WorldWideScience

Sample records for application au formaldehyde

  1. The microcapsule-type formaldehyde scavenger: the preparation and the application in urea-formaldehyde adhesives.

    Science.gov (United States)

    Duan, Hongyun; Qiu, Teng; Guo, Longhai; Ye, Jun; Li, Xiaoyu

    2015-08-15

    The limitation and regulation of formaldehyde emissions (FE) now shows great importance in wood-based materials such as plywood and particle board manufactured for building and furnishing materials. The widely used formaldehyde-based adhesives are one of the main sources of FE from the wood products. In this work, a new kind of long-term effective formaldehyde scavenger in the microcapsule form was prepared by using an intra-liquid desiccation method. The characterizations of the capsule (UC) were performed including the morphologies, the yields, the loading efficiency as well as its sustained-release of urea in aqueous conditions. The prepared UC could be integrated in urea-formaldehyde resins by simply physical blending, and the mixtures were available to be applied as the adhesives for the manufacture of plywood. The bonding strength (BS) and the FE of the bonded plywood in both short (3h) and long (12 week) period were evaluated in detail. It was found that the FE profile of the plywood behaved following a duple exponential law within 12 week. The addition of UC in the adhesive can effectively depress the FE of the plywood not only in a short period after preparation but also in a long-term period during its practical application. The slow released urea would continuously suppress the emission of toxic formaldehyde in a sustained manner without obviously deteriorating on the BS of the adhesives. PMID:25855565

  2. 75 FR 37792 - Formaldehyde Gas; Receipt of Application for Emergency Exemption, Solicitation of Public Comment

    Science.gov (United States)

    2010-06-30

    ... AGENCY Formaldehyde Gas; Receipt of Application for Emergency Exemption, Solicitation of Public Comment... (OSWER) to use formaldehyde gas (CAS No. 82115-62-6) to decontaminate non-food contact surfaces to... Administrator to issue a quarantine exemption for the use of formaldehyde gas on non-food contact surfaces...

  3. Low-power formaldehyde detector for space applications Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Trace contamination of the International Space Station (ISS) by formaldehyde?a known carcinogen? is a significant potential threat to crew health. The spacecraft...

  4. Low-Power Formaldehyde Detector for Space Applications Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Trace contamination of the International Space Station (ISS) by formaldehyde -- a known carcinogen -- is a significant threat to crew health. The spacecraft maximum...

  5. Formaldehyde-releasers: relationship to formaldehyde contact allergy. Contact allergy to formaldehyde and inventory of formaldehyde-releasers

    DEFF Research Database (Denmark)

    de Groot, Anton C; Flyvholm, Mari-Ann; Lensen, Gerda;

    2009-01-01

    This is one of series of review articles on formaldehyde and formaldehyde-releasers (others: formaldehyde in cosmetics, in clothes and in metalworking fluids and miscellaneous). Thirty-five chemicals were identified as being formaldehyde-releasers. Although a further seven are listed in the...... literature as formaldehyde-releasers, data are inadequate to consider them as such beyond doubt. Several (nomenclature) mistakes and outdated information are discussed. Formaldehyde and formaldehyde allergy are reviewed: applications, exposure scenarios, legislation, patch testing problems, frequency of...... sensitization, relevance of positive patch test reactions, clinical pattern of allergic contact dermatitis from formaldehyde, prognosis, threshold for elicitation of allergic contact dermatitis, analytical tests to determine formaldehyde in products and frequency of exposure to formaldehyde and releasers. The...

  6. Application of toxicogenomic profiling to evaluate effects of benzene and formaldehyde: from yeast to human

    Science.gov (United States)

    McHale, Cliona M.; Smith, Martyn T.; Zhang, Luoping

    2014-01-01

    Genetic variation underlies a significant proportion of the individual variation in human susceptibility to toxicants. The primary current approaches to identify gene–environment (GxE) associations, genome-wide association studies (GWAS) and candidate gene association studies, require large exposed and control populations and an understanding of toxicity genes and pathways, respectively. This limits their application in the study of GxE associations for the leukemogens benzene and formaldehyde, whose toxicity has long been a focus of our research. As an alternative approach, we applied innovative in vitro functional genomics testing systems, including unbiased functional screening assays in yeast and a near-haploid human bone marrow cell line (KBM7). Through comparative genomic and computational analyses of the resulting data, we have identified human genes and pathways that may modulate susceptibility to benzene and formaldehyde. We have validated the roles of several genes in mammalian cell models. In populations occupationally exposed to low levels of benzene, we applied peripheral blood mononuclear cell transcriptomics and chromosome-wide aneuploidy studies (CWAS) in lymphocytes. In this review of the literature, we describe our comprehensive toxicogenomic approach and the potential mechanisms of toxicity and susceptibility genes identified for benzene and formaldehyde, as well as related studies conducted by other researchers. PMID:24571325

  7. Demethylation of Wheat Straw Alkali Lignin for Application in Phenol Formaldehyde Adhesives

    Directory of Open Access Journals (Sweden)

    Yan Song

    2016-05-01

    Full Text Available Lignin is a natural biopolymer with a complex three-dimensional network. It is the second most abundant natural polymer on earth. Commercially, lignin is largely obtained from the waste liquors of pulping and bioethanol productions. In this study, wheat straw alkali lignin (WSAL was demethylated by using an in-situ generated Lewis acid under an optimized demethylation process. The demethylation process was monitored by a semi-quantitative Fourier Transform Infrared Spectroscopy (FTIR method. The demethylated wheat straw alkali lignin (D-WSAL was further characterized by Proton Nuclear Magnetic Resonance (1H NMR, Gel Permeation Chromatography (GPC, and titration methods. After the demethylation process, it was found that the relative value of the methoxy group decreased significantly from 0.82 to 0.17 and the phenolic hydroxyl group increased from 5.2% to 16.0%. Meanwhile, the hydroxyl content increased from 6.6% to 10.3%. GPC results suggested that the weighted averaged molecular weight of D-WSAL was lower than that of WSAL with a smaller polydispersity index. The D-WSAL was then used to replace 60 wt % of phenol to prepare lignin-based phenol formaldehyde adhesives (D-LPF. It was found that both the free formaldehyde content and the free phenol content in D-LPF were less than those of the lignin-based phenol formaldehyde adhesives without lignin demethylation (LPF. Gel time of D-LPF was shortened. Furthermore, the wet and dry bonding strengths of lap shear wood samples bonded using D-LPF were higher than those of the samples bonded using LPF. Therefore, D-WSAL has shown good potential for application in phenol formaldehyde adhesives.

  8. Raman spectra of methane, ethylene, ethane, dimethyl ether, formaldehyde and propane for combustion applications

    International Nuclear Information System (INIS)

    Spontaneous Raman scattering measurements of temperature and major species concentration in hydrocarbon-air flames require detailed knowledge of the Raman spectra of the hydrocarbons present when fuels more complex than methane are used. Although hydrocarbon spectra have been extensively studied at room temperature, there are no data available at higher temperatures. Quantum mechanical calculations, when available are not sufficiently accurate for combustion applications. This work presents experimental measurements of spontaneous Stokes–Raman scattering spectra of methane, ethylene, ethane, dimethyl ether, formaldehyde and propane in the temperature range 300–860 K. Raman spectra from heated hydrocarbons jets have been collected with a higher resolution than is generally employed for Raman measurements in combustion applications. A set of synthetic spectra have been generated for each hydrocarbon, providing the basis for extrapolation to higher temperatures. The spectra provided here will enable simultaneous measurements of multiple hydrocarbons in flames. This capability will greatly extend the range of applicability of Raman measurements in combustion applications. In addition, the experimental spectra provide a validation dataset for quantum mechanical models. - Highlights: • Experimental Raman spectra of hydrocarbons in the 300–860 K temperature range. • Experimental Raman spectra of formaldehyde in the 400–860 K temperature range. • “Synthetic” spectra as sum of Gaussian curves to match experimental spectra. • Low resolution spectra typical of combustion application from “synthetic” spectra

  9. Evaluation of Mechanical Properties and Formaldehyde Emission of Plywood Manufactured for Construction Applications

    OpenAIRE

    Mohamed Salem; Martin Böhm; Jaromír Srba

    2013-01-01

    This study was aimed to evaluate some mechanical properties and formaldehyde emission of beech plywood panels manufactured from rotary cut veneers using phenol–formaldehyde (PF) resin. Six plywood panels of 5 plies with 15 mm thickness were manufactured. Modulus of rupture (MOR), modulus of elasticity (MOE) and formaldehyde emission values were determined. The values of MOR and MOE were higher than the EN requirements. Furthermore, the formaldehyde emission values measured by the European sma...

  10. Chemistry of Phosphorylated Formaldehyde Derivatives. Part I

    OpenAIRE

    Vasily P. Morgalyuk

    2014-01-01

    The underinvestigated derivatives of unstable phosphorylated formaldehyde acetals and some of the structurally related compounds, such as thioacetals, aminonitriles, aminomethylphosphinoyl compounds, are considered. Separately considered are halogen aminals of phosphorylated formaldehyde, acetals of phosphorylated formaldehyde of H-phosphinate-type and a phosphorylated gem-diol of formaldehyde. Synthetic methods, chemical properties and examples of practical applications are given.

  11. Trace gas sensing using quantum cascade lasers and a fiber-coupled optoacoustic sensor: Application to formaldehyde

    International Nuclear Information System (INIS)

    We will report here on the design and realization of an optoacoustic sensor for the detection of formaldehyde. The sensor consists of a commercial QCL and a resonant PA cell. Two different cell configurations have been investigated: a 'standard' H cell and an innovative T-cell with an optical fiber directly inserted into. Two different type of sound detector have been employed: electret microphones and optical MEMS-based microphone. As possible applications, we will describe the results obtained in the detection of formaldehyde (CH2O), a gas of great interest for industrial processes and environmental monitoring.

  12. Raman spectra of methane, ethylene, ethane, dimethyl ether, formaldehyde and propane for combustion applications

    Science.gov (United States)

    Magnotti, G.; KC, U.; Varghese, P. L.; Barlow, R. S.

    2015-09-01

    Spontaneous Raman scattering measurements of temperature and major species concentration in hydrocarbon-air flames require detailed knowledge of the Raman spectra of the hydrocarbons present when fuels more complex than methane are used. Although hydrocarbon spectra have been extensively studied at room temperature, there are no data available at higher temperatures. Quantum mechanical calculations, when available are not sufficiently accurate for combustion applications. This work presents experimental measurements of spontaneous Stokes-Raman scattering spectra of methane, ethylene, ethane, dimethyl ether, formaldehyde and propane in the temperature range 300-860 K. Raman spectra from heated hydrocarbons jets have been collected with a higher resolution than is generally employed for Raman measurements in combustion applications. A set of synthetic spectra have been generated for each hydrocarbon, providing the basis for extrapolation to higher temperatures. The spectra provided here will enable simultaneous measurements of multiple hydrocarbons in flames. This capability will greatly extend the range of applicability of Raman measurements in combustion applications. In addition, the experimental spectra provide a validation dataset for quantum mechanical models.

  13. Raman Spectra of Methane, Ethylene, Ethane, Dimethyl ether, Formaldehyde and Propane for Combustion Applications

    KAUST Repository

    Magnotti, G.

    2015-05-09

    Spontaneous Raman scattering measurements of temperature and major species concentration in hydrocarbon-air flames require detailed knowledge of the Raman spectra of the hydrocarbons present when fuels more complex than methane are used. Although hydrocarbon spectra have been extensively studied at room temperature, there are no data available at higher temperatures. Quantum mechanical calculations, when available are not sufficiently accurate for combustion applications. This work presents experimental measurements of spontaneous Stokes-Raman scattering spectra of methane, ethylene, ethane, dimethyl ether, formaldehyde and propane in the temperature range 300-860 K. Raman spectra from heated hydrocarbons jets have been collected with a higher resolution than is generally employed for Raman measurements in combustion applications. A set of synthetic spectra have been generated for each hydrocarbon, providing the basis for extrapolation to higher temperatures. The spectra provided here will enable simultaneous measurements of multiple hydrocarbons in flames. This capability will greatly extend the range of applicability of Raman measurements in combustion applications. In addition, the experimental spectra provide a validation dataset for quantum mechanical models.

  14. Formaldehyde stress

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Formaldehyde,one of the most toxic organic compounds,is produced and processed in human cells.The level of human endogenous formaldehyde is maintained at a low concentration(0.01-0.08 mmol L-1 in blood) under physiological conditions,but the concentration increases during ageing(over 65 years old).Clinical trials have shown that urine formaldehyde concentrations are significantly different between elderly Alzheimer’s patients(n=91) and normal elderly volunteers(n=38)(P<0.001).Abnormally high levels of intrinsic formaldehyde lead to dysfunction in cognition such as learning decline and memory loss.Excess extracellular and intracellular formaldehyde could induce metabolic response and abnormal modifications of cellular proteins such as hydroxymethylation and hyperphosphorylation,protein misfolding,nuclear translocation and even cell death.This cellular response called formaldehyde stress is dependent upon the concentration of formaldehyde.Chronic impairments of the brain resulted from formaldehyde stress could be one of the mechanisms involved in the process of senile dementia during ageing.

  15. Formaldehyde degradation by catalytic oxidation.

    OpenAIRE

    Shirey, W N; Hall, T. A.; Hanel, E; Sansone, E B

    1981-01-01

    Formaldehyde used for the disinfection of a laminar-flow biological safety cabinet was oxidatively degraded by using a catalyst. This technique reduced the formaldehyde concentration in the cabinet from about 5,000 to about 45 mg/m3 in 8 h. This technique should prove useful in other applications.

  16. Evaluation of Mechanical Properties and Formaldehyde Emission of Plywood Manufactured for Construction Applications

    Directory of Open Access Journals (Sweden)

    Mohamed Salem

    2013-06-01

    Full Text Available This study was aimed to evaluate some mechanical properties and formaldehyde emission of beech plywood panels manufactured from rotary cut veneers using phenol–formaldehyde (PF resin. Six plywood panels of 5 plies with 15 mm thickness were manufactured. Modulus of rupture (MOR, modulus of elasticity (MOE and formaldehyde emission values were determined. The values of MOR and MOE were higher than the EN requirements. Furthermore, the formaldehyde emission values measured by the European small-scale chamber (EN 717-1 and gas analysis (EN 717-2 methods were lower than the E1-emmison class. The results showed significant variations (P<0.001 among beech plywood panels, most of them caused by sample heterogeneity, and inconsistency of the values was related to the inter-panel variation. Moreover, a strongly positive correlation between the formaldehyde emission values measured by EN 717-1 and 717-2 methods was found (R2 value of 0.87.

  17. Les frameworks au coeur des applications web

    OpenAIRE

    Moro, Arielle; Daehne, Peter

    2010-01-01

    Depuis quelques années, Internet est vraiment entré dans les mœurs : tant dans les entreprises qu’au sein de chaque foyer. En effet, Internet permet de communiquer à travers le monde en quelques secondes, de vendre toute sorte de produits en déployant des solutions e-commerce facilement et bien d’autres choses. Internet est donc un véritable vecteur de communication, de commerce et à présent, avec le Web 2.0, un vrai berceau d’informations (tant des informations personnelles que des informati...

  18. Ordered Au Nanodisk and Nanohole Arrays: Fabrication and Applications

    KAUST Repository

    Zheng, Yue Bing

    2010-01-01

    We have utilized nanosphere lithography (NSL) to fabricate ordered Au nanodisk and nanohole arrays on substrates and have studied the localized surface plasmon resonance (LSPR) of the arrays. Through these investigations, we demonstrate that the angle- dependent behavior of the LSPR in the Au nanodisk arrays enables real-time observation of exciton-plasmon couplings. In addition, we show that the NSL-fabricated Au nanohole arrays can be applied as templates for patterning micro-/nanoparticles under capillary force. The unique structural and plasmonic characteristics of the Au nanodisk and nano- hole arrays, as well as the low-cost and high-throughput NSL-based nanofabrication technique, render these arrays excellent platforms for numerous engineering applications. © 2010 by ASME.

  19. Problems associated with the use of urea-formaldehyde foam for residential insulation. Part I. The effects of temperature and humidity on formaldehyde release from urea-formaldehyde foam insulation

    Energy Technology Data Exchange (ETDEWEB)

    Long, K.R.; Pierson, D.A.; Brennan, S.T.; Frank, C.W.; Hahne, R.A.

    1979-09-01

    The study is concerned primarily with those properties related to formaldehyde and its application as an ingredient in urea-formaldehyde resins. In particular the effects of temperature and humidity on urea-formaldehyde foam are discussed.

  20. Modification and evaluation of thermal properties of melamine-formaldehyde/n-eicosane microcapsules for thermo-regulation applications

    International Nuclear Information System (INIS)

    A modified process to enhance the latent heat of fusion of n-eicosane microcapsules in melamine-formaldehyde shells is suggested for application in textiles. Deviations in melt enthalpy and phase change temperatures were determined for produced microcapsules by differential scanning calorimetry. Thermo-regulation efficiency of eicosane-microcapsule-treated fabrics was evaluated via fitting the Newton cooling law to the experimental data, and a new constant, α, was defined as the thermal delay factor. Scanning electron microscopy images and particle size distribution analysis were consistent and the particle size was found to be between 0.5 and 2.7 μm. Melamine-formaldehyde/n-eicosane microcapsule composition was confirmed using a Fourier transform infrared spectrophotometry. The microcapsules developed showed excellent heat storage capacities, over 162.4 J/g, over melting and crystallisation ranges compared with previous studies undertaken in this field. - Highlights: • Modified eicosane microcapsules with the highest phase change enthalpies were made. • Newton cooling law was fitted to determine thermal delay in PCM-substrates. • Fine microcapsule units with diameters less than 0.5 μm were prepared. • All pliable PCM-substrates can be thermally assessed using thermal logging method

  1. Fe/Au Core-Shell Nanoparticles for Biomedical Applications

    Science.gov (United States)

    Sra, Amandeep; Leslie-Pelecky, Diandra

    2009-10-01

    The physical properties of nanoparticles, including size, composition and surface chemistry, greatly influence biological and pharmacological properties and, ultimately, their clinical applications. Superparamagnetic iron oxide nanoparticles are widely used for applications such as MRI contrast agents, drug delivery via magnetic targeting and hyperthermia due to their chemical stability and biocompatibility; however, enhancing the saturation magnetization (Ms) of nanoparticles would produce greater sensitivity. Our design strategy involves a bottom-up wet chemistry approach to the synthesis of Fe nanoparticles. Specific advantages of Fe are the high value of Ms (210 emu/g in bulk) coupled with low toxicity; however, Fe nanoparticles must be protected from oxidation, which causes a dramatic reduction in Ms. To circumvent oxidation, Fe nanoparticles are coated with a Au shell that prevents the oxidation of the magnetic core and also provides the nanoparticles with plasmonic properties for optical stimulation. Ligands of various functionalities can be introduced through the well established Au-thiol surface chemistry for different biomedical applications while maintaining the magnetic functionality of the Fe core. In this presentation, we will discuss the physical, chemical and magnetic properties of our Fe/Au nanoparticles and their resistance to oxidation.

  2. Bright, NIR-emitting Au23 from Au25: characterization and applications including biolabeling.

    Science.gov (United States)

    Muhammed, Madathumpady Abubaker Habeeb; Verma, Pramod Kumar; Pal, Samir Kumar; Kumar, R C Arun; Paul, Soumya; Omkumar, Ramakrishnapillai Vyomakesannair; Pradeep, Thalappil

    2009-10-01

    A novel interfacial route has been developed for the synthesis of a bright-red-emitting new subnanocluster, Au(23), by the core etching of a widely explored and more stable cluster, Au(25)SG(18) (in which SG is glutathione thiolate). A slight modification of this procedure results in the formation of two other known subnanoclusters, Au(22) and Au(33). Whereas Au(22) and Au(23) are water soluble and brightly fluorescent with quantum yields of 2.5 and 1.3 %, respectively, Au(33) is organic soluble and less fluorescent, with a quantum yield of 0.1 %. Au(23) exhibits quenching of fluorescence selectively in the presence of Cu(2+) ions and it can therefore be used as a metal-ion sensor. Aqueous- to organic-phase transfer of Au(23) has been carried out with fluorescence enhancement. Solvent dependency on the fluorescence of Au(23) before and after phase transfer has been studied extensively and the quantum yield of the cluster varies with the solvent used. The temperature response of Au(23) emission has been demonstrated. The inherent fluorescence of Au(23) was used for imaging human hepatoma cells by employing the avidin-biotin interaction. PMID:19711391

  3. Photochemical preparation and application research of Au nanoparticles

    Institute of Scientific and Technical Information of China (English)

    DONG; Shou-an; SUN; Jia-lin

    2005-01-01

    Gold nanoparticles protected by organic small molecular compounds or macromolecule have attracted considerable attention and their preparation is one of hotspots in the nano-chemical material field due to their ongoing and potential applications in optics, electronics, catalysts and biosensors. In recent years there are many liquid phase chemistry methods to prepare monodispersed gold particles. Among them, the photochemical method is quite attractive because of its some important advantages for size-controlled synthesis of gold nanoparticles. Therefore, in this paper the recert progress of the photochemical preparing Au nanoparticle materials was briefly introduced and mainly emphasized authors' own works of this area.

  4. 29 CFR 1915.1048 - Formaldehyde.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 7 2010-07-01 2010-07-01 false Formaldehyde. 1915.1048 Section 1915.1048 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR (CONTINUED... Formaldehyde. Note: The requirements applicable to shipyard employment under this section are identical...

  5. Electrodeposition of gold from formaldehyde-sulfite baths: bath stability and deposits characterization

    OpenAIRE

    Juliana L. Cardoso; Sebastião G. dos Santos Filho

    2011-01-01

    It was investigated Au(I)-sulfite baths containing formaldehyde. As a result, high stability was achieved for baths containing formaldehyde concentration close to 10 mL L-1 with a lifetime superior to 600 days. On the other hand, cyclic voltammograms indicated that the increase of formaldehyde concentration in the bath promotes decreasing of the maximum cathodic current, so that, if the formaldehyde concentration is high, the surface areal concentration of gold will be low. Also, the lowest s...

  6. TiAu based shape memory alloys for high temperature applications

    International Nuclear Information System (INIS)

    TiAu (equiatomic) exhibits phase transformation from B2 (ordered bcc) to thermo-elastic orthorhombic B19 martensite at about 875K and thus TiAu is categorized as high temperature shape memory alloy. In this study, recent research and developments related to TiAu based high temperature shape memory alloys will be discussed in the Introduction part. Then some results of our research group related to strengthening of TiAu based high temperature shape memory alloys will be presented. Potential of TiAu based shape memory alloys for high temperature shape memory materials applications will also be discussed. (author)

  7. TiAu based shape memory alloys for high temperature applications

    International Nuclear Information System (INIS)

    TiAu (equiatomic) exhibits phase transformaion from B2 (ordered bcc) to thermo-elastic orthorhombic B19 martensite at about 875K and thus TiAu is categorized as high temperature shape memory alloy. In this study, recent research and developments related to TiAu based high temperature shape memory alloys will be discussed in the Introduction part. Then some results of our research group related to strengthening of TiAu based high temperature shape memory alloys will be presented. Potential of TiAu based shape memory alloys for high temperature shape memory materials applications will also be discussed

  8. Formaldehyde exposure and patterns of concomitant contact allergy to formaldehyde and formaldehyde-releasers

    DEFF Research Database (Denmark)

    Lundov, Michael D; Johansen, Jeanne D; Carlsen, Berit C;

    2010-01-01

    Formaldehyde and formaldehyde-releasers are widely used in consumer products and may often cause contact allergy.......Formaldehyde and formaldehyde-releasers are widely used in consumer products and may often cause contact allergy....

  9. Thermal stability of Mo/Au bilayers for TES applications

    International Nuclear Information System (INIS)

    Mo/Au bilayers are among the most suitable materials to be used as transition-edge sensors (TES) in cryogenic microcalorimeters and bolometers, developed, among other fields, for space missions. For this purpose the thermal stability of TES at temperatures below 150 °C is a critical issue. We report on the dependence of functional properties (superconducting critical temperature, residual resistance and α) as well as on microstructure, chemical composition and interface quality for optimized high quality Mo/Au bilayers on annealing temperature and time. Data show that the functional properties of the bilayers remain stable at T C at T ≥ 200 °C are mainly due to an increase in the average Au grain size and to Au migration along the Mo grain boundaries at the Au/Mo interface. A way to stabilize the functional properties of the Mo/Au bilayers against temperature enhancements is proposed. (paper)

  10. By-passing acidification limitations during the biofiltration of high formaldehyde loads via the application of ozone pulses

    International Nuclear Information System (INIS)

    Highlights: • Ozone addition permits to treat higher formaldehyde loads than ever reported. • Ozone addition acts as an indirect in situ pH regulator, minimizing the accumulation of acid byproducts. • Mineralization of formaldehyde occurs, which has never been reported. • Low ozone levels have no negative effects on biological degradation activity. • The use of hybrid processes allows overcoming biofiltration limitations. -- Abstract: A formaldehyde airstream was treated in a biofilter for an extended period of time. During the first 133 days, the reactor was operated without ozone, whereas over the following 82 days ozone was intermittently implemented. The maximum stable elimination capacity obtained without ozone was around 57 g m−3 h−1. A greater load could not be treated under these conditions, and no significant formaldehyde removal was maintained for inlet loads greater than 65 g m−3 h−1; the activity of microorganisms was then inhibited by the presence of acidic byproducts, and the media acidified (pH −3 h−1). The effect of ozone on the extra cellular polymeric substances detachment from the biofilm could not be confirmed due to the too low biofilter biomass content. Thus, the results suggest that ozone acted as an in situ pH regulator, preventing acidic byproducts accumulation, and allowing the treatment of high loads of formaldehyde

  11. Formaldehyde-releasers: relationship to formaldehyde contact allergy. Contact allergy to formaldehyde and inventory of formaldehyde-releasers

    OpenAIRE

    de Groot, Anton C.; Flyvholm, Mari-Ann; Lensen, Gerda; Menne, Torkil; Coenraads, Pieter-Jan

    2009-01-01

    This is one of series of review articles on formaldehyde and formaldehyde-releasers (others: formaldehyde in cosmetics, in clothes and in metalworking fluids and miscellaneous). Thirty-five chemicals were identified as being formaldehyde-releasers. Although a further seven are listed in the literature as formaldehyde-releasers, data are inadequate to consider them as such beyond doubt. Several (nomenclature) mistakes and outdated information are discussed. Formaldehyde and formaldehyde allerg...

  12. Microfabricated Formaldehyde Gas Sensors

    OpenAIRE

    Cheung, Karen C.; Ko, Frank K.; Jonas Flueckiger

    2009-01-01

    Formaldehyde is a volatile organic compound that is widely used in textiles, paper, wood composites, and household materials. Formaldehyde will continuously outgas from manufactured wood products such as furniture, with adverse health effects resulting from prolonged low-level exposure. New, microfabricated sensors for formaldehyde have been developed to meet the need for portable, low-power gas detection. This paper reviews recent work including silicon microhotplates for metal oxide-based d...

  13. Formaldehyde in pathology departments.

    OpenAIRE

    Clark, R. P.

    1983-01-01

    Toxic effects of formaldehyde in humans are discussed in relation to occupational exposure and tolerance to this agent. Carcinogenic and mutagenic properties of formaldehyde have been reported in animals and this has led to concern about a possible role in human cancer. The current state of affairs is reviewed in the light of a lack of direct evidence linking formaldehyde with cancer in man and in relation to recommended exposure levels. It is important to employ effective means of containmen...

  14. Optical chemical sensors for atmospheric pollutants based on nano porous materials: application to the formaldehyde and the other carbonyl compounds

    International Nuclear Information System (INIS)

    Formaldehyde, a well-identified indoor pollutant, was recently classified as carcinogenic. New regulations for the air quality are expected and therefore there is a need for low-cost sensors, sensitive and selective with a fast response time for the detection of formaldehyde at ppb level. In the present work, we had developed a chemical sensor based on nano-porous matrices doped with Fluoral-P and optical methods of detection. The nano-porous matrices, elaborated via the Sol-Gel process, display nano-pores whose cavity is tailored for the trapping of the targeted pollutant. They provide a first selectivity with the discrimination of the pollutants by their size. A second selectivity is obtained with a molecular probe, Fluoral-P, which reacts specifically with formaldehyde leading to the 3,5- di-acetyl-1,4-dihydro-lutidine (DDL). The kinetics of formation of DDL was studied as function of many parameters such as the concentration of Fluoral-P in the matrix, the pollutant content in gas mixture, the flow rate, the relative humidity of the gas mixtures and interference with other carbonylated compounds. The present chemical sensor can detect, via absorbance measurements, 2 ppb of formaldehyde within 30 min over a O to 60% relative humidity range. Moreover, to detect the total carbonylated compounds, we also explored the potentiality of a chemical sensor using, as a probe molecule, the 2'4-dinitro-phenyl-hydrazine which forms with these compounds the corresponding hydrazones derivatives. A patent was deposited for these two sensors. We have also developed a semi-miniaturized prototype for demonstration, using a flow cell, a miniaturized spectrophotometer, a light source and a lap-top. (author)

  15. Formaldehyde in Our Environment.

    Science.gov (United States)

    Ojanlatva, Ansa; Weeks, Charlie A.

    During the energy crisis of the early 1970s, there was a drive to conserve energy in every segment of society. Citizens were encouraged to insulate their homes and tighten them up to avoid loss of energy. One of the products to emerge from this crisis was urea formaldehyde foam insulation. (Urea formaldehyde is a well-known agent for preserving…

  16. Optical Detection of Formaldehyde

    Science.gov (United States)

    Patty, Kira D.; Gregory, Don A.

    2008-01-01

    The potential for buildup .of formaldehyde in closed space environments poses a direct health hazard to personnel. The National Aeronautic Space Agency (NASA) has established a maximum permitted concentration of 0.04 ppm for 7 to 180 days for all space craft. Early detection is critical to ensure that formaldehyde levels do not accumulate. above these limits. New sensor technologies are needed to enable real time,in situ detection in a compact and reusable form factor. Addressing this need,research into the use of reactive fluorescent dyes which reversibly bind to formaldehyde (liquid or gas) has been conducted to support the development of a formaldehyde.sensor. In the presence of formaldehyde the dyes' characteristic fluorescence peaks shift providing the basis for an optical detection. Dye responses to formaldehyde exposure were characterized; demonstrating the optical detection of formaldehyde in under 10 seconds and down to concentrations of 0.5 ppm. To .incorporate the dye .in.an optical sensor device requires. a means of containing and manipulating the dye. Multiple form factors using two dissimilar sbstrates were considered to determine a suitable configuration. A prototype sensor was demonstrated and considerations for a field able sensor were presented. This research provides a necessary first step toward the development of a compact, reusable; real time optical formaldehyde sensor suitable for use in the U.S. space program,

  17. Formaldehyde-releasers : relationship to formaldehyde contact allergy. Contact allergy to formaldehyde and inventory of formaldehyde-releasers

    NARCIS (Netherlands)

    de Groot, Anton C.; Flyvholm, Mari-ann; Lensen, Gerda; Menne, Torkil; Coenraads, Pieter-Jan

    2009-01-01

    This is one of series of review articles on formaldehyde and formaldehyde-releasers (others: formaldehyde in cosmetics, in clothes and in metalworking fluids and miscellaneous). Thirty-five chemicals were identified as being formaldehyde-releasers. Although a further seven are listed in the literatu

  18. A general analytical model for formaldehyde and VOC emission/sorption in single-layer building materials and its application in determining the characteristic parameters

    Science.gov (United States)

    Xiong, Jianyin; Liu, Cong; Zhang, Yinping

    2012-02-01

    A general analytical model for characterizing emission and sorption of formaldehyde and volatile organic compounds (VOCs) in single-layer building materials is developed. Compared with traditional models, the present model can be applicable for four kinds of typical physical processes, i.e., emission in ventilated and airtight chambers, and sorption in these two types of chambers. Based on the general analytical model, a novel method is proposed to determine the characteristic parameters (the diffusion coefficient, Dm, and the material/air partition coefficient, K) of formaldehyde and VOC sorption in ventilated and airtight chambers. It establishes a linear relationship between the logarithm of dimensionless excess concentration and sorption time, and the Dm and K can be conveniently obtained from the slope and intercept of the regression line. The results of applying the present model are compared with the experimental data in the literature. The good agreement between them not only validates the model but also demonstrates that the measured characteristic parameters are accurate and reliable. The general analytical model should prove useful for unified characterization and prediction of emission/sorption in building materials as well as for parameter measurement.

  19. Microfabricated Formaldehyde Gas Sensors

    Directory of Open Access Journals (Sweden)

    Karen C. Cheung

    2009-11-01

    Full Text Available Formaldehyde is a volatile organic compound that is widely used in textiles, paper, wood composites, and household materials. Formaldehyde will continuously outgas from manufactured wood products such as furniture, with adverse health effects resulting from prolonged low-level exposure. New, microfabricated sensors for formaldehyde have been developed to meet the need for portable, low-power gas detection. This paper reviews recent work including silicon microhotplates for metal oxide-based detection, enzyme-based electrochemical sensors, and nanowire-based sensors. This paper also investigates the promise of polymer-based sensors for low-temperature, low-power operation.

  20. Enzymatic deposition of Au nanoparticles on the designed electrode surface and its application in glucose detection.

    Science.gov (United States)

    Zhang, Hongfang; Liu, Ruixiao; Sheng, Qinglin; Zheng, Jianbin

    2011-02-01

    This paper reported the enzymatic deposition of Au nanoparticles (AuNPs) on the designed 3-mercapto-propionic acid/glucose oxidase/chitosan (MPA/GOD/Chit) modified glassy carbon electrode and its application in glucose detection. Chit served as GOD immobilization matrix and interacted with MPA through electrostatic attraction. AuNPs, without nano-seeds presented on the electrode surface, was produced through the glucose oxidase catalyzed oxidation of glucose. The mechanism of production of AuNPs was confirmed to be that enzymatic reaction products H(2)O(2) in the solution reduce gold complex to AuNPs. The characterizations of the electrode modified after each assembly step was investigated by cyclic voltammetry and electrochemical impedance spectroscopy. Scanning electron microscopy showed the average particle size of the AuNPs is 40nm with a narrow particle size distribution. The content of AuNPs on the electrode surfaces was measured by differential pulse stripping voltammetry. The electrochemical signals on voltammogram showed a linear increase with the glucose concentration in the range of 0.010-0.12mM with a detection limit of 4μM. This provided a method to the determination of glucose. PMID:21115279

  1. Application of Cryopreserved Fibroblast Culture with Au Nanoparticles to Treat Burns.

    Science.gov (United States)

    Volkova, Nataliia; Yukhta, Mariia; Pavlovich, Olena; Goltsev, Anatoliy

    2016-12-01

    The aim was to investigate a possibility of using the cryopreserved human culture of fibroblasts (CrHFC) with gold nanoparticles (AuNPs) to treat experimental burns in rats.The third-degree burns were modeled in white male rats. All the animals with burns were divided into three experimental groups: control group with no wound treatment; group 1 was composed of animals with CrHFC application; and group 2 consisted of those with CrHFC and AuNPs (6 μg/ml) application to a burn surface the next day after the injury. The CrHFC was applied to the methylcellulose gel in a dose of 5 × 10(4) of viable cells per 1 cm(2) of the burn. The animals were removed from the experiment on day 21 after the treatment.The CrHFC use alone and with AuNPs to the surface of burns stimulated the wound healing compared with the control. The effect of using CrHFC was less pronounced compared to the CrHFC application with AuNPs. It was reflected in a slower recovery of burns and moderate lymphocytic infiltration of granulation tissue. Immunofluorescent analysis emphasized that the use of CrHFC with AuNPs accelerated the skin synthetic processes and was helpful in recovering type I and III collagen content on day 21 after therapy.The results were likely related primarily to the unique structure and antimicrobial properties of AuNPs. Our experimental study of the effect of CrHFC with AuNPs application on regenerative processes in burns gives some pre-conditions to the following advanced bio- and nanotechnology developments. PMID:26762263

  2. Nitrite ion-induced fluorescence quenching of luminescent BSA-Au(25) nanoclusters: mechanism and application.

    Science.gov (United States)

    Unnikrishnan, Binesh; Wei, Shih-Chun; Chiu, Wei-Jane; Cang, Jinshun; Hsu, Pang-Hung; Huang, Chih-Ching

    2014-05-01

    Fluorescence quenching is an interesting phenomenon which is highly useful in developing fluorescence based sensors. A thorough understanding of the fluorescence quenching mechanism is essential to develop efficient sensors. In this work, we investigate different aspects governing the nitrite ion-induced fluorescence quenching of luminescent bovine serum albumin stabilized gold nanoclusters (BSA-Au NCs) and their application for detection of nitrite in urine. The probable events leading to photoluminescence (PL) quenching by nitrite ions were discussed on the basis of the results obtained from ultraviolet-visible (UV-Vis) absorption spectroscopy, X-ray photoelectron spectroscopy (XPS), fluorescence measurements, circular dichroism (CD) spectroscopy, zeta potential and dynamic light scattering (DLS) studies. These studies suggested that PL quenching mainly occurred through the oxidation of Au(0) atoms to Au(i) atoms in the core of BSA-Au NCs mediated by nitrite ions. The interference caused by certain species such as Hg(2+), Cu(2+), CN(-), S(2-), glutathione, cysteine, etc. during the nitrite determination by fluorescence quenching was eliminated by using masking agents and optimising the conditions. Based on these findings we proposed a BSA-Au NC-modified membrane based sensor which would be more convenient for the real life applications such as nitrite detection in urine samples. The BSA-Au NC-modified nitrocellulose membrane (NCM) enabled the detection of nitrite at a level as low as 100 nM in aqueous solutions. This Au NC-based paper probe was validated to exhibit good performance for nitrite analysis in environmental water and urine samples, which makes it useful in practical applications. PMID:24634911

  3. Effect of natural compounds on reducing formaldehyde emission from plywood

    Science.gov (United States)

    Uchiyama, Shigehisa; Matsushima, Erica; Kitao, Nahoko; Tokunaga, Hiroshi; Ando, Masanori; Otsubo, Yasufumi

    The effects of natural compounds on reducing formaldehyde emission from plywood were investigated. Urea, catechin and vanillin were examined as the natural formaldehyde reducers. The microemission cell, with an internal volume of 35 ml, the maximum exposed test surface area of 177 cm 2 and an air purge flow rate of 50 ml min -1, was used to measure specific emission rate (SER). In the case of no reducer treatment, formaldehyde emission from plywood was fast and SERs were 4.4 mg m -2 h -1 at 30 °C and 15 mg m -2 h -1 at 60 °C. When this plywood was treated with the natural compounds, the SERs of formaldehyde were decreased at all temperatures. In the case of urea treatment, the SERs of formaldehyde decreased to 0.30 mg m -2 h -1 at 30 °C and 0.65 mg m -2 h -1 at 60 °C. When the urea treatment was applied to the inside of kitchen cabinet (made from plywood; 270 cm wide, 60 cm deep, 250 cm high), the concentration of formaldehyde was reduced substantially from 1600 to 130 μg m -3. The reducing effect of formaldehyde continued during the observation period (6 months), with a mean concentration of 100 μg m -3. Reducers in the plywood would react with released formaldehyde. Application of natural compounds such as urea, catechin and vanillin could provide a simple and effective approach for suppressing formaldehyde emission from plywood.

  4. Application of 198Au grains for carcinoma of oral cavity

    International Nuclear Information System (INIS)

    The purpose of this study is to analyze the results of the treatment using gold grain implants over the past 9 years and to evaluate the usefulness of this treatment method. From January 1985 through April 1993, a total of 45 patients with squamous cell carcinomas of the oral cavity and the oropharynx were treated with 198Au grain (gold grain) at the Department of Radiology, Osaka University Medical School. The initial activity of the grains supplied weekly by the Japan Radioisotope Association was usually 5 mCi (185 MBq), and single implants were usual. In case of combined external irradiation, telecobalt γ-rays or 4 MV X-rays were used for treatment before implant. The local control rate for patients with T1 stages was 80% (20/25) and with T2 stages, 59% (10/17). The local control rate was 71% (10/14) for gold grain alone and 72% (13/18) for external irradiation combined with gold grain implants (combined therapy). In combined therapy, the median of the interval between external irradiation and gold grain implants was 21 days. The treatment interval or patients with recurrent diseases was 22 days, 22, 27, 39 and 46, respectively. The progression rate showed a tendency to increase in the patients with longer interval (more than 21 days), and with partial regression after external irradiation and gold grain implantation is an important factor in combined therapy. Therefore, we emphasize that the time interval should be shorter than 3 weeks. (orig.)

  5. Application of radioisotopes Au -198 to radiometrical field investigation of spraying machine

    Energy Technology Data Exchange (ETDEWEB)

    Goraczko, W.; Kocorowska, E. [Technical Univeristy, Poznan (Poland). Radio and Photo-Chemistry Department

    1997-10-01

    The poster shows application of radioisotope {sup 198}Au to radiometrical field testing of spraying machine. In the research was tested the Polish suspensioned tractor OZS400 type spraying machine. The machine worked in two different variants: without and with the beam stabilisation (oscillatory stabilisation)

  6. Application of radioisotopes Au -198 to radiometrical field investigation of spraying machine

    International Nuclear Information System (INIS)

    The poster shows application of radioisotope 198Au to radiometrical field testing of spraying machine. In the research was tested the Polish suspensioned tractor OZS400 type spraying machine. The machine worked in two different variants: without and with the beam stabilisation (oscillatory stabilisation)

  7. Emission of formaldehyde from furniture

    DEFF Research Database (Denmark)

    Andersen, Helle Vibeke; Klinke, Helene B.; Funch, Lis Winther;

    2014-01-01

    The emission of formaldehyde from a variety of furniture was measured in climate chambers. Most tests show low emission of formaldehyde; however, there are a few exceptions. One product emitted significant amounts of formaldehyde, but according to the Danish Indoor Climate Labelling Criteria for ...

  8. Formaldehyde: an analysis of its respiratory, cutaneous, and immunologic effects

    Energy Technology Data Exchange (ETDEWEB)

    Bardana, E.J. Jr.; Montanaro, A. (Division of Allergy and Clinical Immunology, Oregon Health Sciences University, Portland (USA))

    1991-06-01

    Formaldehyde is truly ubiquitous in our ecology and continuing important commercial applications. Most of us have daily contact with this chemical. The most significant outdoor source of this chemical is gasoline and diesel fuel combustion. The primary indoor source is combustion of tobacco products. Formaldehyde is associated with a disagreeable odor that can produce annoyance symptoms and at higher concentrations can be a transient and completely reversible irritant to the eyes and mucous membranes of the respiratory tract. It is so soluble and rapidly metabolized that it rarely reaches the lower respiratory tract to inflict damage. The exception is in cigarette smokers who actively inhale. Formaldehyde may on rare occasions induce bronchial asthma at relatively high exposure doses. There are no conclusive studies that prove the development of de novo IgE-mediated respiratory tract symptoms secondary to inhalation of formaldehyde vapors. The approach to formaldehyde-induced symptoms should be one of careful documentation of objective physiologic changes.147 references.

  9. Formaldehyde: an analysis of its respiratory, cutaneous, and immunologic effects.

    Science.gov (United States)

    Bardana, E J; Montanaro, A

    1991-06-01

    Formaldehyde is truly ubiquitous in our ecology and continuing important commercial applications. Most of us have daily contact with this chemical. The most significant outdoor source of this chemical is gasoline and diesel fuel combustion. The primary indoor source is combustion of tobacco products. Formaldehyde is associated with a disagreeable odor that can produce "annoyance" symptoms and at higher concentrations can be a transient and completely reversible irritant to the eyes and mucous membranes of the respiratory tract. It is so soluble and rapidly metabolized that it rarely reaches the lower respiratory tract to inflict damage. The exception is in cigarette smokers who actively inhale. Formaldehyde may on rare occasions induce bronchial asthma at relatively high exposure doses. There are no conclusive studies that prove the development of de novo IgE-mediated respiratory tract symptoms secondary to inhalation of formaldehyde vapors. The approach to formaldehyde-induced symptoms should be one of careful documentation of objective physiologic changes. PMID:2048760

  10. Au coated Ni nanowires with tuneable dimensions for biomedical applications

    NARCIS (Netherlands)

    Pondman, K.M.; Maijenburg, A.W.; Celikkol, F.B.; Pathan, A.A.; Kishore, U.D.; Haken, ten B.; Elshof, ten J.E.

    2013-01-01

    Due to their shape anisotropy, high aspect ratio magnetic nanoparticles offer many advantages in biomedical applications. For biocompatibility, it is essential to have full control over the dimensions and surface chemistry of the particles. The aim of this study was to synthesize biocompatible nanow

  11. Au coated Ni nanowires with tuneable dimensions for biomedical applications

    OpenAIRE

    Pondman, K.M.; Maijenburg, A.W.; Celikkol, F.B.; Pathan, A A; Kishore, U.D.; Haken, ten, Bennie; Elshof, ten, J.E.

    2013-01-01

    Due to their shape anisotropy, high aspect ratio magnetic nanoparticles offer many advantages in biomedical applications. For biocompatibility, it is essential to have full control over the dimensions and surface chemistry of the particles. The aim of this study was to synthesize biocompatible nanowires with tuneable dimensions. This was achieved by electrodeposition of Ni in polycarbonate membranes. To ensure biocompatibility, a continuous gold coating was deposited onto the Ni wires by a ne...

  12. Colloidal Au-enhanced surface plasmon resonance imaging: application in a DNA hybridization process

    International Nuclear Information System (INIS)

    The detection of the DNA hybridization mechanism using monodispersed gold nanoparticles as labels is an interesting alternative to increase the sensitivity of the SPR imaging technique. DNA-modified Au nanoparticles (DNA-Au NPs) containing single-stranded (ss) portions of DNA were prepared by monitoring their monolayer formation by UV–vis spectroscopy. The hybridization process between specific thio-oligonucleotides immobilized on the DNA–Au NPs and the corresponding complementary strands is reported and compared with the traditional hybridization process on properly self-assembled thin gold films deposited on glass substrates. A remarkable signal amplification is observed, following the incorporation of colloidal Au into a SPR biosensing experiment, resulting in an increased SPR response to DNA–DNA interactions. In particular Fusarium thiolated DNA (5'HS poly(T)15ATC CCT CAA AAA CTG CCG CT-3) and trichothecenes complementary DNA (5'-AGC GGC AGT TTT TGA GGG AT-3') sequences have been explored due to their possible application to agro-industry for the control of food quality

  13. Large coincidence lattice on Au/Fe3O4 incommensurate structure for spintronic applications

    Science.gov (United States)

    Muñoz-Noval, Alvaro; Rubio-Zuazo, Juan; Salas-Colera, Eduardo; Serrano, Aida; Rubio-Marcos, Fernando; Castro, Germán R.

    2015-11-01

    The design of metallic hybrid systems for spintronics has been widely studied during the past decade, motivated by the promising technological applications of these materials. Nevertheless, the importance of preserving the native structure and properties of the interfaces is often ignored. Here, we present the fabrication of nanocrystalline Au (0 0 1) onto a single oriented Fe3O4 (0 0 1) thin film as a promising hybrid system to develop spintronic devices by growing Au over the Fe3O4 by using a simple one-pot Pulsed Laser Deposition (PLD) approach. The structural coupling between Au nanocrystals and Fe3O4 layer results in the development of an incommensurate structure based on a coincidence lattice of order 35, which preserves the intrinsic properties of the Au nanocrystals, the Fe3O4 matrix and the interface between them. The general strategy described in the present work preserves the structure and main intrinsic properties of the constituting materials, being a fundamental issue for the future development of spintronic devices.

  14. Colloidal Au-enhanced surface plasmon resonance imaging: application in a DNA hybridization process

    Science.gov (United States)

    Manera, M. G.; Spadavecchia, J.; Taurino, A.; Rella, R.

    2010-03-01

    The detection of the DNA hybridization mechanism using monodispersed gold nanoparticles as labels is an interesting alternative to increase the sensitivity of the SPR imaging technique. DNA-modified Au nanoparticles (DNA-Au NPs) containing single-stranded (ss) portions of DNA were prepared by monitoring their monolayer formation by UV-vis spectroscopy. The hybridization process between specific thio-oligonucleotides immobilized on the DNA-Au NPs and the corresponding complementary strands is reported and compared with the traditional hybridization process on properly self-assembled thin gold films deposited on glass substrates. A remarkable signal amplification is observed, following the incorporation of colloidal Au into a SPR biosensing experiment, resulting in an increased SPR response to DNA-DNA interactions. In particular Fusarium thiolated DNA (5'HS poly(T)15ATC CCT CAA AAA CTG CCG CT-3) and trichothecenes complementary DNA (5'-AGC GGC AGT TTT TGA GGG AT-3') sequences have been explored due to their possible application to agro-industry for the control of food quality.

  15. AZO/Au/AZO tri-layer thin films for the very low resistivity transparent electrode applications

    International Nuclear Information System (INIS)

    Highlights: • High-quality Al-doped ZnO (AZO)/Au/AZO transparent conducting oxide films. • AZO films (30 nm) made by RF sputtering; ion sputtering for Au film (5–20 nm). • Effects of Au thickness on optical and electrical properties were analyzed. • The resistivity of 9 × 10−5 Ω cm and the transmittance of 86.2% of the multilayer films were obtained in this study. - Abstract: Aluminum-doped ZnO (AZO)/gold/AZO tri-layer structures with very low resistivity and high transmittance are prepared by simultaneous RF magnetron sputtering (for AZO) and ion sputtering (for Au). The properties of the tri-layer films are investigated at different Au layer thicknesses (5–20 nm). The effects of Au layer thickness and the role of Au on the transmission properties of the tri-layer films were investigated. The very low resistivity of 1.01 × 10−5 Ω cm, mobility of 27.665 cm2 V−1 s−1, and carrier concentration of 4.563 × 1022 cm−3 were obtained at an Au layer thickness of 20 nm. The peak transmittance of 86.18% at 650-nm wavelength was obtained at an Au layer thickness of 8 nm. These results show the films to be a good candidate for high-quality electrode scheme in various display applications

  16. AZO/Au/AZO tri-layer thin films for the very low resistivity transparent electrode applications

    Energy Technology Data Exchange (ETDEWEB)

    Chu, Chien-Hsun [Department of Materials Science and Engineering, National Cheng Kung University, Tainan 70101, Taiwan (China); Wu, Hung-Wei, E-mail: hwwu@mail.ksu.edu.tw [Department of Computer and Communication, Kun Shan University, Tainan 71003, Taiwan (China); Huang, Jow-Lay [Department of Materials Science and Engineering, National Cheng Kung University, Tainan 70101, Taiwan (China); Department of Chemical and Materials Engineering, National University of Kaohsiung, Kaohsiung 81148, Taiwan (China); Research Center for Energy Technology and Strategy, National Cheng Kung University, Tainan 70101, Taiwan (China)

    2014-08-01

    Highlights: • High-quality Al-doped ZnO (AZO)/Au/AZO transparent conducting oxide films. • AZO films (30 nm) made by RF sputtering; ion sputtering for Au film (5–20 nm). • Effects of Au thickness on optical and electrical properties were analyzed. • The resistivity of 9 × 10{sup −5} Ω cm and the transmittance of 86.2% of the multilayer films were obtained in this study. - Abstract: Aluminum-doped ZnO (AZO)/gold/AZO tri-layer structures with very low resistivity and high transmittance are prepared by simultaneous RF magnetron sputtering (for AZO) and ion sputtering (for Au). The properties of the tri-layer films are investigated at different Au layer thicknesses (5–20 nm). The effects of Au layer thickness and the role of Au on the transmission properties of the tri-layer films were investigated. The very low resistivity of 1.01 × 10{sup −5} Ω cm, mobility of 27.665 cm{sup 2} V{sup −1} s{sup −1}, and carrier concentration of 4.563 × 10{sup 22} cm{sup −3} were obtained at an Au layer thickness of 20 nm. The peak transmittance of 86.18% at 650-nm wavelength was obtained at an Au layer thickness of 8 nm. These results show the films to be a good candidate for high-quality electrode scheme in various display applications.

  17. Global observations of formaldehyde

    Science.gov (United States)

    Wittrock, F.; Richter, A.; Heckel, A.; Tarsu, M.; Burrows, J. P.

    Formaldehyde (HCHO) indicates and supports photochemical activity in the atmosphere. Large amounts are expected to found in industrial areas and during biomass burning. HCHO is a major intermediate in the degradation of methane (and many other hydrocarbons). In the absence of heterogenous losses, essentially every methane molecule is converted to HCHO. Therefore it is found throughout the troposphere. It is destroyed via photolysis and reaction with OH. In continental boundary layers, non-methane hydrocarbons (NMHCs) emitted by biogenic and anthropogenic sources dominate over Methane also as a source of HCHO. GOME is the first instrument, that allows observations of Formaldehyde on a global scale giving the opportunity to improve our knowledge about emission fluxes of Methane and NMHCs. This study presents GOME observations of formaldehyde since launch of ERS-2 in 1995. Ground-based measurements are used to validate the GOME HCHO product. In addition time series for selected regions are shown to illustrate the general interannual and interseasonal variation of HCHO depending on the main sources.

  18. High Resolution Formaldehyde Photochemistry

    Science.gov (United States)

    Ernest, C. T.; Bauer, D.; Hynes, A. J.

    2010-12-01

    Formaldehyde (HCHO) is the most abundant and most important organic carbonyl compound in the atmosphere. The sources of formaldehyde are the oxidation of methane, isoprene, acetone, and other volatile organic compounds (VOCs); fossil fuel combustion; and biomass burning. The dominant loss mechanism for formaldehyde is photolysis which occurs via two pathways: (R1) HCHO + hv → HCO + H (R2) HCHO + hv → H2 + CO The first pathway (R1) is referred to as the radical channel, while the second pathway (R2) is referred to as the molecular channel. The products of both pathways play a significant role in atmospheric chemistry. The CO that is produced in the molecular channel undergoes further oxidation to produce CO2. Under atmospheric conditions, the H atom and formyl radical that are produced in the radical channel undergo rapid reactions with O2 to produce the hydroperoxyl radical (HO2) via (R3) and (R4). (R3) HCO + O2 → HO2 + CO (R4) H + O2 → HO2 Thus, for every photon absorbed, the photolysis of formaldehyde can contribute one CO2 molecule to the global greenhouse budget or two HO2 radicals to the tropospheric HOx (OH + HO2) cycle. The HO2 radicals produced during formaldehyde photolysis have also been implicated in the formation of photochemical smog. The HO2 radicals act as radical chain carriers and convert NO to NO2, which ultimately results in the catalytic production of O3. Constraining the yield of HO2 produced via HCHO photolysis is essential for improving tropospheric chemistry models. In this study, both the absorption cross section and the quantum yield of the radical channel (R1) were measured at high resolution over the tropospherically relevant wavelength range 304-330 nm. For the cross section measurements a narrow linewidth Nd:YAG pumped dye laser was used with a multi-pass cell. Partial pressures of HCHO were kept below 0.3 torr. Simultaneous measurement of OH LIF in a flame allowed absolute calibration of the wavelength scale. Pressure

  19. Endogenous formaldehyde turnover in humans compared with exogenous contribution from food sources

    Directory of Open Access Journals (Sweden)

    European Food Safety Authority

    2014-02-01

    Full Text Available The FEEDAP Panel received a request to deliver a scientific opinion on the safety and efficacy of formaldehyde used in feed for all animal species based on dossiers submitted by applicants. In parallel, the ANS Panel evaluated the safety of formaldehyde formed from endogenous production and from dietary sources of methanol, including aspartame. In order to support both evaluations, assistance was requested to the SCER unit to evaluate the oral internal dose of formaldehyde in humans from endogenous production, food-derived from target animals exposed to formaldehyde-treated feed and formaldehyde generated from dietary sources of methanol, including from food additives such as aspartame. Endogenous turnover of formaldehyde was estimated to be approximately 0.61-0.91 mg/kg bw per minute and 878-1310 mg/kg bw per day assuming a half life of 1 1.5 min. Compared with formaldehyde turnover and the background levels of formaldehyde from food sources (1.7-1.4 mg/kg b. w per day for a 60-70 kg person, including from dietary methanol, the relative contribution of exogenous formaldehyde from consumption of animal products (milk, meat from target animals exposed to formaldehyde-treated feed was negligible (<0.001 %. Oral exposure to formaldehyde from aspartame involves metabolism to methanol and further oxidation to formaldehyde. At the current ADI of 40 mg/kg bw per day for aspartame, formaldehyde would be approximately 4 mg/kg bw per day and represent only 0.3-0.4 % of the endogenous turnover of formaldehyde.

  20. Emission of formaldehyde from furniture

    DEFF Research Database (Denmark)

    Andersen, Helle Vibeke; Klinke, Helene B.; Funch, Lis Winther;

    The emission of formaldehyde from 20 pieces of furniture, representing a variety of types, was measured in climate chambers. Most tests show low emissions but certain scenarios of furnishing, including furniture with large surface areas in relation to room volume can emit formaldehyde resulting i...

  1. Investigation of utilization of process of polyethylene waste of low density for creation of competitive materials with application of phenol formaldehyde oligomers

    International Nuclear Information System (INIS)

    Full text: The possibility of the utilization of low density polyethylene wastes by means of their modification with phenol formaldehyde oligomers (Ph FO) and PhFO with the thiourathenes has been investigation. Theology properties of the investigated systems showed that the obtained compositions can be able to be processed by the ordinary methods such as extrusion and casting

  2. Shape and size controlled synthesis of Au nanorods: H2S gas-sensing characterizations and antibacterial application

    International Nuclear Information System (INIS)

    Highlights: • We have demonstrated a facile method to prepare colloid Au nanorods. • The size and shape of Au nanorods can be controlled via seed-mediated growth method. • The H2S gas-sensing properties have been investigated. • The antibacterial application has been conducted. - Abstract: Controlling their size and shape is one of the important issues in the fundamental study and application of colloidal metal nanoparticles. In the current study, different sizes and shapes of Au nanorods were fabricated using a seed-mediated growth method. Material characterization by X-ray diffraction and transmission electron microscopy revealed that the obtained products were made of single-crystal Au nanorods with an average diameter and length of 10 nm and 40 nm, respectively. The Au nanorod-based sensor exhibited significantly high sensitivity and fast response/recovery time to low concentrations (2.5–10 ppm) of H2S at temperatures ranging from 300 °C to 400 °C. Additionally, they exhibited antibacterial effect at low concentration. These results suggested that the fabricated Au nanorods have excellent potential for practical application in air pollution monitoring and biomedicine

  3. Shape and size controlled synthesis of Au nanorods: H{sub 2}S gas-sensing characterizations and antibacterial application

    Energy Technology Data Exchange (ETDEWEB)

    Lanh, Le Thi [College of Sciences, Hue University, 77 Nguyen Hue, Hue City (Viet Nam); Hoa, Tran Thai, E-mail: trthaihoa@yahoo.com [College of Sciences, Hue University, 77 Nguyen Hue, Hue City (Viet Nam); Cuong, Nguyen Duc [College of Sciences, Hue University, 77 Nguyen Hue, Hue City (Viet Nam); Faculty of Hospitality and Tourism, Hue University, 22 Lam Hoang, Hue City (Viet Nam); Khieu, Dinh Quang [College of Sciences, Hue University, 77 Nguyen Hue, Hue City (Viet Nam); Quang, Duong Tuan [College of Education, Hue University, 34 Le Loi, Hue City (Viet Nam); Van Duy, Nguyen; Hoa, Nguyen Duc [International Training Institute for Materials Science, Hanoi University of Science and Technology, Hanoi (Viet Nam); Van Hieu, Nguyen, E-mail: hieu@itims.edu.vn [International Training Institute for Materials Science, Hanoi University of Science and Technology, Hanoi (Viet Nam)

    2015-06-25

    Highlights: • We have demonstrated a facile method to prepare colloid Au nanorods. • The size and shape of Au nanorods can be controlled via seed-mediated growth method. • The H{sub 2}S gas-sensing properties have been investigated. • The antibacterial application has been conducted. - Abstract: Controlling their size and shape is one of the important issues in the fundamental study and application of colloidal metal nanoparticles. In the current study, different sizes and shapes of Au nanorods were fabricated using a seed-mediated growth method. Material characterization by X-ray diffraction and transmission electron microscopy revealed that the obtained products were made of single-crystal Au nanorods with an average diameter and length of 10 nm and 40 nm, respectively. The Au nanorod-based sensor exhibited significantly high sensitivity and fast response/recovery time to low concentrations (2.5–10 ppm) of H{sub 2}S at temperatures ranging from 300 °C to 400 °C. Additionally, they exhibited antibacterial effect at low concentration. These results suggested that the fabricated Au nanorods have excellent potential for practical application in air pollution monitoring and biomedicine.

  4. Fundamental study on the mechanism of DNA degradation in tissues fixed in formaldehyde.

    OpenAIRE

    Tokuda, Y; Nakamura, T.; Satonaka, K; Maeda, S; Doi, K.; Baba, S; Sugiyama, T.

    1990-01-01

    The mechanism of DNA degradation and its clinical applications were examined. When purified lambda phage and extracted liver DNA were fixed in phosphate buffered formaldehyde, the DNA did not degrade, but there was incomplete digestion with endonuclease. Rat liver tissues were fixed under various conditions and DNA extracted. Immediate fixation with buffered formaldehyde at low temperature, or the addition of EDTA to buffered formaldehyde blocked the DNA degradation. Analysis of pulsed field ...

  5. Endogenous formaldehyde turnover in humans compared with exogenous contribution from food sources

    OpenAIRE

    European Food Safety Authority

    2014-01-01

    The FEEDAP Panel received a request to deliver a scientific opinion on the safety and efficacy of formaldehyde used in feed for all animal species based on dossiers submitted by applicants. In parallel, the ANS Panel evaluated the safety of formaldehyde formed from endogenous production and from dietary sources of methanol, including aspartame. In order to support both evaluations, assistance was requested to the SCER unit to evaluate the oral internal dose of formaldehyde in humans from endo...

  6. Formaldehyde mass-transfer properties study

    OpenAIRE

    Zhao, Xiaomin

    2013-01-01

    Formaldehyde, an important feedstock in industrial processes and manufacture, is widely present in numerous consumer products. Emitted by many types of consumer products and indoor materials, indoor air can contain high concentrations of formaldehyde. Exposure to formaldehyde is hazardous to human health. Thus knowledge of formaldehyde mass-transfer properties is critical to efforts to reduce formaldehyde emissions and establish related standards and regulations. The primary objectives...

  7. Formaldehyde in Insulation: Villain or Innocent Bystander?

    OpenAIRE

    Lees, R. E. M.

    1983-01-01

    When urea formaldehyde foam insulation (UFFI) deteriorates, it produces an off-gas mixture whose major constituent is formaldehyde. Most investigative studies of UFFI have concentrated on formaldehyde. Health concerns fall into three groups: irritant characteristics, allergenic capabilities and potential carcinogenicity. Except for the first of these, formaldehyde's hazard potential is not clear. The extent to which formaldehyde may be responsible for UFFI's evil reputation is explored in thi...

  8. Report of the Federal Panel on Formaldehyde.

    OpenAIRE

    1982-01-01

    The Federal Panel on Formaldehyde concluded that definitive experiments exist which demonstrate the mutagenicity and carcinogenicity of formaldehyde under laboratory conditions. Formaldehyde induces both gene mutations and chromosomal aberrations in a variety of test systems. Inhalation of formaldehyde causes cancer of the nose in rats. The concentrations of formaldehyde in inhaled air that caused nasal cancer in Fisher 344 rats are within the same order of magnitude as those to which humans ...

