A new liquid binary cyclohexane - phenol mixture was prepared. The dynamic shear viscosity coefficients of this liquid mixture, for different phenol concentrations and temperatures, were investigated by capillary viscometer made from glass. The dynamic shear viscosity showed an anomaly close to the critical temperature 푇푐 = 17.0 ℃. The anomaly behavior was observed at critical weight concentration of phenol, 푥푐 = 2.70 %. At temperatures above critical one, the experimental data were fitted using mode Coupling Theory. It was found that the dynamic shear viscosity non-critical background had a value of 휂0 = 0.8174 cP. Also, using a pycnometer of 10 ml, density measurements were performed. The expected law for mass density above critical temperature was the power law. The noncritical mass density part was found to have a value of 휌0 = 0.7357 푔푚 푐푚3 . In addition, The isobaric thermal expansion coefficient at critical temperature (훼푝푐) was also deduced and found to have a value of 2.07 × 10−6 ℃−1 . Finally, the derivative of critical temperature with respect to pressure (푇푐 ′ ) was found to have a value 1.22 × 10−4 퐾 푃푎 .
This document discusses key concepts in chemical kinetics including:
1) Chemical kinetics deals with the rates of chemical reactions and their mechanisms.
2) The rate of a reaction is defined as the decrease in reactant concentration or increase in product concentration over time.
3) The order of a reaction refers to the power to which the concentration of a reactant is raised in the rate law expression.
Concept of rate of reaction.
Factors effecting rate of reaction.
Concept of order of reaction.
Methods for the determination of order of reaction.
Pharmaceutical importance and applications of rate and order of reaction.
The document discusses chemical kinetics and factors that affect the rate of chemical reactions. It provides an introduction to kinetics, defines reaction rates, outlines rate laws and rate constants, and describes six key factors that influence reaction rates: the nature of reactants and products, concentration, temperature, catalysts, surface area, and light radiation. Specific examples are given to illustrate concepts like reaction stoichiometry and how different factors alter reaction rates.
1. The document discusses kinetics and factors that affect the rate of chemical reactions such as concentration, temperature, surface area, and catalysts.
2. It explains concepts such as the rate of reaction, instantaneous rate, rate laws, reaction order, molecularity, activation energy, and the Arrhenius equation.
3. Examples of zero-order, first-order, and second-order reactions are provided along with explanations of pseudo-first order and pseudo-second order reactions that can occur when one reactant is in excess.
This set of powerpoint slides revolves around the topic of chemical kinetics. Are you looking for notes on factors affecting speed of reaction? Looking for foolproof ways to calculate the rate of reaction? You have come to the right place!
Excellent as a chemistry study material and as an examination revision tool :) A short and sweet O level topic guide with the things you need to ace in chemical kinetics!
1. The document discusses chemical kinetics, which is the study of reaction rates and their mechanisms. It defines the average and instantaneous rates of reactions in terms of changes in reactant or product concentrations over time.
2. Reaction rates depend on factors like concentration, temperature, and catalysts. The rate law expresses how the rate of a reaction varies with changes in concentration. Generally, reaction rates increase with higher reactant concentrations and decrease over time as concentrations decrease.
3. For reactions where stoichiometric coefficients are not equal to one, the rates of appearance/disappearance must be divided by the appropriate coefficients to make the rates equal. This allows rates to be expressed consistently in terms of changes in concentrations of
This unit includes: rate of a chemical reaction, graphs,, unit of rate, average rate& instantaneous rate,. factors influuncing rate of a reaction, Rate expression & rate constant, Order & molecularity of a reaction,, initiall rate method & integrated rate law equations, numerical problems,, Half life period, Pseudo first order reaction, Temperature of rate of reaction, Activation energy, collision frequency & effective collision, Collision theory, Arrhenius equation,, effect of catalyst on rate of reaction, numerical problems
This document discusses key concepts in chemical kinetics including:
1) Chemical kinetics deals with the rates of chemical reactions and their mechanisms.
2) The rate of a reaction is defined as the decrease in reactant concentration or increase in product concentration over time.
3) The order of a reaction refers to the power to which the concentration of a reactant is raised in the rate law expression.
Concept of rate of reaction.
Factors effecting rate of reaction.
Concept of order of reaction.
Methods for the determination of order of reaction.
Pharmaceutical importance and applications of rate and order of reaction.
The document discusses chemical kinetics and factors that affect the rate of chemical reactions. It provides an introduction to kinetics, defines reaction rates, outlines rate laws and rate constants, and describes six key factors that influence reaction rates: the nature of reactants and products, concentration, temperature, catalysts, surface area, and light radiation. Specific examples are given to illustrate concepts like reaction stoichiometry and how different factors alter reaction rates.
1. The document discusses kinetics and factors that affect the rate of chemical reactions such as concentration, temperature, surface area, and catalysts.
