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Sample records for hf-acetone solutions ionoobmennoe

  1. Anion exchange behavior of Ti, Zr, Hf, Nb and Ta as homologues of Rf and Db in mixed HF-acetone solutions

    International Nuclear Information System (INIS)

    Aksenov, N.V.; Bozhikov, G.A.; Starodub, G.Ya.; Dmitriev, S.N.; Filosofov, D.V.; Jon Sun Jin; Radchenko, V.I.; Lebedev, N.A.; Novgorodov, A.F.

    2009-01-01

    We studied in detail the sorption behavior of Ti, Zr, Hf, Nb and Ta on AG 1 anion exchange resin in HF-acetone mixed solutions as a function of organic cosolvent and acid concentrations. Anion exchange behavior was found to be strongly acetone concentration dependent. The distribution coefficients of Ti, Zr, Hf and Nb increased and those of Ta decreased with increasing content of acetone in HF solutions. With increasing HF concentration, anion exchange equilibrium analysis indicated the formation of fluoride complexes of group-4 elements with charge -3 and Ta with charge -2. For Nb the slope of -2 increased up to -5. Optimal conditions for separation of the elements using AIX chromatography were found. Group-4 elements formed MF 7 3- (M = Ti, Zr, Hf) complexes whose sorption decreased Ti > Hf > Zr in reverse order of complex stability. This fact is of particular interest for studying ion exchange behavior of Rf compared to Ti. The advantages of studying chemical properties of Rf and Db in aqueous HF solutions mixed with organic solvents are briefly discussed

  2. 46 CFR 153.1035 - Acetone cyanohydrin or lactonitrile solutions.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Acetone cyanohydrin or lactonitrile solutions. 153.1035... Special Cargo Procedures § 153.1035 Acetone cyanohydrin or lactonitrile solutions. No person may operate a tankship carrying a cargo of acetone cyanohydrin or lactonitrile solutions, unless that cargo is stabilized...

  3. Wet etching characteristics of a HfSiON high-k dielectric in HF-based solutions

    International Nuclear Information System (INIS)

    Li Yongliang; Xu Qiuxia

    2010-01-01

    The wet etching properties of a HfSiON high-k dielectric in HF-based solutions are investigated. HF-based solutions are the most promising wet chemistries for the removal of HfSiON, and etch selectivity of HF-based solutions can be improved by the addition of an acid and/or an alcohol to the HF solution. Due to densification during annealing, the etch rate of HfSiON annealed at 900 0 C for 30 s is significantly reduced compared with as-deposited HfSiON in HF-based solutions. After the HfSiON film has been completely removed by HF-based solutions, it is not possible to etch the interfacial layer and the etched surface does not have a hydrophobic nature, since N diffuses to the interface layer or Si substrate formation of Si-N bonds that dissolves very slowly in HF-based solutions. Existing Si-N bonds at the interface between the new high-k dielectric deposit and the Si substrate may degrade the carrier mobility due to Coulomb scattering. In addition, we show that N 2 plasma treatment before wet etching is not very effective in increasing the wet etch rate for a thin HfSiON film in our case. (semiconductor technology)

  4. Comparison studies of surface cleaning methods for PAN-based carbon fibers with acetone, supercritical acetone and subcritical alkali aqueous solutions

    International Nuclear Information System (INIS)

    Meng Linghui; Fan Dapeng; Huang Yudong; Jiang Zaixing; Zhang Chunhua

    2012-01-01

    Highlights: ► Cleaning with supercritical acetone is appropriate to wipe off the oxygenated contaminants. ► Cleaning with supercritical acetone causes smaller damage to bulk strength of carbon fibers. ► Cleaning with subcritical alkali aqueous solution can thoroughly remove silicious contaminants. - Abstract: Four kinds of polyacrylonitrile-based carbon fibers were cleaned by three methods and were characterized by X-ray photoelectron spectroscopy, monofilament tensile strength test and atomic force microscopy (AFM). Experimental results of these tests reveal that the method using supercritical acetone or subcritical potassium hydroxide aqueous solution act as the processing medium shows a better cleaning effect compared to the traditional method, Soxhlet extraction with acetone. The method using supercritical acetone is more appropriate to wipe off the oxygenated contaminants on carbon fibers’ surfaces and causes a relatively smaller damage to the bulk strength of each carbon fiber. As far as treating method using the subcritical alkali aqueous solution, it can thoroughly remove silicious contaminants on the surfaces of treated fibers.

  5. Ligands Exchange Process on Gold Nanoparticles in Acetone Solution

    Science.gov (United States)

    Hu, C. L.; Mu, Y. Y.; Bian, Z. C.; Luo, Z. H.; Luo, K.; Huang, A. Z.

    2018-05-01

    The ligands exchange process on gold nanoparticles (GNPs) was proceeded by using hydrophobic group (PPh3) and hydrophilic group (THPO) in acetone solution. The FTIR and XPS results demonstrated that part of THPO was replaced by PPh3 which was dissolved in polar solution (acetone); the results were in accordance with the electrochemical analysis where the differential capacity decreased with increasing exchange time. After 12 h, the exchange process terminated and the final ratio of PPh3 and THPO was about 1.4: 1. This ratio remained unchanged although the PPh3 and THPO modified GNPs re-dispersed in the PPh3 acetone solution demonstrating the stable adsorption of both ligands after exchanging for 12 h. The TEM images showed that the gold nanoparticles were self-assembled from scattered to arranged morphology due to the existence of hydrophilic and hydrophobic ligands and led to Janus gold nanoparticles.

  6. Surface tension anomalies in room temperature ionic liquids-acetone solutions

    Science.gov (United States)

    Abe, Hiroshi; Murata, Keisuke; Kiyokawa, Shota; Yoshimura, Yukihiro

    2018-05-01

    Surface tension anomalies were observed in room temperature ionic liquid (RTIL)-acetone solutions. The RTILs are 1-alkyl-3-methylimidazorium iodide with [Cnmim][I] in a [Cnmim][I]-x mol% acetone. The maximum value of the surface tension appeared at 40 mol% acetone, although density decreased monotonically with an increase in acetone concentration. A small alkyl chain length effect of the Cnmim+ cations was observed in the surface tension. By the Gibbs adsorption isotherm, it was found that I- anion-mediated surface structure became dominant above 40 mol%. In the different [Cnmim][TFSI]-acetone mixtures, normal decay of the surface tension was observed on the acetone concentration scale, where TFSI- is bis(trifluoromethanesulfonyl)imide.

  7. SEMICONDUCTOR TECHNOLOGY: Wet etching characteristics of a HfSiON high-k dielectric in HF-based solutions

    Science.gov (United States)

    Yongliang, Li; Qiuxia, Xu

    2010-03-01

    The wet etching properties of a HfSiON high-k dielectric in HF-based solutions are investigated. HF-based solutions are the most promising wet chemistries for the removal of HfSiON, and etch selectivity of HF-based solutions can be improved by the addition of an acid and/or an alcohol to the HF solution. Due to densification during annealing, the etch rate of HfSiON annealed at 900 °C for 30 s is significantly reduced compared with as-deposited HfSiON in HF-based solutions. After the HfSiON film has been completely removed by HF-based solutions, it is not possible to etch the interfacial layer and the etched surface does not have a hydrophobic nature, since N diffuses to the interface layer or Si substrate formation of Si-N bonds that dissolves very slowly in HF-based solutions. Existing Si-N bonds at the interface between the new high-k dielectric deposit and the Si substrate may degrade the carrier mobility due to Coulomb scattering. In addition, we show that N2 plasma treatment before wet etching is not very effective in increasing the wet etch rate for a thin HfSiON film in our case.

  8. High-temperature x-ray diffraction study of HfTiO4-HfO2 solid solutions

    International Nuclear Information System (INIS)

    Carpenter, D.A.

    1975-01-01

    High-temperature x-ray diffraction techniques were used to determine the axial thermal expansion curves of HfTiO 4 -HfO 2 solid solutions as a function of composition. Data show increasing anisotropy with increasing HfO 2 content. An orthorhombic-to-monoclinic phase transformation was detected near room temperature for compositions near the high HfO 2 end of the orthorhombic phase field and for compositions within the two-phase region (HfTiO 4 solid solution plus HfO 2 solid solution). An orthorhombic-to-cubic phase transformation is indicated by data from oxygen-deficient materials at greater than 1873 0 K. (U.S.)

  9. Electron spectra and mechanism of complexing of uranyl nitrate in water-acetone solutions

    International Nuclear Information System (INIS)

    Zazhogin, A.A.; Zazhogin, A.P.; Komyak, A.I.; Serafimovich, A.I.

    2003-01-01

    Based on the analysis of the luminescence and electronic absorption spectra, the processes of complexing in an aqueous solution of UO 2 (NO 3 ) 2 ·6H 2 O with small additions of acetone have been studied. In a pure aqueous solution, uranyl exists as the complex UO 2 ·5H 2 O. It is shown that the addition of acetone to the solution leads to the displacement of some water molecules out of the first coordination sphere of uranyl and the formation of the uranyl nitrate dihydrate complexes UO 2 (NO 3 ) 2 ·2H 2 O. It has been established that the stability of these complexes is determined by the decrease in the water activity and in the degree of hydration of uranyl and nitrate, which is the result of the local increase in the concentration of acetone molecules (due to their hydrophobicity) in the regions of the solution where uranyl and nitrate ions are found. The experimental facts supported the mechanism proposed are presented. (authors)

  10. Theoretical predictions of hydrolysis and complex formation of group-4 elements Zr, Hf and Rf in HF and HCl solutions

    International Nuclear Information System (INIS)

    Pershina, V.; Trubert, D.; Le Naour, C.; Kratz, J.V.

    2002-01-01

    Fully relativistic molecular density-functional calculations of the electronic structures of hydrated, hydrolyzed and fluoride/chloride complexes have been performed for group-4 elements Zr, Hf, and element 104, Rf. Using the electronic density distribution data, relative values of the free energy change for hydrolysis and complex formation reactions were defined. The results show the following trend for the first hydrolysis step of the cationic species: Zr>Hf>Rf in agreement with experiments. For the complex formation in HF solutions, the trend to a decrease from Zr to Hf is continued with Rf, provided no hydrolysis takes place. At pH>0, further fluorination of hydrolyzed species or fluoro-complexes has an inversed trend in the group Rf≥Zr>Hf, with the difference between the elements being very small. For the complex formation in HCl solutions, the trend is continued with Rf, so that Zr>Hf>Rf independently of pH. A decisive energetic factor in hydrolysis or complex formation processes proved to be a predominant electrostatic metal-ligand interaction. Trends in the K d (distribution coefficient) values for the group-4 elements are expected to follow those of the complex formation

  11. Acetone-based cellulose solvent.

    Science.gov (United States)

    Kostag, Marc; Liebert, Tim; Heinze, Thomas

    2014-08-01

    Acetone containing tetraalkylammonium chloride is found to be an efficient solvent for cellulose. The addition of an amount of 10 mol% (based on acetone) of well-soluble salt triethyloctylammonium chloride (Et3 OctN Cl) adjusts the solvent's properties (increases the polarity) to promote cellulose dissolution. Cellulose solutions in acetone/Et3 OctN Cl have the lowest viscosity reported for comparable aprotic solutions making it a promising system for shaping processes and homogeneous chemical modification of the biopolymer. Recovery of the polymer and recycling of the solvent components can be easily achieved. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. On the stabilization of NbV-solutions by ZrIV and HfIV

    International Nuclear Information System (INIS)

    Soerensen, E.; Bjerre, A.B.

    1987-11-01

    Niobium cannot be separated from zirconium or hafnium when these elements occur together in solution with common anions such as Cl- and SO 4 --. This is ascribed to the copolymerisation of Nb v and the hydrolyzed ionic species of Zr IV v and Hf IV by which the colloidal particles are masked as Zr- and Hf-compounds. In HCl the particles are positively charged as opposed to when they are in sulphate solution where the Zr- and Hf- sulphate complexes confer a negative charge. The two cases are considered separately. (author)

  13. Ionic liquid 1-hexyl-3-methylimidazolium hexafluorophosphate, an efficient solvent for extraction of acetone from aqueous solutions

    International Nuclear Information System (INIS)

    Saien, Javad; Badieh, Marjan Mohammadi Sarab; Norouzi, Mahdi; Salehzadeh, Sadegh

    2015-01-01

    Highlights: • The use of HMIMPF_6 as a green ionic was feasible in the extraction of acetone from water. • The binodal curves were determined by cloud point measurement method. • High level separation factor of acetone between the ionic liquid and water were achieved. • The thermodynamic properties of HMIMPF_6 were obtained by the Density Functional Theory calculations. • The NRTL and UNIQUAC models were applied satisfactorily to correlate the equilibrium data. - Abstract: (Liquid + liquid) equilibrium (LLE) of the chemical system of {water + acetone + 1-Hexyl-3-methylimidazolium hexafluorophosphate (HMIMPF_6) ionic liquid} was studied at different temperatures of (293.2, 298.2 and 303.2) K and under atmospheric pressure of 81.5 kPa. The results show that HMIMPF_6 provides the acetone distribution coefficient and separation factor values within (0.8813 to 1.2351) and (3.0 to 54.4), respectively; indicating the high capability of the ionic liquid for extraction of acetone from aqueous solutions. In most cases, acetone solubility in the ionic liquid is higher than in water, especially at higher solute concentrations. Meanwhile, higher separation factor is relevant to the lower temperature due to lower (water + ionic liquid) miscibility. The consistency of tie line data, at each temperature, was examined with Othmer–Tobias correlation. The values were nicely reproduced with the well-known NRTL and UNIQUAC models. Accordingly, the required thermodynamic properties of HMIMPF_6 were obtained by the Density Functional Theory (DFT) calculations, carried out at the M06/6-311++G"∗"∗ level of theory. The root mean square deviations (RMSD) between experimental and model concentration values were 0.0192 and 0.0255, respectively; indicating close agreement of the both models.

  14. Theoretical-experimental study of the solvation enthalpy of acetone in dilute aqueous solution

    International Nuclear Information System (INIS)

    Arroyo, S. Tolosa; Martin, J.A. Sanson; Garcia, A. Hidalgo

    2005-01-01

    The present paper describes molecular dynamics simulations of aqueous solutions at infinite dilution with acetone as solute. Lennard-Jones with electrostatic term (12-6-1 potentials) were employed to describe the solute-solvent interactions. The Morokuma decomposition scheme of ab initio interaction energies at the SCF level and the ESIE charges on the solute atoms were used to reproduce the exchange and Coulomb electrostatic contributions of the solute-water interaction potential. Some extensions, such as including the dispersion component evaluated at MP2 level, were added to the traditional calculation procedures in order to improve the results of the solvation enthalpy. The results obtained with the EX-DIS-ES model were compared with the experimental calorimetry values, the observed agreement being acceptable

  15. Extraction behavior of Nb and Ta in HF solutions with tributyl phosphate

    International Nuclear Information System (INIS)

    Murakami, M.; Tsuto, S.; Ooe, K.; Goto, S.; Kudo, H.; Haba, H.; Kanaya, J.

    2013-01-01

    Extraction behavior of carrier-free Nb and Ta with tributyl phosphate (TBP) from HF solutions was studied by a batch method. Tantalum is extracted well to an organic phase, while Nb is left in an aqueous phase at 0.053-1.0 M HF concentrations. The similar extraction trends of Nb and Ta are shown in the solid phase extraction using a TBP resin. The extraction equilibria in the solid phase extraction are attained within ∼10 s. (author)

  16. [Removal of high-abundance proteins in plasma of the obese by improved TCA/acetone precipitation method].

    Science.gov (United States)

    Wang, Jun; Feng, Liru; Yu, Wei; Xu, Jian; Yang, Hui; Liu, Xiaoli

    2013-09-01

    To develop an improved trichloroacetic acid (TCA)/acetone precipitation method for removal of high-abundance proteins in plasma of the obese. Volumes of TCA/acetone solution (1, 3, 4, 5, 6, 8, 10 and 20 times of the sample) and concentrations of TCA (10%, 30%, 50%, 60%, 70% TCA/acetone solution) have been investigated to optimize the conditions of sample preparation. SDS-PAGE were used to separate and tested proteins in the supernatant and sediment. The best concentration of the TCA/acetone solution was first determined by SDS-PAGE. The protein in precipitation from 10% TCA/acetone solution processing and the new determined concentration TCA/acetone solution processing were verified by 2-D-SDS-PAGE. And then the digested products of the protein in precipitation and supernatant by trypsin were analyzed by nano HPLC-Chip-MS/MS to verify which is the best concentration to process the plasma. The best volume of TCA/acetone is four times to sample, which less or more TCA/acetone would reduce the removal efficiency of high-abundance proteins. The concentration of TCA in acetone solution should be 60%, which may remove more high-abundance proteins in plasma than 10%, 30%, 50% TCA in acetone solution. If the TCA concentration is more than 60%, the reproducibility will be much poorer due to fast precipitation of proteins. The results of mass identification showed that human plasma prepared with 60% TCA/acetone (4 times sample volume) could be verified more low-abundance proteins than 10%. The most desirable conditions for removal of high-abundance proteins in plasma is 60% TCA/acetone (4 times sample volume), especially for the plasma of obesity.

  17. Maximizing recovery of water-soluble proteins through acetone precipitation.

    Science.gov (United States)

    Crowell, Andrew M J; Wall, Mark J; Doucette, Alan A

    2013-09-24

    Solvent precipitation is commonly used to purify protein samples, as seen with the removal of sodium dodecyl sulfate through acetone precipitation. However, in its current practice, protein loss is believed to be an inevitable consequence of acetone precipitation. We herein provide an in depth characterization of protein recovery through acetone precipitation. In 80% acetone, the precipitation efficiency for six of 10 protein standards was poor (ca. ≤15%). Poor recovery was also observed for proteome extracts, including bacterial and mammalian cells. As shown in this work, increasing the ionic strength of the solution dramatically improves the precipitation efficiency of individual proteins, and proteome mixtures (ca. 80-100% yield). This is obtained by including 1-30 mM NaCl, together with acetone (50-80%) which maximizes protein precipitation efficiency. The amount of salt required to restore the recovery correlates with the amount of protein in the sample, as well as the intrinsic protein charge, and the dielectric strength of the solution. This synergistic approach to protein precipitation in acetone with salt is consistent with a model of ion pairing in organic solvent, and establishes an improved method to recover proteins and proteome mixtures in high yield. Copyright © 2013 Elsevier B.V. All rights reserved.

  18. Characterization of stain etched p-type silicon in aqueous HF solutions containing HNO{sub 3} or KMnO{sub 4}

    Energy Technology Data Exchange (ETDEWEB)

    Mogoda, A.S., E-mail: awad_mogoda@hotmail.com [Department of Chemistry, Faculty of Science, Cairo University, Giza (Egypt); Ahmad, Y.H.; Badawy, W.A. [Department of Chemistry, Faculty of Science, Cairo University, Giza (Egypt)

    2011-04-15

    Research highlights: {yields} Stain etching of p-Si in aqueous HF solutions containing HNO{sub 3} or KMnO{sub 4} was investigated. {yields} The electrical conductivity of the etched Si surfaces was measured using impedance technique. {yields} Scanning electron microscope and energy disperse X-ray were used to analyze the etched surfaces. {yields} Etching in aqueous HF solution containing HNO{sub 3} led to formation of a porous silicon layer. {yields} The formation of the porous silicon layer in HF/KMnO{sub 4} was accompanied by deposition of K{sub 2}SiF{sub 6} on the pores surfaces. - Abstract: Stain etching of p-type silicon in hydrofluoric acid solutions containing nitric acid or potassium permanganate as an oxidizing agent has been examined. The effects of etching time, oxidizing agent and HF concentrations on the electrochemical behavior of etched silicon surfaces have been investigated by electrochemical impedance spectroscopy (EIS). An electrical equivalent circuit was used for fitting the impedance data. The morphology and the chemical composition of the etched Si surface were studied using scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) techniques, respectively. A porous silicon layer was formed on Si etched in HF solutions containing HNO{sub 3}, while etching in HF solutions containing KMnO{sub 4} led to the formation of a porous layer and simultaneous deposition of K{sub 2}SiF{sub 6} inside the pores. The thickness of K{sub 2}SiF{sub 6} layer increases with increasing the KMnO{sub 4} concentration and decreases as the concentration of HF increases.

  19. Solution Structure of Enterocin HF, an Antilisterial Bacteriocin Produced by Enterococcus faecium M3K31.

    Science.gov (United States)

    Arbulu, Sara; Lohans, Christopher T; van Belkum, Marco J; Cintas, Luis M; Herranz, Carmen; Vederas, John C; Hernández, Pablo E

    2015-12-16

    The solution structure of enterocin HF (EntHF), a class IIa bacteriocin of 43 amino acids produced by Enterococcus faecium M3K31, was evaluated by CD and NMR spectroscopy. Purified EntHF was unstructured in water, but CD analysis supports that EntHF adopts an α-helical conformation when exposed to increasing concentrations of trifluoroethanol. Furthermore, NMR spectroscopy indicates that this bacteriocin adopts an antiparallel β-sheet structure in the N-terminal region (residues 1-17), followed by a well-defined central α-helix (residues 19-30) and a more disordered C-terminal end (residues 31-43). EntHF could be structurally organized into three flexible regions that might act in a coordinated manner. This is in agreement with the absence of long-range nuclear Overhauser effect signals between the β-sheet domain and the C-terminal end of the bacteriocin. The 3D structure recorded for EntHF fits emerging facts regarding target recognition and mode of action of class IIa bacteriocins.

  20. Characterisation of cellulose films regenerated from acetone/water coagulants.

    Science.gov (United States)

    Geng, Hongjuan; Yuan, Zaiwu; Fan, Qingrui; Dai, Xiaonan; Zhao, Yue; Wang, Zhaojiang; Qin, Menghua

    2014-02-15

    A precooled aqueous solution of 7 wt% NaOH/12 wt% urea was used to dissolve cellulose up to a concentration of 2 wt%, which was then coagulated in an acetone/water mixture to regenerate cellulose film. The volume ratio of acetone to water (φ) had a dominant influence on film dimensional stability, film-forming ability, micromorphology, and mechanical strength. The film regenerated at φ=2.0 showed excellent performance in both dimensional stability and film-forming ability. Compared to that from pure acetone, the cellulose film from the acetone/water mixture with φ=2.0 was more densely interwoven, since the cellulosic fibrils formed during regeneration had pores with smaller average diameter. The alkali capsulated in the film during film formation could be released at quite a slow rate into the surrounding aqueous solution. The regenerated cellulose film with adjustable structure and properties may have potential applications in drug release and ultra filtration. Copyright © 2013 Elsevier Ltd. All rights reserved.

  1. Quantitative Clinical Diagnostic Analysis of Acetone in Human Blood by HPLC: A Metabolomic Search for Acetone as Indicator

    Directory of Open Access Journals (Sweden)

    Esin Akgul Kalkan

    2016-01-01

    Full Text Available Using high-performance liquid chromatography (HPLC and 2,4-dinitrophenylhydrazine (2,4-DNPH as a derivatizing reagent, an analytical method was developed for the quantitative determination of acetone in human blood. The determination was carried out at 365 nm using an ultraviolet-visible (UV-Vis diode array detector (DAD. For acetone as its 2,4-dinitrophenylhydrazone derivative, a good separation was achieved with a ThermoAcclaim C18 column (15 cm × 4.6 mm × 3 μm at retention time (tR 12.10 min and flowrate of 1 mL min−1 using a (methanol/acetonitrile water elution gradient. The methodology is simple, rapid, sensitive, and of low cost, exhibits good reproducibility, and allows the analysis of acetone in biological fluids. A calibration curve was obtained for acetone using its standard solutions in acetonitrile. Quantitative analysis of acetone in human blood was successfully carried out using this calibration graph. The applied method was validated in parameters of linearity, limit of detection and quantification, accuracy, and precision. We also present acetone as a useful tool for the HPLC-based metabolomic investigation of endogenous metabolism and quantitative clinical diagnostic analysis.

  2. Poly (furfural-acetone) as New Adsorbent for Removal of Cu(II) from Aqueous Solution: Equilibrium Study

    OpenAIRE

    Najim, Tariq S.

    2010-01-01

    The batch removal of Cu(II) from aqueous solution using poly (furfural-acetone), (PFA) as adsorbent was investigated in this study. The influences of initial Cu(II) ion concentration (10 to 120 ppm), pH (4-8) and contact time have been reported. Adsorption of Cu(II) is highly pH-dependent and the result indicate that the optimum pH for the removal was found to be 6. At this pH a small amount of PFA, 2 g/L, could remove as much as 97% of Cu(II) from a solution of initial concentration 10 ppm....

  3. Toward Portable Breath Acetone Analysis for Diabetes Detection

    Science.gov (United States)

    Righettoni, Marco; Tricoli, Antonio

    2013-01-01

    Diabetes is a lifelong condition that may cause death and seriously affects the quality of life of a rapidly growing number of individuals. Acetone is a selective breath marker for diabetes that may contribute to the monitoring of related metabolic disorder and thus simplify the management of this illness. Here, the overall performance of Si-doped WO3 nanoparticles made by flame spray pyrolysis as portable acetone detectors is critically reviewed focusing on the requirements for medical diagnostic. The effect of flow rate, chamber volume and acetone dissociation within the measuring chamber are discussed with respect to the calibration of the sensor response. The challenges for the fabrication of portable breath acetone sensors based on chemo-resistive detectors are underlined indicating possible solutions and novel research directions. PMID:21828897

  4. Concentration Dependences of the Surface Tension and Density of Solutions of Acetone-Ethanol-Water Systems at 293 K

    Science.gov (United States)

    Dadashev, R. Kh.; Dzhambulatov, R. S.; Mezhidov, V. Kh.; Elimkhanov, D. Z.

    2018-05-01

    Concentration dependences of the surface tension and density of solutions of three-component acetone-ethanol-water systems and the bounding binary systems at 273 K are studied. The molar volume, adsorption, and composition of surface layers are calculated. Experimental data and calculations show that three-component solutions are close to ideal ones. The surface tensions of these solutions are calculated using semi-empirical and theoretical equations. Theoretical equations qualitatively convey the concentration dependence of surface tension. A semi-empirical method based on the Köhler equation allows us to predict the concentration dependence of surface tension within the experimental error.

  5. trans-Carbonylchloridobis(tri-p-tolylphosphinerhodium(I acetone solvate

    Directory of Open Access Journals (Sweden)

    Brian R. James

    2008-03-01

    Full Text Available The title compound, [RhCl(C21H21P2(CO]·C3H6O, was precipitated in trace yield from a reaction of RhCl(cod(THP with P(p-tol3 in a 1:1 acetone-d6/CD3OD solution under a hydrogen atmosphere [p-tol = p-tolyl, THP = tris(hydroxymethylphosphine, P(CH2OH3, and cod = 1,5-cyclooctadiene]. The complex displays a square-planar geometry around the RhI atom. The complex molecules and the acetone molecules are linked into a chain along the a axis by intermolecular C—H...Cl and C—H...O hydrogen bonds.

  6. Thermodynamic mixing properties of the UO{sub 2}–HfO{sub 2} solid solution: Density functional theory and Monte Carlo simulations

    Energy Technology Data Exchange (ETDEWEB)

    Yuan, Ke, E-mail: keyuan@umich.edu [Department of Earth and Environmental Sciences, University of Michigan, Ann Arbor, MI 48109 (United States); Ewing, Rodney C. [Department of Earth and Environmental Sciences, University of Michigan, Ann Arbor, MI 48109 (United States); Department of Nuclear Engineering and Radiological Sciences, University of Michigan, Ann Arbor, MI 48109 (United States); Department of Materials Science and Engineering, University of Michigan, Ann Arbor, MI 48109 (United States); Becker, Udo [Department of Earth and Environmental Sciences, University of Michigan, Ann Arbor, MI 48109 (United States)

    2015-03-15

    HfO{sub 2} is a neutron absorber and has been mechanically mixed with UO{sub 2} in nuclear fuel in order to control the core power distribution. During nuclear fission, the temperature at the center of the fuel pellet can reach above 1300 K, where hafnium may substitute uranium and form the binary solid solution of UO{sub 2}–HfO{sub 2}. UO{sub 2} adopts the cubic fluorite structure, but HfO{sub 2} can occur in monoclinic, tetragonal, and cubic structures. The distribution of Hf and U ions in the UO{sub 2}–HfO{sub 2} binary and its atomic structure influence the thermal conductivity and melting point of the fuel. However, experimental data on the UO{sub 2}–HfO{sub 2} binary are limited. Therefore, the enthalpies of mixing of the UO{sub 2}–HfO{sub 2} binary with three different structures were calculated in this study using density functional theory and subsequent Monte Carlo simulations. The free energy of mixing was obtained from thermodynamic integration of the enthalpy of mixing over temperature. From the ΔG of mixing, a phase diagram of the binary was obtained. The calculated UO{sub 2}–HfO{sub 2} binary forms extensive solid solution across the entire compositional range, but there are a variety of possible exsolution phenomena associated with the different HfO{sub 2} polymorphs. As the structure of the HfO{sub 2} end member adopts lower symmetry and becomes less similar to cubic UO{sub 2}, the miscibility gap of the phase diagram expands, accompanied by an increase in cell volume by 7–10% as the structure transforms from cubic to monoclinic. Close to the UO{sub 2} end member, which is relevant to the nuclear fuel, the isometric uranium-rich solid solutions exsolve as the fuel cools, and there is a tendency to form the monoclinic hafnium-rich phase in the matrix of the isometric, uranium-rich solid solution phase.

  7. New Ablation-Resistant Material Candidate for Hypersonic Applications: Synthesis, Composition, and Oxidation Resistance of HfIr3-Based Solid Solution.

    Science.gov (United States)

    Lozanov, Victor V; Baklanova, Natalya I; Bulina, Natalia V; Titov, Anatoly T

    2018-04-18

    The peculiarities of the solid-state interaction in the HfC-Ir system have been studied within the 1000-1600 °C temperature range using a set of modern analytical techniques. It was stated that the interaction of HfC with iridium becomes noticeable at temperatures as low as 1000-1100 °C and results in the formation of HfIr 3 -based substitutional solid solution. The homogeneity range of the HfIr 3± x phase was evaluated and refined as HfIr 2.43 -HfIr 3.36 . The durability of the HfIr 3 -based system under extreme environmental conditions was studied. It was shown that the HfIr 3 -based material displays excellent ablation resistance under extreme environmental conditions. The benefits of the new designed material result from its relative oxygen impermeability and special microstructure similar to superalloys. The results obtained in this work allow us to consider HfIr 3 as a very promising candidate for extreme applications.

  8. The use of acetone to enhance the infiltration of HA nanoparticles into a demineralized dentin collagen matrix.

    Science.gov (United States)

    Besinis, Alexandros; van Noort, Richard; Martin, Nicolas

    2016-03-01

    This study investigates the role of acetone, as a carrier for nano-hydroxyapatite (nano-HA) in solution, to enhance the infiltration of fully demineralized dentin with HA nanoparticles (NPs). Dentin specimens were fully demineralized and subsequently infiltrated with two types of water-based nano-HA solutions (one containing acetone and one without). Characterization of the dentin surfaces and nano-HA particles was performed using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The surface wettability and infiltration capacity of the nano-HA solutions were quantified by means of contact angle measurements and energy dispersive X-ray spectroscopy (EDS), respectively. Contact angle measurements were taken at baseline and repeated at regular intervals to assess the effect of acetone. The P and Ca levels of infiltrated dentin specimens were measured and compared to sound dentin and non-infiltrated controls. The presence of acetone resulted in an eight-fold decrease in the contact angles of the nano-HA solutions recorded on the surface of demineralized dentin compared to nano-HA solutions without acetone (one-way ANOVA, pacetone. Infiltration of demineralized dentin with the nano-HA solution containing acetone restored the lost mineral content by 50%, whereas the mean mineralization values for P and Ca in dentin treated with the acetone-free nano-HA solution were less than 6%. Acetone was shown to act as a vehicle to enhance the capacity to infiltrate demineralized dentin with HA NPs. The successful infiltration of dentin collagen with HA NPs provides a suitable scaffold, whereby the infiltrated HA NPs have the potential to act as seeds that may initiate heterogenous mineral growth when exposed to an appropriate mineral-rich environment. Copyright © 2015 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  9. Acetone poisoning

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/002480.htm Acetone poisoning To use the sharing features on this page, please enable JavaScript. Acetone is a chemical used in many household products. ...

  10. Measurement of natural carbon isotopic composition of acetone in human urine.

    Science.gov (United States)

    Yamada, Keita; Ohishi, Kazuki; Gilbert, Alexis; Akasaka, Mai; Yoshida, Naohiro; Yoshimura, Ryoko

    2016-02-01

    The natural carbon isotopic composition of acetone in urine was measured in healthy subjects using gas chromatography-combustion-isotope ratio mass spectrometry combined with headspace solid-phase microextraction (HS-SPME-GC-C-IRMS). Before applying the technique to a urine sample, we optimized the measurement conditions of HS-SPME-GC-C-IRMS using aqueous solutions of commercial acetone reagents. The optimization enabled us to determine the carbon isotopic compositions within ±0.2 ‰ of precision and ±0.3‰ of error using 0.05 or 0.2 mL of aqueous solutions with acetone concentrations of 0.3-121 mg/L. For several days, we monitored the carbon isotopic compositions and concentrations of acetone in urine from three subjects who lived a daily life with no restrictions. We also monitored one subject for 3 days including a fasting period of 24 h. These results suggest that changes in the availability of glucose in the liver are reflected in changes in the carbon isotopic compositions of urine acetone. Results demonstrate that carbon isotopic measurement of metabolites in human biological samples at natural abundance levels has great potential as a tool for detecting metabolic changes caused by changes in physiological states and disease.

  11. Propagation of evanescent waves in multimode chalcogenide fiber immersed in an aqueous acetone solution: theory and experiment

    Science.gov (United States)

    Korsakova, S. V.; Romanova, E. A.; Velmuzhov, A. P.; Kotereva, T. V.; Sukhanov, M. V.; Shiryaev, V. S.

    2017-04-01

    Chalcogenide fibers are considered as a base for creation of a fiber-optical platform for the mid-IR evanescent wave spectroscopy. In this work, transmittance of a multimode fiber made of Ge26As17Se25Te32 glass, immersed into an aqueous acetone solution was measured in the range of wavelengths 5 - 9 microns at various concentrations of the solution. A theoretical approach based on electromagnetic theory of optical fibers has been applied for analysis of evanescent modes propagation in the fiber. Attenuation coefficients calculated for each HE1m evanescent mode increase with the mode radial order m. This effect can be used for optimisation of the fiber-optic sensing elements for the mid-IR spectroscopy.

  12. Enthalpies of solution of N,N,N',N'-tetramethylurea in amides, dimethylsulphoxide, and acetone at 298.15 K

    International Nuclear Information System (INIS)

    Ivanov, Evgeniy V.; Smirnov, Valeriy I.

    2008-01-01

    The enthalpies of solution Δ sol H m m were determined for N,N,N',N'-tetramethylurea in formamide, N-methylformamide, N,N-dimethylformamide, N,N-dimethylacetamide, dimethylsulphoxide, and acetone. Measurements were made at 298.15 K and molalities m = (0.004 to 0.031) mol . kg -1 with a precise isoperibol ampoule-type calorimeter. Standard enthalpies of solution Δ sol H m 0 and transfer Δ tr H m 0 from one solvent to another were computed. The enthalpies of solution of the solute in the hydrogen-non-bonding media were found to be endothermic and weak depending on the nature of methylation in a solvent molecule. It was concluded that the solvent proton-donor ability and existing steric hindrances for hydrogen bonding and other intermolecular interactions play the key role in solvation of tetramethylurea

  13. Self-Diffusion and Heteroassociation in an Acetone-Chloroform Mixture at 298 K

    Science.gov (United States)

    Golubev, V. A.; Gurina, D. L.; Kumeev, R. S.

    2018-01-01

    The self-diffusion coefficients of acetone and chloroform in a binary acetone-chloroform mixture at 298 K are determined via pulsed field gradient NMR spectroscopy. It is estimated that the hydrodynamic radii of the mixture's components, calculated using the Stokes-Einstein equation, grow as the concentrations of the components fall. It is shown that such behavior of hydrodynamic radii is due to acetone-chloroform heteroassociation. The hydrodynamic radii of monomers and heteroassociates in a 1: 1 ratio are determined along with the constant of heteroassociation, using the proposed model of an associated solution.

  14. Ideal solution behaviour of glassy Cu–Ti, Zr, Hf alloys and properties of amorphous copper

    International Nuclear Information System (INIS)

    Ristić, R.; Cooper, J.R.; Zadro, K.; Pajić, D.; Ivkov, J.; Babić, E.

    2015-01-01

    Highlights: • Ideal solution behaviour (ISB) is established in all Cu–Ti, Zr, Hf glassy alloys. • ISB enables reliable estimates for various properties of amorphous Cu. • ISB also impacts glass forming ability in these and probably other similar alloys. - Abstract: A comprehensive study of selected properties of amorphous (a) Cu–TE alloys (TE = Ti, Zr and Hf) has been performed. Data for average atomic volumes of a-Cu–Hf, Ti alloys combined with literature data show that ideal solution behaviour (Vegard’s law) extends over the whole glass forming range (GFR) in all a-Cu–TE alloys. This enables one to obtain an insight into some properties and probable atomic arrangements for both, a-TEs (Ristić et al., 2010) and a-Cu by extrapolation of the data for alloys. Indeed the atomic volumes and other properties studied for all a-Cu–TE alloys extrapolate to the same values for a-Cu. Depending on the property, these values are either close to those of crystalline (c) Cu, or are close to those for liquid (L) Cu. In particular, the electronic transport properties of a-Cu seem close to those of L-Cu, whereas the static properties, such as the density of states, and Young’s modulus, converge to those of c-Cu. The possible impact of these results on our understanding of a-Cu–TE alloys, including glass forming ability, is discussed

  15. Solute-solvent complex switching dynamics of chloroform between acetone and dimethylsulfoxide-two-dimensional IR chemical exchange spectroscopy.

    Science.gov (United States)

    Kwak, Kyungwon; Rosenfeld, Daniel E; Chung, Jean K; Fayer, Michael D

    2008-11-06

    Hydrogen bonds formed between C-H and various hydrogen bond acceptors play important roles in the structure of proteins and organic crystals, and the mechanisms of C-H bond cleavage reactions. Chloroform, a C-H hydrogen bond donor, can form weak hydrogen-bonded complexes with acetone and with dimethylsulfoxide (DMSO). When chloroform is dissolved in a mixed solvent consisting of acetone and DMSO, both types of hydrogen-bonded complexes exist. The two complexes, chloroform-acetone and chloroform-DMSO, are in equilibrium, and they rapidly interconvert by chloroform exchanging hydrogen bond acceptors. This fast hydrogen bond acceptor substitution reaction is probed using ultrafast two-dimensional infrared (2D-IR) vibrational echo chemical exchange spectroscopy. Deuterated chloroform is used in the experiments, and the 2D-IR spectrum of the C-D stretching mode is measured. The chemical exchange of the chloroform hydrogen bonding partners is tracked by observing the time-dependent growth of off-diagonal peaks in the 2D-IR spectra. The measured substitution rate is 1/30 ps for an acetone molecule to replace a DMSO molecule in a chloroform-DMSO complex and 1/45 ps for a DMSO molecule to replace an acetone molecule in a chloroform-acetone complex. Free chloroform exists in the mixed solvent, and it acts as a reactive intermediate in the substitution reaction, analogous to a SN1 type reaction. From the measured rates and the equilibrium concentrations of acetone and DMSO, the dissociation rates for the chloroform-DMSO and chloroform-acetone complexes are found to be 1/24 ps and 1/5.5 ps, respectively. The difference between the measured rate for the complete substitution reaction and the rate for complex dissociation corresponds to the diffusion limited rate. The estimated diffusion limited rate agrees well with the result from a Smoluchowski treatment of diffusive reactions.

  16. Isothermal cross-sections of Hf-Sc-Ga(800 deg C) and Hf-Ti-Ga (750 deg C) phase diagrams

    International Nuclear Information System (INIS)

    Markiv, V.Ya.; Belyavina, N.N.

    1981-01-01

    Isothermal cross sections of Hf-Sc-Ga (800 deg C) and Hf-Ti-Ga (750 deg C) state diagrams are plotted. The existence of two ternary Hfsub(0.1-0.8)Scsub(0.9)-sub(0.2)Ga and Hfsub(0.8)Scsub(0.2)Gasub(3) phases is stated in the Hf-Sc-Ga system. The crystal structure of these compounds investigated by the powder method belongs to the structural α-MoB and ZrAl 3 types respectively. Continuous rows of (Hf, Sc 5 Ga 5 , (Hf, Ti)Ga 3 and (Hf, Ti)Ga 2 solid solutions are formed in the investigated systems. Essential quantity of the third component dissolve binary Sc 5 Ga 4 , Sc 2 Ga 3 (15 and 30 at % Hf respectively), Hf 5 Ga 4 , HfGa 2 (20, 10 at. % Sc), Hf 5 Ga 4 , HfGa, Hf 5 Ga 3 , Hf 2 Ga 3 (48, 30, 46, 20 at. % Ti) gallides [ru

  17. Determination of total fluoride in HF/HNO3/H2SiF6 etch solutions by new potentiometric titration methods.

    Science.gov (United States)

    Weinreich, Wenke; Acker, Jörg; Gräber, Iris

    2007-03-30

    In the photovoltaic industry the etching of silicon in HF/HNO(3) solutions is a decisive process for cleaning wafer surfaces or to produce certain surface morphologies like polishing or texturization. With regard to cost efficiency, a maximal utilisation of etch baths in combination with highest quality and accuracy is strived. To provide an etch bath control realised by a replenishment with concentrated acids the main constituents of these HF/HNO(3) etch solutions including the reaction product H(2)SiF(6) have to be analysed. Two new methods for the determination of the total fluoride content in an acidic etch solution based on the precipitation titration with La(NO(3))(3) are presented within this paper. The first method bases on the proper choice of the reaction conditions, since free fluoride ions have to be liberated from HF and H(2)SiF(6) at the same time to be detected by a fluoride ion-selective electrode (F-ISE). Therefore, the sample is adjusted to a pH of 8 for total cleavage of the SiF(6)(2-) anion and titrated in absence of buffers. In a second method, the titration with La(NO(3))(3) is followed by a change of the pH-value using a HF resistant glass-electrode. Both methods provide consistent values, whereas the analysis is fast and accurate, and thus, applicable for industrial process control.

  18. Solution chemistry of element 105. Pt. III. Hydrolysis and complex formation of Nb, Ta, Db and Pa in HF and HBr solutions

    International Nuclear Information System (INIS)

    Pershina, V.; Bastug, T.

    1999-01-01

    Calculations of the electronic structure of MF 6 - and MBr 6 - complexes of Nb, Ta, Pa and element 105, Db, formed in HF and HBr solutions have been performed using the Dirac-Slater Discrete Variational method. On the basis of results of these calculations, relative values of the free energy change of reactions of complex formation have been determined. The order of the complex formation for both acids is shown to be Pa >> Nb > Db > Ta. Such a sequence is defined by a predominant electrostatic energy of the metal-ligand interaction. The hydrolysis of compounds, as a reverse process, proved to change as Ta > Db > Nb >> Pa. Using the theory of metal extraction by anion exchange, the following trend in the extraction of the anionic species from both the HF and HBr aqueous solutions has been predicted: Pa >> Nb ≥ Db > Ta. The strength of the ML 6 - complexes is shown to decrease from MF 6 , to MCl 6 and further to MBr 6 - which is reflected by shifting the complex formation process to the area of higher acid concentrations. (orig.)

  19. Production of acetone and conversion of acetone to acetate in the perfused rat liver

    International Nuclear Information System (INIS)

    Gavino, V.C.; Somma, J.; Philbert, L.; David, F.; Garneau, M.; Belair, J.; Brunengraber, H.

    1987-01-01

    The utilization of millimolar concentrations of [2- 14 C]acetone and the production of acetone from acetoacetate were studied in perfused livers from 48-h starved rats. We devised a procedure for determining, in a perfused liver system, the first-order rate constant for the decarboxylation of acetoacetate (0.29 +/- 0.09 h-1, S.E., n = 8). After perfusion of livers with [2- 14 C]acetone, labeled acetate was isolated from the perfusion medium and characterized as [1- 14 C]acetate. No radioactivity was found in lactate or 3-hydroxybutyrate. After 90 min of perfusion with [2- 14 C]acetone, the specific activity of acetate was 30 +/- 4% (n = 13) of the initial specific activity of acetone. We conclude that, in perfused livers from 2-day starved rats, acetone metabolism occurs for the most part via free acetate

  20. Fate of acetone in an outdoor model stream in southern Mississippi, U.S.A.

    Science.gov (United States)

    Rathbun, R.E.; Stephens, D.W.; Shultz, D.J.; Tai, D.Y.

    1988-01-01

    The fate of acetone in water was investigated in an outdoor model stream located in southern Mississippi, U.S.A. Acetone was injected continuously for 32 days resulting in small milligram-perliter concentrations in the stream. Rhodamine-WT dye was injected at the beginning and at the end of the study to determine the time-of-travel and dispersion characteristics of the stream. A 12-h injection of t-butyl alcohol (TBA) was used to determine the volatilization characteristics of the stream. Volatilization controlled the acetone concentration in the stream. Significant bacterial degradation of acetone did not occur, contrary to expectations based on previous laboratory studies. Attempts to induce degradation of the acetone by injecting glucose and a nutrient solution containing bacteria acclimated to acetone were unsuccessful. Possible explanations for the lack of bacterial degradation included a nitrate limitation and a limited residence time in the stream system. ?? 1988.

  1. Mechanism of plutonium metal dissolution in HNO3-HF-N2H4 solution

    International Nuclear Information System (INIS)

    Karraker, D.G.

    1985-01-01

    An oxidation-reduction balance of the products of the dissolution of plutonium metal and alloys in HNO 3 -HF-N 2 H 4 solution shows that the major reactions during dissolution are the reduction of nitrate to NH 3 , N 2 and N 2 O by the metal, and the oxidation of H free radicals to NH 3 by N 2 H 4 . Reactions between HNO 3 and N 2 H 4 produce varying amounts of HN 3 . The reaction rate is greater for delta-Pu than alpha-Pu, and is increased by higher concentrations of HF and HNO 3 . The low yield of reduced nitrogen species indicates that nitrate is reduced on the metal surface without producing a significant concentration of species that react with N 2 H 4 . It is conjectured that intermediate Pu valences and electron transfer within the metal are involved. 7 refs., 3 tabs

  2. Synthesis of complex compounds in the system [ReOG5]2--thiosemicarbazone acetone-Hg-acetone

    International Nuclear Information System (INIS)

    Amindzhanov, A.A.; Kurbanov, N.M.

    1993-01-01

    Present article is devoted to synthesis of complex compounds in the system [ReOG 5 ] 2- -thiosemicarbazone acetone-Hg-acetone. The literature data on complex compounds of various metals with thiosemicarbazone was summarized. The synthesis of complex compounds in the system [ReOG 5 ] 2- -thiosemicarbazone acetone-Hg-acetone was conducted. The complex compounds of rhenium with methyl ident thiosemicarbazone were synthesized.

  3. Extraction of Oxytetracycline Hydrochloride in Aqueous Two-phase System of Acetone and Ammonium Sulfate

    International Nuclear Information System (INIS)

    Han, J.

    2013-01-01

    Summary: Aqueous two-phase system (ATPS) is an efficient implement for separation of various substrates, and extracted by an aqueous two-phase system has been successful ly applied in the downstream processing of various biological compounds. In this research, the extraction of oxytetracycline hydrochloride (OTC-HCl) was carried out in an aqueous two-phase system containing acetone and ammonium sulfate solution, which partitioned the antibiotic to the upper phase. The effects of some parameters on the extraction efficiency of OTC-HCl were studied in detail, including temperature, the volume of acetone, the pH value of ammonium sulfate solution, the concentrations of (NH/sub 4/)/sub 2/ SO/sub 4/ and OTC-HCl. The results showed that the volume of acetone, the pH value of ammonium sulfate solution and the concentration of OTC-HCl in feed had significant effects on the extraction efficiency of OTC-HCl, but the effects of temperature on the extraction of OTC-HCl was not obvious. (author)

  4. Extraction of Oxytetracycline Hydrochloride in Aqueous Two-phase System of Acetone and Ammonium Sulfate

    Energy Technology Data Exchange (ETDEWEB)

    Han, J. [Jiangsu Univ., Zhenjiang (China). Dept. of Food and Biological Engineering

    2013-02-15

    Summary: Aqueous two-phase system (ATPS) is an efficient implement for separation of various substrates, and extracted by an aqueous two-phase system has been successful ly applied in the downstream processing of various biological compounds. In this research, the extraction of oxytetracycline hydrochloride (OTC-HCl) was carried out in an aqueous two-phase system containing acetone and ammonium sulfate solution, which partitioned the antibiotic to the upper phase. The effects of some parameters on the extraction efficiency of OTC-HCl were studied in detail, including temperature, the volume of acetone, the pH value of ammonium sulfate solution, the concentrations of (NH/sub 4/)/sub 2/ SO/sub 4/ and OTC-HCl. The results showed that the volume of acetone, the pH value of ammonium sulfate solution and the concentration of OTC-HCl in feed had significant effects on the extraction efficiency of OTC-HCl, but the effects of temperature on the extraction of OTC-HCl was not obvious. (author)

  5. Sensor gas analyzer for acetone determination in expired air

    Science.gov (United States)

    Baranov, Vitaly V.

    2001-05-01

    Diseases and changes in the way of life change the concentration and composition of the expired air. Our adaptable gas analyzer is intended for the selective analysis of expired air and can be adapted for the solution of current diagnostic and analytical tasks by the user (a physician or a patient). Having analyzed the existing trends in the development of noninvasive diagnostics we have chosen the method of noninvasive acetone detection in expired air, where the acetone concentration correlates with blood and urine glucose concentrations. The appearance of acetone in expired air is indicative of disorders that may be caused not only by diabetes but also be wrong diet, incorrect sportsmen training etc. To control the disorders one should know the acetone concentration in the human body. This knowledge allows one to judge upon the state of the patient, choose a correct diet that will not cause damage to the patient's health, determine sportsmen training efficiency and results and solve the artificial pancreas problem. Our device provide highly accurate analysis, rapid diagnostics and authentic acetone quantification in the patient's body at any time aimed at prediction of the patient's state and assessing the efficiency of the therapy used. Clinical implementation of the device will improve the health and save lives of many thousands of diabetes sufferers.

  6. Enlarging the fission fragment tracks in glass detectors by etching in weak solutions of HF - a safe etchant

    International Nuclear Information System (INIS)

    Singh, V.P.; Sharma, A.P.

    1982-01-01

    The effect of etchant concentration and temperature on track revelation properties of soda glass detectors has been studied. Etch rate ratio, maximum observable diameter and the energy resolution of the fission fragment tracks of 252 Cf in glasses are increased when the samples are etched in 1.25 vol% HF as compared to higher concentrations of HF and other etching solutions. The critical angle of etching is found to decrease with decrease in etchant concentration. The activation energies for bulk etching and track etching have also been estimated. Better results were obtained by using lower etching temperatures. (author)

  7. Acetone production by methylobacteria.

    Science.gov (United States)

    Thomson, A W; O'Neill, J G; Wilkinson, J F

    1976-09-01

    An accumulation of acetone was observed during the metabolism of ethane and products of ethane oxidation by washed suspensions of Methylosinus trichosporium OB3B. This strain possessed an acetoacetate decarboxylase and 3-hydroxybutyrate dehydrogenase, and a decline in poly-beta-hydroxybutyric acid occurred under the same conditions as acetone formation. A pathway of acetone production from poly-beta-hydroxybutyric acid via 3-hydroxybutyrate and acetoacetate was suggested.

  8. Low-temperature fabrication of an HfO2 passivation layer for amorphous indium-gallium-zinc oxide thin film transistors using a solution process.

    Science.gov (United States)

    Hong, Seonghwan; Park, Sung Pyo; Kim, Yeong-Gyu; Kang, Byung Ha; Na, Jae Won; Kim, Hyun Jae

    2017-11-24

    We report low-temperature solution processing of hafnium oxide (HfO 2 ) passivation layers for amorphous indium-gallium-zinc oxide (a-IGZO) thin-film transistors (TFTs). At 150 °C, the hafnium chloride (HfCl 4 ) precursor readily hydrolyzed in deionized (DI) water and transformed into an HfO 2 film. The fabricated HfO 2 passivation layer prevented any interaction between the back surface of an a-IGZO TFT and ambient gas. Moreover, diffused Hf 4+ in the back-channel layer of the a-IGZO TFT reduced the oxygen vacancy, which is the origin of the electrical instability in a-IGZO TFTs. Consequently, the a-IGZO TFT with the HfO 2 passivation layer exhibited improved stability, showing a decrease in the threshold voltage shift from 4.83 to 1.68 V under a positive bias stress test conducted over 10,000 s.

  9. Regeneration of granular activated carbon saturated with acetone and isopropyl alcohol via a recirculation process under H2O2/UV oxidation.

    Science.gov (United States)

    Horng, Richard S; Tseng, I-Chin

    2008-06-15

    This study examines a water-based system, coupling an adsorber and a photoreactor, for regeneration of granular activated carbon (GAC) saturated with acetone and isopropyl alcohol (IPA). Through water recirculation the regeneration reaction was operated in both intermittent and continuous ultraviolet illumination modes. With a periodic dosage of hydrogen peroxide not only was regeneration efficient but it was also catalyzed by GAC in the adsorber. The concentrations of acetone, solution chemical oxygen demand (COD), pH and organic residues on GAC surfaces were measured during regenerations. Both pH and solution COD were found to correlate with regeneration completion as measured by organic residue on GAC surfaces in four regeneration cycles with acetone. Solution pH decreased to the acidic values and then returned to near its original value when organic residues were 0.085-0.255 mg/g GAC, that is, destruction efficiency of adsorbed acetone on the GAC surface was more than 99%. Likewise, solution COD became low (properties in each of eight cycles: adsorptive capacities were 95+/-7 mg acetone/g GAC and 87+/-3 mg IPA/g GAC, and breakthrough time was 0.86+/-0.05 for acetone and 0.78+/-0.03 h for IPA. An economic assessment of the system showed that the operating cost was about 0.04 USD for treating every gram of acetone in the air.

  10. HF effect on dissociation kinetics of plutonium and neptunium complexes with 1,2-diaminocyclohexanetetraacetic acid in nitric acid solutions

    International Nuclear Information System (INIS)

    Nikitina, S.A.; Stepanov, A.V.

    1982-01-01

    Dissociation kinetics of Pusup((4)) and Np sup((4)) complexes with DCTA were investigated in HNO 3 solutions in the presence of HF and arsenazo 3. It was found that HF or NaF produced a differentiating effect on the reactivity of the complexes at [HNO 3 ]=1-6 mol/l as well as inhibiting effect at [HNO 3 ]=0.01 mol/l. Conditions of the differential kinetic analysis of plutonium and neptunium in the mixture and differential spectrophotometric analysis of uranium (6) during the camouflage of neptunium (4) and plutonium (4) were determined

  11. Is breath acetone a biomarker of diabetes? A historical review on breath acetone measurements.

    Science.gov (United States)

    Wang, Zhennan; Wang, Chuji

    2013-09-01

    Since the ancient discovery of the 'sweet odor' in human breath gas, pursuits of the breath analysis-based disease diagnostics have never stopped. Actually, the 'smell' of the breath, as one of three key disease diagnostic techniques, has been used in Eastern-Medicine for more than three thousand years. With advancement of measuring technologies in sensitivity and selectivity, more specific breath gas species have been identified and established as a biomarker of a particular disease. Acetone is one of the breath gases and its concentration in exhaled breath can now be determined with high accuracy using various techniques and methods. With the worldwide prevalence of diabetes that is typically diagnosed through blood testing, human desire to achieve non-blood based diabetic diagnostics and monitoring has never been quenched. Questions, such as is breath acetone a biomarker of diabetes and how is the breath acetone related to the blood glucose (BG) level (the golden criterion currently used in clinic for diabetes diagnostic, monitoring, and management), remain to be answered. A majority of current research efforts in breath acetone measurements and its technology developments focus on addressing the first question. The effort to tackle the second question has begun recently. The earliest breath acetone measurement in clearly defined diabetic patients was reported more than 60 years ago. For more than a half-century, as reviewed in this paper, there have been more than 41 independent studies of breath acetone using various techniques and methods, and more than 3211 human subjects, including 1581 healthy people, 242 Type 1 diabetic patients, 384 Type 2 diabetic patients, 174 unspecified diabetic patients, and 830 non-diabetic patients or healthy subjects who are under various physiological conditions, have been used in the studies. The results of the breath acetone measurements collected in this review support that many conditions might cause changes to breath

  12. 21 CFR 172.802 - Acetone peroxides.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Acetone peroxides. 172.802 Section 172.802 Food and... Multipurpose Additives § 172.802 Acetone peroxides. The food additive acetone peroxides may be safely used in... acetone peroxide, with minor proportions of higher polymers, manufactured by reaction of hydrogen peroxide...

  13. Recycling of acetone by distillation

    International Nuclear Information System (INIS)

    Brennan, D.L.; Campbell, B.A.; Phelan, J.E.; Harper, M.

    1992-09-01

    The Resource Conservation Recovery Act (RCRA) identifies spent acetone solvent as a listed hazardous waste. At Fernald, acetone has been spent that has been contaminated with radionuclides and therefore is identified as a mixed hazardous waste. At the time of this publication there is no available approved method of recycling or disposal of radioactively contaminated spent acetone solvent. The Consent Decree with the Ohio EPA and the Consent Agreement with the United States EPA was agreed upon for the long-term compliant storage of hazardous waste materials. The purpose of this project was to demonstrate the feasibility for safely decontaminating spent acetone to background levels of radioactivity for reuse. It was postulated that through heat distillation, radionuclides could be isolated from the spent acetone

  14. Helium implanted AlHf as studied by 181 Ta TDPAC

    Indian Academy of Sciences (India)

    Measurements on helium implanted sample indicate the binding of helium associated defects by Hf solute clusters. Isochronal annealing measurements indicate the dissociation of the helium implantation induced defects from Hf solute clusters for annealing treatments beyond 650 K. On comparison of the present results ...

  15. NMR investigation and theoretical calculations of the effect of solvent on the conformational analysis of 4',7-di-hydroxy-8-prenylflavan

    Directory of Open Access Journals (Sweden)

    Alcântara Antônio Flávio de Carvalho

    2004-01-01

    Full Text Available The NMR conformational study of 4',7-di-hydroxy-8-prenylflavan 1 was carried out in acetone-d6, DMSO-d6 and CDCl3 which enabled the proposition of three conformations, namely 1a, 1b and 1c, differing in the position of the prenyl group. Geometry optimizations performed using AM1 method showed that 1a (deltaHf = -86.2 kcal/mol is as stable as 1b (deltaHf = -85.1 kcal/mol and 1c (deltaHf = -85.4 kcal/mol. When the solvent was included, the calculations showed that the solute-solvent interactions could be explained either in the light of the electronic intermolecular delocalization or the electrostatic character between solute and solvent. Theoretical calculations (HF/6-31G*, deltaFT/BLYP/6-31G*, and deltaFT/B3LYP/6-31G* showed that the combination of these types of interactions present in each solute-solvent system, dependent on the chemical properties of the solvent, lead to different spatial arrangements of the prenyl group, which in turn determined the conformation of 1.

  16. Beta decomposition processes in Hf-rich Hf--Nb alloys

    International Nuclear Information System (INIS)

    Jones, W.B.; Taggart, R.; Polonis, D.H.

    1978-01-01

    The decomposition of the bcc β-phase by both athermal and isothermal processes has been investigated in Hf-rich Hf--Nb alloys. An all β-phase structure is retained in chill-cast alloys containing 30 to 50 at.% Nb (Cb), although electron diffraction streaking effects and the behavior of the temperature coefficient of electrical resistivity indicate the presence of a bcc lattice instability similar to that reported in solute lean Ti and Zr alloys. Aging a Hf 0 . 65 Nb 0 . 35 alloy at 400 and 600 0 C resulted in the direct precipitation of a fine dispersion of α-phase needles; this morphology differs from the discs of transition α (α/sub t/) which Carpenter et al observed in Nb-rich Nb 0 . 68 Hf 0 . 32 . During continued aging, the needles grow selectively to form colonies or groups of needles in which both the individual needles and the groups of needles have major axes aligned along (110)/sub β/ type directions. The initial α-phase particles exhibit the Burgers orientation relationship with the parent matrix; continued aging changes the electron diffraction patterns in a way that is similar to that observed in aged Ti--Mo and Ti--Mo--Al alloys where they were attributed to the α-phase having a different crystallographic relationship to the β-phase (Type 2 α-phase). The observed changes in the electron diffraction patterns of aged Hf 0 . 65 Nb 0 . 35 cannot be described as resulting from strained Burgers α-phase

  17. 21 CFR 173.210 - Acetone.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Acetone. 173.210 Section 173.210 Food and Drugs..., Lubricants, Release Agents and Related Substances § 173.210 Acetone. A tolerance of 30 parts per million is established for acetone in spice oleoresins when present therein as a residue from the extraction of spice. ...

  18. Viscosities and refractive indices of binary systems acetone+1-propanol, acetone+1,2-propanediol and acetone+1,3-propanediol

    Directory of Open Access Journals (Sweden)

    Živković Emila M.

    2014-01-01

    Full Text Available Viscosities and refractive indices of three binary systems, acetone+1-propanol, acetone+1,2-propanediol and acetone+1,3-propanediol, were measured at eight temperatures (288.15, 293.15, 298.15, 303.15, 308.15, 313.15, 318.15, 323.15K and at atmospheric pressure. From these data viscosity deviations and deviations in refractive index were calculated and fitted to the Redlich-Kister equation. The viscosity modelling was done by two types of models: predictive UNIFAC-VISCO and ASOG VISCO and correlative Teja-Rice and McAlister equations. The refractive indices of binary mixtures were predicted by various mixing rules and compared with experimental data. [Projekat Ministarstva nauke Republike Srbije, br. 172063

  19. HF effect on dissociation kinetics of plutonium and neptunium complexes with 1,2-diaminocyclohexanetetraacetic acid in nitric acid solutions

    Energy Technology Data Exchange (ETDEWEB)

    Nikitina, S.A.; Stepanov, A.V.

    1982-01-01

    Dissociation kinetics of Pusup((4)) and Np sup((4)) complexes with DCTA were investigated in HNO/sub 3/ solutions in the presence of HF and arsenazo 3. It was found that HF or NaF produced a differentiating effect on the reactivity of the complexes at (HNO/sub 3/)=1-6 mol/l as well as inhibiting effect at (HNO/sub 3/)=0.01 mol/l. Conditions of the differential kinetic analysis of plutonium and neptunium in the mixture and differential spectrophotometric analysis of uranium (6) during the camouflage of neptunium (4) and plutonium (4) were determined.

  20. Determination of breath acetone in 149 type 2 diabetic patients using a ringdown breath-acetone analyzer.

    Science.gov (United States)

    Sun, Meixiu; Chen, Zhuying; Gong, Zhiyong; Zhao, Xiaomeng; Jiang, Chenyu; Yuan, Yuan; Wang, Zhennang; Li, Yingxin; Wang, Chuji

    2015-02-01

    Over 90% of diabetic patients have Type 2 diabetes. Although an elevated mean breath acetone concentration has been found to exist in Type 1 diabetes (T1D), information on breath acetone in Type 2 diabetes (T2D) has yet to be obtained. In this study, we first used gas chromatography-mass spectrometry (GC-MS) to validate a ringdown breath-acetone analyzer based on the cavity-ringdown-spectroscopy technique, through comparing breath acetone concentrations in the range 0.5-2.5 ppm measured using both methods. The linear fitting of R = 0.99 suggests that the acetone concentrations obtained using both methods are consistent with a largest standard deviation of ±0.4 ppm in the lowest concentration of the range. Next, 620 breath samples from 149 T2D patients and 42 healthy subjects were collected and tested using the breath analyzer. Four breath samples were taken from each subject under each of four different conditions: fasting, 2 h post-breakfast, 2 h post-lunch, and 2 h post-dinner. Simultaneous blood glucose levels were also measured using a standard diabetic-management blood-glucose meter. For the 149 T2D subjects, their exhaled breath acetone concentrations ranged from 0.1 to 19.8 ppm; four different ranges of breath acetone concentration, 0.1-19.8, 0.1-7.1, 0.1-6.3, and 0.1-9.5 ppm, were obtained for the subjects under the four different conditions, respectively. For the 42 healthy subjects, their breath acetone concentration ranged from 0.1 to 2.6 ppm; four different ranges of breath acetone concentration, 0.3-2.6, 0.1-2.6, 0.1-1.7, and 0.3-1.6 ppm, were obtained for the four different conditions. The mean breath acetone concentration of the 149 T2D subjects was determined to be 1.5 ± 1.5 ppm, which was 1.5 times that of 1.0 ± 0.6 ppm for the 42 healthy subjects. No correlation was found between the breath acetone concentration and the blood glucose level of the T2D subjects and the healthy volunteers. This study using a relatively large number of

  1. PEMISAHAN Zr – Hf SECARA SINAMBUNG MENGGUNAKAN MIXER SETTLER

    Directory of Open Access Journals (Sweden)

    Dwi Biyantoro

    2017-01-01

    Full Text Available ABSTRAK PEMISAHAN Zr – Hf SECARA SINAMBUNG MENGGUNAKANMIXER SETTLER. Telah dilakukan pemisahanZr – Hf secara sinambung menggunakan pengaduk pengenap (mixer settler 16 stage. Larutan umpan adalah zirkon nitrat dengan kadar Zr = 30786 ppm dan Hf = 499 ppm. Ekstraktan dipakai adalah solven 60 % TBP dalam kerosen dan larutan scrubbingyang dipakai adalah asam nitrat 1 M. Umpan masuk pada stageke 5 dikontakkan secara berlawanan arah dengan solven masuk pada stage ke 16 dan larutan scrubbing masuk pada stage ke 1. Tujuan penelitian ini adalah memisahkan unsur Zr dan Hf dari hasil olah pasir zirkon menggunakan solven TBP dengan alat mixer settler16 stage. Analisis umpan dan hasil proses pemisahan untuk zirkonium (Zr dilakukan dengan menggunakan alat pendar sinar-X, sedangkananalisis unsur hafnium (Hf menggunakan Analisis Pengaktifan Neutron (APN. Parameter penelitian dilakukan dengan variasi keasaman asam nitrat dalam umpan dan variasi waktu pada berbagai laju pengadukan. Hasil penelitian pemisahan unsur Zr dengan Hf diperolehkondisi optimum pada keasaman umpan 4 N HNO3, keseimbangan dicapai setelah 3jam dan laju pengadukan 3300 rpm. Hasil ekstrak  unsur zirkon (Zr diperoleh kadar sebesar 28577 ppm dengan efisiensi 92,76 % serta kadar pengotor hafnium (Hf sebesar 95 ppm. Kata Kunci: pemisahan Zr, Hf, ekstraksi, mixer settler, alat pendar sinar-X, APN. ABSTRACT SEPARATION of Zr - Hf CONTINUOUSLY USE THE MIXER SETTLER. Separation of Zr - Hf continuously using mixer settler 16 stage has been done. The feed solution is zircon nitrate concentration of Zr = 30786 ppm  and Hf = 499 ppm. As the solvent used extractant 60 % TBP in 40 % kerosene. Nitric acid solution used srubbing 1 M. The feed entered into stage to 5 is contacted with solvents direction on the stage to 16 and the scrubbing solution enter the stage to 1. The purpose of this study is to separate Zr and Hf of the results from the process of zircon sand using solvent TBP using 16 stage

  2. Electric field gradients at 181Ta sites in HfOx

    International Nuclear Information System (INIS)

    Darriba, G.N.; Rodriguez, A.M.; Saitovitch, H.; Silva, P.R.J.; Pasquevich, A.F.

    2007-01-01

    In the present work we report preliminary results about the possibility to study properties of the order-disorder transition in HfO x solid solutions via the determination of the electric field gradient (EFG) at 181 Ta radioactive probes. Oxygen solution into the metal was achieved by arc melting stoichiometric amounts of metallic Hf and HfO 2 under argon atmosphere. Samples of HfO x with x=0.1 and 0.2 were prepared. Two types of samples were used for the perturbed angular correlation (PAC) experiments by doping alternatively with 181 Ta, by neutron irradiation, the metallic Hf or the hafnium oxide. The PAC results on both samples were identical, with disappearing hyperfine signals of the metal and the oxide, showing a complete diffusion of the probes independent of the way of doping. The PAC signal of the HfO x solid solution consisted in a wide distribution of EFGs due to the oxygen disorder. This scheme held even after long thermal treatments at high temperature (several days at 1273K). Annealing treatments at moderate temperature (600K) were also made. In these cases the samples were cooling at a very low rate. These results, together with those obtained by measuring samples below and above the order temperature are reported

  3. Synergistic effects of sodium 
ascorbate and acetone to restore compromised bond strength 
after enamel bleaching.

    Science.gov (United States)

    Boruziniat, Alireza; Manafi, Safa; Cehreli, Zafer C

    To evaluate the effect of a new experimental solution containing sodium ascorbate (SA) and acetone on reversing compromised bonding to enamel immediately after bleaching. The buccal surface of intact, extracted human premolars (n = 60) was bleached. The teeth were then randomly assigned to 6  groups according to the type of pretreatment applied prior to adhesive procedures: 10% SA in acetone-water solution applied for 1 and 5 min (groups 1 and 2, respectively); aqueous solution of 10% SA applied for 10 min (group 3); 100% acetone applied for 10 min (group 4); no pretreatment (negative control; group 5). An additional group (positive control; group 6) comprised unbleached teeth (n = 12). Two composite microcylinders were bonded on each specimen for evaluation of microshear bond strength (MBS) and failure modes. Data were analyzed using the one-way ANOVA and Tukey's post-hoc and chi-square tests at P = 0.05. Groups 1 and 2 yielded similar MBS values to groups 4 and 6 (positive control). The mean MBS of groups 3 and 5 (negative control) were similar, and significantly lower than that of the positive control group. The application of 10% SA in an acetone-water solution prior to bonding procedures can restore compromised enamel bond strength to its unbleached state within a clinically acceptable time of 1 min.

  4. Radiation-induced heterogeneous polymerization of acrylamide in acetone and acetone--water mixtures

    International Nuclear Information System (INIS)

    Wada, T.; Sekiya, H.; Machi, S.

    1975-01-01

    The effects of temperature, dose rate, and monomer concentration on the heterogeneous polymerization of acrylamide in acetone--water mixtures have been studied. Heterogeneous polymerization takes place in mixtures containing less than 60 vol-percent water. The polymerization is steady in acetone and nonsteady in mixtures containing 10 to 50 vol-percent water. The average rate of polymerization is highest in mixtures with about 20 vol-percent water. Polymer molecular weight increases with the increasing water content in the range 0 to 10 vol-percent and does not change in the range of 30 to 70 vol-percent water. For the polymerization in acetone and an acetone-water 60/40 mixture, the activation energies are 2.3 and -1.8 kcal/mole, the dose rate exponents of rate are 0.78 and 0.52, and the monomer concentration exponents of rate are 0.5 and 1.6, respectively. The polymer molecular weight increases with decreasing dose rate, decreasing temperature, and increasing monomer concentration. These results are discussed in connection with the mechanism of heterogeneous polymerization and the solvent effect

  5. Rubrene endoperoxide acetone monosolvate

    Directory of Open Access Journals (Sweden)

    Kiyoaki Shinashi

    2012-04-01

    Full Text Available The title acetone solvate, C42H28O2·C3H6O [systematic name: 1,3,10,12-tetraphenyl-19,20-dioxapentacyclo[10.6.2.02,11.04,9.013,18]icosa-2(11,3,5,7,9,13,15,17-octaene acetone monosolvate], is a photooxygenation product of rubrene (systematic name: 5,6,11,12-tetraphenyltetracene. The molecule bends at the bridgehead atoms, which are linked by the O—O transannular bond, with a dihedral angle of 49.21 (6° between the benzene ring and the naphthalene ring system of the tetracene unit. In the crystal, the rubrene molecules are linked by C—H...O hydrogen bonds into a column along the c axis. The acetone solvent molecules form a dimer around a crystallographic inversion centre through a carbonyl–carbonyl dipolar interaction. A C—H...O hydrogen bond between the rubrene and acetone molecules is also observed.

  6. Lithium isotope effects in cation exchange chromatography of lithium lactate in water-dimethyl sulfoxide and water-acetone mixed solvent media

    International Nuclear Information System (INIS)

    Oi, Takao; Kondoh, Akiko; Ohno, Etsuko; Hosoe, Morikazu

    1993-01-01

    Lithium isotope separation by ion exchange displacement chromatography of lithium lactate in water-dimethyl sulfoxide (DMSO) and water-acetone mixed solvent media at 25 C was explored. In both the water-DMSO and water-acetone system, the single stage isotope separation factor (S) was a convex function of the mixing ratio of the solvents in the external solution phase; S had its maximum value of 1.00254 at water: DMSO=25:75 v/v and 1.00182 at water: acetone=75:25 v/v. Strong correlations of S with solvent partitions between the solution and the exchanger phases were found in both systems, which was qualitatively explainable by considering the lithium isotope distributions between the two phases based on the fundamental lithium isotope effects and the relative affinities of water, DMSO and acetone towards the lithium ion. (orig.)

  7. Poly (furfural-acetone as New Adsorbent for Removal of Cu(II from Aqueous Solution: Equilibrium Study

    Directory of Open Access Journals (Sweden)

    Tariq S. Najim

    2010-01-01

    Full Text Available The batch removal of Cu(II from aqueous solution using poly (furfural-acetone, (PFA as adsorbent was investigated in this study. The influences of initial Cu(II ion concentration (10 to 120 ppm, pH (4-8 and contact time have been reported. Adsorption of Cu(II is highly pH-dependent and the result indicate that the optimum pH for the removal was found to be 6. At this pH a small amount of PFA, 2 g/L, could remove as much as 97% of Cu(II from a solution of initial concentration 10 ppm. It was observed that an increase in initial concentration of Cu(II leads to decrease in percent removal of Cu(II and increase in amount of Cu(II adsorbed per unit mass of PFA. The adsorption process of Cu(II is tested with four isotherm models, Langmuir, Freundlich, Temkin and Dubinin–Radushkevich (D-R. It was found that all models were applicable and the maximum adsorption capacity was found to be 13.66 mg/g. From the isotherm constants it was confirmed that, the sorption process was physisorption.

  8. Mechanical alloying of Hf and Fe powders

    International Nuclear Information System (INIS)

    Mendoza Zelis, L.; Crespo, E.; Creus, M.; Damonte, L.C.; Sanchez, F.H.; Punte, G.

    1994-01-01

    Pure crystalline Hf and Fe powders were mixed and milled under an argon atmosphere. The evolution of the system with milling time was followed with Moessbauer effect spectroscopy and X-ray diffraction. The results indicate that in the first stages an amorphous Fe-rich alloy was gradually formed together with a solid solution of Hf in Fe beyond the solubility limit. (orig.)

  9. Sodium tripolyphosphate cross-linked chitosan based sensor for enhacing sensing properties towards acetone

    Science.gov (United States)

    Nasution, T. I.; Asrosa, R.; Nainggolan, I.; Balyan, M.; Indah, R.; Wahyudi, A.