  9. A many-body approach to the vibrational structure in molecular electronic spectra. II. Application to nitrogen, carbon monoxide, and formaldehyde

    International Nuclear Information System (INIS)

    The theory developed in the preceding paper is applied to calculate the vibrational structure in optical absorption and electron impact spectra of N2 and CO and in the photoelectron spectra of H2CO and D2CO. In addition, the vibrational structure of a recently measured shake-up line in the photoelectron spectrum of N2 is computed. The influence of anharmonicity effects on the Franck--Condon factors is discussed, and a very simple scheme to take these effects into account is proposed. The one-particle approximation is shown to provide a fairly accurate picture in most cases. For formaldehyde many-body effects are incorporated into the vibrational coupling constants, this incorporation leading to an improved agreement with experiment for all bands. The assignment of the third and the fourth ionization potential of formaldehyde, which has been controversial, is clarified

  10. Nanocomposite of Au Nanoparticles/Helical Carbon Nanofibers and Application in Hydrogen Peroxide Biosensor.

    Science.gov (United States)

    Zhai, Mumu; Cui, Rongjing; Gu, Ning; Zhang, Genhua; Lin, Wang; Yu, Lingjun

    2015-06-01

    A combined sol-gel/hydrogen reduction method has been developed for the mass production of helical carbon nanofibers (HCNFs) by the pyrolysis of acetylene at 425 degrees C in the presence of NiO nanoparticles. The synthesized HCNFs were characterized with scanning electron microscopy (SEM), X-ray diffraction (XRD) and high resolution transmission electron microscopy (HRTEM). The helical-structured carbon nanofibers have a large specific surface area and excellent biocompatibility. A novel enzymatic hydrogen peroxide sensor was then successfully fabricated based on the nanocomposites containing HCNFs and gold nanoparticles (AuNPs). The results indicated that the Au/HCNFs nanocomposites exhibited excellent electrocatalytic activity to the reduction of H2O2, offering a wide linear range from 1.0 μM to 3157 μM with a detection limit as low as 0.46 μM. The apparent Michaelis-Menten constant of the biosensor was 0.61 mM. The as-fabricated biosensor showed a rapid and sensitive amperometric response to hydrogen peroxide with acceptable preparation reproducibility and excellent stability. Because of their low cost and high stability, these novel HCNFs represent seem to be a kind of promising biomaterial and may find wide new applications in scopes such as biocatalysis, immunoassay, environmental monitoring and so on. PMID:26369097

  11. Absorption of formaldehyde in water

    NARCIS (Netherlands)

    Winkelman, Jozef Gerhardus Maria

    2003-01-01

    Deze dissertatie beschrijft theoretisch en experimenteel werk aan de absorptie van formaldehyde in water. Met resultaten hiervan zijn chemisch-technische modellen ontwikkeld voor de beschrijving en optimalisatie van industriële formaldehydeabsorbeurs. Deze samenvatting geeft eerst algemene informati

  12. Compact, Ultrasensitive Formaldehyde Monitor Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This Small Business Innovative Research Phase I proposal seeks to develop an ultrasensitive, laser-based formaldehyde gas sensor system for airborne and...

  13. Electrical conductivity dependence of thin metallic films of Au and Pd as a top electrode in capacitor applications

    International Nuclear Information System (INIS)

    Electrical conductivity dependence of thin metallic films of Au and Pd over the different perovskites was investigated. It is found from electrical properties that crystallographic growth orientation of Au and Pd thin layers attained from X-ray diffraction results indicate the slop of current (I)-voltage (V) plots. Besides, surface morphology and topography was considered using Field Emission Scanning Electron Microscopy and Atomic Force Microscopy, respectively. Obtained results showed the Stranski-Krastanov growth of the Pd and Au. Indeed, diminishing of the root-mean-square roughness of Pd/BiMnO3/SrTiO3 following by Au deposition should be concerned due to growth of Au onto the crack-like parts of the substrate. These crack-like parts appeared due to parasitic phases of the Bi-Mn-O system mainly Mn3O4 (l 0 l) and Mn3O4 (0 0 4 l). The different response in the electrical properties of heterostructures suggests that electrical conductance of the Au and Pd thin metallic films have the crystallographic orientation dependence. Furthermore, polycrystallinity of the thin metallic films are desired in electrode applications due to increase the conductivity of the metallic layers.

  14. Au-SN Flip-Chip Solder Bump for Microelectronic and Optoelectronic Applications

    CERN Document Server

    Yoon, Jeong-Won; Koo, Ja-Myeong; Jung, Seung-Boo

    2007-01-01

    As an alternative to the time-consuming solder pre-forms and pastes currently used, a co-electroplating method of eutectic Au-Sn alloy was used in this study. Using a co-electroplating process, it was possible to plate the Au-Sn solder directly onto a wafer at or near the eutectic composition from a single solution. Two distinct phases, Au5Sn and AuSn, were deposited at a composition of 30at.%Sn. The Au-Sn flip-chip joints were formed at 300 and 400 degrees without using any flux. In the case where the samples were reflowed at 300 degrees, only an (Au,Ni)3Sn2 IMC layer formed at the interface between the Au-Sn solder and Ni UBM. On the other hand, two IMC layers, (Au,Ni)3Sn2 and (Au,Ni)3Sn, were found at the interfaces of the samples reflowed at 400 degrees. As the reflow time increased, the thickness of the (Au,Ni)3Sn2 and (Au,Ni)3Sn IMC layers formed at the interface increased and the eutectic lamellae in the bulk solder coarsened.

  15. Kinetically controlled synthesis of Au102(SPh)44 nanoclusters and catalytic application

    Science.gov (United States)

    Chen, Yongdong; Wang, Jin; Liu, Chao; Li, Zhimin; Li, Gao

    2016-05-01

    We here explore a kinetically controlled synthetic protocol for preparing solvent-solvable Au102(SPh)44 nanoclusters which are isolated from polydispersed gold nanoclusters by solvent extraction and size exclusion chromatography (SEC). The as-obtained Au102(SPh)44 nanoclusters are determined by matrix-assisted laser desorption ionization (MALDI) and electrospray ionization (ESI) mass spectrometry, in conjunction with UV-vis spectroscopy and thermogravimetric analysis (TGA). However, Au99(SPh)42, instead of Au102(SPh)44, is yielded when the polydispersed gold nanoclusters are etched in the presence of excess thiophenol under thermal conditions (e.g., 80 °C). Interestingly, the Au102(SPh)44 nanoclusters also can convert to Au99(SPh)42 with equivalent thiophenol ligands, evidenced by the analyses of UV-vis and MALDI mass spectrometry. Finally, the TiO2-supported Au102(SPh)44 nanocluster catalyst is investigated in the selective oxidation of sulfides into sulfoxides by the PhIO oxidant and gives rise to high catalytic activity (e.g., 80-99% conversion of R-S-R' sulfides with 96-99% selectivity for R-S(&z.dbd;O)-R' sulfoxides). The Au102(SPh)44/TiO2 catalyst also shows excellent recyclability in the sulfoxidation process.We here explore a kinetically controlled synthetic protocol for preparing solvent-solvable Au102(SPh)44 nanoclusters which are isolated from polydispersed gold nanoclusters by solvent extraction and size exclusion chromatography (SEC). The as-obtained Au102(SPh)44 nanoclusters are determined by matrix-assisted laser desorption ionization (MALDI) and electrospray ionization (ESI) mass spectrometry, in conjunction with UV-vis spectroscopy and thermogravimetric analysis (TGA). However, Au99(SPh)42, instead of Au102(SPh)44, is yielded when the polydispersed gold nanoclusters are etched in the presence of excess thiophenol under thermal conditions (e.g., 80 °C). Interestingly, the Au102(SPh)44 nanoclusters also can convert to Au99(SPh)42 with equivalent

  16. Induction of formaldehyde contact sensitivity

    DEFF Research Database (Denmark)

    Andersen, Klaus Ejner; Boman, A; Vølund, A;

    1985-01-01

    The sensitizing potential of aqueous formaldehyde was evaluated with the guinea pig maximization test (GPMT) in two laboratories (Copenhagen and Stockholm) using different guinea pig strains. Six intradermal (0.01%-3%), and 6 topical (0.5%-20%) concentrations were used for induction, and formalde......The sensitizing potential of aqueous formaldehyde was evaluated with the guinea pig maximization test (GPMT) in two laboratories (Copenhagen and Stockholm) using different guinea pig strains. Six intradermal (0.01%-3%), and 6 topical (0.5%-20%) concentrations were used for induction, and...... formaldehyde 1% and 0.1% was used for challenge. The incidence of contact sensitivity depended on the intradermal, but not on the topical induction dose. Statistical analyses showed a non-monotonous (non-linear) dose response relationship. The estimated maximal sensitization rate in Copenhagen was 80% after...... intradermal induction with 0.65% formaldehyde; in Stockholm it was 84% after induction with 0.34%. The data from the two laboratories could be described by parallel displaced dose response curves suggesting that the guinea pig strain used in Stockholm was significantly more susceptible to formaldehyde than...

  17. Synthesis of biocompatible AuAgS/Ag2S nanoclusters and their applications in photocatalysis and mercury detection

    International Nuclear Information System (INIS)

    In this paper, a facile approach for preparation of AuAgS/Ag2S nanoclusters was developed. The unique AuAgS/Ag2S nanoclusters capped with biomolecules exhibit interesting excellent optical and catalytic properties. The fluorescent AuAgS/Ag2S nanoclusters show tunable luminescence depending on the nanocluster size. The apoptosis assay demonstrated that the AuAgS/Ag2S nanoclusters showed low cytotoxicity and good biocompatibility. Therefore, the nanoclusters can be used not only as a probe for labeling cells but also for their photocatalytic activity for photodegradation of organic dye. Moreover, a highly selective and sensitive assay for detection of mercury including Hg2+ and undissociated mercury complexes was developed based on the quenching fluorescent AuAgS/Ag2S nanoclusters, which provides a promising approach for determining various forms of Hg in the mercury-based compounds in environment. These unique nanoclusters may have potential applications in biological labeling, sensing mercury, and photodegradation of various organic pollutants in waste water.Graphical Abstract

  18. Synthesis of biocompatible AuAgS/Ag{sub 2}S nanoclusters and their applications in photocatalysis and mercury detection

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Qian; Chen, Shenna; Zhang, Lingyang; Huang, Haowen, E-mail: hhwn09@163.com; Liu, Fengping [Hunan University of Science and Technology, Key Laboratory of Theoretical Organic Chemistry and Function Molecule, Ministry of Education, Hunan Provincial University Key Laboratory of QSAR/QSPR, School of Chemistry and Chemical Engineering (China); Liu, Xuanyong, E-mail: xyliu@mail.sic.ac.cn [Chinese Academy of Sciences, State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics (China)

    2014-12-15

    In this paper, a facile approach for preparation of AuAgS/Ag{sub 2}S nanoclusters was developed. The unique AuAgS/Ag{sub 2}S nanoclusters capped with biomolecules exhibit interesting excellent optical and catalytic properties. The fluorescent AuAgS/Ag{sub 2}S nanoclusters show tunable luminescence depending on the nanocluster size. The apoptosis assay demonstrated that the AuAgS/Ag{sub 2}S nanoclusters showed low cytotoxicity and good biocompatibility. Therefore, the nanoclusters can be used not only as a probe for labeling cells but also for their photocatalytic activity for photodegradation of organic dye. Moreover, a highly selective and sensitive assay for detection of mercury including Hg{sup 2+} and undissociated mercury complexes was developed based on the quenching fluorescent AuAgS/Ag{sub 2}S nanoclusters, which provides a promising approach for determining various forms of Hg in the mercury-based compounds in environment. These unique nanoclusters may have potential applications in biological labeling, sensing mercury, and photodegradation of various organic pollutants in waste water.Graphical Abstract.

  19. On the formaldehyde release of wood particles

    OpenAIRE

    Roffael, E.; Behn, C.; Dix, B.

    2012-01-01

    The emission of formaldehyde from softwood particles, as measured by the flask method (EN 717-3), depends highly on the particle size. Therefore, no definite value for the formaldehyde release from wood can be given.

  20. Formaldehyde stress responses in bacterial pathogens

    Directory of Open Access Journals (Sweden)

    Nathan Houqian Chen

    2016-03-01

    Full Text Available Formaldehyde is the simplest of all aldehydes and is highly cytotoxic. Its use and associated dangers from environmental exposure have been well documented. Detoxification systems for formaldehyde are found throughout the biological world and they are especially important in methylotrophic bacteria, which generate this compound as part of their metabolism of methanol. Formaldehyde metabolizing systems can be divided into those dependent upon pterin cofactors, sugar phosphates and those dependent upon glutathione. The more prevalent thiol-dependent formaldehyde detoxification system is found in many bacterial pathogens, almost all of which do not metabolize methane or methanol. This review describes the endogenous and exogenous sources of formaldehyde, its toxic effects and mechanisms of detoxification. The methods of formaldehyde sensing are also described with a focus on the formaldehyde responsive transcription factors HxlR, FrmR and NmlR. Finally, the physiological relevance of detoxification systems for formaldehyde in bacterial pathogens is discussed.

  1. Formaldehyde Stress Responses in Bacterial Pathogens.

    Science.gov (United States)

    Chen, Nathan H; Djoko, Karrera Y; Veyrier, Frédéric J; McEwan, Alastair G

    2016-01-01

    Formaldehyde is the simplest of all aldehydes and is highly cytotoxic. Its use and associated dangers from environmental exposure have been well documented. Detoxification systems for formaldehyde are found throughout the biological world and they are especially important in methylotrophic bacteria, which generate this compound as part of their metabolism of methanol. Formaldehyde metabolizing systems can be divided into those dependent upon pterin cofactors, sugar phosphates and those dependent upon glutathione. The more prevalent thiol-dependent formaldehyde detoxification system is found in many bacterial pathogens, almost all of which do not metabolize methane or methanol. This review describes the endogenous and exogenous sources of formaldehyde, its toxic effects and mechanisms of detoxification. The methods of formaldehyde sensing are also described with a focus on the formaldehyde responsive transcription factors HxlR, FrmR, and NmlR. Finally, the physiological relevance of detoxification systems for formaldehyde in bacterial pathogens is discussed. PMID:26973631

  2. ALLERGIC CONTACT DERMATITIS FROM FORMALDEHYDE EXPOSURE.

    OpenAIRE

    Maya Lyapina; Angelina Kisselova-Yaneva; Assya Krasteva; Mariana Tzekova–Yaneva; Maria Dencheva-Garova

    2012-01-01

    Formaldehyde is a ubiquitous chemical agent, a part of our outdoor and indoor working and residential environment. Healthcare workers in difficult occupations are among the most affected by formaldehyde exposure. Formaldehyde is an ingredient of some dental materials. Formaldehyde is well-known mucous membrane irritant and a primary skin sensitizing agent associated with both contact dermatitis (Type IV allergy), and immediate, anaphylactic reactions (Type I allergy). Inhalation exposure to f...

  3. Formaldehyde removal from wastewater applying natural zeolite

    OpenAIRE

    Dovilė Kulikauskaitė; Dainius Paliulis

    2015-01-01

    Formaldehyde is one of the most chemically active compounds which is discharged with untreated or just partially treated industrial wastewater. It is hazardous for environment and humans. Formaldehyde vapors can strongly irritate skin, can cause damage to eyes and harm respiratory tract. As long as formaldehyde causes a toxic effect on environment and living organisms, it is necessary to remove it from wastewater which is directed to natural water. There are many methods used for formaldehyde...

  4. AuCu@Pt Nanoalloys for Catalytic Application in Reduction of 4-Nitrophenol

    Directory of Open Access Journals (Sweden)

    Sadia Mehmood

    2016-01-01

    Full Text Available To enhance and optimize nanocatalyst ability for nitrophenol (4-NP reduction reaction we look beyond Au-metal nanoparticles and describe a new class of Au nanoalloys with controlled composition for core of AuCu-metals and Pt-metal shell. The reduction of 4-NP was investigated in aqueous media spectroscopically on 7.8 nm Au nanospheres (AuNSs, 8.3 nm AuCuNSs, and 9.1 nm AuCu@Pt core-shell NSs in diameter. The rate constants of the catalyzed reaction at room temperature, activation energies, and entropies of activation of reactions catalyzed by the AuCu@Pt core-shell NSs are found to have different values to those of the pure metal NSs. The results strongly support the proposal that catalysis by nanoparticles is taking place efficiently on the surface of NSs. These core-shell nanocatalysts exhibited stability throughout the reduction reaction and proved that heterogonous type mechanisms are most likely to be dominant in nanoalloy based catalysis if the surface of the NSs is not defected upon shell incorporation.

  5. Kinetically controlled synthesis of Au102(SPh)44 nanoclusters and catalytic application.

    Science.gov (United States)

    Chen, Yongdong; Wang, Jin; Liu, Chao; Li, Zhimin; Li, Gao

    2016-05-21

    We here explore a kinetically controlled synthetic protocol for preparing solvent-solvable Au102(SPh)44 nanoclusters which are isolated from polydispersed gold nanoclusters by solvent extraction and size exclusion chromatography (SEC). The as-obtained Au102(SPh)44 nanoclusters are determined by matrix-assisted laser desorption ionization (MALDI) and electrospray ionization (ESI) mass spectrometry, in conjunction with UV-vis spectroscopy and thermogravimetric analysis (TGA). However, Au99(SPh)42, instead of Au102(SPh)44, is yielded when the polydispersed gold nanoclusters are etched in the presence of excess thiophenol under thermal conditions (e.g., 80 °C). Interestingly, the Au102(SPh)44 nanoclusters also can convert to Au99(SPh)42 with equivalent thiophenol ligands, evidenced by the analyses of UV-vis and MALDI mass spectrometry. Finally, the TiO2-supported Au102(SPh)44 nanocluster catalyst is investigated in the selective oxidation of sulfides into sulfoxides by the PhIO oxidant and gives rise to high catalytic activity (e.g., 80-99% conversion of R-S-R' sulfides with 96-99% selectivity for R-S([double bond, length as m-dash]O)-R' sulfoxides). The Au102(SPh)44/TiO2 catalyst also shows excellent recyclability in the sulfoxidation process. PMID:26758553

  6. Electrical performance of Ti-ZnO-Au thin film composite structure for device application

    Science.gov (United States)

    Joshi, Priyanka; Singh, Jitendra; Das, Surajit; Desai, J. V.; Akhtar, Jamil

    2016-04-01

    Thin film layers of Au/Ti approximately 2200 Å thick and ZnO approximately 2.24 µm thick were sputtered sequentially onto silicon dioxide coated Si-wafer. Conventional wisdom confirms the adhesion of gold over zinc oxide (ZnO) by an intermediate layer of titanium for better adhesion. But, in Au/Ti/ZnO/Au/Ti structure, it was observed that with the passing of time the gold diffused into ZnO thin film at room temperature, making a very low resistance between the two gold layers eventually making a conductive path in ZnO. Therefore, electrical connectivity was found between the metal layers. A detailed experimental analysis has been carried out in support of the observed Au diffusion. In the present work, reliability of Ti/Au metallisation and anomalous electrical behavior due to gold diffusion has been studied.

  7. Crystallographic investigation of Au nanoparticles embedded in a SrTiO3 thin film for plasmonics applications by means of synchrotron radiation

    International Nuclear Information System (INIS)

    Self-organized monocrystalline Au nanoparticles with potential applications in plasmonics are grown in a SrTiO3 matrix by a novel two-step deposition process. The crystalline preferred orientation of these Au nanoparticles is investigated by synchrotron hard x-ray diffraction. Nanoparticles preferentially align with the (111) direction along the substrate normal (001), whereas two in-plane orientations are found with [110]SrTiO3∥[110]Au and [100]SrTiO3∥[110]Au. Additionally, a smaller diffraction signal from nanoparticles with the (001) direction parallel to the substrate normal (001) is observed; once again, two in-plane orientations are found, with [100]SrTiO3∥[100]Au and [100]SrTiO3∥[110]Au. The populations of the two in-plane orientations are found to depend on the thickness of the gold film deposited in the first step of the growth

  8. PRODUCTION OF HIGH DENSITY PARTICLEBOARD USING MELAMINE-UREA-FORMALDEHYDE RESIN

    Directory of Open Access Journals (Sweden)

    Setsuo Iwakiri

    2005-12-01

    Full Text Available This research was developed aiming to evaluate the effects of board density and melamine-urea-formaldehyde resin onthe properties of particleboard for semi-structural applications. The boards were manufactured with nominal density of 0.65 g/cm³and 0.90 g/cm³ using urea-formaldehyde resin as control and melamine-urea-formaldehyde. The results showed a better dimensionallystability and mechanical properties of the boards manufactured with higher density and MUF resin content. The fine furnish usedfor external layer of particleboard in the industrial process, could be used for high density homogeneous board to semi-strucuturaluses, such as flooring applications.

  9. Facile Synthesis of Quasi-One-Dimensional Au/PtAu Heterojunction Nanotubes and Their Application as Catalysts in an Oxygen-Reduction Reaction.

    Science.gov (United States)

    Cai, Kai; Liu, Jiawei; Zhang, Huan; Huang, Zhao; Lu, Zhicheng; Foda, Mohamed F; Li, Tingting; Han, Heyou

    2015-05-11

    An intermediate-template-directed method has been developed for the synthesis of quasi-one-dimensional Au/PtAu heterojunction nanotubes by the heterogeneous nucleation and growth of Au on Te/Pt core-shell nanostructures in aqueous solution. The synthesized porous Au/PtAu bimetallic nanotubes (PABNTs) consist of porous tubular framework and attached Au nanoparticles (AuNPs). The reaction intermediates played an important role in the preparation, which fabricated the framework and provided a localized reducing agent for the reduction of the Au and Pt precursors. The Pt7 Au PABNTs showed higher electrocatalytic activity and durability in the oxygen-reduction reaction (ORR) in 0.1 M HClO4 than porous Pt nanotubes (PtNTs) and commercially available Pt/C. The mass activity of PABNTs was 218 % that of commercial Pt/C after an accelerated durability test. This study demonstrates the potential of PABNTs as highly efficient electrocatalysts. In addition, this method provides a facile strategy for the synthesis of desirable hetero-nanostructures with controlled size and shape by utilizing an intermediate template. PMID:25833689

  10. Fabrication of Te and Te-Au Nanowires-Based Carbon Fiber Fabrics for Antibacterial Applications

    Directory of Open Access Journals (Sweden)

    Ting-Mao Chou

    2016-02-01

    Full Text Available Pathogenic bacteria that give rise to diseases every year remain a major health concern. In recent years, tellurium-based nanomaterials have been approved as new and efficient antibacterial agents. In this paper, we developed the approach to directly grow tellurium nanowires (Te NWs onto commercial carbon fiber fabrics and demonstrated their antibacterial activity. Those Te NWs can serve as templates and reducing agents for gold nanoparticles (Au NPs to deposit. Three different Te-Au NWs with varied concentration of Au NPs were synthesized and showed superior antibacterial activity and biocompability. These results indicate that the as-prepared carbon fiber fabrics with Te and Te-Au NWs can become antimicrobial clothing products in the near future.

  11. Cu2O and Au/Cu2O Particles: Surface Properties and Applications in Glucose Sensing

    OpenAIRE

    Yu-Ho Won; Stanciu, Lia A.

    2012-01-01

    In this work we investigated the surface and facet-dependent catalytic properties of metal oxide particles as well as noble metal/metal oxide heterogeneous structures, with cuprous oxide (Cu2O) and Au/Cu2O being selected as model systems. As an example of application, we explored the potential of these materials in developing electrocatalytic devices. Cu2O particles were synthesized in various shapes, then used for testing their morphology-dependent electrochemical properties applied to the d...

  12. Lead Telluride Doped with Au as a Very Promising Material for Thermoelectric Applications

    Directory of Open Access Journals (Sweden)

    Pantelija M. Nikolic

    2015-01-01

    Full Text Available PbTe single crystals doped with monovalent Au or Cu were grown using the Bridgman method. Far infrared reflectivity spectra were measured at room temperature for all samples and plasma minima were registered. These experimental spectra were numerically analyzed and optical parameters were calculated. All the samples of PbTe doped with Au or Cu were of the “n” type. The properties of these compositions were analyzed and compared with PbTe containing other dopants. The samples of PbTe doped with only 3.3 at% Au were the best among the PbTe + Au samples having the lowest plasma frequency and the highest mobility of free carriers-electrons, while PbTe doped with Cu was the opposite. Samples with the lowest Cu concentration of 0.23 at% Cu had the best properties. Thermal diffusivity and electronic transport properties of the same PbTe doped samples were also investigated using a photoacoustic (PA method with the transmission detection configuration. The results obtained with the far infrared and photoacoustic characterization of PbTe doped samples were compared and discussed. Both methods confirmed that when PbTe was doped with 3.3 at% Au, thermoelectric and electrical properties of this doped semiconductor were both significantly improved, so Au as a dopant in PbTe could be used as a new high quality thermoelectric material.

  13. A Room-Temperature Operation Formaldehyde Sensing Material Printed Using Blends of Reduced Graphene Oxide and Poly(methyl methacrylate

    Directory of Open Access Journals (Sweden)

    Wen-Yu Chuang

    2015-11-01

    Full Text Available This work demonstrates a printable blending material, i.e., reduced graphene oxide (RGO mixed with poly(methyl methacrylate (PMMA, for formaldehyde sensing. Based on experimental results, 2% RGO/10% PMMA is an optimal ratio for formaldehyde detection, which produced a 30.5% resistance variation in response to 1000 ppm formaldehyde and high selectivity compared to different volatile organic compounds (VOCs, humidity, CO, and NO. The demonstrated detection limit is 100 ppm with 1.51% resistance variation. Characterization of the developed formaldehyde sensing material was performed by Fourier-transform infrared (FTIR spectrometry, scanning electron microscopy (SEM, and Raman spectroscopy. Based on Raman spectroscopy, the basic sensing mechanism is the band distortion of RGO due to blending with PMMA and the adsorption of formaldehyde. This work establishes insights into the formaldehyde sensing mechanism and explores a potential printable sensing material for diverse applications.

  14. Stabilization of AuNPs by monofunctional triazole linked to ferrocene, ferricenium, or coumarin and applications to synthesis, sensing, and catalysis.

    Science.gov (United States)

    Li, Na; Zhao, Pengxiang; Igartua, María E; Rapakousiou, Amalia; Salmon, Lionel; Moya, Sergio; Ruiz, Jaime; Astruc, Didier

    2014-11-01

    Monofunctional triazoles linked to ferrocene, ferricenium, or coumarin (Cou), easily synthesized by copper-catalyzed azide alkyne (CuAAC) "click" reactions between the corresponding functional azides and (trimethylsilyl)acetylene followed by silyl group deprotection, provide a variety of convenient neutral ligands for the stabilization of functional gold nanoparticles (AuNPs) in polar organic solvents. These triazole (trz)-AuNPs are very useful toward a variety of applications to synthesis, sensing, and catalysis. Both ferrocenyl (Fc) and isostructural ferricenium linked triazoles give rise to AuNP stabilization, although by different synthetic routes. Indeed, the first direct synthesis and stabilization of AuNPs by ferricenium are obtained by the reduction of HAuCl4 upon reaction with a ferrocene derivative, AuNP stabilization resulting from a synergy between electrostatic and coordination effects. The ferricenium/ferrocene trz-AuNP redox couple is fully reversible, as shown by cyclic voltammograms that were recorded with both redox forms. These trz-AuNPs are stable for weeks in various polar solvents, but at the same time, the advantage of trz-AuNPs is the easy substitution of neutral trz ligands by thiols and other ligands, giving rise to applications. Indeed, this ligand substitution of trz at the AuNP surface yields a stable Fc-terminated nanogold-cored dendrimer upon reaction with a Fc-terminated thiol dendron, substitution of Cou-linked trz with cysteine, homocysteine, and glutathione provides remarkably efficient biothiol sensing, and a ferricenium-linked trz-AuNP catalyst is effective for NaBH4 reduction of 4-nitrophenol to 4-aminophenol. In this catalytic example, the additional electrostatic AuNP stabilization modulates the reaction rate and induction time. PMID:25363304

  15. Composition-selective fabrication of ordered intermetallic Au-Cu nanowires and their application to nano-size electrochemical glucose detection

    Science.gov (United States)

    Kim, Si-In; Eom, Gayoung; Kang, Mijeong; Kang, Taejoon; Lee, Hyoban; Hwang, Ahreum; Yang, Haesik; Kim, Bongsoo

    2015-06-01

    Bimetallic nanostructures can provide distinct and improved physicochemical properties by the coupling effect of the two metal components, making them promising materials for a variety of applications. Herein, we report composition-selective fabrication of ordered intermetallic Au-Cu nanowires (NWs) by two-step chemical vapor transport method and their application to nano-electrocatalytic glucose detection. Ordered intermetallic Au3Cu and AuCu3 NWs are topotaxially fabricated by supplying Cu-containing chemicals to pre-synthesized single-crystalline Au NW arrays. The composition of fabricated Au-Cu NWs can be selected by changing the concentration of Cu-containing species. Interestingly, Au3Cu NW electrodes show unique electrocatalytic activity for glucose oxidation, allowing us to detect glucose without interference from ascorbic acid. Such interference-free detection of glucose is attributed to the synergistic effect, induced by incorporation of Cu in Au. We anticipate that Au3Cu NWs could show possibility as efficient nano-size electrochemical glucose sensors and the present fabrication method can be employed to fabricate valuable ordered intermetallic nanostructures.

  16. Corrosion Protection of Al/Au/ZnO Anode for Hybrid Cell Application.

    Science.gov (United States)

    Slaughter, Gymama; Stevens, Brian

    2015-01-01

    Effective protection of power sources from corrosion is critical in the development of abiotic fuel cells, biofuel cells, hybrid cells and biobateries for implantable bioelectronics. Corrosion of these bioelectronic devices result in device inability to generate bioelectricity. In this paper Al/Au/ZnO was considered as a possible anodic substrate for the development of a hybrid cell. The protective abilities of corrosive resistant aluminum hydroxide and zinc phosphite composite films formed on the surface of Al/Au/ZnO anode in various electrolyte environments were examined by electrochemical methods. The presence of phosphate buffer and physiological saline (NaCl) buffer allows for the formation of aluminum hyrdroxide and zinc phosphite composite films on the surface of the Al/Au/ZnO anode that prevent further corrosion of the anode. The highly protective films formed on the Al/Au/ZnO anode during energy harvesting in a physiological saline environment resulted in 98.5% corrosion protective efficiency, thereby demonstrating that the formation of aluminum hydroxide and zinc phosphite composite films are effective in the prevention of anode corrosion during energy harvesting. A cell assembly consisting of the Al/Au/ZnO anode and platinum cathode resulted in an open circuit voltage of 1.03 V. A maximum power density of 955.3 mW/ cm² in physiological saline buffer at a cell voltage and current density of 345 mV and 2.89 mA/ cm², respectively. PMID:26580661

  17. Self-ordering of Au(111) vicinal surfaces and application to nanostructure organized growth

    International Nuclear Information System (INIS)

    This paper reports on Au(111) vicinal surfaces, either regularly stepped surfaces, reconstructed or not, or periodically faceted surfaces, which are well suited to be used as templates for organized growth of clusters. Angles of misorientation with respect to the (111) plane lie between 1 deg. and 12 deg. and two opposite azimuths are considered: (i) [21-bar1-bar], that leads to steps with (100) microfacets, and (ii) [2-bar11], that leads to steps with (111) microfacets. The behaviour of the Au(111) reconstruction in the vicinity of steps depends drastically on the step microstructure, and this is a key point for understanding the various periodic morphologies existing on Au(111) vicinal surfaces. The interaction between the reconstruction and the close-packed steps of the Au(111) surface is interpreted in terms of the relative stability of both types of step. Self-organized morphologies between 10 and 100 nm are interpreted within the framework of elastic theory and by pointing out the crucial role played by the atomic boundary energy term. The microscopic origin of faceting is discussed, proposing two different models depending on each azimuth. Then, we illustrate the use of Au(111) vicinal surfaces as templates for growing long range ordered nanostructures. Examples are given in the case of cobalt growth

  18. Production of radio-gold {sup 199}Au for diagnostic and therapeutic applications

    Energy Technology Data Exchange (ETDEWEB)

    Khandaker, Mayeen Uddin, E-mail: mu-khandaker@um.edu.my; Kassim, Hasan Abu, E-mail: hasanak@um.edu.my [Department of Physics, University of Malaya, 50603 Kuala Lumpur (Malaysia); Haba, Hiromitsu, E-mail: haba@riken.jp [Nishina Center for Accelerator-Based Science, RIKEN, Wako, Saitama 351-0198 (Japan)

    2016-01-22

    Production cross-sections of the {sup nat}Pt(d,x){sup 199}Au reactions have been measured from a 24-MeV deuteron energy down to the threshold by using a stacked-foil activation technique combined with HPGe γ-ray spectrometry. Only a partial agreement is obtained with the existing literature data. Theoretical data extracted from the TENDL-2013 library shows large discrepancy with the measured ones. Physical thick target yield for the {sup 199}Au radionuclide was deduced using the measured cross-sections, and found a general agreement with the directly measured yield available in the literature. This study reveals that a low deuteron energy (<15 MeV) cyclotron and an enriched {sup 198}Pt (100%) target could be used to obtain {sup 199}Au in no carrier added form.

  19. An application of Au thin-film emissivity barrier on Ni alloy

    Energy Technology Data Exchange (ETDEWEB)

    Huang Zhibin [State Key Laboratory of Solidification Processing, School of Materials Science and Engineering, Northwestern Polytechincial University, Xi' an 710072 (China)], E-mail: huangzhibin83@163.com; Zhu Dongmei; Lou Fa; Zhou Wancheng [State Key Laboratory of Solidification Processing, School of Materials Science and Engineering, Northwestern Polytechincial University, Xi' an 710072 (China)

    2008-12-30

    1000 nm-thick Au film was sputter-deposited on two groups of nickel alloy substrates, in which one group (Group A) was oxidated at 800 deg. C for 20 h to form a oxide film before coating gold while another group (Group B) was unoxidated. The gold thin-film is applied to serve as a low emissivity coating to reflect thermal radiation. The gold-coated samples were heated in air at 600 deg. C for 150 h to explore the effect of high-temperature environment on the emissivity of coated Au film. After heat-treatment, the average thermal emissivity at the wavelength of 3-14 {mu}m of Group B greatly increased from 0.18 to 0.82 while that of Group A only increased a little. The diffusion between Au and other nickel alloy elements at 600 deg. C also had been discussed in this paper.

  20. Characterization of self-assembled electrodes based on Au-Pt nanoparticles for PEMFC application

    Energy Technology Data Exchange (ETDEWEB)

    Valenzuela, E. [Politecnica Univ. de Chiapas, Tuxtla Gutierrez, Chiapas (Mexico). Energia y Sustentabilidad; Sebastian, P.J. [Politecnica Univ. de Chiapas, Chiapas (Mexico). Energia y Sustentabilidad; Centro de Investigacion en Energia, UNAM, Morelos (Mexico); Gamboa, S.A. [Centro de Investigacion en Energia, UNAM, Morelos (Mexico); Pal, U. [Inst. de Fisica, Universidad Autonoma de Puebla Univ., Puebla (Mexico). Inst. de Fisica; Gonzalez, I. [Autonoma Metropolitana Univ. (Mexico). Dept. de Quimica

    2008-07-01

    This paper reported on a study in which membrane electrode assemblies (MEAs) were fabricated by depositing Au, Pt and AuPt nanoparticles on Nafion 115 membrane for use in a proton exchange membrane fuel cell (PEMFC). A Rotating Disc Electrode (RDE) was used to measure the nanoparticle catalyst activity. After deposition of the nanoparticles on the membrane, the surface was studied by Scanning Electron Microscopy (SEM) and Energy Dispersive Spectroscopy (EDS). The membrane proton conduction process was studied by Electrochemical Impedance Spectroscopy (EIS) with the 4 probe technique. The MEAs fabricated with Nafion/Metal membranes were evaluated in a PEMFC under standard conditions. Colloidal solutions were used to prepare self-assembled electrodes with nanoparticles deposited on Nafion membrane. The particles deposited on Nafion showed good stability and had homogeneous distribution along the membrane surface. The impedance results revealed an increase in the membrane proton resistance of the self-assembled electrodes compared to unmodified Nafion. The Au-Pt nanoparticles were obtained by chemical reduction. The nanoparticle size in the three systems was about 2 nm. The self-assembled electrodes performed well in standard conditions. The optimum colloidal concentration and immersion time must be determined in order to obtain good catalytic activity and high membrane conductance. The self-assembled Nafion/AuPt had the best open circuit potential (887 mV). The Au and Pt self-assemblies showed a similar performance in terms of maximum power and maximum current density. The performance of the Nafion/Au self-assembly was influenced more by ohmic losses, particularly in the membrane. The maximum power generation was obtained at 0.35 V. The mass transport losses increased after this value, thereby affecting the efficiency of the PEMFC. 2 figs.

  1. Formaldehyde Metabolism and Formaldehyde-induced Alterations in Glucose and Glutathione Metabolism of Cultured Brain Cells

    OpenAIRE

    Tulpule, Ketki

    2013-01-01

    Formaldehyde is an environmental pollutant that is also generated in the body during normal metabolic processes. Interestingly, several pathological conditions are associated with an increase in formaldehyde-generating enzymes in the body. The level of formaldehyde in the brain is elevated with increasing age and in neurodegenerative conditions which may contribute to lowered cognitive functions. Although the neurotoxic potential of formaldehyde is well established, the molecular mechanisms i...

  2. Formaldehyde Stress Responses in Bacterial Pathogens

    OpenAIRE

    Chen, Nathan H.; Djoko, Karrera Y.; Frédéric J. Veyrier; McEwan, Alastair G.

    2016-01-01

    Formaldehyde is the simplest of all aldehydes and is highly cytotoxic. Its use and associated dangers from environmental exposure have been well documented. Detoxification systems for formaldehyde are found throughout the biological world and they are especially important in methylotrophic bacteria, which generate this compound as part of their metabolism of methanol. Formaldehyde metabolizing systems can be divided into those dependent upon pterin cofactors, sugar phosphates and those depend...

  3. Formaldehyde stress responses in bacterial pathogens

    OpenAIRE

    Nathan Houqian Chen; Djoko, Karrera Y.; McEwan, Alastair G.; Frédéric J. Veyrier

    2016-01-01

    Formaldehyde is the simplest of all aldehydes and is highly cytotoxic. Its use and associated dangers from environmental exposure have been well documented. Detoxification systems for formaldehyde are found throughout the biological world and they are especially important in methylotrophic bacteria, which generate this compound as part of their metabolism of methanol. Formaldehyde metabolizing systems can be divided into those dependent upon pterin cofactors, sugar phosphates and those depend...

  4. Smart badge for monitoring formaldehyde exposure concentration

    OpenAIRE

    Fathallah, Houssem,; Lecuire, Vincent; Rondeau, Eric; Le Calvé, Stéphane

    2015-01-01

    Formaldehyde is used by many industrial processes (e.g., paper, wood, textile). The World Health Organization classifies formaldehyde in the category 3 of carcinogenic substances and defines exposure limits in professional context. The objective of CAPFEIN project funded by the French National Research Agency is to develop smart systems enabling to estimate formaldehyde exposure concentrations of employers working in closed environment. This research project gathering researchers in chemistry...

  5. Dynamics of Green AuNP Formation and Their Application in Core-Shell Nanostructures

    DEFF Research Database (Denmark)

    Engelbrekt, Christian; Zhang, Jingdong; Jensen, Palle Skovhus;

    potential, conductivity, pH, turbidity, UV - Vis extinction , core size and hydrodynamic diameter . The synthesized AuNPs have been employed as core particles in advanced core - shell structures with highly porous platinum nanoparticle coating or copper oxide shells. These hold poten- tials as effective...... catalysts in fuel cells and methanol reformers....

  6. Formaldehyde removal from wastewater applying natural zeolite

    Directory of Open Access Journals (Sweden)

    Dovilė Kulikauskaitė

    2015-10-01

    Full Text Available Formaldehyde is one of the most chemically active compounds which is discharged with untreated or just partially treated industrial wastewater. It is hazardous for environment and humans. Formaldehyde vapors can strongly irritate skin, can cause damage to eyes and harm respiratory tract. As long as formaldehyde causes a toxic effect on environment and living organisms, it is necessary to remove it from wastewater which is directed to natural water. There are many methods used for formaldehyde removal from wastewater: biological method, evaporation, membrane separation method. Most of them have disadvantages. Adsorption method has many advantages: it is fast, cheap, and universal, and can be widely used, therefore it was chosen for this research. Experiment was carried out with natural zeolite in different contact time with different concentration formaldehyde solutions. Concentration of formaldehyde was determined applying the Photocolorimetric Method. Method is based on reaction of formaldehyde with chromotropic acid and determination of formaldehyde concentration. Determined average sorption efficiency was highest when formaldehyde concentration was lowest, e. g. 2 mg/l (45.94% after eight hours of contact time with adsorbent. Sorption efficiency was increasing when the contact time increased, but when the contact time increased to 12 hours, sorption efficiency stayed the same because of the saturation of zeolite.

  7. Role of Moving Bed Biofilm Reactor and Sequencing Batch Reactor in Biological Degradation of Formaldehyde Wastewater

    Directory of Open Access Journals (Sweden)

    B. Ayati

    2011-10-01

    Full Text Available Nowadays formaldehyde is used as raw material in many industries. It has also disinfection applications in some public places. Due to its toxicity for microorganisms, chemical or anaerobic biological methods are applied for treating wastewater containing formaldehyde.In this research, formaldehyde removal efficiencies of aerobic biological treatment systems including moving bed biofilm (MMBR and sequencing batch reactors (SBR were investigated. During all experiments, the efficiency of SBR was more than MBBR, but the difference was not significant statistically. According to the results, the best efficiencies were obtained for influent formaldehyde COD of 200 mg/L in MBBR and SBR which were 93% and 99.4%, respectively. The systems were also capable to treat higher formaldehyde concentrations (up to 2500 mg/L with lower removal efficiency. The reaction kinetics followed the Stover-Kincannon second order model. The gram-positive and gram-negative bacillus and coccus as well as the gram-positive binary bacillus were found to be the most dominant species. The results of 13C-NMR analysis have shown that formaldehyde and urea were converted into N-{[(aminocarbonyl amino] methyl}urea and the residual formaldehyde was polymerized at room temperature.

  8. Preparation of Pt/poly (2-Methoxyaniline)-sodium dodecyl sulfate composite and its application for electrocatalytic oxidation of methanol and formaldehyde

    International Nuclear Information System (INIS)

    In this work, poly (2-Methoxyaniline) (P2MA) film was prepared by using successive potential cycling in monomer solution in the presence of sodium dodecyl sulfate (SDS) as an anionic surfactant at the surface of glassy carbon electrode (GCE). Then, electrodeposition at a constant potential (-0.20 V vs. Ag|AgCl|KCl (3 M)) in 0.5 M H2SO4 solution containing 5.0 mM H2PtCl6 was performed for dispersion of Pt nano/microparticles for fabrication of the Pt/P2MA-SDS composite. The as-formed Pt/P2MA-SDS/MGCE was characterized by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX) and electrochemical methods. The SEM studies revealed that the presence of SDS strongly influences the morphology of the polymer film. The electrochemical methanol oxidation reaction was investigated at the Pt/P2MA-SDS/MGCE by cyclic voltammetry and chronoamperometric techniques. The results indicated that the Pt/P2MA-SDS/MGCE in comparison with Pt/MGCE and Pt/P2MA/MGCE exhibits excellent electrocatalytic activity towards the methanol oxidation. The improved performance showed that the P2MA-SDS films significantly increase the effective active surface area of the Pt particles which is due to the synergistic effect between Pt and P2MA-SDS at the electrode surface. Furthermore, the effect of several parameters such as P2MA thickness, 2MA, SDS and CH3OH concentrations towards the methanol oxidation as well as long-term stability of the modified electrode has been investigated. The electrocatalytic oxidation of formaldehyde as an intermediate in the methanol oxidation was also investigated

  9. Application of Au/TiO2–WO3 material in visible light photoreductive ozone sensors

    International Nuclear Information System (INIS)

    Various ratios of TiO2–WO3 and Au/TiO2–WO3 composites were prepared as ozone-sensing materials. These materials were characterized by temperature-programmed reduction, UV–visible reflective spectra, transmission electron microscopy, and X-ray diffraction. A 460-nm blue LED light source was used for the detection of gaseous ozone, and the sensing properties of various ratios of TiO2–WO3 were measured. Among the various weight ratios of TiO2–WO3, the sensor response of the TiO2–WO3 (3:1) was the highest obtained response (23.8) to 2.5 ppm ozone. By adding 0.1 wt.% Au to the TiO2–WO3 (3:1), the sensor response was improved to 64.0. The ozone-sensing properties are attributed to the mechanism of adsorption, photoreduction, desorption, and the surface reaction processes of ozone. - Highlights: • Visible light LED as photo-reductive light source • Application of Au/TiO2–WO3 material for gaseous ozone sensor • High sensor response of 64.0 to 2.5 ppm ozone

  10. Investigation of UF-resins - the Effect of the Formaldehyde/Urea Molar Ratio during Synthesis

    OpenAIRE

    Jeremejeff, Joakim

    2012-01-01

    In this project, urea-formaldehyde (UF) resins were produced and investigated. UF resins are commonly used indoors as wood adhesives in, e.g. particle boards, in different furniture applications and flooring. UF resins are produced by alternating methylolation and condensation reactions, thus reacting urea and formaldehyde with each other and creating longer polymeric chains. The number of alternations, i.e. number of condensation reactions can be varied. The focus laid on the effect of the f...

  11. Formaldehyde-releasers in cosmetics: relationship to formaldehyde contact allergy. Part 2. Patch test relationship to formaldehyde contact allergy, experimental provocation tests, amount of formaldehyde released, and assessment of risk to consumers allergic to formaldehyde.

    Science.gov (United States)

    de Groot, Anton; White, Ian R; Flyvholm, Mari-Ann; Lensen, Gerda; Coenraads, Pieter-Jan

    2010-01-01

    This is the second part of an article on formaldehyde-releasers in cosmetics. The patch test relationship between the releasers in cosmetics to formaldehyde contact allergy is reviewed and it is assessed whether products preserved with formaldehyde-releasers may contain enough free formaldehyde to pose a threat to individuals with contact allergy to formaldehyde. There is a clear relationship between positive patch test reactions to formaldehyde-releasers and formaldehyde contact allergy: 15% of all reactions to 2-bromo-2-nitropropane-1,3-diol and 40-60% of the reactions to the other releasers are caused by a reaction to the formaldehyde in the test material. There is only fragmented data on the amount of free formaldehyde in cosmetics preserved with formaldehyde donors. However, all releasers (with the exception of 2-bromo-2-nitropropane-1,3-diol, for which adequate data are lacking) can, in the right circumstances of concentration and product composition, release >200 p.p.m. formaldehyde, which may result in allergic contact dermatitis. Whether this is actually the case in any particular product cannot be determined from the ingredient labelling. Therefore, we recommend advising patients allergic to formaldehyde to avoid leave-on cosmetics preserved with quaternium-15, diazolidinyl urea, DMDM hydantoin, or imidazolidinyl urea, acknowledging that many would tolerate some products. PMID:20136876

  12. Optical and structural properties of Au-Ag islands films for plasmonic applications

    Energy Technology Data Exchange (ETDEWEB)

    Sancho-Parramon, J.; Janicki, V.; Loncaric, M.; Zorc, H.; Dubcek, P. [Ruder Boskovic Institute, Zagreb (Croatia); Bernstorff, S. [Sincrotrone Trieste, Basovizza Trieste (Italy)

    2011-06-15

    Bimetallic islands films consisting of composite Au-Ag nanoparticles are deposited on glass substrates by electron beam evaporation. Broad tuning of the surface-plasmon resonance (SPR) characteristics can be achieved by controlling film composition, deposition temperature and post-deposition thermal annealing. Optical and structural characterization of the samples enable one to establish the link between the SPR and the morphological and compositional characteristics of nanoparticles. (orig.)

  13. Dynamics of Green AuNP Formation and Their Application in Core-Shell Nanostructures

    OpenAIRE

    Engelbrekt, Christian; Zhang, Jingdong; Jensen, Palle Skovhus; Ulstrup, Jens

    2011-01-01

    The formation of gold nanoparticles in our optimized synthesis is achieved through reduction of tetrachloroauric acid in 2 - (N - morpholino)ethanesulphonic acid (MES) buffered glucose and stabilization by starch at room temperature. The formation has been followed by measuring the electrochemical potential, conductivity, pH, turbidity, UV - Vis extinction , core size and hydrodynamic diameter . The synthesized AuNPs have been employed as core particles in advanced core - shell structures wit...

  14. Characterization of self-assembled electrodes based on Au-Pt nanoparticles for PEMFC application

    Energy Technology Data Exchange (ETDEWEB)

    Valenzuela, E. [Univ. Politecnica de Chiapas (Mexico). Energia y Sustentabilidad; Sebastian, P.J.; Gamboa, S.A.; Joseph, S. [Univ. Nacional Autonoma de Mexico, Morelos (Mexico). Centrode Investigacion en Energia; Pal, U. [Univ. Autonoma de Puebla, Pue (Mexico). Inst. de Fisica; Gonzalez, I. [Univ. Autonoma Metropolitana, Mexico City (Mexico). Dept. de Quimica

    2010-07-01

    This paper described the synthesis and characterization of gold (Au), platinum (Pt) and Au-Pt nanoparticles impregnated on a Nafion membrane in a proton exchange membrane fuel cell (PEMFC). The aim of the study was to fabricate the membrane electrode assembly (MEA) by depositing the nanoparticles on the membrane using an immersion technique. Scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) were used to study the deposition process. Electrochemical impedance spectroscopy (EIS) was used to study the membrane proton conduction process. An elemental mapping analysis was performed in order to study the location of the Au and Pt in the self-assemblies. Results of the study showed that the particles deposited on the Nafion had good stability and a homogenous distribution along the membrane surface. The particles showed a direct relation in size and location with the hydrophilic and hydrophobic distribution phases of the membrane. The main membrane resistance was located between the membrane and the electrolyte. The self-assembled electrodes demonstrated a good performance at standard conditions. 33 refs., 4 tabs., 11 figs.

  15. The electro-oxidation of the mixture of formaldehyde and 2-propanol on gold (100 and (111 single crystal planes in alkaline medium

    Directory of Open Access Journals (Sweden)

    BRANISLAV Z. NIKOLIC

    2000-12-01

    Full Text Available The effect of formaldehyde on the oxidation of 2-propanol and vice versa on gold single crystal planes (100 and 111 was studied. An activating effect in the reaction of the simultaneous oxidation of 2-propanol and formaldehyde was obtained on a gold (100 plane. In the case of a gold (111 electrode, the activation effect was not obtained. It was concluded that the adsorption of formaldehyde on the electrode surface prevents the adsorption of poisoning species formed during the electro-oxidation of 2-propanol on the Au(100 plane, while this is not the case on the Au(111 plane. The different behaviour is caused by the difference in the symmetry of the surface atoms of these two Au single-crystal planes.

  16. Effect of an ozone-generating air-purifying device on reducing concentrations of formaldehyde in air

    Energy Technology Data Exchange (ETDEWEB)

    Esswein, E.J. [Univ. of Utah School of Medicine, Salt Lake City, UT (United States); Boeniger, M.F. [National Institute for Occupational Safety, Cincinnati, OH (United States)

    1994-02-01

    Formaldehyde, an air contaminant found in many indoor air investigations, poses distinct occupational exposure hazards in certain job categories (e.g., mortuary science) but is also of concern when found or suspected in office buildings and homes. A variety of air-purifying devices (APDs) are currently available or marketed for application to reduce or remove concentrations of a variety of indoor air pollutants through the use of ozone as a chemical oxidant. An investigation was conducted to determine if concentrations of formaldehyde similar to those found in industrial hygiene evaluations of funeral homes could be reduced with the use of an ozone-generating APD. An ozone-generating APD was placed in an exposure chamber and formaldehyde-containing embalming solution was allowed to evaporate naturally, creating peak and mean chamber concentrations of 2.5 and 1.3 ppm, respectively. Continuous-reading instruments were used to sample for formaldehyde and ozone. Active sampling methods were also used to sample simultaneously for formaldehyde and a possible reactant product, formic acid. Triplicate measurements were made in each of three evaluations: formaldehyde alone, ozone alone, and formaldehyde and ozone combined. Concentrations of formaldehyde were virtually identical with and without 0.5 ppm ozone. No reduction in formaldehyde concentration was found during a 90-minute evaluation using ozone at this concentration with peak and average concentrations of approximately 2.5 and 1.3 ppm formaldehyde, respectively. The results of this investigation suggest that the use of ozone is ineffective in reducing concentrations of formaldehyde. Because ozone has demonstrated health hazards, and is a regulated air contaminant in both the occupational and ambient environment, the use of ozone as an air purification agent in indoor air does not seem warranted. 25 refs., 5 figs., 4 tabs.

  17. Molecular Dynamics Simulation of Formaldehyde Adsorption and Diffusion in Single-Wall Carbon Nanotube

    Institute of Scientific and Technical Information of China (English)

    Pin Lv; Zhenan Tang; Jun Yu; Yanbing Xue

    2006-01-01

    For gas sensor application, adsorption and diffusion of formaldehyde gas in single-wall carbon nanotube were investigated by using molecular dynamics simulation. The conformations of formaldehyde molecule adsorbed in carbon nanotube were optimized according to principle of minimum energy. The axis of conformatiot is parallel to the axis of carbon nanotube and about 0.3 nm~0.4 nm away from carbon nanotube wall. The conformation, which is different from that of the formaldehyde molecule in the gas-phase, rotates around carbon nanotube axis. The adsorption energy and diffusivity of formaldehyde molecule in single-wall carbon nanotube is of-56.2 kJ/mol and of 0.2× 10-4 cm2/s, respectively.

  18. Electrooxidation of formaldehyde based on nickel-palladium modified ordered mesoporous silicon.

    Science.gov (United States)

    Miao, Fengjuan; Tao, Bairui

    2013-04-01

    Nickel and palladium nanoparticles were finely dispersed on ordered mesoporous silicon microchannels plate (MCP) by electroless plating. The structure and composition of the resulting Ni-Pd/Si MCP were characterized by scanning electron microscopy (SEM) and energy dispersive X-ray spectrometry (EDS). The electrocatalystic properties of Ni-Pd/Si MCP electrode for formaldehyde oxidation have been investigated by cyclic voltammetry. The results show that Ni-Pd/Si MCP has a higher catalytic activity and better steady-state behavior for formaldehyde oxidation. This may be attributed to the synergistic property of high dispersion of Nickel and Palladium nanoparticles and particular properties of mesoporous Si MCP. The present study shows a promising choice of Ni-Pd nanoparticles supported by mesoporous silicon as effective electrocatalyst for formaldehyde electrooxidation in alkaline medium. The results imply that the Ni-Pd/Si MCP nanocomposite has good potential application in formaldehyde fuel cells and sensors. PMID:23763207

  19. Electrogenerated Chemiluminescence Behavior of Au nanoparticles-hybridized Pb (II) metal-organic framework and its application in selective sensing hexavalent chromium.

    Science.gov (United States)

    Ma, Hongmin; Li, Xiaojian; Yan, Tao; Li, Yan; Liu, Haiyang; Zhang, Yong; Wu, Dan; Du, Bin; Wei, Qin

    2016-01-01

    In this work, a novel electrochemiluminescence (ECL) sensor based on Au nanoparticles-hybridized Pb (II)-β-cyclodextrin (Pb-β-CD) metal-organic framework for detecting hexavalent chromium (Cr(VI)) was developed. Pb-β-CD shows excellent ECL behavior and unexpected reducing ability towards Au ions. Au nanoparticles could massively form on the surface of Pb-β-CD (Au@Pb-β-CD) without use of any additional reducing agent. In the presence of coreactant K2S2O8, the ECL emission of Pb-β-CD was enhanced by the formation of Au nanoparticles. Cr(VI) can collisionally quench the ECL behavior of Au@Pb-β-CD/S2O8(2-) system and the detection mechanism was investigated. This ECL sensor is found to have a linear response in the range of 0.01-100 μM and a low detection limit of 3.43 nM (S/N = 3) under the optimal conditions. These results suggest that metal-organic framework Au@Pb-β-CD has great potential in extending the application in the ECL field as an efficient luminophore. PMID:26902375

  20. Electrogenerated Chemiluminescence Behavior of Au nanoparticles-hybridized Pb (II) metal-organic framework and its application in selective sensing hexavalent chromium

    Science.gov (United States)

    Ma, Hongmin; Li, Xiaojian; Yan, Tao; Li, Yan; Liu, Haiyang; Zhang, Yong; Wu, Dan; Du, Bin; Wei, Qin

    2016-01-01

    In this work, a novel electrochemiluminescence (ECL) sensor based on Au nanoparticles-hybridized Pb (II)-β-cyclodextrin (Pb-β-CD) metal-organic framework for detecting hexavalent chromium (Cr(VI)) was developed. Pb-β-CD shows excellent ECL behavior and unexpected reducing ability towards Au ions. Au nanoparticles could massively form on the surface of Pb-β-CD (Au@Pb-β-CD) without use of any additional reducing agent. In the presence of coreactant K2S2O8, the ECL emission of Pb-β-CD was enhanced by the formation of Au nanoparticles. Cr(VI) can collisionally quench the ECL behavior of Au@Pb-β-CD/S2O82− system and the detection mechanism was investigated. This ECL sensor is found to have a linear response in the range of 0.01–100 μM and a low detection limit of 3.43 nM (S/N = 3) under the optimal conditions. These results suggest that metal-organic framework Au@Pb-β-CD has great potential in extending the application in the ECL field as an efficient luminophore. PMID:26902375

  1. Study of the nucleation and growth of antibiotic labeled Au NPs and blue luminescent Au8 quantum clusters for Hg2+ ion sensing, cellular imaging and antibacterial applications

    Science.gov (United States)

    Khandelwal, Puneet; Singh, Dheeraj K.; Sadhu, Subha; Poddar, Pankaj

    2015-11-01

    Herein, we report a detailed experimental study supported by DFT calculations to understand the mechanism behind the synthesis of cefradine (CFD - an antibiotic) labeled gold nanoparticles (Au NPs) by employing CFD as both a mild reducing and capping agent. The analysis of the effect of growth conditions reveals that a higher concentration of HAuCl4 results in the formation of an increasing fraction of anisotropic structures, higher temperature leads to the formation of quasi-spherical particles instead of anisotropic ones, and larger pH leads to the formation of much smaller particles. The cyclic voltammetry (CV) results show that when the pH of the reaction medium increases from 4 to 6, the reduction potential of CFD increases which leads to the synthesis of nanoparticles (in a pH 4 reaction) to quantum clusters (in a pH 6 reaction). The MALDI-TOF mass spectrometry results of supernatant of the pH 6 reaction indicate the formation of [Au8(CFD)2S6] QCs which show fluorescence at ca. 432 nm with a Stokes shift of ca. 95 nm. The blue luminescence from Au8 QCs was applied for sensing of Hg2+ ions on the basis of an aggregation-induced fluorescence quenching mechanism and offers good selectivity and a high sensitivity with a limit of detection ca. 2 nM which is lower than the detection requirement of 10 nM by the U.S. EPA and 30 nM by WHO for drinking water. We have also applied the sensing probe to detect Hg2+ ions in bacterial samples. Further, we have investigated the antibacterial property of as-synthesized Au NPs using MIC, growth curve and cell survival assay. The results show that Au NPs could reduce the cell survival very efficiently rather than the cell growth in comparison to the antibiotic itself. The scanning electron microscopy study shows the degradation and blebbing of the bacterial cell wall upon exposure with Au NPs which was further supported by fluorescence microscopy results. These Au NPs did not show reactive oxygen species generation. We believe

  2. Optical properties of random alloys: application to CuAu and NiPt

    Energy Technology Data Exchange (ETDEWEB)

    Saha, Kamal Krishna; Mookerjee, Abhijit [S N Bose National Centre for Basic Sciences, Block-JD, Sector-III, Salt Lake City, Kolkata-700098 (India)

    2005-07-20

    In an earlier paper we presented a formulation for the calculation of the configuration-averaged optical conductivity in random alloys. Our formulation is based on the augmented-space theorem introduced by one of us (Mookerjee 1973 J. Phys. C: Solid State Phys. 6 1340). In this communication we shall combine the augmented space methodology with the tight-binding linear muffin-tin orbital technique (TB-LMTO) to study the optical conductivities of two alloys, CuAu and NiPt.

  3. Synthesis and SERS application of SiO2@Au nanoparticles

    OpenAIRE

    Saini, Apurve; Maurer, Thomas; Lorenzo, Irene Izquierdo; Santos, Andre Ribeiro; Beal, Jérémie; Goffard, Julie; Gérard, Davy; Vial, Alexandre; Plain, Jérôme

    2014-01-01

    In this letter, we report a chemical route for synthesizing SiO2@Au core-shell nanoparticles. The process includes four steps: i) preparation of the silica cores, ii) grafting gold nanoparticles over SiO2 cores, iii) priming of the silica-coated gold nanoparticles with 2 and 10 nm gold colloids and finally iv) formation of complete shell. The optical extinction spectra were experimentally measured and compared to numerical calculations in order to confirm the dimensions deduced from SEM image...

  4. Highly narrow nanogap-containing Au@Au core-shell SERS nanoparticles: size-dependent Raman enhancement and applications in cancer cell imaging

    Science.gov (United States)

    Hu, Chongya; Shen, Jianlei; Yan, Juan; Zhong, Jian; Qin, Weiwei; Liu, Rui; Aldalbahi, Ali; Zuo, Xiaolei; Song, Shiping; Fan, Chunhai; He, Dannong

    2016-01-01

    Cellular imaging technologies employing metallic surface-enhanced Raman scattering (SERS) tags have gained much interest toward clinical diagnostics, but they are still suffering from poor controlled distribution of hot spots and reproducibility of SERS signals. Here, we report the fabrication and characterization of high narrow nanogap-containing Au@Au core-shell SERS nanoparticles (GCNPs) for the identification and imaging of proteins overexpressed on the surface of cancer cells. First, plasmonic nanostructures are made of gold nanoparticles (~15 nm) coated with gold shells, between which a highly narrow and uniform nanogap (~1.1 nm) is formed owing to polyA anchored on the Au cores. The well controlled distribution of Raman reporter molecules, such as 4,4'-dipyridyl (44DP) and 5,5'-dithiobis(2-nitrobenzoic acid) (DTNB), are readily encoded in the nanogap and can generate strong, reproducible SERS signals. In addition, we have investigated the size-dependent SERS activity of GCNPs and found that with the same laser wavelength, the Raman enhancement discriminated between particle sizes. The maximum Raman enhancement was achieved at a certain threshold of particle size (~76 nm). High narrow nanogap-containing Au@Au core-shell SERS tags (GCTs) were prepared via the functionalization of hyaluronic acid (HA) on GCNPs, which recognized the CD44 receptor, a tumor-associated surface biomarker. And it was shown that GCTs have a good targeting ability to tumour cells and promising prospects for multiplex biomarker detection.Cellular imaging technologies employing metallic surface-enhanced Raman scattering (SERS) tags have gained much interest toward clinical diagnostics, but they are still suffering from poor controlled distribution of hot spots and reproducibility of SERS signals. Here, we report the fabrication and characterization of high narrow nanogap-containing Au@Au core-shell SERS nanoparticles (GCNPs) for the identification and imaging of proteins overexpressed on

  5. Asymmetric Aldol Reaction with Formaldehyde: a Challenging Process.

    Science.gov (United States)

    Meninno, Sara; Lattanzi, Alessandra

    2016-08-01

    The asymmetric aldol reaction with formaldehyde is a fundamental carbon-carbon bond-forming reaction in organic synthesis, as well as in the quest of the origin of life, as it is thought to have been the first "molecular brick" involved in the synthetic path to complex sugars. Products of aldol reactions, i.e., the β-hydroxy carbonyl compounds, are versatile building blocks used to access a great variety of functionalised molecules. The employment of formaldehyde, as a C1 symmetric electrophile, in aldol reactions can be likely considered the most challenging, yet simplest, process to introduce a hydroxymethyl group in an asymmetric fashion. In this account, an overview of the progress achieved in the asymmetric metal- and organocatalysed aldol reaction, using readily available formalin or paraformaldehyde sources, is illustrated. Our recent contribution to this area, with the application of asymmetric hydroxymethylation in cascade processes for the synthesis of γ-butyrolactones, is also shown. PMID:27328802

  6. Formaldehyde preparation methods for pressure and temperature dependent laser-induced fluorescence measurements

    Science.gov (United States)

    Burkert, A.; Müller, D.; Rieger, S.; Schmidl, G.; Triebel, W.; Paa, W.

