Effect of phosphorus on the density and molar volume of Al–Si alloy without solidification shrinkage

2021 ◽  
Vol 112 (10) ◽  
pp. 782-786
Author(s):  
Bo Dang ◽  
Zengyun Jian ◽  
Junfeng Xu
Keyword(s):  
Molar Volume ◽  
Thermophysical Properties ◽  
Liquidus Temperature ◽  
Shrinkage Rate ◽  
Negative Deviation ◽  
Solidification Shrinkage ◽  
Eutectic Transformation ◽  
Vegard’S Law ◽  
Inflection Points ◽  
Starting Point

Abstract The Al–Si alloys exhibit many unique properties, but not enough work has been dedicated to their thermophysical properties. In this work, the effect of phosphorus modifier on the density, molar volume and solidification shrinkage rate of Al-25% Si alloys was investigated by using the indirect Archimedes method. The results show that both density–temperature and molar volume–temperature curves show three inflection points: the liquidus temperature point, the eutectic transformation starting point and the finishing point. The density of the solidus linearly decreases and that of the liquidus linearly increases with phosphorus modifier content. Compared with Vegard’s law, the molar volumes show a negative deviation. Finally, the solidification shrinkage rate is calculated from the densities of solidus and liquidus.

scholarly journals Thermophysical properties of biofuel components derived from biomass

2016 ◽  
Author(s):  
◽  
Mbalenhle B. Nduli
Keyword(s):  
Refractive Index ◽  
Molar Volume ◽  
Binary Mixtures ◽  
Thermophysical Properties ◽  
Excess Molar Volume ◽  
Excess Molar Volumes ◽  
Isentropic Compressibility ◽  
Lorenz Equation ◽  
Molar Volumes ◽  
Increasing Temperature

The thermophysical properties of the binary mixtures containing biofuel components derived from biomass were determined. Experimental densities, speed of sound, and refractive indices for the binary mixtures (methanol or 1-ethyl-3-methylimidazolium acetate [EMIM][OAc] + furfural or furfuryl alcohol ) were measured at T = (298.15, 303.15, 308.15, 313.15 and 318.15) K. From the experimental data, excess molar volume, E m V , isentropic compressibility, s  , molar refractions, R, and deviation in refractive index, Δn, were calculated. The excess molar volumes were found to be negative for all systems studied. The isentropic compressibility were found to be both positive for the whole composition and temperature range and increases slightly with increasing temperature. The deviation in refractive index was positive over the whole composition range. The obtained values of excess molar volumes and changes of refractive index on mixing were satisfactorily correlated by the Redlich–Kister equation. The Lorentz–Lorenz equation was applied to predict the density and calculate the excess molar volume of the binary mixtures.

scholarly journals Converging Newton’s Method With An Inflection Point of A Function

2017 ◽  
Vol 13 (2) ◽  
pp. 73
Author(s):  
Ridwan Pandiya ◽  
Ismail Bin Mohd
Keyword(s):  
Iterative Method ◽  
Newton’S Method ◽  
Newton's Method ◽  
Inflection Point ◽  
Initial Point ◽  
One Dimensional ◽  
Root Finding ◽  
Inflection Points ◽  
Starting Point ◽  
The Relationship

For long periods of time, mathematics researchers struggled in obtaining the appropriate starting point when implementing root finding methods, and one of the most famous and applicable is Newton’s method. This iterative method produces sequence that converges to a desired solution with the assumption that the starting point is close enough to a solution. The word “close enough” indicates that we actually do not have any idea how close the initial point needed so that this point can bring into a convergent iteration. This paper comes to answer that question through analyzing the relationship between inflection points of one-dimensional non-linear function with the convergence of Newton’s method. Our purpose is to illustrate that the neighborhood of an inflection point of a function never fails to bring the Newton’s method convergent to a desired solution

