bluuebunny/crossref_metadata_2025_split huggingface dataset:
Calculation of the Influence of Density on the Thermal Conductivity of Gaseous Mixtures
Authors: Kestin J. , Wakeham W. A. 
Published: July 2012

AbstractThe scheme for the prediction of the thermal conductivity of dense gas mixtures, proposed by Mason and his collaborators, is critically examined, for the first time, with respect to accurate experimental data for eight systems. The systems studied are binary monatomic mixtures of He  Ar and Ne  Ar; a ternary mixture, Ne  Ar  Kr; the mixtures He  H2, He  N2, Ne  N2, and Ar  N2, which involve one polyatomic component; and the mixture H2  D2 which has two polyatomic components. The experimental results used for the comparison refer to a temperature of 27.5°C and extend over the pressure range 0.6–12 MPa. — For binary and ternary systems whose components have molecular mass ratios in the range 1 – 2, the calculation scheme is found to predict the thermal conductivity with a deviation from the experimental data which does not exceed ± 0.8% even when the mixtures contain polyatomic components. However, for mixtures where the molecular mass ratio is larger, the agreement is significantly poorer and deviations amounting to as much as 2.5% are observed. These larger deviations are attributed to the inadequacy of the first‐order kinetic theory formulae upon which the prediction scheme is based.
The system hydrogen ‐ water up to 440°C and 2500 bar pressure
Authors: Seward T. M. , Franck E. U. 
Published: July 2012

AbstractThe system H2— H2O has been studied isochorically from 0.5 to 90 mol‐% H2and up to 440°C and 2500 bar pressure using an autoclave containing two sapphire windows through which phase transitions could be observed at elevated temperatures and pressures. — The system was found to exhibit so‐called “gas‐gas” immiscibility with a critical curve proceeding to higher temperatures and pressures from the critical point of pure water. Within the range of these experiments, the critical temperature of H2—H2O mixtures does not change greatly from that of pure water (e.g.Tc= 381.3°C atpc= 2520 bar for 38 mol‐% H2).pVTmeasurements have been made in the homogeneous region and excess volumes have been calculated at 400°C and at different pressures. At 300 bar, the excess volumes are relatively large and positive (e.g.VE= 58.0 cm3mol−1at 40 mol‐% H2) whereas at 2500 bar, excess volumes of H2—H2O mixtures indicate only small positive or negative departures from ideality.
Molecular dynamics simulation study of the negative hydration effect in aqueous electrolyte solutions
Authors: Geiger A. 
Published: July 2012

AbstractTo study the structure breaking effect in aqueous electrolyte solutions (also termed negative hydration), a series of molecular dynamics simulation runs has been carried out. An originally uncharged, nonpolar spherical solute particle (“Xenon”) is charged step by step fromg1= 0.0etoq1= +0.67e, + 1.0eandq1= +2.0e(eis the positive elementary charge). At zero charge the occurrence of hydrophobic hydration is observed. The surroundings of the divalent cation also shows marked structuring: the normal “positive” ionic hydration. In an intermediate region of charge (atq1= 1.0e) negative hydration is detected, which proves to be a state of minimum order. Structural changes are discussed by using pair and three particle correlation functions. Hydration energies, binding energies and pair interaction energy distributions are determined. The microdynamics is studied by observing the reorientational motion and the self diffusion behaviour of the water molecules in different regions. A zone of increased mobility is located in the vicinity of the ion, which may include the innermost hydration shell. Additionally a system comprising a negatively hydrated anion has also been studied.
Heterogeneous catalytic degradation of chlorofluoromethanes on zinc oxide surfaces
Authors: Filby W. G. , Mintas M. , Güsten H. 
Published: July 2012

AbstractThe decomposition of the spray propellants CFCl3 and CF2Cl2 on the surface of variously treated zinc oxides has been studied by X‐ray photoelectron spectroscopy. Whereas decomposition on “untreated” surfaces could only be induced photolytically ( λ < 400 nm) “activated” surfaces caused both spontaneous dark and additionally, photocatalytic decomposition. Indications are that the mechanism involves interaction between physisorbed substrate molecules and surface electrons of the catalyst. Decomposition causes chlorination of the zinc oxide resulting in a surface approaching hypochlorite‐perchlorate stochiometry.
Master equations for photochemistry with intense infrared light (IV). A unified treatment of case B and case C including nonlinear effects
Authors: Quack Martin 
Published: July 2012

