Determination of Partial Molar Volumes of EPA and DHA Ethyl Esters in Supercritical Carbon Dioxide

Institute of Scientific and Technical Information of China (English)

无

2002-01-01

The use of supercritical-fluid chromatography for determining partial molar volumes of ethyl esters of cis-5,8,11,14,17-eicosapentaenoic acid (EPA) and cis -4,7,10,13,16,19- docosa-hexaenoic acid (DHA) in supercritical carbon dioxide is presented and discussed. Partial molar volumes of EPA and DHA esters are obtained from the variation of the retention properties with the density of mobile phase at 313.15 K, 323.15 K, 333.15 K and in the pressure range from 9 MPa to 21 MPa.

Deptermination of Partial Molar Volumes of EPA and DHA Ethyl Esters in Supercritical Carbon Dioxide

Institute of Scientific and Technical Information of China (English)

MeiHUANG; XianDaWANG; 等

2002-01-01

The use of supercritical-fluid shromatogrphy for determining partial molar volumes of ethyl esters of cis-5,8,11,14,17-eicosapentaenoic acid (EPA) and cis-4,7,10,13,16,19-docosa-hexaenoic acid(DHA) in supercritical carbon dioxide is presented and discussed. Partial molar volumes of EPA and DHA esters are obtained from the variation of the retention properties with the density of mobile phase at 313.15K,323.15K,333.15K and in the pressure range from 9 MPa to 21 MPa.

Partial molar volumes of (acetonitrile + water) mixtures over the temperature range (273.15 to 318.15) K

International Nuclear Information System (INIS)

Yeow, Y. Leong; Leong, Yee-Kwong

2007-01-01

Isothermal molar volume data of (acetonitrile + water) mixtures, between T = 273.15 K and T = 318.15 K, extracted from different sources are combined and treated as a single set to even out minor differences between sources and to increase the number of data points for each temperature. Tikhonov regularization is applied to compute the isothermal first and second derivatives of these data with respect to molar composition. For the reference temperature of 298.15 K, this computation is extended to the third derivative. Generalized Cross Validation is used to guide the selection of the regularization parameter that keeps noise amplification under control. The resulting first derivatives are used to construct the partial molar volume curves which are then checked against published results. Properties of the partial molar volumes are analysed by examining their derivatives. Finally the general shape of the second derivative curve of molar volume is explained qualitatively in terms of tripartite segmentation of the molar composition interval but quantitative comparisons are required to confirm this explanation

Partial molar volumes of some drug and pro-drug substances in 1-octanol at T = 298.15 K

Energy Technology Data Exchange (ETDEWEB)

Manin, Alex N.; Shmukler, Liudmila E.; Safonova, Liubov P. [Institute of Solution Chemistry, Russian Academy of Sciences, 153045 Ivanovo (Russian Federation); Perlovich, German L., E-mail: glp@isc-ras.r [Institute of Solution Chemistry, Russian Academy of Sciences, 153045 Ivanovo (Russian Federation)

2010-03-15

The article deals with measuring the densities of phenol, acetanilide, benzamide, benzoic acid, phenacetin, i-(acetylamino)-benzoic acid, i-hydroxy-benzamide, and i-acetaminophen (where i = 1, 2, 3) in 1-octanol in the wide concentration interval at T = 298.15 K. It also concerns the evaluation of apparent molar volumes and partial molar volumes at infinite dilution, V{sub 2}{sup 0}-bar as well as comparative analysis of the free volumes per molecule in the octanolic solutions, V{sub 2}{sup free}, and in the crystal lattices, V{sub 2}{sup free} (cr), from the nature and position of the substitutes. Also described is the evaluation of the increments of V{sub 2}{sup 0}-bar andV{sub 2}{sup free} for the unsubstituted molecules and isomers and the methods to obtain partial molar volumes for various functional groups at infinite dilution in 1-octanol at T = 298.15 K. Also considered is the limiting partial molar volume of the solutes in terms of the scaled particle theory.

Partial molar volume of proteins studied by the three-dimensional reference interaction site model theory.

Science.gov (United States)

Imai, Takashi; Kovalenko, Andriy; Hirata, Fumio

2005-04-14

The three-dimensional reference interaction site model (3D-RISM) theory is applied to the analysis of hydration effects on the partial molar volume of proteins. For the native structure of some proteins, the partial molar volume is decomposed into geometric and hydration contributions using the 3D-RISM theory combined with the geometric volume calculation. The hydration contributions are correlated with the surface properties of the protein. The thermal volume, which is the volume of voids around the protein induced by the thermal fluctuation of water molecules, is directly proportional to the accessible surface area of the protein. The interaction volume, which is the contribution of electrostatic interactions between the protein and water molecules, is apparently governed by the charged atomic groups on the protein surface. The polar atomic groups do not make any contribution to the interaction volume. The volume differences between low- and high-pressure structures of lysozyme are also analyzed by the present method.

On a relationship between molecular polarizability and partial molar volume in water.

Science.gov (United States)

Ratkova, Ekaterina L; Fedorov, Maxim V

2011-12-28

We reveal a universal relationship between molecular polarizability (a single-molecule property) and partial molar volume in water that is an ensemble property characterizing solute-solvent systems. Since both of these quantities are of the key importance to describe solvation behavior of dissolved molecular species in aqueous solutions, the obtained relationship should have a high impact in chemistry, pharmaceutical, and life sciences as well as in environments. We demonstrated that the obtained relationship between the partial molar volume in water and the molecular polarizability has in general a non-homogeneous character. We performed a detailed analysis of this relationship on a set of ~200 organic molecules from various chemical classes and revealed its fine well-organized structure. We found that this structure strongly depends on the chemical nature of the solutes and can be rationalized in terms of specific solute-solvent interactions. Efficiency and universality of the proposed approach was demonstrated on an external test set containing several dozens of polyfunctional and druglike molecules.

Infinite dilution partial molar volumes of platinum(II) 2,4-pentanedionate in supercritical carbon dioxide.

Science.gov (United States)

Kong, Chang Yi; Siratori, Tomoya; Funazukuri, Toshitaka; Wang, Guosheng

2014-10-03

The effects of temperature and density on retention of platinum(II) 2,4-pentanedionate in supercritical fluid chromatography were investigated at temperatures of 308.15-343.15K and pressure range from 8 to 40MPa by the chromatographic impulse response method with curve fitting. The retention factors were utilized to derive the infinite dilution partial molar volumes of platinum(II) 2,4-pentanedionate in supercritical carbon dioxide. The determined partial molar volumes were small and positive at high pressures but exhibited very large and negative values in the highly compressible near critical region of carbon dioxide. Copyright © 2014 Elsevier B.V. All rights reserved.

Partial molar volume of mefenamic acid in alcohol at temperatures between T=293.15 and T=313.15 K

OpenAIRE

Iqbal, Muhammad J.; Siddiquah, Mahrukh

2006-01-01

Apparent molar volume (Vphi), partial molar volume (V), solute-solute interaction parameter (Sv), partial molar expansivity (E(0)2) and isobaric thermal expansion coefficient (alpha2) of mefenamic acid in six different organic solvents namely, methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, and 2-butanol, have been calculated from the measured solution densities over a temperature range of T=293.15 and T=313.15±0.1K. The solution densities were measured by an automated vibrating tube de...

Dilatometric measurement of the partial molar volume of water sorbed to durum wheat flour.

Science.gov (United States)

Hasegawa, Ayako; Ogawa, Takenobu; Adachi, Shuji

2013-01-01

Moisture sorption isotherms were measured at 25 °C for untreated, dry-heated and pre-gelatinized durum wheat flour samples. The isotherms could be expressed by the Guggenheim-Anderson-de Boer equation. The amount of water sorbed to the untreated flour was highest for low water activity, with water sorbed to the pre-gelatinized and dry-heated flour samples following. The dry-heated and pregelatinized flour samples exhibited the same dependence of the moisture content on the partial molar volume of water at 25 °C as the untreated flour. The partial molar volume of water was ca. 9 cm(3)/mol at a moisture content of 0.03 kg-H2O/kg-d.m. The volume increased with increasing moisture content, and reached a constant value of ca. 17.5 cm(3)/mol at a moisture content of 0.2 kg-H2O/kg-d.m. or higher.

A study of partial molar volumes of citric acid and tartaric acid

Indian Academy of Sciences (India)

Partial molar volumes of citric acid and tartaric acid have been determined in water and binary aqueous mixtures of ethanol (5, 10, 15, 20 and 25% by weight of ethanol) at different temperatures and acid concentrations from the solution density measurements. The data have been evaluated by using Masson equation and ...

Partial Molar Volumes of 15-Crown-5 Ether in Mixtures of N,N-Dimethylformamide with Water.

Science.gov (United States)

Tyczyńska, Magdalena; Jóźwiak, Małgorzata

2014-01-01

The density of 15-crown-5 ether (15C5) solutions in the mixtures of N,N -dimethylformamide (DMF) and water (H 2 O) was measured within the temperature range 293.15-308.15 K using an Anton Paar oscillatory U-tube densimeter. The results were used to calculate the apparent molar volumes ( V Φ ) of 15C5 in the mixtures of DMF + H 2 O over the whole concentration range. Using the apparent molar volumes and Redlich and Mayer equation, the standard partial molar volumes of 15-crown-5 were calculated at infinite dilution ([Formula: see text]). The limiting apparent molar expansibilities ( α ) were also calculated. The data are discussed from the point of view of the effect of concentration changes on interactions in solution.

Note: Nonpolar solute partial molar volume response to attractive interactions with water

Energy Technology Data Exchange (ETDEWEB)

Williams, Steven M.; Ashbaugh, Henry S., E-mail: hanka@tulane.edu [Department of Chemical and Biomolecular Engineering, Tulane University, New Orleans, Louisiana 70118 (United States)

2014-01-07

The impact of attractive interactions on the partial molar volumes of methane-like solutes in water is characterized using molecular simulations. Attractions account for a significant 20% volume drop between a repulsive Weeks-Chandler-Andersen and full Lennard-Jones description of methane interactions. The response of the volume to interaction perturbations is characterized by linear fits to our simulations and a rigorous statistical thermodynamic expression for the derivative of the volume to increasing attractions. While a weak non-linear response is observed, an average effective slope accurately captures the volume decrease. This response, however, is anticipated to become more non-linear with increasing solute size.

Note: Nonpolar solute partial molar volume response to attractive interactions with water.

Science.gov (United States)

Williams, Steven M; Ashbaugh, Henry S

2014-01-07

The impact of attractive interactions on the partial molar volumes of methane-like solutes in water is characterized using molecular simulations. Attractions account for a significant 20% volume drop between a repulsive Weeks-Chandler-Andersen and full Lennard-Jones description of methane interactions. The response of the volume to interaction perturbations is characterized by linear fits to our simulations and a rigorous statistical thermodynamic expression for the derivative of the volume to increasing attractions. While a weak non-linear response is observed, an average effective slope accurately captures the volume decrease. This response, however, is anticipated to become more non-linear with increasing solute size.

Calculation of partial molar volume of components in supercritical ammonia synthesis system

Institute of Scientific and Technical Information of China (English)

Cunwen WANG; Chuanbo YU; Wen CHEN; Weiguo WANG; Yuanxin WU; Junfeng ZHANG

2008-01-01

The partial molar volumes of components in supercritical ammonia synthesis system are calculated in detail by the calculation formula of partial molar volume derived from the R-K equation of state under different conditions. The objectives are to comprehend phase beha-vior of components and to provide the theoretic explana-tion and guidance for probing novel processes of ammonia synthesis under supercritical conditions. The conditions of calculation are H2/N2= 3, at a concentra-tion of NH3 in synthesis gas ranging from 2% to 15%, Concentration of medium in supercritical ammonia syn-thesis system ranging from 20% to 50%, temperature ran-ging from 243 K to 699 K and pressure ranging from 0.1 MPa to 187 MPa. The results show that the ammonia synthesis system can reach supercritical state by adding a suitable supercritical medium and then controlling the reaction conditions. It is helpful for the supercritical ammonia synthesis that medium reaches supercritical state under the conditions of the corresponding total pres-sure and components near the normal temperature or near the critical temperature of medium or in the range of tem-perature of industrialized ammonia synthesis.

Hydration of alcohol clusters in 1-propanol-water mixture studied by quasielastic neutron scattering and an interpretation of anomalous excess partial molar volume.

Science.gov (United States)

Misawa, M; Inamura, Y; Hosaka, D; Yamamuro, O

2006-08-21

Quasielastic neutron scattering measurements have been made for 1-propanol-water mixtures in a range of alcohol concentration from 0.0 to 0.167 in mole fraction at 25 degrees C. Fraction alpha of water molecules hydrated to fractal surface of alcohol clusters in 1-propanol-water mixture was obtained as a function of alcohol concentration. Average hydration number N(ws) of 1-propanol molecule is derived from the value of alpha as a function of alcohol concentration. By extrapolating N(ws) to infinite dilution, we obtain values of 12-13 as hydration number of isolated 1-propanol molecule. A simple interpretation of structural origin of anomalous excess partial molar volume of water is proposed and as a result a simple equation for the excess partial molar volume is deduced in terms of alpha. Calculated values of the excess partial molar volumes of water and 1-propanol and the excess molar volume of the mixture are in good agreement with experimental values.

The (water + acetonitrile) mixture revisited: A new approach for calculating partial molar volumes

International Nuclear Information System (INIS)

Carmen Grande, Maria del; Julia, Jorge Alvarez; Barrero, Carmen R.; Marschoff, Carlos M.; Bianchi, Hugo L.

2006-01-01

Density and viscosity of (water + acetonitrile) mixtures were measured over the whole composition range at the temperatures: (298.15, 303.15, 308.15, 313.15, and 318.15) K. A new mathematical approach was developed which allows the calculation of the derivatives of density with respect to composition avoiding the appearance of local discontinuities. Thus, reliable partial molar volumes and thermal expansion coefficients were obtained

Hydrophobic hydration and the anomalous partial molar volumes in ethanol-water mixtures

International Nuclear Information System (INIS)

Tan, Ming-Liang; Te, Jerez; Cendagorta, Joseph R.; Miller, Benjamin T.; Brooks, Bernard R.; Ichiye, Toshiko

2015-01-01

The anomalous behavior in the partial molar volumes of ethanol-water mixtures at low concentrations of ethanol is studied using molecular dynamics simulations. Previous work indicates that the striking minimum in the partial molar volume of ethanol V E as a function of ethanol mole fraction X E is determined mainly by water-water interactions. These results were based on simulations that used one water model for the solute-water interactions but two different water models for the water-water interactions. This is confirmed here by using two more water models for the water-water interactions. Furthermore, the previous work indicates that the initial decrease is caused by association of the hydration shells of the hydrocarbon tails, and the minimum occurs at the concentration where all of the hydration shells are touching each other. Thus, the characteristics of the hydration of the tail that cause the decrease and the features of the water models that reproduce this type of hydration are also examined here. The results show that a single-site multipole water model with a charge distribution that mimics the large quadrupole and the p-orbital type electron density out of the molecular plane has “brittle” hydration with hydrogen bonds that break as the tails touch, which reproduces the deep minimum. However, water models with more typical site representations with partial charges lead to flexible hydration that tends to stay intact, which produces a shallow minimum. Thus, brittle hydration may play an essential role in hydrophobic association in water

Partial molar volumes of L-alanine, DL-serine, DL-threonine, L-histidine, glycine, and glycylglycine in water, NaCl, and DMSO aqueous solutions at T 298.15 K

International Nuclear Information System (INIS)

Yuan Quan; Li Zhifen; Wang Baohuai

2006-01-01

The apparent molar volumes of L-alanine, DL-serine, DL-threonine, L-histidine, glycine, and glycylglycine in water and in the aqueous solutions of NaCl and DMSO with various concentrations at T = 298.15 K have been measured by the precise vibrating-tube digital densimeter. The calculated partial molar volumes at infinite dilution have been used to obtain corresponding transfer volumes from water to various solutions. The experimental results show that the standard partial molar volumes of the above amino acids and peptide at the dilute DMSO aqueous solutions are very close to those in water. However, the volumes show several types of variations with the increase of the concentrations of DMSO due to different types of side chain of amino acids, which should be discussed specifically. The NaCl changes considerably the infinite dilution standard partial molar volumes of the above amino acids and peptide in the aqueous solutions. The infinite dilution standard partial molar volumes of the each amino acids and peptide increase with the concentrations of NaCl. The experimental results have been rationalized by a cosphere overlap model

Thermodynamic interrelation between excess limiting partial molar characteristics of a liquid nonelectrolyte

International Nuclear Information System (INIS)

Ivanov, Evgeniy V.

2012-01-01

Highlights: ► Excess limiting molar volume may be regarded as a solvation-related characteristic. ► Volumetric and enthalpic effects of dissolution are interrelated thermodynamically. ► Possibility to estimate the partial change in solute compressibility is described. - Abstract: On the basis of thermodynamic analysis, it is concluded that the excess limiting partial molar volume, like the excess limiting partial molar enthalpy, can be considered as a solvation-related characteristic of a liquid nonelectrolyte. A thermodynamically grounded interrelation between standard volumetric and enthalpic effects of solution of a liquid nonelectrolyte (or series of nonelectrolytes) is suggested.

Partial Molar Volumes of Air-Component Gases in Several Liquid n-Alkanes and 1-Alkanols at 313.15 K

Czech Academy of Sciences Publication Activity Database

Izák, Pavel; Cibulka, I.; Heintz, A.

1995-01-01

Roč. 109, č. 2 (1995), s. 227-234 ISSN 0378-3812 Keywords : data density * partial molar volume * gas -liquid mixture Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 1.024, year: 1995

Partial molar volume and isentropic compressibility of symmetrical and asymmetrical quaternary ammonium bromides in aqueous solution

International Nuclear Information System (INIS)

Moreno, Nicolás; Buchner, Richard; Vargas, Edgar F.

2015-01-01

Highlights: • Structural effects of the cations on surrounding water molecules are discussed. • Alkyl-chain geometry determines the hydration of Bu 4 N + isomers. • The “compactness” in the hydration shells varies significantly among the isomers. - Abstract: Values of apparent molar volume and isentropic compressibility of symmetric and asymmetric isomers of tetrabutylammonium bromide, namely tetra-n-butylammonium bromide, tetra-iso-butylammonium bromide, tetra-sec-butylammonium bromide, di-n-butyl-di-iso-butylammonium bromide and di-n-butyl-di-sec-butylammonium bromide, in aqueous solution were determined from density and speed of sound measurements. These properties were obtained as a function of molal concentration within the range of 0.01 < m/mol · kg −1 < 0.1 covering temperatures from 278.15 ⩽ T/K ⩽ 293.15. The partial molar volumes and the apparent isentropic molar compressibility at infinite dilution were calculated and their dependence on temperature examined. The results show that cations with sec-butyl chains have larger structural volumes compared to those with iso-butyl chains. In addition, cations with sec-butyl chains induce smaller structural changes in their hydration shell than the others

Partial molar volumes and viscosities of aqueous hippuric acid solutions containing LiCl and MnCl2 · 4H2O at 303.15 K

Science.gov (United States)

Deosarkar, S. D.; Tawde, P. D.; Zinjade, A. B.; Shaikh, A. I.

2015-09-01

Density (ρ) and viscosity (η) of aqueous hippuric acid (HA) solutions containing LiCl and MnCl2 · 4H2O have been studied at 303.15 K in order to understand volumetric and viscometric behavior of these systems. Apparent molar volume (φv) of salts were calculated from density data and fitted to Massons relation and partial molar volumes (φ{v/0}) at infinite dilution were determined. Relative viscosity data has been used to determine viscosity A and B coefficients using Jones-Dole relation. Partial molar volume and viscosity coefficients have been discussed in terms of ion-solvent interactions and overall structural fittings in solution.

Quadrupole terms in the Maxwell equations: Born energy, partial molar volume, and entropy of ions.

Science.gov (United States)

Slavchov, Radomir I; Ivanov, Tzanko I

2014-02-21

A new equation of state relating the macroscopic quadrupole moment density Q to the gradient of the field ∇E in an isotropic fluid is derived: Q = αQ(∇E - U∇·E/3), where the quadrupolarizability αQ is proportional to the squared molecular quadrupole moment. Using this equation of state, a generalized expression for the Born energy of an ion dissolved in quadrupolar solvent is obtained. It turns out that the potential and the energy of a point charge in a quadrupolar medium are finite. From the obtained Born energy, the partial molar volume and the partial molar entropy of a dissolved ion follow. Both are compared to experimental data for a large number of simple ions in aqueous solutions. From the comparison the value of the quadrupolar length LQ is determined, LQ = (αQ/3ɛ)(1/2) = 1-4 Å. Data for ion transfer from aqueous to polar oil solution are analyzed, which allowed for the determination of the quadrupolarizability of nitrobenzene.

Towards a universal method for calculating hydration free energies: a 3D reference interaction site model with partial molar volume correction

International Nuclear Information System (INIS)

Palmer, David S; Frolov, Andrey I; Ratkova, Ekaterina L; Fedorov, Maxim V

2010-01-01

We report a simple universal method to systematically improve the accuracy of hydration free energies calculated using an integral equation theory of molecular liquids, the 3D reference interaction site model. A strong linear correlation is observed between the difference of the experimental and (uncorrected) calculated hydration free energies and the calculated partial molar volume for a data set of 185 neutral organic molecules from different chemical classes. By using the partial molar volume as a linear empirical correction to the calculated hydration free energy, we obtain predictions of hydration free energies in excellent agreement with experiment (R = 0.94, σ = 0.99 kcal mol -1 for a test set of 120 organic molecules). (fast track communication)

Towards a universal method for calculating hydration free energies: a 3D reference interaction site model with partial molar volume correction.

Science.gov (United States)

Palmer, David S; Frolov, Andrey I; Ratkova, Ekaterina L; Fedorov, Maxim V

2010-12-15

We report a simple universal method to systematically improve the accuracy of hydration free energies calculated using an integral equation theory of molecular liquids, the 3D reference interaction site model. A strong linear correlation is observed between the difference of the experimental and (uncorrected) calculated hydration free energies and the calculated partial molar volume for a data set of 185 neutral organic molecules from different chemical classes. By using the partial molar volume as a linear empirical correction to the calculated hydration free energy, we obtain predictions of hydration free energies in excellent agreement with experiment (R = 0.94, σ = 0.99 kcal mol (- 1) for a test set of 120 organic molecules).

Partial molar volumes of organic solutes in water. XXIII. Cyclic ketones at T = (298 to 573) K and pressures up to 30 MPa

International Nuclear Information System (INIS)

Cibulka, Ivan; Simurka, Lukas; Hnedkovsky, Lubomir; Bolotov, Alexander

2011-01-01

Research highlights: → In this study we examine standard molar volumes of aqueous cyclic ketones. → State parameters of measurements were (298 to 573) K and pressures up to 30 MPa. → Differences in behavior of monoketones and cyclohexane-1,4-dione were observed. → Group contribution method was designed and examined. - Abstract: Density data for dilute aqueous solutions of four cyclic ketones (cyclopentanone, cyclohexanone, cycloheptanone, and cyclohexane-1,4-dione) are presented together with standard molar volumes (partial molar volumes at infinite dilution) calculated from the experimental data. The measurements were performed at temperatures from T = 298 K up to T = 573 K. Experimental pressures were close to the saturated vapor pressure of water, and (15 and 30) MPa. The data were obtained using a high-temperature high-pressure flow vibrating-tube densimeter. Experimental standard molar volumes were correlated as a function of temperature and pressure using an empirical polynomial function. Contributions of the molecular structural segments (methylene and carbonyl groups) to the standard molar volume were also evaluated and analyzed.

Apparent molar volumes and compressibilities of electrolytes and ions in γ-butyrolactone

International Nuclear Information System (INIS)

Krakowiak, Joanna; Wawer, Jarosław; Farmas, Aleksander

2012-01-01

Highlights: ► Density and speed of sound for salts solutions in γ-butyrolactone were measured. ► The apparent molar volumes and compressibilities have been determined. ► The limiting molar quantities are split into independent ionic contributions. ► These data are used to describe ion–solvent interactions. - Abstract: The densities of tetraphenylphosphonium bromide, sodium tetraphenylborate, lithium perchlorate, sodium perchlorate and lithium bromide in γ-butyrolactone at (288.15, 293.15, 298.15, 303.15, 308.15 and 313.15) K and speed of sound at 298.15 K have been measured. From these data apparent molar volumes V Φ at (288.15, 293.15, 298.15, 303.15, 308.15 and 313.15) K and the apparent molar isentropic compressibility K S,Φ , at T = 298.15 K of the salts have been determined. The apparent molar volumes and the apparent molar isentropic compressibilities were fitted to the Redlich, Rosenfeld and Mayer equation as well as to the Pitzer and Masson equations yielding infinite dilution data. The obtained limiting values have been used to estimate the ionic data of the standard partial molar volume and the standard partial isentropic compressibility in γ-butyrolactone solutions.

Theoretical study of the partial molar volume change associated with the pressure-induced structural transition of ubiquitin.

Science.gov (United States)

Imai, Takashi; Ohyama, Shusaku; Kovalenko, Andriy; Hirata, Fumio

2007-09-01

The partial molar volume (PMV) change associated with the pressure-induced structural transition of ubiquitin is analyzed by the three-dimensional reference interaction site model (3D-RISM) theory of molecular solvation. The theory predicts that the PMV decreases upon the structural transition, which is consistent with the experimental observation. The volume decomposition analysis demonstrates that the PMV reduction is primarily caused by the decrease in the volume of structural voids in the protein, which is partially canceled by the volume expansion due to the hydration effects. It is found from further analysis that the PMV reduction is ascribed substantially to the penetration of water molecules into a specific part of the protein. Based on the thermodynamic relation, this result implies that the water penetration causes the pressure-induced structural transition. It supports the water penetration model of pressure denaturation of proteins proposed earlier.

Apparent molar volumes and compressibilities of lanthanum, gadolinium and lutetium trifluoromethanesulfonates in dimethylsulfoxide

International Nuclear Information System (INIS)

Warmińska, Dorota; Wawer, Jarosław

2012-01-01

Highlights: ► Sequence of volumes and compressibilities of Ln 3+ ions in DMSO is: La 3+ > Gd 3+ 3+ . ► Sequence of the partial molar volumes do not change with temperature. ► These results are the consequence of nature of the ion–solvent bonding. - Abstract: Temperature dependencies of the densities of dimethylsulfoxide solutions of lanthanum, gadolinium and lutetium trifluoromethanesulfonates have been determined over a wide range of concentrations. The apparent molar volumes and partial molar volumes of the salts at infinite dilution, as well as the expansibilities of the salts, have been calculated from density data. Additionally, the apparent molar isentropic compressibilities of lanthanum, gadolinium and lutetium trifluoromethanesulfonates have been calculated from sound velocity data at 298.15 K. The data obtained have been interpreted in terms of ion−solvent interactions.

Intrinsic alterations in the partial molar volume on the protein denaturation: surficial Kirkwood-Buff approach.

Science.gov (United States)

Yu, Isseki; Takayanagi, Masayoshi; Nagaoka, Masataka

2009-03-19

The partial molar volume (PMV) of the protein chymotrypsin inhibitor 2 (CI2) was calculated by all-atom MD simulation. Denatured CI2 showed almost the same average PMV value as that of native CI2. This is consistent with the phenomenological question of the protein volume paradox. Furthermore, using the surficial Kirkwood-Buff approach, spatial distributions of PMV were analyzed as a function of the distance from the CI2 surface. The profiles of the new R-dependent PMV indicate that, in denatured CI2, the reduction in the solvent electrostatic interaction volume is canceled out mainly by an increment in thermal volume in the vicinity of its surface. In addition, the PMV of the denatured CI2 was found to increase in the region in which the number density of water atoms is minimum. These results provide a direct and detailed picture of the mechanism of the protein volume paradox suggested by Chalikian et al.

Thermodynamic study of (heptane + amine) mixtures. III: Excess and partial molar volumes in mixtures with secondary, tertiary, and cyclic amines at 298.15 K

International Nuclear Information System (INIS)

Lepori, Luciano; Gianni, Paolo; Spanedda, Andrea; Matteoli, Enrico

2011-01-01

Graphical abstract: Highlights: → Excess volumes of (sec., tert., or cyclic amines + heptane) mixtures. → Excess volumes are positive for small size amines and decrease as the size increases. → Group contributions to predict the partial molar volumes of amines in heptane. → The void volume is larger for sec. and tert. than for linear amines in heptane. → The void volume is much smaller for cyclic than for linear amines in heptane. - Abstract: Excess molar volumes V E at 298.15 K were determined by means of a vibrating tube densimeter for binary mixtures of {heptane + open chain secondary (diethyl to dibutyl) and tertiary (triethyl to tripentyl) amines} as well as for cyclic imines (C 2 , C 3 , C 4 , C 6 , and C 7 ) and primary cycloalkylamines (C 5 , C 6 , C 7 , and C 12 ). The V E values were found positive for mixtures involving small size amines, with V E decreasing as the size increases. Negative V E 's were found for tributyl- and tripentylamine, heptamethylenimine, and cyclododecylamine. Mixtures of heptane with cycloheptylamine showed an s-shaped curve. Partial molar volumes V 0 of amines at infinite dilution in heptane were obtained from V E and compared with V 0 of hydrocarbons and other classes of organic compounds taken from literature. An additivity scheme, based on the intrinsic volume approach, was applied to estimate group (CH 3 , CH 2 , CH, C, NH 2 , NH, N, OH, O, CO, and COO) contributions to V 0 . These contributions, the effect of cyclization on V 0 , and the limiting slope of the apparent excess molar volumes were discussed in terms of solute-solvent and solute-solute interactions.

Fast Computation of Solvation Free Energies with Molecular Density Functional Theory: Thermodynamic-Ensemble Partial Molar Volume Corrections.

Science.gov (United States)

Sergiievskyi, Volodymyr P; Jeanmairet, Guillaume; Levesque, Maximilien; Borgis, Daniel

2014-06-05

Molecular density functional theory (MDFT) offers an efficient implicit-solvent method to estimate molecule solvation free-energies, whereas conserving a fully molecular representation of the solvent. Even within a second-order approximation for the free-energy functional, the so-called homogeneous reference fluid approximation, we show that the hydration free-energies computed for a data set of 500 organic compounds are of similar quality as those obtained from molecular dynamics free-energy perturbation simulations, with a computer cost reduced by 2-3 orders of magnitude. This requires to introduce the proper partial volume correction to transform the results from the grand canonical to the isobaric-isotherm ensemble that is pertinent to experiments. We show that this correction can be extended to 3D-RISM calculations, giving a sound theoretical justification to empirical partial molar volume corrections that have been proposed recently.

Experimental study of the density and derived volumetric (excess, apparent, and partial molar volumes) properties of aqueous 1-propanol mixtures at temperatures from 298 K to 582 K and pressures up to 40 MPa

International Nuclear Information System (INIS)

Abdulagatov, I.M.; Azizov, N.D.

2014-01-01

Highlights: • Density of (water + 1-propanol) mixtures. • Excess molar volumes of (water + 1-propanol) mixtures. • Apparent molar volumes of (water + 1-propanol) mixtures. -- Abstract: Densities of (water + 1-propanol) mixtures have been measured over the temperature range from 298 K to 582 K and at pressures up to 40 MPa using the constant-volume piezometer immersed in a precision liquid thermostat. The measurements were made for six compositions of (0.869, 2.465, 2.531, 7.407, 14.377, and 56.348) mol · kg −1 of 1-propanol. The expanded uncertainty of the density, pressure, temperature, and concentration measurements at the 95% confidence level with a coverage factor of k = 2 is estimated to be 0.06%, 0.05%, 15 mK, and 0.015%, respectively. The derived volumetric properties such as excess (V m E ), apparent (V Φ ), and partial (V ¯ 2 ∞ ) molar volumes were calculated using the measured values of density for the mixture and for pure components (water and 1-propanol). The concentration dependences of the apparent molar volumes were extrapolated to zero concentration to yield the partial molar volumes of 1-propanol at infinite dilution (V ¯ 2 ∞ ). The temperature, pressure, and concentration dependence of density and derived properties of the mixture were studied. All experimental and derived properties (excess, apparent, and partial molar volumes) were compared with the reported data by other authors. The small and negative values of excess molar volume for the mixtures were found at all experimental temperatures, pressures, and over the entire concentration range. The excess molar volume minimum is found at concentration about 0.4 mole fraction of 1-propanol. The concentration minimum of the derived apparent molar volumes V Φ near the 2.5 mol · kg −1 (dilute mixture) was observed

Densities, molar volumes, and isobaric expansivities of (d-xylose+hydrochloric acid+water) systems

International Nuclear Information System (INIS)

Zhang Qiufen; Yan Zhenning; Wang Jianji; Zhang Hucheng

2006-01-01

Densities of (d-xylose+HCl+water) have been measured at temperature in the range (278.15 to 318.15) K as a function of concentration of both d-xylose and hydrochloric acid. The densities have been used to estimate the molar volumes and isobaric expansivity of the ternary solutions. The molar volumes of the ternary solutions vary linearly with mole fraction of d-xylose. The standard partial molar volumes V 2,φ - bar for d-xylose in aqueous solutions of molality (0.2, 0.4, 0.7, 1.1, 1.6, and 2.1) mol.kg -1 HCl have been determined. In the investigated temperature range, the relation: V 2,φ - bar =c 1 +c 2 {(T/K)-273.15} 1/2 , can be used to describe the temperature dependence of the standard partial molar volumes. These results have, in conjunction with the results obtained in water, been used to deduce the standard volumes of transfer, Δ t V - bar , of d-xylose from water to aqueous HCl solutions. An increase in the transfer volume of d-xylose with increasing HCl concentrations has been explained by the stronger interactions of H + with the hydrophilic groups of d-xylose

Thermodynamic properties of peptide solutions 20. Partial molar volumes and isothermal compressions for some tripeptides of sequence gly-X-gly (X = gly, ala, leu, asn, thr, and tyr) in aqueous solution at T = 298.15 K and p = (10–120) MPa

International Nuclear Information System (INIS)

Hedwig, Gavin R.; Høiland, Harald

2016-01-01

Highlights: • Sound speeds were measured for aqueous solutions of some tripeptides at high pressures. • Partial molar volumes and isothermal compressions were derived for T = 298.15 K and p = (10–120) MPa. • The partial molar volumes for non-polar amino acid side-chains decrease with increasing pressure. • The partial molar volumes for polar side-chains do not change significantly with increasing pressure. - Abstract: Sound speeds have been measured for aqueous solutions of six tripeptides of sequence glycyl-X-glycine, where X is one of the amino acids glycine, alanine, leucine, asparagine, threonine, and tyrosine at T = 298.15 K and at the pressures p = (10, 20, 40, 60, 80, 100, and 120) MPa. Using methods described in previous work, these sound speeds were used to derive the partial molar volumes at infinite dilution, V_2"o, the partial molar isentropic compressions at infinite dilution, K_S_,_2"o, and the partial molar isothermal compressions at infinite dilution, K"o_T_,_2 {K"o_T_,_2 = −(∂V_2"o/∂p)_T}, for the tripeptides in aqueous solution at the elevated pressures. The results were used to calculate the partial molar volumes and partial molar isothermal compressions for the various amino acid side-chains over the pressure range p = (10–120) MPa.

Effect of temperature on the partial molar volume, isentropic compressibility and viscosity of DL-2-aminobutyric acid in water and in aqueous sodium chloride solutions

International Nuclear Information System (INIS)

Romero, Carmen M.; Rodríguez, Diana M.; Ribeiro, Ana C.F.; Esteso, Miguel A.

2017-01-01

Highlights: • Apparent volumes, apparent compressibilities, viscosities of DL-2-aminobutyric acid. • Effect of temperature on the values for these properties. • Hydrophobic and hydrophilic interactions and the effect of sodium chloride. - Abstract: Density, sound velocity and viscosity of DL-2-aminobutyric acid in water and in aqueous sodium chloride solutions have been measured at temperatures of (293.15, 298.15, 303.15, 308.15 and 313.15) K. The experimental results were used to determine the apparent molar volume and the apparent molar compressibility as a function of composition at these temperatures. The limiting values of both the partial molar volume and the partial molar adiabatic compressibility at infinite dilution of DL-2-aminobutyric acid in water and in aqueous sodium chloride solutions were determined at each temperature. The experimental viscosity values were adjusted by a least-squares method to a second order equation as proposed by Tsangaris-Martin to obtain the viscosity B coefficient which depends on the size, shape and charge of the solute molecule. The influence of the temperature on the behaviour of the selected properties is discussed in terms of both the solute hydration and the balance between hydrophobic and hydrophilic interactions between the acids and water, and the effect of the sodium chloride concentration.

Measurement and correlation of excess molar volumes for mixtures of 1-propanol and aromatic hydrocarbons

International Nuclear Information System (INIS)

Gahlyan, Suman; Rani, Manju; Maken, Sanjeev Kumar; Lee, Inkyu; Moon, Il

2015-01-01

Excess molar volumes (V m E ) have been measured at 303.15 K for 1-propanol+benzene or toluene or o- or m- or p-xylene mixtures using V-shape dilatometer. The V m E values, for an equimolar composition, vary in the order: benzene>toluene-m-xylene>o-xylene>p-xylene. The V m E data have been used to calculate partial molar volumes, excess partial molar volumes, and apparent molar volumes of 1-propanol and aromatic hydrocarbons over the entire range of composition. The excess volume data have also been interpreted in terms of graph-theoretical approach and Prigogine-Flory-Patterson theory (PFP). While PFP theory fails to predict the V m E values for systems with s-shaped V m E versus x 1 graph, the V m E values calculated by graph theory compare reasonably well with the corresponding experimental values. This graph theory analysis has further yielded information about the state of aggregation of pure components as well as of the mixtures

Partial molar volumes of organic solutes in water. XXIV. Selected alkane-α,ω-diols at temperatures T = 298 K to 573 K and pressures up to 30 MPa

International Nuclear Information System (INIS)

Cibulka, Ivan; Hnědkovský, Lubomír

2013-01-01

Highlights: • Standard molar volumes of three alkane-α,ω-diols (C 5 , C 8 , C 9 ) in water are presented. • Data were obtained in the range T from (298 to 573) K and p up to 30 MPa. • Dependences on carbon atom number, temperature, and pressure are analysed. -- Abstract: Density data for dilute aqueous solutions of three alkane-α,ω-diols (pentane-1,5-diol, octane-1,8-diol, nonane-1,9-diol) are presented together with standard molar volumes (partial molar volumes at infinite dilution) calculated from the experimental data. The measurements were performed at temperatures from T = 298 K up to T = 573 K. Experimental pressures were slightly above the saturation vapour pressure of water, and (15 and 30) MPa. The data were obtained using a high-temperature high-pressure flow vibrating-tube densimeter. Measured standard molar volumes were combined with data previously published for other members of the homologous series and discussed. Experimental standard molar volumes were correlated as a function of temperature and pressure using an empirical polynomial function. Dependences of standard molar volumes on temperature and pressure were analysed. Contributions of the methylene group to the standard molar volume were also evaluated and discussed

Apparent and partial molar volumes of long-chain alkyldimethylbenzylammonium chlorides and bromides in aqueous solutions at T=15 deg. C and T=25 deg. C

International Nuclear Information System (INIS)

Gonzalez-Perez, A.; Ruso, J.M.; Nimo, J.; Rodriguez, J.R.

2003-01-01

Density measurements of dodecyl- (C 12 DBACl), tetradecyl- (C 14 DBACl), hexadecyldimethylbenzylammonium chloride (C 16 DBACl) and of decyl- (C 10 DBABr) and dodecyldimethylbenzylammonium bromide (C 12 DBABr) in aqueous solutions at T=15 deg. C and T=25 deg. C have been carried out. From these results, apparent and partial molar volumes were calculated. Positive deviations from the Debye-Hueckel limiting law provide evidence for limited association at concentrations below the critical micelle concentration. The change of the apparent molar volume upon micellization was calculated. The relevant parameters have been presented in function of the alkyl chain length. Apparent molar volumes of the present compounds in the micellar phase, V phi m , and the change upon micellization, ΔV phi m , have been discussed in terms of temperature and type of counterion

Phase equilibria and excess molar volumes of tetrahydrofuran (1) + deuterium oxide (2)

International Nuclear Information System (INIS)

Lejcek, P.; Matous, J.; Novak, J.P.; Pick, J.

1975-01-01

Vapour + liquid equilibrium at 313.15 and 333.15K, liquid + liquid equilibrium throughout the whole region of limited miscibility, and excess molar volumes at 298.15K have been studied for tetrahydrofuran + deuterium oxide. The mixtures show large positive deviations from Raoult's law and a closed loop of limited miscibility. The modified Redlich-Kister equation has been used for the correlation of the vapour + liquid equilibrium. The computation has been carried out according to a recently proposed procedure which makes it possible to obtain such constants of the correlation relation which are not inconsistent with physical reality, i.e. with the complete miscibility (partial delta 2 G/deltax 1 2 >0) under experimental conditions. Thermodynamic consistency was checked by the classical Redlich-Kister test and the one proposed by Ulrichson and Stevenson. Excess molar volumes are negative at all compositions with a point of inflexion in the water-rich region which indicates the extremes in partial molar volumes. (author)

Aqueous partial molar heat capacities and volumes for NaReO4 and NaTcO4

International Nuclear Information System (INIS)

Lemire, R.J.; Saluja, P.P.S.; Campbell, A.B.

1989-01-01

As part of the Canadian Nuclear Fuel Waste Management Program, data are required to model the equilibrium thermodynamic behavior of key radionuclides at temperatures above 25 degree C. A flow microcalorimeter/densimeter system has been commissioned to measure heat capacities and densities of solutions containing radioactive species. Measurements for solutions of aqueous NaReO 4 (a common analogue for NaTcO 4 ) were made at seven temperatures (15 to 100 degree C) over the concentration range 0.05 to 0.2 mol·kg -1 . Subsequently, measurements were made for NaTcO 4 solutions under similar conditions. The heat capacity and density data are analyzed using Pitzer's ion-interaction model, and values of the NaReO 4 partial molar heat capacities are compared to literature values based on integral heats of solution. The agreement between the two sets of NaReO 4 data is good below 75 degree C, but only fair at the higher temperatures. Values of the partial molar volumes have also been derived. The uncertainties introduced by using thermodynamic data for ReO 4 - , in the absence of data for TcO 4 - , are discussed

Measurement and correlation of excess molar volumes for mixtures of 1-propanol and aromatic hydrocarbons

Energy Technology Data Exchange (ETDEWEB)

Gahlyan, Suman; Rani, Manju; Maken, Sanjeev Kumar [Deenbandhu Chhotu Ram University of Science and Technology, Murthal (India); Lee, Inkyu; Moon, Il [Yonsei University, Seoul (Korea, Republic of)

2015-01-15

Excess molar volumes (V{sub m}{sup E} ) have been measured at 303.15 K for 1-propanol+benzene or toluene or o- or m- or p-xylene mixtures using V-shape dilatometer. The V{sub m}{sup E} values, for an equimolar composition, vary in the order: benzene>toluene-m-xylene>o-xylene>p-xylene. The V{sub m}{sup E} data have been used to calculate partial molar volumes, excess partial molar volumes, and apparent molar volumes of 1-propanol and aromatic hydrocarbons over the entire range of composition. The excess volume data have also been interpreted in terms of graph-theoretical approach and Prigogine-Flory-Patterson theory (PFP). While PFP theory fails to predict the V{sub m}{sup E} values for systems with s-shaped V{sub m}{sup E} versus x{sub 1} graph, the V{sub m}{sup E} values calculated by graph theory compare reasonably well with the corresponding experimental values. This graph theory analysis has further yielded information about the state of aggregation of pure components as well as of the mixtures.

Apparent and standard partial molar heat capacities and volumes of aqueous tartaric acid and its sodium salts at elevated temperature and pressure

International Nuclear Information System (INIS)

Xie Wei; Trevani, Liliana; Tremaine, Peter R.

2004-01-01

Apparent molar heat capacities and volumes have been determined for aqueous solutions of tartaric acid (H 2 Tar, Tar=C 4 H 4 O 6 ), two buffer solutions of (H 2 Tar/NaHTar) and (NaHTar/Na 2 Tar), and solutions of disodium tartrate (Na 2 Tar) at four temperatures in the range 283.15≤T/K≤328.15 at p=1 MPa. Apparent molar volumes for H 2 Tar(aq) and Na 2 Tar(aq) have been measured at temperatures 377.15≤T/K≤529.15 and p=10.4 MPa. The experimental results have been represented with a model to describe the molality and temperature dependence. Extrapolations to infinite dilution yielded standard partial molar heat capacities C p 0 and volumes V 0 for the species H 2 Tar(aq), HTar - (aq) and Tar 2- (aq) over the range of experimental measurements. The temperature dependence of V 0 for Na 2 Tar(aq) is consistent with other aqueous electrolytes, while that of H 2 Tar(aq) may be anomalous, in that it does not show divergence towards increasingly positive values with increasing temperature

Partial molar volume of paracetamol in water, 0.1 M HCl and 0.154 M NaCl at T = (298.15, 303.15, 308.15 and 310.65) K and at 101.325 kPa

Energy Technology Data Exchange (ETDEWEB)

Iqbal, Muhammad Javed [Department of Chemistry, Quaid-i-Azam University, Islamabad, Capital 54320 (Pakistan)]. E-mail: mjiqauchem@yahoo.com; Malik, Qaisar Mahmood [Department of Chemistry, Quaid-i-Azam University, Islamabad, Capital 54320 (Pakistan)]. E-mail: qaisar_@hotmail.com

2005-12-15

The apparent molar volume of paracetamol (4-acetamidophenol) in water, 0.1 M HCl and 0.154 M NaCl as solvents at (298.15, 303.15, 308.15 and 310.65) K temperatures and at a pressure of 101.325 kPa were determined from the density data obtained with the help of a vibrating-tube Anton Paar DMA-48 densimeter. The partial molar volume, V {sub m}, of paracetamol in these solvents at different temperatures was evaluated by extrapolating the apparent molar volume versus molality plots to m = 0. In addition, the partial molar expansivity, E {sup .}, the isobaric coefficient of thermal expansion, {alpha} {sub p}, and the interaction coefficient, S {sub v}, have also been computed. The expansivity data show dependence of E {sup .} values on the structure of the solute molecules.

Partial molar volume of paracetamol in water, 0.1 M HCl and 0.154 M NaCl at T = (298.15, 303.15, 308.15 and 310.65) K and at 101.325 kPa

International Nuclear Information System (INIS)

Iqbal, Muhammad Javed; Malik, Qaisar Mahmood

2005-01-01

The apparent molar volume of paracetamol (4-acetamidophenol) in water, 0.1 M HCl and 0.154 M NaCl as solvents at (298.15, 303.15, 308.15 and 310.65) K temperatures and at a pressure of 101.325 kPa were determined from the density data obtained with the help of a vibrating-tube Anton Paar DMA-48 densimeter. The partial molar volume, V m , of paracetamol in these solvents at different temperatures was evaluated by extrapolating the apparent molar volume versus molality plots to m = 0. In addition, the partial molar expansivity, E . , the isobaric coefficient of thermal expansion, α p , and the interaction coefficient, S v , have also been computed. The expansivity data show dependence of E . values on the structure of the solute molecules

Apparent molar volumes and compressibilities of alkaline earth metal ions in methanol and dimethylsulfoxide

International Nuclear Information System (INIS)

Warminska, Dorota; Wawer, Jaroslaw; Grzybkowski, Waclaw

2010-01-01

Temperature dependencies of density of magnesium (II), calcium (II), strontium (II), barium (II) perchlorates as well as beryllium (II), and sodium trifluoromethanesulfonates in methanol and dimethylsulfoxide have been determined over the composition range studied. From density data the apparent molar volumes and partial molar volumes of the salts at infinite dilution as well as the expansibilities have been evaluated. The apparent molar isentropic compressibilities of alkaline earth metal perchlorates and beryllium (II) and sodium triflates in methanol and DMSO have been calculated from sound speed data obtained at T = 298.15 K.

Application of ERAS-model and Prigogine-Flory-Patterson theory to excess molar volumes for ternary mixtures of (2-chlorobutane + butylacetate + isobutanol) at T = 298.15 K

International Nuclear Information System (INIS)

Khanlarzadeh, K.; Iloukhani, H.

2011-01-01

Highlights: → Density of ternary and three binary mixtures of (2-chlorobutane + butylacetate + isobutanol) determined. → Excess molar volume, partial molar volume and apparent molar volume were calculated. → Excess molar volume was correlated as a function of mole fraction by using the Redlich-Kister and Cibulka equation for all mixtures. → The experimental results have been used to test the applicability of the ERAS-model and PFP theory. - Abstract: Densities of the ternary mixture consisting of {2-chlorobutane (1) + butylacetate (2) + isobutanol (3)} and related binary mixtures were measured over the whole range of composition at T = 298.15 K and ambient pressure. Excess molar volumes V m E for the mixtures were derived and correlated as a function of mole fraction by using the Redlich-Kister and the Cibulka equations for binary and ternary mixtures, respectively. From the experimental data, partial molar volumes, V-bar m,i excess partial molar volumes, V-bar i E partial molar volumes at infinite dilution V-bar m,i 0 and apparent molar volumes V-bar φ,i were also calculated. For all binary mixtures over the entire range of mole fractions V m E data are positive. The experimental results of the constituted binary mixtures have been used to test the applicability of the extended real associated solution (ERAS-model) and Prigogine-Flory-Paterson (PFP) theory.

Molar volume and adsorption isotherm dependence of capillary forces in nanoasperity contacts.

Science.gov (United States)

Asay, David B; Kim, Seong H

2007-11-20

The magnitude of the capillary force at any given temperature and adsorbate partial pressure depends primarily on four factors: the surface tension of the adsorbate, its liquid molar volume, its isothermal behavior, and the contact geometry. At large contacting radii, the adsorbate surface tension and the contact geometry are dominating. This is the case of surface force apparatus measurements and atomic force microscopy (AFM) experiments with micrometer-size spheres. However, as the size of contacting asperities decreases to the nanoscale as in AFM experiments with sharp tips, the molar volume and isotherm of the adsorbate become very important to capillary formation as well as capillary adhesion. This effect is experimentally and theoretically explored with simple alcohol molecules (ethanol, 1-butanol, and 1-pentanol) which have comparable surface tensions but differing liquid molar volumes. Adsorption isotherms for these alcohols on silicon oxide are also reported.

Solubilities and partial molar volumes of N,N′-dibutyl-oxalamide, N,N′-dihexyl-oxalamide, N,N′-dioctyl-oxalamide in supercritical carbon dioxide

International Nuclear Information System (INIS)

Luo, Jie; Yang, Hai-Jian; Jin, Jing; Chang, Fei

2012-01-01

Highlights: ► Three new “CO 2 -philic” compounds were designed and synthesized. ► The tested solubility data were calculated and correlated with two models. ► Satisfactory agreements were obtained between the tested and calculated data. ► AARD was lower than 13% for Chrastil model correlation. ► The partial molar volumes V ¯ 2 for each compound were estimated. - Abstract: Three new potent CO 2 -philic compounds were synthesized and their structures were characterized by FT-IR, NMR, and elemental analysis. The solubility of the three compounds in supercritical CO 2 was determined at T = (313 to 353) K from 9.1 MPa to 15.0 MPa. The experimental data were correlated with two density-based models proposed by Bartle and Chrastil, and the calculated results showed good agreement with the tested data. The calculated data by Bartle model differed from the measured values by (6.76 to 9.60)%, and the average value of absolute relative deviations (AARD) with Chrastil model were observed to be between (7.42 to 12.27)%. Furthermore, solubility data were also utilized to estimate the partial molar volume V ¯ 2 for each compound in the supercritical phase using the theory developed by Kumar and Johnston.

The partial molar heat capacity, expansion, isentropic, and isothermal compressions of thymidine in aqueous solution at T = 298.15 K

International Nuclear Information System (INIS)

Hedwig, Gavin R.; Jameson, Geoffrey B.; Hoiland, Harald

2011-01-01

Highlights: → Solution densities and sound speeds were measured for aqueous solutions of thymidine. → Partial molar volumetric properties at infinite dilution and T = 298.15 K were derived. → The partial molar isentropic and isothermal compressions are of opposite signs. → The partial molar heat capacity for thymidine at infinite dilution was determined. - Abstract: Solution densities have been determined for aqueous solutions of thymidine at T = (288.15, 298.15, 303.15, and 313.15) K. The partial molar volumes at infinite dilution, V 2 0 , obtained from the density data were used to derive the partial molar isobaric expansion at infinite dilution for thymidine at T = 298.15 K, E 2 0 {E 2 0 =(∂V 2 0 /∂T) p }. The partial molar heat capacity at infinite dilution for thymidine, C p,2 0 , at T = 298.15 K has also been determined. Sound speeds have been measured for aqueous solutions of thymidine at T = 298.15 K. The partial molar isentropic compression at infinite dilution, K S,2 0 , and the partial molar isothermal compression at infinite dilution, K T,2 0 {K T,2 0 =-(∂V 2 0 /∂P) T }, have been derived from the sound speed data. The V 2 0 , E 2 0 , C p,2 0 , and K S,2 0 results for thymidine are critically compared with those available from the literature.