    2018-02-01

    In this report, sensing properties of sodium tripolyphosphate (TPP) cross-linked chitosan based sensor has been successfully enhanced towards acetone. Chitosan solutions were cross-linked with sodium TPP in variation of 0.1%, 0.5%, 1% and 1.5% w/v, respectively. The sensors were fabricated in film form using an electrochemical deposition method. The sensing properties of the sensors were observed by exposing the pure chitosan and sodium TPP cross-linked chitosan sensors towards acetone concentrations of 5, 10, 50, 100 and 200 ppm. The measurement results revealed that the maximum response in output voltage value of pure chitosan sensor was 0.35 V while sodium TPP crosslinked chitosan sensors were above 0.35 V towards 5 ppm acetone concentration. When the sensors were exposed towards acetone concentration of 200 ppm, the maximum response of pure chitosan was 0.45 V while sodium TPP crosslinked chitosan sensors were above 0.45 V. Amongst the variation of sodium TPP, the maximum response of 1% sodium TPP was the highest since the maximum response was 0.4 V and 0.6 V towards 5 ppm and 200 ppm acetone concentration, respectively. While the maximum responses of other sodium TPP concentrations were under 0.4 V and 0.6 V towards 5 ppm and 200 ppm acetone concentration. Moreover, 1% sodium TPP cross-linked chitosan based sensor showed good reproducibility and outstanding lifetime. Therefore, 1% sodium TPP cross-linked chitosan based sensor has exhibited remarkable sensing properties as a novel acetone sensor.

  10. Internal catalysis in imine formation from acetone and acetone-d6 and conformationally constrained derivatives of N,N-dimethyl-1,3-propanediamine

    International Nuclear Information System (INIS)

    Hine, J.; Li, W.S.

    1975-01-01

    The kinetics of the reactions of 3-exo-dimethylaminomethyl-2-endo-norbornanamine (1), cis-2-(dimethylaminomethyl)cyclohexylamine (2), and 3-endo-dimethylaminomethyl-2-endo-norbornanamine (3) with acetone, and of these three diamines, neopentylamine, and 2-endo-norbornanamine with acetone-d 6 to give imines were studied at 35 0 and various pH's by use of hydroxylamine to capture the imines as they are formed. Acetone-d 6 was more reactive than acetone in the reactions with hydroxylamine alone as well as in the reactions with each of the diamines; the average k/sup D//k/sup H/ was 1.2. The rate constants for the monoprotonated diamines were so large relative to those for the unprotonated diamines that reliable values for the latter could not be obtained. The dominant reaction mechanism appears to be a reversible formation of the carbinolamine derived from the tertiary-protonated form of the monoprotonated diamine followed by rate-controlling internal acid-catalyzed formation of the iminium ion. The rate constants are compared with those obtained as a by-product of deuterium exchange studies of reactions of 1, 2, 3, and five other monoprotonated diamines by the same mechanism. The comparisons show that structural features that destabilize conformations in which the two amino groups are far apart may decrease the reactivity by relative stabilization []of a cyclic hydrogen-bonded form of the monoprotonated diamine as well as increasing the reactivity by relative stabilization of the transition state. Freezing the H 2 N--C--C--CH 2 NMe 2 dihedral angle of 1,3-diamines at values near 0, 60, and 120 0 does not give large differences in reactivity. Comparison of the rate constants for reactions of unprotonated neopentylamine and 2-endo-norbornanamine with those obtained previously for amines of the type XCH 2 CH 2 NH 2 gives no evidence for steric hindrance. (auth)

  11. Off-line breath acetone analysis in critical illness.

    Science.gov (United States)

    Sturney, S C; Storer, M K; Shaw, G M; Shaw, D E; Epton, M J

    2013-09-01

    Analysis of breath acetone could be useful in the Intensive Care Unit (ICU) setting to monitor evidence of starvation and metabolic stress. The aims of this study were to examine the relationship between acetone concentrations in breath and blood in critical illness, to explore any changes in breath acetone concentration over time and correlate these with clinical features. Consecutive patients, ventilated on controlled modes in a mixed ICU, with stress hyperglycaemia requiring insulin therapy and/or new pulmonary infiltrates on chest radiograph were recruited. Once daily, triplicate end-tidal breath samples were collected and analysed off-line by selected ion flow tube mass spectrometry (SIFT-MS). Thirty-two patients were recruited (20 males), median age 61.5 years (range 26-85 years). The median breath acetone concentration of all samples was 853 ppb (range 162-11 375 ppb) collected over a median of 3 days (range 1-8). There was a trend towards a reduction in breath acetone concentration over time. Relationships were seen between breath acetone and arterial acetone (rs = 0.64, p acetone concentration over time corresponded to changes in arterial acetone concentration. Some patients remained ketotic despite insulin therapy and normal arterial glucose concentrations. This is the first study to look at breath acetone concentration in ICU patients for up to 8 days. Breath acetone concentration may be used as a surrogate for arterial acetone concentration, which may in future have a role in the modulation of insulin and feeding in critical illness.

  12. Thermodynamics of HfCl4-KCl molten mixtures containing HfCl4 up to 33.3 mol. per cent

    International Nuclear Information System (INIS)

    Smirnov, M.V.; Salyulev, A.B.; Kudyakov, V.Ya.

    1980-01-01

    Based on measurements of saturated vapour pressure in components of melted mixtures of HfCl 4 -KCl, depending on temperature and concentration, calculated are the results of changes in activity coefficients of hafnium tetrachloride and potassium chloride on transition from diluted solutions, where the Henry law is met, to those concentrated where the law is disobeyed. Growth in the activity coefficient of HfCl 4 is due to dissociation of complex groups of HfCl 6 2- into complexes with a lesser number of ligands and decreasing relative binding energy of Hf 4+ -Cl - there. In this case, marked changes take place in partial enthalpy and entropy of hafnium tetrachloride mixing. Similar dependences are observed for potassium chloride, but they are expressed considerably weaker. Evaporation enthalpy and entropy are calculated for HfCl 4 and KCl monomers from their melted mixtures of various concentrations

  13. Improvement of the cold flow characteristics of biodiesel containing dissolved polymer wastes using acetone

    Directory of Open Access Journals (Sweden)

    Pouya Mohammadi

    2014-03-01

    Full Text Available Due to the fast fossil fuel depletion and at the same time global warming phenomenon anticipated for the next coming years, the necessity of developing alternative fuels e.g. biofuels (i.e. bioethanol, biodiesel, biogas and etc. has turned into an important concern. Recently, the application of the bio-solvency properties of biodiesel for recycling waste polymers has been highlighted. However, the impact of polymer dissolution on cold flow characteristics of biodiesel was never investigated. The present study was set to explore the impact of different solvents in stabilizing biodiesel-polymer solution. Among them, acetone was proved to be the best fuel stabilizer. Subsequently, cold flow characteristic i.e. cloud point, of the biodiesel-polymer-acetone fuel was found to have improved (decreased due to the inclusion of acetone. Finally, flash point analysis of the fuel blends containing acetone was done to ensured high safety of the fuel blend by dramatically increasing the flash point values of biodiesel-polymer fuel blends.

  14. Search for chemical separations of the element 106 homologues in HF and HF-HCl media

    International Nuclear Information System (INIS)

    Trubert, D.; Monroy-Guzman, F.; Hussonnois, M.; Brillard, L.; Le Naour, C.; Constantinescu, O.

    1996-01-01

    In order to study the chemical properties of element 263 106 in aqueous media, fast, efficient and reproducible chromatographic separations were tested on its assumed homologous: Mo, W and U. Corroborative static and dynamic off-line experiments have shown that after fixation of these three elements on anion-exchange resin in HF medium, selective elution could be achieved by using suitable concentration of HCl - HF and HCl solutions. Separations of short-lived W isotopes, produced through heavy ion irradiation were also performed on-line. (author). 27 refs., 14 figs

  15. Self-Associating Behavior of Acetone in Liquid Krypton.

    Science.gov (United States)

    De Beuckeleer, Liene I; Herrebout, Wouter A

    2016-02-18

    Acetone molecules are inclined to self-associate through dipole-dipole interactions because of their large dipole moment. Infrared spectroscopy of compounds dissolved in liquid noble gases supported by high level ab initio calculations allows investigating the self-associating behavior and determining the thermodynamical properties. In this study, infrared spectra of various concentrations of acetone dissolved in liquid krypton are recorded at constant temperature. Overlapping monomer and dimer spectra are separated by analyzing the obtained data sets with numerical methods based on least-squares fitting. Although acetone is known to self-associate, only a few spectral features have been presented in literature before. In this study, the application of new numerical approaches succeeds in resolving overlapping spectra and allows observing isolated acetone dimer absorption bands for the complete mid infrared spectrum. By use of data sets of spectra recorded at temperatures between 134 and 142 K, the experimental standard dimerization enthalpy was determined to be -10.8 kJ mol(-1). MP2/aug-cc-pVDZ calculations predicted a stacked and planar dimer geometry of which the stacked geometry is more stable. Combining MP2 energies and single point corrections involving CCSD(T) calculations and complete basis set extrapolations based on the MP2/aug-cc-pVDZ equilibrium geometry lead to complexation energy of -28.4 kJ mol(-1) for the stacked geometry and -15.1 kJ mol(-1) for the planar geometry. The corresponding values for the complexation enthalpies in solution, obtained by combining these values with corrections for thermal and solvent influences are -13.7 and -5.8 kJ mol(-1).

  16. Electron thermal capacity in plasma generated at cavitation bubble collapse in D-acetone

    International Nuclear Information System (INIS)

    Kostenko, B.F.; Pribis, J.

    2004-01-01

    The latest experimental data on nuclear reaction product registration at cavitation bubble collapse in deuterated acetone (C 3 D 6 O) still argue in favour of existence of a new possibility to realize the thermonuclear synthesis. Theoretical description based on numerical solution of simultaneous conservation equations for gaseous and liquid phases also confirms this possibility, although it requires further more precise definitions. In particular, description of electron degrees of freedom in dense nonequilibrium plasma generated at the final stage of bubble collapse need specification. Calculations of electron thermal capacity in the deuterated acetone multiple ionization region at electron temperatures T e ≅ 10 4 K and above and compression range ρ/ρ 0 ≅ 1 - 100 have been fulfilled on the basis of direct numerical solution of equation for chemical potential. (author)

  17. Radical Scavenging by Acetone: A New Perspective to Understand Laccase/ABTS Inactivation and to Recover Redox Mediator.

    Science.gov (United States)

    Liu, Hao; Zhou, Pandeng; Wu, Xing; Sun, Jianliang; Chen, Shicheng

    2015-11-04

    The biosynthetic utilization of laccase/mediator system is problematic because the use of organic cosolvent causes significant inhibition of laccase activity. This work explored how the organic cosolvent impacts on the laccase catalytic capacity towards 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) in aqueous solution. Effects of acetone on the kinetic constants of laccase were determined and the results showed Km and Vmax varied exponentially with increasing acetone content. Acetone as well as some other cosolvents could transform ABTS radicals into its reductive form. The content of acetone in media significantly affected the radical scavenging rates. Up to 95% of the oxidized ABTS was successfully recovered in 80% (v/v) acetone in 60 min. This allows ABTS recycles at least six times with 70%-75% of active radicals recovered after each cycle. This solvent-based recovery strategy may help improve the economic feasibility of laccase/ABTS system in biosynthesis.

  18. Enhancing acetone biosynthesis and acetone-butanol-ethanol fermentation performance by co-culturing Clostridium acetobutylicum/Saccharomyces cerevisiae integrated with exogenous acetate addition.

    Science.gov (United States)

    Luo, Hongzhen; Ge, Laibing; Zhang, Jingshu; Ding, Jian; Chen, Rui; Shi, Zhongping

    2016-01-01

    Acetone is the major by-product in ABE fermentations, most researches focused on increasing butanol/acetone ratio by decreasing acetone biosynthesis. However, economics of ABE fermentation industry strongly relies on evaluating acetone as a valuable platform chemical. Therefore, a novel ABE fermentation strategy focusing on bio-acetone production by co-culturing Clostridium acetobutylicum/Saccharomyces cerevisiae with exogenous acetate addition was proposed. Experimental and theoretical analysis revealed the strategy could, enhance C. acetobutylicum survival oriented amino acids assimilation in the cells; control NADH regeneration rate at moderately lower level to enhance acetone synthesis but without sacrificing butanol production; enhance the utilization ability of C. acetobutylicum on glucose and direct most of extra consumed glucose into acetone/butanol synthesis routes. By implementing the strategy using synthetic or acetate fermentative supernatant, acetone concentrations increased to 8.27-8.55g/L from 5.86g/L of the control, while butanol concentrations also elevated to the higher levels of 13.91-14.23g/L from 11.63g/L simultaneously. Copyright © 2015 Elsevier Ltd. All rights reserved.

  19. Acetone utilization by sulfate-reducing bacteria: draft genome sequence of Desulfococcus biacutus and a proteomic survey of acetone-inducible proteins.

    Science.gov (United States)

    Gutiérrez Acosta, Olga B; Schleheck, David; Schink, Bernhard

    2014-07-11

    The sulfate-reducing bacterium Desulfococcus biacutus is able to utilize acetone for growth by an inducible degradation pathway that involves a novel activation reaction for acetone with CO as a co-substrate. The mechanism, enzyme(s) and gene(s) involved in this acetone activation reaction are of great interest because they represent a novel and yet undefined type of activation reaction under strictly anoxic conditions. In this study, a draft genome sequence of D. biacutus was established. Sequencing, assembly and annotation resulted in 159 contigs with 5,242,029 base pairs and 4773 predicted genes; 4708 were predicted protein-encoding genes, and 3520 of these had a functional prediction. Proteins and genes were identified that are specifically induced during growth with acetone. A thiamine diphosphate-requiring enzyme appeared to be highly induced during growth with acetone and is probably involved in the activation reaction. Moreover, a coenzyme B12- dependent enzyme and proteins that are involved in redox reactions were also induced during growth with acetone. We present for the first time the genome of a sulfate reducer that is able to grow with acetone. The genome information of this organism represents an important tool for the elucidation of a novel reaction mechanism that is employed by a sulfate reducer in acetone activation.

  20. Acetone gas-sensing properties of multiple-networked Pd-decorated Bi_2O_3 nanorod sensors

    International Nuclear Information System (INIS)

    Park, Sung Hoon; Kim, Soo Hyun; Lee, Sang Min; Lee, Chong Mu

    2015-01-01

    This study examined the sensing properties of Bi_2O_3 nanorods decorated with Pd nanoparticles. Pd-decorated β-Bi_2O_3 nanorods were prepared by immersing the Bi_2O_3 nanorods in ethanol/(50 mM)PdCl_2 solution followed by UV irradiation and annealing. The Bi_2O_3 nanorods decorated with Pd nanoparticles showed faster and stronger response to acetone gas than the pristine Bi_2O_3 nanorods. Interestingly, the difference in response time between the Pd-decorated Bi_2O_3 nanorod sensor and pristine Bi_2O_3 nanorod sensor increased with increasing the acetone gas concentration. In contrast, the difference in recovery time between the two nanorod sensors decreased with increasing the acetone gas concentration. This difference can be explained using the chemical mechanism. The underlying mechanism for the enhanced response of the Bi_2O_3 nanorods decorated with Pd nanoparticles to acetone gas is also discussed

  1. Electron Thermal Capacity in Plasma Generated at Cavitation Bubble Collapse in D-acetone

    CERN Document Server

    Kostenko, B F

    2004-01-01

    The latest experimental data on nuclear reaction product registration at cavitation bubble collapse in deuterated acetone (C$_3$D$_6$O) still argue in favour of existence of a new possibility to realize the thermonuclear synthesis. Theoretical description based on numerical solution of simultaneous conservation equations for gaseous and liquid phases also confirms this possibility, although it requires further more precise definitions. In particular, description of electron degrees of freedom in very dense nonequilibrium plasma generated at the final stage of bubble collapse needs specification. In the present paper, calculations of electron thermal capacity in the deuterated acetone multiple ionization region at electron temperatures $T_e \\simeq 10^4 $ K and above and compression range $\\rho/\\rho_0 \\simeq 1 \\div 100$ have been fulfilled on the basis of direct numerical solution of equation for chemical potential.

  2. Portable method of measuring gaseous acetone concentrations.

    Science.gov (United States)

    Worrall, Adam D; Bernstein, Jonathan A; Angelopoulos, Anastasios P

    2013-08-15

    Measurement of acetone in human breath samples has been previously shown to provide significant non-invasive diagnostic insight into the control of a patient's diabetic condition. In patients with diabetes mellitus, the body produces excess amounts of ketones such as acetone, which are then exhaled during respiration. Using various breath analysis methods has allowed for the accurate determination of acetone concentrations in exhaled breath. However, many of these methods require instrumentation and pre-concentration steps not suitable for point-of-care use. We have found that by immobilizing resorcinol reagent into a perfluorosulfonic acid polymer membrane, a controlled organic synthesis reaction occurs with acetone in a dry carrier gas. The immobilized, highly selective product of this reaction (a flavan) is found to produce a visible spectrum color change which could measure acetone concentrations to less than ppm. We here demonstrate how this approach can be used to produce a portable optical sensing device for real-time, non-invasive acetone analysis. Copyright © 2013 Elsevier B.V. All rights reserved.

  3. Phage inactivation by triplet acetone

    International Nuclear Information System (INIS)

    Gomes, R.A.

    1985-01-01

    The exposure of lambda phage to triplet acetone is studied. The triplet acetone is obtained from aerobic oxidation of isobutanal catalysed by peroxidase. A decrease of lambda phage ability to infect Escherichia coli is reported, perhaps, partially due to the possible production of lesions in the phage genome. (M.A.C.) [pt

  4. An effective approach for restraining electrochemical corrosion of polycrystalline silicon caused by an HF-based solution and its application for mass production of MEMS devices

    International Nuclear Information System (INIS)

    Liu, Yunfei; Xie, Jing; Zhao, Hui; Luo, Wei; Yang, Jinling; An, Ji; Yang, Fuhua

    2012-01-01

    This paper presents a novel method to effectively protect the structural material polycrystalline silicon (polysilicon) from electrochemical corrosion, which often occurs when the MEMS device is released in HF-based solutions, especially when the device contains a noble metal. This corrosion seriously degrades the electrical and mechanical performance as well as the reliability of MEMS devices. In this method, a photoresist (PR) is employed to cover the noble metal, which is electrically coupled with the underlying polysilicon layer. This PR cover can effectually prevent an HF-based solution from diffusing through and arriving at the surface of the noble metal, thus cutting off the electrical current of the electrochemical corrosion reaction. The polysilicon is well protected for longer than 80 min in 49% concentrated HF solutions by a 3 µm-thick AZ 6130 PR film. This fabrication process is simple, reliable and suitable for mass production of high-end micromechanical disk resonators. Benefiting from the technology breakthrough mentioned above, a novel low-cost microfabrication method for disk resonators with high performance has been developed, and the VHF polysilicon disk resonators with resonance frequencies around 282 MHz and Q values larger than 2000 at atmosphere have been produced at wafer level. (paper)

  5. Zirconium Zr and hafnium Hf

    International Nuclear Information System (INIS)

    Busev, A.I.; Tiptsova, V.G.; Ivanov, V.M.

    1978-01-01

    The basic methods for extracting and determining Zr(4) and Hf(4) are described. Diantipyrinemethane and its alkyl homologs selectively extract Zr and Hf from HNO 3 solutions in the presence of nitrates. Zr is selectively extracted with tetraethyldiamide of heptyl phosphoric acid (in benzene) as well as with 2-thenoyltrifluoroacetone (in an acid). The latter reagents is suitable for rapid determination of 95 Zr in a mixture with 95 Nb and other fragments. The complexometric determination of Zr is based on formation of a stable complex of Zr with EDTA. The titration is carried out in the presence of n-sulfobenzene-azo-pyrocatechol, eriochrome black T. The determination is hindered by Hf, fluoride-, phosphate-, oxalate- and tartrate-ions. The method is used for determining Zr in zircon and eudialyte ore. Zr is determined photometrically with the aid of xylenol orange, arsenazo 3 and pyrocatechol violet (in phosphorites). Hf is determined in the presence of Zr photometrically with the aid of xylenol orange or methyl-thymol blue. The method is based on Zr being masked with hydrogen peroxide in the presence of sulfate-ions

  6. Thermodynamics of HfCl/sub 4/-KCl molten mixtures containing HfCl/sub 4/ up to 33. 3 mol. per cent

    Energy Technology Data Exchange (ETDEWEB)

    Smirnov, M V; Salyulev, A B; Kudyakov, V Ya [AN SSSR, Sverdlovsk. Inst. Ehlektrokhimii

    1980-05-01

    Based on measurements of saturated vapour pressure in components of melted mixtures of HfCl/sub 4/-KCl, depending on temperature and concentration, calculated are the results of changes in activity coefficients of hafnium tetrachloride and potassium chloride on transition from diluted solutions, where the Henry law is met, to those concentrated where the law is disobeyed. Growth in the activity coefficient of HfCl/sub 4/ is due to dissociation of complex groups of HfCl/sub 6//sup 2 -/ into complexes with a lesser number of ligands and decreasing relative binding energy of Hf/sup 4 +/-Cl/sup -/ there. In this case, marked changes take place in partial enthalpy and entropy of hafnium tetrachloride mixing. Similar dependences are observed for potassium chloride, but they are expressed considerably weaker. Evaporation enthalpy and entropy are calculated for HfCl/sub 4/ and KCl monomers from their melted mixtures of various concentrations.

  7. Determination of residual acetone and acetone related impurities in drug product intermediates prepared as Spray Dried Dispersions (SDD) using gas chromatography with headspace autosampling (GCHS).

    Science.gov (United States)

    Quirk, Emma; Doggett, Adrian; Bretnall, Alison

    2014-08-05

    Spray Dried Dispersions (SDD) are uniform mixtures of a specific ratio of amorphous active pharmaceutical ingredient (API) and polymer prepared via a spray drying process. Volatile solvents are employed during spray drying to facilitate the formation of the SDD material. Following manufacture, analytical methodology is required to determine residual levels of the spray drying solvent and its associated impurities. Due to the high level of polymer in the SDD samples, direct liquid injection with Gas Chromatography (GC) is not a viable option for analysis. This work describes the development and validation of an analytical approach to determine residual levels of acetone and acetone related impurities, mesityl oxide (MO) and diacetone alcohol (DAA), in drug product intermediates prepared as SDDs using GC with headspace (HS) autosampling. The method development for these analytes presented a number of analytical challenges which had to be overcome before the levels of the volatiles of interest could be accurately quantified. GCHS could be used after two critical factors were implemented; (1) calculation and application of conversion factors to 'correct' for the reactions occurring between acetone, MO and DAA during generation of the headspace volume for analysis, and the addition of an equivalent amount of polymer into all reference solutions used for quantitation to ensure comparability between the headspace volumes generated for both samples and external standards. This work describes the method development and optimisation of the standard preparation, the headspace autosampler operating parameters and the chromatographic conditions, together with a summary of the validation of the methodology. The approach has been demonstrated to be robust and suitable to accurately determine levels of acetone, MO and DAA in SDD materials over the linear concentration range 0.008-0.4μL/mL, with minimum quantitation limits of 20ppm for acetone and MO, and 80ppm for DAA. Copyright

  8. Nitrate-Dependent Degradation of Acetone by Alicycliphilus and Paracoccus Strains and Comparison of Acetone Carboxylase Enzymes ▿

    Science.gov (United States)

    Dullius, Carlos Henrique; Chen, Ching-Yuan; Schink, Bernhard

    2011-01-01

    A novel acetone-degrading, nitrate-reducing bacterium, strain KN Bun08, was isolated from an enrichment culture with butanone and nitrate as the sole sources of carbon and energy. The cells were motile short rods, 0.5 to 1 by 1 to 2 μm in size, which gave Gram-positive staining results in the exponential growth phase and Gram-negative staining results in the stationary-growth phase. Based on 16S rRNA gene sequence analysis, the isolate was assigned to the genus Alicycliphilus. Besides butanone and acetone, the strain used numerous fatty acids as substrates. An ATP-dependent acetone-carboxylating enzyme was enriched from cell extracts of this bacterium and of Alicycliphilus denitrificans K601T by two subsequent DEAE Sepharose column procedures. For comparison, acetone carboxylases were enriched from two additional nitrate-reducing bacterial species, Paracoccus denitrificans and P. pantotrophus. The products of the carboxylase reaction were acetoacetate and AMP rather than ADP. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis of cell extracts and of the various enzyme preparations revealed bands corresponding to molecular masses of 85, 78, and 20 kDa, suggesting similarities to the acetone carboxylase enzymes described in detail for the aerobic bacterium Xanthobacter autotrophicus strain Py2 (85.3, 78.3, and 19.6 kDa) and the phototrophic bacterium Rhodobacter capsulatus. Protein bands were excised and compared by mass spectrometry with those of acetone carboxylases of aerobic bacteria. The results document the finding that the nitrate-reducing bacteria studied here use acetone-carboxylating enzymes similar to those of aerobic and phototrophic bacteria. PMID:21841031

  9. Fate of acetone in water

    Science.gov (United States)

    Rathbun, R.E.; Stephens, D.W.; Shultz, D.J.

    1982-01-01

    The physical, chemical, and biological processes that might affect the concentration of acetone in water were investigated in laboratory studies. Processes considered included volatilization, adsorption by sediments, photodecomposition, bacterial degradation, and absorption by algae and molds. It was concluded that volatilization and bacterial degradation were the dominant processes determining the fate of acetone in streams and rivers. ?? 1982.

  10. Effect of acetone accumulation on structure and dynamics of lipid membranes studied by molecular dynamics simulations.

    Science.gov (United States)

    Posokhov, Yevgen O; Kyrychenko, Alexander

    2013-10-01

    The modulation of the properties and function of cell membranes by small volatile substances is important for many biomedical applications. Despite available experimental results, molecular mechanisms of action of inhalants and organic solvents, such as acetone, on lipid membranes remain not well understood. To gain a better understanding of how acetone interacts with membranes, we have performed a series of molecular dynamics (MD) simulations of a POPC bilayer in aqueous solution in the presence of acetone, whose concentration was varied from 2.8 to 11.2 mol%. The MD simulations of passive distribution of acetone between a bulk water phase and a lipid bilayer show that acetone favors partitioning into the water-free region of the bilayer, located near the carbonyl groups of the phospholipids and at the beginning of the hydrocarbon core of the lipid membrane. Using MD umbrella sampling, we found that the permeability barrier of ~0.5 kcal/mol exists for acetone partitioning into the membrane. In addition, a Gibbs free energy profile of the acetone penetration across a bilayer demonstrates a favorable potential energy well of -3.6 kcal/mol, located at 15-16Å from the bilayer center. The analysis of the structural and dynamics properties of the model membrane revealed that the POPC bilayer can tolerate the presence of acetone in the concentration range of 2.8-5.6 mol%. The accumulation of the higher acetone concentration of 11.2 mol% results, however, in drastic disordering of phospholipid packing and the increase in the membrane fluidity. The acetone molecules push the lipid heads apart and, hence, act as spacers in the headgroup region. This effect leads to the increase in the average headgroup area per molecule. In addition, the acyl tail region of the membrane also becomes less dense. We suggest, therefore, that the molecular mechanism of acetone action on the phospholipid bilayer has many common features with the effects of short chain alcohols, DMSO, and

  11. The Thermodynamic Characterization of ZrCo–H, HfCo−H, HfNi−H and Zr{sub 1–x}HfxNi(Co) Alloy–H Systems

    Energy Technology Data Exchange (ETDEWEB)

    Flanagan, Ted B., E-mail: ted.flanagan@uvm.edu; Noh, Hak; Luo, Suifang

    2016-08-25

    ZrCo and HfCo intermetallic compounds have the same cubic (CsCl-type) structure and their ternary (Zr{sub 1−x}Hf{sub x})Co alloys are also cubic. ZrNi and HfNi intermetallic compounds have the orthorhombic structure (CrB-type) and the ternary (Zr{sub 1−x}Hf{sub x})Ni alloys also have this structure. Thermodynamic data for hydride formation and decomposition in ZrCo, HfCo and HfNi intermetallic compounds have been determined from reaction calorimetry and from pressure-composition isotherms. Thermodynamic data have been determined for the three ternary alloys: (Zr{sub 0.75}Hf{sub 0.25})Co, (Zr{sub 0.50}Hf{sub 0.50})Co, and (Zr{sub 0.25}Hf{sub 0.75})Co and the four ternary alloys: (Zr{sub 0.875}Hf{sub 0.125})Ni, (Zr{sub 0.75}Hf{sub 0.25})Ni, (Zr{sub 0.50}Hf{sub 0.50})Ni, and (Zr{sub 0.25}Hf{sub 0.75})Ni. This offers the opportunity to learn how the thermodynamic properties of the ternary alloy-H systems change with the stoichiometry of alloys with the same structure. - Highlights: • Calorimetric enthalpies determined for H absorption by ZrCo, HfCo, HfNi are determined. • Ternary alloys, e.g., Zr{sub 1−x}Hf{sub x}Ni, prepared and characterized by x-ray diffraction. • Isotherms for the ternary alloys give thermodynamic parameters for H solution.

  12. Nanosized Hydroxyapatite Precipitation on the Ti—30Ta—xHf Alloys.

    Science.gov (United States)

    Lee, Kang; Jang, Jae- In; Han-Cheol, Choe

    2017-04-01

    In this study, we prepared hydroxyapatite (HAp) layer on the alkali treated Ti–30Ta–xHf alloys using electrochemical deposition method. Ti–30Ta–xHf alloys was anodized in 5 M NaOH solution at 0.3 A for 10 min. Alkali treated Ti–30Ta–xHf surface formed by anodization step which acted as templates and anchorage for growth of the HAp during subsequent pulsed electrochemical deposition process at 85 °C. The phase and morphologies of deposited HAp layer were affected by the Hf contents of Ti–30Ta–xHf alloys. The nano-scale rod-like HAp layer was formed on untreated Ti–30Ta–xHf alloys with partially low crystallinity. In the case of alkali treated Ti–30Ta–xHf, nano-sized needle-like layers were transferred to nano-flake surface and denser morphology as Hf content increased.

  13. Metal-assisted chemical etching in HF/Na2S2O8 OR HF/KMnO4 produces porous silicon

    NARCIS (Netherlands)

    Hadjersi, T.; Gabouze, N.; Kooij, Ernst S.; Zinine, A.; Zinine, A.; Ababou, A.; Chergui, W.; Cheraga, H.; Belhousse, S.; Djeghri, A.

    2004-01-01

    A new metal-assisted chemical etching method using Na2S2O8 or KMnO4 as an oxidizing agent was proposed to form a porous silicon layer on a highly resistive p-type silicon. A thin layer of Ag or Pd is deposited on the Si(100) surface prior to immersion in a solution of HF and Na2S2O8 or HF and KMnO4.

  14. Interaction of silico-12-molybdic acid with acetone

    International Nuclear Information System (INIS)

    Chuvaev, V.F.; Pinchuk, I.N.; Gubin, V.V.

    1984-01-01

    Methods of thermal analysis, mass-spectrometry, IR, PMR, ESR spectroscopy are used to investigate interaction processes of silico-12-molybdic acid H 4 SiMo 12 O 40 with acetone. Reactions in solution and with participation of solid heteropolyacid are studied. Organic products of catalytic and oxidation-reduction reactions are identified. The effect of conditions on the formation of different condensation and oxidation products and the sequence of appropriate reactions is discussed. Transformations of silico-12-molybolic acid are considered

  15. Preparation and study of the critical-mass-free plutonium ceramics with neutron poisons Hf, Gd and Li

    International Nuclear Information System (INIS)

    Timoefeeva, L.F.; Orlov, V.K.; Malyukov, E.E.; Molomin, V.I.; Zhmak, V.A.; Semova, E.A.; Shishkov, N.V.; Nadykto, B.A.

    2002-01-01

    Powder sintering was used to produce homogeneous type oxide ceramics of Pu with Hf, Gd and Li 6 . In all the ceramics, there is the number of neutron poison (Hf, Gd and Li) atoms per plutonium atom needed, according to the physical calculation, for them to be free of critical mass. PuO 2 stabilizers high-temperature modifications of cubic HfO 2 or hexagonal Gd 2 O 3 , however, at the ratio given by the physical calculation, the plutonium is insufficient for their full stabilization. Addition of yttrium oxide as an additive stabilizing the fcc phase of HfO 2 resulted in cubic solid solution (Pu, Hf, Y)O 2-x . Pu/Li/Hf and Pu/Li/Si ceramics produced by sintering of PuO 2 and compound Li 2 HfO 3 or 6 Li 4 SiO 4 powders is characterized with presence of two phases. The method of differential thermal analysis demonstrated the phase stability of (Pu-Hf, Pu-Gd, Pu-Li-Hf) oxide ceramics in the 20-1500degC temperature range. Ceramic (Pu/Li/Si) has several endothermal effects. Tests in boiling water solutions of various composition suggest that the specimens of Pu, Hf oxides and ternary oxides (Pu, Hf, Y)O 2 are less stable in weakly acidic media than in weakly alkaline medium and distilled water. The obtained results were used as a basis to estimate the assumed solid solution region boundaries for binary Hf, Pu and ternary Hf, Pu, Y oxides on the side of HfO 2 . (author)

  16. The magnetic hyperfine field in the 181Ta site in the Co2HfAl and Co2HfGa Heusler alloys

    International Nuclear Information System (INIS)

    Silva, R. da.

    1979-01-01

    The hyperfine magnetic fields at 181 Ta nuclei in Heusler alloys Co 2 HfZ (Z=Al, Ga) have been measured using the time differential perturbed gamma-gamma angular correlation (TDPAC) method. The hyperfine fields obtained from these measurements at the liquid nitrogen temperature are -189 and +- 150 kOersted for Co 2 HfAl and Co 2 HfGa, respectively. The concept that the hyperfine field at the Y site is similar to the solute fields in Fe, Co, Ni and Gd matrices is corroborated. We have verified that ratios H sub(hf) sub(Ta)/T sub(c) and H sub(hf) sub(Ta)μ sub(Co) in Co 2 HfZ compounds (Z=Al, Ga, Sn) do not depend on the nature of Z element. However a dependence in the value of observed field with the s-p element in Z site was noticed. We feel that the samples are not completely ordered cubic as observed by the quadrupole interaction measurements. The results are interpreted in terms of the Campbell-Blandin formalism, and it is shown that the spin polarization of conduction electrons at Hf and Ta have opposite signs. (Author) [pt

  17. HF treatment effect for carbon deposition on silicon (111) by DC sputtering technique

    Energy Technology Data Exchange (ETDEWEB)

    Aji, A. S., E-mail: aji.ravazes70@gmail.com; Darma, Y., E-mail: aji.ravazes70@gmail.com [Quantum Semiconductor and Devices Lab., Physics of Material Electronics Research Division, Department of Physics, Institut Teknologi Bandung (Indonesia)

    2014-03-24

    Surface modifications of Si (111) substrate by HF solution for thin film carbon deposition have been systematically studied. Thin film carbon on Si (111) has been deposited using DC Unbalanced Magnetron Sputtering with carbon pellet doped by 5% Fe as the target. EDAX characterization confirmed that the carbon fraction on Si substrate much higher by dipping a clean Si substrate by HF solution before sputtering process in comparison with carbon fraction on Si substrate just after conventional RCA. Moreover, SEM and AFM images show the uniform thin film carbon on Si with HF treatment, in contrast to the Si without HF solution treatment. These experimental results suggest that HF treatment of Si surface provide Si-H bonds on top Si surface that useful to enhance the carbon deposition during sputtering process. Furthermore, we investigate the thermal stability of thin film carbon on Si by thermal annealing process up to 900 °C. Atomic arrangements during annealing process were characterized by Raman spectroscopy. Raman spectra indicate that thin film carbon on Si is remaining unchanged until 600 °C and carbon atoms start to diffuse toward Si substrate after annealing at 900 °C.

  18. The Effectiveness of HCl and HF Cleaning of Si0.85Ge0.15 Surface

    International Nuclear Information System (INIS)

    Sun, Y

    2008-01-01

    The cleaning of Si 0.85 Ge 0.15 surfaces using HCl and HF solutions is studied using synchrotron radiation photoelectron spectroscopy. The HF solution is found to be effective in removing both the Si oxide and the Ge oxide while the HCl solution can only remove part of the Ge oxide. For samples treated with HF, four spectral components are needed to fit the Ge 3d photoemission spectra. One is the bulk component and the other three are attributed to the surface Ge atoms with mono-hydride, di-hydride and tri-hydride terminations, respectively

  19. Marine Vibrio Species Produce the Volatile Organic Compound Acetone

    OpenAIRE

    Nemecek-Marshall, M.; Wojciechowski, C.; Kuzma, J.; Silver, G. M.; Fall, R.

    1995-01-01

    While screening aerobic, heterotrophic marine bacteria for production of volatile organic compounds, we found that a group of isolates produced substantial amounts of acetone. Acetone production was confirmed by gas chromatography, gas chromatography-mass spectrometry, and high-performance liquid chromatography. The major acetone producers were identified as nonclinical Vibrio species. Acetone production was maximal in the stationary phase of growth and was stimulated by addition of l-leucine...

  20. Sorption behaviour of W, Hf, Lu, U, and Th on ion exchangers from HCl/H2O2 solutions. Model experiments for chemical studies of seaborgium (Sg)

    International Nuclear Information System (INIS)

    Schumann, D.; Andrassy, M.; Nitsche, H.; Misiak, R.; Schaedel, M.; Bruechle, W.; Schausten, B.; Kratz, J.V.

    1997-08-01

    In model experiments with W, Hf, Th, and U radionuclides, a chemical system was developed for the separation of seaborgium from element 104 and heavy actinides, i.e., cation exchange on DOWEX 50 x 8 from solutions containing 0.1-1.0 M HCl and 0.5-2.0 vol.% H 2 O 2 . The system should be suitable for fast on-line experiments if seaborgium exibits a non-uranium-like behaviour. Adding hydrogen peroxide to mixed HCl/HF solutions suppresses the partial sorption of W and, presumably seaborgium, on the cation exchanger. This way, the elution volume can be minimized. Prospects for anion exchange separations of group 6 from 4 elements are also briefly discussed. (orig.)

  1. Fate of acetone in an outdoor model stream with a nitrate supplement, southern Mississippi, U.S.A.

    Science.gov (United States)

    Rathbun, R.E.; Stephens, D.W.; Tai, D.Y.

    1991-01-01

    The fate of acetone in an outdoor model stream to which nitrate was added as a nutrient supplement was determined. The stream, in southern Mississippi, U.S.A. was 234 m long. Water was supplied to the stream by an artesian well at about 1.21 s-1, resulting in a mean water velocity of about 0.5 m min-1. Acetone was injected continuously for 26 days resulting in concentrations of 20-40 mg l-1. A nitrate solution was injected for 21 days resulting in an instream concentration of about 1.7 mg l-1 at the upstream end of the stream. Rhodamine-WT dye was used to determine the travel time and dispersion characteristics of the stream, and t-butyl alcohol was used to determine the volatilization characteristics. Volatilization controlled the fate of acetone in the model stream. The lack of substantial bacterial degradation of acetone was contrary to expectations based on the results of laboratory degradation studies using model stream water enriched with nitrate. A possible explanation for the lack of significant degradation in the model stream may be the limited 6-h residence time of the acetone in the stream. ?? 1991.

  2. Measuring breath acetone for monitoring fat loss: Review.

    Science.gov (United States)

    Anderson, Joseph C

    2015-12-01

    Endogenous acetone production is a by-product of the fat metabolism process. Because of its small size, acetone appears in exhaled breath. Historically, endogenous acetone has been measured in exhaled breath to monitor ketosis in healthy and diabetic subjects. Recently, breath acetone concentration (BrAce) has been shown to correlate with the rate of fat loss in healthy individuals. In this review, the measurement of breath acetone in healthy subjects is evaluated for its utility in predicting fat loss and its sensitivity to changes in physiologic parameters. BrAce can range from 1 ppm in healthy non-dieting subjects to 1,250 ppm in diabetic ketoacidosis. A strong correlation exists between increased BrAce and the rate of fat loss. Multiple metabolic and respiratory factors affect the measurement of BrAce. BrAce is most affected by changes in the following factors (in descending order): dietary macronutrient composition, caloric restriction, exercise, pulmonary factors, and other assorted factors that increase fat metabolism or inhibit acetone metabolism. Pulmonary factors affecting acetone exchange in the lung should be controlled to optimize the breath sample for measurement. When biologic factors are controlled, BrAce measurement provides a non-invasive tool for monitoring the rate of fat loss in healthy subjects. © 2015 The Authors Obesity published by Wiley Periodicals, Inc. on behalf of The Obesity Society (TOS).

  3. First results on the sorption behaviour of Rutherfordium from HCl/HF containing aqueous solution

    Energy Technology Data Exchange (ETDEWEB)

    Schumann, D.; Nitsche, H. [Technische Univ. Dresden (Germany); Taut, S. [Forschungszentrum Rossendorf e.V. (FZR), Dresden (Germany); Jost, D.T.; Gaeggeler, H.W. [Paul Scherrer Inst. (PSI), Villigen (Switzerland); Yakushev, A.B.; Buklanov, G.V.; Domanov, V.P.; Lien Din Thi [Joint Inst. for Nuclear Research, Dubna (Russian Federation); Kubica, B.; Misiak, R.; Szeglowski, Z. [NINP Cracow (Poland)

    1997-09-01

    Rutherfordium shows strong sorption on the cation exchanger DOWEX 50x8 at a concentration of 0.1 M HCl/10{sup -2} M HF. This shows that Rf behaves under these conditions differently from Hf and Zr and more like Th under these conditions. (author) 1 fig., 5 refs.

  4. Study of Physical Properties for Sodium acetate with Water and Water - Acetone mixtures at Different Temperatures

    Directory of Open Access Journals (Sweden)

    Ahmed Mohammed Abbas

    2017-02-01

    Full Text Available In this study binary and ternary solutions are prepared by using the sodium acetate concentrations (0.1, 0.125, 0.2, 0.25, 0.4, 0.5, 0.8, 1 M in water and acetone –water mixtures .The important parameters such as apparent molal volume, the partial molal volume transfer,  apparent  molal compressibility, free energy of activation of viscous flow and thermodynamic activation parameter (enthalpy and entropy determined of sodium acetate in water , 20%, 40% ,60% and 80% V/V acetone –water mixtures at 298.15K, 303.15K, and 308.15K from density and viscosity measurements espectively. The limiting apparent molal volumes and experimental slopes were derived from the Masson equation, have been interpreted in terms of solute–solvent and solute–solute interactions  respectively. The viscosity data were analyzed using theJones–Dole equation and the derived parameter B - coefficient has also been interpreted in terms of solute–solvent interactions in the solutions.

  5. Acetone utilization by sulfate-reducing bacteria: draft genome sequence of Desulfococcus biacutus and a proteomic survey of acetone-inducible proteins

    OpenAIRE

    Gutiérrez Acosta, Olga B; Schleheck, David; Schink, Bernhard

    2014-01-01

    Background The sulfate-reducing bacterium Desulfococcus biacutus is able to utilize acetone for growth by an inducible degradation pathway that involves a novel activation reaction for acetone with CO as a co-substrate. The mechanism, enzyme(s) and gene(s) involved in this acetone activation reaction are of great interest because they represent a novel and yet undefined type of activation reaction under strictly anoxic conditions. Results In this study, a draft genome sequence of D. biacutus ...

  6. Selecting ethanol as an ideal organic solvent probe in radiation chemistry γ-radiolysis of acetone-ethanol system and acetophenone-ethanol system

    International Nuclear Information System (INIS)

    Jin Haofang; Wu Jilan; Fang Xingwang; Zhang Xujia

    1995-01-01

    Radiolysis of acetone-ethanol solution and acetophenone-ethanol solution has been studied in this work. The dependences of G values of the final γ radiolysis products such as H 2 . 2,3-butanediol and acetaldehyde on additive concentration in liquid ethanol have been obtained. There are two kinds of new final products, isopropanol and 2-methyl-2,3-butanediol are detected in irradiated acetone-ethanol solution. As for acetophenone-ethanol system, more new final products are found. In addition, experiments of pulse radiolysis upon acetophenone-ethanol solution have also been performed. The absorption spectrum with λ max at 315nm and 440nm is observed, which is assigned to ketyl radical ion C 6 H 5 (CH 3 )CO - . And the reaction mechanism of the two systems is proposed respectively with a moderate success. (author)

  7. Hf layer thickness dependence of resistive switching characteristics of Ti/Hf/HfO2/Au resistive random access memory device

    Science.gov (United States)

    Nakajima, Ryo; Azuma, Atsushi; Yoshida, Hayato; Shimizu, Tomohiro; Ito, Takeshi; Shingubara, Shoso

    2018-06-01

    Resistive random access memory (ReRAM) devices with a HfO2 dielectric layer have been studied extensively owing to the good reproducibility of their SET/RESET switching properties. Furthermore, it was reported that a thin Hf layer next to a HfO2 layer stabilized switching properties because of the oxygen scavenging effect. In this work, we studied the Hf thickness dependence of the resistance switching characteristics of a Ti/Hf/HfO2/Au ReRAM device. It is found that the optimum Hf thickness is approximately 10 nm to obtain good reproducibility of SET/RESET voltages with a small RESET current. However, when the Hf thickness was very small (∼2 nm), the device failed after the first RESET process owing to the very large RESET current. In the case of a very thick Hf layer (∼20 nm), RESET did not occur owing to the formation of a leaky dielectric layer. We observed the occurrence of multiple resistance states in the RESET process of the device with a Hf thickness of 10 nm by increasing the RESET voltage stepwise.

  8. Solvent Effects on Nuclear Magnetic Resonance 2J(C,Hf and 1J(C,Hf Spin–Spin Coupling Constants in Acetaldehyde

    Directory of Open Access Journals (Sweden)

    Angel Esteban

    2003-02-01

    Full Text Available Abstract: The known solvent dependence of 1J(Cc,Hf and 2J(C1,Hf couplings in acetaldehyde is studied from a theoretical viewpoint based on the density functional theory approach where the dielectric solvent effect is taken into account with the polarizable continuum model. The four terms of scalar couplings, Fermi contact, paramagnetic spin orbital, diamagnetic spin orbital and spin dipolar, are calculated but the solvent effect analysis is restricted to the first term since for both couplings it is by far the dominant contribution. Experimental trends of Δ1J(Cc,Hf and Δ2J(C1,Hf Vs ε (the solvent dielectric constant are correctly reproduced although they are somewhat underestimated. Specific interactions between solute and solvent molecules are studied for dimethylsulfoxide, DMSO, solutions considering two different one-to-one molecular complexes between acetaldehyde and DMSO. They are determined by interactions of type C=O---H---C and S=O---H---C, and the effects of such interactions on 1J(Cc,Hf and 2J(C1,Hf couplings are analyzed. Even though only in a semiquantitative way, it is shown that the effect of such interactions on the solvent effects, of Δ1J(Cc,Hf and Δ2J(C1,Hf, tend to improve the agreement between calculated and experimental values. These results seem to indicate that a continuum dielectric model has not enough flexibility for describing quantitatively solvent effects on spin-spin couplings. Apparently, even for relatively weak hydrogen bonding, the contribution from “direct” interactions is of the same order of magnitude as the “dielectric” effect.

  9. Suspended HfO2 photonic crystal slab on III-nitride/Si platform

    International Nuclear Information System (INIS)

    Wang, Yongjin; Feng, Jiao; Cao, Ziping; Zhu, Hongbo

    2014-01-01

    We present here the fabrication of suspended hafnium oxide (HfO 2 ) photonic crystal slab on a III-nitride/Si platform. The calculations are performed to model the suspended HfO 2 photonic crystal slab. Aluminum nitride (AlN) film is employed as the sacrificial layer to form air gap. Photonic crystal patterns are defined by electron beam lithography and transferred into HfO 2 film, and suspended HfO 2 photonic crystal slab is achieved on a III-nitride/Si platform through wet-etching of AlN layer in the alkaline solution. The method is promising for the fabrication of suspended HfO 2 nanostructures incorporating into a III-nitride/Si platform, or acting as the template for epitaxial growth of III-nitride materials. (orig.)

  10. The Influence of PEG400 and Acetone on Polysulfone Membrane Morphology and Fouling Behaviour

    Directory of Open Access Journals (Sweden)

    P.T.P. Aryanti

    2016-05-01

    Full Text Available Modification of polysulfone ultrafiltration membrane was conducted by blending polysulfone with PEG400 and acetone as additives. The influence of each additive on the resulted membrane morphology and fouling characteristics were investigated. The experimental results showed that the hydrophilicity of the polysulfone membrane was improved by the increase of PEG400 in the polysulfone membrane. The water contact angle of the membrane was decreased from 76.1° to 38.31° when 35 %wt of PEG400 was added into the polysulfone solution, while the water content of the membrane was increased by around 38%. The high concentration of PEG400 in the polysulfone solution led to the formation of longer finger-like cavities in the membrane structure and resulted in a thicker membrane skin layer. The high concentration of PEG400 also contributed to the increase in hydraulic resistance of the membrane due to organic matter fouling. This problem could be minimized by the addition of acetone into the polysulfone solution, which resulted in a lower fouling resistance of organic matter during up to five hours of peat water filtration.

  11. Acetone n-radical cation internal rotation spectrum: The torsional potential surface

    International Nuclear Information System (INIS)

    Shea, Dana A.; Goodman, Lionel; White, Michael G.

    2000-01-01

    The one color REMPI and two color ZEKE-PFI spectra of acetone-d 3 have been recorded. The 3p x Rydberg state of acetone-d 3 lies at 59 362.3 cm-1 and both of the torsional modes are visible in this spectrum. The antigearing Rydberg (a 2 ) mode, v 12 * , has a frequency of 62.5 cm-1, while the previously unobserved gearing (b 1 ) mode, v 17 * , is found at 119.1 cm-1. An ionization potential of 78 299.6 cm-1 for acetone-d 3 has been measured. In acetone-d 3 n-radical cation ground state, the fundamentals of both of the torsional modes have been observed, v 12 + at 51.0 cm-1 and v 17 + at 110.4 cm-1, while the first overtone of v 12 + has been measured at 122.4 cm-1. Deuterium shifts show that v 12 + behaves like a local C 3v rotor, but that v 17 + is canonical. Combining this data with that for acetone-d 0 and aacetone-d 6 has allowed us to fit the observed frequencies to a torsional potential energy surface based on an ab initio C 2v cation ground state geometry. This potential energy surface allows for prediction of the v 17 vibration in acetone-d 0 and acetone-d 6 . The barrier to synchronous rotation is higher in the cation ground state than in the neutral ground state, but significantly lower than in the 3s Rydberg state. The 3p x Rydberg and cation ground state potential energy surfaces are found to be very similar to each other, strongly supporting the contention that the 3p x Rydberg state has C 2v geometry and is a good model for the ion core. The altered 3s Rydberg state potential surface suggests this state has significant valence character. (c) 2000 American Institute of Physics

  12. Electrical behaviour of fully solution processed HfO2 (MOS) in presence of different light illumination

    Science.gov (United States)

    Mondal, Sandip

    2018-04-01

    This experiment demonstrates the electrical behaviors of fully solution processed HfO2(MOS) in presence of different optical illumination. The capacitance voltage measurement was performed at frequency of 100 kHz with a DC gate sweep voltage of ±5V (with additional AC voltage of 100mV) in presence of deep UV (wavelength of 365nm with power of 25W) as well as white light (20W). It is found that there is a large shift in flatband voltage of 120mV due presence of white light during the CV measurement. However there is negligible change in flatband voltage (30mV) has been observed due to illumination of deep UV light.

  13. Proteomic analysis of nitrate-dependent acetone degradation by Alicycliphilus denitrificans strain BC.

    Science.gov (United States)

    Oosterkamp, Margreet J; Boeren, Sjef; Atashgahi, Siavash; Plugge, Caroline M; Schaap, Peter J; Stams, Alfons J M

    2015-06-01

    Alicycliphilus denitrificans strain BC grows anaerobically on acetone with nitrate as electron acceptor. Comparative proteomics of cultures of A. denitrificans strain BC grown on either acetone or acetate with nitrate was performed to study the enzymes involved in the acetone degradation pathway. In the proposed acetone degradation pathway, an acetone carboxylase converts acetone to acetoacetate, an AMP-dependent synthetase/ligase converts acetoacetate to acetoacetyl-CoA, and an acetyl-CoA acetyltransferase cleaves acetoacetyl-CoA to two acetyl-CoA. We also found a putative aldehyde dehydrogenase associated with acetone degradation. This enzyme functioned as a β-hydroxybutyrate dehydrogenase catalyzing the conversion of surplus acetoacetate to β-hydroxybutyrate that may be converted to the energy and carbon storage compound, poly-β-hydroxybutyrate. Accordingly, we confirmed the formation of poly-β-hydroxybutyrate in acetone-grown cells of strain BC. Our findings provide insight in nitrate-dependent acetone degradation that is activated by carboxylation of acetone. This will aid studies of similar pathways found in other microorganisms degrading acetone with nitrate or sulfate as electron acceptor. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  14. Thermal and Ablative Properties of Ipns and Composites of High Ortho Resole Resin and Difurfurylidene Acetone

    Directory of Open Access Journals (Sweden)

    Tariq S. NAJIM

    2008-12-01

    Full Text Available High ortho resole resin was prepared by condensation of phenol with excess of formaldehyde in the presence of magnesium oxide as catalyst. Reaction of furfuraldehyde with acetone in basic medium led to difurfurylidene acetone (DFA. Their interpenetrating polymer network (IPNS were obtained by the reaction of predetermined quantities of difurfurylidene acetone and high ortho resole using p-toluene sulphonic acid (PTSA as curing agent. The thermal behavior of the resins was studied using thermogravimetry (TG under ambient and nitrogen atmospheres over a temperature range of (25-1000 Cº. It was observed that the IPN of 20% DFA – 80% resole has higher thermal stability than that of resole alone and the decomposition temperature was higher by 80 Cº. This behavior was attributed to highly cross linked structure and thermally stable backbone of ploy difurfurylidene acetone due to formation of ladder structure.Impregnation of chopped fiber glass type (E with the polymeric solutions was used to prepare their composites, and the ablative properties were investigated according to ASTM E-285 –80. It was observed that the IPN of (DFA- resol perform better than the resole composite alone.

  15. Comparison of HfCl4, HfI4, TEMA-Hf, and TDMA-Hf as precursors in early growing stages of HfO2 films deposited by ALD: A DFT study

    International Nuclear Information System (INIS)

    Cortez-Valadez, M.; Fierro, C.; Farias-Mancilla, J.R.; Vargas-Ortiz, A.; Flores-Acosta, M.; Ramírez-Bon, R.; Enriquez-Carrejo, J.L.

    2016-01-01

    Highlights: • Hafnium oxide growth on Si(100) by atomic layer deposition was simulated. • The interface structure was considered as silicate and silicide. • The interface was studied employing DFT. • TDMA-Hf precursor show better interface stability. - Abstract: The final structure of HfO 2 films grown by atomic layer deposition (ALD) after reaction with OH − ions has been analyzed by DFT (density functional theory). The interaction of the precursors: HfCl 4 (hafnium tetrachloride), HfI 4 (hafnium tetraiodide), TEMA-Hf (tetrakis-ethylmethylamino hafnium), and TDMA-Hf (tetrakis-dimethylamino hafnium) with HO–H was studied employing the B3LYP (Becke 3-parameter, Lee–Yang–Parr) hybrid functional and the PBE (Perdew–Burke–Ernzerhof) generalized gradient functional. The structural evolution at the Si(100) surface has been analyzed by LDA (local density approximation). The structural parameters: bond length and bond angle, and the vibrational parameters for the optimized structures are also reported. The presence of hafnium silicate at the interface was detected. The infrared spectra and structural parameters obtained in this work agree with previously reported experimental results.

  16. Comparison of HfCl4, HfI4, TEMA-Hf, and TDMA-Hf as precursors in early growing stages of HfO2 films deposited by ALD: A DFT study

    Science.gov (United States)

    Cortez-Valadez, M.; Fierro, C.; Farias-Mancilla, J. R.; Vargas-Ortiz, A.; Flores-Acosta, M.; Ramírez-Bon, R.; Enriquez-Carrejo, J. L.; Soubervielle-Montalvo, C.; Mani-Gonzalez, P. G.

    2016-06-01

    The final structure of HfO2 films grown by atomic layer deposition (ALD) after reaction with OH- ions has been analyzed by DFT (density functional theory). The interaction of the precursors: HfCl4 (hafnium tetrachloride), HfI4 (hafnium tetraiodide), TEMA-Hf (tetrakis-ethylmethylamino hafnium), and TDMA-Hf (tetrakis-dimethylamino hafnium) with HO-H was studied employing the B3LYP (Becke 3-parameter, Lee-Yang-Parr) hybrid functional and the PBE (Perdew-Burke-Ernzerhof) generalized gradient functional. The structural evolution at the Si(100) surface has been analyzed by LDA (local density approximation). The structural parameters: bond length and bond angle, and the vibrational parameters for the optimized structures are also reported. The presence of hafnium silicate at the interface was detected. The infrared spectra and structural parameters obtained in this work agree with previously reported experimental results.

  17. Acetone in the atmosphere: Distribution, sources, and sinks

    Science.gov (United States)

    Singh, H. B.; O'Hara, D.; Herlth, D.; Sachse, W.; Blake, D. R.; Bradshaw, J. D.; Kanakidou, M.; Crutzen, P. J.

    1994-01-01

    Acetone (CH3COCH3) was found to be the dominant nonmethane organic species present in the atmosphere sampled primarily over eastern Canada (0-6 km, 35 deg-65 deg N) during ABLE3B (July to August 1990). A concentration range of 357 to 2310 ppt (= 10(exp -12) v/v) with a mean value of 1140 +/- 413 ppt was measured. Under extremely clean conditions, generally involving Arctic flows, lowest (background) mixing ratios of 550 +/- 100 ppt were present in much of the troposphere studied. Correlations between atmospheric mixing ratios of acetone and select species such as C2H2, CO, C3H8, C2Cl4 and isoprene provided important clues to its possible sources and to the causes of its atmospheric variability. Biomass burning as a source of acetone has been identified for the first time. By using atmospheric data and three-dimensional photochemical models, a global acetone source of 40-60 Tg (= 10(exp 12) g)/yr is estimated to be present. Secondary formation from the atmospheric oxidation of precursor hydrocarbons (principally propane, isobutane, and isobutene) provides the single largest source (51%). The remainder is attributable to biomass burning (26%), direct biogenic emissions (21%), and primary anthropogenic emissions (3%). Atmospheric removal of acetone is estimated to be due to photolysis (64%), reaction with OH radicals (24%), and deposition (12%). Model calculations also suggest that acetone photolysis contributed significantly to PAN formation (100-200 ppt) in the middle and upper troposphere of the sampled region and may be important globally. While the source-sink equation appears to be roughly balanced, much more atmospheric and source data, especially from the southern hemisphere, are needed to reliably quantify the atmospheric budget of acetone.

  18. Thermal expansion studies on HfO2-Gd2O3 system

    International Nuclear Information System (INIS)

    Panneerselvam, G.; Antony, M.P.; Nagarajan, K.

    2014-01-01

    A series of solid solutions containing GdO 1.5 in HfO 2 , (Hf 1-y Gd y ) O 2 (y = 0.15, 0.2, 0.3, 0.41 and 0.505) were prepared by solid state method. Structural characterization and computation of lattice parameter was carried out using room temperature X-ray diffraction measurements

  19. Breath acetone as a potential marker in clinical practice.

    Science.gov (United States)

    Ruzsányi, Veronika; Péter Kalapos, Miklós

    2017-06-01

    In recent decades, two facts have changed the opinion of researchers about the function of acetone in humans. Firstly, it has turned out that acetone cannot be regarded as simply a waste product of metabolism, because there are several pathways in which acetone is produced or broken down. Secondly, methods have emerged making possible its detection in exhaled breath, thereby offering an attractive alternative to investigation of blood and urine samples. From a clinical point of view the measurement of breath acetone levels is important, but there are limitations to its wide application. These limitations can be divided into two classes, technical and biological limits. The technical limits include the storage of samples, detection threshold, standardization of clinical settings, and the price of instruments. When considering the biological ranges of acetone, personal factors such as race, age, gender, weight, food consumption, medication, illicit drugs, and even profession/class have to be taken into account to use concentration information for disorders. In some diseases such as diabetes mellitus and lung cancer, as well as in nutrition-related behavior such as starvation and ketogenic diet, breath acetone has been extensively examined. At the same time, there is a lack of investigations in other cases in which ketosis is also evident, such as in alcoholism or an inborn error of metabolism. In summary, the detection of acetone in exhaled breath is a useful and promising tool for diagnosis and it can be used as a marker to follow the effectiveness of treatments in some disorders. However, further endeavors are needed for clarification of the exact distribution of acetone in different body compartments and evaluation of its complex role in humans, especially in those cases in which a ketotic state also occurs.

  20. Structure, chemistry and luminescence properties of dielectric La{sub x}Hf{sub 1-x}O{sub y} films

    Energy Technology Data Exchange (ETDEWEB)

    Kaichev, V.V., E-mail: vvk@catalysis.ru [Boreskov Institute of Catalysis, Novosibirsk (Russian Federation); Novosibirsk State University, Novosibirsk (Russian Federation); Smirnova, T.P.; Yakovkina, L.V. [Nikolaev Institute of Inorganic Chemistry, Novosibirsk (Russian Federation); Ivanova, E.V.; Zamoryanskaya, M.V. [Ioffe Physical-Technical Institute, St. Petersburg (Russian Federation); Saraev, A.A. [Boreskov Institute of Catalysis, Novosibirsk (Russian Federation); Novosibirsk State University, Novosibirsk (Russian Federation); Pustovarov, V.A. [Ural State Technical University, Ekaterinburg (Russian Federation); Perevalov, T.V.; Gritsenko, V.A. [Novosibirsk State University, Novosibirsk (Russian Federation); Rzhanov Institute of Semiconductor Physics, Novosibirsk (Russian Federation)

    2016-06-01

    Dielectric films of La{sub 2}O{sub 3}, HfO{sub 2}, and La{sub x}Hf{sub 1-x}O{sub y} were synthesized by metal-organic chemical vapor deposition. Structural, chemical, and luminescence properties of the films were studied using X-ray photoelectron spectroscopy, methods of X-ray diffraction and selected area electron diffraction, high-resolution transmission electron microscopy, and a cathodoluminescence technique. It was found that doping of hafnium oxide with lanthanum leads to the formation of a continuous series of solid solutions with a cubic structure. This process is accompanied by the formation of oxygen vacancies in the HfO{sub 2} lattice. Cathodoluminescence spectra of the La{sub x}Hf{sub 1-x}O{sub y}/Si films exhibited a wide band with the maximum near 2.4–2.5 eV, which corresponds to the blue emission. Quantum-chemical calculations showed that this blue band is due to oxygen vacancies in the HfO{sub 2} lattice. - Highlights: • HfO{sub 2} and solid solution La{sub x}Hf{sub 1-x}O{sub y} films were synthesized by MOCVD. • The continuous series of solid solutions with a cubic structure was formed at La doping of HfO{sub 2}. • Cathodoluminescence band at 2.4–2.5 eV is observed due to the oxygen vacancies in La{sub x}Hf{sub 1-x}O{sub y}. • The cathodoluminescence decreases in intensity when the La concentration increases.

  1. Study of plutonium sorption in aluminia column in the system HNO3-HF

    International Nuclear Information System (INIS)

    Araujo, J.A. de.

    1977-01-01

    The column chromatographic method using alumina has been applied successfully to study the sorption-desorption behavior of plutonium traces in HNO 3 -HF and HNO 3 -HF-UO 2 (NO 3 ) 2 systems, aiming to elaborate a process for recovering plutonium traces from reprocessing wastes, mainly in existing solutions where uranium is presented in macro quantities. Basically, the method consists in the sorption of plutonium by percolating a solution containing HNO 3 (0,1 to 0,8M) or uranyl nitrate (1-50 gU/l) and HF(0,1 to 0,3M) through an Al 2 O 3 collumn. The plutonium is fixed on Al 2 O 3 whereas the uranyl ions is collected in the efluent. The adsorption of Pu-III, Pu-IV and Pu-VI in the presence of HF was determined and Pu-IV can be almost completely sorbed. The Pu-IV is eluted by reduction to Pu-III in the column using 3 M HNO 3 -0,005M FeSO 4 at 50 0 C as elutrient. This method is very simple and can be applied for separation and purification of plutonium (traces) from uranyl nitrate or others coming solutions from wet chemistry of irradiated fuels [pt

  2. Effects of humus on acetone-butanol fermentations

    Energy Technology Data Exchange (ETDEWEB)

    Kovats, J

    1963-01-01

    Adding 6 to 8 g humus-rich soil dried at 80/sup 0/ to 100 cc sterilized molasses, containing 3.8 sucrose and 0.1% (NH/sub 4/)/sub 2/HPO/sub 4/, inoculated with acetone-butanol fermentative bacteria, increased acetone, butanol, and ethanol yields by 30, 50, and 40%, respectively. The acetone-to-butanol ratio increased from 1.85 to 2.1-2.3 in low and 2.6-2.8 in high sucrose-molasses concentrations. Yields of total organic solvents increased from 25 to 36-8% of the sucrose present. Inorganic salts from ashed humus soils were only 10 to 20% less effective in enhancing fermentation than the whole soil. It is postulated that the fermentation is enhanced by trace elements present in the soil.

  3. Breath acetone concentration; biological variability and the influence of diet

    International Nuclear Information System (INIS)

    Španěl, Patrik; Dryahina, Kseniya; Rejšková, Alžběta; Chippendale, Thomas W E; Smith, David

    2011-01-01

    Previous measurements of acetone concentrations in the exhaled breath of healthy individuals and the small amount of comparable data for individuals suffering from diabetes are briefly reviewed as a prelude to the presentation of new data on the sporadic and wide variations of breath acetone that occur in ostensibly healthy individuals. Data are also presented which show that following a ketogenic diet taken by eight healthy individuals their breath acetone concentrations increased up to five times over the subsequent 6 h. Similarly, the breath acetone increased six and nine times when a low carbohydrate diet was taken by two volunteers and remained high for the several days for which the diet was continued. These new data, together with the previous data, clearly indicate that diet and natural intra-individual biological and diurnal variability result in wide variations in breath acetone concentration. This places an uncertainty in the use of breath acetone alone to monitor blood glucose and glycaemic control, except and unless the individual acts as their own control and is cognizant of the need for dietary control. (note)

  4. Activation of Acetone and Other Simple Ketones in Anaerobic Bacteria.

    Science.gov (United States)

    Heider, Johann; Schühle, Karola; Frey, Jasmin; Schink, Bernhard

    2016-01-01

    Acetone and other ketones are activated for subsequent degradation through carboxylation by many nitrate-reducing, phototrophic, and obligately aerobic bacteria. Acetone carboxylation leads to acetoacetate, which is subsequently activated to a thioester and degraded via thiolysis. Two different types of acetone carboxylases have been described, which require either 2 or 4 ATP equivalents as an energy supply for the carboxylation reaction. Both enzymes appear to combine acetone enolphosphate with carbonic phosphate to form acetoacetate. A similar but more complex enzyme is known to carboxylate the aromatic ketone acetophenone, a metabolic intermediate in anaerobic ethylbenzene metabolism in denitrifying bacteria, with simultaneous hydrolysis of 2 ATP to 2 ADP. Obligately anaerobic sulfate-reducing bacteria activate acetone to a four-carbon compound as well, but via a different process than bicarbonate- or CO2-dependent carboxylation. The present evidence indicates that either carbon monoxide or a formyl residue is used as a cosubstrate, and that the overall ATP expenditure of this pathway is substantially lower than in the known acetone carboxylase reactions. © 2016 S. Karger AG, Basel.

  5. The effects of inhaled acetone on place conditioning in adolescent rats.

    Science.gov (United States)

    Lee, Dianne E; Pai, Jennifer; Mullapudui, Uma; Alexoff, David L; Ferrieri, Richard; Dewey, Stephen L

    2008-03-01

    Acetone is an ubiquitous ingredient in many household products (e.g., glue solvents, air fresheners, adhesives, nail polish, and paint) that is putatively abused; however, there is little empirical evidence to suggest that acetone alone has any abuse liability. Therefore, we systematically investigated the conditioned response to inhaled acetone in a place conditioning apparatus. Three groups of male, Sprague-Dawley rats were exposed to acetone concentrations of 5000, 10,000 or 20,000 ppm for 1 h in a conditioned place preference apparatus alternating with air for 6 pairing sessions. A place preference test ensued in an acetone-free environment. To test the preference of acetone as a function of pairings sessions, the 10,000 ppm group received an additional 6 pairings and an additional group received 3 pairings. The control group received air in both compartments. Locomotor activity was recorded by infrared photocells during each pairing session. We noted a dose response relationship to acetone at levels 5000-20,000 ppm. However, there was no correlation of place preference as a function of pairing sessions at the 10,000 ppm level. Locomotor activity was markedly decreased in animals on acetone-paired days as compared to air-paired days. The acetone concentrations we tested for these experiments produced a markedly decreased locomotor activity profile that resemble CNS depressants. Furthermore, a dose response relationship was observed at these pharmacologically active concentrations, however, animals did not exhibit a positive place preference.

  6. The effects of inhaled acetone on place conditioning in adolescent rats

    Science.gov (United States)

    Lee, Dianne E.; Pai, Jennifer; Mullapudui, Uma; Alexoff, David L.; Ferrieri, Richard; Dewey, Stephen L.

    2009-01-01

    Introduction Acetone is a ubiquitous ingredient in many household products (e.g., glue solvents, air fresheners, adhesives, nail polish, and paint) that is putatively abused; however, there is little empirical evidence to suggest that acetone alone has any abuse liability. Therefore, we systematically investigated the conditioned response to inhaled acetone in a place conditioning apparatus. Method Three groups of male, Sprague-Dawley rats were exposed to acetone concentrations of 5,000, 10,000 or 20,000 ppm for 1 hour in a conditioned place preference apparatus alternating with air for 6 pairing sessions. A place preference test ensued in an acetone-free environment. To test the preference of acetone as a function of pairings sessions, the 10,000 ppm group received an additional 6 pairings and an additional group received 3 pairings. The control group received air in both compartments. Locomotor activity was recorded by infrared photocells during each pairing session. Results We noted a dose response relationship to acetone at levels 5,000-20,000 ppm. However, there was no correlation of place preference as a function of pairing sessions at the 10,000 ppm level. Locomotor activity was markedly decreased in animals on acetone-paired days as compared to air-paired days. Conclusion The acetone concentrations we tested for these experiments produced a markedly decreased locomotor activity profile that resemble CNS depressants. Furthermore, a dose response relationship was observed at these pharmacologically active concentrations, however, animals did not exhibit a positive place preference. PMID:18096214

  7. HF i dag

    DEFF Research Database (Denmark)

    Lindstrøm, Maria Duclos; Simonsen, Birgitte

    2008-01-01

    Notatet er lavet på baggrund af uddannelsesbiografiske dybdeinterviews med kursister på toårigt HF. Indenfor rammerne af en pilotundersøgelse identificerer notatet fire gennemgående profiler: De pragmatiske, de fagligt usikre, second chance-kursisterne, og de HF-kursister, som har HF som first...

  8. A novel process for preparation of titanium dioxide from Ti-bearing electric furnace slag: NH4HF2-HF leaching and hydrolyzing process.

    Science.gov (United States)

    Zheng, Fuqiang; Guo, Yufeng; Qiu, Guanzhou; Chen, Feng; Wang, Shuai; Sui, Yulei; Jiang, Tao; Yang, Lingzhi

    2018-02-15

    A novel process to prepare titanium dioxide from Ti-bearing electric furnace slag by NH 4 HF 2 -HF leaching and hydrolyzing process has been developed. In this present study, the effects of [NH 4 + ]/[F] mXolar ratio, leaching temperature, [F] concentration, liquid/solid mass ratio, leaching time on the Ti extraction, and the phase transformations have been investigated to reveal the leaching mechanism of Ti-bearing electric furnace slag in NH 4 HF 2 -HF solution. In the NH 4 HF 2 -HF leaching process, the MgTi 2 O 5 and Al 2 TiO 5 are converted to TiF 6 2- and Mg-Al-bearing precipitate. Ti extraction rate reached 98.84% under the optimal conditions. In addition, 98.25% iron ions can be removed in the presence of NaCl prior to hydrolysis process. The effects of pH and temperature on the selective hydrolysis of TiF 6 2- during hydrolysis process were also studied. In the hydrolysis process, the TiF 6 2- is converted to (NH 4 ) 2 TiOF 4 . By calcination, high grade TiO 2 powder with its purity of 99.88% was obtained, using which the products, well crystallized anatase and rutile, were obtained through roasting at 800°C and 1000°C, respectively. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. BaFe{sub 12}O{sub 19} powder with high magnetization prepared by acetone-aided coprecipitation

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Hsuan-Fu, E-mail: hfyu@mail.tku.edu.tw

    2013-09-15

    BaFe{sub 12}O{sub 19} particles with high magnetization were produced using an acetone-aided coprecipitation process. An aqueous solution of iron and barium nitrates, in an Fe{sup 3+}/Ba{sup 2+} molar ratio of 12, was added in a stirred precipitation liquid medium composed of H{sub 2}O, CH{sub 3}(CO)CH{sub 3} and NH{sub 4}OH. After reacting metallic ions with ammonia, the precipitates were formed, centrifugally filtered, freeze dried and calcined. Effects of amount of the acetone in the precipitation liquid medium on the formation of crystalline BaFe{sub 12}O{sub 19} were investigated. The presence of acetone in the precipitation liquid medium can greatly promote formation of the crystalline BaFe{sub 12}O{sub 19} at temperature as low as 650 °C and can enhance magnetization of the derived particles. On the other hand, raising the calcination temperature can effectively accelerate development of crystallite morphology and magnetic characters of the barium hexaferrites. While the barium hexaferrite powder obtained without acetone additions and calcined at 1000 °C had magnetization (measured at 50 kOe; M(50 kOe)) of 63.5 emu/g, remanence magnetization (Mr) of 31.3 emu/g and coercivity (Hc) of 4.7 kOe, the single magnetic domain size BaFe{sub 12}O{sub 19} powder with M(50 kOe) of 70.6 emu/g, Mr of 34.4 emu/g and Hc of 3.7 kOe was produced at 1000 °C, using a precipitation liquid medium of 64 vol% acetone. - Highlights: • BaFe{sub 12}O{sub 19} with high magnetic characters was produced by an acetone-aided coprecipitation. • The effects of acetone addition in the precipitation on the formation of BaFe{sub 12}O{sub 19} were studied. • Acetone presence in the precipitation liquid medium promoted BaFe{sub 12}O{sub 19} formation at ≥650 °C. • BaFe{sub 12}O{sub 19} with M(50 kOe) of 70.6 emu/g, Mr of 34.4 emu/g and Hc of 3.7 kOe was obtained.

  10. Strong blue emission from ZnO nanocrystals synthesized in acetone-based solvent

    International Nuclear Information System (INIS)

    Efafi, B.; Majles Ara, M.H.; Mousavi, S.S.

    2016-01-01

    In this research, ZnO nanocrystals were synthesized by an improved sol–gel method. UV–vis, FTIR and photoluminescence spectra of the ZnO solution synthesized by this route indicated different properties compared to the other preparation methods. It was observed from FTIR that the sol (prepared using acetone) with the low concentration contains a noticeable amount of the Zn–O bond. The PL spectrum with a strong blue emission confirmed that these nanocrystals are good candidate for use in applications where a monochromatic emission is required. To the best of our knowledge, monochromatic emission ZnO devices have been fabricated through high technology instruments but this paper introduces a simple method for preparation of ZnO with the high intensity blue peak. The size and morphology of ZnO nanocrystals have been studied using FESEM. The nanocrystal size was estimated about 70 nm which was in good agreement with XRD data. - Highlights: • Preparation of ZnO nanocrystals through a novel method by the use of acetone as the solvent. • Observation of the strong blue emission peak from the ZnO prepared solution. • Reduction of green emission in the synthesized sample compared to the other methods of preparation.

