits par le Groupe d'étude canadien sur les soins de santé préventifs (Tableau 1). DéCLARATION SOMMAIRE: RECOMMANDATIONS. Copyright © 2016. Published by Elsevier Inc.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vienna, John D.; Todd, Terry A.; Gray, Kimberly D.

The U.S. Department of Energy, Office of Nuclear Energy has chartered an effort to develop technologies to enable safe and cost effective recycle of commercial used nuclear fuel (UNF) in the U.S. Part of this effort includes the evaluation of exiting waste management technologies for effective treatment of wastes in the context of current U.S. regulations and development of waste forms and processes with significant cost and/or performance benefits over those existing. This study summarizes the results of these ongoing efforts with a focus on the highly radioactive primary waste streams. The primary streams considered and the recommended waste formsmore » include: •Tritium separated from either a low volume gas stream or a high volume water stream. The recommended waste form is low-water cement in high integrity containers. •Iodine-129 separated from off-gas streams in aqueous processing. There are a range of potentially suitable waste forms. As a reference case, a glass composite material (GCM) formed by the encapsulation of the silver Mordenite (AgZ) getter material in a low-temperature glass is assumed. A number of alternatives with distinct advantages are also considered including a fused silica waste form with encapsulated nano-sized AgI crystals. •Carbon-14 separated from LWR fuel treatment off-gases and immobilized as a CaCO3 in a cement waste form. •Krypton-85 separated from LWR and SFR fuel treatment off-gases and stored as a compressed gas. •An aqueous reprocessing high-level waste (HLW) raffinate waste which is immobilized by the vitrification process in one of three forms: a single phase borosilicate glass, a borosilicate based glass ceramic, or a multi-phased titanate ceramic [e.g., synthetic rock (Synroc)]. •An undissolved solids (UDS) fraction from aqueous reprocessing of LWR fuel that is either included in the borosilicate HLW glass or is immobilized in the form of a metal alloy in the case of glass ceramics or titanate ceramics. •Zirconium-based LWR fuel cladding hulls and stainless steel (SS) fuel assembly hardware that are washed and super-compacted for disposal or as an alternative Zr purification and reuse (or disposal as low-level waste, LLW) by reactive gas separations. •Electrochemical process salt HLW which is immobilized in a glass bonded Sodalite waste form known as the ceramic waste form (CWF). •Electrochemical process UDS and SS cladding hulls which are melted into an iron based alloy waste form. Mass and volume estimates for each of the recommended waste forms based on the source terms from a representative flowsheet are reported.« less

Paternité des articles et intérêts concurrents : une analyse des recommandations aux auteurs des journaux traitant de pratique pharmaceutique

PubMed Central

Courbon, Ève; Tanguay, Cynthia; Lebel, Denis; Bussières, Jean-François

2014-01-01

RÉSUMÉ Contexte : La présence d’auteurs honorifiques et fantômes ainsi que les intérêts concurrents représentent des difficultés bien documentées, liées à la publication d’articles scientifiques. Il existe des lignes directrices encadrant la rédaction et la publication de manuscrits scientifiques, notamment celles de l’International Committee of Medical Journal Editors (ICMJE). Objectifs : L’objectif principal de cette étude descriptive et transversale visait à recenser les instructions portant sur la paternité des articles et les intérêts concurrents provenant des recommandations aux auteurs des journaux traitant de pratique pharmaceutique. L’objectif secondaire visait à déterminer des mesures correctrices pour une paternité des articles plus transparente. Méthode : La recherche a débuté par l’identification des journaux traitant de pratique pharmaceutique. La consultation des instructions aux auteurs des journaux a permis ensuite de recenser les recommandations destinées à éviter les problèmes de paternité des articles et d’intérêts concurrents. Finalement, les membres de l’équipe de recherche se sont consultés afin de définir des mesures correctrices possibles à l’intention des chercheurs. Résultats : Des 232 journaux traitant de pharmacie, 33 ont été définis comme traitant de pratique pharmaceutique. Un total de 24 (73 %) journaux mentionnaient suivre la politique de l’ICMJE, 14 (42 %) demandaient aux auteurs de remplir un formulaire de déclaration d’intérêts concurrents au moment de la soumission de l’article, 17 (52 %) présentaient une définition de la qualité d’auteur et 5 (15 %) demandaient de détailler les contributions de chaque auteur. Une grille de 40 critères a été élaborée pour définir l’attribution du statut d’auteur. Conclusion : Moins de la moitié des journaux demandait aux auteurs de transmettre un formulaire de déclaration des intérêts concurrents au moment de la soumission d’un article et seulement la moitié des journaux avait donné une définition de la qualité d’auteur. La publication scientifique de travaux sur les pratiques pharmaceutiques n’est pas à l’abri des manques de transparence liés à la publication. L’utilisation d’une grille décrivant la contribution de chaque auteur et la publication en ligne des travaux peuvent contribuer à limiter ces risques. PMID:24970938

Deep proton writing of high aspect ratio SU-8 micro-pillars on glass

NASA Astrophysics Data System (ADS)

Ebraert, Evert; Rwamucyo, Ben; Thienpont, Hugo; Van Erps, Jürgen

2016-12-01

Deep proton writing (DPW) is a fabrication technology developed for the rapid prototyping of polymer micro-structures. We use SU-8, a negative resist, spincoated in a layer up to 720 μm-thick in a single step on borosilicate glass, for irradiation with a collimated 12 MeV energy proton beam. Micro-pillars with a slightly conical profile are irradiated in the SU-8 layer. We determine the optimal proton fluence to be 1.02 × 104 μm-2, with which we are able to repeatably achieve micro-pillars with a top-diameter of 138 ± 1 μm and a bottom-diameter of 151 ± 3 μm. The smallest fabricated pillars have a top-diameter of 57 ± 5 μm. We achieved a root-mean-square sidewall surface roughness between 19 nm and 35 nm for the fabricated micro-pillars, measured over an area of 5 × 63.7 μm. We briefly discuss initial testing of two potential applications of the fabricated micro-pillars. Using ∼100 μm-diameter pillars as waveguides for gigascale integration optical interconnect applications, has shown a 4.7 dB improvement in optical multimode fiber-to-fiber coupling as compared to the case where an air-gap is present between the fibers at the telecom wavelength of 1550 nm. The ∼140 μm-diameter pillars were used for mold fabrication with silicone casting. The resulting mold can be used for hydrogel casting, to obtain hydrogel replicas mimicking human tissue for in vitro bio-chemical applications.

Light-dependent gravitropism and negative phototropism of inflorescence stems in a dominant Aux/IAA mutant of Arabidopsis thaliana, axr2.

PubMed

Sato, Atsuko; Sasaki, Shu; Matsuzaki, Jun; Yamamoto, Kotaro T

2014-09-01

Gravitropism and phototropism of the primary inflorescence stems were examined in a dominant Aux/IAA mutant of Arabidopsis, axr2/iaa7, which did not display either tropism in hypocotyls. axr2-1 stems completely lacked gravitropism in the dark but slowly regained it in light condition. Though wild-type stems showed positive phototropism, axr2 stems displayed negative phototropism with essentially the same light fluence-response curve as the wild type (WT). Application of 1-naphthaleneacetic acid-containing lanolin to the stem tips enhanced the positive phototropism of WT, and reduced the negative phototropism of axr2. Decapitation of stems caused a small negative phototropism in WT, but did not affect the negative phototropism of axr2. p-glycoprotein 1 (pgp1) pgp19 double mutants showed no phototropism, while decapitated double mutants exhibited negative phototropism. Expression of auxin-responsive IAA14/SLR, IAA19/MSG2 and SAUR50 genes was reduced in axr2 and pgp1 pgp19 stems relative to that of WT. These suggest that the phototropic response of stem is proportional to the auxin supply from the shoot apex, and that negative phototropism may be a basal response to unilateral blue-light irradiation when the levels of auxin or auxin signaling are reduced to the minimal level in the primary stems. In contrast, all of these treatments reduced or did not affect gravitropism in wild-type or axr2 stems. Tropic responses of the transgenic lines that expressed axr2-1 protein by the endodermis-specific promoter suggest that AXR2-dependent auxin response in the endodermis plays a more crucial role in gravitropism than in phototropism in stems but no significant roles in either tropism in hypocotyls.

Phosphorus and magnesium interactively modulate the elongation and directional growth of primary roots in Arabidopsis thaliana (L.) Heynh

PubMed Central

Niu, Yaofang; Jin, Gulei; Li, Xin; Tang, Caixian; Zhang, Yongsong; Liang, Yongchao; Yu, Jingquan

2015-01-01

A balanced supply of essential nutrients is an important factor influencing root architecture in many plants, yet data related to the interactive effects of two nutrients on root growth are limited. Here, we investigated the interactive effect between phosphorus (P) and magnesium (Mg) on root growth of Arabidopsis grown in pH-buffered agar medium at different P and Mg levels. The results showed that elongation and deviation of primary roots were directly correlated with the amount of P added to the medium but could be modified by the Mg level, which was related to the root meristem activity and stem-cell division. High P enhanced while low P decreased the tip-focused fluorescence signal of auxin biosynthesis, transport, and redistribution during elongation of primary roots; these effects were greater under low Mg than under high Mg. The altered root growth in response to P and Mg supply was correlated with AUX1, PIN2, and PIN3 mRNA abundance and expression and the accumulation of the protein. Application of either auxin influx inhibitor or efflux inhibitor inhibited the elongation and increased the deviation angle of primary roots, and decreased auxin level in root tips. Furthermore, the auxin-transport mutants aux1-22 and eir1-1 displayed reduced root growth and increased the deviation angle. Our data suggest a profound effect of the combined supply of P and Mg on the development of root morphology in Arabidopsis through auxin signals that modulate the elongation and directional growth of primary root and the expression of root differentiation and development genes. PMID:25922494

De l'importance des orbites periodiques: Detection et applications

NASA Astrophysics Data System (ADS)

Doyon, Bernard

L'ensemble des Orbites Periodiques Instables (OPIs) d'un systeme chaotique est intimement relie a ses proprietes dynamiques. A partir de l'ensemble (en principe infini) d'OPIs cachees dans l'espace des phases, on peut obtenir des quantites dynamiques importantes telles les exposants de Lyapunov, la mesure invariante, l'entropie topologique et la dimension fractale. En chaos quantique (i.e. l'etude de systemes quantiques qui ont un equivalent chaotique dans la limite classique), ces memes OPIs permettent de faire le pont entre le comportement classique et quantique de systemes non-integrables. La localisation de ces cycles fondamentaux est un probleme complexe. Cette these aborde dans un premier temps le probleme de la detection des OPIs dans les systemes chaotiques. Une etude comparative de deux algorithmes recents est presentee. Nous approfondissons ces deux methodes afin de les utiliser sur differents systemes dont des flots continus dissipatifs et conservatifs. Une analyse du taux de convergence des algorithmes est aussi realisee afin de degager les forces et les limites de ces schemes numeriques. Les methodes de detection que nous utilisons reposent sur une transformation particuliere de la dynamique initiale. Cette astuce nous a inspire une methode alternative pour cibler et stabiliser une orbite periodique quelconque dans un systeme chaotique. Le ciblage est en general combine aux methodes de controle pour stabiliser rapidement un cycle donne. En general, il faut connaitre la position et la stabilite du cycle en question. La nouvelle methode de ciblage que nous presentons ne demande pas de connaitre a priori la position et la stabilite des orbites periodiques. Elle pourrait etre un outil complementaire aux methodes de ciblage et de controle actuelles.

Etude par émission acoustique de la dynamique des dislocations pendant la déformation cyclique de polycristaux d'aluminium

NASA Astrophysics Data System (ADS)

Slimani, A.; Fleischmann, P.; Fougères, R.

1992-06-01

The cyclic plasticity of 5N polycrystalline aluminium have been studied at room temperature by measuring the continuous acoustic emission (A.E.) due to dislocations movements in the metal. In this study, original data have been obtained in the understanding of continuous A.E. sources. In comparison with classical interpretation given in the literature, the fact that dislocations are arranged according to a dislocation cell structure from the first cycle has been included in the analysis of the results. From this, it has been shown that the amplitude of the A.E. signal is not directly connected with the plastic strain rate prescribed to the fatigue sample and that the probability density function of dislocation loops created during the cycling can be determined. La plasticité cyclique de l'AI 5N polycristallin a été étudiée à la température ambiante à partir de mesures d'émission acoustique continue (E.A.). L'application de la technique de l'E.A. nous a permis d'obtenir des données originales quant aux mécanismes sources d'E.A. Par rapport aux interprétations classiques de la littérature, nous avons fait intervenir le fait que, dès les premiers cycles, une structure cellulaire de dislocations est établie. Nous montrons que l'amplitude du signal d'E.A. n'est plus liée directement à la vitesse de déformation plastique macroscopique. A partir de cette donnée, l'analyse des résultats d'E.A. permet d'obtenir des informations sur la fonction distribution des boucles de dislocations créées au cours de la déformation cyclique.

Radar response to crop residue cover and tillage application on postharvest agricultural surfaces

NASA Astrophysics Data System (ADS)

McNairn, Heather

Les informations sur les pratiques de conservation des sols comme le labourage et la gestion des residus de culture sont requises afin d'estimer avec exactitude les risques d'erosion des sols. Quoique les micro-ondes soient sensibles aux conditions d'humidite et aux proprietes geometriques des surfaces, il n'en demeure pas moins que l'on connait encore peu sur la sensibilite des micro-ondes polarisees lineaires ou des parametres polarimetriques du ROS en fonction des caracteristiques des residus. A partir de donnees prises a l'aide d'un diffusometre monte sur un camion en 1996 et lors d'une mission SIR-C menee en 1994, cette recherche a demontre que les micro-ondes sont sensibles a la fois a la quantite et au type de couverture de residus, de meme qu'a la teneur en eau des residus. La reponse des polarisations croisees lineaires et de plusieurs parametres polarimetriques, incluant la hauteur pedestre, a permis d'observer qu'une diffusion volumique importante avait lieu en presence de vegetation senescente qui se tenait debout et pour les champs non laboures. La diffusion de surface dominait cependant pour les champs avec de faibles quantites de residus et des residus plus fins. La recherche a toutefois demontre que des conditions de surface complexes etaient crees par differentes combinaisons de residus et de pratiques de labourage. Par consequent, il faudra attendre que des donnees multi-polarisees ou polarimetriques soient acquises par les capteurs prevus a bord du satellite canadien RADARSAT-2 et du satellite ENVISAT de l'Agence spatiale europeenne avant de pouvoir completement caracteriser les champs apres la recolte.

Final Determination - signed October 16, 1985

EPA Pesticide Factsheets

Fianl Determination of the U.S. EPA's Assistant Administrator for External Affairs concerning the Bayou Aux Carpes site in Jefferson Parish, Louisiana pursuant to Section 404(c) of the Clean Water Act.

Anomalous dielectric relaxation in lithium-potassium tantalate crystals

NASA Astrophysics Data System (ADS)

Doussineau, P.; Farssi, Y.; Frénois, C.; Levelut, A.; Toulouse, J.; Ziolkiewicz, S.

1994-08-01

In order to describe the unusual dielectric properties observed in Ki{1-χ}Li{χ}TaO3. crystals a new approchh is proposed. The dynamical Glauber theory, previously applied to spinglasses, is modifiéd by the introduction of the spectral distribution of the random interactions between the dipoles associated with the Li+ ions. Moreover, the dipole corrélations are taken into account by the Onsager réaction field. As a result, the calculated dielectric constant reproduces well the unusual features of the Argand diagrams and, in particular, their finite slope at low frequencies and infinite slope at high frequencies (strophoidal shape). The temperature dépendance of some parameters shows, however, the limits of a spin-glass type model in describing the collective behaviour of randomly distributed dipoles in a highly polarizable medium. Une nouvelle approche est présentée qui permet de décrire les propriétés diélectriques particulières de cristaux mixtes de Ki{1-χ}Li{χ}TaO3. Elle s'appuie sur la théorie dynamique de Glauber, déjà utilisée pour les verres de spins, et modifiée par l'introduction d'une distribution spectrale spécifique aux interactions aléatoires des dipôles électriques associés aux ions Li+. En outre, les corrélations entre dipôles sont prises en compte par le champ de réaction d'Onsager. II s'ensuit que la constante diélectrique complexe ainsi calculée reproduit fidèlement les particularités des diagrammes d'Argand, telles que la pente finie aux basses fréquences et la pente infinie aux hautes fréquences (forme strophoïdale). La dépendance en température de certains paramètres déterminés par le calcul montre les limites de l'analogie avec les verres de spins et met en évidence le rôle d'un réseau très polarisable dans le comportement collectif d'une assemblée de dipôles électriques.

Differential effects of NAA and 2,4-D in reducing floret abscission in cestrum (Cestrum elegans) cut flowers are associated with their differential activation of Aux/IAA homologous genes.

PubMed

Abebie, Bekele; Lers, Amnon; Philosoph-Hadas, Sonia; Goren, Raphael; Riov, Joseph; Meir, Shimon

2008-01-01

A previous study showed that the relative effectiveness of 2,4-dichlorophenoxyacetic acid (2,4-D) compared with that of 1-naphthaleneacetic acid (NAA) in reducing floret bud abscission in cestrum (Cestrum elegans) cut flowers was due to its acropetal transport. The aim of the present study was to examine if the differential effect of these auxins on floret abscission is reflected in the expression of Aux/IAA genes in the floret abscission zone (AZ). cDNAs were isolated by PCR-based cloning from the floret AZ of auxin-treated cut flowers. The expression patterns of the cDNAs in various tissues and the effect of indole-3-acetic acid (IAA), applied with or without cycloheximide, on their expression in the floret AZ were examined by northern blot analysis. The regulation of transcript accumulation in the floret AZ in response to NAA or 2,4-D was measured by real-time PCR during auxin pulsing of cut flowers and vase life, concomitantly with floret abscission. Six isolated cDNAs were identified to represent Aux/IAA homologous genes, designated as Cestrum elegans (Ce)-IAA1 to Ce-IAA6. Four Ce-IAA genes were characterized as early auxin-responsive genes (ARGs), and two (Ce-IAA1 and Ce-IAA5) as late ARGs. Only Ce-IAA5 was AZ-specific in floret buds. A temporal regulation of Ce-IAA transcript levels in the floret AZ was found, with 2,4-D inducing higher expression levels than NAA in floret buds. These Ce-IAA expression levels were negatively correlated with floret abscission. The differential transport characteristics of NAA and 2,4-D in cestrum cut flowers were reflected in differential activation of the Ce-IAA genes identified in the floret AZ. Therefore, Aux/IAA genes can be used as molecular markers to measure auxin activity, which reflects free auxin level in the AZ. Two of the identified genes, Ce-IAA1 and Ce-IAA5, may also have a regulatory role in abscission.