The Partial Molar Volume and Compressibility of FeO in CaO-SiO2 Liquids: Systematic Variation with Fe2+ Coordination Change

Science.gov (United States)

Guo, X.; Lange, R. A.; Ai, Y.

2009-12-01

Iron is an important element in magmatic liquid, since its concentration can range up to 18% in some basaltic liquids, and it has two oxidation states. In order to model magmatic processes, thermodynamic descriptions of silicate melts must include precise information for both the FeO and Fe2O3 components. Currently, the partial molar volume of FeO is not as well known as that for Fe2O3 because of the difficulty of performing double-bob density measurements under reducing conditions. Yet these data are required in order to convert sound speed measurements on FeO-bearing liquids into compressibility data, which in turn are needed extend density models for magmatic liquids to elevated pressures. Moreover, there is growing evidence from the spectroscopic literature that Fe2+ occurs in 4, 5, and 6-fold coordination in silicate melts, and thus it is possible that the partial molar volume and compressibility of FeO may vary with Fe2+ coordination, and thus with melt composition. To explore these issues, we have conducted both density and relaxed sound speed measurements on liquids in the CaO-FeO-SiO2 system, where the CaO/SiO2 ratio was systematically varied at constant FeO concentration (40 mol%). Density was measured between 1594 and 1813K with the double-bob Archimedean method using molybdenum bobs and crucible in a reducing gas (1%CO-99%Ar) environment. The sounds speeds were measured under similar conditions with a frequency-sweep acoustic interferometer. The derived partial molar volume of FeO increases systematically from 13.7 to 15.2 cm3/mol at 1673 K as the CaO/SiO2 ratio increases and the Fe2+ coordination number decreases. From a comparison with the crystalline volume of FeO (halite structure; 12.06 cm3/mol), which serves as a lower limit for VFeO in silicate liquids when Fe2+ is in 6-fold coordination, we estimate that the average Fe2+ coordination in our experimental melts extends up to values between 5 and 4, consistent with the spectroscopic literature. The

Buoyancy Effect of Ionic Vacancy on the Change of the Partial Molar Volume in Ferricyanide-Ferrocyanide Redox Reaction under a Vertical Gravity Field

Directory of Open Access Journals (Sweden)

Yoshinobu Oshikiri

2013-01-01

Full Text Available With a gravity electrode (GE in a vertical gravity field, the buoyancy effect of ionic vacancy on the change of the partial molar volume in the redox reaction between ferricyanide (FERRI and ferrocyanide (FERRO ions was examined. The buoyancy force of ionic vacancy takes a positive or negative value, depending on whether the rate-determining step is the production or extinction of the vacancy. Though the upward convection over an upward electrode in the FERRO ion oxidation suggests the contribution of the positive buoyancy force arising from the vacancy production, the partial molar volume of the vacancy was not measured. On the other hand, for the downward convection under a downward electrode in the FERRI ion reduction, it was not completely but partly measured by the contribution of the negative buoyancy force from the vacancy extinction. Since the lifetime of the vacancy is decreased by the collision between ionic vacancies during the convection, the former result was ascribed to the shortened lifetime due to the increasing collision efficiency in the enhanced upward convection over an upward electrode, whereas the latter was thought to arise from the elongated lifetime due to the decreasing collision efficiency by the stagnation under the downward electrode.

The Voronoi volume and molecular representation of molar volume: equilibrium simple fluids.

Science.gov (United States)

Hunjan, Jagtar Singh; Eu, Byung Chan

2010-04-07

The Voronoi volume of simple fluids was previously made use of in connection with volume transport phenomena in nonequilibrium simple fluids. To investigate volume transport phenomena, it is important to develop a method to compute the Voronoi volume of fluids in nonequilibrium. In this work, as a first step to this goal, we investigate the equilibrium limit of the nonequilibrium Voronoi volume together with its attendant related molar (molal) and specific volumes. It is proved that the equilibrium Voronoi volume is equivalent to the molar (molal) volume. The latter, in turn, is proved equivalent to the specific volume. This chain of equivalences provides an alternative procedure of computing the equilibrium Voronoi volume from the molar volume/specific volume. We also show approximate methods of computing the Voronoi and molar volumes from the information on the pair correlation function. These methods may be employed for their quick estimation, but also provide some aspects of the fluid structure and its relation to the Voronoi volume. The Voronoi volume obtained from computer simulations is fitted to a function of temperature and pressure in the region above the triple point but below the critical point. Since the fitting function is given in terms of reduced variables for the Lennard-Jones (LJ) model and the kindred volumes (i.e., specific and molar volumes) are in essence equivalent to the equation of state, the formula obtained is a reduced equation state for simple fluids obeying the LJ model potential in the range of temperature and pressure examined and hence can be used for other simple fluids.

The Partial Molar Volume and Thermal Expansivity of Fe2O3 in Alkali Silicate Liquids: Evidence for the Average Coordination of Fe3+

Science.gov (United States)

Liu, Q.; Lange, R.

2003-12-01

Ferric iron is an important component in magmatic liquids, especially in those formed at subduction zones. Although it has long been known that Fe3+ occurs in four-, five- and six-fold coordination in crystalline compounds, only recently have all three Fe3+ coordination sites been confirmed in silicate glasses utilizing XANES spectroscopy at the Fe K-edge (Farges et al., 2003). Because the density of a magmatic liquid is largely determined by the geometrical packing of its network-forming cations (e.g., Si4+, Al3+, Ti4+, and Fe3+), the capacity of Fe3+ to undergo composition-induced coordination change affects the partial molar volume of the Fe2O3 component, which must be known to calculate how the ferric-ferrous ratio in magmatic liquids changes with pressure. Previous work has shown that the partial molar volume of Fe2O3 (VFe2O3) varies between calcic vs. sodic silicate melts (Mo et al., 1982; Dingwell and Brearley, 1988; Dingwell et al., 1988). The purpose of this study is to extend the data set in order to search for systematic variations in VFe2O3 with melt composition. High temperature (867-1534° C) density measurements were performed on eleven liquids in the Na2O-Fe2O3-FeO-SiO2 (NFS) system and five liquids in the K2O-Fe2O3-FeO-SiO2 (KFS) system using Pt double-bob Archimedean method. The ferric-ferrous ratio in the sodic and potassic liquids at each temperature of density measurement were calculated from the experimentally calibrated models of Lange and Carmichael (1989) and Tangeman et al. (2001) respectively. Compositions range (in mol%) from 4-18 Fe2O3, 0-3 FeO, 12-39 Na2O, 25-37 K2O, and 43-78 SiO2. Our density data are consistent with those of Dingwell et al. (1988) on similar sodic liquids. Our results indicate that for all five KFS liquids and for eight of eleven NFS liquids, the partial molar volume of the Fe2O3 component is a constant (41.57 ñ 0.14 cm3/mol) and exhibits zero thermal expansivity (similar to that for the SiO2 component). This value

Oxygen from Hydrogen Peroxide. A Safe Molar Volume-Molar Mass Experiment.

Science.gov (United States)

Bedenbaugh, John H.; And Others

1988-01-01

Describes a molar volume-molar mass experiment for use in general chemistry laboratories. Gives background technical information, procedures for the titration of aqueous hydrogen peroxide with standard potassium permanganate and catalytic decomposition of hydrogen peroxide to produce oxygen, and a discussion of the results obtained in three…

Hydrophobic hydration and anomalous excess partial molar volume of tert-butyl alcohol-water mixture studied by quasielastic neutron scattering

International Nuclear Information System (INIS)

Nakada, Masaru; Maruyama, Kenji; Misawa, Masakatsu; Yamamuro, Osamu

2007-01-01

Quasielastic neutron scattering has been used to investigate the hydration of alcohol clusters in tert-butyl alcohol-water mixture. The measurements were made in a range of alcohol concentration, x TBA , from 0.0 to 0.17 in mole fraction at 25degC. Fraction, α, of water molecules hydrated to fractal-surface of alcohol clusters in tert-butyl alcohol-water mixture was obtained as a function of alcohol concentration. Average hydration number N WS of tert-butyl alcohol molecule was derived from the value of α as a function of alcohol concentration. The value of N WS for an isolated alcohol molecule in water was 19-21. The anomalous excess partial molar volume of tert-butyl alcohol-water mixture was interpreted successfully by applying the same model with the same values of volume parameter as used for 1-propanol-water mixture, δ 1 (=-0.36 cm 3 ·mol -1 ) and δ 2 (=0.60 cm 3 ·mol -1 ). (author)

Apparatus to measure vapor pressure, differential vapor pressure, liquid molar volume, and compressibility of liquids and solutions to the critical point. Vapor pressures, molar volumes, and compressibilities of protiobenzene and deuteriobenzene at elevated temperatures

International Nuclear Information System (INIS)

Kooner, Z.S.; Van Hook, W.A.

1986-01-01

An apparatus designed to measure vapor pressure differences between two similar liquids, such as isotopic isomers, or between a solution and its reference solvent at temperatures and pressures extending to the critical point is described. Vapor-phase volume is minimized and pressure is transmitted to the transducer through the liquid, thereby avoiding several experimental difficulties. Liquid can be injected into the heated part of the system by volumetrically calibrated screw injectors, thus permitting measurements of liquid molar volume, compressibility, and expansivity. The addition of a high-pressure circulating pump and injection valve allows the apparatus to be employed as a continuous dilution differential vapor pressure apparatus for determining partial molar free energies of solution. In the second part of the paper data on the vapor pressure, molar volume, compressibility, and expansivity and their isotope effects for C 6 H 6 and C 6 D 6 from room temperature to near the critical temperature are reported

Application of the PFV EoS correlation to excess molar volumes of (1-ethyl-3-methylimidazolium ethylsulfate + alkanols) at different temperatures

International Nuclear Information System (INIS)

Deenadayalu, N.; Sen, S.; Sibiya, P.N.

2009-01-01

The experimental densities for the binary systems of an ionic liquid and an alkanol {1-ethyl-3-methylimidazolium ethylsulfate [EMIM] + [EtSO 4 ] - + methanol or 1-propanol or 2-propanol} were determined at T = (298.15, 303.15, and 313.15) K. The excess molar volumes for the above systems were then calculated from the experimental density values for each temperature. The Redlich-Kister smoothing polynomial was used to fit the experimental results and the partial molar volumes were determined from the Redlich-Kister coefficients. For all the systems studied, the excess molar volume results were negative over the entire composition range for all the temperatures. The excess molar volumes were correlated with the pentic four parameter virial (PFV) equation of state (EoS) model

A principle to correlate extreme values of excess thermodynamic functions with partial molar quantities

Institute of Scientific and Technical Information of China (English)

尉志武; 刘芸; 周蕊; 薛芳渝

2001-01-01

Excess thermodynamic properties are widely used quantitatively for fluids. It was found that at constant temperature and pressure a molar excess quantity of a mutually miscible binary mixture at the extreme points equals the excess partial molar quantities of the two components, i.e.F1E = F2E = FmE , forming a triple cross point. The relationship is hold for properties such as en-thalpy, entropy, Gibbs free energy, and volume, and is applicable for excess functions with multi extreme points. Solutions at extreme points can be referred to as special mixtures. Particularly fora special mixture of Gibbs free energy, activity coefficients of the two components are identical.

A principle to correlate extreme values of excess thermody-namic functions with partial molar quantities

Institute of Scientific and Technical Information of China (English)

无

2001-01-01

Excess thermodynamic properties are widely used quantitatively for fluids. It was found that at constant temperature and pressure a molar excess quantity of a mutually miscible binary mixture at the extreme points equals the excess partial molar quantities of the two components, i.e. , forming a triple cross point. The relationship is hold for properties such as enthalpy, entropy, Gibbs free energy, and volume, and is applicable for excess functions with multi extreme points. Solutions at extreme points can be referred to as special mixtures. Particularly for a special mixture of Gibbs free energy, activity coefficients of the two components are identical.

Application of Prigogine-Flory-Patterson theory to excess molar volume of mixtures of 1-butyl-3-methylimidazolium ionic liquids with N-methyl-2-pyrrolidinone

International Nuclear Information System (INIS)

Qi Feng; Wang Haijun

2009-01-01

The densities of two binary mixtures formed by 1-butyl-3-methylimidazolium tetrafluoroborate [bmim][BF 4 ] and 1-butyl-3-methy limidazolium hexafluorophosphate [bmim][PF 6 ] with compound N-methyl-2-pyrrolidinone have been determined over the full range of composition and range of temperature from (298.15 to 313.15) K and at atmospheric pressure using a vibrating-tube densimeter (DMA4500). Excess molar volumes, V m E , have been obtained from these experimental results, and been fitted by the fourth-order Redlich-Kister equation. From the experimental results, partial molar volumes, apparent molar volume and partial molar volumes at infinite dilution were calculated over the whole composition range. Our results show that V m E decreases slightly when temperature increases in the systems studied. The experimental results have been used to test the applicability of the Prigogine-Flory-Patterson (PFP) theory. The results have been interpreted in terms of ion-dipole interactions and structural factors of the ionic liquid and these organic molecular liquids

Excess molar volumes and isentropic compressibilities of binary

Indian Academy of Sciences (India)

Excess molar volumes (E) and deviation in isentropic compressibilities (s) have been investigated from the density and speed of sound measurements of six binary liquid mixtures containing -alkanes over the entire range of composition at 298.15 K. Excess molar volume exhibits inversion in sign in one binary ...

Molar volume of eutectic solvents as a function of molar composition and temperature☆

Institute of Scientific and Technical Information of China (English)

Farouq S. Mjalli

2016-01-01

The conventional Rackett model for predicting liquid molar volume has been modified to cater for the effect of molar composition of the Deep Eutectic Solvents (DES). The experimental molar volume data for a group of commonly used DES has been used for optimizing the improved model. The data involved different molar compositions of each DES. The validation of the new model was performed on another set of DESs. The average relative deviation of the model on the training and validation datasets was approximately 0.1%while the Rackett model gave a relative deviation of more than 1.6%. The modified model deals with variations in DES molar com-position and temperature in a more consistent way than the original Rackett model which exhibits monotonic performance degradation as temperature moves away from reference conditions. Having the composition of the DES as a model variable enhances the practical utilization of the predicting model in diverse design and process simulation applications.

Solubility comparison and partial molar volumes of 1,2-hexanediol before and after end-group modification by methyl oxalyl chloride and ethyl oxalyl monochloride in supercritical CO2

International Nuclear Information System (INIS)

Zhao, Lu; Yang, Hai-Jian; Cai, Zhuofu

2013-01-01

Highlights: ► Two new “CO 2 -philic” compounds were designed and synthesized. ► The tested solubility data were calculated and correlated with two models. ► Satisfactory agreements were obtained between the tested and calculated data. ► The partial molar volumes V ¯ 2 for three compounds were estimated. - Abstract: Bis(methoxy oxalic)-1,2-haxenediester and bis(ethoxy oxalic)-1,2-haxenediester were synthesized by modifying the end groups of 1,2-hexanediol with methyl oxalyl chloride and ethyl oxalyl monochloride. The solubilities of all three compounds in supercritical carbon dioxide were determined at different conditions of pressures (8.8 to 18.8) MPa and temperatures (313, 333, and 353) K. Then, the solubility data were correlated with the Bartle model and the Chrastil model. The average absolute relative deviation (AARD) for the Bartle model was in the range of (3.89 to 25.46)% which is within a good approximation. The Chrastil model also showed satisfactory agreement and the AARD was in the range of (3.70 to 16.92)%. Furthermore, the partial molar volumes of those compounds were estimated following the theory developed by Kumar and Johnston.

The molar hydrodynamic volume changes of factor VIIa due to GlycoPEGylation

DEFF Research Database (Denmark)

Plesner, Bitten; Westh, Peter; Hvidt, Søren

2011-01-01

The effects of GlycoPEGylation on the molar hydrodynamic volume of recombinant human rFVIIa were investigated using rFVIIa and two GlycoPEGylated recombinant human FVIIa derivatives, a linear 10 kDa PEG and a branched 40 kDa PEG, respectively. Molar hydrodynamic volumes were determined by capillary......, that the molar hydrodynamic volume of the conjugated protein is not just an addition of the molar hydrodynamic volume of the PEG and the protein. The molar hydrodynamic volume of the GlycoPEGylated protein is larger than the volume of its composites. These results suggest that both the linear and the branched...

二氧化碳与2-丁醇二元体系在高压下的亨利系数和偏摩尔体积性质计算%Calculation of Henry's coefficient and partial molar volume of carbon dioxide in 2-butanol at elevated pressures

Institute of Scientific and Technical Information of China (English)

田爱琴; 孙洪博; 陈文涛; 王琳

2012-01-01

Based on vapor-liquid phase equilibria data for CO2+2-butanol binary system from 323K to 353K by constant-volume visual high-pressure cell, the solubility model of CO2 in 2-butanol was established with Krichevsky-Kasarnovsky equation. Henry's coefficients and partial molar volumes of CO2 at infinite dilution were calculated. Meanwhile, Partial molar volumes of CO2 and 2-butanol at equilibrium were calculated from partial molar volumes properties together with Peng-Robinson equation of state and Van der Waals-2 mixed rule. The results showed that Henry's coefficients and partial molar volumes of CO2 at infinite dilution were both the function of temperature, and Henry's coefficients decreased with temperature. The partial molar volumes of CO2 at infinite dilution were negative and the magnitudes decreased with temperature. The calculated effects of partial molar volumes of vapor and liquid phase at equilibrium showed that the partial molar volumes of CO2 and 2-butanol in liquid phase were positive, but in vapor the partial molar volumes of CO2 were negative and the partial molar volumes of 2-butanol were positive. The research provided theoretical basis for deciding supercritical extraction conditions and instructing industrial production.%利用固定体积可视高压釜测量出的在323 K～353 K温度范围内的CO2与2-丁醇二元体系在高压下的汽液相平衡数据,根据Krichevsky-Kasarnovsky方程建立了CO2在液相中的溶解度模型,得到了该二元体系在高压下的亨利系数和CO2在无限稀释溶液中的偏摩尔体积等性质.同时根据偏摩尔体积性质和Peng-Robinson状态方程及Van der Waals-2混合规则来计算该体系在平衡状态下的气、液相的偏摩尔体积.结果表明CO2在2-丁醇中的亨利系数和CO2在无限稀释溶液中的偏摩尔体积均为温度的函数,CO2在2-丁醇中的亨利系数随温度的升高而降低.CO2在无限稀释溶液中的偏摩尔体积(V)1�

Experimental excess molar properties of binary mixtures of (3-amino-1-propanol + isobutanol, 2-propanol) at T = (293.15 to 333.15) K and modelling the excess molar volume by Prigogine–Flory–Patterson theory

International Nuclear Information System (INIS)

Kermanpour, F.; Niakan, H.Z.

2012-01-01

Highlights: ► Density and viscosity of binary mixtures of propanol derivatives were measured at T = (293.15 to 333.15) K. ► The excess molar properties were calculated from these experimental data and correlated by Redlich–Kister equation. ► The PFP model was applied for correlating the excess molar volumes. - Abstract: Density and viscosity of binary mixtures of (x 1 3-amino-1-propanol + x 2 isobutanol) and (x 1 3-amino-1-propanol + x 2 2-propanol) were measured over the entire composition range and from temperatures (293.15 to 333.15) K at ambient pressure. The excess molar volumes and viscosity deviations were calculated and correlated by the Redlich–Kister (RK) equation. The thermal expansion coefficient and its excess value, isothermal coefficient of excess molar enthalpy, and excess partial molar volumes were determined by using the experimental values of density and are described as a function of composition and temperature. The excess molar volumes are negative over the entire mole fraction range for both mixtures and increase with increasing temperature. The excess molar volumes obtained were correlated by the Prigogine–Flory–Patterson (PFP) model. The viscosity deviations of the binary mixtures are negative over the entire composition range and decrease with increasing temperature.

Apparent and standard molar volumes and heat capacities of aqueous Ni(ClO4)2 from 25 to 85oC

International Nuclear Information System (INIS)

Pan, P.; Campbell, A.B.

1997-01-01

Apparent molar heat capacities and volumes of aqueous Ni(ClO 4 ) 2 were measured from 25 to 85 o C over a concentration range of 0.02 to 0.8 mol-kg -1 using a Picker flow microcalorimeter and a Picker vibrating-tube densimeter. An extended Debye-Huckel equation was fitted to the experimental data to obtain expressions for the apparent molar properties as functions of ionic strength for Ni(ClO 4 ) 2 (aq). The standard-state partial molar properties for Ni(ClO 4 ) 2 (aq) in the temperature range 25 to 85 o C were obtained and can be expressed by empirical equations. The standard partial molar heat capacities and volumes for Ni 2+ (aq) from 25 to 86 o C were obtained by using the additivity rule and data for ClO - 4 (aq) in the literature. These values were extrapolated to 300 o C by employing the Helgeson-Kirkham-Flower (HKF) equations, amended to include a standard-state correction term. (author)

Densities, excess molar volumes, speeds of sound and isothermal compressibilities for {2-(2-hexyloxyethoxy)ethanol + n-alkanol} systems at temperatures between (288.15 and 308.15) K

International Nuclear Information System (INIS)

Pal, Amalendu; Gaba, Rekha

2008-01-01

The densities, ρ and the speeds of sound, u, for {2-(2-hexyloxyethoxy)ethanol (C 6 E 2 ) + methanol, +1-propanol, +1-pentanol, and +1-heptanol} have been measured as a function of composition using an Anton-Paar DSA 5000 densimeter at temperatures (288.15, 293.15, 298.15, 303.15, and 308.15) K and atmospheric pressure over the whole concentration range. The ρ and u values were used to calculate excess molar volumes, V E , and excess molar isentropic compressibility, K S,m E , respectively. Also, thermal expansivity, α, partial molar volume, V-bar i , and partial molar volume of the components at infinite dilution, V-bar i 0 , have been calculated. The variation of these properties with composition and temperature of the mixtures are discussed in terms of molecular interactions

293.15 K到333.15 K温度下一些氨基酸及其相应基团水溶液中的偏摩尔体积研究%Studies on Partial Molar Volumes of Some Amino Acids and Their Groups in Aqueous Solutions from 293.15 K to 333.15 K

Institute of Scientific and Technical Information of China (English)

赵长伟; 马沛生; 夏淑倩

2004-01-01

Densities of aqueous solutions of eight amino acids, glycine, L-alanine, L-valine, L-isoleucine, L-serine,L-threonine, L-arginine and L-phenylalanine, are measured as a function of amino acid concentration from 293.15 K to 333.15K. These data are used to calculate the apparent molar volume V and infinite dilution apparent molar volume V0 (partial molar volume). Data of five amino acids are used to correlate partial molar volume V0 using group contribution method to estimate the contributions of the zwitterionic end groups (NH3+,COO-) and CH2group, OH group, CNHNHNH2 group and C6H5(phenyl) group of amino acids. The results show that V0 values for all kinds of groups of amino acids studied increase with increase of temperature except those for CH2 group,which are almost constant within the studied temperature range. Data of other amino acids, L-valine, L-isoleucine and L-threonine, are chosen for comparison with the predicted partial molar volume V0 using the group additivity parameters obtained. The results confirm that this group additivity method has excellent predictive utility.

Densities and apparent molar volumes of aqueous LiI solutions at temperatures from (296 to 600) K and at pressures up to 30 MPa

International Nuclear Information System (INIS)

Abdulagatov, I.M.; Azizov, N.D.

2004-01-01

Densities of five aqueous LiI solutions (0.0906, 0.2832, 0.6621, 1.6046, and 3.0886) mol . kg -1 H 2 O were measured in the liquid phase with a constant-volume piezometer immersed in a precision liquid thermostat. Measurements were made along various isotherms between (296.95 and 600.25) K. The range of pressure was (0.1 to 30) MPa. The total uncertainty of density, pressure, temperature, and concentration measurements was estimated to be less than 0.06%, 0.05%, 15 mK, and 0.014%, respectively. To check and confirm the accuracy of the measurements, (p,V m ,T,x) data were taken for pure water at selected temperatures and pressures. Experimental and calculated (IAPWS formulation) densities for pure water show excellent agreement within their experimental uncertainties (average absolute deviation is 0.02%). Values of saturated densities were determined by extrapolating experimental p - ρ data to the vapour pressure at fixed temperature and composition using a linear interpolating equation. Apparent molar volumes were derived using measured values of density for solutions and pure water. The apparent molar volumes were extrapolated to zero concentration (m → 0) to yield partial molar volumes of electrolyte (LiI) at infinite dilution. The temperature, pressure, and concentration dependence of apparent and partial molar volumes was studied. The measured values of density, apparent and partial molar volume were compared with data reported in the literature by other authors. A polynomial type of equation of state for specific volume was obtained as a function of temperature, pressure, and composition by a least-squares method using the experimental data. The average absolute deviation (AAD) between measured and calculated values from this polynomial equation for density was 0.065%

Thermodynamics of aqueous methyldiethanolamine (MDEA) and methyldiethanolammonium chloride (MDEAH+Cl-) over a wide range of temperature and pressure: Apparent molar volumes, heat capacities, and isothermal compressibilities

International Nuclear Information System (INIS)

Hawrylak, B.; Palepu, R.; Tremaine, Peter R.

2006-01-01

Apparent molar volumes of aqueous methyldiethanolamine and its salt were determined with platinum vibrating tube densitometers over a range of temperatures from 283K= o , heat capacities C p o , and isothermal compressibilities κ T o . The standard partial molar volumes V o for the neutral amine and its salt show increasingly positive and negative values, respectively, at high temperatures and pressures, as predicted by corresponding states and group additivity arguments. The density model and the revised Helgeson-Kirkham-Flowers (HKF) model have been used to represent the temperature and pressure dependence of the standard partial molar properties to yield a full thermodynamic description of the system

Excess molar volumes and isentropic compressibility of binary systems {trioctylmethylammonium bis(trifluoromethysulfonyl)imide + methanol or ethanol or 1-propanol} at different temperatures

International Nuclear Information System (INIS)

Sibiya, P.N.; Deenadayalu, N.

2008-01-01

This paper reports measurements of densities for the binary systems of an ionic liquid and an alkanol at T = (298.15, 303.15, and 313.15) K. The IL is trioctylmethylammonium bis(trifluoromethylsulfonyl)imide [OMA] + [Tf 2 N] - and the alkanols are methanol, or ethanol, or 1-propanol. The speed of sound at T = 298.15 K for the same binary systems was also measured. The excess molar volumes and the isentropic compressibilities for the above systems were then calculated from the experimental densities and the speed of sound, respectively. Redlich-Kister smoothing polynomial equation was used to fit the excess molar volume and the deviation in isentropic compressibility data. The partial molar volumes were determined from the Redlich-Kister coefficients. For all the systems studied, the excess molar volumes have both negative and positive values, while the deviations in isentropic compressibility are negative over the entire composition range

Apparent molar volumes and compressibilities of lanthanum, gadolinium, lutetium and sodium trifluoromethanesulfonates in N,N-dimethylformamide and N,N-dimethylacetamide

International Nuclear Information System (INIS)

Warmińska, Dorota; Fuchs, Anna; Lundberg, Daniel

2013-01-01

Highlights: ► In DMF the sequence values of both volumes and compressibilities of Ln 3+ ions are: La 3+ ≈ Gd 3+ > Lu 3+ . ► In DMA the ionic volumes of lanthanoid(III) metal ions are, within error limits, identical. ► Obtained results are the consequence of an ion–solvent bonding nature. -- Abstract: The concentration and temperature dependencies of density of lanthanum, gadolinium, lutetium and sodium trifluoromethanesulfonates in N,N-dimethylformamide (DMF) and N,N-dimethylacetamide (DMA) have been determined. From density data the apparent molar volumes and partial molar volumes of the salts at infinite dilution as well as the expansibilities have been evaluated. The apparent molar isentropic compressibilities of lanthanum, gadolinium, lutetium and sodium trifluoromethanesulfonates in DMF and DMA have been calculated from sound velocity data obtained at 298.15 K. The results have been discussed in terms of ion–solvent interactions

Molecular theory of partial molar volume and its applications to biomolecular systems

Directory of Open Access Journals (Sweden)

T.Imai

2007-09-01

Full Text Available The paial molar volume (PMV is a thermodynamic quantity which contains important information about the solute-solvent interactions as well as the solute structure in solution.Additionally, the PMV is the most essential quantity in the analysis of the pressure effect on chemical reactions. This aicle reviews the recent developments in molecular theories of the PMV, especially the reference interaction site model (RISMtheory of molecular liquids and its three-dimensional generalization version (3D-RISM, which are combined with the Kirkwood-Buff solution theory to calculate the PMV. This aicle also introduces our recent applications of the theory to some interesting issues concerning the PMV of biomolecules. In addition, theoretical representations of the effects of intramolecular fluctuation on the PMV, which are significant for biomacromolecules, are briefly discussed.

The determination of molar volumes of uranous nitrate and nitric acid in systems of U(NO3)4-HNO3-H2O and U(NO3)4-HNO3-30% TBP kerosene

International Nuclear Information System (INIS)

Tao Chengying

1986-01-01

The data of molar volumes of uranous nitrate and nitric acid are necessary for the calculation of the changes in phase volume during the extraction in U(NO 3 ) 4 -HNO 3 /30%TBP-kerosene system. However, the data of the partial molar volume of U(NO 3 ) 4 are not available in literature. In the present work, the molar volumes of U(NO 3 ) 4 and HNO 3 are calculated by linear fitting of the experimental data. The result of the molar volume of HNO 3 is consistent with those in literature

Excess molar volumes and refractive indices of (methoxybenzene+benzene, or toluene, or o-xylene, or m-xylene, or p-xylene, or mesitylene) binary mixtures between T=(288.15 to 303.15)K

International Nuclear Information System (INIS)

Al-Kandary, Jasem A.; Al-Jimaz, Adel S.; Abdul-Latif, Abdul-Haq M.

2006-01-01

Densities ρ and refractive indices n D for (anisole+benzene, or toluene, or o-xylene, or m-xylene or p-xylene or mesitylene) binary mixtures over the entire range of mole fraction, at temperatures (288.15, 293.15, 298.15, and 303.15)K and atmospheric pressure, have been measured. The excess molar volume V E and molar refraction deviation ΔR m , have been calculated and fitted to the Redlich-Kister polynomial relation to estimate the binary coefficients and standard errors. The excess molar volumes are positive for (anisole+mesitylene) binary mixtures and negative for (anisole+benzene, or toluene, or xylene isomers) binary mixtures at various temperatures. Partial molar volumes V-bar i and partial excess molar volumes V-bar i E have been also derived from the experimental data. The calculated values have been used to explain the dependency of intermolecular interaction between the mixing components on the alkyl substitution on benzene ring

Influence of hydrostatic pressure on dynamics and spatial distribution of protein partial molar volume: time-resolved surficial Kirkwood-Buff approach.

Science.gov (United States)

Yu, Isseki; Tasaki, Tomohiro; Nakada, Kyoko; Nagaoka, Masataka

2010-09-30

The influence of hydrostatic pressure on the partial molar volume (PMV) of the protein apomyoglobin (AMb) was investigated by all-atom molecular dynamics (MD) simulations. Using the time-resolved Kirkwood-Buff (KB) approach, the dynamic behavior of the PMV was identified. The simulated time average value of the PMV and its reduction by 3000 bar pressurization correlated with experimental data. In addition, with the aid of the surficial KB integral method, we obtained the spatial distributions of the components of PMV to elucidate the detailed mechanism of the PMV reduction. New R-dependent PMV profiles identified the regions that increase or decrease the PMV under the high pressure condition. The results indicate that besides the hydration in the vicinity of the protein surface, the outer space of the first hydration layer also significantly influences the total PMV change. These results provide a direct and detailed picture of pressure induced PMV reduction.

Apparent molar volumes and compressibilities of selected electrolytes in dimethylsulfoxide

International Nuclear Information System (INIS)

Warminska, Dorota; Grzybkowski, Waclaw

2010-01-01

Densities at T = (293.15, 298.15, 303.15, 313.15, 323.15, and 333.15) K and sound velocities at T = 298.15 K of tetraphenylphosphonium bromide, sodium tetraphenylborate, sodium bromide, and sodium perchlorate in dimethylsulfoxide have been measured over the composition range from (0 to 0.3) mol . kg -1 . From these data, apparent molar volumes and apparent molar isentropic compressibilities at infinite dilution as well as the expansibilities have been evaluated. The results have been discussed in terms of employing tetraphenylphosphonium tetraphenylborate as a reference electrolyte in splitting the limiting apparent molar volumes and apparent molar isentropic compressibilities into ionic contributions.

Part 2: Limiting apparent molar volume of organic and inorganic 1:1 electrolytes in (water + ethylammonium nitrate) mixtures at 298 K - Thermodynamic approach using Bahe-Varela pseudo-lattice theory

International Nuclear Information System (INIS)

Bouguerra, Sabbah; Bou Malham, Ibrahim; Letellier, Pierre; Mayaffre, Alain; Turmine, Mireille

2008-01-01

Values of partial molar volumes at infinite dilution of 9 inorganic and 4 organic 1:1 electrolytes have been determined in (water + ethylammonium nitrate) (EAN) binary at 298.15 K throughout the composition scale. Our theoretical analysis shows that the values of partial molar volumes at infinite dilution of a solute in a binary are linked to those of the partial molar volumes of the components of mixed solvent. This applies to mixtures of molecular solvents as well as (water + ionic liquid) media. The use of the 'pseudo-lattice theory' of Bahe recently supplemented Varela can be used for calculations and to obtain information about the interactions between 1:1 electrolytes as solutes at infinite dilution and their concentrated saline environment. We show that the 'pseudo-lattice theory' allows accurate description of the behaviours of symmetrical tetraalkylammoniums bromide between the infinitely dilute state and concentrations higher than 2 mol . L -1

Molar Volume Analysis of Molten Ni-Al-Co Alloy by Measuring the Density

Institute of Scientific and Technical Information of China (English)

XIAO Feng; FANG Liang; FU Yuechao; YANG Lingchuan

2004-01-01

The density of molten Ni-Al-Co alloys was measured in the temperature range of 1714～1873K using a modified pycnometric method, and the molar volume of molten alloys was analyzed. The density of molten Ni-Al-Co alloys was found to decrease with increasing temperature and Co concentration in alloys. The molar volume of molten Ni-Al-Co alloys increases with increasing Co concentration in alloys. The molar volume of molten Ni-Al-Co alloys shows a negative deviation from the linear molar volume.

The Partial Molar Volume and Compressibility of the FeO Component in Model Basalts (Mixed CaAl2Si2O8-CaMgSi2O6-CaFeSi2O6 Liquids) at 0 GPa: evidence of Fe2+ in 6-fold coordination

Science.gov (United States)

Guo, X.; Lange, R. A.; Ai, Y.

2010-12-01

FeO is an important component in magmatic liquids and yet its partial molar volume at one bar is not as well known as that for Fe2O3 because of the difficulty of performing double-bob density measurements under reducing conditions. Moreover, there is growing evidence from spectroscopic studies that Fe2+ occurs in 4, 5, and 6-fold coordination in silicate melts, and it is expected that the partial molar volume and compressibility of the FeO component will vary accordingly. We have conducted both density and relaxed sound speed measurements on four liquids in the An-Di-Hd (CaAl2Si2O8-CaMgSi2O6-CaFeSi2O6) system: (1) Di-Hd (50:50), (2) An-Hd (50:50), (3) An-Di-Hd (33:33:33) and (4) Hd (100). Densities were measured between 1573 and 1838 K at one bar with the double-bob Archimedean method using molybdenum bobs and crucibles in a reducing gas (1%CO-99%Ar) environment. The sound speeds were measured under similar conditions with a frequency-sweep acoustic interferometer, and used to calculate isothermal compressibility. All the density data for the three multi-component (model basalt) liquids were combined with density data on SiO2-Al2O3-CaO-MgO-K2O-Na2O liquids (Lange, 1997) in a fit to a linear volume equation; the results lead to a partial molar volume (±1σ) for FeO =11.7 ± 0.3(±1σ) cm3/mol at 1723 K. This value is similar to that for crystalline FeO at 298 K (halite structure; 12.06 cm3/mol), which suggests an average Fe2+ coordination of ~6 in these model basalt compositions. In contrast, the fitted partial molar volume of FeO in pure hedenbergite liquid is 14.6 ± 0.3 at 1723 K, which is consistent with an average Fe2+ coordination of 4.3 derived from EXAFS spectroscopy (Rossano, 2000). Similarly, all the compressibility data for the three multi-component liquids were combined with compressibility data on SiO2-Al2O3-CaO-MgO liquids (Ai and Lange, 2008) in a fit to an ideal mixing model for melt compressibility; the results lead to a partial molar

Pressure Dependence of Molar Volume near the Melting Point in Benzene

Institute of Scientific and Technical Information of China (English)

无

2007-01-01

The pressure dependence of the molar volume was at constant temperatures close to the melting point in benzene. The molar volume of benzene was calculated using experimental data for the thermal expansivity for constant temperatures of 25℃, 28.5℃, 40℃, and 51℃ at various pressures for both the solid and liquid phases. The predictions are in good agreement with the observed volumes in both the solid and liquid phases of benzene. The predicted values of the molar volume for a constant temperature of 28.5℃ in the liquid phase of benzene agree well with experimental data in the literature.

What is the fundamental ion-specific series for anions and cations? Ion specificity in standard partial molar volumes of electrolytes and electrostriction in water and non-aqueous solvents.

Science.gov (United States)

Mazzini, Virginia; Craig, Vincent S J

2017-10-01

The importance of electrolyte solutions cannot be overstated. Beyond the ionic strength of electrolyte solutions the specific nature of the ions present is vital in controlling a host of properties. Therefore ion specificity is fundamentally important in physical chemistry, engineering and biology. The observation that the strengths of the effect of ions often follows well established series suggests that a single predictive and quantitative description of specific-ion effects covering a wide range of systems is possible. Such a theory would revolutionise applications of physical chemistry from polymer precipitation to drug design. Current approaches to understanding specific-ion effects involve consideration of the ions themselves, the solvent and relevant interfaces and the interactions between them. Here we investigate the specific-ion effects trends of standard partial molar volumes and electrostrictive volumes of electrolytes in water and eleven non-aqueous solvents. We choose these measures as they relate to bulk properties at infinite dilution, therefore they are the simplest electrolyte systems. This is done to test the hypothesis that the ions alone exhibit a specific-ion effect series that is independent of the solvent and unrelated to surface properties. The specific-ion effects trends of standard partial molar volumes and normalised electrostrictive volumes examined in this work show a fundamental ion-specific series that is reproduced across the solvents, which is the Hofmeister series for anions and the reverse lyotropic series for cations, supporting the hypothesis. This outcome is important in demonstrating that ion specificity is observed at infinite dilution and demonstrates that the complexity observed in the manifestation of specific-ion effects in a very wide range of systems is due to perturbations of solvent, surfaces and concentration on the underlying fundamental series. This knowledge will guide a general understanding of specific

A Structural Molar Volume Model for Oxide Melts Part III: Fe Oxide-Containing Melts

Science.gov (United States)

Thibodeau, Eric; Gheribi, Aimen E.; Jung, In-Ho

2016-04-01

As part III of this series, the model is extended to iron oxide-containing melts. All available experimental data in the FeO-Fe2O3-Na2O-K2O-MgO-CaO-MnO-Al2O3-SiO2 system were critically evaluated based on the experimental condition. The variations of FeO and Fe2O3 in the melts were taken into account by using FactSage to calculate the Fe2+/Fe3+ distribution. The molar volume model with unary and binary model parameters can be used to predict the molar volume of the molten oxide of the Li2O-Na2O-K2O-MgO-CaO-MnO-PbO-FeO-Fe2O3-Al2O3-SiO2 system in the entire range of compositions, temperatures, and oxygen partial pressures from Fe saturation to 1 atm pressure.

The Component Slope Linear Model for Calculating Intensive Partial Molar Properties: Application to Waste Glasses

International Nuclear Information System (INIS)

Reynolds, Jacob G.

2013-01-01

Partial molar properties are the changes occurring when the fraction of one component is varied while the fractions of all other component mole fractions change proportionally. They have many practical and theoretical applications in chemical thermodynamics. Partial molar properties of chemical mixtures are difficult to measure because the component mole fractions must sum to one, so a change in fraction of one component must be offset with a change in one or more other components. Given that more than one component fraction is changing at a time, it is difficult to assign a change in measured response to a change in a single component. In this study, the Component Slope Linear Model (CSLM), a model previously published in the statistics literature, is shown to have coefficients that correspond to the intensive partial molar properties. If a measured property is plotted against the mole fraction of a component while keeping the proportions of all other components constant, the slope at any given point on a graph of this curve is the partial molar property for that constituent. Actually plotting this graph has been used to determine partial molar properties for many years. The CSLM directly includes this slope in a model that predicts properties as a function of the component mole fractions. This model is demonstrated by applying it to the constant pressure heat capacity data from the NaOH-NaAl(OH 4 H 2 O system, a system that simplifies Hanford nuclear waste. The partial molar properties of H 2 O, NaOH, and NaAl(OH) 4 are determined. The equivalence of the CSLM and the graphical method is verified by comparing results detennined by the two methods. The CSLM model has been previously used to predict the liquidus temperature of spinel crystals precipitated from Hanford waste glass. Those model coefficients are re-interpreted here as the partial molar spinel liquidus temperature of the glass components

Polarization and molar volumes of ortho- and para-deuterium solutions

International Nuclear Information System (INIS)

Milenko, Yu.Ya.; Sibileva, R.M.

1976-01-01

The dielectric constant of liquid solutions of ortho-and para-deuterium is measured over the range of 2.2-91% p-D 2 from 18.7 to 20.4deg K. Data on polarization and molar volumes are obtained for the whole (0-100%) concentration range. Corrected summary to paper [2] is also listed: dielectric constant of ortho- and para-hydrogen liquid solution is measured within a concentration range of 0-97% of o-molecules at 14-20.4deg K. It is established that dependence of the Clausius-Mossotti function for o-p-hydrogen solutions of o-p-composition is linear. Molar volumes of the o-p-mixtures are calculated. The excessive molar volumes are found, positive deviation from additivity, 0.15% is established

Molecular representation of molar domain (volume), evolution equations, and linear constitutive relations for volume transport.

Science.gov (United States)

Eu, Byung Chan

2008-09-07

In the traditional theories of irreversible thermodynamics and fluid mechanics, the specific volume and molar volume have been interchangeably used for pure fluids, but in this work we show that they should be distinguished from each other and given distinctive statistical mechanical representations. In this paper, we present a general formula for the statistical mechanical representation of molecular domain (volume or space) by using the Voronoi volume and its mean value that may be regarded as molar domain (volume) and also the statistical mechanical representation of volume flux. By using their statistical mechanical formulas, the evolution equations of volume transport are derived from the generalized Boltzmann equation of fluids. Approximate solutions of the evolution equations of volume transport provides kinetic theory formulas for the molecular domain, the constitutive equations for molar domain (volume) and volume flux, and the dissipation of energy associated with volume transport. Together with the constitutive equation for the mean velocity of the fluid obtained in a previous paper, the evolution equations for volume transport not only shed a fresh light on, and insight into, irreversible phenomena in fluids but also can be applied to study fluid flow problems in a manner hitherto unavailable in fluid dynamics and irreversible thermodynamics. Their roles in the generalized hydrodynamics will be considered in the sequel.

Excess molar volumes of binary mixtures (an ionic liquid + water): A review

International Nuclear Information System (INIS)

Bahadur, Indra; Letcher, Trevor M.; Singh, Sangeeta; Redhi, Gan G.; Venkatesu, Pannuru; Ramjugernath, Deresh

2015-01-01

Highlights: • Review of excess molar volumes for mixtures of (ionic liquids (ILs) + H 2 O). • 6 cation groups reviewed including imidazolium and pyrrolidinium groups. • 13 anions reviewed including tetraborate, triflate, and hydrogensulphate. • Effects of anion, cation, and temperature investigated. - Abstract: This review covers recent developments in the area of excess molar volumes for mixtures of {ILs (1) + H 2 O (2)} where ILs refers to ionic liquids involving cations: imidazolium, pyridinium, pyrrolidinium, piperidinium, morpholinium and ammonium groups; and anions: tetraborate, triflate, hydrogensulphate, methylsulphate, ethylsulphate, thiocyanate, dicyanamide, octanate, acetate, nitrate, chloride, bromide, and iodine. The excess molar volumes of aqueous ILs were found to cover a wide range of values for the different ILs (ranging from −1.7 cm 3 · mol −1 to 1.2 cm 3 · mol −1 ). The excess molar volumes increased with increasing temperature for all systems studied in this review. The magnitude and in some cases the sign of the excess molar volumes for all the aqueous ILs mixtures, apart from the ammonium ILs, were very dependent on temperature. This was particularly important in the dilute IL concentration region. It was found that the sign and magnitude of the excess molar volumes of aqueous ILs (for ILs with hydrophobic cations), was more dependent on the nature of the anion than on the cation

Application of some geometrical and empirical models to excess molar volume for the multi-component mixtures at T = 298.15 K

International Nuclear Information System (INIS)

Iloukhani, H.; Khanlarzadeh, K.

2012-01-01

Highlights: ► Excess molar volume of quartenary mixtures of 1-chlorobutane, 2-chlorobutane, butylamine, and butylacetate was determined. ► The experimental data were correlated by some empirical and semi empirical models. ► A comparison with PFP theory has been successfully applied from binary data. - Abstract: Densities of the quaternary mixture consisting of {1-chlorobutane (1) + 2-chlorobutane (2) + butylamine (3) + butylacetate (4)} and related ternary mixtures of {1-chlorobutane (1) + 2-chlorobutane (2) + butylamine (3)}, {1-chlorobutane (1) + 2-chlorobutane (2) + butylacetate (4)}, {2-chlorobutane (2) + butylamine (3) + butylacetate (4)}, and binary systems of {1-chlorobutane (1) + 2-chlorobutane (2)}, {2-chlorobutane (2) + butylamine (3)}, were measured over the whole range of composition at T = 298.15 K and ambient pressure. Excess molar volumes, V m E , for the mixtures were derived and correlated as a function of mole fraction by using the Redlich–Kister and the Cibulka equations for binary and ternary mixtures, respectively. From the experimental data, partial molar volumes, V m,i and excess partial molar volumes, V m,i E were also calculated for binary systems. The experimental results of the constituted binary mixtures have been used to test the applicability of the Prigogine–Flory–Paterson (PFP) theory. A number of geometrical and empirical equations were also used to verify their ability to predict ternary and quaternary properties from their lower order mixtures. The experimental data were used to evaluate the nature and type of intermolecular interactions in multi-component mixtures.

Apparent molar volumes and apparent molar heat capacities of aqueous D-lactose · H2O at temperatures from (278.15 to 393.15) K and at the pressure 0.35 MPa

International Nuclear Information System (INIS)

Sargent, J.D.; Niederhauser, T.L.; Woolley, E.M.

2004-01-01

Apparent molar volumes V phi and apparent molar heat capacities C p,phi were determined for aqueous solutions of D-lactose · H 2 O at molalities (0.01 to 0.34) mol · kg -1 at temperatures (278.15 to 393.15) K, and at the pressure 0.35 MPa. Our V phi values were calculated from densities obtained using a vibrating tube densimeter, and our C p,phi values were obtained using a twin fixed-cell, power-compensation, differential-output, temperature-scanning calorimeter. Our results for D-lactose(aq) and for D-lactcose · H 2 O were fitted to functions of m and T and compared with the literature results for aqueous D-glucose and D-galactose solutions. Infinite dilution partial molar volumes V 2 compfn and heat capacities C p,2 compfn are given over the range of temperatures

Partial molar volumes of organic solutes in water. XXVI. 15-Crown-5 and 18-crown-6 ethers at temperatures (298 to 573) K and pressures up to 30 MPa

International Nuclear Information System (INIS)

Cibulka, Ivan

2015-01-01

Highlights: • Density data were obtained in the range T from (298 to 573) K and p up to 30 MPa. • Standard molar volumes of two crown ethers in water are presented. • Group contribution method was designed to estimate standard molar volumes of cyclic ethers. - Abstract: Densities of dilute aqueous solutions of two cyclic ethers, viz. 15-crown-5 and 18-crown-6, measured over the temperature range from (298 to 573) K and at pressures up to 30 MPa using an automated flow vibrating-tube densimeter are reported. Standard molar volumes were evaluated from the measured data. Present data were combined with those obtained previously for several cyclic ethers and predictions of standard molar volumes based on group contribution approach were tested and analysed

Molar volume dependence of the pressure of solid 3He at very low temperatures

International Nuclear Information System (INIS)

Mamiya, T.; Sawada, A.; Fukuyama, H.; Iwahashi, K.; Masuda, Y.

1983-01-01

The pressure of solid 3 He has been measured as a function of temperature T between 0.3 and 50 mK at molar volumes between 24.19 and 23.31 cm 3 . The entropy discontinuity obtained from the pressure jump at the ordering transition turned out to be almost independent of molar volumes, being about 0.40Rln2 in the studied range of molar volumes

Partial molar volumes of organic solutes in water. XXVII. Two aliphatic polyethers (triglyme, tetraglyme) at temperatures T = 298–573 K and pressures up to 30 MPa

International Nuclear Information System (INIS)

Cibulka, Ivan

2016-01-01

Highlights: • Standard molar volumes of two linear aliphatic polyethers in water are presented. • Data were obtained in the range T from (298 to 573) K and p up to 30 MPa. • Data combined with those obtained previously are analyzed and compared with standard molar volumes of cyclic ethers. - Abstract: Densities of dilute aqueous solutions of two linear aliphatic polyethers: 2,5,8,11-tetraoxadodecane (triethylene glycol dimethyl ether, triglyme) and 2,5,8,11,14-pentaoxapentadecane (tetraethylene glycol dimethyl ether, tetraglyme), measured in the temperature range from (298 to 573) K and at pressures up to 30 MPa using an automated flow vibrating-tube densimeter are reported. Standard molar volumes were evaluated from the measured data. The present values complement previous measurements performed for the title polyethers at atmospheric pressure in the temperature range from (278 to 343) K and extend the knowledge to temperature and pressure ranges in which the data on standard molar volumes for lower members of the homologous series (monoglyme, diglyme) are already available.

Excess molar volumes and isentropic compressibilities of binary ...

Indian Academy of Sciences (India)

Excess molar volume; binary liquid mixtures; isentropic compressibility; intermolecular interactions. ... mixtures are essential for fluid flow, mass flow and heat transfer processes in chemical ... Experimentally determined values of density(ρ).

excess molar volumes, and refractive index of binary mixtures

African Journals Online (AJOL)

Preferred Customer

because (a) water molecules have hydroxyl group which can make stronger hydrogen bonding than methanol and (b) water molecules and glycerol have suitable kinetic energy for bulk volumes at high temperature. Thus, the mixture of glycerol + water have big excess molar volume than methanol. The hydrogen bonding ...

Apparent molar volumes and apparent molar heat capacities of aqueous magnesium nitrate, strontium nitrate, and manganese nitrate at temperatures from 278.15 K to 393.15 K and at the pressure 0.35 MPa

International Nuclear Information System (INIS)

Jones, J.S.; Ziemer, S.P.; Brown, B.R.; Woolley, E.M.

2007-01-01

Apparent molar volumes V φ and apparent molar heat capacities C p,φ were determined at the pressure 0.35 MPa for aqueous solutions of magnesium nitrate Mg(NO 3 ) 2 at molalities m = (0.02 to 1.0) mol . kg -1 , strontium nitrate Sr(NO 3 ) 2 at m = (0.05 to 3.0) mol . kg -1 , and manganese nitrate Mn(NO 3 ) 2 at m = (0.01 to 0.5) mol . kg -1 . Our V φ values were calculated from solution densities obtained at T = (278.15 to 368.15) K using a vibrating-tube densimeter, and our C p,φ values were calculated from solution heat capacities obtained at T = (278.15 to 393.15) K using a twin fixed-cell, differential, temperature-scanning calorimeter. Empirical functions of m and T were fitted to our results, and standard state partial molar volumes and heat capacities were obtained over the ranges of T investigated

The molar hydrodynamic volume changes of factor VIIa due to GlycoPEGylation.

Science.gov (United States)

Plesner, Bitten; Westh, Peter; Hvidt, Søren; Nielsen, Anders D

2011-06-01

The effects of GlycoPEGylation on the molar hydrodynamic volume of recombinant human rFVIIa were investigated using rFVIIa and two GlycoPEGylated recombinant human FVIIa derivatives, a linear 10kDa PEG and a branched 40kDa PEG, respectively. Molar hydrodynamic volumes were determined by capillary viscometry and mass spectrometry. The intrinsic viscosities of rFVIIa, its two GlycoPEGylated compounds, and of linear 8kDa, 10kDa, 20kDa and branched 40kDa PEG polymers were determined. The measured intrinsic viscosity of rFVIIa is 6.0mL/g, while the intrinsic viscosities of 10kDa PEG-rFVIIa and 40kDa PEG-rFVIIa are 29.5mL/g and 79.0mL/g, respectively. The intrinsic viscosities of the linear PEG polymers are 20, 22.6 and 41.4mL/g for 8, 10, and 20kDa, respectively, and 61.1mL/g for the branched 40kDa PEG. From the results of the intrinsic viscosity and MALDI-TOF measurements it is evident, that the molar hydrodynamic volume of the conjugated protein is not just an addition of the molar hydrodynamic volume of the PEG and the protein. The molar hydrodynamic volume of the GlycoPEGylated protein is larger than the volume of its composites. These results suggest that both the linear and the branched PEG are not wrapped around the surface of rFVIIa but are chains that are significantly stretched out when attached to the protein. Copyright © 2011 Elsevier B.V. All rights reserved.