    2015-12-01

    Formaldehyde is an excellent tracer for the early phase of ignition of hydrocarbon fuels and can be used, e.g., for characterization of single droplet ignition. However, due to its fast thermal decomposition at elevated temperatures and pressures, the determination of concentration fields from laser-induced fluorescence (LIF) measurements is difficult. In this paper, we address LIF measurements of this important combustion intermediate using a calibration cell. Here, formaldehyde is created from evaporation of paraformaldehyde. We discuss three setups for preparation of formaldehyde/air mixtures with respect to their usability for well-defined heating of formaldehyde/air mixtures. The "basic setup" uses a resist heater around the measurement cell for investigation of formaldehyde near vacuum conditions or formaldehyde/air samples after sequential admixing of air. The second setup, described for the first time in detail here, takes advantage of a constant flow formaldehyde/air regime which uses preheated air to reduce the necessary time for gas heating. We used the constant flow system to measure new pressure dependent LIF excitation spectra in the 343 nm spectral region (414 absorption band of formaldehyde). The third setup, based on a novel concept for fast gas heating via excitation of SF6 (chemically inert gas) using a TEA (transverse excitation at atmospheric pressure) CO2 laser, allows to further minimize both gas heating time and thermal decomposition. Here, an admixture of CO2 is served for real time temperature measurement based on Raman scattering. The applicability of the fast laser heating system has been demonstrated with gas mixtures of SF6 + air, SF6 + N2, as well as SF6 + N2 + CO2 at 1 bar total pressure.

  7. Formaldehyde emission from low mass protostars

    CERN Document Server

    Maret, S

    2003-01-01

    We present a survey of the formaldehyde emission in nine class 0 protostars obtained with the IRAM 30m and the JCMT millimeter telescopes. Using a detailed radiative transfer code of the envelopes surrounding the protostars, we show that all but one of the observed objects show an inner warm evaporation region where the formaldehyde is much more abundant (up to three orders of magnitude) than in the outer cold part. The largest inner formaldehyde abundances are associated with the sources having the lowest submillimetric to bolometric luminosity ratio, i.e. with sources closer to the class I border. These abundances are compared with predictions from recent models of hot core chemistry.

  8. Cause Analysis and Countermeasures of Overproof Formaldehyde of Housing Decoration

    OpenAIRE

    Wenhua Tang; Lianhong Yu

    2013-01-01

    In order to understand the level of indoor formaldehyde pollution of newly decorated houses in Wuhan city and preliminarily discuss indoor formaldehyde pollution factors, chose several new residential areas in Wuhan city, 100 houses which are from these residential districts and were decorated not more than 1 year were randomly selected to be measured indoor air formaldehyde content by portable formaldehyde meter and in the meantime, the questionnaire was carried out about formaldehyde concen...

  9. Detection of formaldehyde in textiles by chromotropic acid method

    OpenAIRE

    Rao Sanath; Shenoy Shruthakirthi; Davis Suraj; Nayak Sudhakar

    2004-01-01

    BACKGROUND: The common causes of textile dermatitis are formaldehyde resins and disperse dyes. There are various methods to detect the presence of formaldehyde in clothing. AIM: To detect the presence of formaldehyde in various types of textiles by the chromotropic acid method and to assess the effect of washing on the formaldehyde content. METHODS: Twenty randomly selected textiles from a local cloth store were tested for formaldehyde by the chromotropic acid method. A purple ring indicated ...

  10. Nasal mucosa changes in students exposed to formaldehyde vapour

    OpenAIRE

    Sherwani, R.; Siddiqui, Rehan Asif; Khan, M. Kamran; S C Sharma

    2002-01-01

    Formaldehyde has been used since ages in the various laboratories. Recently, interest has developed in the possible role of formaldehyde in the development of Squamous Cell Carcinoma. In this study 53 students (undergraduates and postgraduates) were exposed to formaldehyde and they were compared with 25 students (control group) unexposed to formaldehyde. Results have shown that students who were exposed to formaldehyde for a longer time showed mucosal changes as compared to the control group.

  11. Formaldehyde-releasers: relationship to formaldehyde contact allergy. Metalworking fluids and remainder. Part 1

    OpenAIRE

    de Groot, A C; Le Coz, C.J.; Lensen, G J; Flyvholm, M A; Maibach, H I; Coenraads, P.J.

    2010-01-01

    This is the second part of a review article on formaldehyde-releasers used as durable press chemical finishes (DPCF) in textiles. The early finishes contained large amounts of free formaldehyde, which led to many cases of allergic contact dermatitis to clothes in the 1950s and 1960s. Currently, most finishes are based on modified dimethylol dihydroxyethyleneurea, which releases less formaldehyde. Nevertheless, recent studies in the United States and Israel have identified patients reacting to...

  12. Crystallographic investigation of Au nanoparticles embedded in a SrTiO{sub 3} thin film for plasmonics applications by means of synchrotron radiation

    Energy Technology Data Exchange (ETDEWEB)

    Pincini, Davide, E-mail: davide.pincini@mail.polimi.it [European Synchrotron Radiation Facility, CS 40220, 71, avenue des Martyrs, F-38043 Grenoble Cedex 9 (France); Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo Da Vinci 32, 20133 Milano (Italy); Mazzoli, Claudio [Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo Da Vinci 32, 20133 Milano (Italy); Bernhardt, Hendrik; Katzer, Christian; Schmidl, Frank [Institut für Festkörperphysik, Friedrich-Schiller-Universität Jena, Helmholtzweg 5, 07743 Jena (Germany); Uschmann, Ingo [Institut für Optik und Quantenelektronik, Friedrich-Schiller-Universität Jena, Max-Wien-Platz 1, 07743 Jena (Germany); Detlefs, Carsten [European Synchrotron Radiation Facility, CS 40220, 71, avenue des Martyrs, F-38043 Grenoble Cedex 9 (France)

    2015-03-14

    Self-organized monocrystalline Au nanoparticles with potential applications in plasmonics are grown in a SrTiO{sub 3} matrix by a novel two-step deposition process. The crystalline preferred orientation of these Au nanoparticles is investigated by synchrotron hard x-ray diffraction. Nanoparticles preferentially align with the (111) direction along the substrate normal (001), whereas two in-plane orientations are found with [110]{sub SrTiO{sub 3}}∥[110]{sub Au} and [100]{sub SrTiO{sub 3}}∥[110]{sub Au}. Additionally, a smaller diffraction signal from nanoparticles with the (001) direction parallel to the substrate normal (001) is observed; once again, two in-plane orientations are found, with [100]{sub SrTiO{sub 3}}∥[100]{sub Au} and [100]{sub SrTiO{sub 3}}∥[110]{sub Au}. The populations of the two in-plane orientations are found to depend on the thickness of the gold film deposited in the first step of the growth.

  13. Novel electrochemical redox-active species: one-step synthesis of polyaniline derivative-Au/Pd and its application for multiplexed immunoassay

    Science.gov (United States)

    Wang, Liyuan; Feng, Feng; Ma, Zhanfang

    2015-11-01

    Electrochemical redox-active species play crucial role in electrochemically multiplexed immunoassays. A one-pot method for synthesizing four kinds of new electrochemical redox-active species was reported using HAuCl4 and Na2PdCl4 as dual oxidating agents and aniline derivatives as monomers. The synthesized polyaniline derivative-Au/Pd composites, namely poly(N-methyl-o-benzenediamine)-Au/Pd, poly(N-phenyl-o-phenylenediamine)-Au/Pd, poly(N-phenyl-p-phenylenediamine)-Au/Pd and poly(3,3’,5,5’-tetramethylbenzidine)-Au/Pd, exhibited electrochemical redox activity at -0.65 V, -0.3 V, 0.12 V, and 0.5 V, respectively. Meanwhile, these composites showed high H2O2 electrocatalytic activity because of the presence of Au/Pd. The as-prepared composites were used as electrochemical immunoprobes in simultaneous detection of four tumor biomarkers (carcinoembryonic antigen (CEA), carbohydrate antigen 19-9 (CA199), carbohydrate antigen 72-4 (CA724), and alpha fetoprotein (AFP)). This immunoassay shed light on potential applications in simultaneous gastric cancer (related biomarkers: CEA, CA199, CA724) and liver cancer diagnosis (related biomarkers: CEA, CA199, AFP). The present strategy to the synthesize redox species could be easily extended to other polymers such as polypyrrole derivatives and polythiophene derivatives. This would be of great significance in the electrochemical detection of more analytes.

  14. 40 CFR Appendix A to Subpart Hhhh... - Method for Determining Free-Formaldehyde in Urea-Formaldehyde Resins by Sodium Sulfite (Iced...

    Science.gov (United States)

    2010-07-01

    ...-Formaldehyde in Urea-Formaldehyde Resins by Sodium Sulfite (Iced & Cooled) A Appendix A to Subpart HHHH of Part... Appendix A to Subpart HHHH of Part 63—Method for Determining Free-Formaldehyde in Urea-Formaldehyde Resins... Development method of determining free-formaldehyde in urea-formaldehyde resins. This method applies...

  15. Formaldehyde increases intracellular calcium concentration in primary cultured hippocampal neurons partly through NMDA receptors and T-type calcium channels

    Institute of Scientific and Technical Information of China (English)

    Ye-Nan Chi; Xu Zhang; Jie Cai; Feng-Yu Liu; Guo-Gang Xing; You Wan

    2012-01-01

    Objective Formaldehyde at high concentrations is a contributor to air pollution.It is also an endogenous metabolic product in cells,and when beyond physiological concentrations,has pathological effects on neurons.Formaldehyde induces mis-folding and aggregation of neuronal tau protein,hippocampal neuronal apoptosis,cognitive impairment and loss of memory functions,as well as excitation of peripheral nociceptive neurons in cancer pain models.Intracellular calcium ([Ca2+]i) is an important intracellular messenger,and plays a key role in many pathological processes.The present study aimed to investigate the effect of formaldehyde on [Ca2+]i and the possible involvement of N-methyl-D-aspartate receptors (NMDARs) and T-type Ca2+ channels on the cell membrane.Methods Using primary cultured hippocampal neurons as a model,changes of [Ca2+]i in the presence of formaldehyde at a low concentration were detected by confocal laser scanning microscopy.Results Formaldehyde at 1 mmol/L approximately doubled [Ca2+]i.(2R)-amino-5-phosphonopentanoate (AP5,25 μtmol/L,an NMDAR antagonist) and mibefradil (MIB,1 μtmol/L,a T-type Ca2+ channel blocker),given 5 min after formaldehyde perfusion,each partly inhibited the formaldehyde-induced increase of [Ca2+]i,and this inhibitory effect was reinforced by combined application of AP5 and MIB.When applied 3 min before formaldehyde perfusion,AP5 (even at 50 μmol/L) did not inhibit the formaldehyde-induced increase of [Ca2+]i,but MIB (1 μmol/L) significantly inhibited this increase by 70%.Conclusion These results suggest that formaldehyde at a low concentration increases [Ca2+]i in cultured hippocampal neurons; NMDARs and T-type Ca2+ channels may be involved in this process.

  16. ÉTUDE DU TRAITEMENT DES SILOXANES PAR ADSORPTION SUR MATÉRIAUX POREUX : APPLICATION AU TRAITEMENT DES BIOGAZ

    OpenAIRE

    Ricaurte Ortega, Deyanira

    2009-01-01

    Étude du traitement des siloxanes par adsorption sur matériaux poreux : application au traitement des biogaz Les biogaz sont des mélanges à forte teneur en méthane utilisés dans la production de chaleur ou d'électricité. Ils contiennent des quantités plus ou moins importantes de siloxanes qui sont interdits pour de nombreuses utilisations du biogaz. La possibilité d'élimination des siloxanes par adsorption est étudiée. Une étude en réacteurs statiques permet d'évaluer les capacités d'adsorpti...

  17. Health and Environmental Effects Profile for Formaldehyde

    Science.gov (United States)

    The Health and Environmental Effects Profile for formaldehyde was prepared by the Office of Health and Environmental Assessment, Environmental Criteria and Assessment Office, Cincinnati, OH for the Office of Solid Waste and Emergency Response to support listings of hazardous cons...

  18. Photochemical decomposition of Formaldehyde in solution

    International Nuclear Information System (INIS)

    In this work was studied the effect of ultraviolet radiation produced by a mercury low pressure lamp in solutions of formaldehyde. These solutions were exposed to ultraviolet rays at different times. In some of these series of solutions was added a photosensibilizer in order to obtain a high photodecomposition of formaldehyde. The techniques used for determine the products of the decomposition were the following: 1. In order to measure the residual formaldehyde and glioxal, the Hantzsch and 2,4-dinitrophenylhydrazine methods were used. 2. pH's measurements of the solutions, before and after exposition. 3. Paper's chromatography for determine presence of formed acids. 4. Acid-base tritiations for measure total acidification. We observed that when the time of exposition to UV rays was increased, a high photodecomposition of formaldehyde was formed and, besides, a greater quantity of another products. Of the reagents used like photosensibilizers, with the ruthenium reagent, the best results were obtained. (Author)

  19. Contribution of formaldehyde to respiratory cancer.

    OpenAIRE

    Nelson, N.; Levine, R. J.; Albert, R E; Blair, A E; Griesemer, R A; Landrigan, P. J.; L.T. Stayner; Swenberg, J.A.

    1986-01-01

    This article reviews the available data on the carcinogenicity of formaldehyde from experimental and epidemiologic studies and makes recommendations for further research. Two definitive chronic inhalation bioassays on rodents have demonstrated that formaldehyde produces nasal cancer in rats and mice at 14 ppm and in rats at 6 ppm, which is within the domain of present permissible human exposure (8-hr time-weighted average of 3 ppm, a 5 ppm ceiling, and a 10 ppm short-term exposure limit). Bio...

  20. Review of the application of isotopic studies to the genesis of Cu-Au mineralisation at Olympic Dam and Au mineralisation at Porgera, the Tennant Creek district and Yilgarn Craton

    International Nuclear Information System (INIS)

    This paper reviews the application of radiogenic isotopes to the study of four Cu-U and Au deposits or deposit types in the Australasian region: Olympic Dam, Porgera, the Proterozoic Au deposits of the Tennant Creek district and the Archaean gold deposits of the Yilgarn Craton. In each case it has been possible to date the mineralisation and to correlate ore formation with a specific igneous event or stage in crystal evolution. In three cases it was also possible to use radiogenic isotopes to trace the source of the metal(s) or to constrain the fluid pathway. The results of K-Ar , 39Ar/40Ar dating of hydrothermal minerals associated with gold deposits, SHRIMP U-Pb analyses of zircon, and conventional Sr, Nd and Pb isotopic tracing of the ore fluids are reported to illustrate the power of radiogenic isotopes in ore-genesis studies

  1. A highly sensitive pressure sensor using a Au-patterned polydimethylsiloxane membrane for biosensing applications

    International Nuclear Information System (INIS)

    We report on the fabrication and characterization of a highly sensitive pressure sensor using a Au film patterned on a polydimethylsiloxane (PDMS) membrane. The strain-induced change in the film resistance was utilized to perform the quantitative measurement of absolute pressure. The highest sensitivity obtained for a 200 µm thick PDMS film sensor was 0.23/KPa with a range of 50 mm Hg, which is the best result reported so far, over that range, for any pressure sensor on a flexible membrane. The noise-limited pressure resolution was found to be 0.9 Pa (0.007 mm Hg), and a response time of ∼200 ms, are the best reported results for these sensors. The ultrahigh sensitivity is attributed to the strain-induced formation of microcracks, the effect of which on the resistance change was found to be highly reversible within a certain pressure range. A physical model correlating the sensitivity with the sensor parameters and crack geometry has been proposed. (paper)

  2. Fabricating a Homogeneously Alloyed AuAg Shell on Au Nanorods to Achieve Strong, Stable, and Tunable Surface Plasmon Resonances

    KAUST Repository

    Huang, Jianfeng

    2015-08-13

    Colloidal metal nanocrystals with strong, stable, and tunable localized surface plasmon resonances (SPRs) can be useful in a corrosive environment for many applications including field-enhanced spectroscopies, plasmon-mediated catalysis, etc. Here, a new synthetic strategy is reported that enables the epitaxial growth of a homogeneously alloyed AuAg shell on Au nanorod seeds, circumventing the phase segregation of Au and Ag encountered in conventional synthesis. The resulting core–shell structured bimetallic nanorods (AuNR@AuAg) have well-mixed Au and Ag atoms in their shell without discernible domains. This degree of mixing allows AuNR@AuAg to combine the high stability of Au with the superior plasmonic activity of Ag, thus outperforming seemingly similar nanostructures with monometallic shells (e.g., Ag-coated Au NRs (AuNR@Ag) and Au-coated Au NRs (AuNR@Au)). AuNR@AuAg is comparable to AuNR@Ag in plasmonic activity, but that it is markedly more stable toward oxidative treatment. Specifically, AuNR@AuAg and AuNR@Ag exhibit similarly strong signals in surface-enhanced Raman spectroscopy that are some 30-fold higher than that of AuNR@Au. When incubated with a H2O2 solution (0.5 m), the plasmonic activity of AuNR@Ag immediately and severely decayed, whereas AuNR@AuAg retained its activity intact. Moreover, the longitudinal SPR frequency of AuNR@AuAg can be tuned throughout the red wavelengths (≈620–690 nm) by controlling the thickness of the AuAg alloy shell. The synthetic strategy is versatile to fabricate AuAg alloyed shells on different shaped Au, with prospects for new possibilities in the synthesis and application of plasmonic nanocrystals.

  3. Molecular beam epitaxy of GaAs nanowires and their sustainability for optoelectronic applications. Comparing Au- and self-assisted growth methods

    Energy Technology Data Exchange (ETDEWEB)

    Breuer, Steffen

    2011-09-28

    In this work the synthesis of GaAs nanowires by molecular beam epitaxy (MBE) using the vapour-liquid-solid (VLS) mechanism is investigated. A comparison between Au- and self-assisted VLS growth is at the centre of this thesis. While the Au-assisted method is established as a versatile tool for nanowire growth, the recently developed self-assisted variation results from the exchange of Au by Ga droplets and thus eliminates any possibility of Au incorporation. By both methods, we achieve nanowires with epitaxial alignment to the Si(111) substrates. Caused by differences during nanowire nucleation, a parasitic planar layer grows between the nanowires by the Au-assisted method, but can be avoided by the self-assisted method. Au-assisted nanowires grow predominantly in the metastable wurtzite crystal structure, while their self-assisted counterparts have the zincblende structure. All GaAs nanowires are fully relaxed and the strain arising from the lattice mismatch between GaAs and Si of 4.1 % is accommodated by misfit dislocations at the interface. Self-assisted GaAs nanowires are generally found to have vertical and non-polar side facets, while tilted and polar nanofacets were described for Au-assisted GaAs nanowires. We employ VLS nucleation theory to understand the effect of the droplet material on the lateral facets. Optoelectronic applications require long minority carrier lifetimes at room temperature. We fabricate GaAs/(Al,Ga)As core-shell nanowires and analyse them by transient photoluminescence (PL) spectroscopy. The results are 2.5 ns for the self-assisted nanowires as well as 9 ps for the Au-assisted nanowires. By temperature-dependent PL measurements we find a characteristic activation energy of 77 meV that is present only in the Au-assisted nanowires. We conclude that most likely Au is incorporated from the droplets into the GaAs nanowires and acts as a deep, non-radiative recombination centre.

  4. A Fabrication Route for Arrays of Ultra-low-Noise MoAu Transition Edge Sensors on Thin Silicon Nitride for Space Applications

    OpenAIRE

    Glowacka, D. M.; Crane, M.; Goldie, D. J.; Withington, S.

    2014-01-01

    We describe a process route to fabricate arrays of Ultra-low-Noise MoAu Transition Edge Sensors (TESs). The low thermal conductance required for space applications is achieved using 200 nm-thick Silicon Nitride (SiNx ) patterned to form long-thin legs with widths of 2.1 {\\mu}m. Using bilayers formed on SiNx islands from films with 40 nm-thick Mo and Au thicknesses in the range 30 to 280 nm deposited by dc-sputtering in ultra-high vacuum we can obtain tunable transition temperatures in the ran...

  5. EFFECTS OF FORMALDEHYDE AND PARTICLE-BOUND FORMALDEHYDE ON LUNG MACROPHAGE FUNCTIONS

    Science.gov (United States)

    Dr. George Jakab and associates exposed mice to varying levels (ranging from 0.5 to 15 parts per million [ppm]) of formaldehyde alone or to formaldehyde (5 and 2.5 ppm) mixed with carbon black particles. Carbon black particles were chosen because of their similarity to comb...

  6. Formaldehyde-releasers : relationship to formaldehyde contact allergy. Metalworking fluids and remainder. Part 1

    NARCIS (Netherlands)

    de Groot, A.C.; Le Coz, C.J.; Lensen, G.J.; Flyvholm, M.A.; Maibach, H.I.; Coenraads, P.J.

    2010-01-01

    This is the second part of a review article on formaldehyde-releasers used as durable press chemical finishes (DPCF) in textiles. The early finishes contained large amounts of free formaldehyde, which led to many cases of allergic contact dermatitis to clothes in the 1950s and 1960s. Currently, most

  7. Application of {sup 198}Au grains for carcinoma of oral cavity

    Energy Technology Data Exchange (ETDEWEB)

    Shimizutani, K. [Dept. of Oral Radiology, Osaka Dental University, Osaka (Japan); Koseki, Y. [Dept. of Oral Radiology, Osaka Dental University, Osaka (Japan); Inoue, To. [Dept. of Radiation Oncology, Biomedical Research Center, Osaka University Medical School, Osaka (Japan); Teshima, T. [Dept. of Radiology, Osaka University Medical School, Osaka (Japan); Furukawa, S. [Dept. of Oral and Maxillofacial Radiology, Osaka University, Faculty of Dentistry, Osaka (Japan); Kubo, K. [Dept. of Oral and Maxillofacial Radiology, Osaka University, Faculty of Dentistry, Osaka (Japan); Fachihata, H. [Dept. of Oral and Maxillofacial Radiology, Osaka University, Faculty of Dentistry, Osaka (Japan); Masaki, N. [Dept. of Therapeutic Radiology, Center for Adult Diseases, Osaka (Japan); Ikeda, H. [Dept. of Radiation Oncology, National Cancer Center Hospital, Tokyo (Japan); Tanaka, Y. [Dept. of Dentistry, Kobe Municipal Chuo Hospital, Kobe (Japan)

    1995-01-01

    The purpose of this study is to analyze the results of the treatment using gold grain implants over the past 9 years and to evaluate the usefulness of this treatment method. From January 1985 through April 1993, a total of 45 patients with squamous cell carcinomas of the oral cavity and the oropharynx were treated with {sup 198}Au grain (gold grain) at the Department of Radiology, Osaka University Medical School. The initial activity of the grains supplied weekly by the Japan Radioisotope Association was usually 5 mCi (185 MBq), and single implants were usual. In case of combined external irradiation, telecobalt {gamma}-rays or 4 MV X-rays were used for treatment before implant. The local control rate for patients with T1 stages was 80% (20/25) and with T2 stages, 59% (10/17). The local control rate was 71% (10/14) for gold grain alone and 72% (13/18) for external irradiation combined with gold grain implants (combined therapy). In combined therapy, the median of the interval between external irradiation and gold grain implants was 21 days. The treatment interval or patients with recurrent diseases was 22 days, 22, 27, 39 and 46, respectively. The progression rate showed a tendency to increase in the patients with longer interval (more than 21 days), and with partial regression after external irradiation and gold grain implantation is an important factor in combined therapy. Therefore, we emphasize that the time interval should be shorter than 3 weeks. (orig.) [Deutsch] Ziel dieser Untersuchung sind die Analyse der Behandlungsergebnisse der letzten neun Jahre bei Verwendung von Gold-Seed-Implantaten und die Bestimmung der Wertigkeit dieser Methode. Von Januar 1985 bis April 1993 wurden insgesamt 45 Patienten mit Plattenepithelkarzinomen der Mundhoehle und des Oropharynx mit {sup 198}Au-Seeds im Department of Radiology der Osaka University medical School behandelt. Die Ausgangsaktivitaet der Seeds war ueblicherweise 5 mCi (185 MBq), sie wurden woechentlich von der

  8. DNA-templated synthesis of PtAu bimetallic nanoparticle/graphene nanocomposites and their application in glucose biosensor

    OpenAIRE

    Leng, Jing; Wang, Wen-Min; Lu, Li-min; Bai, Ling; Qiu, Xin-Lan

    2014-01-01

    In this paper, single-stranded DNA (ss-DNA) is demonstrated to functionalize graphene (GR) and to further guide the growth of PtAu bimetallic nanoparticles (PtAuNPs) on GR with high densities and dispersion. The obtained nanocomposites (PtAuNPs/ss-DNA/GR) were characterized by transmission electron microscopy (TEM), energy-dispersive X-ray spectrometer (EDS), and electrochemical techniques. Then, an enzyme nanoassembly was prepared by self-assembling glucose oxidase (GOD) on PtAuNP/ss-DNA/GR ...

  9. Formaldehyde Densitometry of Starburst Galaxies

    CERN Document Server

    Mangum, Jeffrey G; Menten, Karl M; Henkel, Christian

    2007-01-01

    With a goal toward deriving the physical conditions in external galaxies, we present a survey of the formaldehyde emission in a sample of starburst systems. By extending a technique used to derive the spatial density in star formation regions in our own Galaxy, we show how the relative intensity of the 1(10)-1(11) and 2(11)-2(12) K-doublet transitions of H2CO can provide an accurate densitometer for the active star formation environments found in starburst galaxies. Relying upon an assumed kinetic temperature and co-spatial emission and absorption from both H2CO transitions, our technique is applied to a sample of nineteen IR-bright galaxies which exhibit various forms of starburst activity. In the five galaxies of our sample where both H2CO transitions were detected we have derived spatial densities. We also use H2CO to estimate the dense gas mass in our starburst galaxy sample, finding similar mass estimates for the dense gas forming stars in these objects as derived using other dense gas tracers. A related...

  10. A NOVEL EOR POLYMER(Ⅰ)——STUDY ON GELATION OF RESORCINOL FORMALDEHYDE SYSTEMS

    Institute of Scientific and Technical Information of China (English)

    ZHUANG Yinfeng; Stanley McCool; G. Paul Willhite; Don W. Green

    1995-01-01

    Factors affecting the gelation of resorcinol-formaldehyde systems have been examined over variable ranges applicable to oilfield use. Gelation of resorcinol-formaldehyde (RF)system was sensitive to pH,salinity and hardness. Generally,this gel system could be used in fresh water or low salinity brine at pH higher than about 9. The application would require careful monitoring of injection fluids to avoid premature gelation or prolonged shut-in times ,especially under conditions of low salinity and high pH. Salinity and hardness compatibilities of the system were improved by sulfomethylation of resorcinol. Aqueous sulfomethylated resorcinol formaldehyde (SMRF)system could be used in brine with higher salinity and hardness and at a wider pH range of 5-10.

  11. Synthèse de nouveaux polyesters “verts” issus de ressources oléagineuses : application au renfort au choc du poly(L-lactide)

    OpenAIRE

    Lebarbe, Thomas

    2013-01-01

    Dans cette étude, plusieurs voies ont été explorées dans l’objectif d’utiliser des polyesters aliphatiques issus de ressources oléagineuses comme additifs pour le renfort au choc du poly(L-lactide) (PLLA). Dans un premier temps, des poly(ester-amide)s (PEAs) ont été synthétisés à partir de dérivés de l’huile de ricin. La relation structure-propriétés des PEAs obtenus a été clairement établie. La dispersion des PEAs (à différents taux) par extrusion à l’état fondu dans une matrice de PLLA a en...

  12. Application of an asymmetric flow field flow fractionation multi-detector approach for metallic engineered nanoparticle characterization - Prospects and limitations demonstrated on Au nanoparticles

    International Nuclear Information System (INIS)

    Highlights: → In this study we present a size- and element selective method, outlined to characterize metallic ENPs, and demonstrated on engineered Au-NP. → A method for quantification of ionic- and particular fraction for nanoparticles in dispersions is presented. → Influence of membrane materials, carrier liquid and flow parameters for A4F was studied. → Comparison of MALLS and DLS for nanoparticle size determination was performed. → Coupling of ICPMS to the A4F, UV/vis and light scattering apparatus is shown. - Abstract: In this work we discuss about the method development, applicability and limitations of an asymmetric flow field flow fractionation (A4F) system in combination with a multi-detector setup consisting of UV/vis, light scattering, and inductively coupled plasma mass spectrometry (ICPMS). The overall aim was to obtain a size dependent-, element specific-, and quantitative method appropriate for the characterization of metallic engineered nanoparticle (ENP) dispersions. Thus, systematic investigations of crucial method parameters were performed by employing well characterized Au nanoparticles (Au-NPs) as a defined model system. For good separation performance, the A4F flow-, membrane-, and carrier conditions were optimized. To obtain reliable size information, the use of laser light scattering based detectors was evaluated, where an online dynamic light scattering (DLS) detector showed good results for the investigated Au-NP up to a size of 80 nm in hydrodynamic diameter. To adapt large sensitivity differences of the various detectors, as well as to guarantee long term stability and minimum contamination of the mass spectrometer a split-flow concept for coupling ICPMS was evaluated. To test for reliable quantification, the ICPMS signal response of ionic Au standards was compared to that of Au-NP. Using proper stabilization with surfactants, no difference for concentrations of 1-50 μg Au L-1 in the size range from 5 to 80 nm for citrate

  13. Evidence for chemical and cellular reactivities of the formaldehyde releaser bronopol, independent of formaldehyde release.

    Science.gov (United States)

    Kireche, Mustapha; Peiffer, Jean-Luc; Antonios, Diane; Fabre, Isabelle; Giménez-Arnau, Elena; Pallardy, Marc; Lepoittevin, Jean-Pierre; Ourlin, Jean-Claude

    2011-12-19

    Formaldehyde and formaldehyde releasers are widely used preservatives and represent an important group of skin sensitizers. Formaldehyde is very often suspected to be the sensitizing agent of formaldehyde-releasers; however, many reported clinical cases of contact allergy to these molecules such as bronopol (2-bromo-2-nitropropane-1,3-diol) indicate negative skin reactions to formaldehyde suggesting a more complex mechanism. The aim of this study was to compare the chemical reactivity and biological activity of formaldehyde with those of two formaldehyde releasers: 2-bromo-2-nitropropane-1,3-diol and 1,3-dimethylol-5,5-dimethylhydantoin. A key step in the sensitization to chemicals is the formation of the hapten-protein antigenic complex via covalent binding between the chemical sensitizer and amino acids in proteins. The chemical reactivity of the three compounds was thus addressed using (13)C NMR analysis of adduct formation upon incubation with a set of nucleophilic amino acids. The biological activity was measured in two in vitro models based on dendritic cells and a monocytic cell line (CD34-DC and THP-1 model) through monitoring of a panel of biomarkers. The results obtained show that 2-bromo-2-nitropropane-1,3-diol produces low amount of free formaldehyde in physiological buffers but that its degradation generates various molecules including 2-bromoethanol. In addition, 2-bromo-2-nitropropane-1,3-diol also generates adducts with amino acids, not observed with formaldehyde alone, that could be explained by the reactivity of 2-bromoethanol. In parallel, in a cellular approach using the human monocytic THP-1 cell line, 2-bromo-2-nitropropane-1,3-diol activates THP-1 cells at concentrations that are not correlated to simple formaldehyde release. This observation is confirmed in the more physiological model CD34-DC. Moreover, in the THP-1 model, the expression profiles of several biomarkers are specific to 2-bromo-2-nitropropane-1,3-diol. Finally, the use in the

  14. Core-shell Au/Ag nanoparticles embedded in silicate sol-gel network for sensor application towards hydrogen peroxide

    Indian Academy of Sciences (India)

    Shanmugam Manivannan; Ramasamy Ramaraj

    2009-09-01

    The electrocatalytic activity of core-shell Au100-Ag ( = 15, 27, 46, and 60) bimetallic nanoparticles embedded in methyl functionalized silicate MTMOS network towards the reduction of hydrogen peroxide was investigated by using cyclic voltammetry and chronoamperometric techniques. Core-shell Au/Ag bimetallic nanoparticles were characterized by absorption spectra and HRTEM. The MTMOS silicate sol-gel embedded Au73Ag27 core-shell nanoparticles modified electrode showed better synergistic electrocatalytic effect towards the reduction of hydrogen peroxide when compared to monometal MTMOS-Aunps and MTMOS-Agnps modified electrodes. These modified electrodes were studied without immobilizing any enzyme in the MTMOS sol-gel matrix. The present study highlights the influence of molar composition of Ag nanoparticles in the Au/Ag bimetallic composition towards the electrocatalytic reduction and sensing of hydrogen peroxide in comparison to monometal Au and Ag nanoparticles.

  15. Comparison of two formaldehyde administration methods of in ovo-injected eggs.

    Science.gov (United States)

    Steinlage, Sara J Throne; Sander, Jean E; Wilson, Jeanna L

    2002-01-01

    Formaldehyde administration in the hatchery can be very useful in decreasing microbial numbers. However, its use is controversial because of the adverse effects that can occur to chicks and people. This study was designed to look at alternative methods of application of formaldehyde in the hatchery. In addition, the study compared the effects of these methods of application on in ovo-and non-in ovo-injected eggs. All in ovo-injected eggs were given diluent only with no vaccine or antibiotic added. In hatchers containing both in ovo-injected eggs and non-in ovo-injected eggs, formaldehyde was administered two ways, dose (DOSE) and constant rate infusion (CRI). In the DOSE hatcher, 12 ml of formaldehyde was administered at one time every 12 hr, whereas in the CRI hatcher, the same volume was administered at a rate of 1 ml/hr over a 12-hr period. A control (CONT) hatcher received 12 ml of distilled water at the same time that the DOSE hatcher was given formaldehyde. In the DOSE hatcher, a peak concentration of formaldehyde of 102 ppm was reached. The CRI was maintained at approximately 20 ppm of formaldehyde. At pipping, the aerosol bacterial load in the hatchers receiving formaldehyde (DOSE, 130 colony-forming units [CFU]/m3; CRI, 82.5 CFU/m3) was significantly less than in the CONT hatcher (235 CFU/m3). At hatch, the CRI (337.5 CFU/m3) was not able to control bacterial levels and only the DOSE hatcher (150 CFU/m3) had a significantly lower aerosol bacterial count. The CRI non-in ovo-injected eggs (93.39%) had a significantly higher percentage of hatch of fertile compared with non-in ovo-injected eggs exposed to water (84.27%). In ovo-injected eggs in CONT and DOSE treatment groups contained significantly higher percentages of visual contamination than non-in on-injected eggs in the same hatchers. This difference had numerical significance only in the treatment groups within the CRI hatcher. The chicks were then placed into replicate treatment groups and grown for 14

  16. Fusion d'images: application au contr\\^ole de la distribution des biopsies prostatiques

    CERN Document Server

    Mozer, Pierre; Chevreau, G; Troccaz, Jocelyne

    2008-01-01

    This paper is about the application of a 3D ultrasound data fusion technique to the 3D reconstruction of prostate biopies in a reference volume. The method is introduced and its evaluation on a series of data coming from 15 patients is described.

  17. Synthesis, characterization and in vitro biocompatibility study of Au/TMC/Fe3O4 nanocomposites as a promising, nontoxic system for biomedical applications

    Directory of Open Access Journals (Sweden)

    Hanieh Shirazi

    2015-08-01

    Full Text Available The unique properties and applications of iron oxide and Au nanoparticles have motivated researchers to synthesize and optimize a combined nanocomposite containing both. By using various polymers such as chitosan, some of the problems of classic core–shell structures (such as reduced saturation magnetization and thick coating have been overcome. In the present study, chitosan and one of its well-known derivatives, N-trimethylchitosan (TMC, were applied to construct three-layer nanocomposites in an Au/polymer/Fe3O4 system. It was demonstrated that replacement of chitosan with TMC reasonably improved the properties of the final nanocomposites including their size, magnetic behavior and thermal stability. Moreover, the results of the MTT assay showed no significant cytotoxicity effect when the Au/TMC/Fe3O4 nanocomposites were applied in vitro. These TMC-containing magnetic nanoparticles are well-coated by Au nanoparticles and have good biocompatibility and can thus play the role of a platform or a label in various fields of application, especially the biomedical sciences and biosensors.

  18. Production of Melamine-Formaldehyde PCM Microcapsules with Ammonia Scavenger used for Residual Formaldehyde Reduction.

    Science.gov (United States)

    Sumiga, Boštjan; Knez, Emil; Vrtačnik, Margareta; Ferk-Savec, Vesna; Starešinič, Marica; Boh, Bojana

    2011-03-01

    Paraffinic phase change materials (PCM) were microencapsulated by in situ polymerization of melamine-formaldehyde prepolymers. Partly methylated trimethylolmelamine was used as an aminoaldehyde prepolymer for the microcapsule wall, a styrene-maleic acid anhydride copolymer as an emulsifier and modifying agent, and ammonia as a scavenger for reducing residual formaldehyde. For the determination of residual formaldehyde in a ppm concentration range, EDANA and malachite green analytical methods were studied, and the EDANA 210.1-99 was applied for the determination of residual formaldehyde in 25 samples of microcapsules, produced in a 200-L reactor. A linear correlation was observed between the added ammonia scavenger concentration and the reduction of residual formaldehyde concentration. Compared with 0.45% (4500 ppm) formaldehyde in a non-treated microcapsule suspension, with ammonia scavenger concentrations 0.80, 0.90 and 1.35%, the concentration of residual formaldehyde dropped to 0.27, 0.20 and 0.09% (i.e. 2700, 2000 and 900 ppm), respectively. Morphological characterisation of microcapsules by SEM and microcapsule wall permeability measurements by gravimetry / mass loss at an elevated temperature (135 °C) suggested that ammonia positively contributed to the wall elasticity / durability, while microcapsules with no ammonia scavenger added tended to have more brittle walls, and were more prone to cracking. PMID:24061938

  19. Détection et suivi visuels robustes d'objets complexes : applications au rendezvous spatial autonome

    OpenAIRE

    Petit, Antoine

    2013-01-01

    In this thesis, we address the issue of fully localizing a known object through computer vision, using a monocular camera, what is a central problem in robotics. A particular attention is here paid on space robotics applications, with the aims of providing a unified visual localization system for autonomous navigation purposes for space rendezvous and proximity operations. Two main challenges of the problem are tackled: initially detecting the targeted object and then tracking it frame-by-fra...

  20. The effect of the alternative solutions to formaldehyde and xylene on tissue processing

    Directory of Open Access Journals (Sweden)

    Ilgin Aydin

    2013-01-01

    Full Text Available Introduction and Aim: To assess the impact of new alternative solutions to formaldehyde and xylene on tissue processing, 13 different tissue processings were designed and performed on thirteen different tissues by using five different fixatives (formaldehyde, Glyo-Fixx® , FineFix® , Cell-block® , Green-Fix® and four different clearing agents (xylene, Sub-X® , Bio-clear® , Shandon Xylene Substitute® . Materials and Methods: Hematoxylin and Eosine stained sections were compared by using qualitative histomorphological criterions. Histochemical and immunohistochemical (IHC staining results were compared with qualitative and quantitative data obtained by a computer program, respectively. Tissue sections were tested for the availability of chromogenic in situ hybridization, deoxyribonucleic acid (DNA and ribonucleic acid (RNA extraction, and DNA quality by polymerase chain reaction. Results: The quality of sections was well for all tissue processings. All alternative solutions were suitable for histochemistry. IHC staining results showed that alternative solutions that contain glyoxal as active agent need optimization for this application. The clearance of signals with chromogenic in situ hybridization were nearly same and well for all tissue samples. Furthermore, tissue processes that do not contain formaldehyde were found to be superior on preservation of nucleic acids. Conclusion: Formaldehyde-free fixatives and alternative clearing agents have potential in routine pathology and research to replace formaldehyde and xylene.

  1. Interface controlled growth of nanostructures in discontinuous Ag and Au thin films fabricated by ion beam sputter deposition for plasmonic applications

    Indian Academy of Sciences (India)

    R Brahma; M Ghanashyam Krishna

    2012-08-01

    The growth of discontinuous thin films of Ag and Au by low energy ion beam sputter deposition is reported. The study focuses on the role of the film–substrate in determining the shape and size of nanostructures achieved in such films. Ag films were deposited using Ar ion energy of 150 eV while the Au films were deposited with Ar ion energies of 250–450 eV. Three types of interfaces were investigated in this study. The first set of film–substrate interfaces consisted of Ag and Au films grown on borosilicate glass and carbon coated Cu grids used as substrates. The second set of films was metallic bilayers in which one of the metals (Ag or Au) was grown on a continuous film of the other metal (Au or Ag). The third set of interfaces comprised of discontinuous Ag and Au films deposited on different dielectrics such as SiO2, TiO2 and ZrO2. In each case, a rich variety of nanostructures including self organized arrays of nanoparticles, nanoclusters and nanoneedles have been achieved. The role of the film–substrate interface is discussed within the framework of existing theories of thin film nucleation and growth. Interfacial nanostructuring of thin films is demonstrated to be a viable technique to realize a variety of nanostructures. The use of interfacial nanostructuring for plasmonic applications is demonstrated. It is shown that the surface Plasmon resonance of the metal nanostructures can be tuned over a wide range of wavelengths from 400 to 700 nm by controlling the film–substrate interface.

  2. BLM protein mitigates formaldehyde-induced genomic instability

    OpenAIRE

    Kumari, Anuradha; Owen, Nichole; Juarez, Eleonora; McCullough, Amanda K.

    2015-01-01

    Formaldehyde is a reactive aldehyde that has been classified as a class I human carcinogen by the International Agency for Cancer Research. There are growing concerns over the possible adverse health effects related to the occupational and environmental human exposures to formaldehyde. Although formaldehyde-induced DNA and protein adducts have been identified, the genomic instability mechanisms and the cellular tolerance pathways associated with formaldehyde exposure are not fully characteriz...

  3. Cfd Engine Applications At Fiat Research Centre Applications de la modélisation 3D au FIAT Research Centre

    Directory of Open Access Journals (Sweden)

    Lisbona M. G.

    2006-12-01

    Full Text Available The CFD (computer fluid dynamic simulation of the complete engine cycle of the 2400 cm3 JTD 10 V engine for the Alfa Romeo 156 is presented. The intake stroke analysis has followed a procedure usually applied at CRF for gasoline engines. Spray and combustion analysis at the selected operating condition of 3500 tr/min and 13 bar BMEP (brake mean effective pressure has given results in fair agreement with the experimental data, but revealed the need of more accurate models for the initial phase of combustion. Finally, the simulation of the exhaust phase has required great care in the set-up of the initial field and boundary conditions. Flow field characteristics are discussed at two crank angles, corresponding to peak values of the exhaust mass flow rate. Cet article présente la simulation 3D du cycle complet du moteur 2400 cm3 JTD 10 V de l'Alfa Romeo 156. L'analyse de la phase d'admission a suivi une procédure habituellement utilisée pour les moteurs à essence. L'analyse du spray et de la combustion au régime choisi de 3500 tr/min et 13 bar de PMI se compare raisonnablement aux essais, mais indique qu'une meilleure description de la phase initiale de la combustion est nécessaire. La simulation de la phase d'échappement a requis une grande attention quant à la spécification du champ initial et des conditions aux limites. On étudie ici les caractéristiques de l'écoulement à deux instants de cycles correspondant à des maxima de débits à l'échappement.

  4. Self-Sufficient Formaldehyde-to-Methanol Conversion by Organometallic Formaldehyde Dismutase Mimic.

    Science.gov (United States)

    van der Waals, Dominic; Heim, Leo E; Vallazza, Simona; Gedig, Christian; Deska, Jan; Prechtl, Martin H G

    2016-08-01

    The catalytic networks of methylotrophic organisms, featuring redox enzymes for the activation of one-carbon moieties, can serve as great inspiration in the development of novel homogeneously catalyzed pathways for the interconversion of C1 molecules at ambient conditions. An imidazolium-tagged arene-ruthenium complex was identified as an effective functional mimic of the bacterial formaldehyde dismutase, which provides a new and highly selective route for the conversion of formaldehyde to methanol in absence of any external reducing agents. Moreover, secondary amines are reductively methylated by the organometallic dismutase mimic in a redox self-sufficient manner with formaldehyde acting both as carbon source and reducing agent. PMID:27380865

  5. Conversion and toxicity characteristics of formaldehyde in acetoclastic methanogenic sludge

    NARCIS (Netherlands)

    Gonzalez-Gil, G.; Kleerebezem, R.; Lettinga, G.

    2002-01-01

    An unadapted mixed methanogenic sludge transformed formaldehyde into methanol and formate. The methanol to formate ratio obtained was 1:1. Formaldehyde conversion proceeded without any lag phase, suggesting the constitutive character of the formaldehyde conversion enzymes involved. Because the rate

  6. 24 CFR 3280.309 - Health Notice on formaldehyde emissions.

    Science.gov (United States)

    2010-04-01

    ... 24 Housing and Urban Development 5 2010-04-01 2010-04-01 false Health Notice on formaldehyde... Construction Requirements § 3280.309 Health Notice on formaldehyde emissions. (a) Each manufactured home shall have a Health Notice on formaldehyde emissions prominently displayed in a temporary manner in...

  7. Developing a Reference Material for Formaldehyde Emissions Testing; Final Report

    Science.gov (United States)

    Exposure to formaldehyde has been shown to produce broad and potentially severe adverse human health effects. With ubiquitous formaldehyde sources in the indoor environment, formaldehyde concentrations in indoor air are usually higher than outdoors, ranging from 10 to 4000 μg/m3....

  8. RELATION BETWEEN MECHANICAL PROPERTIES AND PYROLYSIS TEMPERATURE OF PHENOL FORMALDEHYDE RESIN FOR GAS SEPARATION MEMBRANES

    Directory of Open Access Journals (Sweden)

    MONIKA ŠUPOVÁ

    2012-03-01

    Full Text Available The aim of this paper has been to characterize the relation between the pyrolysis temperature of phenol-formaldehyde resin, the development of a porous structure, and the mechanical properties for the application of semipermeable membranes for gas separation. No previous study has dealt with this problem in its entirety. Phenol-formaldehyde resin showed an increasing trend toward micropore porosity in the temperature range from 500 till 1000°C, together with closure of mesopores and macropores. Samples cured and pyrolyzed at 1000°C pronounced hysteresis of desorption branch. The ultimate bending strength was measured using a four-point arrangement that is more suitable for measuring of brittle materials. The chevron notch technique was used for determination the fracture toughness. The results for mechanical properties indicated that phenol-formaldehyde resin pyrolyzates behaved similarly to ceramic materials. The data obtained for the material can be used for calculating the technical design of gas separation membranes.

  9. Nanorods of all organic porous m-cresol-formaldehyde having photoluminescence at room temperature

    International Nuclear Information System (INIS)

    Cresol-formaldehyde resins are versatile polymer having numerous applications in ion exchange, catalysis, supercapacitors, photoresistant materials, etc. Here, we first report a new nanostructured non-crystalline cresol-formaldehyde material NCF-1, synthesized through hydrothermal condensation of m-cresol and formaldehyde at 363 K under mild alkaline condition in the presence of supramolecular assembly of cationic surfactant, cetyltrimethylammonium bromide (CTAB) as structure directing agent (SDA). The material was characterized by powder X-ray diffraction, TEM, TG-DTA, UV-vis and fluorescence spectroscopy. TEM image analysis revealed nanorod morphology of NCF-1 material with diameter of the rods 30-50 nm and disordered wormhole-like nanostructure with pores of ca. 2.5 nm. These composite materials exhibit photoluminescence property at room temperature, which could be utilized for the fabrication of novel organic optical devices

  10. Contributions au traitement statistique du signal avec des applications biomédicales

    OpenAIRE

    Nguyen, Quang Thang

    2012-01-01

    Cette étude présente des contributions en traitement statistique du signal avec des applications biomédicales. La thèse est divisée en deux parties. La première partie traite de la détection des hotspots à l'interface des protéines. Les hotspots sont les résidus dont les contributions énergétiques sont les plus importantes dans l'interaction entre protéines. Les forêts aléatoires (Random Forests) sont utilisées pour la classification. Une nouvelle famille de descripteurs de hotspot est égalem...

  11. Formaldehyde as hypothetical primer of biohomochirality

    Energy Technology Data Exchange (ETDEWEB)

    Goldanskii, V.I. [N. N. Semenov Institute of Chemical Physics of the Russian Academy of Sciences, Kosygin Street 4, Moscow, 117334 (Russia)

    1996-07-01

    One of the most intriguing and crucial problems of the prebiotic evolution and the origin of life is the explanation of the origin of biohomochirality. A scheme of conversions originated by formaldehyde (FA) as hypothetical primer of biohomochirality is proposed. The merit of FA as executor of this function is based -inter alia - on the distinguished role of FA as one of the earliest and simplest molecules in both warm, terrestrial and cold, extraterrestrial scenarios of the origin of life. The confirmation of the role of FA as primer of biohomochirality would support the option of an RNA world as an alternative to the protein world. The suggested hypothesis puts forward for the first time a concrete sequence of chemical reactions which can lead to biohomochirality. The spontaneous breaking of the mirror symmetry is secured by the application of the well-known Frank scheme (combination of autocatalysis and {open_quote}{open_quote}annihilation{close_quote}{close_quote} of L and D enantiomers) to the series of interactions of FA {open_quote}{open_quote}trimers{close_quote}{close_quote} (i.e. C{sub 3}H{sub 6}O{sub 3} compounds) of (aaa), (apa) and (app) types, where the monomeric groups (a) means {open_quote}{open_quote}achirons{close_quote}{close_quote} (a=CH{sub n}, n{ge}2 and C=M, M=C,O) and (p) mean {open_quote}{open_quote}prochirons{close_quote}{close_quote} (p=HC{asterisk}OM, M=H,C). {copyright} {ital 1996 American Institute of Physics.}

  12. Fluorescent Properties of Au Nanoclusters and Their Biological Applications%金团簇的荧光性质及其生物应用

    Institute of Scientific and Technical Information of China (English)

    任娟; 代雯乐; 付欣; 苏梦; 蔡晶晶; 马占芳

    2011-01-01

    金纳米团簇作为一类新型纳米材料具有独特的光学特性。当金纳米团簇颗粒的尺寸小到与电子的费米波长(〈1nm)相当时,由于量子尺寸效应,金颗粒会受激发射出荧光。作为一种新型荧光材料,金纳米团簇具有发光颜色随团簇尺寸可调、荧光不易猝灭等许多优势。本文主要综述了金纳米团簇的荧光性质及其在生物标记、生物成像以及生物检测等方面的应用。%Au nanoclusters have emerged as a class of materials with unique optical properties.When the size of Au nanocluster decrease to comparable to the Fermi wavelength(1nm) of an electron,it exhibits fluorescent characteristics while they are excited,which resulted from its quantum effect.As a novel fluorescent material,Au nanoclusters show size-dependent emission,a slower photobleaching rate and very good stability.The fluorescent properties of Au nanoclusters and their applications in the fields of biological labeling,biological imaging,and biodetection were mainly reviewed.

  13. Application of EIS with Au-Hg microelectrode in determining electron transfer mechanisms

    Energy Technology Data Exchange (ETDEWEB)

    Bai, X. [College of Marine Studies, University of Delaware, Lewes, DE 19958 (United States); Dexter, S.C. [College of Marine Studies, University of Delaware, Lewes, DE 19958 (United States)]. E-mail: dexter@udel.edu; Luther, G.W. [College of Marine Studies, University of Delaware, Lewes, DE 19958 (United States)

    2006-01-20

    The objective of this study was to investigate the application of microelectrodes with electrochemical impedance spectroscopy (EIS) for distinguishing between one- and two-electron transfer electrochemical reactions occurring within marine microbial biofilms. In our study, both gold and gold-mercury amalgam microelectrodes with tip diameters of 100 {mu}m were used. EIS measurements were performed at the half-wave potentials of the chemicals of interest in 0.5 M NaCl aqueous solutions containing 100 {mu}M each of FeCl{sub 3}, [Fe(Cat){sub 2}]{sup -}, [Fe(Cat){sub 3}]{sup 3-}, [Fe(4NCat){sub 3}]{sup 3-}, MnCl{sub 2}, FeCl{sub 2} and mixed solutions with two of those chemicals in NaCl solution or seawater. The results showed that there was a linear relationship between the impedance Z {sub re}, Z {sub im} and angular frequency {omega} {sup -1/2} obtained at phase angle of 45{sup o} for both one- and two-electron transfer reactions. One-electron transfer reactions could then be distinguished from two-electron transfer reactions by the slopes.

  14. Une chaîne de traitement de l'information géographique au service de l'application de la loi Littoral

    Directory of Open Access Journals (Sweden)

    Patrick GUILLOPÉ

    1994-09-01

    Full Text Available L’application de la loi Littoral nécessitait une approche nouvelle de la part de l’État et la mise en œuvre d’outils nouveaux pour une gestion à long terme. L’apport de traitements automatiques de l’information géographique a été ainsi testé au CETE Normandie-Centre sur trois des grands principes posés par cette loi.

  15. DNA-templated synthesis of PtAu bimetallic nanoparticle/graphene nanocomposites and their application in glucose biosensor

    Science.gov (United States)

    Leng, Jing; Wang, Wen-Min; Lu, Li-Min; Bai, Ling; Qiu, Xin-Lan

    2014-02-01

    In this paper, single-stranded DNA (ss-DNA) is demonstrated to functionalize graphene (GR) and to further guide the growth of PtAu bimetallic nanoparticles (PtAuNPs) on GR with high densities and dispersion. The obtained nanocomposites (PtAuNPs/ss-DNA/GR) were characterized by transmission electron microscopy (TEM), energy-dispersive X-ray spectrometer (EDS), and electrochemical techniques. Then, an enzyme nanoassembly was prepared by self-assembling glucose oxidase (GOD) on PtAuNP/ss-DNA/GR nanocomposites (GOD/PtAuNPs/ss-DNA/GR). The nanocomposites provided a suitable microenvironment for GOD to retain its biological activity. The direct and reversible electron transfer process between the active site of GOD and the modified electrode was realized without any extra electron mediator. Thus, the prepared GOD/PtAuNP/ss-DNA/GR electrode was proposed as a biosensor for the quantification of glucose. The effects of pH, applied potential, and temperature on the performance of the biosensor were discussed in detail and were optimized. Under optimal conditions, the biosensor showed a linearity with glucose concentration in the range of 1.0 to 1,800 μM with a detection limit of 0.3 μM (S/N = 3). The results demonstrate that the developed approach provides a promising strategy to improve the sensitivity and enzyme activity of electrochemical biosensors.

  16. Growth and electrical characterization of thin conductive Au nanoparticle chains on oxidized Si substrates between electrodes for sensor applications

    International Nuclear Information System (INIS)

    Citrate-stabilized colloid Au nanoparticles with an average diameter of 40 nm have been assembled in nanoparticle chains between microelectrodes on oxidized V-groove-etched Si surfaces by the technique of dielectrophoresis. Chain formation was investigated as a function of electrodes configuration and the amplitude and frequency of the applied electric field. Conductive thin (∝100-200 nm thick) single and multiple Au nanoparticle chains, with a length in the range of 1 to 10 μm, were preferentially formed on V-groove lines between the electrodes. Electrical characterization by temperature-dependent current-voltage measurements showed that the Au nanoparticle chains exhibit ohmic conductivity with a resistance in the range of few Ω to few kΩ, depending on the distance between electrodes and the configuration of the Au nanoparticles in the structure. On the contrary, 5 nm diameter tiopronin-stabilized Au NPs chains exhibited nearest- neighbour hopping conductivity and non-linear thermally-activated I-V characteristics. We also tested nanogap formation in the chains by an applied pulse of electric current, in view of applying the nanoparticle chains in the tracing of chemical or biological molecules. The conductive thin Au nanoparticle chains, with or without nanogaps, are interesting building blocks for different sensor devices. (copyright 2008 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  17. Electrocatalytic applications of a vertical Au nanorod array using ultrathin Pt/Ru/Pt layer-by-layer coatings

    International Nuclear Information System (INIS)

    This study compared the electro-oxidation of carbon monoxide adlayers formed on a codeposited and a layer-by-layer deposited Pt/Ru thin overlayer on a Au surface. Vertical arrays of smooth and nanoporous Au nanorods were used as a platform for the Pt/Ru overlayer-coating. The vertical arrays of Au nanorods served as high surface area templates, where the surface area could be controlled as a function of the rod length in a given geometrical surface area. A coating of the Au nanorod arrays with Pt/Ru via Cu underpotential deposition (UPD) steps allowed control of the overlayer thickness with an ultrathin film nature. The electronic modification of the Pt overlayer with a Ru underlayer became increasingly weaker with increasing Pt overlayer thickness. The thick Pt overlayer exhibited CO electro-oxidation that was similar to the electro-oxidation profile on the Pt bulk surface. Coating of the Au nanorod arrays with Pt/Ru through Cu UPD steps demonstrated an optimal electronic response between the Pt outer overlayer and the underlying Ru layer. It is expected that an ultrathin overlayer-coating strategy can be expanded to nanoporous Au nanorod arrays. These finding will facilitate better design of highly active Pt/Ru composite nanostructures for electrocatalysis

  18. Optoelectrical Cooling of Formaldehyde to Sub-Millikelvin Temperatures

    Science.gov (United States)

    Zeppenfeld, Martin

    2016-05-01

    Due to their strong long-range dipole-dipole interactions and large number of internal states, polar molecules cooled to ultracold temperatures enable fascinating applications ranging from ultracold chemistry to investigation of dipolar quantum gases. However, realizing a simple and general technique to cool molecules to ultracold temperatures, akin to laser cooling of atoms, has been a formidable challenge. We present results for opto-electrical Sisyphus cooling applied to formaldehyde (H2 CO). In this generally applicable cooling scheme, molecules repeatedly move up and down electric field gradients of a trapping potential in different rotational states to efficiently extract kinetic energy. A total of about 300,000 molecules are thereby cooled by a factor of 1000 to 400uK, resulting in a record-large ensemble of ultracold molecules. In addition to cooling of the motional degrees of freedom, optical pumping via a vibrational transition allows us to control the internal rotational state. We thereby achieve a purity of over 80% of formaldehyde molecules in a single rotational M-sublevel. Our experiment provides an excellent starting point for precision spectroscopy and investigation of ultracold collisions.

  19. 29 CFR 1926.1148 - Formaldehyde.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 8 2010-07-01 2010-07-01 false Formaldehyde. 1926.1148 Section 1926.1148 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR (CONTINUED) SAFETY AND HEALTH REGULATIONS FOR CONSTRUCTION Toxic and Hazardous Substances § 1926.1148...

  20. Electrospinning formaldehyde cross-linked zein solutions

    Science.gov (United States)

    In order to develop zein fibers with improved physical properties and solvent resistance, formaldehyde was used as the cross-linking reagent before spinning. The cross-linking reaction was carried out in either acetic acid or ethanolic-HCl where the amount of cross-linking reagent was between 1 and...

  1. Application de la methode des sous-groupes au calcul Monte-Carlo multigroupe

    Science.gov (United States)

    Martin, Nicolas

    This thesis is dedicated to the development of a Monte Carlo neutron transport solver based on the subgroup (or multiband) method. In this formalism, cross sections for resonant isotopes are represented in the form of probability tables on the whole energy spectrum. This study is intended in order to test and validate this approach in lattice physics and criticality-safety applications. The probability table method seems promising since it introduces an alternative computational way between the legacy continuous-energy representation and the multigroup method. In the first case, the amount of data invoked in continuous-energy Monte Carlo calculations can be very important and tend to slow down the overall computational time. In addition, this model preserves the quality of the physical laws present in the ENDF format. Due to its cheap computational cost, the multigroup Monte Carlo way is usually at the basis of production codes in criticality-safety studies. However, the use of a multigroup representation of the cross sections implies a preliminary calculation to take into account self-shielding effects for resonant isotopes. This is generally performed by deterministic lattice codes relying on the collision probability method. Using cross-section probability tables on the whole energy range permits to directly take into account self-shielding effects and can be employed in both lattice physics and criticality-safety calculations. Several aspects have been thoroughly studied: (1) The consistent computation of probability tables with a energy grid comprising only 295 or 361 groups. The CALENDF moment approach conducted to probability tables suitable for a Monte Carlo code. (2) The combination of the probability table sampling for the energy variable with the delta-tracking rejection technique for the space variable, and its impact on the overall efficiency of the proposed Monte Carlo algorithm. (3) The derivation of a model for taking into account anisotropic

  2. Biosynthesis and stabilization of Au and Au-Ag alloy nanoparticles by fungus, Fusarium semitectum

    International Nuclear Information System (INIS)

    Crystallized and spherical-shaped Au and Au-Ag alloy nanoparticles have been synthesized and stabilized using a fungus, F . semitectum in an aqueous system. Aqueous solutions of chloroaurate ions for Au and chloroaurate and Ag+ ions (1 : 1 ratio) for Au-Ag alloy were treated with an extracellular filtrate of F . semitectum biomass for the formation of Au nanoparticles (AuNP) and Au-Ag alloy nanoparticles (Au-AgNP). Analysis of the feasibility of the biosynthesized nanoparticles and core-shell alloy nanoparticles from fungal strains is particularly significant. The resultant colloidal suspensions are highly stable for many weeks. The obtained Au and Au-Ag alloy nanoparticles were characterized by the surface plasmon resonance (SPR) peaks using a UV-vis spectrophotometer, and the structure, morphology and size were determined by Fourier transform infrared spectroscopy (FTIR), x-ray diffraction (XRD), and transmission electron microscopy (TEM). Possible optoelectronics and medical applications of these nanoparticles are envisaged.

  3. Photoelectrochemical studies of DNA-tagged biomolecules on Au and Au/Ni/Au multilayer nanowires

    Directory of Open Access Journals (Sweden)

    Swaminathan Viswanathan

    2011-01-01

    Full Text Available Abstract The use of nanowires (NWs for labeling, sensing, and sorting is the basis of detecting biomolecules attached on NWs by optical and magnetic properties. In spite of many advantages, the use of biomolecules-attached NWs sensing by photoelectrochemical (PEC study is almost non-existent. In this article, the PEC study of dye-attached single-stranded DNA on Au NWs and Au-Ni-Au multilayer NWs prepared by pulse electrodeposition are investigated. Owing to quantum-quenching effect, the multilayer Au NWs exhibit low optical absorbance when compared with Au NWs. The tagged Au NWs show good fluorescence (emission at 570 nm, indicating significant improvement in the reflectivity. Optimum results obtained for tagged Au NWs attached on functionalized carbon electrodes and its PEC behavior is also presented. A twofold enhancement in photocurrent is observed with an average dark current of 10 μA for Au NWs coated on functionalized sensing electrode. The importance of these PEC and optical studies provides an inexpensive and facile processing platform for Au NWs that may be suitable for biolabeling applications.

  4. Facile fabrication of truncated octahedral Au nanoparticles and its application for ultrasensitive surface enhanced Raman scattering immunosensing

    International Nuclear Information System (INIS)

    Monodispersed truncated octahedral (TOH) Au nanoparticles (NPs) with an average edge-length of about 16 nm were synthesized using poly(diallyldimethylammonium chloride) (PDDA) both as a stabilizing and reducing agent via a one-step reaction. Remarkably, no seeds, surfactants or additional reductant were used in this reaction. In addition, the PDDA molecules on the surface of the TOH AuNPs make them convenient for use in layer-by-layer assembly by electrostatic interactions. Importantly, the TOH AuNPs show a significant surface enhanced Raman scattering (SERS) activity, and can be directly used for building SERS-active substrates and tags. Based on these promising properties, an ultrasensitive SERS-based immunosensing platform was developed. Using human immunoglobulin (h-IgG) as a model target analyte, a detection limit of 36.56 fg ml−1 was reached. (paper)

  5. Current limitation properties of YBa2Cu3O7-δ/Au thin films: application to transformer connection

    International Nuclear Information System (INIS)

    In view of the development of superconducting fault current limiters, the properties of switching and recovering of YBa2Cu3O7-δ/Au (YBCO/Au) thin films are studied at 77 K and 50 Hz for overcurrents. The bilayers present an abrupt transition to a high dissipative state leading to a current limitation at a maximum value of about 2.5 times the critical current Ic, and allow the development of electric fields of 3 kV m-1 without any damage. After the overcurrent regime, the recovery of the superconducting state under the rated current In is studied as a function of overcurrent parameters. These results show clearly the strong potential of YBCO/Au thin films which can recover their superconducting state under nominal mode. This last point is crucial for transformer connection, as experimentally shown in this paper

  6. Application of Cl2/BCl3/Ar Plasma Treatment in the Improvement of Ti/Al/Mo/Au Ohmic Contacts

    Directory of Open Access Journals (Sweden)

    Jacek Gryglewicz

    2016-01-01

    Full Text Available Significant improvement of Ti/Al/Mo/Au ohmic contacts deposited on previously Cl2/BCl3/Ar plasma treated surface was observed. The standard deviation of contact resistance was crucially reduced due to the incorporation of Cl2/BCl3/Ar plasma treatment. The Cl2:BCl3:Ar gas mixture was used in order to thin the top of AlGaN layer prior to deposition of Ti/Al/Mo/Au ohmic contacts. The surface morphology of AlGaN was investigated using scanning electron microscopy and atomic force microscopy. TLM measurements revealed a consequential decrease of contact resistivity.