  11. Strong blue emission from ZnO nanocrystals synthesized in acetone-based solvent

    Energy Technology Data Exchange (ETDEWEB)

    Efafi, B. [NanoPhotonics Lab., Physics Department, Kharazmi University, Tehran (Iran, Islamic Republic of); Departments of Physics, Iran University of Science & Technology, Tehran (Iran, Islamic Republic of); Majles Ara, M.H., E-mail: majlesara@gmail.com [NanoPhotonics Lab., Physics Department, Kharazmi University, Tehran (Iran, Islamic Republic of); Mousavi, S.S. [NanoPhotonics Lab., Physics Department, Kharazmi University, Tehran (Iran, Islamic Republic of)

    2016-10-15

    In this research, ZnO nanocrystals were synthesized by an improved sol–gel method. UV–vis, FTIR and photoluminescence spectra of the ZnO solution synthesized by this route indicated different properties compared to the other preparation methods. It was observed from FTIR that the sol (prepared using acetone) with the low concentration contains a noticeable amount of the Zn–O bond. The PL spectrum with a strong blue emission confirmed that these nanocrystals are good candidate for use in applications where a monochromatic emission is required. To the best of our knowledge, monochromatic emission ZnO devices have been fabricated through high technology instruments but this paper introduces a simple method for preparation of ZnO with the high intensity blue peak. The size and morphology of ZnO nanocrystals have been studied using FESEM. The nanocrystal size was estimated about 70 nm which was in good agreement with XRD data. - Highlights: • Preparation of ZnO nanocrystals through a novel method by the use of acetone as the solvent. • Observation of the strong blue emission peak from the ZnO prepared solution. • Reduction of green emission in the synthesized sample compared to the other methods of preparation.

  12. [Adsorption characteristics of acetone and butanone onto honeycomb ZSM-5 molecular sieve].

    Science.gov (United States)

    Du, Juan; Luan, Zhi-Qiang; Xie, Qiang; Ye, Ping-Wei; Li, Kai; Wang, Xi-Qin

    2013-12-01

    Adsorption capacity of acetone and acetone-butanone mixture onto honeycomb ZSM-5 molecular sieve was measured in this paper, and the influences of relative humidity, initial adsorbate concentration and airflow velocity on the adsorption process were investigated. Besides, adsorption performance parameters were calculated by Wheeler's equation. The results showed that relative humidity had no obvious influence on the acetone adsorption performance, which suggests that this material has good hydrophobic ability; in the low concentration range, the dynamic saturated adsorption capacity of acetone increased with the increase of initial concentration, but in the occasion of high concentration of acetone gas (more than 9 mg x L(-1)), the dynamic saturated adsorption capacity maintained at a certain level and did not vary with the increase of initial concentration; the increase of air flow velocity resulted in significant increase of acetone adsorption rate constant, at the same time the critical layer thickness of the adsorbent bed also increased significantly. In the cases of acetone-butanone mixture, the adsorption capacity of butanone onto ZSM-5 was clearly higher than that of acetone.

  13. Butanol-acetone fermentation of sugar-cane juice

    Energy Technology Data Exchange (ETDEWEB)

    Perdomo, E V

    1958-01-01

    Sixteen new varieties of Clostridium acetobutylicum of varying activity were isolated from different sources. The most active one was obtained from sugar-cane roots. The effects of 86 additives were studied. The following formulation gave a 32% yield (with respect to sucrose) of solvent mixture (73% BuOH, 19 to 23% acetone, and 3 to 4% EtOH) sugar-cane juice (I) (20/sup 0/ Brix) 250 ml, ground Vicia sativa 1 g, KH/sub 2/PO/sub 4/ 2.5 g, CaCO/sub 3/ 4 g, H/sub 2/O 1000 ml; the pH of this solution was 5.6 to 6.0. Unclarified, it was inverted by invertase; the other components were added and the mixture was sterilized (20 minutes, 15 pounds).

  14. Purification and characterization of acetone carboxylase from Xanthobacter strain Py2

    OpenAIRE

    Sluis, Miriam K.; Ensign, Scott A.

    1997-01-01

    Acetone metabolism in the aerobic bacterium Xanthobacter strain Py2 proceeds by a carboxylation reaction forming acetoacetate as the first detectable product. In this study, acetone carboxylase, the enzyme catalyzing this reaction, has been purified to homogeneity and characterized. Acetone carboxylase was comprised of three polypeptides with molecular weights of 85,300, 78,300, and 19,600 arranged in an α2β2γ2 quaternary structure. The carboxylation of acetone was coupled to the hydrolysis o...

  15. Determination of acetone in saliva by reversed-phase liquid chromatography with fluorescence detection and the monitoring of diabetes mellitus patients with ketoacidosis.

    Science.gov (United States)

    Fujii, Shinya; Maeda, Toshio; Noge, Ichiro; Kitagawa, Yutaka; Todoroki, Kenichiro; Inoue, Koichi; Min, Jun Zhe; Toyo'oka, Toshimasa

    2014-03-20

    In diabetes mellitus (DM) patients with ketoacidosis, ketone bodies, i.e., acetone, acetoacetic acid (AA) and β-hydroxybutyric acid (HA), are increased in the blood and urine. Acetone is also excreted by breathing due to the spontaneous decomposition of AA. Thus, the increase in acetone has been considered as one of the biomarkers for the diagnosis of DM. However, the determination of acetone in one's breath is not recommended because of the sample handling difficulty. We measured acetone in saliva by reversed-phase liquid chromatography (LC) with fluorescence (FL) detection. The proposed method was applied to the determination of acetone in the saliva of healthy volunteers and DM patients with and without ketoacidosis. 3-Pentanone (I.S.) and DBD-H in acetonitrile were added to freshly collected saliva and reacted at room temperature for 20 min in the presence of trifluoroacetic acid. After the reaction, the solution was centrifuged at 10,000 × g and 4 °C for 5 min. The supernatant was separated by reversed-phase LC and the FL detected at 550 nm (excitation at 460 nm). The concentrations of acetone in the DM patients with ketoacidosis were significantly higher than those of the normal subjects and DM patients without ketoacidosis. Furthermore, the total contents of the ketone bodies in the blood correlated with acetone in the saliva of the DM patients. The concentrations of acetone in the saliva of an emergency patient also correlated with the ketone bodies in the blood at each sampling time. The proposed method using LC-FL seems to be useful for the determination of acetone in the saliva of DM patients with ketoacidosis. The method offers a new option for the diagnosis and monitoring of DM patients with ketoacidosis. Copyright © 2014 Elsevier B.V. All rights reserved.

  16. Acetone and Water on TiO(110): H/D Exchange

    International Nuclear Information System (INIS)

    Henderson, Michael A.

    2005-01-01

    Isotopic H/D exchange between coadsorbed acetone and water on the TiO(110) surface was examined using temperature programmed desorption (TPD) as a function of coverage and two surface pretreatments (oxidation and reduction). Coadsorbed acetone and water interact repulsively on reduced TiO(110) based on results from the companion paper to this study, with water exerting a greater influence in destabilizing acetone and acetone having only a nominal influence on water. Despite the repulsive interaction between these coadsorbates, about 0.02 ML of a 1 ML d6-acetone on the reduced surface exhibits H/D exchange with coadsorbed water, with the exchange occurring exclusively in the high temperature region of the d?-acetone TPD spectrum at ∼340 K. The effect was confirmed with combinations of d?-acetone and D?O. The extent of exchange decreased on the reduced surface with water coverages above ∼0.3 ML due to the ability of water to displace coadsorbed acetone from first layer sites to the multilayer. In contrast, the extent of exchange increased by a factor of 3 when the surface was pre-oxidized prior to coadsorption. In this case, there was no evidence for the negative influence of high water coverages on the extent of H/D exchange. Comparison of the TPD spectra from the exchange products (either d?- or d?-acetone depending on the coadsorption pairing) suggests that, in addition to the 340 K exchange process seen on the reduced surface, a second exchange process was observed on the oxidized surface at ∼390 K. In both cases (oxidized and reduced), desorption of the H/D exchange products appeared to be reaction limited and to involve the influence of OH/OD groups (or water formed during recombinative desorption of OH/OD groups) instead of molecularly adsorbed water. The 340 K exchange process is assigned to reaction at step sites and the 390 K exchange process is attributed to the influence of oxygen adatoms deposited during surface oxidation. The H/D exchange

  17. Comparison of HfCl{sub 4}, HfI{sub 4}, TEMA-Hf, and TDMA-Hf as precursors in early growing stages of HfO{sub 2} films deposited by ALD: A DFT study

    Energy Technology Data Exchange (ETDEWEB)

    Cortez-Valadez, M. [Departamento de Investigación en Física, Universidad de Sonora, Apdo. Postal 5-88, 83190 Hermosillo, Son. (Mexico); Fierro, C.; Farias-Mancilla, J.R. [Instituto de Ingeniería y Tecnología, Departamento de Física y Matemáticas, Universidad Autónoma de Ciudad Juárez, Av. del Charro 450, Cd. Juárez C.P. 32310, Chihuahua (Mexico); Vargas-Ortiz, A. [Universidad Autónoma de Sinaloa, Facultad de Ingeniería Mochis, Ciudad Universitaria, C.P. 81223 Los Mochis, Sinaloa (Mexico); Flores-Acosta, M. [Departamento de Investigación en Física, Universidad de Sonora, Apdo. Postal 5-88, 83190 Hermosillo, Son. (Mexico); Ramírez-Bon, R. [Centro de Investigación y Estudios Avanzados del IPN, Unidad Querétaro, Apdo. Postal 1-798, 76001 Querétaro, Qro. (Mexico); Enriquez-Carrejo, J.L. [Instituto de Ingeniería y Tecnología, Departamento de Física y Matemáticas, Universidad Autónoma de Ciudad Juárez, Av. del Charro 450, Cd. Juárez C.P. 32310, Chihuahua (Mexico); and others

    2016-06-15

    Highlights: • Hafnium oxide growth on Si(100) by atomic layer deposition was simulated. • The interface structure was considered as silicate and silicide. • The interface was studied employing DFT. • TDMA-Hf precursor show better interface stability. - Abstract: The final structure of HfO{sub 2} films grown by atomic layer deposition (ALD) after reaction with OH{sup −} ions has been analyzed by DFT (density functional theory). The interaction of the precursors: HfCl{sub 4} (hafnium tetrachloride), HfI{sub 4} (hafnium tetraiodide), TEMA-Hf (tetrakis-ethylmethylamino hafnium), and TDMA-Hf (tetrakis-dimethylamino hafnium) with HO–H was studied employing the B3LYP (Becke 3-parameter, Lee–Yang–Parr) hybrid functional and the PBE (Perdew–Burke–Ernzerhof) generalized gradient functional. The structural evolution at the Si(100) surface has been analyzed by LDA (local density approximation). The structural parameters: bond length and bond angle, and the vibrational parameters for the optimized structures are also reported. The presence of hafnium silicate at the interface was detected. The infrared spectra and structural parameters obtained in this work agree with previously reported experimental results.

  18. Chemical states and electronic structure of a HfO(-2)/Ge(001) interface

    International Nuclear Information System (INIS)

    Seo, Kang-ill; McIntyre, Paul C.; Stanford U., Materials Sci. Dept.; Sun, Shiyu; Lee, Dong-Ick; Pianetta, Piero; SLAC, SSRL; Saraswat, Krishna C.; Stanford U., Elect. Eng. Dept.

    2005-01-01

    We report the chemical bonding structure and valence band alignment at the HfO 2 /Ge (001) interface by systematically probing various core level spectra as well as valence band spectra using soft x-rays at the Stanford Synchrotron Radiation Laboratory. We investigated the chemical bonding changes as a function of depth through the dielectric stack by taking a series of synchrotron photoemission spectra as we etched through the HfO 2 film using a dilute HF-solution. We found that a very non-stoichiometric GeO x layer exists at the HfO 2 /Ge interface. The valence band spectra near the Fermi level in each different film structure were carefully analyzed, and as a result, the valence band offset between Ge and GeO x was determined to be ΔE v (Ge-GeO x ) = 2.2 ± 0.15 eV, and that between Ge and HfO 2 , ΔE v (Ge-HfO 2 ) = 2.7 ± 0.15 eV

  19. Role of WC additive on reaction, solid-solution and densification in HfB2–SiC ceramics

    DEFF Research Database (Denmark)

    Hu, Dong-Li; Zheng, Qiang; Gu, Hui

    2014-01-01

    A comparative study of phase components and compositions was performed for the pressureless sintered HfB2–SiC–WC composites by various analytical methods. The relative decrease of HfB2 phase leads to a new reaction of HfO2 removal by WC to create B2O3. By using SiC instead of Si3N4 as milling med...

  20. Acetone Formation in the Vibrio Family: a New Pathway for Bacterial Leucine Catabolism

    Science.gov (United States)

    Nemecek-Marshall, Michele; Wojciechowski, Cheryl; Wagner, William P.; Fall, Ray

    1999-01-01

    There is current interest in biological sources of acetone, a volatile organic compound that impacts atmospheric chemistry. Here, we determined that leucine-dependent acetone formation is widespread in the Vibrionaceae. Sixteen Vibrio isolates, two Listonella species, and two Photobacterium angustum isolates produced acetone in the presence of l-leucine. Shewanella isolates produced much less acetone. Growth of Vibrio splendidus and P. angustum in a fermentor with controlled aeration revealed that acetone was produced after a lag in late logarithmic or stationary phase of growth, depending on the medium, and was not derived from acetoacetate by nonenzymatic decarboxylation in the medium. l-Leucine, but not d-leucine, was converted to acetone with a stoichiometry of approximately 0.61 mol of acetone per mol of l-leucine. Testing various potential leucine catabolites as precursors of acetone showed that only α-ketoisocaproate was efficiently converted by whole cells to acetone. Acetone production was blocked by a nitrogen atmosphere but not by electron transport inhibitors, suggesting that an oxygen-dependent reaction is required for leucine catabolism. Metabolic labeling with deuterated (isopropyl-d7)-l-leucine revealed that the isopropyl carbons give rise to acetone with full retention of deuterium in each methyl group. These results suggest the operation of a new catabolic pathway for leucine in vibrios that is distinct from the 3-hydroxy-3-methylglutaryl-coenzyme A pathway seen in pseudomonads. PMID:10601206

  1. Apparatus and method for monitoring breath acetone and diabetic diagnostics

    Science.gov (United States)

    Duan, Yixiang [Los Alamos, NM; Cao, Wenqing [Los Alamos, NM

    2008-08-26

    An apparatus and method for monitoring diabetes through breath acetone detection and quantitation employs a microplasma source in combination with a spectrometer. The microplasma source provides sufficient energy to produce excited acetone fragments from the breath gas that emit light. The emitted light is sent to the spectrometer, which generates an emission spectrum that is used to detect and quantify acetone in the breath gas.

  2. High temperature X-ray diffraction studies on HfO2-Gd2O3 system

    International Nuclear Information System (INIS)

    Panneerselvam, G.; Antony, M.P.; Ananthasivan, K.; Joseph, M.

    2016-01-01

    High temperature X-ray diffraction (HTXRD) technique is an important experimental tool for measuring thermal expansion of materials of interest. A series of solid solutions containing GdO 1.5 in HfO 2 ,Hf 1-y Gd y )O 2 (y = 0.15, 0.2, 0.3, 0.41 and 0.505) were prepared by solid state method. Structural characterization and computation of lattice parameter was carried out by using room temperature X-ray diffraction measurements. The room temperature lattice parameter estimated for (Hf 1-y Gd y )O 2 (y=0.15, 0.2, 0.3, 0.41 and 0.505) are 0.51714 nm, 0.51929 nm, 0.52359nm, 0.52789nm and 0.53241 nm, respectively. Thermal expansion coefficients and percentage linear thermal expansion of the HfO 2 -Gd 2 O 3 solid solutions containing 20 and 41 mol% GdO 1.5 were determined using HTXRD in the temperature range 298 to 1673K. The mean linear thermal expansion coefficients of the solid solutions containing 20 and 41 mol. %Gd are 11.65 x 10 -6 K -1 and 12.07 x 10 -6 K -1 , respectively. (author)

  3. Laser-induced fluorescence imaging of acetone inside evaporating and burning fuel droplets

    Science.gov (United States)

    Shringi, D. S.; Shaw, B. D.; Dwyer, H. A.

    2009-01-01

    Laser-induced fluorescence was used to visualize acetone fields inside individual droplets of pure acetone as well as droplets composed of methanol or 1-propanol initially mixed with acetone. Droplets were supported on a horizontal wire and two vaporization conditions were investigated: (1) slow evaporation in room air and (2) droplet combustion, which leads to substantially faster droplet surface regression rates. Acetone was preferentially gasified, causing its concentration in droplets to drop in time with resultant decreases in acetone fluorescence intensities. Slowly vaporizing droplets did not exhibit large spatial variations of fluorescence within droplets, indicating that these droplets were relatively well mixed. Ignition of droplets led to significant variations in fluorescence intensities within droplets, indicating that these droplets were not well mixed. Ignited droplets composed of mixtures of 1-propanol and acetone showed large time-varying changes in shapes for higher acetone concentrations, suggesting that bubble formation was occurring in these droplets.

  4. An engineered non-oxidative glycolysis pathway for acetone production in Escherichia coli.

    Science.gov (United States)

    Yang, Xiaoyan; Yuan, Qianqian; Zheng, Yangyang; Ma, Hongwu; Chen, Tao; Zhao, Xueming

    2016-08-01

    To find new metabolic engineering strategies to improve the yield of acetone in Escherichia coli. Results of flux balance analysis from a modified Escherichia coli genome-scale metabolic network suggested that the introduction of a non-oxidative glycolysis (NOG) pathway would improve the theoretical acetone yield from 1 to 1.5 mol acetone/mol glucose. By inserting the fxpk gene encoding phosphoketolase from Bifidobacterium adolescentis into the genome, we constructed a NOG pathway in E.coli. The resulting strain produced 47 mM acetone from glucose under aerobic conditions in shake-flasks. The yield of acetone was improved from 0.38 to 0.47 mol acetone/mol glucose which is a significant over the parent strain. Guided by computational analysis of metabolic networks, we introduced a NOG pathway into E. coli and increased the yield of acetone, which demonstrates the importance of modeling analysis for the novel metabolic engineering strategies.

  5. Microhardness evaluation alloys Hf-Si-B; Avaliacao de microdureza de ligas Hf-Si-B

    Energy Technology Data Exchange (ETDEWEB)

    Gigolotti, Joao Carlos Janio; Costa, Eliane Fernandes Brasil [Centro Universitario de Volta Redonda (UNIFOA), Volta Redonda, RJ (Brazil); Nunes, Carlos Angelo; Rocha, Elisa Gombio; Coelho, Gilberto Carvalho, E-mail: carlosjanio@uol.com.br, E-mail: eliane-costabrasi@hotmail.com, E-mail: cnunes@demar.eel.usp.br, E-mail: elisarocha@alunos.eel.usp.br, E-mail: coelho@demar.eel.usp.br [Universidade de Sao Paulo (USP), Lorena, SP (Brazil)

    2014-08-15

    The technological advance has generated increasing demand for materials that can be used under high temperature, what includes intermetallic MR-Si-B (MR = refractory metal) alloys with multiphase structures, that can also be applied in oxide environments. Thus, this work had for objective the micro hardness study of the Hf-Si-B system alloys, heat treated at 1600 deg C, in the Hf rich region. Hf-Si-B alloys had been produced with blades of Hf (min. 99.8%), Si (min. 99.998%) and B (min. 99.5%), in the voltaic arc furnace and heat treated at 1600 deg C under argon atmosphere. The relationship of the phases had been previously identified by X-ray diffraction and contrast in backscattered electron imaging mode. The alloys had their hardness analyzed by method Vickers (micro hardness) with load of 0.05 kgf and 0.2 kgf and application time of 20 s. The results, obtained from the arithmetic mean of measurements for each alloy on the heterogeneous region, showed a mean hardness of 11.08 GPA, with small coefficient of variation of 3.8%. The borides HfB2 (19.34 GPa) e HfB - 11.76 GPa, showed the hardness higher than the silicides Hf2Si (8.57 GPa), Hf5Si3 (9.63 GPa), Hf3Si2 (11.66 GPa), Hf5Si4 (10.00 GPa), HfSi (10.02 GPa) e HfSi2 (8.61 GPa). (author)

  6. Acetone production with metabolically engineered strains of Acetobacterium woodii.

    Science.gov (United States)

    Hoffmeister, Sabrina; Gerdom, Marzena; Bengelsdorf, Frank R; Linder, Sonja; Flüchter, Sebastian; Öztürk, Hatice; Blümke, Wilfried; May, Antje; Fischer, Ralf-Jörg; Bahl, Hubert; Dürre, Peter

    2016-07-01

    Expected depletion of oil and fossil resources urges the development of new alternative routes for the production of bulk chemicals and fuels beyond petroleum resources. In this study, the clostridial acetone pathway was used for the formation of acetone in the acetogenic bacterium Acetobacterium woodii. The acetone production operon (APO) containing the genes thlA (encoding thiolase A), ctfA/ctfB (encoding CoA transferase), and adc (encoding acetoacetate decarboxylase) from Clostridium acetobutylicum were cloned under the control of the thlA promoter into four vectors having different replicons for Gram-positives (pIP404, pBP1, pCB102, and pCD6). Stable replication was observed for all constructs. A. woodii [pJIR_actthlA] achieved the maximal acetone concentration under autotrophic conditions (15.2±3.4mM). Promoter sequences of the genes ackA from A. woodii and pta-ack from C. ljungdahlii were determined by primer extension (PEX) and cloned upstream of the APO. The highest acetone production in recombinant A. woodii cells was achieved using the promoters PthlA and Ppta-ack. Batch fermentations using A. woodii [pMTL84151_actthlA] in a bioreactor revealed that acetate concentration had an effect on the acetone production, due to the high Km value of the CoA transferase. In order to establish consistent acetate concentration within the bioreactor and to increase biomass, a continuous fermentation process for A. woodii was developed. Thus, acetone productivity of the strain A. woodii [pMTL84151_actthlA] was increased from 1.2mgL(-1)h(-1) in bottle fermentation to 26.4mgL(-1)h(-1) in continuous gas fermentation. Copyright © 2016 International Metabolic Engineering Society. Published by Elsevier Inc. All rights reserved.

  7. Breath acetone monitoring by portable Si:WO3 gas sensors

    International Nuclear Information System (INIS)

    Righettoni, Marco; Tricoli, Antonio; Gass, Samuel; Schmid, Alex; Amann, Anton; Pratsinis, Sotiris E.

    2012-01-01

    Highlights: ► Portable sensors were developed and tested for monitoring acetone in the human breath. ► Acetone concentrations down to 20 ppb were measured with short response times ( 3 nanostructured films was developed. The chamber volume was miniaturized while reaction-limited and transport-limited gas flow rates were identified and sensing temperatures were optimized resulting in a low detection limit of acetone (∼20 ppb) with short response (10–15 s) and recovery times (35–70 s). Furthermore, the sensor signal (response) was robust against variations of the exhaled breath flow rate facilitating application of these sensors at realistic relative humidities (80–90%) as in the human breath. The acetone content in the breath of test persons was monitored continuously and compared to that of state-of-the-art proton transfer reaction mass spectrometry (PTR-MS). Such portable devices can accurately track breath acetone concentration to become an alternative to more elaborate breath analysis techniques.

  8. Thermodynamic modeling of the Co–Hf system supported by key experiments and first-principles calculations

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Xingxu [School of Materials Science and Engineering, Central South University, Changsha, Hunan 410083 (China); State Key Laboratory of Powder Metallurgy, Central South University, Changsha, Hunan 410083 (China); Liu, Shuhong, E-mail: shhliu@csu.edu.cn [State Key Laboratory of Powder Metallurgy, Central South University, Changsha, Hunan 410083 (China); Sino-German Cooperation Group “Microstructure in Al alloys”, Central South University, Changsha, Hunan 410083 (China); Cheng, Kaiming; Tang, Ying [State Key Laboratory of Powder Metallurgy, Central South University, Changsha, Hunan 410083 (China); Ou, Pengfei [School of Materials Science and Engineering, Central South University, Changsha, Hunan 410083 (China); State Key Laboratory of Powder Metallurgy, Central South University, Changsha, Hunan 410083 (China); Nash, Philip [Thermal Processing Technology Center, Illinois Institute of Technology (IIT), 10 West 32nd Street, Chicago, IL 60616 (United States); Sundman, Bo [INSTN, CEA Saclay, 91191 Gif-Sur-Yvette Cedex (France); Du, Yong [State Key Laboratory of Powder Metallurgy, Central South University, Changsha, Hunan 410083 (China); Sino-German Cooperation Group “Microstructure in Al alloys”, Central South University, Changsha, Hunan 410083 (China); Zheng, Feng [School of Materials Science and Engineering, Central South University, Changsha, Hunan 410083 (China)

    2015-05-20

    Highlights: • Heat contents of Co{sub 2}Hf and CoHf{sub 2} were measured by drop calorimetry. • Enthalpy of formation for Co{sub 23}Hf{sub 6} was computed via first-principles calculations. • Co–Hf system was assessed by means of CALPHAD approach. • Order–disorder model is used to describe B2 (CoHf) and A2 (βHf). • Glass forming range of the Co–Hf amorphous alloys was predicted. - Abstract: Phase equilibria and thermodynamic properties of the Co–Hf system were investigated via calorimetric measurements, first-principles calculations and thermodynamic modeling. Heat contents of Co{sub 2}Hf and CoHf{sub 2} were measured by drop calorimetry from 300 to 1200 °C. The enthalpy of formation for Co{sub 23}Hf{sub 6} at 0 K was computed via first-principles calculations. Based on the experimental measurements and first-principles calculations from the present work and the literature, the Co–Hf system was assessed by means of CALPHAD (CALculation of PHAse Diagram) approach. The excess Gibbs energy of solution phases was modeled with Redlich–Kister polynomial. Sublattice models were employed to describe the homogeneity ranges of Co{sub 2}Hf, CoHf and CoHf{sub 2}. The order–disorder transition between B2 (CoHf) and A2 (βHf) phases was taken into account in the current optimization. Using the optimized parameters, glass forming range (GFR) of the Co–Hf amorphous alloys was predicted to be 15–75 at.% Hf, which is in satisfactory agreement with the experimental observation.

  9. Quantitative Clinical Diagnostic Analysis of Acetone in Human Blood by HPLC: A Metabolomic Search for Acetone as Indicator

    OpenAIRE

    Akgul Kalkan, Esin; Sahiner, Mehtap; Ulker Cakir, Dilek; Alpaslan, Duygu; Yilmaz, Selehattin

    2016-01-01

    Using high-performance liquid chromatography (HPLC) and 2,4-dinitrophenylhydrazine (2,4-DNPH) as a derivatizing reagent, an analytical method was developed for the quantitative determination of acetone in human blood. The determination was carried out at 365?nm using an ultraviolet-visible (UV-Vis) diode array detector (DAD). For acetone as its 2,4-dinitrophenylhydrazone derivative, a good separation was achieved with a ThermoAcclaim C18 column (15?cm ? 4.6?mm ? 3??m) at retention time (t R) ...

  10. Thermal evolution of CaO-doped HfO{sub 2} films and powders

    Energy Technology Data Exchange (ETDEWEB)

    Barolin, S A; Sanctis, O A de [Lab. Materiales Ceramicos, FCEIyA, Universidad Nacional de Rosario, IFIR-CONICET (Argentina); Caracoche, M C; Martinez, J A; Taylor, M A; Pasquevich, A F [Departamento de Fisica, FCE, Universidad Nacional de La Plata, IFLP-CONICET (Argentina); Rivas, P C, E-mail: oski@fceia.unr.edu.a [Facultad de Ciencias Agronomicas y Forestales, Universidad Nacional de La Plata, IFLP (Argentina)

    2009-05-01

    Solid solutions of ZrO2 and HfO2 are potential electrolyte materials for intermediate-temperature SOFC because both are oxygen-ion conductors. The main challenge for these compounds is to reduce the relatively high value of the activation energies vacancies diffusion, which is influenced by several factors. In this work the thermal evolution of CaO-HfO{sub 2} materials have been investigated. (CaO)y-Hf(1-y)O(2-y) (y = 0.06, 0.14 y 0.2) coatings and powders were synthesized by chemical solution deposition (CSD). Films were deposited onto alumina substrates by Dip Coating technique, the burning of organic waste was carried out at 500 deg. C under normal atmosphere and then the films were thermally treated at intervals of temperature rising to a maximum temperature of 1250 deg. C. By means Glazing Incidence X-ray Diffraction (rho-2theta configuration) the phases were studied in the annealed films. On the other hand, the thermal evolution and crystallization process of powders were analyzed in-situ by HT-XRD. The phenomena crystallization occurred in films and powders were analyzed. The activation energies of diffusion of oxygen vacancies of HfO2-14 mole% CaO and HfO2-20 mole% CaO films were measured from the thermal evolution of the relaxation constant measured by Perturbed Angular Correlation Technique.

  11. Heat and mass transfer at adiabatic evaporation of binary zeotropic solutions

    Science.gov (United States)

    Makarov, M. S.; Makarova, S. N.

    2016-01-01

    Results of numerical simulation of heat and mass transfer in a laminar flow of three-component gas at adiabatic evaporation of binary solutions from a flat plate are presented. The studies were carried out for the perfect solution of ethanol/methanol and zeotrope solutions of water/acetone, benzene/acetone, and ethanol/acetone. The liquid-vapor equilibrium is described by the Raoult law for the ideal solution and Carlson-Colburn model for real solutions. The effect of gas temperature and liquid composition on the heat and diffusion flows, and temperature of vapor-gas mixture at the interface is analyzed. The formula for calculating the temperature of the evaporation surface for the binary liquid mixtures using the similarity of heat and mass transfer was proposed. Data of numerical simulations are in a good agreement with the results of calculations based on the proposed dependence for all examined liquid mixtures in the considered range of temperatures and pressures.

  12. A cross-sectional study of breath acetone based on diabetic metabolic disorders.

    Science.gov (United States)

    Li, Wenwen; Liu, Yong; Lu, Xiaoyong; Huang, Yanping; Liu, Yu; Cheng, Shouquan; Duan, Yixiang

    2015-02-26

    Breath acetone is a known biomarker for diabetes mellitus in breath analysis. In this work, a cross-sectional study of breath acetone based on clinical metabolic disorders of type 2 diabetes mellitus (T2DM) was carried out. Breath acetone concentrations of 113 T2DM patients and 56 apparently healthy individuals were measured at a single time point. Concentrations varied from 0.22 to 9.41 ppmv (mean 1.75 ppmv) for T2DM, which were significantly higher than those for normal controls (ranged from 0.32 to 1.96 ppmv, mean 0.72 ppmv, p = 0.008). Observations in our work revealed that breath acetone concentrations elevated to different degrees, along with the abnormality of blood glucose, glycated hemoglobin (HbA1c), triglyceride and cholesterol. Breath acetone showed obviously positive correlations with blood ketone and urine ketone. Possible metabolic relations between breath acetone and diabetic disorders were also discussed. This work aimed at giving an overall assessment of breath acetone from the perspective of clinical parameters for type 2 diabetes.

  13. Treatment of acetone waste gases using slurry-phase airlift embedded with polyacrylamide-entrapped cell beads.

    Science.gov (United States)

    Hwang, Sz-Chwun John; Lin, Yun-Huin; Huang, Ku Shu; Lyuu, Jyuhn-Yih; Hou, Cheng-Ting; Chen, Hsin-Hua; He, Sin-Yi

    2009-10-01

    Acetone is the most common chemical used in the Hsin-chu Science Park in Taiwan. The three-phase airlift bioreactor was designed to absorb acetone into the 39 L of medium solution and then degraded by 2-L polyacrylamide (PAA)-entrapped Thiosphaera pantotropha cell beads. The airlift medium was successfully regenerated and circulated for more than 5 months. The elimination capacity of 350-part per million (ppm) acetone at 10 L x min(-1) was 258.4 g x m(-3) hr(-1) (160.4 g-C x m(-3) hr(-1)) with 100% removal efficiency in Stage II, higher than previously reported biofiltration results. The maximum chemical oxygen demand:nitrogen ratio of 100:2.9 is achieved, and a balanced nutrient state was indicated by the change in redox potential. The pH of the system was maintained at neutral because of the strong buffer agent added to the medium (final buffer intensity, beta = 1.18 x 10(-2) M). The PAA-entrapped cell beads could also provide a good barrier for high salinity gradient environment and the inoculum source to maintain steady operation of the system.

  14. Proteomic analysis of nitrate-dependent acetone degradation by Alicycliphilus denitrificans strain BC

    NARCIS (Netherlands)

    Oosterkamp, M.J.; Boeren, S.; Atashgahi, S.; Plugge, C.M.; Schaap, P.J.; Stams, A.J.M.

    2015-01-01

    Alicycliphilus denitrificans strain BC grows anaerobically on acetone with nitrate as electron acceptor. Comparative proteomics of cultures of A. denitrificans strain BC grown on either acetone or acetate with nitrate was performed to study the enzymes involved in the acetone degradation pathway. In

  15. Catalytic function of the mycobacterial binuclear iron monooxygenase in acetone metabolism.

    Science.gov (United States)

    Furuya, Toshiki; Nakao, Tomomi; Kino, Kuniki

    2015-10-01

    Mycobacteria such as Mycobacterium smegmatis strain mc(2)155 and Mycobacterium goodii strain 12523 are able to grow on acetone and use it as a source of carbon and energy. We previously demonstrated by gene deletion analysis that the mimABCD gene cluster, which encodes a binuclear iron monooxygenase, plays an essential role in acetone metabolism in these mycobacteria. In the present study, we determined the catalytic function of MimABCD in acetone metabolism. Whole-cell assays were performed using Escherichia coli cells expressing the MimABCD complex. When the recombinant E. coli cells were incubated with acetone, a product was detected by gas chromatography (GC) analysis. Based on the retention time and the gas chromatography-mass spectrometry (GC-MS) spectrum, the reaction product was identified as acetol (hydroxyacetone). The recombinant E. coli cells produced 1.02 mM of acetol from acetone within 24 h. Furthermore, we demonstrated that MimABCD also was able to convert methylethylketone (2-butanone) to 1-hydroxy-2-butanone. Although it has long been known that microorganisms such as mycobacteria metabolize acetone via acetol, this study provides the first biochemical evidence for the existence of a microbial enzyme that catalyses the conversion of acetone to acetol. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  16. Adsorption and Reaction of Acetone over CeOX(111) Thin Films

    International Nuclear Information System (INIS)

    Mullins, David R.; Senanayake, Sanjaya D.; Gordon, Wesley O.; Overbury, Steven H.

    2009-01-01

    This study reports the interaction of acetone (CH3COCH3), the simplest ketone, with well ordered CeO2(111) thin film surfaces. The fully oxidized CeO2(111) surface shows a weak interaction with acetone with the sole desorption product (TPD) being acetone at 210 K. The chemisorbed molecule binds to the surface as the ?1-acetone species rather than through a bridge-bonded dioxy-configuration. Exposure of a CeO2(111) surface to acetone at 600K removes oxygen as CO and results in the conversion of Ce4+ to Ce3+. Acetone chemisorbs strongly on reduced CeO2-x(111) with molecular acetone desorbing near 500 K. Decomposition also occurs with H2 desorbing between 450 and 600 K and C reacting with O in the ceria to desorb above 650 K. A stable species exists from 200 to 500 K on the reduced surface that has three unique types of C. High resolution C 1s XPS spectra indicate these are Ce-CH2, C-CH3 and C-O species. C k-edge NEXAFS indicates the presence of C(double b ond)C and C(double b ond)O bonds. It is postulated that the intermediate is a carbanion bonded through both O and C atoms to Ce cations.

  17. Delayed fluorescence of meso-tetraphenylporphyrin in acetone and in dimethylsulphoxide

    International Nuclear Information System (INIS)

    Korinek, M.; Klinger, P.; Dedic, R.; Psencik, J.; Svoboda, A.; Hala, J.

    2007-01-01

    Photodynamic therapy is based on photosensitisation of singlet oxygen by porphyrin-like molecules. We have performed a systematic study of delayed fluorescence of tetraphenylporphyrin in acetone (used as a spectroscopic standard) and in dimethylsulphoxide (clinically used solvent) to obtain spectra, kinetics, and quantum yields, including their dependencies on tetraphenylporphyrin concentration. In dimethylsulphoxide the repopulation of excited singlets and subsequent delayed fluorescence is caused by triplet-triplet quenching with rate constant of (2.2±1.0)x10 9 l mol -1 s -1 . However, repopulation of excited singlets in acetone is also caused by singlet oxygen reaction with triplet tetraphenylporphyrin causing monoexponential delayed fluorescence decay with the lifetime 0.3 μs. Due to much lower viscosity of acetone compared to dimethylsulphoxide, triplet-triplet quenching constant in acetone is much higher (1.7±0.7)x10 10 l mol -1 s -1 . The rate constant for the reaction of singlet oxygen with triplet of tetraphenylporphyrin is (2.0±0.8)x10 10 l mol -1 s -1 in acetone

  18. HF/DF chemical labs

    International Nuclear Information System (INIS)

    Meinzer, R.A.

    1987-01-01

    This paper provides the essential details to understand and design HF/DF and related types of chemical lasers. The basic operation of the HF/DF chemical laser is described. The details of the excitation chemistry are presented and the pertinent laser physics is described. A description of the various laser components is given and the analytical models for the HF/DF chemical laser are discussed. A brief description of the chain reaction HF/DF chemical laser is offered

  19. HF laser

    International Nuclear Information System (INIS)

    Suzuki, Kazuya; Iwasaki, Matae

    1977-01-01

    A review is made of the research and development of HF chemical laser and its related work. Many gaseous compounds are used as laser media successfully; reaction kinetics and technological problems are described. The hybrid chemical laser of HF-CO 2 system and the topics related to the isotope separation are also included. (auth.)

  20. Novel Acetone Metabolism in a Propane-Utilizing Bacterium, Gordonia sp. Strain TY-5▿

    Science.gov (United States)

    Kotani, Tetsuya; Yurimoto, Hiroya; Kato, Nobuo; Sakai, Yasuyoshi

    2007-01-01

    In the propane-utilizing bacterium Gordonia sp. strain TY-5, propane was shown to be oxidized to 2-propanol and then further oxidized to acetone. In this study, the subsequent metabolism of acetone was studied. Acetone-induced proteins were found in extracts of cells induced by acetone, and a gene cluster designated acmAB was cloned on the basis of the N-terminal amino acid sequences of acetone-induced proteins. The acmA and acmB genes encode a Baeyer-Villiger monooxygenase (BVMO) and esterase, respectively. The BVMO encoded by acmA was purified from acetone-induced cells of Gordonia sp. strain TY-5 and characterized. The BVMO exhibited NADPH-dependent oxidation activity for linear ketones (C3 to C10) and cyclic ketones (C4 to C8). Escherichia coli expressing the acmA gene oxidized acetone to methyl acetate, and E. coli expressing the acmB gene hydrolyzed methyl acetate. Northern blot analyses revealed that polycistronic transcription of the acmAB gene cluster was induced by propane, 2-propanol, and acetone. These results indicate that the acmAB gene products play an important role in the metabolism of acetone derived from propane oxidation and clarify the propane metabolism pathway of strain TY-5 (propane → 2-propanol → acetone → methyl acetate → acetic acid + methanol). This paper provides the first evidence for BVMO-dependent acetone metabolism. PMID:17071761

  1. Protein precipitation of diluted samples in SDS-containing buffer with acetone leads to higher protein recovery and reproducibility in comparison with TCA/acetone approach.

    Science.gov (United States)

    Santa, Cátia; Anjo, Sandra I; Manadas, Bruno

    2016-07-01

    Proteomic approaches are extremely valuable in many fields of research, where mass spectrometry methods have gained an increasing interest, especially because of the ability to perform quantitative analysis. Nonetheless, sample preparation prior to mass spectrometry analysis is of the utmost importance. In this work, two protein precipitation approaches, widely used for cleaning and concentrating protein samples, were tested and compared in very diluted samples solubilized in a strong buffer (containing SDS). The amount of protein recovered after acetone and TCA/acetone precipitation was assessed, as well as the protein identification and relative quantification by SWATH-MS yields were compared with the results from the same sample without precipitation. From this study, it was possible to conclude that in the case of diluted samples in denaturing buffers, the use of cold acetone as precipitation protocol is more favourable than the use of TCA/acetone in terms of reproducibility in protein recovery and number of identified and quantified proteins. Furthermore, the reproducibility in relative quantification of the proteins is even higher in samples precipitated with acetone compared with the original sample. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Electrolytically exfoliated graphene-loaded flame-made Ni-doped SnO2 composite film for acetone sensing.

    Science.gov (United States)

    Singkammo, Suparat; Wisitsoraat, Anurat; Sriprachuabwong, Chakrit; Tuantranont, Adisorn; Phanichphant, Sukon; Liewhiran, Chaikarn

    2015-02-11

    In this work, flame-spray-made SnO2 nanoparticles are systematically studied by doping with 0.1-2 wt % nickel (Ni) and loading with 0.1-5 wt % electrolytically exfoliated graphene for acetone-sensing applications. The sensing films (∼12-18 μm in thickness) were prepared by a spin-coating technique on Au/Al2O3 substrates and evaluated for acetone-sensing performances at operating temperatures ranging from 150 to 350 °C in dry air. Characterizations by X-ray diffraction, transmission/scanning electron microscopy, Brunauer-Emmett-Teller analysis, X-ray photoelectron spectroscopy and Raman spectroscopy demonstrated that Ni-doped SnO2 nanostructures had a spheriodal morphology with a polycrystalline tetragonal SnO2 phase, and Ni was confirmed to form a solid solution with SnO2 lattice while graphene in the sensing film after annealing and testing still retained its high-quality nonoxidized form. Gas-sensing results showed that SnO2 sensing film with 0.1 wt % Ni-doping concentration exhibited an optimal response of 54.2 and a short response time of ∼13 s toward 200 ppm acetone at an optimal operating temperature of 350 °C. The additional loading of graphene at 5 wt % into 0.1 wt % Ni-doped SnO2 led to a drastic response enhancement to 169.7 with a very short response time of ∼5.4 s at 200 ppm acetone and 350 °C. The superior gas sensing performances of Ni-doped SnO2 nanoparticles loaded with graphene may be attributed to the large specific surface area of the composite structure, specifically the high interaction rate between acetone vapor and graphene-Ni-doped SnO2 nanoparticles interfaces and high electronic conductivity of graphene. Therefore, the 5 wt % graphene loaded 0.1 wt % Ni-doped SnO2 sensor is a promising candidate for fast, sensitive and selective detection of acetone.

  3. Monitoring the Aggregation of Dansyl Chloride in Acetone through Fluorescence Measurements

    Institute of Scientific and Technical Information of China (English)

    FANG,Yu; YIN,Yi-Qing; 等

    2002-01-01

    The aggregation of dansyl chloride (DNS-Cl) in acetone has been studied in detail by steady-state fluorescence techniques.It has been demonstrated that DNS-Cl is stable in acetone during purification and aggregation study processes.The aggregates are not solvolyzed in acetone,and do not take part n any chemical reactions either.It has been found that DNS-Cl tends to aggregate even when its concentration is much lower than its solubility in acetone.The aggregation is reversible,and both the aggregation and the deaggregation are very slow processes.Introduction of SDS has a positive effect upon the formation and stabilization of the aggregates.

  4. Monitoring the Aggregation of Dansyl Chloride in Acetone through Fluorescence Measurements

    Institute of Scientific and Technical Information of China (English)

    FANG,Yu(房喻); YIN,Yi-Qing(尹艺青); HU,Dao-Dao(胡道道); GAO,Gai-Ling(高改玲)

    2002-01-01

    The aggregation of dansyl chloride (DNS-Cl) in acetone has been studied in detail by steady-state fluorescence techniques. It has been demonstrated that DNS-Cl is stable in acetone during purification and aggregation study processes. The aggregates are not solvolyzed in acetone, and do not take part in any chemical reactions either. It has been found that DNS-Cl tends to aggregate even when its concentration is much lower than its solubility in acetone. The aggregation is reversible, and both the aggregation and the deaggregation are very slow processes.Introduction of SDS has a positive effect upon the formation and stabilization of the aggregates.

  5. Antibacterial Activities and Mechanism of Action of Acetone Extracts from Rabdosia rubescens

    Directory of Open Access Journals (Sweden)

    Li Ping Cheng

    2014-12-01

    Full Text Available The antibacterial activities and mechanism of action of acetone extracts from R. rubescens were reported in this paper. The results showed that 80% acetone extracts had both the highest contents of total phenolics and flavonoids. Acetone extracts showed better antibacterial activities against Gram-positive bacterial strains and there were no inhibitory effects found on tested Gram-negative bacteria. In addition, 80% acetone extracts from R. rubescens had relatively higher antibacterial activities with the lowest values of MIC and MBC at 2.5 mg/mL and 5 mg/mL against B. subtilis. The antibacterial mechanism of 80% acetone extracts against Bacillus subtilis might be described as disrupting cell wall, increasing cell membrane permeability, and finally leading to the leakage of cell constituents

  6. Thermodynamic study of the solubility of ibuprofen in acetone and dichloromethane

    Directory of Open Access Journals (Sweden)

    Diana Marcela Aragón

    2010-06-01

    Full Text Available Thermodynamic functions, Gibbs energy, enthalpy and entropy for the solution processes of ibuprofen (IBP in acetone and dichloromethane (DCM were calculated from solubility values obtained at temperatures ranging from 293.15 K to 313.15 K. The respective thermodynamic functions for mixing and solvation processes as well as the activity coefficients for the solute were calculated. IBP solubility was high and proved similar in both solvents but was greater in DCM than acetone. In addition, the thermodynamic quantities for the transfer process of this drug from cyclohexane to the organic solvents were also calculated in order to estimate the contributions of hydrogen-bonds or of other dipolar interactions. The results were discussed in terms of solute-solvent interactions.As funções termodinâmicas, energia de Gibbs, entalpia e entropia dos processos de solução de ibuprofeno (IBP em acetona e em diclorometano (DCM foram calculadas a partir dos valores de solubilidade, obtidos em intervalos de temperatura de 293,15 K a 313,15 K. As funções termodinâmicas respectivas para os processos de mistura e solvatação e os coeficientes de atividade para o soluto também foram calculados. A solubilidade do IBP foi grande e semelhante em ambos os solventes, mas, maior em DCM do que em acetona. Em adição, as quantidades termodinâmicas relativas ao processo de transferência desse fármaco do cicloexano para os solventes orgânicos foram, também, calculadas com o objetivo de estimar as contribuições devidas às ligações de hidrogênio ou a outras interações dipolares. Os resultados foram discutidos nos termos das interações soluto-solvente.

  7. IR spectra and properties of solid acetone, an interstellar and cometary molecule

    Science.gov (United States)

    Hudson, Reggie L.; Gerakines, Perry A.; Ferrante, Robert F.

    2018-03-01

    Mid-infrared spectra of amorphous and crystalline acetone are presented along with measurements of the refractive index and density for both forms of the compound. Infrared band strengths are reported for the first time for amorphous and crystalline acetone, along with IR optical constants. Vapor pressures and a sublimation enthalpy for crystalline acetone also are reported. Positions of 13C-labeled acetone are measured. Band strengths are compared to gas-phase values and to the results of a density-functional calculation. A 73% error in previous work is identified and corrected.

  8. Heat transfer performance of a pulsating heat pipe charged with acetone-based mixtures

    Science.gov (United States)

    Wang, Wenqing; Cui, Xiaoyu; Zhu, Yue

    2017-06-01

    Pulsating heat pipes (PHPs) are used as high efficiency heat exchangers, and the selection of working fluids in PHPs has a great impact on the heat transfer performance. This study investigates the thermal resistance characteristics of the PHP charged with acetone-based binary mixtures, where deionized water, methanol and ethanol were added to and mixed with acetone, respectively. The volume mixing ratios were 2:1, 4:1 and 7:1, and the heating power ranged from 10 to 100 W with filling ratios of 45, 55, 62 and 70%. At a low filling ratio (45%), the zeotropic characteristics of the binary mixtures have an influence on the heat transfer performance of the PHP. Adding water, which has a substantially different boiling point compared with that of acetone, can significantly improve the anti-dry-out ability inside the PHP. At a medium filling ratio (55%), the heat transfer performance of the PHP is affected by both phase transition characteristics and physical properties of working fluids. At high heating power, the thermal resistance of the PHP with acetone-water mixture is between that with pure acetone and pure water, whereas the thermal resistance of the PHP with acetone-methanol and acetone-ethanol mixtures at mixing ratios of 2:1 and 4:1 is less than that with the corresponding pure fluids. At high filling ratios (62 and 70%), the heat transfer performance of the PHP is mainly determined by the properties of working fluids that affects the flow resistance. Thus, the PHP with acetone-methanol and acetone-ethanol mixtures that have a lower flow resistance shows better heat transfer performance than that with acetone-water mixture.

  9. Pathological effects of acetone cyanohydrin in swiss rats

    Directory of Open Access Journals (Sweden)

    Marcos Natal Rufino

    Full Text Available ABSTRACT Cassava has been widely used for animal and human nutrition. It has also been demonstrated to have antineoplastic and anthelmintic properties. Toxicity due to cassava consumption has been reported in ruminants and laboratory animals; therefore, this study aimed to investigate the toxic effects of acetone cyanohydrin, a metabolite of linamarin that is present in cassava, in Wistar rats. Six groups of five animals each were used to evaluate the toxic effects of acetone cyanohydrin administered at 25 (G1, 50 (G2, 75 (G3, 100 (G4 and 125 (G5 µmol/kg as a single oral dose. The control group received acidified water (pH 3.5. The animals were monitored after administration of acetone cyanohydrin, and clinical symptoms were recorded. Serum enzyme levels were measured to assess the kidney and liver function. During necropsy, tissue samples were collected for histopathological examination. After administration, some animals in the G2, G4, and G5 groups presented neurological symptoms such as convulsions, involuntary muscle contraction, staggering gait, motor coordination disability, prostration, and mydriasis. All of the animals in the G5 and four animals in the G4 group died seven minutes after the administration of acetone cyanohydrin. Animals in the other groups, particularly in G2, recovered from the acute phase. Biochemical analysis revealed hepatic lesions and liver dysfunction. Histopathology revealed severe lesions in both the liver and brain. In conclusion, acetone cyanohydrin has toxic effects in the liver, lung, and central nervous system in rats; however, at concentrations up to 25 µmol/kg, the animals could survive the acute phase.

  10. HF-laser program

    International Nuclear Information System (INIS)

    Anon.

    1978-01-01

    Sandia's HF-laser program for FY 77 and FY 78 was revised in June 1977 in order to meet several new program milestones. Research progress is reported on: objective of HF oscillator-amplifier studies using H 2 -F 2 gas mixtures; characteristics of large-volume oscillator using H 2 -F 2 mixtures; characteristics of large-volume amplifier using H 2 -F 2 mixtures; experimental results of the oscillator-amplifier study; objective of high-quality discharge-initiated SF 6 -HI oscillator-preamplifier system; pin-discharge-initiated oscillator and first beam expander; fast-discharge-initiated preamplifiers; reflecting beam expanders for oscillator-preamplifier system; beam quality of discharge-initiated oscillator-preamplifier system; short pulse option for discharge initiated SF 6 -HI system; H 2 -F 2 electron-beam-initiated oscillator-preamplifier system; chamber for HF-laser focusing experiments; computer study of parasitic oscillations in HF amplifiers and oscillators; kinetics upgrade of HF-laser code; repetitivey ignited flowing H 2 -F 2 -O 2 mixtures; spontaneous detonations in multiatmosphere H 2 -F 2 -O 2 mixtures; high-pressure H 2 -F 2 laser studies; and time sequenced energy extraction on the high xenon laser

  11. High-aspect-ratio HfC nanobelts accompanied by HfC nanowires: Synthesis, characterization and field emission properties

    Energy Technology Data Exchange (ETDEWEB)

    Tian, Song, E-mail: tiansong22@126.com [State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi’an 710072 (China); School of Materials Science and Engineering, Chongqing Jiaotong University, Chongqing 400074 (China); Zhang, Yulei; Ren, Jincui; Qiang, Xinfa; Zhang, Shouyang [State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi’an 710072 (China); Li, Hejun, E-mail: lihejun@nwpu.edu.cn [State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi’an 710072 (China)

    2017-04-30

    Highlights: • HfC naobelts accompanied by HfC nanowires were synthesized by a catalytic CVD method. • HfC nanobelts as a novel structure of HfC ceramic are reported for the first time. • HfC nanobelts have 100–200 μm in lengths and reach up to 10 μm in widths. • The synthesized product is promising field nanoemitters. - Abstract: As a key refractory carbide, hafnium carbide (HfC) is commonly used as structural materials while the field emission (FE) application of HfC in the field of vacuum microelectronics is almost the only one for functional material purposes. Based on its outstanding physical and chemical characteristics, HfC is identified as a potential candidate with satisfactory mechanical properties and long-term and/or high-temperature FE stability for future applications in high-performance field emitters. However, the development of HfC in various FE applications is hindered because it is not facile to fabricate large-scale low-dimensional HfC field nanoemitters. Herein, High-aspect-ratio HfC nanobelts accompanied by HfC nanowires were synthesized on a large scale by a traditional and simple catalytic chemical vapor deposition (CVD) method. Classical vapor–liquid–solid (VLS) theory was employed to explain the growth of the HfC nanowires and nanobelts along axial direction. The thin HfO{sub 2} shell and thin C layer surrounding the nanostructures might give rise to the diameter fluctuation of HfC nanowires and the width increase of HfC nanobelts in lateral direction. Field emission results show that the high-aspect-ratio HfC nanobelts accompanied by the nanowires are promising field nanoemitters, which exhibit excellent field emission properties with a fairly low turn-on field of ∼1.5 V μm{sup −1} and a low current fluctuation less than ∼10%. This suggests that HfC ceramics with high-aspect-ratio nanostructures are ideal cathode material for various field emission applications.

  12. Evidence for an Inducible Nucleotide-Dependent Acetone Carboxylase in Rhodococcus rhodochrous B276

    OpenAIRE

    Clark, Daniel D.; Ensign, Scott A.

    1999-01-01

    The metabolism of acetone was investigated in the actinomycete Rhodococcus rhodochrous (formerly Nocardia corallina) B276. Suspensions of acetone- and isopropanol-grown R. rhodochrous readily metabolized acetone. In contrast, R. rhodochrous cells cultured with glucose as the carbon source lacked the ability to metabolize acetone at the onset of the assay but gained the ability to do so in a time-dependent fashion. Chloramphenicol and rifampin prevented the time-dependent increase in this acti...

  13. Determination of the rate of HF hydration and the effects of HF on moisture condensation

    International Nuclear Information System (INIS)

    McCulla, W.H.

    1982-01-01

    There were four basic questions addressed in this report that relate to the HF interaction in the environment. As to whether HF hydrates in the vapor phase and what the rate of that hydration is, there seems ample evidence that HF hydrates readily in the vapor phase and the rate of that hydration is very fast, i.e., dHF/dt greater than or equal to 25 torr sec -1 . Concerning under what conditions condensation of the hydrate will occur and whether a third body is required for condensation, it was found that HF does effect the dew point or condensation of water and data was presented indicating the extent of that effect. It was also determined that condensation will occur without a third body present. Thus, in attempting to model an HF release for the Safety Analysis Report the hydration of HF and the subsequent heat released may be treated as occurring instantaneously; but the ultimate disposition of the HF will be strongly dependent upon the environmental conditions at the time of the release

  14. Determination of the rate of HF hydration and the effects of HF on moisture condensation

    Energy Technology Data Exchange (ETDEWEB)

    McCulla, W H

    1982-04-30

    There were four basic questions addressed in this report that relate to the HF interaction in the environment. As to whether HF hydrates in the vapor phase and what the rate of that hydration is, there seems ample evidence that HF hydrates readily in the vapor phase and the rate of that hydration is very fast, i.e., dHF/dt greater than or equal to 25 torr sec/sup -1/. Concerning under what conditions condensation of the hydrate will occur and whether a third body is required for condensation, it was found that HF does effect the dew point or condensation of water and data was presented indicating the extent of that effect. It was also determined that condensation will occur without a third body present. Thus, in attempting to model an HF release for the Safety Analysis Report the hydration of HF and the subsequent heat released may be treated as occurring instantaneously; but the ultimate disposition of the HF will be strongly dependent upon the environmental conditions at the time of the release.

  15. High-K rotational bands in {sup 174}Hf and {sup 175}Hf

    Energy Technology Data Exchange (ETDEWEB)

    Gjoerup, N L; Sletten, G [The Niels Bohr Institute, Roskilbe (Denmark); Walker, P M [Surrey Univ., Guildford (United Kingdom). Dept. of Physics; Bentley, M A [Daresbury Lab. (United Kingdom); Cullen, D M; Sharpey-Schafer, J F; Fallon, P; Smith, G [Liverpool Univ. (United Kingdom). Oliver Lodge Lab.

    1992-08-01

    High sensitivity experiments with {sup 48}Ca, {sup 18}O and {sup 9}Be induced reactions using the ESSA-30, TESSA-3 and NORDBALL arrays have provided extensive new information on the high spin level structures of {sup 174}Hf and {sup 175}Hf. During the series of experiments, several new bands have been found and most known bands have been extended considerably. Spin and excitation energy ranges for {sup 174}Hf are now {approx} 35 {Dirac_h} and {approx} 13 MeV, respectively, and for {sup 175}Hf ranges are {approx} 30 {Dirac_h} and {approx} 7 MeV. respectively. Several new high-K structures have been found in {sup 174}Hf and the structure of these and the already known high-K bands in both nuclei together with the new Tilted Axis Cranking approach might explain the small K-hindrances observed for K-isomers in this region. (author). 8 refs., 2 figs.

  16. Phase transitions of amorphous solid acetone in confined geometry investigated by reflection absorption infrared spectroscopy.

    Science.gov (United States)

    Shin, Sunghwan; Kang, Hani; Kim, Jun Soo; Kang, Heon

    2014-11-26

    We investigated the phase transformations of amorphous solid acetone under confined geometry by preparing acetone films trapped in amorphous solid water (ASW) or CCl4. Reflection absorption infrared spectroscopy (RAIRS) and temperature-programmed desorption (TPD) were used to monitor the phase changes of the acetone sample with increasing temperature. An acetone film trapped in ASW shows an abrupt change in the RAIRS features of the acetone vibrational bands during heating from 80 to 100 K, which indicates the transformation of amorphous solid acetone to a molecularly aligned crystalline phase. Further heating of the sample to 140 K produces an isotropic solid phase, and eventually a fluid phase near 157 K, at which the acetone sample is probably trapped in a pressurized, superheated condition inside the ASW matrix. Inside a CCl4 matrix, amorphous solid acetone crystallizes into a different, isotropic structure at ca. 90 K. We propose that the molecularly aligned crystalline phase formed in ASW is created by heterogeneous nucleation at the acetone-water interface, with resultant crystal growth, whereas the isotropic crystalline phase in CCl4 is formed by homogeneous crystal growth starting from the bulk region of the acetone sample.

  17. (RS-Efonidipine acetone hemisolvate

    Directory of Open Access Journals (Sweden)

    Yu-Heng Liu

    2016-09-01

    Full Text Available The asymmetric unit of the title compound, C34H38N3O7P·0.5C3H6O {systematic name: (RS-2-[phenyl(phenylmethylamino]ethyl 5-(5,5-dimethyl-2-oxo-1,3-dioxa-2λ5-phosphacyclohex-2-yl-2,6-dimethyl-4-(3-nitrophenyl-1,4-dihydropyridine-3-carboxylate acetone hemisolvate}, contains one R-efonidipine molecule, one S-efonidipine molecule and half of a solvate acetone molecule. In both efonidipine molecules, the six-membered rings of the dioxaphosphinanyl moieties display a chair conformation and the dihydropyridine rings display a flattened boat conformation. In the crystal, N—H...O, C—H...O hydrogen bonds and weak C—H...π interactions link the molecules into a three-dimensional supramolecular structure. A solvent-accessible void of 199 Å3 is found in the structure; the contribution of the heavily disordered solvate molecule was suppressed by use of the SQUEEZE routine in PLATON [Spek (2015. Acta Cryst. C71, 9–18].

  18. Mass Spectrometry of Intact Proteins Reveals +98 u Chemical Artifacts Following Precipitation in Acetone.

    Science.gov (United States)

    Güray, Melda Z; Zheng, Shi; Doucette, Alan A

    2017-02-03

    Protein precipitation in acetone is frequently employed ahead of mass spectrometry for sample preconcentration and purification. Unfortunately, acetone is not chemically inert; mass artifacts have previously been observed on glycine-containing peptides when exposed to acetone under acidic conditions. We herein report a distinct chemical modification occurring at the level of intact proteins when incubated in acetone. This artifact manifests as one or more satellite peaks in the MS spectrum of intact protein, spaced 98 u above the mass of the unmodified protein. Other artifacts (+84, +112 u) also appear upon incubation of proteins or peptides in acetone. The reaction is pH-sensitive, being suppressed when proteins are exposed to acetone under acidic conditions. The +98 u artifact is speculated to originate through an intermediate product of aldol condensation of acetone to form diacetone alcohol and mesityl oxide. A +98 u product could originate from nucleophilic attack on mesityl oxide or through condensation with diacetone alcohol. Given the extent of modification possible upon exposure of proteins to acetone, particularly following overnight solvent exposure or incubation at room temperature, an awareness of the variables influencing this novel modification is valued by proteomics researchers who employ acetone precipitation for protein purification.

  19. Solvent (acetone-butanol: ab) production

    Science.gov (United States)

    This article describes production of butanol [acetone-butanol-ethanol, (also called AB or ABE or solvent)] by fermentation using both traditional and current technologies. AB production from agricultural commodities, such as corn and molasses, was an important historical fermentation. Unfortunately,...

  20. The reduction of sulfate ions in Musashino woody lignite and in acetone-furfural resin

    Energy Technology Data Exchange (ETDEWEB)

    Kimura, T.

    1986-01-01

    By adding a barium chloride solution to sulfur-containing woody lignite kept in water for two years, it has been confirmed that large quantities of sulfate ions are adsorbed by the lignite. Furthermore, spectroscopic measurements have confirmed the reduction of sulfate ions in an acetone-furfural resin prepared with residual sulfuric acid. These experimental results suggest the possibility of reducing sulfate ions in coal in the absence of sulfate bacteria. 2 refs.

  1. Human sensory response to acetone/air mixtures.

    Science.gov (United States)

    Salthammer, T; Schulz, N; Stolte, R; Uhde, E

    2016-10-01

    The release of organic compounds from building products may influence the perceived air quality in the indoor environment. Consequently, building products are assessed for chemical emissions and for the acceptability of emitted odors. A procedure for odor evaluations in test chambers is described by the standard ISO 16000-28. A panel of eight or more trained subjects directly determines the perceived intensity Π (unit pi) of an air sample via diffusers. For the training of the panelists, a comparative Π-scale is applied. The panelists can use acetone/air mixtures in a concentration range between 20 mg/m(3) (0 pi) and 320 mg/m(3) (15 pi) as reference. However, the training and calibration procedure itself can substantially contribute to the method uncertainty. This concerns the assumed odor threshold of acetone, the variability of panelist responses, and the analytical determination of acetone concentrations in air with online methods as well as the influence of the diffuser geometry and the airflow profile. © 2015 The Authors. Indoor Air published by John Wiley & Sons Ltd.

  2. One-electron reduction of 1,2-dihydroxy-9,10-anthraquinone and some of its transition metal complexes in aqueous solution and in aqueous isopropanol-acetone-mixed solvent: a steady-state and pulse radiolysis study

    International Nuclear Information System (INIS)

    Das, S.; Bhattacharya, A.; Mandal, P.C.; Rath, M.C.; Mukherjee, T.

    2002-01-01

    One-electron reduction of 1,2-dihydroxy-9,10-anthraquinone (DHA) and its complexes with Cu(II), Ni(II) and Fe(III), by acetone ketyl radical, (CH 3 ) 2 C·OH, was carried out in aqueous solution and in aqueous isopropanol acetone mixed solvent using both steady-state gamma radiolysis and pulse radiolysis techniques. The rate constants for the reduction of DHA at different pH values by the ketyl radical are in the order of ∼10 9 dm 3 mol -1 s -1 , whereas those for the metal complexes are comparatively less. These rate constants are, however, in conformity with the one-electron reduction potentials of the ligand in free DHA and in its metal complexes. Decay kinetics of the one-electron reduced semiquinones of the free ligand and its metal complexes suggest disproportionation of the semiquinone in the case of the free ligand and intermolecular electron transfer from the co-ordinated semiquinone radical to the metal centre in the case of the metal complexes

  3. On the adsorption/reaction of acetone on pure and sulfate-modified zirconias.

    Science.gov (United States)

    Crocellà, Valentina; Cerrato, Giuseppina; Morterra, Claudio

    2013-08-28

    In situ FTIR spectroscopy was employed to investigate some aspects of the ambient temperature (actually, IR-beam temperature) adsorption of acetone on various pure and sulfate-doped zirconia specimens. Acetone uptake yields, on all examined systems and to a variable extent, different types of specific molecular adsorption, depending on the kind/population of available surface sites: relatively weak H-bonding interaction(s) with surface hydroxyls, medium-strong coordinative interaction with Lewis acidic sites, and strong H-bonding interaction with Brønsted acidic centres. Moreover acetone, readily and abundantly adsorbed in molecular form, is able to undergo the aldol condensation reaction (yielding, as the main reaction product, adsorbed mesityl oxide) only if the adsorbing material possesses some specific surface features. The occurrence/non-occurrence of the acetone self-condensation reaction is discussed, and leads to conclusions concerning the sites that catalyze the condensation reaction that do not agree with either of two conflicting interpretations present in the literature of acetone uptake/reaction on, mainly, zeolitic systems. In particular, what turns out to be actually necessary for the acetone aldol condensation reaction to occur on the examined zirconia systems is the presence of coordinatively unsaturated O(2-) surface sites of basicity sufficient to lead to the extraction of a proton from one of the CH3 groups of adsorbed acetone.

  4. Breath acetone monitoring by portable Si:WO3 gas sensors

    Science.gov (United States)

    Righettoni, Marco; Tricoli, Antonio; Gass, Samuel; Schmid, Alex; Amann, Anton; Pratsinis, Sotiris E.

    2013-01-01

    Breath analysis has the potential for early stage detection and monitoring of illnesses to drastically reduce the corresponding medical diagnostic costs and improve the quality of life of patients suffering from chronic illnesses. In particular, the detection of acetone in the human breath is promising for non-invasive diagnosis and painless monitoring of diabetes (no finger pricking). Here, a portable acetone sensor consisting of flame-deposited and in situ annealed, Si-doped epsilon-WO3 nanostructured films was developed. The chamber volume was miniaturized while reaction-limited and transport-limited gas flow rates were identified and sensing temperatures were optimized resulting in a low detection limit of acetone (~20 ppb) with short response (10–15 s) and recovery times (35–70 s). Furthermore, the sensor signal (response) was robust against variations of the exhaled breath flow rate facilitating application of these sensors at realistic relative humidities (80–90%) as in the human breath. The acetone content in the breath of test persons was monitored continuously and compared to that of state-of-the-art proton transfer reaction mass spectrometry (PTR-MS). Such portable devices can accurately track breath acetone concentration to become an alternative to more elaborate breath analysis techniques. PMID:22790702

  5. High resolution TDPAC measurements on 181Ta in Hf2Fe, Hf2Co and Hf2Rh at high temperature

    International Nuclear Information System (INIS)

    Cekic, B.; Koicki, S.; Ivanovic, N.; Manasijevic, M.; Koteski, V.; Marjanovic, D.

    1998-01-01

    The time differential perturbed angular correlation measurements (TDPAC-method ) on 181 Ta ion probe in Hf 2 Co, Hf 2 Fe and Hf 2 Rh intermetallic compounds have been performed at 1170 K, using a fast - slow time spectrometer consisting of two BaF 2 detectors. The results of the measurements show the presence of two independent electric quadrupole interactions, compatible with the crystalline structure of these polycrystalline compounds. (authors)

  6. Home-made Detection Device for a Mixture of Ethanol and Acetone

    Directory of Open Access Journals (Sweden)

    Sukon Phanichphant

    2007-02-01

    Full Text Available A device for the detection and determination of ethanol and acetone wasconstructed, consisting of a packed column, a chamber with a sensor head, 2 dc powersupplies, a multimeter and a computer. A commercially available TGS 822 detector head(Figaro Company Limited was used as the sensor head. The TGS 822 detector consists of aSnO2 thick film deposited on the surface of an alumina ceramic tube which contains aheating element inside. An analytical column was coupled with the setup to enhance theseparation of ethanol and acetone before they reached the sensor head. Optimum systemconditions for detection of ethanol and acetone were achieved by varying the flow rate of thecarrier gas, voltage of the heating coil (VH, voltage of the circuit sensor (VC, loadresistance of the circuit sensor (RL and the injector port temperature. The flow of the carriergas was 15 mL/min; the circuit conditions were VH = 5.5 V, VC = 20 V, RL = 68 k ; and theinjection port temperature was 150°C. Under these conditions the retention times (tR forethanol and acetone were 1.95 and 0.57 minutes, respectively. Calibration graphs wereobtained for ethanol and acetone over the concentration range of 10 to 160 mg/L. The limitsof detection (LOD for ethanol and acetone were 9.25 mg/L and 4.41 mg/L respectively.

  7. Interatomic potential to predict the favored and optimized compositions for ternary Cu-Zr-Hf metallic glasses

    International Nuclear Information System (INIS)

    Luo, S. Y.; Cui, Y. Y.; Dai, Y.; Li, J. H.; Liu, B. X.

    2012-01-01

    Under the framework of smoothed and long range second-moment approximation of tight-binding, a realistic interatomic potential was first constructed for the Cu-Zr-Hf ternary metal system. Applying the constructed potential, Monte Carlo simulations were carried out to compare the relative stability of crystalline solid solution versus its disordered counterpart over the entire composition triangle of the system (as a function of alloy composition). Simulations not only reveal that the origin of metallic glass formation but also determine, in the composition triangle, a quadrilateral region, within which metallic glass formation is energetically favored. It is proposed to define the energy differences between the crystalline solid solutions and disordered states as the driving force for amorphization and the corresponding calculations pinpoint an optimized composition locating at an composition of Cu 55 Zr 10 Hf 35 , around which the driving force for metallic glass formation reaches its maximum, suggesting that the ternary Cu-Zr-Hf metallic glasses designed to have the compositions around Cu 55 Zr 10 Hf 35 could be more stable than other alloys in the system. Moreover, for the Cu 55 Zr 10 Hf 35 metallic glass, the Voronoi tessellation calculations reveal some interesting features of its atomic configurations and coordination polyhedra distribution.

  8. Achieving concentrated graphene dispersions in water/acetone mixtures by the strategy of tailoring Hansen solubility parameters

    International Nuclear Information System (INIS)

    Yi Min; Shen Zhigang; Zhang Xiaojing; Ma Shulin

    2013-01-01

    Although exfoliating graphite to give graphene paves a new way for graphene preparation, a general strategy of low-boiling-point solvents and high graphene concentration is still highly required. In this study, using the strategy of tailoring Hansen solubility parameters (HSP), a method based on exfoliation of graphite in water/acetone mixtures is demonstrated to achieve concentrated graphene dispersions. It is found that in the scope of blending two mediocre solvents, tailoring the HSP of water/acetone mixtures to approach the HSP of graphene could yield graphene dispersions at a high concentration of up to 0.21 mg ml -1 . The experimentally determined optimum composition of the mixtures occurs at an acetone mass fraction of ∼75%. The trend of concentration varying with mixture compositions could be well predicated by the model, which relates the concentration to the mixing enthalpy within the scope of HSP theory. The resultant dispersion is highly stabilized. Atomic force microscopic statistical analysis shows that up to ∼50% of the prepared nanosheets are less than 1 nm thick after 4 h sonication and 114g centrifugation. Analyses based on diverse characterizations indicate the graphene sheets to be largely free of basal plane defects and oxidation. The filtered films are also investigated in terms of their electrical and optical properties to show reasonable conductivity and transparency. The strategy of tailoring HSP, which can be easily extended to various solvent systems, and water/acetone mixtures here, extends the scope for large-scale production of graphene in low-boiling-point solutions.

  9. Atomic scale engineering of HfO2-based dielectrics for future DRAM applications

    International Nuclear Information System (INIS)

    Dudek, Piotr

    2011-01-01

    Modern dielectrics in combination with appropriate metal electrodes have a great potential to solve many difficulties associated with continuing miniaturization process in the microelectronic industry. One significant branch of microelectronics incorporates dynamic random access memory (DRAM) market. The DRAM devices scaled for over 35 years starting from 4 kb density to several Gb nowadays. The scaling process led to the dielectric material thickness reduction, resulting in higher leakage current density, and as a consequence higher power consumption. As a possible solution for this problem, alternative dielectric materials with improved electrical and material science parameters were intensively studied by many research groups. The higher dielectric constant allows the use of physically thicker layers with high capacitance but strongly reduced leakage current density. This work focused on deposition and characterization of thin insulating layers. The material engineering process was based on Si cleanroom compatible HfO 2 thin films deposited on TiN metal electrodes. A combined materials science and dielectric characterization study showed that Ba-added HfO 2 (BaHfO 3 ) films and Ti-added BaHfO 3 (BaHf 0.5 Ti 0.5 O 3 ) layers are promising candidates for future generation of state-of-the-art DRAMs. In especial a strong increase of the dielectric permittivity k was achieved for thin films of cubic BaHfO 3 (k∝38) and BaHf 0.5 Ti 0.5 O 3 (k∝90) with respect to monoclinic HfO 2 (k∝19). Meanwhile the CET values scaled down to 1 nm for BaHfO 3 and ∝0.8 nm for BaHf 0.5 Ti 0.5 O 3 with respect to HfO 2 (CET=1.5 nm). The Hf 4+ ions substitution in BaHfO 3 by Ti 4+ ions led to a significant decrease of thermal budget from 900 C for BaHfO 3 to 700 C for BaHf 0.5 Ti 0.5 O 3 . Future studies need to focus on the use of appropriate metal electrodes (high work function) and on film deposition process (homogeneity) for better current leakage control. (orig.)

  10. Analyses of desorbed H2O with temperature programmed desorption technique in sol-gel derived HfO2 thin films

    International Nuclear Information System (INIS)

    Shimizu, H.; Nemoto, D.; Ikeda, M.; Nishide, T.

    2009-01-01

    Hafnium oxide (HfO 2 ) is a promising material for the gate insulator in highly miniaturized silicon (Si) ultra-large-scale-integration (ULSI) devices (32 nm and beyond). In the field chemistry, a sol-gel processing has been used to fabricate HfO 2 thin film with the advantages of low cost, relative simplicity, and easy control of the composition of the layers formed. Temperature-programmed desorption (TPD) has been used not only for analyzing adsorbed gases on the surfaces of bulk sol-gel-derived HfO 2 of sol-gel-derived HfO 2 thin film fired at 350, 450, 550 and 700 deg C in sol-gel derived HfO 2 films in air is investigated using TPD, and also the material characterization of HfO 2 thin films is evaluated by X-ray diffraction (XRD) method. The dielectric constant of the films was also estimated using the capacitance-voltage (C-V) method. TPD is essentially a method of analyzing desorped gases from samples heated by infra-red light as a function of temperature under vacuum conditions using a detector of quadruple mass spectroscopy (QMS). Sol-gel-derived HfO 2 films were fabricated on 76-mm-diameter Si(100) wafers as follows. Hafnia sol solutions were prepared by dissolving HfCl 4 in NH 4 OH solution, followed by the of HCOOH. (author)

  11. Self-diffusion of Er and Hf inpure and HfO2-doped polycrystalline Er2O3

    International Nuclear Information System (INIS)

    Scheidecker, R.W.