Infinitely dilute partial molar properties of proteins from computer simulation.

Science.gov (United States)

Ploetz, Elizabeth A; Smith, Paul E

2014-11-13

A detailed understanding of temperature and pressure effects on an infinitely dilute protein's conformational equilibrium requires knowledge of the corresponding infinitely dilute partial molar properties. Established molecular dynamics methodologies generally have not provided a way to calculate these properties without either a loss of thermodynamic rigor, the introduction of nonunique parameters, or a loss of information about which solute conformations specifically contributed to the output values. Here we implement a simple method that is thermodynamically rigorous and possesses none of the above disadvantages, and we report on the method's feasibility and computational demands. We calculate infinitely dilute partial molar properties for two proteins and attempt to distinguish the thermodynamic differences between a native and a denatured conformation of a designed miniprotein. We conclude that simple ensemble average properties can be calculated with very reasonable amounts of computational power. In contrast, properties corresponding to fluctuating quantities are computationally demanding to calculate precisely, although they can be obtained more easily by following the temperature and/or pressure dependence of the corresponding ensemble averages.

A notable difference between ideal gas and infinite molar volume limit of van der Waals gas

International Nuclear Information System (INIS)

Liu, Q H; Shen, Y; Bai, R L; Wang, X

2010-01-01

The van der Waals equation of state does not sufficiently represent a gas unless a thermodynamic potential with two proper and independent variables is simultaneously determined. The limiting procedures under which the behaviour of the van der Waals gas approaches that of an ideal gas are letting two van der Waals coefficients be zero rather than letting the molar volume become infinitely large; otherwise, the partial derivative of internal energy with respect to pressure at a fixed temperature does not vanish.

A notable difference between ideal gas and infinite molar volume limit of van der Waals gas

Science.gov (United States)

Liu, Q. H.; Shen, Y.; Bai, R. L.; Wang, X.

2010-05-01

The van der Waals equation of state does not sufficiently represent a gas unless a thermodynamic potential with two proper and independent variables is simultaneously determined. The limiting procedures under which the behaviour of the van der Waals gas approaches that of an ideal gas are letting two van der Waals coefficients be zero rather than letting the molar volume become infinitely large; otherwise, the partial derivative of internal energy with respect to pressure at a fixed temperature does not vanish.

Experimental and predicted data of excess molar enthalpies and excess molar volumes for the ternary system (1,3-dichlorobenzene + benzene + 1-chlorohexane) at T = 298.15 K

International Nuclear Information System (INIS)

Mato, Marta M.; Verdes, Pedro V.; Paz Andrade, M.I.; Legido, José Luis

2014-01-01

Graphical abstract: - Highlights: • Experimental enthalpy and densitiy for the mixture 1,3-dichlorobenzene + benzene + 1-chlorohexane were measured. • The excess molar volumes were calculated from the densities of the pure liquids and their mixtures. • The Cibulka equation was used to correlate the ternary contribution of the excess molar properties. • The experimental data were used to test several empirical equations. - Abstract: Experimental excess molar enthalpies, densities and excess molar volumes for the ternary system {x 1 1,3-dichlorobenzene + x 2 benzene + (1 − x 1 − x 2 ) 1-chlorohexane} have been determined at the temperature of 298.15 K and atmospheric pressure. Values of excess molar enthalpies were measured using a Calvet microcalorimeter, and excess molar volumes were determined from the densities of the pure liquids and mixtures, using a vibrating-tube densimeter. The results were fitted by means of different variable degree polynomials. Smooth representations of the results are presented and used to construct constant contours of excess molar enthalpy and excess molar volume on Roozeboom diagrams. Several empirical expressions that have been suggested for use with parameters and predicting excess properties of ternary mixtures from the experimental binary data were tested

Elastic properties and molar volume of rare-earth aluminosilicae glasses

International Nuclear Information System (INIS)

Tanabe, S.; Hirao, K.; Soga, N.

1992-01-01

This paper reports on the elastic properties, molar volume, and glass transition temperature (T g ) of rare-earth-containing aluminosilicate glasses that were investigated in the compositions of SiO 2 --LnAlO 3 and SiO 2 --Ln 3/4 Al 5/4 O 3 , where Ln is Y, La, Nd, Eu, or Yb. The molar volume decreased with decreased ionic size of the Ln 3+ ion, and T g and elastic moduli increased in the same order. The Yb-containing glasses showed the highest Young's modulus among all the oxide glasses, even higher than the highest value ever known fro glass containing Y 2 O 3 , as expected from the smaller ionic radius of Yb 3+ than that of Y 3+ . The bulk modulus was found to be almost proportional to the inverse four-thirds power of the molar volume of glasses in each composition, indicating that Ln 3+ ions can substitute for each other without changing the glass structure except for the size of the local structure around themselves. From the comparison of these properties, the structural role of rate-earth ions in these glasses is discussed

Apparent molar volumes and apparent molar heat capacities of dilute aqueous solutions of ethanol, 1-propanol, and 2-propanol at temperatures from 278.15 K to 393.15 K and at the pressure 0.35 MPa

International Nuclear Information System (INIS)

Origlia-Luster, M.L.; Woolley, E.M.

2003-01-01

Apparent molar volumes V phi and apparent molar heat capacities C p,phi have been determined for dilute aqueous solutions of ethanol, 1-propanol, and 2-propanol at temperatures from 278.15 K to 393.15 K and at the pressure 0.35 MPa. The molalities investigated ranged from 0.05 mol·kg -1 to 1.0 mol·kg -1 . We used a vibrating tube densimeter (DMA 512P, Anton PAAR, Austria) to determine the densities and volumetric properties. Heat capacities were obtained using a twin fixed-cell, power-compensation, differential-output, temperature-scanning calorimeter (NanoDSC 6100, Calorimetry Sciences Corporation, American Fork, UT, USA). The results were fit by regression to equations that describe the surfaces (V phi ,T,m) and (C p,phi ,T,m). Infinite dilution partial molar volumes V 2 0 and heat capacities C 0 p,2 were obtained over the range of temperatures by extrapolation of these surfaces to m=0 mol·kg -1

Excess molar volume and viscosity deviation for binary mixtures of γ-butyrolactone with dimethyl sulfoxide

International Nuclear Information System (INIS)

Krakowiak, Joanna; Śmiechowski, Maciej

2017-01-01

Highlights: • Densities and viscosities of DMSO-GBL binary liquid mixtures were measured. • The volumetric parameters and excess quantities were obtained. • Ab initio calculations were performed for single molecules and dimers in the studied mixture. • The interactions in solutions are weaker than in pure solvents. - Abstract: The densities of binary liquid mixtures of dimethyl sulfoxide and γ-butyrolactone at (293.15, 298.15, 303.15 and 313.15) K and viscosity at T = 298.15 K have been measured at atmospheric pressure over the entire range of concentration. From these data the excess molar volumes V E at (293.15, 298.15, 303.15 and 313.15) K and the viscosity deviation, the excess entropy, and the excess Gibbs energy of activation for viscous flow at T = 298.15 K have been determined. These data were mathematically represented by the Redlich-Kister polynomial. Partial and apparent molar volumes have been calculated for better understanding of the interactions in the binary systems. The obtained data indicate the lack of specific interactions between unlike molecules, which seem to be a little weaker as compared to the interactions in pure solvents.

Excess molar volumes and viscosities of binary mixtures of 1,2

Indian Academy of Sciences (India)

Home; Journals; Journal of Chemical Sciences; Volume 113; Issue 3. Excess molar volumes and viscosities of binary mixtures of 1,2-diethoxyethane with chloroalkanes ... The Bloomfield and Dewan model has been used to calculate viscosity ...

Excess Molar Volume and Apparent Molar Volume of Binary Mixtures of 2—Methyl—3—buten—2—ol with 1—Alcohol at 298.15K

Institute of Scientific and Technical Information of China (English)

LIUDixia; LIHaoran; 等

2002-01-01

Excess molar volumes (VmE) of binary mixtures of 2-methyl-3-buten-2-ol[CH3C(OH)(CH3)CHCH2] with four 1-alcohols:methanol,ethanol,1-propanol and 1-butanol at 298.15K and atmospheric pressure are derived from density measurements with a vibrating-tube densimeter.All the excess volumes are negative in the systems over the entire composition range. The results are correlated with the Redlich-Kister equation.The effects of chain length of 1-alcohols on VmE are discussed.The apparent molar volumes of 2-methyl-3-buten-2-ol and 1-alcohols are calculated respectively.

Octanol-Water Partition Coefficient from 3D-RISM-KH Molecular Theory of Solvation with Partial Molar Volume Correction.

Science.gov (United States)

Huang, WenJuan; Blinov, Nikolay; Kovalenko, Andriy

2015-04-30

The octanol-water partition coefficient is an important physical-chemical characteristic widely used to describe hydrophobic/hydrophilic properties of chemical compounds. The partition coefficient is related to the transfer free energy of a compound from water to octanol. Here, we introduce a new protocol for prediction of the partition coefficient based on the statistical-mechanical, 3D-RISM-KH molecular theory of solvation. It was shown recently that with the compound-solvent correlation functions obtained from the 3D-RISM-KH molecular theory of solvation, the free energy functional supplemented with the correction linearly related to the partial molar volume obtained from the Kirkwood-Buff/3D-RISM theory, also called the "universal correction" (UC), provides accurate prediction of the hydration free energy of small compounds, compared to explicit solvent molecular dynamics [ Palmer , D. S. ; J. Phys.: Condens. Matter 2010 , 22 , 492101 ]. Here we report that with the UC reparametrized accordingly this theory also provides an excellent agreement with the experimental data for the solvation free energy in nonpolar solvent (1-octanol) and so accurately predicts the octanol-water partition coefficient. The performance of the Kovalenko-Hirata (KH) and Gaussian fluctuation (GF) functionals of the solvation free energy, with and without UC, is tested on a large library of small compounds with diverse functional groups. The best agreement with the experimental data for octanol-water partition coefficients is obtained with the KH-UC solvation free energy functional.

Ab initio calculations of partial molar properties in the single-site approximation

DEFF Research Database (Denmark)

Ruban, Andrei; Skriver, Hans Lomholt

1997-01-01

We discuss the application of the single-site approximation in calculations of partial molar quantities, e.g., impurity solution energy, segregation energy, and effective chemical potential, which are related to a variation of the composition of an alloy or its nonequivalent parts. We demonstrate...

Improved method to determine the molar volume and compositions of the NaCl-H2O-CO2 system inclusion

Institute of Scientific and Technical Information of China (English)

2007-01-01

On the basis of Parry’s method (1986), an improved method was established to determine the molar volume (Vm) and compositions (X) of the NaCl-H2O-CO2 (NHC) system inclusion. To use this method, the determination of Vm-X only requires three microthermometric data of a NHC inclusion: partial homog-enization temperature (Th ,CO2), salinity (S) and total homogenization temperature (Th). Theoretically, four associated equations are needed containing four unknown parameters: X CO2, XNaCl, Vm and F (volume fraction of CO2 phase in total inclusion when occurring partial homogenization). When they are released, the Vm-X are determined. The former three equations, only correlated with Th ,CO2, S and F, have simplified expressions:XCO2=f1(Th,CO2,S,F),XNaCl=f2(Th,CO2,S,F),Vm=f3(Th,CO2,S,F). The last one is the thermodynamic relationship of X CO2, XNaCl, Vm and Th:f4(XCO2,XNaCl,Vm,Th)=0.Since the above four associated equations are complicated, it is necessary to adopt iterative technique to release them. The technique can be described by:(i) Freely input a F value (0≤F≤1),with Th ,CO2 and S, into the former three equations. As a result,X CO 2,XNaCl and the molar volume value recorded as Vm1 are derived. (ii) Input the X CO2 and XNaCl gotten in the step above into the last equation, and another molar volume value recorded as Vm2 is determined. (iii) If Vm1 is unequal to Vm2, the calculation will be restarted from “(i)”. The iteration is completed until Vm1 is equal to Vm2, which means that the four associated equations are released. Compared to Parry’s (1986) solution method, the improved method is more convenient to use, as well as more accurate to determine X CO 2. It is available for a NHC inlusion whose partial homogenization temperature is higher than clatherate melting temperature and there are no solid salt crystals in the inclusion at parital homogenization.

Improved method to determine the molar volume and compositions of the NaCl-H2O-CO2 system inclusion

Institute of Scientific and Technical Information of China (English)

SONG YuCai; HU WenXuan; NI Pei; DUAN ZhenHao; ZHANG XueFeng

2007-01-01

On the basis of Parry's method (1986),an improved method was established to determine the molar volume(Vm)and compositions(X)of the NaCl-H2O-CO2(NHC)system inclusion.To use this method,the determination of Vm-X only requires three microthermometric data of a NHC inclusion:partial homogenization temperature(Th,CO2),salinity(s)and total homogenization temperature(Th).Theoretically,four associated equations are needed containing four unknown parameters:Xco2,XNcl,Vm and F (volume fraction of CO2 phase in total inclusion when occurring partial homogenization).When they are released,the Vm-X are determined.The former three equations,only correlated with Th,co2,S and F,have simplified expressions:XCO2=f1(Th,CO2,S,F),XNaCl=f2(Th,CO2,S,F),Vm=f3(Th,CO2,S,F).The last one is the thermodynamic relationship of Xco2,Xnacl,vm and Th:f4(XCO2,XNacl,Vm,Th)=0. Since the above four associated equations are complicated,it is necessary to adopt iterative technique to release them.The technique can be described by:(i)Freely input a F value(0≤F≤1),with Th,co2 and S,into the former three equations.As a result,Xco2,XNacl and the molar volume value recorded as Vm1 are derived.(ii)Input the Xco2 and XNacl gotten in the step above into the last equation,and another molar volume value recorded as Vm2 is determined.(iii) If Vm1 is unequal to Vm2,the calculation will be restarted from"(i)".The iteration is completed until Vm1 is equal to Vm2,which means that the four associated equations are released.Compared to Parry's (1986) solution method,the improved method is more convenient to use,as well as more accurate to determine Xco2.It is available for a NHC inlusion whose partial homogenization temperature is higher than clatherate melting temperature and there are no solid salt crystals in the inclusion at parital homogenization.

Apparent molar volumes and viscosity B-coefficients of caffeine in aqueous thorium nitrate solutions at T = (298.15, 308.15, and 318.15) K

International Nuclear Information System (INIS)

Sinha, Biswajit; Roy, Pran Kumar; Sarkar, Bipul Kumar; Brahman, Dhiraj; Roy, Mahendra Nath

2010-01-01

Apparent molar volumes φ V and viscosity B-coefficients for caffeine in (0.00, 0.03, 0.05, and 0.07) mol . dm -3 aqueous thorium nitrate, Th(NO 3 ) 4 , solutions were determined from solution density and viscosity measurements over the temperature range (298.15 to 318.15) K as function of concentration of caffeine and the relation: φ V 0 =a 0 +a 1 T+a 2 T 2 , have been used to describe the temperature dependence of the standard partial molar volumes φ V 0 . These results have been used to deduce the standard volumes of transfer Δφ V 0 and viscosity B-coefficients of transfer ΔB for caffeine from water to aqueous Th(NO 3 ) 4 solutions for rationalizing various interactions in the ternary solutions. The structure-making or breaking ability of caffeine has been discussed in terms of the sign of (δ 2 φ V 0 /δT 2 ) P . The Friedman-Krishnan co-sphere model was used to explain the transfer volume of caffeine with increasing Th(NO 3 ) 4 molarity. The activation parameters of viscous flow for the ternary solutions were also discussed in terms of transition state theory.

Molar Pregnancy

Science.gov (United States)

... weeks of pregnancy Ovarian cysts Anemia Overactive thyroid (hyperthyroidism) Causes A molar pregnancy is caused by an ... have this complication than a partial molar pregnancy. Prevention If you've had a molar pregnancy, talk ...

Experimental heat capacity of solid hydrogen as a function of molar volume

International Nuclear Information System (INIS)

Krause, J.K.

1978-01-01

Constant volume heat capacity measurements have been made on six solid hydrogen samples with low orthohydrogen concentrations. The measurements extend from approximately 1.5 K to the melting line, with molar volumes ranging from 22.787 cm 3 /mole to 16.193 cm 3 /mole. Although clustering of the ortho molecules was observed, the low temperature heat capacity anomaly due to the orthohydrogen pairs could be described quite well by the assumption of a fixed distribution. The data were corrected to obtain a lattice heat capacity which on extrapolation to T = 0 yielded Debye temperatures and a volume dependent Grueneisen parameter. A modified Mie-Grueneisen approximation was used to define a volume and temperature dependent Grueneisen parameter which was used to calculate the equation of state, P(V,T), and isothermal bulk modulus, B/sub T/(V,T), for the six isochores. An extrapolation of the equation of state to T = 0 and P = 0 by two different methods yields a molar volume which, when compared with other determinations, gives a recommended value of 23.20 +- 0.05 cm 3 /mole. A rapid increase in the conversion rate of orthohydrogen to parahydrogen was observed at approximately theta/sub o/12. The molar volumes along the melting curve also have been determined directly for the first time in this volume range. These results have been used to show that a low temperature Lindemann melting relation is only approximately valid for solid hydrogen to 50 K

Relationship between the partial molar and molar quantity of a thermodynamic state function in a multicomponent mixture – revisited

International Nuclear Information System (INIS)

Näfe, H.

2013-01-01

As far as a multicomponent mixture is concerned, different versions exist in the literature for the relationship between the partial molar and molar quantity of a thermodynamic state function with the most prominent example of the two quantities being the activity coefficient of an arbitrary component and the excess Gibbs free energy of a mixture comprising this component. Since the relationships published so far have to a large degree been derived independently of each other and result from apparently conflicting approaches, they are still considered as separate subjects in the literature. It is demonstrated that despite this curious situation all relationships are equivalent to each other from a mathematical point of view

Densities and volume properties of (water + tert-butanol) over the temperature range of (274.15 to 348.15) K at pressure of 0.1 MPa

International Nuclear Information System (INIS)

Egorov, Gennadiy I.; Makarov, Dmitriy M.

2011-01-01

The densities of {water (1) + tert-butanol (2)} binary mixture were measured over the temperature range (274.15 to 348.15) K at atmospheric pressure using 'Anton Paar' digital vibrating-tube densimeter. Density measurements were carried out over the whole concentration range at (308.15 to 348.15) K. The following volume parameters were calculated: excess molar volumes and thermal isobaric expansivities of the mixture, partial molar volumes and partial molar thermal isobaric expansivities of the components. Concentration dependences of excess molar volumes were fitted with Redlich-Kister equation. The results of partial molar volume calculations using four equations were compared. It was established that for low alcohol concentrations at T ≤ 208 K the inflection points at x 2 ∼ 0.02 were observed at concentration dependences of specific volume. The concentration dependences of partial molar volumes of both water and tert-butanol had extremes at low alcohol content. The temperature dependence of partial molar volumes of water had some inversion at x 2 ∼ 0.65. The temperature dependence of partial molar volumes of tert-butanol at infinite dilution had minimum at ∼288 K. It was discovered that concentration dependences of thermal isobaric expansivities of the mixture at small alcohol content and low temperatures passed through minimum.

Ultrasonic velocities, densities, and excess molar volumes of binary mixtures of N,N-dimethyl formamide with methyl acrylate, or ethyl acrylate, or butyl acrylate, or 2-ethyl hexyl acrylate at T = 308.15 K

Energy Technology Data Exchange (ETDEWEB)

Kondaiah, M. [Department of Physics, Acharya Nagarjuna University, Nagarjuna Nagar 522510, Andhra Pradesh (India); Sravana Kumar, D. [Dr. V.S. Krishna Govt. Degree College, Visakhapatnam, Andhra Pradesh (India); Sreekanth, K. [Department of Physics, Acharya Nagarjuna University, Nagarjuna Nagar 522510, Andhra Pradesh (India); Krishna Rao, D., E-mail: krdhanekula@yahoo.co.in [Department of Physics, Acharya Nagarjuna University, Nagarjuna Nagar 522510, Andhra Pradesh (India)

2011-12-15

Highlights: > Positive values of V{sub m}{sup E}, indicate dispersion forces between acrylic esters and DMF. > V{sub m}{sup E} values compared with Redlich-Kister polynomial. > Partial molar volumes data conclude that weak interactions exist in the systems. > Measured velocity values compared with theoretical values obtained by polynomials. - Abstract: Ultrasonic velocities, u, densities, {rho}, of binary mixtures of N,N-dimethyl formamide (DMF) with methyl acrylate (MA), ethyl acrylate (EA), butyl acrylate (BA), and 2-ethyl hexyl acrylate (EHA), including pure liquids, over the entire composition range have been measured at T = 308.15 K. Using the experimental results, the excess molar volume, V{sub m}{sup E}, partial molar volumes, V-bar {sub m,1}, V-bar{sub m,2}, and excess partial molar volumes, V-bar{sub m,1}{sup E}, V-bar{sub m,2}{sup E} have been calculated. Molecular interactions in the systems have been studied in the light of variation of excess values of calculated properties. The excess properties have been fitted to Redlich-Kister type polynomial and the corresponding standard deviations have been calculated. The positive values of V{sub m}{sup E} indicate the presence of dispersion forces between the DMF and acrylic ester molecules. Further theoretical values of sound velocity in the mixtures have been evaluated using various theories and have been compared with experimental sound velocities to verify the applicability of such theories to the systems studied. Theoretical ultrasonic velocity data have been used to study molecular interactions in the binary systems investigated.

Molar excess volumes of liquid hydrogen and neon mixtures from path integral simulation

International Nuclear Information System (INIS)

Challa, S.R.; Johnson, J.K.

1999-01-01

Volumetric properties of liquid mixtures of neon and hydrogen have been calculated using path integral hybrid Monte Carlo simulations. Realistic potentials have been used for the three interactions involved. Molar volumes and excess volumes of these mixtures have been evaluated for various compositions at 29 and 31.14 K, and 30 atm. Significant quantum effects are observed in molar volumes. Quantum simulations agree well with experimental molar volumes. Calculated excess volumes agree qualitatively with experimental values. However, contrary to the existing understanding that large positive deviations from ideal mixtures are caused due to quantum effects in Ne - H 2 mixtures, both classical as well as quantum simulations predict the large positive deviations from ideal mixtures. Further investigations using two other Ne - H 2 potentials of Lennard - Jones (LJ) type show that excess volumes are very sensitive to the cross-interaction potential. We conclude that the cross-interaction potential employed in our simulations is accurate for volumetric properties. This potential is more repulsive compared to the two LJ potentials tested, which have been obtained by two different combining rules. This repulsion and a comparatively lower potential well depth can explain the positive deviations from ideal mixing. copyright 1999 American Institute of Physics

Excess Molar Volumes and Viscosities of Binary Mixture of Diethyl Carbonate+Ethanol at Different Temperatures

Institute of Scientific and Technical Information of China (English)

MA Peisheng; LI Nannan

2005-01-01

The purpose of this work was to report excess molar volumes and dynamic viscosities of the binary mixture of diethyl carbonate (DEC)+ethanol. Densities and viscosities of the binary mixture of DEC+ethanol at temperatures 293.15 K-343.15 K and atmospheric pressure were determined over the entire composition range. Densities of the binary mixture of DEC+ethanol were measured by using a vibrating U-shaped sample tube densimeter. Viscosities were determined by using Ubbelohde suspended-level viscometer. Densities are accurate to 1.0×10-5 g·cm-3, and viscosities are reproducible within ±0.003 mPa·s. From these data, excess molar volumes and deviations in viscosity were calculated. Positive excess molar volumes and negative deviations in viscosity for DEC+ethanol system are due to the strong specific interactions.All excess molar vo-lumes and deviations in viscosity fit to the Redlich-Kister polynomial equation.The fitting parameters were presented,and the average deviations and standard deviations were also calculated.The errors of correlation are very small.It proves that it is valuable for estimating densities and viscosities of the binary mixture by the correlated equation.

Changes in apparent molar water volume and DKP solubility yield insights on the Hofmeister effect.

Science.gov (United States)

Payumo, Alexander Y; Huijon, R Michael; Mansfield, Deauna D; Belk, Laurel M; Bui, Annie K; Knight, Anne E; Eggers, Daryl K

2011-12-15

This study examines the properties of a 4 × 2 matrix of aqueous cations and anions at concentrations up to 8.0 M. The apparent molar water volume, as calculated by subtracting the mass and volume of the ions from the corresponding solution density, was found to exceed the molar volume of ice in many concentrated electrolyte solutions, underscoring the nonideal behavior of these systems. The solvent properties of water were also analyzed by measuring the solubility of diketopiperazine (DKP) in 2.000 M salt solutions prepared from the same ion combinations. Solution rankings for DKP solubility were found to parallel the Hofmeister series for both cations and anions, whereas molar water volume concurred with the cation series only. The results are discussed within the framework of a desolvation energy model that attributes solute-specific changes in equilibria to solute-dependent changes in the free energy of bulk water.

Relationship between partial and average atomic volumes of components in Au-Ni alloys%Au-Ni合金中组元的平均原子体积和偏摩尔体积的关系

Institute of Scientific and Technical Information of China (English)

谢佑卿

2011-01-01

在系统合金科学框架中建立有关无序合金的平均摩尔性质(体积和势能)的函数.通过对这些函数进行推导,可以得到平均摩尔体积函数、偏摩尔体积函数及派生出与成分相关的函数.在组元的偏摩尔性质和平均摩尔性质之间的普适方程、差分方程、在偏摩尔性质和平均摩尔性质之间不同参数的约束方程和普适的Gibbs-Duhem公式.可以证明从合金平均摩尔性质的不同函数计算的偏摩尔性质是相等的,但总体来说偏摩尔性质不等于给定组元的平均摩尔性质,即偏摩尔性质不能代表相应组元的摩尔性质.通过计算Au-Ni系中组元的偏摩尔体积和平均原子体积以及合金的平均原子体积,证明所建立的公式和函数的正确性.%In the framework of systematic science of alloys,the average molar property (volume and potential energy) functions of disordered alloys were established.From these functions,the average molar property functions,partial molar property functions,derivative functions with respect to composition,general equation of relationship between partial and average molar properties of components,difference equation and constraining equation of different values between partial and average molar properties,as well as general Gibbs-Duhem formula were derived.It was proved that the partial molar properties calculated from various combinative functions of average molar properties of alloys are equal,but in general,the partial molar properties are not equal to the average molar properties of a given component.This means that the partial molar properties cannot represent the corresponding properties of the component.All the equations and functions established in this work were proved to be correct by calculating the results of partial and average atomic volumes of components as well as average atomic volumes of alloys in the Au-Ni system.

Changes in Apparent Molar Water Volume and DKP Solubility Yield Insights on the Hofmeister Effect

Science.gov (United States)

Payumo, Alexander Y.; Huijon, R. Michael; Mansfield, Deauna D.; Belk, Laurel M.; Bui, Annie K.; Knight, Anne E.; Eggers, Daryl K.

2011-01-01

This study examines the properties of a 4 × 2 matrix of aqueous cations and anions at concentrations up to 8.0 M. The apparent molar water volume, as calculated by subtracting the mass and volume of the ions from the corresponding solution density, was found to exceed the molar volume of ice in many concentrated electrolyte solutions, underscoring the non-ideal behavior of these systems. The solvent properties of water were also analyzed by measuring the solubility of diketopiperazine (DKP) in 2.000 M salt solutions prepared from the same ion combinations. Solution rankings for DKP solubility were found to parallel the Hofmeister series for both cations and anions, whereas molar water volume concurred with the cation series only. The results are discussed within the framework of a desolvation energy model that attributes solute-specific changes in equilibria to solute-dependent changes in the free energy of bulk water. PMID:22029390

Apparent molar volumes and viscosity B-coefficients of caffeine in aqueous thorium nitrate solutions at T = (298.15, 308.15, and 318.15) K

Energy Technology Data Exchange (ETDEWEB)

Sinha, Biswajit, E-mail: biswachem@gmail.co [Department of Chemistry, University of North Bengal, Darjeeling 734013 (India); Roy, Pran Kumar; Sarkar, Bipul Kumar; Brahman, Dhiraj [Department of Chemistry, University of North Bengal, Darjeeling 734013 (India); Roy, Mahendra Nath, E-mail: mahendraroy2002@yahoo.co.i [Department of Chemistry, University of North Bengal, Darjeeling 734013 (India)

2010-03-15

Apparent molar volumes phi{sub V} and viscosity B-coefficients for caffeine in (0.00, 0.03, 0.05, and 0.07) mol . dm{sup -3} aqueous thorium nitrate, Th(NO{sub 3}){sub 4}, solutions were determined from solution density and viscosity measurements over the temperature range (298.15 to 318.15) K as function of concentration of caffeine and the relation: phi{sub V}{sup 0}=a{sub 0}+a{sub 1}T+a{sub 2}T{sup 2}, have been used to describe the temperature dependence of the standard partial molar volumes phi{sub V}{sup 0}. These results have been used to deduce the standard volumes of transfer DELTAphi{sub V}{sup 0} and viscosity B-coefficients of transfer DELTAB for caffeine from water to aqueous Th(NO{sub 3}){sub 4} solutions for rationalizing various interactions in the ternary solutions. The structure-making or breaking ability of caffeine has been discussed in terms of the sign of (delta{sup 2}phi{sub V}{sup 0}/deltaT{sup 2}){sub P}. The Friedman-Krishnan co-sphere model was used to explain the transfer volume of caffeine with increasing Th(NO{sub 3}){sub 4} molarity. The activation parameters of viscous flow for the ternary solutions were also discussed in terms of transition state theory.

Age estimation based on pulp chamber volume of first molars from cone-beam computed tomography images.

Science.gov (United States)

Ge, Zhi-pu; Ma, Ruo-han; Li, Gang; Zhang, Ji-zong; Ma, Xu-chen

2015-08-01

To establish a method that can be used for human age estimation on the basis of pulp chamber volume of first molars and to identify whether the method is good enough for age estimation in real human cases. CBCT images of 373 maxillary first molars and 372 mandibular first molars were collected to establish the mathematical model from 190 female and 213 male patients whose age between 12 and 69 years old. The inclusion criteria of the first molars were: no caries, no excessive tooth wear, no dental restorations, no artifacts due to metal restorative materials present in adjacent teeth, and no pulpal calcification. All the CBCT images were acquired with a CBCT unit NewTom VG (Quantitative Radiology, Verona, Italy) and reconstructed with a voxel-size of 0.15mm. The images were subsequently exported as DICOM data sets and imported into an open source 3D image semi-automatic segmenting and voxel-counting software ITK-SNAP 2.4 for the calculation of pulp chamber volumes. A logarithmic regression analysis was conducted with age as dependent variable and pulp chamber volume as independent variables to establish a mathematical model for the human age estimation. To identify the precision and accuracy of the model for human age estimation, another 104 maxillary first molars and 103 mandibular first molars from 55 female and 57 male patients whose age between 12 and 67 years old were collected, too. Mean absolute error and root mean square error between the actual age and estimated age were used to determine the precision and accuracy of the mathematical model. The study was approved by the Institutional Review Board of Peking University School and Hospital of Stomatology. A mathematical model was suggested for: AGE=117.691-26.442×ln (pulp chamber volume). The regression was statistically significant (p=0.000volume of first molar is a useful index for the estimation of human age with reasonable precision and accuracy. Copyright © 2015 Elsevier Ireland Ltd. All rights

Molar concentration-depth profiles at the solution surface of a cationic surfactant reconstructed with angle resolved X-ray photoelectron spectroscopy

International Nuclear Information System (INIS)

Wang Chuangye; Morgner, Harald

2011-01-01

In the current work, we first reconstructed the molar fraction-depth profiles of cation and anion near the surface of tetrabutylammonium iodide dissolved in formamide by a refined calculation procedure, based on angle resolved X-ray photoelectron spectroscopy experiments. In this calculation procedure, both the transmission functions of the core levels and the inelastic mean free paths of the photoelectrons have been taken into account. We have evaluated the partial molar volumes of surfactant and solvent by the densities of such solutions with different bulk concentrations. With those partial molar volumes, the molar concentration-depth profiles of tetrabutylammonium ion and iodide ion were determined. The surface excesses of both surfactant ions were then achieved directly by integrating these depth profiles. The anionic molar concentration-depth profiles and surface excesses have been compared with their counterparts determined by neutral impact ion scattering spectroscopy. The comparisons exhibit good agreements. Being capable of determining molar concentration-depth profiles of surfactant ions by core levels with different kinetic energies may extend the applicable range of ARXPS in investigating solution surfaces.

Partial volume effect in MRI

International Nuclear Information System (INIS)

Maeda, Munehiro; Yoshiya, Kazuhiko; Suzuki, Eiji

1989-01-01

According to the direction and the thickness of the imaging slice in tomography, the border between the tissues becomes unclear (partial volume effect). In the present MRI experiment, we examined border area between fat and water components using phantom in order to investigate the partial volume effect in MRI. In spin echo sequences, the intensity of the border area showed a linear relationship with composition of fat and water. Whereas, in inversion recovery and field echo sequences, we found the parameters to produce an extremely low intensity area at the border region between fat and water. This low intensity area was explained by cancellation of NMR signals from fat and water due to the difference in the direction of magnetic vectors. Clinically, partial volume effect can cause of mis-evaluation of walls, small nodules, tumor capsules and the tumor invasion in the use of inversion recovery and field echo sequences. (author)

To the issue of temperature-dependent behavior of standard molar volumes of components in the binary system (water + tetrahydrofuran) at ambient pressure

International Nuclear Information System (INIS)

Ivanov, Evgeniy V.

2014-01-01

Graphical abstract: The standard molar volume of tetrahydrofuran (THF) in water, V THF ∘ (■), is a close-to-linear function of temperature and becomes increasingly appreciable with rising of the latter. Herewith the molar volume of pure THF, V THF (□), is retained to be larger, as compared to V THF ∘ , over all the temperature range studied. - Highlights: • Densities of aqueous THF at nine temperatures from (278.15 to 318.15) K were measured. • Temperature-dependent standard molar volumes of THF in water were calculated. • The analysis of excess standard molar volumes in the (water + THF) system was made. • The use of Redlich–Kister equation to obtain standard molar volumes is discussed. - Abstract: This report presents a comparative analysis of temperature-dependent data on density of both dilute aqueous solutions of tetrahydrofuran (THF) and dilute solutions of water in THF, as well as standard molar volumes of water or THF as a solute. For this purpose, new results on studying the volume-related properties of THF in a water-rich region at temperatures from (278.15 to 318.15) K, with a step of 5 K, and at the ambient pressure have been derived densimetrically. In discussion, some comments on previously published investigations, being related to temperature-dependent changes in the solution density and standard molar volumes of components of the system (water + THF), have been made

Molar volumes of LiI in H{sub 2}O and D{sub 2}O solutions; Structural hydration interactions

Energy Technology Data Exchange (ETDEWEB)

Jakli, Gy. [KFKI Atomic Energy Research Institute, P.O. Box 49, H-1525 Budapest (Hungary)], E-mail: jakli@aeki.kfki.hu

2009-01-15

According to a recent study of the H{sub 2}O and D{sub 2}O molar volume isotope effect (MVIE) of the alkali metal chloride solutions, neither the standard nor the excess MVIE of the LiCl corresponds to the usual hydrophilic hydration characteristics of the inorganic ions above room temperatures. This phenomenon can not be rationalized by electrostriction, with the collapse of the 'loose' tetrahedral ('ice-like') water structure due to the electrostatic (ion + dipole) interaction. It seemed possible that this unique hydration behaviour of the Li{sup +} would be stronger and could reveal further structural information with a less hydrophilic anion than the chloride. Therefore we have determined the MVIE of the LiI as a function of temperature and concentration. The densities of normal and heavy water solutions of LiI have been measured with six-figure precision at T = (288.15, 298.15, and 308.15) K from (0.03 to 4) molal, m, using a vibrating-tube densitometer. The solvent isotope effect on the apparent molar volume, as well as on the solute and solvent partial molar volumes, was evaluated. As expected, with the rationalization of the MVIE of LiI instead of the geometric structural differences of the isotopic solvents, the energetic contributions have to be considered at all the temperatures investigated. At infinite dilution, a high degree of compensation between the reversed influences of the Li{sup +} and I{sup -} on the activities of the isotopic solvents determines the MVIE. By increasing concentration, the highly asymmetric energetic interactions of the Li{sup +} and the I{sup -} with the solvent apparently result in a 'mutual salting-out' effect. At a concentration {approx}0.7m, a uniquely abrupt structural rearrangement results in a 'solvent-separated ion-pair' solution structure.

Densities, excess molar volumes, and refractive indices of 1,1,2,2-tetrabromoethane and 1-alkanols binary mixtures

International Nuclear Information System (INIS)

Al-Hayan, M.N.M.; Al-Bader, Maher A.M.

2006-01-01

Densities, excess molar volumes, refractive indices, and changes in refractive index on mixing for (1,1,2,2-tetrabromoethane + 1-pentanol, or 1-hexanol, or 1-heptanol, or 1-octanol, or 1-decanol) have been determined at T = 293.15 K and at T = 303.15 K. The excess molar volumes and changes in refractive index have been fitted to Redlich-Kister polynomials. The effect of the chain length of the 1-alkanol on the excess molar volume and the change in the refractive index of its mixtures with 1,1,2,2-tetrabromoethane are discussed. In addition, the refractive indices are compared with calculated values using mixing rules proposed by several authors, and a good agreement is obtained

Densities, excess molar volumes, and refractive indices of 1,1,2,2-tetrachloroethane and 1-alkanols binary mixtures

International Nuclear Information System (INIS)

Al-Hayan, M.N.M.

2006-01-01

Densities, excess molar volumes, refractive indices, and changes in refractive index on mixing for 1,1,2,2-tetrachloroethane + 1-pentanol, or 1-hexanol, or 1-heptanol, or 1-octanol, or 1-decanol have been determined at T = (293.15 and 303.15) K. The excess molar volumes and changes in refractive index have been fitted to Redlich-Kister polynomials. The effect of the chain length of the 1-alkanol on the excess molar volume and the change in the refractive index of its mixtures with 1,1,2,2-tetrachloroethane was discussed. In addition, the refractive indices were compared with calculated values using mixing rules proposed by several authors, and a very good agreement was obtained

Excess molar volumes and viscosities of binary mixtures of 1,2 ...

Indian Academy of Sciences (India)

Unknown

organic solvents 2,3, the present paper reports the excess molar volumes. ) ( *E m. V ... measuring and comparing the viscosities of the pure liquids with the values reported in ..... RKB thanks the University Grants Commission, New Delhi for a fellowship and financial ... Dickinson E, Hunt D C and McLure I A 1975 J. Chem.

Standard molar volumes and heat capacities of aqueous solutions of sodium trifluoromethanesulfonate at temperatures up to 573 K and pressures to 28 MPa

International Nuclear Information System (INIS)

Pourtier, Emilie; Ballerat-Busserolles, Karine; Majer, Vladimir; Šedlbauer, Josef

2013-01-01

Highlights: ► Original HT/HP data for NaTr(aq) obtained using non-commercial instruments. ► First heat capacity data for NaTr(aq) at conditions remote from ambient. ► Correction for association when calculating stand. therm. properties of Tr(aq) anion. - Abstract: Densities and heat capacities of aqueous solutions of sodium trifluoromethanesulfonate (sodium triflate) of concentrations from 0.025 to 0.3 mol · kg −1 were measured with high temperature, high pressure custom-made instruments at temperatures up to 573 K and at pressures up to 28 MPa. Standard molar volumes and standard molar heat capacities were obtained via extrapolation of the apparent molar properties to infinite dilution. The results for volumetric properties are consistent with earlier literature data, but no previous measurements exist for heat capacities of sodium triflate at superambient conditions. The new data were used for calculating the standard molar volumes and heat capacities for the triflate anion and compared with the results for triflic acid that should be essentially identical within the expected error margins. At temperatures above 473 K an effort was made to refine the processing of literature data for HCl(aq), taking into account its partial association, and subsequently to modify the value for Na + ion calculated from the standard thermodynamic values of NaCl(aq) where its ion pairing was already considered. This approach yields reasonable agreement at high temperatures between the values for triflate ion calculated from its salt and those for triflic acid.

Standard partial molar heat capacities and enthalpies of formation of aqueous aluminate under hydrothermal conditions from integral heat of solution measurements

International Nuclear Information System (INIS)

Coulier, Yohann; Tremaine, Peter R.

2014-01-01

Highlights: • Heats of solution of NaAlO 2 (s) were measured at five temperatures up to 250 °C. • Standard molar enthalpies of solution were determined from the measured heats of solution. • Standard molar enthalpies of solution were correlated with the density model. • The density model allows us to determine the standard molar heat capacities of reaction. - Abstract: Heats of solution of sodium aluminum oxide, NaAlO 2 (s), were measured in aqueous sodium hydroxide solutions using a Tian–Calvet heat-flow calorimeter (Setaram, Model C80) with high pressure “batch cells” made of hastelloy C-276, at five temperatures from (373.15 to 523.15) K, steam saturation pressure, and concentrations from (0.02 to 0.09) mol · kg −1 . Standard molar enthalpies of solution, Δ soln H ∘ , and relative standard molar enthalpies, [H ∘ (T) − H ∘ (298.15 K)], of NaAl(OH) 4 (aq) were determined from the measured heats of solution. The results were fitted with the “density” model. The temperature dependence of Δ soln H ∘ from the model yielded the standard molar heat capacities of reaction, Δ soln C p ∘ , from which standard partial molar heat capacities for aqueous aluminate, C p ∘ [A1(OH) 4 − ,aq], were calculated. Standard partial molar enthalpies of formation, Δ f H ∘ , and entropies, S ∘ , of A1(OH) 4 − (aq) were also determined. The values for C p ∘ [A1(OH) 4 − ,aq] agree with literature data determined up to T = 413 K from enthalpy of solution and heat capacity measurements to within the combined experimental uncertainties. They are consistent with differential heat capacity measurements up to T = 573 K from Schrödle et al. (2010) [29] using the same calorimeter, but this method has the advantage that measurements could be made at much lower concentrations in the presence of an excess concentration of ligand. To our knowledge, these are the first standard partial molar heat capacities measured under hydrothermal conditions by the

Densities and apparent molar volumes of HClO4(aq) and Yb(ClO4)3(aq) at elevated temperatures and pressures

International Nuclear Information System (INIS)

Hakin, Andrew W.; Lukacs, Michael J.; Jin Lianliu

2004-01-01

Relative densities have been measured for acidified aqueous solutions of ytterbium perchlorate {Yb(ClO 4 ) 3 } at approximately T=(348.15, 373.15, 398.15, and 423.15) K and p=(10.0, 20.0, and 30.0) MPa over the concentration range 0.01624≤m 2 /(mol · kg -1 ) ≤ 0.2531 using an optically coupled vibrating tube densimeter (OCVTD). Experimental apparent molar volumes have been calculated from the density measurements, and apparent molar volumes for the aqueous perchlorate salt have been calculated using Young's rule. The application of Young's rule requires apparent molar volumes for aqueous perchloric acid (HClO 4 ) solutions over extended temperature and pressure ranges. These values were calculated from densities for aqueous HClO 4 solutions that were measured using the OCVTD at the same temperatures and pressures as those used to investigate the density surface of the acidified aqueous Yb(ClO 4 ) 3 solutions. The temperature, pressure, and composition surfaces of the apparent molar volumes for Yb(ClO 4 ) 3 (aq) and HClO 4 (aq) have been modelled using Pitzer ion-interaction equations. Apparent molar volumes at infinite dilution obtained from these models have been compared to those which can be calculated using the semi-empirical Helgeson, Kirkham, and Flowers equations of state. Values for the apparent molar volume at infinite dilution of the ytterbium trivalent cation have also been calculated using simple additivity principles

Thermodynamic properties of binary mixtures of tetrahydropyran with pyridine and isomeric picolines: Excess molar volumes, excess molar enthalpies and excess isentropic compressibilities

International Nuclear Information System (INIS)

Saini, Neeti; Jangra, Sunil K.; Yadav, J.S.; Sharma, Dimple; Sharma, V.K.

2011-01-01

Research highlights: → Densities, ρ and speeds of sound, u of tetrahydropyran (i) + pyridine or α-, β- or γ-picoline (j) binary mixtures at 298.15, 303.15 and 308.15 K and excess molar enthalpies, H E of the same set of mixtures at 308.15 K have been measured as a function of composition. → The observed densities and speeds of sound values have been employed to determine excess molar volumes, V E and excess isentropic compressibilities, κ S E . → Topology of the constituents of mixtures has been utilized (Graph theory) successfully to predict V E , H E and κ S E data of the investigated mixtures. → Thermodynamic data of the various mixtures have also been analyzed in terms of Prigogine-Flory-Patterson (PFP) theory. - Abstract: Densities, ρ and speeds of sound, u of tetrahydropyran (i) + pyridine or α-, β- or γ- picoline (j) binary mixtures at 298.15, 303.15 and 308.15 K and excess molar enthalpies, H E of the same set of mixtures at 308.15 K have been measured as a function of composition using an anton Parr vibrating-tube digital density and sound analyzer (model DSA 5000) and 2-drop micro-calorimeter, respectively. The resulting density and speed of sound data of the investigated mixtures have been utilized to predict excess molar volumes, V E and excess isentropic compressibilities, κ S E . The observed data have been analyzed in terms of (i) Graph theory; (ii) Prigogine-Flory-Patterson theory. It has been observed that V E , H E and κ S E data predicted by Graph theory compare well with their experimental values.

Partial molar volumes of organic solutes in water. XXVIII. Three aliphatic poly(ethylene glycols) at temperatures T = 298 K–573 K and pressures up to 30 MPa

International Nuclear Information System (INIS)

Cibulka, Ivan

2017-01-01

Highlights: • Standard molar volumes of three poly(ethylene glycols) in water are presented. • Data were obtained in the range T from (298 to 573) K and p up to 30 MPa. • Data are analyzed and compared with those of similar solutes. - Abstract: Densities of dilute aqueous solutions of three poly(ethylene glycols): 3-oxapentane-1,5-diol (diethylene glycol), 3,6-dioxaoctane-1,8-diol (triethylene glycol), and 3,5,9-trioxaundecane-1,11-diol (tetraethylene glycol) measured in the temperature range from (298 to 573) K and at pressures up to 30 MPa using an automated flow vibrating-tube densimeter are reported. Standard molar volumes were evaluated from the measured data. Present data complement both the previous measurements performed at atmospheric pressure in the temperature range from (278 to 343) K and the data already available for the first member of the homologous series (ethylene glycol). A comparison with data previously measured for the homologous series of linear aliphatic polyethers (poly(ethylene glycol) dimethyl ethers, glymes), diethylene glycol monomethyl ether (3,6-dioxaheptan-1-ol), and selected alkane-α,ω-diols is presented.

Ionic molar volumes in methanol mixtures with acetonitrile, N,N-dimethylformamide and propylene carbonate at T = 298.15 K

International Nuclear Information System (INIS)

Pietrzak, A.; Piekarski, H.

2014-01-01

Highlights: • Densities of electrolyte solutions in methanol mixtures were measured at T = 298.15 K. • Apparent molar volumes of sodium cation and iodide anion were determined. • TPTB as a calculation method was used. • Preferential solvation of ions by organic solvents was examined. - Abstract: The densities of dilute solutions of three electrolytes (NaI, NaBPh 4 and Ph 4 PI) in methanol mixtures with propylene carbonate (PC), N,N-dimethylformamide (DMF) and acetonitrile (AN) have been measured by Anton Paar 5000 densimeter at T = 298.15 K. Apparent molar volumes, V Φ have been determined at an electrolyte concentration of 0.06 mol · kg −1 over the entire mixed solvent composition range. Single ionic apparent molar volumes of transfer, Δ t V Φ (ion) were calculated using the tetraphenylphosphonium tetraphenylborate (TPTB) assumption. The results are discussed in terms of ionic preferential solvation

What is the fundamental ion-specific series for anions and cations? Ion specificity in standard partial molar volumes of electrolytes and electrostriction in water and non-aqueous solvents† †Electronic supplementary information (ESI) available. See DOI: 10.1039/c7sc02691a Click here for additional data file.

Science.gov (United States)

Mazzini, Virginia

2017-01-01

The importance of electrolyte solutions cannot be overstated. Beyond the ionic strength of electrolyte solutions the specific nature of the ions present is vital in controlling a host of properties. Therefore ion specificity is fundamentally important in physical chemistry, engineering and biology. The observation that the strengths of the effect of ions often follows well established series suggests that a single predictive and quantitative description of specific-ion effects covering a wide range of systems is possible. Such a theory would revolutionise applications of physical chemistry from polymer precipitation to drug design. Current approaches to understanding specific-ion effects involve consideration of the ions themselves, the solvent and relevant interfaces and the interactions between them. Here we investigate the specific-ion effects trends of standard partial molar volumes and electrostrictive volumes of electrolytes in water and eleven non-aqueous solvents. We choose these measures as they relate to bulk properties at infinite dilution, therefore they are the simplest electrolyte systems. This is done to test the hypothesis that the ions alone exhibit a specific-ion effect series that is independent of the solvent and unrelated to surface properties. The specific-ion effects trends of standard partial molar volumes and normalised electrostrictive volumes examined in this work show a fundamental ion-specific series that is reproduced across the solvents, which is the Hofmeister series for anions and the reverse lyotropic series for cations, supporting the hypothesis. This outcome is important in demonstrating that ion specificity is observed at infinite dilution and demonstrates that the complexity observed in the manifestation of specific-ion effects in a very wide range of systems is due to perturbations of solvent, surfaces and concentration on the underlying fundamental series. This knowledge will guide a general understanding of specific

Variation and decomposition of the partial molar volume of small gas molecules in different organic solvents derived from molecular dynamics simulations.

Science.gov (United States)

Klähn, Marco; Martin, Alistair; Cheong, Daniel W; Garland, Marc V

2013-12-28

The partial molar volumes, V(i), of the gas solutes H2, CO, and CO2, solvated in acetone, methanol, heptane, and diethylether are determined computationally in the limit of infinite dilution and standard conditions. Solutions are described with molecular dynamics simulations in combination with the OPLS-aa force field for solvents and customized force field for solutes. V(i) is determined with the direct method, while the composition of V(i) is studied with Kirkwood-Buff integrals (KBIs). Subsequently, the amount of unoccupied space and size of pre-formed cavities in pure solvents is determined. Additionally, the shape of individual solvent cages is analyzed. Calculated V(i) deviate only 3.4 cm(3) mol(-1) (7.1%) from experimental literature values. Experimental V(i) variations across solutions are reproduced qualitatively and also quantitatively in most cases. The KBI analysis identifies differences in solute induced solvent reorganization in the immediate vicinity of H2 (<0.7 nm) and solvent reorganization up to the third solvation shell of CO and CO2 (<1.6 nm) as the origin of V(i) variations. In all solutions, larger V(i) are found in solvents that exhibit weak internal interactions, low cohesive energy density and large compressibility. Weak internal interactions facilitate solvent displacement by thermal solute movement, which enhances the size of solvent cages and thus V(i). Additionally, attractive electrostatic interactions of CO2 and the solvents, which do not depend on internal solvent interactions only, partially reversed the V(i) trends observed in H2 and CO solutions where electrostatic interactions with the solvents are absent. More empty space and larger pre-formed cavities are found in solvents with weak internal interactions, however, no evidence is found that solutes in any considered solvent are accommodated in pre-formed cavities. Individual solvent cages are found to be elongated in the negative direction of solute movement. This wake behind

Variation and decomposition of the partial molar volume of small gas molecules in different organic solvents derived from molecular dynamics simulations

Science.gov (United States)

Klähn, Marco; Martin, Alistair; Cheong, Daniel W.; Garland, Marc V.