L’expérience d’une patiente qui reçoit des soins pour la démence

PubMed Central

Frank, Christopher; Forbes, Rev Faye

2017-01-01

Résumé Objectif Permettre aux médecins de famille de comprendre « l’expérience vécue » de la démence de la bouche d’une personne atteinte de démence—Faye Forbes, ministre anglicane de 64 ans atteinte de la maladie d’Alzheimer, qui donne son point de vue sur comment vivre avec la démence—et utiliser cette information pour améliorer les soins et les résultats. Sources d’information Une recherche a été effectuée dans MEDLINE sur Ovid entre janvier 2005 et février 2015, à l’aide des mots-clés anglais suivants : dementia, caregiver, perspectives et quality of health care. Les articles qui s’adressaient aux médecins de famille ont été sélectionnés. Des revues pertinentes et des articles de recherche originaux ont été utilisés, le cas échéant, s’ils s’appliquaient aux personnes atteintes de démence et à leurs soignants. Message principal Plusieurs cadres de référence organisent les principales expériences décrites par les patients et leurs soignants. Nous avons utilisé une revue de la littérature qualitative pour fournir un cadre de référence résumant l’expérience de Faye, en fonction des thèmes suivants : tenter d’obtenir un diagnostic, accéder au soutien et aux services, besoins en matière d’information, prise en charge de la maladie, et communication et attitudes. Conclusion Les médecins doivent tenir compte de ces thèmes lorsqu’ils planifient la prise en charge des personnes atteintes de démence. Il importe de tenter de comprendre l’expérience et le point de vue des personnes atteintes de démence et de leurs soignants afin de pouvoir dispenser des soins optimaux. PMID:28115451

Conduite automobile et démence

PubMed Central

Lee, Linda; Molnar, Frank

2017-01-01

Résumé Objectif Fournir aux médecins de première ligne une approche relative aux préoccupations de sécurité au volant lorsque les personnes âgées présentent des troubles de mémoire. Sources d’information L’approche est fondée sur un programme de formation agréé des cliniques de la mémoire, élaboré par la clinique de la mémoire du Centre for Family Medicine. Message principal L’un des aspects les plus difficiles des soins aux personnes atteintes de démence est l’évaluation de la sécurité au volant. Les conducteurs atteints de démence présentent un risque plus élevé de collisions, quoique de nombreux conducteurs dont l’atteinte est légère soient aptes à conduire pendant encore plusieurs années. Puisque l’aptitude à conduire dépend de multiples compétences cognitives et fonctionnelles, de nombreux facteurs entrent en jeu lorsque les cliniciens déterminent si les sujets de préoccupation en matière de cognition se répercutent sur l’aptitude à conduire. Les observations spécifiques tirées de l’anamnèse corroborée et des tests cognitifs effectués en cabinet pourraient aider le médecin à décider s’il doit recommander le patient à un examen pratique complet et aviser les autorités provinciales du transport, conformément aux exigences en matière de déclarations. La communication doit être axée sur le patient et menée avec tact. Conclusion Les médecins de première ligne doivent tenir compte de plusieurs facteurs lorsqu’ils déterminent si les sujets de leurs préoccupations en matière de cognition pourraient se répercuter sur l’aptitude des conducteurs âgés à prendre le volant. PMID:28115452

Integral glass encapsulation for solar arrays

NASA Technical Reports Server (NTRS)

Young, P. R.

1977-01-01

Electrostatic bonding has been used to join silicon solar cells to borosilicate glass without the aid of any organic binders or adhesives. The results of this investigation have been to demonstrate, without question, the feasibility of this process as an encapsulation technique. The potential of ESB for terrestrial solar arrays was clearly shown. The process is fast, reproducible, and produces a permanent bond between glass and silicon that is stronger than the silicon itself. Since this process is a glass sealing technique requiring no organics it makes moisture tight sealing of solar cells possible.

Preparation of actinide boride materials via solid-state metathesis reactions and actinide dicarbollide precursors

NASA Astrophysics Data System (ADS)

Lupinetti, Anthony J.; Fife, Julie; Garcia, Eduardo; Abney, Kent D.

2000-07-01

Information gaps exist in the knowledge base needed for choosing among the alternate processes to be used in the safe conversion of fissile materials to optimal forms for safe interim storage, long-term storage, and ultimate disposition. The current baseline storage technology for various wastes uses borosilicate glasses.1 The focus of this paper is the synthesis of actinide-containing ceramic materials at low and moderate temperatures (200 °C-1000 °C) using molecular and polymeric actinide borane and carborane complexes.

METHOD OF PREPARING RADIOACTIVE CESIUM SOURCES

DOEpatents

Quinby, T.C.

1963-12-17

A method of preparing a cesium-containing radiation source with physical and chemical properties suitable for high-level use is presented. Finely divided silica is suspended in a solution containing cesium, normally the fission-product isotope cesium 137. Sodium tetraphenyl boron is then added to quantitatively precipitate the cesium. The cesium-containing precipitate is converted to borosilicate glass by heating to the melting point and cooling. Up to 60 weight percent cesium, with a resulting source activity of up to 21 curies per gram, is incorporated in the glass. (AEC)

Vacuum Strength of Two Candidate Glasses for a Space Observatory

NASA Technical Reports Server (NTRS)

Manning, Timothy Andrew; Tucker, Dennis S.; Herren, Kenneth A.; Gregory, Don A.

2007-01-01

The strengths of two candidate glass types for use in a space observatory were measured. Samples of ultra-low expansion glass (ULE) and borosilicate (Pyrex) were tested in air and in vacuum at room temperature (20 degrees C) and in vacuum after being heated to 200 degrees C. Both glasses tested in vacuum showed a significant increase in strength over those tested in air. However, there was no statistical difference between the strength of samples tested in vacuum at room temperature and those tested in vacuum after heating to 200 degrees C.

Vacuum Strength of Two Candidate Glasses for a Space Observatory

NASA Technical Reports Server (NTRS)

Manning, T. a.; Tucker, D. S.; Herren, K. A.; Gregory, D. A.

2007-01-01

The strengths of two candidate glass types for use in a space observatory were measured. Samples of ultra-low expansion glass (ULE) and borosilicate (Pyrex) were tested in air and in vacuum at room temperature (20 C) and in vacuum after being heated to 200 C. Both glasses tested in vacuum showed an increase in strength over those tested in air. However, there was no statistical difference between the strength of samples tested in vacuum at room temperature and those tested in vacuum after heating to 200 C.

Low-temperature, high yield synthesis, and convenient isolation of the high-electron-density cluster compound Ta6Br14.8H2O for use in biomacromolecular crystallographic phase determination.

PubMed

Hay, Daniel N T; Messerle, Louis

2002-09-01

Reduction of TaBr(5) with Ga in the presence of KBr in a sealed borosilicate ampule at 400 degrees, followed by aqueous Soxhlet extraction and addition of stannous bromide and hydrobromic acid to the extract, yielded Ta(6)Br(14).8H(2)O in 80-84% yield. The new procedure provides a convenient, low temperature, high yield route to the synthesis of the title compound from inexpensive precursors.

Fabrication of computer-generated holograms using femtosecond laser direct writing.

PubMed

Berlich, René; Richter, Daniel; Richardson, Martin; Nolte, Stefan

2016-04-15

We demonstrate a single-step fabrication method for computer-generated holograms based on femtosecond laser direct writing. Therefore, a tightly arranged longitudinal waveguide array is directly inscribed into a transparent material. By tailoring the individual waveguide length, the phase profile of an incident laser beam can be arbitrarily adapted. The approach is verified in common borosilicate glass by inscribing a designed phase hologram, which forms the desired intensity pattern in its far field. The resulting performance is analyzed, and the potential as well as limitations of the method are discussed.

Pilot production & commercialization of LAPPD ™

DOE Office of Scientific and Technical Information (OSTI.GOV)

Minot, Michael J.; Bennis, Daniel C.; Bond, Justin L.

We present a progress update on plans to establish pilot production and commercialization of Large Area (400 cm2) Picosecond Photodetector (LAPPD™). Steps being taken to commercialize this MCP and LAPPD™ technology and begin tile pilot production are presented including (1) the manufacture of 203 mm×203 mm borosilicate glass capillary arrays (GCAs), (2) optimization of MCP performance and creation of an ALD coating facility to manufacture MCPs and (3) design, construction and commissioning of UHV tile integration and sealing facility to produce LAPPDs. Taken together these plans provide a “pathway toward commercialization”.

A memory module for experimental data handling

NASA Astrophysics Data System (ADS)

De Blois, J.

1985-02-01

A compact CAMAC memory module for experimental data handling was developed to eliminate the need of direct memory access in computer controlled measurements. When using autonomous controllers it also makes measurements more independent of the program and enlarges the available space for programs in the memory of the micro-computer. The memory module has three modes of operation: an increment-, a list- and a fifo mode. This is achieved by connecting the main parts, being: the memory (MEM), the fifo buffer (FIFO), the address buffer (BUF), two counters (AUX and ADDR) and a readout register (ROR), by an internal 24-bit databus. The time needed for databus operations is 1 μs, for measuring cycles as well as for CAMAC cycles. The FIFO provides temporary data storage during CAMAC cycles and separates the memory part from the application part. The memory is variable from 1 to 64K (24 bits) by using different types of memory chips. The application part, which forms 1/3 of the module, will be specially designed for each application and is added to the memory chian internal connector. The memory unit will be used in Mössbauer experiments and in thermal neutron scattering experiments.

Plutonium immobilization in glass and ceramics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Knecht, D.A.; Murphy, W.M.

1996-05-01

The Materials Research Society Nineteenth Annual Symposium on the Scientific Basis for Nuclear Waste Management was held in Boston on November 27 to December 1, 1995. Over 150 papers were presented at the Symposium dealing with all aspects of nuclear waste management and disposal. Fourteen oral sessions and on poster session included a Plenary session on surplus plutonium dispositioning and waste forms. The proceedings, to be published in April, 1996, will provide a highly respected, referred compilation of the state of scientific development in the field of nuclear waste management. This paper provides a brief overview of the selected Symposiummore » papers that are applicable to plutonium immobilization and plutonium waste form performance. Waste forms that were described at the Symposium cover most of the candidate Pu immobilization options under consideration, including borosilicate glass with a melting temperature of 1150 {degrees}C, a higher temperature (1450 {degrees}C) lanthanide glass, single phase ceramics, multi-phase ceramics, and multi-phase crystal-glass composites (glass-ceramics or slags). These Symposium papers selected for this overview provide the current status of the technology in these areas and give references to the relevant literature.« less

Perturbation of auxin homeostasis by overexpression of wild-type IAA15 results in impaired stem cell differentiation and gravitropism in roots.

PubMed

Yan, Da-Wei; Wang, Jing; Yuan, Ting-Ting; Hong, Li-Wei; Gao, Xiang; Lu, Ying-Tang

2013-01-01

Aux/IAAs interact with auxin response factors (ARFs) to repress their transcriptional activity in the auxin signaling pathway. Previous studies have focused on gain-of-function mutations of domain II and little is known about whether the expression level of wild-type Aux/IAAs can modulate auxin homeostasis. Here we examined the perturbation of auxin homeostasis by ectopic expression of wild-type IAA15. Root gravitropism and stem cell differentiation were also analyzed. The transgenic lines were less sensitive to exogenous auxin and exhibited low-auxin phenotypes including failures in gravity response and defects in stem cell differentiation. Overexpression lines also showed an increase in auxin concentration and reduced polar auxin transport. These results demonstrate that an alteration in the expression of wild-type IAA15 can disrupt auxin homeostasis.

Responses to auxin signals: an operating principle for dynamical sensitivity yet high resilience

PubMed Central

Bravi, B.; Martin, O. C.

2018-01-01

Plants depend on the signalling of the phytohormone auxin for their development and for responding to environmental perturbations. The associated biomolecular signalling network involves a negative feedback on Aux/IAA proteins which mediate the influence of auxin (the signal) on the auxin response factor (ARF) transcription factors (the drivers of the response). To probe the role of this feedback, we consider alternative in silico signalling networks implementing different operating principles. By a comparative analysis, we find that the presence of a negative feedback allows the system to have a far larger sensitivity in its dynamical response to auxin and that this sensitivity does not prevent the system from being highly resilient. Given this insight, we build a new biomolecular signalling model for quantitatively describing such Aux/IAA and ARF responses. PMID:29410878

BOREAS TE-6 NPP For The Tower Flux, Carbon Evaluation, and Auxiliary Sites

NASA Technical Reports Server (NTRS)

Hall, Forrest G. (Editor); Curd, Shelaine (Editor); Gower, Stith T.; Vogel, Jason G.

2000-01-01

The BOREAS TE-6 team collected several data sets to examine the influence of vegetation, climate, and their interactions on the major carbon fluxes for boreal forest species. This data set contains estimates of the biomass produced by the plant species at the TF, CEV, and AUX sites in the SSA and NSA for a given year. Temporally, the data cover the years of 1985 to 1995. The plant biomass production (i.e., aboveground, belowground, understory, litterfall), spatial coverage, and temporal nature of measurements varied between the TF, CEV, and AUX sites as deemed necessary by BOREAS principal investigators. The data are stored in tabular ASCII files. The data files are available on a CD-ROM (see document number 20010000884), or from the Oak Ridge National Laboratory (ORNL) Distrobuted Activity Archive Center (DAAC).

Contrôle du marché informel à l’heure de la mondialisation des échanges. Le cas des antirétroviraux au Chili

PubMed Central

Brousselle, Astrid; Morales, Cristián

2013-01-01

Résumé Les nouveaux médicaments pour le VIH/sida ont créé des besoins d’accessibilité aux traitements que les gouvernements n’ont pas toujours réussi à couvrir. Il en résulte l’émergence d’un marché informel des ARV. Par l’analyse de la situation au Chili, nous traitons des différents créneaux d’approvisionnement, des conséquences de l’existence d’un tel marché, ainsi que des moyens envisageables pour réduire les effets indésirables. Les aspects tant microéconomiques que macroéconomiques concernant le marché et l’accessibilité aux médicaments sont abordés. PMID:23997580

GENOME-ENABLED DISCOVERY OF CARBON SEQUESTRATION GENES IN POPLAR

DOE Office of Scientific and Technical Information (OSTI.GOV)

DAVIS J M

2007-10-11

Plants utilize carbon by partitioning the reduced carbon obtained through photosynthesis into different compartments and into different chemistries within a cell and subsequently allocating such carbon to sink tissues throughout the plant. Since the phytohormones auxin and cytokinin are known to influence sink strength in tissues such as roots (Skoog & Miller 1957, Nordstrom et al. 2004), we hypothesized that altering the expression of genes that regulate auxin-mediated (e.g., AUX/IAA or ARF transcription factors) or cytokinin-mediated (e.g., RR transcription factors) control of root growth and development would impact carbon allocation and partitioning belowground (Fig. 1 - Renewal Proposal). Specifically, themore » ARF, AUX/IAA and RR transcription factor gene families mediate the effects of the growth regulators auxin and cytokinin on cell expansion, cell division and differentiation into root primordia. Invertases (IVR), whose transcript abundance is enhanced by both auxin and cytokinin, are critical components of carbon movement and therefore of carbon allocation. Thus, we initiated comparative genomic studies to identify the AUX/IAA, ARF, RR and IVR gene families in the Populus genome that could impact carbon allocation and partitioning. Bioinformatics searches using Arabidopsis gene sequences as queries identified regions with high degrees of sequence similarities in the Populus genome. These Populus sequences formed the basis of our transgenic experiments. Transgenic modification of gene expression involving members of these gene families was hypothesized to have profound effects on carbon allocation and partitioning.« less

Bruit généré par un écoulement turbulent affleurant une cavité à faible nombre de Mach : application aux césures de portes automobiles

NASA Astrophysics Data System (ADS)

Da Silva, Arthur; Kribèche, Ali; Loredo, Alexandre

2009-02-01

Noise produced by turbulent grazing flow over a generic cavity representing car door cavities was measured in a semi-anechoic wind tunnel. Two cavities were studied: one 50 mm large (dimension perpendicular to the airflow), functioning as a Helmholtz resonator, reaching sound pressure levels of 136 dB at 1776 Hz, for a downstream velocity of 54 m/s. The other, of scale 250 mm could not be regarded as a Helmholtz resonator although resonance occurred at 1902 Hz, at a level of 125 dB, for the same velocity. In both cases, noise was caused by Kelvin-Helmholtz instabilities in the mixing layer. To cite this article: A. Da Silva et al., C. R. Mecanique 337 (2009).

Understanding of the mechanical and structural changes induced by alpha particles and heavy ions in the French simulated nuclear waste glass

NASA Astrophysics Data System (ADS)

Karakurt, G.; Abdelouas, A.; Guin, J.-P.; Nivard, M.; Sauvage, T.; Paris, M.; Bardeau, J.-F.

2016-07-01

Borosilicate glasses are considered for the long-term confinement of high-level nuclear wastes. External irradiations with 1 MeV He+ ions and 7 MeV Au5+ ions were performed to simulate effects produced by alpha particles and by recoil nuclei in the simulated SON68 nuclear waste glass. To better understand the structural modifications, irradiations were also carried out on a 6-oxides borosilicate glass, a simplified version of the SON68 glass (ISG glass). The mechanical and macroscopic properties of the glasses were studied as function of the deposited electronic and nuclear energies. Alpha particles and gold ions induced a volume change up to -0.7% and -2.7%, respectively, depending on the glass composition. Nano-indentations tests were used to determine the mechanical properties of the irradiated glasses. A decrease of about -22% to -38% of the hardness and a decrease of the reduced Young's modulus by -8% were measured after irradiations. The evolution of the glass structure was studied by Raman spectroscopy, and also 11B and 27Al Nuclear Magnetic Resonance (MAS-NMR) on a 20 MeV Kr irradiated ISG glass powder. A decrease of the silica network connectivity after irradiation with alpha particles and gold ions is deduced from the structural changes observations. NMR spectra revealed a partial conversion of BO4 to BO3 units but also a formation of AlO5 and AlO6 species after irradiation with Kr ions. The relationships between the mechanical and structural changes are also discussed.

Effective atomic numbers and electron densities of some human tissues and dosimetric materials for mean energies of various radiation sources relevant to radiotherapy and medical applications

NASA Astrophysics Data System (ADS)

Kurudirek, Murat

2014-09-01

Effective atomic numbers, Zeff, and electron densities, neff, are convenient parameters used to characterise the radiation response of a multi-element material in many technical and medical applications. Accurate values of these physical parameters provide essential data in medical physics. In the present study, the effective atomic numbers and electron densities have been calculated for some human tissues and dosimetric materials such as Adipose Tissue (ICRU-44), Bone Cortical (ICRU-44), Brain Grey/White Matter (ICRU-44), Breast Tissue (ICRU-44), Lung Tissue (ICRU-44), Soft Tissue (ICRU-44), LiF TLD-100H, TLD-100, Water, Borosilicate Glass, PAG (Gel Dosimeter), Fricke (Gel Dosimeter) and OSL (Aluminium Oxide) using mean photon energies, Em, of various radiation sources. The used radiation sources are Pd-103, Tc-99, Ra-226, I-131, Ir-192, Co-60, 30 kVp, 40 kVp, 50 kVp (Intrabeam, Carl Zeiss Meditec) and 6 MV (Mohan-6 MV) sources. The Em values were then used to calculate Zeff and neff of the tissues and dosimetric materials for various radiation sources. Different calculation methods for Zeff such as the direct method, the interpolation method and Auto-Zeff computer program were used and agreements and disagreements between the used methods have been presented and discussed. It has been observed that at higher Em values agreement is quite satisfactory (Dif.<5%) between the adopted methods.

Mechanical behavior of a ceramic matrix composite material. M.S. Thesis Final Report

NASA Technical Reports Server (NTRS)

Grosskopf, Paul P.; Duke, John C., Jr.

1991-01-01

Monolithic ceramic materials have been used in industry for hundreds of years. These materials have proven their usefulness in many applications, yet, their potential for critical structural applications is limited. The existence of an imperfection in a monolithic ceramic on the order of several microns in size may be critical, resulting in catastrophic failure. To overcome this extreme sensitivity to small material imperfections, reinforced ceramic materials were developed. A ceramic matrix which has been reinforced with continuous fibers is not only less sensitive to microscopic flaws, but is also able to sustain significant damage without suffering catastrophic failure. A borosilicate glass reinforced with several layers of plain weave silicon carbide cloth (Nicalon) was studied. The mechanical testing which was performed included both flexural and tensile loading configurations. This testing was done not only to determine the material properties, but also to initiate a controlled amount of damage within each specimen. Several nondestructive testing techniques, including acousto-ultrasonics (AU), were performed on the specimens periodically during testing. The AU signals were monitored through the use of an IBM compatible personal computer with a high speed data acquisition board. Software was written which manipulates the AU signals in both the time and frequency domains, resulting in quantitative measures of the mechanical response of the material. The measured AU parameters are compared to both the mechanical test results and data from other nondestructive methods including ultrasonic C-scans and penetrant enhanced x ray radiography.

Slopes To Prevent Trapping of Bubbles in Microfluidic Channels

NASA Technical Reports Server (NTRS)

Greer, Harold E.; Lee, Michael C.; Smith, J. Anthony; Willis, Peter A.