  7. Intrathecal application of 198Au colloid in acute leukemia and non-Hodgkin's lymphoma in chilhood. 2

    International Nuclear Information System (INIS)

    7 children suffering from acute lymphatic leukemia (ALL) and non-Hodgkin's lymphoma, resp., were injected intrathecally with 198Au colloid for metaphylaxis. The children had been cured of 8 relapses of miningosis and received irregularly intrathecal injections of methotrexate for cerebral maintenance therapy. The median cerebral period of remission was 52 weeks. 1 child suffering from ALL had been free from meningosis relapses for 128 weeks. Continuous cytostatic therapy is necessary for methaphylaxis. However, despite of the good results presented, 198Au colloid can not be recommended for long-term therapy because radiation injuries are to be expected. (author)

  8. SYNTHESIS OF CONDENSATION POLYMERS OF SALICYLIC ACID, FORMALDEHYDE AND ALKYL PRIMARY AMINES AND ITS APPLICATION AS A CATALYST FOR THE HYDROLYSIS OF p-NITROPHENYL ACETATE (PNPA) IN AQUEOUS SOLUTION

    Institute of Scientific and Technical Information of China (English)

    HE Binglin(Ho Pinglum); HUANG Wenqiang

    1983-01-01

    As a model of serine hydrolase, the condensation polymers of salicylic acid, formaldehyde and methyl amine, n-propyl amine, n-hexyl amine or n-lauryl amine were prepared by polycondensation catalyzed by sulfuric acid. It was confirmed by potentiometric titration and infrared spectrum that the polymers containing tertiary amino group possess the structure which resembles the internal salt of amino acid in weak basic and weak acidic solution:[-OOC-OH-CH2-H+N-R-CH2-]n R=alkyl group The catalytic reaction of the above polymers for hydrolysis of active ester,p-nitrophenyl acetate (PNPA),was studied .It was found kinetically that the most efficient catalytic effect of polymer was composed of two salicylic acid groups and one tertiary amino group in the polymer chain.The rates of hydrolysis of PNPA increase with increasing of pH values and length of the alkyl group in the side chain of the polymers and the effect of the conformation of the polymer containing tertiary amino group in the buffer solution on the catalytic activity was also investigated. Hydrolysis of PNPA catalyzed by the polymer made of salicylic acid, formaldehyde and n-lauryl amine follows the simple Michaelis-Menten type mechanism . The kinetics parameters were determined as :Km 6.7×10-5 M and Vmax 2.07×10-7 M·min-1.

  9. Formaldehyde assay by capacitance versus voltage and impedance measurements using bi-layer bio-recognition membrane.

    Science.gov (United States)

    Ben Ali, M; Korpan, Y; Gonchar, M; El'skaya, A; Maaref, M A; Jaffrezic-Renault, N; Martelet, C

    2006-12-15

    A novel formaldehyde sensitive biosensor based on bacterial formaldehyde dehydrogenase (FDH) as a bio-recognition element has been developed. The bio-recognition membrane had bi-layer architecture and consisted of FDH, cross-linked with albumin, and of the cofactor NAD at a high concentration level (first layer). The second layer was a negatively charged Nafion membrane, which prevented a leakage of negatively charged NAD molecules from the bio-membrane. As transducers, gold electrodes SiO(2)/Si/SiO(2)/Ti/Au and electrolyte-insulator-semiconductor Si/SiO(2) (EIS) structures have been used. Changes in capacitance and impedance properties of the bio-recognition membrane have been used for monitoring formaldehyde concentration in a bulk solution. It has been shown that formaldehyde can be detected within a concentration range from 1 microM to 20mM depending on the type of transduction used, with a detection limit of 1 and 100 microM for gold-based and EIS-based transducers, respectively. PMID:16516460

  10. Comparison of some morphological and absorption properties of the nanoparticles Au/TiO2 embedded films prepared by different technologies on the substrates for application in the plasmonic solar cell

    International Nuclear Information System (INIS)

    The nanoparticle Au/TiO2 embedded system plays a very important role in the plasmonic solar cell. The features of the nanoparticle embedded system will determine light enhancement, light absorption, scattering and localized surface plasmon resonance (LSPR), aiming to enhance the efficiency of the plasmatic solar cell. The characterizations of nanoparticles Au/TiO2 embedded system consist of many parameters: the sizes of nanoparticles (Au, TiO2), the weight ratio of Au to TiO2, the thickness of the single layer or multilayer of Au/TiO2, the arrangements of Au and TiO2 nanoparticles in integrated-matrix system, the light absorption, scattering and LSPR capacities of the Au/TiO2 system. These parameters, however, depend on the technological conditions, the structure of plasmonic solar cell as well as the used substrate materials. This paper presents some technological developments for nanoparticles Au/TiO2 embedded systems by different methods, including the preparation of the mixer Au/TiO2 solutions and fabrication of the nanoparticle Au/TiO2 systems with different Au percentages on several substrates (glass/ITO and AAO(Al)/Si…), and measured results of the morphological, structural and optical properties using FESEM, EDX, UV–vis spectroscopy. The comparisons of experiment results between different technology conditions and substrates (glass/ITO, AAO(Al)/Si…) are also shown and discussed with the aim of choosing the suitable technological process and technological conditions for application in the plasmonic solar cell. (paper)

  11. Silver Nanopartical over AuFON Substrate for Enhanced Raman Readout and Their Application in Pesticide Monitoring

    Directory of Open Access Journals (Sweden)

    Kun Guo

    2015-04-01

    Full Text Available Surface-enhanced Raman detection of thiram is demonstrated by using Ag-nanoparticles (Ag NPs on Au film over nanosphere (AuFON substrate as the hybrid substrate. The SERS signal of the Ag NPs attached to solid supports is studied. The close coupling together of thousands of Ag NPs on AuFON leads to the generation of hot spots for SERS. The Ag NPs on AuFON can be applied to detect rhodamine-6G (R6G with the detection limitation of 10−11 M and the pesticide thiram in acetone with a detection limit of as low as 0.24 ppm, which is much lower than the maximal residue limit (MRL of 7 ppm in fruit prescribed by the U.S. Environmental Protection Agency (EPA. The hybrid substrates are shown to be highly sensitive for the detection of thriam, which produce highly enhanced Raman signals with good uniformity and reproducibility due to having plenty of hot spots on its surface.

  12. Fast and facile preparation of CTAB based gels and their applications in Au and Ag nanoparticles synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Upadhyay, Ravi Kant, E-mail: rkupadhyay85@gmail.com [Department of Chemistry, School of Natural Sciences, Shiv Nadar University, Gautam Budh Nagar, 201314 Uttar Pradesh (India); Soin, Navneet, E-mail: n.soin@bolton.ac.uk [Knowledge Centre for Materials Chemistry (KCMC), Institute for Materials Research and Innovation (IMRI), University of Bolton, Deane Road, Bolton BL3 5AB (United Kingdom); Saha, Susmita, E-mail: ssaha@bose.res.in [Department of Condensed Matter Physics and Material Sciences, S. N. Bose National Centre for Basic Sciences, Block JD, Sector III, Salt Lake, Kolkata 700 098 (India); Barman, Anjan, E-mail: abarman@bose.res.in [Department of Condensed Matter Physics and Material Sciences, S. N. Bose National Centre for Basic Sciences, Block JD, Sector III, Salt Lake, Kolkata 700 098 (India); Sinha Roy, Susanta, E-mail: susanta.roy@snu.edu.in [Department of Physics, School of Natural Sciences, Shiv Nadar University, Gautam Budh Nagar, 201314 Uttar Pradesh (India)

    2015-04-15

    We have demonstrated that the gel-like mesophase of Cetyltrimethylammonium bromide (CTAB) can be synthesized by judicial adjustment of water to surfactant molar ratio (W{sub 0}), without using any additional salts, gelating agents or co-surfactants. Gel formation was found to be highly dependent on the water to surfactant molar ratio (W{sub 0}), with the lowest value of W{sub 0} (41.5) resulting in rapid gel formation. Environmental scanning electron microscope (ESEM) analysis revealed that the gel was comprised of interconnected cylindrical structures. The presence of hydrogen bonding in the gel-like mesophase was confirmed by Fourier Transform Infrared spectroscopy (FTIR) analysis. Rheology measurements revealed that all the gel samples were highly viscoelastic in nature. Furthermore, Au and Ag containing CTAB gels were explored as precursors for the preparation of spherical Gold (Au) and Silver (Ag) nanoparticles using Sodium borohydride (NaBH{sub 4}) as reducing agent. The effects of NaBH{sub 4} concentration on the particle size and morphology of the Au and Ag nanoparticles have also been studied. - Highlights: • A facile synthesis of CTAB based gel-like mesophase is reported. • CTAB gels were obtained by adjusting water to surfactant molar ratio (W{sub 0}). • FTIR analysis revealed that hydrogen bonding plays a key role in gel formation. • Au, Ag nanoparticles were synthesized by using CTAB gel and NaBH{sub 4}.

  13. Fast and facile preparation of CTAB based gels and their applications in Au and Ag nanoparticles synthesis

    International Nuclear Information System (INIS)

    We have demonstrated that the gel-like mesophase of Cetyltrimethylammonium bromide (CTAB) can be synthesized by judicial adjustment of water to surfactant molar ratio (W0), without using any additional salts, gelating agents or co-surfactants. Gel formation was found to be highly dependent on the water to surfactant molar ratio (W0), with the lowest value of W0 (41.5) resulting in rapid gel formation. Environmental scanning electron microscope (ESEM) analysis revealed that the gel was comprised of interconnected cylindrical structures. The presence of hydrogen bonding in the gel-like mesophase was confirmed by Fourier Transform Infrared spectroscopy (FTIR) analysis. Rheology measurements revealed that all the gel samples were highly viscoelastic in nature. Furthermore, Au and Ag containing CTAB gels were explored as precursors for the preparation of spherical Gold (Au) and Silver (Ag) nanoparticles using Sodium borohydride (NaBH4) as reducing agent. The effects of NaBH4 concentration on the particle size and morphology of the Au and Ag nanoparticles have also been studied. - Highlights: • A facile synthesis of CTAB based gel-like mesophase is reported. • CTAB gels were obtained by adjusting water to surfactant molar ratio (W0). • FTIR analysis revealed that hydrogen bonding plays a key role in gel formation. • Au, Ag nanoparticles were synthesized by using CTAB gel and NaBH4

  14. Magnetic gold nanocatalyst (nanocat-Fe–Au): catalytic applications for the oxidative esterification and hydrogen transfer reactions

    Science.gov (United States)

    An efficient and sustainable protocol is described for the oxidative esterification of aldehydes and the reduction of aromatic nitro compounds that uses magnetically separable and reusable maghemite-supported gold nanocatalyst (nanocat-Fe-Au) under mild conditions. The complex ch...

  15. Afgivelse af formaldehyd fra byggevarer og forbrugerprodukter

    DEFF Research Database (Denmark)

    Kolarik, Barbara; Gunnarsen, Lars; Funch, Llis Winther

    Rapporten præsenterer resultatet af en undersøgelse af formaldehydafgivelse fra 22 mulige kilder i indeklimaet. Undersøgelsen er gennemført for om muligt at finde årsagen til de høje koncentrationer af formaldehyd i indeluften, der blev fundet i enkelte danske boliger under en foregående undersøg......Rapporten præsenterer resultatet af en undersøgelse af formaldehydafgivelse fra 22 mulige kilder i indeklimaet. Undersøgelsen er gennemført for om muligt at finde årsagen til de høje koncentrationer af formaldehyd i indeluften, der blev fundet i enkelte danske boliger under en foregående...

  16. A Fabrication Route for Arrays of Ultra-low-Noise MoAu Transition Edge Sensors on Thin Silicon Nitride for Space Applications

    CERN Document Server

    Glowacka, D M; Goldie, D J; Withington, S

    2014-01-01

    We describe a process route to fabricate arrays of Ultra-low-Noise MoAu Transition Edge Sensors (TESs). The low thermal conductance required for space applications is achieved using 200 nm-thick Silicon Nitride (SiNx ) patterned to form long-thin legs with widths of 2.1 {\\mu}m. Using bilayers formed on SiNx islands from films with 40 nm-thick Mo and Au thicknesses in the range 30 to 280 nm deposited by dc-sputtering in ultra-high vacuum we can obtain tunable transition temperatures in the range 700 to 70 mK. The sensors use large-area absorbers fabricated from high resistivity, thin-film beta-phase Ta to provide impedance-matching to incident radiation. The absorbers are patterned to reduce the heat capacity associated with the nitride support structure and include Au thermalizing features to assist the heat flow into the TES. Arrays of 400 detectors at the pixel spacing required for the long-wavelength band of the far-infrared instrument SAFARI are now being fabricated. Device yields approaching 99% are achi...

  17. 21 CFR 573.460 - Formaldehyde.

    Science.gov (United States)

    2010-04-01

    ... accordance with 5 U.S.C. 552(a) and 1 CFR part 51. You may obtain copies from the Assistant Secretary... Federal Register approves this incorporation by reference in accordance with 5 U.S.C. 552(a) and 1 CFR... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Formaldehyde. 573.460 Section 573.460 Food...

  18. Characterization of alkaline lignins for use in penol-formaldehyde and epoxy resins

    OpenAIRE

    El Mansouri, Nour-Eddine; Yuan, Qiaolong; Huang, Farong

    2011-01-01

    Besides polyurethanes and polyesters, phenolic and epoxy resins are the most prominent applications for technical lignins in thermosetting materials. To evaluate the potential application of lignin raw materials in phenol formaldehyde and epoxy resins, three types of alkaline lignins were characterized in terms of their structures and thermal properties. The lignin samples analyzed were kraft lignin (LIG-1), soda–rice straw lignin (LIG-2), and soda-wheat straw lignin (LIG-3). FTIR and 1H-NMR ...

  19. CHARACTERIZATION OF ALKALINE LIGNINS FOR USE IN PHENOL-FORMALDEHYDE AND EPOXY RESINS

    OpenAIRE

    Nour Eddine El Mansouri,; Qiaolong Yuan Mail; Farong Huang

    2011-01-01

    Besides polyurethanes and polyesters, phenolic and epoxy resins are the most prominent applications for technical lignins in thermosetting materials. To evaluate the potential application of lignin raw materials in phenol formaldehyde and epoxy resins, three types of alkaline lignins were characterized in terms of their structures and thermal properties. The lignin samples analyzed were kraft lignin (LIG-1), soda–rice straw lignin (LIG-2), and soda-wheat straw lignin (LIG-3). FTIR and 1H-NMR ...

  20. Thin-films interdiffusion Ti/Pd/Au, Ti/Au/Pd

    International Nuclear Information System (INIS)

    Rutherford backscattering spectroscopy (RBS) is used to study the interdiffusion in Ti/Pd/Au and Ti/Au/Pd thin films system. The purpose of our study is to prepare an alloy of high resistance against corrosion, due to its important use in space industries, optical and visual receivers. In addition to another scientific results for future applications. Interdiffusion in the Ti/Pd/Au thin film system is measured using Rutherford backscattering. Interdiffusion rates of Pd/Au for temperatures between 200 and 490 centigrade degree have been correlated with the defect structure of the films. Air, as compared with vacuum, annealing enhances interdiffusion in the Ti/Au couple and inhibits interdiffusion in Ti/Pd, Ti/Pd and Ti/Au interdiffusion in the Ti/Pd/Au and Ti/Au/Pd ternary systems is strongly reduced in comparison with interdiffusion in the corresponding Ti/Pd or Ti/Au couples for vacuum annealing. (Author)

  1. Formaldehyde exposure affects growth and metabolism of common bean

    International Nuclear Information System (INIS)

    Recent state and federal directives have slated a substantial increase in the use of methanol as an alternative to gasoline in both fleet and private vehicles in the coming decade. The incomplete combustion of methanol produces formaldehyde vapor, and catalytic converter technology that completely oxidizes formaldehyde has yet to be developed. The approach of this study was to use a range of methanol concentrations encompassing levels currently found or that may occur in the future in the ambient air of some heavily polluted areas to test the potential phytotoxicity of formaldehyde. The study had the following objectives: (1) design and build a formaldehyde vapor generator with sufficient capacity for long-term plant fumigations; (2) determine growth response of common bean to formaldehyde; (3) evaluate physiological and biochemical changes of bean plants associated with formaldehyde exposures. 20 refs., 2 figs., 2 tabs

  2. Experimental Study of a Photocatalytic Reactor for Trace Formaldehyde Removal

    Institute of Scientific and Technical Information of China (English)

    LIU Hong-min; LIAN Zhi-wei; YE Xiao-jiang; SHANG-GUAN Wen-feng

    2005-01-01

    Formaldehyde is the key contaminant influencing building occupants' health in indoor environment. In order to reduce occupants' exposures to formaldehyde, a newly designed photocatalytic reactor was applied in a dynamic HVAC(heating, ventilation and air conditioning) system. The experiments were carried out for the removal of formaldehyde present in air at low parts per million (ppm) concentrations.The initial formaldehyde concentrations were set as1.59 ppm and 0.27 ppm respectively, based on the formaldehyde levels in the polluted places. Experimental results show that the photocatalytic reactor is effective on formaldehyde photodegradation, causes a low pressure drop, and does not make the second pollution of ozone. The kinetic analysis indicates that the kinetics for oxidation processes can be fitted well by a pseudo-first-order kinetic model deduced from Langmuir - Hinshelwood (L-H) model.

  3. Importance of formaldehyde in cloud chemistry

    Science.gov (United States)

    Adewuyi, Y. G.; Cho, S.-Y.; Tsay, R.-P.; Carmichael, G. R.

    1984-01-01

    A physical-chemical model which is an extension of that of Hong and Carmichael (1983) is used to investigate the role of formaldehyde in cloud chemistry. This model takes into account the mass transfer of SO2, O3, NH3, HNO3, H2O2, CO2, HCl, HCHO, O2, OH and HO2 into cloud droplets and their subsequent chemical reactions. The model is used to assess the importance of S(IV)-HCHO adduct formation, the reduction of H2O2 by HCHO, HCHO-free radical interactions, and the formation of HCOOH in the presence of HCHO in cloud droplets. Illustrative calculations indicate that the presence of HCHO inhibits sulfate production rate in cloud droplets. The direct inhibition of sulfate production rate in cloudwater due to nucleophilic addition of HSO3(-) to HCHO(aq) to form hydroxymethanesulfonate is generally low for concentrations of HCHO typical of ambient air. However, inhibition of sulfate production due to formaldehyde-free radical interactions in solution can be important. These formaldehyde-free radical reactions can also generate appreciable quantities of formic acid.

  4. Determination of formaldehyde in food and feed by an in-house validated HPLC method.

    Science.gov (United States)

    Wahed, P; Razzaq, Md A; Dharmapuri, S; Corrales, M

    2016-07-01

    Formalin is carcinogenic and is detrimental to public health. The illegal addition of formalin (37% formaldehyde and 14% methanol) to foods to extend their shelf-life is considered to be a common practice in Bangladesh. The lack of accurate methods and the ubiquitous presence of formaldehyde in foods make the detection of illegally added formalin challenging. With the aim of helping regulatory authorities, a sensitive high performance liquid chromatography method was validated for the quantitative determination of formaldehyde in mango, fish and milk. The method was fit-for-purpose and showed good analytical performance in terms of specificity, linearity, precision, recovery and robustness. The expanded uncertainty was <35%. The validated method was applied to screen samples of fruits, vegetables, fresh fish, milk and fish feed collected from different local markets in Dhaka, Bangladesh. Levels of formaldehyde in food samples were compared with published data. The applicability of the method in different food matrices might mean it has potential as a reference standard method. PMID:26920321

  5. Migration Effect of Temperature on Formaldehyde in Porous Building Materials

    Institute of Scientific and Technical Information of China (English)

    SHEN Xiao-zhong; CHEN Zhen-qian

    2009-01-01

    A coupled heat and formaldehyde migration model based on the non-equilibrium thermodynamic theory and molecule movement theory was developed.The effect of temperature on the transport coefficients was simulated,and the simulation results were vaildated with experimental data from the literatures.The calculation shows that air exchange rate larger than 2h-1 should be prevented,if the purpose is only for formaldehyde emis-sions control.The effects of temperature on formaldehyde migration are obvious.

  6. Formaldehyde scavengers function as novel antigen retrieval agents

    OpenAIRE

    Craig T. Vollert; Moree, Wilna J; Steven Gregory; Bark, Steven J.; Eriksen, Jason L.

    2015-01-01

    Antigen retrieval agents improve the detection of formaldehyde-fixed proteins, but how they work is not well understood. We demonstrate that formaldehyde scavenging represents a key characteristic associated with effective antigen retrieval; under controlled temperature and pH conditions, scavenging improves the typical antigen retrieval process through reversal of formaldehyde-protein adduct formation. This approach provides a rational framework for the identification and development of more...

  7. Nasal mucosa in workers exposed to formaldehyde: a pilot study.

    OpenAIRE

    Boysen, M; Zadig, E; Digernes, V; Abeler, V; Reith, A.

    1990-01-01

    This study evaluates the histological changes, especially the presence of possible precancerous lesions, in the nasal mucosa of workers exposed to formaldehyde. Nasal biopsies of 37 workers occupationally exposed to formaldehyde for more than five years and 37 age matched referents showed a higher degree of metaplastic alterations in the former group. In addition, three cases of epithelial dysplasia were observed among the exposed. These results indicate that formaldehyde may be potentially c...

  8. 40 CFR 721.3800 - Formaldehyde, condensated polyoxyethylene fatty acid, ester with styrenated phenol, ethylene...

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Formaldehyde, condensated... Formaldehyde, condensated polyoxyethylene fatty acid, ester with styrenated phenol, ethylene oxide adduct. (a... generically as formaldehyde, condensated polyoxyethylene fatty acid, ester with styrenated phenol,...

  9. Formaldehyde and LeukemiA: Epidemiology, Potential Mechanisms and Implications for Risk Assessment

    Science.gov (United States)

    Formaldehyde is widely used in the United States and other countries. Occupational and environmental exposures to formaldehyde may be associated with an increased risk of leukemia in exposed individuals. However, risk assessment of formaldehyde and leukemia has been challenging ...

  10. 40 CFR 721.9480 - Resorcinol, formaldehyde substituted carbomonocycle resin (generic).

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Resorcinol, formaldehyde substituted... New Uses for Specific Chemical Substances § 721.9480 Resorcinol, formaldehyde substituted... chemical substance identified generically as resorcinol, formaldehyde substituted carbomonocycle resin...

  11. Effect of Formaldehyde on Asthmatic Response to Inhaled Allergen Challenge

    OpenAIRE

    Ezratty, Véronique; Bonay, Marcel; Neukirch, Catherine; Orset-Guillossou, Gaëlle; Dehoux, Monique; Koscielny, Serge; Cabanes, Pierre-André; Lambrozo, Jacques; Aubier, Michel

    2006-01-01

    Background Exposure to formaldehyde may lead to exacerbation of asthma. Objectives Our aim in this study was to investigate whether exposure to a low level (500 μg/m3) of formaldehyde enhances inhaled allergen responses. Methods Twelve subjects with intermittent asthma and allergy to pollen were exposed, at rest, in a double-blind crossover study to either formaldehyde or purified air for 60 min. The order of exposure to formaldehyde and air-only was randomized, and exposures were separated b...

  12. Degradation of formaldehyde in anaerobic sequencing batch biofilm reactor (ASBBR)

    International Nuclear Information System (INIS)

    The present study evaluated the degradation of formaldehyde in a bench-scale anaerobic sequencing batch reactor, which contained biomass immobilized in polyurethane foam matrices. The reactor was operated for 212 days at 35 deg. C with 8 h sequential cycles, under different affluent formaldehyde concentrations ranging from 31.6 to 1104.4 mg/L (formaldehyde loading rates from 0.08 to 2.78 kg/m3 day). The results indicate excellent reactor stability and over 99% efficiency in formaldehyde removal, with average effluent formaldehyde concentration of 3.6 ± 1.7 mg/L. Formaldehyde degradation rates increased from 204.9 to 698.3 mg/L h as the initial concentration of formaldehyde was increased from around 100 to around 1100 mg/L. However, accumulation of organic matter was observed in the effluent (chemical oxygen demand (COD) values above 500 mg/L) due to the presence of non-degraded organic acids, especially acetic and propionic acids. This observation poses an important question regarding the anaerobic route of formaldehyde degradation, which might differ substantially from that reported in the literature. The anaerobic degradation pathway can be associated with the formation of long-chain oligomers from formaldehyde. Such long- or short-chain polymers are probably the precursors of organic acid formation by means of acidogenic anaerobic microorganisms

  13. PILOT STUDY OF CONTACT SENSITIZATION OF FORMALDEHYDE-RELEASERS, FORMALDEHYDE AND GLUTARALDEHYDE IN DENTAL STUDENTS

    Directory of Open Access Journals (Sweden)

    Lyapina Maya

    2016-03-01

    Full Text Available Introduction: Occupational allergic contact sensitization is common in dental personnel. Some of the most common occupational allergens in dental practice are some formaldehyde-releasers, formaldehyde and glutaraldehyde. Aim: The aim of the present study was to evaluate the rate of contact sensitization to formaldehyde, quaternium-15, imidazolidinyl urea, diazolidinyl urea, and to glutaraldehyde in students of dental medicine and dental patients. Material and methods: A total of 50 participants were included in the study: 40 students of dental medicine exposed to formaldehyde-releasers, formaldehyde and glutaraldehyde during the course of their education; 10 dental patients without occupational exposure to the latter substances served as a control group. All of them were patch-tested with the studied allergens. Results: The sensitization rate to formaldehyde was significantly higher in the group of dental patients if compared to the one of dental students (χ2=5.37; p=0.021. Positive skin patch test reactions to quaternium-15 and to imidazolidinyl urea were observed only in the group of dental students. A significantly higher rate of sensitization to diazolidinyl urea, if compared to the one to imidazolidinyl urea (χ2=5.4; p=0.02 and to quaternium-15 (χ2=6.76; p=0.009, as well as to glutaraldehyde, if compared to the one to quaternium-15 (χ2=3.96; p=0.04 for the whole studied population was established. For the whole studied population, significantly increased rate of concomitant sensitization to formaldehyde and glutaraldehyde (χ2=6.18 p=0.013, as well as to diazolidinyl urea and to glutaraldehyde was established (χ2=9.12 p=0.003. Conclusions: We consider the importance of exposure to diazolidinyl urea, quaternium-15, imidazolidinyl urea and glutaraldehyde during the course of practical education in dentistry for the onset of sensitization. The exposure to formaldehyde is ubiquitous and is difficult to distinguish the roles of

  14. A simple approach to the synthesis of eccentric Au@SiO2 Janus nanostructures and their catalytic applications

    Science.gov (United States)

    Zhao, Yang; Yang, Di; Hu, Huicheng; Chen, Lei; Xu, Yong; Qu, Lili; Yang, Peipei; Zhang, Qiao

    2016-06-01

    In this paper, we present a simple method to synthesize eccentric Au@SiO2 Janus nanoparticles. By simply tuning the concentration of poly(vinyl pyrrolidone) (PVP), the surface of gold nanoparticle can be partially or fully wrapped with the amphiphilic ligand. As a result, Janus nanoparticle or concentric core-shell nanostructures can be obtained, respectively. A systematic study has been carried out to confirm the function of PVP molecules. The as-prepared Janus nanoparticle can act as a catalyst to catalyze the reduction of 4-nitrophenol, while the core-shell nanostructure is not active due to the coverage of dense silica shell. This work provides a robust and scalable method to produce Au@SiO2 Janus nanoparticles.

  15. Intrathecal application of 198Au-colloid in children suffering from leukemia and non-Hodgkin's disease

    International Nuclear Information System (INIS)

    26 children suffering from acute leukemia and non-Hodgkin lymphoma (group 1) received intrathecal Au-198-colloid injections as a prophylactic measure against central nervous system (CNS) relapses. No primary CNS relapses were observed in the period from 1 Sep. 1974 to 31 Oct. 1978. Two children were taken ill at the same time with meningosis leucaemica in the first and second relapse, respectively. Four children (group 2) were treated with Au-198-colloid after overcoming a meningosis leucaemica. It was not possible to prevent another CNS relapse in all four patients of this group. Clinical status, liquor tests and EEG examinations carried out after the therapy showed good tolerance of the gold colloid. (author)

  16. Adsorption between TC-stabilized AuNPs and the phosphate group: application of the PTP1B activity assay.

    Science.gov (United States)

    Lv, Jun; Wang, Xiaonan; Zhang, Yuanyuan; Li, Defeng; Zhang, Juan; Sun, Lizhou

    2015-12-01

    Based on the adsorption between tetracycline (TC) and phosphate groups, a general colorimetric method is explored in this work by using TC-stabilized gold nanoparticles (TC/AuNPs) and 4-aminophenyl phosphate-functionalized Fe3O4 magnetic nanoparticles (APP/MNPs). Taking protein tyrosine phosphatase 1B (PTP1B) as an example, 4-aminophenyl phosphate (APP) can be hydrolyzed into 4-aminophenol (AP) by PTP1B, resulting in the disappearance of the phosphate group on the outer layer of MNPs and the loss of corresponding adsorptive ability. Upon addition of TC/AuNP solution, TC/AuNPs will remain in the supernatant solution after magnetic separation and a high absorbance value can be observed. So PTP1B activity is related to the concentrations of TC/AuNPs in the supernatant solution. In this work, the enzyme activity can be determined at levels as low as 0.0885 U mL(-1) and over a linear detection range as wide as 0.1 U mL(-1) to 0.9 U mL(-1). Moreover, using the proposed method, the inhibition effect of betulinic acid (BA) and sodium orthovanadate (Na3VO4) on PTP1B activity can be tested with IC50 values of 30 μM and 4 μM, respectively. Therefore, a universal platform for the accurate colorimetric analysis of kinase and phosphatase activities can be established through the adsorption between TC and phosphate groups. PMID:26523458

  17. Some characteristics of urea-formaldehyde powder adhesives

    Directory of Open Access Journals (Sweden)

    Miljković Jovan

    2006-01-01

    Full Text Available Urea-formaldehyde (UF glue resins were the most important type of adhesives in the wood industry last 60 years, especially for the production of wood based panels. More convenient spray dried UF powders went into use last two decades. Small and medium private wood processing plants in Serbia prefer to use such powder adhesives, since they are more convenient for small capacity production. There is no production of UF powder resin in Serbia so necessary quantities are imported from abroad including producers from Asia. However, their characteristics are variable, dependent on syntheses steps and not well known among users. Objective of this research was to determine conveniences and lacks in application of two imported UF powder resins in comparison to domestic UF emulsion.

  18. Electronic Characterization of Au/DNA/ITO Metal-Semiconductor-Metal Diode and Its Application as a Radiation Sensor.

    Science.gov (United States)

    Al-Ta'ii, Hassan Maktuff Jaber; Periasamy, Vengadesh; Amin, Yusoff Mohd

    2016-01-01

    Deoxyribonucleic acid or DNA molecules expressed as double-stranded (DSS) negatively charged polymer plays a significant role in electronic states of metal/silicon semiconductor structures. Electrical parameters of an Au/DNA/ITO device prepared using self-assembly method was studied by using current-voltage (I-V) characteristic measurements under alpha bombardment at room temperature. The results were analyzed using conventional thermionic emission model, Cheung and Cheung's method and Norde's technique to estimate the barrier height, ideality factor, series resistance and Richardson constant of the Au/DNA/ITO structure. Besides demonstrating a strongly rectifying (diode) characteristic, it was also observed that orderly fluctuations occur in various electrical parameters of the Schottky structure. Increasing alpha radiation effectively influences the series resistance, while the barrier height, ideality factor and interface state density parameters respond linearly. Barrier height determined from I-V measurements were calculated at 0.7284 eV for non-radiated, increasing to about 0.7883 eV in 0.036 Gy showing an increase for all doses. We also demonstrate the hypersensitivity phenomena effect by studying the relationship between the series resistance for the three methods, the ideality factor and low-dose radiation. Based on the results, sensitive alpha particle detectors can be realized using Au/DNA/ITO Schottky junction sensor. PMID:26799703

  19. The graphene/Au/Ni interface and its application in the construction of a graphene spin filter

    International Nuclear Information System (INIS)

    A modification of the contact of graphene with ferromagnetic electrodes in a model of the graphene spin filter allowing restoration of the graphene electronic structure is proposed. It is suggested for this aim to intercalate into the interface between the graphene and the ferromagnetic (Ni or Co) electrode a Au monolayer to block the strong interaction between the graphene and Ni (Co) and, thus, prevent destruction of the graphene electronic structure which evolves in direct contact of graphene with Ni (Co). It is also suggested to insert an additional buffer graphene monolayer with the size limited by that of the electrode between the main graphene sheet providing spin current transport and the Au/Ni electrode injecting the spin current. This will prevent the spin transport properties of graphene from influencing contact phenomena and eliminate pinning of the graphene electronic structure relative to the Fermi level of the metal, thus ensuring efficient outflow of injected electrons into the graphene. The role of the spin structure of the graphene/Au/Ni interface with enhanced spin–orbit splitting of graphene π states is also discussed, and its use is proposed for additional spin selection in the process of the electron excitation. (paper)

  20. 臭氧去除室内空气甲醛的研究%Effect of ozone on removal of indoor formaldehyde

    Institute of Scientific and Technical Information of China (English)

    李玉华; 王琨; 赵庆良; 袁中新

    2008-01-01

    The application of ozone-generating air-purifying devices (APD) on removing indoor formaldehyde is investigated in this paper. The formaldehyde concentrations are measured in a test room and a control room to ascertain the effects of ozone on the removal of formaldehyde. During the experiments, temperature, humidity, and atmospheric pressure are also monitored simultaneously. Experimental results show that ozone had limited effect on the reduction of indoor formaldehyde. The removal efficiency of formaldehyde is up to 32%. The influence of formaldehyde release rate from particle boards in the rooms on the removal efficiency of formaldehyde is further investigated. The results show that formaldehyde release rate from particle boards had significant influence on reducing indoor formaldehyde concentration.%应用臭氧空气净化器对室内空气甲醛进行去除.实验过程中,检测了实验和对照房间甲醛体积分数,以确定臭氧对甲醛的去除效果.同时对室内温、湿度以及大气压力进行测定.实验结果显示,臭氧对甲醛去除效果有限,最大去除效率为32%.同时考察了人造板甲醛散发速率对臭氧去除甲醛效率的影响.结果显示甲醛散发速率对室内甲醛体积分数的降低有显著影响.

  1. 78 FR 44090 - Formaldehyde; Third-Party Certification Framework for the Formaldehyde Standards for Composite...

    Science.gov (United States)

    2013-07-23

    ... comment date for a proposed rule published June 10, 2013 at 78 FR 34796. Comments, identified by docket... the Federal Register of June 10, 2013 (78 FR 34796) (FRL-9342-4). EPA is hereby extending the comment... AGENCY 40 CFR Part 770 RIN 2070-AJ44 Formaldehyde; Third-Party Certification Framework for...

  2. 78 FR 51696 - Formaldehyde; Third-Party Certification Framework for the Formaldehyde Standards for Composite...

    Science.gov (United States)

    2013-08-21

    ... established in the Federal Register of July 23, 2013 (78 FR 44090) (FRL-9393-9). EPA is hereby extending the..., 2013, Federal Register document (78 FR 34796) (FRL-9342-4). If you have questions, consult the... AGENCY 40 CFR Part 770 RIN 2070-AJ44 Formaldehyde; Third-Party Certification Framework for...

  3. Introduction au droit commercial

    OpenAIRE

    Thirion, Nicolas; Delvaux, Thierry; Benoit-Moury, Anne

    2009-01-01

    Le cours d'introduction au droit commercial, destiné à des non-juristes, a pour objet de décrire, dans ses grandes lignes, le régime juridique applicable à l'organisation et au fonctionnement de l'économie. Les liens avec des disciplines autres que le droit, notamment l'économie et l'histoire, seront privilégiés, afin d'adapter la matière aux besoins et centres d'intérêts d'étudiants en sciences humaines. Après une introduction générale, le cours s'articule autour de la trilogie fondamentale ...

  4. Influence of precision of emission characteristic parameters on model prediction error of VOCs/formaldehyde from dry building material.

    Directory of Open Access Journals (Sweden)

    Wenjuan Wei

    Full Text Available Mass transfer models are useful in predicting the emissions of volatile organic compounds (VOCs and formaldehyde from building materials in indoor environments. They are also useful for human exposure evaluation and in sustainable building design. The measurement errors in the emission characteristic parameters in these mass transfer models, i.e., the initial emittable concentration (C 0, the diffusion coefficient (D, and the partition coefficient (K, can result in errors in predicting indoor VOC and formaldehyde concentrations. These errors have not yet been quantitatively well analyzed in the literature. This paper addresses this by using modelling to assess these errors for some typical building conditions. The error in C 0, as measured in environmental chambers and applied to a reference living room in Beijing, has the largest influence on the model prediction error in indoor VOC and formaldehyde concentration, while the error in K has the least effect. A correlation between the errors in D, K, and C 0 and the error in the indoor VOC and formaldehyde concentration prediction is then derived for engineering applications. In addition, the influence of temperature on the model prediction of emissions is investigated. It shows the impact of temperature fluctuations on the prediction errors in indoor VOC and formaldehyde concentrations to be less than 7% at 23±0.5°C and less than 30% at 23±2°C.

  5. Optimization of Formaldehyde Cross-Linking for Protein Interaction Analysis of Non-Tagged Integrin β1

    Directory of Open Access Journals (Sweden)

    Cordula Klockenbusch

    2010-01-01

    Full Text Available Formaldehyde cross-linking of protein complexes combined with immunoprecipitation and mass spectrometry analysis is a promising technique for analysing protein-protein interactions, including those of transient nature. Here we used integrin β1 as a model to describe the application of formaldehyde cross-linking in detail, particularly focusing on the optimal parameters for cross-linking, the detection of formaldehyde cross-linked complexes, the utility of antibodies, and the identification of binding partners. Integrin β1 was found in a high molecular weight complex after formaldehyde cross-linking. Eight different anti-integrin β1 antibodies were used for pull-down experiments and no loss in precipitation efficiency after cross-linking was observed. However, two of the antibodies could not precipitate the complex, probably due to hidden epitopes. Formaldehyde cross-linked complexes, precipitated from Jurkat cells or human platelets and analyzed by mass spectrometry, were found to be composed of integrin β1, α4 and α6 or β1, α6, α2, and α5, respectively.

  6. Pt@AuNPs integrated quantitative capillary-based biosensors for point-of-care testing application.

    Science.gov (United States)

    Wu, Ze; Fu, Qiangqiang; Yu, Shiting; Sheng, Liangrong; Xu, Meng; Yao, Cuize; Xiao, Wei; Li, Xiuqing; Tang, Yong

    2016-11-15

    Current diagnostic technologies primarily rely on bulky and costly analytical instruments. Therefore, cost-effective and portable diagnosis tools that can be used for point-of-care tests (POCT) are highly desirable. In this study, we report a cost-effective, portable capillary-based biosensor for quantitative detection of biomarkers by the naked eye. This capillary-based biosensor was tested by measuring the distance of blue ink movement, which was directly correlated with the oxygen (O2) produced by efficient core-shell Pt@Au nanoparticles (Pt@AuNPs) catalysts decomposed hydrogen peroxide (H2O2). By linking the Pt@AuNPs with antibodies, capillary-based biosensor sandwich immunoassays were constructed. The concentrations of the target proteins were positively correlated with the distances of ink movement. To demonstrate their performance, the biosensors were used to detect the cancer biomarker sprostate-specific antigen (PSA) and carcinoembryonic antigen (CEA). The linear detection range (LDR) of the capillary-based biosensor for detecting PSA was from 0.02 to 2.5ng/mL, and the limit of detection (LOD) was 0.017ng/mL. LDR of the biosensor for detecting CEA was from 0.063 to 16ng/mL, and the LOD was 0.044ng/mL. For detection of PSA and CEA in clinical serum samples, the detection results of the capillary-based biosensor were well correlate with the results from of chemiluminescence immunoassays (CLIAs). Thus, the capillary-based biosensor may potentially be a useful strategy for point-of-care testing, in addition to being portable and cost effective. PMID:27240013

  7. Resistance of Mycobacterium chelonei-like organisms to formaldehyde.

    OpenAIRE

    Hayes, P S; McGiboney, D L; Band, J. D.; Feeley, J C

    1982-01-01

    Mycobacterium chelonei-like organisms have been isolated from patients in two outbreaks of peritonitis involving chronic peritoneal dialysis machines routinely disinfected with 2 to 3% formaldehyde. Susceptibility studies revealed that water-adapted M. chelonei-like organism strains could survive 2 h of exposure to 10% formaldehyde.

  8. Effect of Formaldehyde on Asthmatic Response to Inhaled Allergen Challenge

    Science.gov (United States)

    Ezratty, Véronique; Bonay, Marcel; Neukirch, Catherine; Orset-Guillossou, Gaëlle; Dehoux, Monique; Koscielny, Serge; Cabanes, Pierre-André; Lambrozo, Jacques; Aubier, Michel

    2007-01-01

    Background Exposure to formaldehyde may lead to exacerbation of asthma. Objectives Our aim in this study was to investigate whether exposure to a low level (500 μg/m3) of formaldehyde enhances inhaled allergen responses. Methods Twelve subjects with intermittent asthma and allergy to pollen were exposed, at rest, in a double-blind crossover study to either formaldehyde or purified air for 60 min. The order of exposure to formaldehyde and air-only was randomized, and exposures were separated by 2 weeks. We also performed an allergen inhalation challenge after each exposure. Airway responsiveness to methacholine and lower airway inflammation (induced sputum) were assessed 8 hr after allergen challenge. Results The median dose of allergen producing a 15% decrease in forced expiratory volume in 1 sec (PD15FEV1) was 0.80 IR (index of reactivity) after formaldehyde exposure compared with 0.25 IR after air-only exposure (p = 0.06). Formaldehyde exposure did not affect allergen-induced increase in responsiveness to methacholine (p = 0.42). We found no formaldehyde-associated effect on the airway inflammatory response, in particular the eosinophilic inflammatory response, induced by the allergen challenge 8 hr before. Conclusion In this study, exposure to 500 μg/m3 formaldehyde had no significant deleterious effect on airway allergen responsiveness of patients with intermittent asthma; we found a trend toward a protective effect. PMID:17384766

  9. Algorithmes Heuristiques et Techniques d'Apprentissage : Applications au Problème de Coloration de Graphe

    OpenAIRE

    Porumbel, Daniel Cosmin

    2009-01-01

    Au cours des trois dernières décennies, les algorithmes heuristiques ont permis de réaliser des progrès remarquables dans la résolution des problèmes difficiles d'optimisation combinatoire. Cependant, la conception de ces algorithmes relève encore plusieurs challenges importants - en particulier, il semble qu'il est toujours difficile d'intégrer dans une heuristique une vue d'ensemble sur l'évolution de la recherche ou sur sa trajectoire. Prenant comme cadre expérimental le problème bien conn...

  10. Performance and application research of the dense direct dyes formaldehyde-free fixing agent TF-234Y%直接染料无醛固色剂TF-234Y浓的性能及应用研究

    Institute of Scientific and Technical Information of China (English)

    张红燕; 陈庆文; 沈立; 金鲜花; 吴彬

    2013-01-01

      A new concentrated direct dyes formaldehyde-free fixing agent TF-234Y was prepared in view of the existing problems in direct dyes fixing agents, the environmental protection and market demands in this paper. The test and analysis of the formaldehyde content, heavy metal ions content and aromatic amine content which can cause cancer etc. proved that the dense fixing agent TF-234Y contained no harmful substances. Experiment results showed that when the fixing agent was applied to the medium or deep color cotton knitted fabric and cotton/brocade/ammonia(80/18/2)blended fabric dyed with direct dyes, the dense fixing agent TF-234Y was able to bviously improve various color fastness and was more excellently than fixing agent Y. Especially the effect of the dense fixing agent TF-234Y on the handle and color change of after treated fabrics was much less than that of fixing agent Y.%  针对目前直接染料固色剂存在的问题以及环保、市场需求,制备出了直接染料无醛固色剂TF-234Y浓。通过对甲醛、重金属离子、致癌芳香胺等指标的检测分析,证实TF-234Y浓不含有害物质,用其对直接染料所染的中、深色棉织物、棉/锦/氨(80/18/2)混纺织物进行固色并检测固色后织物的综合性能,发现TF-234Y浓可以明显提升染色物的各项色牢度,其固色性能优于固色剂Y,尤其是对染色物的手感、色差变化的影响比固色剂Y要小得多。

  11. Magnetic, optical and relaxometric properties of organically coated gold-magnetite (Au-Fe{sub 3}O{sub 4}) hybrid nanoparticles for potential use in biomedical applications

    Energy Technology Data Exchange (ETDEWEB)

    Umut, E., E-mail: eumut@hacettepe.edu.tr [Hacettepe University Physics Engineering Department, 06800 Beytepe-Ankara (Turkey); Pineider, F. [INSTM and Universita degli Studi di Firenze, Department of Chemistry, Via della Lastruccia 3, 50019 Sesto Fiorentino (Italy); CNR-ISTM Padova, 35131 Padova (Italy); Arosio, P. [INSTM and Universita degli Studi di Milano, Department of Molecular Sciences Applied to Biosystems (DISMAB), I-20134 Milano (Italy); Sangregorio, C. [INSTM and Universita degli Studi di Firenze, Department of Chemistry, Via della Lastruccia 3, 50019 Sesto Fiorentino (Italy); CNR-ISTM Milano, 50123 via C.Golgi 19, 20133 Milano (Italy); Corti, M. [INSTM, CNISM and Dipartimento di Fisica ' A.Volta' , Univ. di Pavia, Via Bassi 6, I-27100 Pavia (Italy); Tabak, F. [Hacettepe University Physics Engineering Department, 06800 Beytepe-Ankara (Turkey); Lascialfari, A. [INSTM and Universita degli Studi di Milano, Department of Molecular Sciences Applied to Biosystems (DISMAB), I-20134 Milano (Italy); INSTM, CNISM and Dipartimento di Fisica ' A.Volta' , Univ. di Pavia, Via Bassi 6, I-27100 Pavia (Italy); Ghigna, P. [INSTM and Dipartimento di Chimica Univ. di Pavia, v.le Taramelli 13, I-27100 Pavia (Italy)

    2012-08-15

    We present the magnetic, optical and relaxometric properties of multifunctional Au-Fe{sub 3}O{sub 4} hybrid nanoparticles (HNPs), as possible novel contrast agents (CAs) for magnetic resonance imaging (MRI). The HNPs have been synthesized by wet chemical methods in heterodimer and core-shell geometries and capped with oleylamine. Structural characterization of the samples have been made by X-ray diffraction and transmission electron microscopy, while magnetic properties have been investigated by means of Superconducting Quantum Interference Device-SQUID magnetometry experiments. As required for MRI applications using negative CAs, the samples resulted superparamagnetic at room temperature and well above their blocking temperatures. Optical properties have been investigated by analyzing the optical absorbtion spectra collected in UV-visible region. Relaxometric measurements have been performed on organic suspensions of HNPs and Nuclear Magnetic Resonance (NMR) dispersion curves have been obtained by measuring the longitudinal 1/T{sub 1} and transverse 1/T{sub 2} relaxation rates of solvent protons in the range 10 kHz/300 MHz at room temperature. NMR relaxivities r{sub 1} and r{sub 2} have been compared with ENDOREM{sup Registered-Sign }, one of the commercial superparamagnetic iron oxide based MRI contrast agents. MRI contrast enhancement efficiencies have been investigated also by examining T{sub 2}-weighted MR images of suspensions. The experimental results suggest that the nanoparticles' suspensions are good candidates as negative CAs. - Highlights: Black-Right-Pointing-Pointer Au-Fe{sub 3}O{sub 4} superparamagnetic Hybrid NanoPrticles (HNPs) enhance contrast in MRI. Black-Right-Pointing-Pointer HNPs are expected to have optical activities through observed SPR phenomena. Black-Right-Pointing-Pointer HNPs have relatively high magnetic anisotropy originating from Au/Fe{sub 3}O{sub 4} interface. Black-Right-Pointing-Pointer Magnetic dipolar interactions have

  12. Application of Au-Sn eutectic bonding in hermetic radio-frequency microelectromechanical system wafer level packaging

    Science.gov (United States)

    Wang, Qian; Choa, Sung-Hoon; Kim, Woonbae; Hwang, Junsik; Ham, Sukjin; Moon, Changyoul

    2006-03-01

    Development of packaging is one of the critical issues toward realizing commercialization of radio-frequency-microelectromechanical system (RF-MEMS) devices. The RF-MEMS package should be designed to have small size, hermetic protection, good RF performance, and high reliability. In addition, packaging should be conducted at sufficiently low temperature. In this paper, a low-temperature hermetic wafer level packaging scheme for the RF-MEMS devices is presented. For hermetic sealing, Au-Sn eutectic bonding technology at temperatures below 300°C is used. Au-Sn multilayer metallization with a square loop of 70 µm in width is performed. The electrical feed-through is achieved by the vertical through-hole via filling with electroplated Cu. The size of the MEMS package is 1 mm × 1 mm × 700 µm. The shear strength and hermeticity of the package satisfies the requirements of MIL-STD-883F. Any organic gases or contamination are not observed inside the package. The total insertion loss for the packaging is 0.075 dB at 2 GHz. Furthermore, the robustness of the package is demonstrated by observing no performance degradation and physical damage of the package after several reliability tests.

  13. Application of X-ray photoelectron spectroscopy to characterization of Au nanoparticles formed by ion implantation into SiO2

    International Nuclear Information System (INIS)

    In X-ray photoelectron spectroscopy (XPS) of Au nanoparticles, the width of 5d valence band changes with Au particle size. This enables us to estimate the size of Au nanoparticles by using XPS. In this work, the 5d-band width has been measured for Au nanoparticles formed by ion implantation into SiO2. The 5d-band width is found to be correlated strongly with the Au concentration. As the Au concentration increases, the 5d-band width becomes larger, indicating that the Au nanoparticles with the larger size tend to be formed in the vicinity of the projected range of Au ions. This correlation agrees very well with the results from transmission electron microscopy.

  14. Thermohydraulique des écoulements d'hélium faiblement supercritique en conduite application au refroidissement des écrans de faisceau du LHC

    CERN Document Server

    Hatchadourian, E

    2000-01-01

    Au cours d'observations, au-delà de la mise en évidence d'un effet inattendu, l'effort de compréhension porte tout d'abord vers une description qualitative du phénomène et ensuite quantitative. Puis, lorsque ce phénomène est compris, le travail peut s'orienter vers une étape d'exploitation o le mécanisme est utilisé pour développer de nouvelles voies de recherche ou encore apporter des solutions à des besoins d'ordre technologique. L'étude établie sur le projet du futur collisionneur de particules du CERN en est un exemple convaincant : il s'agit dans un premier temps de définir un modèle simplifié sur l'écoulement d'hélium supercritique dans des tubes soumis à des apports de chaleur, afin de permettre la compréhension des mécanismes essentiels puis developper un modèle plus précis, mais également plus complet, pour l'étude quantitative. L'application directe de cette étude thermohydraulique concerne le refroidissement des écrans de faisceau du LHC. Ces écrans, maintenus à une te...

  15. 21 CFR 177.1460 - Melamine-formaldehyde resins in molded articles.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Melamine-formaldehyde resins in molded articles...-formaldehyde resins in molded articles. Melamine-formaldehyde resins may be safely used as the food-contact...: (a) For the purpose of this section, melamine-formaldehyde resins are those produced when 1 mole...

  16. 21 CFR 177.1900 - Urea-formaldehyde resins in molded articles.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Urea-formaldehyde resins in molded articles. 177...-formaldehyde resins in molded articles. Urea-formaldehyde resins may be safely used as the food-contact surface... conditions: (a) For the purpose of this section, urea-formaldehyde resins are those produced when 1 mole...

  17. 40 CFR 80.56 - Measurement methods for formaldehyde and acetaldehyde.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 16 2010-07-01 2010-07-01 false Measurement methods for formaldehyde... Measurement methods for formaldehyde and acetaldehyde. (a) Formaldehyde and acetaldehyde will be measured by....140 of this chapter for formaldehyde analysis. Diluted exhaust sample volumes must be at least 15...

  18. Spectral Matrix Filtering Applied to Vsp Processing Application du filtrage matriciel au traitement des profils sismiques verticaux

    Directory of Open Access Journals (Sweden)

    Glangeaud F.

    2006-11-01

    données et de séparer ces signaux. Nous montrons que les signaux peuvent être automatiquement séparés sans connaissance a priori sur leurs vitesses apparentes, en fonction du produit scalaire (calculé dans le domaine fréquentiel et de l'amplitude relative des signaux. Nous montrons des exemples d'application sur des données de sismique de puits. Le filtrage matriciel est effectué dans le domaine fréquentiel en utilisant la matrice spectrale construite à l'aide des intercorrélations des différents enregistrements constituant les données à traiter. Les méthodes d'estimation de la matrice spectrale sont des méthodes de moyenne : moyenne en fréquence (méthode du périodogramme lissé et/ou moyenne en distance (lissage réalisé le long des diagonales de la matrice spectrale. Le lissage en fréquence est obtenu par l'intermédiaire d'une fonction de pondération (par exemple fenêtre de Hanning élevée à une puissance donnée appliquée à chaque corrélation. Les moyennes sont utilisées pour décorréler les signaux et de ce fait favoriser la séparation. Une fois correctement estimée, la matrice spectrale est diagonalisée sur toutes les fréquences du spectre moyenné, et décomposée selon ses vecteurs propres qui sont orthogonaux entre eux et normalisés. Chaque vecteur propre a une valeur propre associée qui représente la répartition d'énergie en fonction de la fréquence du modèle lié au vecteur propre. Le filtrage est réalisé par projection des données sur les différents vecteurs propres issus de la matrice spectrale. Il est à noter cependant que la séparation des différents signaux (projection sur vecteur propre n'est réalisée en terme d'indicatrice sismique que si les événements sismiques sont naturellement orthogonaux et alignés sur les vecteurs propres. Glangeaud et al (1989 ont étudié l'influence des amplitudes relatives et du produit scalaire de deux ondes. Si la vitesse apparente d'une onde est connue, cette derni

  19. Atmospheric methanol measurement using selective catalytic methanol to formaldehyde conversion

    Directory of Open Access Journals (Sweden)

    S. J. Solomon

    2005-05-01

    Full Text Available A novel atmospheric methanol measurement technique, employing selective gas-phase catalytic conversion of methanol to formaldehyde followed by detection of the formaldehyde product, has been developed and tested. The effects of temperature, gas flow rate, gas composition, reactor-bed length, and reactor-bed composition on the methanol conversion efficiency of a molybdenum-rich, iron-molybdate catalyst [Mo-Fe-O] were studied. Best results were achieved using a 1:4 mixture (w/w of the catalyst in quartz sand. Optimal methanol to formaldehyde conversion (>95% efficiency occurred at a catalyst housing temperature of 345°C and an estimated sample-air/catalyst contact time of <0.2 s. Potential interferences arising from conversion of methane and a number of common volatile organic compounds (VOC to formaldehyde were found to be negligible under most atmospheric conditions and catalyst housing temperatures. Using the new technique, atmospheric measurements of methanol were made at the University of Bremen campus from 1 to 15 July 2004. Methanol mixing ratios ranged from 1 to 5 ppb with distinct maxima at night. Formaldehyde mixing ratios, obtained in conjunction with methanol by periodically bypassing the catalytic converter, ranged from 0.2 to 1.6 ppb with maxima during midday. These results suggest that selective, catalytic methanol to formaldehyde conversion, coupled with existing formaldehyde measurement instrumentation, is an inexpensive and effective means for monitoring atmospheric methanol.

  20. Atmospheric methanol measurement using selective catalytic methanol to formaldehyde conversion

    Directory of Open Access Journals (Sweden)

    S. J. Solomon

    2005-01-01

    Full Text Available A novel atmospheric methanol measurement technique, employing selective gas-phase catalytic conversion of methanol to formaldehyde followed by detection of the formaldehyde product, has been developed and tested. The effects of temperature, gas flow rate, gas composition, reactor-bed length, and reactor-bed composition on the methanol conversion efficiency of a molybdenum-rich, iron-molybdate catalyst [Mo-Fe-O] were studied. Best results were achieved using a 1:4 mixture (w/w of the catalyst in quartz sand. Optimal methanol to formaldehyde conversion (>95% efficiency occurred at a catalyst housing temperature of 345°C and an estimated sample-air/catalyst contact time of <0.2 seconds. Potential interferences arising from conversion of methane and a number of common volatile organic compounds (VOC to formaldehyde were found to be negligible under most atmospheric conditions and catalyst housing temperatures. Using the new technique, atmospheric measurements of methanol were made at the University of Bremen campus from 1 to 15 July 2004. Methanol mixing ratios ranged from 1 to 5 ppb with distinct maxima at night. Formaldehyde mixing ratios, obtained in conjunction with methanol by periodically bypassing the catalytic converter, ranged from 0.2 to 1.6 ppb with maxima during midday. These results suggest that selective, catalytic methanol to formaldehyde conversion, coupled with existing formaldehyde measurement instrumentation, is an inexpensive and effective means for monitoring atmospheric methanol.

  1. Nanoscaled redox active protein adsorption on Au-dot arrays: An electrochemical scanning probe microscopic investigation for application in nano-biodevices

    Energy Technology Data Exchange (ETDEWEB)

    Yagati, Ajay Kumar; Jung, Mi; Kim, Sang-Uk [Interdisciplinary Program of Integrated Biotechnology, Sogang University, 1 Shinsu-dong, Mapo-gu, Seoul 121-742 (Korea, Republic of); Min, Junhong [College of Bionanotechnology, Kyungwon University, Bokjung-dong, Sujung-gu, Seongnam 461-701 (Korea, Republic of); Choi, Jeong-Woo, E-mail: jwchoi@sogang.ac.k [Interdisciplinary Program of Integrated Biotechnology, Sogang University, 1 Shinsu-dong, Mapo-gu, Seoul 121-742 (Korea, Republic of); Department of Chemical and Biomolecular Engineering, Interdisciplinary Program of Integrated Biotechnology Sogang University, 1 Shinsu-dong, Mapo-gu, Seoul 121-742 (Korea, Republic of)

    2009-11-30

    Highly dense and uniform protein dot arrays on Au-nanodots using size controllable method were fabricated on indium tin oxide (ITO) substrate in order to develop an electrochemical nanobiochip. Cysteine modified azurin was directly immobilized on the fabricated Au-nanodots without any linker materials. Atomic force microscopy was used for characterizing Au-dots formed on ITO substrate. Electrochemical scanning tunneling microscopy (ECSTM) revealed the monolayer formation with an in situ cyclic voltammetry to observe redox behaviour of both bare Au-dots and protein immobilized Au-dots. I-V characteristics were obtained on both bare Au-dots and protein immobilized Au-dots structured on ITO conductive electrodes.

  2. Repérage et typage d'expressions temporelles pour l'annotation sémantique automatique de pages Web - Application au e-tourisme

    OpenAIRE

    Weiser, Stéphanie

    2010-01-01

    Cette thèse présente Adetoa, système dédié au repérage et à l'annotation sémantique automatique d'expressions temporelles dans des pages Web pour une application de e-tourisme. Une étude linguistique détaillée a permis de mettre en avant les caractéristiques et la complexité de l'expression de la temporalité dans les pages Web touristiques. Une étude sémiotique de ce type de pages a montré que les données y étaient organisées de manière fort variée, ne présentant aucune régularité, ce qui ren...

  3. The Development of Conductive Elements for the Selective Detection of Formaldehyde and Cotinine

    Science.gov (United States)

    Antwi-Boampong, Sadik

    The development of new materials and techniques presents an opportunity to revisit old problems. Innovations in materials engineering revolutionize the status quo by expanding the tool kit needed to develop robust solutions to complex problems. Challenges that had hitherto been intractable become surmountable; previously established methods are significantly enhanced; fresh impetus is injected into the materials design engine. In one way or another, every scientist contributes to this dynamic creative process where ideas are incubated and developed through fundamental research that culminates in compelling findings applicable in various realms of science. The work presented herein embodies this ethos. Our investigations have applied the relatively nascent technology of molecular imprinting to develop sensing elements for detection of cotinine and formaldehyde. Additionally, we have used different polymer systems to address the inherent limitations of conventional materials using a simple, cost-effective and efficient materials approach. Specifically, in Part I, we investigate molecular imprinting of nylon-6, polyvinylphenol and ElvamideRTM, with cotinine. We examine the capacity of these materials as polymer hosts for molecular imprinting by studying the effect of cotinine imprinting on their nanomechanical properties. By monitoring variations in mechanical properties induced by cotinine templating, we determine the factors critical for effective imprinting and ultimately demonstrate that polyvinylphenol is the most suitable polymer host. Based on these results, we develop a cotinine-imprinted polyvinylphenol-single walled carbon nanotube sensor that readily detects cotinine. Using electrical, spectral and chromatographic characterization, we rigorously demonstrate the enhanced affinity programmed into the sensing layer via molecular imprinting. Part II is dedicated to a familiar problem: formaldehyde sensing. While this challenge has been a trope of the

  4. Formaldehyde Emission from Wood-Based Panels Bonded with Different Formaldehyde-Based Resins

    Directory of Open Access Journals (Sweden)

    Mohamed Salem

    2011-09-01

    Full Text Available In this study, the formaldehyde emission (FE from different types of particleboard, medium density fiberboard (MDF, and plywood products supplied from a commercial plant in the Czech Republic were evaluated by gas analysis (EN 717-2 and European small chamber (EN 717-1 methods. The significant effects of manufacturing variables (board type and thickness as well as different types of formaldehyde-based resins on FE measured by gas analysis were obtained. When the E1 type adhesives were employed, a wide variation in the quantity of free formaldehyde was observed among the three product types. The FE values of plywood samples measured by gas analysis were lower than those of the particleboard and MDF samples. The correlation between the two methods for the particleboard and MDF were good (R2 = 0.82 and 0.76, respectively and however for plywood (R2 = 0.52 it was not convincing. FE specifi ed in EN 717-2 was comparable with the EN 717-1 values for the same board type and thickness as well as the resin type and below the E1-emission class.