2013-12-01

The partial molar volumes, bar V_i, of the gas solutes H2, CO, and CO2, solvated in acetone, methanol, heptane, and diethylether are determined computationally in the limit of infinite dilution and standard conditions. Solutions are described with molecular dynamics simulations in combination with the OPLS-aa force field for solvents and customized force field for solutes. bar V_i is determined with the direct method, while the composition of bar V_i is studied with Kirkwood-Buff integrals (KBIs). Subsequently, the amount of unoccupied space and size of pre-formed cavities in pure solvents is determined. Additionally, the shape of individual solvent cages is analyzed. Calculated bar V_i deviate only 3.4 cm3 mol-1 (7.1%) from experimental literature values. Experimental bar V_i variations across solutions are reproduced qualitatively and also quantitatively in most cases. The KBI analysis identifies differences in solute induced solvent reorganization in the immediate vicinity of H2 (<0.7 nm) and solvent reorganization up to the third solvation shell of CO and CO2 (<1.6 nm) as the origin of bar V_i variations. In all solutions, larger bar V_i are found in solvents that exhibit weak internal interactions, low cohesive energy density and large compressibility. Weak internal interactions facilitate solvent displacement by thermal solute movement, which enhances the size of solvent cages and thus bar V_i. Additionally, attractive electrostatic interactions of CO2 and the solvents, which do not depend on internal solvent interactions only, partially reversed the bar V_i trends observed in H2 and CO solutions where electrostatic interactions with the solvents are absent. More empty space and larger pre-formed cavities are found in solvents with weak internal interactions, however, no evidence is found that solutes in any considered solvent are accommodated in pre-formed cavities. Individual solvent cages are found to be elongated in the negative direction of solute

Molar volume, thermal expansivity and isothermal compressibility of trans-decahydronaphthalene up to 200MPa and 446K

Institute of Scientific and Technical Information of China (English)

Zhu Hu-Gang; Liu Zhi-Hua; Tian Yi-Ling; Xue Yuan; Yin Liang

2005-01-01

The molar volume isotherms of trans-decahydronaphthalene (C10H18) between 293 and 446 K and at pressures from 10 to 200 MPa have been determined. A modified Tait equation of state is used to fit each experimental molar volume isotherm with a maximum average deviation of 0.029%. The thermal expansivity (cubic expansion coefficient) α and isothermal compressibility κ were determined by fitting the slopes of the isobaric curves and isotherms, respectively.The coefficients in the equation Vm = C1 + C2T + C3T2 - C4p - C5pT have been fitted with an average deviation of 1.03%.

Osmotic coefficients and apparent molar volumes of 1-hexyl-3-methylimidazolium trifluoromethanesulfonate ionic liquid in alcohols

International Nuclear Information System (INIS)

González, Emilio J.; Calvar, Noelia; Macedo, Eugénia A.

2014-01-01

Highlights: • Physical and osmotic properties of [HMim][TfO] in alcohols are reported. • Apparent molar properties and osmotic coefficients were obtained. • Apparent molar volumes were fitted using a Redlich–Meyer type equation. • The osmotic coefficients were modeled with the Extended Pitzer and the MNRTL models. -- Abstract: In this work, density for the binary mixtures of 1-hexyl-3-methylimidazolium trifluoromethanesulfonate in alcohols (1-propanol, or 2-propanol, or 1-butanol, or 2-butanol, or 1-pentanol) was measured at T = 323.15 K and atmospheric pressure. From this property, the corresponding apparent molar volumes were calculated and fitted to a Redlich–Meyer type equation. For these mixtures, the osmotic and activity coefficients, and vapor pressures of these binary systems were also determined at the same temperature using the vapor pressure osmometry technique. The experimental osmotic coefficients were modeled by the Extended Pitzer model of Archer. The parameters obtained in this correlation were used to calculate the mean molal activity coefficients and the excess Gibbs free energy for the studied mixtures

Molar volume, excess enthalpy, and Prigogine-Defay ratio of some silicate glasses with different (P,T) histories.

Science.gov (United States)

Wondraczek, Lothar; Behrens, Harald

2007-10-21

Structural relaxation in silicate glasses with different (p,T) histories was experimentally examined by differential scanning calorimetry and measurements of molar volume under ambient pressure. Temperature and pressure-dependent rates of changes in molar volume and generation of excess enthalpy were determined for sodium trisilicate, soda lime silicate, and sodium borosilicate (NBS) compositions. From the derived data, Prigogine-Defay ratios are calculated and discussed. Changes of excess enthalpy are governed mainly by changes in short-range structure, as is shown for NBS where boron coordination is highly sensitive to pressure. For all three glasses, it is shown how the relaxation functions that underlie volume, enthalpy, and structural relaxation decouple for changes in cooling rates and pressure of freezing, respectively. The magnitude of the divergence between enthalpy and volume may be related to differences in structural sensitivity to changes in the (p,V,T,t) space on different length scales. The findings suggest that the Prigogine-Defay ratio is related to the magnitude of the discussed decoupling effect.

Generalized Partial Volume

DEFF Research Database (Denmark)

Darkner, Sune; Sporring, Jon

2011-01-01

Mutual Information (MI) and normalized mutual information (NMI) are popular choices as similarity measure for multimodal image registration. Presently, one of two approaches is often used for estimating these measures: The Parzen Window (PW) and the Generalized Partial Volume (GPV). Their theoret...... of view as well as w.r.t. computational complexity. Finally, we present algorithms for both approaches for NMI which is comparable in speed to Sum of Squared Differences (SSD), and we illustrate the differences between PW and GPV on a number of registration examples....

Comparison of various state equations for approximation and extrapolation of experimental hydrogen molar volumes in wide temperature and pressure intervals

International Nuclear Information System (INIS)

Didyk, A.Yu.; Altynov, V.A.; Wisniewski, R.

2009-01-01

The numerical analysis of practically all existing formulae such as expansion series, Tait, logarithm, Van der Waals and virial equations for interpolation of experimental molar volumes versus high pressure was carried out. One can conclude that extrapolating dependences of molar volumes versus pressure and temperature can be valid. It was shown that virial equations can be used for fitting experimental data at relatively low pressures P<3 kbar too in distinction to other equations. Direct solving of a linear equation of the third order relatively to volume using extrapolated virial coefficients allows us to obtain good agreement between existing experimental data for high pressure and calculated values

SPAM-assisted partial volume correction algorithm for PET

Energy Technology Data Exchange (ETDEWEB)

Cho, Sung Il; Kang, Keon Wook; Lee, Jae Sung; Lee, Dong Soo; Chung, June Key; Soh, Kwang Sup; Lee, Myung Chul [College of Medicine, Seoul National Univ., Seoul (Korea, Republic of)

2000-07-01

A probabilistic atlas of the human brain (Statistical Probability Anatomical Maps: SPAM) was developed by the International Consortium for Brain Mapping (ICBM). It will be a good frame for calculating volume of interest (VOI) according to statistical variability of human brain in many fields of brain images. We show that we can get more exact quantification of the counts in VOI by using SPAM in the correlation of partial volume effect for simulated PET image. The MRI of a patient with dementia was segmented into gray matter and white matter, and then they were smoothed to PET resolution. Simulated PET image was made by adding one third of the smoothed white matter to the smoothed gray matter. Spillover effect and partial volume effect were corrected for this simulated PET image with the aid of the segmented and smoothed MR images. The images were spatially normalized to the average brain MRI atlas of ICBM, and were multiplied by the probablities of 98 VOIs of SPAM images of Montreal Neurological Institute. After the correction of partial volume effect, the counts of frontal, partietal, temporal, and occipital lobes were increased by 38{+-}6%, while those of hippocampus and amygdala by 4{+-}3%. By calculating the counts in VOI using the product of probability of SPAM images and counts in the simulated PET image, the counts increase and become closer to the true values. SPAM-assisted partial volume correction is useful for quantification of VOIs in PET images.

SPAM-assisted partial volume correction algorithm for PET

International Nuclear Information System (INIS)

Cho, Sung Il; Kang, Keon Wook; Lee, Jae Sung; Lee, Dong Soo; Chung, June Key; Soh, Kwang Sup; Lee, Myung Chul

2000-01-01

A probabilistic atlas of the human brain (Statistical Probability Anatomical Maps: SPAM) was developed by the International Consortium for Brain Mapping (ICBM). It will be a good frame for calculating volume of interest (VOI) according to statistical variability of human brain in many fields of brain images. We show that we can get more exact quantification of the counts in VOI by using SPAM in the correlation of partial volume effect for simulated PET image. The MRI of a patient with dementia was segmented into gray matter and white matter, and then they were smoothed to PET resolution. Simulated PET image was made by adding one third of the smoothed white matter to the smoothed gray matter. Spillover effect and partial volume effect were corrected for this simulated PET image with the aid of the segmented and smoothed MR images. The images were spatially normalized to the average brain MRI atlas of ICBM, and were multiplied by the probablities of 98 VOIs of SPAM images of Montreal Neurological Institute. After the correction of partial volume effect, the counts of frontal, partietal, temporal, and occipital lobes were increased by 38±6%, while those of hippocampus and amygdala by 4±3%. By calculating the counts in VOI using the product of probability of SPAM images and counts in the simulated PET image, the counts increase and become closer to the true values. SPAM-assisted partial volume correction is useful for quantification of VOIs in PET images

Densities and apparent molar volumes of HClO{sub 4}(aq) and Yb(ClO{sub 4}){sub 3}(aq) at elevated temperatures and pressures

Energy Technology Data Exchange (ETDEWEB)

Hakin, Andrew W. E-mail: hakin@uleth.ca; Lukacs, Michael J.; Jin Lianliu

2004-09-01

Relative densities have been measured for acidified aqueous solutions of ytterbium perchlorate {l_brace}Yb(ClO{sub 4}){sub 3}{r_brace} at approximately T=(348.15, 373.15, 398.15, and 423.15) K and p=(10.0, 20.0, and 30.0) MPa over the concentration range 0.01624{<=}m{sub 2}/(mol {center_dot} kg{sup -1}) {<=} 0.2531 using an optically coupled vibrating tube densimeter (OCVTD). Experimental apparent molar volumes have been calculated from the density measurements, and apparent molar volumes for the aqueous perchlorate salt have been calculated using Young's rule. The application of Young's rule requires apparent molar volumes for aqueous perchloric acid (HClO{sub 4}) solutions over extended temperature and pressure ranges. These values were calculated from densities for aqueous HClO{sub 4} solutions that were measured using the OCVTD at the same temperatures and pressures as those used to investigate the density surface of the acidified aqueous Yb(ClO{sub 4}){sub 3} solutions. The temperature, pressure, and composition surfaces of the apparent molar volumes for Yb(ClO{sub 4}){sub 3}(aq) and HClO{sub 4}(aq) have been modelled using Pitzer ion-interaction equations. Apparent molar volumes at infinite dilution obtained from these models have been compared to those which can be calculated using the semi-empirical Helgeson, Kirkham, and Flowers equations of state. Values for the apparent molar volume at infinite dilution of the ytterbium trivalent cation have also been calculated using simple additivity principles.

Excess molar volumes and viscosities of (1,1,2,2-tetrabromoethane + 1-alkanols) at T = (293.15 and 303.15) K

International Nuclear Information System (INIS)

Al-Hayan, M.N.M.; Abdul-latif, Abdul-Haq M.

2006-01-01

Density and viscosity measurements for binary mixtures of (1,1,2,2-tetrabromoethane + 1-pentanol, or + 1-hexanol, or + 1-heptanol, or + 1-octanol, or + 1-decanol) at T = (293.15 and 303.15) K, have been conducted at atmospheric pressure. The excess molar volumes V E , have been calculated from the experimental measurements, and the results were fitted to Redlich-Kister equation. The viscosity data were correlated with the model of Grunberg and Nissan, and McAllister four-body model. The excess molar volumes of (1,1,2,2-tetrabromoethane + 1-pentanol, or + 1-haxanol, or + 1-heptanol, or + 1-octanol) had a sigmoidal shape and the values varied from negative to positive with the increase in the molar fraction of 1,1,2,2-tetrabromoethane. The remaining binary mixture of (1,1,2,2-tetrabromoethane + 1-decanol) was positive over the entire composition range. The effects of the 1-alkanol chain length as well as the temperature on the excess molar volume have been studied. The results have been qualitatively used to explain the molecular interaction between the components of these mixtures

Excess Molar Volume of Binary Mixtures of Methylheptenone+Alkanols at 298.15 K

Institute of Scientific and Technical Information of China (English)

无

2002-01-01

Excess molar volume(VE) data on binary liquid mixtures of methylheptenone (MHO) with methanol, ethanol, n-propanol or n-butanol have been determined from the density measurements at 298.15 K and atmospheric pressure. The values of VE in all the systems over the entire composition range are quantified by the Redlich-Kister equation. The effects of the chain length of alkanols on VE are discussed.

Cul3-mediated Nrf2 ubiquitination and antioxidant response element (ARE) activation are dependent on the partial molar volume at position 151 of Keap1.

Science.gov (United States)

Eggler, Aimee L; Small, Evan; Hannink, Mark; Mesecar, Andrew D

2009-07-29

Nrf2 (nuclear factor erythroid 2-related factor 2) is a transcription factor that activates transcription of a battery of cytoprotective genes by binding to the ARE (antioxidant response element). Nrf2 is repressed by the cysteine-rich Keap1 (kelch-like ECH-associated protein 1) protein, which targets Nrf2 for ubiquitination and subsequent degradation by a Cul3 (cullin 3)-mediated ubiquitination complex. We find that modification of Cys(151) of human Keap1, by mutation to a tryptophan, relieves the repression by Keap1 and allows activation of the ARE by Nrf2. The Keap1 C151W substitution has a decreased affinity for Cul3, and can no longer serve to target Nrf2 for ubiquitination, though it retains its affinity for Nrf2. A series of 12 mutant Keap1 proteins, each containing a different residue at position 151, was constructed to explore the chemistry required for this effect. The series reveals that the extent to which Keap1 loses the ability to target Nrf2 for degradation, and hence the ability to repress ARE activation, correlates well with the partial molar volume of the residue. Other physico-chemical properties do not appear to contribute significantly to the effect. Based on this finding, a structural model is proposed whereby large residues at position 151 cause steric clashes that lead to alteration of the Keap1-Cul3 interaction. This model has significant implications for how electrophiles which modify Cys(151), disrupt the repressive function of Keap1.

A combined experimental and computational investigation of excess molar enthalpies of (nitrobenzene + alkanol) mixtures

International Nuclear Information System (INIS)

Neyband, Razieh Sadat; Zarei, Hosseinali

2015-01-01

Highlights: • Excess molar enthalpies for the binary mixtures of nitrobenzene + alkanols mixtures were measured. • The infinite dilution excess partial molar enthalpies were calculated using the ab initio methods. • The PCM calculations were performed. • The computed excess partial molar enthalpies at infinite dilution were compared to experimental results. - Abstract: Excess molar enthalpies (H m E ) for the binary mixtures of {(nitrobenzene + ethanol), 1-propanol, 2-propanol, 1-butanol and 2-butanol} have been measured over the entire composition range at ambient pressure (81.5 kPa) and temperature 298 K using a Parr 1455 solution calorimeter. From the experimental results, the excess partial molar enthalpies (H i E ) and excess partial molar enthalpies at infinite dilution (H i E,∞ ) were calculated. The excess molar enthalpies (H m E ) are positive for all {nitrobenzene (1) + alkanol (2)} mixtures over the entire composition range. A state-of-the-art computational strategy for the evaluation of excess partial molar enthalpies at infinite dilution was followed at the M05-2X/6-311++G ∗∗ level of theory with the PCM model. The experimental excess partial molar enthalpies at infinite dilution have been compared to the computational data of the ab initio in liquid phase. Integrated experimental and computational results help to clarify the nature of the intermolecular interactions in {nitrobenzene (1) + alkanol (2)} mixtures. The experimental and computational work which was done in this study complements and extends the general research on the computation of excess partial molar enthalpy at infinite dilution of binary mixtures

Determination of the Molar Volume of Hydrogen from the Metal-Acid Reaction: An Experimental Alternative.

Science.gov (United States)

de Berg, Kevin; Chapman, Ken

1996-01-01

Describes an alternative technique for determining the molar volume of hydrogen from the metal-acid reaction in which the metal sample is encased in a specially prepared cage and a pipette filler is used to fill an inverted burette with water. Eliminates some difficulties encountered with the conventional technique. (JRH)

Molecular polarizability of organic molecules and their complexes. Communication LIV. Molar volumes of polyaryl organoelement compounds in solutions, extrapolated to infinite dilution, and steric structure of the molecules

International Nuclear Information System (INIS)

Bulgarevich, S.B.; Burdastykh, T.V.

2008-01-01

Molar volumes in various solvents were determined for organic derivatives of silicon, phosphorus, arsenic, sulfur, and tellurium, containing aryl nuclei capable to internal rotation about single bonds between them and bridging groups. Additive analysis of the molar volumes of these compounds showed that the aryl nuclei are acoplanar with respect to the bridging groups. Most probable is a conrotatory mutual orientation of the aromatic rings. Molar volumes were also determined for a series of compounds with two bridging groups, which can serve as models of an extreme case of mutual proximity of aryl ring planes in diaryl systems with one bridging group. A possibility for considerably simplifying the methods for determination of dipole moments and Kerr constants for compounds whose molar volumes can be calculated by our developed additive scheme is demonstrated [ru

Extended Excluded Volume: Its Origin and Consequences

Czech Academy of Sciences Publication Activity Database

Nezbeda, Ivo; Rouha, M.

2013-01-01

Roč. 85, č. 1 (2013), s. 201-210 ISSN 0033-4545. [International Conference on Solution Chemistry (ICSC-32) /32./. La Grande Motte, 28.08.2011-02.09.2011] R&D Projects: GA AV ČR IAA400720802 Institutional support: RVO:67985858 Keywords : excluded volume * partial molar volume * primitive models Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 3.112, year: 2013

Hydrogen bonding interactions between ethylene glycol and water: density, excess molar volume, and spectral study

Institute of Scientific and Technical Information of China (English)

ZHANG JianBin; ZHANG PengYan; MA Kai; HAN Fang; CHEN GuoHua; WEI XiongHui

2008-01-01

Studies of the density and the excess molar volume of ethylene glycol (EG)-water mixtures were carried out to illustrate the hydrogen bonding interactions of EG with water at different temperatures, The re-sults suggest that a likely complex of 3 ethylene glycol molecules bonding with 4 water molecules in an ethylene glycol-water mixture (EGW) is formed at the maximal excess molar volume, which displays stronger absorption capabilities for SO2 when the concentration of SO2 reaches 400×106 (volume ratio) in the gas phase. Meanwhile, FTIR and UV spectra of EGWs were recorded at various EG concentra-tions to display the hydrogen bonding interactions of EG with water. The FTIR spectra show that the stretching vibrational band of hydroxyl in the EGWs shifts to a lower frequency and the bending vibra-tional band of water shifts to a higher frequency with increasing the EG concentration, respectively. Furthermore, the UV spectra show that the electron transferring band of the hydroxyl oxygen in EG shows red shift with increasing the EG concentration. The frequency shifts in FTIR spectra and the shifts of absorption bands in UV absorption spectra of EGWs are interpreted as the strong hydrogen bonding interactions of the hydrogen atoms in water with the hydroxyl oxygen atoms of EG.

Hydrogen bonding interactions between ethylene glycol and water:density,excess molar volume,and spectral study

Institute of Scientific and Technical Information of China (English)

2008-01-01

Studies of the density and the excess molar volume of ethylene glycol (EG)-water mixtures were carried out to illustrate the hydrogen bonding interactions of EG with water at different temperatures. The re-sults suggest that a likely complex of 3 ethylene glycol molecules bonding with 4 water molecules in an ethylene glycol-water mixture (EGW) is formed at the maximal excess molar volume,which displays stronger absorption capabilities for SO2 when the concentration of SO2 reaches 400×10?6 (volume ratio) in the gas phase. Meanwhile,FTIR and UV spectra of EGWs were recorded at various EG concentra-tions to display the hydrogen bonding interactions of EG with water. The FTIR spectra show that the stretching vibrational band of hydroxyl in the EGWs shifts to a lower frequency and the bending vibra-tional band of water shifts to a higher frequency with increasing the EG concentration,respectively. Furthermore,the UV spectra show that the electron transferring band of the hydroxyl oxygen in EG shows red shift with increasing the EG concentration. The frequency shifts in FTIR spectra and the shifts of absorption bands in UV absorption spectra of EGWs are interpreted as the strong hydrogen bonding interactions of the hydrogen atoms in water with the hydroxyl oxygen atoms of EG.

Predicting pathology in impacted mandibular third molars

Directory of Open Access Journals (Sweden)

Aveek Mukherji

2017-01-01

Full Text Available Introduction: The rising incidence of the impacted mandibular third molars and their association with pathologies is now considered a public health problem. Aims and Objectives: The objective of this study was to assess the position of impacted mandibular third molars that are prone to developing pathologies and to determine the frequency and type of pathological conditions associated with these impacted teeth to facilitate planning for their prophylactic removal. Materials and Methods: Consecutive panoramic radiographs and clinical examination of 300 patients with impacted mandibular third molars were collected. They were segregated according to Pell and Gregory’s classification, Winter’s classification, and according to their state of eruption. These were correlated with associated pathologies based on clinical and radiological criteria. Statistical Analysis Used: Descriptive statistics included computation of percentages, mean, and standard deviations. The statistical test applied for the analysis was Pearson’s Chi-square test (χ2. For this test, confidence interval and P value were set at 93% and ≤0.03, respectively. Results: The pathology most commonly associated with impacted third molars was pericoronitis, which had the highest frequency of occurrence in partially erupted, distoangular, and IA positioned (as per Pell and Gregory classification impacted teeth. Impacted mandibular third molars, which were in IA position, placed mesially, and partially erupted, were prone to develop pathologies such as dental caries and periodontitis. Conclusion: The clinical and radiographical features of impacted third molar may be correlated to the development of their pathological complications. The partially impacted mandibular third molars with mesioangularly aligned in IA position have the highest potential to cause pathological complications.

Optimal transformation for correcting partial volume averaging effects in magnetic resonance imaging

International Nuclear Information System (INIS)

Soltanian-Zadeh, H.; Windham, J.P.; Yagle, A.E.

1993-01-01

Segmentation of a feature of interest while correcting for partial volume averaging effects is a major tool for identification of hidden abnormalities, fast and accurate volume calculation, and three-dimensional visualization in the field of magnetic resonance imaging (MRI). The authors present the optimal transformation for simultaneous segmentation of a desired feature and correction of partial volume averaging effects, while maximizing the signal-to-noise ratio (SNR) of the desired feature. It is proved that correction of partial volume averaging effects requires the removal of the interfering features from the scene. It is also proved that correction of partial volume averaging effects can be achieved merely by a linear transformation. It is finally shown that the optimal transformation matrix is easily obtained using the Gram-Schmidt orthogonalization procedure, which is numerically stable. Applications of the technique to MRI simulation, phantom, and brain images are shown. They show that in all cases the desired feature is segmented from the interfering features and partial volume information is visualized in the resulting transformed images

Computing the partial volume of pressure vessels

Energy Technology Data Exchange (ETDEWEB)

Wiencke, Bent [Nestle USA, Corporate Engineering, 800 N. Brand Blvd, Glendale, CA 91203 (United States)

2010-06-15

The computation of the partial and total volume of pressure vessels with various type of head profiles requires detailed knowledge of the head profile geometry. Depending on the type of head profile the derivation of the equations can become very complex and the calculation process cumbersome. Certain head profiles require numerical methods to obtain the partial volume, which for most application is beyond the scope of practicability. This paper suggests a unique method that simplifies the calculation procedure for the various types of head profiles by using one common set of equations without the need for numerical or complex computation methods. For ease of use, all equations presented in this paper are summarized in a single table format for horizontal and vertical vessels. (author)

Characterization of Mixtures. Part 2: QSPR Models for Prediction of Excess Molar Volume and Liquid Density Using Neural Networks.

Science.gov (United States)

Ajmani, Subhash; Rogers, Stephen C; Barley, Mark H; Burgess, Andrew N; Livingstone, David J

2010-09-17

In our earlier work, we have demonstrated that it is possible to characterize binary mixtures using single component descriptors by applying various mixing rules. We also showed that these methods were successful in building predictive QSPR models to study various mixture properties of interest. Here in, we developed a QSPR model of an excess thermodynamic property of binary mixtures i.e. excess molar volume (V(E) ). In the present study, we use a set of mixture descriptors which we earlier designed to specifically account for intermolecular interactions between the components of a mixture and applied successfully to the prediction of infinite-dilution activity coefficients using neural networks (part 1 of this series). We obtain a significant QSPR model for the prediction of excess molar volume (V(E) ) using consensus neural networks and five mixture descriptors. We find that hydrogen bond and thermodynamic descriptors are the most important in determining excess molar volume (V(E) ), which is in line with the theory of intermolecular forces governing excess mixture properties. The results also suggest that the mixture descriptors utilized herein may be sufficient to model a wide variety of properties of binary and possibly even more complex mixtures. Copyright © 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Measurement and COrrelation on Viscosity and Apparent Molar Volume of Ternary System for L—ascorbic Acid in Aqueous D—Glucose and Sucrose Solutions

Institute of Scientific and Technical Information of China (English)

赵长伟; 马沛生

2003-01-01

Visosities and densities at ,several temperatures from 293.15 K to 313.15K are reported for L-ascorbic acid in aqueous glucose and sucrose solutions at different concentrations.The parameters of density,Viscosity coefficient B and partial molar volume are calculated by regression.The experimental results show that densities and viscositis decrease as temperature increases at the same solute and solvent (glucose and sucrose aueous solution)concentrations,and increase with concentration of glucose and sucrose at the same solute concentration and temperature,B increases with concentration of glucose and sucrose and temaperature,L-ascorbic acid is sturcture-breaker or structure-making for the glucose and sucrose aqueous solutions ,Furthermore,the solute-solvent interactions in ternary systems of water-glucose-electrolyte and water-sucrose-electrolyte are discussed.

Apparent molar volumes and apparent molar heat capacities of Pr(NO3)3(aq), Gd(NO3)3(aq), Ho(NO3)3(aq), and Y(NO3)3(aq) at T (288.15, 298.15, 313.15, and 328.15) K and p = 0.1 MPa

International Nuclear Information System (INIS)

Hakin, Andrew W.; Liu Jinlian; Erickson, Kristy; Munoz, Julie-Vanessa; Rard, Joseph A.

2005-01-01

Relative densities and relative massic heat capacities have been measured for acidified solutions of Y(NO 3 ) 3 (aq), Pr(NO 3 ) 3 (aq), and Gd(NO 3 ) 3 (aq) at T = (288.15, 298.15, 313.15, and 328.15) K and p = 0.1 MPa. In addition, relative densities and massic heat capacities have been measured at the same temperatures and pressure for Y(NO 3 ) 3 (aq) and Ho(NO 3 ) 3 (aq) solutions without excess acid (n.b. measurements at T = 328.15 K for Ho(NO 3 ) 3 (aq) were not performed due to the limited volume of solution available). Apparent molar volumes and apparent molar heat capacities for the aqueous salt solutions have been calculated from the experimental apparent molar properties of the acidified solutions using Young's rule, whereas the apparent molar properties of the solutions without excess acid were calculated directly from the measured densities and massic heat capacities. The two sets of data for the Y(NO 3 ) 3 (aq) systems provide a check of the internal consistency of the Young's rule approach we have utilised. The concentration dependences of the apparent molar volumes and heat capacities of the aqueous salt solutions have been modelled at each investigated temperature using the Pitzer ion interaction equations to yield apparent molar properties at infinite dilution. Complex formation within the aqueous rare earth nitrate systems is discussed qualitatively by probing the concentration dependence of apparent molar volumes and heat capacities. In spite of the complex formation in the aqueous rare earth nitrate systems, there is a high degree of self-consistency between the apparent molar volumes and heat capacities at infinite dilution reported in this manuscript and those previously reported for aqueous rare earth perchlorates

Apparent molal volumes of symmetrical and asymmetrical isomers of tetrabutylammonium bromide in water at several temperatures

International Nuclear Information System (INIS)

Moreno, Nicolás; Malagón, Andrés; Buchner, Richard; Vargas, Edgar F.

2014-01-01

Highlights: • Apparent molal volumes of five isomers of Bu 4 NBr in water have been measured. • The structural effect of branched and linear chains is discussed. • The structural contributions to the ionic volume were calculated. -- Abstract: Apparent molal volumes of a series of differently substituted quaternary ammonium bromides, namely tetra-iso-butyl-, tetra-sec-butyl-, tetra-n-butyl-, di-n-butyl-di-sec-butyl- and di-n-butyl-di-iso-butylammonium bromide have been determined as a function of molal concentration at (298.15, 303.15 and 308.15) K. Partial molar volumes at infinite dilution and ionic molar volumes of these quaternary ammonium cations were determined. Structural volume contributions to the ionic molar volume were also calculated. The symmetric and asymmetric quaternary ammonium cations are “structure making” ions. The contribution of the branched butyl chains predominates over the linear butyl chains in the asymmetric cations

Estudio de volumen molar y refracción molar de miscelas de triglicéridos (triacetina, tributirina o tricaprilina) y alcoholes (etanol, 1-butanol o 1-hexanol)

OpenAIRE

Rodríguez Rodríguez, M.; Galán Vallejo, M.; Muñoz Cueto, María J.

1992-01-01

Values of molar refraction for every studied mixtures show linear plots versus molar fractions of triglyceride. Values of molar volume show this behaviour, but only for tributyrin-butanol or tricaprylin-butanol miscellas. However, in tributyrin-ethanol mixtures, volume contractions have been found, whereas triacetin-butanol and tributyrin-hexanol show volume expansions. These facts are related to the mode of being structured of the alcohol and triglyceride molecules in mixtures. A linea...

Apparent molar volumes and apparent molar heat capacities of aqueous lead nitrate at temperatures from 278.15 K to 393.15 K and at the pressure 0.35 MPa

International Nuclear Information System (INIS)

Brown, B.R.; Niederhauser, T.L.; Merkley, E.D.; Woolley, E.M.

2004-01-01

Apparent molar volumes V phi and apparent molar heat capacities C p,phi were determined for aqueous solutions of lead nitrate [Pb(NO 3 ) 2 ] at m=(0.02 to 0.5) mol · kg -1 , at T=(278.15 to 393.15) K, and at the pressure 0.35 MPa. Our V phi values were calculated from densities obtained using a vibrating-tube densimeter, and our C p,phi values were obtained using a twin fixed-cell, power-compensation, differential-output, temperature-scanning calorimeter. Our results were fitted to functions of m and T and compared with results from the literature

Apparent molar heat capacities and apparent molar volumes of Pr(ClO4)3(aq), Gd(ClO4)3(aq), Ho(ClO4)3(aq), and Tm(ClO4)3(aq) at T=(288.15, 298.15, 313.15, and 328.15) K and p=0.1 MPa

International Nuclear Information System (INIS)

Hakin, Andrew W.; Lian Liu, Jin; Erickson, Kristy; Munoz, Julie-Vanessa

2004-01-01

Acidified aqueous solutions of Pr(ClO 4 ) 3 (aq), Gd(ClO 4 ) 3 (aq), Ho(ClO 4 ) 3 (aq), and Tm(ClO 4 ) 3 (aq) were prepared from the corresponding oxides by dissolution in dilute perchloric acid. Once characterized with respect to trivalent metal cation and acid content, the relative densities of the solutions were measured at T=(288.15, 298.15, 313.15, and 328.15) K and p=0.1 MPa using a Sodev O2D vibrating tube densimeter. The relative massic heat capacities of the aqueous systems were also determined, under the same temperature and pressure conditions, using a Picker Flow Microcalorimeter. All measurements were made on solutions containing rare earth salt in the concentration range 0.01 ≤ m/(mol · kg -1 ) ≤ 0.2. Relative densities and relative massic heat capacities were used to calculate the apparent molar volumes and apparent molar heat capacities of the acidified salt solutions from which the apparent molar properties of the aqueous salt solutions were extracted by the application of Young's Rule. The concentration dependences of the isothermal apparent molar volumes and heat capacities of each aqueous salt solution were modelled using Pitzer ion-interaction equations. These models produced estimates of apparent molar volumes and apparent molar heat capacities at infinite dilution for each set of isothermal V phi,2 and C pphi,2 values. In addition, the temperature and concentration dependences of the apparent molar volumes and apparent molar heat capacities of the aqueous rare earth perchlorate salt solutions were modelled using modified Pitzer ion-interaction equations. The latter equations utilized the Helgeson, Kirkham, and Flowers equations of state to model the temperature dependences (at p=0.1 MPa) of apparent molar volumes and apparent molar heat capacities at infinite dilution. The results of the latter models were compared to those previously published in the literature. Apparent molar volumes and apparent heat capacities at infinite dilution

Studies on the partial specific volume of a poly(ethylene glycol) derivative in different solvent systems

NARCIS (Netherlands)

Tziatzios, C.; Precup, A.A.; Weidl, C.H.; Schubert, U.S.; Schuck, P.; Durchschlag, H.; Mächtle, W.; Broek, van den J.A.; Schubert, D.

2002-01-01

The specific volume of charged supramolecular compounds dissolved in organic solvents varies considerably with the solvent system applied; in addition, it is influenced by the presence of salt. In this study we determined the specific volume of an uncharged molecule from the same molar mass range in

Estudio de volumen molar y refracción molar de miscelas de triglicéridos (triacetina, tributirina o tricaprilina y alcoholes (etanol, 1-butanol o 1-hexanol

Directory of Open Access Journals (Sweden)

Rodríguez Rodríguez, M.

1992-12-01

Full Text Available Values of molar refraction for every studied mixtures show linear plots versus molar fractions of triglyceride. Values of molar volume show this behaviour, but only for tributyrin-butanol or tricaprylin-butanol miscellas. However, in tributyrin-ethanol mixtures, volume contractions have been found, whereas triacetin-butanol and tributyrin-hexanol show volume expansions. These facts are related to the mode of being structured of the alcohol and triglyceride molecules in mixtures. A linear relationship between molar volume and temperature have been found, and also a linear dependence between the coefficient of thermal expansion at constant pressure and the molar fraction of triglyceride.

Los valores de la refracción molar en todas las miscelas estudiadas presentan variaciones lineales frente a la fracción molar de triglicérido. la misma variación que presentan los valores del volumen molar de las miscelas tributirina y tricaprilina en butanol. Sin embargo, en las miscelas de tributirina-etanol se encuentran contracciones de volumen mientras que en las de triacetina-butanol y tributirina-hexanol expansiones, atribuidas en ambos casos a la forma de estructurarse las moléculas de alcohol y triglicérido en las miscelas. Por otra parte, se encuentra una variación lineal entre el volumen molar de las miscelas y la temperatura, y se establece una relación lineal entre el coeficiente de dilatación térmico molar a presión constante y la fracción molar de triglicérido en los cinco sistemas estudiados.

Volumetric, acoustic and viscometric behaviour of dipotassium hydrogen phosphate and disodium hydrogen phosphate in aqueous solution of N-acetyl glycine at different temperatures

International Nuclear Information System (INIS)

Kumar, Harsh; Singla, Meenu; Mittal, Heena

2016-01-01

Highlights: • Densities, speeds of sound, viscosities of phosphate salts in aqueous N-acetyl glycine. • Large values of partial molar volume for dipotassium hydrogen phosphate. • Partial molar volume of transfer are positive for phosphate salts. • Positive B-coefficient values indicate ion–solvent interactions. - Abstract: Densities, speeds of sound and viscosities of dipotassium hydrogen phosphate (DPHP) and disodium hydrogen phosphate (DSHP) in aqueous solutions of N-acetyl glycine (AcGly) are reported at different temperatures. Densities and speeds of sound have been used to calculate apparent molar volume, apparent molar isentropic compression, partial molar volume, partial molar isentropic compression, partial molar volume of transfer, partial molar isentropic compression of transfer and partial molar expansivity. Pair and triplet interaction coefficients have also been calculated. Experimental viscosities have been used to determine B-coefficients. Further pair and triplet interaction coefficients have also been calculated. The results are discussed in terms of solute–solvent interactions.

A Structural Molar Volume Model for Oxide Melts Part I: Li2O-Na2O-K2O-MgO-CaO-MnO-PbO-Al2O3-SiO2 Melts—Binary Systems

Science.gov (United States)

Thibodeau, Eric; Gheribi, Aimen E.; Jung, In-Ho

2016-04-01

A structural molar volume model was developed to accurately reproduce the molar volume of molten oxides. As the non-linearity of molar volume is related to the change in structure of molten oxides, the silicate tetrahedral Q-species, calculated from the modified quasichemical model with an optimized thermodynamic database, were used as basic structural units in the present model. Experimental molar volume data for unary and binary melts in the Li2O-Na2O-K2O-MgO-CaO-MnO-PbO-Al2O3-SiO2 system were critically evaluated. The molar volumes of unary oxide components and binary Q-species, which are model parameters of the present structural model, were determined to accurately reproduce the experimental data across the entire binary composition in a wide range of temperatures. The non-linear behavior of molar volume and thermal expansivity of binary melt depending on SiO2 content are well reproduced by the present model.

Densities and apparent molar volumes for aqueous solutions of HNO3-UO2(NO3)2 at 298.15 K

International Nuclear Information System (INIS)

Yang-Xin Yu; Tie-Zhu Bao; Guang-Hua Gao; Yi-Gui Li

1999-01-01

In order to obtain the exact information of atomic number density in the ternary system of HNO 3 -UO 2 (NO 3 ) 2 -H 2 O, the densities were measured with an Anton-Paar DMA60/602 digital density meter thermostated at 298.15±0.01 K. The apparent molal volumes for the systems were calculated from the experimental data. The present measured apparent molar volumes have been fitted to the Pitzer ion-interaction model, which provides an adequate representation of the experimental data for mixed aqueous electrolyte solutions up to 6.2 mol/kg ionic strength. This fit yields θ V , and Ψ V , which are the first derivatives with respect to pressure of the mixing interaction parameters for the excess free energy. With the mixing parameters θ V , and ψ V , the densities and apparent molar volumes of the ternary system studied in this work can be calculated with good accuracy, as shown by the standard deviations. (author)

Molar development in sheep: morphology, radiography, microhardness

International Nuclear Information System (INIS)

Milhaud, G.; Nezit, J.

1991-01-01

The chronology of molar development is studied from radiographic and macroscopic observations on 48 south Pre-Alps were living under optimal nutritional conditions. It was found that the first molar started its development in utero, the second molar at one month after birth, and the third molar, at 9-10 months. The first molar emerged into the oral cavity at 3 months, the second at 9 months and the third molar at 18 months. The first molar began the development of its roots at 6-7 months, the second molar at 11-12 months and the third molar at 20-22 months. The first molar reached completion of the growth of its roots at 3.5-4 years, the second and the third molars at about 6 years. The molars show the particularity of being functional during the three months which follow their eruption although the development of the crown is not completed. Then the accelerated wear is only partially compensated by the growth of the roots. The study also shows how the combined effects of wear and dentine deposit in the pulp cavity affect the morphology of molars. It reveals the marked hardness of enamel (240 Vickers units) and the low resistance of dentine at the surface of attrition (30 Vickers units)

The in vitro effect of Antimicrobial Photodynamic Therapy on dental microcosm biofilms from partially erupted permanent molars: A pilot study.

Science.gov (United States)

de Oliveira, Fabiana Sodré; Cruvinel, Thiago; Cusicanqui Méndez, Daniela Alejandra; Dionísio, Evandro José; Rios, Daniela; Machado, Maria Aparecida Andrade Moreira

2018-03-01

Antimicrobial Photodynamic Therapy (aPDT) could enhance the prevention of dental caries lesions in pits and fissures of partially erupted molars, by killing microorganisms from complex dental biofilms. This pilot study aimed to evaluate the effect of Antimicrobial Photodynamic Therapy (aPDT) on the viability of specific microorganism groups of dental microcosm biofilms from occlusal surfaces of first permanent molars in eruption. Dental microcosm biofilms grown on bovine enamel blocks, from dental plaque collected on occlusal surfaces of a partially erupted lower right first permanent molar, with McBain medium plus 1% sucrose in anaerobic condition at 37 °C for 72 h. The experiments were performed in eight groups: L-P- = no treatment (control), L18.75P- = 18.75 J/cm 2 LED, L37.5P- = 37.5 J/cm 2 LED, L75P- = 75 J/cm 2 LED, L-P+ = 200 mM TBO, L18.75P+ = 200 mM TBO + 18.75 J/cm 2 LED, L37.5P+ = 200 mM TBO + 37.5 J/cm 2 LED, and L75P+ = 200 mM TBO + 75 J/cm 2 LED. The counts of total microorganisms, total streptococci and mutans streptococci were determined on selective media agar plates by colony-forming units per mL. The log-transformed counts were analyzed by Kruskal-Wallis and post-hoc Dunn's test (P < 0.05). The counts of all microorganisms treated in the group L75P+ were statistically lower than those treated in L-P-. The aPDT promoted a significant reduction of microorganisms, with a trend of dose-dependent effect. TBO-mediated aPDT was effective in reducing the viability of specific microbial groups in dental microcosm biofilms originated from occlusal of permanent molars in eruption. Copyright © 2017 Elsevier B.V. All rights reserved.

Excess Molar Volumes of the Heptane ů 1-Chloropentane System at High Pressures and Elevated Temperatures

Czech Academy of Sciences Publication Activity Database

Linek, Jan; Morávková, Lenka

2001-01-01

Roč. 55, č. 6 (2001), s. 382-385 ISSN 0366-6352. [28th International Conference of SSCHE. Tatranské Matliare, 21.05.2001-25.05.2001] R&D Projects: GA ČR GA203/00/0600 Institutional research plan: CEZ:AV0Z4072921 Keywords : measurement * excess molar volumes * apparatus Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 0.349, year: 2001

Quantification of brain tissue through incorporation of partial volume effects

Science.gov (United States)

Gage, Howard D.; Santago, Peter, II; Snyder, Wesley E.

1992-06-01

This research addresses the problem of automatically quantifying the various types of brain tissue, CSF, white matter, and gray matter, using T1-weighted magnetic resonance images. The method employs a statistical model of the noise and partial volume effect and fits the derived probability density function to that of the data. Following this fit, the optimal decision points can be found for the materials and thus they can be quantified. Emphasis is placed on repeatable results for which a confidence in the solution might be measured. Results are presented assuming a single Gaussian noise source and a uniform distribution of partial volume pixels for both simulated and actual data. Thus far results have been mixed, with no clear advantage being shown in taking into account partial volume effects. Due to the fitting problem being ill-conditioned, it is not yet clear whether these results are due to problems with the model or the method of solution.

2-甲基-3-丁烯-2-醇+直链一元醇二元体系的过量摩尔体积和表观摩尔体积298.15 K)%Excess Molar Volume and Apparent Molar Volume of Binary Mixtures of 2-Methyl-3-buten-2-ol with 1-Alcohol at 298.15 K

Institute of Scientific and Technical Information of China (English)

刘迪霞; 李浩然; 邓东顺; 韩世钧

2002-01-01

Excess molar volumes (VEm) of binary mixtures of 2-methyl-3-buten-2-ol [CH3C(OH)(CH3)CHCH2]with four 1-alcohols: methanol, ethanol, 1-propanol and 1-butanol at 298.15 K and atmospheric pressure are derived from density measurements with a vibrating-tube densimeter. All the excess volumes are negative in the systems over the entire composition range. The results are correlated with the Redlich-Kister equation. The effects of chain length of 1-alcohols on VmE are discussed. The apparent molar volumes of 2-methyl-3-buten-2-ol and 1-alcohols are calculated respectively.

Partial volume and aliasing artefacts in helical cone-beam CT

International Nuclear Information System (INIS)

Zou Yu; Sidky, Emil Y; Pan, Xiaochuan

2004-01-01

A generalization of the quasi-exact algorithms of Kudo et al (2000 IEEE Trans. Med. Imaging 19 902-21) is developed that allows for data acquisition in a 'practical' frame for clinical diagnostic helical, cone-beam computed tomography (CT). The algorithm is investigated using data that model nonlinear partial volume averaging. This investigation leads to an understanding of aliasing artefacts in helical, cone-beam CT image reconstruction. An ad hoc scheme is proposed to mitigate artefacts due to the nonlinear partial volume and aliasing artefacts

Blending Octane Number of Ethanol on a Volume and Molar Basis in SI and HCCI Combustion Modes

KAUST Repository

Waqas, Muhammad Umer; Morganti, Kai; Masurier, Jean-Baptiste; Johansson, Bengt

2017-01-01

The blending behavior of ethanol in five different hydrocarbon base fuels with octane numbers of approximately 70 and 84 was examined under Spark-Ignited (SI) and Homogeneous Charge Compression Ignited (HCCI) operating conditions. The Blending octane number (BON) was used to characterize the blending behavior on both a volume and molar basis. Previous studies have shown that the blending behavior of ethanol generally follows several well-established rules. In particular, non-linear blending effects are generally observed on a volume basis (i.e. BON > RON or MON of pure ethanol; 108 and 89, respectively), while linear blending effects are generally observed on a molar basis (i.e. BON = RON or MON of pure ethanol). This work firstly demonstrates that the non-linear volumetric blending effects traditionally observed under SI operating conditions are also observed under HCCI operating conditions. In keeping with previous studies, the degree of this non-linearity is shown to be a function of the base fuel composition and octane number. By contrast, the molar blending approach is shown to behave differently depending on the chosen combustion mode, with some non-linearity observed under HCCI operating conditions (i.e. BON RON or MON of pure ethanol). This suggests that the well-established blending rules for SI operating conditions may not always be relevant to other combustion modes that operate with globally lean or diluted air-fuel mixtures. This has implications for the design of future fuel specifications.

Blending Octane Number of Ethanol on a Volume and Molar Basis in SI and HCCI Combustion Modes

KAUST Repository

Waqas, Muhammad Umer

2017-10-08

The blending behavior of ethanol in five different hydrocarbon base fuels with octane numbers of approximately 70 and 84 was examined under Spark-Ignited (SI) and Homogeneous Charge Compression Ignited (HCCI) operating conditions. The Blending octane number (BON) was used to characterize the blending behavior on both a volume and molar basis. Previous studies have shown that the blending behavior of ethanol generally follows several well-established rules. In particular, non-linear blending effects are generally observed on a volume basis (i.e. BON > RON or MON of pure ethanol; 108 and 89, respectively), while linear blending effects are generally observed on a molar basis (i.e. BON = RON or MON of pure ethanol). This work firstly demonstrates that the non-linear volumetric blending effects traditionally observed under SI operating conditions are also observed under HCCI operating conditions. In keeping with previous studies, the degree of this non-linearity is shown to be a function of the base fuel composition and octane number. By contrast, the molar blending approach is shown to behave differently depending on the chosen combustion mode, with some non-linearity observed under HCCI operating conditions (i.e. BON RON or MON of pure ethanol). This suggests that the well-established blending rules for SI operating conditions may not always be relevant to other combustion modes that operate with globally lean or diluted air-fuel mixtures. This has implications for the design of future fuel specifications.

Probabilistic Characterization of Partial Volume Effects in Imaging of Rectangular Objects

Energy Technology Data Exchange (ETDEWEB)

Bulaevskaya, V. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

2015-05-06

In imaging, a partial volume effect refers to the problem that arises when the system resolution is low relative to the size of the object being imaged [1, 2]. In this setting, it is likely that most voxels occupied by the object are only partially covered, and that the fraction covered in each voxel is low. This makes the problem of object detection and image segmentation very difficult because the algorithms designed for these purposes rely on pixel summary statistics. If the area covered by the object is very low in relatively many of the total number of the voxels the object occupies, these summary statistics may not reach the thresholds required to detect this object. It is thus important to understand the extent of partial volume effect for a given object size and resolution. This technical report focuses on rectangular objects and derives the probability distributions for three quantities for such objects: 1) the number of fully covered voxels, 2) the number of partially covered voxels, and 3) the fractions of the total volume covered in the partially covered voxels. The derivations are first shown for 2-D settings and are then extended to 3-D settings.

Interactions of glutamine dipeptides with sodium dodecyl sulfate in aqueous solution measured by volume, conductivity, and fluorescence spectra

Energy Technology Data Exchange (ETDEWEB)

Yan Zhenning, E-mail: yanzzn@zzu.edu.cn [Department of Chemistry, Zhengzhou University, Zhengzhou, Henan 450001 (China); Sun Ximeng; Li Weiwei; Li Yu [Department of Chemistry, Zhengzhou University, Zhengzhou, Henan 450001 (China); Wang Jianji [Department of Chemistry, Henan Normal University, Xinxiang, Henan 453007 (China)

2011-10-15

Highlights: > Ion-ion and ion-polar group interactions are dominant interactions. > The SDS addition and temperature increase cause a dehydration effect on dipeptides. > The addition of dipeptide in water decreases the c{sub cmc} of SDS. > Enthalpy-entropy compensation takes place during micellization. > Micelle aggregation number was decreased by addition of glutamine dipeptides. - Abstract: Densities, conductivities, and fluorescence spectra of {l_brace}sodium dodecyl sulfate (SDS) + glutamine dipeptide + water{r_brace} mixtures were measured as a function of temperature. The density data have been utilized to calculate apparent molar volumes, standard partial molar volumes (V{sub 2,{phi}}{sup o}), standard partial molar volumes of transfer from water to aqueous SDS solutions ({Delta}{sub t}V{sup o}), the hydration number, partial molar expansibility (E{sub {phi}}{sup o}), and Hepler's constant of glutamine dipeptides. The critical micellar concentration (c{sub cmc}) and the degree of counterion dissociation of SDS micelles obtained from electrical conductivity data have been estimated at various concentrations of glutamine dipeptide. Thermodynamic parameters of micellization of SDS in aqueous dipeptide solutions have been determined from c{sub cmc} values and an enthalpy-entropy compensation effect was observed for the ternary systems. The pyrene fluorescence spectra were used to study the change of micropolarity produced by the interaction of SDS with glutamine dipeptide, and the aggregation behavior of SDS. The results have been interpreted in terms of solute-solvent interactions and structural changes in the mixed solutions.

Cone beam volume tomography: an imaging option for diagnosis of complex mandibular third molar anatomical relationships.

Science.gov (United States)

Danforth, Robert A; Peck, Jerry; Hall, Paul

2003-11-01

Complex impacted third molars present potential treatment complications and possible patient morbidity. Objectives of diagnostic imaging are to facilitate diagnosis, decision making, and enhance treatment outcomes. As cases become more complex, advanced multiplane imaging methods allowing for a 3-D view are more likely to meet these objectives than traditional 2-D radiography. Until recently, advanced imaging options were somewhat limited to standard film tomography or medical CT, but development of cone beam volume tomography (CBVT) multiplane 3-D imaging systems specifically for dental use now provides an alternative imaging option. Two cases were utilized to compare the role of CBVT to these other imaging options and to illustrate how multiplane visualization can assist the pretreatment evaluation and decision-making process for complex impacted mandibular third molar cases.

A Molar Pregnancy within the Fallopian Tube

Directory of Open Access Journals (Sweden)

Laura Allen

2016-01-01

Full Text Available Background. Discussion of the incidence of molar pregnancy and ectopic pregnancy. Role of salpingostomy and special considerations for postoperative care. Case. The patient is a 29-year-old G7P4 who presented with vaginal bleeding in the first trimester and was initially thought to have a spontaneous abortion. Ultrasound was performed due to ongoing symptoms and an adnexal mass was noted. She underwent uncomplicated salpingostomy and was later found to have a partial molar ectopic pregnancy. Conclusion. This case illustrates the rare occurrence of a molar ectopic pregnancy. There was no indication of molar pregnancy preoperatively and this case highlights the importance of submitting and reviewing pathological specimens.

Density, viscosity and excess molar volume of binary mixtures of tri-n-octylamine + diluents (n-heptane, n-octane, n-nonane, and n-decane) at various temperatures

International Nuclear Information System (INIS)

Fang, Sheng; Zuo, Xiao-Bo; Xu, Xue-Jiao; Ren, Da-Hai

2014-01-01

Highlights: • Densities and viscosities of tri-n-octylamine + n-heptane, +n-octane, +n-nonane, or +n-decane are determined. • The excess molar volume is calculated. • The Grunberg and Nissan equation and Fang and He equation are used to correlate the binary viscosities. -- Abstract: Densities (ρ) and viscosities (η) for binary mixtures of tri-n-octylamine (TOA) + n-heptane, TOA + n-octane, TOA + n-nonane, and TOA + n-decane are determined at T (283.15, 293.15, and 303.15) K and atmospheric pressure. The excess molar volume is calculated from the density data and is correlated by a Redlich–Kister type equation. The excess molar volume is negative for all the four systems. The results show that the volume accommodation effect is predominant in these systems. The Grunberg and Nissan equation and Fang and He equation for binary mixtures are used to correlate the experimental viscosity data. The Fang and He equation gives an average absolute deviation (AAD%) of 0.8% for TOA with alkane mixtures, better than that of 3.8% given by the Grunberg and Nissan equation

Excess molar volumes and deviation in viscosities of binary liquid mixtures of acrylic esters with hexane-1-ol at 303.15 and 313.15 K

Directory of Open Access Journals (Sweden)

Sujata S. Patil

2014-12-01

Full Text Available Densities and viscosities for the four binary liquid mixtures of methyl acrylate, ethyl acrylate, butyl acrylate and methyl methacrylate with hexane-1-ol at temperatures 303.15 and 313.15 K and at atmospheric pressure were measured over the entire composition range. These values were used to calculate excess molar volumes and deviation in viscosities which were fitted to Redlich–Kister polynomial equation. Recently proposed Jouyban Acree model was also used to correlate the experimental values of density and viscosity. The mixture viscosities were correlated by several semi-empirical approaches like Hind, Choudhary–Katti, Grunberg–Nissan, Tamura and Kurata, McAllister three and four body model equations. A graphical representation of excess molar volumes and deviation in isentropic compressibility shows positive nature whereas deviation in viscosity shows negative nature at both temperatures for all four binary liquid mixtures. Positive values of excess molar volumes show that volume expansion is taking place causing rupture of H-bonds in self associated alcohols. The results were discussed in terms of molecular interactions prevailing in the mixtures.