    1979-01-01

    Using a tracer technique, self-diffusion of Er and Hf was measured over the approximate temperature interval of 1600 to 1970 0 C in pure and HfO 2 -doped polycryatalline Er 2 O 3 . Up to about 10 m/o HfO 2 dopant level, the Er self-diffusion coefficients followed a relationship based on cation vacancies. Above 10 m/o HfO 2 , deviation from this relationship occurred, apparently due to clustering of cation vacancies and oxygen interstitials around the dopant hafnia ion. The activation energy for the self-diffusion of Er in pure Er 2 O 3 was 82.2 Kcal/mole and increased with the HfO 2 dopant level present. Self-diffusion of Hf was measured in pure Er 2 O 3 having two impurity levels, and a separation of the grain boundary. The volume diffusion of Hf showed both extrinsic and intrinsic behavior with the transition temperature increasing with the impurity level present in Er 2 O 3 . The activation energy for Hf volume diffusion in the intrinsic region was high, i.e. 235 -+ 9.5 Kcal/mole. The grain boundary diffusion was apparently extrinsic over the entire temperature interval Very low Hf self diffusion rates were found in both pure and HfO 2 doped Er 2 O 3 compositions. Despite a clustering effect, the HfO 2 dopant increased the Hf volume diffusion coefficients

  12. The effects of a co-solvent on fabrication of cellulose acetate membranes from solutions in 1-ethyl-3-methylimidazolium acetate

    KAUST Repository

    Kim, Dooli

    2016-08-15

    Ionic liquids have been considered green solvents for membrane fabrication. However, the high viscosity of their polymer solutions hinders the formation of membranes with strong mechanical properties. In this study, acetone was explored as a co-solvent with the ionic liquid 1-ethyl-3-methylimidazolium acetate ([EMIM]OAc) to dissolve cellulose acetate. The effects of acetone on the thermodynamic and kinetic aspects of the polymer solutions were studied and the physicochemical properties and separation capability of their resultant membranes were analyzed. The Hansen solubility parameters of [EMIM]OAc were measured by the software HSPiP and these data demonstrated that acetone was a suitable co-solvent to increase the solubility of cellulose acetate. The Gibbs free energy of mixing ΔGm was estimated to determine the proper composition of the polymer solution with better solubility. The study of the kinetics of phase separation showed that the demixing rate of the CA polymer solution in acetone and [EMIM]OAc was higher than that for solutions in [EMIM]OAc only. The membranes prepared from the former solution had higher water permeance and better mechanical stability than those prepared from the later solution. Adding acetone as a co-solvent opened the opportunity of fabricating membranes with higher polymer concentrations for higher separation capability and better mechanical properties. © 2016

  13. The effects of a co-solvent on fabrication of cellulose acetate membranes from solutions in 1-ethyl-3-methylimidazolium acetate

    KAUST Repository

    Kim, Dooli; Le, Ngoc Lieu; Nunes, Suzana Pereira

    2016-01-01

    Ionic liquids have been considered green solvents for membrane fabrication. However, the high viscosity of their polymer solutions hinders the formation of membranes with strong mechanical properties. In this study, acetone was explored as a co-solvent with the ionic liquid 1-ethyl-3-methylimidazolium acetate ([EMIM]OAc) to dissolve cellulose acetate. The effects of acetone on the thermodynamic and kinetic aspects of the polymer solutions were studied and the physicochemical properties and separation capability of their resultant membranes were analyzed. The Hansen solubility parameters of [EMIM]OAc were measured by the software HSPiP and these data demonstrated that acetone was a suitable co-solvent to increase the solubility of cellulose acetate. The Gibbs free energy of mixing ΔGm was estimated to determine the proper composition of the polymer solution with better solubility. The study of the kinetics of phase separation showed that the demixing rate of the CA polymer solution in acetone and [EMIM]OAc was higher than that for solutions in [EMIM]OAc only. The membranes prepared from the former solution had higher water permeance and better mechanical stability than those prepared from the later solution. Adding acetone as a co-solvent opened the opportunity of fabricating membranes with higher polymer concentrations for higher separation capability and better mechanical properties. © 2016

  14. Carbonylation as a key reaction in anaerobic acetone activation by Desulfococcus biacutus.

    Science.gov (United States)

    Gutiérrez Acosta, Olga B; Hardt, Norman; Schink, Bernhard

    2013-10-01

    Acetone is activated by aerobic and nitrate-reducing bacteria via an ATP-dependent carboxylation reaction to form acetoacetate as the first reaction product. In the activation of acetone by sulfate-reducing bacteria, acetoacetate has not been found to be an intermediate. Here, we present evidence of a carbonylation reaction as the initial step in the activation of acetone by the strictly anaerobic sulfate reducer Desulfococcus biacutus. In cell suspension experiments, CO was found to be a far better cosubstrate for acetone activation than CO2. The hypothetical reaction product, acetoacetaldehyde, is extremely reactive and could not be identified as a free intermediate. However, acetoacetaldehyde dinitrophenylhydrazone was detected by mass spectrometry in cell extract experiments as a reaction product of acetone, CO, and dinitrophenylhydrazine. In a similar assay, 2-amino-4-methylpyrimidine was formed as the product of a reaction between acetoacetaldehyde and guanidine. The reaction depended on ATP as a cosubstrate. Moreover, the specific activity of aldehyde dehydrogenase (coenzyme A [CoA] acylating) tested with the putative physiological substrate was found to be 153 ± 36 mU mg(-1) protein, and its activity was specifically induced in extracts of acetone-grown cells. Moreover, acetoacetyl-CoA was detected (by mass spectrometry) after the carbonylation reaction as the subsequent intermediate after acetoacetaldehyde was formed. These results together provide evidence that acetoacetaldehyde is an intermediate in the activation of acetone by sulfate-reducing bacteria.

  15. Beta decomposition of (Hf/sub x/Zr/sub 1-x/)80Nb20 ternary alloys

    International Nuclear Information System (INIS)

    Jones, W.B.; Taggart, R.; Polonis, D.H.

    1978-01-01

    The processes of beta decomposition have been examined in ternary alloys of the form (Hf/sub x/Zr/sub 1-x/) 80 Nb 20 to determine the influence of Hf additions to a basic Zr 80 Nb 20 composition. In the chill cast condition, Hf additions have been found to decrease the temperature coefficient of electrical resistivity from a value of -0.0015%/K for the binary Zr 80 Nb 20 alloy to a value of -0.011%/K for a (Hf 50 Zr 50 ) 80 Nb 20 ternary alloy. This change is explained in terms of the bcc lattice instability typical of Ti, Zr, and Hf alloys. The Hf additions enhance the kinetics of omega-phase precipitation during aging at 648 K. The aging of a (Hf 05 Zr 95 ) 80 Nb 20 alloy for 12 h results in the precipitation of a high volume fraction of cuboidal shaped omega-phase particles. A phase separation which results in the formation of solute lean discs (β/sub l/) occurs together with the precipitation of the omega-phase. These discs formed both randomly within the matrix and heterogeneously along dislocations and at grain boundaries

  16. Recent trends in acetone, butanol, and ethanol (ABE production

    Directory of Open Access Journals (Sweden)

    Keikhosro Karim

    2015-12-01

    Full Text Available Among the renewable fuels considered as a suitable substitute to petroleum-based gasoline, butanol has attracted a great deal of attention due to its unique properties. Acetone, butanol, and ethanol (ABE can be produced biologically from different substrates, including sugars, starch, lignocelluloses, and algae. This process was among the very first biofuel production processes which was commercialized during the First World War. The present review paper discusses the different aspects of the ABE process and the recent progresses made. Moreover, the microorganisms and the biochemistry of the ABE fermentation as well as the feedstocks used are reviewed. Finally, the challenges faced such as low products concentration and products` inhibitory effects on the fermentation are explained and different possible solutions are presented and reviewed.

  17. Derivatization reaction-based surface-enhanced Raman scattering (SERS) for detection of trace acetone.

    Science.gov (United States)

    Zheng, Ying; Chen, Zhuo; Zheng, Chengbin; Lee, Yong-Ill; Hou, Xiandeng; Wu, Li; Tian, Yunfei

    2016-08-01

    A facile method was developed for determination of trace volatile acetone by coupling a derivatization reaction to surface-enhanced Raman scattering (SERS). With iodide modified Ag nanoparticles (Ag IMNPs) as the SERS substrate, acetone without obvious Raman signal could be converted to SERS-sensitive species via a chemical derivatization reaction with 2,4-dinitrophenylhydrazine (2,4-DNPH). In addition, acetone can be effectively separated from liquid phase with a purge-sampling device and then any serious interference from sample matrices can be significantly reduced. The optimal conditions for the derivatization reaction and the SERS analysis were investigated in detail, and the selectivity and reproducibility of this method were also evaluated. Under the optimal conditions, the limit of detection (LOD) for acetone was 5mgL(-1) or 0.09mM (3σ). The relative standard deviation (RSD) for 80mgL(-1) acetone (n=9) was 1.7%. This method was successfully used for the determination of acetone in artificial urine and human urine samples with spiked recoveries ranging from 92% to 110%. The present method is convenient, sensitive, selective, reliable and suitable for analysis of trace acetone, and it could have a promising clinical application in early diabetes diagnosis. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. Evaluation of acetone vapors toxicity on Plodia interpunctella (Hubner) (Lepidoptera: Pyralidae) eggs.

    Science.gov (United States)

    Pourmirza, Ali Asghr; Nasab, Fershteh Sadeghi; Zadeh, Abas Hossein

    2007-08-01

    The efficacy of acetone vapors against carefully aged eggs of Plodia interpunctella (Hubner) at 17+/-1 and 27+/-1 degrees C at different dosage levels of acetone over various exposure times was determined. Acetone was found to be toxic to Indian meal moth eggs. Considerable variation in the susceptibility of different age groups of eggs was apparent in the fiducial limits of the LD50 values. An inverse relationship between LD50 values and exposure times was observed in age groups of tested eggs. At 27+/-1 degrees C and 24 h exposure period, eggs aged 1-2 day-old were more tolerant to acetone than other age groups, followed by 0-1 day-old, 2-3 day-old and 3-4 day-old eggs. A similar pattern of susceptibility of eggs was observed at 72 h exposure. In all bioassays, eggs exposed to higher dosages of acetone developed at smaller rate. This was significant for the eggs, which were exposed to the highest dosage for 24 h. Increasing the temperature from 17+/-1 to 27+/-1 degrees C greatly increased the efficacy of acetone. At 27+/-1 degrees C eggs of P. interpunctella were killed by less than one-third of the dosage required for control at 17+/-1 degrees C. Acetone achieved 50% mortality with a dosage of 82.76 mg L(-1) in 1-2 day-old eggs at 27+/-1 degrees C. At this temperature hatching was retarded and greatly diminished when eggs aged 1-2 day-old were exposed to 80 mg L(-1) of acetone for the 24 h exposure period. There was no evidence of a hatch delay longer than the time spent under vapors for eggs exposed at 17+/-1 or 27+/-1 degrees C, indicating that some development must have occurred under fumigation.

  19. Weak carbonyl-methyl intermolecular interactions in acetone clusters explored by IR plus VUV spectroscopy

    International Nuclear Information System (INIS)

    Guan, Jiwen; Hu, Yongjun; Xie, Min; Bernstein, Elliot R.

    2012-01-01

    Highlights: ► The carbonyl overtone of acetone clusters is observed by IR-VUV spectroscopy. ► Acetone molecules in the dimer are stacked with an antiparallel way. ► The structure of the acetone trimer and the tetramer are the cyclic structures. ► The carbonyl groups would interact with the methyl groups in acetone clusters. ► These weak interactions are further confirmed by H/D substitution experiment. -- Abstract: Size-selected IR–VUV spectroscopy is employed to detect vibrational characteristics in the region 2850 ∼ 3550 cm −1 of neutral acetone and its clusters (CH 3 COCH 3 ) n (n = 1–4). Features around 3440 cm −1 in the spectra of acetone monomer and its clusters are assigned to the carbonyl stretch (CO) overtone. These features red-shift from 3455 to 3433 cm −1 as the size of the clusters increases from the monomer to the tetramer. Based on calculations, the experimental IR spectra in the C=O overtone region suggest that the dominant structures for the acetone trimer and tetramer should be cyclic in the supersonic expansion sample. This study also suggests that the carbonyl groups interact with the methyl groups in the acetone clusters. These weak interactions are further confirmed by the use of deuterium substitution.

  20. Solvents (butanol, acetone, and ethanol)

    Energy Technology Data Exchange (ETDEWEB)

    Yarovenko, V L; Nakhmanovich, B M

    1963-07-17

    The method involves use of carbohydrate containing plant raw-material, e.g., hydrolyzates of corn cob and pulp. The material is subjected to fermentation with acetone-butanol bacteria with addition of starch-industry wastes as source of proteins (gluten and gluten-containing water) and nutrient salts.

  1. Corrosion Characteristics of Ti-29Nb-xHf Ternary Alloy for Biomaterials

    Energy Technology Data Exchange (ETDEWEB)

    Pak, Sun Young; Choi, Han Chul [Chosun Univ., Kwangju (Korea, Republic of)

    2015-12-15

    The Cp-Ti and Ti-6Al-4V alloys were widely used for dental materials due to their mechanical properties and good corrosion resistance. However, Cp-Ti was known as bio-inert materials, Ti-6Al-4V alloy has a problem such as high Young modulus, potential loss of the surrounding bone, and to the release of potentially toxic ions from the alloy. To overcome this problem, Ti alloys containing Nb and Hf elements have been used for biomaterials due to low toxicity and high corrosion resistance. Especially, alloying element of Nb was known as β phase stabilizer. The β phase alloy was widely used to replace currently used implant materials. The corrosion resistances of Ti-29Nb-xHf ternary alloys were dependent on Hf content in oral environment solution.

  2. Fermentation and genomic analysis of acetone-uncoupled butanol production by Clostridium tetanomorphum.

    Science.gov (United States)

    Gong, Fuyu; Bao, Guanhui; Zhao, Chunhua; Zhang, Yanping; Li, Yin; Dong, Hongjun

    2016-02-01

    In typical acetone-butanol-ethanol (ABE) fermentation, acetone is the main by-product (50 % of butanol mass) of butanol production, resulting in a low yield of butanol. It is known that some Clostridium tetanomorphum strains are able to produce butanol without acetone in nature. Here, we described that C. tetanomorphum strain DSM665 can produce 4.16 g/L butanol and 4.98 g/L ethanol at pH 6.0, and 9.81 g/L butanol and 1.01 g/L ethanol when adding 1 mM methyl viologen. Butyrate and acetate could be reassimilated and no acetone was produced. Further analysis indicated that the activity of the acetate/butyrate:acetoacetyl-CoA transferase responsible for acetone production is lost in C. tetanomorphum DSM665. The genome of C. tetanomorphum DSM665 was sequenced and deposited in DDBJ, EMBL, and GenBank under the accession no. APJS00000000. Sequence analysis indicated that there are no typical genes (ctfA/B and adc) that are typically parts of an acetone synthesis pathway in C. tetanomorphum DSM665. This work provides new insights in the mechanism of clostridial butanol production and should prove useful for the design of a high-butanol-producing strain.

  3. An isotope dependent study of acetone in its lowest excited triplet state

    International Nuclear Information System (INIS)

    Gehrtz, M.; Brauchle, C.; Voitlaender, J.

    1984-01-01

    The lowest excited triplet state T 1 of acetone-h 6 and acetone-d 6 was investigated with a pulsed dye laser equipped ODMR spectrometer. Acetone is found to be bent in T 1 and the out-of-plane distortion angle is estimated to be approx.= 38 0 . The observed zero-field splitting (ZFS) is surprisingly small. Both the spin-spin and the spin-orbit (SO) contribution to the ZFS are evaluated. The SO tensor contribution is calculated from a correlation between the deuterium effects on the ZFS parameters and the population rates. The sub-level selective kinetics of the acetone T 1 is largely determined by the mixing of the x- and z-level characteristics owing to magnetic axis rotation caused by the excited state out-of-plane distortion. Considerable deuterium effects are observed on the kinetic data and on the microwave transition frequencies. In all cases the spin-specific isotope effects (due to the promoting modes) and the global effects (due to the Franck-Condon factors) are specified. For the population rates and the SO contribution to ZFS, the inverse global isotope effects (deuterium factor > 1) was found for the first time. Based on the isotope dependence of the rates, the mechanisms of (vibrationally induced) SO coupling in acetone are discussed. It is concluded that non-adiabatic contributions have to be taken into account for the smallest population rate only, but that otherwise the adiabatic SO coupling mechanisms by far dominates in the acetone photophysics. (author)

  4. A new class of materials with promising thermoelectric properties: MNiSn (M=Ti, Zr, Hf)

    Energy Technology Data Exchange (ETDEWEB)

    Hohl, H; Ramirez, A P; Kaefer, W; Fess, K; Thurner, Ch; Kloc, Ch; Bucher, E

    1997-07-01

    TiNiSn, ZrNiSn and HfNiSn are members of a large group of intermetallic compounds which crystallize in the cubic MgAgAs-type structure. Polycrystalline samples of these compounds have been prepared and investigated for their thermoelectric properties. With thermopowers of about {minus}200 {micro}V/K and resistivities of a few m{Omega}cm, power factors S{sup 2}/{rho} as high as 38 {micro}W/K{sup 2}cm were obtained at 700 K. These remarkably high power factors are, however, accompanied by a thermal conductivity, solid solutions Zr{sub 1{minus}x}Hf{sub x}NiSn, Zr{sub 1{minus}x}Ti{sub x}NiSn, and Hf{prime}{sub 1{minus}x}Ti{sub x}NiSn were formed. The figure of merit of Zr{sub 0.5}Hf{sub 0.5}NiSn at 700 K (ZT = 0.41) exceeds the end members ZrNiSn (ZT = 0.26) and HfNiSn (ZT = 0.22).

  5. Solubility of nicotinic acid in water, ethanol, acetone, diethyl ether, acetonitrile, and dimethyl sulfoxide

    International Nuclear Information System (INIS)

    Gonçalves, Elsa M.; Minas da Piedade, Manuel E.

    2012-01-01

    Highlights: ► We determined the solubility of nicotinic acid in six solvents by the gravimetric method. ► We found that, regardless of the solvent, the same monoclinic solid phase was in equilibrium with the solution. ► We determined the activity coefficients of nicotinic acid in the six solvents. ► We found that the solubility trends seem to be determined by the polarity and polarizability of the solvent. - Abstract: The mole fraction equilibrium solubility of nicotinic acid in six solvents (water, ethanol, dimethyl sulfoxide, acetone, acetonitrile and diethyl ether) differing in polarity, polarizability, and hydrogen-bonding ability, was determined over the temperature range (283 to 333) K, using the gravimetric method. The results obtained led to the solubility order dimethyl sulfoxide (DMSO) ≫ ethanol > water > acetone > diethyl ether > acetonitrile. An analysis based on various solvent descriptors, indicated that this trend seems to be mainly determined by the polarity and polarizability of the solvent. The activity coefficients of nicotinic acid in the different solvents, under saturation conditions, were determined as a function of the temperature and it was found that DMSO exhibits enhanced solubility relative to an ideal solution while the opposite is observed for all other solvents. Both the solvent and the fact that nicotinic acid is primarily zwitterionic in aqueous solution and non-zwitterionic in non-aqueous media, did not affect the nature of the solid phases in equilibrium with the different solutions. Indeed, X-ray powder diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, and differential scanning calorimetry analysis indicated that, despite some differences in particle size and morphology, the starting material and the solid products obtained at the end of the solubility studies in the six solvents used in this work were all crystalline and corresponded to the same monoclinic phase.

  6. Performance of Cr-doped ZnO for acetone sensing

    Energy Technology Data Exchange (ETDEWEB)

    Al-Hardan, N.H., E-mail: naif_imen@ukm.my [Institute of Microengineering and Nanoelectronics (IMEN), Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor (Malaysia); Abdullah, M.J.; Aziz, A. Abdul [School of Physics, Universiti Sains Malaysia, 11800 USM, Penang (Malaysia)

    2013-04-01

    Zinc oxide (ZnO) doped with chromium (Cr) was synthesized by reactive co-sputtering for gas sensing applications. The effect of varying the contents of Cr (from 1 to 4 at%) on the ZnO gas sensor response was studied. X-ray diffraction analysis reveals the high orientation of c-axis of the prepared films. The optimum operating temperature of the undoped ZnO was 400 °C and shifted to 300 °C for the Cr-doped ZnO under the acetone vapour. The 1% Cr doping ZnO gas sensor was most sensitive for the acetone vapour. The ability of the 1% Cr-doped ZnO to produce repeatable results under different acetone vapour concentrations was tested. The timing properties of the doped Cr ZnO gas sensor were 70 and 95 s for the rise and recovery time respectively.

  7. Selective bio-oxidation of propane to acetone using methane-oxidizing Methylomonas sp. DH-1.

    Science.gov (United States)

    Hur, Dong Hoon; Nguyen, Thu Thi; Kim, Donghyuk; Lee, Eun Yeol

    2017-07-01

    Propane is the major component of liquefied petroleum gas (LPG). Nowadays, the use of LPG is decreasing, and thus utilization of propane as a chemical feedstock is in need of development. An efficient biological conversion of propane to acetone using a methanotrophic whole cell as the biocatalyst was proposed and investigated. A bio-oxidation pathway of propane to acetone in Methylomonas sp. DH-1 was analyzed by gene expression profiling via RNA sequencing. Propane was oxidized to 2-propanol by particulate methane monooxygenase and subsequently to acetone by methanol dehydrogenases. Methylomonas sp. DH-1 was deficient in acetone-converting enzymes and thus accumulated acetone in the absence of any enzyme inhibition. The maximum accumulation, average productivity and specific productivity of acetone were 16.62 mM, 0.678 mM/h and 0.141 mmol/g cell/h, respectively, under the optimized conditions. Our study demonstrates a novel method for the bioconversion of propane to acetone using methanotrophs under mild reaction condition.

  8. Multiphoton ionization and fragmentation study of acetone using 308 nm laser radiation

    Science.gov (United States)

    Liu Houxiang, Li Shutao, Han Jingcheng, Zhu Rong, Guan Yifu, Wu Cunkai

    1988-10-01

    Multiphoton ionization and fragmentation (MPI-F) of acetone molecules using 308 nm laser radiation was studied by using a molecular beam and quadrupole mass spectrometer. The ion peaks of acetone molecule appear at m/e=15 and 43, corresponding to the two fragments CH3+ and CH3CO+. It is considered that these two ions are, respectively, formed by direct (2+1) and 2-photon ionization of methyl and acetyl radicals, generated by photodissociation of acetone molecule.

  9. Efficient acetone-butanol-ethanol production by Clostridium beijerinckii from sugar beet pulp.

    Science.gov (United States)

    Bellido, Carolina; Infante, Celia; Coca, Mónica; González-Benito, Gerardo; Lucas, Susana; García-Cubero, María Teresa

    2015-08-01

    Sugar beet pulp (SBP) has been investigated as a promising feedstock for ABE fermentation by Clostridium beijerinckii. Although lignin content in SBP is low, a pretreatment is needed to enhance enzymatic hydrolysis and fermentation yields. Autohydrolysis at pH 4 has been selected as the best pretreatment for SBP in terms of sugars release and acetone and butanol production. The best overall sugars release yields from raw SBP ranged from 66.2% to 70.6% for this pretreatment. The highest ABE yield achieved was 0.4g/g (5.1g/L of acetone and 6.6g/L butanol) and 143.2g ABE/kg SBP (62.3g acetone and 80.9g butanol) were obtained when pretreated SBP was enzymatically hydrolyzed at 7.5% (w/w) solid loading. Higher solid loadings (10%) offered higher acetone and butanol titers (5.8g/L of acetone and 7.8g/L butanol). All the experiments were carried out under not-controlling pH conditions reaching about 5.3 in the final samples. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. Reconciliation of the excess 176Hf conundrum in meteorites: Recent disturbances of the Lu-Hf and Sm-Nd isotope systematics

    Science.gov (United States)

    Bast, Rebecca; Scherer, Erik E.; Sprung, Peter; Mezger, Klaus; Fischer-Gödde, Mario; Taetz, Stephan; Böhnke, Mischa; Schmid-Beurmann, Hinrich; Münker, Carsten; Kleine, Thorsten; Srinivasan, Gopalan

    2017-09-01

    The long-lived 176Lu-176Hf and 147Sm-143Nd radioisotope systems are commonly used chronometers, but when applied to meteorites, they can reveal disturbances. Specifically, Lu-Hf isochrons commonly yield dates up to ∼300 Myr older than the solar system and varying initial 176Hf/177Hf values. We investigated this problem by attempting to construct mineral and whole rock isochrons for eucrites and angrites. Meteorites from different parent bodies exhibit similar disturbance features suggesting that a common process is responsible. Minerals scatter away from isochron regressions for both meteorite classes, with low-Hf phases such as plagioclase and olivine typically being most displaced above (or left of) reference isochrons. Relatively Hf-rich pyroxene is less disturbed but still to the point of steepening Lu-Hf errorchrons. Using our Lu-Hf and Sm-Nd data, we tested various Hf and Lu redistribution scenarios and found that decoupling of Lu/Hf from 176Hf/177Hf must postdate the accumulation of significant radiogenic 176Hf. Therefore early irradiation or diffusion cannot explain the excess 176Hf. Instead, disturbed meteorite isochrons are more likely caused by terrestrial weathering, contamination, or common laboratory procedures. The partial dissolution of phosphate minerals may predominantly remove rare earth elements including Lu, leaving relatively immobile and radiogenic Hf behind. Robust Lu-Hf (and improved Sm-Nd) meteorite geochronology will require the development of chemical or physical methods for removing unsupported radiogenic Hf and silicate-hosted terrestrial contaminants without disturbing parent-daughter ratios.

  11. Uptake of acetone, ethanol and benzene to snow and ice: effects of surface area and temperature

    International Nuclear Information System (INIS)

    Abbatt, J P D; Bartels-Rausch, T; Ullerstam, M; Ye, T J

    2008-01-01

    The interactions of gas-phase acetone, ethanol and benzene with smooth ice films and artificial snow have been studied. In one technique, the snow is packed into a cylindrical column and inserted into a low-pressure flow reactor coupled to a chemical-ionization mass spectrometer for gas-phase analysis. At 214 and 228 K, it is found for acetone and ethanol that the adsorbed amounts per surface area match those for adsorption to thin films of ice formed by freezing liquid water, when the specific surface area of the snow (as determined from Kr adsorption at 77 K) and the geometric surface area of the ice films are used. This indicates that freezing thin films of water leads to surfaces that are smooth at the molecular level. Experiments performed to test the effect of film growth on ethanol uptake indicate that uptake is independent of ice growth rate, up to 2.4 μm min -1 . In addition, traditional Brunauer-Emmett-Teller (BET) experiments were performed with these gases on artificial snow from 238 to 266.5 K. A transition from a BET type I isotherm indicative of monolayer formation to a BET type II isotherm indicative of multilayer uptake is observed for acetone at T≥263 K and ethanol at T≥255 K, arising from solution formation on the ice. When multilayer formation does not occur, as was the case for benzene at T≤263 K and for acetone at T≤255 K, the saturated surface coverage increased with increasing temperature, consistent with the quasi-liquid layer affecting adsorption prior to full dissolution/multilayer formation.

  12. An analysis of human response to the irritancy of acetone vapors

    NARCIS (Netherlands)

    Arts, J.H.E.; Mojet, J.; Gemert, L.J. van; Emmen, H.H.; Lammers, J.H.C.M.; Marquart, J.; Woutersen, R.A.; Feron, V.J.

    2002-01-01

    Studies on the irritative effects of acetone vapor in humans and experimental animals have revealed large differences in the lowest acetone concentration found to be irritative to the respiratory tract and eyes. This has brought on much confusion in the process of setting occupational exposure

  13. Clinical trials update from the Heart Failure Society of America Meeting 2009: FAST, IMPROVE-HF, COACH galectin-3 substudy, HF-ACTION nuclear substudy, DAD-HF, and MARVEL-1.

    Science.gov (United States)

    Lainscak, Mitja; Coletta, Alison P; Sherwi, Nasser; Cleland, John G F

    2010-02-01

    This article presents findings and a commentary on late-breaking trials presented during the meeting of the Heart Failure Society of America in September 2009. Unpublished reports should be considered as preliminary, since analyses may change in the final publication. The FAST trial showed somewhat better performance of intrathoracic impedance for prediction of deterioration in patients with heart failure (HF) when compared with daily weighing. The IMPROVE-HF study reported the benefits of education on the management of patients with systolic HF. Galectin-3 appeared a useful method for improving risk stratification of patients with chronic HF in a substudy of the COACH trial. A nuclear substudy of the HF-ACTION trial failed to demonstrate that resting myocardial perfusion imaging, a measure of myocardial scar and viability, was clinically useful. A small randomized controlled trial (DAD-HF) suggested that the use of low-dose dopamine in patients with acutely decompensated HF was associated with less deterioration in renal function and less hypokalaemia. The MARVEL-1 trial raises further concerns about the safety of myoblast transplantation in ischaemic HF.

  14. Ab initio theoretical study of dipole-bound anions of molecular complexes: (HF)3- and (HF)4- anions

    Science.gov (United States)

    Ramaekers, Riet; Smith, Dayle M. A.; Smets, Johan; Adamowicz, Ludwik

    1997-12-01

    Ab initio calculations have been performed to determine structures and vertical electron detachment energy (VDE) of the hydrogen fluoride trimer and tetramer anions, (HF)3- and (HF)4-. In these systems the excess electron is bound by the dipole field of the complex. It was determined that, unlike the neutral complexes which prefer the cyclic structures, the equilibrium geometries of the anions have "zig-zag" shapes. For both complexes the predicted VDEs are positive [210 meV and 363 meV for (HF)3- and (HF)4-, respectively], indicating that the anions are stable systems with respect to the vertical electron detachment. These results were obtained at the coupled-cluster level of theory with single, double and triple excitations [CCSD(T) method; the triple-excitation contribution in this method is calculated approximately using the perturbation approach] with the anion geometries obtained using the second-order Møller-Plesset perturbation theory (MP2) method. The same approach was also used to determine the adiabatic electron affinities (AEA) of (HF)3 and (HF)4. In addition to the electronic contribution, we also calculated the contributions (using the harmonic approximation) resulting from different zero-point vibration energies of the neutral and anionic clusters. The calculations predicted that while the AEA of (HF)3 is positive (44 meV), the AEA for (HF)4 is marginally negative (-16 meV). This suggests that the (HF)3- anion should be a stable system, while the (HF)4- is probably metastable.

  15. A Portable Real-Time Ringdown Breath Acetone Analyzer: Toward Potential Diabetic Screening and Management.

    Science.gov (United States)

    Jiang, Chenyu; Sun, Meixiu; Wang, Zhennan; Chen, Zhuying; Zhao, Xiaomeng; Yuan, Yuan; Li, Yingxin; Wang, Chuji

    2016-07-30

    Breath analysis has been considered a suitable tool to evaluate diseases of the respiratory system and those that involve metabolic changes, such as diabetes. Breath acetone has long been known as a biomarker for diabetes. However, the results from published data by far have been inconclusive regarding whether breath acetone is a reliable index of diabetic screening. Large variations exist among the results of different studies because there has been no "best-practice method" for breath-acetone measurements as a result of technical problems of sampling and analysis. In this mini-review, we update the current status of our development of a laser-based breath acetone analyzer toward real-time, one-line diabetic screening and a point-of-care instrument for diabetic management. An integrated standalone breath acetone analyzer based on the cavity ringdown spectroscopy technique has been developed. The instrument was validated by using the certificated gas chromatography-mass spectrometry. The linear fittings suggest that the obtained acetone concentrations via both methods are consistent. Breath samples from each individual subject under various conditions in total, 1257 breath samples were taken from 22 Type 1 diabetic (T1D) patients, 312 Type 2 diabetic (T2D) patients, which is one of the largest numbers of T2D subjects ever used in a single study, and 52 non-diabetic healthy subjects. Simultaneous blood glucose (BG) levels were also tested using a standard diabetic management BG meter. The mean breath acetone concentrations were determined to be 4.9 ± 16 ppm (22 T1D), and 1.5 ± 1.3 ppm (312 T2D), which are about 4.5 and 1.4 times of the one in the 42 non-diabetic healthy subjects, 1.1 ± 0.5 ppm, respectively. A preliminary quantitative correlation (R = 0.56, p acetone concentration and the mean individual BG levels does exist in 20 T1D subjects with no ketoacidosis. No direct correlation is observed in T1D subjects, T2D subjects, and healthy subjects. The results

  16. Experimental results of acetone hydrogenation on a heat exchanger type reactor for solar chemical heat pump; Solar chemical heat pump ni okeru acetone suisoka hanno netsu kaishu jikken

    Energy Technology Data Exchange (ETDEWEB)

    Takashima, T; Doi, T; Tanaka, T; Ando, Y [Electrotechnical Laboratory, Tsukuba (Japan); Miyahara, R; Kamoshida, J [Shibaura Institute of Technology, Tokyo (Japan)

    1996-10-27

    With the purpose of converting solar heat energy to industrial heat energy, an experiment of acetone hydrogenation was carried out using a heat exchanger type reactor that recovers heat generated by acetone hydrogenation, an exothermic reaction, and supplies it to an outside load. In the experiment, a pellet-like activated carbon-supported ruthenium catalyst was used for the acetone hydrogenation with hydrogen and acetone supplied to the catalyst layer at a space velocity of 400-1,200 or so. In the external pipe of the double-pipe type reactor, a heating medium oil was circulated in parallel with the flow of the reactant, with the heat of reaction recovered that was generated from the acetone hydrogenation. In this experiment, an 1wt%Ru/C catalyst and a 5wt%Ru/C catalyst were used so as to examine the effects of variation in the space velocity. As a result, from the viewpoint of recovering the heat of reaction, it was found desirable to increase the reaction speed by raising catalytic density and also to supply the reactant downstream inside the reaction pipe by increasing the space velocity. 1 ref., 6 figs., 1 tab.

  17. Behaviour at the indicator scale of the elements Zr, Hf and 104, Nb,Ta and Pa (105) in very complexation media; Comportement a l`echelle des indicateurs des elements Zr, Hf, et 104, Nb, Ta, et Pa (105) en milieux tres complexants

    Energy Technology Data Exchange (ETDEWEB)

    Monroy Guzman, F. [Institut de Physique Nucleaire, CNRS - IN2P3 Universite Paris Sud, 91406 Orsay Cedex (France)

    1997-12-31

    In order to determine the chemical properties of the trans-actinide elements of Z = 104 and 105 in aqueous solutions we studied their behaviour to ion exchange resin in different complex media. Due to the very short lifetimes (some tens of seconds) et to the low yield of these elements (a few atoms per irradiation hour) only very fast radiochemical techniques can be used. These severe constraints impose comparative studies of these elements with their most likely homologues to be carried out. The corresponding homologues were the elements of group 4 (Zr and Hf) for the element 104 and the elements of group 5 (Nb and Ta) and also Pa for the element 105. The complexation properties of the elements at indicator scale were determined in the media of HF, NH{sub 4}/HClO{sub 4}, NH{sub 4}SCN/HClO{sub 4}, NH{sub 4}SCN/HF and HCl/HF by ion exchange chromatography. The studies in fluorides media allowed us to identify the complexes in solution and to explain the shape of the experimentally observed sorption curves. The decrease of sorption for higher acid concentration in case of HF/HCl medium was interpreted by formation of chloro-fluoro-complexes. In case of the mixture NH{sub 4}SCN/HF, the particularly pronounced anti-synergic effects were observed and discussed. At the same time studies of the Hf and Ta short-lived isotopes were carried out by means of the RACHEL facility operating by the Orsay Tandem accelerator. These realistic simulations allowed optimization of different production, transportation and separation stages of the trans-actinide elements. The two experiments of 104 element production showed that this element forms in HF very stable anionic complexes similarly to its homologues Zr and Hf. (authors). 181 refs.

  18. Behaviour at the indicator scale of the elements Zr, Hf and 104, Nb,Ta and Pa (105) in very complexation media; Comportement a l`echelle des indicateurs des elements Zr, Hf, et 104, Nb, Ta, et Pa (105) en milieux tres complexants

    Energy Technology Data Exchange (ETDEWEB)

    Monroy Guzman, F [Institut de Physique Nucleaire, CNRS - IN2P3 Universite Paris Sud, 91406 Orsay Cedex (France)

    1998-12-31

    In order to determine the chemical properties of the trans-actinide elements of Z = 104 and 105 in aqueous solutions we studied their behaviour to ion exchange resin in different complex media. Due to the very short lifetimes (some tens of seconds) et to the low yield of these elements (a few atoms per irradiation hour) only very fast radiochemical techniques can be used. These severe constraints impose comparative studies of these elements with their most likely homologues to be carried out. The corresponding homologues were the elements of group 4 (Zr and Hf) for the element 104 and the elements of group 5 (Nb and Ta) and also Pa for the element 105. The complexation properties of the elements at indicator scale were determined in the media of HF, NH{sub 4}/HClO{sub 4}, NH{sub 4}SCN/HClO{sub 4}, NH{sub 4}SCN/HF and HCl/HF by ion exchange chromatography. The studies in fluorides media allowed us to identify the complexes in solution and to explain the shape of the experimentally observed sorption curves. The decrease of sorption for higher acid concentration in case of HF/HCl medium was interpreted by formation of chloro-fluoro-complexes. In case of the mixture NH{sub 4}SCN/HF, the particularly pronounced anti-synergic effects were observed and discussed. At the same time studies of the Hf and Ta short-lived isotopes were carried out by means of the RACHEL facility operating by the Orsay Tandem accelerator. These realistic simulations allowed optimization of different production, transportation and separation stages of the trans-actinide elements. The two experiments of 104 element production showed that this element forms in HF very stable anionic complexes similarly to its homologues Zr and Hf. (authors). 181 refs.

  19. Responses of lone star tick (acari: ixodidae) nymphs to the repellent deet applied in acetone and ethanol solutions in vitro bioassays

    Science.gov (United States)

    Behavioral bioassays remain a standard tool in the discovery, development, and registration of repellents. Although tick repellent bioassays tend to be rather uncomplicated, several factors can influence their outcomes. Typically repellent bioassays use a solvent, such as acetone or ethanol, to disp...

  20. Diagnosis by acetone for deterioration of breathing transformers containing an adsorbent in the insulating oil; Acetone ni yoru kyuchakuzai iri kaihogata hen`atsuki no keinen rekkado shindan

    Energy Technology Data Exchange (ETDEWEB)

    Awata, M.; Mizuno, K.; Ueda, T. [Chubu Electric Power Co. Ltd., Nagoya (Japan); Ota, N.; Ishii, T.; Tsukioka, H.

    1997-04-20

    The high-precision diagnosis for deterioration of a breathing transformer containing an adsorbent was investigated. An adsorbent (activated alumina) may be contained in oil to eliminate the deterioration product in insulating oil or the moisture. In this case, the deterioration component furfural in insulating paper is adsorbed. The concentration in furfural oil cannot be thus used for deterioration diagnosis. Acetone and furan with good relation between the adsorption characteristics for activated alumina and the insulating paper deterioration in an accelerated deterioration test can be effectively used as a new deterioration index component of insulating paper. The disassembly survey showed that acetone is valid as the index component of deterioration diagnosis. Furan is not detected in a breathing transformer, but effective in diaphragm-type and nitrogen-sealed transformers. The adsorption of acetone by activated alumina requires no correction for the change in oil temperature at about 10{degree}C. The solubility of acetone for insulating oil is 60 times at 20{degree}C as high as CO2, and the discharge rate from a breather is little (1/25). Therefore, acetone is much more excellent than CO2 as the precision of a deterioration index. 21 refs., 15 figs., 4 tabs.

  1. Simultaneous determination of bromide and iodide as acetone derivatives by gas chromatography and electron capture detection in natural waters and biological fluids

    International Nuclear Information System (INIS)

    Maros, L.; Kaldy, M.; Igaz, S.

    1989-01-01

    Oxidation of bromide and iodide ions in acidic solutions in the presence of acetone forms the corresponding acetone derivatives. Iodate was reduced with thiosulfate prior to the determination. After extraction with benzene the bromo- and iodoacetone were measured by gas chromatography using electron capture detection. The bromide and iodide contents of rainwater, drinking water, river water, seawater, oil brine, common salt, cow milk, and human blood serum were determined. The relative standard deviations for bromide at 10/sup /minus/7/ M and for iodide at 10/sup /minus/8/ M concentration were 1.9% and 3.0%, respectively, using 10-mL sample for the determination without preconcentration

  2. Mixed Messages from Garnet Lu-Hf and Sm-Nd Geochronology

    Science.gov (United States)

    Vervoort, J. D.; Wang, D.; Johnson, T. A.

    2017-12-01

    Garnet geochronology provides important information on the timing and conditions of metamorphism. As a major indicator mineral formed during metamorphism, its direct dating can not only help establish the timing of metamorphism, provide the "t" for P-T-t paths, but also, if the dated garnet can be placed in a textural context, can provide information on the timing of deformational features. With advances in chemistry and mass spectrometry, garnet Lu-Hf and Sm-Nd geochronology has become an important geochronological tool and we can now reliably (if not routinely) date a wide variety of garnet compositions formed under diverse conditions. In the course of dating a variety of lithologies using both Lu-Hf and Sm-Nd isotope systems, however, some intriguing results have emerged. Although there are many examples where the Lu-Hf and Sm-Nd systems give the same date within uncertainty, there are also many cases where these systems yield significantly different dates, and the differences between these dates can be considerable—many 10's of Ma of and even 100's of Ma. For example, in garnet-bearing Mesoproterozoic gneisses from across the Blue Ridge Province in Virginia, both Lu-Hf and Sm-Nd analyses (determined on the same solutions) define narrow time spans, but with the Sm-Nd dates systematically younger (for orthogneisses Lu-Hf dates are 1032 to 1019 Ma whereas Sm-Nd dates are 965 to 949 Ma—a difference of 67 to 80 Ma). There are many other examples of systematically younger Sm-Nd garnet dates in both the literature and with our ongoing research. Potential explanations for these differences include: 1) strong partitioning of Lu into garnet during growth yielding ages weighted toward the beginning of growth; 2) faster Lu diffusion from high Lu regions after garnet formation, potentially leading to isochron rotation and anomalously old Lu-Hf dates; and 3) differences in closure temperatures of the two isotope systems. We will review several examples of divergent Lu-Hf

  3. Acetaminophen and acetone sensing capabilities of nickel ferrite nanostructures

    Science.gov (United States)

    Mondal, Shrabani; Kumari, Manisha; Madhuri, Rashmi; Sharma, Prashant K.

    2017-07-01

    Present work elucidates the gas sensing and electrochemical sensing capabilities of sol-gel-derived nickel ferrite (NF) nanostructures based on the electrical and electrochemical properties. In current work, the choices of target species (acetone and acetaminophen) are strictly governed by their practical utility and concerning the safety measures. Acetone, the target analyte for gas sensing measurement is a common chemical used in varieties of application as well as provides an indirect way to monitor diabetes. The gas sensing experiments were performed within a homemade sensing chamber designed by our group. Acetone gas sensor (NF pellet sensor) response was monitored by tracking the change in resistance both in the presence and absence of acetone. At optimum operating temperature 300 °C, NF pellet sensor exhibits selective response for acetone in the presence of other common interfering gases like ethanol, benzene, and toluene. The electrochemical sensor fabricated to determine acetaminophen is prepared by coating NF onto the surface of pre-treated/cleaned pencil graphite electrode (NF-PGE). The common name of target analyte acetaminophen is paracetamol (PC), which is widespread worldwide as a well-known pain killer. Overdose of PC can cause renal failure even fatal diseases in children and demand accurate monitoring. Under optimal conditions NF-PGE shows a detection limit as low as 0.106 μM with selective detection ability towards acetaminophen in the presence of ascorbic acid (AA), which co-exists in our body. Use of cheap and abundant PGE instead of other electrodes (gold/Pt/glassy carbon electrode) can effectively reduce the cost barrier of such sensors. The obtained results elucidate an ample appeal of NF-sensors in real analytical applications viz. in environmental monitoring, pharmaceutical industry, drug detection, and health monitoring.

  4. An acetone bio-sniffer (gas phase biosensor) enabling assessment of lipid metabolism from exhaled breath.

    Science.gov (United States)

    Ye, Ming; Chien, Po-Jen; Toma, Koji; Arakawa, Takahiro; Mitsubayashi, Kohji

    2015-11-15

    Several volatile organic compounds (VOCs) are released from human breath or skin. Like chemical substances in blood or urine, some of these vapors can provide valuable information regarding the state of the human body. A highly sensitive acetone biochemical gas sensor (bio-sniffer) was developed and used to measure exhaled breath acetone concentration, and assess lipid metabolism based on breath acetone analysis. A fiber-optic biochemical gas sensing system was constructed by attaching a flow-cell with nicotinamide adenine dinucleotide (NADH)-dependent secondary alcohol dehydrogenase (S-ADH) immobilized membrane onto a fiber-optic NADH measurement system. The NADH measurement system utilizes an ultraviolet-light emitting diode with peak emission of 335 nm as an excitation light source. NADH is consumed by the enzymatic reaction of S-ADH, and the consumption is proportional to the concentration of acetone vapor. Phosphate buffer which contained NADH was circulated into the flow-cell to rinse products and the excessive substrates from the optode. The change of fluorescent emitted from NADH is analyzed by the PMT. Hence, fluorescence intensity decreased as the acetone concentration increased. The relationship between fluorescence intensity and acetone concentration was identified from 20 ppb to 5300 ppb. This interval included the concentration of acetone vapor in the breath of healthy people and those suffering from disorders of carbohydrate metabolism. Finally, the acetone bio-sniffer was used to measure breath acetone during an exercise stress test on an ergometer after a period of fasting. The concentration of acetone in breath was shown to significantly increase after exercise. This biosensor allows rapid, highly sensitive and selective measurement of lipid metabolism. Copyright © 2015 Elsevier B.V. All rights reserved.

  5. Catalytic Hydrogenation of Acetone to Isopropanol: An Environmentally Benign Approach

    Directory of Open Access Journals (Sweden)

    Ateeq Rahman

    2011-01-01

    Full Text Available The catalytic hydrogenation of acetone is an important area of catalytic process to produce fine chemicals. Hydrogenation of acetone has important applications for heat pumps, fuel cells or in fulfilling the sizeable demand for the production of 2-propanol. Catalytic vapour phase hydrogenation of acetone has gained attention over the decades with variety of homogeneous catalysts notably Iridium, Rh, Ru complexes and heterogeneous catalysts comprising of Raney Nickel, Raney Sponge, Ni/Al2O3, Ni/SiO2, or Co-Al2O3, Pd, Rh, Ru, Re, or Fe/Al2O3 supported on SiO2 or MgO and even CoMgAl, NiMg Al layered double hydroxide, Cu metal, CuO, Cu2O. Nano catalysts are developed for actone reduction Ni maleate, cobalt oxide prepared in organic solvents. Author present a review on acetone hydrogenation under different conditions with various homogeneous and heterogeneous catalysts studied so far in literature and new strategies to develop economic and environmentally benign approach. ©2010 BCREC UNDIP. All rights reserved(Received: 16th June 2010, Revised: 18th October 2010; Accepted: 25th October 2010[How to Cite:Ateeq Rahman. (2010. Catalytic Hydrogenation of Acetone to Isopropanol: An Environmentally Benign Approach. Bulletin of Chemical Reaction Engineering and Catalysis, 5(2: 113-126. doi:10.9767/bcrec.5.2.798.113-126][DOI: http://dx.doi.org/10.9767/bcrec.5.2.798.113-126 || or local:  http://ejournal.undip.ac.id/index.php/bcrec/article/view/798

  6. MO-HF-C alloy composition

    International Nuclear Information System (INIS)

    Whelan, E.P.; Kalns, E.

    1987-01-01

    This patent describes, as an article of manufacture, a cast ingot of a molybdenum-hafnium-carbon alloy consisting essentially by weight of about 0.6% to about 1% Hf, about 0.045% to about 0.08% C, and the balance essentially molybdenum. The amount of Hf and C present are substantially stoichiometric with respect to HfC and within about +-15% of stoichiometry. The ingot is characterized in that it has a substantially less tendency to crack compared to alloys containing Hf in excess of about 1% by weight and carbon in excess of 0.08% by weight, without substantial diminution in strength properties of the alloy

  7. Breath acetone to monitor life style interventions in field conditions: an exploratory study.

    Science.gov (United States)

    Samudrala, Devasena; Lammers, Gerwen; Mandon, Julien; Blanchet, Lionel; Schreuder, Tim H A; Hopman, Maria T; Harren, Frans J M; Tappy, Luc; Cristescu, Simona M

    2014-04-01

    To assess whether breath acetone concentration can be used to monitor the effects of a prolonged physical activity on whole body lipolysis and hepatic ketogenesis in field conditions. Twenty-three non-diabetic, 11 type 1 diabetic, and 17 type 2 diabetic subjects provided breath and blood samples for this study. Samples were collected during the International Four Days Marches, in the Netherlands. For each participant, breath acetone concentration was measured using proton transfer reaction ion trap mass spectrometry, before and after a 30-50 km walk on four consecutive days. Blood non-esterified free fatty acid (NEFA), beta-hydroxybutyrate (BOHB), and glucose concentrations were measured after walking. Breath acetone concentration was significantly higher after than before walking, and was positively correlated with blood NEFA and BOHB concentrations. The effect of walking on breath acetone concentration was repeatedly observed on all four consecutive days. Breath acetone concentrations were higher in type 1 diabetic subjects and lower in type 2 diabetic subjects than in control subjects. Breath acetone can be used to monitor hepatic ketogenesis during walking under field conditions. It may, therefore, provide real-time information on fat burning, which may be of use for monitoring the lifestyle interventions. Copyright © 2014 The Obesity Society.

  8. Study on the adducts formation of Zr and Hf chelates

    International Nuclear Information System (INIS)

    Ree, Chin Taik; Jung, Young Sam; Park, Jun Kown

    1986-01-01

    The synergistic effect observed in Zr(IV) and Hf(IV) extraction from strong perchloric acid solutions by the mixtures of 2-Thenoyltri-fluoroacetone(TTA) and Octanols is shown to be caused by the formation of a mixed complex, M(TTA) 3 XS (M=Zr(IV), HF(IV), X=ClO 4 - , S=Octanol). One of the four TTA molecules coordinated at lower HClO 4 concentration to the metal as bidendate ligand seems to be changed to monodendate due to increasing HClO 4 concentration. The monodenate TTA ligand leaves the coordination site, finally, due to the activity of perchlorate at higher concentration and the additional coordination of an Octanol molecule seems to be allowed to the vaccant site which shows the synergistic extraction phenomena. (Author)

  9. The rotational excitation of HF by H

    Science.gov (United States)

    Desrousseaux, Benjamin; Lique, François

    2018-06-01

    The HF molecule is a key tracer of molecular hydrogen in diffuse interstellar medium (ISM). Accurate modelling of the HF abundance in such media requires one to model its excitation by both radiation and collisions. In diffuse ISM, the dominant collisional partners are atomic and molecular hydrogen. We report quantum time-independent calculations of collisional cross-sections and rate coefficients for the rotational excitation of HF by H. The reactive hydrogen exchange channels are taken into account in the scattering calculations. For the first time, HF-H rate coefficients are provided for temperature ranging from 10 to 500 K. The strongest collision-induced rotational HF transitions are those with Δj = 1, and the order of magnitude of the new HF-H rate coefficients is similar to that of the HF-H2 ones previously computed. As a first application, we simulate the excitation of HF by both H and H2 in typical diffuse ISM. We show that, depending on the rotational transition, hydrogen atoms increase or decrease the simulated excitation temperatures compared to collisional excitation only due to H2 molecules. Such results suggest that the new HF-H collisional data have to be used for properly modelling the abundance of HF in diffuse ISM.

  10. Simultaneous analysis of rotational and vibrational-rotational spectra of DF and HF to obtain irreducible molecular constants for HF

    International Nuclear Information System (INIS)

    Horiai, Koui; Uehara, Hiromichi

    2011-01-01

    Graphical abstract: Available rotational and vibrational-rotational spectral lines of DF and HF are analyzed simultaneously using a non-Born-Oppenheimer effective Hamiltonian. Research highlights: → Simultaneous analysis of DF and HF spectral data. → Application of a non-Born-Oppenheimer effective Hamiltonian. → Twenty irreducible molecular constants for HF have been determined. - Abstract: Analytic expressions of corrections for the breakdown of the Born-Oppenheimer approximation to Dunham's Y ij with optimal parameters, i.e., determinable clusters of expansion coefficients, are applied to a data analysis of the rotational and vibrational-rotational transitions of HF reported in the literature. All the available spectral lines of the two isotopologues, DF and HF, are simultaneously fitted to a single set of molecular parameters of HF within experimental errors. Fitting of a data set of 595 spectral transitions for DF and HF has generated only 20 minimal independent parameter values, i.e., 'irreducible' molecular constants of HF, that are sufficient to precisely generate 82 Y ij coefficients and 144 band constants in total: 41 Y ij and 72 band constants each for DF and HF.

  11. Interactions of ionic liquids and acetone: thermodynamic properties, quantum-chemical calculations, and NMR analysis.

    Science.gov (United States)

    Ruiz, Elia; Ferro, Victor R; Palomar, Jose; Ortega, Juan; Rodriguez, Juan Jose

    2013-06-20

    The interactions between ionic liquids (ILs) and acetone have been studied to obtain a further understanding of the behavior of their mixtures, which generally give place to an exothermic process, mutual miscibility, and negative deviation of Raoult's law. COSMO-RS was used as a suitable computational method to systematically analyze the excess enthalpy of IL-acetone systems (>300), in terms of the intermolecular interactions contributing to the mixture behavior. Spectroscopic and COSMO-RS results indicated that acetone, as a polar compound with strong hydrogen bond acceptor character, in most cases, establishes favorable hydrogen bonding with ILs. This interaction is strengthened by the presence of an acidic cation and an anion with dispersed charge and non-HB acceptor character in the IL. COSMO-RS predictions indicated that gas-liquid and vapor-liquid equilibrium data for IL-acetone systems can be finely tuned by the IL selection, that is, acting on the intermolecular interactions between the molecular and ionic species in the liquid phase. NMR measurements for IL-acetone mixtures at different concentrations were also carried out. Quantum-chemical calculations by using molecular clusters of acetone and IL species were finally performed. These results provided additional evidence of the main role played by hydrogen bonding in the behavior of systems containing ILs and HB acceptor compounds, such as acetone.

  12. Atomic scale engineering of HfO{sub 2}-based dielectrics for future DRAM applications

    Energy Technology Data Exchange (ETDEWEB)

    Dudek, Piotr

    2011-02-14

    Modern dielectrics in combination with appropriate metal electrodes have a great potential to solve many difficulties associated with continuing miniaturization process in the microelectronic industry. One significant branch of microelectronics incorporates dynamic random access memory (DRAM) market. The DRAM devices scaled for over 35 years starting from 4 kb density to several Gb nowadays. The scaling process led to the dielectric material thickness reduction, resulting in higher leakage current density, and as a consequence higher power consumption. As a possible solution for this problem, alternative dielectric materials with improved electrical and material science parameters were intensively studied by many research groups. The higher dielectric constant allows the use of physically thicker layers with high capacitance but strongly reduced leakage current density. This work focused on deposition and characterization of thin insulating layers. The material engineering process was based on Si cleanroom compatible HfO{sub 2} thin films deposited on TiN metal electrodes. A combined materials science and dielectric characterization study showed that Ba-added HfO{sub 2} (BaHfO{sub 3}) films and Ti-added BaHfO{sub 3} (BaHf{sub 0.5}Ti{sub 0.5}O{sub 3}) layers are promising candidates for future generation of state-of-the-art DRAMs. In especial a strong increase of the dielectric permittivity k was achieved for thin films of cubic BaHfO{sub 3} (k{proportional_to}38) and BaHf{sub 0.5}Ti{sub 0.5}O{sub 3} (k{proportional_to}90) with respect to monoclinic HfO{sub 2} (k{proportional_to}19). Meanwhile the CET values scaled down to 1 nm for BaHfO{sub 3} and {proportional_to}0.8 nm for BaHf{sub 0.5}Ti{sub 0.5}O{sub 3} with respect to HfO{sub 2} (CET=1.5 nm). The Hf{sup 4+} ions substitution in BaHfO{sub 3} by Ti{sup 4+} ions led to a significant decrease of thermal budget from 900 C for BaHfO{sub 3} to 700 C for BaHf{sub 0.5}Ti{sub 0.5}O{sub 3}. Future studies need to focus

  13. Conditioned Place Preference to Acetone Inhalation and the Effects on Locomotor Behavior and 18FDG Uptake

    Energy Technology Data Exchange (ETDEWEB)

    Pai, J.C.; Dewey, S.L.; Schiffer, W.; Lee, D.

    2006-01-01

    Acetone is a component in many inhalants that have been widely abused. While other solvents have addictive potential, such as toluene, it is unclear whether acetone alone contains addictive properties. The locomotor, relative glucose metabolism and abusive effects of acetone inhalation were studied in animals using the conditioned place preference (CPP) paradigm and [18F]2-fluorodeoxy-D-glucose (18FDG) imaging. The CPP apparatus contains two distinct conditioning chambers and a middle adaptation chamber, each lined with photocells to monitor locomotor activity. Adolescent Sprague-Dawley rats (n=16; 90-110 g) were paired with acetone in least preferred conditioning chamber, determined on the pretest day. The animals were exposed to a 10,000 ppm dose for an hour, alternating days with air. A CPP test was conducted after the 3rd, 6th and 12th pairing. In these same animals, the relative glucose metabolism effects were determined using positron emission tomography (PET) imaging with 18FDG. Following the 3rd pairing, there was a significant aversion to the acetone paired chamber (190.9 ± 13.7 sec and 241.7 ± 16.9 sec, acetone and air, respectively). After the 6th pairing, there was no significant preference observed with equal time spent in each chamber (222 ± 21 sec and 207 ± 20 sec, acetone and air-paired, respectively). A similar trend was observed after the 12th pairing (213 ± 21 sec and 221 ± 22 sec, acetone and air-paired, respectively). Locomotor analysis indicated a significant decrease (p<0.05) from air pairings to acetone pairings on the first and sixth pairings. The observed locomotor activity was characteristic of central nervous system (CNS) depressants, without showing clear abusive effects in this CPP model. In these studies, acetone vapors were not as reinforcing as other solvents, shown by overall lack of preference for the acetone paired side of the chamber. PET imaging indicated a regionally specific distribution of 18FDG uptake following

  14. Purification and Characterization of the Acetone Carboxylase of Cupriavidus metallidurans Strain CH34

    Science.gov (United States)

    Rosier, Caroline; Leys, Natalie; Henoumont, Céline; Mergeay, Max

    2012-01-01

    Acetone carboxylase (Acx) is a key enzyme involved in the biodegradation of acetone by bacteria. Except for the Helicobacteraceae family, genome analyses revealed that bacteria that possess an Acx, such as Cupriavidus metallidurans strain CH34, are associated with soil. The Acx of CH34 forms the heterohexameric complex α2β2γ2 and can carboxylate only acetone and 2-butanone in an ATP-dependent reaction to acetoacetate and 3-keto-2-methylbutyrate, respectively. PMID:22492439

  15. Fermentation of sugar solutions to butanol, acetone, and ethanol

    Energy Technology Data Exchange (ETDEWEB)

    Karsch, W; Schoeder, K

    1956-04-05

    A three-stage (two preliminary and one main stage) fermentation process with a high yield of fermentation products (BuOH, Me/sub 2/CO, and EtOH) due to the addition of Ca(OAc)/sub 2/ or AcOH is described. According to this the acetate is added in the first and second stages only; this saves a large amount of acetate. The acetate level of the solution can also be regulated by mixing fermentable solutions of different AcOH content.

  16. A fully integrated standalone portable cavity ringdown breath acetone analyzer

    Science.gov (United States)

    Sun, Meixiu; Jiang, Chenyu; Gong, Zhiyong; Zhao, Xiaomeng; Chen, Zhuying; Wang, Zhennan; Kang, Meiling; Li, Yingxin; Wang, Chuji

    2015-09-01

    Breath analysis is a promising new technique for nonintrusive disease diagnosis and metabolic status monitoring. One challenging issue in using a breath biomarker for potential particular disease screening is to find a quantitative relationship between the concentration of the breath biomarker and clinical diagnostic parameters of the specific disease. In order to address this issue, we need a new instrument that is capable of conducting real-time, online breath analysis with high data throughput, so that a large scale of clinical test (more subjects) can be achieved in a short period of time. In this work, we report a fully integrated, standalone, portable analyzer based on the cavity ringdown spectroscopy technique for near-real time, online breath acetone measurements. The performance of the portable analyzer in measurements of breath acetone was interrogated and validated by using the certificated gas chromatography-mass spectrometry. The results show that this new analyzer is useful for reliable online (online introduction of a breath sample without pre-treatment) breath acetone analysis with high sensitivity (57 ppb) and high data throughput (one data per second). Subsequently, the validated breath analyzer was employed for acetone measurements in 119 human subjects under various situations. The instrument design, packaging, specifications, and future improvements were also described. From an optical ringdown cavity operated by the lab-set electronics reported previously to this fully integrated standalone new instrument, we have enabled a new scientific tool suited for large scales of breath acetone analysis and created an instrument platform that can even be adopted for study of other breath biomarkers by using different lasers and ringdown mirrors covering corresponding spectral fingerprints.

  17. A fully integrated standalone portable cavity ringdown breath acetone analyzer.

    Science.gov (United States)

    Sun, Meixiu; Jiang, Chenyu; Gong, Zhiyong; Zhao, Xiaomeng; Chen, Zhuying; Wang, Zhennan; Kang, Meiling; Li, Yingxin; Wang, Chuji

    2015-09-01

    Breath analysis is a promising new technique for nonintrusive disease diagnosis and metabolic status monitoring. One challenging issue in using a breath biomarker for potential particular disease screening is to find a quantitative relationship between the concentration of the breath biomarker and clinical diagnostic parameters of the specific disease. In order to address this issue, we need a new instrument that is capable of conducting real-time, online breath analysis with high data throughput, so that a large scale of clinical test (more subjects) can be achieved in a short period of time. In this work, we report a fully integrated, standalone, portable analyzer based on the cavity ringdown spectroscopy technique for near-real time, online breath acetone measurements. The performance of the portable analyzer in measurements of breath acetone was interrogated and validated by using the certificated gas chromatography-mass spectrometry. The results show that this new analyzer is useful for reliable online (online introduction of a breath sample without pre-treatment) breath acetone analysis with high sensitivity (57 ppb) and high data throughput (one data per second). Subsequently, the validated breath analyzer was employed for acetone measurements in 119 human subjects under various situations. The instrument design, packaging, specifications, and future improvements were also described. From an optical ringdown cavity operated by the lab-set electronics reported previously to this fully integrated standalone new instrument, we have enabled a new scientific tool suited for large scales of breath acetone analysis and created an instrument platform that can even be adopted for study of other breath biomarkers by using different lasers and ringdown mirrors covering corresponding spectral fingerprints.

  18. Change of Exhaled Acetone Concentration in a Diabetic Patient with Acute Decompensated Heart Failure.

    Science.gov (United States)

    Yokokawa, Tetsuro; Ichijo, Yasuhiro; Houtsuki, Yu; Matsumoto, Yoshiyuki; Oikawa, Masayoshi; Yoshihisa, Akiomi; Sugimoto, Koichi; Nakazato, Kazuhiko; Suzuki, Hitoshi; Saitoh, Shu-Ichi; Shimouchi, Akito; Takeishi, Yasuchika

    2017-10-21

    In heart failure patients, exhaled acetone concentration, a noninvasive biomarker, is increased according to heart failure severity. Moreover, exhaled acetone concentration is also known to be affected by diabetes mellitus. However, there have been no reports on exhaled acetone concentration in heart failure patients with diabetes mellitus. A 77-year old man was admitted to our hospital with acute decompensated heart failure and atrioventricular block. He had controlled diabetes mellitus under insulin treatment with hemoglobin A1c of 6.5%. He underwent treatment of diuretics and permanent pacemaker implantation. His condition improved and he was discharged at Day 12. Due to the heart failure improvement, his levels of exhaled acetone concentration decreased from 1.623 ppm at admission to 0.664 ppm at discharge. This is the first report to reveal a change of exhaled acetone concentration in a diabetic patient with acute decompensated heart failure.

  19. Phase and Microstructural Correlation of Spark Plasma Sintered HfB2-ZrB2 Based Ultra-High Temperature Ceramic Composites

    Directory of Open Access Journals (Sweden)

    Ambreen Nisar

    2017-07-01

    Full Text Available The refractory diborides (HfB2 and ZrB2 are considered as promising ultra-high temperature ceramic (UHTCs where low damage tolerance limits their application for the thermal protection system in re-entry vehicles. In this regard, SiC and CNT have been synergistically added as the sintering aids and toughening agents in the spark plasma sintered (SPS HfB2-ZrB2 system. Herein, a novel equimolar composition of HfB2 and ZrB2 has shown to form a solid-solution which then allows compositional tailoring of mechanical properties (such as hardness, elastic modulus, and fracture toughness. The hardness of the processed composite is higher than the individual phase hardness up to 1.5 times, insinuating the synergy of SiC and CNT reinforcement in HfB2-ZrB2 composites. The enhanced fracture toughness of CNT reinforced composite (up to a 196% increment surpassing that of the parent materials (ZrB2/HfB2-SiC is attributed to the synergy of solid solution formation and enhanced densification (~99.5%. In addition, the reduction in the analytically quantified interfacial residual tensile stress with SiC and CNT reinforcements contribute to the enhancement in the fracture toughness of HfB2-ZrB2-SiC-CNT composites, mandatory for aerospace applications.

  20. Development of HF-systems for electron storage systems

    International Nuclear Information System (INIS)

    Androsov, V.P.; Karnaukhov, I.M.; Popkov, Yu.P.; Reva, S.N.; Telegin, Yu.N.

    1999-01-01

    Development of HF systems for electron storages is described. Its final task is construction of 100 kW HF station at 699,3 MHz frequency consisting from low-power HF system, klystron amplifier, wave line for HF power transmission and accelerating section. Functional parameters of HF station are given

  1. TaxHf1−xB2–SiC multiphase oxidation protective coating for SiC-coated carbon/carbon composites

    International Nuclear Information System (INIS)

    Ren, Xuanru; Li, Hejun; Fu, Qiangang; Li, Kezhi

    2014-01-01

    Highlights: • Ta x Hf 1−x B 2 –SiC coating was prepared on SiC coated C/C by in-situ reaction method. • TaB 2 and HfB 2 were introduced in the form of solid solution Ta x Hf 1−x B 2 . • The coating could protect C/C for 1480 h with only 0.57% mass loss at 1773 K in air. • Oxidation layer consists of out Ta–Si–O compound layer and inner SiO 2 glass layer. • Ta–Si–O compound silicate layer presents a better stability than SiO 2 glass layer. - Abstract: A Ta x Hf 1−x B 2 –SiC coating was prepared by in-situ reaction method on SiC coated C/C composites. Ta x Hf 1−x B 2 phase is the form of solid solution between TaB 2 and HfB 2 . Isothermal oxidation behavior at 1773 K and ablation behavior of the coated C/C were tested. Ta x Hf 1−x B 2 –SiC/SiC coating could protect the C/C from oxidation at 1773 K for 1480 h and ablation above 2200 K for 40 s. During oxidation, oxides of Ta and Hf atoms exist as “pinning phases” in the compound glass layer consisted of outer Ta–Si–O compound silicate layer and inner SiO 2 glass layer, which was responsible for the excellent oxidation resistance

  2. Sensing behavior of acetone vapors on TiO_2 nanostructures — application of density functional theory

    Directory of Open Access Journals (Sweden)

    V. Nagarajan

    2017-12-01

    Full Text Available The electronic properties of TiO_2 nanostructure are explored using density functional theory. The adsorption properties of acetone on TiO_2 nanostructure are studied in terms of adsorption energy, average energy gap variation and Mulliken charge transfer. The density of states spectrum and the band structure clearly reveals the adsorption of acetone on TiO_2 nanostructures. The variation in the energy gap and changes in the density of charge are observed upon adsorption of acetone on n-type TiO_2 base material. The results of DOS spectrum reveal that the transfer of electrons takes place between acetone vapor and TiO_2 base material. The findings show that the adsorption property of acetone is more favorable on TiO_2 nanostructure. Suitable adsorption sites of acetone on TiO_2 nanostructure are identified at atomistic level. From the results, it is confirmed that TiO_2 nanostructure can be efficiently utilized as a sensing element for the detection of acetone vapor in a mixed environment.

  3. (Ternary liquid + liquid) equilibria for (water + acetone + α-pinene, or β-pinene, or limonene) mixtures

    International Nuclear Information System (INIS)

    Li Xiaoli; Tamura, Kazuhiro

    2010-01-01

    (Ternary liquid + liquid) equilibria (tie-lines) of (water + acetone + α-pinene) at T = (288.15, 298.15, and 308.15) K and (water + acetone + β-pinene, or limonene) at T = 298.15 K have been measured. The experimental (ternary liquid + liquid) equilibrium data have been correlated successfully by the original UNIQUAC and modified UNIQUAC models. The modified UNIQUAC model reproduced accurately the experimental results for the (water + acetone + α-pinene) system at all the temperatures but fairly agreed with the experimental data for the (water + acetone + β-pinene, or limonene) systems.

  4. A two-stage combined trickle bed reactor/biofilter for treatment of styrene/acetone vapor mixtures.

    Science.gov (United States)

    Vanek, Tomas; Halecky, Martin; Paca, Jan; Zapotocky, Lubos; Gelbicova, Tereza; Vadkertiova, Renata; Kozliak, Evguenii; Jones, Kim

    2015-01-01

    Performance of a two-stage biofiltration system was investigated for removal of styrene-acetone mixtures. High steady-state acetone loadings (above C(in)(Ac) = 0.5 g.m(-3) corresponding to the loadings > 34.5 g.m(-3).h(-1)) resulted in a significant inhibition of the system's performance in both acetone and styrene removal. This inhibition was shown to result from the acetone accumulation within the upstream trickle-bed bioreactor (TBR) circulating mineral medium, which was observed by direct chromatographic measurements. Placing a biofilter (BF) downstream to this TBR overcomes the inhibition as long as the biofilter has a sufficient bed height. A different kind of inhibition of styrene biodegradation was observed within the biofilter at very high acetone loadings (above C(in)(Ac) = 1.1 g.m(-3) or 76 g.m(-3).h(-1) loading). In addition to steady-state measurements, dynamic tests confirmed that the reactor overloading can be readily overcome, once the accumulated acetone in the TBR fluids is degraded. No sizable metabolite accumulation in the medium was observed for either TBR or BF. Analyses of the biodegradation activities of microbial isolates from the biofilm corroborated the trends observed for the two-stage biofiltration system, particularly the occurrence of an inhibition threshold by excess acetone.

  5. Coulomb-nuclear interference measurements of 168Yb, 176Hf, 178Hf, and 180Hf and lifetime measurements in 186Hg

    International Nuclear Information System (INIS)

    Nettles, W.G.

    1979-01-01

    Alpha scattering measurements were performed at center-of-mass energies near the Coulomb barrier. These energies allow for nuclear as well as pure Coulomb forces to play a significant role in the excitation process. The interference of these two forces is very sensitive to the sign of the E4 ground-state moment, whereas pure Coulomb excitation is not. Systematics of the E4 moments of the rare earth mass region indicate a transition in the magnitude and sign of the reduced matrix element of the M(E4) operator between 0 + and 4 + states from small and positive to large and negative between Yb and W. Previous Coulomb-nuclear interference measurements show that this reduced matrix element for 180 Hf is large and negative. The present results agree with that conclusion. It is also shown that the above reduced matrix element for 178 Hf, like that of 180 Hf, is large and negative. The small and positive moment (matrix element) for 168 Yb is seen to be consistent with the experimental data. No conclusions are drawn for the E4 moment in 176 Hf. The measurement of nuclear lifetimes shorter than 500 ps requires the use of plastic scintilltor detectors. These detectors, however have very poor energy resolution. A system is described that uses plastic scintillators with a magnetic lens spectrometer for energy selection. The system was used to measure the lifetime of the 522-keV 0 + sate in 186 Hf. A data analysis method using higher-order distribution moments is also presented

  6. Zeolites as alcohol adsorbents from aqueous solutions

    Directory of Open Access Journals (Sweden)

    Cekova Blagica

    2006-01-01

    Full Text Available The potential usage of zeolites as adsorbents for the removal of organic molecules from water was investigated in a series of experiments with aqueous solutions of lower alcohols. This could represent a simple solution to the problem of cleaning up industrial wastewater as well as recovering valuable chemicals at relatively low costs. Adsorption isotherms of the Langmuir type were applied, and calculations showed that the amount of propanol adsorbed on silicalite corresponded to approximately 70% of the pore volume. The adsorption process is simple, and recovery of the more concentrated products is easily done by heat treatment and/or at lowered pressures. Adsorption experiments with aqueous acetone showed that silicalite had approximately the same adsorption capacity for acetone as for n-propanol. Heats of adsorption were determined calorimetrically.

  7. European coordination for coastal HF radar data in EMODnet Physics

    Science.gov (United States)

    Mader, Julien; Novellino, Antonio; Gorringe, Patrick; Griffa, Annalisa; Schulz-Stellenfleth, Johannes; Montero, Pedro; Montovani, Carlo; Ayensa, Garbi; Vila, Begoña; Rubio, Anna; Sagarminaga, Yolanda

    2015-04-01

    Historically, joint effort has been put on observing open ocean, organizing, homogenizing, sharing and reinforcing the impact of the acquired information based on one technology: ARGO with profilers Argo floats, EuroSites, ESONET-NoE, FixO3 for deep water platforms, Ferrybox for stations in ships of opportunities, and GROOM for the more recent gliders. This kind of networking creates synergies and makes easier the implementation of this source of data in the European Data exchange services like EMODnet, ROOSs portals, or any applied services in the Blue economy. One main targeted improvement in the second phase of EMODnet projects is the assembling of data along coastline. In that sense, further coordination is recommended between platform operators around a specific technology in order to make easier the implementation of the data in the platforms (4th EuroGOOS DATAMEQ WG). HF radar is today recognized internationally as a cost-effective solution to provide high spatial and temporal resolution current maps (depending on the instrument operation frequency, covering from a few kilometres offshore up to 200 km) that are needed for many applications for issues related to ocean surface drift or sea state characterization. Significant heterogeneity still exists in Europe concerning technological configurations, data processing, quality standards and data availability. This makes more difficult the development of a significant network for achieving the needed accessibility to HF Radar data for a pan European use. EuroGOOS took the initiative to lead and coordinate activities within the various observation platforms by establishing a number of Ocean Observing Task Teams such as HF-Radars. The purpose is to coordinate and join the technological, scientific and operational HF radar communities at European level. The goal of the group is on the harmonization of systems requirements, systems design, data quality, improvement and proof of the readiness and standardization of

  8. Crystal structure of the binder phase in a model HfC-TiC-Ni material

    International Nuclear Information System (INIS)

    Heiligers, Christiane; Neethling, Johannes H.

    2008-01-01

    The crystal structure of the binder phase in a model HfC-TiC-Ni sample produced by hot pressing is investigated. The nature of the binder depends on the amount of Hf and Ti that remains in solution with Ni after cooling. Four different crystal structures are identified by analysis of electron diffraction patterns obtained using transmission electron microscopy techniques and the composition of the phases determined by energy dispersive X-ray spectrometry. Three of the phases are cubic; Ni, Ni 3 (Ti,Hf) and Ni 23 (Ti,Hf) 6 with lattice parameters of 3.52 ± 0.05, 3.52 ± 0.03 and 10.70 ± 0.40 A, respectively. The hexagonal phase is an intermetallic Ni 3 Ti phase, with lattice parameters of a = b = 5.00 ± 0.20 A and c = 8.16 ± 0.20 A. The crystal structures are confirmed by simulations of the electron diffraction patterns using JEMS software

  9. Skin barrier disruption by acetone: observations in a hairless mouse skin model

    NARCIS (Netherlands)

    Rissmann, R.; Oudshoorn, M.H.M.; Hennink, W.E.; Ponec, M.; Bouwstra, J.A.