  5. Analysis of benzoyl-peroxide and formaldehyde as dental allergens by FT-SPR method

    International Nuclear Information System (INIS)

    In parallel with the appearance of new dental materials the number of induced allergic diseases increases. Based on this fact more sensitive detection of allergens is major importance. The Fourier-Transform Surface Plasmon Resonance (FT-SPR) is a sensitive, broadly applicable real-time method for analysing thin layers of materials on gold surfaces. FT-SPR measurement is performed at a fixed angel of incident light, and reflectivity is measured over a range of wavelength in the near infrared. In our study the formaldehyde and benzoyl-peroxide were examined as members of the most common dental allergens by FT-SPR spectroscopy. The aim of this work was the investigation of the suitability of this method for the direct detection of these materials. Different concentrations of formaldehyde and benzoyl-peroxide solutions were measured from this purpose. The individual spectra were measured for all of the solutions, and calibration curves were calculated for the materials for the possibility of the determination of an unknown concentration. In addition, series measurements were performed whereby the association and dissociation properties of formaldehyde or benzoyl-peroxide were described. The results of the experiments proved that the method capable to measure directly these materials and can provide appropriate calibration curves for determination of unknown concentrations

  6. Preparation and characterization of microencapsulated phase change material with low remnant formaldehyde content

    Energy Technology Data Exchange (ETDEWEB)

    Li Wei [Tianjin Municipal Key Lab of Fiber Modification and Functional Fibers, Institute of Functional Fibers, Tianjin Polytechnic University, Tianjin 300160 (China); Zhang Xingxiang [Tianjin Municipal Key Lab of Fiber Modification and Functional Fibers, Institute of Functional Fibers, Tianjin Polytechnic University, Tianjin 300160 (China)], E-mail: zhangpolyu@yahoo.com.cn; Wang Xuechen; Niu Jianjin [Tianjin Municipal Key Lab of Fiber Modification and Functional Fibers, Institute of Functional Fibers, Tianjin Polytechnic University, Tianjin 300160 (China)

    2007-12-15

    Microencapsulated phase change materials (MicroPCMs) were synthesized by in situ polymerization using melamine-formaldehyde (MF) resin as shell and n-octadecane as core. The employed MF prepolymer was prepared by incorporating formaldehyde once and melamine for three times. The effects of dropping rate of MF prepolymer on the surface morphology, dispersibility and thermal stability of the microcapsules were systematically investigated using scanning electronic microscopy (SEM), wide-angle X-ray diffraction (WAXD), differential scanning calorimetry (DSC) and thermogravimetry analysis (TG). The results show that, with the dropping rate of the MF prepolymer decreasing, the flocculation phenomenon of microcapsules decreases and the globular surface becomes smoother; and the thermal stability increases regularly. The average diameter of the microcapsules is about 2.2 {mu}m and the diameter distribution is narrow. The enthalpy of the microcapsules containing 59 wt% n-octadecane is 144 J g{sup -1}. In addition, the remnant formaldehyde content of the microcapsules is 68.6 mg kg{sup -1}, which is highly attractive for the application of MicroPCMs.

  7. IRIS Toxicological Review of Formaldehyde (Inhalation) (External Review Draft 2010)

    Science.gov (United States)

    UPDATE EPA is currently revising its Integrated Risk Information System (IRIS) assessment of formaldehyde to address the 2011 NAS peer review recommendations. This assessment addresses both noncancer and cancer human health effects that are relevant to assessing ...

  8. Enhanced Sensing Characteristics in MEMS-based Formaldehyde Gas Sensor

    CERN Document Server

    Wang, Yu-Hsiang; Lee, Chia-Yen; Ma, R -H; Chou, Po-Cheng

    2008-01-01

    This study has successfully demonstrated a novel self-heating formaldehyde gas sensor based on a thin film of NiO sensing layer. A new fabrication process has been developed in which the Pt micro heater and electrodes are deposited directly on the substrate and the NiO thin film is deposited above on the micro heater to serve as sensing layer. Pt electrodes are formed below the sensing layer to measure the electrical conductivity changes caused by formaldehyde oxidation at the oxide surface. Furthermore, the upper sensing layer and NiO/Al2O3 co-sputtering significantly increases the sensitivity of the gas sensor, improves its detection limit capability. The microfabricated formaldehyde gas sensor presented in this study is suitable not only for industrial process monitoring, but also for the detection of formaldehyde concentrations in buildings in order to safeguard human health.

  9. Formaldehyde Profiler Using Laser Induced Fluorescence Technique Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Formaldehyde (HCHO) is a key trace species that is of great interest to atmospheric scientists in NASA and other research institutions. In this SBIR project, we...

  10. Preparation of phenol formaldehyde resin from phenolated wood

    Institute of Scientific and Technical Information of China (English)

    LIGai-yun; QINTe-fu; TohmuraShin-ichiro; IkedaAtsushi

    2004-01-01

    The technique for preparing phenol formaldehyde resin from phenolated wood (PWF) and its characters were studied and analyzed. Poplar (Populus spp.) wood meal was liquefied by phenol in the presence of sulfuric acid as a catalyst. After the liquefied products were cooled, alkaline catalyst and formaldehyde were added. The mixture was kept at (60±2)℃ for lh and then was heated to (85±2)℃ for lh. The influence of molar ratio of formaldehyde to phenol (F/P) was investigated. The results showed when the molar ratio of formaldehyde to phenol was over 1.8, the PWF adhesives had high bond quality, bond durability and extremely low aldehydes emissions.

  11. Status of iodine in formaldehyde-preserved milk - revisited

    International Nuclear Information System (INIS)

    The results of an investigation into the effect of formaldehyde preservation of raw milk in view of the differences observed by Murthy (J. Dairy Sci.; 45:1066 (1962) and J. Dairy Sci.; 49:1190 (1966)) and Thomas (personal communication. (1976)) are reported. The use of the specific electrode method for iodine analysis of formaldehyde-preserved milk has also been investigated. It was found that the Thomas preservation technique for 4 litre milk samples for 131I analysis was acceptable, and an aliquot of the formaldehyde-preserved milk can be analyzed for total iodide concentration by the electrode method. Milk samples may also be preserved for stable iodide measurement (without iodide carrier addition) by addition of formaldehyde at 0.5 M concentration. (U.K.)

  12. Formaldehyde Profiler Using Laser Induced Fluorescence Technique Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Formaldehyde (HCHO) is of great interest to atmospheric scientists in NASA and other research institutions. In this SBIR project, we propose to build an airborne or...

  13. Formaldehyde Surface Distributions and Variability in the Mexico City Basin

    Science.gov (United States)

    Junkermann, W.; Mohr, C.; Steinbrecher, R.; Ruiz Suarez, L.

    2007-05-01

    Formaldehyde ambient air mole fractions were measured throughout the dry season in March at three different locations in the Mexico City basin. The continuously running instruments were operated at Tenago del Aire, a site located in the Chalco valley in the southern venting area of the basin, at the Intituto Mexicano del Petroleo (IMP) in the northern part of the city and about 30 km north of the city at the campus of the Universidad Tecnològica de Tecamac (UTTEC). The technique used is the Hantzsch technology with a time resolution of 2 minutes and a detection limit of 100 ppt. Daily maxima peaked at 35 ppb formaldehyde in the city and about 15 to 20 ppb at the other sites. During night formaldehyde levels dropped to about 5 ppb or less. It is evident that the observed spatial and temporal variability in near surface formaldehyde distributions is strongly affected by local and regional advection processes.

  14. Microbial urea-formaldehyde degradation involves a new enzyme, methylenediurease.

    Science.gov (United States)

    Jahns, T; Schepp, R; Siersdorfer, C; Kaltwasser, H

    1998-01-01

    The enzymic mechanism of metabolization of urea-formaldehyde condensation products (methyleneureas; MU) and the fate of the degradation products ammonium, urea and formaldehyde were studied in bacteria isolated from garden soil, which were able to use methyleneureas as the sole source of nitrogen for growth. An organism identified as Ochrobactrum anthropi completely degraded methylenediurea (MDU) and dimethylenetriurea (DMTU) to urea, ammonia, formaldehyde and carbon dioxide. An enzyme designated as methylenediurease (methylenediurea deiminase; MDUase) was responsible for the degradation of both MDU and DMTU as well as higher polymerized MU. Growth on MU as the nitrogen source specifically induced the synthesis of this enzyme, which seems to be located in the periplasm of the bacterium. Under these growth conditions, urease as well as NAD-specific formaldehyde and formiate dehydrogenase were expressed to high levels, efficiently using the products of MU degradation, and high-affinity transport systems for urea and ammonia were synthesized scavenging the environment for these products. PMID:10526991

  15. The effect of formaldehyde on the radiation sterilization of peat

    International Nuclear Information System (INIS)

    Sterilization of peat by combined effect of Co60- gamma-radiation and formaldehyde has been studied. The degree of sterilization has been determined by the method of count of microorganisms colonies grown on culture agar extracted from peat. It has been determined that with the increase of formaldehyde concentration in peat from 0 to 0.6%, sterilization dose decreases from 10 kGy to zero. The decrease in sterilization dose by 40% results in the same decrease in sterilization cost as in this case the cost of formaldehyde can be ignored in comparison with radiation cost. The given method is recommended for use to decrease the sterilization dose in objects where the effect of residual formaldehyde does not matter

  16. Strain distributions of confined Au/Ag and Ag/Au nanoparticles

    Institute of Scientific and Technical Information of China (English)

    黄红华; 章英; 刘晓山; 骆兴芳; 袁彩雷; 叶双莉

    2015-01-01

    The strain distributions of Au/Ag and Ag/Au nanoparticles confined in the Al2O3 matrix with different core sizes are investigated by using the finite element method, respectively. The simulation results clearly indicate that the compressive strains exerted on the Au/Ag and Ag/Au nanoparticles can be induced by the Al2O3 matrix. Moreover, it can be found that the strain gradient existing in a Au/Ag nanoparticle is much larger than that in a Ag/Au nanoparticle, which could be due to the larger Young’s modulus of Au than that of Ag. With the core size increasing, the strain gradient existing in the Au/Ag nanoparticle becomes larger, while the strain gradient existing in the Ag/Au nanoparticle keeps constant. These different strain distributions may have significant infl uences on the structures and morphologies of the Au/Ag and Ag/Au nanoparticles, leading to the different physical properties for potential applications.

  17. Contact allergy to formaldehyde. Diagnosis and clinical relevance.

    OpenAIRE

    Dubnika, Inese

    2014-01-01

    Preservatives are biologically active substances mainly used in water-based products to prevent the growth of microorganisms. Most people are exposed to them on a daily basis. Formaldehyde is one of the oldest and most commonly used preservatives. However, it is a well-known contact sensitiser in dermatitis patients. The aims of this work were: i) to investigate the prevalence of contact allergy to formaldehyde using the baseline patch test series; ii) to determine the optimal pat...

  18. Aging-associated excess formaldehyde leads to spatial memory deficits

    OpenAIRE

    Zhiqian Tong; Chanshuai Han; Wenhong Luo; Hui Li; Hongjun Luo; Min Qiang; Tao Su; Beibei Wu; Ying Liu; Xu Yang; You Wan; Dehua Cui; Rongqiao He

    2013-01-01

    Recent studies show that formaldehyde participates in DNA demethylation/methylation cycle. Emerging evidence identifies that neuronal activity induces global DNA demethylation and re-methylation; and DNA methylation is a critical step for memory formation. These data suggest that endogenous formaldehyde may intrinsically link learning-responsive DNA methylation status and memory formation. Here, we report that during spatial memory formation process, spatial training induces an initial global...

  19. Injection Seeded Laser for Formaldehyde Differential Fluorescence Lidar

    Science.gov (United States)

    Schwemmer, G.; Yakshin, M.; Prasad, C.; Hanisco, T.; Mylapore, A. R.; Hwang, I. H.; Lee, S.

    2016-06-01

    We describe the design and development of an injection seeded Nd:YVO4 laser for use in a differential fluorescence lidar for measuring atmospheric formaldehyde profiles. A high repetition rate Q-switched laser is modified to accept injection seed input to spectrally narrow and tune the output. The third harmonic output is used to excite formaldehyde (HCHO) fluorescence when tuned to a HCHO absorption line. Spectral confirmation is made with the use of a photoacoustic cell and grating spectrometer.

  20. Atmospheric methanol measurement using selective catalytic methanol to formaldehyde conversion

    OpenAIRE

    Solomon, S. J.; Custer, T.; G. Schade; Soares Dias, A. P.; J. Burrows

    2005-01-01

    A novel atmospheric methanol measurement technique, employing selective gas-phase catalytic conversion of methanol to formaldehyde followed by detection of the formaldehyde product, has been developed and tested. The effects of temperature, gas flow rate, gas composition, reactor-bed length, and reactor-bed composition on the methanol conversion efficiency of a molybdenum-rich, iron-molybdate catalyst [Mo-Fe-O] were studied. Best results were achieved using a 1:4 mixture (w/w) of the...

  1. Flow Injection Spectrophotometric Determination of Formaldehyde Using New Color Reaction

    OpenAIRE

    Murase Fernández, Sara Keiko

    2008-01-01

    Formaldehyde (HCHO) is the most common air pollutant of the aldehyde family. It is known to be a toxic and carcinogenic compound present in both residential indoor and industrial environments. Exposition to formaldehyde in higher concentrations (over 0,1 ppmv) can cause well-known effects as irritation of the eyes and upper respiratory tract, headache, nausea, difficulty in breathing, allergic skin reactions, among others. Rapid and reliable methods are still required for the d...

  2. Separation of long RNA by agarose-formaldehyde gel electrophoresis

    OpenAIRE

    Mansour, Farrah H.; Pestov, Dimitri G.

    2013-01-01

    We describe a method to facilitate electrophoretic separation of high molecular weight RNA species, such as ribosomal RNAs and their precursors, on agarose-formaldehyde gels. Two alternative “pK-matched” buffer systems were substituted for the traditionally used MOPS-based conductive media. The key advantages include shortened run times, a five-fold reduction in formaldehyde concentration, a significantly improved resolution of long RNAs, and consistency in separation. The new procedure has a...

  3. Formaldehyde and Glyoxal: New Products in the SCIAMACHY Operational Processor

    OpenAIRE

    Hrechanyy, Serhiy; De Smedt, Isabelle; Kretschel, Klaus; Lichtenberg, Günter; Meringer, Markus; Wittrock, Folkard

    2010-01-01

    In sommer of 2010 version 6 of the SCIAMACHY operational processor is planned to be delivered to ESA. The SCIAMACHY Quality Working Group recommended an implementation of the formaldehyde (HCHO) and glyoxal (CHOCHO) vertical columns into version 6 of the off-line processor. They are formed during the oxidation of volatile organic compounds (VOCs) emitted by plants, anthropogenic activities, and biomass burning. Due to a rather short lifetime of formaldehyde and glyoxal, their distribution...

  4. Au/Sn共晶键合技术在MEMS封装中的应用%Application of the Au/Sn Eutectic Bonding Technology in the Packaging of MEMS

    Institute of Scientific and Technical Information of China (English)

    胥超; 徐永青; 杨拥军; 杨志

    2014-01-01

    研究了Au/Sn共晶圆片键合技术在MEMS气密性封装中的应用.设计了共晶键合多层材料的结构和密封环图形,盖帽层采用Ti/Ni/Au/Sn/Au结构,器件层采用Ti/Ni/Au结构,盖帽层腔体尺寸为4.5mm×4.5 mm×20 μm,Au/Sn环的宽度为700 μm,优化了键合工艺,对影响气密性的因素(如组分配比、键合前处理和键合温度等)进行了分析.两层硅片在氮气气氛中靠静态的压力实现紧密接触.在峰值温度为300℃、持续时间为2 min的条件下实现了良好的键合效果,其剪切力平均值达到16.663 kg,漏率小于2×10-3 Pa·cm3/s,满足检验标准(GJB548A)的要求,验证了Au/Sn共晶键合技术在MEMS气密封装中的适用性.

  5. Formaldehyde-releasers in cosmetics : relationship to formaldehyde contact allergy Part 1. Characterization, frequency and relevance of sensitization, and frequency of use in cosmetics

    NARCIS (Netherlands)

    de Groot, Anton C.; White, Ian R.; Flyvholm, Mari-Ann; Lensen, Gerda; Coenraads, Pieter-Jan

    2010-01-01

    In this part of a series of review articles on formaldehyde-releasers and their relationship to formaldehyde contact allergy, formaldehyde-releasers in cosmetics are discussed. In this first part of the article, key data are presented including frequency of sensitization and of their use in cosmetic

  6. The Formaldehyde Masers in NGC 7538 and G29.96-0.02: VLBA, MERLIN, and VLA Observations

    CERN Document Server

    Hoffman, I M; Palmer, P; Richards, A M S; Hoffman, Ian M.; Palmer, Patrick

    2003-01-01

    The 6 cm formaldehyde (H2CO) maser sources in the compact HII regions NGC 7538-IRS1 and G29.96-0.02 have been imaged at high resolution (beams < 50 mas). Using the VLBA and MERLIN, we find the angular sizes of the NGC 7538 masers to be ~10 mas (30 AU) corresponding to brightness temperatures ~10^8 K. The angular sizes of the G29.96-0.02 masers are ~20 mas (130 AU) corresponding to brightness temperatures ~10^7 K. Using the VLA, we detect 2 cm formaldehyde absorption from the maser regions. We detect no emission in the 2 cm line, indicating the lack of a 2 cm maser and placing limits on the 6 cm excitation process. We find that both NGC 7538 maser components show an increase in intensity on 5-10 year timescales while the G29.96-0.02 masers show no variability over 2 years. A search for polarization provides 3-sigma upper limits of 1% circularly polarized and 10% linearly polarized emission in NGC 7538 and of 15% circularly polarized emission in G29.96-0.02. A pronounced velocity gradient of 28 km/s/arcsecon...

  7. Formaldehyde in dentistry: a review of mutagenic and carcinogenic potential

    Energy Technology Data Exchange (ETDEWEB)

    Lewis, B.B.; Chestner, S.B.

    1981-09-01

    For many years there has been controversy over the value of antimicrobial drugs for intracanal dressings in endodontics. Formocresol, a formaldehyde compound, has evolved as the preferred drug for routine endodontic procedures, as well as pediatric endodontics. The increase in the use of formaldehyde has been complicated by the introduction of paraformaldehyde pastes for filling root canals. Neither of these formulas has ever been standardized. The doses are arbitrary, and the common dose of formocresol has been shown to be many times greater than the minimum dose needed for effect. The efficacy of paraformaldehyde pastes is questionable and remains clouded by inconclusive evidence, conflicting research, inadequate terminology, and a lack of convincing statistical evidence. The clinical use and delivery of formocresol and paraformaldehyde pastes remain arbitrary and unscientific. Formaldehyde has a known toxic mutagenic and carcinogenic potential. Many investigations have been conducted to measure the risk of exposure to formaldehyde; it is clear that formaldehyde poses a carcinogenic risk in humans. There is a need to reevaluate the rationale underlying the use of formaldehyde in dentistry particularly in light of its deleterious effects.

  8. Electrogenerated Chemiluminescence Behavior of Au nanoparticles-hybridized Pb (II) metal-organic framework and its application in selective sensing hexavalent chromium

    OpenAIRE

    Hongmin Ma; Xiaojian Li; Tao Yan; Yan Li; Haiyang Liu; Yong Zhang; Dan Wu; Bin Du; Qin Wei

    2016-01-01

    In this work, a novel electrochemiluminescence (ECL) sensor based on Au nanoparticles-hybridized Pb (II)-β-cyclodextrin (Pb-β-CD) metal-organic framework for detecting hexavalent chromium (Cr(VI)) was developed. Pb-β-CD shows excellent ECL behavior and unexpected reducing ability towards Au ions. Au nanoparticles could massively form on the surface of Pb-β-CD (Au@Pb-β-CD) without use of any additional reducing agent. In the presence of coreactant K2S2O8, the ECL emission of Pb-β-CD was enhanc...

  9. Time evolution of relativistic d + Au and Au + Au collisions

    CERN Document Server

    Wolschin, G; Mizoguchi, T; Suzuki, N; Biyajima, Minoru; Mizoguchi, Takuya; Suzuki, Naomichi; Wolschin, Georg

    2006-01-01

    The evolution of charged-particle production in collisions of heavy ions at relativistic energies is investigated as function of centrality in a nonequilibrium-statistical framework. Precise agreement with recent d + Au and Au + Au data at sqrt(s_NN) = 200 GeV is found in a Relativistic Diffusion Model with three sources for particle production. Only the midrapidity source comes very close to local equilibrium, whereas the analyses of the overall pseudorapidity distributions show that the systems remain far from statistical equilibrium.

  10. Self-assembly of thiolated cyanine aggregates on Au(111) and Au nanoparticle surfaces

    Science.gov (United States)

    Menéndez, Guillermo O.; Cortés, Emiliano; Grumelli, Doris; Méndez de Leo, Lucila P.; Williams, Federico J.; Tognalli, Nicolás G.; Fainstein, Alejandro; Vela, María Elena; Jares-Erijman, Elizabeth A.; Salvarezza, Roberto C.

    2012-01-01

    Heptamethinecyanine J-aggregates display sharp, intense fluorescence emission making them attractive candidates for developing a variety of chem-bio-sensing applications. They have been immobilized on planar thiol-covered Au surfaces and thiol-capped Au nanoparticles by weak molecular interactions. In this work the self-assembly of novel thiolated cyanine (CNN) on Au(111) and citrate-capped AuNPs from solutions containing monomers and J-aggregates has been studied by using STM, XPS, PM-IRRAS, electrochemical techniques and Raman spectroscopy. Data show that CNN species adsorb on the Au surfaces by forming thiolate-Au bonds. We found that the J-aggregates are preferentially adsorbed on the Au(111) surface directly from the solution while adsorbed CNN monomers cannot organize into aggregates on the substrate surface. These results indicate that the CNN-Au interaction is not able to disorganize the large J-aggregates stabilized by π-π stacking to optimize the S-Au binding site but it is strong enough to hinder the π-π stacking when CNNs are chemisorbed as monomers. The optical properties of the J-aggregates remain active after adsorption. The possibility of covalently bonding CNN J-aggregates to Au planar surfaces and Au nanoparticles controlling the J-aggregate/Au distance opens a new path regarding their improved stability and the wide range of biological applications of both CNN and AuNP biocompatible systems.Heptamethinecyanine J-aggregates display sharp, intense fluorescence emission making them attractive candidates for developing a variety of chem-bio-sensing applications. They have been immobilized on planar thiol-covered Au surfaces and thiol-capped Au nanoparticles by weak molecular interactions. In this work the self-assembly of novel thiolated cyanine (CNN) on Au(111) and citrate-capped AuNPs from solutions containing monomers and J-aggregates has been studied by using STM, XPS, PM-IRRAS, electrochemical techniques and Raman spectroscopy. Data show

  11. First principles calculations of the optical and plasmonic response of Au alloys and intermetallic compounds.

    Science.gov (United States)

    Keast, V J; Barnett, R L; Cortie, M B

    2014-07-30

    Pure Au is widely used in plasmonic applications even though its use is compromised by significant losses due to damping. There are some elements that are less lossy than Au (e.g. Ag or Al) but they will normally oxidize or corrode under ambient conditions. Here we examine whether alloying Au with a second element would be beneficial for plasmonic applications. In order to evaluate potential alternatives to pure Au, the density of states (DOS), dielectric function and plasmon quality factor have been calculated for alloys and compounds of Au with Al, Cd, Mg, Pd, Pt, Sn, Ti, Zn and Zr. Substitutional alloying of Au with Al, Cd, Mg and Zn was found to slightly improve the plasmonic response. Of the large number of intermetallic compounds studied, only AuAl2, Au3Cd, AuMg, AuCd and AuZn were found to be suitable for plasmonic applications. PMID:25001413

  12. Transport de particules massives dans un fluide turbulent: Application a l'erosion due au sable sur les parois d'une turbine hydraulique

    Science.gov (United States)

    Bergeron, Stephen

    Le transport de particules massives par un champ turbulent est un vaste domaine de la mécanique des fluides. Il possède de nombreuses applications comme par exemple le transport de sable dans une turbine hydraulique. En raison de la dureté des grains de quartz et des grandes vitesses de collision avec les parois métalliques, un phénomène d'érosion intensif se produit. Les dommages résultants peuvent diminuer le rendement de la turbine au cours des quelques mois suivant la mise en opération. L'objectif de cette thèse est de mettre au point un outil permettant de prédire ces zones d'érosion. Ce projet de recherche en contexte industriel a été réalisé en collaboration avec la compagnie General Electric Hydro du Canada. Dans un régime hautement turbulent, il est possible d'obtenir une expression suffisamment générale en utilisant une formulation partiellement empirique: l'équation de Basset- Boussinesq-Oseen modifiée. Ce choix de modèle tient compte du niveau de précision recherché et de la méthode numérique employée afin de résoudre la phase fluide. Il permet aussi d'éliminer plusieurs ambiguïtés fréquemment rencontrées dans la littérature et implementées dans certains codes commerciaux courants. La formulation mathématique du problème est effectuée dans un espace mixte Euler-Lagrange. Les paramètres dynamiques sont relies au type de particules et à l'intensité de la turbulence. Le code numérique résultant est le plus performant développé à ce jour (août 1998). Les trajectoires de plusieurs centaines de milliers de particules peuvent être simulées et visualisées de manière interactive sur une station de travail (SGI R4K, R8K et R10K). L'utilisateur du logiciel est libre de se déplacer dans l'espace à l'aide d'un environnement similaire a un ``simulateur de vol''. Il peut ainsi analyser les détails du processus d'érosion de même que l'écoulement du fluide dans la turbine. Les zones d'érosion obtenues à l

  13. Ethylated Urea - Ether - Modified Urea - Formaldehyde Resins,

    Directory of Open Access Journals (Sweden)

    Mathew Obichukwu EDOGA

    2006-07-01

    Full Text Available First, phenol - formaldehyde (PF and urea - formaldehyde (UFII resins were separately conventionally prepared in our laboratory. Also, UF resin synthesized from the acid modified synthesis procedure was synthesized in a purely acid medium of pH 1.0, FU molar ratio of 1.0 and at 50oC (one-stage acid modified-synthesis procedure. Subsequently, the UF resin II was modified during synthesis by incorporating ethylated urea-ether (EUER (i.e. UFIII and glycerol (GLYC (i.e. UFV cured with and without acid curing agent. The structural and physicochemical analyses of the various resin samples were carried out.The results showed that the unmodified UF resin (UF II synthesized in acid medium of pH 1.0, F/U molar ratio 1.0, and at 50oC, cured in absence of acid curing catalyst, showed features in their spectra which are consistent with a tri-, and/or tetra-substituted urea in the reaction to give a 3 - dimensional network cured UF resin. Modification of the UF resin(UF II with ethylated urea-ether and glycerol to produce UF resins III and respectively V prominently increased the absorbance of methylene and ether groups in the spectra which are consistent with increased hydrophobicity and improved hydrolytic stability. For the conventional UF resin (UF I, the only clear distinction between spectra for the UF resin II and UF resins (III/V is the presence of diminished peaks for methylene groups at 2.2 ppm. The relationship between the logarithmic viscosity of cured PF resin with time showed continuos dependence of viscosity with time during cure up to 70 minutes. Similar trends were shown by UF resins (III/V, cured in absence of acid catalyst. In contrast, the conventional UF resins I and UF IV (i.e. UF II cured with NH4CL showed abrupt discontinuity in viscosity with time just after about 20 minutes of cure.

  14. Effect of formaldehyde inactivation on poliovirus.

    Science.gov (United States)

    Wilton, Thomas; Dunn, Glynis; Eastwood, David; Minor, Philip D; Martin, Javier

    2014-10-01

    Inactivated polio vaccines, which have been used in many countries for more than 50 years, are produced by treating live poliovirus (PV) with formaldehyde. However, the molecular mechanisms underlying virus inactivation are not well understood. Infection by PV is initiated by virus binding to specific cell receptors, which results in viral particles undergoing sequential conformational changes that generate altered structural forms (135S and 80S particles) and leads to virus cell entry. We have analyzed the ability of inactivated PV to bind to the human poliovirus receptor (hPVR) using various techniques such as ultracentrifugation, fluorescence-activated cell sorting flow cytometry and real-time reverse transcription-PCR (RT-PCR). The results showed that although retaining the ability to bind to hPVR, inactivated PV bound less efficiently in comparison to live PV. We also found that inactivated PV showed resistance to structural conversion in vitro, as judged by measuring changes in antigenicity, the ability to bind to hPVR, and viral RNA release at high temperature. Furthermore, viral RNA from inactivated PV was shown to be modified, since cDNA yields obtained by RT-PCR amplification were severely reduced and no infectious virus was recovered after RNA transfection into susceptible cells. Importance: This study represents a novel insight into the molecular mechanisms responsible for poliovirus inactivation. We show that inactivation with formaldehyde has an effect on early steps of viral replication as it reduces the ability of PV to bind to hPVR, decreases the sensitivity of PV to convert to 135S particles, and abolishes the infectivity of its viral RNA. These changes are likely responsible for the loss of infectivity shown by PV following inactivation. Techniques used in this study represent new approaches for the characterization of inactivated PV products and could be useful in developing improved methods for the production and quality control testing of

  15. Fabrication of macroporous Pt and PtAu electrodes for electrochemical application through galvanic replacement at macroporous Cu electrode electrodeposited at polystyrene template from room temperature ionic liquid

    International Nuclear Information System (INIS)

    Highlights: ► Macroporous Pt and PtAu electrodes were prepared through galvanic replacement. ► Galvanic replacement occurred at macroporous Cu electrodes in aqueous solutions. ► Macroporous Cu electrodes were electrodeposited from ionic liquid at PS template. ► Surfactant played an important role on the formation of macroporous structures. ► Macroporous PtAu revealed good electrocatalytic activity to ethanol oxidation. -- Abstract: Macroporous Pt and PtAu electrodes (MP-Pt and MP-PtAu) were prepared through galvanic replacement at macroporous Cu electrodes, which were formed by electrodeposition of Cu at Au-coated indium tin oxide (Au/ITO) electrodes covered with ordered arrays of polystyrene (PS) nanospheres (PS/Au/ITO) in N-butyl-N-methylpyrrolidinium dicyanamide room temperature ionic liquid (BMP-DCA RTIL). After dissolving the PS templates in tetrahydrofuran (THF), macroporous Cu electrodes (MP-Cu/Au/ITO; denoted as MP-Cu hereafter) were obtained. The surface of a MP-Cu was spontaneously replaced by Pt or Pt/Au when a MP-Cu was immersed in an aqueous solution containing H2PtCl6 or H2PtCl6/HAuCl4 to form the MP-Pt (actually, MP-Pt/Cu/Au/ITO) or MP-PtAu electrodes. The atomic ratios of Au in PtAu could be adjusted by changing the concentration of HAuCl4 in the mixtures of H2PtCl6/HAuCl4. The electrodeposition potential, the time of replacement reaction, the concentrations of H2PtCl6 and HAuCl4, and the content of surfactant, which influence the structure of macroporous electrodes, were investigated. The surface morphologies of these macroporous electrodes were characterized with scanning electron microscope (SEM). MP-PtAu electrodes showed the better performance than the MP-Pt electrodes on the electrocatalytic oxidation of ethanol in alkaline solutions

  16. Méthode de vieillissement accéléré au dioxyde de chlore : application au polyamide 66 non stabilisé et non chargé

    OpenAIRE

    Dauseins, J.; El Mazry, Chaker; Mallet, J; Colin, Xavier; CORREC, Olivier

    2014-01-01

    Dans l'objectif d'étudier à long terme des accessoires utilisés dans les réseaux intérieurs d'eau, le Centre scientifique et technique du bâtiment (CSTB) a mis au point un banc d'essai de vieillissement accéléré au dioxyde de chlore sur sa plateforme expérimentale Aquasim. Les premières études réalisées avec le banc montrent que ce désinfectant de l'eau potable attaque aussi les matériaux polymères. Initialement utilisé pour détruire les micro-organismes, il n'est pas totalement sélectif puis...

  17. Contribution à l'élaboration d'un guide de bonnes pratiques de la gestion des ressources humaines au sein des structures vétérinaires : application au personnel non vétérinaire

    OpenAIRE

    Debeaupuits, Julien

    2014-01-01

    La réussite d'un vétérinaire ne passe plus seulement par ses compétences scientifiques, il doit aussi gérer ses capitaux, son personnel, ...Le vétérinaire est un véritable entrepreneur. Le nombre de salariés non vétérinaires au sein des structures vétérinaires augmente au fil des années. De nombreuses études démontrent l'importance d'une bonne gestion des ressources humaines. Même si ces notions sont parmi les plus dificiles à gérer pour le clinicien, la réussite de cette partie du management...

  18. Indoor air quality: radon and formaldehyde

    International Nuclear Information System (INIS)

    The WHO Regional Office for Europe has taken a leading role at the international level in reviewing and stimulating research and action on the potential health hazards of indoor air pollutants. A subject is given on page vi. It is now much more generally recognized than even five years ago that the use of particular materials for construction of buildings or for furniture and fittings is accompanied by certain risks, especially in view of the ''tightening'' of buildings to reduce energy costs, and increased reliance on central heating and air conditioning. For the last three years, the Regional Office, with the support of the Government of the Netherlands, has been developing a set of air quality guidelines for Europe. In addition to major air pollutants such as sulfur dioxide and particulates, these guidelines cover some 25 other inorganic and organic substances, including radon and formaldehyde. In 1985, a working group reviewed the latter two substances in relation to the ongoing indoor air quality programme of the Regional Office and also as part of the air quality guidelines. In view of the importance of these substances, it was decided to issue a separate report in the Environmental Health Series. The complete air quality guidelines will be published in mid-1987. (author)

  19. Exposure to formaldehyde: a challenge of occupational health significance

    International Nuclear Information System (INIS)

    The use of formaldehyde as the fixative for general microscopic demonstration of tissues in medical laboratory establishments is as significant as the diagnosis of the underlying ailment. Instantaneous human exposure to formaldehyde elicits symptoms that may include watery eyes, headache, inflamed throat and dyspnea. The gaseous chemical is toxic, allergenic and carcinogenic. A study to determine the incidence of human exposure to formaldehyde was carried out at the University Teaching Hospital in Lusaka, Zambia from January to December, 2007. Anonymous questionnaires on various aspects of human exposure to formaldehyde were given to laboratory technical personnel. Exposure to formaldehyde was determined using general consideration model comprising points awarded to participants according to their responses. Five points represented the maximum level of exposure, while one point denoted the minimum encounter. There were 8 incidents of formaldehyde pollution, with five being emissions from 210-litre formalin receptacles whose stoppers were inadvertently left loose overnight, while three involved accidental breakage of Winchester bottles of formalin. A total of 115 people were exposed during the year. Fifteen (13.0 percent) participants scored one point each, while 20 (17.4 percent) participants obtained 2 points each. Thirty-five (30.4 percent) participants got 3 points each, while 30 (26.0 percent) participants received 4 points each. Twenty-five (21.7 percent) participants attained 5 points each. Human exposure to formaldehyde is an issue of occupational health concern. Participants with a score of 3 points or more need regular medical check ups in order to safeguard their health. Programs on effective management of hazardous chemicals are worth setting up.(author)

  20. A comparative study of Ge/Au/Ni/Au-based ohmic contact on graphene

    International Nuclear Information System (INIS)

    Superior graphene—metal contacts can improve the performance of graphene devices. We report on an experimental demonstration of Ge/Au/Ni/Au-based ohmic contact on graphene. The transfer length method (TLM) is adopted to measure the resistivity of graphene-metal contacts. We designed a process flow, which can avoid residual photoresist at the interface of metal and graphene. Additionally, rapid thermal annealing (RTA) at different temperatures as a post-processing method is studied to improve graphene—metal contact. The results reveal that the contact resistivity of graphene and Ge/Au/Ni/Au can reach 10−5 Ω·cm2 after RTA, and that 350 °C is optimum annealing temperature for the contact of graphene—Ge/Au/Ni/Au. This paper provides guidance for fabrication and applications of graphene devices. (semiconductor technology)

  1. Synthesis and characterization of Au-alumina nanocomposites prepared by atom beam co-sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Tiwari, Manisha; Annapoorni, S. [Department of Physics and Astrophysics, University of Delhi, Delhi 110007 (India); Agarwal, D.C.; Avasthi, D.K. [Inter University Accelerator Centre, P.O. Box 10502, New Delhi 110067 (India); Mohapatra, S. [School of Basic and Applied Sciences, Guru Gobind Singh Indraprastha University, Dwarka, New Delhi 110075 (India); Pivin, J.C. [CSNSM, IN2P3-CNRS, Batiment 108, 1405 Orsay Campus (France)

    2012-12-15

    Nanocomposite thin films of Au-alumina with varying Au contents were synthesized by atom beam co-sputtering. The Au content and the thickness of nanocomposite films were determined by Rutherford backscattering spectrometry. Transmission electron microscopy studies reveal the presence of Au nanoparticles with bimodal size distribution in nanocomposites for lower Au content. Overlapping Au nanoparticles were observed for higher Au content. The increase in size of Au nanocrystals is observed with increase in Au concentration as also evident by glancing angle X-ray diffraction studies. Ultraviolet (UV)-visible absorption studies revealed surface plasmon resonance (SPR) peak which showed a red shift from 519 to 602 nm with increasing Au content of the nanocomposites. Preliminary study exploring the interaction between Au nanoparticles in the nanocomposites and bovine serum albumin (BSA) showed the Au nanoparticles to be BSA sensitive, indicating their possible applications in biosensors. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  2. Advanced Catalysts for the Ambient Temperature Oxidation of Carbon Monoxide and Formaldehyde

    Science.gov (United States)

    Nalette, Tim; Eldridge, Christopher; Yu, Ping; Alpetkin, Gokhan; Graf, John

    2010-01-01

    The primary applications for ambient temperature carbon monoxide (CO) oxidation catalysts include emergency breathing masks and confined volume life support systems, such as those employed on the Shuttle. While Hopcalite is typically used in emergency breathing masks for terrestrial applications, in the 1970s, NASA selected a 2% platinum (Pt) on carbon for use on the Shuttle since it is more active and also more tolerant to water vapor. In the last 10-15 years there have been significant advances in ambient temperature CO oxidation catalysts. Langley Research Center developed a monolithic catalyst for ambient temperature CO oxidation operating under stoichiometric conditions for closed loop carbon dioxide (CO2) laser applications which is also advertised as having the potential to oxidize formaldehyde (HCHO) at ambient temperatures. In the last decade it has been discovered that appropriate sized nano-particles of gold are highly active for CO oxidation, even at sub-ambient temperatures, and as a result there has been a wealth of data reported in the literature relating to ambient/low temperature CO oxidation. In the shorter term missions where CO concentrations are typically controlled via ambient temperature oxidation catalysts, formaldehyde is also a contaminant of concern, and requires specially treated carbons such as Calgon Formasorb as untreated activated carbon has effectively no HCHO capacity. This paper examines the activity of some of the newer ambient temperature CO and formaldehyde (HCHO) oxidation catalysts, and measures the performance of the catalysts relative to the NASA baseline Ambient Temperature Catalytic Oxidizer (ATCO) catalyst at conditions of interest for closed loop trace contaminant control systems.

  3. Modelisation et commande des redresseurs triphases fonctionnant a haut rendement et a faible taux de distorsion harmonique: Application au redresseur triphase de vienne

    Science.gov (United States)

    Belhadj Youssef, Nesrine

    Les problemes de la qualite de l'onde electrique constituent l'une des preoccupations majeures des fournisseurs de l'energie et des organismes specialises en qualite d'energie. Ce sujet a gagne davantage d'ampleur avec l'utilisation ascendante des convertisseurs de l'energie electrique dans la majorite des applications industrielles et domestiques. Dans le cadre de cette these, on s'interesse plus particulierement au type des convertisseurs alternatif/continu, dont le fonctionnement adequat implique la parfaite regulation du bus DC de tension, l'attenuation des harmoniques de courants, la compensation de l'energie reactive et la maximisation du rendement energetique. Ces differents criteres doivent etre maintenus pour diverses conditions de fonctionnement, c'est-a-dire independamment des variations parametriques auxquelles le systeme peut etre sujet. Il s'avere donc indispensable d'adopter des techniques de commande efficaces, ce qui passe par une modelisation correcte du convertisseur. L'optimisation du nombre de capteurs dans le circuit est egalement un facteur cle a prendre en consideration.

  4. CONCEPTION-ET-MODELISATION-D’UN-MICROLEVIER-PIEZORESISTI- APPLICATION-AU-MICROSCOPE-A-FORCE-ATOMIQUE-inistère

    OpenAIRE

    MEDJAHDI, Nadjia

    2014-01-01

    Dans le cadre de ce mémoire, nous avons modélisé le comportement du microlevier piézorésistif, nous avons étudié une de ces applications : c’est le microscope à force atomique. Enfin, nous nous sommes attachés à concevoir un microlevier piézorésistif pouvant servir de produit consommable pour l’AFM. Dans le premier chapitre, nous avons rappelé quelques notions de base sur les microsystèmes. Nous avons aussi donné les principaux types de microsystèmes à savoir les microcapteu...

  5. Comparison of ozone and formaldehyde as poultry hatchery disinfectants.

    Science.gov (United States)

    Whistler, P E; Sheldon, B W

    1989-10-01

    Ozone and formaldehyde were compared as poultry hatchery disinfectants in a poultry setter, and evaluated for effectiveness. Escherichia coli, Pseudomonas fluorescens, Salmonella typhimurium, and Proteus spp. were inoculated onto open petri plates and exposed to ozone or onto filter paper strips and exposed to ozone or formaldehyde in a poultry setter. Ozone (1.41 to 1.68% by weight) resulted in significant bacterial reductions of greater than 4 log10 on the open plates and greater than 3 log10 on filter paper strips, whereas formaldehyde (triple strength) resulted in greater than 7 log10 reduction on filter paper strips. Ozone was similarly lethal to organisms on filter paper strips at 90% relative humidity (RH) and 13.9 C, and at 50% RH and 37.7 C. Although under the conditions of this study formaldehyde (triple strength) was more lethal than ozone, ozone killed greater than 99.9% of the starting microbial populations. In the event that formaldehyde can no longer be used in the hatchery, an effective alternative may be ozone. PMID:2511564

  6. Formaldehyde as a basis for residential ventilation rates

    Energy Technology Data Exchange (ETDEWEB)

    Sherman, M.H.; Hodgson, A.T.

    2002-04-28

    Traditionally, houses in the U.S. have been ventilated by passive infiltration in combination with active window opening. However in recent years, the construction quality of residential building envelopes has been improved to reduce infiltration, and the use of windows for ventilation also may have decreased due to a number of factors. Thus, there has been increased interest in engineered ventilation systems for residences. The amount of ventilation provided by an engineered system should be set to protect occupants from unhealthy or objectionable exposures to indoor pollutants, while minimizing energy costs for conditioning incoming air. Determining the correct ventilation rate is a complex task, as there are numerous pollutants of potential concern, each having poorly characterized emission rates, and poorly defined acceptable levels of exposure. One ubiquitous pollutant in residences is formaldehyde. The sources of formaldehyde in new houses are reasonably understood, and there is a large body of literature on human health effects. This report examines the use of formaldehyde as a means of determining ventilation rates and uses existing data on emission rates of formaldehyde in new houses to derive recommended levels. Based on current, widely accepted concentration guidelines for formaldehyde, the minimum and guideline ventilation rates for most new houses are 0.28 and 0.5 air changes per hour, respectively.

  7. System for dosing formaldehyde vapor at the ppb level

    International Nuclear Information System (INIS)

    Formaldehyde is one of the most relevant compounds for indoor air pollution. It is toxic, allergenic and carcinogenic and acts already at the ppb level. State-of-the-art detection methods are based on the wet chemical analysis of formaldehyde derivates. This is a complex and time-consuming approach and hinders the collection of real-time data. However, the use of wet chemistry allows for the simple calibration based on formalin solutions. By using gas sensors, online monitoring of indoor air quality is, in principle, possible. To find out whether their performance is good enough, calibration is the first issue to be resolved. Formaldehyde vapor at low concentrations has to be used, and temperature, humidity and flow rate have to be kept constant. This paper discusses the different possibilities of dosing formaldehyde and how to better meet the gas sensor calibration demands. The authors favor the use of an aqueous formaldehyde solution obtained by the depolymerization of paraformaldehyde in combination with a permeation tube used as external reference. Moreover, in the paper it is demonstrated that metal oxide sensors are appropriate detectors to calibrate the system for concentrations even down to 20 ppb. Consequently, the presented system is able to characterize gas sensors and can be used for the development of new devices which monitor indoor air quality

  8. Doppler-Free Spectroscopy of Weak Transitions: An Analytical Model Applied to Formaldehyde

    CERN Document Server

    Zeppenfeld, M; Pinkse, P W H; Rempe, G

    2007-01-01

    Experimental observation of Doppler-free signals for weak transitions can be greatly facilitated by an estimate for the expected amplitude of the signal. We derive an analytical model which allows the Doppler-free signal amplitude to be estimated for small Doppler-free signals. Application of this model to formaldehyde allows the amplitude of experimentally observed Doppler-free signals to be reproduced to within a factor of two and the relative amplitude of different lines to be reproduced to within a few percent.

  9. Preparation of Au Nanoparticles Immobilized Cross-Linked Poly(4-vinylpyridine) Nanofibers and Their Catalytic Application for the Reduction of 4-Nitrophenol.

    Science.gov (United States)

    Qin, Qi-Hu; Na, Hui; Zhang, Chunyu; Yu, Qizhou; Zhang, Xue-Quan; Zhang, He-Xin

    2015-05-01

    Catalytic nanofibers are prepared by the immobilization of Au nanoparticles (AuNPs) onto the surface of cross-linked electrospun poly(4-vinylpyridine) (P4VP) nanofibers. The crosslinking of the P4VP nanofibers by 1,4-diiodobutane via quaternization reaction greatly enhances the stability of the nanofibers against the solvent dissolution, which can then be used as promising platform for the immobilization of catalytic metal nanoparticles. The AuNPs immobilized cross-linked P4VP nanofibers have shown a good catalytic activity for the reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP). PMID:26505022

  10. Au-Loaded Titanium Dioxide Nanoparticles Synthesized by Modified Sol-Gel/Impregnation Methods and Their Application to Dye-Sensitized Solar Cells

    OpenAIRE

    Hathaithip Ninsonti; Weerasak Chomkitichai; Akira Baba; Natda Wetchakun; Wiyong Kangwansupamonkon; Sukon Phanichphant; Kazunari Shinbo; Keizo Kato; Futao Kaneko

    2014-01-01

    Au-loaded TiO2 nanoparticles were synthesized by the modified sol-gel method together with the impregnation method. Anatase phase of TiO2 was obtained in all samples with an average particle size of 20 nm. For the enhancement of DSSCs, the dye-sensitized solar cells composed of the ITO/Au-loaded TiO2/N-719/electrolyte/Pt were fabricated. Au-loaded TiO2 films were deposited by using squeegee method. Finally, the fabricated cells were studied upon an irradiation of solar light to study the perf...

  11. Facile synthesis and intraparticle self-catalytic oxidation of dextran-coated hollow Au-Ag nanoshell and its application for chemo-thermotherapy.

    Science.gov (United States)

    Jang, Hongje; Kim, Young-Kwan; Huh, Hyun; Min, Dal-Hee

    2014-01-28

    Galvanic replacement reaction is a useful method to prepare various hollow nanostructures. We developed fast and facile preparation of biocompatible and structurally robust hollow Au-Ag nanostructures by using dextran-coated Ag nanoparticles. Oxidation of the surface dextran alcohols was enabled by catalytic activity of the core Au-Ag nanostructure, introducing carbonyl groups that are useful for further bioconjugation. Subsequent doxorubicin (Dox) conjugation via Schiff base formation was achieved, giving high payload of approximately 35 000 Dox per particle. Near-infrared-mediated photothermal conversion showed high efficacy of the Dox-loaded Au-Ag nanoshell as a combinational chemo-thermotherapy to treat cancer cells. PMID:24383549

  12. Détection d'intrusions comportementale par diversification de COTS : application au cas des serveurs web

    OpenAIRE

    Majorczyk, Frédéric

    2008-01-01

    version non-définitive de la thèse, présentée lors de la soutenance. L'informatique et en particulier l'Internet jouent un rôle grandissant dans notre société. Un grand nombre d'applications critiques d'un point de vue de leur sécurité sont déployées dans divers domaines comme le domaine militaire, la santé, le commerce électronique, etc. La sécurité des systèmes informatiques devient alors une problématique essentielle tant pour les individus que pour les entreprises ou les états. Il est ...

  13. Plasmid-mediated formaldehyde resistance in Escherichia coli: characterization of resistance gene.

    OpenAIRE

    Kümmerle, N; Feucht, H H; Kaulfers, P M

    1996-01-01

    The formaldehyde resistance mechanisms in the formaldehyde-resistant strain Escherichia coli VU3695 were investigated. A large (4.6-kb) plasmid DNA fragment encompassing the formaldehyde resistance gene was sequenced. A single 1,107-bp open reading frame encoding a glutathione- and NAD-dependent formaldehyde dehydrogenase was identified and sequenced, and the enzyme was expressed in an in vitro assay and purified. Amino acid sequence homology studies showed 62.4 to 63.2% identity with class I...

  14. Formaldehyde treatment of proteins can constrain presentation to T cells by limiting antigen processing.

    OpenAIRE

    Di Tommaso, A; De Magistris, M T; Bugnoli, M.; Marsili, I; Rappuoli, R; Abrignani, S.

    1994-01-01

    Proteins to be used as vaccines are frequently treated with formaldehyde, although little is known about the effects of this treatment on protein antigenicity. To investigate the effect of formaldehyde treatment on antigen recognition by T cells, we compared the in vitro T-cell response to proteins that have been formaldehyde treated with the response to untreated proteins. We found that peripheral blood mononuclear cells from individuals vaccinated with three formaldehyde-treated proteins (p...

  15. Relationship between formaldehyde and quaternium-15 contact allergy. Influence of strength of patch test reactions

    OpenAIRE

    de Groot, Anton C.; Blok, Janine; Coenraads, Pieter-Jan

    2010-01-01

    Objectives: To test our hypothesis that patients with stronger patch test reactions to formaldehyde are more likely to react to quaternium-15, attesting to the aetiological role for formaldehyde in such co-reactivity. Methods: Retrospective analysis of all patients patch tested with formaldehyde and quaternium-15 in the European baseline series between 1994 and 2009 (TRUE test (R)). Results: In a group of 86 patients allergic to formaldehyde, 73% co-reacted to quaternium-15; in the subgroup o...

  16. Formaldehyde-Induced Genome Instability is Suppressed by an XPF-dependent Pathway

    OpenAIRE

    Kumari, Anuradha; Lim, Yun Xin; Newell, Amy Hanlon; Olson, Susan B; McCullough, Amanda K.

    2011-01-01

    Formaldehyde is a reactive chemical that is commonly used in the production of industrial, laboratory, household, and cosmetic products. The causal association between formaldehyde exposure and increased incidence of cancer led the International Agency for Research on Cancer to classify formaldehyde as a carcinogen. Formaldehyde-induced DNA-protein crosslinks (DPCs) elicit responses involving nucleotide excision repair (NER) and homologous recombination (HR) repair pathways; however, little i...

  17. Reduction of formaldehyde concentrations in the air and cadaveric tissues by ammonium carbonate

    OpenAIRE

    Kawamata, Seiichi; Kodera, Haruo

    2004-01-01

    The reduction of formaldehyde by ammonium carbonate was examined in cadavers and in vitro. Formaldehyde concentrations in the air (10 cm above human cadavers) and in various cadaveric tissues were measured with or without perfusion of ammonium carbonate solution into formaldehyde-fixed cadavers. Air samples were monitored using Kitagawa gas detector tubes. For measurement of formaldehyde in tissues, muscles and organs were cut into small pieces and tissue fluids were separated out by centrifu...

  18. Degradation of Residual Formaldehyde in Fabric by Photo-catalysis

    Institute of Scientific and Technical Information of China (English)

    YAO Yadong; GUO Xiangli; KANG Yunqing; LI Xieji; CHEN Aizheng; YANG Weizhong; YIN Guangfu

    2008-01-01

    The residual formaldehyde (HCHO) in fabric was degraded using photo-catalysis assisted by the compound catalyst of nano-TiO2 and nano-ZnO. The effects of several factors on the degradation,such as the composing of catalyst, irradiation time, pH value and the H2CHO concentration of the immersed solution were investigated. Results showed that H2CHO of the immersed solution had degraded 93% after 5 h irradiation, and the degradation ratio of formaldehyde could be improved and the aging of the fabric can be avoided with the addition of ZnO nanoparticles and pH value of the immersed-fibric solution. The fabric with residual formaldehyde about 1 800 μg/g can be efficiently treated to satisfy the China National Standard(GB/2912.1-1998) with the photo-catalytic degradation.

  19. The distribution of deuterated formaldehyde within Orion-KL

    CERN Document Server

    Favre, Cecile; Neill, Justin; Crockett, Nathan; Zhang, Qizhou; Lis, Dariusz

    2015-01-01

    We report the first high angular resolution imaging (3.4\\arcsec $\\times$ 3.0\\arcsec) of deuterated formaldehyde (HDCO) toward Orion--KL, carried out with the Submillimeter Array (SMA). We find that the spatial distribution of the formaldehyde emission systematically differs from that of methanol: while methanol is found towards the inner part of the region, HDCO is found in colder gas that wraps around the methanol emission on four sides. The HDCO/H$_2$CO ratios are determined to be 0.003--0.009 within the region, up to an order of magnitude higher than the D/H measured for methanol. These findings strengthen the previously suggested hypothesis that there are differences in the chemical pathways leading to HDCO (via deuterated gas phase chemistry) and deuterated methanol (through conversion of formaldehyde into methanol on the surface of icy grain mantles).

  20. Formulation of lignin phenol formaldehyde resins as a wood adhesive

    International Nuclear Information System (INIS)

    This work describes the potential of reducing phenol with lignin in phenol formaldehyde resin formulation. The physical and chemical properties between lignin phenol formaldehyde resin (LPF) and commercial phenol formaldehyde resin (CPF) were compared. Phenol had been replaced by lignin [that was extracted from black liquor of oil palm empty fruit bunch (EFB)] in synthesizing resin with a ratio lignin to phenol 1:1. The IR spectra showed that there were similarities in functional groups between LPF resin and CPF resin. The comparison of physical strength properties via tensile strength test between LPF resin and CPF resin showed that the newly formulated resin has higher bonding strength compared to commercial resin. Kinematics viscosity test showed that LPF resin has lower kinematics viscosity compared to CPF resin in 21 days storage time. SEM images for both resin showed similarities in the effect of resin penetration into woods vessel existed. (author)

  1. Microencapsulation of a fatty acid with Poly(melamine–urea–formaldehyde)

    International Nuclear Information System (INIS)

    Highlights: • Decanoic(capric) acid microcapsules were prepared with different capsule wall materials. • The one-step in situ polymerization technique was used. • Leakage-free, thermally stable microPCMs was prepared with Poly(MUF). • Influence of different surfactants on encapsulation and thermal properties reported. - Abstract: The main purpose of this study is to obtain leakage-free, thermally stable decanoic acid microcapsules (microPCMs) for thermal energy storage applications. Decanoic acid (capric acid) is an environmentally friendly fatty acid since it is obtained from vegetable and animal oils. MicroPCMs were prepared with different capsule wall materials via a one-step in situ polymerization technique. The properties of microencapsulated PCMs have been analyzed by scanning electron microscopy (SEM), differential scanning calorimetry (DSC), thermal gravimetric analyzer (TGA), Fourier transform infrared (FTIR) spectra analysis and particle size analyzer. The microPCMs prepared using Poly(urea–formaldehyde) (PUF) exhibit higher heat capacities and the microPCMs prepared using Poly(melamine–formaldehyde) (PMF) exhibit higher thermal stabilities. In order to obtain microPCMs with better properties such as suitable latent heat and better heat resistance at high temperatures, we microencapsulated decanoic acid with Poly (melamine–urea–formaldehyde) (PMUF). Furthermore, the effects of surfactants on microPCMs with PMUF were investigated by SEM, a particle size analyzer, DSC, and TGA. The results show that the binary surfactant system was a suitable emulsifier for this process. We determined that the melting temperature was close to 33 °C, the latent heat storage capacity was about 88 J/g, and the mean particle diameter was 0.28 μm for microPCMs with PMUF. We recommend decanoic acid microencapsulated with PMUF for thermally stable and leakage-free applications above 95 °C

  2. Ultra-relativistic Au+Au and d+Au collisions:

    Science.gov (United States)

    Back, B. B.; Baker, M. D.; Ballintijn, M.; Barton, D. S.; Betts, R. R.; Bickley, A. A.; Bindel, R.; Budzanowski, A.; Busza, W.; Carroll, A.; Chai, Z.; Decowski, M. P.; García, E.; Gburek, T.; George, N.; Gulbrandsen, K.; Gushue, S.; Halliwell, C.; Hamblen, J.; Hauer, M.; Heintzelman, G. A.; Henderson, C.; Hofman, D. J.; Hollis, R. S.; Hołyński, R.; Holzman, B.; Iordanova, A.; Johnson, E.; Kane, J. L.; Katzy, J.; Khan, N.; Kucewicz, W.; Kulinich, P.; Kuo, C. M.; Lin, W. T.; Manly, S.; McLeod, D.; Mignerey, A. C.; Nouicer, R.; Olszewski, A.; Pak, R.; Park, I. C.; Pernegger, H.; Reed, C.; Remsberg, L. P.; Reuter, M.; Roland, C.; Roland, G.; Rosenberg, L.; Sagerer, J.; Sarin, P.; Sawicki, P.; Seals, H.; Sedykh, I.; Skulski, W.; Smith, C. E.; Stankiewicz, M. A.; Steinberg, P.; Stephans, G. S. F.; Sukhanov, A.; Tang, J.-L.; Tonjes, M. B.; Trzupek, A.; Vale, C.; van Nieuwenhuizen, G. J.; Vaurynovich, S. S.; Verdier, R.; Veres, G. I.; Wenger, E.; Wolfs, F. L. H.; Wosiek, B.; Woźniak, K.; Wuosmaa, A. H.; Wysłouch, B.

    In this talk I will review PHOBOS data on charged particle multiplicities, obtained in Au+Au and d+Au collisions at RHIC. The general features of the Au+Au pseudorapidity distributions results will be discussed and compared to those of /line{p}p collisions. The total charged particle multiplicity, scaled by the number of participant pairs, is observed to be about 40% higher in Au+Au collisions than in /line{p}p and d+Au systems, but, surprisingly at the same level of e+e- collisions. Limiting fragmentation scaling is seen to be obeyed in Au+Au collisions.

  3. An ultra-fast illuminating fluorescent probe for monitoring formaldehyde in living cells, shiitake mushrooms, and indoors.

    Science.gov (United States)

    He, Longwei; Yang, Xueling; Ren, Mingguang; Kong, Xiuqi; Liu, Yong; Lin, Weiying

    2016-07-21

    An ultra-fast illuminating fluorescent formaldehyde (FA) probe (R6-FA) was designed and synthesized, and it exhibited a significant response to both FA in aqueous solution and as a gas. We have employed R6-FA not only to image FA in living cells, but also to detect FA in dried shiitake mushrooms and indoors for the first time, indicating its broad potential applications for monitoring FA in living systems, the food industry, and the environment. PMID:27398723

  4. 40 CFR 721.7046 - Formaldehyde, polymer with substituted phenols, glycidyl ether.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Formaldehyde, polymer with substituted... New Uses for Specific Chemical Substances § 721.7046 Formaldehyde, polymer with substituted phenols... substance identified as formaldehyde, polymer with substituted phenols, glycidyl ether (PMN P-93-955)...

  5. 40 CFR 721.3807 - Formaldehyde, polymer with phenol and 1,2,3-propanetriol, methylated.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Formaldehyde, polymer with phenol and... Significant New Uses for Specific Chemical Substances § 721.3807 Formaldehyde, polymer with phenol and 1,2,3... chemical substance identified as formaldehyde, polymer with phenol and 1,2,3-propanetriol, methylated...

  6. Relationship between formaldehyde and quaternium-15 contact allergy. Influence of strength of patch test reactions

    NARCIS (Netherlands)

    de Groot, Anton C.; Blok, Janine; Coenraads, Pieter-Jan

    2010-01-01

    Objectives: To test our hypothesis that patients with stronger patch test reactions to formaldehyde are more likely to react to quaternium-15, attesting to the aetiological role for formaldehyde in such co-reactivity. Methods: Retrospective analysis of all patients patch tested with formaldehyde and

  7. 40 CFR 721.3805 - Formaldehyde, reaction products with 1,3-benzenedimethanamine and bisphenol A.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Formaldehyde, reaction products with 1... SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.3805 Formaldehyde, reaction products... to reporting. (1) The chemical substance identified as formaldehyde, reaction products with...

  8. 24 CFR 3280.308 - Formaldehyde emission controls for certain wood products.

    Science.gov (United States)

    2010-04-01

    ... 24 Housing and Urban Development 5 2010-04-01 2010-04-01 false Formaldehyde emission controls for... Body and Frame Construction Requirements § 3280.308 Formaldehyde emission controls for certain wood products. (a) Formaldehyde emission levels. All plywood and particleboard materials bonded with a...

  9. 40 CFR 721.3810 - Formaldehyde, polymers with substituted phenols (generic).

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Formaldehyde, polymers with... New Uses for Specific Chemical Substances § 721.3810 Formaldehyde, polymers with substituted phenols... identified generically as Formaldehyde, polymers with substituted phenols (PMN P-99-0558) is subject...

  10. Sonochemical fabrication of CdSe{sub x}Te{sub 1-x}/Au nanotubes and their potential application in biosensing

    Energy Technology Data Exchange (ETDEWEB)

    Lu Feng; Liu Shanhu, E-mail: liushanhu@163.com; Jiang Liping; Zhu Junjie, E-mail: jjzhu@nju.edu.cn [Nanjing University, State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering (China)

    2013-01-15

    CdSe{sub x}Te{sub 1-x} semiconductor alloy nanotubes (with an external diameter of 140 nm and an internal diameter of 100 nm) were successfully prepared based on the sacrificial template of Cd(OH)Cl nanorods, and were further in situ assembled with gold nanoparticles (AuNPs) via a sonochemical approach to form the CdSe{sub x}Te{sub 1-x}/Au nanotubes. The prepared CdSe{sub x}Te{sub 1-x}/Au nanotubes were characterized by X-ray diffraction, field emission scanning electron microscopy, transmission electron microscopy, energy-dispersive spectrometry, and X-ray photoelectron spectra. CdSe{sub x}Te{sub 1-x}/Au nanotubes could integrate the advantages of the electronic properties of CdSeTe and the biocompatible properties of AuNPs. A novel biosensor was fabricated after the immobilization of hemoglobin (Hb) on CdSe{sub x}Te{sub 1-x}/Au nanotubes. The immobilized Hb exhibited fast direct electron transfer and good electrocatalytic performance to H{sub 2}O{sub 2}.

  11. Synthesis of double-shelled sea urchin-like yolk-shell Fe3O4/TiO2/Au microspheres and their catalytic applications

    International Nuclear Information System (INIS)

    Double-shelled sea urchin-like yolk-shell Fe3O4/TiO2/Au microspheres were successfully synthesized through loading Au nanoparticles on the Fe3O4/TiO2 support by a in situ reduction of HAuCl4 with NaBH4 aqueous solution. These microspheres possess tunable cavity size, adjustable shell layers, high structural stability and large specific surface area. The Au nanoparticles of approximately 5 nm in diameter were loaded both on the TiO2 nanofibers and inside the cavities of sea urchin-like yolk-shell Fe3O4/TiO2 microspheres. The sea urchin-like structure composed of TiO2 nanofibers ensure the good distribution of the Au nanoparticles, while the novel double-shelled yolk-shell structure guarantees the high stability of the Au nanoparticles. Furthermore, the Fe3O4 magnetic core facilitates the convenient recovery of the catalyst by applying an external magnetic field. The Fe3O4/TiO2/Au microspheres display excellent activities and recycling properties in the catalytic reduction of 4-nitrophenol (4-NP): the rate constant is 1.84 min−1 and turnover frequency is 5457 h−1. (paper)

  12. A study on the effect of low energy ion beam irradiation on Au/TiO2 system for its application in photoelectrochemical splitting of water

    Science.gov (United States)

    Verma, Anuradha; Srivastav, Anupam; Sharma, Dipika; Banerjee, Anamika; Sharma, Shailja; Satsangi, Vibha Rani; Shrivastav, Rohit; Avasthi, Devesh Kumar; Dass, Sahab

    2016-07-01

    Nanostructured TiO2 thin films were deposited on indium tin oxide (ITO) substrate via sol-gel technique and were modified by plasmonic Au layer. The plasmonic Au modified TiO2 (Au/TiO2) thin films were then irradiated with 500 keV Ar2+ ion beam at different ion fluences viz. 1 × 1016, 3 × 1016 and 1 × 1017 to study the effect of nuclear energy deposition on the morphology, crystallinity, band gap, surface plasmon resonance (SPR) peak exhibited by Au particles and photoelectrochemical properties of the system. Prepared thin films were characterized by X-ray diffractometry (XRD), scanning electron microscopy (SEM), Rutherford backscattering spectrometry (RBS) measurements and UV-visible spectroscopy. The photoelectrochemical measurements revealed that both Au/TiO2 and Au/TiO2 thin film irradiated at 1 × 1016 fluence exhibits enhanced photoelectrochemical response in comparison to pristine TiO2. The film irradiated at 1 × 1016 fluence offered maximum applied bias photon-to-current efficiency (ABPE) and shows 6 times increment in photocurrent density which was attributed to more negative flat band potential, maximum decrease in band gap, high open circuit voltage (Voc) and reduced charge transfer resistance.