Apparent molar volumes for dilute solutions of NaClO4 and [Co(en) 3](ClO4)3 in D2O and H2O at 278-318 K

International Nuclear Information System (INIS)

Bottomley, G.A.; Glossop, L.G.

1981-01-01

Apparent molar volumes for dilute solutions of NaClO 4 and [Co(en) 3 ](ClO 4 ) 3 in D 2 O and H 2 O were measured by using a dilatometry technique at 278, 298 and 318K. Comparison of limiting slopes with the Debye-Huckel predictions from the dielectric constant and compressibility of H 2 O and D 2 O is complicated by ion pairing. The apparent molar volumes for NaClO 4 were less in D 2 O than in H 2 O. The complex [Co(en) 3 ](ClO 4 ) 3 when studied in D 2 O had its amine protons exchanged by deuterium; this did not allow a direct comparison of the apparent molar volumes of the protonated complex in each solvent system, but revealed a large isotope effect. The apparent molar volumes of the [Co(en) 3 ](ClO 4 ) 3 showed a much larger temperature dependence than that of NaClO 4

Estudio de mezclas de disolventes orgánicos y triglicéridos de aceite de linaza o los ácidos grasos libres. I.- Volumen molar, refracción molar y viscosidad dinámica

Directory of Open Access Journals (Sweden)

Mantell Serrano, C.

1995-06-01

Full Text Available Measurements of molar volume, refraction index and dynamic viscosity in mixtures of fatty acids or triglycerides and trichloroethylene, tetrachloroethylene and hexane were realized. Temperature range studied was 278-313 K each 5 K. The relationship between molar volume and molar fraction show high correlation coefficient In fatty acids with trichloroethylene and tetrachloroethylene mixtures. On the other hand, hexane mixtures show little contractions of molar volume at low molar fractions. Triglyceride mixtures present important deviations with regard to the ideality of the molar volume. The adjusts obtained for the molar volume values versus temperature are acceptable, calculating the coefficients of thermal expansion of the studied mixtures. Equally, the adjust of the experimental results of viscosity for two prediction equations are studied: one of additive type and the other of parabolic type.

Se han realizado medidas del volumen molar, índice de refracción y viscosidad dinámica en el intervalo de temperatura de 278 K a 313 K cada 5 K, a mezclas de ácidos grasos o triglicéridos con tricloroetileno, tetracloroetileno y hexano. Las mezclas de ácidos grasos con tricloroetileno y tetracloroetileno, presentan unos altos coeficientes de correlación para los valores del volumen molar frente a la fracción molar, mientras que las mezclas con hexano, a fracciones molares bajas, manifiestan una pequeña contracción del volumen molar. Las mezclas de triglicéridos presentan importantes desviaciones con respecto a la Idealidad del volumen molar. Los ajustes obtenidos para los valores del volumen molar frente a la temperatura son aceptables, determinándose los valores del coeficiente de dilatación volumétrica a presión constante de las mezclas estudiadas. Igualmente se ha estudiado el ajuste de los resultados experimentales de viscosidad a dos ecuaciones de predicción: una del tipo aditiva y otra del tipo parabólico.

Association of the Mandibular Third Molar Position to the Pericoronitis

Directory of Open Access Journals (Sweden)

Tsvetan Tsvetanov

2018-02-01

Full Text Available Introduction: Pericoronitis is inflammation of the soft tissues surrounding the crown of a partially erupted tooth. Objective: To provide measurement of lower third molar angulation and determine relationship between mandibular third molar position and presence of pericoronitis. Material and methods: We studied 104 patients with lower third molar pericoronitis with clinical manifestations and measurement of lower third molar angulation. The mean age of patients was 25.7 years (range 18-35 years. Results: In this study was used the following statistical analysis, Pearson correlation coefficient and Spearman’s correlation coefficient (nonparametric version of the Pearson correlation coefficient for measure of the linear correlation between two variables - pericoronitis and angulation of the lower third molars. The chi-square test was used to assesses case incidences. The level of significance was p<0.05. 36.04% of partially impacted mandibular third molars were mesioangular followed by the vertical (25.47%, horizontal (18.97%, distoangular (9.21%, buccal (5.42% and lingual (3.79% position. The lowest part of the mandibular third molars is located in the ramus of mandible (1.08%. The present study was found in relation to mesioangular, distoangular, vertical impaction and pericoronitis (p<0.05. Conclusion: We conclude that the position of lower third molar may be able to be associated with presence of pericoronitis.

Molecular analysis of 16S rRNA genes identifies potentially periodontal pathogenic bacteria and archaea in the plaque of partially erupted third molars.

Science.gov (United States)

Mansfield, J M; Campbell, J H; Bhandari, A R; Jesionowski, A M; Vickerman, M M

2012-07-01

Small subunit rRNA sequencing and phylogenetic analysis were used to identify cultivable and uncultivable microorganisms present in the dental plaque of symptomatic and asymptomatic partially erupted third molars to determine the prevalence of putative periodontal pathogens in pericoronal sites. Template DNA prepared from subgingival plaque collected from partially erupted symptomatic and asymptomatic mandibular third molars and healthy incisors was used in polymerase chain reaction with broad-range oligonucleotide primers to amplify 16S rRNA bacterial and archaeal genes. Amplicons were cloned, sequenced, and compared with known nucleotide sequences in online databases to identify the microorganisms present. Two thousand three hundred two clones from the plaque of 12 patients carried bacterial sequences from 63 genera belonging to 11 phyla, including members of the uncultivable TM7, SR1, and Chloroflexi, and difficult-to-cultivate Synergistetes and Spirochaetes. Dialister invisus, Filifactor alocis, Fusobacterium nucleatum, Porphyromonas endodontalis, Prevotella denticola, Tannerella forsythia, and Treponema denticola, which have been associated with periodontal disease, were found in significantly greater abundance in pericoronal compared with incisor sites. Dialister invisus and F nucleatum were found in greater abundance in sites exhibiting clinical symptoms. The archaeal species, Methanobrevibacter oralis, which has been associated with severe periodontitis, was found in 3 symptomatic patients. These findings have provided new insights into the complex microbiota of pericoronitis. Several bacterial and archaeal species implicated in periodontal disease were recovered in greater incidence and abundance from the plaque of partially erupted third molars compared with incisors, supporting the hypothesis that the pericoronal region may provide a favored niche for periodontal pathogens in otherwise healthy mouths. Copyright © 2012 American Association of Oral and

Apparent molar volumes and apparent molar heat capacities of Pr(NO{sub 3}){sub 3}(aq), Gd(NO{sub 3}){sub 3}(aq), Ho(NO{sub 3}){sub 3}(aq), and Y(NO{sub 3}){sub 3}(aq) at T (288.15, 298.15, 313.15, and 328.15) K and p = 0.1 MPa

Energy Technology Data Exchange (ETDEWEB)

Hakin, Andrew W. [Department of Chemistry and Biochemistry, University of Lethbridge, 4401 University Drive, Lethbridge, Alberta, T1K 3M4 (Canada)]. E-mail: hakin@uleth.ca; Liu Jinlian [Department of Chemistry and Biochemistry, University of Lethbridge, 4401 University Drive, Lethbridge, Alberta, T1K 3M4 (Canada); Erickson, Kristy [Department of Chemistry and Biochemistry, University of Lethbridge, 4401 University Drive, Lethbridge, Alberta, T1K 3M4 (Canada); Munoz, Julie-Vanessa [Department of Chemistry and Biochemistry, University of Lethbridge, 4401 University Drive, Lethbridge, Alberta, T1K 3M4 (Canada); Rard, Joseph A. [Energy and Environment Directorate, Lawrence Livermore National Laboratory, University of California, Livermore, CA 94550 (United States)

2005-02-01

Relative densities and relative massic heat capacities have been measured for acidified solutions of Y(NO{sub 3}){sub 3}(aq), Pr(NO{sub 3}){sub 3}(aq), and Gd(NO{sub 3}){sub 3}(aq) at T = (288.15, 298.15, 313.15, and 328.15) K and p = 0.1 MPa. In addition, relative densities and massic heat capacities have been measured at the same temperatures and pressure for Y(NO{sub 3}){sub 3}(aq) and Ho(NO{sub 3}){sub 3}(aq) solutions without excess acid (n.b. measurements at T = 328.15 K for Ho(NO{sub 3}){sub 3}(aq) were not performed due to the limited volume of solution available). Apparent molar volumes and apparent molar heat capacities for the aqueous salt solutions have been calculated from the experimental apparent molar properties of the acidified solutions using Young's rule, whereas the apparent molar properties of the solutions without excess acid were calculated directly from the measured densities and massic heat capacities. The two sets of data for the Y(NO{sub 3}){sub 3}(aq) systems provide a check of the internal consistency of the Young's rule approach we have utilised. The concentration dependences of the apparent molar volumes and heat capacities of the aqueous salt solutions have been modelled at each investigated temperature using the Pitzer ion interaction equations to yield apparent molar properties at infinite dilution. Complex formation within the aqueous rare earth nitrate systems is discussed qualitatively by probing the concentration dependence of apparent molar volumes and heat capacities. In spite of the complex formation in the aqueous rare earth nitrate systems, there is a high degree of self-consistency between the apparent molar volumes and heat capacities at infinite dilution reported in this manuscript and those previously reported for aqueous rare earth perchlorates.

A contact-free volumetric measurement of facial volume after third molar osteotomy: proof of concept.

Science.gov (United States)

Brüllmann, Dan; Jürchott, Lena Marie; John, Christoph; Trempler, Christina; Schwanecke, Ulrich; Schulze, Ralf K W

2014-01-01

The present study tested the reliability of an optical scanning device for the objective assessment of postoperative facial swelling. Twenty control subjects bearing a defined volume of water (10-30 mL) in an intraorally carried balloon were tested to assess the measurement accuracy of the device. As a proof of concept, facial volumes of 59 surgical cases were recorded before osteotomy and 1 and 7 days after intervention with the use of a structured light scanner. The median difference between the applied and the measured volumes was 0.67 mL for the control test with the artificial swelling simulated using water balloons. For subjects having third molar osteotomy, extraoral volume increased to 5.29 cm(3) 1 day after surgery (95% CI 5.22-8.52) and decreased to 0.00 mL (95% CI 0.85-2.55) after 7 days. Contact-free visible-light 3-dimensional scanning is reliable for the objective assessment of postoperative facial swelling. Copyright © 2014 Elsevier Inc. All rights reserved.

Prevalence of missing and impacted third molars in adults aged 25 years and above

Energy Technology Data Exchange (ETDEWEB)

Jung, Yun Hoa; Cho, Bong Hae [Dept. of Oral and Maxillofacial Radiology, School of Dentistry, Pusan National University, Yansan (Korea, Republic of)

2013-12-15

The purpose of this study was to determine the prevalence of missing and impacted third molars in people aged 25 years and above. The study sample of 3,799 patients was chosen randomly from patients who visited Pusan National University Dental Hospital and had panoramic radiographs taken. The data collected included presence and impaction state, angulation, and depth of impaction of third molars, and radiographically detected lesions of third molars and adjacent second molars. A greater percentage of men than women retained at least one third molar. The incidence of third molars decreased with increasing age. The incidence of partially impacted third molars greatly declined after the age of 30. Vertically impacted maxillary third molars and horizontally impacted mandibular third molars were most frequent in all age groups. Among the maxillary third molars, those impacted below the cervical line of the second molar were most frequent in all age groups, and among the mandibular third molars, deeply impacted third molars were most frequent in those aged over 40. Dental caries was the most common radiographic lesion of the third molars. Mesioangularly impacted third molars showed radiographic lesions in 13 (9.5%) adjacent maxillary second molars and 117 (27.4%) mandibular second molars. The number of remaining third molars decreased and the percentage of Class C depth increased with age. Caries was the most frequent lesion in third molars. Partially impacted mesioangular third molars showed a high incidence of caries or periodontal bone loss of the adjacent second molar. Regular oral examination will be essential to keep asymptomatic third molars in good health.

Prevalence of missing and impacted third molars in adults aged 25 years and above

International Nuclear Information System (INIS)

Jung, Yun Hoa; Cho, Bong Hae

2013-01-01

The purpose of this study was to determine the prevalence of missing and impacted third molars in people aged 25 years and above. The study sample of 3,799 patients was chosen randomly from patients who visited Pusan National University Dental Hospital and had panoramic radiographs taken. The data collected included presence and impaction state, angulation, and depth of impaction of third molars, and radiographically detected lesions of third molars and adjacent second molars. A greater percentage of men than women retained at least one third molar. The incidence of third molars decreased with increasing age. The incidence of partially impacted third molars greatly declined after the age of 30. Vertically impacted maxillary third molars and horizontally impacted mandibular third molars were most frequent in all age groups. Among the maxillary third molars, those impacted below the cervical line of the second molar were most frequent in all age groups, and among the mandibular third molars, deeply impacted third molars were most frequent in those aged over 40. Dental caries was the most common radiographic lesion of the third molars. Mesioangularly impacted third molars showed radiographic lesions in 13 (9.5%) adjacent maxillary second molars and 117 (27.4%) mandibular second molars. The number of remaining third molars decreased and the percentage of Class C depth increased with age. Caries was the most frequent lesion in third molars. Partially impacted mesioangular third molars showed a high incidence of caries or periodontal bone loss of the adjacent second molar. Regular oral examination will be essential to keep asymptomatic third molars in good health.

Experimental investigation of thermodynamic properties of binary mixture of acetic acid + n-butanol and acetic acid + water at temperature from 293.15 K to 343.15 K

Science.gov (United States)

Paul, M. Danish John; Shruthi, N.; Anantharaj, R.

2018-04-01

The derived thermodynamic properties like excess molar volume, partial molar volume, excess partial molar volume and apparent volume of binary mixture of acetic acid + n-butanolandacetic acid + water has been investigated using measured density of mixtures at temperatures from 293.15 K to 343.15.

Permittivity, molar volume and crytical phenomena near the lambda-point in liquid 4He

International Nuclear Information System (INIS)

Panov, V.I.; Khvostikov, V.A.

1982-01-01

The permittivity, molar volume and thermal expansion coefficient at the saturated vapor pressure are measured for liquid helium 4 He in the temperature range from 1.4 to 4.2 K. It is shown that the thermal expansion coefficient at saturated vapor pressure near the lambda-transition can be described with a high degree of accuracy by a logarithmic function. The values of the critical indexes obtained by studying the nature of the divergence of the isobaric thermal expansion coefficient at 1x10sup(-5) Tsub(lambda) and α'=0.000+-0.0025 for T 4 He near the lambda transition

Apparent molar heat capacities and apparent molar volumes of Pr(ClO{sub 4}){sub 3}(aq), Gd(ClO{sub 4}){sub 3}(aq), Ho(ClO{sub 4}){sub 3}(aq), and Tm(ClO{sub 4}){sub 3}(aq) at T=(288.15, 298.15, 313.15, and 328.15) K and p=0.1 MPa

Energy Technology Data Exchange (ETDEWEB)

Hakin, Andrew W. E-mail: hakin@uleth.ca; Lian Liu, Jin; Erickson, Kristy; Munoz, Julie-Vanessa

2004-09-01

Acidified aqueous solutions of Pr(ClO{sub 4}){sub 3}(aq), Gd(ClO{sub 4}){sub 3}(aq), Ho(ClO{sub 4}){sub 3}(aq), and Tm(ClO{sub 4}){sub 3}(aq) were prepared from the corresponding oxides by dissolution in dilute perchloric acid. Once characterized with respect to trivalent metal cation and acid content, the relative densities of the solutions were measured at T=(288.15, 298.15, 313.15, and 328.15) K and p=0.1 MPa using a Sodev O2D vibrating tube densimeter. The relative massic heat capacities of the aqueous systems were also determined, under the same temperature and pressure conditions, using a Picker Flow Microcalorimeter. All measurements were made on solutions containing rare earth salt in the concentration range 0.01 {<=} m/(mol {center_dot} kg{sup -1}) {<=} 0.2. Relative densities and relative massic heat capacities were used to calculate the apparent molar volumes and apparent molar heat capacities of the acidified salt solutions from which the apparent molar properties of the aqueous salt solutions were extracted by the application of Young's Rule. The concentration dependences of the isothermal apparent molar volumes and heat capacities of each aqueous salt solution were modelled using Pitzer ion-interaction equations. These models produced estimates of apparent molar volumes and apparent molar heat capacities at infinite dilution for each set of isothermal V{sub phi,2} and C{sub pphi,2} values. In addition, the temperature and concentration dependences of the apparent molar volumes and apparent molar heat capacities of the aqueous rare earth perchlorate salt solutions were modelled using modified Pitzer ion-interaction equations. The latter equations utilized the Helgeson, Kirkham, and Flowers equations of state to model the temperature dependences (at p=0.1 MPa) of apparent molar volumes and apparent molar heat capacities at infinite dilution. The results of the latter models were compared to those previously published in the literature. Apparent

Prevalence of missing and impacted third molars in adults aged 25 years and above

Science.gov (United States)

Jung, Yun-Hoa

2013-01-01

Purpose The purpose of this study was to determine the prevalence of missing and impacted third molars in people aged 25 years and above. Materials and Methods The study sample of 3,799 patients was chosen randomly from patients who visited Pusan National University Dental Hospital and had panoramic radiographs taken. The data collected included presence and impaction state, angulation, and depth of impaction of third molars, and radiographically detected lesions of third molars and adjacent second molars. Results A greater percentage of men than women retained at least one third molar. The incidence of third molars decreased with increasing age. The incidence of partially impacted third molars greatly declined after the age of 30. Vertically impacted maxillary third molars and horizontally impacted mandibular third molars were most frequent in all age groups. Among the maxillary third molars, those impacted below the cervical line of the second molar were most frequent in all age groups, and among the mandibular third molars, deeply impacted third molars were most frequent in those aged over 40. Dental caries was the most common radiographic lesion of the third molars. Mesioangularly impacted third molars showed radiographic lesions in 13 (9.5%) adjacent maxillary second molars and 117 (27.4%) mandibular second molars. Conclusion The number of remaining third molars decreased and the percentage of Class C depth increased with age. Caries was the most frequent lesion in third molars. Partially impacted mesioangular third molars showed a high incidence of caries or periodontal bone loss of the adjacent second molar. Regular oral examination will be essential to keep asymptomatic third molars in good health. PMID:24380060

Excess molar volumes of the ternary system {methylcyclohexane (1)+cyclohexane (2)+n-alkanes (3)} at T=298.15 K

International Nuclear Information System (INIS)

Iloukhani, Hossein; Rezaei-Sameti, Mahdi

2005-01-01

Densities were experimentally determined in the whole range of composition at T=298.15 K for the ternary system {methylcyclohexane (1)+cyclohexane (2)+n-alkanes (3)} and for the seven corresponding binary systems. The n-alkanes include n-hexane, n-heptane, and n-octane. Excess molar volumes, V E , were calculated for the binaries and ternaries systems. The V 123 E data are positive over the entire range of composition for the systems {methylcyclohexane (1)+cyclohexane (2)+n-heptane (3) or n-octane (3)} at three fixed compositions (f m =X 1 /X 2 ). For the system {methylcyclohexane (1)+cyclohexane (2)+n-hexane (3)}, the V E values showed positive for f m =0.3 and negative for f m =3. The V E data exhibit, an inversion in sign in the mixture containing f m =1 for later ternary system. Several empirical expressions are used to predict and correlate the ternary excess molar volumes from experimental results on the constituted binaries and analyzed to gain insight about liquid mixture interactions

Excess molar volumes of (an alkanol plus a branched chain ether) at the temperature 298.15 K and the application of the ERAS model

CSIR Research Space (South Africa)

Letcher, TM

1997-12-01

Full Text Available Phase Equilibria 140 (1997) 207-220 The excess molar the temperature volumes of (an alkanol + a branched chain ether) at 298.15 K and the application of the ERAS model Trevor M. Letcher * , Penny U. Govender ? Drpartnwnt... V,,? results presented here, together with the previously reported data for the molar excess enthalpy Hi, has been used to test the Extended Real Associated Solution (ERAS) model. 0 1997 Elsevier Science B.V. Ke...

Partial drift volume due to a self-propelled swimmer

Science.gov (United States)

Chisholm, Nicholas G.; Khair, Aditya S.

2018-01-01

We assess the ability of a self-propelled swimmer to displace a volume of fluid that is large compared to its own volume via the mechanism of partial drift. The swimmer performs rectilinear locomotion in an incompressible, unbounded Newtonian fluid. The partial drift volume D is the volume of fluid enclosed between the initial and final profiles of an initially flat circular disk of marked fluid elements; the disk is initially aligned perpendicular to the direction of locomotion and subsequently distorted due to the passage of the swimmer, which travels a finite distance. To focus on the possibility of large-scale drift, we model the swimmer simply as a force dipole aligned with the swimming direction. At zero Reynolds number (Re =0 ), we demonstrate that D grows without limit as the radius of the marked fluid disk h is made large, indicating that a swimmer at Re =0 can generate a partial drift volume much larger than its own volume. Next, we consider a steady swimmer at small Re , which is modeled as the force-dipole solution to Oseen's equation. Here, we find that D no longer diverges with h , which is due to inertial screening of viscous forces, and is effectively proportional to the magnitude of the force dipole exerted by the swimmer. The validity of this result is extended to Re ≥O (1 ) —the realm of intermediate-Re swimmers such as copepods—by taking advantage of the fact that, in this case, the flow is also described by Oseen's equations at distances much larger than the characteristic linear dimension of the swimmer. Next, we utilize an integral momentum balance to demonstrate that our analysis for a steady inertial swimmer also holds, in a time-averaged sense, for an unsteady swimmer that does not experience a net acceleration over a stroke cycle. Finally, we use experimental data to estimate D for a few real swimmers. Interestingly, we find that D depends heavily on the kinematics of swimming, and, in certain cases, D can be significantly greater

Density, viscosity, surface tension, and molar volume of propylene glycol + water mixtures from 293 to 323 K and correlations by the Jouyban–Acree model

Directory of Open Access Journals (Sweden)

Ibrahim S. Khattab

2017-02-01

Full Text Available Density, viscosity, surface tension and molar volume of propylene glycol + water mixtures at 293, 298, 303, 308, 313, 318, and 323 K are reported, compared with the available literature data and the Jouyban–Acree model was used for mathematical correlation of the data. The mean relative deviation (MRD was used as an error criterion and the MRD values for data correlation of density, viscosity, surface tension and molar volume at different investigated temperatures are 0.1 ± 0.1%, 7.6 ± 6.4%, 3.4 ± 3.7%, and 0.4 ± 0.4%, respectively. The corresponding MRDs for the predicted properties after training the model using the experimental data at 298 K are 0.1 ± 0.2%, 12.8 ± 9.3%, 4.7 ± 4.1% and 0.6 ± 0.5%, respectively for density, viscosity, surface tension, and molar volume data.

Volumetric properties of binary liquid-phase mixture of (water + glycerol) at temperatures of (278.15 to 323.15) K and pressures of (0.1 to 100) MPa

International Nuclear Information System (INIS)

Egorov, Gennadiy I.; Makarov, Dmitriy M.

2014-01-01

Highlights: • Coefficients of compressibility of liquid binary mixture (water + glycerol) were measured. • Partial molar volumes of the components and excess molar volumes of the mixture were calculated. • Molar isothermal compression, molar isobaric expansion and molar isochoric elasticity of the mixture were evaluated. • Analysis of volume characteristics confirms glycerol hydrophilic nature. - Abstract: The coefficients of compressibility, k = ΔV/V o , of liquid binary mixture of {water (1) + glycerol (2)} were measured over the whole composition range at pressures from (0.1 to 100) MPa and temperatures from (278.15 to 323.15) K. Excess molar volumes of the mixture, V m E , partial molar volumes of the mixture components, V ¯ i , as well as their limiting values, molar isothermal compression K T,m , molar isobaric expansion E P,m , molar isochoric elasticity (isochoric coefficient of thermal pressure) β m were calculated. It was revealed that with glycerol molar fraction increasing the coefficients of compressibility, k, decreased to x 2 ≈ 0.3 ÷ 0.4 (where x 2 was glycerol molar fraction), and further changed insignificantly. It was shown that all isobars of excess molar volumes were negative and their absolute values, V m E , decreased on temperature and pressure rising. No extremes were observed on concentration dependences of partial molar volumes of glycerol in the mixture at its low concentrations. Under the state parameters studied limiting partial volumes of water and glycerol decrease with pressure rising but increase with temperature growth. Dependences of molar isothermal compression and molar isochoric elasticity on glycerol molar fraction passed extremes, and similar dependences of molar isobaric expansion had the temperature inversion regions

Anatomically guided voxel-based partial volume effect correction in brain PET : Impact of MRI segmentation

NARCIS (Netherlands)

Gutierrez, Daniel; Montandon, Marie-Louise; Assal, Frederic; Allaoua, Mohamed; Ratib, Osman; Loevblad, Karl-Olof; Zaidi, Habib

2012-01-01

Partial volume effect is still considered one of the main limitations in brain PET imaging given the limited spatial resolution of current generation PET scanners. The accuracy of anatomically guided partial volume effect correction (PVC) algorithms in brain PET is largely dependent on the

Hitchhiker'S Guide to Voxel Segmentation for Partial Volume Correction of in Vivo Magnetic Resonance Spectroscopy

Directory of Open Access Journals (Sweden)

Scott Quadrelli

2016-01-01

Full Text Available Partial volume effects have the potential to cause inaccuracies when quantifying metabolites using proton magnetic resonance spectroscopy (MRS. In order to correct for cerebrospinal fluid content, a spectroscopic voxel needs to be segmented according to different tissue contents. This article aims to detail how automated partial volume segmentation can be undertaken and provides a software framework for researchers to develop their own tools. While many studies have detailed the impact of partial volume correction on proton magnetic resonance spectroscopy quantification, there is a paucity of literature explaining how voxel segmentation can be achieved using freely available neuroimaging packages.

Spectrum of excess partial molar absorptivity. Part II: a near infrared spectroscopic study of aqueous Na-halides.

Science.gov (United States)

Sebe, Fumie; Nishikawa, Keiko; Koga, Yoshikata

2012-04-07

Our earlier thermodynamic studies suggested that F(-) and Cl(-) form hydration shells with the hydration number 14 ± 2 and 2.3 ± 0.6, respectively, and leave the bulk H(2)O away from hydration shells unperturbed. Br(-) and I(-), on the other hand, form hydrogen bonds directly with the momentarily existing hydrogen bond network of H(2)O, and retard the degree of entropy-volume cross fluctuation inherent in liquid H(2)O. The effect of the latter is stronger for I(-) than Br(-). Here we seek additional information about this qualitative difference between Cl(-) and (Br(-) and I(-)) pair by near infrared (NIR) spectroscopy. We analyze the ν(2) + ν(3) band of H(2)O in the range 4600-5500 cm(-1) of aqueous solutions of NaCl, NaBr and NaI, by a new approach. From observed absorbance, we calculate excess molar absorptivity, ε(E), excess over the additive contributions of solute and solvent. ε(E) thus contains information about the effect of inter-molecular interactions in the ν(2) + ν(3) spectrum. The spectrum of ε(E) shows three bands; two negative ones at 5263 and 4873 cm(-1), and the positive band at 5123 cm(-1). We then define and calculate the excess partial molar absorptivity of each salt, ε(E)(salt). From the behaviour of ε(E)(salt) we suggest that the negative band at 5263 cm(-1) represents free H(2)O without much hydrogen bonding under the influence of local electric field of ions. Furthermore, from a sudden change in the x(salt) (mole fraction of salt) dependence of ε(E)(salt), we suggest that there is an ion-pairing in x(salt) > 0.032, 0.036, and 0.04 for NaCl, NaBr and NaI respectively. The positive band of ε(E) at 5123 cm(-1) is attributed to a modestly organized hydrogen bond network of H(2)O (or liquid-likeness), and the x(salt) dependence of ε indicated a qualitative difference in the effect of Cl(-) from those of Br(-) and I(-). Namely, the values of ε(E)(salt) stay constant for Cl(-) but those for Br(-) and I(-) decrease smoothly on

Different partial volume correction methods lead to different conclusions

DEFF Research Database (Denmark)

Greve, Douglas N; Salat, David H; Bowen, Spencer L

2016-01-01

A cross-sectional group study of the effects of aging on brain metabolism as measured with (18)F-FDG-PET was performed using several different partial volume correction (PVC) methods: no correction (NoPVC), Meltzer (MZ), Müller-Gärtner (MG), and the symmetric geometric transfer matrix (SGTM) usin...

FMDP Reactor Alternative Summary Report: Volume 3 - partially complete LWR alternative

International Nuclear Information System (INIS)

Greene, S.R.; Fisher, S.E.; Bevard, B.B.

1996-09-01

The Department of Energy Office of Fissile Materials Disposition (DOE/MD) initiated a detailed analysis activity to evaluate each of ten plutonium disposition alternatives that survived an initial screening process. This document, Volume 3 of a four volume report summarizes the results of these analyses for the partially complete LWR (PCLWR) reactor based plutonium disposition alternative

FMDP Reactor Alternative Summary Report: Volume 3 - partially complete LWR alternative

Energy Technology Data Exchange (ETDEWEB)

Greene, S.R.; Fisher, S.E.; Bevard, B.B. [and others

1996-09-01

The Department of Energy Office of Fissile Materials Disposition (DOE/MD) initiated a detailed analysis activity to evaluate each of ten plutonium disposition alternatives that survived an initial screening process. This document, Volume 3 of a four volume report summarizes the results of these analyses for the partially complete LWR (PCLWR) reactor based plutonium disposition alternative.

Thermodynamics of proton dissociation from aqueous bicarbonate: apparent molar volumes and apparent molar heat capacities of potassium carbonate and potassium bicarbonate at T=(278.15 to 393.15) K and at the pressure 0.35 MPa

International Nuclear Information System (INIS)

Sorenson, E.C.; Woolley, E.M.

2004-01-01

We have determined the apparent molar volumes V phi and apparent molar heat capacities C p,phi of aqueous potassium carbonate and potassium bicarbonate solutions in the ranges (0.014≤m/(mol · kg -1 )≤0.51) and (278.15≤T/K≤393.15) at the pressure p=0.35 MPa. Corrections for speciation due to hydrolysis and disproportionation in solution were applied using Young's rule, and semi-empirical equations representing (V phi ,m,T) and (C p,phi ,m,T) for the species {2K + , CO 3 2- (aq)} and {K + , HCO 3 - (aq)} were fitted to the experimental results. We have used these equations to estimate the change in volume Δ r V m , change in heat capacity Δ r C p,m , enthalpy change Δ r H m , entropy change Δ r S m , and equilibrium molality quotient pQ for the second proton dissociation reaction from aqueous carbonic acid

Solute-solvent interactions in 2,4-dihydroxyacetophenone isonicotinoylhydrazone solutions in N, N-dimethylformamide and dimethyl sulfoxide at 298-313 K on ultrasonic and viscometric data

Science.gov (United States)

Dikkar, A. B.; Pethe, G. B.; Aswar, A. S.

2016-02-01

The speed of sound ( u), density (ρ), and viscosity (η) of 2,4-dihydroxyacetophenone isonicotinoylhydrazone (DHAIH) have been measured in N, N-dimethyl formamide and dimethyl sulfoxide at equidistance temperatures 298.15, 303.15, 308.15, and 313.15 K. These data were used to calculate some important ultrasonic and thermodynamic parameters such as apparent molar volume ( V ϕ s st ), apparent molar compressibility ( K ϕ), partial molar volume ( V ϕ 0 ) and partial molar compressibility ( K ϕ 0 ), were estimated by using the values of ( V ϕ 0 ) and ( K ϕ), at infinite dilution. Partial molar expansion at infinite dilution, (ϕ E 0 ) has also been calculated from temperature dependence of partial molar volume V ϕ 0 . The viscosity data have been analyzed using the Jones-Dole equation, and the viscosity, B coefficients are calculated. The activation free energy has been calculated from B coefficients and partial molar volume data. The results have been discussed in the term of solute-solvent interaction occurring in solutions and it was found that DHAIH acts as a structure maker in present systems.

PREDICTION OF THE MIXING ENTHALPIES OF BINARY LIQUID ALLOYS BY MOLECULAR INTERACTION VOLUME MODEL

Institute of Scientific and Technical Information of China (English)

H.W.Yang; D.P.Tao; Z.H.Zhou

2008-01-01

The mixing enthalpies of 23 binary liquid alloys are calculated by molecular interaction volume model (MIVM), which is a two-parameter model with the partial molar infinite dilute mixing enthalpies. The predicted values are in agreement with the experimental data and then indicate that the model is reliable and convenient.

Mandibular molar root morphology in Neanderthals and Late Pleistocene and recent Homo sapiens.

Science.gov (United States)

Kupczik, Kornelius; Hublin, Jean-Jacques

2010-11-01

Neanderthals have a distinctive suite of dental features, including large anterior crown and root dimensions and molars with enlarged pulp cavities. Yet, there is little known about variation in molar root morphology in Neanderthals and other recent and fossil members of Homo. Here, we provide the first comprehensive metric analysis of permanent mandibular molar root morphology in Middle and Late Pleistocene Homo neanderthalensis, and Late Pleistocene (Aterian) and recent Homo sapiens. We specifically address the question of whether root form can be used to distinguish between these groups and assess whether any variation in root form can be related to differences in tooth function. We apply a microtomographic imaging approach to visualise and quantify the external and internal dental morphologies of both isolated molars and molars embedded in the mandible (n=127). Univariate and multivariate analyses reveal both similarities (root length and pulp volume) and differences (occurrence of pyramidal roots and dental tissue volume proportion) in molar root morphology among penecontemporaneous Neanderthals and Aterian H. sapiens. In contrast, the molars of recent H. sapiens are markedly smaller than both Pleistocene H. sapiens and Neanderthals, but share with the former the dentine volume reduction and a smaller root-to-crown volume compared with Neanderthals. Furthermore, we found the first molar to have the largest average root surface area in recent H. sapiens and Neanderthals, although in the latter the difference between M(1) and M(2) is small. In contrast, Aterian H. sapiens root surface areas peak at M(2). Since root surface area is linked to masticatory function, this suggests a distinct occlusal loading regime in Neanderthals compared with both recent and Pleistocene H. sapiens. Copyright © 2010 Elsevier Ltd. All rights reserved.

Apparent molar volumes, isobaric expansion coefficients, and isentropic compressibilities, and their H/D isotope effects for some aqueous carbohydrate solutions

International Nuclear Information System (INIS)

Bernal, P.J.; Van Hook, W.A.

1986-01-01

The molar volumes, isobaric expansion coefficients, and isentropic compressibilities of solutions of a number of carbohydrates and their deuterated isomers were determined in H 2 O and D 2 O between 288.15 and 328.15 K and over a wide range of solute-to-solvent mole ratios. The results are discussed in terms of the specific hydration model. (author)

Study of the seroma volume changes in the patients who underwent Accelerated Partial Breast Irradiation

International Nuclear Information System (INIS)

Kim, Dae Ho; Son, Sang Jun; Mun, Jun Ki; Seo, Seok Jin; Lee, Je Hee

2016-01-01

By analyzing seroma volume changes in the patients who underwent Partial breast radiation therapy after breast conserving surgery, we try to contribute to the improvement of radiotherapy effect. Enrolled 20 patients who underwent partial breast radiation therapy by ViewRay MRIdian System were subject. After seeking for the size of the removed sample in the patients during surgery and obtained seroma volume changes on a weekly basis. On the Basis of acquired volume, it was compared with age, term from start of the first treatment after surgery, BMI (body mass index) and the extracted sample size during surgery. And using the ViewRay MRIdian RTP System, the figure was analyzed by PTV(=seroma volume + margin) to obtain a specific volume of the Partial breast radiation therapy. The changes of seroma volume from MR simulation to the first treatment (a week) is 0~5% in 8, 5~10% in 3, 10 to 15% in 2, and 20% or more in 5 people. Two patients(A, B patient) among subjects showed the biggest change. The A patient's 100% of the prescribed dose volume is 213.08 cc, PTV is 181.93 cc, seroma volume is 15.3 cc in initial plan. However, while seroma volume decreased 65.36% to 5.3 cc, 100% of the prescribed dose volume was reduced to 3.4% to 102.43 cc and PTV also did 43.6% to 102.54 cc. In the case of the B patient, seroma volume decreased 42.57% from 20.2 cc to 11.6 cc. Because of that, 100% of the prescribed dose volume decreased 8.1% and PTV also did to 40%. As the period between the first therapy and surgery is shorter, the patient is elder and the size of sample is smaller than 100 cc, the change grow bigger. It is desirable to establish an adaptive plan according to each patient's changes of seroma volume through continuous observation. Because partial breast patients is more sensitive than WBRT patients about dose conformity in accordance with the volume change

A Comparison of Different Volumes of Articaine for Inferior Alveolar Nerve Block for Molar Teeth with Symptomatic Irreversible Pulpitis.

Science.gov (United States)

Abazarpoor, Ramin; Parirokh, Masoud; Nakhaee, Nouzar; Abbott, Paul V

2015-09-01

Achieving anesthesia in mandibular molar teeth with irreversible pulpitis is very difficult. The aim of this study was to compare the efficacy of 1.8 mL and 3.6 mL articaine for an inferior alveolar nerve block (IANB) when treating molars with symptomatic irreversible pulpitis. In a randomized, double-blind clinical trial, 82 first mandibular molar teeth with symptomatic irreversible pulpitis randomly received conventional IANB injection either with 1 (1.8 mL) or 2 cartridges (3.6 mL) of 4% articaine with 1:100,000 epinephrine. The patients recorded their pain before and during access cavity preparation as well as during root canal instrumentation using a Heft-Parker visual analog scale. No or mild pain was considered as successful anesthesia. Data were analyzed by t and chi-square tests. Eighty patients were eligible to participate in this study, which showed that 3.6 mL articaine provided a significantly higher success rate (77.5%) of IANBs compared with 1.8 mL of the same anesthetic solution (27.5%) although neither group had 100% successful anesthesia (P < .001). Increasing the volume of articaine provided a significantly higher success rate of IANBs in mandibular first molar teeth with symptomatic irreversible pulpitis, but it did not result in 100% anesthetic success. Copyright © 2015 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Excess molar enthalpies and volumes of binary mixtures of two hydrofluoroethers with hexane, or benzene, or ethanol, or 1-propanol, or 2-butanone at T=298.15 K

International Nuclear Information System (INIS)

Ogawa, Hideo; Karashima, Shinya; Takigawa, Takayo; Murakami, Sachio

2003-01-01

Excess molar enthalpies and volumes at T=298.15 K are reported for binary mixtures of {1,1,2,3,3,3-hexafluoro-1-methoxypropane (HFE-356mec), [CF 3 CHFCF 2 -O-CH 3 ], or 1,1,2,2-tetrafluoro-1-(2,2,2-trifluoroethoxy)ethane (HFE-347pc-f) [CHF 2 CF 2 -O-CH 2 CF 3 ] + hexane (Hx), or benzene (Bz), or ethanol (EtOH), or 1-propanol (PrOH), or 2-butanone (MEK)}. The results of excess molar enthalpies are endothermic over the whole range of concentration, except for the MEK systems, in which excess molar enthalpies are exothermic over the whole range of concentration, and the EtOH systems, in which they are exothermic in the smaller mole fraction range. On the other hand, excess molar volumes are positive over the whole concentration range for all the mixtures. The values of the excess molar enthalpies for the (HFE-347pc-f + Hx) system show the linear composition dependence in the range of ca. 0.3< x<0.7, suggesting the quasi-stable state in solution. The results are explained by means of the destruction of the dipolar interactions and hydrogen bond in the pure component liquids, the difference of the dispersion interactions between the pure component liquid and solution, and the formation of the intermolecular hydrogen bond and dipolar interaction between unlike molecules

Fate of third molar in line of mandibular angle fracture - Retrospective study

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Preetha Balaji

2015-01-01

Conclusion: The present study fails to identify any concrete factors that would predict the failure of the retained third molar that were involved in the line of mandibular fractures. The proof presented here, especially with low complication rates indicate that all impacted third molar along the line of fracture be removed and unless necessary, the partially erupted teeth would also be extracted. In such a situation, the rate of infection and survival of the third molar would have been entirely different.

Whole object surface area and volume of partial-view 3D models

International Nuclear Information System (INIS)

Mulukutla, Gopal K; Proussevitch, Alexander A; Genareau, Kimberly D; Durant, Adam J

2017-01-01

Micro-scale 3D models, important components of many studies in science and engineering, are often used to determine morphological characteristics such as shape, surface area and volume. The application of techniques such as stereoscopic scanning electron microscopy on whole objects often results in ‘partial-view’ models with a portion of object not within the field of view thus not captured in the 3D model. The nature and extent of the surface not captured is dependent on the complex interaction of imaging system attributes (e.g. working distance, viewing angle) with object size, shape and morphology. As a result, any simplistic assumptions in estimating whole object surface area or volume can lead to significant errors. In this study, we report on a novel technique to estimate the physical fraction of an object captured in a partial-view 3D model of an otherwise whole object. This allows a more accurate estimate of surface area and volume. Using 3D models, we demonstrate the robustness of this method and the accuracy of surface area and volume estimates relative to true values. (paper)

Solvation behaviour of biologically active compounds in aqueous solutions of antibacterial drug amoxicillin at different temperatures

International Nuclear Information System (INIS)

Singla, Meenu; Kumar, Harsh; Jindal, Rajeev

2014-01-01

Highlights: • Densities and speeds of sound of amino acids in aqueous amoxicillin solutions. • Partial molar volumes and compressibility of transfer. • Group contribution have been calculated. • (Ion + hydrophilic) and (hydrophilic + hydrophilic) interactions are present. • Pair-wise interactions are dominant in the mixtures. - Abstract: The interactions of glycine (Gly), L-alanine (Ala), L-valine (Val) and L-Leucine (Leu) with drug amoxicillin (AMX) as a function of temperature have been investigated by combination of volumetric and acoustic measurements. Densities and speeds of sound of amino acids in aqueous solutions of amoxicillin have been measured at T = (305.15, 310.15 and 315.15) K and atmospheric pressure. The apparent molar volume (V ϕ ), the partial molar volume (V ϕ 0 ) and standard partial molar volumes of transfer (ΔV ϕ 0 ) for amino acids from water to aqueous amoxicillin solutions have been calculated from density data. Group contributions of amino acids to partial molar volume were determined. Partial molar isentropic compression (κ ϕ,s ) and partial molar isentropic compression of transfer (Δκ ϕ,S 0 ) have been calculated from speed of sound data. The pair and triplet interaction coefficient have been calculated from both the properties. The results have been explained based on competing patterns of interactions of co-solvents and the solute

Excess Molar Volumes and Viscosities for Binary Mixtures of 1-Alkoxypropan-2-ols with 1-Butanol,and 2-Butanol at 298.15 K and Atmospheric Pressure

Institute of Scientific and Technical Information of China (English)

PAL Amalendu; GABA Rekha

2007-01-01

Excess molar volumes VEm and kinematic viscosities v have been measured as a function of composition for binary mixtures of propylene glycol monomethyl ether (1-methoxy-2-propanol),MeOCH2CH(OH)Me,propylene glycol monoethyl ether (1-ethoxy-2-propanol), EtOCH2CH(OH)Me,propylene glycol monopropyl ether (1-propoxy-2-propanol), PrOCH2CH(OH)Me, propylene glycol monobutyl ether (1-butoxy-2-propanol),BuOCH2CH(OH)Me,and propylene glycol tert-butyl ether (1-tert-butoxy-2-propanol),t-BuOCH2CH(OH)Me with 1-butanol,and 2-butanol,at 298.15 K and atmospheric pressure.The excess molar volumes are negative across the entire range of composition for all the systems with 1-butanol,and positive for the systems 2-butanol+1-methoxy-2-propanol,and +1-propoxy-2-propanol,negative for the systems 2-butanol+1-butoxy-2-propanol,and change sign for the systems 2-butanol+1-ethoxy-2-propanol,and +1-tert-butoxy-2-propanol.From the experimental data,the deviation in dynamic viscosity η from Σxiηi has been calculated.Both excess molar volumes and viscosity deviations have been correlated using a Redlich-Kister type polynomial equation by the method of least-squares for the estimation of the binary coefficients and the standard errors.

Study of the seroma volume changes in the patients who underwent Accelerated Partial Breast Irradiation

Energy Technology Data Exchange (ETDEWEB)

Kim, Dae Ho; Son, Sang Jun; Mun, Jun Ki; Seo, Seok Jin; Lee, Je Hee [Dept. of Radiation Oncology, Seoul National University Hospital, Seoul (Korea, Republic of)

2016-06-15

By analyzing seroma volume changes in the patients who underwent Partial breast radiation therapy after breast conserving surgery, we try to contribute to the improvement of radiotherapy effect. Enrolled 20 patients who underwent partial breast radiation therapy by ViewRay MRIdian System were subject. After seeking for the size of the removed sample in the patients during surgery and obtained seroma volume changes on a weekly basis. On the Basis of acquired volume, it was compared with age, term from start of the first treatment after surgery, BMI (body mass index) and the extracted sample size during surgery. And using the ViewRay MRIdian RTP System, the figure was analyzed by PTV(=seroma volume + margin) to obtain a specific volume of the Partial breast radiation therapy. The changes of seroma volume from MR simulation to the first treatment (a week) is 0~5% in 8, 5~10% in 3, 10 to 15% in 2, and 20% or more in 5 people. Two patients(A, B patient) among subjects showed the biggest change. The A patient's 100% of the prescribed dose volume is 213.08 cc, PTV is 181.93 cc, seroma volume is 15.3 cc in initial plan. However, while seroma volume decreased 65.36% to 5.3 cc, 100% of the prescribed dose volume was reduced to 3.4% to 102.43 cc and PTV also did 43.6% to 102.54 cc. In the case of the B patient, seroma volume decreased 42.57% from 20.2 cc to 11.6 cc. Because of that, 100% of the prescribed dose volume decreased 8.1% and PTV also did to 40%. As the period between the first therapy and surgery is shorter, the patient is elder and the size of sample is smaller than 100 cc, the change grow bigger. It is desirable to establish an adaptive plan according to each patient's changes of seroma volume through continuous observation. Because partial breast patients is more sensitive than WBRT patients about dose conformity in accordance with the volume change.

Raman Line Imaging of Poly(ε-caprolactone)/Carbon Dioxide Solutions at High Pressures: A Combined Experimental and Computational Study for Interpreting Intermolecular Interactions and Free-Volume Effects.

Science.gov (United States)

Pastore Carbone, Maria Giovanna; Musto, Pellegrino; Pannico, Marianna; Braeuer, Andreas; Scherillo, Giuseppe; Mensitieri, Giuseppe; Di Maio, Ernesto

2016-09-01

In the present study, a Raman line-imaging setup was employed to monitor in situ the CO2 sorption at elevated pressures (from 0.62 to 7.10 MPa) in molten PCL. The method allowed the quantitative measurement of gas concentration in both the time-resolved and the space-resolved modes. The combined experimental and theoretical approach allowed a molecular level characterization of the system. The dissolved CO2 was found to occupy a volume essentially coincident with its van der Waals volume and the estimated partial molar volume of the probe did not change with pressure. Lewis acid-Lewis base interactions with the PCL carbonyls was confirmed to be the main interaction mechanism. The geometry of the supramolecular complex and the preferential interaction site were controlled more by steric than electronic effects. On the basis of the indications emerging from Raman spectroscopy, an equation of state thermodynamic model for the PCL-CO2 system, based upon a compressible lattice fluid theory endowed with specific interactions, has been tailored to account for the interaction types detected spectroscopically. The predictions of the thermodynamic model in terms of molar volume of solution have been compared with available volumetric measurements while predictions for CO2 partial molar volume have been compared with the values estimated on the basis of Raman spectroscopy.

Calculation of the capnographic index based on expiratory molar mass-volume-curves--a suitable tool to screen for cystic fibrosis lung disease.

Science.gov (United States)

Fuchs, Susanne I; Junge, Sibylle; Ellemunter, Helmut; Ballmann, Manfred; Gappa, Monika

2013-05-01

Volumetric capnography reflecting the course of CO2-exhalation is used to assess ventilation inhomogeneity. Calculation of the slope of expiratory phase 3 and the capnographic index (KPIv) from expirograms allows quantification of extent and severity of small airway impairment. However, technical limitations have hampered more widespread use of this technique. Using expiratory molar mass-volume-curves sampled with a handheld ultrasonic flow sensor during tidal breathing is a novel approach to extract similar information from expirograms in a simpler manner possibly qualifying as a screening tool for clinical routine. The aim of the present study was to evaluate calculation of the KPIv based on molar mass-volume-curves sampled with an ultrasonic flow sensor in patients with CF and controls by assessing feasibility, reproducibility and comparability with the Lung Clearance Index (LCI) derived from multiple breath washout (MBW) used as the reference method. Measurements were performed in patients with CF and healthy controls during a single test occasion using the EasyOne Pro, MBW Module (ndd Medical Technologies, Switzerland). Capnography and MBW were performed in 87/96 patients with CF and 38/42 controls, with a success rate of 90.6% for capnography. Mean age (range) was 12.1 (4-25) years. Mean (SD) KPIv was 6.94 (3.08) in CF and 5.10 (2.06) in controls (p=0.001). Mean LCI (SD) was 8.0 (1.4) in CF and 6.2 (0.4) in controls (p=molar mass-volume-curves is feasible. KPIv is significantly different between patients with CF and controls and correlates with the LCI. However, individual data revealed a relevant overlap between patients and controls requiring further evaluation, before this method can be recommended for clinical use. Copyright © 2012 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.

Apparent molar volumes and isentropic compressibilities of benzyltrialkylammonium chlorides in water at (293.15, 303.15, 313.15, 323.15, and 333.15) K

International Nuclear Information System (INIS)

Duman, Osman; Ayranci, Erol

2009-01-01

Densities and ultrasound speeds of benzyltrialkylammonium chlorides (BTAACls) were measured accurately in aqueous solutions at five temperatures (293.15, 303.15, 313.15, 323.15, and 333.15) K. The data were utilized in determining apparent molar volumes, V Φ , and apparent molar isentropic compressibilities, K SΦ . Infinite dilution values of these apparent molar quantities, V Φ 0 andK SΦ 0 , were determined by extrapolation procedures. Contribution of CH 2 groups, along the alkyl groups of BTAACls, to V Φ 0 andK SΦ 0 values were derived from plots of these quantities as a function of number of additional CH 2 groups in going from benzyltrimethylammonium chloride to benzyltributylammonium chloride. The temperature dependencies of V Φ 0 andK SΦ 0 values were examined on the basis of isobaric expansivity. Apparent molar isobaric expansivities at infinite dilution, E Φ 0 , were obtained from the slopes of V Φ 0 versus temperature data. Concentration dependencies of V Φ and K SΦ were examined. A fair correlation was observed between V Φ 0 andK SΦ 0 values of the three BTAACls.

Densities, Ultrasonic Speeds, and Excess Properties of Binary Mixtures of Diethylene Glycol with 1-Butanol, 2-Butanol, and 1,4-Butanediol at Different Temperatures

Science.gov (United States)

Ali, Anwar; Ansari, Sana; Uzair, Sahar; Tasneem, Shadma; Nabi, Firdosa

2015-11-01

Densities ρ and ultrasonic speeds u for pure diethylene glycol, 1-butanol, 2-butanol, and 1,4-butanediol and for their binary mixtures over the entire composition range were measured at 298.15 K, 303.15 K, 308.15 K, and 313.15 K. Using these data, the excess molar volumes, VE_m, deviations in isentropic compressibilities, {\\varDelta }ks, apparent molar volumes, V_{φi} , partial molar volumes, overline{V}_{m,i} , and excess partial molar volumes, overline{V}_{m,i}^E , have been calculated over the entire composition range, and also the excess partial molar volumes of the components at infinite dilution, overline{V}_{m,i}^{E,infty } have been calculated. The excess functions have been correlated using the Redlich-Kister equation at different temperatures. The variations of these derived parameters with composition and temperature are presented graphically.

Excess molar volume, viscosity, and refractive index study for the ternary mixture {2-methyl-2-butanol (1) + tetrahydrofuran (2) + propylamine (3)} at different temperatures. Application of the ERAS-model and Peng-Robinson-Stryjek-Vera equation of state

International Nuclear Information System (INIS)

Fattahi, M.; Iloukhani, H.

2010-01-01

Densities, viscosities, and refractive indices of the ternary mixture consist of {2-methyl-2-butanol (1) + tetrahydrofuran (THF) (2) + propylamine (3)} at a temperature of 298.15 K and related binary mixtures were measured at temperatures of (288.15, 298.15, and 308.15) K at ambient pressure. Data were used to calculate the excess molar volumes and the deviations of the viscosity and refractive index. The Redlich-Kister and the Cibulka equations were used for correlating binary and ternary properties, respectively. The ERAS-model has been applied for describing the binary and ternary excess molar volumes and also Peng-Robinson-Stryjek-Vera (PRSV) equation of state (EOS) has been used to predict the binary and ternary excess molar volumes and viscosities.