AbstractA unified master equation for unimolecular reactions induced by monochromatic infrared radiation (URIMIR) is presented. Its effective rate coefficient matrix covers both case B (Pauli equation) and case C, properly including the nonlinearity of the latter. Exact quantum mechanical model solutions are compared with results from the approximate unified master equation. The exact analytical solutions of the master equation are presented for the URIMIR of some realistic molecular models. The important new properties of the transition range between case B and case C are quantitatively discussed with respect to time dependent and steady state level populations, time dependent and steady state rate coefficients and their nonlinear intensity dependence, and with respect to the influence of molecular properties. The role of case C for the interpretation of static field effects and its importance for efficient isotope separation are pointed out.
A Molecular Beam Apparatus for the Investigation of Radical Reactions: The Reaction CH3 + Br2 → CH3Br + Br at a Collision Energy of 36 kJ/mol
Authors: Somssich P. , Strein K. , Schmiedel H. 
Published: July 2012

AbstractThe reaction of CH3 + Br2 → CH3Br + Br was studied in a crossed molecular beam apparatus at a collision energy of 36.3 kJ/mol. Two heatable nozzles provide intensive and fast beams of Br2 (950 m/sec) and CH3 radicals (2096 m/sec), the latter of which are formed by pyrolysis of (CH3)2Hg. By using a pseudorandom TOF chopper, velocity analysis of the product CH3Br was made possible despite the very low flux involved. The CH3Br product angular distribution peaks at a center of mass angle of θ ∼ 100°. The reactive scattering of CH3Br can still be characterized as backward scattering with respect to the CH3 beam although an unmistakable tendency towards sideward scattering with increasing collision energy is observed, when compared to measurements at an energy of only 18 kJ/mol. The proportion of the average translational energy after the collision was found to be approximately 0.5 of Etot. The observed distribution leads to the conclusion that the dominant potential surface of the reaction is of the repulsive type (late downhill).
The Temperature Dependence of the Binary Diffusion Coefficients of the Systems Ne‐CO2, Kr‐CO2 and Xe‐CO2
Authors: Robjohns H. L. , Dunlop Peter J. 
Published: July 2012

AbstractBinary diffusion coefficients are reported for the systems Ne‐CO2, Kr‐CO2 and Xe‐CO2 over the temperature range 277 – 323 K, and combined with accurate second virial coefficients to obtain (m, 6, 8) potentials for the unlike‐interactions. These potentials, together with others for the like‐interactions, have been used to calculate binary viscosities for comparison with existing data.
Neutron Scattering from Concentrated Micellar Solutions
Authors: Hayter John B. 
Published: July 2012

AbstractAqueous solutions of sodium dodecyl sulphate have been studied by neutron small‐angle scattering at concentrations up to 0.8 mol dm−3, with up to 0.2 mol dm−3 of added NaCl. The data were analysed taking specific account of intermicellar correlations, to obtain a single micelle form‐factor which is consistent with a Hartley‐like model with a rough outer surface. The measured structural parameters were used to predict the solution dynamics, and the results were confirmed using dynamic neutron spin‐echo spectroscopy.
Melting Curves, Densities, Viscosities and Thermodynamic Excess Properties of 1,2,4‐Trichlorobenzene + n‐Decane and + n‐Tetradecane
Authors: Atrops H. , Kalali H. E. , Kohler F. 
Published: July 2012

AbstractMelting curves, viscosities and densities have been determined for the mixtures of 1,2,4‐trichlorobenzene + n‐decane and + n‐tetradecane. Derived thermodynamic excess properties (excess Gibbs energy gE and excess volume vE) can be combined with literature data on trichlorobenzene + n‐alkane systems to establish an unusual trend of mixing properties with chain length of n‐alkane. Also viscosities of equimolar mixtures of trichlorobenzene with various n‐alkanes and of benzene with various n‐alkanes have been measured, in order to collect more material on the behaviour of n‐alkane mixtures.
The Reversible Hydration of Carbonyl Compounds in Aqueous Solution Part II: The Kinetics of the Keto/Gem‐diol Transition
Authors: Buschmann Hans‐JüRgen , Dutkiewicz Edward , Knoche Wilhelm 
Published: July 2012

AbstractThe kinetics of hydration of 17 different carbonyl compounds have been studied in acidic solution. The reactions have been found to be acid‐catalysed. For the aliphatic aldehydes propanal to hexanal the rate constants are k0 = (3.5 ± 1) · 10−3 s−1 and kH = (450 ± 30) dm3 mol−1 s−1 and for α‐keto acids they are in the ranges k0 = (0.13 to 0.40) s−1 and kH = (1 to 6) dm3 mol−1 s−1. For halogenated acetones the rate constants depend strongly on the substituents. The large negative value for the reaction entropy ΔS0 = −70 J mol−1 K−1 indicates that three water molecules are involved in the hydration process.
Selfsensitization of the Photopolymerization of Diacetylenes Studied in Multilayers
Authors: Bubeck C. , Tieke B. , Wegner G. 
Published: July 2012