  13. Chemical and physical basics of routine formaldehyde fixation

    Directory of Open Access Journals (Sweden)

    Rooban Thavarajah

    2012-01-01

    Full Text Available Formaldehyde is the widely employed fixative that has been studied for decades. The chemistry of fixation has been studied widely since the early 20 th century. However, very few studies have been focused on the actual physics/chemistry aspect of process of this fixation. This article attempts to explain the chemistry of formaldehyde fixation and also to study the physical aspects involved in the fixation. The factors involved in the fixation process are discussed using well documented mathematical and physical formulae. The deeper understanding of these factors will enable pathologist to optimize the factors and use them in their favor.

  14. Chemical and physical basics of routine formaldehyde fixation.

    Science.gov (United States)

    Thavarajah, Rooban; Mudimbaimannar, Vidya Kazhiyur; Elizabeth, Joshua; Rao, Umadevi Krishnamohan; Ranganathan, Kannan

    2012-09-01

    Formaldehyde is the widely employed fixative that has been studied for decades. The chemistry of fixation has been studied widely since the early 20(th) century. However, very few studies have been focused on the actual physics/chemistry aspect of process of this fixation. This article attempts to explain the chemistry of formaldehyde fixation and also to study the physical aspects involved in the fixation. The factors involved in the fixation process are discussed using well documented mathematical and physical formulae. The deeper understanding of these factors will enable pathologist to optimize the factors and use them in their favor. PMID:23248474

  15. Some effects of formaldehyde on the upper respiratory tract

    Energy Technology Data Exchange (ETDEWEB)

    Ballenger, J.J.

    1984-11-01

    Being highly soluble in water gaseous formaldehyde (HCHO) is virtually completely removed by the nose during nasal respiration so that nasal disease may follow. This report is a review of pertinent information that is known about the effect of formaldehyde on the nose both in animals and humans. It is evident from the literature that rats develop nasal carcinoma at ambient levels of HCHO occasionally encountered by humans and it is hoped that this report will elucidate the possible threat HCHO presents to humans.

  16. Injection Seeded Laser for Formaldehyde Differential Fluorescence Lidar

    Directory of Open Access Journals (Sweden)

    Schwemmer G.

    2016-01-01

    Full Text Available We describe the design and development of an injection seeded Nd:YVO4 laser for use in a differential fluorescence lidar for measuring atmospheric formaldehyde profiles. A high repetition rate Q-switched laser is modified to accept injection seed input to spectrally narrow and tune the output. The third harmonic output is used to excite formaldehyde (HCHO fluorescence when tuned to a HCHO absorption line. Spectral confirmation is made with the use of a photoacoustic cell and grating spectrometer.

  17. Resorcinol–formaldehyde based carbon nanospheres by electrospraying

    Indian Academy of Sciences (India)

    Chandra S Sharma; Sandip Patil; Suman Saurabh; Ashutosh Sharma; R Venkataraghavan

    2009-06-01

    Carbon nanospheres were synthesized using sol–gel processing of organic and aqueous resorcinol formaldehyde (RF) sols combined with electrospraying technique. RF sol was electrosprayed to form nanodroplets which were collected on a Si wafer. After oven drying at 60°C for 12 h, RF nano-droplets were pyrolyzed at 900°C in an inert atmosphere to yield the carbon nanospheres. This study reports the optimization of various process parameters including needle diameter, applied electric potential and liquid flow rate in order to get spherical, mono-disperse particles. For the organic RF sol, the optimized parameters, needle diameter 0.241 mm, electric potential, 1.5 kV/cm and a flow rate of 0.8 ml/h, enabled the synthesis of nearly monodispersed carbon nano-spheres with diameter of 30.2 ± 7.1 nm. With the same conditions, aqueous RF sol produced irregularly shaped nanoparticles with a smaller mean diameter and much higher variance (17.4 ± 8.0 nm). The surface properties were significantly influenced by the surface morphologies as demonstrated by the water contact angle (WCA) studies. The surface covered with the RF derived carbon nano-spheres was extremely hydrophilic (WCA 10.1°) as compared to a much weaker hydrophilicity of the RF derived carbon films (WCA 83.3°). The hydrophilic carbon nanospheres reported here may have potential applications as adsorbents and in controlled drug delivery, biosensors and carbon-based microelectromechanical systems (C-MEMS) including bio-MEMS.

  18. Structural, electronic and magnetic properties of Au-based monolayer derivatives in honeycomb structure

    Science.gov (United States)

    Kapoor, Pooja; Sharma, Munish; Kumar, Ashok; Ahluwalia, P. K.

    2016-05-01

    We present electronic properties of atomic layer of Au, Au2-N, Au2-O and Au2-F in graphene-like structure within the framework of density functional theory (DFT). The lattice constant of derived monolayers are found to be higher than the pristine Au monolayer. Au monolayer is metallic in nature with quantum ballistic conductance calculated as 4G0. Similarly, Au2-N and Au2-F monolayers show 4G0 and 2G0 quantum conductance respectively while semiconducting nature with calculated band gap of 0.28 eV has been observed for Au2-O monolayer. Most interestingly, half metalicity has been predicted for Au2-N and Au2-F monolayers. Our findings may have importance for the application of these monolayers in nanoelectronic and spintronics.

  19. Collective flow in Au + Au collisions

    International Nuclear Information System (INIS)

    Based on a preliminary sample of Au + Au collisions in the EOS time projection chamber at the Bevalac, we study sideward flow as a function of bombarding energy between 0.25A GeV and 1.2A GeV. We focus on the increase in in-plane transverse momentum per nucleon with fragment mass. We also find event shapes to be close to spherical in the most central collisions, independent of bombarding energy and fragment mass up to 4He

  20. CHARACTERIZATION OF ALKALINE LIGNINS FOR USE IN PHENOL-FORMALDEHYDE AND EPOXY RESINS

    Directory of Open Access Journals (Sweden)

    Nour Eddine El Mansouri

    2011-05-01

    Full Text Available Besides polyurethanes and polyesters, phenolic and epoxy resins are the most prominent applications for technical lignins in thermosetting materials. To evaluate the potential application of lignin raw materials in phenol formaldehyde and epoxy resins, three types of alkaline lignins were characterized in terms of their structures and thermal properties. The lignin samples analyzed were kraft lignin (LIG-1, soda–rice straw lignin (LIG-2, and soda-wheat straw lignin (LIG-3. FTIR and 1H-NMR methods were used to determine their structure. Gel permeation chromatography (GPC was used to determine the molecular weight distribution (MWD. Differential scanning calorimetry (DSC was used to measure the glass transition temperature (Tg, and thermogravimetric analysis (TGA to determine the thermal stability of lignin samples. Results showed that kraft lignin (LIG-1 has moderate hydroxyl-group content, is rich in G-type units, and has good thermal stability. These properties make it more suitable for direct use in phenol formaldehyde resins, and it is therefore a good raw material for this purpose. The alkaline soda-rice straw lignin (LIG-2 with a high hydroxyl-group content and excellent thermal stability is most suited to preparing lignin-based epoxy resins.

  1. Susceptibility of Mycobacterium immunogenum and Pseudomonas fluorescens to Formaldehyde and Non-Formaldehyde Biocides in Semi-Synthetic Metalworking Fluids

    Directory of Open Access Journals (Sweden)

    Suresh B. Selvaraju

    2011-01-01

    Full Text Available Mycobacterium immunogenum, a newly identified member of the Mycobacterium chelonae_M. abscessus complex is considered a potential etiological agent for hypersensitivity pneumonitis (HP in machine workers exposed to contaminated metalworking fluid (MWF. This study investigated the biocidal efficacy of the frequently applied commercial formaldehyde-releasing (HCHO biocides Grotan and Bioban CS 1135 and non-HCHO type biocides Kathon 886 MW (isothiazolone and Preventol CMK 40 (phenolic toward this emerging mycobacterial species (M. immunogenum in HP-linked MWFs, alone and in presence of a representative of the Gram-negative bacterial contaminants, Pseudomonas fluorescens, using two semi-synthetic MWF matrices (designated Fluid A and Fluid B. Relative biocide susceptibility analysis indicated M immunogenum to be comparatively more resistant (2–1600 fold than P. fluorescens to the tested biocides under the varied test conditions. In terms of minimum inhibitory concentration, Kathon was the most effective biocide against M. immunogenum. Fluid factors had a major effect on the biocide susceptibility. Fluid A formulation provided greater protective advantage to the test organisms than Fluid B. Fluid dialysis (Fluid A led to an increased biocidal efficacy of Grotan, Kathon and Preventol against M. immunogenum further implying the role of native fluid components. Used fluid matrix, in general, increased the resistance of the two test organisms against the biocides, with certain exceptions. M. immunogenum resistance increased in presence of the co-contaminant P. fluorescens. Collectively, the results show a multifactorial nature of the biocide susceptibility of MWF-colonizing mycobacteria and highlight the importance of more rigorous efficacy testing and validation of biocides prior to and during their application in metalworking fluid operations.

  2. In vitro model for decontamination of human skin: formaldehyde.

    Science.gov (United States)

    Zhai, H; Barbadillo, S; Hui, X; Maibach, H I

    2007-04-01

    Decontamination of a chemical from skin is often an emergency measure. This study utilized an in vitro model to compare the decontamination capacity of three model decontaminant solutions (tap water, isotonic saline, and hypertonic saline). Human cadaver skin was dosed (approximately 0.25 microg on 3 cm(2) per skin) with radio-labeled [(14)C]-formaldehyde. After a defined exposure time (1, 3, and 30 min post-dosing, respectively), the surface skin was washed three times (4ml per time) with each solution. After washing, the skin was stripped with tape discs twice. Lastly, the wash solutions, strippings, receptor fluid, and remainder of skin were liquid scintillation analyzer counted to determine the amounts of formaldehyde. Additionally, an evaporation test at different exposure times (1min, 3min, 15min, 30min, and 60min, respectively) was conducted to monitor formaldehyde % evaporation. There were no statistical differences among these groups except isotonic saline, at 3min post-exposure (in wash solutions), showed a significantly difference (pisotonic saline may be effective in removing formaldehyde from skin. However, results from this model need validation in vivo. The model may provide a facile and robust method of accelerating knowledge of decontamination mechanism and lead to enhanced efficacy. PMID:17123683

  3. Solid-State Microwave Synthesis of Melamine-Formaldehyde Resin

    OpenAIRE

    Subhash Bajia; Rashmi Sharma; Birbal Bajia

    2009-01-01

    An efficient synthesis of melamine-formaldehyde resin has been achieved using conventional as well as microwave irradiations (without and with solid support) in different molar ratio. Resin samples were tested for their chemical as well as physical properties. The structure of all the resin has been supported by their spectral data

  4. Microwave Assisted Synthesis of Phenol-Formaldehyde Resole

    OpenAIRE

    Subhash Chandra Bajia; Pawan Swarnkar; Sudesh Kumar; Birbal Bajia

    2007-01-01

    An efficient synthesis of phenol-formaldehyde resin has been achieved by using conventional as well as microwave irradiation. Resin samples were tested for their physical and chemical properties. The structures of the resins have been supported by their spectral analysis.

  5. Sol-gel based sensor for selective formaldehyde determination

    International Nuclear Information System (INIS)

    We report the development of transparent sol-gels with entrapped sensitive and selective reagents for the detection of formaldehyde. The sampling method is based on the adsorption of formaldehyde from the air and reaction with β-diketones (for example acetylacetone) in a sol-gel matrix to produce a yellow product, lutidine, which was detected directly. The proposed method does not require preparation of samples prior to analysis and allows both screening by visual detection and quantitative measurement by simple spectrophotometry. The detection limit of 0.03 ppmv formaldehyde is reported which is lower than the maximum exposure concentrations recommended by both the World Health Organisation (WHO) and the Occupational Safety and Health Administration (OSHA). This sampling method was found to give good reproducibility, the relative standard deviation at 0.2 and 1 ppmv being 6.3% and 4.6%, respectively. Other carbonyl compounds i.e. acetaldehyde, benzaldehyde, acetone and butanone do not interfere with this analytical approach. Results are provided for the determination of formaldehyde in indoor air.

  6. Sol-gel based sensor for selective formaldehyde determination

    Energy Technology Data Exchange (ETDEWEB)

    Bunkoed, Opas [Trace Analysis and Biosensor Research Center, Prince of Songkla University, Hat Yai, Songkhla 90112 (Thailand); Department of Chemistry and Center for Innovation in Chemistry, Faculty of Science, Prince of Songkla University, Hat Yai, Songkhla 90112 (Thailand); Davis, Frank [Cranfield Health, Cranfield University, Bedford MK43 0AL (United Kingdom); Kanatharana, Proespichaya, E-mail: proespichaya.K@psu.ac.th [Trace Analysis and Biosensor Research Center, Prince of Songkla University, Hat Yai, Songkhla 90112 (Thailand); Department of Chemistry and Center for Innovation in Chemistry, Faculty of Science, Prince of Songkla University, Hat Yai, Songkhla 90112 (Thailand); Thavarungkul, Panote [Trace Analysis and Biosensor Research Center, Prince of Songkla University, Hat Yai, Songkhla 90112 (Thailand); Department of Physics, Faculty of Science, Prince of Songkla University, Hat Yai, Songkhla 90112 (Thailand); Higson, Seamus P.J., E-mail: s.p.j.higson@cranfield.ac.uk [Cranfield Health, Cranfield University, Bedford MK43 0AL (United Kingdom)

    2010-02-05

    We report the development of transparent sol-gels with entrapped sensitive and selective reagents for the detection of formaldehyde. The sampling method is based on the adsorption of formaldehyde from the air and reaction with {beta}-diketones (for example acetylacetone) in a sol-gel matrix to produce a yellow product, lutidine, which was detected directly. The proposed method does not require preparation of samples prior to analysis and allows both screening by visual detection and quantitative measurement by simple spectrophotometry. The detection limit of 0.03 ppmv formaldehyde is reported which is lower than the maximum exposure concentrations recommended by both the World Health Organisation (WHO) and the Occupational Safety and Health Administration (OSHA). This sampling method was found to give good reproducibility, the relative standard deviation at 0.2 and 1 ppmv being 6.3% and 4.6%, respectively. Other carbonyl compounds i.e. acetaldehyde, benzaldehyde, acetone and butanone do not interfere with this analytical approach. Results are provided for the determination of formaldehyde in indoor air.

  7. The methods of formaldehyde emission testing of engine: A review

    Science.gov (United States)

    Zhang, Chunhui; Geng, Peng; Cao, Erming; Wei, Lijiang

    2015-12-01

    A number of measurements have been provided to detect formaldehyde in the atmosphere, but there are no clear unified standards in engine exhaust. Nowadays, formaldehyde, an unregulated emission from methanol engine, has been attracting increasing attention by researchers. This paper presents the detection techniques for formaldehyde emitted from the engines applied in recent market, introducing the approaches in terms of unregulated emission tests of formaldehyde, which involved gas chromatography, liquid chromatography, chromatography-mass spectrometry, chromatography-spectrum, Fourier infrared spectroscopy and spectrophotometry. The author also introduces the comparison regarding to the advantages of the existing detection techniques based on the principle, to compare with engine exhaust sampling method, the treatment in advance of detection, obtaining approaches accessing to the qualitative and quantitative analysis of chromatograms or spectra. The accuratest result obtained was chromatography though it cannot be used continuously. It also can be utilized to develop high requirements of emissions and other regulations. Fourier infrared spectroscopy has the advantage of continuous detection for a variety of unregulated emissions and can be applied to the bench in variable condition. However, its accuracy is not as good as chromatography. As the conclusion, a detection technique is chosen based on different requirements.

  8. Further revealing of the photo-dissociation of formaldehyde

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    @@ Dr. YIN Hongming with the CAS Dalian Institute of Chemical Physics has discovered two main reaction paths of formaldehyde's photochemical decomposition. His latest research progress, which was published in the first issue of Chinese Science Bulletin in 2008, may shed new light on the reaction mechanism of its radical channel.

  9. Concentrations of Glyoxal and Formaldehyde During CALNEX 2010

    Science.gov (United States)

    Henry, S. B.; Digangi, J. P.; Boyle, E.; Calnex Science Team

    2010-12-01

    Atmospheric oxidation of volatile organic compounds (VOCs) via the HOx-NOx cycle can lead to elevated concentrations of tropospheric ozone and secondary organic aerosol (SOA), both of which have been shown to be detrimental to human health. A detailed and mechanistic understanding of the VOC-HOx-NOx cycle is vital for improving the predictive capabilities of models for ozone and SOA. Accurate projection of oxidized VOCs is an important aspect of validating the photochemical mechanisms in models, which can then be used to evaluate regulation strategies. Glyoxal and formaldehyde are produced though oxidation of many important VOCs, and thus are powerful tracers of photooxidation via the HOx-NOx cycle. We report measurements of glyoxal and formaldehyde in Bakersfield, California located in the San Joaquin Valley during the CALNEX 2010 campaign (May 15th through June 30th). These measurements, with relevant trends and correlations, will be presented. Glyoxal:formaldehyde ratios will also be examined during this period. This ratio has been related to the source of VOCs dominating an air mass (i.e. anthropogenic versus biogenic). Both compounds were measured in situ with both high sensitivity and high temporal resolution (30 second) via laser induced emission techniques. Glyoxal was quantified by phosphorescence (MAD-LIP instrument) and formaldehyde by fluorescence (FILIF instrument). The measurements presented herein are useful for comparisons with current atmospheric models in order to evaluate the representation of photochemical oxidation in models. Furthermore, these data are also valuable points of comparison for satellite column retrieval data.

  10. 78 FR 34820 - Formaldehyde Emissions Standards for Composite Wood Products

    Science.gov (United States)

    2013-06-10

    ... currently in effect in California under a California Air Resources Board (CARB) Airborne Toxic Control Measure (ATCM) (Ref. 2). By aligning with the CARB ATCM requirements, EPA seeks to avoid differing or... of the CARB ATCM. In 2007, CARB issued an ATCM to reduce formaldehyde emissions from hardwood...

  11. Organocatalytic removal of formaldehyde adducts from RNA and DNA bases

    Science.gov (United States)

    Karmakar, Saswata; Harcourt, Emily M.; Hewings, David S.; Lovejoy, Alexander F.; Kurtz, David M.; Ehrenschwender, Thomas; Barandun, Luzi J.; Roost, Caroline; Alizadeh, Ash A.; Kool, Eric T.

    2015-09-01

    Formaldehyde is universally used to fix tissue specimens, where it forms hemiaminal and aminal adducts with biomolecules, hindering the ability to retrieve molecular information. Common methods for removing these adducts involve extended heating, which can cause extensive degradation of nucleic acids, particularly RNA. Here, we show that water-soluble bifunctional catalysts (anthranilates and phosphanilates) speed the reversal of formaldehyde adducts of mononucleotides over standard buffers. Studies with formaldehyde-treated RNA oligonucleotides show that the catalysts enhance adduct removal, restoring unmodified RNA at 37 °C even when extensively modified, while avoiding the high temperatures that promote RNA degradation. Experiments with formalin-fixed, paraffin-embedded cell samples show that the catalysis is compatible with common RNA extraction protocols, with detectable RNA yields increased by 1.5-2.4-fold using a catalyst under optimized conditions and by 7-25-fold compared with a commercial kit. Such catalytic strategies show promise for general use in reversing formaldehyde adducts in clinical specimens.

  12. Flow-injection chemiluminescence determination of formaldehyde in water

    Czech Academy of Sciences Publication Activity Database

    Motyka, Kamil; Mikuška, Pavel; Večeřa, Zbyněk; Onjia, A.

    Hamburg : University of Hamburg, 2006 - (Broekaert, J.). A60 [ISEAC34. International Symposium on Environmental Analytical Chemistry /34./. 04.06.2006-08.06.2006, Hamburg] Institutional research plan: CEZ:AV0Z40310501 Keywords : formaldehyde * FIA * chemiluminescence Subject RIV: CB - Analytical Chemistry, Separation

  13. A mathematical model for the absorption and metabolism of formaldehyde vapour by humans

    International Nuclear Information System (INIS)

    Epidemiological studies of occupational exposure to formaldehyde gas (HCHO) have suggested possible links between concentration and duration of exposure, and elevated risks of leukaemia and other cancers at sites distant from the site of contact. Formaldehyde is a highly water soluble gas which, when inhaled, reacts rapidly at the site of contact and is quickly metabolised by enzymes in the respiratory tissue. Inhaled formaldehyde is almost entirely absorbed in the respiratory tract and, for formaldehyde induced toxicity to occur at distant sites, HCHO must enter the blood and be transported to systemic tissues via the circulatory system. A mathematical model describing the absorption and removal of inhaled formaldehyde in the nasal tissue is therefore formulated to predict the proportion of formaldehyde entering into the blood. Accounting for the spatial distribution of the formaldehyde concentration and the metabolic activity within the mucosa, the concentration of formaldehyde in the mucus, the epithelium and the blood has been determined and was found to attain a steady-state profile within a few seconds of exposure. The increase of the formaldehyde concentration in the blood was predicted to be insignificant compared with the existing pre-exposure levels in the body, indicating that formaldehyde is rapidly removed in the nasal tissue. The results of the model thus suggest that it is highly unlikely that following inhalation by the nose, formaldehyde itself will cause toxicity at sites other than the initial site of contact in the respiratory tract

  14. Formaldehyde as an antiseptic in the production of alcohol from molasses

    Energy Technology Data Exchange (ETDEWEB)

    Rosa, M.; Vernerova, J.; Stros, F.

    1962-01-01

    The effect of formaldehyde as an antiseptic for the noncontaminated alcohol fermentation of molasses was examined with five different yeast-mash batches containing formaldehyde 0.01%. Following 24 hour cultivation, increase in the activity of formaldehyde-inoculated mash was lowered by 47%; the formaldehyde decreased the alcohol fermentation and lessened the rate of fermentation of sugar by 20% in noncontaminated mash. The decrease in the fermentation rate was also observed during the entire course of fermentation. On the other hand, formaldehyde addition to molasses contaminated with lactic acid bacteria accelerated the fermentation rate by inhibiting the bacterial growth; the degree of retardation due to the contamination was greater than that due to the antiseptic. The view that formaldehyde decreased the effectiveness of growth substances by binding the amino acid present in mash mixtures could not be confirmed; it was believed that formaldehyde was absorbed by yeast cells even through the entities thus destroyed could not be differentiated from living cells by methylene blue. Higher resistance of yeast cultures to formaldehyde was obtained by repeated transfers of the yeast in media containing formaldehyde. It was concluded that formaldehyde added to contaminated molasses inhibited the further growth of the contamination, increased yield of ethanol on the basis of the sugar, and simultaneously decreased the net yield of ethanol in contrast to the yield from noncontaminated mashes in the absence of formaldehyde.

  15. Synthesis of SERS active Au nanowires in different noncoordinating solvents

    International Nuclear Information System (INIS)

    Au nanowires with length up to micrometers were synthesized through a simple and one-pot solution growth method. HAuCl4 was reduced in a micellar structure formed by 1-octadecylamine and oleic acid in hexane, heptane, toluene and chloroform, respectively. As the non-polarity of noncoordinating solvents can affect the nucleation and growth rates of Au nanostructures, Au nanowires with different diameters could be obtained by changing the noncoordinating solvents in the synthetic process. The influences of the solvents on the morphology of Au nanowires were systematically studied. When using hexane as reaction solvent, the product turned to be high portion of Au nanowires with more uniform size than the others. Furthermore, surface-enhanced Raman scattering (SERS) spectrum of 2-thionaphthol was obtained on the Au nanowire-modified substrate, indicating that the as-synthesized Au nanowires have potential for highly sensitive optical detection application.

  16. Au-Free GaN High-Electron-Mobility Transistor with Ti/Al/W Ohmic and WN X Schottky Metal Structures for High-Power Applications

    Science.gov (United States)

    Hsieh, Ting-En; Lin, Yueh-Chin; Chu, Chung-Ming; Chuang, Yu-Lin; Huang, Yu-Xiang; Shi, Wang-Cheng; Dee, Chang-Fu; Majlis, Burhanuddin Yeop; Lee, Wei-I.; Chang, Edward Yi

    2016-07-01

    In this study, an Au-free AlGaN/GaN high-electron-mobility transistor (HEMT) with Ti/Al/W ohmic and WN x Schottky metal structures is fabricated and characterized. The device exhibits smooth surface morphology after metallization and shows excellent direct-current (DC) characteristics. The device also demonstrates better performance than the conventional HEMTs under high voltage stress. Furthermore, the Au-free AlGaN/GaN HEMT shows stable device performance after annealing at 400°C. Thus, the Ti/Al/W ohmic and WN X Schottky metals can be applied in the manufacturing of GaN HEMT to replace the Au based contacts to reduce the manufacturing costs of the GaN HEMT devices with comparable device performance.

  17. Au-Free GaN High-Electron-Mobility Transistor with Ti/Al/W Ohmic and WN X Schottky Metal Structures for High-Power Applications

    Science.gov (United States)

    Hsieh, Ting-En; Lin, Yueh-Chin; Chu, Chung-Ming; Chuang, Yu-Lin; Huang, Yu-Xiang; Shi, Wang-Cheng; Dee, Chang-Fu; Majlis, Burhanuddin Yeop; Lee, Wei-I.; Chang, Edward Yi

    2016-04-01

    In this study, an Au-free AlGaN/GaN high-electron-mobility transistor (HEMT) with Ti/Al/W ohmic and WNx Schottky metal structures is fabricated and characterized. The device exhibits smooth surface morphology after metallization and shows excellent direct-current (DC) characteristics. The device also demonstrates better performance than the conventional HEMTs under high voltage stress. Furthermore, the Au-free AlGaN/GaN HEMT shows stable device performance after annealing at 400°C. Thus, the Ti/Al/W ohmic and WN X Schottky metals can be applied in the manufacturing of GaN HEMT to replace the Au based contacts to reduce the manufacturing costs of the GaN HEMT devices with comparable device performance.

  18. TiO2 nanotube arrays co-loaded with Au nanoparticles and reduced graphene oxide: Facile synthesis and promising photocatalytic application

    International Nuclear Information System (INIS)

    Graphical abstract: Methyl orange (MO) can be efficiently removed through photodegradation process using a novel photocatalyst, Au nanoparticles and reduced graphene oxide co-loaded TiO2 nanotube arrays. Highlights: •The photocatalyst is prepared by an one-step constant potential deposition process. •The ternary photocatalyst shows effective separation of photogenerated charges. •The photocatalyst displays almost 100% photocatalytic removal of methyl orange. •The photocatalyst is easily recovered with excellent cycling stability. -- Abstract: Au nanoparticles and reduced graphene oxide co-loaded TiO2 nanotube arrays (Au/RGO–TiO2 NTs) were prepared through a simple one-step constant-potential electrolysis of chloroauric acid and graphene oxide on TiO2 NTs. Compared with Au–TiO2 NTs, RGO–TiO2 NTs and un-modified TiO2 NTs, the Au/RGO–TiO2 NTs exhibited high efficiency in photocatalytic degradation of methyl orange (MO) under simulated solar light irradiation. The highly efficient photocatalytic activity is associated with broad absorption in the visible light region, increased photoinduced charge separation through transferring photogenerated electrons from TiO2 NTs to both Au and RGO, as well as the strong adsorption ability of RGO to MO molecules. Moreover, the Au/RGO–TiO2 NTs has an excellent stability. This work provides an insight into designing and synthesizing new TiO2 NTs-based hybrid materials for effective visible light-activated photocatalysis

  19. Anthracycline-Formaldehyde Conjugates and Their Targeted Prodrugs

    Science.gov (United States)

    Koch, Tad H.; Barthel, Benjamin L.; Kalet, Brian T.; Rudnicki, Daniel L.; Post, Glen C.; Burkhart, David J.

    The sequence of research leading to a proposal for anthracycline cross-linking of DNA is presented. The clinical anthracycline antitumor drugs are anthraquinones, and as such are redox active. Their redox chemistry leads to induction of oxidative stress and drug metabolites. An intermediate in reductive glycosidic cleavage is a quinone methide, once proposed as an alkylating agent of DNA. Subsequent research now implicates formaldehyde as a mediator of anthracycline-DNA cross-linking. The cross-link at 5'-GC-3' sites consists of a covalent linkage from the amino group of the anthracycline to the 2-amino group of the G-base through a methylene from formaldehyde, hydrogen bonding from the 9-OH to the G-base on the opposing strand, and hydrophobic interactions through intercalation of the anthraquinone. The combination of these interactions has been described as a virtual cross-link of DNA. The origin of the formaldehyde in vivo remains a mystery. In vitro, doxorubicin reacts with formaldehyde to give firstly a monomeric oxazolidine, doxazolidine, and secondly a dimeric oxazolidine, doxoform. Doxorubicin reacts with formaldehyde in the presence of salicylamide to give the N-Mannich base conjugate, doxsaliform. Doxsaliform is several fold more active in tumor cell growth inhibition than doxorubicin, but doxazolidine and doxoform are orders of magnitude more active than doxorubicin. Exploratory research on the potential for doxsaliform and doxazolidine as targeted cytotoxins is presented. A promising lead design is pentyl PABC-Doxaz, targeted to a carboxylesterase enzyme overexpressed in liver cancer cells and/or colon cancer cells.

  20. Recognizing indoor formaldehyde in binary gas mixtures with a micro gas sensor array and a neural network

    Science.gov (United States)

    Lv, Pin; Tang, Zhenan; Wei, Guangfen; Yu, Jun; Huang, Zhengxing

    2007-09-01

    Low-concentration formaldehyde (HCHO) together with ethanol/toluene/acetone/α-pinene (as an interference gas of HCHO) is detected with a micro gas sensor array, composed of eight tin oxide (SnO2) thin film gas sensors with Au, Cu, Pt or Pd metal catalysts. The characteristics of the multi-dimensional signals from the eight sensors are evaluated. A multilayer neural network with an error backpropagation (BP) learning algorithm, plus the principal component analysis (PCA) technique, is implemented to recognize these indoor volatile organic compounds (VOC). The results show that the micro gas sensor array, plus the multilayer neural network, is very effective in recognizing 0.06 ppm HCHO in single gas component and in binary gas mixtures, toluene/ethanol/α-pinene with small relative error.

  1. Production of Formaldehyde by Detergent-Treated Cells of a Methanol Yeast, Candida boidinii S2 Mutant Strain AOU-1

    OpenAIRE

    Sakai, Yasuyoshi; Tani, Yoshiki

    1988-01-01

    Treatment of cells of a methanol yeast, Candida boidinii, with the cationic detergent cetyldimethylbenzyl-ammonium chloride (Cation M2) improved the production of formaldehyde. Formaldehyde production was improved twofold with respect to the initial amount of formaldehyde and 1.61-fold with respect to the final amount of formaldehyde after a 12-h reaction under optimized detergent treatment conditions. The treatment caused formaldehyde and formate dehydrogenases to leak out of the cells more ...

  2. Applicability of near-infrared hyperspectral imagery (NIR-HI) for sensor based sorting of an epithermal Au-Ag ore

    NARCIS (Netherlands)

    Dalm, M.; Buxton, M.W.N.; Van Ruitenbeek, F.J.A.

    2015-01-01

    In the presented study test work was performed with near-infrared hyperspectral imagery (NIR-HI) on 36 ore samples from a South-American epithermal Au-Ag mine. The aim of the test work was to investigate if NIR-HI provides information about the alteration mineralogy of samples that can be used to pr

  3. One-step construction of an electrode modified with electrodeposited Au/SiO2 nanoparticles, and its application to the determination of NADH and ethanol

    International Nuclear Information System (INIS)

    A new electrode was developed by one-step potentiostatic electrodeposition (at -2. 0 V for 20 s) of Au/SiO2 nanoparticles on a glassy carbon electrode. The resulting electrode (nano-Au/SiO2/GCE) was characterized by scanning electronic microscopy, X-ray photoelectron spectroscopy and electrochemical techniques. The electrochemical behavior of dihydronicotinamide adenine dinucleotide (NADH) at the nano-Au/SiO2/GCE were thoroughly investigated. Compared to the unmodified electrode, the overpotential decreased by about 300 mV, and the current response significantly increased. These changes indicated that the modified electrode showed excellent catalytic activity in the oxidation of NADH. A linear relationship was obtained in the NADH concentration range from 1. 0 x 10-6 to 1. 0 x 10-4 mol L-1. In addition, amperometric sensing of ethanol at the nano-Au/SiO2/GCE in combination with alcohol dehydrogenase and nicotinamide adenine dinucleotide was successfully demonstrated. A wide linear response was also found for ethanol in the range from 5. 0 x 10-5 to 1. 0 x 10-3 mol L-1 and 1. 0 x 10-3 to 1. 0 x 10-2 mol L-1, respectively. The method was successfully applied to determine ethanol in beer and biological samples. (author)

  4. Preparation and Characterization of Au-ZrO2-SiO2 Nanocomposite Spheres and Their Application in Enrichment and Detection of Organophosphorus Agents

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Yuqi; Tu, Haiyang; Zhang, Aidong; Du, Dan; Lin, Yuehe

    2012-03-01

    Au-ZrO{sub 2}-SiO{sub 2} nanocomposite spheres were synthesized and used as selective sorbents for the solid-phase extraction (SPE) of orananophosphorous agents. A non-enzymatic electrochemical sensor based on an Au-ZrO{sub 2}-SiO{sub 2} modified electrode was developed for selective detection of orananophosphorous pesticides (OPs). The Au-ZrO{sub 2}-SiO{sub 2} nanocomposite spheres were synthesized by hydrolysis and condensation of zirconia n-butoxide (TBOZ) on the surface of SiO{sub 2} spheres and then introduction of gold nanoparticles on the surface. Transmission electron microscope and X-ray photoelectron spectroscopy were performed to characterize the formation of the nanocomposite sphere. Fast extraction of OP was achieved by Au-ZrO{sub 2}-SiO{sub 2} modified electrode within 5 min via the specific affinity between zirconia and phosphoric group. The assay yields a broad concentration range of paraoxon-ethyl from 1.0 to 500 ng/mL{sup -1} with a detection limit 0.5 ng/mL{sup -1}. This selective and sensitive method holds great promise for the enrichment and detection of OPs.

  5. The synthesis of Au@C@Pt core-double shell nanocomposite and its application in enzyme-free hydrogen peroxide sensing

    Science.gov (United States)

    Zhang, Yayun; Li, Yuhui; Jiang, Yingying; Li, Yancai; Li, Shunxing

    2016-08-01

    A novel Au@C@Pt core-double shell nanocomposite was synthesized and used to fabricate enzyme-free electrochemical sensor for rapid and sensitive detection of hydrogen peroxide (H2O2). The well-designed Au@C@Pt core-double shell nanocomposite was characterized by scanning electron microscopy (SEM), transmission electron microscope (TEM) and energy-dispersed spectrum (EDS). The Au@C@Pt core-double shell nanocomposite modified glassy carbon electrode (Au@C@Pt/GCE) exhibits good electrocatalytic activity towards H2O2 reduction at 0.0 V and can be used as H2O2 sensor. The sensor displays two wide linear ranges towards H2O2 detection. The one is 9.0 μM-1.86 mM with high sensitivity of 144.7 μA mM-1 cm-2, and the other is 1.86 mM-7.11 mM with sensitivity of 80.1 μA mM-1 cm-2. When signal to noise (S/N) is 3, the calculated detection limit (LOD) is 0.13 μM. Furthermore, the interference from the common interfering species such as glucose, ascorbic acid, dopamine and uric acid can be effectively avoided to H2O2 detection. Additionally, the H2O2 sensor also displays good stability and reproducibility.

  6. Evolution of thermal micro-measurement technique for various applications; Evolution des techniques de micromesures thermiques au travers de quelques applications

    Energy Technology Data Exchange (ETDEWEB)

    Thiery, L.; Bailly, Y.; Lanzetta, F.; Gualous, H.; Gavignet, E. [Institut de genie energetique (ICE), Institut des microtechniques de Franche-Comte (IMFC), Universite de Franche-Comte, 90 - Belfort (France)

    1998-01-01

    The thermoelectric sensors made at present in our laboratory have junction dimensions from e few micrometers to 0.5 {mu}m. Two techniques are used: welding of ultra-thin wires and vacuum deposition (PVD). Two applications related to the first one will be presented: the detection of periodic field of temperature for photothermal microscopy and acoustic resonator characterization. In the latter, the comparison of simultaneous pressure and temperature will lead us to improve the knowledge of thermo-acoustic phenomena. The deposition technique allows us to create either simple thermoelectric couples, multiple as thermopiles; or heat (and light) flow sensors. Our work is presented in that field, with the development of a laser light sensor designed to image its light profile for large emission bandwidth and power densities. Finally, the description followed by an example of application is shown in the case of the heat flow measurement between a laminar gaseous flow and a wall. By comparison, we show that the use of such sensors could be worthwhile to replace the usual temperature sensors in the estimation of the heat transfer coefficient at the gas-wall boundary. (authors) 27 refs.

  7. Formaldehyde Densitometry of Starburst Galaxies: Density-Independent Global Star Formation

    CERN Document Server

    Mangum, Jeffrey G; Henkel, Christian; Menten, Karl M

    2013-01-01

    Accurate techniques which allow for the derivation of the spatial density in star formation regions are rare. A technique which has found application for the derivation of spatial densities in Galactic star formation regions utilizes the density-sensitive properties of the K-doublet transitions of formaldehyde (H2CO). In this paper, we present an extension of our survey of the formaldehyde 1(10)-1(11) (lambda = 6.2 cm) and 2(11)-2(12) (lambda = 2.1 cm) K-doublet transitions of H2CO in a sample of 56 starburst systems (Mangum etal. 2008). We have extended the number of galaxies in which both transitions have been detected from 5 to 13. We have improved our spatial density measurements by incorporating kinetic temperatures based upon NH3 measurements of 11 of the galaxies with a total of 14 velocity components in our sample (Mangum etal. 2013). Our spatial density measurements lie in a relatively narrow range of from 10^(4.5) to 10^(5.5) cm^(-3). This implies that the Schmidt-Kennicutt relation between L_(IR) a...

  8. DFT study of formaldehyde adsorption on vacancy defected graphene doped with B, N, and S

    International Nuclear Information System (INIS)

    Highlights: • The existence of vacancy in graphene enhanced the adsorption of H2CO molecule. • There was chemical bond forming between H2CO molecule and dopants (B, N, and S) in modified graphene. • The adsorption of H2CO molecule changed the conductivity of B and S doped defected graphene. - Abstract: The adsorption of formaldehyde (H2CO) on modified graphene sheets, combining vacancy and dopants (B, N, and S), was investigated by employing the density functional theory (DFT). It was found that the vacancy-defected graphene was more sensitive to absorb H2CO molecule compared with the pristine one. Furthermore, the H2CO molecule tended to be chemisorbed on vacancy-defected graphene with dopants, which exhibited larger adsorption energy and net charge transfer than that of one without dopants. The results of partial electronic density of states (PDOS) indicated that the defect-dopant combination effect on the adsorption process was mainly owing to the contribution of the hybridization between dopants and C atoms around the vacancy. We hope our results will be useful for the application of graphene for chemical sensors to detect formaldehyde gas

  9. Evaluation of formaldehyde emission from particleboard using the large chamber and desiccator method at various loading ratios

    Institute of Scientific and Technical Information of China (English)

    QUE Ze-li; WANG Fei-bin; MA Ling-fei; Furuno Takeshi

    2013-01-01

    We studied formaldehyde emission from uncoated particleboard with 16-mm thickness using the large chamber and the desiccator method.A chamber of 28.4 m3 was installed to simulate a mobile home.The formaldehyde off-gassing properties of particleboard were evaluated using the chamber.The relationship between the concentration obtained by the chamber and the values by the desiccator test was discussed in this study under different conditions of conditioning day,air exchange,and loading ratio.These two methods were compared and discussed regarding the formaldehyde emission level.Three loading ratios,0.429 m2/m3,0.264 m2/m3,and 0.132 m2/m3,were chosen to represent different applications of particleboard products.There was strong correlation between emissions and air exchange rates at equal product-loading ratios in the large chamber,the related coefficient R2 exceeded 0.90.There was also an indication of a generic correlation between the large chamber and the two-hour desiccator test with a single product designated loading ratio,air exchange rate,and climatic conditions.

  10. Gold catalysts supported on nanosized iron oxide for low-temperature oxidation of carbon monoxide and formaldehyde

    Science.gov (United States)

    Tang, Zheng; Zhang, Weidong; Li, Yi; Huang, Zuming; Guo, Huishan; Wu, Feng; Li, Jinjun

    2016-02-01

    This study aimed to optimize synthesis of gold catalyst supported on nanosized iron oxide and to evaluate the activity in oxidation of carbon monoxide and formaldehyde. Nanosized iron oxide was prepared from a colloidal dispersion of hydrous iron oxide through a dispersion-precipitation method. Gold was adsorbed onto nanosized iron oxide under self-generated basic conditions. Characterization results indicate that the iron oxide consisted of hematite/maghemite composite with primary particle sizes of 6-8 nm. Gold was highly dispersed on the surface of the support. The catalysts showed good activity in the oxidation of airborne carbon monoxide and formaldehyde. The optimal pH for their synthesis was ∼7. The catalytic performance could be enhanced by extending the adsorption time of gold species on the support within 21 h. The optimized catalyst was capable of achieving complete oxidation of 1% carbon monoxide at -20 °C and 33% conversion of 450 ppm formaldehyde at ambient temperature. The catalyst may be applicable to indoor air purification.

  11. Measurements of Formaldehyde and TVOC Emission from Paints and Coating Materials using Small Chamber Method for Building Composites

    Institute of Scientific and Technical Information of China (English)

    Jin-A KIM; Sumin KIM; Hyun-Joong KIM; Janghoo SEO

    2012-01-01

    An optimal test method for paint is proposed; additionally,the Field and Laboratory Emission Cell (FLEC) method used in Europe is applied as a substitute for the 20 L small chamber method.The emission factors of total volatile organic compounds (TVOC) and formaldehyde from oil-based paint,emulsion paint,and water-dispersion paint with a coating weight of 300 g/m2,cured for 24/48 hours,were measured using the 20 L small chamber method.The emission rate of TVOC and formaldehyde from all paints began to stabilize after approximately 7 days after 24/48 hours of curing even though Korean standards stipulate that paint should be measured and analyzed after the third day of application.The emission factor of TVOC and formaldehyde from oil-based,emulsion,and water-dispersion paints were also measured using the FLEC method.There was good correlation between the 20 L small chamber method and the FLEC method for oil-based,emulsion,and water-dispersion paint emissions.With the FLEC method,using paints prepared under identical conditions,the emission rate was stable 24 hours after installation of samples because the air flow rate of FLEC is much higher than that of a 20 L small chamber,and the relative cell volume of FLEC is much smaller than that of a 20 L small chamber.

  12. Hydraulic Permeability of Resorcinol-Formaldehyde Resin

    International Nuclear Information System (INIS)

    An ion exchange process using spherical resorcinol-formaldehyde (RF) resin is the baseline process for removing cesium from the dissolved salt solution in the high-level waste tanks at the Hanford Site, using large scale columns as part of the Waste Treatment Plant (WTP). The RF resin is also being evaluated for use in the proposed small column ion exchange (SCIX) system, which is an alternative treatment option at Hanford and at the Savannah River Site (SRS). A recirculating test loop with a small ion exchange column was used to measure the effect of oxygen uptake and radiation exposure on the permeability of a packed bed of the RF resin. The lab-scale column was designed to be prototypic of the proposed Hanford columns at the WTP. Although the test equipment was designed to model the Hanford ion exchange columns, the data on changes in the hydraulic permeability of the resin will also be valuable for determining potential pressure drops through the proposed SCIX system. The superficial fluid velocity in the lab-scale test (3.4-5.7 cm/s) was much higher than is planned for the full-scale Hanford columns to generate the maximum pressure drop expected in those columns (9.7 psig). The frictional drag from this high velocity produced forces on the resin in the lab-scale tests that matched the design basis of the full-scale Hanford column. Any changes in the resin caused by the radiation exposure and oxygen uptake were monitored by measuring the pressure drop through the lab-scale column and the physical properties of the resin. Three hydraulic test runs were completed, the first using fresh RF resin at 25 C, the second using irradiated resin at 25 C, and the third using irradiated resin at 45 C. A Hanford AP-101 simulant solution was recirculated through a test column containing 500 mL of Na-form RF resin. Known amounts of oxygen were introduced into the primary recirculation loop by saturating measured volumes of the simulant solution with oxygen and reintroducing

  13. Hydraulic Permeability of Resorcinol-Formaldehyde Resin

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, Paul Allen [ORNL

    2010-01-01

    An ion exchange process using spherical resorcinol-formaldehyde (RF) resin is the baseline process for removing cesium from the dissolved salt solution in the high-level waste tanks at the Hanford Site, using large scale columns as part of the Waste Treatment Plant (WTP). The RF resin is also being evaluated for use in the proposed small column ion exchange (SCIX) system, which is an alternative treatment option at Hanford and at the Savannah River Site (SRS). A recirculating test loop with a small ion exchange column was used to measure the effect of oxygen uptake and radiation exposure on the permeability of a packed bed of the RF resin. The lab-scale column was designed to be prototypic of the proposed Hanford columns at the WTP. Although the test equipment was designed to model the Hanford ion exchange columns, the data on changes in the hydraulic permeability of the resin will also be valuable for determining potential pressure drops through the proposed SCIX system. The superficial fluid velocity in the lab-scale test (3.4-5.7 cm/s) was much higher than is planned for the full-scale Hanford columns to generate the maximum pressure drop expected in those columns (9.7 psig). The frictional drag from this high velocity produced forces on the resin in the lab-scale tests that matched the design basis of the full-scale Hanford column. Any changes in the resin caused by the radiation exposure and oxygen uptake were monitored by measuring the pressure drop through the lab-scale column and the physical properties of the resin. Three hydraulic test runs were completed, the first using fresh RF resin at 25 C, the second using irradiated resin at 25 C, and the third using irradiated resin at 45 C. A Hanford AP-101 simulant solution was recirculated through a test column containing 500 mL of Na-form RF resin. Known amounts of oxygen were introduced into the primary recirculation loop by saturating measured volumes of the simulant solution with oxygen and reintroducing

  14. Formaldehyde-releasers in cosmetics: relationship to formaldehyde contact allergy. Part 1. Characterization, frequency and relevance of sensitization, and frequency of use in cosmetics.

    Science.gov (United States)

    de Groot, Anton C; White, Ian R; Flyvholm, Mari-Ann; Lensen, Gerda; Coenraads, Pieter-Jan

    2010-01-01

    In this part of a series of review articles on formaldehyde-releasers and their relationship to formaldehyde contact allergy, formaldehyde-releasers in cosmetics are discussed. In this first part of the article, key data are presented including frequency of sensitization and of their use in cosmetics. In Europe, low frequencies of sensitization have been observed to all releasers: 2-bromo-2-nitropropane-1,3-diol 0.4-1.2%, diazolidinyl urea 0.5-1.4%, imidazolidinyl urea 0.3-1.4%, quaternium-15 0.6-1.9% (for DMDM hydantoin no recent data are available). All releasers score (far) higher prevalences in the USA; the possible explanations for this are discussed. The relevance of positive patch test reactions has been insufficiently investigated. In the USA, approximately 20% of cosmetics and personal care products (stay-on products: 17%, rinse-off products 27%) contain a formaldehyde-releaser. The use of quaternium-15 is decreasing. For Europe, there are no comparable recent data available. In the second part of the article, the patch test relationship of the releasers in cosmetics to formaldehyde contact allergy will be reviewed and it will be assessed whether products preserved with formaldehyde-releasers may contain enough free formaldehyde to pose a threat to individuals who have contact allergy to formaldehyde. PMID:20136875

  15. B36 borophene as an electronic sensor for formaldehyde: Quantum chemical analysis

    Science.gov (United States)

    Shahbazi Kootenaei, Amirhossein; Ansari, Goodarz

    2016-08-01

    Pristine carbon nanotubes and graphene show great sensitivity toward several lethal gases but cannot identify some extremely toxic chemicals such as formaldehyde (HCOH). Recent successful synthesis of all-boron graphene-like sheets attracted strong interest in exploring their possible applications. Herein, we inspected the potential application of B36 borophene sheet as a sensor for HCOH detection, using density functional theory computations. Different theoretical levels including B97D and Minnesota 06 functionals with different basis sets were employed. It was predicted that the electrical conductivity of B36 borophene significantly increases at the presence of HCOH molecules, thereby generating an electrical signal. The electrical signal is increased by increasing the number of adsorbed HCOH molecules, indicating that this sensor is sensitive to the concentration (or pressure) of HCOH gas. These results suggest that the pristine borophene may be used in the HCOH chemical sensors.

  16. Au pair trajectories

    DEFF Research Database (Denmark)

    Dalgas, Karina Märcher

    2015-01-01

    workers from the global South, the first article demonstrates how Facebook can be a fruitful methodological tool in the aspiration to open up the research to new themes of inquiry. However, rather than disregarding the au pairs’ economic problems, the dissertation shows how their family participation and......Since 2000, thousands of young Filipino migrants have come to Denmark as au pairs. Officially, they are there to “broaden their cultural horizons” by living temporarily with a Danish host family, but they also conduct domestic labor in exchange for food and money, which allows them to send...... pair-sending families in the Philippines, this dissertation examines the long-term trajectories of these young Filipinas. It shows how the au pairs’ local and transnational family relations develop over time and greatly influence their life trajectories. A focal point of the study is how au pairs...

  17. An Engineering Evaluation of Spherical Resorcinol Formaldehyde Resin

    Energy Technology Data Exchange (ETDEWEB)

    Birdwell Jr, Joseph F [ORNL; Lee, Denise L [ORNL; Taylor, Paul Allen [ORNL; Collins, Robert T [ORNL; Hunt, Rodney Dale [ORNL

    2010-09-01

    A small column ion exchange (SCIX) system has been proposed for removal of cesium from caustic, supernatant, and dissolved salt solutions stored or generated from high-level tank wastes at the US Department of Energy (DOE) Hanford Site and Savannah River Sites. In both instances, deployment of SCIX systems, either in-tank or near-tank, is a means of expediting waste pretreatment and dispositioning with minimal or no new infrastructure requirements. Conceptually, the treatment approach can utilize a range of ion exchange media. Previously, both crystalline silicotitanate (CST), an inorganic, nonelutable sorbent, and resorcinol-formaldehyde (RF), an organic, elutable resin, have been considered for cesium removal from tank waste. More recently, Pacific Northwest National Laboratory (PNNL) evaluated use of SuperLig{reg_sign} 644, an elutable ion exchange medium, for the subject application. Results of testing indicate hydraulic limitations of the SuperLig{reg_sign} resin, specifically a high pressure drop through packed ion exchange columns. This limitation is likely the result of swelling and shrinkage of the irregularly shaped (granular) resin during repeated conversions between sodium and hydrogen forms as the resin is first loaded then eluted. It is anticipated that a similar flow limitation would exist in columns packed with conventional, granular RF resin. However, use of spherical RF resin is a likely means of mitigating processing limitations due to excessive pressure drop. Although size changes occur as the spherical resin is cycled through loading and elution operations, the geometry of the resin is expected to effectively mitigate the close packing that leads to high pressure drops across ion exchange columns. Multiple evaluations have been performed to determine the feasibility of using spherical RF resin and to obtain data necessary for design of an SCIX process. The work performed consisted of examination of radiation effects on resin performance

  18. Decomposition of formaldehyde by EPD photocatalyst filters in HVAC

    Institute of Scientific and Technical Information of China (English)

    Chien-Chih Chen; Ching-Song Jwo; Tun-Ping Teng

    2011-01-01

    This study used electrophoretic deposition (EPD) to apply titanium oxide (TiO2) coating on stainless steel filters and investigated the effectiveness of photocatalytic oxidation of formaldehyde by TiO2 under various conditions of heating ventilation air conditioning (HVAC).The results showed photocatalytic efficiency could reach 35.59% at 21 ℃ and 36.39% at 26℃ with 7 photocatalyst filters and 5 UVC lamps,the overall efficiency of formaldehyde removal of 52.37% at 21 ℃,and 56.8% at 26℃.By all experimental data can be found that the temperature for the photocatalytic performance is not obvious in the range of this study.

  19. Simple, rapid method for the preparation of isotopically labeled formaldehyde

    Science.gov (United States)

    Hooker, Jacob Matthew; Schonberger, Matthias; Schieferstein, Hanno; Fowler, Joanna S.

    2011-10-04

    Isotopically labeled formaldehyde (*C.sup..sctn.H.sub.2O) is prepared from labeled methyl iodide (*C.sup..sctn.H.sub.3I) by reaction with an oxygen nucleophile having a pendant leaving group. The mild and efficient reaction conditions result in good yields of *C.sup..sctn.H.sub.2O with little or no *C isotopic dilution. The simple, efficient production of .sup.11CH.sub.2O is described. The use of the .sup.11CH.sub.2O for the formation of positron emission tomography tracer compounds is described. The reaction can be incorporated into automated equipment available to radiochemistry laboratories. The isotopically labeled formaldehyde can be used in a variety of reactions to provide radiotracer compounds for imaging studies as well as for scintillation counting and autoradiography.

  20. persimmon tannin-formaldehyde gel decontamination of dilute aqueous solutions

    International Nuclear Information System (INIS)

    in the present work, the extracted juice of unripe astringent persimmon fruit, designated as (kakishibu) was found to have an extremely high affinity for uranium ion. to develop efficient adsorbent for uranium ion the juice was immobilized in formaldehyde. the removal of uranium ion onto the formed gel was found to be affected by several factors such as, concentration of formaldehyde in gel, equilibration time, solution ph, concentration of uranium ion, mass of adsorbent, presence of some cations and anions . the sorption isotherm was discussed in the light of Freundlich and Langmuir models. from Freundlich equation, the exponent 1/n was found in the range of 1>1/n0, δS0 and δG0 were calculated . the capacity of adsorbent was also determined by column technique and found to 20.20 mg/g

  1. Terahertz spectroscopy of deuterated formaldehyde using a frequency multiplication chain

    Science.gov (United States)

    Zakharenko, Olena; Motiyenko, Roman A.; Margulès, Laurent; Huet, Thérèse R.

    2015-11-01

    The rotational spectra of deuterated formaldehyde HDCO and D2CO were recorded between 1.1 and 1.52 THz in order to benchmark new terahertz frequency multiplication chain used in the Lille spectrometer. Important spectrometer parameters such as sensitivity, measurement accuracy, and harmonic composition of the radiation source have been tested using the newly measured spectra. For each of the main deuterated isotopic species of formaldehyde the existent datasets from high resolution measurements were augmented by more than 300 new distinct transition frequencies. Most of these frequencies were measured with an accuracy better than 30 kHz. In addition, the high sensitivity of the spectrometer provided by the new frequency multiplication chain allowed observation, assignment and analysis of 13C, 17O, 18O, and 13C18O isotopic species of HDCO and D2CO. For some of these isotopologues the rotational parameters were determined for the first time.

  2. Phase Space Structures Explain Hydrogen Atom Roaming in Formaldehyde Decomposition.

    Science.gov (United States)

    Mauguière, Frédéric A L; Collins, Peter; Kramer, Zeb C; Carpenter, Barry K; Ezra, Gregory S; Farantos, Stavros C; Wiggins, Stephen

    2015-10-15

    We re-examine the prototypical roaming reaction--hydrogen atom roaming in formaldehyde decomposition--from a phase space perspective. Specifically, we address the question "why do trajectories roam, rather than dissociate through the radical channel?" We describe and compute the phase space structures that define and control all possible reactive events for this reaction, as well as provide a dynamically exact description of the roaming region in phase space. Using these phase space constructs, we show that in the roaming region, there is an unstable periodic orbit whose stable and unstable manifolds define a conduit that both encompasses all roaming trajectories exiting the formaldehyde well and shepherds them toward the H2···CO well. PMID:26499774

  3. Formaldehyde and Glyoxal: New Products in the SCIAMACHY Operational Processor

    Science.gov (United States)

    Hrechanyy, Serhiy; de Smedt, Isabelle; Kretschel, Klaus; Lichtenberg, Günter; Meringer, Markus; Wittrock, Folkard

    In sommer of 2010 version 6 of the SCIAMACHY operational processor is planned to be deliv-ered to ESA. The SCIAMACHY Quality Working Group recommended an implementation of the formalde-hyde (HCHO) and glyoxal (CHOCHO) vertical columns into version 6 of the off-line processor. They are formed during the oxidation of volatile organic compounds (VOCs) emitted by plants, anthropogenic activities, and biomass burning. Due to a rather short lifetime of formaldehyde and glyoxal, their distribution maps, obtained by the SCIAMACHY, represent the emission fields of their precursors, VOCs. The descriptions of reference algorithm as well as all the cross-sections for formaldehyde and glyoxal retrievals were delivered to DLR by the Belgian Institute for Space Aeronomy (BIRA) (I. De Smedt, 2008) and by the IUP (F. Wittrock, 2006), respectively. Both retrievals are based on the DOAS technique. For the formaldehyde retrieval the spectral region of 328.5-346 nm was recommended. The absorption cross-sections of HCHO, O3, NO2, BrO, OClO, a Ring spectrum and a polynomial of the fifth order are included into the fitting procedure. Before conversion to the vertical columns, the slant columns have to be normal-ized by subtracting the slant columns measured over Pacific ocean, where the only source of formaldehyde is methane oxidation. After the conversion to the vertical columns, part of HCHO removed during the previous procedure has to be re-added to the final vertical column by adding of the mean vertical column calculated by the tropospheric chemistry model IMAGES (J.-F. Müller, 1995). This normalization is necessary to compensate for the offset introduced by the solar reference measurements and interferences by other absorbers. For the determination of glyoxal columns, the spectral region 435-457 nm was selected. In this case, the absorption cross-sections of CHOCHO, O3, NO2, H2O, O4, a Ring spectrum and a cubic polynomial are included in the fitting procedure. The normalization of

  4. Molecularly Imprinted Polymer Nanoparticles for Formaldehyde Sensing with QCM

    Science.gov (United States)

    Hussain, Munawar; Kotova, Kira; Lieberzeit, Peter A.

    2016-01-01

    Herein, we report on molecularly imprinted polymers (MIPs) for detecting formaldehyde vapors in air streams. A copolymer thin film consisting of styrene, methacrylic acid, and ethylene glycol dimethacrylate on quartz crystal microbalance (QCM) yielded a detection limit of 500 ppb formaldehyde in dry air. Surprisingly, these MIPs showed specific behavior when tested against a range of volatile organic compounds (VOCs), such as acetaldehyde, methanol, formic acid, and dichloromethane. Despite thus being a suitable receptor in principle, the MIPs were not useful for measurements at 50% humidity due to surface saturation by water. This was overcome by introducing primary amino groups into the polymer via allyl amine and by changing the coating morphology from thin film to nanoparticles. This led to the same limit of detection (500 ppb) and selectivity as before, but at the real-life conditions of 50% relative humidity. PMID:27376287

  5. A measuring method of photo-electric cross section. Application to high-Z elements between 40 keV and 220 keV. Measurement of K absorption edge energy of Au, Th, U, Pu

    International Nuclear Information System (INIS)

    This study first describes a bent crystal monochromator developed for the production of monochromatic beams in a continuous energy range from 30 to 250 keV; it is completed by a metrological application of the device (determination of K absorption edge energy of Au, Th, U, Pu). A method and the associated experimental procedure were developed to measure the photo-electric cross section for high-Z elements; the results are presented with a relative uncertainty ranging between 3 and 6%. Finally, the experimental values are compared with values calculated from theories using self-consistent potential models

  6. Indoor air quality control techniques. Radon, formaldehyde, combustion products

    International Nuclear Information System (INIS)

    This book reviews and evaluates existing indoor air quality control techniques. The indoor air pollutants of most concern are radon, formaldehyde, and certain combustion products-nitrogen dioxide, carbon monoxide, carbon dioxide, and various respirable particles. Many techniques exist to control the concentration of these pollutants and other indoor pollutants that are only now being recognized as significant. The purpose of the book is to provide a current review and evaluation of these control techniques

  7. Investigations on potential co-mutagenic effects of formaldehyde

    Energy Technology Data Exchange (ETDEWEB)

    Speit, Günter, E-mail: guenter.speit@uni-ulm.de; Linsenmeyer, Regina; Duong, Giang; Bausinger, Julia

    2014-02-15

    Highlights: • A549 cells were exposed to formaldehyde in combination with various mutagens. • Formaldehyde did not affect the induction and removal of DNA damage (comet assay). • Formaldehyde did not affect the induction of micronuclei by the mutagens tested. • The expression of the O{sup 6}-methylguanine-DNA methyltransferase was not affected. - Abstract: The genotoxicity and mutagenicity of formaldehyde (FA) has been well-characterized during the last years. Besides its known direct DNA-damaging and mutagenic activity in sufficiently exposed cells, FA at low concentrations might also enhance the mutagenic and carcinogenic effects of other environmental mutagens by interfering with the repair of DNA lesions induced by these mutagens. To further assess potential co-mutagenic effects of FA, we exposed A549 human lung cells to FA in combination with various mutagens and measured the induction and removal of DNA damage by the comet assay and the production of chromosomal mutations by the cytokinesis-block micronucleus assay (CBMN assay). The mutagens tested were ionizing radiation (IR), (±)-anti-B[a]P-7,8-dihydrodiol-9,10-epoxide (BPDE), N-nitroso-N-methylurea (methyl nitrosourea; MNU) and methyl methanesulfonate (MMS). FA (10–75 μM) did not enhance the genotoxic and mutagenic activity of these mutagens under the test conditions applied. FA alone and in combination with MNU or MMS did not affect the expression (mRNA level) of the gene of the O{sup 6}-methylguanine-DNA methyltransferase (MGMT) in A549 cells. The results of these experiments do not support the assumption that low FA concentrations might interfere with the repair of DNA damage induced by other mutagens.

  8. Biodegradation of polystyrene, poly(metnyl methacrylate), and phenol formaldehyde.

    Science.gov (United States)

    Kaplan, D L; Hartenstein, R; Sutter, J

    1979-01-01

    The biodegradation of three synthetic 14C-labeled polymers, poly(methyl methacrylate), phenol formaldehyde, and polystyrene, was studied with 17 species of fungi in axenic cultures, five groups of soil invertebrates, and a variety of mixed microbial communities including sludges, soils, manures, garbages, and decaying plastics. Extremely low decomposition rates were found. The addition of cellulose and mineral failed to increase decomposition rates significantly. PMID:533278

  9. Phase Space Structures Explain Hydrogen Atom Roaming in Formaldehyde Decomposition

    OpenAIRE

    Mauguiere, Frederic A L; Collins, Peter R C; Kramer, Zeb C.; Carpenter, Barry K.; Ezra, Gregory S.; Farantos, Stavros; Wiggins, Stephen R

    2015-01-01

    We re-examine the prototypical roaming reaction—hydrogen atom roaming in formaldehyde decomposition—from a phase space perspective. Specifically, we address the question “why do trajectories roam, rather than dissociate through the radical channel?” We describe and compute the phase space structures that define and control all possible reactive events for this reaction, as well as provide a dynamically exact description of the roaming region in phase space. Using these phase space constructs,...

  10. The Recycling of Resorcinol Formaldehyde Latex Coated Nylon 66

    OpenAIRE

    Wroe, Sarah

    2013-01-01

    The Waste (England and Wales) Regulations encourage business to recycle their waste, as an alternative to landfill. This study has evaluated a number of processing techniques with respect to a difficult to recycle, technical textile, in order to develop recycling opportunities. Resorcinol formaldehyde latex (RFL) coated nylon 66 is a high performance fabric used as an interface to reinforce rubber products such as timing belts.The characteristics of the RFL coated woven fabric, assessed in co...