Efficacy of orally administered prednisolone versus partial endodontic treatment on pain reduction in emergency care of acute irreversible pulpitis of mandibular molars: study protocol for a randomized controlled trial.

Science.gov (United States)

Kérourédan, Olivia; Jallon, Léonard; Perez, Paul; Germain, Christine; Péli, Jean-François; Oriez, Dominique; Fricain, Jean-Christophe; Arrivé, Elise; Devillard, Raphaël

2017-03-28

Irreversible pulpitis is a highly painful inflammatory condition of the dental pulp which represents a common dental emergency. Recommended care is partial endodontic treatment. The dental literature reports major difficulties in achieving adequate analgesia to perform this emergency treatment, especially in the case of mandibular molars. In current practice, short-course, orally administered corticotherapy is used for the management of oral pain of inflammatory origin. The efficacy of intraosseous local steroid injections for irreversible pulpitis in mandibular molars has already been demonstrated but resulted in local comorbidities. Oral administration of short-course prednisolone is simple and safe but its efficacy to manage pain caused by irreversible pulpitis has not yet been demonstrated. This trial aims to evaluate the noninferiority of short-course, orally administered corticotherapy versus partial endodontic treatment for the emergency care of irreversible pulpitis in mandibular molars. This study is a noninferiority, open-label, randomized controlled clinical trial conducted at the Bordeaux University Hospital. One hundred and twenty subjects will be randomized in two 1:1 parallel arms: the intervention arm will receive one oral dose of prednisolone (1 mg/kg) during the emergency visit, followed by one morning dose each day for 3 days and the reference arm will receive partial endodontic treatment. Both groups will receive planned complete endodontic treatment 72 h after enrollment. The primary outcome is the proportion of patients with pain intensity below 5 on a Numeric Scale 24 h after the emergency visit. Secondary outcomes include comfort during care, the number of injected anesthetic cartridges when performing complete endodontic treatment, the number of antalgic drugs and the number of patients coming back for consultation after 72 h. This randomized trial will assess the ability of short-term corticotherapy to reduce pain in irreversible

Improved prediction of octanol-water partition coefficients from liquid-solute water solubilities and molar volumes

Science.gov (United States)

Chiou, C.T.; Schmedding, D.W.; Manes, M.

2005-01-01

A volume-fraction-based solvent-water partition model for dilute solutes, in which the partition coefficient shows a dependence on solute molar volume (V??), is adapted to predict the octanol-water partition coefficient (K ow) from the liquid or supercooled-liquid solute water solubility (Sw), or vice versa. The established correlation is tested for a wide range of industrial compounds and pesticides (e.g., halogenated aliphatic hydrocarbons, alkylbenzenes, halogenated benzenes, ethers, esters, PAHs, PCBs, organochlorines, organophosphates, carbamates, and amidesureas-triazines), which comprise a total of 215 test compounds spanning about 10 orders of magnitude in Sw and 8.5 orders of magnitude in Kow. Except for phenols and alcohols, which require special considerations of the Kow data, the correlation predicts the Kow within 0.1 log units for most compounds, much independent of the compound type or the magnitude in K ow. With reliable Sw and V data for compounds of interest, the correlation provides an effective means for either predicting the unavailable log Kow values or verifying the reliability of the reported log Kow data. ?? 2005 American Chemical Society.

Relation between heat of vaporization, ion transport, molar volume, and cation-anion binding energy for ionic liquids.

Science.gov (United States)

Borodin, Oleg

2009-09-10

A number of correlations between heat of vaporization (H(vap)), cation-anion binding energy (E(+/-)), molar volume (V(m)), self-diffusion coefficient (D), and ionic conductivity for 29 ionic liquids have been investigated using molecular dynamics (MD) simulations that employed accurate and validated many-body polarizable force fields. A significant correlation between D and H(vap) has been found, while the best correlation was found for -log(DV(m)) vs H(vap) + 0.28E(+/-). A combination of enthalpy of vaporization and a fraction of the cation-anion binding energy was suggested as a measure of the effective cohesive energy for ionic liquids. A deviation of some ILs from the reported master curve is explained based upon ion packing and proposed diffusion pathways. No general correlations were found between the ion diffusion coefficient and molecular volume or the diffusion coefficient and cation/anion binding energy.

Excess Molar Volumes of (Octane + 1-Chlorobutane) at Temperatures between 298.15 K and 328.15 K and at Pressures up to 40 MPa

Czech Academy of Sciences Publication Activity Database

Morávková, Lenka; Linek, Jan

2003-01-01

Roč. 35, č. 1 (2003), s. 113-121 ISSN 0021-9614 R&D Projects: GA ČR GA203/00/0600 Institutional research plan: CEZ:AV0Z4072921 Keywords : densities * excess molar volumes * mixtures Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 0.986, year: 2003

Deciduous molar hypomineralization and molar incisor hypomineralization

NARCIS (Netherlands)

Elfrink, M.E.C.; ten Cate, J.M.; Jaddoe, V.W.V.; Hofman, A.; Moll, H.A.; Veerkamp, J.S.J.

2012-01-01

This study was embedded in the Generation R Study, a population-based prospective cohort study from fetal life until young adulthood. This study focused on the relationship between Deciduous Molar Hypomineralization (DMH) and Molar Incisor Hypomineralization (MIH). First permanent molars develop

Thermodynamic study on some alkanediol solutions: Measurement and modeling

International Nuclear Information System (INIS)

Moosavi, Mehrdad; Motahari, Ahmad; Omrani, Abdollah; Rostami, Abbas Ali

2013-01-01

Highlights: • Measuring densities and viscosities for binary mixtures of some alkanediols. • Finding excess molar volume, partial molar volume and thermal expansion coefficient. • Fitting excess molar volume values with PFP and Redlich–Kister polynomial equations. • Deducing excess Gibbs free energy of activation and other thermodynamic parameters. • Predicting viscosity values with different single parameter semi empirical equations. - Abstract: The densities ρ and viscosities η of 1,2-ethanediol with 1,2-propanediol or 1,3-propanediol, and 1,2-propanediol with 1,3-propanediol binary liquid mixtures over the entire concentration range at temperatures (298.15 to 308.15) K with 5 K interval were measured. The experimental data were used to calculate the excess molar volume V m E , partial molar volume V ¯ m,i , partial molar volume at infinite dilution V ¯ i ∞ , apparent molar volume V φi , coefficient of thermal expansion α p , excess coefficient of thermal expansion α p E , excess viscosity η E , excess Gibbs energy of activation ΔG *E , and other thermodynamic parameters. A Redlich–Kister equation and Prigogine–Flory–Patterson (PFP) model was applied to correlate the excess molar volume results. Moreover, the viscosity data were correlated with the Grunberg–Nissan, Tamura–Kurata, Hind–Ubbelohde and Katti–Chaudhary equations. Good agreement was found between experimental data and modeling results

Double versus single cartridge of 4% articaine infiltration into the retro-molar area for lower third molar surgery.

Science.gov (United States)

Sawang, Kamonpun; Chaiyasamut, Teeranut; Kiattavornchareon, Sirichai; Pairuchvej, Verasak; Bhattarai, Bishwa Prakash; Wongsirichat, Natthamet

2017-06-01

There are no studies regarding 4% articaine infiltration injection into the retro-molar area for an impacted lower third molar (LITM) surgery. This study aimed to evaluate the efficacy of infiltration using 1.7 ml (single cartridge: SC) of 4% articaine versus 3.4 ml (double cartridges: DC) of 4% articaine with 1:100,000 epinephrine in LITM surgery. This study involved 30 healthy patients with symmetrical LITM. The patients were assigned to receive either a DC or SC of 4% articaine with 1:100,000 epinephrine as a local anesthetic for each operation. Onset, duration, profoundness, need for additional anesthetic administration, total volume of anesthetic used, vitality of the tooth, and pain score during operation were recorded. The DC of 4 % articaine had a significantly higher success rate (83.3%) than did the SC (53.3%; P molar region can be an alternative anesthetic for LITM surgery.

Excess molar volume along with viscosity, refractive index and relative permittivity for binary mixtures of exo-tetrahydrodicyclopentadiene with four octane isomers

International Nuclear Information System (INIS)

Yue, Lei; Qin, Xiaomei; Wu, Xi; Xu, Li; Guo, Yongsheng; Fang, Wenjun

2015-01-01

Highlights: • Binary mixtures of JP-10 with octane isomers are studied as model hydrocarbon fuels. • Density, viscosity, refractive index and relative permittivity are determined. • Excess molar volumes and viscosity deviations are calculated and correlated. - Abstract: The fundamental physical properties including density, viscosity, refractive index and relative permittivity, have been measured for binary mixtures of exo-tetrahydrodicyclopentadiene (JP-10) with four octane isomers (n-octane, 3-methylheptane, 2,4-dimethylhexane and 2,2,4-trimethylpentane) over the whole composition range at temperatures T = (293.15 to 313.15) K and pressure p = 0.1 MPa. The values of excess molar volume (V m E ), viscosity deviation (Δη), refractive index deviation (Δn D ) and relative permittivity deviation (Δε r ) are then calculated. All of the values of V m E and Δη are observed to be negative, while those of Δn D and Δε r are close to zero. The effects of temperature and composition on the variation of V m E values are discussed. The negative values of V m E and Δη are conductive to high-density and low-resistance of fuels, which is favorable for the design and preparation of advanced hydrocarbon fuels

Effects of concentration, temperature and solvent composition on density and apparent molar volume of the binary mixtures of cationic-anionic surfactants in methanol-water mixed solvent media.

Science.gov (United States)

Bhattarai, Ajaya; Chatterjee, Sujeet Kumar; Niraula, Tulasi Prasad

2013-01-01

The accurate measurements on density of the binary mixtures of cetyltrimethylammonium bromide and sodium dodecyl sulphate in pure water and in methanol(1) + water (2) mixed solvent media containing (0.10, 0.20, and 0.30) volume fractions of methanol at 308.15, 318.15, and 323.15 K are reported. The concentrations are varied from (0.03 to 0.12) mol.l(-1) of sodium dodecyl sulphate in presence of ~ 5.0×10(-4) mol.l(-1) cetyltrimethylammonium bromide. The results showed almost increase in the densities with increasing surfactant mixture concentration, also the densities are found to decrease with increasing temperature over the entire concentration range, investigated in a given mixed solvent medium and these values are found to decrease with increasing methanol content in the solvent composition. The concentration dependence of the apparent molar volumes appear to be negligible over the entire concentration range, investigated in a given mixed solvent medium and the apparent molar volumes increase with increasing temperature and are found to decrease with increasing methanol content in the solvent composition.

Apparent CBF decrease with normal aging due to partial volume effects: MR-based partial volume correction on CBF SPECT.

Science.gov (United States)

Inoue, Kentaro; Ito, Hiroshi; Goto, Ryoi; Nakagawa, Manabu; Kinomura, Shigeo; Sato, Tachio; Sato, Kazunori; Fukuda, Hiroshi

2005-06-01

Several studies using single photon emission tomography (SPECT) have shown changes in cerebral blood flow (CBF) with age, which were associated with partial volume effects by some authors. Some studies have also demonstrated gender-related differences in CBF. The present study aimed to examine age and gender effects on CBF SPECT images obtained using the 99mTc-ethyl cysteinate dimer and a SPECT scanner, before and after partial volume correction (PVC) using magnetic resonance (MR) imaging. Forty-four healthy subjects (29 males and 15 females; age range, 27-64 y; mean age, 50.0 +/- 9.8 y) participated. Each MR image was segmented to yield grey and white matter images and coregistered to a corresponding SPECT image, followed by convolution to approximate the SPECT spatial resolution. PVC-SPECT images were produced using the convoluted grey matter MR (GM-MR) and white matter MR images. The age and gender effects were assessed using SPM99. Decreases with age were detected in the anterolateral prefrontal cortex and in areas along the lateral sulcus and the lateral ventricle, bilaterally, in the GM-MR images and the SPECT images. In the PVC-SPECT images, decreases in CBF in the lateral prefrontal cortex lost their statistical significance. Decreases in CBF with age found along the lateral sulcus and the lateral ventricle, on the other hand, remained statistically significant, but observation of the spatially normalized MR images suggests that these findings are associated with the dilatation of the lateral sulcus and lateral ventricle, which was not completely compensated for by the spatial normalization procedure. Our present study demonstrated that age effects on CBF in healthy subjects could reflect morphological differences with age in grey matter.

[Surgery of lower third molars and lesions of the lingual nerve].

Science.gov (United States)

Chiapasco, M; Pedrinazzi, M; Motta, J; Crescentini, M; Ramundo, G

1996-11-01

The authors describe a technical expedient applied during the removal of totally or partially impacted lower third molars, in order to prevent lingual nerve damage. EXPERIMENTAL ASSAY: Retrospective study. The sample includes 1835 extractions of totally or partially impacted lower third molars, performed on 1030 patients, 493 males and 537 females, aging between 12 and 72 years. All the operations were carried out under local anaesthesia with standardization of the surgical protocol. A mucoperiosteal paramarginal flap was used in case of germectomy, whereas a mucoperiosteal marginal flap with mesial releasing incision was used in case of fully mature teeth. Ostectomy and tooth sectioning were performed using a round and fissure bur respectively, assembled on a straight low-speed handpiece and under irrigation with sterile saline. The authors reported only one case of transient lingual nerve paresthesia (0.05%) which occurred in a 19-years old female presenting a totally impacted third molar mesial-lingual inclination. Symptoms disappeared spontaneously one week postoperatively. Therefore the overall incidence of permanent nerve damage was equal to 0%. The data reported in literature show a lingual nerve lesion incidence ranging between 0% and 22%. With this simple surgical expedient the incidence of permanent lingual damage was 0%. Thus, it is the authors' opinion that this simple expedient should be applied in all cases of impacted third molar removal.

Treatment of ectopically erupting maxillary permanent first molars with a distal extended stainless steel crown.

Science.gov (United States)

Roberts, M W

1986-01-01

The exaggerated mesial eruption of the permanent first molar can result in the tooth becoming impacted, or the premature atypical resorption and exfoliation of the primary molar, with a resultant loss of space. A stainless steel crown with a distal guide plane was placed on a primary molar to correct the aberrant eruption angle of the permanent tooth. This procedure can be used successfully for both partially and totally tissue-impacted teeth, and is described in this report.

Analysis of Partial Volume Effects on Arterial Input Functions Using Gradient Echo: A Simulation Study

DEFF Research Database (Denmark)

Kjølby, Birgitte Fuglsang; Mikkelsen, Irene Klærke; Pedersen, Michael

2009-01-01

of an AIF voxel including the relaxation properties of blood and tissue. Artery orientations parallel and perpendicular to the main magnetic field were investigated and AIF voxels were modeled to either include or be situated close to a large artery. The impact of partial volume effects on quantitative...... perfusion metrics was investigated for the gradient echo pulse sequence at 1.5 T and 3.0 T. It is shown that the tissue contribution broadens and introduces fluctuations in the AIF. Furthermore, partial volume effects bias perfusion metrics in a nonlinear fashion, compromising quantitative perfusion...

Thermodynamic study on some alkanediol solutions: Measurement and modeling

Energy Technology Data Exchange (ETDEWEB)

Moosavi, Mehrdad; Motahari, Ahmad; Omrani, Abdollah, E-mail: omrani@umz.ac.ir; Rostami, Abbas Ali

2013-06-10

Highlights: • Measuring densities and viscosities for binary mixtures of some alkanediols. • Finding excess molar volume, partial molar volume and thermal expansion coefficient. • Fitting excess molar volume values with PFP and Redlich–Kister polynomial equations. • Deducing excess Gibbs free energy of activation and other thermodynamic parameters. • Predicting viscosity values with different single parameter semi empirical equations. - Abstract: The densities ρ and viscosities η of 1,2-ethanediol with 1,2-propanediol or 1,3-propanediol, and 1,2-propanediol with 1,3-propanediol binary liquid mixtures over the entire concentration range at temperatures (298.15 to 308.15) K with 5 K interval were measured. The experimental data were used to calculate the excess molar volume V{sub m}{sup E}, partial molar volume V{sup ¯}{sub m,i}, partial molar volume at infinite dilution V{sup ¯}{sub i}{sup ∞}, apparent molar volume V{sub φi}, coefficient of thermal expansion α{sub p}, excess coefficient of thermal expansion α{sub p}{sup E}, excess viscosity η{sup E}, excess Gibbs energy of activation ΔG{sup *E}, and other thermodynamic parameters. A Redlich–Kister equation and Prigogine–Flory–Patterson (PFP) model was applied to correlate the excess molar volume results. Moreover, the viscosity data were correlated with the Grunberg–Nissan, Tamura–Kurata, Hind–Ubbelohde and Katti–Chaudhary equations. Good agreement was found between experimental data and modeling results.

Volumetric study of (diethylamine + water) mixtures between (278.15 and 308.15) K

International Nuclear Information System (INIS)

Lampreia, Isabel M.S.; Dias, Florbela A.; Mendonca, Angela F.S.S.

2004-01-01

Densities have been measured for aqueous mixtures of diethylamine at the temperatures: (278.15, 288.15, 293.15, 298.15, and 308.15) K, for the entire composition range. The data have been used to calculate apparent molar, excess molar and excess partial molar volumes. Limiting values of excess partial molar volumes and expansions have been derived as well. The discussion has been undertaken comparing the obtained values with those of parent studies in related compounds

Properties of pure n-butylammonium nitrate ionic liquid and its binary mixtures of with alcohols at T = (293.15 to 313.15) K

International Nuclear Information System (INIS)

Xu, Yingjie; Chen, Bin; Qian, Wu; Li, Haoran

2013-01-01

Highlights: ► Densities and viscosities of (N4NO 3 + alcohols) mixtures were measured. ► Coefficient of thermal expansion, molecular volume, standard entropy, and lattice energy were obtained. ► Excess molar volumes, viscosity deviations, and partial molar volumes were calculated. ► Redlich–Kister polynomial was used to correlate the excess properties. ► The intermolecular interactions between N4NO 3 and alcohols were analysed. -- Abstract: Values of the density and viscosity of the pure ionic liquid n-butylammonium nitrate (N4NO 3 ) and its binary mixtures with methanol, ethanol, 1-propanol, and 1-butanol were measured at temperature ranging from T = (293.15 to 313.15) K. The thermal expansion coefficient, molecular volume, standard entropy, and lattice energy of N4NO 3 were deduced from the experimental density results. The temperature dependence of the viscosity of N4NO 3 was fitted to the fluidity equation. Excess molar volumes V E and viscosity deviations Δη for the binary mixtures were calculated and fitted to the Redlich–Kister equation with satisfactory results. Both excess molar volumes and viscosity deviations show negative deviations for (N4NO 3 + alcohol) mixtures. The effect of the temperature and the size of the alcohol on the excess molar volumes and viscosity deviations are discussed and analysed. Other derived properties, such as the apparent molar volume, partial molar volume, excess partial molar volume, thermal expansion coefficient, and excess thermal expansion coefficient of the above-mentioned systems were also calculated

Influência da temperatura, da massa molar e da distribuição de massa molar na tensão superficial de PS, PP e PE: experimento e teoria

Directory of Open Access Journals (Sweden)

Moreira José C.

2003-01-01

Full Text Available Neste trabalho a influência da temperatura, da massa molar (n e da distribuição de massa molar (MWD na tensão superficial de poliestireno (PS foi avaliada utilizando o método da gota pendente. A influência da temperatura na tensão superficial de polipropileno isotático (i-PP e de polietileno de baixa densidade (PELBD também foi estudada aqui. As teorias de Patterson-Rastogi e Dee-Sauer foram utilizadas em conjunção com a teoria de equação de estado de Flory, Orwoll, e Vrij (FOV para prever a tensão superficial (gama utilizando dados de pressão-volume-temperatura (PVT dos polímeros. Ambas teorias prevêem que a tensão superficial diminui linearmente com o aumento da temperatura e aumenta com a massa molar concordando com os resultados experimentais. Entretanto, ambas teorias subestimam a mudança de entropia de formação de superfície por unidade de área a volume constante para sistemas poliméricos de baixa massa molar e polidisperso e subestimam o efeito da distribuição de massa molar na tensão superficial

Influence of Zinc on the Surface Tension, Density and Molar Volume of (Ag-Sneut +Zn Liquid Alloys

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Gąsior W.

2016-03-01

Full Text Available The dilatometric and maximum bubble pressure methods were applied for the measurements of the density and surface tension of liquid (Ag-Sneut +Zn lead-free solders. The experiments were carried out in the temperature range from 515 to 1223 K for the alloys of the zinc concentration equaling 0.01, 0.02, 0.04, 0.05, 0.1 and 0.2 of the mole fraction. It was found that the temperature dependence of both the density and the surface tension could be thought as linear, so they were interpreted by straight line equations. The experimental data of the molar volume of the investigated alloys were described by the polynomial dependent on the composition and temperature.

In vitro comparative evaluation of cleaning efficacy and volumetric filling in primary molars: Cone beam computed tomography evaluation

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Anshula Neeraj Deshpande

2017-01-01

Full Text Available Introduction: Pulpectomy of primary teeth is mostly carried out with hand files and broaches which is tricky and time consuming procedure. The development of new design features like varying tapers, non-cutting safety tips and varying length of cutting blades have resulted in new generation of rotary instruments. Aim: To compare and evaluate cleaning efficacy, canal preparation and volumetric filling using conventional files and rotary V Taper files through cone beam computed tomography. Materials and Method: Thirty extracted primary molars were selected. The teeth were randomly divided into three groups each containing 10 teeth i.e. 30 canals in each group. Group A was instrumented with K files; Group B rotary V Taper files and Group C was Hybrid group. Sodium hypochlorite (1% was used for irrigation. Root canal filling was done with Zinc Oxide Eugenol cement in all groups. The volumetric analysis i.e. Percentage of Volume (POV of the root canal filling in primary molars was done through CBCT Software. Result: In present study, p- value was found to be significant (<0.05. Almost 100% of canals of hybrid group were fully filled and 63.3% of canals of hand filing group were partially filled. The filling was found to be dense and no. of voids was least in hybrid group. Conclusion: Clinical time required in primary molar endodontics, especially with unpredictability and difficulty of canal morphology, is inevitable. The study confirms superior ability of rotary-file systems to shape severely curved canals with less time and significant decrease in procedural errors like partial filling, voids and inappropriate canal preparation.

Density, excess volume, and excess coefficient of thermal expansion of the binary systems of dimethyl carbonate with butyl methacrylate, allyl methacrylate, styrene, and vinyl acetate at T = (293.15, 303.15, and 313.15) K

International Nuclear Information System (INIS)

Wisniak, Jaime; Cortez, Gladis; Peralta, Rene D.; Infante, Ramiro; Elizalde, Luis E.; Amaro, Tlaloc A.; Garcia, Omar; Soto, Homero

2008-01-01

Densities of the binary systems of dimethyl carbonate with butyl methacrylate, allyl methacrylate, styrene, and vinyl acetate have been measured as a function of the composition at (293.15, 303.15, and 313.15) K at atmospheric pressure, using an Anton Paar DMA 5000 oscillating U-tube densimeter. The excess molar volumes are negative for the (dimethyl carbonate + vinyl acetate) system and positive for the three other binaries, and become more so as the temperature increases from (293.15 to 313.15) K. The apparent volumes were used to calculate the values of the partial excess molar volumes at infinite dilution. The excess coefficient of thermal expansion is positive for the four binary systems. The calculated excess molar volumes were correlated with the Redlich-Kister equation and with a series of Legendre polynomials. An explanation of the results is offered based on the FT-IR (ATR) spectra of several mixtures of the different systems

Density, excess volume, and excess coefficient of thermal expansion of the binary systems of dimethyl carbonate with butyl methacrylate, allyl methacrylate, styrene, and vinyl acetate at T = (293.15, 303.15, and 313.15) K

Energy Technology Data Exchange (ETDEWEB)

Wisniak, Jaime [Department of Chemical Engineering, Ben-Gurion University of the Negev, Beer-Sheva 84105 (Israel)], E-mail: wisniak@bgumail.bgu.ac.il; Cortez, Gladis; Peralta, Rene D.; Infante, Ramiro; Elizalde, Luis E. [Centro de Investigacion en Quimica Aplicada, Saltillo 25253, Coahuila (Mexico); Amaro, Tlaloc A.; Garcia, Omar; Soto, Homero [Facultad de Ciencias Quimicas, Universidad Autonoma de Coahuila, Saltillo 25280, Coahuila (Mexico)

2008-12-15

Densities of the binary systems of dimethyl carbonate with butyl methacrylate, allyl methacrylate, styrene, and vinyl acetate have been measured as a function of the composition at (293.15, 303.15, and 313.15) K at atmospheric pressure, using an Anton Paar DMA 5000 oscillating U-tube densimeter. The excess molar volumes are negative for the (dimethyl carbonate + vinyl acetate) system and positive for the three other binaries, and become more so as the temperature increases from (293.15 to 313.15) K. The apparent volumes were used to calculate the values of the partial excess molar volumes at infinite dilution. The excess coefficient of thermal expansion is positive for the four binary systems. The calculated excess molar volumes were correlated with the Redlich-Kister equation and with a series of Legendre polynomials. An explanation of the results is offered based on the FT-IR (ATR) spectra of several mixtures of the different systems.

Density, viscosity, isothermal (vapour + liquid) equilibrium, excess molar volume, viscosity deviation, and their correlations for chloroform + methyl isobutyl ketone binary system

International Nuclear Information System (INIS)

Clara, Rene A.; Gomez Marigliano, Ana C.; Solimo, Horacio N.

2007-01-01

Density and viscosity measurements for pure chloroform and methyl isobutyl ketone at T = (283.15, 293.15, 303.15, and 313.15) K as well as for the binary system {x 1 chloroform + (1 - x 1 ) methyl isobutyl ketone} at the same temperatures were made over the whole concentration range. The experimental results were fitted to empirical equations, which permit the calculation of these properties over the whole concentration and temperature ranges studied. Data of the binary mixture were further used to calculate the excess molar volume and viscosity deviation. The (vapour + liquid) equilibrium (VLE) at T = 303.15 K for this binary system was also measured in order to calculate the activity coefficients and the excess molar Gibbs energy. This binary system shows no azeotrope and negative deviations from ideal behaviour. The excess or deviation properties were fitted to the Redlich-Kister polynomial relation to obtain their coefficients and standard deviations

Investigation on molecular interaction of amino acids in aqueous disodium hydrogen phosphate solutions with reference to volumetric and compressibility measurements

International Nuclear Information System (INIS)

Kumar, Harsh; Singla, Meenu; Jindal, Rajeev

2014-01-01

Highlights: • Densities and speeds of sound of amino acids in aqueous disodium hydrogen phosphate. • Partial molar volumes and compressibility of transfer. • Positive values of transfer volume indicates interactions between ions of amino acids and TSC. • Ion–hydrophilic and hydrophilic–hydrophilic interactions are present. • Pair-wise interactions are dominant in the mixtures. -- Abstract: The interactions of amino acids glycine (Gly), L-alanine (Ala), and L-valine (Val) with disodium hydrogen phosphate (DSHP) as a function of temperature have been investigated by combination of volumetric and acoustic measurements. Densities (ρ) and speeds of sound (u) of amino acids in aqueous solutions of disodium hydrogen phosphate have been measured at T = (288.15, 293.15, 298.15, 303.15 and 308.15) K and atmospheric pressure. The apparent molar volume (V ϕ ), the partial molar volume (V ϕ 0 ) and standard partial molar volumes of transfer (ΔV ϕ 0 ) for amino acids from water to aqueous disodium hydrogen phosphate solutions have been calculated from density data. Partial molar adiabatic compressibility (κ ϕ,s ) and partial molar adiabatic compressibility of transfer (Δκ ϕ,S 0 ) have been calculated from speed of sound data. The pair (V AB , κ AB ) and triplet (V ABB , κ ABB ) interaction coefficient have been calculated from both the properties. The results have been explained based on competing patterns of interactions of co-solvents and the solute

MOLAR UPRIGHTING

Directory of Open Access Journals (Sweden)

Eka Erwansyah

2006-04-01

Full Text Available The mesial tipping of molar is frequently found in orthodontic cases. This molar malposition must be corrected since it may cause periodontal disorders, occlusal interferences, and temporomandibular joint dysfunction, and is often needed in planning a fixed bridge. This paper is a literature study to discuss about appliance designs, indication, and contraindications, and complication and treatment protocols of molar uprighting by fixed orthodontic appliances. By knowing the techniques of molar uprighting, the moments mentioned above can be avoided.

Intrusion of an overerupted molar using orthodontic miniscrew implant: A preprosthodontic therapy

Directory of Open Access Journals (Sweden)

Indumathi Sivakumar

2014-01-01

Full Text Available The purpose of this case report is to demonstrate the use of orthodontic miniscrew implant in the intrusion of overerupted molar as a preprosthodontic therapy. A 37-year-old woman with an overerupted maxillary right first molar encroaching on the opposing mandibular edentulous space was successfully intruded using a single miniscrew implant and partial fixed orthodontic appliance. The prosthodontic clinician may adopt this conservative and cost-effective strategy in their routine practice and avoid clinical crown reduction.

Quantitative analysis of CT brain images: a statistical model incorporating partial volume and beam hardening effects

International Nuclear Information System (INIS)

McLoughlin, R.F.; Ryan, M.V.; Heuston, P.M.; McCoy, C.T.; Masterson, J.B.

1992-01-01

The purpose of this study was to construct and evaluate a statistical model for the quantitative analysis of computed tomographic brain images. Data were derived from standard sections in 34 normal studies. A model representing the intercranial pure tissue and partial volume areas, with allowance for beam hardening, was developed. The average percentage error in estimation of areas, derived from phantom tests using the model, was 28.47%. We conclude that our model is not sufficiently accurate to be of clinical use, even though allowance was made for partial volume and beam hardening effects. (author)

Fusión de un tercer molar mandibular con un cuarto molar supernumerario Fusion of mandibular third molar with supernumerary fourth molar

Directory of Open Access Journals (Sweden)

C. López Carriches

2008-10-01

Full Text Available La fusión dental es la unión de dos gérmenes dentales normalmente separados, mientras que la geminación se define como el intento de división de un único germen dental. La fusión y geminación de molares es poco frecuente en la dentición permanente. Describimos un caso clínico de un tercer molar inferior derecho fusionado a un cuarto molar supernumerario en un paciente varón de 36 años que ha presentado repetidos episodios de pericoronaritis. Tras el estudio radiológico se realiza la exodoncia del cordal semiincluido bajo anestesia local. Llevamos a cabo una revisión bibliográfica al respecto.Dental fusion is the union of two tooth buds that normally are separated, while gemination is defined as an attempt by a single tooth bud to divide. The fusion and gemination of molars is uncommon in permanent teeth. We report a clinical case of a right lower third molar fused to a supernumerary fourth molar in a 36-year-old male patient with repeated episodes of inflammation. After the radiologic study, the semi-impacted third molar was extracted under local anesthesia. The literature was reviewed.

Volumetric and viscometric studies of glucose in binary aqueous solutions of urea at different temperatures

International Nuclear Information System (INIS)

Samanta, T.; Saharay, S.K.

2010-01-01

Densities and viscosities of glucose in (1.0, 2.5, and 5.0) mass% aqueous urea solutions have been measured at T = (298.15, 303.15, 308.15, and 313.15) K, respectively. Apparent molar volumes, limiting partial molar volume, and relative viscosity have been obtained from the density and viscosity results. Limiting partial molar expansibilities have also been calculated from the temperature dependence of limiting partial molar volumes. The viscosity data have been analyzed by using the modified Jones-Dole equation. The results are used to establish the nature of solute-solute and solute-solvent interactions. Transition state treatment of the relative viscosity was also used for the calculation of activation parameters of viscous flow. Pour findings show that the solute acts as a water structure former and provides strong solute-solvent interaction.

Volumetric and viscometric studies of urea in binary aqueous solutions of glucose at different temperatures

International Nuclear Information System (INIS)

Samanta, T.; Ray, A.

2010-01-01

Densities and viscosities of urea in (1.0, 2.5, and 5.0) mass% of aqueous glucose solutions have been measured at T = (298.15, 303.15, 308.15, and 313.15) K, respectively. Apparent molar volumes, limiting partial molar volume, and relative viscosity have been obtained from the density and viscosity data. Limiting partial molar expansibilities have also been calculated from the temperature dependence of limiting partial molar volumes. The viscosity data has been analyzed using the Jones-Dole equation. The results are used to establish the nature of solute-solute and solute-solvent interactions. The activation parameters of viscous flow have also been calculated on the basis of transition state treatment of the relative viscosity. Result shows that the solute acts as water structure breaker and posses' weak solute-solvent interaction.

Volumetric properties of room temperature ionic liquid 1. The system of {l_brace}1-methyl-3-ethylimidazolium ethyl sulfate+water{r_brace} at temperature in the range (278.15 to 333.15) K

Energy Technology Data Exchange (ETDEWEB)

Lu Xingmei [Department of Chemistry, Shenyang Normal University, Shenyang 110034 (China); Department of Chemistry, Liaoning University, Shenyang 110036 (China); Xu Weiguo [Institute of Salt Lakes, Chinese Academy of Science, Xining 810008 (China); Gui Jinsong [Department of Chemistry, Shenyang Normal University, Shenyang 110034 (China); Li Huawei [Department of Chemistry, Shenyang Normal University, Shenyang 110034 (China); Yang Jiazhen [Institute of Salt Lakes, Chinese Academy of Science, Xining 810008 (China)]. E-mail: jzyanglnu@yahoo.com.cn

2005-01-01

This paper reports densities of aqueous solutions of ionic liquid (IL) 1-methyl-3-ethylimidazolium ethyl sulfate (EMISE) that were measured gravimetrically at temperatures (278.15 to 333.15) K. The values of the apparent molar volume, {sup {phi}}V{sub B} and partial molar volume, V-bar B, were determined and apparent molar expansibilities {sup {phi}}E=(({partial_derivative}{phi}{sub B})/{partial_derivative}T)){sub p} of EMISE and the coefficients of thermal expansion of the solutions, {alpha}, were calculated. The values of the apparent molar volume, {sup {phi}}V{sub B}, were fitted by the method of least-squares to a Pitzer's equation to determine the parameters, {beta}{sub MX}{sup (0)V}, {beta}{sub MX}{sup (1)V}, and C{sub MX}{sup V}.

Apparent molar volumes and apparent molar heat capacities of aqueous tetrahydrofuran, dimethyl sulfoxide, 1,4-dioxane, and 1,2-dimethoxyethane at temperatures from 278.15 K to 393.15 K and at the pressure 0.35 MPa

International Nuclear Information System (INIS)

Swenson, D.M.; Blodgett, M.B.; Ziemer, S.P.; Woolley, E.M.

2008-01-01

We determined apparent molar volumes V φ at 278.15 ≤ (T/K) ≤ 368.15 and apparent molar heat capacities C p,φ at 278.15 ≤ (T/K) ≤ 393.15 at p = 0.35 MPa for aqueous solutions of tetrahydrofuran at m from (0.016 to 2.5) mol . kg -1 , dimethyl sulfoxide at m from (0.02 to 3.0) mol . kg -1 , 1,4-dioxane at m from (0.015 to 2.0) mol . kg -1 , and 1,2-dimethoxyethane at m from (0.01 to 2.0) mol . kg -1 . Values of V φ were determined from densities measured with a vibrating-tube densimeter, and values of C p,φ were determined with a twin fixed-cell, differential, temperature-scanning calorimeter. Empirical functions of m and T for each compound were fitted to our V φ and C p,φ results

Volumetric property of glycine, L-serine, L-alanine and L-proline in aqueous solutions of 1-phenylpiperazinium tetrafluoroborate

International Nuclear Information System (INIS)

Xie, Hujun; Zhao, Lijiang; Liu, Chengcheng; Cao, Yifan; Lu, Xiaoxing; Lei, Qunfang; Fang, Wenjun

2016-01-01

Highlights: • Volumetric property of four amino acids in aqueous solutions of [Phpi][BF_4] were measured. • The standard partial molar volume, transparent partial molar volume and hydration number were calculated. • [Phpi][BF_4] interacts strongly with four kinds of amino acids. • Hydrophilic–hydrophobic and hydrophobic–hydrophobic interactions play the dominant roles in ternary systems. • The ternary systems are generated via multiple hydrogen bond interactions. - Abstract: The densities of aqueous solutions of glycine, L-serine, L-alanine, L-proline with the ionic liquid (IL), 1-phenylpiperazinium tetrafluoroborate ([Phpi][BF_4]) at the IL concentrations of (0.025, 0.055 and 0.100) mol·kg"−"1 have been measured at the temperatures of (298.15, 303.15 and 308.15) K. On the basis of the experimental results, the apparent molar volume (V_Φ), standard partial molar volume (V_Φ"0), transfer partial molar volume (Δ_t_rV_Φ"0) and hydration number (n_H) have been calculated. The hydrophilic–hydrophilic, hydrophobic–hydrophilic and hydrophobic–hydrophobic interactions are involved in the studied systems of {[Phpi][BF_4] + amino acids + H_2O. These volumetric parameters can help to understand the mixing effects and other complex biological processes between amino acids and ionic liquid aqueous solution.

Partial volume correction in SPECT reconstruction with OSEM

Energy Technology Data Exchange (ETDEWEB)

Erlandsson, Kjell, E-mail: k.erlandsson@ucl.ac.uk [Institute of Nuclear Medicine, University College London and University College London Hospital, London NW1 2BU (United Kingdom); Thomas, Ben; Dickson, John; Hutton, Brian F. [Institute of Nuclear Medicine, University College London and University College London Hospital, London NW1 2BU (United Kingdom)

2011-08-21

SPECT images suffer from poor spatial resolution, which leads to partial volume effects due to cross-talk between different anatomical regions. By utilising high-resolution structural images (CT or MRI) it is possible to compensate for these effects. Traditional partial volume correction (PVC) methods suffer from various limitations, such as correcting a single region only, returning only regional mean values, or assuming a stationary point spread function (PSF). We recently presented a novel method in which PVC was combined with the reconstruction process in order to take into account the distance dependent PSF in SPECT, which was based on filtered backprojection (FBP) reconstruction. We now present a new method based on the iterative OSEM algorithm, which has advantageous noise properties compared to FBP. We have applied this method to a series of 10 brain SPECT studies performed on healthy volunteers using the DATSCAN tracer. T1-weighted MRI images were co-registered to the SPECT data and segmented into 33 anatomical regions. The SPECT data were reconstructed using OSEM, and PVC was applied in the projection domain at each iteration. The correction factors were calculated by forward projection of a piece-wise constant image, generated from the segmented MRI. Images were also reconstructed using FBP and standard OSEM with and without resolution recovery (RR) for comparison. The images were evaluated in terms of striatal contrast and regional variability (CoV). The mean striatal contrast obtained with OSEM, OSEM-RR and OSEM-PVC relative to FBP were 1.04, 1.42 and 1.53, respectively, and the mean striatal CoV values are 1.05, 1.53, 1.07. Both OSEM-RR and OSEM-PVC results in images with significantly higher contrast as compared to FBP or OSEM, but OSEM-PVC avoids the increased regional variability of OSEM-RR due to improved structural definition.

Pressão interna e refração molar dos sistemas dimetilsulfóxido + tiofeno, dimetilsulfóxido + piridina a 298,15K

OpenAIRE

AZNAREZ, Silvia Beatriz; POSTIGO, Miguel Ángelo; MARTINS, Adair

1999-01-01

Pressão interna, volume livre, refração molar e propriedades termodinâmicas de excesso de misturas líquidas binárias de dimetil sulfóxido + tiofeno e dimetil sulfóxido + piridina a 298.15K foram calculadas a partir de medidas experimentais de densidades, tensão superficial e índice de refração. A relação entre a pressão interna, volume molar de excesso, refração molar, e a interação molecular dos sistemas binários é examinada. Internal pressure, free volume, molar refraction and excess mol...

Volumetric properties of binary mixtures of N-ethylformamide with tetrahydrofuran, 2-butanone, and ethylacetate from T = (293.15 to 313.15) K

International Nuclear Information System (INIS)

Gadžurić, Slobodan; Nikolić, Aleksandar; Vraneš, Milan; Jović, Branislav; Damjanović, Marko; Dožić, Sanja

2012-01-01

Highlights: ► Densities of N-ethylformamide mixtures with ketones and esters were measured. ► Excess molar volumes were fitted to Redlich–Kister polynomial equation. ► Excess molar volumes are negative in the whole mole fraction range. ► Increase of the temperature has influence on N-ethylformamide self-association. ► Complex formation between the components was not observed. - Abstract: Densities of binary liquid mixtures of N-ethylformamide (NEF) with tetrahydrofuran (THF), 2-butanone (B), and ethylacetate (EA) were measured at temperatures from (293.15 to 313.15) K and at atmospheric pressure over the whole composition range. Excess molar volumes, V E , have been obtained from values of the experimental density and were fitted to the Redlich–Kister polynomial equation. The V E values for all three mixtures are negative over the entire composition and temperature ranges. The V E values become more negative as the temperature increases for all binary mixtures studied. Other volumetric properties, such as isobaric thermal expansion coefficients, partial molar volumes, apparent molar volumes, partial molar excess volumes and excess thermal expansions have been calculated.

Root canal morphology of primary molars: a micro-computed tomography study.

Science.gov (United States)

Fumes, A C; Sousa-Neto, M D; Leoni, G B; Versiani, M A; da Silva, L A B; da Silva, R A B; Consolaro, A

2014-10-01

This was to investigate the root canal morphology of primary molar teeth using micro-computed tomography. Primary maxillary (n = 20) and mandibular (n = 20) molars were scanned at a resolution of 16.7 μm and analysed regarding the number, location, volume, area, structured model index (SMI), area, roundness, diameters, and length of canals, as well as the thickness of dentine in the apical third. Data were statistically compared by using paired-sample t test, independent sample t test, and one-way analysis of variance with significance level set as 5%. Overall, no statistical differences were found between the canals with respect to length, SMI, dentine thickness, area, roundness, and diameter (p > 0.05). A double canal system was observed in the mesial and mesio-buccal roots of the mandibular and maxillary molars, respectively. The thickness in the internal aspect of the roots was lower than in the external aspect. Cross-sectional evaluation of the roots in the apical third showed flat-shaped canals in the mandibular molars and ribbon- and oval-shaped canals in the maxillary molars. External and internal anatomy of the primary first molars closely resemble the primary second molars. The reported data may help clinicians to obtain a thorough understanding of the morphological variations of root canals in primary molars to overcome problems related to shaping and cleaning procedures, allowing appropriate management strategies for root canal treatment.

Effect of dipotassium hydrogen phosphate on thermodynamic properties of glycine and L-alanine in aqueous solutions at different temperatures

International Nuclear Information System (INIS)

Kumar, Harsh; Kaur, Kirtanjot

2012-01-01

Highlights: ► Densities and speeds of sound of amino acids in DKHP. ► Apparent molar volume and apparent molar compressibilities were calculated. ► The partial molar expansibilities at infinite dilution φ E 0 were obtained. ► Hydration number n H was calculated. ► The results are discussed in terms of solute–solvent interactions. - Abstract: Densities, ρ, speed of sound, u for glycine, L-alanine have been measured in aqueous solutions of dipotassium hydrogen phosphate (DKHP) ranging from 0.2, 0.4, 0.6 and 0.8 mol·kg −1 at temperatures T = (288.15, 298.15, 308.15 and 318.15) K. The different parameters such as apparent molar volume, limiting apparent molar volume, transfer volume, partial molar expansibility have been derived from density data. Experimental speeds of sound data were used to estimate apparent molar adiabatic compressibility, limiting apparent molar adiabatic compressibility, transfer parameter and hydration number. These parameters have been discussed in the light of ion-ion and ion-solvent interactions.

The effect of 2,2,2-trifluoroethanol on water studied by using third derivatives of Gibbs energy, G

DEFF Research Database (Denmark)

Ohgi, Hiroyo; Imamura, Hiroshi; Yonenaga, Kazuki

2016-01-01

We determined the excess partial molar enthalpy and the excess partial molar volume, HTFEE, VTFEE, of 2,2,2-trifluoroethanol (TFE) in TFE-H2O at 25.0 °C. We then evaluate the TFE-TFE interactions in terms of enthalpy and volume, HTFE-TFEE and VTFE-TFEE, graphically without resorting to any model...

Acoustic and volumetric properties of betaine hydrochloride drug in aqueous D(+)-glucose and sucrose solutions

International Nuclear Information System (INIS)

Ryshetti, Suresh; Gupta, Akash; Tangeda, Savitha Jyostna; Gardas, Ramesh L.

2014-01-01

Highlights: • Density and speed of sound are measured for B.HCl drug in aq. D(+)-glucose and sucrose. • Solvation behavior of B.HCl drug studied in aqueous D(+)-glucose and sucrose. • Cosphere overlap model is used to understand the transfer partial molar volume. • Hepler’s constant indicated structure making ability of B.HCl drug in studied systems. - Abstract: The densities (ρ) and speeds of sound (u) of betaine hydrochloride (B.HCl) drug (0.01 to 0.06) mol · kg −1 in (0.10, 0.20 and 0.30) mol · kg −1 aqueous D(+)-glucose and sucrose solutions are reported as a function of temperature at T = (293.15 to 313.15) K and atmospheric pressure. The values of density (ρ) and speed of sound (u) are obtained with high precision. These values have been used to estimate the apparent molar volume (V 2,ϕ ), partial molar volume (V 2 ∞ ), transfer partial molar volume (Δ t V 2 ∞ ), apparent molar isentropic compressibility (K s,2,ϕ ), partial molar isentropic compressibility (K s,2 ∞ ), transfer partial molar compressibility (Δ t K s,2 ∞ ), hydration number (N H ), partial molar expansion (E 2 ∞ ) and Hepler’s constant (∂ 2 V 2 ∞ /∂T 2 ) P . Furthermore, pair (V AB and K AB ) and triplet (V ABB and K ABB ) interaction coefficients have been computed from the values of Δ t V 2 ∞ and Δ t K s,2 ∞ . The co-sphere overlap model is used to understand the values of Δ t V 2 ∞ and Δ t K s,2 ∞ . The positive values of (∂ 2 V 2 ∞ /∂T 2 ) P indicate structure making ability of betaine hydrochloride in aqueous D(+)-glucose and sucrose solutions at the temperatures and compositions investigated

AXIAL MODIFICATIONS OF PERMANENT LOWER MOLARS AFTER PREMATURE LOSSES OF TEMPORARY MOLARS.

Science.gov (United States)

Cernei, E R; Mavru, R B; Zetu, Irina Nicoleta

2016-01-01

The aim of our study was to determine the impact of premature loss of temporary lower molars upon the longitudinal axis of the first and second permanent molars. The study groups included 61 patients, 6-9 year olds with premature loss of primary molars and a control group of 24 patients with intact temporary teeth. We evaluated the angle between longitudinal axis of first and second lower permanent molars and occlusal plane. It was observed that premature loss of lower second deciduous molar modifies more the vertical axis of first and second permanent molars than the premature loss of first lower primary molar. Reducing space occurs mainly through mesial inclination of molars that separates the edentulous breach. Temporary loss of both lower first molars on the same quadrant causes an accelerated eruption of both premolars increasing the prevalence of eruption sequence: "4-5-3-7". The preservation of the occlusal morpho-functional complex using space maintainers mainly when the premature loss of the second primary molars occurs is the best interceptive treatment option.

Finite volume for three-flavour Partially Quenched Chiral Perturbation Theory through NNLO in the meson sector

International Nuclear Information System (INIS)

Bijnens, Johan; Rössler, Thomas

2015-01-01

We present a calculation of the finite volume corrections to meson masses and decay constants in three flavour Partially Quenched Chiral Perturbation Theory (PQChPT) through two-loop order in the chiral expansion for the flavour-charged (or off-diagonal) pseudoscalar mesons. The analytical results are obtained for three sea quark flavours with one, two or three different masses. We reproduce the known infinite volume results and the finite volume results in the unquenched case. The calculation has been performed using the supersymmetric formulation of PQChPT as well as with a quark flow technique. Partial analytical results can be found in the appendices. Some examples of cases relevant to lattice QCD are studied numerically. Numerical programs for all results are available as part of the CHIRON package.

Finite volume for three-flavour Partially Quenched Chiral Perturbation Theory through NNLO in the meson sector

Energy Technology Data Exchange (ETDEWEB)

Bijnens, Johan; Rössler, Thomas [Department of Astronomy and Theoretical Physics, Lund University,Sölvegatan 14A, SE 223-62 Lund (Sweden)

2015-11-16

We present a calculation of the finite volume corrections to meson masses and decay constants in three flavour Partially Quenched Chiral Perturbation Theory (PQChPT) through two-loop order in the chiral expansion for the flavour-charged (or off-diagonal) pseudoscalar mesons. The analytical results are obtained for three sea quark flavours with one, two or three different masses. We reproduce the known infinite volume results and the finite volume results in the unquenched case. The calculation has been performed using the supersymmetric formulation of PQChPT as well as with a quark flow technique. Partial analytical results can be found in the appendices. Some examples of cases relevant to lattice QCD are studied numerically. Numerical programs for all results are available as part of the CHIRON package.

The influence of premature loss of temporary upper molars on permanent molars.

Science.gov (United States)

Cernei, E R; Maxim, Dana Cristiana; Zetu, Irina Nicoleta

2015-01-01

Premature loss of primary molars due to dental caries and their complications has been associated with space loss and eruptive difficulties, especially when the loss occurs early. The aim of our study was to determine the impact of premature loss of temporary upper molars upon the longitudinal axis of the first and second upper permanent molar. The study group included 64 patients 6-9 years old with premature loss of primary molars and a control group of 48 patients with intact temporary teeth. It was evaluated the angle between longitudinal axis of first and second upper permanent molars and occlusal plane. The sofware used is Easy Dent 4 Viewer®.The data were analyzed by using the Statistical Package for the Social Sciences (version 20.0; SPSS, Chicago, III). It was observed that premature loss of upper second deciduous molars modifies greater the vertical axis of the permanent molars than the premature loss of first upper primary molar. First upper primary molar loss cause an acceleration eruption of first premolar, which will produce a distal inclintion of the both permanent molars. The use of space maintainers after premature loss of the second upper temporary molar is a last solution in preventing tridimensional lesions in the dental arch and occlusion.

Studies　on　Partial　Molar　Volumes　of　Some　Amino　Acids　and　Their　Groups　in　Aqueous　Solutions　from　293.15　K　to　333.15　K

Institute of Scientific and Technical Information of China (English)

赵长伟; 马沛生; 夏淑倩

2004-01-01

Abstract Densities of aqueous solutions of eight amino acids, glycine, L-alanine, L-valine, L-isoleucine, L-serine, L-threonine, L-arginine and L-phenylalanine, are measured as a function of amino acid concentration from 293.15 K to 333.15 K. These data are used to calculate the apparent molar volume Vφ0 and infinite dilution apparent molar volume Vφ0 (partial molar volume). Data of five amino acids are used to correlate partial molar volume Vφ0 using group contribution method to estimate the contributions of the zwitterionic end groups (NH+,COO-) and CH2 group, OH group, CNHNHNH2 group and C6H5(phenyl) group of amino acids. The results show that Vφ0 values for all kinds of groups of amino acids studied increase with increase of temperature except those for CH2φ group, which are almost constant within the studied temperature range. Data of other amino acids, L-valine, L-isoleucine and L-threonine, are chosen for comparison with the predicted partial molar volume Vφ0 using the group additivity parameters obtained. The results confirm that this group additivity method has excellent predictive utility.

Solute-solvent interactions in solutions of 2-hydroxy-5-chloro-3-nitroacetophenone isonicotinoylhydrazone in N, N-dimethylformamide at 298-313 K according to ultrasonic and viscometric data

Science.gov (United States)

Dikkar, A. B.; Pethe, G. B.; Aswar, A. S.

2015-12-01

Density (ρ), speed of sound ( u), and viscosity (η), measurements have been carried on 2-hydroxy- 5-chloro-3-nitroacetophenone isonicotinoylhydrazone (HCNAIH) in N, N-dimethylformamide at 298.15, 303.15, 308.15, and 313.15 K. Adiabatic compressibility (βs), intermolecular free length ( L f), acoustic impedance ( Z), internal pressure ( P int), the apparent molar volume ( V w), limiting apparent molar volume ( V w 0), partial molar expansibility (wE 0), apparent molar adiabatic compressibility ( K w), limiting apparent molar adiabatic compressibility ( K w 0), viscosity B coefficients of Jones-Dole equation have been calculated. The activation free energy (Δμ 2 0 *) for viscous flow in solution have been calculated from B coefficient and partial molar volume data. The calculated parameters are used to interpret the solute-solvent interactions and structure forming/breaking ability of solute in DMF.

Estudios físico-químicos de miscelas de aceites vegetales XIV. Volumen molar, refracción molar y viscosidad de disoluciones de estearato de metilo en ciciohexano, hexano, tetracloroetileno o tricloroetileno

Directory of Open Access Journals (Sweden)

Muñoz Cueto, María J.