2010-01-01

The idea of designing a microfluidic channel to slope upward along the direction of flow of the liquid in the channel has been conceived to help prevent trapping of gas bubbles in the channel. In the original application that gave rise to this idea, the microfluidic channels are parts of micro-capillary electrophoresis (microCE) devices undergoing development for use on Mars in detecting compounds indicative of life. It is necessary to prevent trapping of gas bubbles in these devices because uninterrupted liquid pathways are essential for sustaining the electrical conduction and flows that are essential for CE. The idea is also applicable to microfluidic devices that may be developed for similar terrestrial microCE biotechnological applications or other terrestrial applications in which trapping of bubbles in microfluidic channels cannot be tolerated. A typical microCE device in the original application includes, among other things, multiple layers of borosilicate float glass wafers. Microfluidic channels are formed in the wafers, typically by use of wet chemical etching. The figure presents a simplified cross section of part of such a device in which the CE channel is formed in the lowermost wafer (denoted the channel wafer) and, according to the present innovation, slopes upward into a via hole in another wafer (denoted the manifold wafer) lying immediately above the channel wafer. Another feature of the present innovation is that the via hole in the manifold wafer is made to taper to a wider opening at the top to further reduce the tendency to trap bubbles. At the time of reporting the information for this article, an effort to identify an optimum technique for forming the slope and the taper was in progress. Of the techniques considered thus far, the one considered to be most promising is precision milling by use of femtosecond laser pulses. Other similar techniques that may work equally well are precision milling using a focused ion beam, or a small diamond-tipped drill bit.

Prise en charge en cabinet des lésions cérébrales traumatiques légères chez les enfants et les adolescents

PubMed Central

Garcia-Rodriguez, Juan Antonio; Thomas, Roger E.

2014-01-01

Résumé Objectif Fournir aux médecins de famille de l’information à jour, pratique et factuelle sur les lésions cérébrales traumatiques légères et les commotions cérébrales dans la population pédiatrique. Sources d’information Une recherche a été effectuée dans MEDLINE (de 1950 à février 2013), la base de données des revues systématiques Cochrane (de 2005 à 2013), le registre central Cochrane des essais contrôlés (de 2005 à 2013) et DARE (2005 à 2013) à l’aide de mots-clés liés aux commotions cérébrales et aux traumatismes crâniens. Des lignes directrices, énoncés de position, articles et rapports de recherche originaux pertinents aux lésions cérébrales traumatiques légères ont été sélectionnés. Message principal Le traumatisme est la cause principale de décès chez les enfants de plus d’un an et, dans ce groupe, le traumatisme crânien est la cause la plus fréquente d’incapacité et de décès. Neuf pour cent des blessures sportives rapportées chez les élèves du secondaire sont associées à une lésion cérébrale traumatique légère. Les médecins de famille doivent effectuer une anamnèse ciblée et un examen physique et neurologique, utiliser les instruments d’évaluation standardisés (Échelle de Glasgow; Outil d’évaluation des commotions cérébrales dans le sport, version 3; version pédiatrique de l’Outil d’évaluation des commotions cérébrales dans le sport; et échelle BESS [Balance Error Scoring System]), expliquer aux parents comment surveiller leurs enfants, décider des circonstances où les soignants ne sont pas une ressource dûment responsable, faire un suivi prompt auprès des patients, guider le retour sécuritaire au jeu ou à l’école et décider dans quelles circonstances un test neuropsychologique est nécessaire au suivi à long terme. Conclusion La prise en charge par le médecin de famille des lésions cérébrales traumatiques légères chez les enfants repose sur une anamnèse détaillée, un examen physique et neurologique, le recours à des instruments validés qui fourniront un cadre objectif et des suivis périodiques.

Soins primaires aux adultes ayant une déficience développementale

PubMed Central

Sullivan, William F.; Berg, Joseph M.; Bradley, Elspeth; Cheetham, Tom; Denton, Richard; Heng, John; Hennen, Brian; Joyce, David; Kelly, Maureen; Korossy, Marika; Lunsky, Yona; McMillan, Shirley

2011-01-01

Résumé Objectif Mettre à jour les lignes directrices canadiennes de 2006 sur les soins primaires aux adultes ayant une déficience développementale (DD) et présenter des recommandations pratiques fondées sur les connaissances actuelles pour traiter des problèmes de santé particuliers chez des adultes ayant une DD. Qualité des preuves Des professionnels de la santé expérimentés participant à un colloque et un groupe de travail subséquent ont discuté et convenu des révisions aux lignes directrices de 2006 en se fondant sur une recherche documentaire exhaustive, la rétroaction obtenue des utilisateurs du guide de pratique et les expériences cliniques personnelles. La plupart des preuves disponibles dans ce domaine viennent de l’opinion d’experts ou de déclarations consensuelles publiées (niveau III). Message principal Les adultes ayant une DD ont des problèmes de santé complexes, dont plusieurs diffèrent de ceux de la population en général. De bons soins primaires permettent d’identifier les problèmes de santé particuliers dont souffrent les adultes ayant une DD pour améliorer leur qualité de vie et leur accès aux soins de santé et prévenir la morbidité et le décès prématuré. Ces lignes directrices résument les problèmes de santé générale, physique, comportementale et mentale des adultes ayant une DD que devraient connaître les professionnels des soins primaires et présentent des recommandations pour le dépistage et la prise en charge en se basant sur les connaissances actuelles que les cliniciens peuvent mettre en pratique. En raison de l’interaction des facteurs biologiques, psychoaffectifs et sociaux qui contribuent à la santé et au bien-être des adultes ayant une DD, ces lignes directrices insistent sur la participation des aidants, l’adaptation des interventions, au besoin, et la consultation auprès de divers professionnels de la santé quand ils sont accessibles. Elles mettent aussi en évidence la nature éthique des soins. Les lignes directrices sont formulées dans le contexte d’un cadre éthique qui tient compte des questions comme le consentement éclairé et l’évaluation des bienfaits pour la santé par rapport aux risques de préjudice. Conclusion La mise en œuvre des lignes directrices proposées ici améliorerait la santé des adultes ayant une DD et minimiserait les disparités sur les plans de la santé et des soins de santé entre les adultes ayant une DD et la population en général.

Electromagnetics and Electrothermal Approach to Evaluate Failures in Microelectronic Devices Caused by Electrostatic Discharges: Stochastical Aspects of the Device Reliability.

DTIC Science & Technology

1987-08-01

C C CALL THE ELSV SUBROUTINE TO INVERT THE MATRIX. EPO .1D-09 . CALL ELSV(Z,AUX1,AUX2,tN, DE ,EP) WRITE(93,118) DE 118 FORMAT(5X,’ DE -,1E) C C MULTIPLY...IFCABS(W).LT.EP)GO TO 17 DO 13 I=1,N Y’=A( I,K)/W DO 13 J=1,N 13 AC I,J)=A(I,J)-B(J)*Y DE =O.DO DO.15 J=1,N B(J)0O.DO DO 16 I=1,N 16 B(J)=B(J)+A(I,J...15 DE - DE +C(J)*B(J) RETURN 1. DE -1.DO RETURN -18- IMPLICIT COMPLEX*16 (C) IMPLICIT REAL*8 (A-B,E-H,P-z) C C C THIS PROGRAM GIVES THE POTENTIAL AND THE

BOREAS TE-10 Leaf Optical Properties

NASA Technical Reports Server (NTRS)

Hall, Forrest G. (Editor); Papagno, Andrea (Editor); Chan, Stephen S.; Middleton, Elizabeth

2000-01-01

The Boreal Ecosystem-Atmospheric Study (BOREAS) TE-10 (Terrestrial Ecology) team collected several data sets in support of its efforts to characterize and interpret information on the reflectance, transmittance, gas exchange, oxygen evolution, and biochemical properties of boreal vegetation. This data set describes the spectral optical properties (reflectance and transmittance) of boreal forest conifers and broadleaf tree leaves as measured with a Spectron Engineering SE590 spectroradiometer at the Southern Study Area Old Black Spruce (SSA OBS), Old Jack Pine (OJP), Young Jack Pine (YJP), Old Aspen (OA), Old Aspen Auxiliary (OA-AUX), Young Aspen Auxiliary (YA-AUX), and Young Aspen (YA) sites. The data were collected during the growing seasons of 1994 and 1996 and are stored in tabular ASCII files. The data files are available on a CD-ROM (see document number 20010000884), or from the Oak Ridge National Laboratory (ORNL) Distributed Active Archive Center (DAAC).

Neutron Radiation Affects the Expression of Genes Involved in the Response to Auxin, Senescence and Oxidative Stress in Arabidopsis

NASA Astrophysics Data System (ADS)

Fortunati, A.; Tassone, P.; Migliaccio, F.

2008-06-01

Researches were conducted on the effect of neutron radiation on the expression of genes auxin activated or connected with the process of senescence in Arabidopsis plants. The research was done by applying the real-time polymerase chain reaction (PCR) technique. The results indicated that the auxin response factors (ARFs) genes are clearly downregulated, whereas the indolacetic acid-induced (Aux/IAAs) genes in some cases were upregulated. By contrast in the mutants for auxin transport aux1 and eir1 the ARFs genes were upregulated. In addition, both in the wildtype and mutants, some already known genes activated by stress and senescence were significantly upregulated. On the basis of these researches we conclude that the process of senescence induced by irradiation is, at least in part, controlled by the physiology of the hormone auxin.

Betons durables a base de cendres d'ecorces de riz

NASA Astrophysics Data System (ADS)

Wilson, William

De nos jours, le développement durable est devenu une nécessité dans l'ensemble des sphères d'activité de notre monde, et particulièrement dans le domaine du béton. En effet, le développement des sociétés passe inévitablement par l'augmentation des infrastructures; le béton est le matériau principalement utilisé et son empreinte environnementale considérable gagnerait à être diminuée. L'industrie et la recherche sont très actives à ce niveau et la science des bétons durables est en pleine expansion. Dans ce contexte, une piste de solution est l'utilisation de résidus industriels ou agricoles comme ajouts cimentaires, ce qui permet de remplacer partiellement le ciment très polluant, tout en produisant des bétons avec une meilleure durabilité. Les cendres d'écorce de riz (RHA) présentent ainsi un potentiel cimentaire similaire aux meilleurs ajouts cimentaires actuellement utilisés, mais les applications concrètes de ce nouveau matériau demeurent peu développées à ce jour. Le présent projet a donc été conçu afin d'illustrer le potentiel des RHA d'une part dans les pays industrialisés pour améliorer la durabilité des bétons hautes performances (BHP) et pour améliorer les propriétés à l'état frais des bétons autoplaçants (BAP); et d'autre part, dans les pays en développement pour démocratiser les bétons durables produits avec des technologies adaptées aux réalités locales. Une première phase réalisée avec des RHA de haute qualité (RHAI) a ainsi été consacrée aux applications en pays industrialisés. La caractérisation des RHAI a indiqué une composition de 90% de silice amorphe, des particules légèrement plus grossières que le ciment, et une microstructure très poreuse et absorbante. Afin de pallier à cette absorption d'eau, l'optimisation du type de superplastifiant a permis de déterminer que l'utilisation du Plastol 5000 ou de l'Adva 405 avec les RHAI favorise un équilibre optimal entre dispersion initiale, rétention d'affaissement et résistances mécaniques. L'optimisation du dosage en RHAI a démontré que 10 ou 15% en remplacement du ciment améliore significativement la durabilité, que les résistances mécaniques sont peu affectées par le dosage en RHAI, et que 20% (ou plus) de RHAI entraîne des problèmes de maniabilité associés à une consistance rhéo-épaississante. Suite à ces optimisations, le bon potentiel des RHAI pour améliorer la durabilité des BHP a été déterminé en comparaison avec la fumée de silice (FS) et le métakaolin : le retrait endogène a été diminué par un effet de cure interne, les perméabilités aux chlorures ont été diminuées au même niveau que par la FS, et la résistance à l'écaillage a été améliorée possiblement par diminution du ressuage de surface. Finalement, l'augmentation de la viscosité par les RHAI a été utilisée avantageusement dans les BAP où un dosage de 10% a permis d'éviter la ségrégation sans utiliser d'adjuvant modificateur de viscosité très coûteux. Une deuxième phase a consisté à optimiser l'utilisation sur bétons de RHA produites avec un four à écorces de riz artisanal fabriqué selon un modèle actuellement utilisé au Burkina Faso (RHAG). Ces RHAG ont été broyées à la même granulométrie que les RHAI et des performances mécaniques similaires ont été obtenues. Une méthode de caractérisation simplifiée adaptée aux réalités du terrain a aussi été développée : elle permet d'optimiser le broyage en limitant les outils nécessaires à un tamis de 45 tm et à une balance. Un béton pour dalle a par la suite été développé à partir d'une recette typique de béton du Burkina Faso : ce béton avec RHAG a développé des résistances similaires à un contrôle, tout en permettant des économies de 23% sur le ciment. En conclusion, ce projet a réussi à illustrer le potentiel des RHA pour favoriser le développement durable dans différents types de bétons, dans différents contextes et avec des méthodes adaptées aux technologies disponibles. Suite à ce bref résumé, je vous invite fortement à poursuivre votre lecture pour en apprendre encore davantage. Mots-clés : Béton durable, matériaux cimentaires, ajouts cimentaires alternatifs, cendres d'écorces de riz (RHA/Rice Husk Ash), caractérisation, performances mécaniques, durabilité.

Precipitate hydrolysis process for the removal of organic compounds from nuclear waste slurries

DOEpatents

Doherty, Joseph P.; Marek, James C.

1989-01-01

A process for removing organic compounds from a nuclear waste slurry comprising reacting a mixture of radioactive waste precipitate slurry and an acid in the presence of a catalytically effective amount of a copper (II) catalyst whereby the organic compounds in the precipitate slurry are hydrolyzed to form volatile organic compounds which are separated from the reacting mixture. The resulting waste slurry, containing less than 10 percent of the orginal organic compounds, is subsequently blended with high level radioactive sludge and transferred to a virtrification facility for processing into borosilicate glass for long-term storage.

Vitrification of waste

DOEpatents

Wicks, G.G.

1999-04-06

A method is described for encapsulating and immobilizing waste for disposal. Waste, preferably, biologically, chemically and radioactively hazardous, and especially electronic wastes, such as circuit boards, are placed in a crucible and heated by microwaves to a temperature in the range of approximately 300 C to 800 C to incinerate organic materials, then heated further to a temperature in the range of approximately 1100 C to 1400 C at which temperature glass formers present in the waste will cause it to vitrify. Glass formers, such as borosilicate glass, quartz or fiberglass can be added at the start of the process to increase the silicate concentration sufficiently for vitrification.

Study of physical properties of strontium based alumino-borosilicate glasses

NASA Astrophysics Data System (ADS)

Kaur, Mandeep; Kaur, Gurbinder; Kumar, V.

2018-05-01

In the present study, an attempt has been made to study the influence of CaO/Mgo ratio (R) on different physical properties of (10+x)CaO-(10-x)-MgO-10SrO-10B2O3-20Al2O3-40SiO2 glasses. The novel glass series has been synthesized by melt quenching technique. The parameters like reflection loss and dielectric constant have been determined. Also, molar refraction, molar electronic polarizability and oxygen packing density have been calculated on the basis of measured values of density, molar volume and refractive index of the glasses.

Dynamic Ring-on-Ring Equibiaxial Flexural Strength of Borosilicate Glass

DTIC Science & Technology

2010-01-01

Flexure Strength and Dynamic Fatigue of Soda – Lime – Silica Float Glass ,’’ J. Am. Ceram. Soc., 85 [7] 1777–1782 (2002). 9. A. Borger, R. Danzer, and P...on the Strength and Fatigue Behavior of Indented Soda – Lime Glass ,’’ Glass Technol., 32 [2] 51– 54 (1991). 16. J. J. Jr. Mecholsky, S. W. Freiman, and... Soda – Lime Glass Rods by a Statistical Approach,’’ J. Eur. Ceram. Soc., 11 341–346 (1993). 28. S. R. Choi and J. A. Salem, ‘‘Ultra-fast Fracture

Effect of Loading Rates and Surface Conditions on the Flexural Strength of Borosilicate Glass

DTIC Science & Technology

2009-01-01

strength of etched soda - lime glass rods.32 According to this model, an idealized surface crack is uniformly attacked by acid at every point so that this...R. Lin, ‘‘Effect of Polymer Coatings on the Strength and Fatigue Behavior of Indented Soda - Lime Glass ,’’ Glass Technol., 32 [2] 51–4 (1991). 10J. J...Scott Glaesemann, K. Jakus, and J. E. Ritter Jr., ‘‘Strength Variability of Indented Soda - Lime Glass ,’’ J. Am. Ceram. Soc., 70 [6] 441–4 (1987). 12C

New techniques for fusion bonding and replication for large glass reflectors

NASA Technical Reports Server (NTRS)

Angel, J. R. P.

1983-01-01

Lightweight, space-deployable glass honeycomb telescope primary mirror structures are produced by a novel method which involves the heating to softening temperature of many borosilicate or silica glass tube sections that are packed to form a honeycomb matrix and filled with a high expansion coefficient refractory sand. The close packed tubes yield a hexagonal-cell honeycomb. Attention is given to the results of an experiment in which a highly refractory master was used to shape a honeycomb of less refractory glass, employing a 1-micron thick, vacuum-deposited gold coating as a parting layer between the two.

Reference commercial high-level waste glass and canister definition

NASA Astrophysics Data System (ADS)

Slate, S. C.; Ross, W. A.; Partain, W. L.

1981-09-01

Technical data and performance characteristics of a high level waste glass and canister intended for use in the design of a complete waste encapsulation package suitable for disposal in a geologic repository are presented. The borosilicate glass contained in the stainless steel canister represents the probable type of high level waste product that is produced in a commercial nuclear-fuel reprocessing plant. Development history is summarized for high level liquid waste compositions, waste glass composition and characteristics, and canister design. The decay histories of the fission products and actinides (plus daughters) calculated by the ORIGEN-II code are presented.

Magnetic field effects on shear and normal stresses in magnetorheological finishing.

PubMed

Lambropoulos, John C; Miao, Chunlin; Jacobs, Stephen D

2010-09-13

We use a recent experimental technique to measure in situ shear and normal stresses during magnetorheological finishing (MRF) of a borosilicate glass over a range of magnetic fields. At low fields shear stresses increase with magnetic field, but become field-independent at higher magnetic fields. Micromechanical models of formation of magnetic particle chains suggest a complex behavior of magnetorheological (MR) fluids that combines fluid- and solid-like responses. We discuss the hypothesis that, at higher fields, slip occurs between magnetic particle chains and the immersed glass part, while the normal stress is governed by the MRF ribbon elasticity.

Study of CdTe quantum dots grown using a two-step annealing method

NASA Astrophysics Data System (ADS)

Sharma, Kriti; Pandey, Praveen K.; Nagpal, Swati; Bhatnagar, P. K.; Mathur, P. C.

2006-02-01

High size dispersion, large average radius of quantum dot and low-volume ratio has been a major hurdle in the development of quantum dot based devices. In the present paper, we have grown CdTe quantum dots in a borosilicate glass matrix using a two-step annealing method. Results of optical characterization and the theoretical model of absorption spectra have shown that quantum dots grown using two-step annealing have lower average radius, lesser size dispersion, higher volume ratio and higher decrease in bulk free energy as compared to quantum dots grown conventionally.

Humidity-Induced Charge Leakage and Field Attenuation in Electric Field Microsensors

PubMed Central

Zhang, Haiyan; Fang, Dongming; Yang, Pengfei; Peng, Chunrong; Wen, Xiaolong; Xia, Shanhong

2012-01-01

The steady-state zero output of static electric field measuring systems often fluctuates, which is caused mainly by the finite leakage resistance of the water film on the surface of the electric field microsensor package. The water adsorption has been calculated using the Boltzmann distribution equation at various relative humidities for borosilicate glass and polytetrafluoroethylene surfaces. At various humidities, water film thickness has been calculated, and the induced charge leakage and field attenuation have been theoretically investigated. Experiments have been performed with microsensors to verify the theoretical predictions and the results are in good agreement. PMID:22666077

Enhancing Patient Safety through the Use of a Pharmaceutical Glass Designed To Prevent Cracked Containers.