  11. Investigation of the Wood/Phenol-Formaldehyde Adhesive Interphase Morphology

    OpenAIRE

    Laborie, Marie-Pierre Genevieve

    2002-01-01

    This work addresses the morphology of the wood/ Phenol-Formaldehyde (PF) adhesive interphase using yellow-poplar. In this case, morphology refers to the scale or dimension of adhesive penetration into wood. The objective is to develop methods for revealing ever smaller levels of wood/resin morphology. Dynamic techniques that are commonly utilized in polymer blend studies are investigated as potential methods for probing the wood/ adhesive interphase morphology. These are Dynamic Mechanica...

  12. Effets de site : évalutation expérimentale et modélisations multidimensionnelles : application au site test EURO-SEISTEST (Grèce)

    OpenAIRE

    Riepl, Judith

    1997-01-01

    L'objectif de cette thèse est, l'étude fine des effets d'amplification suite à la géologie locale, notamment dans des bassins sédimentaires, ainsi que l'évaluation des avantages et Iimites des méthodes d'estimations. La partie expérimentale est basée sur des données acquises au site test EURO-SEISTEST, le premier site-test en Europe occidentale proche de Thessalonique (Grèce). Après une évaluation des effets d'amplification au site même et une étude de leur stabilité en fonction de plusieurs ...

  13. Proposition d'un modèle de simplification d'un système documentaire. Application au sein de Turbomeca

    OpenAIRE

    Barroso, Ludovic; Maranzana, Nicolas; Douvrendelle, Franck

    2015-01-01

    La gestion de la qualité est un domaine central pour les entreprises. Associé au système de vérification et au système d'analyse des résultats, c'est à travers ce troisième pilier, le système documentaire, que les entreprises formalisent leur organisation. Fréquemment les systèmes documentaires des sociétés sont volumineux, difficiles à maîtriser et ne suscitent plus autant d'intérêt pour leur personnel. Le modèle proposé ici présente la manière dont on peut améliorer l'efficacité du système ...

  14. Oxidation and reduction kinetics of eutectic SnPb, InSn, and AuSn: a knowledge base for fluxless solder bonding applications

    OpenAIRE

    Kuhmann, Jochen Friedrich; Preuss, A.; Adolphi, B.; K. Maly; Wirth, T.; Oesterle, W.; Pittroff, W.; Weyer, G.; Fanciulli, M.

    1998-01-01

    For microelectronics and especially for upcoming new packaging technologies in micromechanics and photonics fluxless, reliable and economic soldering technologies are needed. In this article, we consequently focus on the oxidation and reduction kinetics of three commonly used eutectic solder alloys: (1) SnPb; (2) InSn; (3) AuSn. The studies of the oxidation kinetics show that the growth of the native oxide, which covers the solder surfaces from the start of all soldering operations is self-li...

  15. Investigation of the detoxification mechanism of formaldehyde-treated tetanus toxin

    DEFF Research Database (Denmark)

    Thaysen-Andersen, Morten; Jørgensen, Sys Borcher; Wilhelmsen, Ellen Sloth;

    2007-01-01

     The tetanus vaccine is based on the extremely potent tetanus neurotoxin (TeNT), which is converted by treatment with formaldehyde and lysine into the non-toxic, but still immunogenic tetanus toxoid (TTd). This formaldehyde-induced detoxification, which to a large extend determines the quality and...... and formaldehyde in the detoxification process and (ii) characterisation of the chemically detoxified TTd. (i) We examined a number of TTd components that was produced by varying the concentrations of formaldehyde and lysine during the inactivation. Toxicity tests showed that the detoxification failed...... when the lysine or formaldehyde concentration was < or =1/5 or < or =1/10, respectively, of the standard level. Gel-electrophoretic analyses showed that inter-chain cross-linking was formaldehyde-dependent and, furthermore, revealed that inter-chain cross-linking was not the only requirement for the...

  16. Property of nano-SiO2/urea formaldehyde resin

    Institute of Scientific and Technical Information of China (English)

    Lin Qiaojia; Yang Guidi; Liu Jinghong; Rao Jiuping

    2006-01-01

    In this paper,we discuss the effects of a nanometer silicon dioxide (nano-SiO2) coupling agent,dispersal methods and the amount of nano-SiO2/urea formaldehyde resin.The results of our study indicate that when nano-SiO2,using KH-550 silane as a coupling agent,was added to UF resin by discontinuous ultrasonic vibration its properties improved effectively.When the content of nano-SiO2 was below 1.5%, the amount of free formaldehyde decreased,and the viscosity and bonding strength of resin increased with an increase in the added nano-SiO2,which did not prolong the curing time.The performance indices of plywood,particleboard and medium density fiberboard (MDF),hot-pressed by nano-SiO2 (I%)/UF resin (F/U molar ratio=l.2), exceeded the requirements of the National Standard. Their free formaldehyde emission reached E1 grade.Finally,we analyzed the mechanism of the strengthening effects of nano-SiO2 on UF resin by means of infrared spectrum analysis and X-ray photoelectronic spectrum (XPS).

  17. Effects of formaldehyde and acetaldehyde inhalation on rat pulmonary mechanics

    Energy Technology Data Exchange (ETDEWEB)

    Saldiva, P.H.; do Rio Caldeira, M.P.; Massad, E.; Calheiros, D.F.; Cardoso, L.M.; Boehm, G.M.S.; Saldiva, C.D.

    1985-10-01

    Two groups of 12 male Wistar rats received either 243 ppm of acetaldehyde or 5.7 ppm of formaldehyde for 8 h a day, 5 days a week during 5 weeks. These levels represent three times the threshold limit values (TLV) for these substances in Brazilian legislation. The animals were evaluated by pulmonary function tests before and after exposure to the pollutants. The data obtained from these rats were compared with those of 12 controls, housed in identical conditions for the same length of time but breathing normal air. The results showed an increase of the functional residual capacity, residual volume, total lung capacity and respiratory frequency in the rats exposed to acetaldehyde atmosphere. The animals exposed to formaldehyde did not present pulmonary function alterations when compared with the controls. The damage caused by acetaldehyde to the peripheral regions of the lung parenchyma, affecting small airways or altering pulmonary elastic properties, is discussed. It is suggested that the Brazilian TLV for acetaldehyde (78 ppm) is not as safe as that for formaldehyde (1.6 ppm).

  18. Low-density carbonized resorcinol-formaldehyde foams

    International Nuclear Information System (INIS)

    This report documents research and development on resorcinol- formaldehyde-based foam materials conducted between 1986 and June 1990, when the effort was discontinued. The foams discussed are resorcinol-formaldehyde (RF) foam, carbonized RF (CRF) foam, and two composite foams, a polystyrene/RF (PS/RF) foam and its carbonized derivative (CPR). The RF foams are synthesized by the polycondensation of resorcinol with formaldehyde in a slightly basic solution. Their structure and density depend strongly on the concentration of the sodium carbonate catalyst. The have an interconnected bead structure similar to that of silica aerogels; bead sizes range from 30 to 130 Angstrom, and cell sizes are less than 0.1 μm. We have achieved densities of 16 to 200 mg/cm3. The RF foams can be pyrolyzed in an inert atmosphere to form a vitreous carbon foam (CRF), which has a similar microstructure but much higher mechanical strength. The PS/RF foams are obtained by filling the 2- to 3-μm cells of PS foam (a low-density hydrocarbon foam we have developed) with RF. The resultant foams have the outstanding handling and machinability of the PS foam matrix and the small cell size of RF. Pyrolyzing PS/RF foams causes depolymerization and loss of the PS; the resulting CPR foams have a structure similar to the PS foams in which CRF both replicates and fills the PS cells

  19. Codetermination of crystal structures at high pressure: Combined application of theory and experiment to the intermetallic compound AuGa2

    Science.gov (United States)

    Godwal, B. K.; Stackhouse, S.; Yan, J.; Speziale, S.; Militzer, Burkhard; Jeanloz, R.

    2013-03-01

    A combination of x-ray diffraction at high pressures and first-principles calculations reveals the sequence of crystal-structural phase transitions in AuGa2 from cubic (Fm3¯m) to orthorhombic (Pnma) at 10 (±4) GPa and then to monoclinic (P21/n) at 33 (±6) GPa. Neither theory nor experiment would have been adequate, on their own, in documenting this sequence of phases, but together they confirm a sequence differing from the Fm3¯m→Pnma→P63/mmc transitions predicted for CaF2 and Pnma → P1121/a transition reported for PbCl2 and SnCl2. The combined results from theory and experiment also allow us to constrain the equations of state of the three phases of AuGa2. Calculations on the analog PbCl2 predict a transition to the P21/n phase seen in AuGa2 that could, therefore, be a common high-pressure phase for PbCl2-structured compounds.

  20. Application of ZnO quantum dots dotted carbon nanotube for sensitive electrochemiluminescence immunoassay based on simply electrochemical reduced Pt/Au alloy and a disposable device

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Fang; Deng, Wenping; Zhang, Yan [Key Laboratory of Chemical Sensing and Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan, 250022 (China); Ge, Shenguang [Shandong Provincial Key Laboratory of Preparation and Measurement of Building Materials, University of Jinan, Jinan, 250022 (China); Yu, Jinghua, E-mail: ujn.yujh@gmail.com [Key Laboratory of Chemical Sensing and Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan, 250022 (China); Song, Xianrang, E-mail: sxr@vip.163.com [Cancer Research Center, Shandong Tumor Hospital, Jinan, 250012 (China)

    2014-03-01

    Highlights: • A sandwich-type electrochemluminence immunosensor was fabricated. • Simply electrochemical reduced Pt/Au alloy was selected as immunosensing probes. • ZnO@CNT composite was first employed as signal amplification label. Abstract: We report on a disposable microdevice suitable for sandwich-type electrochemiluminescence (ECL) detection of prostate specific antigen (PSA). The method is making use of ZnO quantum dots dotted carbon nanotube (ZnO@CNT) and simply electrochemical reduced Pt/Au alloy. The latter was selected as immunosensing probe to modify screen-printed carbon electrode, due to its excellent electrical property. For further ultrasensitive, low-potential and stable ECL detection, ZnO@CNT composite was first synthesized using a facile solvothermal method, and employed as signal amplification label. In this work, two working electrodes in one device were used for one determination to obtain more exact results based on screen-print technique. Taking advantage of dual-amplification effects of the Pt/Au and ZnO@CNT, this immunosensor could detect the PSA quantitatively, in the range of 0.001–500 ng mL⁻¹, with a low detection limit of 0.61 pg mL⁻¹. The resulting versatile immunosensor possesses high sensitivity, satisfactory reproducibility and regeneration. This simple and specific strategy has vast potential to be used in other biological assays.

  1. Green synthesis, characterization of Au-Ag core-shell nanoparticles using gripe water and their applications in nonlinear optics and surface enhanced Raman studies

    Science.gov (United States)

    Kirubha, E.; Palanisamy, P. K.

    2014-12-01

    In recent years there has been excessive progress in the ‘green’ chemistry approach for the synthesis of gold and silver nanoparticles. Bimetallic nanoparticles have gained special significance due to their unique tunable optical properties. Herein we report a facile one-pot, eco-friendly synthesis of Au-Ag bimetallic core-shell nanoparticles using gripe water as reducing as well as stabilizing agent. The as-synthesized Au-Ag nanoparticles are characterized using UV-Vis spectroscopy to determine the surface plasmon resonance, and using transmission electron microscopy to study the morphology and the particle size. The optical nonlinearity of the bimetallic nanoparticles investigated by z-scan technique using femtosecond Ti:sapphire is in the order of 109. The nonlinear optical parameters such as the nonlinear refractive index n2, nonlinear absorption coefficient β and the third order nonlinear susceptibility χ3 are measured for various wavelengths from 700 nm to 950 nm. The Au-Ag nanoparticles are also used in surface enhanced Raman spectroscopic studies to enhance the Raman signals of rhodamine 6G.

  2. High-energy X-ray focusing and applications to pair distribution function investigation of Pt and Au nanoparticles at high pressures

    Science.gov (United States)

    Hong, Xinguo; Ehm, Lars; Zhong, Zhong; Ghose, Sanjit; Duffy, Thomas S.; Weidner, Donald J.

    2016-02-01

    We report development of micro-focusing optics for high-energy x-rays by combining a sagittally bent Laue crystal monchromator with Kirkpatrick-Baez (K-B) X-ray focusing mirrors. The optical system is able to provide a clean, high-flux X-ray beam suitable for pair distribution function (PDF) measurements at high pressure using a diamond anvil cell (DAC). A focused beam of moderate size (10-15 μm) has been achieved at energies of 66 and 81 keV. PDF data for nanocrystalline platinum (n-Pt) were collected at 12.5 GPa with a single 5 s X-ray exposure, showing that the in-situ compression, decompression, and relaxation behavior of samples in the DAC can be investigated with this technique. PDFs of n-Pt and nano Au (n-Au) under quasi-hydrostatic loading to as high as 71 GPa indicate the existence of substantial reduction of grain or domain size for Pt and Au nanoparticles at pressures below 10 GPa. The coupling of sagittally bent Laue crystals with K-B mirrors provides a useful means to focus high-energy synchrotron X-rays from a bending magnet or wiggler source.

  3. The Vital Function of Fe3O4@Au nanocomposites for Hydrolase Biosensor Design and Its Application in Detection of Methyl Parathion

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Yuting; Zhang, Weiying; Lin, Yuehe; Du, Dan

    2013-02-04

    A nanocomposite of gold nanoparticles (AuNPs) decorating a magnetic Fe3O4 core was synthesized using cysteamine (SH–NH2) as linker, and characterized by TEM, XPS, UV and electrochemistry. Then a hydrolase biosensor, based on self-assembly of methyl parathion hydrolase (MPH) on the Fe3O4@Au nanocomposite, was developed for sensitive and selective detection of the organophosphorus pesticide (OP) methyl parathion. The magnetic nanocomposite provides an easy way to construct the enzyme biosensor by simply exerting an external magnetic field, and also provides a simple way to renew the electrode surface by removing the magnet. Unlike inhibition-based enzyme biosensors, the hydrolase is not poisoned by OPs and thus is reusable for continuous measurement. AuNPs not only provide a large surface area, high loading efficiency and fast electron transfer, but also stabilize the enzyme through electrostatic interactions. The MPH biosensor shows rapid response and high selectivity for detection of methyl parathion, with a linear range from 0.5 to 1000 ng/mL and a detection limit of 0.1 ng/mL. It also shows acceptable reproducibility and stability. The simplicity and ease of operation of the proposed method has great potential for on-site detection of P–S containing pesticides and provides a promising strategy to construct a robust biosensor.

  4. Micro reactor for heterogeneous catalysis / application: hydrogen storage from methyl-cyclohexane; Microreacteur pour la catalyse heterogene / application au stockage d'hydrogene a partir du methylcyclohexane

    Energy Technology Data Exchange (ETDEWEB)

    Roumanie, M.; Pijolat, C. [Ecole Nationale Superieure des Mines, Centre SPIN, Dept. MICC, LPMG-URA CNRS D2021, 42 - Saint-Etienne (France); Meille, V.; Bellefon, C. de [CNRS - CPE, Lab. de Genie des Procedes Catalytiques, 69 - Villeurbanne (France); Pouteau, P.; Delattre, C. [CEA Grenoble, Lab. d' Electronique et de Technologie de l' Intrumentation, LETI, 38 (France)

    2005-07-01

    The use of micro-technology and the miniaturization of various systems such as micro-fuel cell is a current field of activity. The aim of this work is to study and to realize an autonomous catalytic micro-reactor for hydrogen release from methyl-cyclohexane. For this reaction of dehydrogenation, the common catalyst is platinum supported on alumina. Consequently, the general objectives of this work are: (i)to develop a micro-reactor with its heaters, sensors..., (ii)to deposit catalysts in the micro-reactor, and (iii)to study the catalytic conversion of this system. The chip used has been developed by the CEA-LETI for biomedical application especially DNA chip. It is comprising several channels etched in silicon substrate with a classic deep reactive ion etching process. These channels of 100 {mu}m depth are structured with pillars to increase the surface and thus improve the overall reaction rate compare to a channel without pillar. The structured micro-reactor is molecularly bonded with a silicon cover to form an airtight devices. As the silicon is transparent to the infrared wavelength a CCD camera is used to observe the bonding quality. The chips are then connected with micro-tubes to test them. The first tested solution consists in a polyimide-glass capillary of 100 {mu}m OD and 40 {mu}m ID stuck inside the channel entrance and glued with a ceramic cement or glass. A second solution is currently under development with metallic capillaries. The reaction studied is extremely endothermic with a heat of reaction of 204 kJ/mol. Consequently it is necessary to include in this system some heaters to have an autonomous micro-reactor. Thick film resistances of platinum have been deposited by the screen printing and used as micro-heaters. The tests of micro-heaters are realized using the infrared thermographic camera. As the silicon is transparent to infrared wavelength, a sputtered platinum layer has been deposited on the opposite face of the resistances. This layer

  5. A Formaldehyde Exposure Assessment Tool for Occupants of FEMA Temporary Housing Units

    OpenAIRE

    Parthasarathy, Srinandini

    2011-01-01

    The report outlines the methodology used to develop a web-based tool to assess the formaldehyde exposure of the occupants of Federal Emergency Management Administration (FEMA) temporary housing units (THUs) after Hurricanes Katrina and Rita in 2005. Linear regression models were built using available data to retrospectively estimate the indoor temperature and relative humidity, formaldehyde emission factors and concentration, and hence the formaldehyde exposures. The interactive web-tool allo...

  6. Malignant melanomas of the nasal cavity after occupational exposure to formaldehyde.

    OpenAIRE

    Holmstrom, M.; Lund, V J

    1991-01-01

    Formaldehyde is a well known nasal carcinogen in rodents, but so far there has been no convincing evidence that workers occupationally exposed to formaldehyde have an increased risk of nasal cancer. In this study three cases of malignant melanoma of the nasal mucosa in persons occupationally exposed to formaldehyde for a long time are presented. The occurrence of such a rare tumour in patients with significant exposure to a known carcinogen warrants further investigation.

  7. Formaldehyde and Leukemia: Epidemiology, Potential Mechanisms and Implications for Risk Assessment

    OpenAIRE

    Zhang, Luoping; Freeman, Laura E. Beane; Nakamura, Jun; Hecht, Stephen S.; Vandenberg, John J.; Smith, Martyn T.; Sonawane, Babasaheb R

    2010-01-01

    Formaldehyde is widely used in the United States and other countries. Occupational and environmental exposures to formaldehyde may be associated with an increased risk of leukemia in exposed individuals. However, risk assessment of formaldehyde and leukemia has been challenging due to inconsistencies in human and animal studies and the lack of a known mechanism for leukemia induction. Here we provide a summary of the symposium at the Environmental Mutagen Society Meeting in 2008, which focuse...

  8. Sinonasal adenoid cystic carcinoma following formaldehyde exposure in the operating theatre

    OpenAIRE

    Sandvik, Anniken; Klingen, Tor Audun; Langård, Sverre

    2014-01-01

    We present a case report of an auxiliary nurse who developed an adenoid cystic carcinoma in her left maxillary sinus following occupational exposure to formaldehyde in the operating theatre. Currently, the epidemiological evidence that formaldehyde can cause cancer in humans is considered to be limited. Previous case-control-studies of formaldehyde and sinonasal cancer have mainly investigated subjects who were concomitantly exposed to wood dust, a known risk factor to the development of sino...

  9. An approach to mechanism-based cancer risk assessment for formaldehyde.

    OpenAIRE

    Conolly, R B; Andersen, M E

    1993-01-01

    The established carcinogenicity of formaldehyde in the rat and suggestive epidemiological evidence that formaldehyde may be a human carcinogen have led to its regulation by U.S. Federal agencies as a probable human carcinogen. These risk assessments have typically been based on tumor data in F344 rats exposed chronically to formaldehyde by inhalation and used the inhaled concentration as a measure of dose and the linearized multistage model (LMS) for dose-response characterization. Low-dose r...

  10. Gel Characteristics of Urea-Formaldehyde Resin under Shear Flow Conditions

    OpenAIRE

    Dang-liang Wang; Han-ying Bai; Gao Yue

    2013-01-01

    Urea-formaldehyde resin (UFR), one of chemical grouts in which the major ingredients are urea-formaldehyde and resin, is widely used in Chinese coal mines grouting. The gel characteristics of urea-formaldehyde resin (UFR) chemical grout under static conditions have been studied by many researchers. However, there is little research carried out on the gel characteristics under shear flow conditions. In fact, chemical grout like UFR keeps in shear flow conditions before gelling in the grouting ...

  11. Formaldehyde catabolism is essential in cells deficient for the Fanconi anemia DNA-repair pathway.

    Science.gov (United States)

    Rosado, Ivan V; Langevin, Frédéric; Crossan, Gerry P; Takata, Minoru; Patel, Ketan J

    2011-12-01

    Metabolism is predicted to generate formaldehyde, a toxic, simple, reactive aldehyde that can damage DNA. Here we report a synthetic lethal interaction in avian cells between ADH5, encoding the main formaldehyde-detoxifying enzyme, and the Fanconi anemia (FA) DNA-repair pathway. These results define a fundamental role for the combined action of formaldehyde catabolism and DNA cross-link repair in vertebrate cell survival. PMID:22081012

  12. Low-Dose Formaldehyde Delays DNA Damage Recognition and DNA Excision Repair in Human Cells

    OpenAIRE

    Luch, Andreas; Frey, Flurina C. Clement; Meier, Regula; Fei, Jia; Naegeli, Hanspeter

    2014-01-01

    Objective Formaldehyde is still widely employed as a universal crosslinking agent, preservative and disinfectant, despite its proven carcinogenicity in occupationally exposed workers. Therefore, it is of paramount importance to understand the possible impact of low-dose formaldehyde exposures in the general population. Due to the concomitant occurrence of multiple indoor and outdoor toxicants, we tested how formaldehyde, at micromolar concentrations, interferes with general DNA damage recogni...

  13. Low-dose formaldehyde delays DNA damage recognition and DNA excision repair in human cells

    OpenAIRE

    Luch, Andreas; Frey, Flurina C. Clement; Meier, Regula; Fei, Jia; Naegeli, Hanspeter

    2014-01-01

    OBJECTIVE: Formaldehyde is still widely employed as a universal crosslinking agent, preservative and disinfectant, despite its proven carcinogenicity in occupationally exposed workers. Therefore, it is of paramount importance to understand the possible impact of low-dose formaldehyde exposures in the general population. Due to the concomitant occurrence of multiple indoor and outdoor toxicants, we tested how formaldehyde, at micromolar concentrations, interferes with general DNA damage recogn...

  14. Susceptibility of Mycobacterium immunogenum and Pseudomonas fluorescens to Formaldehyde and Non-Formaldehyde Biocides in Semi-Synthetic Metalworking Fluids

    OpenAIRE

    Selvaraju, Suresh B.; Yadav, Jagjit S.; Khan, Izhar U. H.

    2011-01-01

    Mycobacterium immunogenum, a newly identified member of the Mycobacterium chelonae_M. abscessus complex is considered a potential etiological agent for hypersensitivity pneumonitis (HP) in machine workers exposed to contaminated metalworking fluid (MWF). This study investigated the biocidal efficacy of the frequently applied commercial formaldehyde-releasing (HCHO) biocides Grotan and Bioban CS 1135 and non-HCHO type biocides Kathon 886 MW (isothiazolone) and Preventol CMK 40 (phenolic) towar...

  15. Electrocatalytic oxidation of small organic molecules on Pt-Au nanoparticles supported by POMAN-MWCNTs

    Science.gov (United States)

    Dong, Qi-Zhi; Li, Li-Li; Chen, Qian-Shan; Guo, Can-Cheng; Yu, Gang

    2015-08-01

    Poly ( o-methoxyaniline) and multi-wall carbon nanotube composite (POMAN-MWCNT) films were deposited onto the platinum (Pt) electrode surface by cyclic voltammetry (CV). Then, platinum and gold (Au) nano-particles were deposited by CV and the double potential deposition method to modify the composite film on the Pt electrode. The morphology of the composite film was characterized by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and its electrocatalytic activity toward methanol and formaldehyde oxidation was studied by CV and other electrochemical methods. The results demonstrated that Pt-Au/POMAN-MWCNTs obtained by the double potential deposition method had a much higher catalytic activity and better anti-poisoning property for electrooxidation of methanol and formaldehyde. The improved catalytic performance could be attributed to the uniformly distribution of duel-metal nanoparticles and the synergistic effect between Pt and Au metals. The abstract should briefly state the problem or purpose of the research, indicate the methodology used, summarize the principal findings and major conclusions.

  16. Microwave Assisted Solvent Free Synthesis of Azomethines from Aryl Aldehydes on Melamin Formaldehyde as Solid Support

    OpenAIRE

    Ramin Rezaei; Mohammadi, Mohammad K; Tahereh Ranjbar

    2011-01-01

    Various aryl aldehydes underwent prompt one pot conversion into the corresponding azomethines in high yields by reacting with hydroxylamine hydrochloride supported on melamine formaldehyde under microwave irradiation.

  17. Formaldehyde Concentration in the Air and in Cadavers at the Gross Anatomy Laboratory in Hiroshima University

    OpenAIRE

    Kurose, Tomoyuki; Kodera, Haruto; Aoyama, Hirohiko; Kawamata, Seiichi

    2004-01-01

    The formaldehyde concentration in the air and in various tissues of 35 human cadavers were measured during a gross anatomy course held at the Faculty of Medicine of Hiroshima University in the 2003 educational year. Atmospheric formaldehyde levels were 0.25-0.55 ppm and thus less than the upper limit of the guideline for formaldehyde exposure (0.5 ppm) set by the Japan Society for Occupational Health (1988) except for one out of 10 measurements. The formaldehyde concentrations in tissues were...

  18. A Formaldehyde Exposure Assessment Tool for Occupants of FEMA Temporary Housing Units

    Energy Technology Data Exchange (ETDEWEB)

    Parthasarathy, Srinandini; Spears, Michael; Maddalena, Randy L.; Russell, Marion L; Apte, Michael G.

    2010-10-01

    The report outlines the methodology used to develop a web-based tool to assess the formaldehyde exposure of the occupants of Federal Emergency Management Administration (FEMA) temporary housing units (THUs) after Hurricanes Katrina and Rita in 2005. Linear regression models were built using available data to retrospectively estimate the indoor temperature and relative humidity, formaldehyde emission factors and concentration, and hence the formaldehyde exposures. The interactive web-tool allows the user to define the inputs to the model to evaluate formaldehyde exposures for different scenarios.

  19. Simultaneous Elimination of Formaldehyde and Ozone Byproduct Using Noble Metal Modified TiO2 Films in the Gaseous VUV Photocatalysis

    Directory of Open Access Journals (Sweden)

    Pingfeng Fu

    2012-01-01

    Full Text Available Simultaneous removal of low concentration formaldehyde (HCHO and ozone byproduct was investigated in the gaseous VUV (vacuum ultraviolet photocatalysis by using noble metal modified TiO2 films. Noble metal (Pt, Au, or Pd nanoparticles were deposited on TiO2 films with ultrafine particle size and uniform distribution. Under 35 h VUV irradiation, the HCHO gas (ca. 420 ppbv was dynamically degraded to a level of 10~45 ppbv without catalyst deactivation, and over 50% O3 byproduct was in situ decomposed in the reactor. However, under the same conditions, the outlet HCHO concentration remained at 125~178 ppbv in the O3 + UV254 nm photocatalysis process and 190~260 ppbv in the UV254 nm photocatalysis process. And the catalyst deactivation also appeared under UV254 nm irradiation. Metallic Pt or Au could simultaneously increase the elimination of HCHO and ozone, but the PdO oxide seemed to inhibit the HCHO oxidation in the UV254 nm photocatalysis. Deposition of metallic Pt or Au reduces the recombination of h+/e− pairs and thus increases the HCHO oxidation and O3 reduction reactions. In addition, adsorbed O3 may be partly decomposed by photogenerated electrons trapped on metallic Pt or Au nanoparticles under UV irradiation.

  20. ExoMol line lists VIII: A variationally computed line list for hot formaldehyde

    CERN Document Server

    Al-Refaie, Ahmed F; Tennyson, Jonathan; Yurchenko, Sergei N

    2015-01-01

    A computed line list for formaldehyde, H$_2{}^{12}$C$^{16}$O, applicable to temperatures up to $T=1500$~K is presented. An empirical potential energy and {\\it ab initio} dipole moment surfaces are used as the input to nuclear motion program TROVE. The resulting line list, referred to as \\textit{AYTY}, contains 10.3 million rotational-vibrational states and around 10 billion transition frequencies. Each transition includes associated Einstein-$A$ coefficients and absolute transition intensities, for wavenumbers below 10~000 cm\\(^{-1}\\) and rotational excitations up to \\(J=70\\). Room-temperature spectra are compared with laboratory measurements and data currently available in the HITRAN database. These spectra show excellent agreement with experimental spectra and highlight the gaps and limitations of the HITRAN data. The full line list is available from the CDS database as well as at \\url{www.exomol.com}.

  1. An attempt to apply the rad-equivalence notion to the biological effects on formaldehyde

    International Nuclear Information System (INIS)

    A renewal of interest for formaldehyde (FA) arose three years ago when it was shown that ultraviolet (UV) sensitive bacterial mutants were also sensitive to FA. These mutants are defective either in the exicision of UV induced pyrimidine dimers or in DNA polymerase I. In other words it appears that there is to some extents an overlap in the recognition and repair of UV and FA induced lesions in wild type cells. The genetic effects of this simple molecule on an unicellular eucaryotic organism Saccharomyces cerevisiae which is genetically well known is studied. One of the aim is to establish for several end-points the validity and extent of applicability of the rad-equivalence notion. For comparison some experiments is also performed with mammalian cells cultivated in vitro

  2. Component conversion from pure Au nanorods to multiblock Ag-Au-Ag nanorods assisted by Pt nanoframe templates

    Science.gov (United States)

    Lee, Sangji; Jang, Hee-Jeong; Jang, Ho Young; Kim, Seong Kyu; Park, Sungho

    2016-06-01

    We developed a new method for synthesizing multiblock Ag-Au-Ag nanorods using Pt nanoframes that had been deposited on the edges of Au nanorod seeds. As a function of Au etching time, the length of the Au nanorod decreased symmetrically starting from the two ends, leading to the formation of empty inner space at the ends. Subsequent reduction of Ag ions could be selectively performed in the inner space confined by Pt nanoframes and the resulting Ag-Au-Ag nanorods exhibited characteristic LSPR modes originating from each block component (in a transverse direction) and SPR coupling (in a longitudinal direction). The high quality of the resulting multiblock nanorods enabled observation of the longitudinal quadrupole mode that was induced by Ag-Au SPR coupling in a long axis. The mode exhibited high sensitivity in accordance with the change in the surrounding media, demonstrating great potential for sensor applications.We developed a new method for synthesizing multiblock Ag-Au-Ag nanorods using Pt nanoframes that had been deposited on the edges of Au nanorod seeds. As a function of Au etching time, the length of the Au nanorod decreased symmetrically starting from the two ends, leading to the formation of empty inner space at the ends. Subsequent reduction of Ag ions could be selectively performed in the inner space confined by Pt nanoframes and the resulting Ag-Au-Ag nanorods exhibited characteristic LSPR modes originating from each block component (in a transverse direction) and SPR coupling (in a longitudinal direction). The high quality of the resulting multiblock nanorods enabled observation of the longitudinal quadrupole mode that was induced by Ag-Au SPR coupling in a long axis. The mode exhibited high sensitivity in accordance with the change in the surrounding media, demonstrating great potential for sensor applications. Electronic supplementary information (ESI) available. See DOI: 10.1039/c6nr03484e

  3. Formaldehyde-releasers in cosmetics: relationship to formaldehyde contact allergy Part 1. Characterization, frequency and relevance of sensitization, and frequency of use in cosmetics

    OpenAIRE

    de Groot, Anton C.; White, Ian R.; Flyvholm, Mari-Ann; Lensen, Gerda; Coenraads, Pieter-Jan

    2010-01-01

    In this part of a series of review articles on formaldehyde-releasers and their relationship to formaldehyde contact allergy, formaldehyde-releasers in cosmetics are discussed. In this first part of the article, key data are presented including frequency of sensitization and of their use in cosmetics. In Europe, low frequencies of sensitization have been observed to all releasers: 2-bromo-2-nitropropane-1,3-diol 0.4-1.2%, diazolidinyl urea 0.5-1.4%, imidazolidinyl urea 0.3-1.4%, quaternium-15...

  4. γ-radiation synthesis of temperature sensitive polymer polyNIPAAm and application in concentration of Au3+ in dilute aqueous solution

    International Nuclear Information System (INIS)

    A Water-soluble temperature sensitive polymer, polyNIPAAm, was synthesized by radiation technology in H2O-THF mixed solutions and further, in simple alcohols, ketones and Cl-containing organic compounds as the solvents. The results showed that all the synthesis was successful. Several polyNIPAAms with different molecular weight were obtained in this way. In addition, the concentration effects of Au2+ in dilute aqueous solutions was investigated by using polyNIPAAm obtained in this work. The concentration coefficient could come up to more than 90%. The effects of acidity and concentration coefficient in the solution were investigated. The optimum conditions were obtained

  5. Direct electron transfer biosensor for hydrogen peroxide carrying nanocomplex composed of horseradish peroxidase and Au-nanoparticle – Characterization and application to bienzyme systems

    Directory of Open Access Journals (Sweden)

    Yusuke Okawa

    2015-09-01

    Full Text Available A reagentless electrochemical biosensor for hydrogen peroxide was fabricated. The sensor carries a monolayer of nanocomplex composed of horseradish peroxidase and Au-nanoparticle, and responds to hydrogen peroxide through the highly efficient direct electron transfer at a mild electrode potential without any soluble mediator. Formation of the nanocomplex was studied with visible spectroscopy and size exclusion chromatography. The sensor performance was analyzed based on a hydrodynamic electrochemical technique and enzyme kinetics. The sensor was applied to fabrication of sensors for glucose and uric acid through further modification of the nanocomplex-carrying electrode with the corresponding hydrogen peroxide-generating oxidases, glucose oxidase and urate oxidase, respectively.

  6. Modélisation et simulation d'un écoulement sous vibration. Application au soudage par ultrasons de composites à matrice thermoplastique.

    OpenAIRE

    Levy, Arthur

    2010-01-01

    Les matériaux composites occupent une place de plus en plus importante dans l'industrie, en particulier aéronautique. Les composites à matrice thermoplastique suscitent aujourd'hui dans ce secteur un très fort engouement par rapport à leurs concurrents thermodurcissables. Le présent travail de thèse se concentre sur le soudage de matériaux composites à matrice thermoplastique. Le procédé de soudage ultrasons consiste à dissiper un travail mécanique au niveau de l'interface. La température aug...

  7. Thiol-PEG-carboxyl-stabilized Fe2O3/Au nanoparticles targeted to CD105: Synthesis, characterization and application in MR imaging of tumor angiogenesis

    International Nuclear Information System (INIS)

    Objective: To detect tumor angiogenesis in tumor-bearing mice using thiol-PEG-carboxyl-stabilized Fe2O3/Au nanoparticles targeted to CD105 on magnetic resonance imaging (MRI). Methods: Fe2O3/Au nanoparticles (hybrids) were prepared by reducing Au3+ on the surface of Fe2O3 nanoparticles. Hybrids were stabilized with thiol-PEG-carboxyl via the Au–S covalent bond, and further conjugated with anti-CD105 antibodies through amide linkages. Characteristics of the hybrid-PEG-CD105 nanoparticles were evaluated. Using these nanoparticles, the labeling specificity of human umbilical vein endothelial cells (HUVECs) was evaluated in vitro. MRI T2*-weighted images were obtained at different time points after intravenous administration of the hybrid-PEG-CD105 nanoparticles in the tumor-bearing mice. After MR imaging, the breast cancer xenografts were immediately resected for immunohistochemistry staining and Prussian blue staining to measure the tumor microvessel density (MVD) and evaluate the labeling of blood microvessels by the hybrid-PEG-CD105 nanoparticles in vivo. Results: The mean diameter of the hybrid-PEG-CD105 nanoparticles was 56.6 ± 8.0 nm, as measured by transmission electron microscopy (TEM). Immune activity of the hybrid-PEG-CD105 nanoparticles was 53% of that of the anti-CD105 antibody, as detected by enzyme-linked immunosorbent assay (ELISA). The specific binding of HUVECs with the hybrid-PEG-CD105 nanoparticles was proved by immunostaining and Prussian blue staining in vitro. For breast cancer xenografts, the combination of the hybrid-PEG-CD105 nanoparticles with blood microvessels was detectable by MRI after 60 min administration of the contrast agent. The T2* relative signal intensity (SIR) was positively correlated with the tumor MVD (R2 = 0.8972). Conclusion: Anti-CD105 antibody-coupled, thiol-PEG-carboxyl-stabilized core–shell Fe2O3/Au nanoparticles can efficiently target CD105 expressed by HUVECs. Furthermore, the hybrid-PEG-CD105 nanoparticles can be

  8. Preliminary study: Formaldehyde exposure in laboratories of Sharjah university in UAE

    Directory of Open Access Journals (Sweden)

    Hafiz Omer Ahmed

    2011-01-01

    Full Text Available Objectives : Laboratory technicians, students, and instructors are at high risk, because they deal with chemicals including formaldehyde. Thus, this preliminary study was conducted to measure the concentration of formaldehyde in the laboratories of the University of Sharjah in UAE. Materials and Methods: Thirty-two air samples were collected and analyzed for formaldehyde using National Institute for Occupational Safety and Health (NIOSH method 3500. In this method, formaldehyde reacts with chromotropic acid in the presence of sulfuric acid to form a colored solution. The absorbance of the colored solution is read in spectrophotometer at wavelength 580 nm and is proportional to the quantity of the formaldehyde in the solution. Results: For the anatomy laboratory and in the presence of the covered cadaver, the mean concentration of formaldehyde was found to be 0.100 ppm with a range of 0.095-0.105 ppm. Whereas for the other laboratories, the highest mean concentration of formaldehyde was 0.024 ppm in the general microbiology laboratory and the lowest mean concentration of formaldehyde was 0.001 ppm in the environmental health laboratory. The 8-hour (time-weighted average concentration of formaldehyde was found to be ranging between 0.0003 ppm in environmental health laboratory and 0.026 ppm in the anatomy laboratory. Conclusions: The highest level of concentration of formaldehyde in the presence of the covered cadaver in anatomy laboratory exceeded the recommended ceiling standard established by USA-NIOSH which is 0.1 ppm, but below the ceiling standard established by American Conference of Governmental Industrial Hygienists which is 0.3 ppm. Thus, it is recommended that formaldehyde levels should be measured periodically specially during the dissection in the anatomy laboratory, and local exhaust ventilation system should be installed and personal protective equipment such as safety glass and gloves should be available and be used to prevent

  9. Violence et ordre politique au Nigeria

    OpenAIRE

    Fourchard, Laurent

    2007-01-01

    International audience De nombreuses analyses ont associé le retour d'un régime civil au Nigeria en 1999 au développement d'organisations armées privées et au regain de conflits dits religieux, inter-ethniques ou communautaires. L'application controversée de la charia dans douze Etats du nord et les actions de guérilla dans la région pétrolière du delta ont ainsi largement focalisé l'attention des médias. Le retour de la " démocratie " témoignerait-t-il d'un déclin de l'Etat ? Ces violence...

  10. Développement d’une méthode d’hygiénisation thermique des effluents au moyen d’échangeurs de chaleur (application au lisier porcin)

    OpenAIRE

    Cunault, C.

    2012-01-01

    / La plupart des traitements classiques appliqués aux effluents ont peu d’impact sur les microorganismes pathogènes. Aussi une méthode de traitement thermique des effluents a été développée et son efficacité de désinfection a été évaluée. Son principe repose sur l’application d’un couple temps/température. L’effluent est chauffé en continu puis maintenu chaud avant d’être refroidi. Le système comprend deux échangeurs de chaleur qui permettent de recycler jusqu...

  11. 40 CFR 721.10189 - Fatty acids, tall-oil, reaction products with (butoxymethyl) oxirane formaldehyde-phenol polymer...

    Science.gov (United States)

    2010-07-01

    ... products with (butoxymethyl) oxirane formaldehyde-phenol polymer glycidyl ether, morpholinepropanamine...-phenol polymer glycidyl ether, morpholinepropanamine, propylene glycol diamine and aliphatic polyamine, N... products with (butoxymethyl) oxirane formaldehyde-phenol polymer glycidyl ether,...

  12. Reduction of graphene oxide by 100 MeV Au ion irradiation and its application as H2O2 sensor

    International Nuclear Information System (INIS)

    Graphene oxide (GO) synthesized from a modified Hummer’s method was reduced (referred, rGO) by using 100 MeV Au ion species and its response to the sense H2O2 was investigated. The changes in the atomic composition and structural properties of rGO after irradiation were studied using x-ray diffraction, Fourier transform infrared spectroscopy and x-ray photo-electron spectroscopy. These results suggested that the removal of the oxygen-containing functional groups and the improvement of the electrochemical performance of reduced graphene oxide (rGO) after ion irradiation. Raman spectroscopic results revealed the increase in the disorder parameter (I D/I G) after Au ion irradiation and also the formation of a large number of small sp2 domains due to the electronic energy loss of ion beam. The resultant rGO was investigated for H2O2 sensing using electrochemical techniques and it showed a good response. (paper)

  13. M\\TiO₂ (M=Au, Ag) transparent aqueous sols and its application on polymeric surface antibacterial post-treatment.

    Science.gov (United States)

    Wu, Liangzhuan; Yu, Yuan; Song, Le; Zhi, Jinfang

    2015-05-15

    In this paper, we reported a simple and mild chemical method for synthesis of crystalline metal\\TiO2 (M=Au, Ag) transparent aqueous sols at low temperature (80°C). It should be found that the as-synthesized metal\\TiO2 sols could easily be coated on the flexible PET surfaces of the through the as-developed electroless-plating-like solution deposition (EPLSD) procedure. The as-prepared metal\\TiO2 sols and related flexible thin film were characterized by TEM, SEM, XRD, UV-vis, and FTIR analysis. The results showed that the Au and Ag nanoparticles can significantly improve the optical absorption properties of TiO2 due to the surface plasmon generated by the noble metal, which in turn enhanced the photo-induced antibacterial performance of the as-prepared metal\\TiO2 flexible film. Moreover, the photo-generated electrons could transfer between the metal and titanium dioxide under different irradiation (ultraviolet or visible light), which could significantly reduce the recombination of photo-induced electrons and holes, resulting in the better photo-induced antibacterial performance. Therefore, the EPLSD procedure may be used as a general polymeric surface antibacterial post-treatment procedure for preparing the metal\\TiO2 flexible film because of the noble metal enhanced antibacterial performance. PMID:25678155

  14. Electrodisintegration of 197Au

    International Nuclear Information System (INIS)

    Cross sections for the (e, xn) reaction on 197Au have been measured for 1= 4 were calculated by means of an intranuclear cascade model. Good agreement is found for x = 7 is discussed. No evidence is found for giant resonances in regions above the giant dipole resonance. (Auth.)

  15. Catalytic activity of Au nanoparticles

    DEFF Research Database (Denmark)

    Larsen, Britt Hvolbæk; Janssens, Ton V.W.; Clausen, Bjerne;

    2007-01-01

    Au is usually viewed as an inert metal, but surprisingly it has been found that Au nanoparticles less than 3–5 nm in diameter are catalytically active for several chemical reactions. We discuss the origin of this effect, focusing on the way in which the chemical activity of Au may change with par......Au is usually viewed as an inert metal, but surprisingly it has been found that Au nanoparticles less than 3–5 nm in diameter are catalytically active for several chemical reactions. We discuss the origin of this effect, focusing on the way in which the chemical activity of Au may change...... with particle size. We find that the fraction of low-coordinated Au atoms scales approximately with the catalytic activity, suggesting that atoms on the corners and edges of Au nanoparticles are the active sites. This effect is explained using density functional calculations....

  16. Roaming Under the Microscope: Trajectory Study of Formaldehyde Dissociation.

    Science.gov (United States)

    Houston, Paul L; Conte, Riccardo; Bowman, Joel M

    2016-07-14

    The photodissociation of formaldehyde was studied using quasi-classical trajectories to investigate "roaming," or events involving trajectories that proceed far from the minimum energy pathway. Statistical analysis of trajectories performed over a range of nine excitation energies from 34 500 to 41 010 cm(-1) (including zero-point energy) provides characterization of the roaming phenomenon and insight into the mechanism. The trajectories are described as projections onto three coordinates: the distance from the CO center of mass to the furthest H atom and the azimuthal and polar coordinates of that H atom with respect to the CO axis. The trajectories are used to construct a "minimum energy" potential energy surface showing the potential for any binary combination of these three coordinates that is at a minimum energy with respect to values of the other coordinates encountered during the trajectories. We also construct flux diagrams for roaming, transition-state, and radical pathways, as well as "reaction configuration" plots that show the distribution of reaction geometries for roaming and transition-state pathways. These constructs allow characterization of roaming in formaldehyde as, principally, internal rotation of the roaming H atom around the CO axis at a slowly varying and elongated distance from the CO center of mass. The rotation is nearly uniform, and is sometimes accompanied by rotation in the polar coordinate. The roaming state of formaldehyde can be treated as a separate kinetic entity, much as one might treat an isomer. Rate constants for the formation of and reaction from this roaming state are derived from the trajectory data as a function of excitation energy. PMID:26885745

  17. Interface Effects on Tunneling Magnetoresistance in Organic Spintronics with Flexible Amine-Au Links

    OpenAIRE

    Gorjizadeh, Narjes; Quek, Su Ying

    2013-01-01

    Organic spintronics is a promising emerging field, but the sign of the tunneling magnetoresistance (TMR) is highly sensitive to interface effects, a crucial hindrance to applications. A key breakthrough in molecular electronics was the discovery of amine-Au link groups that give reproducible conductance. Using first principles calculations, we predict that amine-Au links give improved reproducibility in organic spintronics junctions with Au-covered Fe leads. The Au layers allow only states wi...

  18. Area and Personal Exposure Levels to Formaldehyde and Its Variation among Undergraduate Students during Gross Anatomy Laboratory Practice

    OpenAIRE

    Pensri Watchalayann; Adul Tapyai; Kajorn Lakchayapakorn

    2014-01-01

    Formaldehyde emitted from the cadavers in Gross Anatomy Laboratory may fluctuate leading to a variation in exposure level of the participants during practice. This study aimed to evaluate the variation of formaldehyde levels and to determine the relationship between area and personal exposure concentration. Formaldehyde levels were measured in six sampling areas repeatedly during three types of study sessions; thoracic, abdominal, and brain and nerve study session. The highest formaldehyde le...

  19. Changes in respiratory function after one and three hours of exposure to formaldehyde in non-smoking subjects.

    OpenAIRE

    Akbar-Khanzadeh, F; Mlynek, J S

    1997-01-01

    OBJECTIVE: To determine the changes in respiratory function within one hour and three hours of exposure to formaldehyde and investigate the relation between exposure to formaldehyde and acute changes in respiratory function. METHOD: Respiratory function of 50 non-smoking medical students exposed to formaldehyde in a gross anatomy laboratory were compared with respiratory function of 36 non-exposed, non-smoking physiotherapy students. Formaldehyde concentrations were measured in the breathing ...

  20. Magnetic susceptibilities of liquid Cr-Au, Mn-Au and Fe-Au alloys

    Energy Technology Data Exchange (ETDEWEB)

    Ohno, S.; Shimakura, H. [Niigata University of Pharmacy and Applied Life Sciences, Higashijima, Akiha-ku, Niigata 956-8603 (Japan); Tahara, S. [Faculty of Science, University of the Ryukyus, Nishihara-cho, Okinawa 903-0213 (Japan); Okada, T. [Niigata College of Technology, Kamishin’eicho, Nishi-ku, Niigata 950-2076 (Japan)

    2015-08-17

    The magnetic susceptibility of liquid Cr-Au, Mn-Au, Fe-Au and Cu-Au alloys was investigated as a function of temperature and composition. Liquid Cr{sub 1-c}Au{sub c} with 0.5 ≤ c and Mn{sub 1-c}Au{sub c} with 0.3≤c obeyed the Curie-Weiss law with regard to their dependence of χ on temperature. The magnetic susceptibilities of liquid Fe-Au alloys also exhibited Curie-Weiss behavior with a reasonable value for the effective number of Bohr magneton. On the Au-rich side, the composition dependence of χ for liquid TM-Au (TM=Cr, Mn, Fe) alloys increased rapidly with increasing TM content, respectively. Additionally, the composition dependences of χ for liquid Cr-Au, Mn-Au, and Fe-Au alloys had maxima at compositions of 50 at% Cr, 70 at% Mn, and 85 at% Fe, respectively. We compared the composition dependences of χ{sub 3d} due to 3d electrons for liquid binary TM-M (M=Au, Al, Si, Sb), and investigated the relationship between χ{sub 3d} and E{sub F} in liquid binary TM-M alloys at a composition of 50 at% TM.

  1. Wettability of Poplar Wood Impregnated by Phenol-formaldehyde Resin

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    In this study,plantation poplar wood was first impregnated by low molecular weight phenol-formaldehyde(PF) resin solution by vacuum-pressure process.And then the wettability of sanded and non-sanded radial and tangential sections from un-impregnated and impregnated poplar wood was tested respectively by the measurement of contact angles using different liquids.Finally,the surface free energy of different samples was estimated by the plot extrapolation method.The results showed that the wettability of woo...

  2. Preparation and characterization of phenolic-melamine-formaldehyde composite aerogel

    International Nuclear Information System (INIS)

    Phenolic-doped melamine-formaldehyde (MF) aerogels were investigated by adding resorcin to MF sol before the formation of crosslink. The solvents in wet gel were then exchanged with ethanol. After CO2 supercritical drying process, the doped MF areogels were prepared with the lowest density of about 50 kg · m-3. The samples were also characterized by HR-TEM, FESEM, IR absorption spectroscopy and thermogravimetric analyses. The results indicates that the structures of the aerogels are different by changing the mole ratio of melamine to resorcin, and the thermal stability is improved under the temperature of 300 degree C. (authors)

  3. Formaldehyde degradation by UV/TiO2/O3 process using continuous flow mode

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The degradation of formaldehyde gas was studied using UV/TiO2/O3 process under the condition of continuous flow mode.The effects of humidity,initial formaldehyde concentration,residence time and ozone adding amount on degradation of formaldehyde gas were investigated.The experimental results indicated that the combination of ozonation with photocatalytic oxidation on the degradation of formaldehyde showed a synergetic action,e.g.,it could considerably increase decomposing of formaldehyde.The degradation efficiency of formaldehyde was between 73.6% and 79.4% while the initial concentration in the range of 1.84-24 mg/m3 by O3/TiO2/UV process.The optimal humidity was about 50% in UV/TiO2/O3 processs and degradation of formaldehyde increases from 39.0% to 94.1% when the ozone content increased from 0 to 141 mg/m3.Furthermore.the kinetics of formaldehyde degradation coefficient K of 0.0268 m3/mg were obtained.

  4. Mortality among a cohort of garment workers exposed to formaldehyde: an update

    OpenAIRE

    Pinkerton, L; Hein, M.; Stayner, L

    2004-01-01

    Aims: To evaluate the mortality experience of 11 039 workers exposed to formaldehyde for three months or more in three garment plants. The mean time weighted average formaldehyde exposure at the plants in the early 1980s was 0.15 ppm but past exposures may have been substantially higher.

  5. 78 FR 52567 - Formaldehyde Standard; Extension of the Office of Management and Budget's (OMB) Approval of...

    Science.gov (United States)

    2013-08-23

    ... Order No. 1-2012 (77 FR 3912). Signed at Washington, DC, on August 19, 2013. David Michaels, Assistant... Occupational Safety and Health Administration Formaldehyde Standard; Extension of the Office of Management and... the information collection requirements specified in the standard on Formaldehyde (29 CFR...

  6. 40 CFR 721.10134 - Formaldehyde, polymer with dialkylphenylamine, dialkylphenol and trimethylhexanediamine (generic).

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Formaldehyde, polymer with... CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.10134 Formaldehyde, polymer... significant new uses subject to reporting. (1) The chemical substance identified generically as...

  7. Developing a Reference Material for Diffusion-Controlled Formaldehyde Emissions Testing

    Science.gov (United States)

    Emissions of formaldehyde from building materials can contaminate indoor air and create significant risks to human health. The need to control formaldehyde emissions from indoor materials is made more urgent by the prevailing drive to improve building energy by decreasing ventil...

  8. 75 FR 17163 - Formaldehyde Standard; Extension of the Office of Management and Budget's (OMB) Approval of...

    Science.gov (United States)

    2010-04-05

    ... Act of 1995 (44 U.S.C. 3506 et seq.) and Secretary of Labor's Order No. 5-2007 (72 FR 31160). Signed... Occupational Safety and Health Administration Formaldehyde Standard; Extension of the Office of Management and... specified in the Standard on Formaldehyde (29 CFR 1910.1048). The standard protects workers from the...

  9. 40 CFR Appendix B to Subpart Nnn... - Free Formaldehyde Analysis of Insulation Resins by Hydroxylamine Hydrochloride

    Science.gov (United States)

    2010-07-01

    ... with a high FF content. 2. Principle 2.1a. The basis for this method is the titration of the...—Free Formaldehyde Analysis of Insulation Resins by Hydroxylamine Hydrochloride 1. Scope This method was... method. The sample should contain approximately 0.3 grams free formaldehyde to ensure complete...

  10. Solid phase microextraction method development for measuring Henry's Law constants of formaldehyde in aqueous solutions

    Science.gov (United States)

    Formaldehyde (HCHO) has been of special concern as an indoor air pollutant because of its existence in a wide range of products and its adverse health effects. The air-water partitioning behavior of volatile organic compounds (VOCs) such as formaldehyde is an important process th...

  11. Determination of formaldehyde in frozen fish with formaldehyde dehydrogenase using a flow injection system with an incorporated gel-filtration chromatrography column

    DEFF Research Database (Denmark)

    Bechmann, Iben Ell

    1996-01-01

    A flow injection analysis (FIA) system for determination of formaldehyde in frozen fish products is described. The system provides a rapid and selective determination of formaldehyde in aqueous fish extracts by the combination of a deproteinization procedure and a stopped-now enzymatic approach in...... a FIA system. The FIA system is furnished with a gel-filtration chromatography column for on-line removal of the proteins from the extract before the enzymatic analysis is performed. Compared with the standard methods for determination of formaldehyde in fish products the present method is much...... faster and less affected by interferences. The limit of detection for the proposed method is 2.5 mg/l of formaldehyde. The sampling frequency is about 10 determinations per hour....

  12. Determination of Formaldehyde in Frozen Fish with Formaldehyde Dehydrogenase Using a Flow Injection System with an Incorporated Gel-filtration Chromatography Column

    DEFF Research Database (Denmark)

    Bechmann, Iben Ellegaard

    1996-01-01

    A flow injection analysis (FIA) system for determination of formaldehyde in frozen fish products is described. The system provides a rapid and selective determination of formaldehyde in aqueous fish extracts by the combination of a deproteinization procedure and a stopped-flow enzymatic approach in...... a FIA system. The FIA system is furnished with a gel-filtration chromatography column for on-line removal of the proteins from the extract before the enzymatic analysis is performed. Compared with the standard methods for determination of formaldehyde in fish products the present method is much...... faster and less affected by interferences. The limit of detection for the proposed method is 2.5 mg/l of formaldehyde. The sampling frequency is about 10 determinations per hour....

  13. LA DIVERSITÉ DÉPLOYÉE AU SEIN DE L’UNIVERSITÉ D’ENTREPRISE : L’APPLICATION CONCRÈTE D’UNE VALEUR ADOPTÉE PAR LA DIRECTION GÉNÉRALE

    Directory of Open Access Journals (Sweden)

    Virginia Drummond-Guitel

    2009-09-01

    Full Text Available La diversité devenue une valeur incontournable adoptée par les grands groupes, encore faut-t-il trouver les moyens concrets pour l’intégrer dans les pratiques des ressources humaines et dans les mentalités des personnes. Le présent papier a pour but de montrer comment les valeurs de la diversité adoptées par la direction générale ont été déclinées et appliquées dans un processus de sélection de candidats pour une formation continue au sein d’une grande organisation internationale. A travers l’application d’une méthode qualitative de recherche, 10 (dix dirigeants ayant conçu la formation et 42 (quarante-deux managers ayant suivi le programme confirment l’atteinte du but stratégique de cette formation, autrement dit, l’atteinte d’une vision partagée (SENGE, 1991, à travers la consolidation d’un fort sentiment d’appartenance à la culture organisationnelle (SCHEIN, 1995. Les managers ont été sélectionnés selon leurs différentes professions, cultures nationales et différents secteurs d’activités, confirmant ainsi une promotion de la diversité au sein de l’organisation.

  14. 金-硅共晶键合技术及其应用%Au-Si Eutectic Bonding Technology and Its Application

    Institute of Scientific and Technical Information of China (English)

    陈颖慧; 施志贵; 郑英彬; 王旭光; 张慧

    2015-01-01

    采用金属过渡层来实现硅-硅低温键合,首先介绍了选择钛金作为金属过渡层的原因和金硅共晶键合的基本原理,然后探索了不同键合面积和不同金层厚度对金硅共晶键合质量的影响规律,开展了图形化的硅晶圆和硅盖板之间的低温共晶键合实验研究,获取了最优键合面积的阈值和最优金层厚度。最后将该低温金硅共晶键合技术应用到MEMS器件圆片级封装实验中,实验结果表明较好地实现了MEMS惯性器件的封装强度,但是还存在密封性差的缺陷,需进一步进行实验改进。%In this paper, metal medium was adopted to realize the low temperature Si-Si bonding.First, the reason for choosing Ti/Au as metal medium was presented , and the principle of Au-Si eutectic bond-ing was introduced .Then the effect of bonding area and metal thickness on Au-Si eutectic bonding quality was explored .The low temperature eutectic bonding between patterned silicon wafer and smooth silicon wafer was researched by experiment .The best bonding area and the optimal metal thickness were obtained .At last , the low temperature eutectic bonding technology was applied in the MEMS wafer level package .Results show that the low temperature eutectic bonding technology can satisfy the bonding strength of MEMS inertial devices .However , the leakproofness of bonding was not enough , which needs to be further improved .

  15. 40 CFR 721.10190 - Formaldehyde, polymer with aliphatic diamine and phenol, reaction products with 4-methyl-2...

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Formaldehyde, polymer with aliphatic... Formaldehyde, polymer with aliphatic diamine and phenol, reaction products with 4-methyl-2-pentanone (generic... identified generically as formaldehyde, polymer with aliphatic diamine and phenol, reaction products with...

  16. 40 CFR 86.120-94 - Gas meter or flow instrumentation calibration; particulate, methanol and formaldehyde measurement.

    Science.gov (United States)

    2010-07-01

    ... calibration; particulate, methanol and formaldehyde measurement. 86.120-94 Section 86.120-94 Protection of... Procedures § 86.120-94 Gas meter or flow instrumentation calibration; particulate, methanol and formaldehyde measurement. (a) Sampling for particulate, methanol and formaldehyde emissions requires the use of gas...

  17. 40 CFR 721.5560 - Formaldehyde, polymer with (chloromethyl) oxirane and phenol, reaction products with 6H-dibenz[c...

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Formaldehyde, polymer with... Formaldehyde, polymer with (chloromethyl) oxirane and phenol, reaction products with 6H-dibenz oxaphosphorin-6... identified as formaldehyde, polymer with (chloromethyl) oxirane and phenol, reaction products with...

  18. 40 CFR 86.1320-90 - Gas meter or flow instrumentation calibration; particulate, methanol, and formaldehyde measurement.

    Science.gov (United States)

    2010-07-01

    ... calibration; particulate, methanol, and formaldehyde measurement. 86.1320-90 Section 86.1320-90 Protection of... instrumentation calibration; particulate, methanol, and formaldehyde measurement. (a) Sampling for particulate, methanol and formaldehyde emissions requires the use of gas meters or flow instrumentation to...

  19. 24 CFR 3280.406 - Air chamber test method for certification and qualification of formaldehyde emission levels.

    Science.gov (United States)

    2010-04-01

    ... certification and qualification of formaldehyde emission levels. 3280.406 Section 3280.406 Housing and Urban... qualification of formaldehyde emission levels. (a) Preconditioning. Preconditioning of plywood or particleboard... with the Standard Test Method for Determining Formaldehyde Levels from Wood Products Under Defined...

  20. 21 CFR 175.380 - Xylene-formaldehyde resins condensed with 4,4′-isopropylidenediphenol-epichlorohydrin epoxy resins.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Xylene-formaldehyde resins condensed with 4,4â²... Xylene-formaldehyde resins condensed with 4,4′-isopropylidenediphenol-epichlorohydrin epoxy resins. The...) The resins are produced by the condensation of xylene-formaldehyde resin and...

  1. Endogenous Formaldehyde Is a Hematopoietic Stem Cell Genotoxin and Metabolic Carcinogen.

    Science.gov (United States)

    Pontel, Lucas B; Rosado, Ivan V; Burgos-Barragan, Guillermo; Garaycoechea, Juan I; Yu, Rui; Arends, Mark J; Chandrasekaran, Gayathri; Broecker, Verena; Wei, Wei; Liu, Limin; Swenberg, James A; Crossan, Gerry P; Patel, Ketan J

    2015-10-01

    Endogenous formaldehyde is produced by numerous biochemical pathways fundamental to life, and it can crosslink both DNA and proteins. However, the consequences of its accumulation are unclear. Here we show that endogenous formaldehyde is removed by the enzyme alcohol dehydrogenase 5 (ADH5/GSNOR), and Adh5(-/-) mice therefore accumulate formaldehyde adducts in DNA. The repair of this damage is mediated by FANCD2, a DNA crosslink repair protein. Adh5(-/-)Fancd2(-/-) mice reveal an essential requirement for these protection mechanisms in hematopoietic stem cells (HSCs), leading to their depletion and precipitating bone marrow failure. More widespread formaldehyde-induced DNA damage also causes karyomegaly and dysfunction of hepatocytes and nephrons. Bone marrow transplantation not only rescued hematopoiesis but, surprisingly, also preserved nephron function. Nevertheless, all of these animals eventually developed fatal malignancies. Formaldehyde is therefore an important source of endogenous DNA damage that is counteracted in mammals by a conserved protection mechanism. PMID:26412304

  2. The effect of urea pretreatment on the formaldehyde emission and properties of straw particleboard

    Institute of Scientific and Technical Information of China (English)

    Hojat Hematabadi; Rabi Behrooz

    2012-01-01

    For manufacturing low-formaldehyde emission particleboard from wheat straw and urea-formaldehyde (UF) resins using urea treatment for indoor environments,we investigated the influence of urea treatment on the formaldehyde emission,physical and mechanical properties of the manufactured particleboard.Wheat straws were treated at three levels of urea concentration (5%,10%,15%) and 95℃ as holding temperature.Wheat straw particleboards were manufactured using hot press at 180℃ and 3 MPa with two types of UF adhesive (UF-45,UF-91).Then the formaldehyde emission values,physical properties and mechanical properties were considered.The results show that the formaldehyde emission value was decreased by increasing urea concentration.Furthermore,the results indicate that the specimens under urea treatment have better mechanical and physical properties compared with control specimens.Also specimens under urea treatment at 10% concentration and UF-91 type adhesive have the most optimum physical and mechanical strength.

  3. Combined effect of formaldehyde and gamma-irradiation. Vitamin complex effect

    International Nuclear Information System (INIS)

    Combined inhalation effect of formaldehyde and gamma-irradiation on the activities of alcohol and aldehyde dehydrogenases in rat lung tissue was studied. The possibility of fitting the parameters studied by the vitamin PP, A and E and complex was shown. At investigation of white rats in conditions of formaldehyde inhalation in concentration 10 mg/m3 and gamma-irradiation by dose 0.25 Gy the changes of activities of alcohol and aldehyde dehydrogenases in the rat lung tissue were detected. An injection of PP, A and E vitamin complex after combined effect of formaldehyde and gamma-irradiation contributes to normalization of studied parameters. The K(C-1) constant is reduced. On this basis it is proposed that in such conditions formaldehyde stabilizes membranes and protects important metabolic processes against damages. Thus, vitamin complex is capable to level a toxic combined effect of formaldehyde and gamma-irradiation. 9 refs., 1 tab

  4. Airborne In-Situ Measurements of Formaldehyde Over California: First Results from the Compact Formaldehyde Fluorescence Experiment (COFFEE) Instrument

    Science.gov (United States)

    Marrero, Josette Elizabeth; Saint Clair, Jason; Yates, Emma L.; Gore, Warren; Swanson, Andrew K.; Iraci, Laura T.; Hanisco, Thomas F.