AbstractThe photoreactivity of multimolecular Langmuir‐Blodgett layers is studied with optical absorption spectroscopy. Whereas the polymerization of monomeric layers can be initiated by UV‐irradiation only, irradiation of partially polymerized layers with visible light up to λ ≤ 500 nm leads to a continuation of the reaction. The maximal polymer yield obtained with UV‐ and visible light irradiation is the same. The action spectra of the chain growth of partially polymerized layers and of the photoconductivity correspond to each other. A new mechanism of the chain growth is proposed.
Fast Reaction Rates in IR‐Photochemistry: c‐C4F8 → 2 C2F4
Authors: Quack M. , Seyfang G. 
Published: July 2012

AbstractQuantitative experimental results are reported for the photo‐decomposition of octafluorocyclobutane under irradiation with intense, mono‐chromatic light from a pulsed TEA‐CO2‐laser in the range of the v21 fundamental near 963 cm−1. The IR‐photochemical rate coefficient is found to bemagnified imagefor irradiation with P 8 at 954.6 cm−1, close to the optimum frequency. It is shown that the intensity dependence is linear to a good approximation by comparing irradiation with intense self‐mode‐locked pulse trains and smooth single mode pulses of low peak intensity, generated by means of an intracavity absorber. Results on the frequency dependence and upon the influence of inert gas pressure in the IR‐photochemistry of C4F8 are reported. The experimental results are found to compare well with theoretical predictions based on a Pauli equation treatment and simple models for the rate coefficient matrix.
The Thermal Conductivity of n‐Nonane and n‐Undecane at Pressures up to 500 MPa in the Temperature Range 35–90°C
Authors: Menashe J. , Wakeham W. A. 
Published: July 2012

AbstractThe paper presents new measurements of the thermal conductivity of two normal alkanes, n‐nonane, and n‐undecane, in the liquid phase. The measurements have been carried out within the temperature range 35 to 90°C and over the pressure range 50–500 MPa in a transient hot‐wire instrument. The experimental data, which have been corrected for the effects of radiation absorption, have an estimated uncertainty of ±0.7%. — A heuristic modification of the Enskog theory of transport processes in dense fluids is proposed, which leads to a simple means of representing the entire body of thermal conductivity data for each fluid with an accuracy commensurate with that of the measurements themselves. For each fluid the only temperature dependent parameter of the correlation scheme is a density independent core volume. It is therefore possible to predict the density dependence of the thermal conductivity of the fluid at any temperature from a single measurement at just one density.
The Chemisorption of Carbon Monoxide on a Co(10&1macr;0) Single Crystal Surface. Studied by LEED, UPS, EELS, AES and Work Function Measurements
Authors: Papp H. 
Published: July 2012

AbstractThe chemisorption of CO on Co(10&1macr;0) has been investigated by LEED, UPS, EELS, Auger and sp measurements. CO is molecularly adsorbed between 100 and 420 K. This can be deduced from UP spectra, EEL spectra and the reversibility of the sp and the LEED results. The initial isosteric heat of adsorption has a value of about 145 kJ/mol and drops to about 120 kJ/mol when a p(2 × 1) overlayer structure is completed. The final structure obtained at 300 K is a well ordered c(2 × 1) CO overlayer.
Blue‐green Chemiluminescence in the System C2H2/O/H. Formation of the Emitters CH(A2Δ), C2(d3Πg) and C2H*
Authors: Grebe J. , Homann K. H. 
Published: July 2012

AbstractA kinetic study of the chemiluminescence of the emitters CH(A2Δ), C2(d3Πg) and C2H* in a mixture of acetylene, oxygen and hydrogen atoms has been performed using a low pressure discharge flow reactor at 2.66 mbar and 298 K under largely varying initial conditions. The absolute concentrations of the emitters could be quantitatively simulated and correlated to the simultaneous formation of higher hydrocarbons in this system when the following formation reactions of the excited species are assumedmagnified imageThese reactions are in particular accord with the dependence of the chemiluminescence on the concentration of free hydrogen atoms.
Reversible Electrochemical Graphite Salt Formation from Aqueous Salt Electrolytes
Authors: Krohn H. , Beck F. , Junge H. 
Published: July 2012