1991-02-01

Full Text Available In the miscelies studied, molar volume and molar refraction values show linear dependence with the molar fraction of methyl stearate. Viscosity values fit Hildebrand's modified equation, where the "V_o" parameter is a linear function of the molar fraction of methyl stearate. Regarding with this three physico-chemical properties, the mixtures studied behave like ideal mixtures of two organic liquids without ionization.

En todas las miscelas estudiadas los valores del volumen molar y de la refracción molar presentan variaciones lineales en función de la fracción molar de estearato de metilo. Los valores de viscosidad de las miscelas estudiadas se ajustan a la ecuación de fluidez de Hildebrand modificada, siendo su parámetro "V_o" función lineal de la fracción molar de estearato de metilo. En relación con estas tres características, el comportamiento de las miscelas estudiadas no difiere significativamente del correspondiente a una mezcla "ideal" de dos líquidos orgánicos sin ionizar.

Three-dimensional quantitative analysis of adhesive remnants and enamel loss resulting from debonding orthodontic molar tubes.

Science.gov (United States)

Janiszewska-Olszowska, Joanna; Tandecka, Katarzyna; Szatkiewicz, Tomasz; Sporniak-Tutak, Katarzyna; Grocholewicz, Katarzyna

2014-09-10

Presenting a new method for direct, quantitative analysis of enamel surface. Measurement of adhesive remnants and enamel loss resulting from debonding molar tubes. Buccal surfaces of fifteen extracted human molars were directly scanned with an optic blue-light 3D scanner to the nearest 2 μm. After 20 s etching molar tubes were bonded and after 24 h storing in 0.9% saline - debonded. Then 3D scanning was repeated. Superimposition and comparison were proceeded and shape alterations of the entire objects were analyzed using specialized computer software. Residual adhesive heights as well as enamel loss depths have been obtained for the entire buccal surfaces. Residual adhesive volume and enamel loss volume have been calculated for every tooth. The maximum height of adhesive remaining on enamel surface was 0.76 mm and the volume on particular teeth ranged from 0.047 mm3 to 4.16 mm3. The median adhesive remnant volume was 0.988 mm3. Mean depths of enamel loss for particular teeth ranged from 0.0076 mm to 0.0416 mm. Highest maximum depth of enamel loss was 0.207 mm. Median volume of enamel loss was 0.104 mm3 and maximum volume was 1.484 mm3. Blue-light 3D scanning is able to provide direct precise scans of the enamel surface, which can be superimposed in order to calculate shape alterations. Debonding molar tubes leaves a certain amount of adhesive remnants on the enamel, however the interface fracture pattern varies for particular teeth and areas of enamel loss are present as well.

Vapor-liquid Phase Equilibria for CO2+Tertpentanol Binary System at Elevated Pressures

Institute of Scientific and Technical Information of China (English)

WANG Lin; LUO Jian-cheng; YANG Hao; CHEN Kai-xun

2011-01-01

Vapor-liquid phase equilibrium data of tertpentanol in carbon dioxide were measured at temperatures of 313.4,323.4,333.5 and 343.5 K and in the pressure range of 4.56-11.44 MPa.The phase equilibium apparatus used in the work was a variable-volume high-pressure cell.The experimental data were reasonably correlated with Peng-Robinson equation of state(PR-EOS) together with van der Waals-2 two-parameter mixing rules.Henry's Law constants and partial molar volumes of CO2 at infinite dilution were estimated with Krichevsky-Kasarnovsky equation,and Henry's Law constants increase with increasing temperature,however,partial molar volumes of CO2 at infinite dilution are negative whose magnitudes decrease with temperature.Partial molar volumes of CO2 and tertpentanol in liquid phase at equilibrium were calculated.

A finite element analysis of the stress distribution to the mandible from impact forces with various orientations of third molars*

Science.gov (United States)

Liu, Yun-feng; Wang, Russell; Baur, Dale A.; Jiang, Xian-feng

2018-01-01

Objective: To investigate the stress distribution to the mandible, with and without impacted third molars (IM3s) at various orientations, resulting from a 2000-Newton impact force either from the anterior midline or from the body of the mandible. Materials and methods: A 3D mandibular virtual model from a healthy dentate patient was created and the mechanical properties of the mandible were categorized to 9 levels based on the Hounsfield unit measured from computed tomography (CT) images. Von Mises stress distributions to the mandibular angle and condylar areas from static impact forces (Load I-front blow and Load II left blow) were evaluated using finite element analysis (FEA). Six groups with IM3 were included: full horizontal bony, full vertical bony, full 450 mesioangular bony, partial horizontal bony, partial vertical, and partial 450 mesioangular bony impaction, and a baseline group with no third molars. Results: Von Mises stresses in the condyle and angle areas were higher for partially than for fully impacted third molars under both loading conditions, with partial horizontal IM3 showing the highest fracture risk. Stresses were higher on the contralateral than on the ipsilateral side. Under Load II, the angle area had the highest stress for various orientations of IM3s. The condylar region had the highest stress when IM3s were absent. Conclusions: High-impact forces are more likely to cause condylar rather than angular fracture when IM3s are missing. The risk of mandibular fracture is higher for partially than fully impacted third molars, with the angulation of impaction having little effect on facture risk. PMID:29308606

Third derivative thermodynamic quantities of aqueous tetrahydrofuran at 25 degrees C

DEFF Research Database (Denmark)

Westh, Peter; Yoshida, Koh; Inaba, Akira

2015-01-01

–THF interaction functions, HETHF–THF, and SETHF–THF. Using the literature density data, the effect of THF on the excess partial molar volume of THF, VETHF–THF, was also evaluated. Furthermore, we directly determined the partial molar entropy-volume cross fluctuation density of THF, View the MathML sourceδ......We measured the excess chemical potential, μΕTHF, the excess partial molar enthalpy and entropy of solute tetrahydrofuran (THF), HETHF and SETHF, in THF–H2O at 25 °C. Using these second derivatives of G, we graphically evaluated the third derivative quantities; the enthalpic, entropic THF...

Determination of micelle formation of ketorolac tromethamine in aqueous media by acoustic measurements

International Nuclear Information System (INIS)

Savaroglu, Gokhan; Genc, Lütfi

2013-01-01

Graphical abstract: Value of critical micelle concentration (CMC) were detected by speed of sound and determined by an analytical method based on the Phillips definition of the CMC. Highlights: ► The aim of this study was to investigate the aggregation behaviour of KT. ► Influence of KT concentration and temperature upon volumetric properties was studied. ► CMC of KT aqueous solution was determined by using speeds of sound measurements. - Abstract: Density and speed of sound of ketorolac tromethamine in aqueous solutions have been measured as a function of concentration at atmospheric pressure and in the temperature range from 293.15 to 313.15 K. Apparent molar volumes, apparent isentropic compressibility and isentropic compressibility values have also been calculated from the experimental density and speed of sound data. Partial molar volume and partial molar isentropic compressibility are obtained from fitting procedures the data on apparent molar volume, V φ , and apparent isentropic compressibility, K φ(S) . Partial molar volume, V φ 0 , and partial molar isentropic compressibility, k φ(S) 0 , are informative thermodynamic characteristics that reflect solute hydration. The critical micelle concentration (CMC) was determined from speed of sound data by an analytical method based on the Phillips definition of the CMC. Using these results, it was possible to establish the solvent–drug interactions.

Enthalpy of dilution and volumetric properties of N-glycylglycine in aqueous xylitol solutions at T = 298.15 K

Energy Technology Data Exchange (ETDEWEB)

Liu Min, E-mail: panpanliumin@163.co [College of Chemistry and Chemical Engineering, Liao Cheng University, Liaocheng, Shandong 252059 (China); Wang Lili; Li Guangqian; Dong Lina; Sun Dezhi [College of Chemistry and Chemical Engineering, Liao Cheng University, Liaocheng, Shandong 252059 (China); Zhu Lanying [College of Life Science and Bioengineering, Liao Cheng University, Liaocheng, Shandong 252059 (China); Di Youying [College of Chemistry and Chemical Engineering, Liao Cheng University, Liaocheng, Shandong 252059 (China)

2011-06-15

Highlights: Enthalpies of dilution of N-glycylglycine in aqueous xylitol solutions were determined at 298.15 K. The homogeneous enthalpic interaction coefficients were calculated. Apparent molar volumes of the ternary systems were calculated from the data of densities. Limiting partial molar volumes and limiting partial molar volumes of transfer were deduced. - Abstract: The enthalpy of dilution of N-glycylglycine ({Delta}{sub dil}H{sub m}) in aqueous xylitol solutions has been determined by means of flow-mix isothermal microcalorimetry at the temperature of 298.15 K. The homogeneous enthalpic interaction coefficients (h{sub 2}, h{sub 3}, and h{sub 4}) which characterize the interactions of examined N-glycylglycine in aqueous xylitol solutions have been calculated according to the excess enthalpy concept based on the values of dilution enthalpy. It has been found that the enthalpic pair interaction coefficients (h{sub 2}) in the systems investigated are negative and become less negative as the molality of xylitol increases. Values of the density ({rho}) of the ternary homogeneous systems were also measured with a quartz vibrating-tube densimeter at the temperature of 298.15 K. The values of the apparent molar volume (V{sub {phi}}) of the ternary systems were calculated from the data of density, which have been used to deduce limiting partial molar volumes of N-glycylglycine (V{sub {phi}}{sup o}) and limiting partial molar volumes of transfer ({Delta}{sub trs}V{sub {phi}}{sup o}) from water to aqueous xylitol solutions at different concentrations. The results have been discussed based on solute-solute interactions and solvation effects.

Enthalpy of dilution and volumetric properties of N-glycylglycine in aqueous xylitol solutions at T = 298.15 K

International Nuclear Information System (INIS)

Liu Min; Wang Lili; Li Guangqian; Dong Lina; Sun Dezhi; Zhu Lanying; Di Youying

2011-01-01

Highlights: → Enthalpies of dilution of N-glycylglycine in aqueous xylitol solutions were determined at 298.15 K. → The homogeneous enthalpic interaction coefficients were calculated. → Apparent molar volumes of the ternary systems were calculated from the data of densities. → Limiting partial molar volumes and limiting partial molar volumes of transfer were deduced. - Abstract: The enthalpy of dilution of N-glycylglycine (Δ dil H m ) in aqueous xylitol solutions has been determined by means of flow-mix isothermal microcalorimetry at the temperature of 298.15 K. The homogeneous enthalpic interaction coefficients (h 2 , h 3 , and h 4 ) which characterize the interactions of examined N-glycylglycine in aqueous xylitol solutions have been calculated according to the excess enthalpy concept based on the values of dilution enthalpy. It has been found that the enthalpic pair interaction coefficients (h 2 ) in the systems investigated are negative and become less negative as the molality of xylitol increases. Values of the density (ρ) of the ternary homogeneous systems were also measured with a quartz vibrating-tube densimeter at the temperature of 298.15 K. The values of the apparent molar volume (V φ ) of the ternary systems were calculated from the data of density, which have been used to deduce limiting partial molar volumes of N-glycylglycine (V φ o ) and limiting partial molar volumes of transfer (Δ trs V φ o ) from water to aqueous xylitol solutions at different concentrations. The results have been discussed based on solute-solute interactions and solvation effects.

Low-tmperature Heat Capacities and Standard Molar Enthalpy of Formation of 4-Nitrobenzyl Alcohol

Institute of Scientific and Technical Information of China (English)

MENG, Qingfen; TAN, Zhicheng; WANG, Xiaohuan; DONG, Yaping; LI, Wu; SHI, Quan

2009-01-01

Low-temperature heat capacities of 4-nitrobenzyl alcohol (4-NBA) have been measured by a high precision automated adiabatic calorimeter over the temperature range from 78 to 396 K. The melting temperature, the molar calculated in the range from 80 to 400 K at the interval of 5 K. The constant-volume energy and standard molar en- at T=298.15 K. The standard molar enthalpy of formation has been derived, ΔfHom(C7H7NO3, s)=-(206.49± namic quantities through a Hess thermochemical cycle.

Volumetric properties of (piperidine + water) binary system: Measurements and modeling

International Nuclear Information System (INIS)

Afzal, Waheed; Valtz, Alain; Coquelet, Christophe; Richon, Dominique

2008-01-01

Densities of pure piperidine (CAS No.: 110-89-4) and of its mixtures with water have been measured over the whole range of compositions at temperatures from 283.15 K to 347.15 K using Anton Paar TM digital vibrating tube densimeter. The density of this system has been found increasing with mass fraction of water. Excess molar volumes have been calculated using the measured experimental densities and correlated using the Redlich-Kister equation. Redlich-Kister equation parameters have been adjusted on experimental data. In addition, partial molar volumes and partial excess molar volumes at infinite dilution have been calculated for each component

Finite-volume and partial quenching effects in the magnetic polarizability of the neutron

Science.gov (United States)

Hall, J. M. M.; Leinweber, D. B.; Young, R. D.

2014-03-01

There has been much progress in the experimental measurement of the electric and magnetic polarizabilities of the nucleon. Similarly, lattice QCD simulations have recently produced dynamical QCD results for the magnetic polarizability of the neutron approaching the chiral regime. In order to compare the lattice simulations with experiment, calculation of partial quenching and finite-volume effects is required prior to an extrapolation in quark mass to the physical point. These dependencies are described using chiral effective field theory. Corrections to the partial quenching effects associated with the sea-quark-loop electric charges are estimated by modeling corrections to the pion cloud. These are compared to the uncorrected lattice results. In addition, the behavior of the finite-volume corrections as a function of pion mass is explored. Box sizes of approximately 7 fm are required to achieve a result within 5% of the infinite-volume result at the physical pion mass. A variety of extrapolations are shown at different box sizes, providing a benchmark to guide future lattice QCD calculations of the magnetic polarizabilities. A relatively precise value for the physical magnetic polarizability of the neutron is presented, βn=1.93(11)stat(11)sys×10-4 fm3, which is in agreement with current experimental results.

Mass-action model analysis of the apparent molar volume and heat capacity of pluronics in water and liposome suspensions at 25 °C.

Science.gov (United States)

Quirion, François; Meilleur, Luc; Lévesque, Isabelle

2013-07-09

Pluronics are block copolymers composed of a central block of polypropylene oxide and two side chains of polyethylene oxide. They are used in water to generate aggregates and gels or added to phospholipid suspensions to prepare microparticles for drug delivery applications. The structure of these systems has been widely investigated. However, little is known about the mechanisms leading to these structures. This investigation compares the apparent molar volumes and heat capacities of Pluronics F38, F108, F127, P85, P104, and P103 at 25 °C in water and in the presence of lecithin liposomes. The changes in molar volumes, heat capacities, and enthalpies generated by a mass-action model are in good agreement with the loss of hydrophobic hydration of the polypropylene oxide central block of the Pluronics. However, the molecularity of the endothermic transitions is much smaller than the aggregation numbers reported in the literature for the same systems. It is suggested that Pluronics go through dehydration of their central block to form unimolecular or small entities having a hydrophobic polypropylene oxide core. In water, these entities would assemble athermally to form larger aggregates. In the presence of liposomes, they would be transferred into the hydrophobic lecithin bilayers of the liposomes. Light transmission experiments suggest that the liposome suspensions are significantly altered only when the added Pluronics are in the dehydrated state.

Volumetric studies of some amino acids in aqueous medium at different temperatures

International Nuclear Information System (INIS)

Jamal, M.A.; Iqbal, M.

2011-01-01

Apparent molar volume (fiV), partial molar volume (V/sup 0), solute-solute interaction parameter (Sv), partial molar expansivity (E/sub 0/) and isobaric thermal expansion co-efficient (a) of twelve amino acids namely, alanine, arginine, asparagine, glutamic acid, glycine, histidine, leucine, lysine HCl, proline, serine, threonine and valine in water have been calculated from the measured solution densities over a temperature range of 283.15 to 313.15 +- 0.01 K. The solution densities were measured by using electronic vibrating tube density meter at 283.15 to 313.15 K and then partial molar volume and expansivity were determined by using least square fit method. Amino acid-water interactions were interpreted in terms of partial molar volume, V/sup 0/ data with particular reference to structural features of solute molecules, such as hydrogen bonding, side group interactions etc. Salvations of amino acids were also described in terms of electrostrictive hydration at the charged ends whereas the intervening part of the molecule was believed to involve less strong interaction with the solvent. The behavior of these parameters has been used to investigate the solute-solute and solute-solvent interactions as well as the effect of temperature on these interactions. (author)

Excess Molar Volume, Viscosity and Heat Capacity for the Binary Mixture of p-Xylene and Acetic Acid at Different Temperatures%对二甲苯和醋酸二元液体混合物在不同温度下的超额摩尔体积、粘度和热容

Institute of Scientific and Technical Information of China (English)

杨长生; 马沛生; 唐多强; 尹秋响; 赵长伟

2002-01-01

Experimental densities, viscosities and heat capacities at different temperatures were presented overthe entire range of mole fraction for the binary mixture of p-xylene and acetic acid. Density values were used in thedetermination of excess molar volumes, VE. At the same time, the excess viscosity and excess molar heat capacitieswere calculated. The values of VE, ηE and cpE were fitted to the Redlich-Kister equation. Good agreements wereobserved. The excess molar volumes are positive with a large maximum value located in the central concentrationrange. The excess viscosity has an opposite trend to the excess molar volume VE. ηE values are negative over theentire range of the mixture. The cure of dependence of cEp on concentration has a special shape. The molecularinteraction between p-xylene and acetic acid is discussed.

Three-dimensional analysis of third molar development to estimate age of majority.

Science.gov (United States)

Márquez-Ruiz, Ana Belén; Treviño-Tijerina, María Concepción; González-Herrera, Lucas; Sánchez, Belén; González-Ramírez, Amanda Rocío; Valenzuela, Aurora

2017-09-01

Third molars are one of the few biological markers available for age estimation in undocumented juveniles close the legal age of majority, assuming an age of 18years as the most frequent legal demarcation between child and adult status. To obtain more accurate visualization and evaluation of third molar mineralization patterns from computed tomography images, a new software application, DentaVol©, was developed. Third molar mineralization according to qualitative (Demirjian's maturational stage) and quantitative parameters (third molar volume) of dental development was assessed in multi-slice helical computed tomography images of both maxillary arches displayed by DentaVol© from 135 individuals (62 females and 73 males) aged between 14 and 23years. Intra- and inter-observer agreement values were remarkably high for both evaluation procedures and for all third molars. A linear correlation between third molar mineralization and chronological age was found, with third molar maturity occurring earlier in males than in females. Assessment of dental development with both procedures, by using DentaVol© software, can be considered a good indicator of age of majority (18years or older) in all third molars. Our results indicated that virtual computed tomography imaging can be considered a valid alternative to orthopantomography for evaluations of third molar mineralization, and therefore a complementary tool for determining the age of majority. Copyright © 2017 The Chartered Society of Forensic Sciences. Published by Elsevier B.V. All rights reserved.

Effect of restoration volume on stresses in a mandibular molar: a finite element study.

Science.gov (United States)

Wayne, Jennifer S; Chande, Ruchi; Porter, H Christian; Janus, Charles

2014-10-01

There can be significant disagreement among dentists when planning treatment for a tooth with a failing medium-to-large--sized restoration. The clinician must determine whether the restoration should be replaced or treated with a crown, which covers and protects the remaining weakened tooth structure during function. The purpose of this study was to evaluate the stresses generated in different sized amalgam restorations via a computational modeling approach and reveal whether a predictable pattern emerges. A computer tomography scan was performed of an extracted mandibular first molar, and the resulting images were imported into a medical imaging software package for tissue segmentation. The software was used to separate the enamel, dentin, and pulp cavity through density thresholding and surface rendering. These tissue structures then were imported into 3-dimensional computer-aided design software in which material properties appropriate to the tissues in the model were assigned. A static finite element analysis was conducted to investigate the stresses that result from normal occlusal forces. Five models were analyzed, 1 with no restoration and 4 with increasingly larger restoration volume proportions: a normal-sized tooth, a small-sized restoration, 2 medium-sized restorations, and 1 large restoration as determined from bitewing radiographs and occlusal surface digital photographs. The resulting von Mises stresses for dentin-enamel of the loaded portion of the tooth grew progressively greater as the size of the restoration increased. The average stress in the normal, unrestored tooth was 4.13 MPa, whereas the smallest restoration size increased this stress to 5.52 MPa. The largest restoration had a dentin-enamel stress of 6.47 MPa. A linear correlation existed between restoration size and dentin-enamel stress, with an R(2) of 0.97. A larger restoration volume proportion resulted in higher dentin-enamel stresses under static loading. A comparison of the von Mises

Volumetric studies of some amino acids in binary aqueous solutions ...

Indian Academy of Sciences (India)

Unknown

0 values of glycine, L-alanine, and L-valine in aqueous MgCl2⋅6H2O solutions at. 298⋅15 K in order to describe the temperature dependence behaviour of partial molar quantities. Group contributions to partial molar volumes have been determined for the amino acids. The trends of transfer volumes (∆Vφ. 0) have been ...

Twisted finite-volume corrections to K{sub l3} decays with partially-quenched and rooted-staggered quarks

Energy Technology Data Exchange (ETDEWEB)

Bernard, Claude [Department of Physics, Washington University,One Brookings Drive, Saint Louis (United States); Bijnens, Johan [Department of Astronomy and Theoretical Physics, Lund University,Sölvegatan 14A, SE 223-62 Lund (Sweden); Gámiz, Elvira [CAFPE and Departamento de Física Teórica y del Cosmos, Universidad de Granada,Campus de Fuente Nueva, E-18002 Granada (Spain); Relefors, Johan [Department of Astronomy and Theoretical Physics, Lund University,Sölvegatan 14A, SE 223-62 Lund (Sweden)

2017-03-23

The determination of |V{sub us}| from kaon semileptonic decays requires the value of the form factor f{sub +}(q{sup 2}=0) which can be calculated precisely on the lattice. We provide the one-loop partially quenched chiral perturbation theory expressions both with and without including the effects of staggered quarks for all form factors at finite volume and with partially twisted boundary conditions for both the vector current and scalar density matrix elements at all q{sup 2}. We point out that at finite volume there are more form factors than just f{sub +} and f{sub −} for the vector current matrix element but that the Ward identity is fully satisfied. The size of the finite-volume corrections at present lattice sizes is small. This will help improve the lattice determination of f{sub +}(q{sup 2}=0) since the finite-volume error is the dominant error source for some calculations. The size of the finite-volume corrections may be estimated on a single lattice ensemble by comparing results for various twist choices.

White matter atlas of the human spinal cord with estimation of partial volume effect.

Science.gov (United States)

Lévy, S; Benhamou, M; Naaman, C; Rainville, P; Callot, V; Cohen-Adad, J

2015-10-01

Template-based analysis has proven to be an efficient, objective and reproducible way of extracting relevant information from multi-parametric MRI data. Using common atlases, it is possible to quantify MRI metrics within specific regions without the need for manual segmentation. This method is therefore free from user-bias and amenable to group studies. While template-based analysis is common procedure for the brain, there is currently no atlas of the white matter (WM) spinal pathways. The goals of this study were: (i) to create an atlas of the white matter tracts compatible with the MNI-Poly-AMU template and (ii) to propose methods to quantify metrics within the atlas that account for partial volume effect. The WM atlas was generated by: (i) digitalizing an existing WM atlas from a well-known source (Gray's Anatomy), (ii) registering this atlas to the MNI-Poly-AMU template at the corresponding slice (C4 vertebral level), (iii) propagating the atlas throughout all slices of the template (C1 to T6) using regularized diffeomorphic transformations and (iv) computing partial volume values for each voxel and each tract. Several approaches were implemented and validated to quantify metrics within the atlas, including weighted-average and Gaussian mixture models. Proof-of-concept application was done in five subjects for quantifying magnetization transfer ratio (MTR) in each tract of the atlas. The resulting WM atlas showed consistent topological organization and smooth transitions along the rostro-caudal axis. The median MTR across tracts was 26.2. Significant differences were detected across tracts, vertebral levels and subjects, but not across laterality (right-left). Among the different tested approaches to extract metrics, the maximum a posteriori showed highest performance with respect to noise, inter-tract variability, tract size and partial volume effect. This new WM atlas of the human spinal cord overcomes the biases associated with manual delineation and partial

Study of intermolecular interactions in binary mixtures of 2-(dimethylamino)ethanol with methanol and ethanol at various temperatures

International Nuclear Information System (INIS)

Pandey, Puneet Kumar; Pandey, Vrijesh Kumar; Awasthi, Anjali; Nain, Anil Kumar; Awasthi, Aashees

2014-01-01

Graphical abstract: The densities and ultrasonic speeds of the binary mixtures over the entire composition range were measured at various temperatures at atmospheric pressure. The excess molar volumes, isentropic compressibilities, and molar isentropic compressions have been calculated. The variations of these parameters with composition and temperature are discussed. The IR spectra were recorded they further supported the conclusion drawn from excess parameters, which indicates the presence of intermolecular hydrogen bonding between the oxygen atom of DMAE molecules and hydrogen atom of methanol and ethanol molecules in these mixtures.. - Highlights: • The study reports density and ultrasonic velocity data of 2-(dimethylamino)ethanol + methanol/ethanol mixtures. • To elucidate the interactions in 2-(dimethylamino)ethanol + methanol/ethanol binary mixtures. • Provides information on nature and relative strength of interactions in these mixtures. • Correlates physicochemical properties with interactions in these mixtures. - Abstract: The densities, ρ and ultrasonic speeds, u of the binary mixtures of 2-(dimethylamino)ethanol (DMAE) with methanol/ethanol, including those of pure liquids, over the entire composition range were measured at 298.15, 308.15 and 318.15 K. From the experimental data, the excess molar volumes, V m E and excess isentropic compressibilities, κ s E have been calculated. The excess partial molar volumes, V ¯ m,1 E and V ¯ m,2 E and excess partial molar isentropic compressions, K ¯ s,m,1 E and K ¯ s,m,2 E over the whole composition range; and partial molar volumes, V ¯ m,1 ° and V ¯ m,2 ° , partial molar isentropic compressions, K ¯ s,m,1 ° and K ¯ s,m,2 ° , excess partial molar volumes, V ¯ m,1 °E and V ¯ m,2 °E , and excess partial molar isentropic compressions, K ¯ s,m,1 °E and K ¯ s,m,2 °E at infinite dilution have also been calculated. The variations of these parameters with composition and temperature are

Determinations of enthalpy and partial molar enthalpy in the alloys Bi–Cd–Ga–In–Zn, Bi–Cd–Ga–Zn and Au–Cu–Sn

International Nuclear Information System (INIS)

Arslan, Hüseyin

2015-01-01

In the present study, the relations of thermodynamic associated with Chou's general solution model (GSM), the models of Muggianu and Toop have been used in order to calculate the mixing enthalpy and partial molar mixing enthalpy of mixing of Bi–Cd–Ga–In–Zn, Bi–Cd–Ga–Zn with equimolar section at a temperature of 730 K and Au–Cu–Sn with the section x Au /x Cu = 1/1 on the entire molar fraction range as a function of alloy composition at a temperature of 900 K. Some negativities are reported in the selected alloys mentioned above, particularly at high temperatures for the human health as well as difficulties in experimental measurement and high costs. Moreover, aim of us is to close the current article gap seen in the literature. In order to close the current gap seen in the literature, the article on the thermodynamic properties of the Bi–Cd–Ga–In–Zn alloys are presented in this study. - Highlights: • Thermodynamic properties of alloys in the study in given conditions were treated. • The activity of Bi seen in all models shows greatly positive deviation from ideality. • The enthalpy of Sn shows small negative values in x Au /x Cu = 1 at 900 K. • The activity of Sn shows negative deviation from ideality in the same conditions

Evaluation of Molar Volume Effect for Calculation of Diffusion in Binary Systems

Czech Academy of Sciences Publication Activity Database

Vach, Marek; Svojtka, Martin

2012-01-01

Roč. 43, č. 6 (2012), s. 1446-1453 ISSN 1073-5615 R&D Projects: GA AV ČR IAA3013006 Institutional support: RVO:67985831 Keywords : difussion profile * molar efect * regression function Subject RIV: DB - Geology ; Mineralogy Impact factor: 1.212, year: 2012

Endodontic management of a mandibular third molar fused with a fourth molar.

Science.gov (United States)

Turell, I L; Zmener, O

1999-05-01

Developmental anomalies in permanent molars frequently require surgical intervention. A case of a mandibular third molar fused with a fourth molar which was successfully treated with conservative endodontic therapy is reported.

Excess Molar Volume,Viscosity and Heat Capacity for the Mixture of 1,2—Propanediol—Water at Different Temperatures

Institute of Scientific and Technical Information of China (English)

杨长生; 马沛生; 唐多强; 靳凤民

2003-01-01

Experimental densities,viscosities and heat capacities at different emperatures were presented over the entire mole fraction range for the binary mixture of 1,2-propanediol and water,Density values were used in the determination of excess molar volumes,VE,At the same time,the excess viscosity was in vestigated,The values of VE and ηE were fitted to the Redlich-kister equation.Good agreement was observed,The excess volumes are negative over the entire range of composition.They show an U-shaped-concentration dependence and decrease in abolute values with increase of temperature,Values of ηE are negative over the entire range of the composition,and has a trend very similar to that of VE ,The analysis shows that at any temperature the specific heat of mixture is a linear function of the composition as x1>20%,All the extended lines intersect at one point.An empirical equation is obtained to calculate the specific heat to mixture at any composition and temperature in the experimental range.

STEREOCHEMICAL ASPECTS OF HYDRATION OF CARBOHYDRATES IN AQUEOUS-SOLUTIONS .3. DENSITY AND ULTRASOUND MEASUREMENTS

NARCIS (Netherlands)

GALEMA, SA; HOILAND, H

1991-01-01

Density and ultrasound measurements have been performed in aqueous solutions of pentoses, hexoses, methylpyranosides, and disaccharides as a function of molality of carbohydrate (0-0.3 mol kg-1). Partial molar volumes, partial molar isentropic compressibilities, and hydration numbers have been

Thermodynamic properties of deep eutectic solvent and ionic liquid mixtures at temperatures from 293.15 K to 343.15 K

Science.gov (United States)

Achsah, R. S.; Shyam, S.; Mayuri, N.; Anantharaj, R.

2018-04-01

Deep eutectic solvents (DES) and ionic liquids (ILs) have their applications in various fields of research and in industries due to their attractive physiochemical properties. In this study, the combined thermodynamic properties of DES (choline chloride-glycerol) + IL1 (1-butyl-3-methylimiazolium acetate) and DES(choline chloride-glycerol) + IL2 (1-ethyl-3-methylimadzolium ethyl sulphate) have been studied. The thermodynamic properties such as excess molar volume, partial molar volume, excess partial molar volume and apparent molar volume were calculated for different mole fractions ranging from 0 to 1 and varying temperatures from 293.15 K to 343.15 K. In order to know the solvent properties of DESs and ILs mixtures at different temperatures and their molecular interactions to enhance the solvent performance and process efficiency at fixed composition and temperature the thermodynamic properties were analyzed.

Density, excess properties, electrical conductivity and viscosity of 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide + γ-butyrolactone binary mixtures

International Nuclear Information System (INIS)

Vraneš, Milan; Papović, Snežana; Tot, Aleksandar; Zec, Nebojša; Gadžurić, Slobodan

2014-01-01

Highlights: • Densities of [bmim][NTf 2 ] mixtures with γ-butyrolactone were measured. • Excess properties were calculated. • Nature of interactions between IL and GBL were discussed. • Specific conductivity and viscosity were also measured. • Walden plot is presented. - Abstract: Density, electrical conductivity and viscosity of binary liquid mixtures of 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, [bmim][NTf 2 ], with γ-butyrolactone (GBL) were measured at temperatures from (293.15 to 323.15) K and at atmospheric pressure over the whole composition range. Excess molar volumes have been calculated from the experimental densities and were fitted with Redlich–Kister polynomial equation. Other volumetric properties, such as isobaric thermal expansion coefficients, partial molar volumes, apparent molar volumes and partial molar volumes at infinite dilution have been also calculated, in order to obtain information about interactions between GBL and selected ionic liquid

Study of thermodynamic and acoustic behaviour of nicotinic acid in binary aqueous mixtures of D-lactose

Science.gov (United States)

Sharma, Ravi; Thakur, R. C.

2017-07-01

In the present study, the thermodynamic properties such as partial molar volumes, partial molar expansibilities, partial molar compressibilities, partial molar heat capacities and isobaric thermal expansion coefficient of different solutions of nicotinic acid in binary aqueous mixtures of D-lactose have been determined at different temperatures (298.15, 303.15, 308.15, 313.15) K. Masson's equation is used to interpret the data in terms of solute-solute and solute-solvent interactions. In the present study it has been found that nicotinic acid behaves as structure maker in aqueous and binary aqueous mixtures of D-lactose.

[A phd completed 10. Implant-supported removable partial -dentures in a Kennedy Class I-situation in the mandible].

Science.gov (United States)

Jensen-Louwerse, C

2017-06-01

Implant-supported removable partial dentures in the mandible often cause problems, which means that patients wear their dentures seldom if at all. A solution is to place implants that the dentures can be snapped onto. There is, however, no consensus about the best position of the implants in the mandible yet. In addition, it is worthwhile to balance the cost of treatment with its effectiveness. In a randomised cross-over clinical trial involving 30 patients with a shortened dental arch, the implant-supported removable partial denture in the mandible was evaluated based on the experience of the patient, mean time of wearing, chewing ability and the clinical and radiographic parameters in relation to 2 different implant positions: 2 in the pre-molar region or 2 in the molar region. The cost-effectiveness of both treatments was also evaluated. From the patient's point of view, the implant-supported removable partial dentures are best supported by implants placed in the molar region. The research also revealed, however, that significantly more bleeding occurred around implants placed in the molar region and from a clinical perspective placement in the pre-molar region would have preference. The cost-effectiveness of the treatment with an implant-supported removable partial denture depends on the choice of outcome measurement and monetary threshold.

Apparent molar volumes and apparent molar heat capacities of aqueous adonitol, dulcitol, glycerol, meso-erythritol, myo-inositol, D-sorbitol, and xylitol at temperatures from (278.15 to 368.15) K and at the pressure 0.35 MPa

Energy Technology Data Exchange (ETDEWEB)

Blodgett, M.B. [Department of Chemistry and Biochemistry, Brigham Young University, Provo, UT, 84602-5700 (United States); Ziemer, S.P. [Department of Chemistry and Biochemistry, Brigham Young University, Provo, UT, 84602-5700 (United States); Brown, B.R. [Department of Chemistry and Biochemistry, Brigham Young University, Provo, UT, 84602-5700 (United States); Niederhauser, T.L. [Department of Chemistry and Biochemistry, Brigham Young University, Provo, UT, 84602-5700 (United States); Woolley, E.M. [Department of Chemistry and Biochemistry, Brigham Young University, Provo, UT, 84602-5700 (United States)]. E-mail: earl_woolley@byu.edu

2007-04-15

Apparent molar volumes V {sub {phi}} were determined for aqueous adonitol, dulcitol, glycerol, meso-erythritol, myo-inositol, D-sorbitol, and xylitol at temperatures from (278.15 to 368.15) K and at the pressure 0.35 MPa, and apparent molar heat capacities C {sub p,{phi}} of the same solutions were determined at temperatures from (278.15 to 363.15) K at the same pressure. Molalities m/(mol . kg{sup -1}) of the solutions were in the range (0.02 {<=} m {<=} 3.2) for adonitol, (0.02 {<=} m {<=} 0.15) for dulcitol, (0.02 {<=} m {<=} 5.0) for glycerol, (0.02 {<=} m {<=} 3.0) for meso-erythritol, (0.02 {<=} m {<=} 0.5) for myo-inositol, (0.02 {<=} m {<=} 2.0) for D-sorbitol, and (0.02 {<=} m {<=} 2.7) for xylitol. A vibrating tube densimeter was used to obtain solution densities and a fixed-cell temperature scanning calorimeter was used to obtain heat capacities. Values of V {sub {phi}} and C {sub p,{phi}} for these sugar alcohols are discussed relative to one another and compared to values from the literature, where available.

Thermophysical properties of binary blends of cyclohexane with some esters

Directory of Open Access Journals (Sweden)

Pradhan Rajendra

2017-01-01

Full Text Available From the densities (ρ and viscosities (η measured for three binary blends consisting of methyl acetate (MA, ethyl acetate (EA and methyl salicylate (MS over the entire composition range with cyclohexane (CH at 298.15–318.15 K under atmospheric pressure, the excess molar volumes (VEm and excess viscosities (ηE were derived. In addition, the excess isentropic compressibilities (KEs excess intermolecular free lengths (LEf and excess molar refractions (R Em were derived from measured ultrasonic speeds of sound (u and refractive indices (nD for the binary blends at 298.15 K. Various derived properties are discussed in terms of molecular interactions and structural effects. Partial molar volumes ( 0 Vm,1 and 0 Vm,2 and excess partial molar volumes ( 0,E Vm,1 and 0,E Vm,2 at infinite dilution are also discussed in terms of volume changes in the blends. Furthermore, the excess molar volumes (V Em and viscosities (η of the blends were correlated with the Prigogine–Flory–Paterson (PFP theory and the Peng–Robinson Equation of State (PR-EOS.

Multi-tissue partial volume quantification in multi-contrast MRI using an optimised spectral unmixing approach.

Science.gov (United States)

Collewet, Guylaine; Moussaoui, Saïd; Deligny, Cécile; Lucas, Tiphaine; Idier, Jérôme

2018-06-01

Multi-tissue partial volume estimation in MRI images is investigated with a viewpoint related to spectral unmixing as used in hyperspectral imaging. The main contribution of this paper is twofold. It firstly proposes a theoretical analysis of the statistical optimality conditions of the proportion estimation problem, which in the context of multi-contrast MRI data acquisition allows to appropriately set the imaging sequence parameters. Secondly, an efficient proportion quantification algorithm based on the minimisation of a penalised least-square criterion incorporating a regularity constraint on the spatial distribution of the proportions is proposed. Furthermore, the resulting developments are discussed using empirical simulations. The practical usefulness of the spectral unmixing approach for partial volume quantification in MRI is illustrated through an application to food analysis on the proving of a Danish pastry. Copyright © 2018 Elsevier Inc. All rights reserved.

Effect of hydrophilic additives on volumetric and viscosity properties of amino acids in aqueous solutions at T = (283.15 to 333.15) K

International Nuclear Information System (INIS)

Sastry, Nandhibatla V.; Valand, Pinakin H.; Macwan, Pradip M.

2012-01-01

Highlights: ► Densities and viscosities of amino acids in aqueous additive solutions at different temperatures. ► Side chain partial molar volumes, V ¯ 2,tr ∘ and transfer volumes ΔV tr ∘ were calculated. ► Temperature effect on volumetric functions and B-coefficients were analyzed. ► Hydrophobic side chains facilitate the solute–solute interactions and hydrophobic hydration. - Abstract: Apparent molar volumes and partial molar volumes at infinite dilution, V ¯ 2 ∘ for amino acids (glycine, L-valine, L-leucine, L-phenylalanine, and L-aspargine) aqueous solutions in sucrose (0.05 to 0.2 (w/w)), urea (0.05), 2,3-butane diol (0.05) and 2-butoxyethanol (0.05) as additives have been calculated from the experimental densities at T = (283.15 to 233.15) K. Limiting partial molar expansibilities, E 2 ∘ , side chain partial molar volumes, V ¯ 2,tr ∘ and transfer volumes (from water to aqueous additive environment), ΔV tr ∘ for both the amino acids and their side chains have also been calculated. Relative viscosities for same systems were also calculated over the same temperature range and were analyzed in terms of Jones–Dole equation to calculate B-coefficients. The analysis of volumetric functions and B-coefficients suggests that the solute–co-solute interactions are more favored at elevated temperatures and in presence of high concentration of sucrose. Otherwise the hydrophobic side chains facilitate the solute–solute interactions and also time induced hydrophobic hydration in the bulk water.

Theoretical study for volume changes associated with the helix-coil transition of peptides.

Science.gov (United States)

Imai, T; Harano, Y; Kovalenko, A; Hirata, F

2001-12-01

We calculate the partial molar volumes and their changes associated with the coil(extended)-to-helix transition of two types of peptide, glycine-oligomer and glutamic acid-oligomer, in aqueous solutions by using the Kirkwood-Buff solution theory coupled with the three-dimensional reference interaction site model (3D-RISM) theory. The volume changes associated with the transition are small and positive. The volume is analyzed by decomposing it into five contributions following the procedure proposed by Chalikian and Breslauer: the ideal volume, the van der Waals volume, the void volume, the thermal volume, and the interaction volume. The ideal volumes and the van der Waals volumes do not change appreciably upon the transition. In the both cases of glycine-peptide and glutamic acid-peptide, the changes in the void volumes are positive, while those in the thermal volumes are negative, and tend to balance those in the void volumes. The change in the interaction volume of glycine-peptide does not significantly contribute, while that of glutamic acid-peptide makes a negative contribution. Copyright 2001 John Wiley & Sons, Inc. Biopolymers 59: 512-519, 2001

Excess molar volumes and deviation in viscosities of binary liquid mixtures of acrylic esters with hexane-1-ol at 303.15 and 313.15K

OpenAIRE

Patil, Sujata S.; Mirgane, Sunil R.; Arbad, Balasaheb R.

2014-01-01

Densities and viscosities for the four binary liquid mixtures of methyl acrylate, ethyl acrylate, butyl acrylate and methyl methacrylate with hexane-1-ol at temperatures 303.15 and 313.15 K and at atmospheric pressure were measured over the entire composition range. These values were used to calculate excess molar volumes and deviation in viscosities which were fitted to Redlich–Kister polynomial equation. Recently proposed Jouyban Acree model was also used to correlate the experimental value...

Fusion of mandibular third molar with supernumerary fourth molar

OpenAIRE

López Carriches, C.; Leco Berrocal, I.; Baca Pérez-Bryan, R.

2008-01-01

La fusión dental es la unión de dos gérmenes dentales normalmente separados, mientras que la geminación se define como el intento de división de un único germen dental. La fusión y geminación de molares es poco frecuente en la dentición permanente. Describimos un caso clínico de un tercer molar inferior derecho fusionado a un cuarto molar supernumerario en un paciente varón de 36 años que ha presentado repetidos episodios de pericoronaritis. Tras el estudio radiológico se realiza la exodoncia...

Comparative analysis of unilateral removable partial denture and classical removable partial denture by using finite element method

Directory of Open Access Journals (Sweden)

Radović Katarina

2010-01-01

Full Text Available Introduction. Various mobile devices are used in the therapy of unilateral free-end saddle. Unilateral dentures with precise connectivity elements are not used frequently. In this paper the problem of applying and functionality of unilateral freeend saddle denture without major connector was taken into consideration. Objective. The aim was to analyze and compare a unilateral RPD (removable partial denture and a classical RPD by calculating and analyzing stresses under different loads. Methods. 3D models of unilateral removable partial denture and classical removable partial denture with casted clasps were made by using computer program CATIA V5 (abutment teeth, canine and first premolar, with crowns and abutment tissues were also made. The models were built in full-scale. Stress analyses for both models were performed by applying a force of 300 N on the second premolar, a force of 500 N on the first molar and a force of 700 N on the second molar. Results. The Fault Model Extractor (FME analysis and calculation showed the complete behavior of unilateral removable partial denture and abutments (canine and first premolar, as well as the behavior of RPD under identical loading conditions. Applied forces with extreme values caused high stress levels on both models and their abutments within physiological limits. Conclusion. Having analyzed stresses under same conditions, we concluded that the unilateral RPD and classical RPD have similar physiological values.

Finite volume for three-flavour Partially Quenched Chiral Perturbation Theory through NNLO in the meson sector

Science.gov (United States)

Bijnens, Johan; Rössler, Thomas

2015-11-01

We present a calculation of the finite volume corrections to meson masses and decay constants in three flavour Partially Quenched Chiral Perturbation Theory (PQChPT) through two-loop order in the chiral expansion for the flavour-charged (or off-diagonal) pseudoscalar mesons. The analytical results are obtained for three sea quark flavours with one, two or three different masses. We reproduce the known infinite volume results and the finite volume results in the unquenched case. The calculation has been performed using the supersymmetric formulation of PQChPT as well as with a quark flow technique.

Thermophysical properties of binary mixtures of triethoxysilane, methyltriethoxysilane, vinyltriethoxysilane and 3-mercaptopropyltriethoxysilane with ethylbenzene at various temperatures

International Nuclear Information System (INIS)

Zhang, Yindi; Dong, Hong; Wu, Chuan; Yu, Lijiao

2014-01-01

Highlights: • Values of ρ and n D of binary mixtures containing organosilicon compounds at different temperatures were measured. • α, V m E , V ¯ i E,∞ , (n 2 ) E , R m and ΔR m were studied. • The excess molar volumes, excess squared refraction indices and the deviations in molar refractions were negative. - Abstract: The density and refractive index were determined for binary mixtures of triethoxysilane, methyltriethoxysilane, vinyltriethoxysilane and 3-mercaptopropyltriethoxysilane with ethylbenzene at different temperatures (T = 288.15, 298.15, 308.15, 318.15 and 328.15 K) and atmospheric pressure using a DMA4500 and RXA170 combined system. The excess molar volume (V m E ), partial excess volume at infinite dilution (V ¯ i E,∞ ), isobaric coefficient of thermal expansion (α), excess squared refraction indices [(n 2 ) E ], Lorentz–Lorenz molar refraction (R m ) and the deviation in molar refraction (ΔR m ) have been calculated using this data. The results have been incorporated into the Redlich–Kister equation and used to estimate the binary interaction parameter and standard deviation. In addition, the excess molar volume (V m E ) was calculated and correlated using the Legendre polynomials. The value of partial excess volume at infinite dilution (V ¯ i E,∞ ) for these binary systems at different temperatures was calculated from either the adjustable parameters of Redlich–Kister smoothing equation or the Legendre polynomials. The isobaric coefficient of thermal expansion (α) of the binary systems was estimated using the temperature dependence of the densities. The results indicate that the excess molar volumes, excess squared refraction indices and the deviations in molar refractions at each temperature were negative. These phenomena are a result of a number of factors including: the partial interstitial accommodation effect, disruption in the orientational order of the pure components and steric structure

[Correlation between the lower first permanent molar axis and the premature loss of temporary molars].

Science.gov (United States)

Petcu, Ana; Maxim, A; Haba, Danisia

2009-01-01

The aim of our study was to determine the impact of premature loss of temporary molars upon the longitudinal axis of the first permanent molar. The study sample was formed by 94 orthopanthomografies of child patients with premature loss of lower temporary molars (first or second) after clinical eruption of the first permanent molar. All panoramic radiographs have been realized with the same panoramic unit with 1.4% magnification coefficient and were analyzed using a standardized technique of tracing the images of teeth and bone on matte acetate paper. It was evaluated the angle between longitudinal axis of first permanent lower molar and occlusal plane. It was observed that premature loss of lower second deciduous molar modifies greater the vertical axis of first permanent molar (between 61 degrees and 79 degrees) then premature loss of first lower primary molar. This is perhaps because the loss of space in the case of premature exfoliation of first primary molar is due more to distal drift of canine then mesial drift of molars. The drift to mesial of first permanent molar is more accentuated proportional with the age at which appeared premature loss and so it is loss of leeway space.

Combining MRI with PET for partial volume correction improves image-derived input functions in mice

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Evans, Eleanor; Buonincontri, Guido [Wolfson Brain Imaging Centre, University of Cambridge, Cambridge (United Kingdom); Izquierdo, David [Athinoula A Martinos Centre, Harvard University, Cambridge, MA (United States); Methner, Carmen [Department of Medicine, University of Cambridge, Cambridge (United Kingdom); Hawkes, Rob C [Wolfson Brain Imaging Centre, University of Cambridge, Cambridge (United Kingdom); Ansorge, Richard E [Department of Physics, University of Cambridge, Cambridge (United Kingdom); Kreig, Thomas [Department of Medicine, University of Cambridge, Cambridge (United Kingdom); Carpenter, T Adrian [Wolfson Brain Imaging Centre, University of Cambridge, Cambridge (United Kingdom); Sawiak, Stephen J [Wolfson Brain Imaging Centre, University of Cambridge, Cambridge (United Kingdom); Behavioural and Clinical Neurosciences Institute, University of Cambridge, Cambridge (United Kingdom)

2014-07-29

Kinetic modelling in PET requires the arterial input function (AIF), defined as the time-activity curve (TAC) in plasma. This measure is challenging to obtain in mice due to low blood volumes, resulting in a reliance on image-based methods for AIF derivation. We present a comparison of PET- and MR-based region-of-interest (ROI) analysis to obtain image-derived AIFs from the left ventricle (LV) of a mouse model. ROI-based partial volume correction (PVC) was performed to improve quantification.

Combining MRI with PET for partial volume correction improves image-derived input functions in mice

International Nuclear Information System (INIS)

Evans, Eleanor; Buonincontri, Guido; Izquierdo, David; Methner, Carmen; Hawkes, Rob C; Ansorge, Richard E; Kreig, Thomas; Carpenter, T Adrian; Sawiak, Stephen J

2014-01-01

Kinetic modelling in PET requires the arterial input function (AIF), defined as the time-activity curve (TAC) in plasma. This measure is challenging to obtain in mice due to low blood volumes, resulting in a reliance on image-based methods for AIF derivation. We present a comparison of PET- and MR-based region-of-interest (ROI) analysis to obtain image-derived AIFs from the left ventricle (LV) of a mouse model. ROI-based partial volume correction (PVC) was performed to improve quantification.

Density of Ni-Al Alloys in Liquid and Solid-Liquid Coexistence State Measured by a Modified Pycnometric Method

Institute of Scientific and Technical Information of China (English)

Liang FANG; Feng XIAO; Zushu LI; Zainan TAO

2004-01-01

The density of Ni-Al alloys in both liquid state and solid-liquid coexistence state was measured with a modified pycnometric method. It was found that the density of NI-Al alloys decreases with increasing temperature and Al concentration in the alloys. The molar volume of liquid Ni-Al binary alloys increases with the increase of temperature and Al concentration. The partial molar volume of Al in NI-Al binary alloy was calculated approximately. The molar volume of liquid NI-Al alloy determined in the present work shows a negative deviation from the ideal linear molar volume.

[Hyperthyroidism in molar pregnancy].

Science.gov (United States)

Boufettal, H; Mahdoui, S; Noun, M; Hermas, S; Samouh, N

2014-03-01

Hyperthyroidism is a rare complication of molar pregnancy. We report a 39-year-old woman who presented a thyrotoxic syndrome accompanying a molar pregnancy. Serum thyroid hormones were elevated and returned to normal level after uterine evacuation of a molar pregnancy. The authors detail the role of thyroid stimulating property of human gonadotropin chorionic hormone and its structural changes during the gestational trophoblastic diseases. These changes give the latter the thyroid stimulating properties and signs of hyperthyroidism. Molar pregnancy may be a cause of hyperthyroidism. The diagnosis of molar pregnancy should be a mention to thyrotoxicosique syndrome in a woman of childbearing age. Copyright © 2013. Published by Elsevier SAS.

Pathological (late) fractures of the mandibular angle after lower third molar removal: a case series.

Science.gov (United States)

Cutilli, Tommaso; Bourelaki, Theodora; Scarsella, Secondo; Fabio, Desiderio Di; Pontecorvi, Emanuele; Cargini, Pasqualino; Junquera, Luis

2013-04-30

Pathological (late) fracture of the mandibular angle after third molar surgery is very rare (0.005% of third molar removals). There are 94 cases reported in the literature; cases associated with osseous pathologies such as osteomyelitis or any local and systemic diseases that may compromise mandibular bone strength have not been included. We describe three new cases of pathological (late) fracture of the mandibular angle after third molar surgery. The first patient was a 27-year-old Caucasian man who had undergone surgical removal of a 3.8, mesioangular variety, class II-C third molar 20 days before admission to our clinic. The fracture of his left mandibular angle, complete and composed, occurred during chewing. The second patient was a 32-year-old Caucasian man. He had undergone surgical removal of a 3.8, mesioangular variety, class II-B third molar 22 days before his admission. The fracture, which occurred during mastication, was studied by computed tomography that showed reparative tissue in the fracture site. The third patient was a 36-year-old Caucasian man who had undergone surgical removal of a 3.8, vertical variety, class II-C third molar 25 days before the observation. In this case the fracture of his mandibular angle was oblique (unfavorable), complete and composed. The fracture had occurred during chewing. We studied the fracture by optical projection tomography and computed tomography.All of the surgical removals of the 3.8 third molars, performed by the patients' dentists who had more than 10 years of experience, were difficult. We treated the fractures with open surgical reduction, internal fixation by titanium miniplates and intermaxillary elastic fixation removed after 6 weeks. The literature indicates that the risk of pathological (late) fracture of the mandibular angle after third molar surgery for total inclusions (class II-III, type C) is twice that of partial inclusions due to the necessity of ostectomies more generous than those for partial

Effect of Hydroxylamine Sulfate on Volumetric Behavior of Glycine, L-Alanine, and L-Arginine in Aqueous Solution

Directory of Open Access Journals (Sweden)

Jie Chen

2013-01-01

Full Text Available The apparent molar volumes of glycine, L-alanine, and L-arginine in aqueous hydroxylamine sulfate solutions have been determined at T=298.15 K and atmospheric pressure. The standard partial molar volumes, V20, corresponding partial molar volumes of transfer, ΔtrV20, and hydration numbers, NH, have been calculated for these α-amino acids from the experimental data. The ΔtrV20 values are positive for glycine, L-alanine, and L-arginine and are all increased with the increase in the concentration of hydroxylamine ions. These parameters obtained from the volumetric data are interpreted in terms of various mixing effects between amino acids and hydroxylamine sulfate in aqueous solutions.