    2016-01-01

    Formaldehyde (HCHO) is one of the most abundant oxygenated volatile organic compounds (VOCs) in the atmosphere, playing a role multiple atmospheric processes. Measurements of HCHO can be used to help quantify convective transport, the abundance of VOCs, and ozone production in urban environments. The Compact Formaldehyde FluorescencE Experiment (COFFEE) instrument uses Non-Resonant Laser Induced Fluorescence (NR-LIF) to detect trace concentrations of HCHO as part of the Alpha Jet Atmospheric eXperiment (AJAX) payload. Developed at NASA GSFC, COFFEE is a small, low maintenance instrument with a sensitivity of 100 pptv and a quick response time (1 sec). The COFFEE instrument has been customized to fit in an external wing pod on the Alpha Jet aircraft based at NASA ARC. The instrument can operate over a broad range of altitudes, from boundary layer to lower stratosphere, making it well suited for the Alpha Jet, which can access altitudes from the surface up to 40,000 ft. Results of the first COFFEE science flights preformed over the California's Central Valley will be presented. Boundary layer measurements and vertical profiles in the tropospheric column will both be included. This region is of particular interest, due to its elevated levels of HCHO, revealed in satellite images, as well as its high ozone concentrations. In addition to HCHO, the AJAX payload includes measurements of atmospheric ozone, methane, and carbon dioxide. Formaldehyde is one of the few urban pollutants that can be measured from space. Plans to compare in-situ COFFEE data with satellite-based HCHO observations such as those from OMI (Aura) and OMPS (SuomiNPP) will also be presented.

  5. Une approche par formalisme de green réduit pour le calcul des structures en contact dynamique : application au contact pneumatique/chaussée

    OpenAIRE

    Meftah, Rabie

    2011-01-01

    Le travail de cette thèse s'inscrit dans le cadre de la réduction du bruit du traffic routier. Le contact pneumatique/chaussée représente la principale source de ce phénomène dès la vitesse de 50 km/h. Dans ce contexte, une nouvelle démarche de modélisation du comportement dynamique d'un pneumatique roulant sur une chaussée rigide est développée. Au niveau du pneumatique, un modèle périodique est adopté pour calculer les fonctions de Green du pneumatique dans la zone de contact. Ce modèle per...

  6. Oxidation and reduction kinetics of eutectic SnPb, InSn, and AuSn: a knowledge base for fluxless solder bonding applications

    DEFF Research Database (Denmark)

    Kuhmann, Jochen Friedrich; Preuss, A.; Adolphi, B.;

    1998-01-01

    For microelectronics and especially for upcoming new packaging technologies in micromechanics and photonics fluxless, reliable and economic soldering technologies are needed. In this article, we consequently focus on the oxidation and reduction kinetics of three commonly used eutectic solder alloys......: (1) SnPb; (2) InSn; (3) AuSn. The studies of the oxidation kinetics show that the growth of the native oxide, which covers the solder surfaces from the start of all soldering operations is self-limiting. The rate of oxidation on the molten, metallic solder surfaces is significantly reduced...... and reduction kinetics, are applied to flip-chip (FC) bonding experiments in vacuum with and without the injection of H2. Wetting in vacuum is excellent but the self-alignment during flip-chip soldering is restricted. The desired, perfectly self-aligned FC-bonds have been only achieved, using evaporated...

  7. Etude en laboratoire de l'anisotropie des roches par méthode ultrasonique : Application au gneiss de Valabres (Alpes-Maritimes)

    OpenAIRE

    Gasc Barbier, Muriel; Wassermann, Jérôme

    2013-01-01

    Parmi les essais non destructifs, l'auscultation des roches par méthode ultrasonore est un moyen couramment utilisé pour caractériser l'état initial d'un spécimen au laboratoire. S'il est courant de faire ces mesures pour caractériser l'état de fracturation d'une roche, ce type de mesure est moins utilisé pour caractériser l'état d'anisotropie. Des essais de compression uniaxiale avec mesure des vitesses des ondes élastiques ont été réalisés sur des gneiss carottés parallèlement et perpendicu...

  8. 15-µm-pitch Cu/Au interconnections relied on self-aligned low-temperature thermosonic flip-chip bonding technique for advanced chip stacking applications

    Science.gov (United States)

    Thanh Tung, Bui; Kato, Fumiki; Watanabe, Naoya; Nemoto, Shunsuke; Kikuchi, Katsuya; Aoyagi, Masahiro

    2014-01-01

    In this paper, we report the development of reliable fine-pitch micro bump interconnections that used a high-precision room-temperature bonding approach. The accuracy of the bonding process is improved by modifying conventional bump/planar-bonding-pad interconnections to form self-aligned micro bumps/truncated inverted pyramid (TIP) bonding pads, i.e., misalignment self-correction elements (MSCEs). Thermosonic flip-chip bonding (FCB) is utilized to form reliable bonds between these MSCEs at acceptable low temperatures. By applying the proposed bonding approach, the demonstration of fine-pitch Cu bump to Au bonding pad interconnects chip stacking has been realized. Microstructure analyses reveal that 15-µm-pitch micro bump joints are fabricated at room temperature.

  9. Mise en evidence de mouvements de sable a partir d'images satellitales ; application au piemont sud de l'atlas saharien(Algerie

    Directory of Open Access Journals (Sweden)

    ABDELLAOUI ABDELKADER

    2010-09-01

    Full Text Available La zone d’étude se localise au piémont sud de l’Atl as saharien (Algérie et concerne le site de la vil le de Laghouat et ses environs limitrophes. Les principaux éléments orogr aphiques sont représentés par Djebel Ahmar (883m a u Sud-Ouest, Djebel Oum Deloua (1023m au Nord-Ouest, formant un syncli nal perché, et un peu plus au Nord-Ouest le grand s ynclinal du Milok, de direction atlasique. Le principal cours d’eau qui t raverse la zone Est Oued M’zi d’orientation Nord-Ou est-Sud-Est, empruntant par la suite une direction globale sous-latitudinale, à p artir de l’extrémité Sud-Ouest du Djebel Oum Deloua . Son affluent le plus important est Oued Messaad, avec un écoulement Sud-Ouest-Nord -Est. Cette zone comprend différentes formes et formation s sableuses dont la disposition est tributaire des ensembles orographiques, de la topographie de détail et des d irections du transport éolien. La population de Laghouat, ville présaharienne, est passée d’environ 6000 habitants en 1830 à 42800 ha bitants en 1977 et à 119043 habitants en 2003, soit une variation d e 178% (c’est-à-dire une multiplication par un fact eur de 2,8 sur une période de 26 ans entre 1977 et 2003. L’extension du bâti, sous la pression des besoins croissants en logemen ts, arrive à l’heure actuelle aux limites des massifs avoisinants (dépôt s sableux sur les flancs et des zones inondables. Le sable constitue ainsi un facteur de risque permanent de plus en plus ressent i pour la santé publique, la qualité de vie, mais é galement un danger pour les zones de mise en valeur agricole, notamment du Mekh areg à l’Est de Laghouat. Il devient alors pertinen t de mettre au point un moyen de localisation et de surveillance de la d ynamique des édifices de sable dans la région. Les traitements conventionnels de l’image satellita le (compositions colorées, indices thématiques ne permettent pas de différencier correctement le voile sableux

  10. Une architecture générique de Systèmes de recommandation de combinaison d'items : application au domaine du tourisme

    OpenAIRE

    Picot-Clémente, Romain

    2011-01-01

    Cette thèse apporte une généralisation du principe de recommandation des systèmes de recommandation. Au lieu de considérer une recommandation comme un item, elle est considérée comme une combinaison constituée de plusieurs items suivant un pattern donné. Une recommandation d'un seul item est alors un cas particulier de ce type de recommandation. L'architecture de système de recommandation proposé se base sur une architecture dérivée des travaux en systèmes hypermédia adaptatifs. Trois couches...

  11. The transport of gold and molybdenum through hydration in aqueous vapor and vapor-like fluids: Application to porphyry Au and Mo deposits

    Science.gov (United States)

    Hurtig, N. C.; Williams-Jones, A. E.

    2013-12-01

    The hypothesis that vapor is a viable medium for the transport of gold and molybdenum in ore forming magmatic-hydrothermal systems is supported by fluid inclusion data, analyses of volcanic gas condensates and the occurrence of metal-rich incrustations around fumaroles. Experiments have shown that hydration of metal species in water vapor is an essential factor in making such transport possible [1,2,3]. Indeed, hydration has been shown to increase concentrations of Au and Mo in the aqueous vapor phase by several orders of magnitude over those calculated using volatility data. Nevertheless metal concentrations determined experimentally in previous studies are substantially lower than those reported for vapor inclusions in magmatic hydrothermal systems, and are limited to one or two dominant hydrated metal species. To bridge this gap, we performed a series of new experiments extending the density-range to near critical vapor density, and intermediate-density in the case of supercritical fluids. Experiments were carried out in batch-type Ti autoclaves at temperatures between 300 and 500 °C and pressures up to 366 bar in HCl-bearing water vapor. Oxygen fugacity was buffered either by the assemblage MoO2/MoO3 or WO2/WO3 or graphite. Gold and molybdenum concentrations measured in the experimental condensates ranged from 0.9 ppb and 3 ppm in low-density vapor at 300 °C to 4.6 ppm and 481 ppm at 297 bar and 400 °C, respectively. The fugacity of both metals increased exponentially with increasing water fugacity, resulting in an increase in metal solubility between 1 and 3 orders of magnitude from the lowest pressures investigated. Curves representing the experimentally determined relationship between metal fugacity and fH2O were fitted to a step-wise hydration model to extract a set of logarithmic equilibrium constants for P and T extrapolation. We have used the above data to model Au and Mo mobilization in magmatic-hydrothermal vapor plumes. This modeling shows that the

  12. Effect of Silicon on Activity Coefficients of Siderophile Elements (P, Au, Pd, As, Ge, Sb, and In) in Liquid Fe, with Application to Core Formation

    Science.gov (United States)

    Righter, K.; Pando, K.; Danielson, L. R.; Humayun, M.; Righter, M.; Lapen, T.; Boujibar, A.

    2016-01-01

    Earth's core contains approximately 10 percent light elements that are likely a combination of S, C, Si, and O, with Si possibly being the most abundant. Si dissolved into Fe liquids can have a large effect on the magnitude of the activity coefficient of siderophile elements (SE) in Fe liquids, and thus the partitioning behavior of those elements between core and mantle. The effect of Si can be small such as for Ni and Co, or large such as for Mo, Ge, Sb, As. The effect of Si on many siderophile elements is unknown yet could be an important, and as yet unquantified, influence on the core-mantle partitioning of SE. Here we report new experiments designed to quantify the effect of Si on the partitioning of P, Au, Pd, and many other SE between metal and silicate melt. The results will be applied to Earth, for which we have excellent constraints on the mantle siderophile element concentrations.

  13. MAGIC with formaldehyde applied to dosimetry of HDR brachytherapy source

    International Nuclear Information System (INIS)

    The use of polymer gel dosimeters in brachytherapy can allow the determination of three-dimensional dose distributions in large volumes and with high spatial resolution if an adequate calibration process is performed. One of the major issues in these experiments is the polymer gel response dependence on dose rate when high dose rate sources are used and the doses in the vicinity of the sources are to be determinated. In this study, the response of a modified MAGIC polymer gel with formaldehyde around an Iridium-192 HDR brachytherapy source is presented. Experimental results obtained with this polymer gel were compared with ionization chamber measurements and with Monte Carlo simulation with PENELOPE. A maximum difference of 3.10% was found between gel dose measurements and Monte Carlo simulation at a radial distance of 18 mm from the source. The results obtained show that the gel's response is strongly influenced by dose rate and that a different calibration should be used for the vicinity of the source and for regions of lower dose rates. The results obtained in this study show that, provided the proper calibration is performed, MAGIC with formaldehyde can be successfully used to accurate determinate dose distributions form high dose rate brachytherapy sources.

  14. Efficient H2 production over Au/graphene/TiO2 induced by surface plasmon resonance of Au and band-gap excitation of TiO2

    International Nuclear Information System (INIS)

    Highlights: • Both surface plasmon resonance and band-gap excitation were used for H2 production. • Au/Gr/TiO2 composite photocatalyst was synthesized. • Au/Gr/TiO2 exhibited enhancement of light absorption and charge separation. • H2 production rate of Au/Gr/TiO2 was about 2 times as high as that of Au/TiO2. - Abstract: H2 production over Au/Gr/TiO2 composite photocatalyst induced by surface plasmon resonance of Au and band-gap excitation of TiO2 using graphene (Gr) as an electron acceptor has been investigated. Electron paramagnetic resonance study indicated that, in this composite, Gr collected electrons not only from Au with surface plasmon resonance but also from TiO2 with band-gap excitation. Surface photovoltage and UV–vis absorption measurements revealed that compared with Au/TiO2, Au/Gr/TiO2 displayed more effective photogenerated charge separation and higher optical absorption. Benefiting from these advantages, the H2 production rate of Au/Gr/TiO2 composite with Gr content of 1.0 wt% and Au content of 2.0 wt% was about 2 times as high as that of Au/TiO2. This work represents an important step toward the efficient application of both surface plasmon resonance and band-gap excitation on the way to converting solar light into chemical energy

  15. Etre touareg au Mali

    OpenAIRE

    Edmond BERNUS

    1992-01-01

    Après une présentation générale de leur espace, de leur culture commune, des stéréotypes dont ils font l'objet, les Touaregs maliens sont décrits dans leurs diversités régionales. Les révoltes passées, celle de Firhoun, le héros de 1916, puis celle de l'Adrar des Iforas en 1963-64 contre le gouvernement de Modibo Keita, précédent la révolte qui s'étend depuis 1990 au Niger et au Mali avec des guerriers sachant manier armes et voitures. Attaques et répression sauvage se succèdent dans une spir...

  16. Modélisation paramétrique non linéaire des machines asynchrones et démarche d'optimisation associée. Application au dimensionnement dans les véhicules hybrides.

    OpenAIRE

    Pugsley, Gareth

    2004-01-01

    Ce travail concerne l'étude des machines asynchrones à cage dans les applications de traction automobile, en particulier pour les véhicules hybrides. Nous avons développé des modèles et des méthodes utiles pour analyser et dimensionner de telles machines électriques. Nous avons tout d'abord mis au point un modèle électromagnétique non linéaire de la machine, déterminé à partir d'un nombre restreint de calculs "éléments finis". Ce modèle a ensuite été adapté pour réaliser des études de sensibi...

  17. Antibacterial Au nanostructured surfaces

    Science.gov (United States)

    Wu, Songmei; Zuber, Flavia; Brugger, Juergen; Maniura-Weber, Katharina; Ren, Qun

    2016-01-01

    We present here a technological platform for engineering Au nanotopographies by templated electrodeposition on antibacterial surfaces. Three different types of nanostructures were fabricated: nanopillars, nanorings and nanonuggets. The nanopillars are the basic structures and are 50 nm in diameter and 100 nm in height. Particular arrangement of the nanopillars in various geometries formed nanorings and nanonuggets. Flat surfaces, rough substrate surfaces, and various nanostructured surfaces were compared for their abilities to attach and kill bacterial cells. Methicillin-resistant Staphylococcus aureus, a Gram-positive bacterial strain responsible for many infections in health care system, was used as the model bacterial strain. It was found that all the Au nanostructures, regardless their shapes, exhibited similar excellent antibacterial properties. A comparison of live cells attached to nanotopographic surfaces showed that the number of live S. aureus cells was technological platform for engineering Au nanotopographies by templated electrodeposition on antibacterial surfaces. Three different types of nanostructures were fabricated: nanopillars, nanorings and nanonuggets. The nanopillars are the basic structures and are 50 nm in diameter and 100 nm in height. Particular arrangement of the nanopillars in various geometries formed nanorings and nanonuggets. Flat surfaces, rough substrate surfaces, and various nanostructured surfaces were compared for their abilities to attach and kill bacterial cells. Methicillin-resistant Staphylococcus aureus, a Gram-positive bacterial strain responsible for many infections in health care system, was used as the model bacterial strain. It was found that all the Au nanostructures, regardless their shapes, exhibited similar excellent antibacterial properties. A comparison of live cells attached to nanotopographic surfaces showed that the number of live S. aureus cells was information (ESI) available. See DOI: 10.1039/c5nr06157a

  18. Multicenter Patch Testing With a Resol Resin Based on Phenol and Formaldehyde Within the International Contact Dermatitis Research Group

    DEFF Research Database (Denmark)

    Isaksson, M.; Ale, I.; Andersen, Klaus Ejner;

    2015-01-01

    Background Contact allergy to phenol-formaldehyde resins (PFRs) based on phenol and formaldehyde is not detected by a p-tertiary-butylphenol-formaldehyde resin included in most baseline patch test series. Objective The aims of this study were to investigate the contact allergy rate to PFR-2 in an.......2%) reacted to PFR-2. Of those 28 individuals, one had a positive reaction to formaldehyde and 2 to p-tertiary-butylphenol-formaldehyde resin. Simultaneous allergic reactions were noted to colophonium in 3, to Myroxylon pereirae in 5, and to fragrance mix I in 8. Conclusions The contact allergy frequency in...

  19. Synthesis and electrocatalytic activity of Au/Pt bimetallic nanodendrites for ethanol oxidation in alkaline medium.

    Science.gov (United States)

    Han, Xinyi; Wang, Dawei; Liu, Dong; Huang, Jianshe; You, Tianyan

    2012-02-01

    Gold/Platinum (Au/Pt) bimetallic nanodendrites were successfully synthesized through seeded growth method using preformed Au nanodendrites as seeds and ascorbic acid as reductant. Cyclic voltammograms (CVs) of a series of Au/Pt nanodendrites modified electrodes in 1M KOH solution containing 1M ethanol showed that the electrocatalyst with a molar ratio (Au:Pt) of 3 exhibited the highest peak current density and the lowest onset potential. The peak current density of ethanol electro-oxidation on the Au(3)Pt(1) nanodendrites modified glassy carbon electrode (Au(3)Pt(1) electrode) is about 16, 12.5, and 4.5 times higher than those on the polycrystalline Pt electrode, polycrystalline Au electrode, and Au nanodendrites modified glassy carbon electrode (Au dendrites electrode), respectively. The oxidation peak potential of ethanol electro-oxidation on the Au(3)Pt(1) electrode is about 299 and 276 mV lower than those on the polycrystalline Au electrode and Au dendrites electrode, respectively. These results demonstrated that the Au/Pt bimetallic nanodendrites may find potential application in alkaline direct ethanol fuel cells (ADEFCs). PMID:22071516

  20. Tourisme et communautés rurales au Venezuela : vers une application des principes du Développement Durable

    Directory of Open Access Journals (Sweden)

    Olivier Dehoorne

    2008-02-01

    Full Text Available L’évolution récente du tourisme international au Venezuela est particulièrement intéressante : l'activité touristique qui reste très largement concentrée sur la côte caribéenne, et notamment l’île de Margarita, se diversifie au profit de nouveaux centres d’intérêt dans les régions intérieures. L’affichage de nouvelles volontés politiques sur la scène régionale et internationale, sous l’impulsion du président Chavez, a perturbé le marché touristique national qui était dominé pour les clientèles nord-américaines ; le Venezuela apparaît désormais aux yeux des Etats-Unis comme un pays à risque, instable. C’est dans ce contexte que s’inscrit le « Programa Andes Tropicales » [PAT] qui soutient le  développement rural dans les parcs nationaux ; ce programme repose sur la participation des populations locales et leur implication dans les politiques de conservation des ressources naturelles et culturelles sources de revenus. Le soutien financier des microprojets familiaux et communautaires doivent permettent de lutter contre la pauvreté.The recent evolution of international tourism in Venezuela is particularly interesting. Even if tourism activity remains heavily concentrated on the Caribbean coast, in particular on the island of Margarita, it is nevertheless diversifying gradually to make way for new areas of interest in the country’s interior. The display of new political will on the regional and international scene, under the leadership of President Chavez, has disrupted the national tourism market which was dominated by North American customers. Venezuela now appears in the eyes of the United States as a country that is at risk,and therefore unstable. It is in this context that the “Programa Andes Tropicales" [PAT] was developed to promote rural development in national parks; This program is based on the participation and involvement of local populations in the development of appropriate

  1. Isolation and characterization of the tertiary amine Alamine 304 hydrochioride. Its application on the extraction of Co(II, Au(III and Pt(IV

    Directory of Open Access Journals (Sweden)

    López-Delgado, Aurora

    2000-06-01

    Full Text Available Amine Alamine 304 dissolved in xylene reacts with hydrochloric acid to form the amine chloride (R3NH+Cl- and the amine dichloride (R3NH2Cl2. The former compound was isolated and characterized by chemical analysis, X-ray powder diffraction, infrared spectroscopy and scanning electron microscopy. Lattice parameters of the isolated amine chloride were determined and refined by least-square numerical treatment (monoclinic cell, with a = 29.017(4 Å, b = 14.564(7 Å, c = 5.043(1 Å, b = 95.68(3 ° and V = 2,120 Å3. The amine chloride is a potential anion-exchanger with metals, thus data on the liquid-liquid extraction of Co(II, Au(III and Pt(IV are also reported.

    La amina Alamine 304 disuelta en xileno reacciona con el ácido clorhídrico para formar el cloruro de la amina (R3NH+Cl- y el dicloruro de amina (R3NH2Cl2. El primero de estos compuestos se aisló y caracterizó mediante análisis químico, difracción de rayos X, espectroscopia de IR y microscopía electrónica de barrido. Se determinaron y refinaron los parámetros de red del cloruro de amina (monoclínico, a = 29,017(4 Å, b = 14,564(7 Å, c = 5,043(1 Å, b = 95,68(3 ° y V = 2.120 Å3. El cloruro de amina actúa como un intercambiador aniónico con ciertos metales, por lo que se incluyen datos sobre la extracción líquido-líquido de Co(II, Au(III y Pt(IV.

  2. Magnetic susceptibilities of liquid Cr-Au, Mn-Au and Fe-Au alloys

    International Nuclear Information System (INIS)

    The magnetic susceptibility of liquid Cr-Au, Mn-Au, Fe-Au and Cu-Au alloys was investigated as a function of temperature and composition. Liquid Cr1-cAuc with 0.5 ≤ c and Mn1-cAuc with 0.3≤c obeyed the Curie-Weiss law with regard to their dependence of χ on temperature. The magnetic susceptibilities of liquid Fe-Au alloys also exhibited Curie-Weiss behavior with a reasonable value for the effective number of Bohr magneton. On the Au-rich side, the composition dependence of χ for liquid TM-Au (TM=Cr, Mn, Fe) alloys increased rapidly with increasing TM content, respectively. Additionally, the composition dependences of χ for liquid Cr-Au, Mn-Au, and Fe-Au alloys had maxima at compositions of 50 at% Cr, 70 at% Mn, and 85 at% Fe, respectively. We compared the composition dependences of χ3d due to 3d electrons for liquid binary TM-M (M=Au, Al, Si, Sb), and investigated the relationship between χ3d and EF in liquid binary TM-M alloys at a composition of 50 at% TM

  3. Formaldehyde and H110a observations towards 6.7 GHz methanol maser sources

    CERN Document Server

    Okoh, Daniel; Zhou, Jian Jun; Tang, Xin Di; Chukwude, Augustine; Urama, Johnson; Okeke, Pius

    2014-01-01

    Intriguing work on observations of 4.83 GHz formaldehyde (H2CO) absorptions and 4.87 GHz H110a radio recombination lines (RRLs) towards 6.7 GHz methanol (CH3OH) maser sources is presented. Methanol masers provide ideal sites to probe the earliest stages of massive star formation, while 4.8 GHz formaldehyde absorptions are accurate probes of physical conditions in dense $(10^{3} - 10^{5} cm^{-3})$ and low temperature molecular clouds towards massive star forming regions. The work is aimed at studying feature similarities between the formaldehyde absorptions and the methanol masers so as to expand knowledge of events and physical conditions in massive star forming regions. A total of 176 methanol maser sources were observed for formaldehyde absorptions, and formaldehyde absorptions were detected 138 of them. 53 of the formaldehyde absorptions were newly detected. We noted a poor correlation between the methanol and formaldehyde intensities, an indication that the signals (though arise from about the same region...

  4. Observations of Carbon Isotopic Fractionation in Interstellar Formaldehyde

    Science.gov (United States)

    Wirstrom, E. S.; Charnley, S. B.; Geppert, W. D.; Persson, C. M.

    2012-01-01

    Primitive Solar System materials (e.g. chondrites. IDPs, the Stardust sample) show large variations in isotopic composition of the major volatiles (H, C, N, and O ) even within samples, witnessing to various degrees of processing in the protosolar nebula. For ex ample. the very pronounced D enhancements observed in IDPs [I] . are only generated in the cold. dense component of the interstellar medium (ISM), or protoplanetary disks, through ion-molecule reactions in the presence of interstellar dust. If this isotopic anomaly has an interstellar origin, this leaves open the possibility for preservation of other isotopic signatures throughout the form ation of the Solar System. The most common form of carbon in the ISM is CO molecules, and there are two potential sources of C-13 fractionation in this reservoir: low temperature chemistry and selective photodissociation. While gas-phase chemistry in cold interstellar clouds preferentially incorporates C-13 into CO [2], the effect of self-shielding in the presence of UV radiation instead leads to a relative enhancement of the more abundant isotopologue, 12CO. Solar System organic material exhibit rather small fluctuations in delta C-13 as compared to delta N-15 and delta D [3][1], the reason for which is still unclear. However, the fact that both C-13 depleted and enhanced material exists could indicate an interstellar origin where the two fractionation processes have both played a part. Formaldehyde (H2CO) is observed in the gas-phase in a wide range of interstellar environments, as well as in cometary comae. It is proposed as an important reactant in the formation of more complex organic molecules in the heated environments around young stars, and formaldehyde polymers have been suggested as the common origin of chondritic insoluable organic matter (IOM) and cometary refractory organic solids [4]. The relatively high gas-phase abundance of H2CO observed in molecular clouds (10(exp- 9) - 10(exp- 8) relative to H2) makes

  5. Guinea pig maximization tests with formaldehyde releasers. Results from two laboratories

    DEFF Research Database (Denmark)

    Andersen, Klaus Ejner; Boman, A; Hamann, K;

    1984-01-01

    The guinea pig maximization test was used to evaluate the sensitizing potential of formaldehyde and 6 formaldehyde releasers (Forcide 78, Germall 115, Grotan BK, Grotan OX, KM 200 and Preventol D2). The tests were carried out in 2 laboratories (Copenhagen and Stockholm), and although we intended...... the procedures to be the same, discrepancies were observed, possibly due to the use of different animal strains, test concentrations and vehicles. The sensitizing potential was in general found to be stronger in Stockholm compared to Copenhagen: formaldehyde sensitized 50% of the guinea pigs in...

  6. Mechanism for the addition of carbenoid CH2ClLi to formaldehyde

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Ab initio HF/6-31G* calculations have been performed for the addition mechanism of carbenoid CH2ClLi with formaldehyde in tetrahydrofuran. An early complex of formaldehyde with CH2ClLi is first formed with quite exothermic effect. Only a little activation energy of 14.6 kJ/mol is needed for the complex developing into the product through a transition state with coplanar bicyclic structure. In this process, the eletrophilic attack of carbonyl carbon of formaldehyde is more active than the nucleophilic attack of carbon of carbenoid. The exothermal effect of this addition process is up to 216.5 kJ/mol.

  7. Mechanism for the addition of carbenoid CH2ClLi to formaldehyde

    Institute of Scientific and Technical Information of China (English)

    李吉海[1; 孙昌俊[2; 刘少杰[3; 冯圣玉[4; 冯大诚[5

    2000-01-01

    Ab initlo HF/6-31G* calculations have been performed for the addition mechanism of carbenoid CH2CILi with formaldehyde in tetrahydrofuran. An early complex of formaldehyde with CH2CILi is first formed with quite exothermic effect. Only a little activation energy of 14.6 kJ/mol is needed for the complex developing into the product through a transition state with coplanar bicyclic structure. In this process, the eletrophilic attack of carbonyl carbon of formaldehyde is more active than the nucleophilic attack of carbon of carbenoid. The exothermal effect of this addition process is up to 216.5 kJ/mol.

  8. Immunogenicity of formaldehyde and binary ethylenimine inactivated infectious bursal disease virus in broiler chicks

    Institute of Scientific and Technical Information of China (English)

    HABIB Mudasser; HUSSAIN Iftikhar; IRSHAD Hamid; YANG Zong-zhao; SHUAI Jiang-bing; CHEN Ning

    2006-01-01

    Infectious bursal disease virus (IBDV) was inactivated by two different chemicals-formaldehyde and binary ethylenimine (BEI). Formaldehyde was used at 0.1% and 0.2%, while BEI was used at concentrations of 0.001 and 0.002 mol/L.These four vaccines were tested for their efficiency in generating humoral immune response in different groups of broiler chicks.Both BEI-inactivated vaccines gave relatively higher antibody titers and were almost twice as efficient as formaldehyde-inactivated ones.

  9. Electrochemical detection of organic gases: The development of a formaldehyde sensor

    Energy Technology Data Exchange (ETDEWEB)

    Baltruschat, H.; Anastasijevic, N.A.; Beltowska-Brzezinska, M.; Hambitzer, G.; Heitbaum, J. (Witten-Herdecke Univ., Witten (Germany, F.R.). Inst. fuer Physikalische Chemie)

    1990-09-01

    Using differential electrochemical mass spectrometry, we determined the amount of H{sub 2}-evolution occuring during formaldehyde oxidation as a function in the potential region of the first oxidation. In the second wave, the oxidation product is CO{sub 2} in pH 8 solution, as opposed to more alcaline solutions where only formiate is formed. Formaldehyde is reduced to methanol at potentials negative of the RHE. - An electrochemical formaldehyde sensor was built with a sensitivity below 1 ppm. Cross sensitivities towards alcohols can be lowered by UPD of Ag or Hg. (orig.).

  10. Migration of formaldehyde and melamine monomers from kitchen- and tableware made of melamine plastic

    DEFF Research Database (Denmark)

    Lund, K.H.; Petersen, J.H.

    2006-01-01

    mg kg(-1)) and formaldehyde (15 mg kg(-1)) was found after three successive exposures to the food stimulant 3% acetic acid after 2 h at 70 degrees C. To investigate the effects of long-term use, migration tests were performed with two types of cups from a day nursery. Furthermore, medium-term use was...... studied by ten successive exposures of a plate to 3% acetic acid for 30 min at 95 degrees C. The results indicate that continuous migration of formaldehyde and melamine takes place during the lifetime of these articles. The molar ratio of released formaldehyde to melamine was seen to decrease from 12 to...

  11. Laser-induced reaction and polymerization of formaldehyde in low-temperature amorphous solids

    Science.gov (United States)

    Wight, Charles A.; Tang, Thomas W.; Mansueto, Edward S.

    1989-10-01

    Photochemical reactions of formaldehyde with chlorine have been investigated in thin films from 10-77 K. The amorphous films are formed by deposition of gaseous formaldehyde doped with small amounts of Cl2 onto an optical window mounted at the cold tip of a close-cycle refrigerator. Excimer laser irradiation at 308 nm dissociates some of the chlorine molecules to atoms, initiating chemical reactions within the solid. Polymerization of the solid is initiated in the presence of a strong acid (e.g., HCl). Photopolymerization has also been achieved by photoexcitation of small amounts of 2-nitrophenol doped into solid formaldehyde.

  12. L’olivier au Maroc

    Directory of Open Access Journals (Sweden)

    El Mouhtadi Issam

    2014-03-01

    Full Text Available L’olivier est une culture traditionnelle sur le pourtour de la Méditerranée. Il est donc naturel de trouver cet arbre au Maroc où il est présent depuis des siècles. Cultivé surtout traditionnellement jusqu’à ses dernières années, il fait l’objet maintenant d’un plan de valorisation très ambitieux pour non seulement garder le Royaume à son niveau actuel (2e producteur mondial pour l’olive de conserve et 6e pour l’huile d’olive mais pour conquérir de nouveaux marchés au niveau mondial et profiter ainsi de l’engouement que connaît cette huile reconnue pour ses bienfaits. Le plan national « Maroc Vert » permet ainsi, grâce à des subventions conséquentes, non seulement de renouveler les vergers existant avec la variété traditionnelle picholine du Maroc, mais également la plantation de nouvelles variétés en super-intensif dans le but d’industrialiser au maximum de nouveaux vergers. Il en est de même pour la transformation des olives en huile de bonne qualité avec la mise en place d’unités de trituration modernes qui doivent supplanter à terme la multitude de « maâsra » et réduire ainsi l’impact environnemental dû aux margines. L’olive ne sera plus dans l’avenir que représentée par son huile et ses formes comestibles, mais les résidus de son extraction seront valorisés soit sous forme de combustible élaboré pour le grignon, soit sous forme d’une base de chimie verte pour les sous-produits du raffinage. D’autres applications sont actuellement à l’étude, car le Maroc à compris, comme tous les autres grands pays producteurs, que l’olive était un nouveau gisement de richesses.

  13. Charge transport through O-deficient Au-MgO-Au junctions

    KAUST Repository

    Fadlallah, M. M.

    2009-12-29

    Metal-oxide heterostructures have been attracting considerable attention in recent years due to various technological applications. We present results of electronic structure and transport calculations for the Au-MgO-Au (metal-insulator-metal) heterostructure based on density-functional theory and the nonequilibrium Green’s functions method. The dependence of the conductance of the heterostructure on the thickness of the MgO interlayer and the interface spacing is studied. In addition, we address the effects of O vacancies. We observe deviations from an exponentially suppressed conductance with growing interlayer thickness caused by Au-O chemical bonds. Electronic states tracing back to O vacancies can increase the conductance. Furthermore, this effect can be enhanced by enlarging the interface spacing as the vacancy induced Mg states are shifted toward the Fermi energy.

  14. Dynamic features of rod-shaped Au nanoclusters

    Science.gov (United States)

    So, Woong Young; Das, Anindita; Wang, Shuxin; Zhao, Shuo; Byun, Hee Young; Lee, Dana; Kumar, Santosh; Jin, Rongchao; Peteanu, Linda A.

    2015-08-01

    Gold nanoclusters hold many potential applications such as biosensing and optics due to their emission characteristics, small size, and non-toxicity. However, their low quantum yields remain problematic for further applications, and their fluorescence mechanism is still unclear. To increase the low quantum yields, various methods have been performed: doping, tuning structures, and changing number of gold atoms. In the past, most characterizations have been performed on spherical shaped nanoclusters; in this paper, several characterizations of various rod-shaped Au nanoclusters specifically on Au25 are shown. It has been determined that the central gold atom in Au25 nano-rod is crucial in fluorescence. Furthermore, single molecule analysis of silver doped Au25 nano-rod revealed that it has more photo-stability than conjugated polymers and quantum dots.

  15. Radiation-chemical hardening of phenol-formaldehyde oligomers

    International Nuclear Information System (INIS)

    Radiation-chemical hardening of phenol formaldehyde oligomers of the resol type has been studied in the presence of furfural and diallylphthalate diluents. The samples have been hardened on an electron accelerator at an electron energy of 1.0-1.1 MeV and a dose rate of 2-3 Mrad/s. The kinetics of hardening has been studied on the yield of gel fraction within the range of absorbed doses from 7 to 400 Mrad. Radiation-chemical hardening of the studied compositions is activated with sensitizers, namely, amines, metal chlorides, and heterocyclic derivatives of metals. Furfural and diallylphthalate compositions are suitable for forming glass-fibre plastic items by the wet method and coatings under the action of ionizing radiations

  16. Adsorption of uranium with multiwall carbon nanotubes modified by formaldehyde

    International Nuclear Information System (INIS)

    Purified multiwall carbon nanotubes (MWCNTs) were modified with formaldehyde and the dispersibility of MWCNTs was greatly improved after modification. The modified MWCNTs were used to study the adsorption of uranium from aqueous solution. pH, contact time, temperature, initial concentration of uranium and modified MWCNTs concentrations were investigated to estimate the adsorptive properties. The results show that uranium adsorption percentage strongly depends on the pH, initial concentration of uranium and modified MWCNTs content, and is slightly influenced by contact time, temperature and ionic strength. The adsorptivity increases over the range of pH=2.0-7.0. The maximum adsorptivity is 46.44 mg/g as the initial concentration of uranium reaches 50 μg/mL. The equilibrium data obey both Langmuir and Freundlich isotherms well, and the maximal theoretical adsorption capacity is 55.87 mg/g for the modified MWCNTs. (authors)

  17. Nanoporous Pt Catalyst Modified by Sn Electrodeposition for Electrochemical Oxidation of Formaldehyde%Nanoporous Pt Catalyst Modified by Sn Electrodeposition for Electrochemical Oxidation of Formaldehyde

    Institute of Scientific and Technical Information of China (English)

    易清风; 左葛琨琨

    2012-01-01

    A nanoporous Pt particles-modified Ti (nanoPt/Ti) electrode was prepared through a simple hydrothennal method using aqueous H2PtC16 as a precursor and formaldehyde as a reduction agent. The nanoPt/Ti electrode was then modified with limited amounts of tin particles generated by cyclic potential scans in the range of -0.20 to 0.50 V in a 0.01 mol,L 1 SnCI2 solution, to synthesize a Sn-modified nanoporous Pt catalyst (SrdnanoPt/Ti). Electroactivity of the nanoPt/Ti and Sn/nanoPt/Ti electrodes towards formaldehyde oxidation in a 0.5 moloL-I H2804 solution was evaluated by cyclic voltammetry and chronoamperometry. Electrooxidation of formaldehyde on the nanoPt/Ti electrode takes place at a potential of 0.45 V and then presents high anodic current densities due to the large real surface area of the nanoPt/Ti electrode. The formaldehyde oxidation rate is dramatically increased on the Sn/nanoPt/Ti electrode at the most negative potentials, where anodic formaldehyde oxidation is completely suppressed on the nanoPt/Ti electrode. Chronoamperogramms (CA) of the Sn/nanoPt/Ti electrode display stable and large quasisteady state current densities at more negative potential steps. Amperometric data obtained at a potential step of 100 mV show a linear dependence of the current density for formaldehyde oxidation upon formaldehyde concentration in the range of 0.003 to 0.1 mol.L-l with a sensitivity of 59.29 mA~cm-2 (mol,L-l)-1. A detection limit of 0.506 mmol.L-l formaldehyde was found. The superior electroactivity of the Sn/nanoPt/Ti electrode for formaldehyde oxidation can be illustrated by a socalled bifunctional mechanism which is involved in the oxidation of poisoning adsorbed CO species via the surface reaction with OH adsorbed on neighboring Sn sites.

  18. Des femmes au tribunal

    OpenAIRE

    Le Pape, Marc

    2010-01-01

    Les archives judiciaires constituent une source essentielle pour les études des sociabilités africaines en situation coloniale. Cet article prend appui sur l’analyse des procès tenus, entre 1923 et 1939, au tribunal du premier degré d’Abidjan, il vise à décrire les argumentations contradictoires par lesquelles femmes et hommes expliquent leurs différends dans l’espace du prétoire. Les registres issus des « juridictions indigènes » permettent également d’apprécier sur quels repères se fondent ...

  19. Massignon face au sionisme

    OpenAIRE

    Mayeres, Agathe

    2010-01-01

    En 1916, Louis Massignon participe aux négociations franco-britanniques qui envisagent, dans la perspective de la capitulation probable des empires centraux, le futur partage de l’Empire ottoman. Dans ce contexte, Massignon cherche à se situer face la question sioniste qui, pour lui, est avant tout un problème de politique orientale.Sous l’influence d'Aaron Aaronsohn, l’islamologue éprouve d’abord pour les pionniers d’Eretz Israel, au regard de leurs réalisations agricoles, une sympathie enth...

  20. Des ignames au riz

    OpenAIRE

    Ivanoff, Jacques

    2003-01-01

    L'igname a toujours été une nourriture importante pour les populations littorales et nomades du monde insulindien. Cependant, avec l'installation du héros civilisateur Gaman le Malais chez le peuple de la reine Sibian, le riz va devenir la composante essentielle des repas moken. En intégrant Gaman en son sein, la société moken va devoir répondre au double défi posé par la menace de la riziculture et de l'islam. En donnant femme à Gaman, en adoptant le nomadisme pour échapper à l'islam ...

  1. Vivre, vivre au Japon

    OpenAIRE

    Tardits, Manuel

    2014-01-01

    Comment faire face au caractère récurrent des catastrophes naturelles et liées à l’homme ? À la prévention, on se doit d’adjoindre une vision écologique plus large et renouvelée. Un débat sur le modèle énergétique du nucléaire et sur nos modèles de développement urbains et sociétaux s’impose.

  2. Introduction au titre I

    OpenAIRE

    2015-01-01

    Pline a eu dans sa carrière d’homme public à défendre les intérêts de l’Etat et des particuliers, à épurer des comptes, à juger et arbitrer. Ainsi le voulait l’ordonnancement du cursus honorum du Bas-Empire, héritier sur tous ces points de la tradition des charges publiques de la République. Les premières tâches du petiturus furent essentiellement judiciaires - on songe au vigintivirat - et elles se poursuivirent par des fonctions de moyenne importance (préture consulat) puis de haute adminis...

  3. Fluctuations Magnetiques des Gaz D'electrons Bidimensionnels: Application AU Compose Supraconducteur LANTHANE(2-X) Strontium(x) Cuivre OXYGENE(4)

    Science.gov (United States)

    Benard, Pierre

    Nous presentons une etude des fluctuations magnetiques de la phase normale de l'oxyde de cuivre supraconducteur La_{2-x}Sr _{x}CuO_4 . Le compose est modelise par le Hamiltonien de Hubbard bidimensionnel avec un terme de saut vers les deuxiemes voisins (modele tt'U). Le modele est etudie en utilisant l'approximation de la GRPA (Generalized Random Phase Approximation) et en incluant les effets de la renormalisation de l'interaction de Hubbard par les diagrammes de Brueckner-Kanamori. Dans l'approche presentee dans ce travail, les maximums du facteur de structure magnetique observes par les experiences de diffusion de neutrons sont associes aux anomalies 2k _{F} de reseau du facteur de structure des gaz d'electrons bidimensionnels sans interaction. Ces anomalies proviennent de la diffusion entre particules situees a des points de la surface de Fermi ou les vitesses de Fermi sont tangentes, et conduisent a des divergences dont la nature depend de la geometrie de la surface de Fermi au voisinage de ces points. Ces resultats sont ensuite appliques au modele tt'U, dont le modele de Hubbard usuel tU est un cas particulier. Dans la majorite des cas, les interactions ne determinent pas la position des maximums du facteur de structure. Le role de l'interaction est d'augmenter l'intensite des structures du facteur de structure magnetique associees a l'instabilite magnetique du systeme. Ces structures sont souvent deja presentes dans la partie imaginaire de la susceptibilite sans interaction. Le rapport d'intensite entre les maximums absolus et les autres structures du facteur de structure magnetique permet de determiner le rapport U_ {rn}/U_{c} qui mesure la proximite d'une instabilite magnetique. Le diagramme de phase est ensuite etudie afin de delimiter la plage de validite de l'approximation. Apres avoir discute des modes collectifs et de l'effet d'une partie imaginaire non-nulle de la self-energie, l'origine de l'echelle d'energie des fluctuations magnetiques est examinee

  4. LA DIVERSITÃ DÃPLOYÃE AU SEIN DE LâUNIVERSITÃ DâENTREPRISE : LâAPPLICATION CONCRÃTE DâUNE VALEUR ADOPTÃE PAR LA DIRECTION GÃNÃRALE

    Directory of Open Access Journals (Sweden)

    Virginia Drummond-Guitel

    2009-09-01

    Full Text Available La diversité devenue une valeur incontournable adoptée par les grands groupes, encore faut-t-il trouver les moyens concrets pour lâintégrer dans les pratiques des ressources humaines et dans les mentalités des personnes. Le présent papier a pour but de montrer comment les valeurs de la diversité adoptées par la direction générale ont été déclinées et appliquées dans un processus de sélection de candidats pour une formation continue au sein dâune grande organisation internationale. A travers lâapplication dâune méthode qualitative de recherche, 10 (dix dirigeants ayant conçu la formation et 42 (quarante-deux managers ayant suivi le programme confirment lâatteinte du but stratégique de cette formation, autrement dit, lâatteinte dâune vision partagée (SENGE, 1991, à travers la consolidation dâun fort sentiment dâappartenance à la culture organisationnelle (SCHEIN, 1995. Les managers ont été sélectionnés selon leurs différentes professions, cultures nationales et différents secteurs dâactivités, confirmant ainsi une promotion de la diversité au sein de lâorganisation.

  5. SCIAMACHY formaldehyde observations: constraint for isoprene emission estimates over Europe?

    Directory of Open Access Journals (Sweden)

    G. Dufour

    2009-03-01

    Full Text Available Formaldehyde (HCHO is an important intermediate compound in the degradation of volatile organic compounds (VOCs in the troposphere. Sources of HCHO are largely dominated by its secondary production from VOC oxidation, methane and isoprene being the main precursors in unpolluted areas. As a result of the moderate lifetime of HCHO, its spatial distribution is determined by reactive hydrocarbon emissions. We focus here on Europe and investigate the influence of the different emissions on HCHO tropospheric columns with the CHIMERE chemical transport model in order to interpret the comparisons between SCIAMACHY and simulated HCHO columns. Europe was never specifically studied before for these purposes using satellite observations. The bias between measurements and model is less than 20% on average. The differences are discussed according to the errors on the model and the observations and remaining discrepancies are attributed to a misrepresentation of biogenic emissions. This study requires the characterisation of: (1 the model errors and performances concerning formaldehyde. The errors on the HCHO columns, mainly related to chemistry and mixed emission types, are evaluated to 2×1015 molecule/cm2 and the model performances evaluated using surface measurements are satisfactory (~13%; (2 the observation errors that define the needs in spatial and temporal averaging for meaningful comparisons. Using SCIAMACHY observations as constraint for biogenic isoprene emissions in an inverse modelling scheme reduces their uncertainties by about a factor of two in region of intense emissions. The retrieved correction factors for the isoprene emissions range from a factor of 0.15 (North Africa to a factor of 2 (Poland, the United Kingdom depending on the regions.

  6. Spherical Resorcinol-Formaldehyde Synthesis by Inverse Suspension Polymerization

    International Nuclear Information System (INIS)

    Base catalyzed sol-gel polycondensation of resorcinol (1,3-dihydroxybenzene) with formaldehyde by inverse suspension polymerization leads to the formation of uniform, highly cross-linked, translucent, spherical gels, which have increased selectivity and capacity for cesium ion removal from high alkaline solutions. Because of its high selectivity for cesium ion, resorcinol-formaldehyde (R-F) resins are being considered for process scale column radioactive cesium removal by ion-exchange at the Waste Treatment and Immobilization Plant (WTP), which is now under construction at the Hanford site. Other specialty resins such as Superlig(regsign) 644 have been ground and sieved and column tested for process scale radioactive cesium removal but show high pressure drops across the resin bed during transition from column regeneration to loading and elution. Furthermore, van Deemter considerations indicate better displacement column chromatography by the use of spherical particle beads rather than irregularly shaped ground or granular particles. In our studies batch contact equilibrium experiments using a high alkaline simulant show a definite increase in cesium loading onto spherical R-F resin. Distribution coefficient (Kd) values ranged from 777 to 429 mL/g in the presence of 0.1M and 0.7M potassium ions, respectively. Though other techniques for making R-F resins have been employed, to our knowledge no one has made spherical R-F resins by inverse suspension polymerization. Moreover, in this study we discuss the data comparisons to known algebraic isotherms used to evaluate ion-exchange resins for WTP plant scale cesium removal operations

  7. Ag-Modified In2O3/ZnO Nanobundles with High Formaldehyde Gas-Sensing Performance

    Directory of Open Access Journals (Sweden)

    Fang Fang

    2015-08-01

    Full Text Available Ag-modified In2O3/ZnO bundles with micro/nano porous structures have been designed and synthesized with by hydrothermal method continuing with dehydration process. Each bundle consists of nanoparticles, where nanogaps of 10–30 nm are present between the nanoparticles, leading to a porous structure. This porous structure brings high surface area and fast gas diffusion, enhancing the gas sensitivity. Consequently, the HCHO gas-sensing performance of the Ag-modified In2O3/ZnO bundles have been tested, with the formaldehyde-detection limit of 100 ppb (parts per billion and the response and recover times as short as 6 s and 3 s, respectively, at 300 °C and the detection limit of 100 ppb, response time of 12 s and recover times of 6 s at 100 °C. The HCHO sensing detect limitation matches the health standard limitation on the concentration of formaldehyde for indoor air. Moreover, the strategy to synthesize the nanobundles is just two-step heating and easy to scale up. Therefore, the Ag-modified In2O3/ZnO bundles are ready for industrialization and practical applications.

  8. ASSESSING ANTHROPOGENIC IMPACT ON SECONDARY POLLUTANT FORMATION IN THE SOUTH EASTERN US VIA AIRBORNE FORMALDEHYDE MEASUREMENTS

    Science.gov (United States)

    This project will provide a critical, publically available formaldehyde dataset during the SOAS campaign. The major expected result will be an improved understanding of the influence of anthropogenic VOC and NOx emissions on secondary pollutant concentrations and properties...

  9. 一种甲醛检测仪%A Formaldehyde Detector

    Institute of Scientific and Technical Information of China (English)

    韩明轩; 李耀

    2015-01-01

    This paper introduces a formaldehyde detector, using formaldehyde sensor module ZE08-CH2O. The mcureceives and process, LCD display results, alarm while the formaldehyde exceed the standard. This paper gives the design of hardware system design,the software system for the detection of formaldehyde, and the test chart.%该文介绍了一款甲醛检测仪,采用甲醛传感模组ZE08-CH2O,单片机接收处理、LCD显示结果,当甲醛超标时报警。文中给出了该甲醛检测仪的硬件系统设计、软件系统设计,测试图。

  10. Localization of formaldehyde production during frozen storage of European hake ( Merluccius merluccius )

    DEFF Research Database (Denmark)

    Rey-Mansilla, M.D.; Sotelo, C.G.; Aubourg, S.P.;

    2001-01-01

    The formation of dimethylamine and formaldehyde from trimethylamine N-oxide by the enzyme trimethylamine N-oxide demethylase in whole hake during frozen storage was studied. The objective was to check if there were parts of the muscle with a higher production of dimethylamine and formaldehyde, and...... over the viscera, and the tail. The second variable was the temperature of storage, -11 degreesC or -18 degreesC. Finally, the influence of kidneys during storage, comparing fish with and without kidneys, was also evaluated. No differences were found in dimethylamine and formaldehyde production between...... fish with and without kidneys stored at -18 degreesC. However at -11 degreesC the amounts of dimethylamine and formaldehyde detected in fish without kidneys were, in some cases, higher than in those with kidneys. Kidney removal does not have a statistically significant influence on DMA and FA...

  11. Ventilation of indoor formaldehyde and estimation of its emission and air exchange rate

    Institute of Scientific and Technical Information of China (English)

    WANG Kun; ZHAO Qing-liang; LI Wen-pu; LI Yu-hua

    2007-01-01

    Residents living in the cold areas such as Harbin generally experience a residence time of approximately 6 months in chilly winter without frequent natural ventilation. To find out the influence of a short period of ventilation on the indoor formaldehyde concentration inside a new building, an investigation was conducted for the instance of twice ventilation in a day through window opening. The results showed that the initial concentration of formaldehyde was 3.53 - 8.48 times as high as the concentration after 10 min ventilation. After closing the window, the indoor formaldehyde concentration increased with time and followed an exponential equation of C = C0exp( - b * t) + (a + Cw) [ 1 - exp( - b * t) ] with correlation coefficient (R2) of 0. 945 -0. 999, based on the statistical analysis of 14 groups of measurement data. The developed equation can be used to estimate the emission rate of indoor formaldehyde sources and the air exchange rate of the test room simultaneously.

  12. A theoretical study on the water-mediated asynchronous addition between urea and formaldehyde

    Institute of Scientific and Technical Information of China (English)

    Tao-Hong Li; Xiao-Guang Xie; Guan-Ben Du

    2013-01-01

    The reaction between urea and formaldehyde in water solution was theoretically investigated by using B3LYP and MP2 methods,It was found that the addition of the nitrogen atom in urea to the carbonyl group in formaldehyde precedes the proton transfer and the proton migration from water to the carbonyl group occurs before the proton abstraction from the nitrogen,With one or two water molecules involved in the TS,the activation energy barrier is lowered compared to the TS of the mechanism with no water participation.The energy change along the reaction coordinate clearly shows that a zwitterionic-like intermediate does not exist on the PES.The reaction between urea and formaldehyde occurs in a concerted mechanism but with asynchronous characters.This is different from the stepwise mechanism recently found for the amination reactions of formaldehyde.

  13. The Effects of Ferulic Acid Against Oxidative Stress and Inflammation in Formaldehyde-Induced Hepatotoxicity.

    Science.gov (United States)

    Gerin, Fethullah; Erman, Hayriye; Erboga, Mustafa; Sener, Umit; Yilmaz, Ahsen; Seyhan, Hatice; Gurel, Ahmet

    2016-08-01

    This study was designed to elucidate the protective effects of ferulic acid (FA) on formaldehyde-induced hepatotoxicity by measuring some routine biochemical parameters, cytokine levels, and oxidative stress-related parameters in addition to YKL-40 in male Wistar albino rats. Tissue superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px) activities, and tissue malondialdehyde (MDA) levels were measured. Also, serum YKL-40, TNF-α, IL-6, IL-1β, IL-8, total protein, albumin, total bilirubin concentrations, and AST, ALT, ALP, and LDH activities were measured. Histological specimens were examined in light microscopy. Formaldehyde significantly increased tissue MDA, and serum cytokine levels and also decreased activities of antioxidant enzymes. FA treatment decreased MDA and cytokine levels and increased activities of antioxidant enzymes. FA also alleviated degeneration due to formaldehyde toxicity. We suggested that FA can be used as a promising hepatoprotective agent against formaldehyde toxicity because of the obvious beneficial effects on oxidative stress parameters. PMID:27235018

  14. Migration of formaldehyde and melamine monomers from kitchen- and tableware made of melamine plastic

    DEFF Research Database (Denmark)

    Lund, K.H.; Petersen, J.H.

    2006-01-01

    Migration of one or both formaldehyde and/or melamine monomers was found in seven of ten tested melamine samples bought on the Danish market. The samples were a bowl, a jug, a mug, a ladle, and different cups and plates. No violation of the European Union-specific migration limits for melamine (30...... mg kg(-1)) and formaldehyde (15 mg kg(-1)) was found after three successive exposures to the food stimulant 3% acetic acid after 2 h at 70 degrees C. To investigate the effects of long-term use, migration tests were performed with two types of cups from a day nursery. Furthermore, medium-term use was...... studied by ten successive exposures of a plate to 3% acetic acid for 30 min at 95 degrees C. The results indicate that continuous migration of formaldehyde and melamine takes place during the lifetime of these articles. The molar ratio of released formaldehyde to melamine was seen to decrease from 12 to...

  15. Partial oxidation of methane to formaldehyde on Mo03, Fe203 and ferromolybdenum catalysts

    Directory of Open Access Journals (Sweden)

    José Daniel Del Río

    2010-04-01

    Full Text Available One of the main challenges for catalysis has been direct methane conversion to useful products such as methanol and formaldehyde. Formaldehyde is currently produced by a three-step industrial process with syngas and metha- nol as intermediate products. MoO , Fe O and Fe (MoO catalysts were used with four different Mo/Fe molar 3\t2 3 2 4 3 ratios (0.5, 1, 1.5, 2 in this work. The ferromolybdenum catalyst was prepared by coprecipitation. Pure oxides are more active; however they are not formaldehyde selective, but carbon oxide (CO, CO selective. The ferro- molybdenum catalysts showed better HCHO selectivity at low conversions; the molybdenum oxide content did not show increased in catalytic activity. Increased reaction temperature did not increase formaldehyde selectivity.

  16. Histopathological Effects of Formaldehyde (CH2O on Rainbow Trout (Oncorhynchus mykiss Walbaum, 1792

    Directory of Open Access Journals (Sweden)

    Cafer BULUT

    2015-04-01

    Full Text Available Formaldehyde is commonly used as a disinfectant and also in a control of fish disease in aquaculture sector. However, this widespread use, can lead to environmental degradation and can cause negative effects on the treated fish with. In this study 250 mg/L (1 hour and 500 mg/L (45 min concentrations of formaldehyde were used. From the results of the histopathological findings degeneration was determined in the epithelial cells and pilar in the gill lamellae, lymphoid infiltration interlamellar necrosis and degeneration of the muscle tissue, dilatation in the liver, congestion in veins, degeneration in hepatocytes, damage in the blood vessels of fish which were treated with formaldehyde. In conclusion; formaldehyde was found to have a negative impact in histological examination in applied rainbow trout. Therefore, it was concluded that it should be used consciously and according the needs in aquaculture.

  17. Studies of the structure and phase transitions of nano-confined pentanedithiol and its application in directing hierarchical molecular assemblies on Au(1 1 1)

    Science.gov (United States)

    Pawlicki, Alison; Avery, Erin; Jurow, Matthew; Ewers, Bradley; Vilan, Ayelet; Drain, Charles Michael; Batteas, James

    2016-03-01

    Directing molecular devices into pre-designed integrated electronic circuits while enforcing selectivity and hierarchy is an inherent challenge for molecular electronics. Here we explore ways to direct the assembly of electrically-active molecular monolayers into specific locations as well as controlling their internal organization. We have accomplished this by two consecutive surface reactions: (1) forming pentanedithiol (C5DT) domains within an inert alkanethiol self-assembled monolayer (SAM) on Au; and (2) selectively binding porphyrin derivatives to the C5DT domains. The C5DT domains were fabricated by phase segregation during co-adsorption from a mixed C5DT/dodecanethiol (C12) solution and nanografting with Atomic Force Microscopy (AFM). AFM revealed that co-absorbed and nanografted C5DT domains were in a standing-up phase and scanning tunneling microscopy (STM) showed that their molecular organization within about 5 nm, 40 nm, 50 nm and 120 nm domains, was dependent upon the size of the domain, such that structure of the C5DT transitions from (\\sqrt{3}   ×  \\sqrt{3} ) R30°, to (2  ×  2), and ultimately to a disordered phase with increasing domain size. This is due to the varying degrees of influence of the surrounding C12; providing sufficient van der Waals interactions as well as a geometric confinement to stabilize the standing-up phase of the C5DT. Understanding the molecular configuration of dithiol SAMs affords their use as a reactive template to subsequently bind active head groups. As a proof of principle, porphyrins with a pendant pentafluorophenyl ring were attached to the C5DT domains by a ‘click’ reaction between the fluorinated ring and the free thiol on the surface. From AFM and STM, these porphyrin derivatives reacted selectively with the C5DT domains with some porphyrins binding directly to the C5DT, subsequently allowing additional localized porphyrin deposition through pi-stacking.

  18. La veille informationnelle en éducation pour répondre au défi de la société de la connaissance au XXI ème siècle :
    Application à la conception d'une plateforme de veille et de partage de connaissance en éducation : Commun@utice

    OpenAIRE

    Pinte, Jean-Paul

    2006-01-01

    Il est désormais admis que le potentiel des technologies de l'information et de la communication (TIC) apporte un nouveau défi au monde moderne et favorise un accès de masse au savoir conforté depuis le début des années 90 par l'avènement du réseau Internet. Appréhender cette nouvelle donne et y adhérer pour accompagner le progrès humain restent au XXI° siècle des défis de taille.Les diverses transitions de notre société du stade industriel au stade de société de l'information et de la connai...

  19. Interactive effects of ozone and formaldehyde on the nasal respiratory lining epithelium in rats

    International Nuclear Information System (INIS)

    The combined effects on the nasal epithelium of mixtures of ozone and formaldehyde at cytotoxic and noncytotoxic concentrations were examined. Male Wistar rats were exposed by inhalation during 22 h/d for 3 consecutive days to 0.3, 1.0, or 3.0 ppm formaldehyde, or to 0.2, 0.4, or 0.8 ppm ozone, or to mixtures of 0.4 ppm ozone and 0.3, 1.0, or 3.0 ppm formaldehyde, or to 1.0 ppm formaldehyde and 0.2, 0.4, or 0.8 ppm ozone, or they were sham-exposed to clean air. The noses were examined for pathological changes at six standard cross levels by light microscopy and for epithelial cell proliferation by counting [3H-methyl]thymidine-labeled cells at cross levels II and III. Ozone at 0.4 ppm or 0.8 ppm or formaldehyde at 3 ppm enhanced cell proliferation at cross level II at all locations, except for the epithelium of the septum, which was not affected by ozone. At cross level III ozone alone did not induce cell proliferation, but formaldehyde at 0.3 and 1 ppm tended to reduce cell proliferation while at 3 ppm proliferation was slightly stimulated. The combined exposure to 0.4 ppm ozone and 0.3 ppm formaldehyde induced less cell proliferation at cross levels II and III when compared with that of 0.4 ppm ozone alone. Less cell proliferation was also seen at cross level II when animals were exposed to 0.4 or 0.8 ppm ozone in combination with 1 ppm formaldehyde than when exposed to these ozone concentrations alone. A more than additive increase in cell proliferation was found at cross level II after exposure to 0.4 ppm ozone in combination with 3 ppm formaldehyde, and at cross level III in animals exposed to 0.4 ppm ozone and 1 or 3 ppm formaldehyde. Treatment-related histopathological nasal changes, such as disarrangement, loss of cilia, and hyper/metaplasia of the epithelium were seen at 0.2, 0.4, and 0.8 ppm ozone and at 3 ppm formaldehyde

  20. Interactive effects of ozone and formaldehyde on the nasal respiratory lining epithelium in rats

    Energy Technology Data Exchange (ETDEWEB)

    Reuzel, P.G.; Wilmer, J.W.; Woutersen, R.A.; Zwart, A.; Rombout, P.J.; Feron, V.J. (TNO-CIVO Toxicology and Nutrition Institute, Zeist (Netherlands))

    1990-01-01

    The combined effects on the nasal epithelium of mixtures of ozone and formaldehyde at cytotoxic and noncytotoxic concentrations were examined. Male Wistar rats were exposed by inhalation during 22 h/d for 3 consecutive days to 0.3, 1.0, or 3.0 ppm formaldehyde, or to 0.2, 0.4, or 0.8 ppm ozone, or to mixtures of 0.4 ppm ozone and 0.3, 1.0, or 3.0 ppm formaldehyde, or to 1.0 ppm formaldehyde and 0.2, 0.4, or 0.8 ppm ozone, or they were sham-exposed to clean air. The noses were examined for pathological changes at six standard cross levels by light microscopy and for epithelial cell proliferation by counting (3H-methyl)thymidine-labeled cells at cross levels II and III. Ozone at 0.4 ppm or 0.8 ppm or formaldehyde at 3 ppm enhanced cell proliferation at cross level II at all locations, except for the epithelium of the septum, which was not affected by ozone. At cross level III ozone alone did not induce cell proliferation, but formaldehyde at 0.3 and 1 ppm tended to reduce cell proliferation while at 3 ppm proliferation was slightly stimulated. The combined exposure to 0.4 ppm ozone and 0.3 ppm formaldehyde induced less cell proliferation at cross levels II and III when compared with that of 0.4 ppm ozone alone. Less cell proliferation was also seen at cross level II when animals were exposed to 0.4 or 0.8 ppm ozone in combination with 1 ppm formaldehyde than when exposed to these ozone concentrations alone. A more than additive increase in cell proliferation was found at cross level II after exposure to 0.4 ppm ozone in combination with 3 ppm formaldehyde, and at cross level III in animals exposed to 0.4 ppm ozone and 1 or 3 ppm formaldehyde. Treatment-related histopathological nasal changes, such as disarrangement, loss of cilia, and hyper/metaplasia of the epithelium were seen at 0.2, 0.4, and 0.8 ppm ozone and at 3 ppm formaldehyde.