AbstractCyclic electrochemical intercalation/deintercalation of anions from aqueous salt solutions in crystalline graphite electrodes has been investigated. The practical electrode was polypropylene bound natural graphite “CPP”. The main candidates for the salts were NaClO4, NaBF4, Na2SO4 and KF in the concentration range of 0.1 – 12 M. – Current efficiencies α with ClO−4 and BF−4 are lower as in aqueous acids due to side reactions, which increase with increasing dilution and temperature. No pH‐effect on α has been found between pH 1 – 12. Under favourable conditions (8 M NaClO4 at 20 °C or 4 M NaClO4 at 0 °C), α's as high as 80% have been observed. A pronounced formation effect is found upon galvanostatic cycling. In Na2SO4, α drops to zero at pH 3 due to the lack of HSO−4‐ions. No intercalation of F− ions is detected from aqueous KF. – Intercalation potential E1 shows Nernst behaviour with regard to anions in solution and intercalated anions. The slope of Nernst curve is 59 mV per decade as expected. E1 is much more positive than in aqueous acid of the same concentration due to the absence of solvate acid depolarization. The anions are desolvated, but not discharged upon intercalation. No indication of an in situ formation of solvate acid has been found. – For comparison, intercalation of anions from perchlorates in CH3OH, CH3COOH, and CH3CN has been investigated. – The potential application in an aqueous Zn/graphite accumulator is discussed. This battery has – with 4 M NaClO4 – an open circuit voltage of 2.58 V.
The Viscosity and Diffusion Coefficients of Binary Mixtures of Nitrous Oxide with Ar, N2, and CO2
Authors: Kestin J. , Ro S. T. 
Published: July 2012

AbstractIn our continuing search for extensions to the KRW law of corresponding states, we performed measurements of the low‐density viscosity of binary mixtures containing the mildly polar gas: N2O. This was combined with one monatomic gas (Ar), one diatomic gas (N2) and one somewhat more complex species (CO2). — Measurements of viscosity accurate to ±0.3% and direct calculations of binary diffusion coefficients confirm that the data fit into the general KRW scheme in that it is possible to discover optimum scaling factors ϱij and ϵij (i = j and i ± j) which correlate our data in terms of the universal collision integrals Ω11 and Ω22.
Strain stiffening in collagen I networks
Authors: Motte Stéphanie , Kaufman Laura J. 
Published: July 2012

AbstractBiopolymer gels exhibit strain stiffening that is generally not seen in synthetic gels. Here, we investigate the strain‐stiffening behavior in collagen I gels that demonstrate elasticity derived from a variety of sources including crosslinking through telopeptides, bundling through low‐temperature gelation, and exogenous crosslinking with genipin. In all cases, it is found that these gels exhibit strain stiffening; in general, onset of strain stiffening occurs earlier, yield strain is lower, and degree of strain stiffening is smaller in higher concentration gels and in those displaying thick fibril bundles. Recovery after exposure to high strains is substantial and similar in all gels, suggesting that much of the stiffening comes from reversible network deformations. A key finding of this study is that collagen I gels of identical storage and loss moduli may display different nonlinear responses and different capacities to recover from high strain. © 2012 Wiley Periodicals, Inc.
Regulation of late endosomal/lysosomal maturation and trafficking by cortactin affects Golgi morphology
Authors: Kirkbride Kellye C. , Hong Nan Hyung , French Christi L. , Clark Emily S. , Jerome W. Gray , Weaver Alissa M. 
Published: July 2012

AbstractCortactin is a branched actin regulator and tumor‐overexpressed protein that promotes vesicular trafficking at a variety of cellular sites, including endosomes and the trans‐Golgi network. To better understand its role in secretory trafficking, we investigated its function in Golgi homeostasis. Here, we report that knockdown (KD) of cortactin leads to a dramatic change in Golgi morphology by light microscopy, dependent on binding the Arp2/3 actin‐nucleating complex. Surprisingly, there was little effect of cortactin‐KD on anterograde trafficking of the constitutive cargo vesicular stomatitis virus glycoprotein (VSVG), Golgi assembly from endoplasmic reticulum membranes upon Brefeldin A washout, or Golgi ultrastructure. Instead, electron microscopy studies revealed that cortactin‐KD cells contained a large number of immature‐appearing late endosomal/lysosomal (LE/Lys) hybrid organelles, similar to those found in lysosomal storage diseases. Consistent with a defect in LE/Lys trafficking, cortactin‐KD cells also exhibited accumulation of free cholesterol and retention of the retrograde Golgi cargo mannose‐6‐phosphate receptor in LE. Inhibition of LE maturation by treatment of control cells with Rab7 siRNA or chloroquine led to a compact Golgi morphology similar to that observed in cortactin‐KD cells. Furthermore, the Golgi morphology defects of cortactin‐KD cells could be rescued by removal of cholesterol‐containing lipids from the media, suggesting that buildup of cholesterol‐rich membranes in immature LE/Lys induced disturbances in retrograde trafficking. Taken together, these data reveal that LE/Lys maturation and trafficking are highly sensitive to cortactin‐regulated branched actin assembly and suggests that cytoskeletal‐induced Golgi morphology changes can be a consequence of altered trafficking at late endosomes. © 2012 Wiley Periodicals, Inc.
Social context induces two unique patterns of c‐Fos expression in adolescent and adult rats
Authors: Varlinskaya Elena I. , Vogt Brent A. , Spear Linda P. 
Published: July 2012