    2009-01-01

    To disrupt the barrier function of the skin, different in vivo methods have been established, e.g., by acetone wiping or tape-stripping. In this study, the acetone-induced barrier disruption of hairless mice was investigated in order to establish a reliable model to study beneficial, long-term

  10. Impact of Exhaled Breath Acetone in the Prognosis of Patients with Heart Failure with Reduced Ejection Fraction (HFrEF. One Year of Clinical Follow-up.

    Directory of Open Access Journals (Sweden)

    Fabiana G Marcondes-Braga

    Full Text Available The identification of new biomarkers of heart failure (HF could help in its treatment. Previously, our group studied 89 patients with HF and showed that exhaled breath acetone (EBA is a new noninvasive biomarker of HF diagnosis. However, there is no data about the relevance of EBA as a biomarker of prognosis.To evaluate whether EBA could give prognostic information in patients with heart failure with reduced ejection fraction (HFrEF.After breath collection and analysis by gas chromatography-mass spectrometry and by spectrophotometry, the 89 patients referred before were followed by one year. Study physicians, blind to the results of cardiac biomarker testing, ascertained vital status of each study participant at 12 months.The composite endpoint death and heart transplantation (HT were observed in 35 patients (39.3%: 29 patients (32.6% died and 6 (6.7% were submitted to HT within 12 months after study enrollment. High levels of EBA (≥3.7μg/L, 50th percentile were associated with a progressively worse prognosis in 12-month follow-up (log-rank = 11.06, p = 0.001. Concentrations of EBA above 3.7μg/L increased the risk of death or HT in 3.26 times (HR = 3.26, 95%CI = 1.56-6.80, p = 0.002 within 12 months. In a multivariable cox regression model, the independent predictors of all-cause mortality were systolic blood pressure, respiratory rate and EBA levels.High EBA levels could be associated to poor prognosis in HFrEF patients.

  11. Impact of Exhaled Breath Acetone in the Prognosis of Patients with Heart Failure with Reduced Ejection Fraction (HFrEF). One Year of Clinical Follow-up

    Science.gov (United States)

    Saldiva, Paulo H. N.; Mangini, Sandrigo; Issa, Victor S.; Ayub-Ferreira, Silvia M.; Bocchi, Edimar A.

    2016-01-01

    Background The identification of new biomarkers of heart failure (HF) could help in its treatment. Previously, our group studied 89 patients with HF and showed that exhaled breath acetone (EBA) is a new noninvasive biomarker of HF diagnosis. However, there is no data about the relevance of EBA as a biomarker of prognosis. Objectives To evaluate whether EBA could give prognostic information in patients with heart failure with reduced ejection fraction (HFrEF). Methods After breath collection and analysis by gas chromatography-mass spectrometry and by spectrophotometry, the 89 patients referred before were followed by one year. Study physicians, blind to the results of cardiac biomarker testing, ascertained vital status of each study participant at 12 months. Results The composite endpoint death and heart transplantation (HT) were observed in 35 patients (39.3%): 29 patients (32.6%) died and 6 (6.7%) were submitted to HT within 12 months after study enrollment. High levels of EBA (≥3.7μg/L, 50th percentile) were associated with a progressively worse prognosis in 12-month follow-up (log-rank = 11.06, p = 0.001). Concentrations of EBA above 3.7μg/L increased the risk of death or HT in 3.26 times (HR = 3.26, 95%CI = 1.56–6.80, p = 0.002) within 12 months. In a multivariable cox regression model, the independent predictors of all-cause mortality were systolic blood pressure, respiratory rate and EBA levels. Conclusions High EBA levels could be associated to poor prognosis in HFrEF patients. PMID:28030609

  12. Combustion synthesized hierarchically porous WO{sub 3} for selective acetone sensing

    Energy Technology Data Exchange (ETDEWEB)

    Dong, Chengjun; Liu, Xu; Guan, Hongtao; Chen, Gang; Xiao, Xuechun [Department of Materials Science and Engineering, Yunnan University, 650091, Kunming (China); Djerdj, Igor [Ruđer Bošković Institute, Bijenička 54, 10000, Zagreb (Croatia); Wang, Yude, E-mail: ydwang@ynu.edu.cn [Department of Materials Science and Engineering, Yunnan University, 650091, Kunming (China); Yunnan Province Key Lab of Mico-Nano Materials and Technology, Yunnan University, 650091, Kunming (China)

    2016-12-01

    An easy, inexpensive combustion route was designed to synthesize hierarchically porous WO{sub 3}. The tungsten source was fresh peroxiotungstic acid by dissolving tungsten powder into hydrogen peroxide. To promote the combustion reaction, a combined fuel of both glycine and hydrazine hydrate was used. The microstructure was well-connected pores comprised of subunit nanoparticles. Upon exposing towards acetone gas, the porous WO{sub 3} based sensor exhibits high gas response, rapid response and recovery, and good selectivity in the range of 5–1000 ppm under working temperature of 300 °C. This excellent sensing performance was plausibly attributed to the porous morphology, which hence provides more active sites for the gas molecules' reaction. - Graphical abstract: Hierarchically porous WO{sub 3} synthesized by combustion process exhibits high gas response, rapid response and recovery, and excellent selectivity for acetone, making it to be promising candidates for practical detectors for acetone. - Highlights: • Hierarchically porous WO{sub 3} synthesized by combustion process. • Hierarchically porous WO{sub 3} exhibits high gas response and excellent selectivity for acetone. • The excellent sensing property was plausibly attributed to the porous morphology.

  13. Gadolinium-, Calcium-, copper- and zirc complexes with riboflavin in acetone and acetonitrile

    International Nuclear Information System (INIS)

    Lugina, L.N.; Romanenko, V.I.; Davidenko, N.K.

    1983-01-01

    Using the methods of solubility and spectrophotometry, stability copstants Of complexes RFMSSUp(n+) (RF=riboflavin, Mnsup(n+)=Cdsup(3+), Ca 2+ , Cu 2+ and Zn 2+ ) in acetone and acetonitrile against the background of 1 mol/l LiClO 4 x3H 2 O have been determined. It was found that stability of copper and zinc complexes with riboflavin in acetone is higher than in acetonitrile, whereas the stability of gadolinium and calcium complexes, on the contrary, is higher in acetonitrile than in acetone. It is shown that the character of the absorption spectrum change of riboflavin in complexing with metal ions depends on the nature of coordinating cation

  14. Application of finite inverse gas chromatography in hypromellose acetate succinate-water-acetone systems.

    Science.gov (United States)

    Chiu, Sheng-Wei; Sturm, Derek R; Moser, Justin D; Danner, Ronald P

    2016-09-30

    A modification of a GC was developed to investigate both infinitely dilute and finite concentrations of solvents in polymers. Thermodynamic properties of hypromellose acetate succinate (HPMCAS-L)-acetone-water systems are important for the optimization of spray-drying processes used in pharmaceutical manufacturing of solid dispersion formulations. These properties, at temperatures below the glass transition temperature, were investigated using capillary column inverse gas chromatography (CCIGC). Water was much less soluble in the HPMCAS-L than acetone. Experiments were also conducted at infinitely dilute concentrations of one of the solvents in HPMCAS-L that was already saturated with the other solvent. Overall the partitioning of the water was not significantly affected by the presence of either water or acetone in the polymer. The acetone partition coefficient decreased as either acetone or water was added to the HPMCAS-L. A representation of the HPMCAS-L structure in terms of UNIFAC groups has been developed. With these groups, the UNIFAC-vdw-FV model did a reasonable job of predicting the phase equilibria in the binary and ternary systems. The Flory-Huggins correlation with fitted interaction parameters represented the data well. Copyright © 2016 Elsevier B.V. All rights reserved.

  15. High-temperature grain size stabilization of nanocrystalline Fe–Cr alloys with Hf additions

    Energy Technology Data Exchange (ETDEWEB)

    Li, Lulu, E-mail: lli18@ncsu.edu; Saber, Mostafa; Xu, Weizong; Zhu, Yuntian; Koch, Carl C.; Scattergood, Ronald O.

    2014-09-08

    The influence of 1–4 at% Hf additions on the thermal stability of mechanically alloyed nanocrystalline Fe–14Cr alloys was studied in this work. XRD-calculated grain size and microhardness results were reported versus isochronal annealing treatments up to 1100 °C. Microstructural evolution was investigated using channeling contrast FIB imaging and TEM. Grain size of samples with 4 at% Hf was found to be maintained in the nanoscale range at temperatures up to 1000 °C. Zener pinning was considered as a major source of high temperature grain size stabilization. By comparing the Orowan strengthening contribution to the total hardness, the deviation of grain size predictions from the actual grain size in Fe–14Cr–4Hf suggests the presence of thermodynamic stabilization by the solute segregation to grain boundaries (GBs). A predictive thermodynamic model indicates that the thermodynamic stabilization can be expected.

  16. Oscillatory bromate-oxalic acid-Ce-acetone-sulfuric acid reaction, in CSTR

    International Nuclear Information System (INIS)

    Pereira, Janaina A.M.; Faria, Roberto B.

    2004-01-01

    Periodic oscillations were observed for the first time, in a CSTR, in the system bromate-oxalic acid-Ce(IV)-acetone-sulfuric acid, in a CSTR. A reaction between Ce(IV) and acetone, until now not described in the literature and occurring before the addition of the reagents to the reactor, was identified as a decisive factor for the appearing of the regular oscillations. (author)

  17. Kinetic features of cadmium electrodeposition in iodide water-acetone electrolytes

    International Nuclear Information System (INIS)

    Kuznetsov, V.V.; Skibina, L.M.; Khalikov, R.R.

    2006-01-01

    Based on the data of chronopotentiometric, galvanostatic, potentiodynamic, and impedance measurements, the composition of aqueous acetone electrolyte is studied for its effect on the rate of cadmium(II) electroreduction in iodide media. The adsorption of I - ions on the cadmium cathode surface is shown to depend on the interaction mechanism between the components of water-acetone mixtures. During a competitive adsorption of anions and organic solvent molecules, this affects the mechanism and the rate of electrodeposition and also the coating quality [ru

  18. Hf på VUC

    DEFF Research Database (Denmark)

    Pless, Mette; Hansen, Niels-Henrik Møller

    . Konkret har forskningsprojektet 3 mål: At afdække hf-kursisternes tidligere uddannelsesforløb og -erfaringer, før de starter på hf på VUC.At afdække, hvordan mødet med uddannelsens studiemiljø opleves af kursisterne, og ikke mindst kursisternes oplevelse af undervisningsformer, lærere mm.At afdække, hvad...

  19. Thermodynamic analysis of acetone sensing in Pd/AlGaN/GaN heterostructure Schottky diodes at low temperatures

    International Nuclear Information System (INIS)

    Das, Subhashis; Majumdar, Shubhankar; Kumar, Rahul; Ghosh, Saptarsi; Biswas, Dhrubes

    2016-01-01

    An AlGaN/GaN heterostructure based metal–semiconductor–metal symmetrically bi-directional Schottky diode sensor structure has been employed to investigate acetone sensing and to analyze thermodynamics of acetone adsorption at low temperatures. The AlGaN/GaN heterostructure has been grown by plasma-assisted molecular beam epitaxy on Si (111). Schottky diode parameters at different temperatures and acetone concentrations have been extracted from I–V characteristics. Sensitivity and change in Schottky barrier height have been studied. Optimum operating temperature has been established. Coverage of acetone adsorption sites at the AlGaN surface and the effective equilibrium rate constant of acetone adsorption have been explored to determine the endothermic nature of acetone adsorption enthalpy.

  20. The influence of thermal treatment on the phase development in HfO2-Al2O3 and ZrO2-Al2O3 systems

    International Nuclear Information System (INIS)

    Stefanic, G.; Music, S.; Trojko, R.

    2005-01-01

    Amorphous precursors of HfO 2 -AlO 1.5 and ZrO 2 -AlO 1.5 systems covering the whole concentration range were co-precipitated from aqueous solutions of the corresponding salts. The thermal behaviour of the amorphous precursors was examined by differential thermal analysis, X-ray powder diffraction (XRD), laser Raman spectroscopy and scanning electron microscopy. The crystallization temperature of both systems increased with increase in the AlO 1.5 content, from 530 to 940 deg. C in the HfO 2 -AlO 1.5 system, and from 405 to 915 deg. C in the ZrO 2 -AlO 1.5 system. The results of phase analysis indicate an extended capability for the incorporation of Al 3+ ions in the metastable HfO 2 - and ZrO 2 -type solid solutions obtained after crystallization of amorphous co-gels. Precise determination of lattice parameters, performed using whole-powder-pattern decomposition method, showed that the axial ratio c f /a f in the ZrO 2 - and HfO 2 -type solid solutions with 10 mol% or more of Al 3+ approach 1. The tetragonal symmetry of these samples, as determined by laser Raman spectroscopy, was attributed to the displacement of the oxygen sublattice from the ideal fluorite positions. It was found that the lattice parameters of the ZrO 2 -type solid solutions decreased with increasing Al 3+ content up to ∼10 mol%, whereas above 10 mol%, further increase of the Al 3+ content has very small influence on the unit-cell volume of both HfO 2 - and ZrO 2 -type solid solutions. The reason for such behaviour was discussed. The solubility of Hf 4+ and Zr 4+ ions in the aluminium oxides lattice appeared to be negligible

  1. (Liquid + liquid) equilibria for (water + 1-propanol or acetone + β-citronellol) at different temperatures

    International Nuclear Information System (INIS)

    Li, Hengde; Han, Yongtao; Huang, Cheng; Yang, Chufen

    2015-01-01

    Graphical abstract: (Liquid + liquid) equilibrium data for systems composed of β-citronellol and aqueous 1-propanol or acetone are presented. Distribution ratios of 1-propanol and acetone in the mixtures are examined. The effect of the temperature on the ternary (liquid + liquid) equilibria is evaluated and discussed. - Highlights: • Ternary (liquid + liquid) equilibria containing β-citronellol are presented. • Distribution ratios of 1-propanol and acetone in the mixtures are examined. • The effect on the temperature of the systems is evaluated and discussed. - Abstract: On this paper, experimental (liquid + liquid) equilibrium (LLE) results are presented for systems composed of β-citronellol and aqueous 1-propanol or acetone. To evaluate the phase separation properties of β-citronellol in aqueous mixtures, LLE values for the ternary systems (water + 1-propanol + β-citronellol) and (water + acetone + β-citronellol) were determined with a tie-line method at T = (283.15, 298.15, and 313.15 ± 0.02) K and atmospheric pressure. The reliability of the experimental tie-lines was verified by the Hand and Bachman equations. Ternary phase diagrams, distribution ratios of 1-propanol and acetone in the mixtures are shown. The effect of the temperature on the ternary (liquid + liquid) equilibria was examined and discussed. The experimental LLE values were satisfactorily correlated by extended UNIQUAC and modified UNIQUAC models

  2. Solubility measurement and correlation of 4-nitrophthalimide in (methanol, ethanol, or acetone) + N,N-dimethylformamide mixed solvents at temperatures from 273.15 K to 323.15 K

    International Nuclear Information System (INIS)

    Li, Rongrong; Han, Shuo; Du, Cunbin; Cong, Yang; Wang, Jian; Zhao, Hongkun

    2016-01-01

    Highlights: • Solubility of 4-nitrophthalimide in binary mixed solvents were determined. • Solubility data were correlated and calculated by four models. • The standard dissolution enthalpy for the dissolution processes were calculated. - Abstract: The solubility of 4-nitrophthalimide in binary (methanol + N,N-dimethylformamide (DMF), ethanol + DMF) and (acetone + DMF) solvent mixtures were investigated by the isothermal dissolution equilibrium method under atmosphere pressure. These studies were carried out at different mass fractions of methanol, ethanol or acetone ranging from 0.1 to 0.9 at temperature T = (273.15–323.15) K. For the nine groups of each solvent mixture studied, the solubility of 4-nitrophthalimide in mixed solutions increased with increasing temperature and mass fraction of methanol, ethanol or acetone for the three systems including (methanol + DMF), (ethanol + DMF) and (acetone + DMF). At the same temperature and mass fraction of methanol, ethanol or acetone, the mole fraction solubility of 4-nitrophthalimide in (acetone + DMF) was greater than that in the other two binary solvents. In addition, the experimental mole fraction solubility was correlated by four models (Jouyban–Acree model, van’t Hoff–Jouyban–Acree model, modified Apelblat–Jouyban–Acree model and Sun model). The Jouyban–Acree model gave best representation for the experimental solubility values. Furthermore, the standard molar enthalpies of 4-nitrophthalimide during the dissolving process (Δ sol H o ) were also obtained in this work, and the results show that the dissolution process is endothermic. The experimental solubility and the models used in this work will be helpful in separating 4-nitrophthalimide from its isomeric mixtures.

  3. Photodissociation of the acetone cation at 355 nm using the velocity imaging technique

    Science.gov (United States)

    Jackson, William M.; Xu, Dadong

    2000-09-01

    Photodissociation of acetone cations, CH3COCH3+, at 355 nm has been studied by means of the ion velocity imaging technique. Acetone cations are produced via direct photoionization of a supersonic beam of acetone at 118 nm generated by frequency tripling the 355 nm laser. Only the acetyl cation, CH3CO+, could be detected as a dissociation product in the time-of-flight mass spectrometer. The acetyl ion signal depends upon the fifth power of the 355 nm laser energy, while the acetone ion signal depends upon the third power. This suggests that the fragment ion is produced via two-photon absorption of 355 nm photons by the acetone cation. The total translational energy distribution and angular distribution of acetyl cation were derived from the 2D images of CH3CO+ for the reaction CH3COCH3++2hν355nm→CH3CO++CH3*. The translational energy distribution suggests that methyl radicals are produced in two electronically excited states, the Rydberg 3s 1 2A1' and the valence 1 2A″ states. The anisotropy parameter β shows that the Rydberg state is formed via a perpendicular excitation and the valence state via a parallel transition.

  4. Iminium-ion formation and deuterium exchange by acetone in the presence of pyrrolidine, pyrazolidine, isoxazolidine, and their acyclic analogues

    International Nuclear Information System (INIS)

    Hine, J.; Evangelista, R.A.

    1980-01-01

    Equilibrium constants for iminium-ion-formation in the reaction of in acetone in aqueous solution at 35 0 C with pyrazolidinium, isoxazolidinium, O,N-dimethylhydroxylammonium, and N,N'-dimethylhydrazinium ions were found to be 9.33, 8.96, 0.117, and 0.057 M -1 , respectively. The kinetics of hydrolysis of the iminium ions were studied in every case except that of the N-isopropylidene-O,N-dimethylhydroxylammonium ion, whose hydrolysis is too fast to follow by the techniques used with the other iminium ions. The rate of hydrolysis of the N-isopropylidenepyrazolidinium ion is independent of the pH from about pH 3 to 6; it is hydrogen ion catalyzed at lower pHs and hydroxide ion catalyzed at higher pHs. The rate of hydrolysis of N-isopropylidenisoxazolidinium ions is Ph independent from pH 0.5 to about 2, increases until about pH 4, remains pH independent until pH 6.5, and has become too fast to measure above pH 8. Both reactions are general base catalyzed in all the buffers studied. A mechanism is described to fit the kinetics of each of these reactions. The dedeuteration of acetone-d 6 was studied pyridine buffers in the presence of each of the four hydrazine and hydroxylamine derivatives and also in the presence of the dimethylammonium and pyrrolidinium ion. All six of these secondary ammonium ions catalyze the dedeuteration by transforming the acetone-d 6 to an iminium ion that is dedeuterated by pyridine more rapidly than the ketone is. The iminium-ion formation is a relatively rapid equilibrium in all cases except that of pyrrolidinium ions, where the intermediate iminium ion loses deuterium and hydrolyzes at comparable rates, and possibly the case of dimethylammonium ions, where the amount of catalysis via iminium-ion formation is too small to reveal mechanistic details. The effect of structure on the efficiency of catalysis of dedeuteration via iminium-ion formation is discussed. 3 figures, 7 tables

  5. Poly aniline Nano fiber as Modified Cladding for Optical Fiber Sensor to Detect Acetone Vapor

    International Nuclear Information System (INIS)

    Akhiruddin maddu; Ahmad aminuddin; Setyanto Tri Wahyudi; Hamdani Zain

    2008-01-01

    In this research, we used poly aniline nano fiber as modified cladding material for a fiber optic sensor system to detect the acetone vapor. The sensor was designed based on variation of evanescent field absorption on the core-modified cladding interface when exposed with varied acetone vapor. Poly aniline nano fiber synthesized by interfacial polymerization was coated onto the un-cladded core and acts as sensing element. Response of the fiber optic sensor was investigated by measuring the transmission light intensity via fiber optic sensor system while exposed with acetone vapor. Based on the sensor response curve, it is obtained a very fast response time of 30 s and recovery time of 10 s. The fiber optic sensor also exhibits a good reversibility and repeatability. Sensitivity of the sensor to variation of acetone vapor pressure was obtained 1.25 %/mmHg, that means the transmission intensity of the sensor changes 1.25 % for acetone vapor change of 1 mmHg. (author)

  6. Y-Doped ZnO Nanorods by Hydrothermal Method and Their Acetone Gas Sensitivity

    Directory of Open Access Journals (Sweden)

    Peng Yu

    2013-01-01

    Full Text Available Pure and yttrium- (Y- doped (1 at%, 3 at%, and 7 at% ZnO nanorods were synthesized using a hydrothermal process. The crystallography and microstructure of the synthesized samples were characterized by X-ray diffraction (XRD, scanning electron microscopy (SEM, and energy dispersive X-ray spectroscopy (EDX. Comparing with pure ZnO nanorods, Y-doped ZnO exhibited improved acetone sensing properties. The response of 1 at% Y-doped ZnO nanorods to 100 ppm acetone is larger than that of pure ZnO nanorods. The response and recovery times of 1 at% Y-doped ZnO nanorods to 100 ppm acetone are about 30 s and 90 s, respectively. The gas sensor based on Y-doped ZnO nanorods showed good selectivity to acetone in the interfere gases of ammonia, benzene, formaldehyde, toluene, and methanol. The formation mechanism of the ZnO nanorods was briefly analyzed.

  7. Upper Bound for Neutron Emission from Sonoluminescing Bubbles in Deuterated Acetone

    International Nuclear Information System (INIS)

    Camara, C. G.; Putterman, S. J.; Hopkins, S. D.; Suslick, K. S.

    2007-01-01

    An experimental search for nuclear fusion inside imploding bubbles of degassed deuterated acetone at 0 degree sign C driven by a 15 atm sound field and seeded with a neutron generator reveals an upper bound that is a factor of 10 000 less than the signal reported by Taleyarkhan et al. The strength of our upper bound is limited by the weakness of sonoluminescence, which we ascribe to the relatively high vapor pressure of acetone

  8. Damages induced in lambda phage DNA by enzyme-generated triplet acetone

    International Nuclear Information System (INIS)

    Menck, C.F.; Cabral Neto, J.B.; Gomes, R.A.; Faljoni-Alario, A.

    1985-01-01

    Exposure of lambda phage to triplet acetone, generated during the aerobic oxidation of isobutanal by peroxidase, leads to genome lesions. The majority of these lesions are detected as DNA single-strand breaks only in alkaline conditions, so true breaks were not observed. Also, no sites sensitive to UV-endonuclease from Micrococcus luteus were found in DNA from treated phage. The participation of triplet acetone in the generation of such DNA damage is discussed. (Author) [pt

  9. Determining the Sensitivity of the Hf-Nd Proxy to Glacial Weathering

    Science.gov (United States)

    Namsinh, A.; Scher, H.; Piotrowski, A. M.

    2017-12-01

    The history of polar ice sheets through the Cenozoic is incompletely known. Estimates of the onset of northern hemisphere glaciation range from the Pliocene to mid-Eocene and precursor Antarctic glaciations are believed to have commenced in the middle Eocene. Uncertainty surrounding the history of ice sheets has resulted in debates about the sensitivity of ice sheets to changes in atmospheric CO2 through the Cenozoic. Geochemical proxies for continental weathering — particularly those that are sensitive to mechanical breakdown of the upper continental crust by ice sheets — could improve the fidelity of paleoclimate reconstructions of ice sheet history. Coupled hafnium (Hf) and neodymium (Nd) isotopes in seawater and authigenic sediment phases show a strong correlation with mechanical weathering rates, however the proxy has not been systematically tested on Pleistocene time scales. We measured the Hf and Nd isotope ratios of authigenic and detrital phases of sediment cores from 1150 m to 4045 m depth on the Rockall Plateau in the NE Atlantic Ocean. Our study is limited to the LGM, deglaciation and Holocene intervals. The authigenic fraction was extracted from bulk sediments by leaching with dilute hydroxylamine hydrochloride and EDTA to prevent readsorption of Hf. A stronger leach solution was then used to isolate the terrigenous detrital fraction. The fidelity of the seawater signal obtained by leaching is assessed by comparison of leachate eNd values to previously published eNd values from uncleaned forams from the same depth intervals. Initial tests with Holocene and deglacial samples verify that leachate eNd values are statistically indistinguishable from uncleaned forams. Shale-normalized REE patterns for leachates reveal negative Ce anomalies and a MREE enrichment typical of Fe-Mn oxydydroxide phases. Coupled Hf-Nd isotopes from authigenic leachates from our initial tests fall along the Seawater Array when plotted on a Hf-Nd isotope diagram, confirming

  10. Creep Properties of NiAl-1Hf Single Crystals Re-Investigated

    Science.gov (United States)

    Whittenberger, J. Daniel; Locci, Ivan E.; Darolia, Ram; Bowman, Randy R.

    2000-01-01

    ingots were subjected to several heat treatment schedules, examined by transmission electron microscopy, and tested in both compression and tension. An example of the microstructure found in a [001]-oriented NiAl-1Hf specimen after a solution treatment at 1317 C for 50 hr followed by air cooling is illustrated in the image on the left, where the NiAl matrix contains a uniform distribution of nanometer-scale Gphase (Ni16Hf6Si7) precipitates. Other heat treating schedules produced microstructures with nanometer-sized G-phase cubes and plates or, in an extreme case, produced a microstructure with all the G-phase converted to Heusler (Ni2AlHf) particles. The results of 1027 C creep strength and strain rate testing are illustrated which summarizes data from tensile and compressive testing of samples cut from all four NiAl-1Hf ingots and subjected to a variety of heat treatment schedules. With one exception, all the strength values lie in a narrow band that spans six orders of magnitude in strain rate. The only factor that produced results outside of this band was the heat treatment schedule that dissolved all the G-phase and replaced it with Heusler precipitates. The results portrayed in this figure lead to the important practical conclusion that the elevated-temperature creep properties of NiAl-1Hf single crystals are reproducible and are not affected by small variations in alloy chemistry from ingot to ingot or by different initial distributions of G-phase in the heat-treated alloy. The only variable in this study that produced a significant and delerious effect on mechanical strength was a post-solution heat treatment that lead to the complete disappearance of the G-phase in favor of Heusler precipitates.

  11. Pyrolysis and liquefaction of acetone and mixed acetone/ tetralin swelled Mukah Balingian Malaysian sub-bituminous coal-The effect on coal conversion and oil yield

    International Nuclear Information System (INIS)

    Mohd Pauzi Abdullah; Mohd Azlan Mohd Ishak; Khudzir Ismail

    2008-01-01

    The effect of swelling on Mukah Balingian (MB) Malaysian sub-bituminous coal macrostructure was observed by pyrolysing the swelled coal via thermogravimetry under nitrogen at ambient pressure. The DTG curves of the pyrolyzed swelled coal samples show the presence of evolution peaks at temperature ranging from 235 - 295 degree Celsius that are due to releasing of light molecular weight hydrocarbons. These peaks, however, were not present in the untreated coal, indicating some changes in the coal macrostructure has occurred in the swelled coal samples. The global pyrolysis kinetics for coal that follows the first-order decomposition reaction was used to evaluate the activation energy of the pyrolyzed untreated and swelled coal samples. The results thus far have shown that the activation energy for the acetone and mixed acetone/ tetralin-swelled coal samples exhibit lower values than untreated coal, indicating less energy is required during the pyrolysis process due to the weakening of the coal-coal macromolecular interaction network. Moreover, liquefaction on the swelled coal samples that was carried out at temperatures ranging from 360 to 450 degree Celsius at 4 MPa of nitrogen pressure showed the enhancement of the coal conversion and oil yield at temperature of 420 degree Celsius, with retrogressive reaction started to dominate at higher temperature as indicated by decreased and increased in oil yield and high molecular weight pre-asphaltene, respectively. These observations suggest that the solvent swelling pre-treatment using acetone and mixed acetone/ tetralin can improve the coal conversion and oil yields at less severe liquefaction condition. (author)

  12. Mobility and molecular ions of dimethyl methyl phosphonate, methyl salicylate and acetone

    Science.gov (United States)

    Nowak, D. M.

    1983-06-01

    The mobilities of positive and negative reactant ions are reported for (H2O)nH(+); (H2O)2O2 and (H2O)2CO3(-) ion clusters. The formation of positive DMMP monomer and dimer is reported, and equilbria molecular reactions are reported. Acetone is reported as forming a dimer at 81 ppb with a reduced mobility (K sub o) of 1.82, Methyl salicylate is shown to form a protonated and hydrated positive monomer. Mixtures of DMMP and methyl salicylate with acetone showed a substantial change in DMMP ion clustering and little or no change in the methyl salicylate mobility spectra. Negative ions were not observed for DMMP, methyl salicylate, acetone and the mixtures under the conditions reported.

  13. Ultratrace Measurement of Acetone from Skin Using Zeolite: Toward Development of a Wearable Monitor of Fat Metabolism.

    Science.gov (United States)

    Yamada, Yuki; Hiyama, Satoshi; Toyooka, Tsuguyoshi; Takeuchi, Shoji; Itabashi, Keiji; Okubo, Tatsuya; Tabata, Hitoshi

    2015-08-04

    Analysis of gases emitted from human skin and contained in human breath has received increasing attention in recent years for noninvasive clinical diagnoses and health checkups. Acetone emitted from human skin (skin acetone) should be a good indicator of fat metabolism, which is associated with diet and exercise. However, skin acetone is an analytically challenging target because it is emitted in very low concentrations. In the present study, zeolite was investigated for concentrating skin acetone for subsequent semiconductor-based analysis. The adsorption and desorption characteristics of five zeolites with different structures and those hydrophobicities were compared. A hydrophobic zeolite with relatively large pores (approximately 1.6 times larger than the acetone molecule diameter) was the best concentrator of skin acetone among the zeolites tested. The concentrator developed using zeolite was applied in a semiconductor-based gas sensor in a simulated mobile environment where the closed space was frequently collapsed to reflect the twisting and elastic movement of skin that would be encountered in a wearable device. These results could be used to develop a wearable analyzer for skin acetone, which would be a powerful tool for preventing and alleviating lifestyle-related diseases.

  14. Biofiltration of mixtures of gas-phase styrene and acetone with the fungus Sporothrix variecibatus

    International Nuclear Information System (INIS)

    Rene, Eldon R.; Spackova, Radka; Veiga, Maria C.; Kennes, Christian

    2010-01-01

    The biodegradation performance of a biofilter, inoculated with the fungus Sporothrix variecibatus, to treat gas-phase styrene and acetone mixtures under steady-state and transient conditions was evaluated. Experiments were carried out by varying the gas-flow rates (0.05-0.4 m 3 h -1 ), leading to empty bed residence times as low as 17.1 s, and by changing the concentrations of gas-phase styrene (0.01-6.3 g m -3 ) and acetone (0.01-8.9 g m -3 ). The total elimination capacities were as high as 360 g m -3 h -1 , with nearly 97.5% removal of styrene and 75.6% for acetone. The biodegradation of acetone was inhibited by the presence of styrene, while styrene removal was affected only slightly by the presence of acetone. During transient-state experiments, increasing the overall pollutant load by almost 3-fold, i.e., from 220 to 600 g m -3 h -1 , resulted in a sudden drop of removal efficiency (>90-70%), but still high elimination capacities were maintained. Periodic microscopic observations revealed that the originally inoculated Sporothrix sp. remained present in the reactor and actively dominant in the biofilm.

  15. Study of the exhaled acetone in type 1 diabetes using quantum cascade laser spectroscopy.

    Science.gov (United States)

    Reyes-Reyes, Adonis; Horsten, Roland C; Urbach, H Paul; Bhattacharya, Nandini

    2015-01-06

    The acetone concentration exhaled in the breath of three type 1 diabetes patients (two minors and one adult) and one healthy volunteer is studied using a quantum cascade laser-based spectroscopic system. Using the acetone signature between 1150 and 1250 cm(-1) and a multiline fitting method, the concentration variations on the order of parts per billion by volume were measured. Blood glucose and ketone concentrations in blood measurements were performed simultaneously to study their relation with acetone in exhaled breath. We focus on personalized studies to better understand the role of acetone in diabetes. For each volunteer, we performed a series of measurements over a period of time, including overnight fastings of 11 ± 1 h and during ketosis-hyperglycemia events for the minors. Our results highlight the importance of performing personalized studies because the response of the minors to the presence of ketosis was consistent but unique for each individual. Also, our results emphasize the need for performing more studies with T1D minors, because the acetone concentration in the breath of the minors differs, with respect to those reported in the literature, which are based on adults.

  16. Solvents (butanol, acetone, and ethanol). [USSR Patent

    Energy Technology Data Exchange (ETDEWEB)

    Yarovenko, V L; Nakhmanovich, B M

    1963-07-17

    The method involves use of carbohydrate-containing plant raw-material, e.g. hydrolyzates of corn cob and pulp. The material is subjected to fermentation with acetone-butanol bacteria with addition of starch-industry wastes as source of proteins (gluten and gluten-containing water) and nutrient salts.

  17. Positron annihilation studies in Hf doped YBCO

    International Nuclear Information System (INIS)

    Gopalan, P.; Priya, E.R.; Premila, M.; Sundar, C.S.; Gopinathan, K.P.

    1992-01-01

    The variation of positron lifetime and oxygen stoichiometry as a function of quench temperature has been measured in undoped and 0.5at%, 0.75at%, and 1.0 at% Hf doped YBCO. In both the undoped and Hf doped samples, the lifetime decreases and the oxygen content increases as the quench temperature is lowered from 900degC to 300degC. The lifetime in the tetragonal phase (900degC) decreases with the increase in Hf content, whereas in the orthorhombic phase (450degC) it increases. The difference in lifetime between the tetragonal and orthorhombic phases decreases with the increase in the Hf content. These trends are discussed in terms of the influence of Hf doping on the oxygen content and the positron density distribution in YBCO

  18. Profiling and relative quantification of phosphatidylethanolamine based on acetone stable isotope derivatization

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Xiang [Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences, Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture (China); Hubei Key Laboratory of Lipid Chemistry and Nutrition (China); Wei, Fang, E-mail: willasa@163.com [Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences, Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture (China); Hubei Key Laboratory of Lipid Chemistry and Nutrition (China); Xu, Ji-qu; Lv, Xin; Dong, Xu-yan [Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences, Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture (China); Hubei Key Laboratory of Lipid Chemistry and Nutrition (China); Han, Xianlin [Center for Metabolic Origins of Disease, Sanford Burnham Prebys Medical Discovery Institute, Orlando, FL 32827 (United States); College of Basic Medical Sciences, Zhejiang Chinese Medical University, 548 Bingwen Road, Hangzhou, Zhejiang 310053 (China); Quek, Siew-young [School of Chemical Science, The University of Auckland, Auckland 1142 (New Zealand); Huang, Feng-hong [Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences, Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture (China); Hubei Key Laboratory of Lipid Chemistry and Nutrition (China); Chen, Hong, E-mail: chenhong@oilcrops.cn [Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences, Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture (China); Hubei Key Laboratory of Lipid Chemistry and Nutrition (China)

    2016-01-01

    Phosphatidylethanolamine (PE) is considered to be one of the pivotal lipids for normal cellular function as well as disease initiation and progression. In this study, a simple, efficient, reliable, and inexpensive method for the qualitative analysis and relative quantification of PE, based on acetone stable isotope derivatization combined with double neutral loss scan-shotgun electrospray ionization tandem-quadrupole mass spectrometry analysis (ASID-DNLS-Shotgun ESI-MS/MS), was developed. The ASID method led to alkylation of the primary amino groups of PE with an isopropyl moiety. The use of acetone (d{sub 0}-acetone) and deuterium-labeled acetone (d{sub 6}-acetone) introduced a 6 Da mass shift that was ideally suited for relative quantitative analysis, and enhanced sensitivity for mass analysis. The DNLS model was introduced to simultaneously analyze the differential derivatized PEs by shotgun ESI-MS/MS with high selectivity and accuracy. The reaction specificity, labeling efficiency, and linearity of the ASID method were thoroughly evaluated in this study. Its excellent applicability was validated by qualitative and relative quantitative analysis of PE species presented in liver samples from rats fed different diets. Using the ASID-DNLS-Shotgun ESI-MS/MS method, 45 PE species from rat livers have been identified and quantified in an efficient manner. The level of total PEs tended to decrease in the livers of rats on high fat diets compared with controls. The levels of PE 32:1, 34:3, 34:2, 36:3, 36:2, 42:10, plasmalogen PE 36:1 and lyso PE 22:6 were significantly reduced, while levels of PE 36:1 and lyso PE 16:0 increased. - Highlights: • A novel isotope reagent acetone was explored for the derivatization of PEs. • The labeling reaction was carried out under mild conditions with high specificity. • Enhanced detection sensitivity of PEs was achieved after derivatization. • The ASID-DNLS-Shotgun MS/MS method was used to relative quantification of PEs.

  19. Free energy of mixing of acetone and methanol: a computer simulation investigation.

    Science.gov (United States)

    Idrissi, Abdenacer; Polok, Kamil; Barj, Mohammed; Marekha, Bogdan; Kiselev, Mikhail; Jedlovszky, Pál

    2013-12-19

    The change of the Helmholtz free energy, internal energy, and entropy accompanying the mixing of acetone and methanol is calculated in the entire composition range by the method of thermodynamic integration using three different potential model combinations of the two compounds. In the first system, both molecules are described by the OPLS, and in the second system, both molecules are described by the original TraPPE force field, whereas in the third system a modified version of the TraPPE potential is used for acetone in combination with the original TraPPE model of methanol. The results reveal that, in contrast with the acetone-water system, all of these three model combinations are able to reproduce the full miscibility of acetone and methanol, although the thermodynamic driving force of this mixing is very small. It is also seen, in accordance with the finding of former structural analyses, that the mixing of the two components is driven by the entropy term corresponding to the ideal mixing, which is large enough to overcompensate the effect of the energy increase and entropy loss due to the interaction of the unlike components in the mixtures. Among the three model combinations, the use of the original TraPPE model of methanol and modified TraPPE model of acetone turns out to be clearly the best in this respect, as it is able to reproduce the experimental free energy, internal energy, and entropy of mixing values within 0.15 kJ/mol, 0.2 kJ/mol, and 1 J/(mol K), respectively, in the entire composition range. The success of this model combination originates from the fact that the use of the modified TraPPE model of acetone instead of the original one in these mixtures improves the reproduction of the entropy of mixing, while it retains the ability of the original model of excellently reproducing the internal energy of mixing.

  20. Ge interactions on HfO2 surfaces and kinetically driven patterning of Ge nanocrystals on HfO2

    International Nuclear Information System (INIS)

    Stanley, Scott K.; Joshi, Sachin V.; Banerjee, Sanjay K.; Ekerdt, John G.

    2006-01-01

    Germanium interactions are studied on HfO 2 surfaces, which are prepared through physical vapor deposition (PVD) and by atomic layer deposition. X-ray photoelectron spectroscopy and temperature-programed desorption are used to follow the reactions of germanium on HfO 2 . Germanium chemical vapor deposition at 870 K on HfO 2 produces a GeO x adhesion layer, followed by growth of semiconducting Ge 0 . PVD of 0.7 ML Ge (accomplished by thermally cracking GeH 4 over a hot filament) also produces an initial GeO x layer, which is stable up to 800 K. PVD above 2.0 ML deposits semiconducting Ge 0 . Temperature programed desorption experiments of ∼1.0 ML Ge from HfO 2 at 400-1100 K show GeH 4 desorption below 600 K and GeO desorption above 850 K. These results are compared to Ge on SiO 2 where GeO desorption is seen at 550 K. Exploiting the different reactivity of Ge on HfO 2 and SiO 2 allows a kinetically driven patterning scheme for high-density Ge nanoparticle growth on HfO 2 surfaces that is demonstrated

  1. Electric Field Gradients at Hf and Fe Sites in Hf2Fe Recalculated

    International Nuclear Information System (INIS)

    Belosevic-Cavor, J.; Cekic, B.; Novakovic, N.; Koteski, V.; Milosevic, Z.

    2004-01-01

    The electric field gradients (EFG) of the Hf 2 Fe intermetallic compound were calculated using the full-potential linearized augmented plain-wave (FP-LAPW) method as embodied in the WIEN 97 code. The obtained values are compared with other ab-initio calculations and on a qualitative basis with the previously reported experimental data obtained from TDPAC. The calculated results, -23.1.10 21 V/m 2 and 2.7.10 21 V/m 2 for Hf 48f and Fe 32e position, respectively, are in excellent agreement with experimental data (23.4.10 21 V/m 2 and 2.7.10 21 V/m 2 ), better than those reported in earlier calculations. The calculated EFG for Hf 16c position (4.2.10 21 V/m 2 ) is stronger than the experimental one (1.1.10 21 V/m 2 ).

  2. Brief Communication: Comparison of formol-acetone concentration ...

    African Journals Online (AJOL)

    Background: Formol-ether concentration technique is taken as a gold standard method to detect most intestinal parasites; however, because of its low safety and hazardous impact a need for better technique has a paramount importance. Objective: To evaluate a formol- acetone concentration method in comparison with the ...

  3. Evaluation of the amorphous content of lactose by solution calorimetry and Raman spectroscopy.

    Science.gov (United States)

    Katainen, Erja; Niemelä, Pentti; Harjunen, Päivi; Suhonen, Janne; Järvinen, Kristiina

    2005-11-15

    Solution calorimetry can be used to determine the amorphous content of a compound when the solubility and dissolution rate of the compound in the chosen solvent are reasonably high. Sometimes, it can be difficult find a solvent in which a sample is freely soluble. The present study evaluated the use of solution calorimetry for the assessment of the amorphous content of a sample that is poorly soluble in a solvent. Physical mixtures of lactose and spray-dried lactose samples (the amorphous content varied from 0 to 100%) were analyzed by a solution calorimeter and the results were compared with Raman spectroscopy determinations. The heat of solvation of the samples was determined by solution calorimetry in organic solvents MeOH, EtOH, ACN, THF, acetone (400mg sample/100ml solvent). Lactose is virtually insoluble in ACN, THF and acetone and very slightly soluble in EtOH and MeOH. The amorphous content of the samples could not be determined by solution calorimetry in EtOH, ACN, THF or acetone. However, an excellent correlation was observed between the heat of solvation and the amorphous content of the samples in MeOH. Furthermore, the heat of solvation values of the samples in MeOH showed a linear correlation with the Raman quantifications. Therefore, our results demonstrate that solution calorimetry may represent a rapid and simple method for determining the amorphous content also in samples that are not freely soluble in the solvent.

  4. Microstructural characterization of as-cast hf-b alloys

    Directory of Open Access Journals (Sweden)

    João Carlos Jânio Gigolotti

    2012-04-01

    Full Text Available An accurate knowledge of several metal-boron phase diagrams is important to evaluation of higher order systems such as metal-silicon-boron ternaries. The refinement and reassessment of phase diagram data is a continuous work, thus the reevaluation of metal-boron systems provides the possibility to confirm previous data from an investigation using higher purity materials and better analytical techniques. This work presents results of rigorous microstructural characterization of as-cast hafnium-boron alloys which are significant to assess the liquid composition associated to most of the invariant reactions of this system. Alloys were prepared by arc melting high purity hafnium (minimum 99.8% and boron (minimum 99.5% slices under argon atmosphere in water-cooled copper crucible with non consumable tungsten electrode and titanium getter. The phases were identified by scanning electron microscopy, using back-scattered electron image mode and X-ray diffraction. In general, a good agreement was found between our data and those from the currently accepted Hafnium-Boron phase diagram. The phases identified are αHfSS and B-RhomSS, the intermediate compounds HfB and HfB2 and the liquide L. The reactions are the eutectic L ⇔ αHfSS + HfB and L ⇔ HfB2 + B-Rhom, the peritectic L + HfB2 ⇔ HfB and the congruent formation of HfB2.

  5. Synthesis and solution self-assembly of side-chain cobaltocenium-containing block copolymers.

    Science.gov (United States)

    Ren, Lixia; Hardy, Christopher G; Tang, Chuanbing

    2010-07-07

    The synthesis of side-chain cobaltocenium-containing block copolymers and their self-assembly in solution was studied. Highly pure monocarboxycobaltocenium was prepared and subsequently attached to side chains of poly(tert-butyl acrylate)-block-poly(2-hydroxyethyl acrylate), yielding poly(tert-butyl acrylate)-block-poly(2-acryloyloxyethyl cobaltoceniumcarboxylate). The cobaltocenium block copolymers exhibited vesicle morphology in the mixture of acetone and water, while micelles of nanotubes were formed in the mixture of acetone and chloroform.

  6. Dielectric barrier discharge micro-plasma emission spectrometry for the detection of acetone in exhaled breath.

    Science.gov (United States)

    Yang, Ting; Gao, Dong-Xue; Yu, Yong-Liang; Chen, Ming-Li; Wang, Jian-Hua

    2016-01-01

    Acetone is a predominant volatile organic compound (VOC) in the exhaled breath and a promising biomarker for diabetes and ketoacidosis. A non-thermal micro-plasma generated in a planar dielectric barrier discharge (DBD) is used as a radiation source for the excitation of gaseous acetone followed by its quantification with optical emission spectrometry (OES). Gaseous acetone can be directly sampled, while liquid acetone is evaporated by heated tungsten coil and then introduced into the DBD micro-plasma by a helium carrier flow for performing optical emission and detection at a 519 nm emission line. In the present study, the exhaled breath is collected and transferred into aqueous medium for sampling. With a sampling volume of 7 μL in a micro-drop, a linear range of 40-1600 mg L(-1) is obtained along with a detection limit of 44 ng and a precision of 5.7% RSD. The present system is successfully applied to the determination of breath acetone for both diabetic patients and healthy volunteers. Copyright © 2015 Elsevier B.V. All rights reserved.

  7. Involvement of an ATP-dependent carboxylase in a CO2-dependent pathway of acetone metabolism by Xanthobacter strain Py2.

    OpenAIRE

    Sluis, M K; Small, F J; Allen, J R; Ensign, S A

    1996-01-01

    The metabolism of acetone by the aerobic bacterium Xanthobacter strain Py2 was investigated. Cell suspensions of Xanthobacter strain Py2 grown with propylene or glucose as carbon sources were unable to metabolize acetone. The addition of acetone to cultures grown with propylene or glucose resulted in a time-dependent increase in acetone-degrading activity. The degradation of acetone by these cultures was prevented by the addition of rifampin and chloramphenicol, demonstrating that new protein...

  8. Acetone-butanol-ethanol competitive sorption simulation from single, binary, and ternary systems in a fixed-bed of KA-I resin.

    Science.gov (United States)

    Wu, Jinglan; Zhuang, Wei; Ying, Hanjie; Jiao, Pengfei; Li, Renjie; Wen, Qingshi; Wang, Lili; Zhou, Jingwei; Yang, Pengpeng

    2015-01-01

    Separation of butanol based on sorption methodology from acetone-butanol-ethanol (ABE) fermentation broth has advantages in terms of biocompatibility and stability, as well as economy, and therefore gains much attention. In this work a chromatographic column model based on the solid film linear driving force approach and the competitive Langmuir isotherm equations was used to predict the competitive sorption behaviors of ABE single, binary, and ternary mixture. It was observed that the outlet concentration of weaker retained components exceeded the inlet concentration, which is an evidence of competitive adsorption. Butanol, the strongest retained component, could replace ethanol almost completely and also most of acetone. In the end of this work, the proposed model was validated by comparison of the experimental and predicted ABE ternary breakthrough curves using the real ABE fermentation broth as a feed solution. © 2014 American Institute of Chemical Engineers.

  9. Acetone production using silicon nanoparticles and catalyst compositions

    KAUST Repository

    Chaieb, Saharoui; Demellawi, Jehad El; Al-Talla, Zeyad

    2015-01-01

    Embodiments of the present disclosure provide for a catalytic reaction to produce acetone, a catalyst that include a mixture of silicon particles (e.g., about 1 to 20 nm in diameter) and a solvent, and the like.

  10. Acetone production using silicon nanoparticles and catalyst compositions

    KAUST Repository

    Chaieb, Sahraoui

    2015-12-10

    Embodiments of the present disclosure provide for a catalytic reaction to produce acetone, a catalyst that include a mixture of silicon particles (e.g., about 1 to 20 nm in diameter) and a solvent, and the like.

  11. Relationship of O2 Photodesorption in Photooxidation of Acetone on TiO2

    International Nuclear Information System (INIS)

    Henderson, Michael A.

    2008-01-01

    Organic photooxidation on TiO2 invariably involves the coexistence of organic species with oxygen on the surface at the same time. In the case of acetone and oxygen, both species exhibit their own interesting photochemistry on TiO2, but interdependences between the two are not understood. In this study, a rutile TiO2(110) surface possessing 7% surface oxygen vacancy sites is used as a model surface to probe the relationship between O2 photodesorption and acetone photodecomposition. Temperature programmed desorption (TPD) and photon stimulated desorption (PSD) measurements indicate that coadsorbed oxygen is essential to acetone photodecomposition on this surface, however the form of oxygen (molecular and dissociative) is not known. The first steps in acetone photodecomposition on TiO2(110) involve thermal activation with oxygen to form an acetone diolate ((CH3)2COO) species followed by photochemical decomposition to adsorbed acetate (CH3COO) and an ejected CH3 radical that is detected in PSD. Depending on the surface conditions, O2 PSD is also observed during the latter process. However, the time scales for the two PSD events (CH3 and O2) are quite different, with the former occurring at ∼10 times faster than the latter. By varying the preheating conditions or performing pre-irradiation on an O2 exposed surface, it becomes clear that the two PSD events are uncorrelated. That is, the O2 species responsible for O2 PSD is not a significant participant in the photochemistry of acetone on TiO2(110) and likely originates from a minority form of O2 on the surface. The CH3 and O2 PSD events do not appear to be in competition with each other suggesting either that ample charge carriers exist under the experimental conditions employed or that different charge carriers or excitation mechanisms are involved

  12. Calculation of the local power peaking near WWER-440 control assemblies with Hf plates

    International Nuclear Information System (INIS)

    Hegyi, Gy.; Hordosy, G.; Kereszturi, A.; Maraszy, Cs.; Temesvari, E.

    2003-01-01

    The original coupler design of the WWER-440 assemblies had the following well known deficiency: The relatively large amount of water in the coupler between the absorber and fuel port of the control assembly can cause undesirably sharp power peaking in the fuel rods next to the coupler. The power peaking can be especially high after control rod withdrawal when the coupler reached low burnup level region of the adjacent assembly. The modernized coupler design overcomes the original problem by applying a thin Hf plate in the critical region. The very complicated structure of the coupler requires the verification of the core design methods by high precision 3D Monte Carlo calculations. The paper presents an MCNP reference calculation on the control rod coupler benchmark with Hf absorber plates. The benchmark solution with the KARATE-440 code system is also presented. The need for treating the Hf burnout in the reflector region is investigated (Authors)

  13. Processing of beet-sugar molasses in the acetone-butyl alcohol industry

    Energy Technology Data Exchange (ETDEWEB)

    Zalesskaya, M I; Logotkin, I S; Marfina, A M; Gus' kova, N P; Chekasina, E V

    1958-01-01

    Possibility of partial replacement of flour by beet-sugar molasses (I) in acetone-BuOH fermentation was investigated on a commercial scale. Detailed regimes of experiments carried out in two trials were given. Yields of fermentation (kg/1000 kg starch of mash) were: 125.3, 214.4, and 31.5 of acetone, BuOH and EtOH, respectively, for pure flour-mash; 123.3, 215.3, and 28.7 of acetone, BuOH, and EtOH, respectively, at 10% flour replaced by I; 127.8, 205.9, and 51.8, respectively, at 50% flour replaced by I; and 120.17, 216.48, and 42.3, respectively, at 62% flour replaced by I. Inoculum, grown in the seed-mash containing flour only, was not mixed with fermentor-mash until the stage of acid production by the inoculum was reached. During the fermentation of mashes in which 62% flour was replaced by I, a slight foaming was observed.

  14. Acetone-Linked Peptides: A Convergent Approach for Peptide Macrocyclization and Labeling.

    Science.gov (United States)

    Assem, Naila; Ferreira, David J; Wolan, Dennis W; Dawson, Philip E

    2015-07-20

    Macrocyclization is a broadly applied approach for overcoming the intrinsically disordered nature of linear peptides. Herein, it is shown that dichloroacetone (DCA) enhances helical secondary structures when introduced between peptide nucleophiles, such as thiols, to yield an acetone-linked bridge (ACE). Aside from stabilizing helical structures, the ketone moiety embedded in the linker can be modified with diverse molecular tags by oxime ligation. Insights into the structure of the tether were obtained through co-crystallization of a constrained S-peptide in complex with RNAse S. The scope of the acetone-linked peptides was further explored through the generation of N-terminus to side chain macrocycles and a new approach for generating fused macrocycles (bicycles). Together, these studies suggest that acetone linking is generally applicable to peptide macrocycles with a specific utility in the synthesis of stabilized helices that incorporate functional tags. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. The Marangoni convection induced by acetone desorption from the falling soap film

    Science.gov (United States)

    Sha, Yong; Li, Zhangyun; Wang, Yongyi; Huang, Jiali

    2012-05-01

    By means of the falling soap film tunnel and the Schlieren optical method, the Marangoni convection were observed directly in the immediate interfacial neighborhood during the desorption process of acetone from the falling soap film. Moreover, the hydraulic characteristics of the falling soap film tunnel, the acetone concentration, the surface tension of the soap liquid and the mass transfer has been investigated in details through the experimental or theoretical method.

  16. Biofiltration of mixtures of gas-phase styrene and acetone with the fungus Sporothrix variecibatus

    Energy Technology Data Exchange (ETDEWEB)

    Rene, Eldon R.; Spackova, Radka; Veiga, Maria C. [University of La Coruna, Dpt. of Chemical Engineering, Campus da Zapateira, Rua da Fraga, 10, 15008 La Coruna (Spain); Kennes, Christian, E-mail: kennes@udc.es [University of La Coruna, Dpt. of Chemical Engineering, Campus da Zapateira, Rua da Fraga, 10, 15008 La Coruna (Spain)

    2010-12-15

    The biodegradation performance of a biofilter, inoculated with the fungus Sporothrix variecibatus, to treat gas-phase styrene and acetone mixtures under steady-state and transient conditions was evaluated. Experiments were carried out by varying the gas-flow rates (0.05-0.4 m{sup 3} h{sup -1}), leading to empty bed residence times as low as 17.1 s, and by changing the concentrations of gas-phase styrene (0.01-6.3 g m{sup -3}) and acetone (0.01-8.9 g m{sup -3}). The total elimination capacities were as high as 360 g m{sup -3} h{sup -1}, with nearly 97.5% removal of styrene and 75.6% for acetone. The biodegradation of acetone was inhibited by the presence of styrene, while styrene removal was affected only slightly by the presence of acetone. During transient-state experiments, increasing the overall pollutant load by almost 3-fold, i.e., from 220 to 600 g m{sup -3} h{sup -1}, resulted in a sudden drop of removal efficiency (>90-70%), but still high elimination capacities were maintained. Periodic microscopic observations revealed that the originally inoculated Sporothrix sp. remained present in the reactor and actively dominant in the biofilm.

  17. Anion exchange behaviour of Zr, Hf, Nb, Ta and Pa as homologues of RF and Db in fluoride medium

    International Nuclear Information System (INIS)

    Monroy G, F.; Trubert, D.; Brillard, L.; Hussonnois, M.; Constantinescu, O.; Le Naour, C.

    2010-01-01

    Studies of the chemical property of trans actinide elements are very difficult due to their short half-lives and extremely small production yields. However it is still possible to obtain considerable information about their chemical properties, such as the most stable oxidation states in aqueous solution, complexing ability, etc., comparing their behaviour with their lighter homologous in the periodic table. In order to obtain a better knowledge of the behaviour of rutherfordium, RF (element 104), dub nium, Db (element 105) in HF medium, the sorption properties of Zr, Hf, Nb, Ta an Pa, homologues of RF and Db, were studied in NH 4 F/HClO 4 medium in this work. Stability constants of the fluoride complexes of these elements were experimentally obtained from K d obtained at different F - and H + concentrations. The anionic complexes: [Zr(Hf)F 5 ] - , [Zr(Hf)F 6 ] 2- , [Zr(Hf)F 7 ] 3- , [Ta(Pa)F 6 ] - , [Ta(Pa)F 7 ] 2- , [Ta(Pa)F 8 ] 3- , [NbOF 4 ] - and [NbOF 5 ] 2- are present as predominant species in the HF range over investigation. (Author)

  18. High energy HF pulsed lasers

    International Nuclear Information System (INIS)

    Patterson, E.L.; Gerber, R.A.

    1976-01-01

    Recent experiments show that pulsed HF lasers are capable of producing high energy with good efficiency. Preliminary experiments show that the laser radiation from the high-gain medium can be controlled with a low-power probe laser beam or with low-level feedback. These results indicate that the HF laser may have potential for second-generation laser fusion experiments

  19. Decryptification of Acid Phosphatase in Arthrospores of Geotrichum Species Treated with Dimethyl Sulfoxide and Acetone

    Science.gov (United States)

    Cotter, David A.; Martel, Anita J.; MacDonald, Paul

    1975-01-01

    Decryptification of acid phosphatase in Geotrichum sp. arthrospores was accomplished using acetone or dimethyl sulfoxide treatment. Both dimethyl sulfoxide and acetone irreversibly destroyed the integrity of the spore membranes without solubilizing acid phosphatase. PMID:1167386

  20. Tracking magmatic processes through Zr/Hf ratios in rocks and Hf and Ti zoning in zircons: An example from the Spirit Mountain batholith, Nevada

    Science.gov (United States)

    Lowery, Claiborne L.E.; Miller, C.F.; Walker, B.A.; Wooden, J.L.; Mazdab, F.K.; Bea, F.

    2006-01-01

    Zirconium and Hf are nearly identical geochemically, and therefore most of the crust maintains near-chondritic Zr/Hf ratios of ???35-40. By contrast, many high-silica rhyolites and granites have anomalously low Zr/Hf (15-30). As zircon is the primary reservoir for both Zr and Hf and preferentially incorporates Zr, crystallization of zircon controls Zr/ Hf, imprinting low Zr/Hf on coexisting melt. Thus, low Zr/Hf is a unique fingerprint of effective magmatic fractionation in the crust. Age and compositional zonation in zircons themselves provide a record of the thermal and compositional histories of magmatic systems. High Hf (low Zr/ Hf) in zircon zones demonstrates growth from fractionated melt, and Ti provides an estimate of temperature of crystallization (TTiZ) (Watson and Harrison, 2005). Whole-rock Zr/Hf and zircon zonation in the Spirit Mountain batholith, Nevada, document repeated fractionation and thermal fluctuations. Ratios of Zr/Hf are ???30-40 for cumulates and 18-30 for high-SiO2 granites. In zircons, Hf (and U) are inversely correlated with Ti, and concentrations indicate large fluctuations in melt composition and TTiZ (>100??C) for individual zircons. Such variations are consistent with field relations and ion-probe zircon geochronology that indicate a >1 million year history of repeated replenishment, fractionation, and extraction of melt from crystal mush to form the low Zr/Hf high-SiO2 zone. ?? 2006 The Mineralogical Society.

  1. Vacuum-jacketed hydrofluoric acid solution calorimeter

    Science.gov (United States)

    Robie, R.A.

    1965-01-01

    A vacuum-jacketed metal calorimeter for determining heats of solution in aqueous HF was constructed. The reaction vessel was made of copper and was heavily gold plated. The calorimeter has a cooling constant of 0.6 cal-deg -1-min-1, approximately 1/4 that of the air-jacketed calorimeters most commonly used with HF. It reaches equilibrium within 10 min after turning off the heater current. Measurements of the heat of solution of reagent grade KCl(-100 mesh dried 2 h at 200??C) at a mole ratio of 1 KCl to 200 H2O gave ??H = 4198??11 cal at 25??C. ?? 1965 The American Institute of Physics.

  2. Ex-Situ and In-Situ Ellipsometric Studies of the Thermal Oxide on InP

    Science.gov (United States)

    1990-12-06

    ion---- Distribution/ Availabilit ? Codes£v l llt Codes Avail and/or Dist| Special Abstract The thermally grown InP oxide as etched by an aqueous...aqueous NH4OH/NH4F, and Law(17) has reported observations of orientational ordering of water and organic solvents on pyrex surfaces by in-situ...minutes, followed by a sequence of acetone, deionized water (d. i. water ) rinse. After being dipped in a concentrated aqueous HF solution for 15 seconds

  3. Profiling and relative quantification of phosphatidylethanolamine based on acetone stable isotope derivatization.

    Science.gov (United States)

    Wang, Xiang; Wei, Fang; Xu, Ji-Qu; Lv, Xin; Dong, Xu-Yan; Han, Xianlin; Quek, Siew-Young; Huang, Feng-Hong; Chen, Hong

    2016-01-01

    Phosphatidylethanolamine (PE) is considered to be one of the pivotal lipids for normal cellular function as well as disease initiation and progression. In this study, a simple, efficient, reliable, and inexpensive method for the qualitative analysis and relative quantification of PE, based on acetone stable isotope derivatization combined with double neutral loss scan-shotgun electrospray ionization tandem-quadrupole mass spectrometry analysis (ASID-DNLS-Shotgun ESI-MS/MS), was developed. The ASID method led to alkylation of the primary amino groups of PE with an isopropyl moiety. The use of acetone (d0-acetone) and deuterium-labeled acetone (d6-acetone) introduced a 6 Da mass shift that was ideally suited for relative quantitative analysis, and enhanced sensitivity for mass analysis. The DNLS model was introduced to simultaneously analyze the differential derivatized PEs by shotgun ESI-MS/MS with high selectivity and accuracy. The reaction specificity, labeling efficiency, and linearity of the ASID method were thoroughly evaluated in this study. Its excellent applicability was validated by qualitative and relative quantitative analysis of PE species presented in liver samples from rats fed different diets. Using the ASID-DNLS-Shotgun ESI-MS/MS method, 45 PE species from rat livers have been identified and quantified in an efficient manner. The level of total PEs tended to decrease in the livers of rats on high fat diets compared with controls. The levels of PE 32:1, 34:3, 34:2, 36:3, 36:2, 42:10, plasmalogen PE 36:1 and lyso PE 22:6 were significantly reduced, while levels of PE 36:1 and lyso PE 16:0 increased. Copyright © 2015 Elsevier B.V. All rights reserved.

  4. Lidar/DIAL detection of acetone at 3.3 μm by a tunable OPO laser system

    Science.gov (United States)

    Puiu, A.; Fiorani, L.; Rosa, O.; Borelli, R.; Pistilli, M.; Palucci, A.

    2014-08-01

    In this paper we report, for the first time to our knowledge, on lidar/DIAL detection of acetone vapors at 3.3 μm by means of an optical parametric tunable laser system. After a preliminary spectroscopic study in an absorption cell, the feasibility of a differential absorption (DIAL) lidar for the detection of acetone vapors has been investigated in the laboratory, simulating the experimental conditions of a field campaign. Having in mind measurements in a real scenario, a study of possible atmospheric intereferents has been performed, looking for all known compounds that share acetone IR absorption in the spectral band selected for its detection. Possible interfering species from urban and industrial atmospheres were investigated and limits of acetone detection in both environments were identified. This study confirmed that a lidar system can detect a low concentration of acetone at considerable distances.

  5. Study of Direct-Contact HfO2/Si Interfaces

    Directory of Open Access Journals (Sweden)

    Noriyuki Miyata

    2012-03-01

    Full Text Available Controlling monolayer Si oxide at the HfO2/Si interface is a challenging issue in scaling the equivalent oxide thickness of HfO2/Si gate stack structures. A concept that the author proposes to control the Si oxide interface by using ultra-high vacuum electron-beam HfO2 deposition is described in this review paper, which enables the so-called direct-contact HfO2/Si structures to be prepared. The electrical characteristics of the HfO2/Si metal-oxide-semiconductor capacitors are reviewed, which suggest a sufficiently low interface state density for the operation of metal-oxide-semiconductor field-effect-transistors (MOSFETs but reveal the formation of an unexpected strong interface dipole. Kelvin probe measurements of the HfO2/Si structures provide obvious evidence for the formation of dipoles at the HfO2/Si interfaces. The author proposes that one-monolayer Si-O bonds at the HfO2/Si interface naturally lead to a large potential difference, mainly due to the large dielectric constant of the HfO2. Dipole scattering is demonstrated to not be a major concern in the channel mobility of MOSFETs.

  6. Thermoelectric properties of doped BaHfO_3

    International Nuclear Information System (INIS)

    Dixit, Chandra Kr.; Bhamu, K. C.; Sharma, Ramesh

    2016-01-01

    We have studied the structural stability, electronic structure, optical properties and thermoelectric properties of doped BaHfO_3 by full potential linearized augmented plane wave (FP-LAPW) method. The electronic structure of BaHfO_3 doped with Sr shows enhances the indirect band gaps of 3.53 eV, 3.58 eV. The charge density plots show strong ionic bonding in Ba-Hf, and ionic and covalent bonding between Hf and O. Calculations of the optical spectra, viz., the dielectric function, refractive index and extinction coefficient are performed for the energy range are calculated and analyzed. Thermoelectric properties of semi conducting are also reported first time. The doped BaHfO_3 is approximately wide band gap semiconductor with the large p-type Seebeck coefficient. The power factor of BaHfO_3 is increased with Sr doping, decreases because of low electrical resistivity and thermal conductivity.

  7. Application of Raman Spectroscopy for the Detection of Acetone Dissolved in Transformer Oil

    Science.gov (United States)

    Gu, Z.; Chen, W.; Du, L.; Shi, H.; Wan, F.

    2018-05-01

    The CLRS detection characteristics of acetone dissolved in transformer oil were analyzed. Raman spectral peak at 780 cm-1 was used as the characteristic spectral peak for qualitative and quantitative analyses. The effect of the detection depth and the temperature was investigated in order to obtain good Raman signals. The optimal detection depth and temperature were set as 3 mm and room temperature. A quantitative model relation between concentration and the Raman peak intensity ratio I 780/I 893 was constructed via the least-squares method. The results demonstrated that CLRS can quantitatively detect the concentration of acetone in transformer oil and CLRS has potential as a useful alternative for accelerating the in-situ analysis of the concentration of acetone in transformer oil.

  8. Application of Raman Spectroscopy for the Detection of Acetone Dissolved in Transformer Oil

    Science.gov (United States)

    Gu, Z.; Chen, W.; Du, L.; Shi, H.; Wan, F.

    2018-05-01

    The CLRS detection characteristics of acetone dissolved in transformer oil were analyzed. Raman spectral peak at 780 cm-1 was used as the characteristic spectral peak for qualitative and quantitative analyses. The effect of the detection depth and the temperature was investigated in order to obtain good Raman signals. The optimal detection depth and temperature were set as 3 mm and room temperature. A quantitative model relation between concentration and the Raman peak intensity ratio I 780/ I 893 was constructed via the least-squares method. The results demonstrated that CLRS can quantitatively detect the concentration of acetone in transformer oil and CLRS has potential as a useful alternative for accelerating the in-situ analysis of the concentration of acetone in transformer oil.

  9. Crystal structures of KM(AsF6)3 (M2+ = Mg, Co, Mn, Zn), KCu(SbF6)3 and [Co(HF)2]Sr[Sr(HF)]2-[Sr(HF)2]2[AsF6]12

    International Nuclear Information System (INIS)

    Mazej, Zoran; Goreshnik, Evgeny

    2015-01-01

    The KM(AsF 6 ) 3 (M 2+ = Mg, Co, Mn, Zn) and KCu(SbF 6 ) 3 compounds crystallize isotypically to previously known KNi(AsF 6 ) 3 . The main features of the structure of these compounds are rings of MF 6 octahedra sharing apexes with AsF 6 octahedra connected into infinite tri-dimensional frameworks. In this arrangement cavities are formed where K + cations are placed. Single crystals of CoSr 5 (AsF 6 ) 12 .8HF were obtained as one of the products after the crystallization of 3KF/CoF 2 /SrF 2 mixture in the presence of AsF 5 in anhydrous HF. The CoSr 5 (AsF 6 ) 12 .8HF is monoclinic, C/2c (No.15), with a = 26.773(5) Aa, b = 10.087(2) Aa, c = 21.141(5) Aa, β = 93.296(13) circle , V = 5699.9(19) Aa 3 at 200 K, and Z = 4. There are three crystallographically non-equivalent Sr 2+ cations in the crystal structure of CoSr 5 (AsF 6 ) 12 .8HF. The Sr1 is coordinated by ten fluorine atoms from eight different [AsF 6 ]- anions, meanwhile Sr2 and Sr3 are bound to nine fluorine atoms provided by one HF and eight AsF 6 units or by two HF and six AsF 6 units, respectively. The Co 2+ is coordinated distorted-octahedrally by six fluorine atoms from two HF molecules and four different AsF 6 units. All those moieties in the crystal structure of [Co(HF) 2 ]Sr[Sr(HF)] 2 [Sr(HF) 2 ] 2 [AsF 6 ] 12 are connected into tridimensional framework. The CoSr 5 (AsF 6 ) 12 .8HF is a unique example of compound where HF molecules are directly bound via fluorine atoms to two different metal centres.

  10. Acetone and acetaldehyde determination in tomato juice by isotopic dilution

    International Nuclear Information System (INIS)

    Piva, M.-T.; Crouzet, J.

    1977-01-01

    Acetone and acetaldehyde content of tomato juice were determined by isotope dilution techniques. The juice is added to 14 C labelled compounds, carried along by nitrogen at low pressure. The mixture of 2.4 dinitrophenylhydrazones obtained from volatile compounds is separated by thin layer chromatography on silica gel and then on alumina. A determination of radioactivity and concentration of acetone and acetaldehyde 2,4 dinitrophenylhydrazones obtained after separation and elution allow to calculate the content of these two compounds in the initial product with the same sample. This technique could be used for determination of methanol and ethanol after transformation in 3,5 dinitrobenzoates [fr

  11. Optical acetone vapor sensors based on chiral nematic liquid crystals and reactive chiral dopants

    NARCIS (Netherlands)

    Cachelin, P.; Green, J.P.; Peijs, T.; Heeney, M.; Bastiaansen, C.W.M.

    2016-01-01

    Accurate monitoring of exposure to organic vapors, such as acetone, is an important part of maintaining a safe working environment and adhering to long- and short-term exposure limits. Here, a novel acetone vapor detection system is described based on the use of a reactive chiral dopant in a nematic

  12. Biodegradation of airborne acetone/styrene mixtures in a bubble column reactor.

    Science.gov (United States)

    Vanek, T; Silva, A; Halecky, M; Paca, J; Ruzickova, I; Kozliak, E; Jones, K

    2017-07-29

    The ability of a bubble column reactor (BCR) to biodegrade a mixture of styrene and acetone vapors was evaluated to determine the factors limiting the process efficiency, with a particular emphasis on the presence of degradation intermediates and oxygen levels. The results obtained under varied loadings and ratios were matched with the dissolved oxygen levels and kinetics of oxygen mass transfer, which was assessed by determination of k L a coefficients. A 1.5-L laboratory-scale BCR was operated under a constant air flow of 1.0 L.min -1 , using a defined mixed microbial population as a biocatalyst. Maximum values of elimination capacities/maximum overall specific degradation rates of 75.5 gC.m -3 .h -1 /0.197 gC.gdw -1 .h -1 , 66.0 gC.m -3 .h -1 /0.059 gC.gdw -1 .h -1 , and 45.8 gC.m -3 .h -1 /0.027 gC.gdw -1 .h -1 were observed for styrene/acetone 2:1, styrene-rich and acetone-rich mixtures, respectively, indicating significant substrate interactions and rate limitation by biological factors. The BCR removed both acetone and styrene near-quantitatively up to a relatively high organic load of 50 g.m -3 .h -1 . From this point, the removal efficiencies declined under increasing loading rates, accompanied by a significant drop in the dissolved oxygen concentration, showing a process transition to oxygen-limited conditions. However, the relatively efficient pollutant removal from air continued, due to significant oxygen mass transfer, up to a threshold loading rate when the accumulation of acetone and degradation intermediates in the aqueous medium became significant. These observations demonstrate that oxygen availability is the limiting factor for efficient pollutant degradation and that accumulation of intermediates may serve as an indicator of oxygen limitation. Microbial (activated sludge) analyses revealed the presence of amoebae and active nematodes that were not affected by variations in operational conditions.

  13. Investigation of efficiency of air cleaning from acetone using a segmental construction biofilter

    Directory of Open Access Journals (Sweden)

    Denas Bacevičius

    2015-10-01

    Full Text Available Volatile organic compounds, e. g. acetone, have a direct impact on climate change, decrease of ozone in the air, and on the growth of greenhouse effect. One of the most popular air purifying methods from VOC is a biological air cleaning. Experimental investigations were conducted to determine the efficiency of the new structure of biofilter with polypropylene plates segments. During the investigations the efficiency of segmental construction biofilter of air purification at different initial concentrations of pollutants was determined. Different concentrations of pollutants were estimated during the acetone dilution with water. During the tests the efficiency of biofilter air purification from acetone vapor and its change under different concentrations of vapors was set. Based on test results, the maximum efficiency of biofilter air purification was up to 93%. Studies have shown that increasing the allowable pollutant concentration, the efficiency of air purification unit decreases. Increasing the concentration of supplied acetone vapor into the biofilter from 232 to 701 mg/m3, cleaning efficiency decreased from 92.8 to 82.3%. Since microorganisms fail to oxidize organic compounds, the filter works better at lower initial concentrations of pollutants.

  14. Relationship between CCR and NT-proBNP in Chinese HF patients, and their correlations with severity of HF.

    Science.gov (United States)

    Lu, Zhigang; Wang, Bo; Wang, Yunliang; Qian, Xueqing; Zheng, Wei; Wei, Meng

    2014-01-01

    To evaluate the relationship between creatinine clearance rate (CCR) and the level of N-terminal pro-B-type natriuretic peptide (NT-proBNP) in heart failure (HF) patients and their correlations with HF severity. Two hundred and one Chinese patients were grouped according to the New York Heart Association (NYHA) classification as NYHA 1-2 and 3-4 groups and 135 cases out of heart failure patients as control group. The following variables were compared among these three groups: age, sex, body mass index (BMI), smoking status, hypertension, diabetes, NT-proBNP, creatinine (Cr), uric acid (UA), left ventricular end-diastolic diameter (LVEDD), and CCR. The biomarkers of NT-proBNP, Cr, UA, LVEDD, and CCR varied significantly in the three groups, and these variables were positively correlated with the NHYA classification. The levels of NT-proBNP and CCR were closely related to the occurrence of HF and were independent risk factors for HF. At the same time, there was a significant negative correlation between the levels of NT-proBNP and CCR. The area under the receiver operating characteristic curve suggested that the NT-proBNP and CCR have high accuracy for diagnosis of HF and have clinical diagnostic value. NT-proBNP and CCR may be important biomarkers in evaluating the severity of HF.