Volumetric properties of the (tetrahydrofuran + water) and (tetra-n-butyl ammonium bromide + water) systems: Experimental measurements and correlations

International Nuclear Information System (INIS)

Belandria, Veronica; Mohammadi, Amir H.; Richon, Dominique

2009-01-01

In this communication, we report experimental density data for the binary mixtures of (water + tetrahydrofuran) and (water + tetra-n-butyl ammonium bromide) at atmospheric pressure and various temperatures. The densities were measured using an Anton Paar TM digital vibrating-tube densimeter. For the (tetrahydrofuran + water) system, excess molar volumes have been calculated using the experimental densities and correlated using the Redlich-Kister equation. The Redlich-Kister equation parameters have been adjusted on experimental results. The partial molar volumes and partial excess molar volumes at infinite dilution have also been calculated for each component. A simple density equation was finally applied to correlate the measured density of the (tetra-n-butyl ammonium bromide + water) system.

Volumetric and ultrasonic studies of an antidepressant drug in aqueous and alcoholic medium over temperature range 298.15-313.15 k

International Nuclear Information System (INIS)

Jamal, M.A.; Khosa, M.K.; Muneer, M.; Shahzad, K.

2013-01-01

Escitalopram oxalate is an amphiphilic serotonin specific reuptake inhibitor-antidepressant drug. Ultrasonic velocity (u) and density (d) measurements were carried out for Escitalopram oxalate in aqueous and alcoholic systems as a function of concentration in a range of molality, m (0.0075-0.04) mol Kg-1 at 298.15-313.15 K using an Anton Paar density sound analyzer (DSA 5000M). Using these experimental values, the acoustical parameters such as apparent molar adiabatic compressibility and partial molar volume (V phi) was apparent molar volume (V phi (K computed for all the systems. The Partial molar expansivity (E/sup 0/) and second derivative values, (partial drive V/sup 0/partial drive T/sup 2/), have also been estimated. The critical micelle concentrations of this drug were obtained from ultrasound velocity measurement by using recently developed least square fitting algorithm. The results are interpreted in the light of structure-making or structure-breaking effects of escitalopram oxalate in the mixtures. (author)

Target volume delineation in external beam partial breast irradiation: less inter-observer variation with preoperative- compared to postoperative delineation

NARCIS (Netherlands)

Leij, F. van der; Elkhuizen, P.H.M.; Janssen, T.M.; Poortmans, P.M.P.; Sangen, M. van der; Scholten, A.N.; Vliet-Vroegindeweij, C. van; Boersma, L.J.

2014-01-01

The challenge of adequate target volume definition in external beam partial breast irradiation (PBI) could be overcome with preoperative irradiation, due to less inter-observer variation. We compared the target volume delineation for external beam PBI on preoperative versus postoperative CT scans of

The partial volume effect in the quantification of 1H magnetic resonance spectroscopy in Alzheimer's disease and aging.

Science.gov (United States)

Mato Abad, Virginia; Quirós, Alicia; García-Álvarez, Roberto; Loureiro, Javier Pereira; Alvarez-Linera, Juan; Frank, Ana; Hernández-Tamames, Juan Antonio

2014-01-01

1H-MRS variability increases due to normal aging and also as a result of atrophy in grey and white matter caused by neurodegeneration. In this work, an automatic process was developed to integrate data from spectra and high-resolution anatomical images to quantify metabolites, taking into account tissue partial volumes within the voxel of interest avoiding additional spectra acquisitions required for partial volume correction. To evaluate this method, we use a cohort of 135 subjects (47 male and 88 female, aged between 57 and 99 years) classified into 4 groups: 38 healthy participants, 20 amnesic mild cognitive impairment patients, 22 multi-domain mild cognitive impairment patients, and 55 Alzheimer's disease patients. Our findings suggest that knowing the voxel composition of white and grey matter and cerebrospinal fluid is necessary to avoid partial volume variations in a single-voxel study and to decrease part of the variability found in metabolites quantification, particularly in those studies involving elder patients and neurodegenerative diseases. The proposed method facilitates the use of 1H-MRS techniques in statistical studies in Alzheimer's disease, because it provides more accurate quantitative measurements, reduces the inter-subject variability, and improves statistical results when performing group comparisons.

SECOND MOLAR UPRIGHTING AFTER PREMATURE LOSS OF MANDIBULAR FIRST PERMANENT MOLAR--CASE REPORT.

Science.gov (United States)

Cernei, E R; Mavru, R B; Zetui, Irina Nicoleta

2015-01-01

Uprighting a tipped molar by using an uprighting spring is a fundamental orthodontic treatment technique. Following a weak anchorage done only by the anterior teeth the permanent lower second molar will rotate around its center of resistance, and besides the distalizing movement will occur its extrusion. Following the reaction, the mandibular anterior teeth will have a movement of intrusion. All these elements will lead to anterior open bite. Correction of vertical problems has become easier with the advent of mini-implants. U.I patient aged 24 years presenting for aesthetic and functional disorders. Clinical examination reveals intraoral Class I molar malocclusion on the right sight, upper narrowing arch with a slight overbite, and the both permanent first molars on the left side lost prematurely. The tooth 37 is inclined at 600 degrees to the plane of occlusion. To avoid front opening occlusion we used an orthodontic miniscrew inserted between the canine and the first premolar on the same side to achieve the second molar up righting. Lower second molar uprighting was achieved without unwanted movements in anterior mandibular region and without molar extrusion. Using mini implants in uprighting a tipped molar will achieve the desired tooth movement and will reduce the number of unwanted side effects and eventually to improve patient's esthetics.

A molecular dynamics study of ambient and high pressure phases of silica: structure and enthalpy variation with molar volume.

Science.gov (United States)

Rajappa, Chitra; Sringeri, S Bhuvaneshwari; Subramanian, Yashonath; Gopalakrishnan, J

2014-06-28

Extensive molecular dynamics studies of 13 different silica polymorphs are reported in the isothermal-isobaric ensemble with the Parrinello-Rahman variable shape simulation cell. The van Beest-Kramer-van Santen (BKS) potential is shown to predict lattice parameters for most phases within 2%-3% accuracy, as well as the relative stabilities of different polymorphs in agreement with experiment. Enthalpies of high-density polymorphs - CaCl2-type, α-PbO2-type, and pyrite-type - for which no experimental data are available as yet, are predicted here. Further, the calculated enthalpies exhibit two distinct regimes as a function of molar volume-for low and medium-density polymorphs, it is almost independent of volume, while for high-pressure phases a steep dependence is seen. A detailed analysis indicates that the increased short-range contributions to enthalpy in the high-density phases arise not only from an increased coordination number of silicon but also shorter Si-O bond lengths. Our results indicate that amorphous phases of silica exhibit better optimization of short-range interactions than crystalline phases at the same density while the magnitude of Coulombic contributions is lower in the amorphous phase.

Brain extraction in partial volumes T2*@7T by using a quasi-anatomic segmentation with bias field correction.

Science.gov (United States)

Valente, João; Vieira, Pedro M; Couto, Carlos; Lima, Carlos S

2018-02-01

Poor brain extraction in Magnetic Resonance Imaging (MRI) has negative consequences in several types of brain post-extraction such as tissue segmentation and related statistical measures or pattern recognition algorithms. Current state of the art algorithms for brain extraction work on weighted T1 and T2, being not adequate for non-whole brain images such as the case of T2*FLASH@7T partial volumes. This paper proposes two new methods that work directly in T2*FLASH@7T partial volumes. The first is an improvement of the semi-automatic threshold-with-morphology approach adapted to incomplete volumes. The second method uses an improved version of a current implementation of the fuzzy c-means algorithm with bias correction for brain segmentation. Under high inhomogeneity conditions the performance of the first method degrades, requiring user intervention which is unacceptable. The second method performed well for all volumes, being entirely automatic. State of the art algorithms for brain extraction are mainly semi-automatic, requiring a correct initialization by the user and knowledge of the software. These methods can't deal with partial volumes and/or need information from atlas which is not available in T2*FLASH@7T. Also, combined volumes suffer from manipulations such as re-sampling which deteriorates significantly voxel intensity structures making segmentation tasks difficult. The proposed method can overcome all these difficulties, reaching good results for brain extraction using only T2*FLASH@7T volumes. The development of this work will lead to an improvement of automatic brain lesions segmentation in T2*FLASH@7T volumes, becoming more important when lesions such as cortical Multiple-Sclerosis need to be detected. Copyright © 2017 Elsevier B.V. All rights reserved.

Apparent molar volumes and apparent molar heat capacities of aqueous adonitol, dulcitol, glycerol, meso-erythritol, myo-inositol, D-sorbitol, and xylitol at temperatures from (278.15 to 368.15) K and at the pressure 0.35 MPa

International Nuclear Information System (INIS)

Blodgett, M.B.; Ziemer, S.P.; Brown, B.R.; Niederhauser, T.L.; Woolley, E.M.

2007-01-01

Apparent molar volumes V φ were determined for aqueous adonitol, dulcitol, glycerol, meso-erythritol, myo-inositol, D-sorbitol, and xylitol at temperatures from (278.15 to 368.15) K and at the pressure 0.35 MPa, and apparent molar heat capacities C p,φ of the same solutions were determined at temperatures from (278.15 to 363.15) K at the same pressure. Molalities m/(mol . kg -1 ) of the solutions were in the range (0.02 ≤ m ≤ 3.2) for adonitol, (0.02 ≤ m ≤ 0.15) for dulcitol, (0.02 ≤ m ≤ 5.0) for glycerol, (0.02 ≤ m ≤ 3.0) for meso-erythritol, (0.02 ≤ m ≤ 0.5) for myo-inositol, (0.02 ≤ m ≤ 2.0) for D-sorbitol, and (0.02 ≤ m ≤ 2.7) for xylitol. A vibrating tube densimeter was used to obtain solution densities and a fixed-cell temperature scanning calorimeter was used to obtain heat capacities. Values of V φ and C p,φ for these sugar alcohols are discussed relative to one another and compared to values from the literature, where available

Volumetric properties of ammonium nitrate in N,N-dimethylformamide

International Nuclear Information System (INIS)

Vranes, Milan; Dozic, Sanja; Djeric, Vesna; Gadzuric, Slobodan

2012-01-01

Highlights: ► We observed interactions and changes in the solution using volumetric properties. ► The greatest influence on the solvent–solvent interactions has temperature. ► The smallest influence temperature has on the ion–ion interactions. ► Temperature has no influence on concentrated systems and partially solvated melts. - Abstract: The densities of the ammonium nitrate in N,N-dimethylformamide (DMF) mixtures were measured at T = (308.15 to 348.15) K for different ammonium nitrate molalities in the range from (0 to 6.8404) mol·kg −1 . From the obtained density data, volumetric properties (apparent molar volumes and partial molar volumes) have been evaluated and discussed in the term of respective ionic and dipole interactions. From the apparent molar volume, determined at various temperatures, the apparent molar expansibility and the coefficients of thermal expansion were also calculated.

New finite volume methods for approximating partial differential equations on arbitrary meshes

International Nuclear Information System (INIS)

Hermeline, F.

2008-12-01

This dissertation presents some new methods of finite volume type for approximating partial differential equations on arbitrary meshes. The main idea lies in solving twice the problem to be dealt with. One addresses the elliptic equations with variable (anisotropic, antisymmetric, discontinuous) coefficients, the parabolic linear or non linear equations (heat equation, radiative diffusion, magnetic diffusion with Hall effect), the wave type equations (Maxwell, acoustics), the elasticity and Stokes'equations. Numerous numerical experiments show the good behaviour of this type of method. (author)

Volumetric properties of binary mixtures of ionic liquid 1-butyl-3-methylimidazolium octylsulfate with water or propanol in the temperature range of 278.15K to 328.15K

International Nuclear Information System (INIS)

Orchilles, A. Vicent; Gonzalez-Alfaro, Vicenta; Miguel, Pablo J.; Vercher, Ernesto; Martinez-Andreu, Antoni

2006-01-01

Densities of 1-butyl-3-methylimidazolium octylsulfate ([bmim][OcOSO 3 ]) solutions in water and 1-propanol have been measured with an oscillating-tube densimeter at temperatures from 278.15K to 328.15K. From these densities, apparent molar volumes V φ of [bmim][OcOSO 3 ] in both solvents have been calculated, and its dependence on the molality has been treated with the Redlich and Meyer equation. Debye-Huckel limiting slopes for 1-propanol at working temperatures have been calculated, and apparent molar volumes of [bmim][OcOSO 3 ] at infinite dilution V φ o in both solvents have been evaluated. The partial molar volume at infinite dilution of [bmim][OcOSO 3 ] in water is higher than in 1-propanol and augments when the temperature augments. On the other hand, the partial molar volume at infinite dilution of [bmim][OcOSO 3 ] in 1-propanol decreases when the temperature augments

Impact of partial-volume correction in oncological PET studies. A systematic review and meta-analysis

Energy Technology Data Exchange (ETDEWEB)

Cysouw, Matthijs C.F.; Kramer, Gerbrand M.; Hoekstra, Otto S. [VU University Medical Centre, Department of Radiology and Nuclear Medicine, Amsterdam (Netherlands); Schoonmade, Linda J. [VU University Medical Centre, Department of Medical Library, Amsterdam (Netherlands); Boellaard, Ronald [VU University Medical Centre, Department of Radiology and Nuclear Medicine, Amsterdam (Netherlands); University Medical Centre Groningen, Department of Nuclear Medicine and Molecular Imaging, Groningen (Netherlands); Vet, Henrica C.W. de [VU University Medical Centre, Department of Epidemiology and Biostatistics, Amsterdam (Netherlands)

2017-11-15

Positron-emission tomography can be useful in oncology for diagnosis, (re)staging, determining prognosis, and response assessment. However, partial-volume effects hamper accurate quantification of lesions <2-3 x the PET system's spatial resolution, and the clinical impact of this is not evident. This systematic review provides an up-to-date overview of studies investigating the impact of partial-volume correction (PVC) in oncological PET studies. We searched in PubMed and Embase databases according to the PRISMA statement, including studies from inception till May 9, 2016. Two reviewers independently screened all abstracts and eligible full-text articles and performed quality assessment according to QUADAS-2 and QUIPS criteria. For a set of similar diagnostic studies, we statistically pooled the results using bivariate meta-regression. Thirty-one studies were eligible for inclusion. Overall, study quality was good. For diagnosis and nodal staging, PVC yielded a strong trend of increased sensitivity at expense of specificity. Meta-analysis of six studies investigating diagnosis of pulmonary nodules (679 lesions) showed no significant change in diagnostic accuracy after PVC (p = 0.222). Prognostication was not improved for non-small cell lung cancer and esophageal cancer, whereas it did improve for head and neck cancer. Response assessment was not improved by PVC for (locally advanced) breast cancer or rectal cancer, and it worsened in metastatic colorectal cancer. The accumulated evidence to date does not support routine application of PVC in standard clinical PET practice. Consensus on the preferred PVC methodology in oncological PET should be reached. Partial-volume-corrected data should be used as adjuncts to, but not yet replacement for, uncorrected data. (orig.)

Removable molar power arm

Directory of Open Access Journals (Sweden)

Raj Kumar Verma

2013-01-01

Full Text Available Attachment of force elements from the gingival hook of maxillary molar tubes during the retraction of the anterior teeth is very common in orthodontic practice. As the line of force passes below the center of resistance (CR of molar, it results its mesial tipping and also anchorage loss. To overcome this problem, the line of force should pass along the CR of molar. This article highlights a method to overcome this problem by attaching a removable power arm to the headgear tube of molar tube during the retraction of the anterior teeth.

Using cone beam computed thomography in planning the extraction of impacted third molars

Directory of Open Access Journals (Sweden)

Vlahović Zoran

2016-01-01

Full Text Available The panoramic radiography is the most used diagnostic imaging method in planning impacted lower third molar extractions. However, often panoramic radiography does not provide enough information in treatment planning for performing safely surgical extraction of impacted third molars. CBCT (Cone beam computed tomography provides more precise information in diagnostic analysis especially for planning surgical procedures where complications can be expected due to close relationship between mandibular canal and lower impacted third molars. The aim of this study is comparative analysis of panoramic radiography and CBCT in evaluating the topographic relationship between mandibular canal and impacted third molars. The study included 50 patients with close relationship between mandibular canal and impacted third molars detected using panoramic radiography. After panoramic radiography analysis CBCT was performed in order to diagnose, plan and prevent complications during the surgical tooth extraction. CBCT examination considered comparative analysis with panoramic radiography, marking, volume rendering and assessment of mandibular canal in buccolingual direction. Out of total patients where suprimposition of mandibular canal and impacted third molar on panoramic radiography was detected, in 32 patients mandibular chanal was localised on lingual side. Mandibular canal was positioned at bucal side in 18 of 50 patients. Results of this research indicate that panoramic radiography can be useful in everyday practice for diagnosis, planning and preparing lower third molar extractions, but in cases where close relationship between mandibular canal and lower third molars is detected CBCT is recommended as more precise radiographic imaging method in order to prevent complications.

Adaptive partial volume classification of MRI data

International Nuclear Information System (INIS)

Chiverton, John P; Wells, Kevin

2008-01-01

Tomographic biomedical images are commonly affected by an imaging artefact known as the partial volume (PV) effect. The PV effect produces voxels composed of a mixture of tissues in anatomical magnetic resonance imaging (MRI) data resulting in a continuity of these tissue classes. Anatomical MRI data typically consist of a number of contiguous regions of tissues or even contiguous regions of PV voxels. Furthermore discontinuities exist between the boundaries of these contiguous image regions. The work presented here probabilistically models the PV effect using spatial regularization in the form of continuous Markov random fields (MRFs) to classify anatomical MRI brain data, simulated and real. A unique approach is used to adaptively control the amount of spatial regularization imposed by the MRF. Spatially derived image gradient magnitude is used to identify the discontinuities between image regions of contiguous tissue voxels and PV voxels, imposing variable amounts of regularization determined by simulation. Markov chain Monte Carlo (MCMC) is used to simulate the posterior distribution of the probabilistic image model. Promising quantitative results are presented for PV classification of simulated and real MRI data of the human brain.

Effect of partial volume correction on muscarinic cholinergic receptor imaging with single-photon emission tomography in patients with temporal lobe epilepsy

International Nuclear Information System (INIS)

Weckesser, M.; Ziemons, K.; Griessmeier, M.; Sonnenberg, F.; Langen, K.J.; Mueller-Gaertner, H.W.; Hufnagel, A.; Elger, C.E.; Hacklaender, T.; Holschbach, M.

1997-01-01

Animal experiments and preliminary results in humans have indicated alterations of hippocampal muscarinic acetylcholine receptors (mAChR) in temporal lobe epilepsy. Patients with temporal lobe epilepsy often present with a reduction in hippocampal volume. The aim of this study was to investigate the influence of hippocampal atrophy on the quantification of mAChR with single photon emission tomography (SPET) in patients with temporal lobe epilepsy. Cerebral uptake of the muscarinic cholinergic antagonist [ 123 I]4-iododexetimide (IDex) was investigated by SPET in patients suffering from temporal lobe epilepsy of unilateral (n=6) or predominantly unilateral (n=1) onset. Regions of interest were drawn on co-registered magnetic resonance images. Hippocampal volume was determined in these regions and was used to correct the SPET results for partial volume effects. A ratio of hippocampal IDex binding on the affected side to that on the unaffected side was used to detect changes in muscarinic cholinergic receptor density. Before partial volume correction a decrease in hippocampal IDex binding on the focus side was found in each patient. After partial volume no convincing differences remained. Our results indicate that the reduction in hippocampal IDex binding in patients with epilepsy is due to a decrease in hippocampal volume rather than to a decrease in receptor concentration. (orig.). With 2 figs., 2 tabs

Target volume delineation in external beam partial breast irradiation: Less inter-observer variation with preoperative- compared to postoperative delineation

International Nuclear Information System (INIS)

Leij, Femke van der; Elkhuizen, Paula H.M.; Janssen, Tomas M.; Poortmans, Philip; Sangen, Maurice van der; Scholten, Astrid N.; Vliet-Vroegindeweij, Corine van; Boersma, Liesbeth J.

2014-01-01

The challenge of adequate target volume definition in external beam partial breast irradiation (PBI) could be overcome with preoperative irradiation, due to less inter-observer variation. We compared the target volume delineation for external beam PBI on preoperative versus postoperative CT scans of twenty-four breast cancer patients

Properties of L-ascorbic acid in water and binary aqueous mixtures of D-glucose and D-fructose at different temperatures

Science.gov (United States)

Sharma, Ravi; Thakur, R. C.; Sani, Balwinder; Kumar, Harsh

2017-12-01

Using density and sound velocity partial molar volumes, partial molar adiabatic compressibilities, partial molar expansibilities and structure of L-ascorbic acid have been determined in water and aqueous mixtures of D-glucose and D-fructose at different concentrations and temperatures. Masson's equation was used to analyze the measured data. The obtained parameters have been interpreted in terms of solute-solute and solute-solvent interactions. It is found that the L-ascorbic acid acts as structure breaker in water as well in binary studied mixtures.

Maxillary second molar impaction in the adjacent ectopic third molar: Report of five rare cases

Science.gov (United States)

Souki, Bernardo Q.; Cheib, Paula L.; de Brito, Gabriela M.; Pinto, Larissa S. M. C.

2015-01-01

Maxillary second molar impaction in the adjacent ectopic third molar is a rare condition that practitioners might face in the field of pediatric dentistry and orthodontics. The early diagnosis and extraction of the adjacent ectopic third molar have been advocated, and prior research has reported a high rate of spontaneous eruption following third molar removal. However, some challenges in the daily practice are that the early diagnosis of this type of tooth impaction is difficult with conventional radiographic examination, and sometimes the early surgical removal of the maxillary third molar must be postponed because of the risks of damaging the second molar. The objective of this study is to report a case series of five young patients with maxillary second molar impaction and to discuss the difficulty of early diagnosis with the conventional radiographic examination, and unpredictability of self-correction. PMID:26321848

Maxillary second molar impaction in the adjacent ectopic third molar: Report of five rare cases

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Bernardo Q Souki

2015-01-01

Full Text Available Maxillary second molar impaction in the adjacent ectopic third molar is a rare condition that practitioners might face in the field of pediatric dentistry and orthodontics. The early diagnosis and extraction of the adjacent ectopic third molar have been advocated, and prior research has reported a high rate of spontaneous eruption following third molar removal. However, some challenges in the daily practice are that the early diagnosis of this type of tooth impaction is difficult with conventional radiographic examination, and sometimes the early surgical removal of the maxillary third molar must be postponed because of the risks of damaging the second molar. The objective of this study is to report a case series of five young patients with maxillary second molar impaction and to discuss the difficulty of early diagnosis with the conventional radiographic examination, and unpredictability of self-correction.

The premature loss of primary first molars: space loss to molar occlusal relationships and facial patterns.

Science.gov (United States)

Alexander, Stanley A; Askari, Marjan; Lewis, Patricia

2015-03-01

To investigate space changes with the premature loss of primary first molars and their relationship to permanent molar occlusion and facial forms. Two hundred twenty-six participants (ranging in age from 7 years 8 months to 8 years 2 months; 135 female, 91 male) met all inclusion criteria designed to study space loss as a result of the premature loss of the primary first molar. After 9 months, space loss was evaluated in relationship to molar occlusion and facial form. Statistical evaluation was performed with the paired t-test and with a two-way analysis of variance for independent groups. Patients with leptoprosopic facial form and end-on molar occlusions all exhibited a statistically significant difference when compared to controls in terms of space loss (P molar occlusion displayed space loss as well (P molar occlusion displayed space loss in the maxilla (P molar occlusions showed no significant difference in space loss. The relationship between the first permanent molar occlusion and facial form of the child has an influence on the loss of space at the primary first molar site.

Volumetric properties of dichloromethane with aniline or nitrobenzene at different temperatures: A theoretical and experimental study

International Nuclear Information System (INIS)

Su Liyan; Wang Haijun

2009-01-01

The densities for binary mixtures of dichloromethane with aniline, or nitrobenzene, respectively, including those of pure liquids, were measured over the entire composition range at T = (288.15, 293.15, 298.15, and 303.15) K and atmospheric pressure using a vibrating-tube densimeter. From the experimental results, the excess molar volumes, V m E , partial molar volumes, V i -bar, the apparent molar volume, V φi , and the partial molar excess volumes at infinite dilution, (V i E -bar) ∞ , were calculated over whole composition range. Negative values of V m E for (dichloromethane + aniline) attributed to the formation of the charge transfer complex, while for (dichloromethane + nitrobenzene) system, the free volume effect played a dominant role. The extent of negative deviations in V m E values follows the order: nitrobenzene > aniline. The Prigogine-Flory-Patterson (PFP) theory and its applicability in predicting V m E at T = 298.15 K were tested. There is a good agreement in general between the experimental V m E values and those predicted by PFP theory

Measurement and Correlation on Viscosity and Apparent Molar Volume of Ternary System for L-ascorbic Acid in Aqueous D-Glucose and Sucrose Solutions%L-抗坏血酸在葡萄糖和蔗糖溶液中的黏度及其热力学性质的研究

Institute of Scientific and Technical Information of China (English)

赵长伟; 马沛生

2003-01-01

Viscosities and densities at several temperatures from 293.15 K to 313.15 K are reported for L-ascorbic acid in aqueous glucose and sucrose solutions at different concentrations. The parameters of density, viscosity coefficient B and partial molar volume are calculated by regression. The experimental results show that densities and viscosities decrease as temperature increases at the same solute and solvent (glucose and sucrose aqueous solution) concentrations, and increase with concentration of glucose and sucrose at the same solute concentration and temperature. B increases with concentration of glucose and sucrose and temperature. L-ascorbic acid is structure-breaker or structure-making for the glucose and sucrose aqueous solutions. Furthermore, the solute-solvent interactions in ternary systems of water-glucose-electrolyte and water-sucrose-electrolyte are discussed.

An innovative technique to distalize maxillary molar using microimplant supported rapid molar distalizer

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Meenu Goel

2013-01-01

Full Text Available Introduction: In recent years, enhancements in implants have made their use possible as a mode of absolute anchorage in orthodontic patients. In this paper, the authors have introduced an innovative technique to unilaterally distalize the upper left 1 st molar to obtain an ideal Class I molar relationship from a Class II existing molar relationship with an indigenous designed distalizer. Clinical Innovation: For effective unilateral diatalization of molar, a novel cantilever sliding jig assembly was utilized with coil spring supported by a buccally placed single micro implant. The results showed 3 mm of bodily distalization with 1 mm of intrusion and 2° of distal tipping of upper left 1 st molar in 1.5 months. Discussion: This appliance is relatively easy to insert, well-tolerated, and requires minimal patient cooperation compared to other present techniques of molar distalization. Moreover, it is particularly useful in cases that are Class II on one side and Class I on the other, with a minor midline discrepancy and nominal overjet. Patient acceptance level was reported to be within patients physiological and comfort limits.

Are Hypomineralized Primary Molars and Canines Associated with Molar-Incisor Hypomineralization?

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da Silva Figueiredo Sé, Maria Jose; Ribeiro, Ana Paula Dias; Dos Santos-Pinto, Lourdes Aparecida Martins; de Cassia Loiola Cordeiro, Rita; Cabral, Renata Nunes; Leal, Soraya Coelho

2017-11-01

The purpose of this study was to evaluate the prevalence of and relationship between hypomineralized second primary molars (HSPM) and hypomineralized primary canines (HPC) with molar-incisor hypomineralization (MIH) in 1,963 schoolchildren. The European Academy of Paediatric Dentistry (EAPD) criterion was used for scoring HSPM/HPC and MIH. Only children with four permanent first molars and eight incisors were considered in calculating MIH prevalence (n equals 858); for HSPM/HPC prevalence, only children with four primary second molars (n equals 1,590) and four primary canines (n equals 1,442) were considered. To evaluate the relationship between MIH/HSPM, only children meeting both criteria cited were considered (n equals 534), as was true of MIH/HPC (n equals 408) and HSPM/HPC (n equals 360; chi-square test and logistic regression). The prevalence of MIH was 14.69 percent (126 of 858 children). For HSPM and HPC, the prevalence was 6.48 percent (103 of 1,592) and 2.22 percent (32 of 1,442), respectively. A significant relationship was observed between MIH and both HSPM/HPC (PMIH based on HSPM was 6.31 (95 percent confidence interval [CI] equals 2.59 to 15.13) and for HPC was 6.02 (95 percent CI equals 1.08 to 33.05). The results led to the conclusion that both hypomineralized second primary molars and hypomineralized primary canines are associated with molar-incisor hypomineralization, because children with HSPM/HPC are six times more likely to develop MIH.

Mini implant supported molar tubes: A novel method for attaching the molar tubes

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Nitin V Muralidhar

2017-01-01

Full Text Available Banding or bonding procedures have been the only means of attaching molar tubes onto the permanent molar teeth till date in the field of orthodontics. This clinical innovation aims to include the use of mini implant for the purpose of attaching the molar tubes thereby eliminating the iatrogenic effects of banding and bonding of the teeth.

Molar Incisor Hypomineralization, Prevalence, and Etiology

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Sulaiman Mohammed Allazzam

2014-01-01

Full Text Available Aim. To evaluate the prevalence and possible etiological factors associated with molar incisor hypomineralization (MIH among a group of children in Jeddah, Saudi Arabia. Methods. A group of 8-12-year-old children were recruited (n=267  from the Pediatric Dental Clinics at the Faculty of Dentistry, King Abdulaziz University. Children had at least one first permanent molar (FPM, erupted or partially erupted. Demographic information, children’s medical history, and pregnancy-related data were obtained. The crowns of the FPM and permanent incisors were examined for demarcated opacities, posteruptive breakdown (PEB, atypical restorations, and extracted FPMs. Children were considered to have MIH if one or more FPM with or without involvement of incisors met the diagnostic criteria. Results. MIH showed a prevalence of 8.6%. Demarcated opacities were the most common form. Maxillary central incisors were more affected than mandibular (P=0.01. The condition was more prevalent in children with history of illnesses during the first four years of life including tonsillitis (P=0.001, adenoiditis (P=0.001, asthma (P=0.001, fever (P=0.014, and antibiotics intake (P=0.001. Conclusions. The prevalence of MIH is significantly associated with childhood illnesses during the first four years of life including asthma, adenoid infections, tonsillitis, fever, and antibiotics intake.

South African Journal of Chemistry - Vol 62 (2009)

African Journals Online (AJOL)

Excess Molar Volumes and Partial Molar Volumes of Binary Systems (Ionic Liquid + Methanol or Ethanol or 1-Propanol) at T = (298.15, 303.15 and 313.15) K · EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT. PN Sibiya, N Deenadayalu, 20-25 ...

Non-covalent interactions between {N,N′-bis[(2-pyridinyl)methylene]-1, 2-benzenediamine]-bis(nitrato)}Cu(II) with pyridoxine hydrochloride in methanol at T = (298.15, 308.15 and 318.15) K

International Nuclear Information System (INIS)

Brahman, Dhiraj; Sinha, Biswajit

2014-01-01

Highlights: • Methanolic solution of pyridoxine hydrochloride used as solvent. • {N,N′-bis[(2-pyridinyl)methylene]-1, 2-benzenediamine]-bis(nitrato)}Cu(II) used as solute. • Partial molar volumes and viscosity B-coefficients of the solute were determined. • Weak 1:1 association between the complex and pyridoxine hydrochloride found. • Non-covalent interactions and Cu(II) complex acts as a net structure maker in the ternary solutions. - Abstract: Non-covalent interactions between of {N,N′-bis[(2-pyridinyl)methylene]-1, 2-benzenediamine]-bis(nitrato)}Cu(II) with pyridoxine hydrochloride in methanol were investigated by a combination of physico-chemical and spectrophotometric methods at T = (298.15, 308.15 and 318.15) K under ambient pressure. From measured density and viscosity data the apparent molar volume (ϕ V ), the slope (S V ∗ ), standard partial molar volume (ϕ V 0 ), standard transfer volume (Δ t ϕ V 0 ), isobaric apparent molar expansibility (ϕ E ), standard isobaric partial molar expansibility (ϕ E 0 ), the viscosity B-coefficient, its temperature derivative (∂B/∂T), solvation number (S n ) were calculated and discussed on the basis of specific or non-specific (solute + cosolute) and (solute + solvent) interactions. Thermodynamics of viscous flow were discussed on the basis of the transition state theory. Spectrophotometric results indicated 1:1 (solute + cosolute) interaction between the complex and pyridoxine hydrochloride

Theory of chromatography of partially cyclic polymers: Tadpole-type and manacle-type macromolecules.

Science.gov (United States)

Vakhrushev, Andrey V; Gorbunov, Alexei A

2016-02-12

A theory of chromatography is developed for partially cyclic polymers of tadpole- and manacle-shaped topological structures. We present exact equations for the distribution coefficient K at different adsorption interactions; simpler approximate formulae are also derived, relevant to the conditions of size-exclusion, adsorption, and critical chromatography. Theoretical chromatograms of heterogeneous partially cyclic polymers are simulated, and conditions for good separation by topology are predicted. According to the theory, an effective SEC-radius of tadpoles and manacles is mostly determined by the molar mass M, and by the linear-cyclic composition. In the interactive chromatography, the effect of molecular topology on the retention becomes significant. At the critical interaction point, partial dependences K(Mlin) and K(Mring) are qualitatively different: while being almost independent of Mlin, K increases with Mring. This behavior could be realized in critical chromatography-for separation of partially cyclic polymers by the number and molar mass of cyclic elements. Copyright © 2015 Elsevier B.V. All rights reserved.

MMP20 Overexpression Disrupts Molar Ameloblast Polarity and Migration.

Science.gov (United States)

Shin, M; Chavez, M B; Ikeda, A; Foster, B L; Bartlett, J D

2018-02-01

Ameloblasts responsible for enamel formation express matrix metalloproteinase 20 (MMP20), an enzyme that cleaves enamel matrix proteins, including amelogenin (AMELX) and ameloblastin (AMBN). Previously, we showed that continuously erupting incisors from transgenic mice overexpressing active MMP20 had a massive cell infiltrate present within their enamel space, leading to enamel mineralization defects. However, effects of MMP20 overexpression on mouse molars were not analyzed, although these teeth more accurately represent human odontogenesis. Therefore, MMP20-overexpressing mice ( Mmp20 +/+ Tg + ) were assessed by multiscale analyses, combining several approaches from high-resolution micro-computed tomography to enamel organ immunoblots. During the secretory stage at postnatal day 6 (P6), Mmp20 +/+ Tg + mice had a discontinuous ameloblast layer and, unlike incisors, molar P12 maturation stage ameloblasts abnormally migrated away from the enamel layer into the stratum intermedium/stellate reticulum. TOPflash assays performed in vitro demonstrated that MMP20 expression promoted β-catenin nuclear localization and that MMP20 expression promoted invasion through Matrigel-coated filters. However, for both assays, significant differences were eliminated in the presence of the β-catenin inhibitor ICG-001. This suggests that MMP20 activity promotes cell migration via the Wnt pathway. In vivo, the unique molar migration of amelogenin-expressing ameloblasts was associated with abnormal deposition of ectopic calcified nodules surrounding the adherent enamel layer. Enamel content was assessed just prior to eruption at P15. Compared to wild-type, Mmp20 +/+ Tg + molars exhibited significant reductions in enamel thickness (70%), volume (60%), and mineral density (40%), and MMP20 overexpression resulted in premature cleavage of AMBN, which likely contributed to the severe defects in enamel mineralization. In addition, Mmp20 +/+ Tg + mouse molar enamel organs had increased levels

Investigation on molecular interactions of antibiotics in alcohols using volumetric and acoustic studies at different temperatures

International Nuclear Information System (INIS)

Naseem, Bushra; Iftikhar, Madeeha

2017-01-01

Highlights: • Antibiotics in different alcohols are used to study their interactions in solutions. • Density and sound velocity for antibiotic solutions are measured at different temperatures. • Apparent molar volume and isentropic compressibility are used to calculate partial molar quantities. • Acoustical parameters are calculated and discussed in terms of solute–solute and solute–solvent interactions. - Abstract: The density and sound velocity for pure alcohols (methanol, ethanol, iso-propanol and n-butanol) and molal solutions of nitroimidazoles (metronidazole (MNZ) and dimetridazole (DMZ) have been measured at different temperatures (293.15–313.15 K). Different volumetric and acoustical parameters like apparent molar volume (V ϕ ), partial molar volume (VЛљ ϕ ), apparent molar isentropic compressibility (K ϕ ), partial molar isentropic compressibility (KЛљ ϕ ), hydration number (n H ), acoustic impedance (Z) and intermolecular free length (L f ) of antibiotic solutions were calculated from the experimental values of density and sound velocity. The derived values have been used to explore the solute–solute and solute–solvent interactions. The V ϕ values are positive and K ϕ values are negative in both antibiotics, indicative of strong solute–solvent interactions and closely packed structure of antibiotics in alcohols. The decreasing trend of L f with increasing antibiotic concentration shows the presence of strong intermolecular interactions in solutions.

Solvation of ionic liquids based on N-alkyl-N-methylmorpholinium cations in N,N-dimethylformamide and dimethyl sulfoxide – A volumetric and acoustic study

International Nuclear Information System (INIS)

Marcinkowski, Łukasz; Szepiński, Emil; Kloskowski, Adam; Namieśnik, Jacek; Warmińska, Dorota

2017-01-01

Highlights: • V ϕ of DMSO and DMF solutions of [Mor1,R][BF 4 ] increase with increasing IL concentration at all investigated temperatures. • Ion–ion interaction are stronger for DMF solutions than corresponding for DMSO. • DMSO interacts more effectively with ionic liquids studied than DMF. • Obtained results are the consequence of the cation size of the ionic liquid. - Abstract: Apparent molar volumes and molar isentropic compressibilities for N-ethyl-N-methylmorpholinium and N-decyl-N-methylmorpholinium tetrafluoroborates in N,N-dimethylformamide (DMF) and dimethyl sulfoxide (DMSO) have been determined from density and speed of sound measurements over the temperature range T = (298.15, 303.15, 308.15, 313.15, 318.15 and 328.15) K at experimental pressure p = 0.1 MPa. This data has been used to calculate partial molar volumes and partial molar isentropic compressibilities at infinite dilution. The partial molar expansion coefficients and their secondary derivative have been estimated as well. The obtained results indicate that dimethyl sulfoxide interacts more effectively with ionic liquids studied than N,N-dimetylformamide and ion–ion interaction are stronger for N,N-dimetylformamide solutions than corresponding in dimethyl sulfoxide. Moreover the temperature dependence of the limiting apparent molar volumes and compressibilities is a result of temperature influence on the electrostriction effect, the ordering of a bulk solvent and number solvent molecules in the nearest presence of the salt.

Volumetric behaviour of amino acids and their group contributions in aqueous lactose solutions at different temperatures

Energy Technology Data Exchange (ETDEWEB)

Pal, Amalendu, E-mail: palchem@sify.co [Department of Chemistry, Kurukshetra University, Kurukshetra 136 119 (India); Chauhan, Nalin [Department of Chemistry, Kurukshetra University, Kurukshetra 136 119 (India)

2011-02-15

Densities, {rho}, for glycine, L-alanine, L-valine, and L-leucine [(0.05 to 0.30) m] in aqueous lactose solutions ranging from pure water to 6 mass% lactose were determined at T = (293.15, 298.15, 303.15, and 308.15) K. The density was used to compute apparent molar volume, V{sub {phi}}, partial molar volume at infinite dilution, V{sub {phi}}{sup o}, and experimental slope, S{sub V} were obtained and interpreted in terms of solute-solvent and solute-solute interactions. These data were used to calculate the ({partial_derivative}V{sub {phi}}{sup 0}/{partial_derivative}T){sub P} values. The partial molar volume of transfer, {Delta}V{sub {phi}}{sup 0} from water to aqueous lactose solutions at infinite dilution has also been calculated. In addition to this, the linear correlation of V{sub {phi}}{sup 0} with number of carbon atoms in the alkyl chain of amino acids was utilized to determine the respective contributions of NH{sub 3}{sup +}COO{sup -}, and CH{sub 2} groups to V{sub {phi}}{sup 0}.

Volumetric and surface properties of pure ionic liquid n-octyl-pyridinium nitrate and its binary mixture with alcohol

International Nuclear Information System (INIS)

Jiang Haichao; Wang Jianying; Zhao Fengyun; Qi Guodi; Hu Yongqi

2012-01-01

Highlights: ► Density and surface tension of [Ocpy][NO 3 ] were measured. ► Thermal expansion coefficient, molecular volume, and standard entropies were obtained. ► The critical temperature and enthalpy of vaporization were discussed. ► Density and surface tension were measured for (ionic liquid + alcohols) mixtures. ► Excess molar volumes and surface tension deviations were fitted to Redlich–Kister equation. - Abstract: The density and surface tension for pure ionic liquid N-octyl-pyridinium nitrate were measured from (293.15 to 328.15) K. The coefficient of thermal expansion, molecular volume, standard entropies, and lattice energy were calculated from the experimental density values. The critical temperature, surface entropy, surface enthalpy, and enthalpy of vaporization were also studied from the experimental surface tension results. Density and surface tension were also determined for binary mixtures of (N-octyl-pyridinium nitrate + alcohol) (methanol, ethanol, and 1-butanol) systems over the whole composition range at 298.15 K and atmospheric pressure. Excess molar volumes and surface tension deviations for the binary systems have been calculated and were fitted to a Redlich–Kister equation to determine the fitting parameters and the root mean square deviations. The partial molar volume, excess partial molar volume, and apparent molar volume of the component IL and alcohol in the binary mixtures were also discussed.

Thermophysical properties of ionic liquid {1-butyl-3-methylimidazolium bromide [bmim][Br] in alkoxyalkanols + water} mixtures at different temperatures

International Nuclear Information System (INIS)

Pal, Amalendu; Kumar, Harsh; Kumar, Bhupinder; Sharma, Pooja; Kaur, Kirtanjot

2013-01-01

Highlights: ► Densities and speeds of sound of alkoxyalkanols in [bmim][Br]. ► Synthesis of room temperature ionic liquid [bmim][Br]. ► Partial molar volumes and compressibility of transfer. ► Apparent molar expansivities and the Hepler’s constant were calculated. ► Solute–solute and solute–solvent interactions and the structural changes of the solutes. - Abstract: The interactions of alkoxyalkanols with the ionic liquid 1-butyl-3-methylimidazolium bromide [bmim][Br] as a function of temperature were investigated by combination of volumetric and acoustic methods. The density, ρ, and speed of sound, u, of ethylene glycol monomethyl ether, diethylene glycol monomethyl ether, and triethylene glycol monomethyl ether (0.00–1.01 mol·kg −1 ) in aqueous 1-butyl-3-methylimidazolium bromide solutions ranging from pure water to 0.29 mass% of ionic liquid have been measured at T = (288.15, 298.15 and 308.15) K and atmospheric pressure. The apparent molar volume (V φ ) and adiabatic compressibility (K φ,S ) of alkoxyalkanols in aqueous ionic liquid solution were determined at the measured temperatures. The partial molar volume (V φ 0 ) and partial molar adiabatic compressibility (K φ 0 ) of alkoxyalkanols at infinite dilution were evaluated. Transfer volumes (ΔV φ 0 ) and transfer adiabatic compressibility (ΔK φ 0 ) at infinite dilution from water to aqueous ionic liquid solution were also calculated. The temperature dependence of the apparent molar volume was used to calculate apparent molar expansivity (φ E 0 ) and the Hepler’s constant values, (∂ 2 V φ 0 /∂T 2 ). The results were explained on the basis of competing patterns of interactions of co-solvent and the solute.

Extrações de molares na Ortodontia Molar extractions in orthodontics

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Marco Antônio Schroeder

2011-12-01

Full Text Available O tratamento ortodôntico com extração de molares em pacientes adultos é tecnicamente mais complexo, devido a inúmeros fatores. Em geral, o espaço a ser fechado é maior do que o espaço dos pré-molares e, por isso, a ancoragem é crítica e o tempo de tratamento mais longo. É comum esses casos apresentarem algum grau de comprometimento periodontal por causa da idade dos pacientes e, portanto, necessitam de maior controle da mecânica ortodôntica para reduzir os efeitos colaterais do fechamento do espaço. Por isso, bons resultados de finalização são mais difíceis de ser alcançados. Sendo assim, este artigo tem como objetivo apresentar as razões para a indicação de extração de molares nos tratamentos ortodônticos, as contraindicações, as diferentes fases da mecânica ortodôntica, esclarecer os fatores envolvidos nesse tipo de planejamento e tratamento e apresentar casos clínicos tratados com extração de molares.Orthodontic treatment with extraction of molars in adult patients is technically more complex due to a number of factors. In general, the space to be closed is greater than premolar spaces rendering critical anchorage and longer treatment time. Often such cases exhibit some degree of periodontal involvement due to patient age. Hence, the need for greater control over orthodontic mechanics to reduce the side effects of space closure. Therefore, good finishing results can be more difficult to achieve. Thus, the purpose of this article is to determine the reasons for molar extraction indications, describe different stages of orthodontic mechanics, and explain the issues involved in this kind of planning and treatment. Additionally, it aims at describing some treatments with molar extractions.

Differential Expression of p63 in Hydropic and Molar Gestations

International Nuclear Information System (INIS)

Masood, S.; Kehar, S. I.; Shawana, S.; Aamir, I.

2015-01-01

Objective:To observe the differential expression of p63 in hydropic and molar gestation. Study Design: Cross-sectional analytical study. Place and Duration of Study: Department of Pathology, Basic Medical Sciences Institute, Jinnah Postgraduate and Medical Centre, Karachi, from January 2006 to June 2013. Methodology: Ninety placental biopsies including 30 cases each of hydropic abortions, partial hydatidiform mole and complete hydatidiform mole were analyzed for morphological features and results of immunohistochemical staining. Results were described as frequency. Significance was determined using test of proportions with significance at p < 0.05. Results: Out of 30 cases of hydropic abortion, 6 were negative, 15 were weak, 4 were moderate and 5 showed strong degree of intensity for p63. Out of 30 cases of partial hydatidiform mole, 3 were negative, 2 showed weak, 4 showed moderate and 21 cases showed strong degree of intensity for p63. All 30 cases of complete hydatidiform mole strongly stained for p63. Conclusion: The intensity of staining of p63 was stronger in cases of molar pregnancy as compared to hydropic abortion. There was loss of p63 expression in cytotrophoblastic cells in all abortions. In limited resources settings, where facilities for PCR/FISH and DNA ploidy analysis is not available, the authors advocate p63 in routine clinical practice to provide the most refined diagnosis of hydatidiform moles. (author)

Super-resolution reconstruction in frequency, image, and wavelet domains to reduce through-plane partial voluming in MRI

International Nuclear Information System (INIS)

Gholipour, Ali; Afacan, Onur; Scherrer, Benoit; Prabhu, Sanjay P.; Warfield, Simon K.; Aganj, Iman; Sahin, Mustafa

2015-01-01

Purpose: To compare and evaluate the use of super-resolution reconstruction (SRR), in frequency, image, and wavelet domains, to reduce through-plane partial voluming effects in magnetic resonance imaging. Methods: The reconstruction of an isotropic high-resolution image from multiple thick-slice scans has been investigated through techniques in frequency, image, and wavelet domains. Experiments were carried out with thick-slice T2-weighted fast spin echo sequence on the Academic College of Radiology MRI phantom, where the reconstructed images were compared to a reference high-resolution scan using peak signal-to-noise ratio (PSNR), structural similarity image metric (SSIM), mutual information (MI), and the mean absolute error (MAE) of image intensity profiles. The application of super-resolution reconstruction was then examined in retrospective processing of clinical neuroimages of ten pediatric patients with tuberous sclerosis complex (TSC) to reduce through-plane partial voluming for improved 3D delineation and visualization of thin radial bands of white matter abnormalities. Results: Quantitative evaluation results show improvements in all evaluation metrics through super-resolution reconstruction in the frequency, image, and wavelet domains, with the highest values obtained from SRR in the image domain. The metric values for image-domain SRR versus the original axial, coronal, and sagittal images were PSNR = 32.26 vs 32.22, 32.16, 30.65; SSIM = 0.931 vs 0.922, 0.924, 0.918; MI = 0.871 vs 0.842, 0.844, 0.831; and MAE = 5.38 vs 7.34, 7.06, 6.19. All similarity metrics showed high correlations with expert ranking of image resolution with MI showing the highest correlation at 0.943. Qualitative assessment of the neuroimages of ten TSC patients through in-plane and out-of-plane visualization of structures showed the extent of partial voluming effect in a real clinical scenario and its reduction using SRR. Blinded expert evaluation of image resolution in

Super-resolution reconstruction in frequency, image, and wavelet domains to reduce through-plane partial voluming in MRI

Energy Technology Data Exchange (ETDEWEB)

Gholipour, Ali, E-mail: ali.gholipour@childrens.harvard.edu; Afacan, Onur; Scherrer, Benoit; Prabhu, Sanjay P.; Warfield, Simon K. [Department of Radiology, Boston Children’s Hospital, Boston, Massachusetts 02115 and Harvard Medical School, Boston, Massachusetts 02115 (United States); Aganj, Iman [Radiology Department, Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Boston, Massachusetts 02129 and Harvard Medical School, Boston, Massachusetts 02115 (United States); Sahin, Mustafa [Department of Neurology, Boston Children’s Hospital, Boston, Massachusetts 02115 and Harvard Medical School, Boston, Massachusetts 02115 (United States)

2015-12-15

Purpose: To compare and evaluate the use of super-resolution reconstruction (SRR), in frequency, image, and wavelet domains, to reduce through-plane partial voluming effects in magnetic resonance imaging. Methods: The reconstruction of an isotropic high-resolution image from multiple thick-slice scans has been investigated through techniques in frequency, image, and wavelet domains. Experiments were carried out with thick-slice T2-weighted fast spin echo sequence on the Academic College of Radiology MRI phantom, where the reconstructed images were compared to a reference high-resolution scan using peak signal-to-noise ratio (PSNR), structural similarity image metric (SSIM), mutual information (MI), and the mean absolute error (MAE) of image intensity profiles. The application of super-resolution reconstruction was then examined in retrospective processing of clinical neuroimages of ten pediatric patients with tuberous sclerosis complex (TSC) to reduce through-plane partial voluming for improved 3D delineation and visualization of thin radial bands of white matter abnormalities. Results: Quantitative evaluation results show improvements in all evaluation metrics through super-resolution reconstruction in the frequency, image, and wavelet domains, with the highest values obtained from SRR in the image domain. The metric values for image-domain SRR versus the original axial, coronal, and sagittal images were PSNR = 32.26 vs 32.22, 32.16, 30.65; SSIM = 0.931 vs 0.922, 0.924, 0.918; MI = 0.871 vs 0.842, 0.844, 0.831; and MAE = 5.38 vs 7.34, 7.06, 6.19. All similarity metrics showed high correlations with expert ranking of image resolution with MI showing the highest correlation at 0.943. Qualitative assessment of the neuroimages of ten TSC patients through in-plane and out-of-plane visualization of structures showed the extent of partial voluming effect in a real clinical scenario and its reduction using SRR. Blinded expert evaluation of image resolution in

Volumetric, viscosity, and electrical conductivity properties of aqueous solutions of two n-butylammonium-based protic ionic liquids at several temperatures

International Nuclear Information System (INIS)

Xu, Yingjie

2013-01-01

Highlights: • Densities and viscosities of N4AC + water and N4NO 3 + water mixtures were measured. • Volumetric and viscosity properties were calculated. • Redlich–Kister equation was used to correlate the excess molar volumes and viscosity deviations. • Electrical conductivity was fitted according to the empirical Casteel–Amis equation. • The interactions and structural effects of N4AC or N4NO 3 with water were analyzed. -- Abstract: Densities and viscosities of (n-butylammonium acetate (N4AC) protic ionic liquid + water) and (n-butylammonium nitrate (N4NO 3 ) protic ionic liquid + water) mixtures were measured at T = (293.15, 298.15, 303.15, 308.15, and 313.15) K under atmospheric pressure. Electrical conductivities of the above-mentioned systems were determined at 298.15 K. Excess molar volumes and viscosity deviations were obtained from the experimental results and fitted to the Redlich–Kister equation with satisfactory results. Other volumetric properties, such as apparent molar volumes, partial molar volumes, and excess partial molar volumes were also calculated. The concentration dependence of electrical conductivity was fitted according to the empirical Casteel–Amis equation. Based on the measured and derived properties, the molecular interactions and structural factors in the above-mentioned systems were discussed