AbstractThe study assessed possible age differences in brain activation patterns to low dose ethanol (.5 g/kg intraperitoneally) and the influence of social context on this activation. Early adolescent or young adult male Sprague–Dawley rats were placed either alone or with an unfamiliar partner of the same age and sex following saline or ethanol administration. c‐Fos protein immunoreactivity was used to index neuronal activation in 15 regions of interest. Ethanol had little effect on c‐Fos activation. In adolescents, social context activated an “autonomic” network including the basolateral and central amygdala, bed nucleus of the stria terminalis, lateral hypothalamus, and lateral septum. In contrast, when adult rats were alone, activation was evident in a “reward” network that included the substantia nigra, nucleus accumbens, anterior cingulate and orbitofrontal cortices, lateral parabrachial nucleus, and locus coeruleus.© 2012 Wiley Periodicals, Inc. Dev Psychobiol 55: 684–697, 2013.
Risk assessment and risk management at the Canadian Food Inspection Agency (CFIA): A perspective on the monitoring of foods for chemical residues
Authors: Bietlot Henri P. , Kolakowski Beata 
Published: July 2012

AbstractThe Canadian Food Inspection Agency (CFIA) uses ‘Ranked Risk Assessment’ (RRA) to prioritize chemical hazards for inclusion in monitoring programmes or method development projects based on their relative risk. The relative risk is calculated for a chemical by scoring toxicity and exposure in the ‘risk model scoring system’ of the Risk Priority Compound List (RPCL). The relative ranking and the risk management options are maintained and updated in the RPCL. The ranking may be refined by the data generated by the sampling and testing programs.The two principal sampling and testing programmes are the National Chemical Residue Monitoring Program (NCRMP) and the Food Safety Action Plan (FSAP). The NCRMP sampling plans focus on the analysis of federally registered products (dairy, eggs, honey, meat and poultry, fresh and processed fruit and vegetable commodities, and maple syrup) for residues of veterinary drugs, pesticides, environmental contaminants, mycotoxins, and metals. The NCRMP is complemented by the Food Safety Action Plan (FSAP) targeted surveys. These surveys focus on emerging chemical hazards associated with specific foods or geographical regions for which applicable maximum residue limits (MRLs) are not set. The data from the NCRMP and FSAP also influence the risk management (follow‐up) options. Follow‐up actions vary according to the magnitude of the health risk, all with the objective of preventing any repeat occurrence to minimize consumer exposure to a product representing a potential risk to human health. © Her Majesty the Queen in Right of Canada 2012. Drug Testing and Analysis © 2012 John Wiley & Sons, Ltd.
Fabrication of Flexible α‐Alumina Fibers Composed of Nanosheets
Authors: Zhang Pingping , Chen Dairong , Jiao Xiuling 
Published: July 2012

AbstractFlexible α‐alumina nanofibers were fabricated by the sol–gel method combined with an electrospinning process. The sol was prepared with aluminum isopropoxide and aluminum nitrate as the precursors, nitric acid as the catalyst, and ethanol aqueous solution as the solvent. Small amounts of anhydrous magnesium sulfate as additive acted to stabilize the γ‐Al2O3 structure and retard its conversion to α‐Al2O3 firstly, and subsequently MgAl2O4 was formed at the grain boundaries to inhibit grain growth. Polyvinylpyrrolidone (PVP) was applied to tune sol viscosity. The fibers with diameters of 300–400 nm are composed of α‐Al2O3 nanosheets with thickness in the range of 20–50 nm and stack along [0001] at the axial direction. The fibers exhibited good flexibility and thermal stability.