PubMed

Schaut, Robert A; Hoff, Kyle C; Demartino, Steven E; Denson, William K; Verkleeren, Ronald L

2017-01-01

An essential role of packaging material for the storage and delivery of drug products is to provide adequate protection against contamination and loss of sterility. This is especially important for parenteral containers, as lack of sterility or contamination can result in serious adverse events including death. Nonetheless, cracked parenteral containers are an important source of container integrity failures for injectable drugs and pose a serious risk for patients. Despite significant investments in inspection technology, each year many injectable drugs are investigated and recalled for sterility risks associated with cracked borosilicate containers. Multiple studies and the many difficulties in detection of cracked containers suggest that the magnitude of the public health risk is even larger than the recall rate would suggest. Here we show that the root cause of cracked parenteral containers (low internal energy following annealing) is inherent to the glasses currently used for primary packaging of the majority of injectable drugs. We also describe a strengthened aluminosilicate glass that has been designed to prevent cracks in parenteral containers through the use of an engineered stress profile in the glass. Laboratory tests that simulate common filling line damage events show that the strengthened aluminosilicate glass is highly effective at preventing cracks. Significant safety benefits have been demonstrated in other industries from the use of special stress profiles in glass components to mitigate failure modes that may result in harm to humans. Those examples combined with the results described here suggest that a significant improvement in patient safety can be achieved through the use of strengthened aluminosilicate glass for parenteral containers. LAY ABSTRACT: Cracks are small cuts or gaps in a container which provide a pathway for liquid, gas, or microbes through a glass container. When these defects are introduced to conventional glass containers holding injectable medicines, the affected drug can pose serious risks to the patient receiving that medication. Specifically, the drug product may become less effective or even non-sterile, which could lead to bloodstream infections and, in some cases, death. This article presents a review of some previously documented cases of cracked glass containers that led to patient infections and deaths. Following a survey of common crack locations in glass vials, lab-based methods for replicating these cracks are presented. These methods are then used to compare the fracture response of vials made from conventional borosilicate glass and strengthened aluminosilicate glass. The results show that stable cracks are essentially prevented (at least 31 times less likely to occur) in the strengthened aluminosilicate glass containers (relative to conventional borosilicate glass). This improvement in safety is similar to improvements already engineered into other glass product designs by utilizing stored strain energy to mitigate certain failure modes. © PDA, Inc. 2017.

Glasses for immobilization of low- and intermediate-level radioactive waste

NASA Astrophysics Data System (ADS)

Laverov, N. P.; Omel'yanenko, B. I.; Yudintsev, S. V.; Stefanovsky, S. V.; Nikonov, B. S.

2013-03-01

Reprocessing of spent nuclear fuel (SNF) for recovery of fissionable elements is a precondition of long-term development of nuclear energetics. Solution of this problem is hindered by the production of a great amount of liquid waste; 99% of its volume is low- and intermediate-level radioactive waste (LILW). The volume of high-level radioactive waste (HLW), which is characterized by high heat release, does not exceed a fraction of a percent. Solubility of glasses at an elevated temperature makes them unfit for immobilization of HLW, the insulation of which is ensured only by mineral-like matrices. At the same time, glasses are a perfect matrix for LILW, which are distinguished by low heat release. The solubility of borosilicate glass at a low temperature is so low that even a glass with relatively low resistance enables them to retain safety of under-ground LILW depositories without additional engineering barriers. The optimal technology of liquid confinement is their concentration and immobilization in borosilicate glasses, which are disposed in shallow-seated geological repositories. The vitrification of 1 m3 liquid LILW with a salt concentration of ˜300 kg/m3 leaves behind only 0.2 m3 waste, that is, 4-6 times less than by bitumen impregnation and 10 times less than by cementation. Environmental and economic advantages of LILW vitrification result from (1) low solubility of the vitrified LILW in natural water; (2) significant reduction of LILW volume; (3) possibility to dispose the vitrified waste without additional engineering barriers under shallow conditions and in diverse geological media; (4) the strength of glass makes its transportation and storage possible; and finally (5) reliable longterm safety of repositories. When the composition of the glass matrix for LILW is being chosen, attention should be paid to the factors that ensure high technological and economic efficiency of vitrification. The study of vitrified LILW from the Kursk nuclear power plant with high-power channel reactors (HPCR; equivalent Russian acronym, RBMK) and the Kalinin nuclear power plant with pressurized water reactors (PWR; equivalent Russian acronym VVER) after their 14-yr storage in the shallow-seated repository at the MosNPO Radon testing ground has confirmed the safety of repositories ensured by confinement properties of borosilicate matrix. The most efficient vitrification technology is based on cold crucible induction melting. If the content of a chemical element in waste exceeds its solubility in glass, a crystalline phase is formed in the course of vitrification, so that the glass ceramics become a matrix for such waste. Vitrified waste with high Fe; Na and Al; Na, Fe, and Al; Na and B is characterized. The composition of frit and its proportion to waste depends on waste composition. This procedure requires careful laboratory testing.

Comprehensive Analysis of the Soybean (Glycine max) GmLAX Auxin Transporter Gene Family

PubMed Central

Chai, Chenglin; Wang, Yongqin; Valliyodan, Babu; Nguyen, Henry T.

2016-01-01

The phytohormone auxin plays a critical role in regulation of plant growth and development as well as plant responses to abiotic stresses. This is mainly achieved through its uneven distribution in plant via a polar auxin transport process. Auxin transporters are major players in polar auxin transport. The AUXIN RESISTENT 1/LIKE AUX1 (AUX/LAX) auxin influx carriers belong to the amino acid permease family of proton-driven transporters and function in the uptake of indole-3-acetic acid (IAA). In this study, genome-wide comprehensive analysis of the soybean AUX/LAX (GmLAX) gene family, including phylogenic relationships, chromosome localization, and gene structure, was carried out. A total of 15 GmLAX genes, including seven duplicated gene pairs, were identified in the soybean genome. They were distributed on 10 chromosomes. Despite their higher percentage identities at the protein level, GmLAXs exhibited versatile tissue-specific expression patterns, indicating coordinated functioning during plant growth and development. Most GmLAXs were responsive to drought and dehydration stresses and auxin and abscisic acid (ABA) stimuli, in a tissue- and/or time point- sensitive mode. Several GmLAX members were involved in responding to salt stress. Sequence analysis revealed that promoters of GmLAXs contained different combinations of stress-related cis-regulatory elements. These studies suggest that the soybean GmLAXs were under control of a very complex regulatory network, responding to various internal and external signals. This study helps to identity candidate GmLAXs for further analysis of their roles in soybean development and adaption to adverse environments. PMID:27014306

Distribution of enteric bacteria in Antarctic seawater surrounding the Port-aux-Français permanent station (Kerguelen Island).

PubMed

Delille, D; Gleizon, F

2003-09-01

Untreated sewage has been released from Port-aux Français station, Kerguelen Island, into the Southern Ocean for more than 50 years. We investigated the spatial distribution of faecal bacteria indicators during a one-year survey conducted in seawater off Morbihan Bay near the French permanent station of the Kerguelen Island (49 degrees 21(')S, 70 degrees 30(')E). Seawater samples were taken bimonthly from nine stations evenly distributed around the sewage outfalls of the station. Escherichia coli and enterococci were estimated using specific microplates (Miniaturized method for the enumeration of E. coli or enterococci in surface and waste waters, "MU/EC or MU/SF methods", BIO-RAD( Copyright)). In order to evaluate the role of seasonal changes of environmental parameters on the survival of enteric bacteria, total and saprophytic bacterial abundances were also estimated in all seawater samples. High densities of faecal bacteria (maximum 10(4) cells 100 ml(-1)) were found in seawater surrounding the sewage outfall. However, enteric bacterial counts decreased rapidly with increasing distance from the outfall. In all samples collected further than 2 km from the outfall, the bacterial indicators were absent or present in small numbers (<10 cells 100 ml(-1)). Faecal coliforms were not detected in samples collected at pristine sites located 10 km from Port-aux-Français. Despite these low contamination levels, faecal bacteria were always detected in the vicinity of the sewage outfall during the seasonal survey. The concentration of faecal bacteria may be related to the number of people inhabiting the station.

Maladies reliées aux loisirs aquatiques

PubMed Central

Sanborn, Margaret; Takaro, Tim

2013-01-01

Résumé Objectif Passer en revue les facteurs de risque, la prise en charge et la prévention des maladies reliées aux loisirs aquatiques en pratique familiale. Sources des données Des articles originaux et de synthèse entre janvier 1998 et février 2012 ont été identifiés à l’aide de PubMed et des expressions de recherche en anglais water-related illness, recreational water illness et swimmer illness. Message principal Il y a un risque de 3 % à 8 % de maladies gastrointestinales (MGI) après la baignade. Les groupes à risque élevé de MGI sont les enfants de moins de 5 ans, surtout s’ils n’ont pas été vaccinés contre le rotavirus, les personnes âgées et les patients immunodéficients. Les enfants sont à plus grand risque parce qu’ils avalent plus d’eau quand ils nagent, restent dans l’eau plus longtemps et jouent dans l’eau peu profonde et le sable qui sont plus contaminés. Les adeptes des sports dans lesquels le contact avec l’eau est abondant comme le triathlon et le surf cerf-volant sont aussi à risque élevé et même ceux qui s’adonnent à des activités impliquant un contact partiel avec l’eau comme la navigation de plaisance et la pêche ont un risque de 40 % à 50 % fois plus grand de MGI par rapport à ceux qui ne pratiquent pas de sports aquatiques. Il y a lieu de faire une culture des selles quand on soupçonne une maladie reliée aux loisirs aquatiques et l’échelle clinique de la déshydratation est utile pour l’évaluation des besoins de traitement chez les enfants affectés. Conclusion Les maladies reliées aux loisirs aquatiques est la principale cause de MGI durant la saison des baignades. La reconnaissance que la baignade est une source importante de maladies peut aider à prévenir les cas récurrents et secondaires. On recommande fortement le vaccin contre le rotavirus chez les enfants qui se baignent souvent.

Insuffisance cervicale et cerclage cervical.

PubMed

Brown, Richard; Gagnon, Robert; Delisle, Marie-France

2016-12-01

La présente directive clinique a pour but de fournir un cadre de référence que les cliniciens pourront utiliser pour identifier les femmes qui sont exposées aux plus grands risques de connaître une insuffisance cervicale, ainsi que pour déterminer les circonstances en présence desquelles la mise en place d'un cerclage pourrait s'avérer souhaitable. RéSULTATS: La littérature publiée a été récupérée par l'intermédiaire de recherches menées dans PubMed ou MEDLINE, CINAHL et The Cochrane Library en 2012 au moyen d'un vocabulaire contrôlé (p. ex. « uterine cervical incompetence ») et de mots clés appropriés (p. ex. « cervical insufficiency », « cerclage », « Shirodkar », « cerclage », « MacDonald », « cerclage », « abdominal », « cervical length », « mid-trimester pregnancy loss »). Les résultats ont été restreints aux analyses systématiques, aux essais comparatifs randomisés / essais cliniques comparatifs et aux études observationnelles. Aucune restriction n'a été appliquée en matière de date ou de langue. Les recherches ont été mises à jour de façon régulière et intégrées à la directive clinique jusqu'en janvier 2011. La littérature grise (non publiée) a été identifiée par l'intermédiaire de recherches menées dans les sites Web d'organismes s'intéressant à l'évaluation des technologies dans le domaine de la santé et d'organismes connexes, dans des collections de directives cliniques, dans des registres d'essais cliniques et auprès de sociétés de spécialité médicale nationales et internationales. La qualité des résultats est évaluée au moyen des critères décrits dans le rapport du Groupe d'étude canadien sur les soins de santé préventifs (Tableau). RECOMMANDATIONS. Copyright © 2016. Published by Elsevier Inc.

Miroirs multicouches C/SI a incidence normale pour la region spectrale 25-40 nanometres

NASA Astrophysics Data System (ADS)

Grigonis, Marius

Nous avons propose la nouvelle combinaison de materiaux, C/Si, pour la fabrication de miroirs multicouches a incidence normale dans la region spectrale 25-40 nm. Les resultats experimentaux montrent que cette combinaison possede une reflectivite d'environ ~25% dans la region spectrale 25-33 nm et une reflectivite d'environ ~23% dans la region spectrale 33-40 nm. Ces valeurs de reflectivite sont les plus grandes obtenues jusqu'a maintenant dans la region spectrale 25-40 nm. Les miroirs multicouches ont ete par la suite caracterises par microscopie electronique a transmission, par diverses techniques de diffraction des rayons X et par spectroscopies d'electrons AES et ESCA. La resistance des miroirs aux temperatures elevees a ete egalement etudiee. Les resultats fournis par les methodes de caracterisation indiquent que cette combinaison possede des caracteristiques tres prometteuses pour son application comme miroir pour les rayons X mous.

Propriétés optiques du silicium mésoporeux et ses applications potentielles

NASA Astrophysics Data System (ADS)

Lévy-Clément, C.; Bastide, S.

2002-04-01

Une couche de silicium poreux formée électrochimiquement à la surface de l'émetteur d'une jonction p-n+ peut jouer efficacement le rôle d'une couche antireflet pour les cellules solaires au silicium. En ajustant la densité de courant et le temps de formation, des simple et double-couches antireflet aux propriétés optiques optimisées ont pu être réalisées, conduisant à des réflectivités effectives respectives de 7.3 et 2.7 % sur l'ensemble du spectre solaire utile pour les cellules (400-1000 nm). De hauts rendements de conversion de l'énergie solaire, de l'ordre de 13-13.4 %, sont ainsi actuellement obtenus pour des cellules au silicium multicristallin avec une couche antireflet de silicium poreux.

Auxin enhances grafting success in Carya cathayensis (Chinese hickory).

PubMed

Saravana Kumar, R M; Gao, Liu Xiao; Yuan, Hu Wei; Xu, Dong Bin; Liang, Zhao; Tao, Shen Chen; Guo, Wen Bin; Yan, Dao Liang; Zheng, Bing Song; Edqvist, Johan

2018-03-01

Application of auxin to root stock and scion increases the success rate of grafting in Chinese hickory. The nuts of the Chinese hickory (Carya cathayensis) tree are considered both delicious and healthy. The popularity and high demand result is that the hickory nuts are of very high economical value for horticulture. This is particularly true for the Zhejiang province in eastern China where this tree is widely cultivated. However, there are several difficulties surrounding the hickory cultivation, such as for example long vegetative growth, tall trees, labour-intensive nut picking, and slow variety improvements. These complications form a great bottleneck in the expansion of the hickory industry. The development of an efficient grafting procedure could surpass at least some of these problems. In this study, we demonstrate that application of the auxin indole-3-acetic acid promotes the grafting process in hickory, whereas application of the auxin transport inhibitor 1-N-naphthylphthalamic acid inhibits the grafting process. Furthermore, we have identified hickory genes in the PIN, ABCB, and AUX/LAX-families known to encode influx and efflux carriers in the polar transport of auxin. We show that increased expression of several of these genes, such as CcPIN1b and CcLAX3, is correlating with successful grafting.

Materials Data on Sb4Au(Xe2F11)2 (SG:2) by Materials Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kristin Persson

Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

Immobilized TiO2 on glass spheres applied to heterogeneous photocatalysis: photoactivity, leaching and regeneration process.

PubMed

Cunha, Deivisson Lopes; Kuznetsov, Alexei; Achete, Carlos Alberto; Machado, Antonio Eduardo da Hora; Marques, Marcia

2018-01-01

Heterogeneous photocatalysis using titanium dioxide as catalyst is an attractive advanced oxidation process due to its high chemical stability, good performance and low cost. When immobilized in a supporting material, additional benefits are achieved in the treatment. The purpose of this study was to develop a simple protocol for impregnation of TiO 2 -P25 on borosilicate glass spheres and evaluate its efficiency in the photocatalytic degradation using an oxidizable substrate (methylene blue), in a Compound Parabolic Concentrator (CPC) reactor. The assays were conducted at lab-scale using radiation, which simulated the solar spectrum. TiO 2 leaching from the glass and the catalyst regeneration were both demonstrated. A very low leaching ratio (0.03%) was observed after 24 h of treatment, suggesting that deposition of TiO 2 resulted in good adhesion and stability of the photocatalyst on the surface of borosilicate. This deposition was successfully achieved after calcination of the photocatalyst at 400 °C (TiO 2 -400 °C). The TiO 2 film was immobilized on glass spheres and the powder was characterized by scanning electron microscopy (SEM), X-ray diffraction and BET. This characterization suggested that thermal treatment did not introduce substantial changes in the measured microstructural characteristics of the photocatalyst. The immobilized photocatalyst degraded more than 96% of the MB in up to 90 min of reaction. The photocatalytic activity decreased after four photocatalytic cycles, but it was recovered by the removal of contaminants adsorbed on the active sites after washing in water under UV-Vis irradiation. Based on these results, the TiO 2 -400 °C coated on glass spheres is potentially a very attractive option for removal of persistent contaminants present in the environment.

Surface roughness mediated adhesion forces between borosilicate glass and gram-positive bacteria.

PubMed

Preedy, Emily; Perni, Stefano; Nipiĉ, Damijan; Bohinc, Klemen; Prokopovich, Polina

2014-08-12

It is well-known that a number of surface characteristics affect the extent of adhesion between two adjacent materials. One of such parameters is the surface roughness as surface asperities at the nanoscale level govern the overall adhesive forces. For example, the extent of bacterial adhesion is determined by the surface topography; also, once a bacteria colonizes a surface, proliferation of that species will take place and a biofilm may form, increasing the resistance of bacterial cells to removal. In this study, borosilicate glass was employed with varying surface roughness and coated with bovine serum albumin (BSA) in order to replicate the protein layer that covers orthopedic devices on implantation. As roughness is a scale-dependent process, relevant scan areas were analyzed using atomic force microscope (AFM) to determine Ra; furthermore, appropriate bacterial species were attached to the tip to measure the adhesion forces between cells and substrates. The bacterial species chosen (Staphylococci and Streptococci) are common pathogens associated with a number of implant related infections that are detrimental to the biomedical devices and patients. Correlation between adhesion forces and surface roughness (Ra) was generally better when the surface roughness was measured through scanned areas with size (2 × 2 μm) comparable to bacteria cells. Furthermore, the BSA coating altered the surface roughness without correlation with the initial values of such parameter; therefore, better correlations were found between adhesion forces and BSA-coated surfaces when actual surface roughness was used instead of the initial (nominal) values. It was also found that BSA induced a more hydrophilic and electron donor characteristic to the surfaces; in agreement with increasing adhesion forces of hydrophilic bacteria (as determined through microbial adhesion to solvents test) on BSA-coated substrates.