  15. Epitaxial YBa2Cu3O7-x nanocomposite films and coated conductors from BaMO3 (M = Zr, Hf) colloidal solutions

    Science.gov (United States)

    Obradors, X.; Puig, T.; Li, Z.; Pop, C.; Mundet, B.; Chamorro, N.; Vallés, F.; Coll, M.; Ricart, S.; Vallejo, B.; Pino, F.; Palau, A.; Gázquez, J.; Ros, J.; Usoskin, A.

    2018-04-01

    Superconducting nanocomposites are the best material choice to address the performance required in power applications and magnets working under high magnetic fields. However, it is still challenging to sort out how to achieve the highest superconducting performance using attractive and competitive manufacturing processes. Colloidal solutions have been recently developed as a novel and very promising low cost route to manufacture nanocomposite coated conductors. Well dispersed and stabilized preformance nanoparticle solutions are first prepared with high concentrations and then mixed with the YBa2Cu3O7 metalorganic precursor solutions to generate colloidal solutions to grow the nanocomposite films. Here we demonstrate, for the first time, that non-reactive BaZrO3 and BaHfO3 perovskite preformed nanoparticles are suitable for growing high quality thin and thick films, and coated conductors with a homogeneous distribution and controlled particle size using this fabrication method. Additionally, we extend the nanoparticle content of the nanocomposites up to 20%-25% mol without any degradation of the superconducting properties. Thick nanocomposite films, up to 0.8 μm, have been prepared with a single deposition of low-fluorine solutions using an ink jet printing dispenser and we demonstrate that the preformed nanoparticles display only a very limited coarsening during the growth process and so high critical current densities J c (B) under high magnetic fields. These films show the highest critical currents achieved so far based on the colloidal solution approach, I c = 220 A/cm-w at 77 K and self-field, and they still have a high potential for further increase in the film thickness. Finally, we also show that nanocomposite YBa2Cu3O7-BaZrO3 coated conductors based on an alternating beam assisted deposited YSZ buffer layer on stainless steel metallic substrates can be developed based on these novel colloidal solutions. Non-reactive preformed oxide perovskite

  16. Role of Acetone in the Formation of Highly Dispersed Cationic Polystyrene Nanoparticles

    Directory of Open Access Journals (Sweden)

    Ernawati Lusi

    2017-03-01

    Full Text Available A modified emulsion polymerisation synthesis route for preparing highly dispersed cationic polystyrene (PS nanoparticles is reported. The combined use of 2,2′-azobis[2-(2-imidazolin- 2-ylpropane] di-hydrochloride (VA-044 as the initiator and acetone/water as the solvent medium afforded successful synthesis of cationic PS particles as small as 31 nm in diameter. A formation mechanism for the preparation of PS nanoparticles was proposed, whereby the occurrence of rapid acetone diffusion caused spontaneous rupture of emulsion droplets into smaller droplets. Additionally, acetone helped to reduce the surface tension and increase the solubility of styrene, thus inhibiting aggregation and coagulation among the particles. In contrast, VA-044 initiator could effectively regulate the stability of the PS nanoparticles including both the surface charge and size. Other reaction parameters i.e. VA-044 concentration and reaction time were examined to establish the optimum polymerisation conditions.

  17. Solution growth and scintillation properties of 9-phenylcarbazole

    Science.gov (United States)

    van Loef, Edgar V.; Markosyan, Gary; Shirwadkar, Urmila; McClish, Mickel; Shah, Kanai S.

    2017-12-01

    In this paper we report on the crystal growth and characterization of 9-phenylcarbazole (PCz). Crystals of PCz were obtained by the solution growth technique. Several organic solvents were investigated including heptane, cyclohexane, toluene, xylene, methanol, ethanol, and acetone. The largest crystals of the highest quality were grown from acetone. Radioluminescence spectra of pure PCz crystals exhibit a broad emission band peaking at 381 nm. Adding a small amount of an impurity (dopant) shifts the emission wavelength to 446 nm which is a better match to standard bialkali photomultiplier tubes. Single crystals of pure PCz have low light yields (typically security, nuclear non-proliferation, nuclear physics, and non-destructive testing.

  18. Co-production of acetone and ethanol with molar ratio control enables production of improved gasoline or jet fuel blends.

    Science.gov (United States)

    Baer, Zachary C; Bormann, Sebastian; Sreekumar, Sanil; Grippo, Adam; Toste, F Dean; Blanch, Harvey W; Clark, Douglas S

    2016-10-01

    The fermentation of simple sugars to ethanol has been the most successful biofuel process to displace fossil fuel consumption worldwide thus far. However, the physical properties of ethanol and automotive components limit its application in most cases to 10-15 vol% blends with conventional gasoline. Fermentative co-production of ethanol and acetone coupled with a catalytic alkylation reaction could enable the production of gasoline blendstocks enriched in higher-chain oxygenates. Here we demonstrate a synthetic pathway for the production of acetone through the mevalonate precursor hydroxymethylglutaryl-CoA. Expression of this pathway in various strains of Escherichia coli resulted in the co-production of acetone and ethanol. Metabolic engineering and control of the environmental conditions for microbial growth resulted in controllable acetone and ethanol production with ethanol:acetone molar ratios ranging from 0.7:1 to 10.0:1. Specifically, use of gluconic acid as a substrate increased production of acetone and balanced the redox state of the system, predictively reducing the molar ethanol:acetone ratio. Increases in ethanol production and the molar ethanol:acetone ratio were achieved by co-expression of the aldehyde/alcohol dehydrogenase (AdhE) from E. coli MG1655 and by co-expression of pyruvate decarboxylase (Pdc) and alcohol dehydrogenase (AdhB) from Z. mobilis. Controlling the fermentation aeration rate and pH in a bioreactor raised the acetone titer to 5.1 g L(-1) , similar to that obtained with wild-type Clostridium acetobutylicum. Optimizing the metabolic pathway, the selection of host strain, and the physiological conditions employed for host growth together improved acetone titers over 35-fold (0.14-5.1 g/L). Finally, chemical catalysis was used to upgrade the co-produced ethanol and acetone at both low and high molar ratios to higher-chain oxygenates for gasoline and jet fuel applications. Biotechnol. Bioeng. 2016;113: 2079-2087. © 2016 Wiley

  19. Action mechanism of hydrogen gas on deposition of HfC coating using HfCl{sub 4}-CH{sub 4}-H{sub 2}-Ar system

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yalei, E-mail: yaleipm@csu.edu.cn [State Key Laboratory of Powder Metallurgy, Central South University, Changsha, 410083 (China); School of Metallurgy and Environment, Central South University, Changsha, 410083 (China); Li, Zehao [State Key Laboratory of Powder Metallurgy, Central South University, Changsha, 410083 (China); Xiong, Xiang, E-mail: xiongx@csu.edu.cn [State Key Laboratory of Powder Metallurgy, Central South University, Changsha, 410083 (China); Li, Xiaobin [School of Metallurgy and Environment, Central South University, Changsha, 410083 (China); Chen, Zhaoke; Sun, Wei [State Key Laboratory of Powder Metallurgy, Central South University, Changsha, 410083 (China)

    2016-12-30

    Highlights: • HfC coatings were deposited on C/C composites by LPCVD using HfCl4-CH4-H2-Ar system. • Action mechanism of H2 on structure and growth behavior of HfC coating was studied. • Increased H2 concentration leads to transformation in growth mechanism of coating. - Abstract: Hafnium carbide coatings were deposited on carbon/carbon composites by low pressure chemical vapor deposition using HfCl{sub 4}-CH{sub 4}-H{sub 2}-Ar system. The microstructure, mechanical and ablation resistance performance of HfC coatings deposited with various H{sub 2} concentrations were investigated. The effect of hydrogen gas on the deposition of HfC coating was also discussed. Results show that all of the deposited coatings are composed of single cubic HfC phase, the hydrogen gas acted as a crucial role in determining the preferred orientation, microstructure and growth behavior of HfC coatings. During the deposition process, the gas phase supersaturation of the reaction species can be controlled by adjusting the hydrogen gas concentration. When deposited with low hydrogen gas concentration, the coating growth was dominated by the nucleation of HfC, which results in the particle-stacked structure of HfC coating. Otherwise, the coating growth was dominated by the crystal growth at high hydrogen gas concentration, which leads to the column-arranged structure of HfC coating. Under the ablation environment, the coating C2 exhibits better configurational stability and ablation resistance. The coating structure has a significant influence on the mechanical and ablation resistance properties of HfC coating.

  20. Measurements of acetone yields from the OH-initiated oxidation of terpenes by proton-transfer-reaction mass spectrometry

    International Nuclear Information System (INIS)

    Wisthaler, A.; Lindinger, W.; Jensen, N.R.; Winterhalter, R.; Hjorth, J.

    2002-01-01

    Biogenic VOCs (Volatile Organic Compounds) are known to be emitted in large quantities from vegetation exceeding largely global emissions of anthropogenic VOCs. Monoterpenes (C 10 H 16 ) are important constituents of biogenic VOC emissions. The atmospheric oxidation of Monoterpenes appears to be a potentially relevant source of acetone in the atmosphere. Acetone is present as a significant trace gas in the whole troposphere and influences in particular the atmospheric chemistry in the upper troposphere by substantially contributing to the formation of HO x radicals and peroxyacetyl nitrate (PAN). Acetone is formed promptly, following attack by the OH-radical on the terpene, via a series of highly unstable radical intermediates, but it is also formed slowly via the degradation of stable non-radical intermediates such as pinonaldehyde and nopinone. In order to investigate the relative importance of these processes, the OH-initiated oxidation of α-pinene and β-pinene was investigated in a chamber study, where the concentrations of monoterpenes, acetone, pinonaldehyde and nopinone were monitored by proton-transfer-reaction mass spectrometry (PTR-MS). It was found that significant amounts of acetone are formed directly, whenα-pinene and β-pinene are oxidized by the OH radical, but also secondary chemistry (degradation of primary reaction products) gives a significant contribution to the formation of acetone from monoterpenes. It can be concluded that atmospheric oxidation of monoterpenes contributes a significant fraction to the global acetone source strength. (nevyjel)

  1. Resistive switching characteristics of solution-processed organic-inorganic blended films for flexible memory applications

    Science.gov (United States)

    Baek, Il-Jin; Cho, Won-Ju

    2018-02-01

    We developed a hybrid organic-inorganic resistive random access memory (ReRAM) device that uses a solution-process to overcome the disadvantages of organic and inorganic materials for flexible memory applications. The drawbacks of organic and inorganic materials are a poor electrical characteristics and a lack of flexibility, respectively. We fabricated a hybrid organic-inorganic switching layer of ReRAM by blending HfOx or AlOx solution with PMMA solution and investigated the resistive switching behaviour in Ti/PMMA/Pt, Ti/PMMA-HfOx/Pt and Ti/PMMA-AlOx/Pt structures. It is found that PMMA-HfOx or PMMA-AlOx hybrid switching layer has a larger memory window, more stable durability and retention characteristics, and a better set/reset voltage distribution than PMMA layer. Further, it is confirmed that the flexibility of the PMMA-HfOx and PMMA-AlOx blended films was almost similar to that of the organic PMMA film. Thus, the solution-processed organic-inorganic blended films are considered a promising material for a non-volatile memory device on a flexible or wearable electronic system.

  2. The magnetic properties of $^{\\rm 177}$Hf and $^{\\rm 180}$Hf in the strong coupling deformed model

    OpenAIRE

    Muto, S.; Stone, N. J.; Bingham, C. R.; Stone, J. R.; Walker, P. M.; Audi, G.; Gaulard, C.; Köster, U.; Nikolov, J.; Nishimura, K.; Ohtsubo, T.; Podolyak, Z.; Risegari, L.; Simpson, G. S.; Veskovic, M.

    2014-01-01

    This paper reports NMR measurements of the magnetic dipole moments of two high-K isomers, the 37/2$^-$, 51.4 m, 2740 keV state in $^{\\rm 177}$Hf and the 8$^-$, 5.5 h, 1142 keV state in $^{\\rm 180}$Hf by the method of on-line nuclear orientation. Also included are results on the angular distributions of gamma transitions in the decay of the $^{\\rm 177}$Hf isotope. These yield high precision E2/M1 multipole mixing ratios for transitions in bands built on the 23/2$^+$, 1.1 s, isomer at 1315 keV ...

  3. Preparation of Curcumin Loaded Egg Albumin Nanoparticles Using Acetone and Optimization of Desolvation Process.

    Science.gov (United States)

    Aniesrani Delfiya, D S; Thangavel, K; Amirtham, D

    2016-04-01

    In this study, acetone was used as a desolvating agent to prepare the curcumin-loaded egg albumin nanoparticles. Response surface methodology was employed to analyze the influence of process parameters namely concentration (5-15%w/v) and pH (5-7) of egg albumin solution on solubility, curcumin loading and entrapment efficiency, nanoparticles yield and particle size. Optimum processing conditions obtained from response surface analysis were found to be the egg albumin solution concentration of 8.85%w/v and pH of 5. At this optimum condition, the solubility of 33.57%, curcumin loading of 4.125%, curcumin entrapment efficiency of 55.23%, yield of 72.85% and particles size of 232.6 nm were obtained and these values were related to the values which are predicted using polynomial model equations. Thus, the model equations generated for each response was validated and it can be used to predict the response values at any concentration and pH.

  4. Hf isotope evidence for a hidden mantle reservoir

    DEFF Research Database (Denmark)

    Bizzarro, Martin; Simonetti, A.; Stevenson, R.K.

    2002-01-01

    High-precision Hf isotopic analyses and U-Pb ages of carbonatites and kimberlites from Greenland and eastern North America, including Earth's oldest known carbonatite (3 Ga), indicate derivation from an enriched mantle source. This previously unidentified mantle reservoir-marked by an unradiogenic...... Hf isotopic composition and preserved in the deep mantle for at least 3 b.y.-may account for the mass imbalance in Earth's Hf-Nd budget. The Hf isotopic data presented here support a common mantle source region and genetic link between carbonatite and some oceanic-island basalt volcanoes....

  5. Anion exchange behaviour of Zr, Hf, Nb, Ta and Pa as homologues of RF and Db in fluoride medium

    Energy Technology Data Exchange (ETDEWEB)

    Monroy G, F. [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico); Trubert, D.; Brillard, L.; Hussonnois, M.; Constantinescu, O.; Le Naour, C., E-mail: fabiola.monroy@inin.gob.m [Institut de Physique Nucleaire, F-91406 Orsay, France (France)

    2010-07-01

    Studies of the chemical property of trans actinide elements are very difficult due to their short half-lives and extremely small production yields. However it is still possible to obtain considerable information about their chemical properties, such as the most stable oxidation states in aqueous solution, complexing ability, etc., comparing their behaviour with their lighter homologous in the periodic table. In order to obtain a better knowledge of the behaviour of rutherfordium, RF (element 104), dub nium, Db (element 105) in HF medium, the sorption properties of Zr, Hf, Nb, Ta an Pa, homologues of RF and Db, were studied in NH{sub 4}F/HClO{sub 4} medium in this work. Stability constants of the fluoride complexes of these elements were experimentally obtained from K{sub d} obtained at different F{sup -} and H{sup +} concentrations. The anionic complexes: [Zr(Hf)F{sub 5}]{sup -}, [Zr(Hf)F{sub 6}]{sup 2-}, [Zr(Hf)F{sub 7}]{sup 3-}, [Ta(Pa)F{sub 6}]{sup -}, [Ta(Pa)F{sub 7}]{sup 2-}, [Ta(Pa)F{sub 8}]{sup 3-}, [NbOF{sub 4}]{sup -} and [NbOF{sub 5}]{sup 2-} are present as predominant species in the HF range over investigation. (Author)

  6. Polypyrrole nanoparticles fabricated via Triton X-100 micelles template approach and their acetone gas sensing property

    Energy Technology Data Exchange (ETDEWEB)

    Li, Fake; Li, Hang [Department of Clinical Laboratory Medcine, Research Institute of Surgery, Daping Hospital, Third Military Medical University, Chongqing 400042 (China); Jiang, Hongmin [26th Research Institute, Chinese Electronics Scientific and Technical Group Company, Chongqing 400060 (China); Zhang, Kejun; Chang, Kai; Jia, Shuangrong; Jiang, Wenbin; Shang, Ya; Lu, Weiping [Department of Clinical Laboratory Medcine, Research Institute of Surgery, Daping Hospital, Third Military Medical University, Chongqing 400042 (China); Deng, Shaoli, E-mail: dengsl072@yahoo.com.cn [Department of Clinical Laboratory Medcine, Research Institute of Surgery, Daping Hospital, Third Military Medical University, Chongqing 400042 (China); Chen, Ming, E-mail: chenming1971@yahoo.com [Department of Clinical Laboratory Medcine, Research Institute of Surgery, Daping Hospital, Third Military Medical University, Chongqing 400042 (China)

    2013-09-01

    Nano-scaled polypyrrole (PPy) particles have been successfully synthesized with the help of Triton X-100 micelles via soft template approach. The polypyrrole nanoparticles have been spin-coated on surface acoustic wave (SAW) transducers to demonstrate their sensing capability toward acetone gas exposure. Field Emission Scanning Electron Microscopes (FE-SEM) and Fourier transform infrared (FT-IR) spectroscopy have been utilized to characterize these PPy nanoparticles. The PPy nanoparticles have an average diameter of 95 nm. The responses of the sensors are linearly associated with the acetone concentrations in the range from 5.5 ppm to 80 ppm. In response to 5.5 ppm acetone exposure, the response and recovery time are 9 s and 8.3 s, respectively. SAW sensors coated with PPy nanoparticles were potentially useful to detect acetone.

  7. Polypyrrole nanoparticles fabricated via Triton X-100 micelles template approach and their acetone gas sensing property

    International Nuclear Information System (INIS)

    Li, Fake; Li, Hang; Jiang, Hongmin; Zhang, Kejun; Chang, Kai; Jia, Shuangrong; Jiang, Wenbin; Shang, Ya; Lu, Weiping; Deng, Shaoli; Chen, Ming

    2013-01-01

    Nano-scaled polypyrrole (PPy) particles have been successfully synthesized with the help of Triton X-100 micelles via soft template approach. The polypyrrole nanoparticles have been spin-coated on surface acoustic wave (SAW) transducers to demonstrate their sensing capability toward acetone gas exposure. Field Emission Scanning Electron Microscopes (FE-SEM) and Fourier transform infrared (FT-IR) spectroscopy have been utilized to characterize these PPy nanoparticles. The PPy nanoparticles have an average diameter of 95 nm. The responses of the sensors are linearly associated with the acetone concentrations in the range from 5.5 ppm to 80 ppm. In response to 5.5 ppm acetone exposure, the response and recovery time are 9 s and 8.3 s, respectively. SAW sensors coated with PPy nanoparticles were potentially useful to detect acetone.

  8. Magnetic properties of Hf177 and Hf180 in the strong-coupling deformed model

    Science.gov (United States)

    Muto, S.; Stone, N. J.; Bingham, C. R.; Stone, J. R.; Walker, P. M.; Audi, G.; Gaulard, C.; Köster, U.; Nikolov, J.; Nishimura, K.; Ohtsubo, T.; Podolyak, Z.; Risegari, L.; Simpson, G. S.; Veskovic, M.; Walters, W. B.

    2014-04-01

    This paper reports NMR measurements of the magnetic dipole moments of two high-K isomers, the 37/2-, 51.4 m, 2740 keV state in Hf177 and the 8-, 5.5 h, 1142 keV state in Hf180 by the method of on-line nuclear orientation. Also included are results on the angular distributions of γ transitions in the decay of the Hf177 isotope. These yield high precision E2/M1 multipole mixing ratios for transitions in bands built on the 23/2+, 1.1 s, isomer at 1315 keV and on the 9/2+, 0.663 ns, isomer at 321 keV. The new results are discussed in the light of the recently reported finding of systematic dependence of the behavior of the gR parameter upon the quasiproton and quasineutron make up of high-K isomeric states in this region.

  9. NASOPHARYNGEAL CONCENTRATIONS IN THE HUMAN VOLUNTEER BREATHING ACETONE

    Science.gov (United States)

    In an effort to examine the absorption of a common chemical into the nasopharyngeal region in humans, a 57 year old male volunteer inhaled uniformly labeled 13C-acetone at 1.4 ppm for 30 min while performing different breathing maneuvers; nose inhale, nose exhale (NINE); mouth ...

  10. An acetone microsensor with a ring oscillator circuit fabricated using the commercial 0.18 μm CMOS process.

    Science.gov (United States)

    Yang, Ming-Zhi; Dai, Ching-Liang; Shih, Po-Jen

    2014-07-17

    This study investigates the fabrication and characterization of an acetone microsensor with a ring oscillator circuit using the commercial 0.18 μm complementary metal oxide semiconductor (CMOS) process. The acetone microsensor contains a sensitive material, interdigitated electrodes and a polysilicon heater. The sensitive material is α-Fe2O3 synthesized by the hydrothermal method. The sensor requires a post-process to remove the sacrificial oxide layer between the interdigitated electrodes and to coat the α-Fe2O3 on the electrodes. When the sensitive material adsorbs acetone vapor, the sensor produces a change in capacitance. The ring oscillator circuit converts the capacitance of the sensor into the oscillation frequency output. The experimental results show that the output frequency of the acetone sensor changes from 128 to 100 MHz as the acetone concentration increases 1 to 70 ppm.

  11. Mesocrystals luminescent BaZrHfO{sub 3} synthesized via hydrothermal process assisted by microwave

    Energy Technology Data Exchange (ETDEWEB)

    Fassbender, Rafael Uarth, E-mail: uarth.fisica@gmail.com

    2016-07-01

    Full text: The Barium Zirconate (BaZrO{sub 3}), is a ceramic oxide belonging to the functional group of perovskites (ABO{sub 3}), this compound can be doped with hafniun (Hf) in solid solution by microwave assisted hydrothermal method (MAH) radioluminescent increases their properties. This method allows to obtain barium zirconate at low temperature as 140 deg C and short times as 160 minutes. The choice of Hafnium (Hf) as a dopant is based on its similarity with Zirconium (Zr), another good reason for this choice is that the Hafnium has intrinsic luminescent characteristics. In general, radioluminescent materials have high density and high atomic mass (atomic number of Hafnium is 72), thereby facilitating the absorption of ionizing radiation to convert it into visible light, this characteristic is strongly dependent on the morphology and especially the electronic structure of (BaZrO{sub 3}). This work consisted in production of barium zirconate powders doped 1-2-4-8-16% (Hf) using (MAH) method. For the characterization of the powders was employed methods : a) X-ray diffraction, b) Raman Spectroscopy, c) Xanes, d) photoluminescence spectroscopy. After the electronic and structural characterization the powders were introduced in a polymeric resin (nylon-BZO), one new characterizations will be performed to validate the results obtained in the production of films to the results already obtained for the powders. We conclude so far, that the powders-doped with 16% Hf has an intense luminescent emission compared to the powders with less concentration of Hf. The small structural change that causes the Hf in (BZO) is considered as a secondary factory. (author)

  12. Oxidation behavior of Hf-modified platinum aluminide coatings during thermal cycling

    Directory of Open Access Journals (Sweden)

    Liya Ye

    2018-02-01

    Full Text Available Platinum aluminide coatings with different Hf contents were fabricated by using HfCl4. The oxidation kinetics and the rumpling behavior of oxide scale were investigated. After thermal cycling, the coating with 0.46 wt% Hf showed least weight gain. With the increase of Hf content, rumpling extent of the scale decreased. Meanwhile, HfO2 preferentially formed in the scale resulting in the increase of scale thickness. The oxidation of excessive Hf even caused the spallation of the scale. The results in the present study indicate that although Hf plays an important role in decreasing rumpling extent of TGO, the oxidation of Hf decreases the adhesion of the scale. Keywords: Pt-Al coating, Hf, Oxidation, Rumpling

  13. Gallium-67 citrate used as a tracer of acetone production routes

    International Nuclear Information System (INIS)

    Mesquita, Carlos Henrique de; Calvo, Wilson A.P.; Aoki, Pedro E.; Silva, Valdir Cosmos da; Haraguchi, Marcio I.; Velo, Alexandre F.; Alvarez, Alexandre G.; Paixão, Leticia B.; Hamada, Margarida M.

    2017-01-01

    In this work the pathway of the chemical product and the kinetics parameters were evaluated in a laboratory plant settled, using 40 GBq of 67 Ga citrate as radiotracer and 18 NaI(Tl) radiation detectors. The AnaComp program was used to estimate the kinetic parameters of the acetone production. The yield of the acetone production was estimated by the percentage ratio between the areas under the curve (AUC) of the curve profiles of the final product compartment divided by the concentration found inside the chemical reactor whose result was 87% yield during the first 30 minutes of reaction. (author)

  14. Gallium-67 citrate used as a tracer of acetone production routes

    Energy Technology Data Exchange (ETDEWEB)

    Mesquita, Carlos Henrique de; Calvo, Wilson A.P.; Aoki, Pedro E.; Silva, Valdir Cosmos da; Haraguchi, Marcio I.; Velo, Alexandre F.; Alvarez, Alexandre G.; Paixão, Leticia B.; Hamada, Margarida M., E-mail: chmesqui@usp.br [Instituto de Pesquisas Energéticas e Nucleares (IPEN/CNEN-SP), São Paulo, SP (Brazil)

    2017-07-01

    In this work the pathway of the chemical product and the kinetics parameters were evaluated in a laboratory plant settled, using 40 GBq of {sup 67}Ga citrate as radiotracer and 18 NaI(Tl) radiation detectors. The AnaComp program was used to estimate the kinetic parameters of the acetone production. The yield of the acetone production was estimated by the percentage ratio between the areas under the curve (AUC) of the curve profiles of the final product compartment divided by the concentration found inside the chemical reactor whose result was 87% yield during the first 30 minutes of reaction. (author)

  15. Effects of HfB2 and HfN Additions on the Microstructures and Mechanical Properties of TiB2-Based Ceramic Tool Materials

    Science.gov (United States)

    An, Jing; Song, Jinpeng; Liang, Guoxing; Gao, Jiaojiao; Xie, Juncai; Cao, Lei; Wang, Shiying; Lv, Ming

    2017-01-01

    The effects of HfB2 and HfN additions on the microstructures and mechanical properties of TiB2-based ceramic tool materials were investigated. The results showed that the HfB2 additive not only can inhibit the TiB2 grain growth but can also change the morphology of some TiB2 grains from bigger polygons to smaller polygons or longer ovals that are advantageous for forming a relatively fine microstructure, and that the HfN additive had a tendency toward agglomeration. The improvement of flexural strength and Vickers hardness of the TiB2-HfB2 ceramics was due to the relatively fine microstructure; the decrease of fracture toughness was ascribed to the formation of a weaker grain boundary strength due to the brittle rim phase and the poor wettability between HfB2 and Ni. The decrease of the flexural strength and Vickers hardness of the TiB2-HfN ceramics was due to the increase of defects such as TiB2 coarse grains and HfN agglomeration; the enhancement of fracture toughness was mainly attributed to the decrease of the pore number and the increase of the rim phase and TiB2 coarse grains. The toughening mechanisms of TiB2-HfB2 ceramics mainly included crack bridging and transgranular fracture, while the toughening mechanisms of TiB2-HfN ceramics mainly included crack deflection, crack bridging, transgranular fracture, and the core-rim structure. PMID:28772821

  16. Effects of HfB2 and HfN Additions on the Microstructures and Mechanical Properties of TiB2-Based Ceramic Tool Materials

    Directory of Open Access Journals (Sweden)

    Jing An

    2017-04-01

    Full Text Available The effects of HfB2 and HfN additions on the microstructures and mechanical properties of TiB2-based ceramic tool materials were investigated. The results showed that the HfB2 additive not only can inhibit the TiB2 grain growth but can also change the morphology of some TiB2 grains from bigger polygons to smaller polygons or longer ovals that are advantageous for forming a relatively fine microstructure, and that the HfN additive had a tendency toward agglomeration. The improvement of flexural strength and Vickers hardness of the TiB2-HfB2 ceramics was due to the relatively fine microstructure; the decrease of fracture toughness was ascribed to the formation of a weaker grain boundary strength due to the brittle rim phase and the poor wettability between HfB2 and Ni. The decrease of the flexural strength and Vickers hardness of the TiB2-HfN ceramics was due to the increase of defects such as TiB2 coarse grains and HfN agglomeration; the enhancement of fracture toughness was mainly attributed to the decrease of the pore number and the increase of the rim phase and TiB2 coarse grains. The toughening mechanisms of TiB2-HfB2 ceramics mainly included crack bridging and transgranular fracture, while the toughening mechanisms of TiB2-HfN ceramics mainly included crack deflection, crack bridging, transgranular fracture, and the core-rim structure.

  17. Simulation of macromolecule self-assembly in solution: A multiscale approach

    Energy Technology Data Exchange (ETDEWEB)

    Lavino, Alessio D., E-mail: alessiodomenico.lavino@studenti.polito.it; Barresi, Antonello A., E-mail: antonello.barresi@polito.it; Marchisio, Daniele L., E-mail: daniele.marchisio@polito.it [Dipartimento di Scienza Applicata e Tecnologia, Istituto di Ingegneria Chimica, Politecnico di Torino, C.so Duca degli Abruzzi 24, 10129 Torino (Italy); Pasquale, Nicodemo di, E-mail: nicodemo.dipasquale@manchester.ac.uk [School of Chemistry, The University of Manchester, Oxford Road, Manchester M13 9PL, UnitedKingdom (United Kingdom); Carbone, Paola, E-mail: paola.carbone@manchester.ac.uk [School of Chemical Engineering and Analytical Science, The University of Manchester, Oxford Road, Manchester M13 9PL, UnitedKingdom (United Kingdom)

    2015-12-17

    One of the most common processes to produce polymer nanoparticles is to induce self-assembly by using the solvent-displacement method, in which the polymer is dissolved in a “good” solvent and the solution is then mixed with an “anti-solvent”. The polymer ability to self-assemble in solution is therefore determined by its structural and transport properties in solutions of the pure solvents and at the intermediate compositions. In this work, we focus on poly-ε-caprolactone (PCL) which is a biocompatible polymer that finds widespread application in the pharmaceutical and biomedical fields, performing simulation at three different scales using three different computational tools: full atomistic molecular dynamics (MD), population balance modeling (PBM) and computational fluid dynamics (CFD). Simulations consider PCL chains of different molecular weight in solution of pure acetone (good solvent), of pure water (anti-solvent) and their mixtures, and mixing at different rates and initial concentrations in a confined impinging jets mixer (CIJM). Our MD simulations reveal that the nano-structuring of one of the solvents in the mixture leads to an unexpected identical polymer structure irrespectively of the concentration of the two solvents. In particular, although in pure solvents the behavior of the polymer is, as expected, very different, at intermediate compositions, the PCL chain shows properties very similar to those found in pure acetone as a result of the clustering of the acetone molecules in the vicinity of the polymer chain. We derive an analytical expression to predict the polymer structural properties in solution at different solvent compositions and use it to formulate an aggregation kernel to describe the self-assembly in the CIJM via PBM and CFD. Simulations are eventually validated against experiments.

  18. Um estudo teórico de propriedades moleculares em complexos de hidrogênio trimoleculares C2H4···2HF, C2H2···2HF e C3h6···2HF A theoretical study of molecular properties of C2H4···2HF, C2H2···2HF AND C3H6···2HF trimolecular hydrogen-bonded complexes

    Directory of Open Access Journals (Sweden)

    Boaz G. Oliveira

    2008-01-01

    Full Text Available We present a theoretical study of molecular properties in C2H4···2HF, C2H2···2HF and C3H6···2HF trimolecular hydrogen-bonded complexes. From B3LYP/6-311++G(d,p calculations, the most important structural deformations are related to the C=C (C2H4, C≡C (C2H2, C-C (C3H6 and HF bond lengths. According to the Bader's atoms in molecules and CHELPG calculations, it was identified a tertiary interaction between the fluorine atom of the second hydrofluoric acid molecule and hydrogen atoms of the ethylene and acetylene within the C2H4···2HF and C2H2···2HF complexes, respectively. Additionally, the evaluation of the infrared spectrum characterized the new vibrational modes and bathochromic effect of the HF molecules.

  19. Lidar/DIAL detection of acetone at 3.3 μm by a tunable OPO laser system

    International Nuclear Information System (INIS)

    Puiu, A; Fiorani, L; Borelli, R; Pistilli, M; Palucci, A; Rosa, O

    2014-01-01

    In this paper we report, for the first time to our knowledge, on lidar/DIAL detection of acetone vapors at 3.3 μm by means of an optical parametric tunable laser system. After a preliminary spectroscopic study in an absorption cell, the feasibility of a differential absorption (DIAL) lidar for the detection of acetone vapors has been investigated in the laboratory, simulating the experimental conditions of a field campaign. Having in mind measurements in a real scenario, a study of possible atmospheric intereferents has been performed, looking for all known compounds that share acetone IR absorption in the spectral band selected for its detection. Possible interfering species from urban and industrial atmospheres were investigated and limits of acetone detection in both environments were identified. This study confirmed that a lidar system can detect a low concentration of acetone at considerable distances. (paper)

  20. Design and Fabrication of Interdigital Nanocapacitors Coated with HfO2

    Directory of Open Access Journals (Sweden)

    Gabriel González

    2015-01-01

    Full Text Available In this article nickel interdigital capacitors were fabricated on top of silicon substrates. The capacitance of the interdigital capacitor was optimized by coating the electrodes with a 60 nm layer of HfO2. An analytical solution of the capacitance was compared to electromagnetic simulations using COMSOL and with experimental measurements. Results show that modeling interdigital capacitors using Finite Element Method software such as COMSOL is effective in the design and electrical characterization of these transducers.

  1. An acetone breath analyzer using cavity ringdown spectroscopy: an initial test with human subjects under various situations

    International Nuclear Information System (INIS)

    Wang, Chuji; Surampudi, Anand B

    2008-01-01

    We have developed a portable breath acetone analyzer using cavity ringdown spectroscopy (CRDS). The instrument was initially tested by measuring the absorbance of breath gases at a single wavelength (266 nm) from 32 human subjects under various conditions. A background subtraction method, implemented to obtain absorbance differences, from which an upper limit of breath acetone concentration was obtained, is described. The upper limits of breath acetone concentration in the four Type 1 diabetes (T1D) subjects, tested after a 14 h overnight fast, range from 0.80 to 3.97 parts per million by volume (ppmv), higher than the mean acetone concentration (0.49 ppmv) in non-diabetic healthy breath reported in the literature. The preliminary results show that the instrument can tell distinctive differences between the breath from individuals who are healthy and those with T1D. On-line monitoring of breath gases in healthy people post-exercise, post-meals and post-alcohol-consumption was also conducted. This exploratory study demonstrates the first CRDS-based acetone breath analyzer and its potential application for point-of-care, non-invasive, diabetic monitoring

  2. Collision-Induced Dissociation Study of Strong Hydrogen-Bonded Cluster Ions Y-(HF) n (Y=F, O2) Using Atmospheric Pressure Corona Discharge Ionization Mass Spectrometry Combined with a HF Generator.

    Science.gov (United States)

    Sakamoto, Kenya; Sekimoto, Kanako; Takayama, Mitsuo

    2017-01-01

    Hydrogen fluoride (HF) was produced by a homemade HF generator in order to investigate the properties of strong hydrogen-bonded clusters such as (HF) n . The HF molecules were ionized in the form of complex ions associated with the negative core ions Y - produced by atmospheric pressure corona discharge ionization (APCDI). The use of APCDI in combination with the homemade HF generator led to the formation of negative-ion HF clusters Y - (HF) n (Y=F, O 2 ), where larger clusters with n ≥4 were not detected. The mechanisms for the formation of the HF, F - (HF) n , and O 2 - (HF) n species were discussed from the standpoints of the HF generator and APCDI MS. By performing energy-resolved collision-induced dissociation (CID) experiments on the cluster ions F - (HF) n ( n =1-3), the energies for the loss of HF from F - (HF) 3 , F - (HF) 2 , and F - (HF) were evaluated to be 1 eV or lower, 1 eV or higher, and 2 eV, respectively, on the basis of their center-of-mass energy ( E CM ). These E CM values were consistent with the values of 0.995, 1.308, and 2.048 eV, respectively, obtained by ab initio calculations. The stability of [O 2 (HF) n ] - ( n =1-4) was discussed on the basis of the bond lengths of O 2 H-F - (HF) n and O 2 - H-F(HF) n obtained by ab initio calculations. The calculations indicated that [O 2 (HF) 4 ] - separated into O 2 H and F - (HF) 3 .

  3. Acetone photophysics at 282 nm excitation at elevated pressure and temperature. II: Fluorescence modeling

    Science.gov (United States)

    Hartwig, Jason; Raju, Mandhapati; Sung, Chih-Jen

    2017-07-01

    This is the second in a series of two papers that presents an updated fluorescence model and compares with the new experimental data reported in the first paper, as well as the available literature data, to extend the range of acetone photophysics to elevated pressure and temperature conditions. This work elucidates the complete acetone photophysical model in terms of each and every competing radiative and non-radiative rate. The acetone fluorescence model is then thoroughly examined and optimized based on disparity with recently conducted elevated pressure and temperature photophysical calibration experiments. The current work offers insight into the competition between non-radiative and vibrational energy decay rates at elevated temperature and pressure and proposes a global optimization of model parameters from the photophysical model developed by Thurber (Acetone Laser-Induced Fluorescence for Temperature and Multiparameter Imaging in Gaseous Flows. PhD thesis, Stanford University Mechanical Engineering Department, 1999). The collisional constants of proportionality, which govern vibrational relaxation, are shown to be temperature dependent at elevated pressures. A new oxygen quenching rate is proposed which takes into account collisions with oxygen as well as the oxygen-assisted intersystem crossing component. Additionally, global trends in ketone photophysics are presented and discussed.

  4. Investigation of new type Cu-Hf-Al bulk glassy alloys

    International Nuclear Information System (INIS)

    Nagy, E; Ronto, V; Solyom, J; Roosz, A

    2009-01-01

    In the last years new type Cu-Hf-Al ternary alloys were developed with high glass forming ability and ductility. The addition of Al to Cu-Hf alloys results in improvements in glass formation, thermal stability and mechanical properties of these alloys. We have investigated new Cu-based bulk amorphous alloys in Cu-Hf-Al ternary system. The alloys with Cu 49 Hf 42 Al 9 , Cu 46 Hf 45 Al 9 , Cu 50 Hf 42.5 Al 7.5 and Cu 50 Hf 45 Al 5 compositions were prepared by arc melting. The samples were made by centrifugal casting and were investigated by X-ray diffraction method. Thermodynamic properties were examined by differential scanning calorimetry and the structure of the crystallising phases by scanning electron microscopy. The determination of liquidus temperatures of alloys were measured by differential thermal analysis.

  5. Rapid and selective detection of acetone using hierarchical ZnO gas sensor for hazardous odor markers application

    International Nuclear Information System (INIS)

    Jia, Qianqian; Ji, Huiming; Zhang, Ying; Chen, Yalu; Sun, Xiaohong; Jin, Zhengguo

    2014-01-01

    Highlights: • ZnO spheres fabricated via solvothermal method are with (0 0 2) polar facet exposed. • Response time of ZnO sensor for detecting 100 ppm acetone is as short as 3 s. • R a /R g toward 100 ppm acetone is 33 when operated at 230 °C. • ZnO sensor exhibits good selectivity against other toxic gases and water vapor. • Porous structure and exposure of polar facet contribute to good sensing properties. - Abstract: Hierarchical nanostructured ZnO dandelion-like spheres were synthesized via solvothermal reaction at 200 °C for 4 h. The products were pure hexagonal ZnO with large exposure of (0 0 2) polar facet. Side-heating gas sensor based on hierarchical ZnO spheres was prepared to evaluate the acetone gas sensing properties. The detection limit to acetone for the ZnO sensor is 0.25 ppm. The response (R a /R g ) toward 100 ppm acetone was 33 operated at 230 °C and the response time was as short as 3 s. The sensor exhibited remarkable acetone selectivity with negligible response toward other hazardous gases and water vapor. The high proportion of electron depletion region and oxygen vacancies contributed to high gas response sensitivity. The hollow and porous structure of dandelion-like ZnO spheres facilitated the diffusion of gas molecules, leading to a rapid response speed. The largely exposed (0 0 2) polar facets could adsorb acetone gas molecules easily and efficiently, resulting in a rapid response speed and good selectivity of hierarchical ZnO spheres gas sensor at low operating temperature

  6. Enhanced resistive switching and multilevel behavior in bilayered HfAlO/HfAlO{sub x} structures for non-volatile memory applications

    Energy Technology Data Exchange (ETDEWEB)

    Faita, F. L., E-mail: fabriciofaita@gmail.com [Centre of Physics, University of Minho, Campus de Gualtar, 4710-057 Braga (Portugal); Departamento de Física, Universidade Federal de Santa Catarina, Campus Trindade, 88040-900 Florianópolis, SC (Brazil); Silva, J. P. B., E-mail: josesilva@fisica.uminho.pt [Centre of Physics, University of Minho, Campus de Gualtar, 4710-057 Braga (Portugal); IFIMUP and IN-Institute of Nanoscience and Nanotechnology, Departamento de Física e Astronomia, Faculdade de Ciências da Universidade do Porto, 4169-007 Porto (Portugal); Pereira, M.; Gomes, M. J. M. [Centre of Physics, University of Minho, Campus de Gualtar, 4710-057 Braga (Portugal)

    2015-12-14

    In this work, hafnium aluminum oxide (HfAlO) thin films were deposited by ion beam sputtering deposition technique on Si substrate. The presence of oxygen vacancies in the HfAlO{sub x} layer deposited in oxygen deficient environment is evidenced from the photoluminescence spectra. Furthermore, HfAlO(oxygen rich)/HfAlO{sub x}(oxygen poor) bilayer structures exhibit multilevel resistive switching (RS), and the switching ratio becomes more prominent with increasing the HfAlO layer thickness. The bilayer structure with HfAlO/HfAlO{sub x} thickness of 30/40 nm displays the enhanced multilevel resistive switching characteristics, where the high resistance state/intermediate resistance state (IRS) and IRS/low resistance state resistance ratios are ≈10{sup 2} and ≈5 × 10{sup 5}, respectively. The switching mechanisms in the bilayer structures were investigated by the temperature dependence of the three resistance states. This study revealed that the multilevel RS is attributed to the coupling of ionic conduction and the metallic conduction, being the first associated to the formation and rupture of conductive filaments related to oxygen vacancies and the second with the formation of a metallic filament. Moreover, the bilayer structures exhibit good endurance and stability in time.

  7. In-situ atomic layer deposition growth of Hf-oxide

    International Nuclear Information System (INIS)

    Karavaev, Konstantin

    2010-01-01

    We have grown HfO 2 on Si(001) by atomic layer deposition (ALD) using HfCl 4 , TEMAHf, TDMAHf and H 2 O as precursors. The early stages of the ALD were investigated with high-resolution photoelectron spectroscopy and X-ray absorption spectroscopy. We observed the changes occurring in the Si 2p, O 1s, Hf 4f, Hf 4d, and Cl 2p (for HfCl 4 experiment) core level lines after each ALD cycle up to the complete formation of two layers of HfO 2 . The investigation was carried out in situ giving the possibility to determine the properties of the grown film after every ALD cycle or even after a half cycle. This work focused on the advantages in-situ approach in comparison with ex-situ experiments. The study provides to follow the evolution of the important properties of HfO 2 : contamination level, density and stoichiometry, and influence of the experimental parameters to the interface layer formation during ALD. Our investigation shows that in-situ XPS approach for ALD gives much more information than ex-situ experiments. (orig.)

  8. In-situ atomic layer deposition growth of Hf-oxide

    Energy Technology Data Exchange (ETDEWEB)

    Karavaev, Konstantin

    2010-06-17

    We have grown HfO{sub 2} on Si(001) by atomic layer deposition (ALD) using HfCl{sub 4}, TEMAHf, TDMAHf and H{sub 2}O as precursors. The early stages of the ALD were investigated with high-resolution photoelectron spectroscopy and X-ray absorption spectroscopy. We observed the changes occurring in the Si 2p, O 1s, Hf 4f, Hf 4d, and Cl 2p (for HfCl{sub 4} experiment) core level lines after each ALD cycle up to the complete formation of two layers of HfO{sub 2}. The investigation was carried out in situ giving the possibility to determine the properties of the grown film after every ALD cycle or even after a half cycle. This work focused on the advantages in-situ approach in comparison with ex-situ experiments. The study provides to follow the evolution of the important properties of HfO{sub 2}: contamination level, density and stoichiometry, and influence of the experimental parameters to the interface layer formation during ALD. Our investigation shows that in-situ XPS approach for ALD gives much more information than ex-situ experiments. (orig.)

  9. Surface characteristics of hydroxyapatite-coated layer prepared on nanotubular Ti–35Ta–xHf alloys by EB-PVD

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Yong-Hoon [Department of Dental Materials and Research Center of Nano-Interface Activation for Biomaterials, School of Dentistry, Chosun University, Gwangju (Korea, Republic of); Biomechanics and Tissue Engineering Laboratory, Division of Orthodontics, College of Dentistry, The Ohio State University, Columbus, OH (United States); Moon, Byung-Hak [Department of Dental Materials and Research Center of Nano-Interface Activation for Biomaterials, School of Dentistry, Chosun University, Gwangju (Korea, Republic of); Choe, Han-Cheol, E-mail: hcchoe@chosun.ac.kr [Department of Dental Materials and Research Center of Nano-Interface Activation for Biomaterials, School of Dentistry, Chosun University, Gwangju (Korea, Republic of); Brantley, William A. [Division of Restorative, Prosthetic and Primary Care Dentistry, College of Dentistry, The Ohio State University, Columbus, OH (United States)

    2013-12-31

    In this study, we investigated the surface characteristics of hydroxyapatite (HA)-coated layers prepared by electron-beam physical vapor deposition (EB-PVD) on nanotubular Ti–35Ta–xHf alloys (x = 3, 7, and 15 wt.%). Ti–35Ta–xHf alloys were first prepared by arc melting. Formation of a nanotube structure on these alloys was achieved by an electrochemical method in 1 M H{sub 3}PO{sub 4} + 0.8 wt.% NaF electrolytes. The HA coatings were then deposited on the nanotubular surface by an EB-PVD method. The surface characteristics were analyzed by field-emission scanning electron microscopy, energy-dispersive X-ray spectroscopy, and X-ray diffraction (XRD). The electrochemical behavior was examined using a potentiodynamic polarization test in 0.9% NaCl solution. The Ti–35Ta–xHf alloys had an equiaxed grain structure with α″ + β phases, and the α″ phase disappeared with increases in Hf content. The Ti–35Ta–15Hf alloy showed higher β-phase peak intensity in the XRD patterns than that for the lower Hf-content alloys. A highly ordered nanotubular oxide layer was formed on the Ti–35Ta–15Hf alloy, and the tube length depended on Hf content. The HA coating surface formed at traces of the nanotubular titanium oxide layer and completely covered the tips of the nanotubes with a cluster shape. From the potentiodynamic polarization tests, the incorporation of Hf element and formation of the nanotubular structure were the main factors for achieving lower current density. In particular, the surface of the HA coating on the nanotubular structure exhibited higher corrosion resistance than that of the nanotubular titanium oxide structure without an HA coating. - Highlights: • Hydroxyapatite (HA) was coated on nanotubular Ti–35Ta–xHf alloys, using EB-PVD. • Increasing the Hf content reduced the relative proportion of α″ martensite to β-Ti in the microstructures. • The detailed nanotubular structure formed by anodization depended on alloy composition

  10. Surface characteristics of hydroxyapatite-coated layer prepared on nanotubular Ti–35Ta–xHf alloys by EB-PVD

    International Nuclear Information System (INIS)

    Jeong, Yong-Hoon; Moon, Byung-Hak; Choe, Han-Cheol; Brantley, William A.

    2013-01-01

    In this study, we investigated the surface characteristics of hydroxyapatite (HA)-coated layers prepared by electron-beam physical vapor deposition (EB-PVD) on nanotubular Ti–35Ta–xHf alloys (x = 3, 7, and 15 wt.%). Ti–35Ta–xHf alloys were first prepared by arc melting. Formation of a nanotube structure on these alloys was achieved by an electrochemical method in 1 M H 3 PO 4 + 0.8 wt.% NaF electrolytes. The HA coatings were then deposited on the nanotubular surface by an EB-PVD method. The surface characteristics were analyzed by field-emission scanning electron microscopy, energy-dispersive X-ray spectroscopy, and X-ray diffraction (XRD). The electrochemical behavior was examined using a potentiodynamic polarization test in 0.9% NaCl solution. The Ti–35Ta–xHf alloys had an equiaxed grain structure with α″ + β phases, and the α″ phase disappeared with increases in Hf content. The Ti–35Ta–15Hf alloy showed higher β-phase peak intensity in the XRD patterns than that for the lower Hf-content alloys. A highly ordered nanotubular oxide layer was formed on the Ti–35Ta–15Hf alloy, and the tube length depended on Hf content. The HA coating surface formed at traces of the nanotubular titanium oxide layer and completely covered the tips of the nanotubes with a cluster shape. From the potentiodynamic polarization tests, the incorporation of Hf element and formation of the nanotubular structure were the main factors for achieving lower current density. In particular, the surface of the HA coating on the nanotubular structure exhibited higher corrosion resistance than that of the nanotubular titanium oxide structure without an HA coating. - Highlights: • Hydroxyapatite (HA) was coated on nanotubular Ti–35Ta–xHf alloys, using EB-PVD. • Increasing the Hf content reduced the relative proportion of α″ martensite to β-Ti in the microstructures. • The detailed nanotubular structure formed by anodization depended on alloy composition. • The

  11. First discovery of acetone extract from cottonseed oil sludge as a novel antiviral agent against plant viruses.

    Science.gov (United States)

    Zhao, Lei; Feng, Chaohong; Hou, Caiting; Hu, Lingyun; Wang, Qiaochun; Wu, Yunfeng

    2015-01-01

    A novel acetone extract from cottonseed oil sludge was firstly discovered against plant viruses including Tobacco mosaic virus (TMV), Rice stripe virus (RSV) and Southern rice black streaked dwarf virus (SRBSDV). Gossypol and β-sitosterol separated from the acetone extract were tested for their effects on anti-TMV and analysed by nuclear magnetic resonance (NMR) assay. In vivo and field trials in different geographic distributions and different host varieties declared that this extract mixture was more efficient than the commercial agent Ningnanmycin with a broad spectrum of anti-plant-viruses activity. No phytotoxic activity was observed in the treated plants and environmental toxicology showed that this new acetone extract was environmentally friendly, indicating that this acetone extract has potential application in the control of plant virus in the future.

  12. [Modification of the pattern of fatty acids of erythrocytes’ membranes due to the acetone intoxication].

    Science.gov (United States)

    Momot, T V; Kushnerova, N F; Rakhmanin, Yu A

    Results of the study of the impact of acetone intoxication on the fatty acids pattern of the general lipids of erythrocytes’ membranes in rats are presented. The inhalation exposure of acetone was carried out in the inoculation chamber with the volume of 100 liters. The chamber was designed for the type of B.A. Kurlyandsky with self-contained system of purification and air regeneration and specified parameters of temperature (20-22С) and air humidity. The flow rate of the air and aerosolized acetone passed through the chamber accounted of 10 liters/min. Concentration of acetone in the chamber was sustained at the level of 206 ± 3,9 mg/m that corresponds to maximum permissible concentration for acetone vapor in the air of a working area. The time of exposure was 6 hours per day for 3 weeks in a monotonous mode, excluding weekend, and was based upon specific parameters of environment simulation in industry. The acetone impact was shown to be accompanied by the gain in the quantity of all kinds of saturated fatty acids and the fall of unsaturated fatty acids in general lipids of erythrocytes ’ membranes in rats and in the structure ofphospholipid fractions. In the content of phosphatydilcholine and phosphatydilethanolamine, as a basic structural phospholipids of biological membranes, there was noted the increase in palmitic and stearic acids. In the range offatty acids of the n-6 family the amount of linoleic and arachidonic acids decreased. In the array of fatty acids of the n-3 family the content of linolenic, eicosapentaenoic and docosahexaenoic acids (n-3 family) declined. Redistribution of fatty acids in the erythrocytes membrane towards to such alteration in quantity as the increasing of saturation and decreasing of the unsaturated fatty acids supposes the change of its physical and chemical properties, permeability, lability and complexity of passing erythrocyte via microcircular channels.

  13. Thermoelectric properties of doped BaHfO{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Dixit, Chandra Kr., E-mail: ckparadise@gmail.com, E-mail: sharmarameshfgiet@gmail.com [Dept. of Physics, Dr. Shakuntala Misra National Rehabilitation University, Lucknow-229001, U.P India (India); Bhamu, K. C. [Department of Physics, Goa University, Goa-403 206 (India); Sharma, Ramesh, E-mail: ckparadise@gmail.com, E-mail: sharmarameshfgiet@gmail.com [Dept. of Physics, Feroze Gandhi Institute of Engineering & Technology, Raebareli-229001, U.P India (India)

    2016-05-06

    We have studied the structural stability, electronic structure, optical properties and thermoelectric properties of doped BaHfO{sub 3} by full potential linearized augmented plane wave (FP-LAPW) method. The electronic structure of BaHfO{sub 3} doped with Sr shows enhances the indirect band gaps of 3.53 eV, 3.58 eV. The charge density plots show strong ionic bonding in Ba-Hf, and ionic and covalent bonding between Hf and O. Calculations of the optical spectra, viz., the dielectric function, refractive index and extinction coefficient are performed for the energy range are calculated and analyzed. Thermoelectric properties of semi conducting are also reported first time. The doped BaHfO{sub 3} is approximately wide band gap semiconductor with the large p-type Seebeck coefficient. The power factor of BaHfO{sub 3} is increased with Sr doping, decreases because of low electrical resistivity and thermal conductivity.

  14. Some problems of local production of acetone and butanol

    Energy Technology Data Exchange (ETDEWEB)

    Fang, C; Chang, Y P

    1959-01-01

    Conditions of laboratory and plant cultivation of acetone-butanol fermentation bacteria are considered (effects of pH of the medium, temperature, and starch content in raw material on yield of fermentation products) and also the conditions of isolation of the final products produced.

  15. In vitro antimycobacterial activity of acetone extract of Glycyrrhiza glabra

    Directory of Open Access Journals (Sweden)

    Swapna S. Nair

    2015-08-01

    Full Text Available Context: Glycyrrhiza glabra (licorice has been used since ages as expectorant, antitussive and demulcent. G. glabra has been indicated in Ayurveda as an antimicrobial agent for the treatment of respiratory infections and tuberculosis. Aims: To evaluate the antimycobacterial activity of acetone extract of G. glabra by in vitro techniques. Methods: The anti-tubercular activity of acetone extract of G. glabra, obtained by Soxhlet extraction, was evaluated against Mycobacterium tuberculosis H37Rv (ATCC 27294. The in vitro anti-tubercular activity was determined by Resazurin Microtiter Plate Assay (REMA and colony count method. Further, the anti-tubercular activity of acetone extract of G. glabra was determined in human macrophage U937 cell lines and was compared against that of the standard drugs isoniazid, rifampicin and ethambutol. Results: G. glabra extract showed significant activity against Mycobacterium tuberculosis, when evaluated by REMA/colony count methods and in U937 human macrophage cell lines infected with Mycobacterium tuberculosis H37Rv. The activity of the extract was comparable to those of standard drugs. It was observed that the extract showed time and concentration dependent antimycobacterial activity. Conclusions: The present study reveals that G. glabra extract has promising anti-tubercular activity by preliminary in vitro techniques and in U937 macrophage cell line. Therefore, it has the definite potential to be developed as an affordable, cost-effective drug against tuberculosis.

  16. Hydrate phase equilibria of furan, acetone, 1,4-dioxane, TBAC and TBAF

    International Nuclear Information System (INIS)

    Kamran-Pirzaman, Arash; Pahlavanzadeh, Hassan; Mohammadi, Amir H.

    2013-01-01

    Highlights: • Experimental hydrate dissociation conditions are reported for CO 2 /methane + some water soluble/insoluble hydrate formers. • An isochoric pressure-search method was used to generate the experimental data. • The data are compared with the corresponding literature data in the presence of pure water. • The hydrate promotion effects of acetone, 1,4-dioxane, furan, TBAC and TBAF are discussed. -- Abstract: In this communication, we first report experimental hydrate dissociation pressures for the methane/carbon dioxide + furan/acetone/1,4-dioxane + water and the methane + tetra n-butyl ammonium chloride (TBAC) + water as well as the carbon dioxide + tetra n-butyl ammonium floride (TBAF) + water systems in the temperature ranges of (269.9 to 303.3) K. An isochoric pressure-search method was used to generate the experimental data. The hydrate dissociation data are compared with the corresponding literature data, if exists, and the literature data in the presence of pure water and acceptable agreement is observed. A discussion is made on hydrate promotion effects of acetone, 1,4-dioxane, furan, TBAC and TBAF

  17. HF-START: A Regional Radio Propagation Simulator

    Science.gov (United States)

    Hozumi, K.; Maruyama, T.; Saito, S.; Nakata, H.; Rougerie, S.; Yokoyama, T.; Jin, H.; Tsugawa, T.; Ishii, M.

    2017-12-01

    HF-START (HF Simulator Targeting for All-users' Regional Telecommunications) is a user-friendly simulator developed to meet the needs of space weather users. Prediction of communications failure due to space weather disturbances is of high priority. Space weather users from various backgrounds with high economic impact, i.e. airlines, telecommunication companies, GPS-related companies, insurance companies, international amateur radio union, etc., recently increase. Space weather information provided by Space Weather Information Center of NICT is, however, too professional to be understood and effectively used by the users. To overcome this issue, I try to translate the research level data to the user level data based on users' needs and provide an immediate usable data. HF-START is positioned to be a space weather product out of laboratory based truly on users' needs. It is originally for radio waves in HF band (3-30 MHz) but higher frequencies up to L band are planned to be covered. Regional ionospheric data in Japan and southeast Asia are employed as a reflector of skywave mode propagation. GAIA (Ground-to-topside model of Atmosphere and Ionosphere for Aeronomy) model will be used as ionospheric input for global simulation. To evaluate HF-START, an evaluation campaign for Japan region will be launched in coming months. If the campaign successes, it will be expanded to southeast Asia region as well. The final goal of HF-START is to provide the near-realtime necessary radio parameters as well as the warning message of radio communications failure to the radio and space weather users.

  18. A photoelectron and TPEPICO investigation of the acetone radical cation.

    Science.gov (United States)

    Rennie, Emma E; Boulanger, Anne-Marie; Mayer, Paul M; Holland, David M P; Shaw, David A; Cooper, Louise; Shpinkova, Larisa G

    2006-07-20

    The valence shell photoelectron spectrum, threshold photoelectron spectrum, and threshold photoelectron photoion coincidence (TPEPICO) mass spectra of acetone have been measured using synchrotron radiation. New vibrational progressions have been observed and assigned in the X 2B2 state photoelectron bands of acetone-h6 and acetone-d6, and the influence of resonant autoionization on the threshold electron yield has been investigated. The dissociation thresholds for fragment ions up to 31 eV have been measured and compared to previous values. In addition, kinetic modeling of the threshold region for CH3* and CH4 loss leads to new values of 78 +/- 2 kJ mol(-1) and 75 +/- 2 kJ mol(-1), respectively, for the 0 K activation energies for these two processes. The result for the methyl loss channel is in reasonable agreement with, but slightly lower than, that of 83 +/- 1 kJ mol(-1) derived in a recent TPEPICO study by Fogleman et al. The modeling accounts for both low-energy dissociation channels at two different ion residence times in the mass spectrometer. Moreover, the effects of the ro-vibrational population distribution, the electron transmission efficiency, and the monochromator band-pass are included. The present activation energies yield a Delta(f)H298 for CH3CO+ of 655 +/- 3 kJ mol(-1), which is 4 kJ mol(-1) lower than that reported by Fogleman et al. The present Delta(f)H298 for CH3CO+ can be combined with the Delta(f)H298 for CH2CO (-47.5 +/- 1.6 kJ mol(-1)) and H+ (1530 kJ mol(-1)) to yield a 298 K proton affinity for ketene of 828 +/- 4 kJ mol(-1), in good agreement with the value (825 kJ mol(-1)) calculated at the G2 level of theory. The measured activation energy for CH4 loss leads to a Delta(f)H298 (CH2CO+*) of 873 +/- 3 kJ mol(-1).

  19. Studies on acetone sensing characteristics of ZnO thin film prepared by sol–gel dip coating

    Energy Technology Data Exchange (ETDEWEB)

    Muthukrishnan, Karthika; Vanaraja, Manoj [School of Electrical & Electronics Engineering, SASTRA University, Thanjavur, 613401 (India); Boomadevi, Shanmugam [Department of Physics, National Institute of Technology, Tiruchirappalli, 620015 (India); Karn, Rakesh Kumar [School of Electrical & Electronics Engineering, SASTRA University, Thanjavur, 613401 (India); Singh, Vijay [Department of Chemical Engineering, Konkuk University, Seoul, 143-701 (Korea, Republic of); Singh, Pramod K. [Solar Energy Institute, Ege University, Bornova, 35100, Izmir (Turkey); Material Research Laboratory, School of Basic Sciences and Research, Sharda University, Greater Noida, 201310, U. P. (India); Pandiyan, Krishnamoorthy, E-mail: krishpandiyan@ece.sastra.edu [School of Electrical & Electronics Engineering, SASTRA University, Thanjavur, 613401 (India)

    2016-07-15

    Acetone sensing characteristics of Zinc Oxide thin films prepared by dip coating method are discussed in this paper. The sol for dip coating was synthesized using Zinc nitrate hexahydrate (Zn (NO{sub 3}){sub 2}. 6H{sub 2}O) and organic polymer sodium carboxy methyl cellulose (Na-CMC) as a starting material. Crystallinity and crystallite size of the prepared thin film was characterised by X-ray diffraction (XRD). Morphology was studied using field emission scanning electron microscopy (FESEM). The gas sensing characteristics was studied using chemiresistive method, by exposing the film to various concentrations of acetone at room temperature. Further, for comparative study ethanol and acetaldehyde has also been tested. Gas sensing parameters such us response, selectivity, lowest detection limit, response/recovery time of the thin film towards acetone were also reported. - Highlights: • ZnO has successfully synthesized using cheap and ease method. • Detail characterization have carried out and explained. • Sensing behaviour has been studied. • Acetone sensor has been fabricated.

  20. A simple procedure for preparing chitin oligomers through acetone precipitation after hydrolysis in concentrated hydrochloric acid.

    Science.gov (United States)

    Kazami, Nao; Sakaguchi, Masayoshi; Mizutani, Daisuke; Masuda, Tatsuhiko; Wakita, Satoshi; Oyama, Fumitaka; Kawakita, Masao; Sugahara, Yasusato

    2015-11-05

    Chitin oligomers are of interest because of their numerous biologically relevant properties. To prepare chitin oligomers containing 4-6 GlcNAc units [(GlcNAc)4-6], α- and β-chitin were hydrolyzed with concentrated hydrochloric acid at 40 °C. The reactant was mixed with acetone to recover the acetone-insoluble material, and (GlcNAc)4-6 was efficiently recovered after subsequent water extraction. Composition analysis using gel permeation chromatography and MALDI-TOF mass spectrometry indicated that (GlcNAc)4-6 could be isolated from the acetone-insoluble material with recoveries of approximately 17% and 21% from the starting α-chitin and β-chitin, respectively. The acetone precipitation method is highly useful for recovering chitin oligomers from the acid hydrolysate of chitin. The changes in the molecular size and higher-order structure of chitin during the course of hydrolysis were also analyzed, and a model that explains the process of oligomer accumulation is proposed. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. Validation of Zr and Hf analysis contained on water phase using k_0-neutron activation analysis method

    International Nuclear Information System (INIS)

    Wisjachudin Faisa; Sutisna

    2010-01-01

    At conversion of Zr-sand to Zircon Oxide, the Hf content in product process should not be more than 100 ppm. While Zr and Hf are two elements that have a similar chemical property Hs, they are difficult to analyze by ordinary chemical analysis. One of reliable analytical method that can be used to quantify Zr and Hf is the instrumental neutron activation analysis. Related to this problem, a result of k_0-Instrumental Neutron Activation Analysis (k_0-INAA) on Zr and Hf (in aqueous phase) has been validated. A number of 200 µL SPEX Pure standard solution which have a concentration of 1 g/L pipeted into a cleaned micro vial, then dried at a temperature of 40°C for 24 hours. Samples, together with flux monitors, were irradiated simultaneously at 15 MW power (thermal neutron flux around 4.1 x 10"1"7n. m"-"2.s"-"1) for 30 minutes in the rabbit facility of GA. Siwabessy reactor. Counting of the irradiated sample have been done using a high resolution HPGe detector (FWHM = 1.9 keV at Eγ 1332.5 keV of "6"0Co,Peak to Compton ratio ~ 40). The analytical results showed a relative standard deviation (RSD) of Zr is 6.6 % with average uncertainty of 3.08 % and a detection limit of 0.1 mg, while RSD of Hf = 8.2 %, with average uncertainty of 8.04 % and a detection limit of 0.3 mg. Recovery obtained was 106,0 % and 96,0 % for Zr and Hf respectively. These results are relatively better compared to the previous result using the Standard Reference Material (SRM) 1633b Coal Fly Ash which have RSD Hf was 20.6 %. (author)

  2. Low lying magnetic dipole strength distribution in 176Hf

    International Nuclear Information System (INIS)

    Kuliev, A. A.; Ertugral, F.; Yakut, H.; Bektasoglu, M.; Guliyev, E.

    2006-01-01

    In this study the scissors mode 1 + states are systematically investigated within the rotational invariant Quasiparticle Random Phase Approximation (QRPA) for 1 76Hf isotopes. We consider the 1 + vibrations generated by the isovector spin-spin interactions and the isoscalar (h 0 ) and isovector (h 1 ) quadrupole type separable forces restoring the broken symmetry by a deformed mean field. It has been shown that restoration of the broken rotational symmetry of the Hamiltonian essentially decreases the B(M1) value of the low lying 1 + states and increases the collectivization of the scissors mode excitations in the spectroscopic energy region. Agreement between the calculated mean excitation energies as well as the summed B(M1) value of the scissors mode excitations and the available experimental data of 1 76Hf is rather good. For instance, distributions of the calculated B(M1) transition strengths in the 1 76 Hf isotopes with respect to K π =1 + excitations is represented in Figure. Thus, we see that the models which use the Hamiltonian with broken rotational symmetry strongly overestimate the M1 strength at low energy. These results indicate an importance of the models which are free from the low-energy spurious states. The marked differences between the results for 1 + states, calculated in rotational invariant (RI) and non-rotational invariant (NRI) model indicate the importance of the approaches which are free from spurious low-energy solutions. A separation of the rotational state from the 1 + states changes somewhat the distribution of the B(M1) strength in the spectroscopic energy region and increases the fragmentation of the scissors mode 1 + excitations in agreement with the experimental data

  3. Ferromagnetic characteristics of HfFe2

    International Nuclear Information System (INIS)

    Novakovic, N.; Belosevic-Cavor, J.; Cekic, B.; Manasijevic, M.; Milosevic, Z. . E-mail address of correspoding author: novnik@rt270.vin.bg.ac.yu; Novakovic, N.)

    2003-01-01

    The magnetic hyperfine fields at 181 Ta ion-probe sites in the HfFe 2 polycrystalline binary compound were measured using the time-differential perturbed angular correlation (TDPAC) method. Measurements were performed in the absence of polarizing external magnetic field, at room temperature. The existence of two different structures, dominant cubic MgCu 2 -type and hexagonal MgZn 2 -type in our HfFe 2 sample was refined. Both structures are ferromagnetic with Curie temperatures, which differ significantly (588 K for MgCu 2 and 427 K for MgZn 2 ). The corresponding values of hyperfine fields are H hf 13.8±0.1 T for MgCu 2 -type structure and H hf = 8.0±0.2 T for MgZn 2 -type structure. Calculations using LAPW-Wien 97 program package are in progress and preliminary results are in good agreement with experiment. The analysis includes qualitative explanation of the exchange interactions mechanism between magnetic dipole moment of the observed 181 Ta ion-probe and magnetic dipole moments of the nearest neighbours on the corresponding coordination polyhedra. All these results will be published recently. (author)

  4. Separation of hafnium from zirconium in their tetrachloride solution in molten alkali metal chlorides

    Energy Technology Data Exchange (ETDEWEB)

    Salyulev, A B; Kudyakov, V Ya; Smirnov, M V; Moskalenko, N I [AN SSSR, Sverdlovsk. Inst. Ehlektrokhimii

    1984-08-01

    The coefficient of HfCl/sub 4/ and ZrCl/sub 4/ separation in the process of vapour sublimation from their solutions in molten NaCl, KCl, CsCl, NaCl-KCl and NaCl-CsCl equimolar mixtures is found to vary in the series from approximately 1.10 to approximately 1.22 and practically not to depend on the temperature (in the 600-910 deg) range and concentration (2-25 mol.% ZrCl/sub 4/+HfCl/sub 4/). HfCl/sub 4/ and ZrCl/sub 4/ are shown to form almost perfect solutions with each other, which in their turn form imperfect solutions with molten alkali metal chlorides, with the strength of hafnium complex chloride anions increasing higher than that of zirconium in the series from NaCl to CsCl.

  5. Separation of hafnium from zirconium in their tetrachloride solution in molten alkali metal chlorides

    International Nuclear Information System (INIS)

    Salyulev, A.B.; Kudyakov, V.Ya.; Smirnov, M.V.; Moskalenko, N.I.

    1984-01-01

    The coefficient of HfCl 4 and ZrCl 4 separation in the process of vapour sublimation from their solutions in molten NaCl, KCl, CsCl, NaCl-KCl and NaCl-CsCl equimolar mixtures is found to vary in the series from approximately 1.10 to approximately 1.22 and practically not to depend on the temperature (in the 600-910 deg) range and concentration (2-25 mol.% ZrCl 4 +HfCl 4 ). HfCl 4 and ZrCl 4 are shown to form almost perfect solutions with each other, which in their turn form imperfect solutions with molten alkali metal chlorides, with the strength of hafnium complex chloride anions increasing higher than that of zirconium in the series from NaCl to CsCl

  6. Inert Reassessment Document for Acetone - CAS No. 67-64-1

    Science.gov (United States)

    Acetone is a highly volatile chemical that is used as an inert ingredient, a solvent/co-solvent, in a variety of pesticide products (including outdoor yard, garden and turf products, and agricultural crop products).

  7. Acetone and Butanone Metabolism of the Denitrifying Bacterium “Aromatoleum aromaticum” Demonstrates Novel Biochemical Properties of an ATP-Dependent Aliphatic Ketone Carboxylase

    Science.gov (United States)

    Schühle, Karola

    2012-01-01

    The anaerobic and aerobic metabolism of acetone and butanone in the betaproteobacterium “Aromatoleum aromaticum” is initiated by their ATP-dependent carboxylation to acetoacetate and 3-oxopentanoic acid, respectively. Both reactions are catalyzed by the same enzyme, acetone carboxylase, which was purified and characterized. Acetone carboxylase is highly induced under growth on acetone or butanone and accounts for at least 5.5% of total cell protein. The enzyme consists of three subunits of 85, 75, and 20 kDa, respectively, in a (αβγ)2 composition and contains 1 Zn and 2 Fe per heterohexamer but no organic cofactors. Chromatographic analysis of the ATP hydrolysis products indicated that ATP was exclusively cleaved to AMP and 2 Pi. The stoichiometry was determined to be 2 ATP consumed per acetone carboxylated. Purified acetone carboxylase from A. aromaticum catalyzes the carboxylation of acetone and butanone as the only substrates. However, the enzyme shows induced (uncoupled) ATPase activity with many other substrates that were not carboxylated. Acetone carboxylase is a member of a protein family that also contains acetone carboxylases of various other organisms, acetophenone carboxylase of A. aromaticum, and ATP-dependent hydantoinases/oxoprolinases. While the members of this family share several characteristic features, they differ with respect to the products of ATP hydrolysis, subunit composition, and metal content. PMID:22020645

  8. Rapid and selective detection of acetone using hierarchical ZnO gas sensor for hazardous odor markers application.

    Science.gov (United States)

    Jia, Qianqian; Ji, Huiming; Zhang, Ying; Chen, Yalu; Sun, Xiaohong; Jin, Zhengguo

    2014-07-15

    Hierarchical nanostructured ZnO dandelion-like spheres were synthesized via solvothermal reaction at 200°C for 4h. The products were pure hexagonal ZnO with large exposure of (002) polar facet. Side-heating gas sensor based on hierarchical ZnO spheres was prepared to evaluate the acetone gas sensing properties. The detection limit to acetone for the ZnO sensor is 0.25ppm. The response (Ra/Rg) toward 100ppm acetone was 33 operated at 230°C and the response time was as short as 3s. The sensor exhibited remarkable acetone selectivity with negligible response toward other hazardous gases and water vapor. The high proportion of electron depletion region and oxygen vacancies contributed to high gas response sensitivity. The hollow and porous structure of dandelion-like ZnO spheres facilitated the diffusion of gas molecules, leading to a rapid response speed. The largely exposed (002) polar facets could adsorb acetone gas molecules easily and efficiently, resulting in a rapid response speed and good selectivity of hierarchical ZnO spheres gas sensor at low operating temperature. Copyright © 2014 Elsevier B.V. All rights reserved.

  9. Metal-Exchanged β Zeolites as Catalysts for the Conversion of Acetone to Hydrocarbons

    Directory of Open Access Journals (Sweden)

    Aurora J. Cruz-Cabeza

    2012-01-01

    Full Text Available Various metal-β zeolites have been synthesized under similar ion-exchange conditions. During the exchange process, the nature and acid strength of the used cations modified the composition and textural properties as well as the Brönsted and Lewis acidity of the final materials. Zeolites exchanged with divalent cations showed a clear decrease of their surface Brönsted acidity and an increase of their Lewis acidity. All materials were active as catalysts for the transformation of acetone into hydrocarbons. Although the protonic zeolite was the most active in the acetone conversion (96.8% conversion, the metal-exchanged zeolites showed varied selectivities towards different products of the reaction. In particular, we found the Cu-β to have a considerable selectivity towards the production of isobutene from acetone (over 31% yield compared to 7.5% of the protonic zeolite. We propose different reactions mechanisms in order to explain the final product distributions.

  10. Shock-Tube Measurement of Acetone Dissociation Using Cavity-Enhanced Absorption Spectroscopy of CO.

    Science.gov (United States)

    Wang, Shengkai; Sun, Kai; Davidson, David F; Jeffries, Jay B; Hanson, Ronald K

    2015-07-16

    A direct measurement for the rate constant of the acetone dissociation reaction (CH3COCH3 = CH3CO + CH3) was conducted behind reflected shock wave, utilizing a sub-ppm sensitivity CO diagnostic achieved by cavity-enhanced absorption spectroscopy (CEAS). The current experiment eliminated the influence from secondary reactions and temperature change by investigating the clean pyrolysis of <20 ppm acetone in argon. For the first time, the acetone dissociation rate constant (k1) was directly measured over 5.5 orders of magnitude with a high degree of accuracy: k1 (1004-1494 K, 1.6 atm) = 4.39 × 10(55) T(-11.394) exp(-52 140K/T) ± 24% s(-1). This result was seen to agree with most previous studies and has bridged the gap between their temperature and pressure conditions. The current work also served as an example demonstration of the potential of using the CEAS technique in shock-tube kinetics studies.