Towards a balanced view of innovations

2016 ◽  
Vol 54 (2) ◽  
pp. 441-454 ◽  
Author(s):  
Christiane Prange ◽  
Bodo B. Schlegelmilch
Keyword(s):  
Empirical Research ◽  
Design Methodology ◽  
Punctuated Equilibrium ◽  
Punctuated Equilibrium Theory ◽  
Comprehensive Investigation ◽  
Content Type ◽  
Inflection Points ◽  
Starting Point ◽  
Managerial Implications ◽  
Practical Implications

Purpose – Based on theoretical input from punctuated equilibrium theory and the exploration vs exploitation paradigm, a set of innovation drivers and propositions is developed. The purpose of this paper is to present a starting point for a more comprehensive investigation of companies’ innovation trajectories towards balance. Design/methodology/approach – The paper builds on a thorough analysis of the literature and suggests the notion of “strategic inflection points” (SIPs). These points are supposed to mark the transgression between innovation types as reflected in respective performance enhancements. Findings – The propositions developed in this paper serve as a basis for further understanding and for subsequent empirical research. Practical implications – Managerial implications relate to the understanding that companies need to balance innovation types in order to increase performance. Originality/value – This paper discusses a variety of innovation types and suggests the notion of SIPs.

scholarly journals Optical Properties, Excess Volume Prediction from Refractive Index and Intermolecular Interactions in Dibutylamine + Isomeric Butanol

2021 ◽  
Vol 33 (6) ◽  
pp. 1287-1293
Author(s):  
Kavitha Kumari ◽  
Sanjeev Maken
Keyword(s):  
Refractive Index ◽  
Optical Properties ◽  
Standard Deviation ◽  
Molar Volume ◽  
Binary Mixtures ◽  
Co2 Capture ◽  
Thermophysical Properties ◽  
Excess Molar Volume ◽  
Excess Volume ◽  
Refractive Index Data

The alkyl or alkanol amines are widely used as absorbent for CO2 capture owing to interaction between amines and CO2. In order to increase the CO2 loading in amine based absorbents, blending of amine with alkanol may be one option. As thermophysical properties of of utmost importance in designing, in present work, the refractive index of dibutylamine (DBA) and isomeric butanol as well as their binary mixtures at 298.15 K to 308.15 K were measured. The Δn are found positive for DBA + isomeric butanol mixtures. The Δn values were correlated with Redlich-Kister polynomial. The refractive index data were also predicted by various correlations and results were expressed in terms of standard deviation. The Δn values were also employed to calculate the excess molar volume of the present binary mixtures. Further Δn data analysed in terms of intermolecular interaction among DBA (1) + isomeric butanol (2) mixtures.

Molar Volumes in Molten NaBr, RbBr, NaBr-TlBr and RbBr-TlBr

1973 ◽  
Vol 28 (11) ◽  
pp. 1854-1856
Author(s):  
E. R. Buckle ◽  
P. E. Tsaoussoglou
Keyword(s):  
Molar Volume ◽  
Binary Mixtures ◽  
Excess Volume ◽  
Negative Deviation ◽  
Molar Volumes ◽  
Strong Negative Deviation ◽  
Localized Orbital

Densities in molten NaBr and RbBr and molar volumes in their binary mixtures with TlBr are reported. The pyknometric method again gave slightly higher densities (0.1 - 0.2%) than previous Archimedean methods. In the mixtures the excess volume is no greater than ±1% but its variation with composition and temperature broadly resembles that in the MX-TIX systems reported previously. A relationship is apparent between the overall trend in the molar volume with composition and temperature and the variation in the Tl-X overlap by nmr. Together with the stoichiometry, this suggests that in the region of strong negative deviation coordination is high and localized orbital overlap low between cations and anions.

scholarly journals Converging Newton’s Method With An Inflection Point of A Function

2017 ◽  
Vol 13 (2) ◽  
pp. 73
Author(s):  
Ridwan Pandiya ◽  
Ismail Bin Mohd
Keyword(s):  
Iterative Method ◽  
Newton’S Method ◽  
Newton's Method ◽  
Inflection Point ◽  
Initial Point ◽  
One Dimensional ◽  
Root Finding ◽  
Inflection Points ◽  
Starting Point ◽  
The Relationship