Immobilized TiO2 on glass spheres applied to heterogeneous photocatalysis: photoactivity, leaching and regeneration process

PubMed Central

Kuznetsov, Alexei; Achete, Carlos Alberto; Machado, Antonio Eduardo da Hora; Marques, Marcia

2018-01-01

Heterogeneous photocatalysis using titanium dioxide as catalyst is an attractive advanced oxidation process due to its high chemical stability, good performance and low cost. When immobilized in a supporting material, additional benefits are achieved in the treatment. The purpose of this study was to develop a simple protocol for impregnation of TiO2-P25 on borosilicate glass spheres and evaluate its efficiency in the photocatalytic degradation using an oxidizable substrate (methylene blue), in a Compound Parabolic Concentrator (CPC) reactor. The assays were conducted at lab-scale using radiation, which simulated the solar spectrum. TiO2 leaching from the glass and the catalyst regeneration were both demonstrated. A very low leaching ratio (0.03%) was observed after 24 h of treatment, suggesting that deposition of TiO2 resulted in good adhesion and stability of the photocatalyst on the surface of borosilicate. This deposition was successfully achieved after calcination of the photocatalyst at 400 °C (TiO2-400 °C). The TiO2 film was immobilized on glass spheres and the powder was characterized by scanning electron microscopy (SEM), X-ray diffraction and BET. This characterization suggested that thermal treatment did not introduce substantial changes in the measured microstructural characteristics of the photocatalyst. The immobilized photocatalyst degraded more than 96% of the MB in up to 90 min of reaction. The photocatalytic activity decreased after four photocatalytic cycles, but it was recovered by the removal of contaminants adsorbed on the active sites after washing in water under UV-Vis irradiation. Based on these results, the TiO2-400 °C coated on glass spheres is potentially a very attractive option for removal of persistent contaminants present in the environment. PMID:29527416

Optoelectronic properties and interfacial durability of CNT and ITO on boro-silicate glass and PET substrates with nano- and heterostructural aspects

NASA Astrophysics Data System (ADS)

Park, Joung-Man; Wang, Zuo-Jia; Kwon, Dong-Jun; DeVries, Lawrence

2011-02-01

Nano- and hetero-structures of carbon nanotube (CNT) and indium tin oxide (ITO) can control significantly piezoelectric and optoelectronic properties in Microelectromechanical Systems (MEMS) as sensing and actuator under cyclic loading. Optimized preparing conditions were obtained for multi-functional purpose of the specimen by obtaining the best dispersion and turbidity in the solution. Optical transmittance and electrical properties were investigated for CNT and ITO dipping and spraying coating on boro-silicate glass and polyethylene terephthalate (PET) substrates by electrical resistance measurement under cyclic loading and wettability test. Uniform dip-coating was performed using Wilhelmy plate method due to its simple and convenience. Spraying coating was applied to the specimen additionally. The change in the electrical resistance and optical properties of coated layer were mainly dependent upon the number of dip-coating, the concentration of CNT and ITO solutions, and the surface treatment condition. Electric properties of coating layers were measured using four-point probe method, and surface resistance was calculated using a dual configuration method. Optical transmittance of CNT and ITO coated PET film was also evaluated using UV spectrum. Surface energy and their hydrophilic and hydrophobic properties of CNT and ITO coated substrates were investigated by wettability test via static and dynamic contact angle measurements. As the elapsing time of cyclic loading passed, the stability of surface resistance and thus comparative interfacial adhesion between coated layer and substrates was evaluated to compare the thermodynamic work of adhesion, Wa. As dip-coating number increased, surface resistance of coated CNT decreased, whereas the transmittance decreased step-by-step due to the thicker CNT and ITO networked layer. Nano- and heterostructural effects of CNT and ITO solution on the optical and electrical effects have been studied continuously.

Complexing agents and pH influence on chemical durability of type I moulded glass containers.

PubMed

Biavati, Alberto; Poncini, Michele; Ferrarini, Arianna; Favaro, Nicola; Scarpa, Martina; Vallotto, Marta

2017-06-16

Among the factors that affect the glass surface chemical durability, pH and complexing agents presence in aqueous solution have the main role (1). Glass surface attack can be also related to the delamination issue with glass particles appearance in the pharmaceutical preparation. A few methods to check for glass containers delamination propensity and some control guidelines have been proposed (2,3). The present study emphasizes the possible synergy between a few complexing agents with pH on the borosilicate glass chemical durability. Hydrolytic attack was performed in small volume 23 ml type I glass containers autoclaved according to EP or USP for 1 hour at 121°C, in order to enhance the chemical attack due to time, temperature and the unfavourable surface/volume ratio. 0,048 M or 0.024 M (moles/liter) solutions of the acids citric, glutaric, acetic, EDTA (ethylenediaminetetraacetic acid) and sodium phosphate with water for comparison, were used for the trials. The pH was adjusted ± 0,05 units at fixed values 5,5-6,6-7-7,4-8-9 by LiOH diluted solution. Since silicon is the main glass network former, silicon release into the attack solutions was chosen as the main index of the glass surface attack and analysed by ICPAES. The work was completed by the analysis of the silicon release in the worst attack conditions, of moulded glass, soda lime type II and tubing borosilicate glass vials to compare different glass compositions and forming technologies. Surface analysis by SEM was finally performed to check for the surface status after the worst chemical attack condition by citric acid. Copyright © 2017, Parenteral Drug Association.

Influence of P{sub 2}O{sub 5} and Al{sub 2}O{sub 3} content on the structure of erbium-doped borosilicate glasses and on their physical, thermal, optical and luminescence properties

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bourhis, Kevin, E-mail: k.bourhis@argolight.com; Massera, Jonathan; Petit, Laeticia

2015-03-15

Highlights: • Reorganization of the glass structure induced by the addition of P{sub 2}O{sub 5} or Al{sub 2}O{sub 3}. • Emission properties related to the presence of P or Al in the Er{sup 3+} coordination shell. • Declustering observed upon addition of P{sub 2}O{sub 5}. • No declustering upon addition of Al{sub 2}O{sub 3}. - Abstract: The effect of P{sub 2}O{sub 5} and/or Al{sub 2}O{sub 3} addition in Er-doped borosilicate glasses on the physical, thermal, optical, and luminescence properties is investigated. The changes in these glass properties are related to the glass structure modifications induced by the addition of P{submore » 2}O{sub 5} and/or Al{sub 2}O{sub 3}, which were probed by FTIR, {sup 11}B MAS NMR and X-ray photoelectron spectroscopies. Variations of the polymerization degree of the silicate tetrahedra and modifications in the {sup [3]}B/{sup [4]}B ratio are explained by a charge compensation mechanism due to the formation of AlO{sub 4}, PO{sub 4} groups and the formation of Al-O-P linkages in the glass network. From the absorption and luminescence properties of the Er{sup 3+} ions at 980 nm and 1530 nm, declustering is suspected for the highest P{sub 2}O{sub 5} concentrations while for the highest Al{sub 2}O{sub 3} concentrations no declustering is observed.« less

Method for printing functional protein microarrays

NASA Technical Reports Server (NTRS)

Delehanty, James B.; Ligler, Frances S.

2003-01-01

Piezoelectric dispensing of proteins from borosilicate glass capillaries is a popular method of protein biochip fabrication that offers the advantages of sample recovery and noncontact with the printing substrate. However, little regard has been given to the quantitative aspects of dispensing minute volumes (1 nL or less) at the low protein concentrations (20 micrograms/mL or less) typically used in microprinting. Specifically, loss of protein sample due to nonspecific adsorption to the glass surface of the dispensing capillaries can limit the amount of protein delivered to the substrate. We demonstrate the benefits of a low ionic strength buffer containing the carrier protein BSA that effectively minimizes the ionic strength-dependent phenomenon of nonspecific protein adsorption to borosilicate glass. Over the concentration range of 20-2.5 micrograms/mL, the dispensing of a reference IgG in 10 mM PBS including 0.1% BSA resulted in the deposition of 3.6- to 44-fold more IgG compared to the deposition of IgG in standard 150 mM PBS in the absence of BSA. Furthermore, when the IgG was dispensed with carrier protein, the resulting spots exhibited a more uniform morphology. In a direct immunoassay for cholera toxin, capture antibody spots dispensed in 10 mM PBS containing 0.1% BSA produced fluorescent signals that were 2.8- to 4.3-fold more intense than antibody spots that were dispensed in 150 mM PBS without BSA. Interestingly, no differences were observed in the specific activities of the capture antibodies as a result of printing in the different buffers. The implications of these results on the future development of protein biochips are discussed.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fox, K. M.

The U.S. Department of Energy (DOE), Office of Environmental Management (EM) is sponsoring an international, collaborative project to develop a fundamental model for sulfate solubility in nuclear waste glass. The solubility of sulfate has a significant impact on the achievable waste loading for nuclear waste forms within the DOE complex. These wastes can contain relatively high concentrations of sulfate, which has low solubility in borosilicate glass. This is a significant issue for low-activity waste (LAW) glass and is projected to have a major impact on the Hanford Tank Waste Treatment and Immobilization Plant (WTP). Sulfate solubility has also been amore » limiting factor for recent high level waste (HLW) sludge processed at the Savannah River Site (SRS) Defense Waste Processing Facility (DWPF). The low solubility of sulfate in glass, along with melter and off-gas corrosion constraints, dictate that the waste be blended with lower sulfate concentration waste sources or washed to remove sulfate prior to vitrification. The development of enhanced borosilicate glass compositions with improved sulfate solubility will allow for higher waste loadings and accelerate mission completion.The objective of the current scope being pursued by SHU is to mature the sulfate solubility model to the point where it can be used to guide glass composition development for DWPF and WTP, allowing for enhanced waste loadings and waste throughput at these facilities. A series of targeted glass compositions was selected to resolve data gaps in the model and is identified as Stage III. SHU fabricated these glasses and sent samples to SRNL for chemical composition analysis. SHU will use the resulting data to enhance the sulfate solubility model and resolve any deficiencies. In this report, SRNL provides chemical analyses for the Stage III, simulated HLW glasses fabricated by SHU in support of the sulfate solubility model development.« less

Differentiation between Trichophyton mentagrophytes and T. rubrum by sorbitol assimilation.

PubMed Central

Rezusta, A; Rubio, M C; Alejandre, M C

1991-01-01

Trichophyton rubrum was easily differentiated from T. mentagrophytes by its ability to assimilate sorbitol with an API 20C AUX strip. One hundred percent of 36 T. rubrum strains and none of 147 T. mentagrophytes strains assimilated sorbitol. PMID:1993760

morphogen: Translation into Morphologically Rich Languages with Synthetic Phrases

DTIC Science & Technology

2013-10-01

specific trans - lation phrases. These “synthetic phrases” augment the standard translation grammars and decoding proceeds normally with a standard...Genitive case grandparent(poss) Hebrew Suffix ים ( masculine plural) parent=NNS after=NNS Prefix א (first person sing. + future) child(nsubj)=I child(aux

An experimental study on Sodalite and SAP matrices for immobilization of spent chloride salt waste

NASA Astrophysics Data System (ADS)

Giacobbo, Francesca; Da Ros, Mirko; Macerata, Elena; Mariani, Mario; Giola, Marco; De Angelis, Giorgio; Capone, Mauro; Fedeli, Carlo

2018-02-01

In the frame of Generation IV reactors a renewed interest in pyro-processing of spent nuclear fuel is underway. Molten chloride salt waste arising from the recovering of uranium and plutonium through pyro-processing is one of the problematic wastes for direct application of vitrification or ceramization. In this work, Sodalite and SAP have been evaluated and compared as potential matrices for confinement of spent chloride salt waste coming from pyro-processing. To this aim Sodalite and SAP were synthesized both in pure form and mixed with different glass matrices, i.e. commercially available glass frit and borosilicate glass. The confining matrices were loaded with mixed chloride salts to study their retention capacities with respect to the elements of interest. The matrices were characterized and leached for contact times up to 150 days at room temperature and at 90 °C. SEM analyses were also performed in order to compare the matrix surface before and after leaching. Leaching results are discussed and compared in terms of normalized releases with similar results reported in literature. According to this comparative study the SAP matrix with glass frit binder resulted in the best matrix among the ones studied, with respect to retention capacities for both matrix and spent fuel elements.

Separating and stabilizing phosphate from high-level radioactive waste: process development and spectroscopic monitoring.

PubMed

Lumetta, Gregg J; Braley, Jenifer C; Peterson, James M; Bryan, Samuel A; Levitskaia, Tatiana G

2012-06-05

Removing phosphate from alkaline high-level waste sludges at the Department of Energy's Hanford Site in Washington State is necessary to increase the waste loading in the borosilicate glass waste form that will be used to immobilize the highly radioactive fraction of these wastes. We are developing a process which first leaches phosphate from the high-level waste solids with aqueous sodium hydroxide, and then isolates the phosphate by precipitation with calcium oxide. Tests with actual tank waste confirmed that this process is an effective method of phosphate removal from the sludge and offers an additional option for managing the phosphorus in the Hanford tank waste solids. The presence of vibrationally active species, such as nitrate and phosphate ions, in the tank waste processing streams makes the phosphate removal process an ideal candidate for monitoring by Raman or infrared spectroscopic means. As a proof-of-principle demonstration, Raman and Fourier transform infrared (FTIR) spectra were acquired for all phases during a test of the process with actual tank waste. Quantitative determination of phosphate, nitrate, and sulfate in the liquid phases was achieved by Raman spectroscopy, demonstrating the applicability of Raman spectroscopy for the monitoring of these species in the tank waste process streams.

The cotton transcription factor TCP14 functions in auxin-mediated epidermal cell differentiation and elongation.

PubMed

Wang, Miao-Ying; Zhao, Pi-Ming; Cheng, Huan-Qing; Han, Li-Bo; Wu, Xiao-Min; Gao, Peng; Wang, Hai-Yun; Yang, Chun-Lin; Zhong, Nai-Qin; Zuo, Jian-Ru; Xia, Gui-Xian

2013-07-01

Plant-specific TEOSINTE-BRANCHED1/CYCLOIDEA/PCF (TCP) transcription factors play crucial roles in development, but their functional mechanisms remain largely unknown. Here, we characterized the cellular functions of the class I TCP transcription factor GhTCP14 from upland cotton (Gossypium hirsutum). GhTCP14 is expressed predominantly in fiber cells, especially at the initiation and elongation stages of development, and its expression increased in response to exogenous auxin. Induced heterologous overexpression of GhTCP14 in Arabidopsis (Arabidopsis thaliana) enhanced initiation and elongation of trichomes and root hairs. In addition, root gravitropism was severely affected, similar to mutant of the auxin efflux carrier PIN-FORMED2 (PIN2) gene. Examination of auxin distribution in GhTCP14-expressing Arabidopsis by observation of auxin-responsive reporters revealed substantial alterations in auxin distribution in sepal trichomes and root cortical regions. Consistent with these changes, expression of the auxin uptake carrier AUXIN1 (AUX1) was up-regulated and PIN2 expression was down-regulated in the GhTCP14-expressing plants. The association of GhTCP14 with auxin responses was also evidenced by the enhanced expression of auxin response gene IAA3, a gene in the AUXIN/INDOLE-3-ACETIC ACID (Aux/IAA) family. Electrophoretic mobility shift assays showed that GhTCP14 bound the promoters of PIN2, IAA3, and AUX1, and transactivation assays indicated that GhTCP14 had transcription activation activity. Taken together, these results demonstrate that GhTCP14 is a dual-function transcription factor able to positively or negatively regulate expression of auxin response and transporter genes, thus potentially acting as a crucial regulator in auxin-mediated differentiation and elongation of cotton fiber cells.

The Cotton Transcription Factor TCP14 Functions in Auxin-Mediated Epidermal Cell Differentiation and Elongation1[C][W

PubMed Central

Wang, Miao-Ying; Zhao, Pi-Ming; Cheng, Huan-Qing; Han, Li-Bo; Wu, Xiao-Min; Gao, Peng; Wang, Hai-Yun; Yang, Chun-Lin; Zhong, Nai-Qin; Zuo, Jian-Ru; Xia, Gui-Xian

2013-01-01

Plant-specific TEOSINTE-BRANCHED1/CYCLOIDEA/PCF (TCP) transcription factors play crucial roles in development, but their functional mechanisms remain largely unknown. Here, we characterized the cellular functions of the class I TCP transcription factor GhTCP14 from upland cotton (Gossypium hirsutum). GhTCP14 is expressed predominantly in fiber cells, especially at the initiation and elongation stages of development, and its expression increased in response to exogenous auxin. Induced heterologous overexpression of GhTCP14 in Arabidopsis (Arabidopsis thaliana) enhanced initiation and elongation of trichomes and root hairs. In addition, root gravitropism was severely affected, similar to mutant of the auxin efflux carrier PIN-FORMED2 (PIN2) gene. Examination of auxin distribution in GhTCP14-expressing Arabidopsis by observation of auxin-responsive reporters revealed substantial alterations in auxin distribution in sepal trichomes and root cortical regions. Consistent with these changes, expression of the auxin uptake carrier AUXIN1 (AUX1) was up-regulated and PIN2 expression was down-regulated in the GhTCP14-expressing plants. The association of GhTCP14 with auxin responses was also evidenced by the enhanced expression of auxin response gene IAA3, a gene in the AUXIN/INDOLE-3-ACETIC ACID (Aux/IAA) family. Electrophoretic mobility shift assays showed that GhTCP14 bound the promoters of PIN2, IAA3, and AUX1, and transactivation assays indicated that GhTCP14 had transcription activation activity. Taken together, these results demonstrate that GhTCP14 is a dual-function transcription factor able to positively or negatively regulate expression of auxin response and transporter genes, thus potentially acting as a crucial regulator in auxin-mediated differentiation and elongation of cotton fiber cells. PMID:23715527

Lithofacies variation across the Mammoth Cave-Pope Megagroup boundary -- a sequence stratigraphic approach

DOE Office of Scientific and Technical Information (OSTI.GOV)

McDonald, T.A.; Tabor, E.; Marzolf, J.E.

1994-04-01

Regional stratigraphic relations in southern Illinois suggest a major unconformity near the top of the St. Genevieve Limestone. Large exposures below the unconformity within the Anna quarries display a retrogradational parasequence-stacking pattern. Eight to 12 m-thick parasequences comprise thinning-upward marine bioclastic wackestone overlain by oolitic and bioclastic thickening-upward eolian( ) grainstone. An eolian origin for the bioclastic grainstones is supported by large scale cross stratification (0.5 to 2 m-thick sets), reworked character of rounded, coated bioclasts, and preserved duneforms. At the quarries, the unconformity is directly overlain by mudstones and sandstones. Thinning-upward mudstones interbedded with very thin (1 to 3more » cm thick) intraclastic packstone tempestites crop out in a roadcut about 500 m NE of the quarries. Small-scale ripples and absence of trace fossils in lower mudstone units suggest an estuarine or lagoonal, brackish-waver environment. The trace fossil Conostichus and horizontal burrows appear abruptly in the upper, thin mudstone units. Highly bioturbated green and red shales overlying a 1 to 4 m-thick covered interval in a roadcut 610 m farther north are interbedded with tidally deposited, medium- to coarse-grained, bioclastic grainstones. The shale-draped, medium cross-bedded grainstones document ten or more tidal bundles. The cross-bedded grainstone is overlain by wavy- to flaser-bedded very fine-grained sandstone suggestive of sand flat origin. These sandstones are overlain by the Aux Vases Sandstone. Numerous low-angle bounding surfaces within the Aux Vases enclose low-angle, wedge-planar cross-bedding. A single irregular surface coated by a few centimeters of poorly sorted unstratified sandstone defines a ravinement surface near the base of the Aux Vases Sandstone.« less

A role for the gene regulatory module microRNA172/TARGET OF EARLY ACTIVATION TAGGED 1/FLOWERING LOCUS T (miRNA172/TOE1/FT) in the feeding sites induced by Meloidogyne javanica in Arabidopsis thaliana.

PubMed

Díaz-Manzano, Fernando E; Cabrera, Javier; Ripoll, Juan-José; Del Olmo, Iván; Andrés, Mari Fe; Silva, Ana Cláudia; Barcala, Marta; Sánchez, María; Ruíz-Ferrer, Virginia; de Almeida-Engler, Janice; Yanofsky, Martin F; Piñeiro, Manuel; Jarillo, Jose Antonio; Fenoll, Carmen; Escobar, Carolina

2018-01-01

Root knot nematodes (RKNs) penetrate into the root vascular cylinder, triggering morphogenetic changes to induce galls, de novo formed 'pseudo-organs' containing several giant cells (GCs). Distinctive gene repression events observed in early gall/GCs development are thought to be mediated by post-transcriptional silencing via microRNAs (miRNAs), a process that is far from being fully characterized. Arabidopsis thaliana backgrounds with altered activities based on target 35S::MIMICRY172 (MIM172), 35S::TARGET OF EARLY ACTIVATION TAGGED 1 (TOE1)-miR172-resistant (35S::TOE1 R ) and mutant (flowering locus T-10 (ft-10)) lines were used for functional analysis of nematode infective and reproductive parameters. The GUS-reporter lines, MIR172A-E::GUS, treated with auxin (IAA) and an auxin-inhibitor (a-(phenyl ethyl-2-one)-indole-3-acetic acid (PEO-IAA)), together with the MIR172C AuxRE::GUS line with two mutated auxin responsive elements (AuxREs), were assayed for nematode-dependent gene expression. Arabidopsis thaliana backgrounds with altered expression of miRNA172, TOE1 or FT showed lower susceptibility to the RKNs and smaller galls and GCs. MIR172C-D::GUS showed restricted promoter activity in galls/GCs that was regulated by auxins through auxin-responsive factors. IAA induced their activity in galls while PEO-IAA treatment and mutations in AuxRe motifs abolished it. The results showed that the regulatory module miRNA172/TOE1/FT plays an important role in correct GCs and gall development, where miRNA172 is modulated by auxins. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

Diversification, phylogeny and evolution of auxin response factor (ARF) family: insights gained from analyzing maize ARF genes.