  11. Nitrogen-Containing Functional Groups-Facilitated Acetone Adsorption by ZIF-8-Derived Porous Carbon

    Directory of Open Access Journals (Sweden)

    Liqing Li

    2018-01-01

    Full Text Available Nitrogen-doped porous carbon (ZC is prepared by modification with ammonia for increasing the specific surface area and surface polarity after carbonization of zeolite imidazole framework-8 (ZIF-8. The structure and properties of these ZCs were characterized by Transmission electron microscopy, X-ray diffraction, N2 sorption, X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy. Through static adsorption tests of these carbons, the sample obtained at 600 °C was selected as an excellent adsorbent, which exhibited an excellent acetone capacity of 417.2 mg g−1 (25 °C with a very large surface area and high-level nitrogen doping (13.55%. The microporosity, surface area and N-containing groups of the materials, pyrrolic-N, pyridinic-N, and oxidized-N groups in particular, were found to be the determining factors for acetone adsorption by means of molecular simulation with density functional theory. These findings indicate that N-doped microporous carbon materials are potential promising adsorbents for acetone.

  12. Problems induced by the use of acetone as a solvent to dose chlorpyrifos in a microecosystem

    NARCIS (Netherlands)

    Kersting, K.

    1995-01-01

    Recycling aquatic microecosystems consisting of three subsystems with a total volume of 7.5 L were used to study the effects of the insecticide chlorpyrifos. The poorly soluble chlorpyrifos was dosed dissolved in 0.5 ml of acetone. Acetone was found to be responsible for some of the observed

  13. HF-voltage testing of accelerating system functional model

    International Nuclear Information System (INIS)

    Gladkov, A.V.; Stepanov, V.B.

    1989-01-01

    Owing to ambiguity in interpreting the notion of the electron strength of the operating HF device in an acceleator a technique of measurements and result processing, based on statistical analysis of the data is suggested. Experimental testing on electric strength of structures with HF focusing was carried out using a bench in the form of a cylindrical vacuum container inside which a double H-resonator with HF quadrupole electrodes without surface modulation was installed. The dependences obtained permit to evaluate the bahaviour of the HF device from the viewpoint of electric strength and radiation hazard for the whole range of possible values of voltage on the basis of data on the frequency of breakdowns and radiation situation only in one experimental point. 12 refs.; 8 figs

  14. The isobutylene-isobutane alkylation process in liquid HF revisited.

    Science.gov (United States)

    Esteves, P M; Araújo, C L; Horta, B A C; Alvarez, L J; Zicovich-Wilson, C M; Ramírez-Solís, A

    2005-07-07

    Details on the mechanism of HF catalyzed isobutylene-isobutane alkylation were investigated. On the basis of available experimental data and high-level quantum chemical calculations, a detailed reaction mechanism is proposed taking into account solvation effects of the medium. On the basis of our computational results, we explain why the density of the liquid media and stirring rates are the most important parameters to achieve maximum yield of alkylate, in agreement with experimental findings. The ab initio Car-Parrinello molecular dynamics calculations show that isobutylene is irreversibly protonated in the liquid HF medium at higher densities, leading to the ion pair formation, which is shown to be a minimum on the potential energy surface after optimization using periodic boundary conditions. The HF medium solvates preferentially the fluoride anion, which is found as solvated [FHF](-) or solvated F(-.)(HF)(3). On the other hand, the tert-butyl cation is weakly solvated, where the closest HF molecules appear at a distance of about 2.9 Angstrom with the fluorine termination of an HF chain.

  15. Sequential sputtered Co-HfO{sub 2} granular films

    Energy Technology Data Exchange (ETDEWEB)

    Chadha, M.; Ng, V.

    2017-03-15

    A systematic study of magnetic, magneto-transport and micro-structural properties of Co-HfO{sub 2} granular films fabricated by sequential sputtering is presented. We demonstrate reduction in ferromagnetic-oxide formation by using HfO{sub 2} as the insulting matrix. Microstructure evaluation of the films showed that the film structure consisted of discrete hcp-Co grains embedded in HfO{sub 2} matrix. Films with varying compositions were prepared and their macroscopic properties were studied. We correlate the variation in these properties to the variation in film microstructure. Our study shows that Co-HfO{sub 2} films with reduced cobalt oxide and varying properties can be prepared using sequential sputtering technique. - Highlights: • Co-HfO{sub 2} granular films were prepared using sequential sputtering. • A reduction in ferromagnetic-oxide formation is observed. • Co-HfO{sub 2} films display superparamagnetism and tunnelling magneto-resistance. • Varying macroscopic properties were achieved by changing film composition. • Applications can be found in moderate MR sensors and high –frequency RF devices.

  16. trans-Carbonylchloridobis[dicyclohexyl(4-isopropylphenylphosphane]rhodium(I acetone monosolvate

    Directory of Open Access Journals (Sweden)

    Sizwe Makhoba

    2011-09-01

    Full Text Available The title rhodium Vaska-type complex, trans-[RhCl{P(C6H112(C6H4-4-C3H72}2(CO], crystallizes with an accompanying acetone solvent molecule. The metal atom shows a distorted square-planar coordination environment with selected important geometrical parameters of Rh—P = 2.3237 (6 and 2.3253 (6 Å, Rh—Cl = 2.3724 (6 Å, Rh—C = 1.802 (2 Å, P—Rh—P = 173.42 (2° and Cl—Rh—C = 179.13 (7°. Effective cone angles for the two P atoms are 165 and 161°, respectively. Both isopropyl groups and the acetone molecule are disordered with occupancy values of 0.523 (5:0.477 (5, 0.554 (8:0.446 (8 and 0.735 (4:0.265 (4, respectively. The crystal packing is stabilized by weak C—H...O and C—H...Cl contacts.

  17. HF Interference, Procedures and Tools (Interferences HF, procedures et outils)

    Science.gov (United States)

    2007-06-01

    the actual ambient noise floor situation. Besides these HF radio links, special units such as crisis reaction forces are using low power radios for...the origin point on the ground. For ease of arithmetic and typography , the latter option is preferable. The dipole-modelled PLT is located at x = H1

  18. The salting-out of molibdoferrats(II from aqueous solutions by the organic solvents

    Directory of Open Access Journals (Sweden)

    Mykola V. Nikolenko

    2016-12-01

    Full Text Available The aim of this work was to develop a method for producing of molybdoferrate(II precipitates by salting-out them from aqueous solutions by means of organic solvents. Dependence of the composition of molybdoferrate(II precipitates on the pH of the reaction solutions was studied. Experiments on salting-out of molybdoferrate(II with various organic solvents were carried out. As a result it was found that the best reagent for the molybdoferrate(II salting-out is acetone. By its use, lowest quantity of the ammonium sulfate impurities was obtained. It is also of importance that by using of acetone the process of regeneration by distillation of the reaction solutions is characterized by the lowest energy consumption. A functional relationship between the solubility of molybdoferrates(II and dielectric constant of the medium was established. By increasing the dielectric constant of the solvent solubility of molybdoferrates(II rapidly increases. The linearized dependence ln(lnS–ln(1/e was proposed to predict the solubility of molybdoferrates(II in various aqueous-organic solutions.

  19. HF band filter bank multi-carrier spread spectrum

    Energy Technology Data Exchange (ETDEWEB)

    Laraway, Stephen Andrew; Moradi, Hussein; Farhang-Boroujeny, Behrouz

    2015-10-01

    Abstract—This paper describes modifications to the filter bank multicarrier spread spectrum (FB-MC-SS) system, that was presented in [1] and [2], to enable transmission of this waveform in the HF skywave channel. FB-MC-SS is well suited for the HF channel because it performs well in channels with frequency selective fading and interference. This paper describes new algorithms for packet detection, timing recovery and equalization that are suitable for the HF channel. Also, an algorithm for optimizing the peak to average power ratio (PAPR) of the FBMC- SS waveform is presented. Application of this algorithm results in a waveform with low PAPR. Simulation results using a wide band HF channel model demonstrate the robustness of this system over a wide range of delay and Doppler spreads.

  20. Nuclear quadrupole interactions in ferroelectric compounds of HF181

    International Nuclear Information System (INIS)

    Kunzler, J.V.

    1971-01-01

    Measurements of nuclear quadrupole interaction constants in perovkite-type compounds of PbHfO 3 , SnhfO 3 , CaHfO 3 e SrHfO 3 have been performed using the perturbed angular correlation technique. A range of fundamental frequencies from 150 to 550 Megaradians persecond was determined. The variation of quadrupole constants has been discussed through the molecular orbital theory

  1. Biological activities of Umbilicaria crustulosa (Ach. frey acetone extract

    Directory of Open Access Journals (Sweden)

    Zlatanović Ivana

    2017-01-01

    Full Text Available This paper reports for the first time the effect of an acetone extract of Umbilicaria crustulosa on the micronucleus distribution of human lymphocytes, and on the cholinesterase activity and antioxidant activity by the cupric ion reducing antioxidant capacity (CUPRAC method. Additionally, the total phenolic compounds (TPC and the antioxidant properties were estimated via DPPH, ABTS and TRP assays. Moreover, the antibacterial activity against two Gram-positive and three Gram-negative bacteria were determined. Acetone extract of U. crustulosa at concentration of 1 and 2 μg mL-1 decreased a frequency of micronuclei (MN by 10.8 and 16.8 %, respectively, acting more or slightly less than the synthetic protector amifostine (AMF, WR-2721, 11.4 %, at concentration of 1 μg mL-1. The tested extract did not inhibit cholinesterase activity nor did it exhibit activity toward the examined bacteria. The extract reduced the concentration of DPPH and ABTS radicals by 88.7 and 96.2 %, respectively. Values for total reducing power (TRP and cupric reducing capacity (CUPRAC were 0.6197±0.0166 μg ascorbic acid equivalents (AAE per mg of dry extract, and 19.7641±1.6546 μg trolox equivalents (TE per mg of dry extract, respectively. The total phenol content was 350.4188 ±14.587 μg gallic acid equivalents (GAE per mg of dry extract. The results of the present study showed that U. crustulosa acetone extract is a promising candidate for in vivo experiments considering its antioxidant activity and protective effect on human lymphocytes. [Projekat Ministarstva nauke Republike Srbije, br. 172047

  2. Theoretical studies of mechanisms of cycloaddition reaction between difluoromethylene carbene and acetone

    Science.gov (United States)

    Lu, Xiu Hui; Yu, Hai Bin; Wu, Wei Rong; Xu, Yue Hua

    Mechanisms of the cycloaddition reaction between singlet difluoromethylene carbene and acetone have been investigated with the second-order Møller-Plesset (MP2)/6-31G* method, including geometry optimization and vibrational analysis. Energies for the involved stationary points on the potential energy surface (PES) are corrected by zero-point energy (ZPE) and CCSD(T)/6-31G* single-point calculations. From the PES obtained with the CCSD(T)//MP2/6-31G* method for the cycloaddition reaction between singlet difluoromethylene carbene and acetone, it can be predicted that path B of reactions 2 and 3 should be two competitive leading channels of the cycloaddition reaction between difluoromethylene carbene and acetone. The former consists of two steps: (i) the two reactants first form a four-membered ring intermediate, INT2, which is a barrier-free exothermic reaction of 97.8 kJ/mol; (ii) the intermediate INT2 isomerizes to a four-membered product P2b via a transition state TS2b with an energy barrier of 24.9 kJ/mol, which results from the methyl group transfer. The latter proceeds in three steps: (i) the two reactants first form an intermediate, INT1c, through a barrier-free exothermic reaction of 199.4 kJ/mol; (ii) the intermediate INT1c further reacts with acetone to form a polycyclic intermediate, INT3, which is also a barrier-free exothermic reaction of 27.4 kJ/mol; and (iii) INT3 isomerizes to a polycyclic product P3 via a transition state TS3 with an energy barrier of 25.8 kJ/mol.

  3. Lu-Hf and Sm-Nd garnet geochronology

    DEFF Research Database (Denmark)

    Smit, Matthijs Arjen; Scherer, Erik E.; Mezger, Klaus

    2013-01-01

    To investigate the systematics of the 176Lu–176Hf and 147Sm–143Nd garnet chronometers, we performed REE and isotope analyses on garnet crystals of different size (0.55–3.1 mm radius) from a single granulite specimen (Archean Pikwitonei Granulite Domain, Manitoba, Canada). The Lu–Hf dates are simi...

  4. Robust tribo-mechanical and hot corrosion resistance of ultra-refractory Ta-Hf-C ternary alloy films.

    Science.gov (United States)

    Yate, Luis; Coy, L Emerson; Aperador, Willian

    2017-06-08

    In this work we report the hot corrosion properties of binary and ternary films of the Ta-Hf-C system in V 2 O 5 -Na 2 SO 4 (50%wt.-50%wt.) molten salts at 700 °C deposited on AISI D3 steel substrates. Additionally, the mechanical and nanowear properties of the films were studied. The results show that the ternary alloys consist of solid solutions of the TaC and HfC binary carbides. The ternary alloy films have higher hardness and elastic recoveries, reaching 26.2 GPa and 87%, respectively, and lower nanowear when compared to the binary films. The corrosion rates of the ternary alloys have a superior behavior compared to the binary films, with corrosion rates as low as 0.058 μm/year. The combination and tunability of high hardness, elastic recovery, low nanowear and an excellent resistance to high temperature corrosion demonstrates the potential of the ternary Ta-Hf-C alloy films for applications in extreme conditions.

  5. Detection and sensing mechanism of acetone with modeling using Pd/TiO{sub 2}/Si structure

    Energy Technology Data Exchange (ETDEWEB)

    Yadava, Lallan, E-mail: nisaly06@rediffmail.com; Verma, Ritesh; Singh, Ravi S.

    2012-01-31

    A grided Pd/TiO{sub 2}/Si (Pdtisin) gas sensor is fabricated to detect hydrocarbons such as acetone, ethanol and trichloroethylene. The sensitivity measurements are carried out in various ambient (O{sub 2}, N{sub 2} and Ar) at room temperature which revealed that fabricated structure attains maximal response for acetone in contrast to other vapors examined. The study of ambient-effect on the device shows that it out-performs in oxygen ambient. A catalytic oxidation mechanism for detection of acetone with a model based upon Langmuir law of adsorption and Frenkel-Poole theory of electronic emission for the description of sensing behavior and vindication of experimental results have been proposed.

  6. Graphene oxide foams and their excellent adsorption ability for acetone gas

    International Nuclear Information System (INIS)

    He, Yongqiang; Zhang, Nana; Wu, Fei; Xu, Fangqiang; Liu, Yu; Gao, Jianping

    2013-01-01

    Graphical abstract: - Highlights: • GO and RGO foams were prepared using a simple and green method, unidirectional freeze-drying. • The porous structure of the foams can be adjusted by changing GO concentrations. • GO and RGO foams show good adsorption efficiency for acetone gas. - Abstract: Graphene oxide (GO) and reduced graphene oxide (RGO) foams were prepared using a unidirectional freeze-drying method. These porous carbon materials were characterized by thermal gravimetric analysis, differential scanning calorimetry, X-ray photoelectron spectroscopy and scanning electron microscopy. The adsorption behavior of the two kinds of foams for acetone was studied. The result showed that the saturated adsorption efficiency of the GO foams was over 100%, and was higher than that of RGO foams and other carbon materials

  7. Development and validation of a house finch interleukin-1β (HfIL-1β) ELISA system.

    Science.gov (United States)

    Kim, Sungwon; Park, Myeongseon; Leon, Ariel E; Adelman, James S; Hawley, Dana M; Dalloul, Rami A

    2017-08-30

    A unique clade of the bacterium Mycoplasma gallisepticum (MG), which causes chronic respiratory disease in poultry, has resulted in annual epidemics of conjunctivitis in North American house finches since the 1990s. Currently, few immunological tools have been validated for this songbird species. Interleukin-1β (IL-1β) is a prototypic multifunctional cytokine and can affect almost every cell type during Mycoplasma infection. The overall goal of this study was to develop and validate a direct ELISA assay for house finch IL-1β (HfIL-1β) using a cross-reactive chicken antibody. A direct ELISA approach was used to develop this system using two different coating methods, carbonate and dehydration. In both methods, antigens (recombinant HfIL-1b or house finch plasma) were serially diluted in carbonate-bicarbonate coating buffer and either incubated at 4 °C overnight or at 60 °C on a heating block for 2 hr. To generate the standard curve, rHfIL-1b protein was serially diluted at 0, 3, 6, 9, 12, 15, 18, 21, and 24 ng/mL. Following blocking and washing, anti-chicken IL-1b polyclonal antibody was added, plates were later incubated with detecting antibodies, and reactions developed with tetramethylbenzidine solution. A commercially available anti-chicken IL-1β (ChIL-1β) polyclonal antibody (pAb) cross-reacted with house finch plasma IL-1β as well as bacterially expressed recombinant house finch IL-1β (rHfIL-1β) in immunoblotting assays. In a direct ELISA system, rHfIL-1β could not be detected by an anti-ChIL-1β pAb when the antigen was coated with carbonate-bicarbonate buffer at 4°C overnight. However, rHfIL-1β was detected by the anti-ChIL-1β pAb when the antigen was coated using a dehydration method by heat (60°C). Using the developed direct ELISA for HfIL-1β with commercial anti-ChIL-1β pAb, we were able to measure plasma IL-1β levels from house finches. Based on high amino acid sequence homology, we hypothesized and demonstrated cross-reactivity of

  8. A Sub-ppm Acetone Gas Sensor for Diabetes Detection Using 10 nm Thick Ultrathin InN FETs

    Science.gov (United States)

    Kao, Kun-Wei; Hsu, Ming-Che; Chang, Yuh-Hwa; Gwo, Shangjr; Yeh, J. Andrew

    2012-01-01

    An indium nitride (InN) gas sensor of 10 nm in thickness has achieved detection limit of 0.4 ppm acetone. The sensor has a size of 1 mm by 2.5 mm, while its sensing area is 0.25 mm by 2 mm. Detection of such a low acetone concentration in exhaled breath could enable early diagnosis of diabetes for portable physiological applications. The ultrathin InN epilayer extensively enhances sensing sensitivity due to its strong electron accumulation on roughly 5–10 nm deep layers from the surface. Platinum as catalyst can increase output current signals by 2.5-fold (94 vs. 37.5 μA) as well as reduce response time by 8.4-fold (150 vs. 1,260 s) in comparison with bare InN. More, the effect of 3% oxygen consumption due to breath inhalation and exhalation on 2.4 ppm acetone gas detection was investigated, indicating that such an acetone concentration can be analyzed in air. PMID:22969342

  9. A Negative Correlation Between Blood Glucose and Acetone Measured in Healthy and Type 1 Diabetes Mellitus Patient Breath.

    Science.gov (United States)

    Rydosz, Artur

    2015-07-01

    Exhaled acetone analysis has long been recognized as a supplementary tool for diagnosis and monitoring diabetes, especially type 1 diabetes. It is essential, therefore to determine the relationship between exhaled acetone concentration and glucose in blood. Usually, a direct linear correlation between this both compounds has been expected. However, in some cases we can observe a reverse correlation. When blood glucose was increasing, breath acetone declined. The breath analysis as a supplementary tool for diagnosing and monitoring diabetes makes sense only in case of utilization of portable analyzers. This need has created a market for gas sensors. However, commercially available acetone gas sensors are developed for measuring samples at several tens part per million. The exhaled acetone concentration was measured using commercial acetone gas sensor (TGS 822, 823 Figaro, Arlington Heights, IL, USA Inc) with micropreconcentrator in low temperature cofired ceramics. The reference analyzer-mass spectrometry (HPR-20 QIC, Hiden Analytical, Warrington, UK) was used. Twenty-two healthy volunteers with no history of any respiratory disease participated in the research, as did 31 patients diagnosed with type 1 diabetes. Respectively, 3 healthy volunteer and 5 type 1 diabetes mellitus subjects with reverse trend were selected. The linear fitting coefficient various from 0.1139 to 0.9573. Therefore, it is necessary to determine the correlation between blood glucose concentrations and under different conditions, for example, insulin levels, as well as correlate the results with clinical tests, for example, Hb1Ac. It is well known that the concentration of acetone is strongly influenced by diet, insulin treatment, and so on. Therefore, much more complex analysis with long-term measurements are required. Thus, presented results should be regarded as tentative, and validation studies with the analysis of clinical test and in a large number of patients, including control groups

  10. Solution blow spun Poly(lactic acid)/Hydroxypropyl methylcellulose nanofibers with antimicrobial properties

    Science.gov (United States)

    Poly(lactic acid) (PLA) nanofibers containing hydroxypropyl methylcellulose (HPMC) and tetracycline hydrochloride (THC) were solution blow spun from two different solvents, chloroform/acetone (CA, 80:20 v/v) and 2,2,2-triflouroethanol (TFE). The diameter distribution, chemical, thermal, thermal stab...

  11. Microwave Plasma Enhanced Chemical Vapor Deposition of Diamond in Vapor of Methanol-Based Liquid Solutions

    National Research Council Canada - National Science Library

    Tzeng, Yonhua

    2000-01-01

    .... Liquid solutions are prepared by mixing methanol with other carbon containing liquid compounds which contain a greater than one ratio of carbon to oxygen such as acetone, ethanol, and iso-propanol...

  12. Sensitive and selective cataluminescence-based sensor system for acetone and diethyl ether determination.

    Science.gov (United States)

    Wang, Qihui; Li, Bo; Wang, Yuhuai; Shou, Zhouxiang; Shi, Guolong

    2015-05-01

    A three-dimensional hierarchical CdO nanostructure with a novel bio-inspired morphology is reported. The field emission scanning electronic microscopy, transmission electron microscopy and X-ray diffractometer were employed to characterize the as-prepared samples. In gas-sensing measurements, acetone and diethyl ether were employed as target gases to investigate cataluminescence (CTL) sensing properties of the CdO nanostructure. The results show that the as-fabricated CdO nanostructure exhibited outstanding CTL properties such as stable intensity, high signal/noise values, short response and recovery time. The limit of detection of acetone and diethyl ether was ca. 6.5 ppm and 6.7 ppm, respectively, which was below the standard permitted concentrations. Additionally, a principal components analysis method was used to investigate the recognizable ability of the CTL sensor, and it was found that acetone and diethyl ether can be distinguished clearly. The performance of the bio-inspired CdO nanostructure-based sensor system suggested the promising application of the CdO nanostructure as a novel highly efficient CTL sensing material. Copyright © 2014 John Wiley & Sons, Ltd.

  13. Determination of the distribution coefficient of 46 elements on tin dioxide in 0.1N HNO3-acetone media

    International Nuclear Information System (INIS)

    Jaffrezic-Renault, N.

    1977-01-01

    The use of radioactive indicators for the determination of the distribution coefficients of 46 elements on SnO 2 in 0.1N HNO 3 -acetone media is described. The determination has been carried out in static conditions: labelled element solution has been agitated with SnO 2 for two hours; the elements have been labelled with radioisotopes generally obtained by (n, γ) reaction, by irradiating a part of the used salt in EL 3 or OSIRIS reactor in the C.E.N. Saclay (France). Results show that the elements may be classified into several groups, according to their oxidation state. (T.I.)

  14. Inhalation developmental toxicology studies: Teratology study of acetone in mice and rats: Final report

    Energy Technology Data Exchange (ETDEWEB)

    Mast, T.J.; Evanoff, J.J.; Rommereim, R.L.; Stoney, K.H.; Weigel, R.J.; Westerberg, R.B.

    1988-11-01

    Acetone, an aliphatic ketone, is a ubiquitous industrial solvent and chemical intermediate; consequently, the opportunity for human exposure is high. The potential for acetone to cause developmental toxicity was assessed in Sprague-Dawley rats exposed to 0, 440, 2200, or 11000 ppm, and in Swiss (CD-1) mice exposed to 0, 440, 2200, and 6600 ppm acetone vapors, 6 h/day, 7 days/week. Each of the four treatment groups consisted of 10 virgin females (for comparison), and approx.32 positively mated rats or mice. Positively mated mice were exposed on days 6-17 of gestation (dg), and rats on 6-19 dg. The day of plug or sperm detection was designated as 0 dg. Body weights were obtained throughout the study period, and uterine and fetal body weights were obtained at sacrifice (rats, 20 dg; mice, 18 dg). Implants were enumerated and their status recorded. Live fetuses were sexed and examined for gross, visceral, skeletal, and soft-tissue craniofacial defects. 46 refs., 6 figs., 27 tabs.

  15. Oxidative polymerization of lignins by laccase in water-acetone mixture.

    Science.gov (United States)

    Fiţigău, Ionița Firuța; Peter, Francisc; Boeriu, Carmen Gabriela

    2013-01-01

    The enzymatic oxidative polymerization of five technical lignins with different molecular properties, i.e. Soda Grass/Wheat straw Lignin, Organosolv Hardwood Lignin, Soda Wheat straw Lignin, Alkali pretreated Wheat straw Lignin, and Kraft Softwood was studied. All lignins were previously fractionated by acetone/water 50:50 (v/v) and the laccase-catalyzed polymerization of the low molecular weight fractions (Mw Reactivity of lignin substrates in laccase-catalyzed reactions was determined by monitoring the oxygen consumption. The oxidation reactions in 50% acetone in water mixture proceed with high rate for all tested lignins. Polymerization products were analyzed by size exclusion chromatography, FT-IR, and (31)P-NMR and evidence of important lignin modifications after incubation with laccase. Lignin polymers with higher molecular weight (Mw up to 17500 g/mol) were obtained. The obtained polymers have potential for applications in bioplastics, adhesives and as polymeric dispersants.

  16. Regularities in electroconductivity and thermo-emf in systems of binary continuous solid solutions of metals

    International Nuclear Information System (INIS)

    Vedernikov, M.V.; Dvunitkin, V.G.; Zhumagulov, A.

    1978-01-01

    Given are new experimental data about specific electric resistance of 10 systems of binary continuous solid metal solutions at the temperatures of 293 and 4.2 K: Cr-V, Mo-Nb, Mo-V, Cr-Mo, Nb-V, Ti-Zr, Hf-Zr, Hf-Ti, Sc-Zr, Sc-Hf. For the first time a comparative analysis of all available data on the resistance dependence on the composition of systems of continuous solid solutions, which covers 21 systems, is carried out. The ''resistance-composition'' dependence for such alloy systems is found to be of two types. The dependence of the first type is characteristic of the systems, formed by two isoelectronic metals, the dependence of the second type - for the systems, formed by non-isoelectronic metals. Thermo-emf of each type of solid solutions differently depends on their compositions

  17. Solid phase crystallisation of HfO2 thin films

    International Nuclear Information System (INIS)

    Modreanu, M.; Sancho-Parramon, J.; O'Connell, D.; Justice, J.; Durand, O.; Servet, B.

    2005-01-01

    In this paper, we report on the solid phase crystallisation of carbon-free HfO 2 thin films deposited by plasma ion assisted deposition (PIAD). After deposition, the HfO 2 films were annealed in N 2 ambient for 3 h at 350, 550 and 750 deg. C. Several characterisation techniques including X-ray reflectometry (XRR), X-ray diffraction (XRD), spectroscopic ellipsometry (SE) and atomic force microscopy (AFM) were used for the physical characterisation of as-deposited and annealed HfO 2 . XRD has revealed that the as-deposited HfO 2 film is in an amorphous-like state with only traces of crystalline phase and that the annealed films are in a highly crystalline state. These results are in good agreement with the SE results showing an increase of refractive index by increasing the annealing temperature. XRR results show a significant density gradient over the as-deposited film thickness, which is characteristic of the PIAD method. The AFM measurements show that the HfO 2 layers have a smooth surface even after annealing at 750 deg. C. The present study demonstrates that the solid phase crystallisation of HfO 2 PIAD thin films starts at a temperature as low as 550 deg. C

  18. Synthesis and evaluation of inhaled [11C]butane and intravenously injected [11C]acetone as potential radiotracers for studying inhalant abuse

    International Nuclear Information System (INIS)

    Gerasimov, Madina R.; Ferrieri, Richard A.; Pareto, Deborah; Logan, Jean; Alexoff, David; Ding Yushin

    2005-01-01

    The phenomenon of inhalant abuse is a growing problem in the US and many countries around the world. Yet, relatively little is known about the pharmacokinetic properties of inhalants that underlie their abuse potential. While the synthesis of 11 C-labeled toluene, acetone and butane has been proposed in the literature, none of these compounds has been developed as radiotracers for PET studies. In the present report we extend our previous studies with [ 11 C]toluene to include [ 11 C]acetone and [ 11 C]butane with the goal of comparing the pharmacokinetic profiles of these three volatile abused substances. Both [ 11 C]toluene and [ 11 C]acetone were administered intravenously and [ 11 C]butane was administered via inhalation to anesthesized baboons. Rapid and efficient uptake of radiolabeled toluene and acetone into the brain was followed by fast clearance in the case of toluene and slower kinetics in the case of acetone. [ 11 C]Butane was detected in the blood and brain following inhalation, but the levels of radioactivity in both tissues dropped to half of the maximal values over the period of less than a minute. To our knowledge, this is the first reported study of the in vivo brain pharmacokinetics of labeled acetone and butane in nonhuman primates. These data provide insight into the pharmacokinetic features possibly associated with the abuse liability of toluene, acetone and butane

  19. Chemical reactions in the nitrogen-acetone ice induced by cosmic ray analogues: relevance for the Solar system

    Science.gov (United States)

    de Barros, A. L. F.; Andrade, D. P. P.; da Silveira, E. F.; Alcantara, K. F.; Boduch, P.; Rothard, H.

    2018-02-01

    The radiolysis of 10:1 nitrogen:acetone mixture, condensed at 11 K, by 40 MeV 58Ni11 + ions is studied. These results are representative of studies concerning Solar system objects, such as transneptunian objects, exposed to cosmic rays. Bombardment by cosmic rays triggers chemical reactions leading to synthesis of larger molecules. In this work, destruction cross-sections of acetone and nitrogen molecules in solid phase are determined and compared with those for pure acetone. The N2 column density decreases very fast indicating that, under irradiation, nitrogen leaves quickly a porous sample. The most abundant molecular species formed in the radiolysis are C3H6, C2H6, N3, CO, CH4 and CO2. Some N-bearing species are also formed, but with low production yield. Dissolving acetone in nitrogen decreases the formation cross-sections of CH4, CO2 and H2CO, while increases those for CO and C2H6 species. This fact may explain the presence of C2H6 in Pluto's surface where CH4 is not pure, but diluted in an N2 matrix. The formation of more complex molecules, such as HNCO and, possibly, glycine is observed, suggesting the formation of small prebiotic species in objects beyond Neptune from acetone diluted in a N2 matrix irradiated by cosmic rays.

  20. Simultaneous determination of methanol, acetaldehyde, acetone, and ethanol in human blood by gas chromatography with flame ionization detection.

    Science.gov (United States)

    Schlatter, J; Chiadmi, F; Gandon, V; Chariot, P

    2014-01-01

    Methanol, acetaldehyde, acetone, and ethanol, which are commonly used as biomarkers of several diseases, in acute intoxications, and forensic settings, can be detected and quantified in biological fluids. Gas chromatography (GC)-mass spectrometry techniques are complex, require highly trained personnel and expensive materials. Gas chromatographic determinations of ethanol, methanol, and acetone have been reported in one study with suboptimal accuracy. Our objective was to improve the assessment of these compounds in human blood using GC with flame ionization detection. An amount of 50 µl of blood was diluted with 300 µl of sterile water, 40 µl of 10% sodium tungstate, and 20 µl of 1% sulphuric acid. After centrifugation, 1 µl of the supernatant was injected into the gas chromatograph. We used a dimethylpolysiloxane capillary column of 30 m × 0.25 mm × 0.25 µm. We observed linear correlations from 7.5 to 240 mg/l for methanol, acetaldehyde, and acetone and from 75 to 2400 mg/l for ethanol. Precision at concentrations 15, 60, and 120 mg/l for methanol, acetaldehyde, and acetone and 150, 600, and 1200 mg/ml for ethanol were 0.8-6.9%. Ranges of accuracy were 94.7-98.9% for methanol, 91.2-97.4% for acetaldehyde, 96.1-98.7% for acetone, and 105.5-111.6% for ethanol. Limits of detection were 0.80 mg/l for methanol, 0.61 mg/l for acetaldehyde, 0.58 mg/l for acetone, and 0.53 mg/l for ethanol. This method is suitable for routine clinical and forensic practices.

  1. Volumetric studies and thermodynamics of viscous flow of hydroxamic acids in acetone + water solvent at temperatures 303.15 and 313.15 K

    International Nuclear Information System (INIS)

    Tiwari, Vaishali; Pande, Rama

    2006-01-01

    Densities ρ and viscosities η of two hydroxamic acids, N-phenyl-2-chlorobenzo- and N-o-tolyl-4-chlorobenzo-, have been determined as a function of their concentration in aqueous acetone solution at temperatures 303.15 and 313.15 K. Apparent molar volumes, standard-state partial molar volumes and relative viscosities have been calculated. The viscosity data have been analyzed using Jones-Dole equation. The activation thermodynamic parameters of viscous flow have been evaluated using Feakins equation. These were obtained to throw light on the mechanism of viscous flow. Thermodynamic interactions in solutions have been studied in terms of a number of excess functions calculated from the experimental data. The effect of hydroxamic acid concentration and temperature on these parameters has been discussed. The results were interpreted in the light of solute-solvent interactions in aquo-organic media

  2. Investigation of hybrid plasma-catalytic removal of acetone over CuO/γ-Al2O3 catalysts using response surface method.

    Science.gov (United States)

    Zhu, Xinbo; Tu, Xin; Mei, Danhua; Zheng, Chenghang; Zhou, Jinsong; Gao, Xiang; Luo, Zhongyang; Ni, Mingjiang; Cen, Kefa

    2016-07-01

    In this work, plasma-catalytic removal of low concentrations of acetone over CuO/γ-Al2O3 catalysts was carried out in a cylindrical dielectric barrier discharge (DBD) reactor. The combination of plasma and the CuO/γ-Al2O3 catalysts significantly enhanced the removal efficiency of acetone compared to the plasma process using the pure γ-Al2O3 support, with the 5.0 wt% CuO/γ-Al2O3 catalyst exhibiting the best acetone removal efficiency of 67.9%. Catalyst characterization was carried out to understand the effect the catalyst properties had on the activity of the CuO/γ-Al2O3 catalysts in the plasma-catalytic reaction. The results indicated that the formation of surface oxygen species on the surface of the catalysts was crucial for the oxidation of acetone in the plasma-catalytic reaction. The effects that various operating parameters (discharge power, flow rate and initial concentration of acetone) and the interactions between these parameters had on the performance of the plasma-catalytic removal of acetone over the 5.0 wt% CuO/γ-Al2O3 catalyst were investigated using central composite design (CCD). The significance of the independent variables and their interactions were evaluated by means of the Analysis of Variance (ANOVA). The results showed that the gas flow rate was the most significant factor affecting the removal efficiency of acetone, whilst the initial concentration of acetone played the most important role in determining the energy efficiency of the plasma-catalytic process. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. Structural analysis of flavonoids in solution through DFT 1H NMR chemical shift calculations: Epigallocatechin, Kaempferol and Quercetin

    Science.gov (United States)

    De Souza, Leonardo A.; Tavares, Wagner M. G.; Lopes, Ana Paula M.; Soeiro, Malucia M.; De Almeida, Wagner B.

    2017-05-01

    In this work, we showed that comparison between experimental and theoretical 1H NMR chemical shift patterns, calculated using Density Functional Theory (DFT), can be used for the prediction of molecular structure of flavonoids in solution, what is experimentally accessible for gas phase (electron diffraction methods) and solid samples (X-ray diffraction). The best match between B3LYP/6-31G(d,p)-PCM 1H NMR calculations for B ring rotated structures and experimental spectra can provide information on the conformation adopted by polyphenols in solution (usually DMSO-d6, acetone-d6 as solvents), which may differ from solid state and gas phase observed structures, and also DFT optimized geometry in the vacuum.

  4. HF Radar observations of the Dardanelles outflow current in North Eastern Aegean using validated WERA HF radar data

    Directory of Open Access Journals (Sweden)

    Z. KOKKINI

    2014-12-01

    Full Text Available A two-site WERA HF radar station was installed in November 2009 at the eastern coast of Lemnos Island in North Aegean Sea, aiming to monitor the surface inflow of Black Sea waters exiting from the Dardanelles Strait, as well as to constitute a coastal management tool for incidents of oil-pollution or save-and-rescue operations. Strong interference by foreign transmissions is a source of noise deteriorating the quality of the backscattered signal, thus significantly reducing the HF radar’s effective data return rate. In order to ameliorate this problem, further quality-control and data gap interpolating procedures have been developed and applied, to be used in addition to the procedures incorporated and used by the manufacturer’s signal processing software. The second-level processing involves traditional despiking in the temporal domain, preceding Empirical Orthogonal Function analysis. The latter is used not only to filter high-frequency noise but also to fill data gaps in time and space. The data reconstruction procedure has been assessed via comparison of (a HF radial with CODE-type drifter radial velocities as well as (b HF-derived virtual drifter tracks with actual drifter tracks. The main circulation features and their variability, as revealed by the reconstructed fields, are presented.

  5. Acetone improves the topographical homogeneity of liquid phase exfoliated few-layer black phosphorus flakes.

    Science.gov (United States)

    Gomez Perez, Juan; Konya, Zoltan; Kukovecz, Akos

    2018-06-12

    Liquid phase exfoliation of 2D materials has issues related to the sorption of the solvent, the oxidation of the sample during storage, and the topographical inhomogeneity of the exfoliated material. N-methyl-2-pyrrolidone (NMP), a common solvent for black phosphorus (BP) exfoliation, has additional drawbacks like the formation of by-products during sonication and poor solvent volatility. Here we demonstrate an improvement in the topographical homogeneity (i.e. thickness and lateral dimensions) of NMP-exfoliated BP flakes after resuspension in acetone. The typical size of monolayers and bilayers stabilised in acetone was 99.8±27.4 nm and 159.1±57 nm, respectively. These standard deviations represent a threefold improvement over those of the NMP-exfoliated originals. Phosphorene can also be exfoliated directly in acetone by very long ultrasonication. The product suspension enjoys the same dimensional homogeneity benefits, which confirms that this effect is an intrinsic property of the acetone-BP system. The quality and stability of the exfoliated flakes was checked by XRD, TEM, electron diffraction and Raman spectroscopy. Thermal expansion coefficients of the A1g, B2g and A2g Raman modes were calculated for drop-casted samples as -0.01828 cm-1/K, -0.03056 cm-1/K and -0.03219 cm-1/K, respectively. The flakes withstand 20 minutes in O2 flow at 373 K without lattice distortion. . © 2018 IOP Publishing Ltd.

  6. HF-laser program

    International Nuclear Information System (INIS)

    Anon.

    1978-01-01

    The HF laser is an attractive candidate driver for a large-system ICF scientific demonstration facility, for an ICF experimental power reactor and for a commercial laser--fusion power reactor. Previous accomplishments of the program have included demonstrations of high efficiency and high energy capability, efficient energy extraction from HF amplifiers, good beam quality and focusability, and short-pulse generation and amplification. In the reporting period, beam quality has been determined to be near-diffraction limited for a short pulsewidth (6 ns to 25 ns) oscillator-amplifier chain, suppression of amplified spontaneous emission has been demonstrated on an individual spectral line, high-pressure characteristics have been determined for the Phoenix I amplifier, and detailed comparisions between the kinetic code and experiments have been made. Details of two major upcoming experiments are also included. The first is energy extraction and beam quality measurements on the Phoenix I amplifier operating under saturated output power conditions. The second experiment, using a newly designed amplifier (Phoenix II), is designed to demonstrate the concept of angular-multiplexing: a pulse width-compression scheme

  7. Chemical stability and defect formation in CaHfO3

    KAUST Repository

    Alay-E-Abbas, Syed Muhammad

    2014-04-01

    Defects in CaHfO3 are investigated by ab initio calculations based on density functional theory. Pristine and anion-deficient CaHfO 3 are found to be insulating, whereas cation-deficient CaHfO 3 is hole-doped. The formation energies of neutral and charged cation and anion vacancies are evaluated to determine the stability in different chemical environments. Moreover, the energies of the partial and full Schottky defect reactions are computed. We show that clustering of anion vacancies in the HfO layers is energetically favorable for sufficiently high defect concentrations and results in metallicity. © 2014 EPLA.

  8. Chemical stability and defect formation in CaHfO3

    KAUST Repository

    Alay-E-Abbas, Syed Muhammad; Nazir, Safdar; Mun Wong, Kin; Shaukat, Ali; Schwingenschlö gl, Udo

    2014-01-01

    Defects in CaHfO3 are investigated by ab initio calculations based on density functional theory. Pristine and anion-deficient CaHfO 3 are found to be insulating, whereas cation-deficient CaHfO 3 is hole-doped. The formation energies of neutral and charged cation and anion vacancies are evaluated to determine the stability in different chemical environments. Moreover, the energies of the partial and full Schottky defect reactions are computed. We show that clustering of anion vacancies in the HfO layers is energetically favorable for sufficiently high defect concentrations and results in metallicity. © 2014 EPLA.

  9. Determination of the two methyl group orientations at vapor/acetone interface with polarization null angle method in SFG vibrational spectroscopy

    Science.gov (United States)

    Chen, Hua; Gan, Wei; Wu, Bao-hua; Wu, Dan; Zhang, Zhen; Wang, Hong-fei

    2005-06-01

    We report a direct measurement of the orientation of the two CH 3 groups of acetone molecule at the vapor/acetone interface. The interfacial acetone molecule is found well-ordered, with one methyl group points away around 14.4° ± 1.9° and another into the bulk liquid around 102.8° ± 1.9° from the interface normal, and thus the C dbnd O group points into the bulk around 135.8° ± 1.9°. These results directly confirmed the highly ordered and even crystal like interfacial structure of the vapor/acetone interface from previous MD simulation. The general formulation and accurate determination of the orientational parameter D can be used to treat interfaces with complex molecular orientations.

  10. Development of Cu-Hf-Al ternary systems and tungsten wire/particle reinforced Cu48Hf43Al9 bulk metallic glass composites for strengthening

    International Nuclear Information System (INIS)

    Park, Joyoung; An, Jihye; Choi-Yim, Haein

    2010-01-01

    Stable bulk glass forming alloys can be developed over a wide range of compositions in Cu-Hf-Al ternary systems starting from the Cu 49 Hf 42 Al 9 bulk metallic glass. Ternary Cu-Hf-Al alloys can be cast directly from the melt into copper molds to form fully amorphous strips with thicknesses of 1 to 6 mm. The maximum critical diameter of the new Cu-Hf-Al ternary alloy was 6 mm. X-ray diffraction patterns were used to confirm the amorphous nature of the ternary Cu-Hf-Al alloys. To increase the toughness of these metallic glasses, we reinforced the Cu 48 Hf 43 Al 9 bulk metallic glass-forming liquid with a 50% volume fraction of tungsten particles and an 80% volume fraction of tungsten wires with diameters of 242.4 μm. Composites with a critical diameter of 7 mm and length 70 mm were synthesized. The structure of the composites was confirmed by using X-ray diffraction (XRD), and the scanning electron microscopy (SEM). The mechanical properties of the composites were studied in compression tests. The thermal stability and the crystallization processes of the Cu-Hf-Al alloys and composites were investigated by using differential scanning calorimetry (DSC). Values of the glass transition temperature (T g ), the crystallization temperature (T x ), and the supercooled liquid region (ΔT = T x - T g ) are given in this paper.

  11. Do Hf isotopes in magmatic zircons represent those of their host rocks?

    Science.gov (United States)

    Wang, Di; Wang, Xiao-Lei; Cai, Yue; Goldstein, Steven L.; Yang, Tao

    2018-04-01

    Lu-Hf isotopic system in zircon is a powerful and widely used geochemical tracer in studying petrogenesis of magmatic rocks and crustal evolution, assuming that zircon Hf isotopes can represent initial Hf isotopes of their parental whole rock. However, this assumption may not always be valid. Disequilibrium partial melting of continental crust would preferentially melt out non-zircon minerals with high time-integrated Lu/Hf ratios and generate partial melts with Hf isotope compositions that are more radiogenic than those of its magma source. Dissolution experiments (with hotplate, bomb and sintering procedures) of zircon-bearing samples demonstrate this disequilibrium effect where partial dissolution yielded variable and more radiogenic Hf isotope compositions than fully dissolved samples. A case study from the Neoproterozoic Jiuling batholith in southern China shows that about half of the investigated samples show decoupled Hf isotopes between zircons and the bulk rocks. This decoupling could reflect complex and prolonged magmatic processes, such as crustal assimilation, magma mixing, and disequilibrium melting, which are consistent with the wide temperature spectrum from ∼630 °C to ∼900 °C by Ti-in-zircon thermometer. We suggest that magmatic zircons may only record the Hf isotopic composition of their surrounding melt during crystallization and it is uncertain whether their Hf isotopic compositions can represent the primary Hf isotopic compositions of the bulk magmas. In this regard, using zircon Hf isotopic compositions to trace crustal evolution may be biased since most of these could be originally from disequilibrium partial melts.

  12. Lu{sub 2}O{sub 3}:Tb,Hf storage phosphor

    Energy Technology Data Exchange (ETDEWEB)

    Kulesza, Dagmara; Trojan-Piegza, Joanna [Faculty of Chemistry, University of Wroclaw, 14 F. Joliot-Curie Street, 50-383 Wroclaw (Poland); Zych, Eugeniusz, E-mail: zych@wchuwr.p [Faculty of Chemistry, University of Wroclaw, 14 F. Joliot-Curie Street, 50-383 Wroclaw (Poland)

    2010-03-15

    Lu{sub 2}O{sub 3}:Tb,Hf ceramics containing 0.1% of Tb and 0-1.5% of Hf were prepared in reducing atmosphere at 1700 {sup o}C and their thermoluminescence properties were systematically studied. For comparison Tb,Ca co-doped specimen was also fabricated and investigated. The Tb,Hf ceramics shows basically a single TL band located around 180 {sup o}C as found with heating rate of 15 {sup o}C/min. Ceramics singly doped with Tb show complex TL glow curves indicating the presence of traps of very different depths. On the other hand Tb,Ca co-doping is beneficial for the development of shallow traps with the main TL band around 70 {sup o}C. Hence, the aliovalent impurities, Ca{sup 2+} and Hf{sup 4+}, strongly influenced the traps structure in Lu{sub 2}O{sub 3}:Tb ceramics, each of them in its own specific way. Isothermal decay of Lu{sub 2}O{sub 3}:Tb,Hf at 185 {sup o}C was recorded and its shape suggest that multiple hole trapping occurs in the Lu{sub 2}O{sub 3}:Tb,Hf ceramics. Due to the different traps depths the Lu{sub 2}O{sub 3}:Tb,Hf ceramics possess properties typical for storage phosphors, while Lu{sub 2}O{sub 3}:Tb,Ca is a persistent luminescent material rather.

  13. Toluene metabolism in isolated rat hepatocytes: effects of in vivo pretreatment with acetone and phenobarbital

    Energy Technology Data Exchange (ETDEWEB)

    Smith-Kielland, A.; Ripel, A. (National Inst. of Forensic Toxicology, Oslo (Norway))

    1993-02-01

    Hepatocytes isolated from control, acetone- and phenobarbital-pretreated rats were used to study the metabolic conversion of toluene to benzyl alcohol, benzaldehyde, benzoic acid and hippuric acid at low (<100 [mu]M) and high (100-500 [mu]M) toluene concentrations. The baseline formation rates of toluene metabolites (benzyl alcohol, benzoic acid and hippuric acid) were 2.9[+-]1.7 and 10.0[+-]2.3 nmol/mg cell protein/60 min at low and high toluene concentrations, respectively. In vivo pretreatment of rats with acetone and phenobarbital increased the formation of metabolites: at low toluene concentrations 3- and 5-fold, respectively; at high toluene concentrations no significant increase (acetone) and 8-fold increase (phenobarbital). Apparent inhibition by ethanol, 7 and 60 mM, was most prominent at low toluene concentrations: 63% and 69%, respectively, in control cells; 84% and 91% in acetone-pretreated cells, and 32% (not significant) and 51% in phenobarbital-pretreated cells. Ethanol also caused accumulation of benzyl alcohol. The apparent inhibition by isoniazid was similar to that of ethanol at low toluene concentrations. Control and acetone-pretreated cells were apparently resistant towards metyrapone; the decrease was 49% and 64% in phenobarbital-pretreated cells at low and high toluene concentrations, respectively. In these cells, the decrease in presence of combined ethanol and metyrapone was 95% (low toluene concentrations). 4-Methylpyrazole decreased metabolite formation extensively in all groups. Benzaldehyde was only found in the presence of an aldehyde dehydrogenase inhibitor. Increased ratio benzoic/hippuric acid was observed at high toluene concentrations. These results demonstrate that toluene oxidation may be studied by product formation in isolated hepatocytes. However, the influence of various enzymes in the overall metabolism could not be ascertained due to lack of inhibitor specificity. (orig.).

  14. Activity Coefficients of Acetone-Chloroform Solutions: An Undergraduate Experiment. Undergraduate Experiment.

    Science.gov (United States)

    Ozog, J. Z.; Morrison, J. A.

    1983-01-01

    Presents information, laboratory procedures, and results of an undergraduate experiment in which activity coefficients for a two-component liquid-vapor system are determined. Working in pairs, students can perform the experiment with 10 solutions in a given three-hour laboratory period. (Author/JN)

  15. Working-up sugar-beet molasses in the acetone-butyl alcohol plants in Poland

    Energy Technology Data Exchange (ETDEWEB)

    Logotkin, I S; Zaritskii, I M

    1959-01-01

    The basic setup common to all Polish acetone and butanol plants is the addition of rye or wheat meal to the fermentation. A culture of Clostridium acetobutylicum, after spore formation, is mixed in a special apparatus with the meal, where it is kept for 18 hours at 37/sup 0/ and then treated with molasses; a culture is prepared which is used later in the fermentor. Independently a mixture of meal and molasses is mixed in an autoclave with H/sub 2/O, sterilized, and cooled. The resulting mash is mixed in the fermentor with the culture mentioned, where the fermentation liberates CO/sub 2/ and hydrogen which are recovered. The mixture is then heated, distilled, and rectified, where, in addition to slops, the desired products are obtained. The Polish plants figure that for each long ton of sugar contained in the molasses they recover butyl alcohol 178.0, acetone 83.7, and ethanol 7.3kg, and they use in addition to the molasses and bacilli cultures 58.4 tons of steam and 16 kg of NaOH long ton of the acetone-butyl alcohol mixture recovered.

  16. Effects of HfO{sub 2}/Co interface and Co/HfO{sub 2} interface on anomalous Hall behavior in perpendicular Co/Pt multilayers

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Shao-Long [Department of Materials Science and Engineering, College of Engineering, Peking University, Beijing 100871 (China); Yang, Guang [Department of Materials Physics and Chemistry, University of Science and Technology Beijing, Beijing 100083 (China); Teng, Jiao, E-mail: tengjiao@mater.ustb.edu.cn [Department of Materials Physics and Chemistry, University of Science and Technology Beijing, Beijing 100083 (China); Guo, Qi-Xun; Liu, Yi-Wei; Li, Xu-Jing [Department of Materials Physics and Chemistry, University of Science and Technology Beijing, Beijing 100083 (China); Yu, Guang-Hua, E-mail: ghyu@mater.ustb.edu.cn [Department of Materials Physics and Chemistry, University of Science and Technology Beijing, Beijing 100083 (China)

    2017-07-01

    Highlights: • Anomalous Hall effect in perpendicular Co/Pt multilayers is studied. • Thermally stable AHE feature is obtained in [Pt/Co]{sub 3}/HfO{sub 2}/Pt multilayers. • Good thermal stability is due to enhanced intrinsic and side-jump contributions. - Abstract: Effects of the HfO{sub 2}/Co interface and the Co/HfO{sub 2} interface on thermal stability of anomalous Hall effect (AHE) in perpendicular Co/Pt multilayers have been studied. It is observed that thermally stable AHE behavior cannot be obtained in perpendicular Co/Pt multilayers with the HfO{sub 2}/Co interface, mainly due to Co-Pt interdiffusion during annealing. In contrast, thermally stable AHE feature is observed in perpendicular Co/Pt multilayers with the Co/HfO{sub 2} interface despite Co-Pt interdiffusion, which is owing to the enhancement of the side jump and intrinsic contributions to the AHE through interfacial modification after annealing.

  17. SOLUTION THERMODYNAMICS OF TRICLOSAN AND TRICLOCARBAN IN SOME VOLATILE ORGANIC SOLVENTS

    OpenAIRE

    DELGADO, Daniel R.; R. HOLGUIN, Andres; MARTÍNEZ, Fleming

    2012-01-01

    Thermodynamic functions of Gibbs energy, enthalpy, and entropy for the solution processes of the antimicrobial drugs Triclosan and Triclocarban in five volatile organic solvents were calculated from solubility values at temperatures from 293.15 to 313.15 K. Triclosan and Triclocarban solubility was determined in acetone, acetonitrile (AcCN), ethyl acetate (AcOEt), methanol (MetOH), and cyclohexane (CH). The excess of Gibbs energy and the activity coefficients of the solutes were also calculat...

  18. A routine high-precision method for Lu-Hf isotope geochemistry and chronology

    Science.gov (United States)

    Patchett, P.J.; Tatsumoto, M.

    1981-01-01

    A method for chemical separation of Lu and Hf from rock, meteorite and mineral samples is described, together with a much improved mass spectrometric running technique for Hf. This allows (i) geo- and cosmochronology using the176Lu???176Hf+??- decay scheme, and (ii) geochemical studies of planetary processes in the earth and moon. Chemical yields for the three-stage ion-exchange column procedure average 90% for Hf. Chemical blanks are international mass spectrometric standard; suitable aliquots, prepared from a single batch of JMC 475, are available from Denver. Lu-Hf analyses of the standard rocks BCR-1 and JB-1 are given. The potential of the Lu-Hf method in isotope geochemistry is assessed. ?? 1980 Springer-Verlag.

  19. Lifetime of the first excited 2{sup +} state in {sup 172}Hf and {sup 174}Hf

    Energy Technology Data Exchange (ETDEWEB)

    Gerst, Rosa-Belle; Stegemann, Simon; Jolie, Jan; Regis, Jean-Marc; Rudigier, Matthias; Saed-Samii, Nima; Zell, Karl Oskar [Institut fuer Kernphysik, Universitaet zu Koeln, Zuelpicher Str. 77, 50937 Koeln (Germany)

    2014-07-01

    Using the {sup 170}Yb(α,2n) and {sup 172}Yb(α,2n) reactions the lifetimes of the first excited 2{sup +} state in {sup 172}Hf and {sup 174}Hf have been measured in fast-timing experiments using the Cologne Orange-Spectrometer and 6 LaBr{sub 3}(Ce)-Detectors. The lifetimes were obtained analyzing e{sup -}-γ-coincidence time-spectra with the slope method. The new and more precise lifetimes correct existing, outdated lifetimes in nuclear databases. Additionally, the systematics of the B(E2,2{sub 1}{sup +}→0{sub 1}{sup +}) is studied.

  20. Flotation separation of hafnium(IV) from aqueous solutions

    International Nuclear Information System (INIS)

    Downey, D.M.; Narick, C.N.; Cohen, T.A.

    1985-01-01

    A simple, rapid method for the separation of hafnium from aqueous solutions was investigated using sup(175+181)Hf tracer. Cationic hafnium complex ions were floated from dilute acid solutions with sodium lauryl sulfate (SLS) and anionic hafnium complexes were floated from basic and oxalic acid solutions with hexadecyltrimethyl ammonium bromide (HTMAB). The conditions necessary for quantitative recovery of the metal and mechanisms of flotation are described. (author)

  1. DSC and curing kinetics study of epoxy grouting diluted with furfural -acetone slurry

    Science.gov (United States)

    Yin, H.; Sun, D. W.; Li, B.; Liu, Y. T.; Ran, Q. P.; Liu, J. P.

    2016-07-01

    The use of furfural-acetone slurry as active diluents of Bisphenol-A epoxy resin (DGEBA) groutings has been studied by dynamic and non-isothermal DSC for the first time. Curing kinetics study was investigated by non-isothermal differential scanning calorimetries at different heating rates. Activation enery (Ea) was calculated based on Kissinger and Ozawa Methods, and the results showed that Ea increased from 58.87 to 71.13KJ/mol after the diluents were added. The furfural-acetone epoxy matrix could cure completely at the theoretical curing temperature of 365.8K and the curing time of 139mins, which were determined by the kinetic model parameters.

  2. Histochemical detection of GM1 ganglioside using cholera toxin-B subunit. Evaluation of critical factors optimal for in situ detection with special emphasis to acetone pre-extraction

    Science.gov (United States)

    Petr, T.; Šmíd, V.; Šmídová, J.; Hůlková, H.; Jirkovská, M.; Elleder, M.; Muchová, L.; Vítek, L.; Šmíd, F.

    2010-01-01

    A comparison of histochemical detection of GM1 ganglioside in cryostat sections using cholera toxin B-subunit after fixation with 4% formaldehyde and dry acetone gave tissue-dependent results. In the liver no pre-treatment showed detectable differences related to GM1 reaction products, while studies in the brain showed the superiority of acetone pre-extraction (followed by formaldehyde), which yielded sharper images compared with the diffuse, blurred staining pattern associated with formaldehyde. Therefore, the aim of our study was to define the optimal conditions for the GM1 detection using cholera toxin B-subunit. Ganglioside extractability with acetone, the ever neglected topic, was tested comparing anhydrous acetone with acetone containing admixture of water. TLC analysis of acetone extractable GM1 ganglioside from liver sections did not exceed 2% of the total GM1 ganglioside content using anhydrous acetone at −20°C, and 4% at room temperature. The loss increased to 30.5% using 9:1 acetone/water. Similarly, photometric analysis of lipid sialic acid, extracted from dried liver homogenates with anhydrous acetone, showed the loss of gangliosides into acetone 3.0±0.3% only. The loss from dried brain homogenate was 9.5±1.1%. Thus, anhydrous conditions (dry tissue samples and anhydrous acetone) are crucial factors for optimal in situ ganglioside detection using acetone pre-treatment. This ensures effective physical fixation, especially in tissues rich in polar lipids (precipitation, prevention of in situ diffusion), and removal of cholesterol, which can act as a hydrophobic blocking barrier. PMID:20558344

  3. Histochemical detection of GM1 ganglioside using cholera toxin-B subunit. Evaluation of critical factors optimal for in situ detection with special emphasis to acetone pre-extraction

    Directory of Open Access Journals (Sweden)

    T. Petr

    2010-05-01

    Full Text Available A comparison of histochemical detection of GM1 ganglioside in cryostat sections using cholera toxin B-subunit after fixation with 4% formaldehyde and dry acetone gave tissue-dependent results. In the liver no pre-treatment showed detectable differences related to GM1 reaction products, while studies in the brain showed the superiority of acetone pre-extraction (followed by formaldehyde, which yielded sharper images compared with the diffuse, blurred staining pattern associated with formaldehyde. Therefore, the aim of our study was to define the optimal conditions for the GM1 detection using cholera toxin B-subunit. Ganglioside extractability with acetone, the ever neglected topic, was tested comparing anhydrous acetone with acetone containing admixture of water. TLC analysis of acetone extractable GM1 ganglioside from liver sections did not exceed 2% of the total GM1 ganglioside content using anhydrous acetone at -20°C, and 4% at room temperature. The loss increased to 30.5% using 9:1 acetone/water. Similarly, photometric analysis of lipid sialic acid, extracted from dried liver homogenates with anhydrous acetone, showed the loss of gangliosides into acetone 3.0±0.3% only. The loss from dried brain homogenate was 9.5±1.1%. Thus, anhydrous conditions (dry tissue samples and anhydrous acetone are crucial factors for optimal in situ ganglioside detection using acetone pre-treatment. This ensures effective physical fixation, especially in tissues rich in polar lipids (precipitation, prevention of in situ diffusion, and removal of cholesterol, which can act as a hydrophobic blocking barrier.

  4. Photocatalytic degradation of acetone and butane on mesoporous titania layers

    Czech Academy of Sciences Publication Activity Database

    Štengl, Václav; Houšková, Vendula; Bakardjieva, Snejana; Murafa, Nataliya

    2010-01-01

    Roč. 34, č. 9 (2010), s. 1999-2005 ISSN 1144-0546 R&D Projects: GA ČR GA203/08/0334 Institutional research plan: CEZ:AV0Z40320502 Keywords : thin-films * gaseous acetone * oxidation * TIO2 Subject RIV: CA - Inorganic Chemistry Impact factor: 2.631, year: 2010

  5. Breath acetone concentration; biological variability and the influence of diet

    Czech Academy of Sciences Publication Activity Database

    Španěl, Patrik; Dryahina, Kseniya; Rejšková, A.; Chippendale, T. W. E.; Smith, D.

    2011-01-01

    Roč. 32, č. 8 (2011), N23-N31 ISSN 0967-3334 R&D Projects: GA ČR GP203/09/P172 Institutional research plan: CEZ:AV0Z40400503 Keywords : acetone * breath * ketogenic diet Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 1.677, year: 2011

  6. Draft revision of human factors guideline HF-010

    International Nuclear Information System (INIS)

    Lee, Hyun Chul; Lee, Yong Hee; Oh, In Seok; Lee, Jung Woon; Cha, Woo Chang; Lee, Dhong Ha

    2003-05-01

    The Application of Human Factors to the design of Man-Machine Interfaces System(MMIS) in the nuclear power plant is essential to the safety and productivity of the nuclear power plants, human factors standards and guidelines as well as human factors analysis methods and experiments are weightily used to the design application. A Korean engineering company has developed a human factors engineering guideline, so-call HF-010, and has used it for human factors design, however the revision of HF-010 is necessary owing to lack of the contents related to the advanced MMI(Man-Machine Interfaces). As the results of the reviews of HF-010, it is found out that the revision of Section 9. Computer Displays of HF-010 is urgent, thus the revision was drafted on the basis of integrated human factors design guidelines for VDT, human factors design guidelines for PMAS SPADES display, human factors design guidelines for PMAS alarm display, and human factors design guidelines for electronic displays developed by the surveillance and operation support project of KOICS. The draft revision of HF-010 Section 9 proposed in this report can be utilized for the human factors design of the advanced MMI, and the high practical usability of the draft can be kept up through the continuous revision according to the advancement of digital technology

  7. Kinetic Model of Resin-Catalyzed Decomposition of Acetone Cyanohydrin in Organic Solvent

    Institute of Scientific and Technical Information of China (English)

    章亭洲; 杨立荣; 朱自强; 吴坚平

    2003-01-01

    Decomposition of acetone cyanohydrin is the first-step reaction for preparing (S)-α-cyano-3-phenoxybenzyl alcohol (CPBA) by the one-pot method in organic media. Considering the compatibility of biocatalysts with chemical catalysts and the successive operation in the bioreactor, anion exchange resin (D301) was used as catalyst for this reaction. External diffusion limitation was excluded by raising rotational speed to higher than 190r·min-1 in both solvents. Internal diffusion limitation was verified to be insignificant in this reaction system. The effect of acetone cyanohydrin concentration on the reaction was also investigated. An intrinsic kinetic model was proposed when the mass transfer limitation was excluded, and the average deviation of the model is 10.5%.

  8. Toxicity study of di(2-ethylhexyl)phthalate (DEHP) in combination with acetone in rats

    DEFF Research Database (Denmark)

    Dalgaard, M.; Østergaard, G.; Lam, Henrik Rye

    2000-01-01

    In two separate studies with exposure duration 9 weeks or 4 weeks, male Wistar rats were dosed with di(2-ethylhexyl)phthalate (DEHP) by gavage and exposed to drinking water with or without acetone (0.5% wt/v in the 9-week study, 1.0% wt/v in the 4-week study). In the 9-week study the doses of DEHP...... were 0, 125, 250, 500 or 1000 mg/kg b.wt. In the 4-week study the doses of DEHP were increased to 1000, 5000 and 10,000 mg/kg b.wt. In the 9-week study, the relative liver weight was increased in the rats exposed to 500 and 1000 mg/kg b.wt. No interaction of DEHP and acetone was observed in any...... of the measured parameters. In the 4-week study DEHP, at the highest dose level, resulted in severe general toxicity. The group exposed to DEHP in combination with acetone was more affected. Male fertility was decreased. Body weight was decreased, and the relative weight of the liver, kidney, heart, brain...

  9. Nuclear quadrupole interactions in ferroelectric compounds of HF/sup 181/

    Energy Technology Data Exchange (ETDEWEB)

    Kunzler, J V

    1971-01-01

    Measurements of nuclear quadrupole interaction constants in perovkite-type compounds of PbHfO/sub 3/, SnhfO/sub 3/, CaHfO/sub 3/ e SrHfO/sub 3/ have been performed using the perturbed angular correlation technique. A range of fundamental frequencies from 150 to 550 Megaradians per second was determined. The variation of quadrupole constants has been discussed through the molecular orbital theory.

  10. Reliability assessment of ultra-thin HfO2 films deposited on silicon wafer

    International Nuclear Information System (INIS)

    Fu, Wei-En; Chang, Chia-Wei; Chang, Yong-Qing; Yao, Chih-Kai; Liao, Jiunn-Der

    2012-01-01

    Highlights: ► Nano-mechanical properties on annealed ultra-thin HfO 2 film are studied. ► By AFM analysis, hardness of the crystallized HfO 2 film significantly increases. ► By nano-indention, the film hardness increases with less contact stiffness. ► Quality assessment on the annealed ultra-thin films can thus be achieved. - Abstract: Ultra-thin hafnium dioxide (HfO 2 ) is used to replace silicon dioxide to meet the required transistor feature size in advanced semiconductor industry. The process integration compatibility and long-term reliability for the transistors depend on the mechanical performance of ultra-thin HfO 2 films. The criteria of reliability including wear resistance, thermal fatigue, and stress-driven failure rely on film adhesion significantly. The adhesion and variations in mechanical properties induced by thermal annealing of the ultra-thin HfO 2 films deposited on silicon wafers (HfO 2 /SiO 2 /Si) are not fully understood. In this work, the mechanical properties of an atomic layer deposited HfO 2 (nominal thickness ≈10 nm) on a silicon wafer were characterized by the diamond-coated tip of an atomic force microscope and compared with those of annealed samples. The results indicate that the annealing process leads to the formation of crystallized HfO 2 phases for the atomic layer deposited HfO 2 . The HfSi x O y complex formed at the interface between HfO 2 and SiO 2 /Si, where the thermal diffusion of Hf, Si, and O atoms occurred. The annealing process increases the surface hardness of crystallized HfO 2 film and therefore the resistance to nano-scratches. In addition, the annealing process significantly decreases the harmonic contact stiffness (or thereafter eliminate the stress at the interface) and increases the nano-hardness, as measured by vertically sensitive nano-indentation. Quality assessments on as-deposited and annealed HfO 2 films can be thereafter used to estimate the mechanical properties and adhesion of ultra-thin HfO 2

  11. Chemical reaction at the interface between pentacene and HfO2

    International Nuclear Information System (INIS)

    Kang, S.J.; Yi, Y.; Kim, K.H.; Yoo, C.Y.; Moewes, A.; Cho, M.H.; Denlinger, J.D.; Whang, C.N.; Chang, G.S.

    2005-01-01

    The electronic structure and the interface formation at the interface region between pentacene and HfO2 are investigated using x-ray photoelectron spectroscopy (XPS), ultraviolet photoelectron spectroscopy (UPS), and x-ray emission spectroscopy (XES). The measured C 1s XPS spectra of pentacene indicate that chemical bonding occurs at the interface between pentacene and HfO2. The carbon of pentacene reacts with oxygen belonging to HfO2 and band bending occurs at the interface due to a redistribution of charge. The determined interface dipole and band bending between pentacene and HfO2 are 0.04 and 0.1 eV, respectively. The highest occupied molecular orbital (HOMO) level is observed at 0.68 eV below the Fermi level. This chemical reaction allows us to grow a pentacene film with large grains onto HfO2. We conclude that high performance pentacene thin film transistors can be obtained by inserting an ultrathin HfO2 layer between pentacene and a gate insulator

  12. α-chymotrypsin in water-acetone and water-dimethyl sulfoxide mixtures: Effect of preferential solvation and hydration.

    Science.gov (United States)

    Sirotkin, Vladimir A; Kuchierskaya, Alexandra A

    2017-10-01

    We investigated water/organic solvent sorption and residual enzyme activity to simultaneously monitor preferential solvation/hydration of protein macromolecules in the entire range of water content at 25°C. We applied this approach to estimate protein destabilization/stabilization due to the preferential interactions of bovine pancreatic α-chymotrypsin with water-acetone (moderate-strength H-bond acceptor) and water-DMSO (strong H-bond acceptor) mixtures. There are three concentration regimes for the dried α-chymotrypsin. α-Chymotrypsin is preferentially hydrated at high water content. The residual enzyme activity values are close to 100%. At intermediate water content, the dehydrated α-chymotrypsin has a higher affinity for acetone/DMSO than for water. Residual enzyme activity is minimal in this concentration range. The acetone/DMSO molecules are preferentially excluded from the protein surface at the lowest water content, resulting in preferential hydration. The residual catalytic activity in the water-poor acetone is ∼80%, compared with that observed after incubation in pure water. This effect is very small for the water-poor DMSO. Two different schemes are operative for the hydrated enzyme. At high and intermediate water content, α-chymotrypsin exhibits preferential hydration. However, at intermediate water content, in contrast to the dried enzyme, the initially hydrated α-chymotrypsin possesses increased preferential hydration parameters. At low water content, no residual enzyme activity was observed. Preferential binding of DMSO/acetone to α-chymotrypsin was detected. Our data clearly demonstrate that the hydrogen bond accepting ability of organic solvents and the protein hydration level constitute key factors in determining the stability of protein-water-organic solvent systems. © 2017 Wiley Periodicals, Inc.

  13. Multi-shelled ZnCo2O4 yolk-shell spheres for high-performance acetone gas sensor

    Science.gov (United States)

    Xiong, Ya; Zhu, Zongye; Ding, Degong; Lu, Wenbo; Xue, Qingzhong

    2018-06-01

    In the present study, multi-shelled ZnCo2O4 yolk-shell spheres have been successfully prepared by using carbonaceous microspheres as templates. It is found that the multi-shelled ZnCo2O4 yolk-shell spheres based sensor shows optimal sensing performances (response value of 38.2, response/recovery time of 19 s/71 s) toward 500 ppm acetone at 200 °C. In addition, this sensor exhibits a low detection limit of 0.5 ppm acetone (response value of 1.36) and a good selectivity toward hydrogen, methane, ethanol, ammonia and carbon dioxide. Furthermore, it is demonstrated that acetone gas response of multi-shelled ZnCo2O4 yolk-shell spheres is significantly better than that of ZnCo2O4 nanotubes and ZnCo2O4 nanosheets. High acetone response of the multi-shelled ZnCo2O4 yolk-shell spheres is attributed to the enhanced gas accessibility of the multi-shell morphology caused by the small crystalline size and high specific surface area while the short response/recovery time is mainly related to the rapid gas diffusion determined by the highly porous structure. Our work puts forward an exciting opportunity in designing various yolk-shelled structures for multipurpose applications.

  14. Thermodynamics and economic feasibility of acetone production from syngas using the thermophilic production host Moorella thermoacetica

    DEFF Research Database (Denmark)

    Redl, Stephanie Maria Anna; Sukumara, Sumesh; Ploeger, Tom

    2017-01-01

    -gas via condensation. Results: In this study we analyzed the production of acetone from syngas with the hypothetical production host derived from Moorella thermoacetica in a bubble column reactor at 60 degrees C with respect to thermodynamic and economic feasibility. We determined the cost of syngas...... production from basic oxygen furnace (BOF) process gas, from natural gas, and from corn stover and identified BOF gas as an economically interesting source for syngas. Taking gasliquid mass transfer limitations into account, we applied a thermodynamics approach to derive the CO to acetone conversion rate...... under the process conditions. We estimated variable costs of production of 389 $/t acetone for a representative production scenario from BOF gas with costs for syngas as the main contributor. In comparison, the variable costs of production from natural gas-and corn stover-derived syngas were determined...

  15. Large Magnetic Anisotropy in HfMnP

    Science.gov (United States)

    Parker, David; Lamichhane, Tej; Taufour, Valentin; Masters, Morgan; Thimmaiah, Srinivasa; Bud'Ko, Ser'gey; Canfield, Paul

    We present a theoretical and experimental study of two little-studied manganese phosphide ferromagnets, HfMnP and ZrMnP, with Curie temperatures above room temperature. We find an anisotropy field in HfMnP approaching 10 T - larger than that of the permanent magnet workhorse NdFeB magnets. From theory we determine the source of this anisotropy. Our results show the potential of 3d-element-based magnetic materials for magnetic applications.

  16. Acetone sensors based on microsheet-assembled hierarchical Fe2O3 with different Fe3+ concentrations

    Science.gov (United States)

    Wang, Han; Yan, Lei; Li, Shuo; Li, Yu; Liu, Li; Du, Liting; Duan, Haojie; Cheng, Yali

    2018-02-01

    Several different morphologies of microsheet-assembled Fe2O3 have been fabricated by hydrothermal method using diverse concentrations of Fe3+ precursor solutions (0.025, 0.020, 0.015, 0.010 mol/L Fe3+). The as-synthesized materials have been characterized by scanning electron microscope (SEM), X-ray powder diffraction (XRD), and energy-dispersive X-ray spectrometry (EDS). The SEM images reflect that the morphologies of as-synthesized materials are affected by the concentrations of Fe3+ in precursor solutions. The less concentration of Fe3+, the more porous of Fe2O3 microflowers, and thinner of slices distributed on the surface. Furthermore, gas sensors based on these Fe2O3 microflowers manufactured and tested to various common gases. The optimum response value to 100 ppm acetone is 52 at the working temperature of 220 °C. Meanwhile, the Fe2O3 microflower sensors possess ultrafast response-recovery speed, which are 8 and 19 s, respectively. The possible sensing mechanism was mainly attributed to the high surface area, three-dimensional porous structure.

  17. A comparative study of amorphous InGaZnO thin-film transistors with HfOxNy and HfO2 gate dielectrics

    International Nuclear Information System (INIS)

    Zou, Xiao; Tong, Xingsheng; Fang, Guojia; Yuan, Longyan; Zhao, Xingzhong

    2010-01-01

    High-κ HfO x N y and HfO 2 films are applied to amorphous InGaZnO (a-IGZO) devices as gate dielectric using radio-frequency reactive sputtering. The electrical characteristics and reliability of a-IGZO metal–insulator–semiconductor (MIS) capacitors and thin-film transistors (TFTs) are then investigated. Experimental results indicate that the nitrogen incorporation into HfO 2 can effectively improve the interface quality and enhance the reliability of the devices. Electrical properties with an interface-state density of 5.2 × 10 11 eV −1 cm −2 , capacitance equivalent thickness of 1.65 nm, gate leakage current density of 3.4 × 10 −5 A cm −2 at V fb +1 V, equivalent permittivity of 23.6 and hysteresis voltage of 110 mV are obtained for an Al/HfO x N y /a-IGZO MIS capacitor. Superior performance of HfO x N y /a-IGZO TFTs has also been achieved with a low threshold voltage of 0.33 V, a high saturation mobility of 12.1 cm 2 V −1 s −1 and a large on–off current ratio up to 7 × 10 7 (W/L = 500/20 µm) at 3 V

  18. Patterned forests of vertically-aligned multiwalled carbon nanotubes using metal salt catalyst solutions.

    Science.gov (United States)

    Garrett, David J; Flavel, Benjamin S; Baronian, Keith H R; Downard, Alison J

    2013-01-01

    A simple method for producing patterned forests of multiwalled carbon nanotubes (MWCNTs) is described. An aqueous metal salt solution is spin-coated onto a substrate patterned with photoresist by standard methods. The photoresist is removed by acetone washing leaving the acetone-insoluble catalyst pattern on the substrate. Dense forests of vertically aligned (VA) MWCNTs are grown on the patterned catalyst layers by chemical vapour deposition. The procedures have been demonstrated by growing MWCNT forests on two substrates: silicon and conducting graphitic carbon films. The forests adhere strongly to the substrates and when grown directly on carbon film, offer a simple method of preparing MWCNT electrodes.