For long periods of time, mathematics researchers struggled in obtaining the appropriate starting point when implementing root finding methods, and one of the most famous and applicable is Newton’s method. This iterative method produces sequence that converges to a desired solution with the assumption that the starting point is close enough to a solution. The word “close enough” indicates that we actually do not have any idea how close the initial point needed so that this point can bring into a convergent iteration. This paper comes to answer that question through analyzing the relationship between inflection points of one-dimensional non-linear function with the convergence of Newton’s method. Our purpose is to illustrate that the neighborhood of an inflection point of a function never fails to bring the Newton’s method convergent to a desired solution

Density of Ni-Co-Al Ternary Alloys in Liquid States Measured by a Modified Pycnometric Method

2007 ◽  
Vol 546-549 ◽  
pp. 1339-1344 ◽  
Author(s):  
Liang Fang ◽  
F. Xiao ◽  
S.F. Zhang ◽  
L.C. Yang ◽  
L.C. Yang ◽  
...  
Keyword(s):  
Molar Volume ◽  
Sessile Drop ◽  
Ternary Alloys ◽  
Aluminum Concentration ◽  
Al Alloy ◽  
Maximum Difference ◽  
Negative Deviation ◽  
Liquid States ◽  
Increasing Temperature ◽  
The Ideal

The density of Ni-Co-Al ternary alloys with a relative fixed mole ratio of Ni/Co(xNi:xCo≈86:14) and aluminum concentration change from 0 to 10% mass fraction in liquid states were measured by a modified pycnometric method(MPM). It was found that the density of the liquid Ni-Co-Al alloy decreases with increasing temperature, Al concentration and the ratio of Al concentration to Ni concentration in the alloy. The temperature coefficient of density changes with increasing the Al concentration or the ratio of Al concentration to Ni concentration in the ternary alloys. The measured densities by MPM were comparable with that by the modified sessile drop method, the maximum difference of density between them was about ±0.56%. The molar volume of liquid Ni-Co-Al alloy increases with increasing temperature and changed with increasing Al concentration. And the partial molar volume of aluminum in Ni-Co-Al alloy was calculated approximately. The molar volume of liquid Ni-Co-Al ternary alloy determined in the present work shows a negative deviation from the ideal linear molar volume.

scholarly journals Thermodynamic properties of the dodecylbenzenesulfonic acid-acetone binary liquid mixture using a modified flory theory

2018 ◽  
Vol 20 (1) ◽  
pp. 30
Author(s):  
Ali A Jazie
Keyword(s):  
Molar Volume ◽  
Mole Fraction ◽  
Excess Molar Volume ◽  
Chemical Engineering ◽  
Liquid Mixture ◽  
Binary Liquid Mixture ◽  
Maximum Deviation ◽  
Negative Deviation ◽  
Temperature Range ◽  
Binary Liquid

<p>Prigogine–Flory–Patterson (P-F-P) theory was applied for the correlation the experimental data of excess molar volume for the binary liquid mixture of DBSA-Acetone at the temperature range of (293.15-303.15 K). The three contribution terms (pressure, interaction and free volume) in the P-F-P equation were compared with the total effect of P-F-P equation. A positive excess molar volume were obtained at all the range of mole fraction and at all the temperatures. The maximum value of excess molar volume was positioned at the 0.4 mole fraction. Eyring-Flory-Huggins theory was found useful in the estimation of the viscosity deviation variation with mole fraction at the same temperature range. A negative deviation was found in the viscosity for all the range of temperature and mole fraction. The maximum deviation in the viscosity was found at the mole fraction of 0.4. The increase in the negative deviation values with temperature was interpreted as a result of the decrease in the attractive forces between the like molecules.</p><p>Chemical Engineering Research Bulletin 20(2018) 30-35</p>