PubMed

Wang, Yijun; Deng, Dexiang; Shi, Yating; Miao, Nan; Bian, Yunlong; Yin, Zhitong

2012-03-01

Auxin response factors (ARFs), member of the plant-specific B3 DNA binding superfamily, target specifically to auxin response elements (AuxREs) in promoters of primary auxin-responsive genes and heterodimerize with Aux/IAA proteins in auxin signaling transduction cascade. In previous research, we have isolated and characterized maize Aux/IAA genes in whole-genome scale. Here, we report the comprehensive analysis of ARF genes in maize. A total of 36 ARF genes were identified and validated from the B73 maize genome through an iterative strategy. Thirty-six maize ARF genes are distributed in all maize chromosomes except chromosome 7. Maize ARF genes expansion is mainly due to recent segmental duplications. Maize ARF proteins share one B3 DNA binding domain which consists of seven-stranded β sheets and two short α helixes. Twelve maize ARFs with glutamine-rich middle regions could be as activators in modulating expression of auxin-responsive genes. Eleven maize ARF proteins are lack of homo- and heterodimerization domains. Putative cis-elements involved in phytohormones and light signaling responses, biotic and abiotic stress adaption locate in promoters of maize ARF genes. Expression patterns vary greatly between clades and sister pairs of maize ARF genes. The B3 DNA binding and auxin response factor domains of maize ARF proteins are primarily subjected to negative selection during selective sweep. The mixed selective forces drive the diversification and evolution of genomic regions outside of B3 and ARF domains. Additionally, the dicot-specific proliferation of ARF genes was detected. Comparative genomics analysis indicated that maize, sorghum and rice duplicate chromosomal blocks containing ARF homologs are highly syntenic. This study provides insights into the distribution, phylogeny and evolution of ARF gene family.

Pollution Atmosphérique et Santé: Corrélation ou Causalité? Le Cas de la Relation entre l'Exposition aux Particules et la Mortalité Cardio-pulmonaire.

PubMed

Dab, William; Ségala, Claire; Dor, Frédéric; Festy, Bernard; Lameloise, Philippe; Moullec, Yvon Le; Tertre, Alain Le; Médina, Sylvia; Quénel, Philippe; Wallaert, Benoît; Zmirou, Et Denis

2001-02-01

De nombreuses études épidémiologiques ont observé dans des contextes différents une faible relation à court terme entre les particules et la mortalité cardio-pulmonaire, même quand les normes de qualité de l'air n'étaient pas dépassées. La causalité de cette relation est un enjeu de santé publique en raison de l'importance de la population exposée. Notre objectif est de faire l'inventaire critique des arguments utilisés dans 15 revues de la littérature publiées. Nous expliquons l'importance de distinguer la validité de la causalité et analysons de façon systématique les différents critères de jugement dans le contexte des études écologiques temporelles. Notre conclusion est que la relation observée est valide et que la plupart des critères de causalité sont respectés. Diminuer le niveau d'exposition des populations aux particules est souhaitable. En Europe, en agissant à la source, notamment sur les émissions Diesel, on diminuera aussi d'autres polluants qui peuvent jouer un rôle sanitaire. Aux États-Unis, la situation est plus complexe car les particules sont surtout secondaires. Il est également indispensable de poursuivre les recherches pour mieux connaître les déterminants des expositions globales des individus et mieux comprendre le rôle toxique des différents facteurs physico-chimiques des particules.

Microscopie par rayons X dans la fenêtre de l'eau : faisabilité et intérêt pour la biologie d'un instrument de laboratoire

NASA Astrophysics Data System (ADS)

Adam, J. F.; Moy, J. P.

2005-06-01

La biologie étudie des structures ou des phénomènes sub-cellulaires. Pour cela la microscopie est la technique d'observation privilégiée. La résolution spatiale de la microscopie optique s'avère bien souvent insuffisante pour de telles observations. Les techniques plus résolvantes, comme la microscopie électronique par transmission sont souvent destructrices et d'une complexité peu adaptée aux besoins des biologistes. La microscopie par rayons X dans la fenêtre de l'eau permet l'imagerie rapide de cellules dans leur milieu naturel, nécessite peu de préparation et offre des résolutions de quelques dizaines de nanomètres. De plus, il existe un bon contraste naturel entre les structures carbonées (protéines, lipides) et l'eau. Actuellement cette technique est limitée aux centres de rayonnement synchrotron, ce qui impose une planification et des déplacements incompatibles avec les besoins de la biologie. Un tel microscope fonctionnant avec uns source de laboratoire serait d'une grande utilité. Ce document présente un état de l'art de la microscopie par rayons X dans la fenêtre de l'eau. Un cahier des charges détaillé pour un appareil de laboratoire ayant les performances optiques requises par les biologistes est présenté et confronté aux microscopes X de laboratoire déjà existants. Des solutions concernant la source et les optiques sont également discutées.

Realization and characterization of a beam of titanium atoms

NASA Astrophysics Data System (ADS)

Azaroual, E. M.; Luc, P.; Vetter, R.

1992-06-01

A dense thermal beam of titanium atoms has been realized using a tungsten crucible inside a high temperature oven (leqslant 2 300 K). Its flux (≈ 10^{14} atom/cm^2/s) and its long term stability have been measured by means of a quartz balance, its angular divergence has been evaluated from the size of a metallic spot deposited on a glass plate. A spectroscopic investigation performed via the laser-induced fluorescence technique has led to the measurement of the isotope shifts between ^{46}Ti, ^{48}Ti and ^{50}Ti, for six visible 3d^2 4s^2 a ^3FJ''to 3d^2 4s4p z ^5DJ' transitions. This beam offers the characteristics required to apply high resolution laser techniques to reaction dynamics crossed-beam experiments. Un jet intense de titane atomique a été réalisé à partir d'un creuset de tungstène porté à haute température (leqslant 2 300 K). Le flux (≈ 10^{14} atomes/cm^2/s) et la stabilité à long terme du jet ont été mesurés avec une balance à quartz ; la divergence angulaire a été évaluée à partir de la dimension de dépôts métalliques sur des lames-témoin. Le jet a également été caractérisé par spectroscopie : la technique de fluorescence induite par laser a permis de mesurer le déplacement spectral dû aux isotopes 46, 48 et 50 de Ti, pour six transitions visibles du type 3d^2 4s^2 a ^3FJ''to 3d^2 4s4p z ^5DJ'. Le jet réalisé offre les caractéristiques requises pour l'application des techniques laser à haute résolution aux expériences de dynamique réactionnelle en faisceaux croisés.

Graviresponse and its regulation from the aspect of molecular levels in higher plants: growth and development, and auxin polar transport in etiolated pea seedlings under microgravity.

PubMed

Miyamoto, Kensuke; Hoshino, Tomoki; Hitotsubashi, Reiko; Tanimoto, Eiichi; Ueda, Junichi

2003-10-01

In STS-95 space experiments we have demonstrated that microgravity conditions resulted in automorphosis in etiolated pea (Pisum sativum L. cv. Alaska) seedlings (Ueda et al. 1999). Automorphosis-like growth and development in etiolated pea seedlings were also induced under simulated microgravity conditions on a 3-dimensional (3-D) clinostat, epicotyls being the most oriented toward the direction far from the cotyledons. Detail analysis of epicotyl bending revealed that within 36 h after watering, no significant difference in growth direction of epicotyls was observed in between seedlings grown on the 3-D clinostat and under 1 g conditions, differential growth near the cotyledonary node resulting in epicotyl bending of ca. 45 degrees toward the direction far from the cotyledons. Thereafter epicotyls continued to grow almost straightly keeping this orientation on the 3-D clinostat. On the other hand, the growth direction in etiolated seedlings changed to antigravity direction by negative gravitropic response under 1 g conditions. Automorphological epicotyl bending was also phenocopied by the application of auxin polar transport inhibitors such as 9-hydroxyfluorene-9-carboxylic acid, N-(1-naphtyl)phthalamic acid and 2,3,5-triiodobenzoic acid. These results together with the fact that auxin polar transport activity in etiolated pea epicotyls was substantially reduced in space suggested that reduced auxin polar transport is closely related to automorphosis. Strenuous efforts to learn how gravity contributes to the auxin polar transport in etiolated pea epicotyls in molecular bases resulted in successful identification of PsPIN2 and PsAUX1 encoding putative auxin-efflux and influx carrier proteins, respectively. Based on the results of these gene expression under simulated microgravity conditions, a possible role of PsPIN2 and PsAUX1 genes for auxin polar transport in etiolated pea seedlings will be discussed.

Temperature profiles for laser-induced heating of nanocrystals embedded in glass matrices

NASA Astrophysics Data System (ADS)

Bhatnagar, Promod K.; Nagpal, Swati

2001-05-01

Quantum confined nanostructures are very important because of their application towards optoelectronic devices. Commercial colored glass filters, which have large semiconductor particles, are being used to manufacture nanocrystals by suitable heat treatments. The progress in this area has been hampered by high size dispersion of these dots in the glass matrix which leads to reduction in higher order susceptibility thereby reducing non-linearity. In the present paper attempt has been made to theoretically model the temperature profiles of a laser irradiated CdS doped Borosilicate sample. Laser being used has a beam diameter of 1.5 mm and energy for 10 nsec pulse is 10 mJ. Two different particle radii of 5 nm and 10 nm have been considered. It is found that larger particles reach higher temperatures for the same pulse characteristics. This is because smaller particles have larger surface to volume ratio and hence dissipates out heat faster to the surrounding. Hence bigger particles will reach dissolution temperature faster than smaller particle and particle beyond a certain size should dissolve in the glass matrix when a sample is heat treated by laser. This could lead to a reduction in size dispersion of the nanocrystals. Also photodarkening effect found in semiconductor doped glasses is a big handicap for practical application of these materials in fast optical switching and non-linear optical devices. Photodarkening effect has been established to be a photochemical effect and it is important to study the temperature profiles around a particle since it will effect the impurity migration.

DNA migration mechanism analyses for applications in capillary and microchip electrophoresis

PubMed Central

Forster, Ryan E.; Hert, Daniel G.; Chiesl, Thomas N.; Fredlake, Christopher P.; Barron, Annelise E.

2009-01-01

In 2009, electrophoretically driven DNA separations in slab gels and capillaries have the sepia tones of an old-fashioned technology in the eyes of many, even while they remain ubiquitously used, fill a unique niche, and arguably have yet to reach their full potential. For comic relief, what is old becomes new again: agarose slab gel separations are used to prepare DNA samples for “next-gen” sequencing platforms (e.g., the Illumina and 454 machines)—dsDNA molecules within a certain size range are “cut out” of a gel and recovered for subsequent “massively parallel” pyrosequencing. In this review, we give a Barron lab perspective on how our comprehension of DNA migration mechanisms in electrophoresis has evolved, since the first reports of DNA separations by CE (∼1989) until now, 20 years later. Fused silica capillaries, and borosilicate glass and plastic microchips, quietly offer increasing capacities for fast (and even “ultra-fast”), efficient DNA separations. While the channel-by-channel scaling of both old and new electrophoresis platforms provides key flexibility, it requires each unique DNA sample to be prepared in its own micro- or nanovolume. This Achille's heel of electrophoresis technologies left an opening through which pooled-sample, next-gen DNA sequencing technologies rushed. We shall see, over time, whether sharpening understanding of transitions in DNA migration modes in crosslinked gels, nanogel solutions, and uncrosslinked polymer solutions will allow electrophoretic DNA analysis technologies to flower again. Microchannel electrophoresis, after a quiet period of metamorphosis, may emerge sleeker and more powerful, to claim its own important niche applications. PMID:19582705

Reaction cured glass and glass coatings

NASA Technical Reports Server (NTRS)

Goldstein, H. E.; Leiser, D. B.; Katvala, V. W. (Inventor)

1978-01-01

The invention relates to reaction cured glass and glass coatings prepared by reacting a compound selected from the group consisting of silicon tetraboride, silicon hexaboride, other boron silicides, boron and mixtures with a reactive glass frit composed of a porous high silica borosilicate glass and boron oxide. The glassy composites of the present invention are useful as coatings on low density fibrous porous silica insulations used as heat shields and for articles such as reaction vessels that are subjected to high temperatures with rapid heating and cooling and that require resistance to temperature and repeated thermal shock at temperatures up to about 1482C (2700PF).

Method for dissolution and stabilization of silica-rich fibers

DOEpatents

Jantzen, Carol M.

1997-01-01

A method for dissolving silica-rich fibers such as borosilicate fibers, fiberglass and asbestos to stabilize them for disposal. The method comprises (1) immersing the fibers in hot, five-weight-percent sodium hydroxide solution until the concentration of dissolved silica reaches equilibrium and a only a residue is left (about 48 hours), then immersing the residue in hot, five-weight-percent nitric acid until the residue dissolves (about 96 hours). After adjusting the pH of the dissolved fibers to be caustic, the solution can then be added to a waste vitrification stream for safe disposal. The method is useful in disposing contaminated HEME and HEPA filters.

Precipitate hydrolysis process for the removal of organic compounds from nuclear waste slurries

DOEpatents

Doherty, J.P.; Marek, J.C.

1987-02-25

A process for removing organic compounds from a nuclear waste slurry comprising reacting a mixture of radioactive waste precipitate slurry and an acid in the presence of a catalytically effective amount of a copper(II) catalyst whereby the organic compounds in the precipitate slurry are hydrolyzed to form volatile organic compounds which are separated from the reacting mixture. The resulting waste slurry, containing less than 10 percent of the original organic compounds, is subsequently blended with high level radioactive sludge land transferred to a vitrification facility for processing into borosilicate glass for long-term storage. 2 figs., 3 tabs.

Pest Oxidation Regime in the Hi-Nicalon(Trademark)/BN/SiC Composite

NASA Technical Reports Server (NTRS)

Ogbuji, Linus U. J. T.

1998-01-01

SiC-SiC composites are prone to pest degradation at intermediate temperatures where the formation of a protective scale of silica by direct oxidation of SiC is too slow to offer effective protection from attack by ambient gases. The attack results in the removal of the BN interphase and its replacement by a borosilicate liquid (which dissolves and weakens the fiber) and finally by SiO2, (which embrittles the composite by bonding fiber to fiber or to matrix). This paper reports a study aimed at mapping out the temperature range of such pest degradation and the severity of its effect.

Glass needs for a growing photovoltaics industry

DOE PAGES

Burrows, Keith; Fthenakis, Vasilis

2014-10-18

With the projected growth in photovoltaics, the demand for glass for the solar industry will far exceed the current supply, and thousands of new float-glass plants will have to be built to meet its needs over the next 20 years. Such expansion will provide an opportunity for the solar industry to obtain products better suited to their needs, such as low-iron glass and borosilicate glass at the lowest possible price. While there are no significant technological hurdles that would prevent the flat glass industry from meeting the solar industry’s projected needs, to do so will require advance planning and substantialmore » investments.« less

Vitrification of waste

DOEpatents

Wicks, George G.

1999-01-01

A method for encapsulating and immobilizing waste for disposal. Waste, preferably, biologically, chemically and radioactively hazardous, and especially electronic wastes, such as circuit boards, are placed in a crucible and heated by microwaves to a temperature in the range of approximately 300.degree. C. to 800.degree. C. to incinerate organic materials, then heated further to a temperature in the range of approximately 1100.degree. C. to 1400.degree. C. at which temperature glass formers present in the waste will cause it to vitrify. Glass formers, such as borosilicate glass, quartz or fiberglass can be added at the start of the process to increase the silicate concentration sufficiently for vitrification.

Process for utilizing low-cost graphite substrates for polycrystalline solar cells

NASA Technical Reports Server (NTRS)

Chu, T. L. (Inventor)

1978-01-01

Low cost polycrystalline silicon solar cells supported on substrates were prepared by depositing successive layers of polycrystalline silicon containing appropriate dopants over supporting substrates of a member selected from the group consisting of metallurgical grade polycrystalline silicon, graphite and steel coated with a diffusion barrier of silica, borosilicate, phosphosilicate, or mixtures thereof such that p-n junction devices were formed which effectively convert solar energy to electrical energy. To improve the conversion efficiency of the polycrystalline silicon solar cells, the crystallite size in the silicon was substantially increased by melting and solidifying a base layer of polycrystalline silicon before depositing the layers which form the p-n junction.

Cluster shading modifies amino acids in grape (Vitis vinifera L.) berries in a genotype- and tissue-dependent manner.

PubMed

Guan, Le; Wu, Benhong; Hilbert, Ghislaine; Li, Shaohua; Gomès, Eric; Delrot, Serge; Dai, Zhanwu

2017-08-01

Amino acid composition of the grape berry at harvest is important for wine making. The present study investigates the complex interplay between tissue, cultivar and light conditions that determine berry amino acid content. Twenty amino acids were assessed in the berry skin and pulp of two grape cultivars (Gamay Noir and Gamay Fréaux), grown under either light exposure or cluster shading conditions. In all samples, cluster shading significantly reduced most amino acids, except gamma-aminobutyric acid (GABA) and phenylalanine. However, the magnitude of the decrease was stronger in the skin (67.0% decrease) than in the pulp (30.4%) and stronger in cv. Gamay Noir (69.7%) than in Gamay Fréaux (30.7%). Cluster shading also significantly modified amino acid composition by decreasing the proline content while increasing the GABA content. These results are of oenological interest for shaping the amino acid composition of the must and improving wine quality. Copyright © 2017 Elsevier Ltd. All rights reserved.

Dégénérescence Maculaire Liée à l' âge et Risque d' Accident Vasculaire Cérébral

PubMed Central

Biousse, Valérie; Bousser, Marie-Germaine; Gaudric, Alain

2010-01-01

La dégénérescence maculaire liée à l' âge (DMLA) et les accidents vasculaires cérébraux (AVC) affectent un nombre important de sujets de plus de 40 ans à travers le monde et contribuent largement aux dépenses de la santé. Les causes de la DMLA restent mystérieuses et de nombreuses études épidémiologiques ont suggéré une association entre DMLA et facteurs de risque cardio-vasculaire associés aux AVC. Il a également été suggéré que les patients atteints de DMLA ont un risque plus important d' AVC que la population générale du même âge. Les arguments en faveur de cette association entre DMLA et AVC sont résumés dans cet article. PMID:18401309

J. M. Despréaux' lichens from the Canary Islands and West Africa: an account of a 19th century collection found in an English archive.

PubMed

Aguirre-Hudson, Begoña; Whitworth, Isabella; Spooner, Brian M

2011-01-01

This is an historical and descriptive account of 28 herbarium specimens, 27 lichens and an alga, found in the archives of Charles Chalcraft, a descendant of the Bedford family, who were dye manufacturers in Leeds, England, in the 19th century. The lichens comprise 13 different morphotypes collected in the Canary Islands and West Africa by the French botanist J. M. Despréaux between 1833 and 1839. The collections include samples of "Roccella fuciformis", "R. phycopsis" and "R. tinctoria" (including the fertile morphotype "R. canariensis"), "Ramalina crispatula" and "R. cupularis", two distinct morphotypes of "Sticta", "S. canariensis" and "S. dufouri", "Physconia enteroxantha", "Pseudevernia furfuracea var. ceratea" and "Pseudocyphellaria argyracea". The herbarium also includes authentic material of "Parmotrema tinctorum" and a probable syntype of "Seirophora scorigena". Most of these species are known as a source of the purple dye orchil, which was used to dye silk and wool.