  19. Analysis of O-Glycopeptides by Acetone Enrichment and Capillary Electrophoresis-Mass Spectrometry.

    Science.gov (United States)

    Mancera-Arteu, Montserrat; Giménez, Estela; Benavente, Fernando; Barbosa, José; Sanz-Nebot, Victòria

    2017-11-03

    Acetone precipitation was evaluated as a rapid, simple, low-cost, and efficient method for the selective purification of O-glycopeptides from enzymatic digests of glycoproteins. Ovalbumin (OVA), human and bovine α 1 -acid glycoprotein (hAGP and bAGP), human apolipoprotein C-III (APO-C3), and recombinant human erythropoietin (rhEPO) were used to obtain enzymatic digests with a broad and varied set of peptides, N-glycopeptides, and O-glycopeptides. After digestion and before capillary electrophoresis mass spectrometry (CE-MS) analysis, the amount of ice-cold acetone added to the digests was optimized to maximize recoveries of O-glycopeptides. Furthermore, the different behavior of peptides, N- and O-glycopeptides was explained by studying with multivariate data analysis methods the influence of several physicochemical parameters and properties related to their composition and structure. Principal component analysis (PCA) and, afterward, partial least-squares discriminant analysis (PLS-DA) were used to identify the most significant variables and their importance to differentiate between peptides, N-glycopeptides and O-glycopeptides, or within these classes. This information was useful to understand precipitation of these compounds after addition of acetone and for the selection of the optimal conditions for purification of specific O-glycopeptide biomarkers. Special attention was paid to O 126 -glycopeptide glycoforms of rhEPO because of their applicability in biopharmaceutical quality control and doping analysis.

  20. Ti-catalyzed HfSiO4 formation in HfTiO4 films on SiO2 studied by Z-contrast scanning electron microscopy

    Directory of Open Access Journals (Sweden)

    Elizabeth Ellen Hoppe

    2013-08-01

    Full Text Available Hafnon (HfSiO4 as it is initially formed in a partially demixed film of hafnium titanate (HfTiO4 on fused SiO2 is studied by atomic number (Z contrast high resolution scanning electron microscopy, x-ray diffraction, and Raman spectroscopy and microscopy. The results show exsoluted Ti is the catalyst for hafnon formation by a two-step reaction. Ti first reacts with SiO2 to produce a glassy Ti-silicate. Ti is then replaced by Hf in the silicate to produce HfSiO4. The results suggest this behavior is prototypical of other Ti-bearing ternary or higher order oxide films on SiO2 when film thermal instability involves Ti exsolution.

  1. Solidification Rate Dependence of Microstructures and Transformation Behavior of Ti-Ni-Hf Alloys.

    Science.gov (United States)

    Kim, Dong-Jo; Kim, Yeon-Wook; Nam, Tae-Hyun

    2018-09-01

    The microstructures and transformation behavior of Ti-49Ni-20Hf, Ti-49.5Ni-20Hf and Ti-50.3Ni- 20Hf alloys, when prepared by conventional casting, were investigated and compared with the properties of the alloys prepared by melt spinning. The area fraction of (Ti,Hf)2Ni in Ti-Ni-Hf alloys decreased to 3.9% from 9.4% as Ni content rose to 50.3 at% from 49 at%. Several cracks were observed in the hot-rolled Ti-49Ni-20Hf alloy sheet but none were found in the Ti-50.3Ni-20Hf alloy sheet. The B2-B19' transformation start temperature (Ms) decreased to 476 K from 580 K as Ni content increased to 50.3 at% from 49 at%. All the as-spun ribbons were amorphous, and the activation energy for crystallization ranged from 167.8 kJ/mol to 182.7 kJ/mol based on Ni content. When annealing temperature ranged from 810 K to 873 K, crystalline Ti-Ni-Hf alloys without (Ti,Hf)2Ni particles were obtained. At annealing temperatures higher than 873 K, very fine (Ti,Hf)2Ni particles, less than 20 nm in size, were found embedded in a crystalline matrix.

  2. Hf-Nd Isotopic Correlation in the Deccan Flood Basalt Province

    Science.gov (United States)

    Saha, A.; Basu, A. R.; Barling, J.; Anbar, A. D.; Hooper, P. R.

    2001-12-01

    Hafnium isotopes along with other isotopic and geochemical characteristics, including incompatible trace elements, of several of the lower formations of the Deccan Flood Basalt Province were analyzed to characterize petrogenesis of different tholeiitic lava suites, especially with respect to potential mantle and crustal sources. The rare earth elements of the different formations (from top to bottom- Mahabaleshwar, Ambenali, Bushe, Khandala and Neral) all show an LREE-enriched signature, concentrations varying between 30 to 60 times chondrite for La. (La/Lu)n values range from 4.1 to above 8 with the exception of Ambenali, which has a less LREE-enriched signature with (La/Lu)n values ranging between 3.6 to 5.3. Hafnium isotopic data of the lower formations of the Deccan show initial \\epsilonHf(T) values covering a range from -3 to -28. 176Lu/177Hf varies between 0.20 to 0.70. f(Lu/Hf) varies within a narrow range, between -0.90 to -0.97 while f(Sm/Nd) ranges from -0.84 to -0.86. Bushe gives the lowest range of \\epsilonHf(T) from -21 to -28 with the corresponding \\epsilonNd(T) varying between -4.0 and -16.9, while Khandala for almost the same range of neodymium isotopic values has \\epsilonHf(T) between -11 and -15. The \\epsilonHf(T) values of Neral is in between those of Khandala and Bushe, around -19. Ambenali, has the narrowest range with \\epsilonHf(T) of -3 and \\epsilonNd(T) between 3 and 5. The Ambenali suite reflects the least contaminated of the Deccan suite of lavas as analyzed here and previously confirmed by other isotopic studies. In Hf-Nd isotope correlation plot, the lower Deccan formations of Neral, Khandala and Bushe define individual subparallel arrays that are shallower than the oceanic basalt array and the overall terrestrial array, including the crustal array, although the bulk of the lower formation data fall within the crustal array of Vervoort et al (1999). From these subparallel Hf-Nd arrays, it is evident that the other end

  3. QAPP for Hydraulic Fracturing (HF) Surface Spills Data Analysis

    Science.gov (United States)

    This QAPP provides information concerning the analysis of spills associated with hydraulic fracturing. This project is relevant to both the chemical mixing and flowback and produced water stages of the HF water cycle as found in the HF Study Plan.

  4. Direct currents produced by hf heating of plasma

    International Nuclear Information System (INIS)

    Klima, R.

    1974-01-01

    In addition to the well-known diffusion currents, toroidal direct currents arise in h.f. heated plasmas as a result of a momentum transfer from the h.f. field to plasma particles. The estimates of steady-state conditions are given for these currents. Particularly, the possibility of stationary operation of a Tokamak device is analyzed. (author)

  5. Butanol-acetone fermentation. Bibliographic synthesis and current trends

    Energy Technology Data Exchange (ETDEWEB)

    Marchal, R. (Institut Francais du Petrole, Rueil-Malmaison (France))

    This article gives a synthesis of what is known about butyl-acetone fermentation from both the microbiological and technological standpoints. Different aspects of the metabolism of the microorganism used and of how it is regulated are considered. The performances of fermentation on traditional substrates (cornmeal or molasses) are compared with those recently obtained using Jerusalem artichokes at Institut Francais du Petrole as part of a new project on this fermentation for the purpose of producing substitute fuel.

  6. In-cloud multiphase behaviour of acetone in the troposphere: gas uptake, Henry's law equilibrium and aqueous phase photooxidation.

    Science.gov (United States)

    Poulain, Laurent; Katrib, Yasmine; Isikli, Estelle; Liu, Yao; Wortham, Henri; Mirabel, Philippe; Le Calvé, Stéphane; Monod, Anne

    2010-09-01

    Acetone is ubiquitous in the troposphere. Several papers have focused in the past on its gas phase reactivity and its impact on tropospheric chemistry. However, acetone is also present in atmospheric water droplets where its behaviour is still relatively unknown. In this work, we present its gas/aqueous phase transfer and its aqueous phase photooxidation. The uptake coefficient of acetone on water droplets was measured between 268 and 281K (γ=0.7 x 10(-2)-1.4 x 10(-2)), using the droplet train technique coupled to a mass spectrometer. The mass accommodation coefficient α (derived from γ) was found in the range (1.0-3.0±0.25) x 10(-2). Henry's law constant of acetone was directly measured between 283 and 298K using a dynamic equilibrium system (H((298K))=(29±5)Matm(-1)), with the Van't Hoff expression lnH(T)=(5100±1100)/T-(13.4±3.9). A recommended value of H was suggested according to comparison with literature. The OH-oxidation of acetone in the aqueous phase was carried out at 298K, under two different pH conditions: at pH=2, and under unbuffered conditions. In both cases, the formation of methylglyoxal, formaldehyde, hydroxyacetone, acetic acid/acetate and formic acid/formate was observed. The formation of small amounts of four hydroperoxides was also detected, and one of them was identified as peroxyacetic acid. A drastic effect of pH was observed on the yields of formaldehyde, one hydroperoxide, and, (to a lesser extent) acetic acid/acetate. Based on the experimental observations, a chemical mechanism of OH-oxidation of acetone in the aqueous phase was proposed and discussed. Atmospheric implications of these findings were finally discussed. Copyright © 2010 Elsevier Ltd. All rights reserved.

  7. Flotation separation of hafnium(IV) from aqueous solutions

    Energy Technology Data Exchange (ETDEWEB)

    Downey, D.M.; Narick, C.N.; Cohen, T.A.

    1985-09-01

    A simple, rapid method for the separation of hafnium from aqueous solutions was investigated using sup(175 + 181)Hf tracer. Cationic hafnium complex ions were floated from dilute acid solutions with sodium lauryl sulfate (SLS) and anionic hafnium complexes were floated from basic and oxalic acid solutions with hexadecyltrimethyl ammonium bromide (HTMAB). The conditions necessary for quantitative recovery of the metal and mechanisms of flotation are described. (author). 21 refs.; 5 figs.

  8. Comparison of 14 MeV isomer production of 178m2Hf and 179m2Hf using Feshbach-Kerman-Koonin and exciton preequilibrium models

    International Nuclear Information System (INIS)

    Chadwick, M.B.; Young, P.G.

    1993-01-01

    The 178m2 Hf(16+) isomeric state has a 31-yr half life and could pose serious radioactive problems in nuclear fusion reactors if its production in 14 MeV neutron-induced reactions is significant. We present statistical/preequilibrium model calculations for the production of this isomer in the 179 Hf(n, 2n) 178m2 Hf reaction, as well as the 25-days 12.5 - isomer in the 179 Hf(n,n') 179m2 Hf reaction, using two different preequilibrium models: the exciton model and the Feshbach-Kerman-Koonin (FKK) theory. Our calculations which use the exciton model agree well with measurements, but those with the FKK theory underestimate measurements. Our calculations axe the first to probe angular momentum transfer effects in the FKK theory and suggest that, as it is presently applied, high spin-transfer reactions are underestimated. We suggest modifications to the FKK statistical averaging procedure which may result in an improved agreement with experiment

  9. Electrochemical investigation of the surface energy: Effect of the HF concentration on electroless silver deposition onto p-Si (1 1 1)

    International Nuclear Information System (INIS)

    Ye Weichun; Chang Yanlong; Ma Chuanli; Jia Bingyu; Cao Guiyan; Wang Chunming

    2007-01-01

    Electroless silver deposition onto p-silicon (1 1 1) from 0.005 mol l -1 AgNO 3 solutions with different HF concentration was investigated by using an electrochemical direct current polarization method and open circuit potential-time (Ocp-t) technique. The fact that three-dimensional (3D) growth of silver onto silicon is favored with increasing the HF concentration was ascribed to the drop of the surface energy and approved by electrochemical direct current polarization, Ocp-t technique and atomic force microscopy (AFM). The drop slope of open-circuit potential, K -ΔE(OCP)/t , was educed from the mixed-potential theory. K -ΔE(OCP)/t as well as the deposition rate determined by an inductively coupled plasma atomic emission spectrometry (ICP-AES), increased with the HF concentration, yet was not a linear function. Results were explained by the stress generation and relaxation mechanisms

  10. Temperature Programmed Desorption of Quench-condensed Krypton and Acetone in Air; Selective Concentration of Ultra-trace Gas Components.

    Science.gov (United States)

    Suzuki, Taku T; Sakaguchi, Isao

    2016-01-01

    Selective concentration of ultra-trace components in air-like gases has an important application in analyzing volatile organic compounds in the gas. In the present study, we examined quench-condensation of the sample gas on a ZnO substrate below 50 K followed by temperature programmed desorption (TPD) (low temperature TPD) as a selective gas concentration technique. We studied two specific gases in the normal air; krypton as an inert gas and acetone as a reactive gas. We evaluated the relationship between the operating condition of low temperature TPD and the lowest detection limit. In the case of krypton, we observed the selective concentration by exposing at 6 K followed by thermal desorption at about 60 K. On the other hand, no selectivity appeared for acetone although trace acetone was successfully concentrated. This is likely due to the solvent effect by a major component in the air, which is suggested to be water. We suggest that pre-condensation to remove the water component may improve the selectivity in the trace acetone analysis by low temperature TPD.

  11. Effects of acetone-soaking treatment on the performance of polymer solar cells based on P3HT/PCBM bulk heterojunction

    International Nuclear Information System (INIS)

    Liu Yu-Xuan; Lü Long-Feng; Ning Yu; Lu Yun-Zhang; Lu Qi-Peng; Zhang Chun-Mei; Fang Yi; Hu Yu-Feng; Lou Zhi-Dong; Teng Feng; Hou Yan-Bing; Tang Ai-Wei

    2014-01-01

    The improvement of the acetone-soaking treatment to the performance of polymer solar cells based on the P3HT/PCBM bulk heterojunction is reported. Undergoing acetone-soaking, the PCBM does not distribute uniformly in the vertical direction, a PCBM enrichment layer forms on the top of the active layer, which is beneficial to the collection of the carriers and blocking the inverting diffusion carriers. X-ray photoelectron spectroscopy (XPS) analysis reveals that the PCBM weight ratio on the top of the active layer increases by 20% after the acetone-soaking treatment. Due to the nonuniform distribution of PCBM, the short-circuit current density, the open-circuit voltage, and the fill factor are enhanced significantly. Finally, the power conversion efficiency of the acetone-soaking device increases by 31% compared with the control device. (interdisciplinary physics and related areas of science and technology)

  12. KINETIC STUDY OF SELECTIVE GAS-PHASE OXIDATION OF ISOPROPANOL TO ACETONE USING MONOCLINIC ZRO2 AS A CATALYST

    Directory of Open Access Journals (Sweden)

    Mohammad Sadiq

    2015-08-01

    Full Text Available Zirconia was prepared by a precipitation method and calcined at 723 K, 1023 K, and 1253 K in order to obtain monoclinic zirconia. The prepared zirconia was characterized by XRD, SEM, EDX, surface area and pore size analyzer, and particle size analyzer. Monoclinic ZrO2 as a catalyst was used for the gas-phase oxidation of isopropanol to acetone in a Pyrex-glass-flow-type reactor with a temperature range of 443 K - 473 K. It was found that monoclinic ZrO2 shows remarkable catalytic activity (68% and selectivity (100% for the oxidation of isopropanol to acetone. This kinetic study reveals that the oxidation of isopropanol to acetone follows the L-H mechanism.

  13. Fermentation of molasses-flour mashes by acetone-butanol bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Chekasina, E V

    1962-01-01

    With Clostridium acetobutylicum used in a continuous fermentation, where the mash passes through 5 to 12 fermenters, sufficient conversion of starch to mono- and disaccharides will occur; the number of fermenters were chosen and mash changed so that fresh mash remains for 34 hours in the cycle. After a 29 hour fermentation average yields were: acetone 4.5, ethanol 3.0, butanol 7.5%.

  14. Heavy ion studies with CMS HF calorimeter

    International Nuclear Information System (INIS)

    Damgov, I.; Genchev, V.; Kolosov, V.A.; Lokhtin, I.P.; Petrushanko, S.V.; Sarycheva, L.I.; Teplov, S.Yu.; Shmatov, S.V.; Zarubin, P.I.

    2001-01-01

    The capability of the very forward (HF) calorimeter of the CMS detector at LHC to be applied to specific studies with heavy ion beams is discussed. The simulated responses of the HF calorimeter to nucleus-nucleus collisions are used for the analysis of different problems: reconstruction of the total energy flow in the forward rapidity region, accuracy of determination of the impact parameter of collision, study of fluctuations of the hadronic-to-electromagnetic energy ratio, fast inelastic event selection

  15. Hf{sub 3}Fe{sub 4}Sn{sub 4} and Hf{sub 9}Fe{sub 4−x}Sn{sub 10+x}: Two stannide intermetallics with low-dimensional iron sublattices

    Energy Technology Data Exchange (ETDEWEB)

    Calta, Nicholas P. [Department of Chemistry, Northwestern University (United States); Kanatzidis, Mercouri G., E-mail: m-kanatzidis@northwestern.edu [Department of Chemistry, Northwestern University (United States); Materials Science Division, Argonne National Laboratory (United States)

    2016-04-15

    This article reports two new Hf-rich intermetallics synthesized using Sn flux: Hf{sub 3}Fe{sub 4}Sn{sub 4} and Hf{sub 9}Fe{sub 4−x}Sn{sub 10+x}. Hf{sub 3}Fe{sub 4}Sn{sub 4} adopts an ordered variant the Hf{sub 3}Cu{sub 8} structure type in orthorhombic space group Pnma with unit cell edges of a=8.1143(5) Å, b=8.8466(5) Å, and c=10.6069(6) Å. Hf{sub 9}Fe{sub 4−x}Sn{sub 10+x}, on the other hand, adopts a new structure type in Cmc2{sub 1} with unit cell edges of a=5.6458(3) Å, b=35.796(2) Å, and c=8.88725(9) Å for x=0. It exhibits a small amount of phase width in which Sn substitutes on one of the Fe sites. Both structures are fully three-dimensional and are characterized by pseudo one- and two-dimensional networks of Fe–Fe homoatomic bonding. Hf{sub 9}Fe{sub 4−x}Sn{sub 10+x} exhibits antiferromagnetic order at T{sub N}=46(2) K and its electrical transport behavior indicates that it is a normal metal with phonon-dictated resistivity. Hf{sub 3}Fe{sub 4}Sn{sub 4} is also an antiferromagnet with a rather high ordering temperature of T{sub N}=373(5) K. Single crystal resistivity measurements indicate that Hf{sub 3}Fe{sub 4}Sn{sub 4} behaves as a Fermi liquid at low temperatures, indicating strong electron correlation. - Graphical abstract: Slightly different growth conditions in Sn flux produce two new intermetallic compounds: Hf{sub 3}Fe{sub 4}Sn{sub 4} and Hf{sub 9}Fe{sub 4−x}Sn{sub 10+x}. - Highlights: • Single crystals of both Hf{sub 3}Fe{sub 4}Sn{sub 4} and Hf{sub 9}Fe{sub 4−x}Sn{sub 10+x} were grown using Sn flux. • The crystal structures were determined using single crystal X-ray diffraction. • The Fe moments in Hf{sub 3}Fe{sub 4}Sn{sub 4} display AFM order below T{sub N}=373 K. • The Fe moments in Hf{sub 9}Fe{sub 4−x}Sn{sub 10+x} display AFM order below T{sub N}=46 K.

  16. Comparison of HF radar measurements with Eulerian and Lagrangian surface currents

    Science.gov (United States)

    Röhrs, Johannes; Sperrevik, Ann Kristin; Christensen, Kai Håkon; Broström, Göran; Breivik, Øyvind

    2015-05-01

    High-frequency (HF) radar-derived ocean currents are compared with in situ measurements to conclude if the radar observations include effects of surface waves that are of second order in the wave amplitude. Eulerian current measurements from a high-resolution acoustic Doppler current profiler and Lagrangian measurements from surface drifters are used as references. Directional wave spectra are obtained from a combination of pressure sensor data and a wave model. Our analysis shows that the wave-induced Stokes drift is not included in the HF radar-derived currents, that is, HF radars measure the Eulerian current. A disputed nonlinear correction to the phase velocity of surface gravity waves, which may affect HF radar signals, has a magnitude of about half the Stokes drift at the surface. In our case, this contribution by nonlinear dispersion would be smaller than the accuracy of the HF radar currents, hence no conclusion can be made. Finally, the analysis confirms that the HF radar data represent an exponentially weighted vertical average where the decay scale is proportional to the wavelength of the transmitted signal.

  17. Nanotube formation and morphology change of Ti alloys containing Hf for dental materials use

    International Nuclear Information System (INIS)

    Jeong, Yong-Hoon; Lee, Kang; Choe, Han-Cheol; Ko, Yeong-Mu; Brantley, William A.

    2009-01-01

    In this paper, Ti-Hf (10, 20, 30 and 40 wt.%) alloys were prepared by arc melting, and subjected to heat treatment for 24 h at 1000 o C in an argon atmosphere. Formation of surface nanotubes was achieved by anodizing a Ti-Hf alloy in 1.0 M H 3 PO 4 electrolytes with small amounts of NaF at room temperature. Microstructures of the alloys and nanotube morphology were examined by field-emission scanning electron microscopy (FE-SEM) and X-ray diffraction (XRD). The homogenized Ti-Hf alloys had a needle-like microstructure of α phase, and nanotubes formed on Ti-xHf alloys had the anatase phase after treatment that promoted crystallization. Uniform nanotubes formed for Hf contents up to 20 wt.%. Irregular nanotubes formed on the Ti-30Hf and Ti-40Hf alloys. The structure of the irregular layers on the Ti-30Hf and Ti-40Hf alloys had nanotubes of two sizes. Increasing the Hf content in Ti led to the formation of nanotubes with more narrow size. The pores in the nanotubes typically had a diameter ranging from 80-120 nm and a length of approximately 1.7 μm. It is concluded that nanotube morphology on Ti-Hf alloys can controlled by varying the amount of Hf.

  18. Analysis of the origin and importance of acetone and isopropanol levels in the blood of the deceased for medico-legal testimony.

    Science.gov (United States)

    Borowska-Solonynko, A; Siwińska-Ziółkowska, A; Piotrkowicz, M; Wysmołek, M; Demkow, M

    2014-01-01

    The aim of the study was to analyze the incidence of acetone and isopropanol in the blood of the deceased, and to assess cases in which the compounds have been detected with a focus on their origin and usefulness for medico-legal testimony. The study material consisted of results of tests detecting ethyl alcohol and reports of autopsies performed at the Department of Forensic Medicine, Medical University of Warsaw, from January 2008 to April 2009 - a total of 2,475 cases. The test group proper (group B) comprised only those cases in which acetone was detected in blood, either with or without isopropanol [n = 202 (8.2%)]. The blood levels of isopropanol varied depending on the cause of death. The need for differentiating the origin of isopropanol in the case of its presence in the blood of the deceased was pointed out. The results of the present study show that the differentiation should be based on the isopropanol and acetone concentration ratio, as isopropanol concentration alone is not sufficient for preparing expert opinions. Even high concentrations of isopropanol, when accompanied by even higher concentrations of acetone, imply that isopropanol could have been formed as a result of acetone transformations. Isopropanol concentrations exceeding acetone levels strongly point to the exogenous origin of isopropanol, particularly when high levels of ethanol are concurrently detected.

  19. Behaviour of potassium hexabromoruthenate (4) in solutions

    International Nuclear Information System (INIS)

    Rudnitskaya, O.V.; Miroshnichenko, I.V.; Pichkov, V.N.

    1989-01-01

    Behaviour of potassium hexabromoruthenate in HBr, H 2 O-acetone, dimethylformamide, dimetnylsulfoxide (DMSO) solutions is investigated by means of absorption and ESR specroscopy. Complex is shown to be labile, interacts easily with solvents forming ruthenium complexes in more low oxidation degrees. Hexabromoruthenate-ion is formed in concentrated HBr, while in DMSO the formation of ruthenium (3) and (2) bromide-dimethylsulfoxide complexes occurs gradually, final product is trans-[Ru(DMSO) 4 Br 2

  20. Oxidation behavior of TiC, ZrC, and HfC dispersed in oxide matrices

    International Nuclear Information System (INIS)

    Arun, R.; Subramanian, M.; Mehrotra, G.M.

    1990-01-01

    The oxidation behavior of hot pressed TiC-Al 2 O 3 , TiC-ZrO 2 , ZrC-ZrO 2 , and HfC-HfO 2 composites has been investigated at 1273 K. The oxidation of TiC, ZrC, and HfC in hot-pressed composites containing ZrO 2 and HfO 2 has been found to be extremely rapid. The kinetics of oxidation of TiC and a 90 wt% TiC-Al 2 O 3 composite appear to be faster compared to that of pure TiC. X-ray diffraction results for hot-pressed ZrC-HfO 2 and HfC-HfO 2 composites indicate partial stabilization of tetragonal ZrO 2 and HfO 2 phases in these composites

  1. Uranyl fluoride luminescence in acidic aqueous solutions

    International Nuclear Information System (INIS)

    Beitz, J.V.; Williams, C.W.

    1996-01-01

    Luminescence emission spectra and decay rates are reported for uranyl species in acidic aqueous solutions containing HF or added NaF. The longest luminescence lifetime, 0.269 ± 0.006 ms, was observed from uranyl in 1 M HF + 1 M HClO 4 at 296 K and decreased with increasing temperature. Based on a luminescence dynamics model that assumes equilibrium among electronically excited uranyl fluoride species and free fluoride ion, this long lived uranyl luminescence in aqueous solution is attributed primarily to UO 2 F 2 . Studies on the effect of added LiNO 3 or Na 2 WO 4 ·2H 2 O showed relatively weak quenching of uranyl fluoride luminescence which suggests that high sensitivity determination of the UF 6 content of WF 6 gas should be feasible via uranyl luminescence analysis of hydrolyzed gas samples of impure WF 6

  2. [Effect of a multifunctional instrument (HF scissors) in parotis surgery].

    Science.gov (United States)

    Strauss, G; Schaller, S; Gollnick, I

    2014-03-01

    Lateral parotidectomy is a demanding surgical procedure and requires a large number of instruments with a high frequency (HF) of alternating. Many functions, such as preparing, spreading, coagulating and cutting could be combined by using scissors with an integrated function of bipolar coagulation. This study has targeted an investigation of technical application, influence on surgery time, frequency of HF application and change of instruments. In the period between 01 April 2011 and 30 September 2012 (18 months) 35 procedures of lateral parotidectomy in 35 patients were investigated. In all cases lateral parotidectomy was carried out with a similar technique (modified extracapsular preparation). Workflow data were used from a control group in the period between 01 January 2009 and 31 December 2010 (24 months). The following parameters from both groups were documented and evaluated: incision-suture times (subdivided into nine sections of the procedure), change of instruments, period of application for HF function and early facial nerve function (6 h and 6 days after surgery according to House-Brackmann). Additionally, in the HF+ group a questionnaire that facilitated subjective evaluation of instruments was analyzed. It was possible to perform the surgery in both groups with neither technical nor surgical intraoperative complications. Incision-suture times showed an average reduction of 31.6 min (34.8 %) in the HF+ group. There was a reduction in the change of instruments compared to a conventional group (CONV) by up to 62.7 %. With the deployment of HF scissors there was a clear increase in the use of HF surgery by more than 100 % when comparing incision-suture times. Evaluation of both groups according to House-Brackmann showed a similar postoperative facial nerve function. The surgeons involved were of the opinion that in all 35 surgeries with HF scissors the intervention was easier and more comfortable. The use of HF scissors is appropriate for parotid gland

  3. Microhardness variation and related microstructure in Al-Cu alloys prepared by HF induction melting and RF sputtering

    Science.gov (United States)

    Boukhris, N.; Lallouche, S.; Debili, M. Y.; Draissia, M.

    2009-03-01

    The materials under consideration are binary aluminium-copper alloys (10 at% to 90.3 at%Cu) produced by HF melting and RF magnetron sputtering. The resulting micro structures have been observed by standard metallographic techniques, X-ray powder diffraction, scanning electron microscopy and transmission electron microscopy. Vickers microhardness of bulk Al-Cu alloys reaches a maximum of 1800 MPa at 70.16 at%Cu. An unexpected metastable θ ' phase has been observed within aluminium grain in Al-37 at%Cu. The mechanical properties of a family of homogeneous Al{1-x}Cu{x} (0 Al-Cu targets have been investigated. The as-deposited microstructures for all film compositions consisted of a mixture of the two expected face-centred-cubic (fcc) Al solid solution and tetragonal θ (Al{2}Cu) phases. The microhardness regularly increases and the grain size decreases both with copper concentration. This phenomenon of significant mechanical strengthening of aluminium by means of copper is essentially due to a combination between solid solution effects and grain size refinement. This paper reports some structural features of different Al-Cu alloys prepared by HF melting and RF magnetron on glass substrate sputtering.

  4. Methanogenic degradation of acetone by an enrichment culture

    OpenAIRE

    Platen, Harald; Schink, Bernhard

    1987-01-01

    An anaerobic enrichment culture degraded 1 mol of acetone to 2 tool of methane and 1 tool of carbon dioxide. Two microorganisms were involved in this process, a filament-forming rod similar to Methanothrix sp. and an unknown rod with round to slightly pointed ends. Both organisms formed aggregates up to 300 gm in diameter. No fluorescing bacteria were observed indicating that hydrogen or formate-utilizing methanogens are not involved in this process. Acetate was utilized in this culture by th...

  5. Cross-Selectivity Enhancement of Poly(vinylidene fluoride-hexafluoropropylene-Based Sensor Arrays for Detecting Acetone and Ethanol

    Directory of Open Access Journals (Sweden)

    Ali Daneshkhah

    2017-03-01

    Full Text Available Two methods for cross-selectivity enhancement of porous poly(vinylidene fluoride-hexafluoropropylene (PVDF-HFP/carbon black (CB composite-based resistive sensors are provided. The sensors are tested with acetone and ethanol in the presence of humid air. Cross-selectivity is enhanced using two different methods to modify the basic response of the PVDF-HFP/CB sensing platform. In method I, the adsorption properties of PVDF-HFP/CB are altered by adding a polyethylene oxide (PEO layer or by treating with infrared (IR. In method II, the effects of the interaction of acetone and ethanol are enhanced by adding diethylene carbonate (DEC or PEO dispersed in DEC (PEO/DEC to the film. The results suggest the approaches used in method I alter the composite ability to adsorb acetone and ethanol, while in method II, they alter the transduction characteristics of the composite. Using these approaches, sensor relative response to acetone was increased by 89% compared with the PVDF-HFP/CB untreated film, whereas sensor relative response to ethanol could be decreased by 57% or increased by 197%. Not only do these results demonstrate facile methods for increasing sensitivity of PVDF-HFP/CB film, used in parallel they demonstrate a roadmap for enhancing system cross-selectivity that can be applied to separate units on an array. Fabrication methods, experimental procedures and results are presented and discussed.

  6. Acetone in theGlobal Troposphere: Its Possible Role as a Global Source of PAN

    Science.gov (United States)

    Singh, H. B.; Kanakidou, M.

    1994-01-01

    Oxygenated hydrocarbons are thought to be important components of the atmosphere but, with the exception of formaldehyde, very little about their distribution and fate is known. Aircraft measurements of acetone (CH3COCH3), PAN (CH3CO3NO2) and other organic species (e. g. acetaldehyde, methanol and ethanol) have been performed over the Pacific, the southern Atlantic, and the subarctic atmospheres. Sampled areas extended from 0 to 12 km altitude over latitudes of 70 deg N to 40 deg S. All measurements are based on real time in-situ analysis of cryogenically preconcentrated air samples. Substantial concentrations of these oxygenated species (10-2000 ppt) have been observed at all altitudes and geographical locations in the troposphere. Important sources include, emissions from biomass burning, plant and vegetation, secondary oxidation of primary non-methane hydrocarbons, and man-made emissions. Direct measurements within smoke plumes have been used to estimate the biomass burning source. Photochemistry studies are used to suggest that acetone could provide a major source of peroxyacetyl radicals in the atmosphere and play an important role in sequestering reactive nitrogen. Model calculations show that acetone photolysis contributes significantly to PAN formation in the middle and upper troposphere.

  7. Low-Frequency Waves in HF Heating of the Ionosphere

    Science.gov (United States)

    Sharma, A. S.; Eliasson, B.; Milikh, G. M.; Najmi, A.; Papadopoulos, K.; Shao, X.; Vartanyan, A.

    2016-02-01

    Ionospheric heating experiments have enabled an exploration of the ionosphere as a large-scale natural laboratory for the study of many plasma processes. These experiments inject high-frequency (HF) radio waves using high-power transmitters and an array of ground- and space-based diagnostics. This chapter discusses the excitation and propagation of low-frequency waves in HF heating of the ionosphere. The theoretical aspects and the associated models and simulations, and the results from experiments, mostly from the HAARP facility, are presented together to provide a comprehensive interpretation of the relevant plasma processes. The chapter presents the plasma model of the ionosphere for describing the physical processes during HF heating, the numerical code, and the simulations of the excitation of low-frequency waves by HF heating. It then gives the simulations of the high-latitude ionosphere and mid-latitude ionosphere. The chapter also briefly discusses the role of kinetic processes associated with wave generation.

  8. Plutonium determination in solution with excess hydrofluoric acid

    International Nuclear Information System (INIS)

    Krtil, J.; Kuvik, V.; Spevackova, V.

    1975-01-01

    The determination is described of plutonium in solutions in the presence of fluoride ions resulting from the hydrolysis of PuF 6 . The method is based on reduction of Pu(VI) by excess of Fe(II) and on re-titration of Fe(II) with ceric salt. The effect of fluoride ions on plutonium determination was studied. It was found that a 3 mole excess of HF with respect to Pu decreased the results of Pu determination. The interference of fluoride ions was eliminated by a two-fold evaporation of the solution to be titrated with HNO 3 to dryness or by complex formation with boric arid. The amount of 20.50 mg Pu in the presence of a 10 mole excess of fluoride ions (17 mg HF) was determined with an error of +- 0.09 mg ). (author)

  9. Studies on the in vitro time kill assessment of crude acetone and ...

    African Journals Online (AJOL)

    STORAGESEVER

    2008-10-20

    Oct 20, 2008 ... infection even after treating such wounds with H. pedunculatum leaf. Perhaps .... acetone extract was evaporated to dryness under reduced pressure at 40oC ... ml of Mueller Hinton broth and recovery medium containing 3%.

  10. Comparison of formol-acetone concentration method with that of the ...

    African Journals Online (AJOL)

    Bernt Lindtjorn

    which consists of ether as a fat solvent for detecting out parasites from intestinal debris and thus increases the positivity rates, is believed to be superior over the other ... and petrol can be a better substitute (5, 6, 7). However, among these solvents, acetone has been rated as “safe” in comparison to the ether effect on health ...

  11. Evaluation of the Acetone and Aqueous Extracts of Mature Stem Bark of Sclerocarya birrea for Antioxidant and Antimicrobial Properties

    Directory of Open Access Journals (Sweden)

    Nicoline F. Tanih

    2012-01-01

    Full Text Available We assayed the antimicrobial activity of acetone and aqueous extracts of the stem bark of Sclerocarya birrea on some selected bacteria and fungi species including; Streptococcus pyogenes, Plesiomonas shigelloides, Aeromonas hydrophila, Salmonella typhimurium, Cryptococcus neoformans, Candida glabrata, Trichosporon mucoides, and Candida krusei using both agar well diffusion and minimum inhibitory concentration (MIC assays. Based on the levels of activity, the acetone extract was examined for total polyphenolic content, radical scavenging and antioxidant activities. Total phenols of the extract were determined spectrophotometrically. The antioxidant activity was determined by the DPPH, ABTS and reducing power. All the bacteria and fungi species were susceptible to the plant extracts. The acetone extract was the most active for the bacterial species with MIC (0.156–0.625 mg/mL while the aqueous extract was the most active for the fungi species with MIC (0.3125–1.25 mg/mL. The polyphenolic compounds were found as 27.2 mg/g tannic acid equivalent, 25.2 mg/g quercetin equivalent, 9.1 mg/g quercetin equivalent for phenols, flavonoid and flavonols respectively. The acetone extract exhibited a remarkable ability to scavenge radicals, strong reducing ability and a potential source of natural antioxidants. Both the acetone and aqueous extracts of S. birrea may provide a target for drug discovery.

  12. A novel UV-photolysis approach with acetone and isopropyl alcohol for the rapid determination of fluoride in organofluorine-containing drugs by spectrophotometry.

    Science.gov (United States)

    Mullapudi, Venkata Balarama Krishna; Dheram, Karunasagar

    2018-01-01

    A UV photolysis decomposition (UVPD) method for the determination of fluoride in fluorine containing pharmaceuticals by spectrophotometry is reported. It is based on the use of high intensity UV-irradiation in the presence of a digesting solution comprising a mixture of acetone and isopropanol. For the optimization of the UVPD procedure, three bulk drugs (levofloxacin, nebivolol and efavirenz) were chosen as representatives of three diverse compounds containing a single fluorine atom, two fluorine atoms, and trifluoromethyl groups respectively. Operational conditions of the UVPD method, such as concentration and volume of reagents (acetone and isopropyl alcohol), and UV irradiation time (1-6 minutes) were optimized. The efficiency of digestion was evaluated by the determination of fluoride in sample digests. Using the developed method, it was possible for complete conversion of the organofluoride to free fluoride ion for its subsequent determination by spectrophotometry based on bleaching of Zr-xylenol orange-color complex. Quantitative recovery (>98%) of the fluorine in the drug samples could be achieved using a mixture of 2% acetone + 2% isopropyl alcohol + 0.003% Na 2 CO 3 in just 5 minutes of UV irradiation, which can be considered an important aspect considering the difficulties involved in the cleavage of the CF bond. Accuracy was evaluated by comparison of results obtained by the UVPD method with the values estimated using formula weight of the compound and no statistical difference was observed between the results. Therefore, the proposed method is suitable for application in routine analysis of fluoride in organofluorine-containing drugs. Copyright © 2016. Published by Elsevier B.V.

  13. Biological activities of Umbilicaria crustulosa (Ach.) frey acetone extract

    OpenAIRE

    Zlatanović Ivana; Stanković Miroslava; Stankov-Jovanović Vesna; Mitić Violeta; Zrnzević Ivana; Đorđević Aleksandra; Stojanović Gordana

    2017-01-01

    This paper reports for the first time the effect of an acetone extract of Umbilicaria crustulosa on the micronucleus distribution of human lymphocytes, and on the cholinesterase activity and antioxidant activity by the cupric ion reducing antioxidant capacity (CUPRAC) method. Additionally, the total phenolic compounds (TPC) and the antioxidant properties were estimated via DPPH, ABTS and TRP assays. Moreover, the antibacterial activity against two Gram-positive and three Gram-negative bacteri...

  14. Hydrogenation and hydrodeoxygenation of difurfurylidene acetone to liquid alkanes over Raney Ni and the supported Pt catalysts

    International Nuclear Information System (INIS)

    Li, Yuping; Huang, Xiaoming; Zhang, Qian; Chen, Lungang; Zhang, Xinghua; Wang, Tiejun; Ma, Longlong

    2015-01-01

    Highlights: • The C_8−C_1_4 alkane yield of 82.9% was obtained in the two-step hydrogenation/HDO process. • Protonation effect from methanol solvent increased F_2A conversion in the two-step process. • The rate-determining step was acyl C=O bond hydrogenation in the first step of F_2A hydrogenation. • The acidic centers from SiO_2−ZrO_2 activated the acyl and oxygen atoms of intermediates. • Acidity of SiO_2−ZrO_2 and Pt active centers of 1 wt%Pt/SiO_2−ZrO_2 resulted stable HDO performance. - Abstract: Direct HDO process for difurfurylidene acetone dimer (F_2A) conversion to liquid alkanes (C_8−C_1_4) at 260 °C in a batch reactor was investigated over different material supported 1 wt%Pt catalysts, including SAPO-11, HZSM-5, SiO_2−Al_2O_3, MCM-22, and home-made SiO_2−ZrO_2. C_8−C_1_4 alkanes of 55.8% was obtained over the optimized 1 wt%Pt/SiO_2−ZrO_2 due to its proper pore size of 9.0 nm and moderate acidic centers, together with more than 10% carbon yield of the oxygenated hydrocarbons, including C_1_1−C_1_3 chain alcohols & ketones and the hydrogenated F_2A dimers with furan ring (H-F_2A dimers). To improve the liquid alkane yield, a two-step process for F_2A conversion was also investigated, which included low-temperature hydrogenation at 50 °C over Raney Ni catalyst in a batch reactor and the subsequent high-temperature hydrodeoxygenation (HDO) at 280 °C over 1 wt%Pt/SiO_2−ZrO_2 in a fixed-bed reactor. The selectivity of 1,5-di(tetrahydro-2-furanyl)-3-pentanol (II-c) was the highest of 83.0% among the hydrogenated intermediates of H-F_2A dimers due to the protonation effect of methanol as the solvent and the hydrogenation of C=C bonds by Ni active centers. In the same time, the high content of this saturated alcohol H-dimer of II-C increased the solubility and stability of the intermediates in methanol solvent. High carbon yield of C_8−C_1_4 alkanes of 82.9%(mol) was obtained after oxygen atom removal from H-F_2A dimers via

  15. The Effect of Acetone Amount Ratio as Co-Solvent to Methanol in Transesterification Reaction of Waste Cooking Oil

    Science.gov (United States)

    Julianto, T. S.; Nurlestari, R.

    2018-04-01

    The production of biodiesel from waste cooking oil by transesterification reaction using acetone as co-solvent has been carried out. This research studied the optimal amount ratio of acetone as co-solvent to methanol in the transesterification process using homogeneous alkaline catalyst KOH 1% (w/w) of waste cooking oil at room temperature for 15 minutes of reaction time. Mole ratio of waste cooking oil to methanol is 1:12. Acetone was added as co-solvent in varied amount ratio to methanol are 1:4, 1:2, and 1:1, respectively. The results of fatty acid methyl esters (FAME) were analysed using GC-MS instrument. The results showed that the optimal ratio is 1:4 with 99.93% of FAME yield.

  16. Crystal structures of KM(AsF{sub 6}){sub 3} (M{sup 2+} = Mg, Co, Mn, Zn), KCu(SbF{sub 6}){sub 3} and [Co(HF){sub 2}]Sr[Sr(HF)]{sub 2}-[Sr(HF){sub 2}]{sub 2}[AsF{sub 6}]{sub 12}

    Energy Technology Data Exchange (ETDEWEB)

    Mazej, Zoran; Goreshnik, Evgeny [Jozef Stefan Institute, Ljubljana (Slovakia). Dept. of Inorganic Chemisrty and Technology

    2015-05-01

    The KM(AsF{sub 6}){sub 3} (M{sup 2+} = Mg, Co, Mn, Zn) and KCu(SbF{sub 6}){sub 3} compounds crystallize isotypically to previously known KNi(AsF{sub 6}){sub 3}. The main features of the structure of these compounds are rings of MF{sub 6} octahedra sharing apexes with AsF{sub 6} octahedra connected into infinite tri-dimensional frameworks. In this arrangement cavities are formed where K{sup +} cations are placed. Single crystals of CoSr{sub 5}(AsF{sub 6}){sub 12}.8HF were obtained as one of the products after the crystallization of 3KF/CoF{sub 2}/SrF{sub 2} mixture in the presence of AsF{sub 5} in anhydrous HF. The CoSr{sub 5}(AsF{sub 6}){sub 12}.8HF is monoclinic, C/2c (No.15), with a = 26.773(5) Aa, b = 10.087(2) Aa, c = 21.141(5) Aa, β = 93.296(13) {sup circle}, V = 5699.9(19) Aa{sup 3} at 200 K, and Z = 4. There are three crystallographically non-equivalent Sr{sup 2+} cations in the crystal structure of CoSr{sub 5}(AsF{sub 6}){sub 12}.8HF. The Sr1 is coordinated by ten fluorine atoms from eight different [AsF{sub 6}]- anions, meanwhile Sr2 and Sr3 are bound to nine fluorine atoms provided by one HF and eight AsF{sub 6} units or by two HF and six AsF{sub 6} units, respectively. The Co{sup 2+} is coordinated distorted-octahedrally by six fluorine atoms from two HF molecules and four different AsF{sub 6} units. All those moieties in the crystal structure of [Co(HF){sub 2}]Sr[Sr(HF)]{sub 2}[Sr(HF){sub 2}]{sub 2}[AsF{sub 6}]{sub 12} are connected into tridimensional framework. The CoSr{sub 5}(AsF{sub 6}){sub 12}.8HF is a unique example of compound where HF molecules are directly bound via fluorine atoms to two different metal centres.

  17. Structural effect of ferrocenecarboxymethylated polymers on their electrical behavior under the exposure to methanol and acetone vapors

    International Nuclear Information System (INIS)

    Hachawee, Kosin; Lerdwijitjarud, Wanchai; Sittattrakul, Amnard; Sirivat, Anuvat

    2008-01-01

    Functionalized ferrocenecarboxymethylated polymers, i.e. poly(vinylbenzyl ferrocenecarboxymethylate) (PVBFCC), poly(vinylbenzyl ferrocenecarboxymethylate-co-ethoxyethylmethacrylate) with the mole ratio between vinylbenzyl ferrocenecarboxymethylate and ethoxyethylmethacrylate of 75:25 (Co-PVBFCC 75/25) and 50:50 (Co-PVBFCC 50/50), and ferrocenecarboxymethylated polysulfone (BPSFCC) were investigated for their electrical behavior under the vapors of methanol and acetone and nitrogen gas. Electrical conductivity responses of the four ferrocenecarboxymethylated polymers in the presence of lithium perchlorate were measured when they were exposed to nitrogen gas, and methanol and acetone vapors. Main factors that affect the electrical conductivity and sensitivity of these electroactive ferrocene polymers originate from the polymer structure and the type of the passing gas or vapor. Ferrocenecarboxymethylated polymers with higher degrees of substitution of ferrocene units possess good electrical conductivity under the atmosphere of mixed N 2 /methanol vapor, while ferrocenecarboxymethylated polymers with more flexible chain and/or larger free volumes give higher electrical conductivity under the atmosphere of mixed N 2 /acetone vapor. The gas or vapor molecule with higher polarity and smaller size enhances the electrical conductivity of the ferrocene polymers. Our results clearly indicate that the synthesized ferrocenecarboxymethylated polymers have potential to be used as methanol or acetone sensor materials

  18. Study of bulk Hafnium oxide (HfO2) under compression

    Science.gov (United States)

    Pathak, Santanu; Mandal, Guruprasad; Das, Parnika

    2018-04-01

    Hafnium oxide (HfO2) is a technologically important material. This material has K-value of 25 and band gap 5.8 eV. A k value of 25-30 is preferred for a gate dielectric [1]. As it shows good insulating and capacitive properties, HfO2 is being considered as a replacement to SiO2 in microelectronic devices as gate dielectrics. On the other hand because of toughening mechanism due to phase transformation induced by stress field observed in these oxides, HFO2 has been a material of investigations in various configurations for a very long time. However the controversies about phase transition of HfO2 under pressure still exists. High quality synchrotron radiation has been used to study the structural phase transition of HfO2 under pressure.

  19. Trapping proton transfer intermediates in the disordered hydrogen-bonded network of cryogenic hydrofluoric acid solutions.

    Science.gov (United States)

    Ayotte, Patrick; Plessis, Sylvain; Marchand, Patrick

    2008-08-28

    A molecular-level description of the structural and dynamical aspects that are responsible for the weak acid behaviour of dilute hydrofluoric acid solutions and their unusual increased acidity at near equimolar concentrations continues to elude us. We address this problem by reporting reflection-absorption infrared spectra (RAIRS) of cryogenic HF-H(2)O binary mixtures at various compositions prepared as nanoscopic films using molecular beam techniques. Optical constants for these cryogenic solutions [n(omega) and k(omega)] are obtained by iteratively solving Fresnel equations for stratified media. Modeling of the experimental RAIRS spectra allow for a quantitative interpretation of the complex interplay between multiple reflections, optical interference and absorption effects. The evolution of the strong absorption features in the intermediate 1000-3000 cm(-1) range with increasing HF concentration reveals the presence of various ionic dissociation intermediates that are trapped in the disordered H-bonded network of cryogenic hydrofluoric acid solutions. Our findings are discussed in light of the conventional interpretation of why hydrofluoric acid is a weak acid revealing molecular-level details of the mechanism for HF ionization that may be relevant to analogous elementary processes involved in the ionization of weak acids in aqueous solutions.

  20. Small signal gain measurements in a small scale HF overtone laser

    Energy Technology Data Exchange (ETDEWEB)

    Wisniewski, C.F.; Hewett, K.B.; Manke, G.C. II; Hager, G.D. [Air Force Research Laboratory, Directed Energy Directorate, 3550 Aberdeen Ave SE, Kirtland AFB, NM 87117-5776 (United States); Crowell, P.G. [Northrup Grumman Information Technology, Science and Technology Operating Unit, Advanced Technology Division, P.O. Box 9377, Albuquerque, NM 87119-9377 (United States); Truman, C.R. [Mechanical Engineering Department, University of New Mexico, Albuquerque, NM 87131 (United States)

    2003-07-01

    The overtone gain medium of a small-scale HF overtone laser was probed using a sub-Doppler tunable diode laser. Two-dimensional spatially resolved small signal gain and temperature maps were generated for several ro-vibrational transitions in the HF (v=2{yields}v=0) overtone band. Our results compare well with previous measurements of the overtone gain in a similar HF laser device. (orig.)

  1. Activation parameters and excess thermodyanamic functions of hydroxamic acids in acetone-water mixture at 303.15 K and 313.15 K: A viscometric approach

    Directory of Open Access Journals (Sweden)

    Ajita Dixit

    2007-04-01

    Full Text Available Experimental values of density and viscosity of N-arylsubstituted hydroxamic acids were evaluated at T = 303.15 K and 313.15 K in acetone-water mixture as a function of their concentration. The properties of solutes were obtained as an intercept of plots C vs η of solutions. Applying these data, viscosity-B-coefficients, activation parameters (Δμ10≠ and (Δμ20≠ and excess thermodynamic functions, viz., excess molar volume (VE, excess viscosity, ηE and excess molar free energy of activation of flow, (GE were calculated. The value of interaction parameter, d, of Grunberg and Nissan expression have also been calculated and reported. Analysis of these data suggests that specific interactions are present in the system.

  2. Integrated magnetics design for HF-link power converters

    Energy Technology Data Exchange (ETDEWEB)

    Ljusev, P.; Andersen, Michael A.E.

    2005-07-01

    This paper deals with the design of integrated magnetics for HF-link converters, where the two integrated magnetic components on the same core do not necessarily belong to the same voltage loop. Depending on the specific HF-link converter topology, the proposed integrated magnetics can either alleviate the derivation of independent auxiliary supply voltages from the main transformer or integrate other magnetic structures, thus saving board space and cutting costs. (au)

  3. Effect of Gold Dispersion on the Photocatalytic Activity of Mesoporous Titania for the Vapor-Phase Oxidation of Acetone

    Directory of Open Access Journals (Sweden)

    S. V. Awate

    2008-01-01

    Full Text Available Mesostructured titanium dioxide photocatalyst, having uniform crystallite size (6–12 nm and average pore diameter of ∼4.2 nm, was synthesized by using a low-temperature nonsurfactant hydrothermal route, employing tartaric acid as a templating agent. Gold additions from 0.5 to 2 wt% were incorporated, either during the hydrothermal process or by postsynthesis wet impregnation. Compared to the impregnation-prepared samples, the samples synthesized hydrothermally contained smaller-size (≤1 nm gold clusters occluded in the pores of the host matrix. Whereas CO2 and H2O were the main reaction products in UV-assisted vapor-phase oxidation of acetone using these catalysts, C2H6 and HCO2CH3 were also produced for higher acetone concentrations in air. The conversion of acetone was found to increase with decrease in the size of both TiO2 and gold particles. In situ IR spectroscopy revealed that titania and gold particles serve as independent adsorption and reaction sites for acetone and oxygen molecules. Acetone molecules adsorb exclusively at TiO2 surface, giving rise to a strongly adsorbed (condensed state as well as to the formation of formate- and methyl formate-type surface species. Hydroxyl groups at titania surface participate directly in these adsorption steps. Nanosize gold particles, on the other hand, were primarily responsible for the adsorption and activation of oxygen molecules. Mechanistic aspects of the photochemical processes are discussed on the basis of these observations.

  4. Comparison of voiding function and nociceptive behavior in two rat models of cystitis induced by cyclophosphamide or acetone

    Science.gov (United States)

    Saitoh, Chikashi; Yokoyama, Hitoshi; Chancellor, Michael B.; de Groat, William C.; Yoshimura, Naoki

    2009-01-01

    Aims Nociceptive behavior and its relationship with bladder dysfunction were investigated in two cystitis models, which were induced by intraperitoneal (ip) injection of cyclophosphamide (CYP) or intravesical instillation of acetone, using freely moving, non-catheterized conscious rats. Methods Female Sprague-Dawley rats were used. Cystitis was induced by ip injection of CYP (100 and 200mg/kg) or intravesical instillation of acetone (10, 30 and 50%) via a polyethylene catheter temporarily inserted into the bladder through the urethra. Then the incidence of nociceptive behavior (immobility with decreased breathing rates) was scored. Voided urine was collected simultaneously and continuously to measure bladder capacity. The plasma extravasation in the bladder was quantified by an evans blue (EB) dye leakage technique. Results CYP (100mg/kg, ip) induced nociceptive behavior without affecting bladder capacity or EB concentration in the bladder. A higher dose of CYP (200mg/kg, ip) decreased bladder capacity and increased EB levels as well as nociceptive behavior. In contrast, intravesical instillation of acetone (30%) decreased bladder capacity and increased EB levels, but evoked nociceptive behavior less frequently compared with CYP-treated animals. In capsaicin pretreated rats, nociceptive behavior induced by CYP or acetone was reduced; however, the overall effects of CYP or acetone on bladder capacity and bladder EB levels were unaffected. Conclusions These results suggest that there is a difference in the induction process of nociceptive behavior and small bladder capacity after two different types of bladder irritation and that C-fiber sensitization is more directly involved in pain sensation than reduced bladder capacity. PMID:19618450

  5. Comparative studies of citric acid, acetone-butanol, and alcohol fermentation processes in beet molasses from several sugar factories

    Energy Technology Data Exchange (ETDEWEB)

    Kovats, J; Zuckerind, Z

    1963-01-01

    Citric acid (I) fermentation is the most sensitive to volatile acids and coloring matter contents of molasses, and butanol fermentation, the least. Citric acid and alcohol production decrease as volatile acids and coloring matter increase, but this last factor has a favorable effect on the acetone-butanol fermentation. Molasses which are suitable for citric acid production are also suitable for alcohol but not always for acetone-butanol.

  6. Enhanced acetone-butanol-ethanol production from lignocellulosic hydrolysates by using starchy slurry as supplement.

    Science.gov (United States)

    Yang, Ming; Kuittinen, Suvi; Vepsäläinen, Jouko; Zhang, Junhua; Pappinen, Ari

    2017-11-01

    This study aims to improve acetone-butanol-ethanol production from the hydrolysates of lignocellulosic material by supplementing starchy slurry as nutrients. In the fermentations of glucose, xylose and the hydrolysates of Salix schwerinii, the normal supplements such as buffer, minerals, and vitamins solutions were replaced with the barley starchy slurry. The ABE production was increased from 0.86 to 14.7g/L by supplementation of starchy slurry in the fermentation of xylose and the utilization of xylose increased from 29% to 81%. In the fermentations of hemicellulosic and enzymatic hydrolysates from S. schwerinii, the ABE yields were increased from 0 and 0.26 to 0.35 and 0.33g/g sugars, respectively. The results suggested that the starchy slurry supplied the essential nutrients for ABE fermentation. The starchy slurry as supplement could improve the ABE production from both hemicellulosic and cellulosic hydrolysate of lignocelluloses, and it is particularly helpful for enhancing the utilization of xylose from hemicelluloses. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. The human gastric pathogen Helicobacter pylori has a potential acetone carboxylase that enhances its ability to colonize mice

    Directory of Open Access Journals (Sweden)

    Weinberg Michael V

    2008-01-01

    Full Text Available Abstract Background Helicobacter pylori colonizes the human stomach and is the etiological agent of peptic ulcer disease. All three H. pylori strains that have been sequenced to date contain a potential operon whose products share homology with the subunits of acetone carboxylase (encoded by acxABC from Xanthobacter autotrophicus strain Py2 and Rhodobacter capsulatus strain B10. Acetone carboxylase catalyzes the conversion of acetone to acetoacetate. Genes upstream of the putative acxABC operon encode enzymes that convert acetoacetate to acetoacetyl-CoA, which is metabolized further to generate two molecules of acetyl-CoA. Results To determine if the H. pylori acxABC operon has a role in host colonization the acxB homolog in the mouse-adapted H. pylori SS1 strain was inactivated with a chloramphenicol-resistance (cat cassette. In mouse colonization studies the numbers of H. pylori recovered from mice inoculated with the acxB:cat mutant were generally one to two orders of magnitude lower than those recovered from mice inoculated with the parental strain. A statistical analysis of the data using a Wilcoxin Rank test indicated the differences in the numbers of H. pylori isolated from mice inoculated with the two strains were significant at the 99% confidence level. Levels of acetone associated with gastric tissue removed from uninfected mice were measured and found to range from 10–110 μmols per gram wet weight tissue. Conclusion The colonization defect of the acxB:cat mutant suggests a role for the acxABC operon in survival of the bacterium in the stomach. Products of the H. pylori acxABC operon may function primarily in acetone utilization or may catalyze a related reaction that is important for survival or growth in the host. H. pylori encounters significant levels of acetone in the stomach which it could use as a potential electron donor for microaerobic respiration.

  8. Cathodic reduction of benzil in acetone and in dichloromethane

    Energy Technology Data Exchange (ETDEWEB)

    Quintanilla, Gloria [Departamento de Quimica Organica, Universidad de Alcala, 28871 Alcala de Henares, Madrid (Spain)], E-mail: gloria.quintanilla@uah.es; Liebeck, Miriam; Bengtsson, Carina; Arnold, Lena; Barba, Fructuoso [Departamento de Quimica Organica, Universidad de Alcala, 28871 Alcala de Henares, Madrid (Spain)

    2008-02-15

    The cathodic reduction of benzil has been carried out at a controlled potential on a mercury cathode in two different SSE (solvent-supporting-electrolyte) conditions: (a) acetone/lithium perchlorate in absence of electrophile where 2,3-diphenyl-5-methyl-furan and 1,2-diphenyl-2-hydroxy-1,4-pentanedione were obtained as main products and (b) dichloromethane/tetrabuthylammonium chloride with the addition of oxalyl chloride as electrophile, where a fast electron transfer took place.

  9. Synthesis and Conformational Assignment of N-(E-Stilbenyloxymethylenecarbonyl-Substituted Hydrazones of Acetone and o-(m- and p- Chloro- (nitro- benzaldehydes by Means of and NMR Spectroscopy

    Directory of Open Access Journals (Sweden)

    Przemysław Patorski

    2013-01-01

    Full Text Available Eighteen new N-(E-stilbenyloxyalkylcarbonyl-substituted hydrazones of ortho- (meta- and para- chloro- (nitro- benzaldehydes 1–18 and two analogous hydrazones of acetone 19-20 were prepared. The stereochemical behavior of 1–18 in dimethyl-d6 sulfoxide solution has been studied by NMR and NMR techniques, using spectral data of 19 and 20 as supporting material. The E-geometrical isomers and cis-/trans-amide conformers have been found for these hydrazones. Energy barriers of isomers are reported.

  10. Fretting wear of ZrN and Zr(21% Hf)N coatings

    Energy Technology Data Exchange (ETDEWEB)

    Atar, E. [Gebze Inst. of Tech., Material Science and Engineering Dept., Kocaeli (Turkey); Cimenoglu, H.; Kayali, E.S. [Istanbul Technical Univ., Dept. of Metallurgy and Materials Engineering, Istanbul (Turkey)

    2004-07-01

    In this study, the wear behaviours of ZrN and Zr(21% Hf)N coatings, deposited on hardened AISI D2 cold work tool steel were examined by a fretting wear tester. The hardness of ZrN and Zr(21% Hf)N coatings were almost the same, where as they exhibited different wear resistance. Addition of 21% Hf to ZrN coating achieved about 25% increase in the wear resistance. (orig.)

  11. Fretting wear of ZrN and Zr(21% Hf)N coatings

    International Nuclear Information System (INIS)

    Atar, E.; Cimenoglu, H.; Kayali, E.S.

    2004-01-01

    In this study, the wear behaviours of ZrN and Zr(21% Hf)N coatings, deposited on hardened AISI D2 cold work tool steel were examined by a fretting wear tester. The hardness of ZrN and Zr(21% Hf)N coatings were almost the same, where as they exhibited different wear resistance. Addition of 21% Hf to ZrN coating achieved about 25% increase in the wear resistance. (orig.)

  12. Reliability assessment of ultra-thin HfO{sub 2} films deposited on silicon wafer

    Energy Technology Data Exchange (ETDEWEB)

    Fu, Wei-En [Center for Measurement Standards, Industrial Technology Research Institute, Room 216, Building 8, 321 Kuang Fu Road Sec. 2, Hsinchu, Taiwan (China); Chang, Chia-Wei [Department of Materials Science and Engineering, National Cheng Kung University, 1 University Road, Tainan 70101, Taiwan (China); Chang, Yong-Qing [Center for Measurement Standards, Industrial Technology Research Institute, Room 216, Building 8, 321 Kuang Fu Road Sec. 2, Hsinchu, Taiwan (China); Yao, Chih-Kai [Department of Materials Science and Engineering, National Cheng Kung University, 1 University Road, Tainan 70101, Taiwan (China); Liao, Jiunn-Der, E-mail: jdliao@mail.ncku.edu.tw [Department of Materials Science and Engineering, National Cheng Kung University, 1 University Road, Tainan 70101, Taiwan (China)

    2012-09-01

    Highlights: Black-Right-Pointing-Pointer Nano-mechanical properties on annealed ultra-thin HfO{sub 2} film are studied. Black-Right-Pointing-Pointer By AFM analysis, hardness of the crystallized HfO{sub 2} film significantly increases. Black-Right-Pointing-Pointer By nano-indention, the film hardness increases with less contact stiffness. Black-Right-Pointing-Pointer Quality assessment on the annealed ultra-thin films can thus be achieved. - Abstract: Ultra-thin hafnium dioxide (HfO{sub 2}) is used to replace silicon dioxide to meet the required transistor feature size in advanced semiconductor industry. The process integration compatibility and long-term reliability for the transistors depend on the mechanical performance of ultra-thin HfO{sub 2} films. The criteria of reliability including wear resistance, thermal fatigue, and stress-driven failure rely on film adhesion significantly. The adhesion and variations in mechanical properties induced by thermal annealing of the ultra-thin HfO{sub 2} films deposited on silicon wafers (HfO{sub 2}/SiO{sub 2}/Si) are not fully understood. In this work, the mechanical properties of an atomic layer deposited HfO{sub 2} (nominal thickness Almost-Equal-To 10 nm) on a silicon wafer were characterized by the diamond-coated tip of an atomic force microscope and compared with those of annealed samples. The results indicate that the annealing process leads to the formation of crystallized HfO{sub 2} phases for the atomic layer deposited HfO{sub 2}. The HfSi{sub x}O{sub y} complex formed at the interface between HfO{sub 2} and SiO{sub 2}/Si, where the thermal diffusion of Hf, Si, and O atoms occurred. The annealing process increases the surface hardness of crystallized HfO{sub 2} film and therefore the resistance to nano-scratches. In addition, the annealing process significantly decreases the harmonic contact stiffness (or thereafter eliminate the stress at the interface) and increases the nano-hardness, as measured by vertically

  13. Simultaneous measurements of HF-enhanced plasma waves and artificial field-aligned irregularities at Arecibo

    International Nuclear Information System (INIS)

    Noble, S.T.; Djuth, F.T.

    1990-01-01

    Two radar systems with beams intersecting in the HF-modified F region were used to simultaneously measure HF-enhanced plasma lines (HFPLs) and artificial geomagnetic field-aligned irregularities (AFAIs). The Arecibo 430-MHz radar was used for the HFPL observations, and a portable 49.92-MHz backscatter radar was deployed on the island of Guadeloupe to monitor the AFAIs. The experiment was desgined to examine the degree to which HF-induced plasma turbulence influences the development of AFAIs. When the HF beam is stepped up in power, sustained HFPLs and AFAIs are first observed at the same HF power level, indicating that ponderomotively driven instabilities may be involved in the early time development of AFAIs. As the HF power is increased, the HFPL backscatter power begins to saturate at ∼70 MW effective radiated power (ERP). However, the backscatter from AFAIs is linearly dependent on HF power, even at the highest (120 MW ERP) HF power levels available at Arecibo. This suggests that additional processes may contribute to the development of AFAIs. For example, ponderomotively driven instabilities may give rise to weak geomagnetic field-aligned irregularities that are subsequently driven unstable by processes excited near the upper hybrid resonance. It is also likely that AFAIs greatly impact the development of HF-induced plasma turbulence at late times (>1 s) following HF turn-on. Once the ionosphere is preconditioned by high-power HF modifications, AFAIs and HFPLs can be simultaneously sustained at a much lower HF power level than that needed to originally excite them. The nature of the preconditioning process is currently not well understood. New theoretical initiatives are clearly needed to guide future experimental activity in this area

  14. Pulsed inductive HF laser

    Energy Technology Data Exchange (ETDEWEB)

    Razhev, A M; Kargapol' tsev, E S [Institute of Laser Physics, Siberian Branch, Russian Academy of Sciences, Novosibirsk (Russian Federation); Churkin, D S; Demchuk, S V [Novosibirsk State University, Novosibirsk (Russian Federation)

    2016-03-31

    We report the results of experimentally investigated dependences of temporal, spectral and spatial characteristics of an inductive HF-laser generation on the pump conditions. Gas mixtures H{sub 2} – F{sub 2}(NF{sub 3} or SF6{sub 6}) and He(Ne) – H{sub 2} – F{sub 2}(NF{sub 3} or SF{sub 6}) were used as active media. The FWHM pulse duration reached 0.42 μs. This value corresponded to a pulsed power of 45 kW. For the first time, the emission spectrum of an inductive HF laser was investigated, which consisted of seven groups of bands with centres around the wavelengths of 2732, 2736, 2739, 2835, 2837, 2893 and 2913 nm. The cross section profile of the laser beam was a ring with a diameter of about 20 mm and width of about 5 mm. Parameters of laser operation in the repetitively pulsed regime were sufficiently stable. The amplitude instability of light pulses was no greater than 5% – 6%. (lasers)

  15. Mechanism for suppression of radiation-induced segregation by oversized solute addition in austenitic stainless steel

    Science.gov (United States)

    Hackett, Micah Jeremiah

    The objective of this thesis is to quantify the effect of oversized solutes on radiation-induced segregation in austenitic stainless steels and to determine the mechanism of this effect. Zr or Hf additions to austenitic stainless steels demonstrated a reduction in radiation-induced segregation of Cr and Ni at the grain boundary after proton irradiation at 400°C and 500°C to low doses, but the solute effect disappeared at higher doses. Rate theory modeling of RIS was extended to incorporate a solute-vacancy trapping mechanism to predict the effect of solutes on RIS. The model showed that RIS is most sensitive to the solute-vacancy binding energy. First principles calculations were used to determine a binding energy of 1.08 eV for Zr and 0.71 eV for Hf. Model and experiment agreed in showing suppression of Cr depletion at doses of 3 dpa at 400°C and 1 dpa at 500°C, and experimental results were consistent with the model in showing greater effectiveness of Zr relative to Hf due to a larger binding energy. The dislocation loop microstructure was measured at 400°C, 3 and 7 dpa, and a significant decrease in loop density and total loop line length in the oversized solute alloys relative to the reference alloys. The loop microstructure results were consistent with RIS results by confirming enhanced recombination of point defects by solute-vacancy trapping. Increases in RIS with dose indicated a loss of solute effectiveness, which was consistent with an observed increase in loop line length from 3 to 7 dpa. The loss of solute effectiveness at high dose is attributed to a loss of oversized solute from the matrix due to coarsening of carbide precipitates. X-ray diffraction identified a microstructure with ZrC or HfC precipitates prior to irradiation. Precipitate coarsening was identified as the most likely mechanism for the loss of solute effectiveness on RIS by the following: (1) diffusion analysis suggested significant solute diffusion by the vacancy flux to

  16. Antioxidant effect of water and acetone extracts of Fucus vesiculosuson oxidative stability of skin care emulsions

    DEFF Research Database (Denmark)

    Poyato, Candelaria; Thomsen, Birgitte Raagaard; Hermund, Ditte Baun

    2017-01-01

    A water and an acetone extract of the Icelandic brown algae Fucus vesiculosus were evaluated as potential natural sources of antioxidant compounds in skin care emulsions. To assess their efficacy in inhibiting lipid oxidation caused by photo- or thermoxidation, they were stored in darkness and room...... temperature. High temperature also caused greater increments in the droplet size of the emulsions. The analysis of the tocopherol content, peroxide value and volatile compounds during the storage revealed that, whereas both water and acetone extracts showed (at 2 mg/g of emulsion) protective effect against...

  17. Biodegradation of isopropanol and acetone under denitrifying conditions by Thauera sp. TK001 for nitrate-mediated microbially enhanced oil recovery.

    Science.gov (United States)

    Fida, Tekle Tafese; Gassara, Fatma; Voordouw, Gerrit

    2017-07-15

    Amendment of reservoir fluid with injected substrates can enhance the growth and activity of microbes. The present study used isopropyl alcohol (IPA) or acetone to enhance the indigenous anaerobic nitrate-reducing bacterium Thauera sp. TK001. The strain was able to grow on IPA or acetone and nitrate. To monitor effects of strain TK001 on oil recovery, sand-packed columns containing heavy oil were flooded with minimal medium at atmospheric or high (400psi) pressure. Bioreactors were then inoculated with 0.5 pore volume (PV) of minimal medium containing Thauera sp. TK001 with 25mM of acetone or 22.2mM of IPA with or without 80mM nitrate. Incubation without flow for two weeks and subsequent injection with minimal medium gave an additional 17.0±6.7% of residual oil in place (ROIP) from low-pressure bioreactors and an additional 18.3% of ROIP from the high-pressure bioreactors. These results indicate that acetone or IPA, which are commonly used organic solvents, are good substrates for nitrate-mediated microbial enhanced oil recovery (MEOR), comparable to glucose, acetate or molasses, tested previously. This technology may be used for coupling biodegradation of IPA and/or acetone in waste streams to MEOR where these waste streams are generated in close proximity to an oil field. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Lu-Hf isotope systematics of fossil biogenic apatite and their effects on geochronology

    Science.gov (United States)

    Herwartz, Daniel; Münker, Carsten; Tütken, Thomas; Hoffmann, J. Elis; Wittke, Andreas; Barbier, Bruno

    2013-01-01

    Reliable methods for direct dating of biogenic apatite from pre-Pleistocene fossils are currently not available, and recent attempts using the Lu-Hf decay system yielded highly inaccurate ages for both bones and teeth. The geological processes accounting for this poor accuracy of Lu-Hf chronometry are not yet understood. Here we explore Lu-Hf systematics in fossil bones and teeth in detail, by applying five different sample digestion techniques that are tested on bones and composites of bone and sediment. Our current dataset implies that dissolution methods only slightly affect the resulting Lu-Hf ages, while clear differences between the individual digestion techniques became apparent for element concentrations. By analysing the insoluble leftovers from incomplete sample dissolution, four main reservoirs of Hf in fossil bones were identified: (1) a radiogenic end-member associated with apatite; (2) an unradiogenic end-member represented by the authigenic minerals or the embedding sediment; (3) a highly unradiogenic end-member that can be attributed to detrital zircon; and (4) a moderately soluble phase (probably a Zr(Hf)-phosphate) that yielded very low Lu/Hf but a highly radiogenic Hf isotope composition at the same time. This Zr(Hf)-phase must have been precipitated within the fossil bone sample at a late stage of burial history, thereby incorporating radiogenic 176Hf released from apatite surfaces over geological timescales. A second focus of our study is the effect of different sediment matrices and of crystal size on the preservation of pristine Lu-Hf isotope compositions in bioapatite. Because near-depositional Lu-Hf ages of phosphate fossils have previously been reported for the London Clay (England) and a calcareous marl from Tendaguru (Tanzania), we herein investigate specimens fossilised in carbonate matrices (calcareous marl from Oker, Germany; carbonate concretions from the Santana Formation, Brazil; carbonate from the Eifel, Germany) and argillaceous

  19. Hydrogen fluoride (HF) substance flow analysis for safe and sustainable chemical industry.

    Science.gov (United States)

    Kim, Junbeum; Hwang, Yongwoo; Yoo, Mijin; Chen, Sha; Lee, Ik-Mo

    2017-11-01

    In this study, the chemical substance flow of hydrogen fluoride (hydrofluoric acid, HF) in domestic chemical industries in 2014 was analyzed in order to provide a basic material and information for the establishment of organized management system to ensure safety during HF applications. A total of 44,751 tons of HF was made by four domestic companies (in 2014); import amount was 95,984 tons in 2014 while 21,579 tons of HF was imported in 2005. The export amount of HF was 2180 tons, of which 2074 ton (China, 1422 tons, U.S. 524 tons, and Malaysia, 128 tons) was exported for the manufacturing of semiconductors. Based on the export and import amounts, it can be inferred that HF was used for manufacturing semiconductors. The industries applications of 161,123 tons of HF were as follows: manufacturing of basic inorganic chemical substance (27,937 tons), manufacturing of other chemical products such as detergents (28,208 tons), manufacturing of flat display (24,896 tons), and manufacturing of glass container package (22,002 tons). In this study, an analysis of the chemical substance flow showed that HF was mainly used in the semiconductor industry as well as glass container manufacturing. Combined with other risk management tools and approaches in the chemical industry, the chemical substance flow analysis (CSFA) can be a useful tool and method for assessment and management. The current CSFA results provide useful information for policy making in the chemical industry and national systems. Graphical abstract Hydrogen fluoride chemical substance flows in 2014 in South Korea.

  20. Preparation and enhanced oxidation performance of a Hf-doped single-phase Pt-modified aluminide coating

    International Nuclear Information System (INIS)

    Yang, Y.F.; Jiang, C.Y.; Yao, H.R.; Bao, Z.B.; Zhu, S.L.; Wang, F.H.

    2016-01-01

    Graphical abstract: Tiny Hf particles were successfully incorporated into Pt plating via simple electro-plating method. The hafnium particles were either nipped at Pt grain boundaries or wrapped inside Pt grains, and most of them were below 3 μm in size, showing a uniform distribution within the Pt plating. - Highlights: • A Hf-rich belt formed between outer (Ni,Pt)Al and IDZ after aluminisation. • Hf-doped coating showed much decreased mass gain and oxidation rate constant k_p. • Hf-rich belt acted as diffusion barrier by restraining diffusions of Al and W. • Degradation of β was effectively postponed by the unique Hf addition. • Hf-doped coating exhibited lighter oxide scale rumpling tendency. - Abstract: A Hf-doped β-(Ni,Pt)Al coating was prepared by co-deposition of a Pt-Hf composite plating and successive aluminisation. Then, a distinct Hf-rich belt was formed internally between the outer additive (Ni,Pt)Al coating and interdiffusion zone. An isothermal oxidation test at 1100 °C revealed a relatively lower oxidation rate constant and decreased oxide scale rumpling tendency for the Hf-doped coating during which the Hf-rich belt partly acted as an effective diffusion barrier. The unique addition of Hf into a β-(Ni,Pt)Al coating can delay the transitional oxidation period from transient alumina to stable one and postpone the degradation from β to γ'.