Crystal structure images of large gold clusters and growing crystals by HRTEM

1984 ◽  
Vol 42 ◽  
pp. 428-429
Author(s):  
L.R. Wallenberg ◽  
J.-O. Bovin ◽  
G. Schmid
Keyword(s):  
Crystal Structure ◽  
Nucleation And Growth ◽  
Close Packing ◽  
Gold Clusters ◽  
Molecular Weight Determination ◽  
Growth Mechanisms ◽  
Starting Point ◽  
Different Types ◽  
Nucleation And Growth Mechanisms ◽  
Points Of View

Metallic clusters are interesting from various points of view, e.g. as a mean of spreading expensive catalysts on a support, or following heterogeneous and homogeneous catalytic events. It is also possible to study nucleation and growth mechanisms for crystals with the cluster as known starting point.Gold-clusters containing 55 atoms were manufactured by reducing (C6H5)3PAuCl with B2H6 in benzene. The chemical composition was found to be Au9.2[P(C6H5)3]2Cl. Molecular-weight determination by means of an ultracentrifuge gave the formula Au55[P(C6H5)3]Cl6 A model was proposed from Mössbauer spectra by Schmid et al. with cubic close-packing of the 55 gold atoms in a cubeoctahedron as shown in Fig 1. The cluster is almost completely isolated from the surroundings by the twelve triphenylphosphane groups situated in each corner, and the chlorine atoms on the centre of the 3x3 square surfaces. This gives four groups of gold atoms, depending on the different types of surrounding.

Two isoprenylated flavonoids from Dorstenia psilurus activate AMPK, stimulate glucose uptake, inhibit glucose production and lower glycemia

2019 ◽  
Vol 476 (24) ◽  
pp. 3687-3704 ◽  
Author(s):  
Aphrodite T. Choumessi ◽  
Manuel Johanns ◽  
Claire Beaufay ◽  
Marie-France Herent ◽  
Vincent Stroobant ◽  
...  
Keyword(s):  
Glucose Uptake ◽  
Human Cancer ◽  
Glucose Production ◽  
Liver Mitochondria ◽  
New Drugs ◽  
Structural Isomer ◽  
Rat Liver Mitochondria ◽  
Ionization Mass ◽  
Ampk Activation ◽  
Starting Point

Root extracts of a Cameroon medicinal plant, Dorstenia psilurus, were purified by screening for AMP-activated protein kinase (AMPK) activation in incubated mouse embryo fibroblasts (MEFs). Two isoprenylated flavones that activated AMPK were isolated. Compound 1 was identified as artelasticin by high-resolution electrospray ionization mass spectrometry and 2D-NMR while its structural isomer, compound 2, was isolated for the first time and differed only by the position of one double bond on one isoprenyl substituent. Treatment of MEFs with purified compound 1 or compound 2 led to rapid and robust AMPK activation at low micromolar concentrations and increased the intracellular AMP:ATP ratio. In oxygen consumption experiments on isolated rat liver mitochondria, compound 1 and compound 2 inhibited complex II of the electron transport chain and in freeze–thawed mitochondria succinate dehydrogenase was inhibited. In incubated rat skeletal muscles, both compounds activated AMPK and stimulated glucose uptake. Moreover, these effects were lost in muscles pre-incubated with AMPK inhibitor SBI-0206965, suggesting AMPK dependency. Incubation of mouse hepatocytes with compound 1 or compound 2 led to AMPK activation, but glucose production was decreased in hepatocytes from both wild-type and AMPKβ1−/− mice, suggesting that this effect was not AMPK-dependent. However, when administered intraperitoneally to high-fat diet-induced insulin-resistant mice, compound 1 and compound 2 had blood glucose-lowering effects. In addition, compound 1 and compound 2 reduced the viability of several human cancer cells in culture. The flavonoids we have identified could be a starting point for the development of new drugs to treat type 2 diabetes.

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