Validation materielle d'une architecture generique de reseaux avioniques basee sur une gestion modulaire de la redondance

NASA Astrophysics Data System (ADS)

Tremblay, Jose-Philippe

Les systemes avioniques ne cessent d'evoluer depuis l'apparition des technologies numeriques au tournant des annees 60. Apres le passage par plusieurs paradigmes de developpement, ces systemes suivent maintenant l'approche " Integrated Modular Avionics " (IMA) depuis le debut des annees 2000. Contrairement aux methodes anterieures, cette approche est basee sur une conception modulaire, un partage de ressources generiques entre plusieurs systemes et l'utilisation plus poussee de bus multiplexes. La plupart des concepts utilises par l'architecture IMA, bien que deja connus dans le domaine de l'informatique distribuee, constituent un changement marque par rapport aux modeles anterieurs dans le monde avionique. Ceux-ci viennent s'ajouter aux contraintes importantes de l'avionique classique telles que le determinisme, le temps reel, la certification et les cibles elevees de fiabilite. L'adoption de l'approche IMA a declenche une revision de plusieurs aspects de la conception, de la certification et de l'implementation d'un systeme IMA afin d'en tirer profit. Cette revision, ralentie par les contraintes avioniques, est toujours en cours, et offre encore l'opportunite de developpement de nouveaux outils, methodes et modeles a tous les niveaux du processus d'implementation d?un systeme IMA. Dans un contexte de proposition et de validation d'une nouvelle architecture IMA pour un reseau generique de capteurs a bord d?un avion, nous avons identifie quelques aspects des differentes approches traditionnelles pour la realisation de ce type d?architecture pouvant etre ameliores. Afin de remedier a certaines des differentes lacunes identifiees, nous avons propose une approche de validation basee sur une plateforme materielle reconfigurable ainsi qu'une nouvelle approche de gestion de la redondance pour l'atteinte des cibles de fiabilite. Contrairement aux outils statiques plus limites satisfaisant les besoins pour la conception d'une architecture federee, notre approche de validation est specifiquement developpee de maniere a faciliter la conception d'une architecture IMA. Dans le cadre de cette these, trois axes principaux de contributions originales se sont degages des travaux executes suivant les differents objectifs de recherche enonces precedemment. Le premier axe se situe au niveau de la proposition d'une architecture hierarchique de reseau de capteurs s'appuyant sur le modele de base de la norme IEEE 1451. Cette norme facilite l'integration de capteurs et actuateurs intelligents a tout systeme de commande par des interfaces normalisees et generiques.

Parasitémie asymptomatique chez les enfants de moins de 5 ans, enfants en âge scolaire et prise en charge des épisodes fébriles dans les ménages de Lubumbashi, République Démocratique du Congo

PubMed Central

Mukomena, Sompwe Eric; Philipe, Cilundika Mulenga; Désiré, Mashinda Kulimba; Pascal, Lutumba Tshindele; Ali, Mapatano Mala; Oscar, Luboya Numbi

2016-01-01

Introduction longtemps négligé, le paludisme asymptomatique est actuellement reconnu comme potentielle menace et frein au contrôle du paludisme. En RD Congo, la prévalence de cette parasitémie est peu documentée. L'objectif de cette étude était de déterminer la prévalence de la parasitémie asymptomatique aussi bien chez les enfants de moins de 5 ans que ceux âgés de plus de cinq ans aux regards des interventions de masse en cours (MILDS). Méthodes il s'agit d'une étude transversale menée chez les écoliers et chez les enfants de moins de cinq ans dans les ménages de Lubumbashi. Les écoles, les écoliers et les enfants de moins de 5 ans avaient été sélectionnés aléatoirement. Les frottis, gouttes épaisses et les tests rapides avaient été prélevés et lues. Résultats sur 350 écoliers examinés, 43 soit une prévalence de 12,3%, IC 95% (9,14-16,04) avaient une goutte épaisse positive. Dans tous les 43 cas, seul le Plasmodium falciparum a été identifié.314 ménages, soit 90,5% ont déclaré avoir recouru aux antipaludéens pour soigner la fièvre de leurs enfants à domicile. Plus d'1/3 des enfants dans les ménages, soit 39,9% des interviewés avait avoué avoir recouru aux antipyrétiques pour soulager la fièvre de leurs enfants, 19,7% à la quinine et seulement moins de 2% aux ACT à base de Lumefantrine. En considérant l'utilisation des TDR, la prévalence due à la parasitémie asymptomatique est de 3% IC 95% (2,075-4,44), mais quand on considère la microscopie comme le gold standard, cette prévalence est de 1,9%, IC 95% (1,13-3,01). Conclusion le paludisme asymptomatique n'est pas exempt de toute conséquence sur la santé, il est donc important de mener des enquêtes pareilles pour identifier les nouvelles stratégies de contrôle du paludisme. PMID:27642433

Vulvovaginite : Dépistage et prise en charge de la trichomonase, de la candidose vulvovaginale et de la vaginose bactérienne.

PubMed

van Schalkwyk, Julie; Yudin, Mark H

2016-12-01

Analyser les données probantes et formuler des recommandations quant au dépistage et à la prise en charge de la candidose vulvovaginale, de la trichomonase et de la vaginose bactérienne. Parmi les issues évaluées, on trouve l'efficacité de l'antibiothérapie, les taux de guérison en ce qui concerne les infections simples et compliquées, et les implications de ces pathologies pendant la grossesse. RéSULTATS: La littérature publiée a été récupérée par l'intermédiaire de recherches menées dans MEDLINE, EMBASE, CINAHL et The Cochrane Library en juin 2013 au moyen d'un vocabulaire contrôlé (p. ex. « vaginitis », « trichomoniasis », « vaginal candidiasis ») et de mots clés (p. ex. « bacterial vaginosis », « yeast », « candidiasis », « trichomonas vaginalis », « trichomoniasis », « vaginitis », « treatment ») appropriés. Les résultats ont été restreints aux analyses systématiques, aux essais comparatifs randomisés / essais cliniques comparatifs et aux études observationnelles. Aucune restriction n'a été appliquée en matière de date, mais les résultats ont été limités aux documents rédigés en anglais ou en français. Les recherches ont été mises à jour de façon régulière et intégrées à la directive clinique jusqu'en mai 2014. La littérature grise (non publiée) a été identifiée par l'intermédiaire de recherches menées dans les sites Web d'organismes s'intéressant à l'évaluation des technologies dans le domaine de la santé et d'organismes connexes, dans des collections de directives cliniques et auprès de sociétés de spécialité médicale nationales et internationales. La qualité des résultats est évaluée au moyen des critères décrits par le Groupe d'étude canadien sur les soins de santé préventifs (Tableau 1). DéCLARATIONS SOMMAIRES: RECOMMANDATIONS. Copyright © 2016. Published by Elsevier Inc.

Monte Carlo Simulations of the Dissolution of Borosilicate and Aluminoborosilicate Glasses in Dilute Aqueous Solutions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kerisit, Sebastien N.; Pierce, Eric M.

The aim of this study was to provide atomic-level insights into the dissolution behavior of borosilicate and aluminoborosilicate glasses to complement and help interpret previous experimental work on the NeB glass series studied by Pierce et al. [Pierce E. M., Reed L. R., Shaw W. J., McGrail B. P., Icenhower J. P., Windisch C. F., Cordova E. A. and Broady J. (2010) Experimental determination of the effect of the ratio of B/Al on glass dissolution along the nepheline (NaAlSiO4) - Malinkoite (NaBSiO4) join. Geochim. Cosmochim. Acta 74, 2634-2654]. The composition of these glasses was 50 mol% SiO2 - 25 mol%more » Na2O - (25-x) mol% Al2O3 - x mol% B2O3, with x varying from 0 to 20 mol%. In the first part of this work, the different structural features of these glasses (e.g., presence of non-bridging oxygens, partition of boron between trigonal and tetrahedral bonding environments, and formation of boroxol rings), identified in the study of Pierce et al., were implemented in the Monte Carlo program. Their effects on the dissolution of borosilicate and aluminosilicate glasses were then evaluated individually and led to the following conclusions. (1) The dependence of the dissolution rate on the amount of non-bridging oxygens was found to be linear at all Si/B ratios and the accelerating effect of non-bridging oxygens was shown to increase with increasing Si/B ratio. (2) The formation of boroxol rings and of clusters of boroxol rings resulted in an increase of the dissolution rate at all Si/B ratios and, again, the extent of the rate increase was strongly dependent on the Si/B ratio. (3) For aluminosilicate glasses, the implementation of the aluminum avoidance rule was found to increase the rate of dissolution relative to that obtained for a random distribution. In the second part of this work, Monte Carlo simulations were performed to model the dissolution of the NeB glasses in dilute conditions. One of the conclusions that emerged from the study of Pierce et al. was that either the rupture of the Al-O bonds or that of the Si-O bonds was the rate-limiting step controlling the dissolution of the NeB glasses. The Monte Carlo simulations carried out in this work enabled us to refine this conclusion. Indeed, the simulations showed that, at low B/Al ratios, the rupture of both Al-O-Si and Si-O-Si linkages contributed to the dissolution rate whereas, at high B/Al ratios, the dissolution rate was independent of the rupture of Al-O-Si linkages and was controlled by S1 sites (silicon sites at the glass-water interface with one bond to nearest-neighbor sites) and dissolution via detachment of clusters.« less

The Communicative Computer Compares: A CALL Design Project for Elementary French.

ERIC Educational Resources Information Center

Kyle, Patricia J.

A computer lesson entitled "Aux Jeux Olympiques" (To the Olympic Games) simulates an ongoing situational dialog between the French student and the PLATO computer system. It offers an international setting for functional learning exercises focusing on students' understanding and use of comparative constructions, selected verbs, and other linguistic…

Properties of Organic Superconductors.

DTIC Science & Technology

1983-09-01

fBEDrrrF) 4 (ReO 4 ) 2 , devient supraconducteur pour des pressions suptrseures A 4 kbar avec une temperature de transition aol environs dce 2 K. A plus...coupl6es aux 6lectrons. Ces experiences sont incompatibles avec linterpr~tation expliquant lorigine /I/ du pic A 29 cm- 1 par un pseudogap supraconducteur

30 CFR Appendix to Part 553 - List of U.S. Geological Survey Topographic Maps

Code of Federal Regulations, 2013 CFR

2013-07-01

...; Three Mile Bay; Tigre Lagoon; Timbalier Island; Triumph; Venice; Weeks; West of Johnson Bayou; Western... Islands; Tivoli SE; Turtle Bay; Umbrella Point; Virginia Point; West of Johnson Bayou; Whites Ranch...; Hollingers Island; Isle Aux Herbes; Kreole; Lillian; Little Dauphin Island; Little Point Clear; Magnolia...

30 CFR Appendix to Part 553 - List of U.S. Geological Survey Topographic Maps

Code of Federal Regulations, 2012 CFR

2012-07-01

...; Three Mile Bay; Tigre Lagoon; Timbalier Island; Triumph; Venice; Weeks; West of Johnson Bayou; Western... Islands; Tivoli SE; Turtle Bay; Umbrella Point; Virginia Point; West of Johnson Bayou; Whites Ranch...; Hollingers Island; Isle Aux Herbes; Kreole; Lillian; Little Dauphin Island; Little Point Clear; Magnolia...

30 CFR Appendix to Part 553 - List of U.S. Geological Survey Topographic Maps

Code of Federal Regulations, 2014 CFR

2014-07-01

...; Three Mile Bay; Tigre Lagoon; Timbalier Island; Triumph; Venice; Weeks; West of Johnson Bayou; Western... Islands; Tivoli SE; Turtle Bay; Umbrella Point; Virginia Point; West of Johnson Bayou; Whites Ranch...; Hollingers Island; Isle Aux Herbes; Kreole; Lillian; Little Dauphin Island; Little Point Clear; Magnolia...

Déprescrire les inhibiteurs de la pompe à protons

PubMed Central

Farrell, Barbara; Pottie, Kevin; Thompson, Wade; Boghossian, Taline; Pizzola, Lisa; Rashid, Farah Joy; Rojas-Fernandez, Carlos; Walsh, Kate; Welch, Vivian; Moayyedi, Paul

2017-01-01

Résumé Objectif Formuler des lignes directrices fondées sur les données probantes pour aider les cliniciens à décider du moment et de la façon sécuritaire de réduire la dose des inhibiteurs de la pompe à protons (IPP) ou d’en arrêter le traitement; se concentrer sur le niveau le plus élevé des données disponibles et obtenir les commentaires des professionnels de première ligne durant le processus de rédaction, de révision et d’adoption des lignes directrices. Méthodologie L’équipe était formée de 5 professionnels de la santé (1 médecin de famille, 3 pharmaciens et 1 gastro-entérologue) et de 5 membres sans droit de vote; les membres ont divulgué tout conflit d’intérêts. Le processus d’élaboration des lignes directrices a eu recours à l’approche GRADE (Grading of Recommendations Assessment, Development and Evaluation), de même qu’à un examen minutieux des données probantes dans le cadre de rencontres en personne, au téléphone et en ligne. Particulièrement, le processus d’élaboration des lignes directrices a inclus une revue systématique d’essais portant sur la déprescription des IPP et un examen de comptes rendus sur les torts liés à l’emploi continu des IPP. Les synthèses narratives sur les préférences des patients ainsi que les publications traitant des répercussions sur les ressources ont éclairé les recommandations. L’équipe a peaufiné le texte sur le contenu et les recommandations des lignes directrices par consensus, et a synthétisé les considérations cliniques afin de répondre aux questions courantes des cliniciens de première ligne. Une version préliminaire des lignes directrices a été distribuée aux cliniciens, puis aux associations de professionnels de la santé aux fins d’examen, et des révisions ont été apportées au texte à chaque étape. Un algorithme d’appui décisionnel a été conçu de concert avec les lignes directrices. Recommandations Les présentes lignes directrices recommandent de déprescrire les IPP (réduire la dose, mettre fin au traitement ou passer à l’administration « sur demande ») chez les adultes qui ont terminé un traitement d’au moins 4 semaines avec un IPP contre le pyrosis, l’œsophagite ou le reflux gastro-œsophagien léger à modéré, et dont les symptômes sont disparus. Les recommandations ne s’appliquent pas aux patients atteints ou qui ont déjà été atteints de l’œsophage de Barrett, d’une œsophagite grave de stade C ou D, ou d’antécédents connus d’ulcères gastro-intestinaux hémorragiques. Conclusion Les présentes lignes directrices émettent des recommandations pratiques pour décider du moment et de la façon de réduire la dose des inhibiteurs de la pompe à protons (IPP) ou d’en arrêter le traitement. Elles visent à contribuer au processus de décision conjointement avec le patient et non à dicter la décision.

SUMMARY OF FY11 SULFATE RETENTION STUDIES FOR DEFENSE WASTE PROCESSING FACILITY GLASS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fox, K.; Edwards, T.

2012-05-08

This report describes the results of studies related to the incorporation of sulfate in high level waste (HLW) borosilicate glass produced at the Savannah River Site (SRS) Defense Waste Processing Facility (DWPF). A group of simulated HLW glasses produced for earlier sulfate retention studies was selected for full chemical composition measurements to determine whether there is any clear link between composition and sulfate retention over the compositional region evaluated. In addition, the viscosity of several glasses was measured to support future efforts in modeling sulfate solubility as a function of predicted viscosity. The intent of these studies was to developmore » a better understanding of sulfate retention in borosilicate HLW glass to allow for higher loadings of sulfate containing waste. Based on the results of these and other studies, the ability to improve sulfate solubility in DWPF borosilicate glasses lies in reducing the connectivity of the glass network structure. This can be achieved, as an example, by increasing the concentration of alkali species in the glass. However, this must be balanced with other effects of reduced network connectivity, such as reduced viscosity, potentially lower chemical durability, and in the case of higher sodium and aluminum concentrations, the propensity for nepheline crystallization. Future DWPF processing is likely to target higher waste loadings and higher sludge sodium concentrations, meaning that alkali concentrations in the glass will already be relatively high. It is therefore unlikely that there will be the ability to target significantly higher total alkali concentrations in the glass solely to support increased sulfate solubility without the increased alkali concentration causing failure of other Product Composition Control System (PCCS) constraints, such as low viscosity and durability. No individual components were found to provide a significant improvement in sulfate retention (i.e., an increase of the magnitude necessary to have a dramatic impact on blending, washing, or waste loading strategies for DWPF) for the glasses studied here. In general, the concentrations of those species that significantly improve sulfate solubility in a borosilicate glass must be added in relatively large concentrations (e.g., 13 to 38 wt % or more of the frit) in order to have a substantial impact. For DWPF, these concentrations would constitute too large of a portion of the frit to be practical. Therefore, it is unlikely that specific additives may be introduced into the DWPF glass via the frit to significantly improve sulfate solubility. The results presented here continue to show that sulfate solubility or retention is a function of individual glass compositions, rather than a property of a broad glass composition region. It would therefore be inappropriate to set a single sulfate concentration limit for a range of DWPF glass compositions. Sulfate concentration limits should continue to be identified and implemented for each sludge batch. The current PCCS limit is 0.4 wt % SO{sub 4}{sup 2-} in glass, although frit development efforts have led to an increased limit of 0.6 wt % for recent sludge batches. Slightly higher limits (perhaps 0.7-0.8 wt %) may be possible for future sludge batches. An opportunity for allowing a higher sulfate concentration limit at DWPF may lay lie in improving the laboratory experiments used to set this limit. That is, there are several differences between the crucible-scale testing currently used to define a limit for DWPF operation and the actual conditions within the DWPF melter. In particular, no allowance is currently made for sulfur partitioning (volatility versus retention) during melter processing as the sulfate limit is set for a specific sludge batch. A better understanding of the partitioning of sulfur in a bubbled melter operating with a cold cap as well as the impacts of sulfur on the off-gas system may allow a higher sulfate concentration limit to be established for the melter feed. This approach would have to be taken carefully to ensure that a sulfur salt layer is not formed on top of the melt pool while allowing higher sulfur based feeds to be processed through DWPF.« less

Application of the Evacuated Canister System for Removing Residual Molten Glass From the West Valley Demonstration Project High-Level Waste Melter

DOE Office of Scientific and Technical Information (OSTI.GOV)

May, Joseph J.; Dombrowski, David J.; Valenti, Paul J.

The principal mission of the West Valley Demonstration Project (WVDP) is to meet a series of objectives defined in the West Valley Demonstration Project Act (Public Law 96-368). Chief among these is the objective to solidify liquid high-level waste (HLW) at the WVDP site into a form suitable for disposal in a federal geologic repository. In 1982, the Secretary of Energy formally selected vitrification as the technology to be used to solidify HLW at the WVDP. One of the first steps in meeting the HLW solidification objective involved designing, constructing and operating the Vitrification (Vit) Facility, the WVDP facility thatmore » houses the systems and subsystems used to process HLW into stainless steel canisters of borosilicate waste-glass that satisfy waste acceptance criteria (WAC) for disposal in a federal geologic repository. HLW processing and canister production began in 1996. The final step in meeting the HLW solidification objective involved ending Vit system operations and shut ting down the Vit Facility. This was accomplished by conducting a discrete series of activities to remove as much residual material as practical from the primary process vessels, components, and associated piping used in HLW canister production before declaring a formal end to Vit system operations. Flushing was the primary method used to remove residual radioactive material from the vitrification system. The inventory of radioactivity contained within the entire primary processing system diminished by conducting the flushing activities. At the completion of flushing activities, the composition of residual molten material remaining in the melter (the primary system component used in glass production) consisted of a small quantity of radioactive material and large quantities of glass former materials needed to produce borosilicate waste-glass. A special system developed during the pre-operational and testing phase of Vit Facility operation, the Evacuated Canister System (ECS), was deployed at the West Valley Demonstration Project to remove this radioactively dilute, residual molten material from the melter before Vit system operations were brought to a formal end. The ECS consists of a stainless steel canister of the same size and dimensions as a standard HLW canister that is equipped with a special L-shaped snorkel assembly made of 304L stainless steel. Both the canister and snorkel assembly fit into a stainless steel cage that allows the entire canister assembly to be positioned over the melter as molten glass is drawn out by a vacuum applied to the canister. This paper describes the process used to prepare and apply the ECS to complete molten glass removal before declaring a formal end to Vit system operations and placing the Vit Facility into a safe standby mode awaiting potential deactivation.« less

Interventions et techniques de diagnostic prénatal visant l'obtention d'un prélèvement fœtal à des fins diagnostiques : Risques et avantages pour la mère et le fœtus.

PubMed

Wilson, R Douglas; Gagnon, Alain; Audibert, François; Campagnolo, Carla; Carroll, June

2016-12-01

Offrir aux fournisseurs de soins de maternité et à leurs patientes des lignes directrices factuelles contemporaines en ce qui concerne les services de counseling traitant des risques et des avantages maternels propres à la tenue des interventions diagnostiques prénatales orientées par échographie (et/ou des techniques permettant l'établissement d'un diagnostic génétique) nécessaires dans les cas où il a été établi pendant la période prénatale que la grossesse serait exposée à des risques, ainsi qu'en ce qui concerne la prise de décisions subséquentes quant à la prise en charge de la grossesse (questions abordant des aspects tels que le niveau du fournisseur de soins obstétricaux, la surveillance prénatale, le lieu où devraient se dérouler les soins et l'accouchement, et la décision de poursuivre ou d'interrompre la grossesse). La présente directive clinique se limite aux services de counseling traitant des risques et des avantages maternels, et aux décisions en matière de prise en charge de la grossesse pour les femmes qui nécessitent (ou qui envisagent) la mise en œuvre d'une intervention ou d'une technique effractive orientée par échographie aux fins de l'établissement d'un diagnostic prénatal. Femmes enceintes identifiées, à la suite de la mise en œuvre de protocoles établis de dépistage prénatal (taux sériques maternels ± imagerie, résultats d'analyse de l'ADN acellulaire indiquant des risques élevés, résultats anormaux au moment de l'imagerie fœtale diagnostique ou antécédents familiaux de troubles héréditaires), comme étant exposées à un risque accru d'anomalie génétique fœtale. Ces femmes pourraient nécessiter ou demander des services de counseling au sujet des risques et des avantages pour la grossesse de la tenue d'une intervention effractive orientée par échographie visant à déterminer l'étiologie, le diagnostic, et/ou la pathologie de possibles anomalies fœtales. RéSULTATS: La littérature publiée a été récupérée par l'intermédiaire de recherches menées dans Medline, PubMed et The Cochrane Library jusqu'en juin 2014 au moyen d'un vocabulaire contrôlé (« prenatal diagnosis », « amniocentesis », « chorionic villi sampling », « cordocentesis ») et de mots clés (« prenatal screening », « prenatal genetic counselling », « post-procedural pregnancy loss rate ») appropriés. Les résultats ont été restreints aux analyses systématiques, aux études observationnelles et aux essais comparatifs randomisés / essais cliniques comparatifs publiés en anglais entre janvier 1985 et juin 2014. Les recherches ont été mises à jour de façon régulière et intégrées à la directive clinique jusqu'en juin 2014. La littérature grise (non publiée) a été identifiée par l'intermédiaire de recherches menées dans les sites Web d'organismes s'intéressant à l'évaluation des technologies dans le domaine de la santé et d'organismes connexes, dans des collections de directives cliniques, dans des registres d'essais cliniques et auprès de sociétés de spécialité médicale nationales et internationales. La qualité des résultats a été évaluée au moyen des critères décrits dans le rapport du Groupe d'étude canadien sur les soins de santé préventifs (Tableau 1). AVANTAGES, DéSAVANTAGES ET COûTS: Consentement éclairé de la patiente, transfert des connaissances, évaluation du risque génétique prénatal, soulagement de l'anxiété, création d'anxiété, défense des droits, compréhension du dépistage fœtal, limites du dépistage fœtal, choix en matière de prise en charge de la grossesse, complication de la grossesse ou fausse couche, soins opportuns et améliorés pour l'accouchement d'un enfant présentant une morbidité reconnue. RECOMMANDATIONS. Copyright © 2016. Published by Elsevier Inc.

Method for dissolution and stabilization of silica-rich fibers

DOEpatents

Jantzen, C.M.

1997-11-11

A method is described for dissolving silica-rich fibers such as borosilicate fibers, fiberglass and asbestos to stabilize them for disposal. The method comprises (1) immersing the fibers in hot, five-weight-percent sodium hydroxide solution until the concentration of dissolved silica reaches equilibrium and a only a residue is left (about 48 hours), then immersing the residue in hot, five-weight-percent nitric acid until the residue dissolves (about 96 hours). After adjusting the pH of the dissolved fibers to be caustic, the solution can then be added to a waste vitrification stream for safe disposal. The method is useful in disposing contaminated HEME and HEPA filters. 1 fig.

Visible supercontinuum generation from a tunable mid-infrared laser

NASA Astrophysics Data System (ADS)

Marble, Christopher B.; O'Connor, Sean P.; Nodurft, Dawson T.; Yakovlev, Vladislav V.; Wharmby, Andrew W.

2018-02-01

Calcium fluoride, BK7 and fused silica are common optical materials used in lenses and windows. In this report, we discuss supercontinuum generation using tunable femtosecond mid-IR laser pulses with wavelengths ranging from 2.7 μm to 7.0 μm and pulse energies between 3 and 18 microjoules. We observed harmonic generation in fused silica and BK7, but not supercontinuum generation. Other borosilicate targets generated supercontinuum in both visible and near infrared regions of the spectrum. The visible supercontinuum was, in some instances, strong enough to be observed directly by the human eye. These results contribute to ongoing work being done to refine eye safety standards for femtosecond lasers.

Thermal Protection Supplement for Reducing Interface Thermal Mismatch

NASA Technical Reports Server (NTRS)

Stewart, David A. (Inventor); Leiser, Daniel B. (Inventor)

2017-01-01

A thermal protection system that reduces a mismatch of thermal expansion coefficients CTE between a first material layer (CTE1) and a second material layer (CTE2) at a first layer-second layer interface. A portion of aluminum borosilicate (abs) or another suitable additive (add), whose CTE value, CTE(add), satisfies (CTE(add)-CTE1)(CTE(add)-CTE2)<0, is distributed with variable additive density,.rho.(z;add), in the first material layer and/or in the second material layer, with.rho.(z;add) near the materials interface being relatively high (alternatively, relatively low) and.rho.(z;add) in a region spaced apart from the interface being relatively low (alternatively, relatively high).

Cesium titanium silicate and method of making

DOEpatents

Balmer, Mari L.

1997-01-01

The invention is the new material, a ternary compound of cesium, silica, and titania, together with a method of making the ternary compound, cesium titanium silicate pollucite. More specifically, the invention is Cs.sub.2 Ti.sub.2 Si.sub.4 O.sub.13 pollucite which is a new crystalline phase representing a novel class of Ti-containing zeolites. Compositions contain relatively high Cs.sub.2 O and TiO.sub.2 loadings and are durable glass and ceramic materials. The amount of TiO.sub.2 and Cs.sub.2 that can be incorporated into these glasses and crystalline ceramics far exceeds the limits set for the borosilicate high level waste glass.

Cesium titanium silicate and method of making

DOEpatents

Balmer, M.L.

1997-01-07

The invention is the new material, a ternary compound of cesium, silica, and titania, together with a method of making the ternary compound, cesium titanium silicate pollucite. More specifically, the invention is Cs{sub 2}Ti{sub 2}Si{sub 4}O{sub 13} pollucite which is a new crystalline phase representing a novel class of Ti-containing zeolites. Compositions contain relatively high Cs{sub 2}O and TiO{sub 2} loadings and are durable glass and ceramic materials. The amount of TiO{sub 2} and Cs{sub 2} that can be incorporated into these glasses and crystalline ceramics far exceeds the limits set for the borosilicate high level waste glass. 10 figs.

A Role for the Mannose-Sensitive Hemagglutinin in Biofilm Formation by Vibrio cholerae El Tor

PubMed Central

Watnick, Paula I.; Fullner, Karla Jean; Kolter, Roberto

1999-01-01

While much has been learned regarding the genetic basis of host-pathogen interactions, less is known about the molecular basis of a pathogen’s survival in the environment. Biofilm formation on abiotic surfaces represents a survival strategy utilized by many microbes. Here it is shown that Vibrio cholerae El Tor does not use the virulence-associated toxin-coregulated pilus to form biofilms on borosilicate but rather uses the mannose-sensitive hemagglutinin (MSHA) pilus, which plays no role in pathogenicity. In contrast, attachment of V. cholerae to chitin is shown to be independent of the MSHA pilus, suggesting divergent pathways for biofilm formation on nutritive and nonnutritive abiotic surfaces. PMID:10348878

Emotional and behavioural reactions to moral transgressions: cross-cultural and individual variations in India and Britain.

PubMed

Laham, Simon M; Chopra, Sonavi; Lalljee, Mansur; Parkinson, Brian

2010-02-01

Reactions to moral transgressions are subject to influence at both the cultural and individual levels. Transgressions against an individual's rights or against social conventions of hierarchy may elicit different reactions in individualistic and collectivistic cultures. In the current study, affective and behavioural reactions to transgressions of autonomy (rights) and community (hierarchy) were examined in India and Britain. Results revealed that although reactions to autonomy transgressions are similar in India and Britain, Indian participants express more moral outrage than do Britons in response to transgressions of community. Results also supported the contention of emotion-specificity in affective moral reaction: Participants in both India and Britain reported anger in response to autonomy transgressions, but contempt in response to violations of community. Importantly, these results extend previous research by demonstrating the importance of emotion specificity in moral reactions, as opposed to categorization or dilemma resolution. In addition, an individual difference measure of respect for persons was shown to moderate reactions to moral transgressions. Specifically, participants with high respect for persons were less negative to violators of the community ethic, but not the autonomy ethic. These findings highlight the importance of examining emotion-specific responses in the moral domain and introduce a significant individual difference variable, respect for persons, into the psychology of morality. Les réactions aux transgressions morales sont susceptibles d'influence à la fois aux niveaux culturel et individuel. Les transgressions contre les droits d'un individu ou contre les conventions sociales d'hiérarchie peuvent susciter de différentes réactions dans les cultures individualiste et collectiviste. Dans la présente étude, les réactions affective et comportementale aux transgressions de l'autonomie (droits) et de la communauté (hiérachie) ont été examinées en Inde et en Grande-Bretagne. Les résultats ont indiqué que, malgré la similitude des réactions aux transgressions de l'autonomie en Inde et en Grande-Bretagne, les participants indiens ont exprimé plus d'indignation morale que les britanniques en réponse aux transgressions de la communauté. Les résultats ont également appuyé la controverse de la spécifité de l'émotion dans la relation morale affective: les participants à la fois en Inde et en Grande-Bretagne ont rapporté de la colère en réponse aux transgressions de l'autonomie mais du mépris en réponse aux transgressions de la communauté. De façon importante, ces résultats ont élargi la recherche passée en démontrant l'importance de la spécificité de l'émotion dans les réactions morales, contrairement à la catégorisation ou à la solution du dilemme. En plus, il a été démontré qu'une mesure des différences individuelles du respect envers les personnes a modéré les réactions aux transgressions morales. Spécifiquement, les participants ayant un grand respect envers les personnes ont été moins négatifs envers les violateurs de l'éthique de la communauté mais pas de l'éthique de l'autonomie. Ces résultats soulignent l'importance d'examiner les réponses spécifique à l'émotion dans le domaine moral et introduisent une variable des différences individuelles, soit le respect envers les personnes, dans la psychologie de la moralité. Las reacciones a las transgresiones morales están sujetas a la influencia a niveles culturales e individuales. Las transgresiones contra los derechos individuales o convenciones sociales de jerarquías pueden provocar distintas reacciones en las culturas individualistas y colectivistas. En el presente estudio, se examinaron las reacciones afectivas y conductuales a las transgresiones contra la autonomía (derechos) y comunidad (jerarquía) en la India y en Gran Bretaña. Los resultados demostraron que, aunque las reacciones a las transgresiones contra la autonomía fueran parecidas en la India y en Gran Bretaña, los participantes indios expresaron más indignación moral que los británicos en la respuesta a la transgresión contra la comunidad. Los resultados también apoyan la visión de la especificidad emocional en la reacción afectiva moral: los participantes en la India y también en Gran Bretaña mostraron ira en respuesta a la transgresión contra la autonomía y desprecio en respuesta a la violación de la comunidad. De forma importante, estos resultados amplían los estudios anteriores demostrando la importancia de la especificidad emocional en las reacciones morales frente a la categorización o resolución de los dilemas. Adicionalmente, las medidas de las diferencias individuales en el respeto para personas moderan las reacciones a la transgresión moral. Específicamente, los participantes con alto respeto para personas fueron menos negativos a la hora de violar la ética de la comunidad pero no la ética de la autonomía. Estos resultados subrayan la importancia de estudiar las respuestas emocionales específicas en el dominio moral e introducen una variable de diferencias individuales significativas, respeto para personas, dentro de la psicología de la moralidad.

Implementation en VHDl/FPGA d'afficheur video numerique (AVN) pour des applications aerospatiales

NASA Astrophysics Data System (ADS)

Pelletier, Sebastien

L'objectif de ce projet est de developper un controleur video en langage VHDL afin de remplacer la composante specialisee presentement utilisee chez CMC Electronique. Une recherche approfondie des tendances et de ce qui se fait actuellement dans le domaine des controleurs video est effectuee afin de definir les specifications du systeme. Les techniques d'entreposage et d'affichage des images sont expliquees afin de mener ce projet a terme. Le nouveau controleur est developpe sur une plateforme electronique possedant un FPGA, un port VGA et de la memoire pour emmagasiner les donnees. Il est programmable et prend peu d'espace dans un FPGA, ce qui lui permet de s'inserer dans n'importe quelle nouvelle technologie de masse a faible cout. Il s'adapte rapidement a toutes les resolutions d'affichage puisqu'il est modulaire et configurable. A court terme, ce projet permettra un controle ameliore des specifications et des normes de qualite liees aux contraintes de l'avionique.

Experiences in porting NASTRAN (R) to non-traditional platforms

NASA Technical Reports Server (NTRS)

Davis, Gregory L.; Norton, Robert L.

1991-01-01

The 1990 UNIX version of NASTRAN was ported to two new platforms that are not supported by COSMIC: the Sun SPARC workstation and the Apple Macintosh using the A/UX version of UNIX. The experiences of the authers in porting NASTRAN is summarized here. Suggestions for users who might attempt similar ports are given.

L'Enseignement de la Prononciation Francaise aux Niveaux Phonemique et Phonetique (The Teaching of French Pronunciation at the Phonemic and Phonetic Levels)

ERIC Educational Resources Information Center

Maire, Jean-Francois

1975-01-01

Gives the justification, text, and examples of two recordings illustrating the phonetic oppositions of four French vowels. The tapes were produced and tested at the Universite de Lausanne, and are intended for language laboratory use. (Text is in French.) (MSE)

Development of a High Level Architecture Federation of Ship Replenishment at Sea

DTIC Science & Technology

2011-10-01

utiliser une infrastructure de simulation appelée architecture de haut niveau (HLA) afin de fournir des environne - ments de simulation interarmées...fournir un environnement de simulation qui modélise l’interactions entre les divers composants afin de simuler les conditions qui mènent aux

Pratique d'apprentissage en ligne aux etudes superieures (Online Learning for Higher Education).

ERIC Educational Resources Information Center

Marchand, Louise

2001-01-01

Online learning requires new approaches to teaching and learning. At the University of Montreal, 28 graduate students in education and adult students specializing in educational technology attended an experimental distance education course. Students identified advantages and disadvantages of online learning/teaching and reflected on how the course…

Brassinosteroid control of shoot gravitropism interacts with ethylene and depends on auxin signaling components.

PubMed

Vandenbussche, Filip; Callebert, Pieter; Zadnikova, Petra; Benkova, Eva; Van Der Straeten, Dominique

2013-01-01

To reach favorable conditions for photosynthesis, seedlings grow upward when deprived of light upon underground germination. To direct their growth, they use their negative gravitropic capacity. Negative gravitropism is under tight control of multiple hormones. By counting the number of standing plants in a population or by real time monitoring of the reorientation of gravistimulated seedlings of Arabidopsis thaliana, we evaluated the negative gravitropism of ethylene or brassinosteroid (BR) treated plants. Meta-analysis of transcriptomic data on AUX/IAA genes was gathered, and subsequent mutant analysis was performed. Ethylene and BR have opposite effects in regulating shoot gravitropism. Lack of BR enhances gravitropic reorientation in 2-d-old seedlings, whereas ethylene does not. Lack of ethylene signaling results in enhanced BR sensitivity. Ethylene and BRs regulate overlapping sets of AUX/IAA genes. BRs regulate a wider range of auxin signaling components than ethylene. Upward growth in seedlings depends strongly on the internal hormonal balance. Endogenous ethylene stimulates, whereas BRs reduce negative gravitropism in a manner that depends on the function of different, yet overlapping sets of auxin signaling components.

La prévention des blessures chez les enfants et les adolescents : une démarche de santé publique

PubMed Central

Yanchar, Natalie L; Warda, Lynne J; Fuselli, Pamela

2012-01-01

RÉSUMÉ La majorité des blessures dont sont victimes les enfants et les adolescents sont évitables. Le présent document de principes contient des renseignements généraux, des conseils et une déclaration d’engagement à l’égard de la prévention des blessures au Canada. Il sert de base sur laquelle construire en s’attardant d’abord aux définitions, à l’étendue et aux priorités en matière de prévention des blessures. Il contient également une description du fardeau et du profil des blessures non intentionnelles, de même que les principes d’interventions de prévention efficaces. La version intégrale renferme une liste de ressources en vue d’obtenir des données et de l’information probante (www.cps.ca). Enfin, le présent document de principes peut être utilisé pour la défense généralisée de la prévention des blessures.

Pilot Production of Large Area Microchannel Plates and Picosecond Photodetectors

NASA Astrophysics Data System (ADS)

Minot, M.; Adams, B.; Abiles, M.; Bond, J.; Craven, C.; Cremer, T.; Foley, M.; Lyashenko, A.; Popecki, M.; Stochaj, M.; Worstell, W.; Elam, J.; Mane, A.; Siegmund, O.; Ertley, C.

2016-09-01

Pilot production performance is reported for large area atomic layer deposition (ALD) coated microchannel plates (ALD-GCA-MCPs) and for Large Area Picosecond Photodetectors (LAPPD™) which incorporate them. "Hollowcore" glass capillary array (GCA) substrates are coated with ALD resistive and emissive layers to form the ALDGCA- MCPs, an approach that facilitates independent selection of glass substrates that are mechanically stronger and that have lower levels of radioactive alkali elements compared to conventional MCP lead glass, reducing background noise[1,2,3,4]. ALD-GCA-MCPs have competitive gain ( 104 each or 107 for a chevron pair ), enhanced lifetime and gain stability (7 C cm-2 of charge extraction), reduced background levels (0.028 events cm-2 sec-1) and low gamma-ray detection efficiency. They can be fabricated in large area (20cm X 20 cm) planar and curved formats suitable for use in high radiation environment applications, including astronomy, space instrumentation, and remote night time sensing. The LAPPD™ photodetector incorporates these ALD-GCA-MCPs in an all-glass hermetic package with top and bottom plates and sidewalls made of borosilicate float glass. Signals are generated by a bi-alkali Na2KSb photocathode, amplified with a stacked chevron pair of ALD-GCA-MCPs. Signals are collected on RF strip-line anodes integrated into to the bottom plates which exit the detector via pin-free hermetic seals under the side walls [5]. Tests show that LAPPDTMs have electron gains greater than 107, submillimeter spatial resolution for large (multiphoton) pulses and several mm for single photons, time resolution less than 50 picoseconds for single photons, predicted resolution less than 5 picoseconds for large pulses, high stability versus charge extraction[6], and good uniformity for applications including astrophysics, neutron detection, high energy physics Cherenkov light detection, and quantum-optical photon-correlation experiments.