2. It explains concepts such as the rate of reaction, instantaneous rate, rate laws, reaction order, molecularity, activation energy, and the Arrhenius equation.
3. Examples of zero-order, first-order, and second-order reactions are provided along with explanations of pseudo-first order and pseudo-second order reactions that can occur when one reactant is in excess.
This set of powerpoint slides revolves around the topic of chemical kinetics. Are you looking for notes on factors affecting speed of reaction? Looking for foolproof ways to calculate the rate of reaction? You have come to the right place!
Excellent as a chemistry study material and as an examination revision tool :) A short and sweet O level topic guide with the things you need to ace in chemical kinetics!
1. The document discusses chemical kinetics, which is the study of reaction rates and their mechanisms. It defines the average and instantaneous rates of reactions in terms of changes in reactant or product concentrations over time.
2. Reaction rates depend on factors like concentration, temperature, and catalysts. The rate law expresses how the rate of a reaction varies with changes in concentration. Generally, reaction rates increase with higher reactant concentrations and decrease over time as concentrations decrease.
3. For reactions where stoichiometric coefficients are not equal to one, the rates of appearance/disappearance must be divided by the appropriate coefficients to make the rates equal. This allows rates to be expressed consistently in terms of changes in concentrations of
This unit includes: rate of a chemical reaction, graphs,, unit of rate, average rate& instantaneous rate,. factors influuncing rate of a reaction, Rate expression & rate constant, Order & molecularity of a reaction,, initiall rate method & integrated rate law equations, numerical problems,, Half life period, Pseudo first order reaction, Temperature of rate of reaction, Activation energy, collision frequency & effective collision, Collision theory, Arrhenius equation,, effect of catalyst on rate of reaction, numerical problems
This document discusses chemical kinetics, which is the study of reaction rates. It defines kinetics and lists some of its applications in pharmaceutical sciences like drug stability, dissolution, and pharmacokinetics. It then describes the molecularity and common types of reactions like unimolecular, bimolecular, and termolecular. The rest of the document discusses factors that influence reaction rates such as temperature, solvents, ionic strength, and dielectric constant. It also covers reaction orders, methods for determining order, and concepts like half-life. Catalysis is mentioned as another factor that can increase reaction rates.
Dr. Mohammed Hamoda - Composting of Mixtures of Municipal Solid Wastes and Se...Hudhaib Al-Allatti
1. The document discusses composting mixtures of municipal solid waste and sewage sludge in Kuwait to deal with increasing waste quantities and limited landfill space.
2. Experiments were conducted using in-vessel composting units to process different mixtures of waste at controlled temperatures. Volatile solids and organic carbon reductions were evaluated.
3. Co-composting mixtures of waste was more effective than individual waste streams, with up to 38% reduction in volatile solids over 30 days. Controlled-temperature in-vessel composting also performed better than outdoor windrows.
Chemical kinetics is the study of reaction rates and mechanisms. The rate of a reaction describes how quickly reactants are converted to products and is affected by factors like concentration, temperature, catalysts, and surface area. The rate law expresses the reaction rate in terms of reactant concentrations and can be used to determine the order of a reaction. Integrated rate laws relate concentration over time and are used to calculate quantities like half-life, the time for half the reactants to be consumed.
Difference between order and molecularity of a reaction 2310Prawin Ddy
The order of a reaction refers to the sum of the powers of the concentration terms in the rate equation. It represents the number of molecules or atoms involved in the rate determining step. The document discusses zero, first, second, and third order reactions, providing examples and equations for determining the rate constant and half-life for each order. Molecularity refers to the actual number of reactant species involved in the elementary reaction step and can only be 1, 2, or 3, whereas order is a measurable property determined from the rate equation.
The effect of dielectric constant on the kinetics of reaction between plasm...Alexander Decker
This document summarizes a study that investigated the effect of increasing ethanol concentration on the rate of reaction between plasma albumin and formaldehyde. The rate constant was determined at various dielectric constants and temperatures by measuring absorption in ethanol-water mixtures containing plasma albumin and formaldehyde. The rate constant decreased with increasing ethanol concentration. Activation energy and other thermodynamic parameters also decreased with decreasing dielectric constant (increasing ethanol proportion). A linear relationship was observed between the log of the rate constant and the reciprocal of dielectric constant, indicating three mechanistic changes. The rate increased in water but decreased in ethanol, suggesting reaction rates were slowed by progressive ethanol addition. In conclusion, the reaction was second-order and its rate decreased with increasing ethanol concentration in accordance with
The International Journal of Engineering & Science is aimed at providing a platform for researchers, engineers, scientists, or educators to publish their original research results, to exchange new ideas, to disseminate information in innovative designs, engineering experiences and technological skills. It is also the Journal's objective to promote engineering and technology education. All papers submitted to the Journal will be blind peer-reviewed. Only original articles will be published.
This document discusses kinetics and order of reactions. It defines zero, first, and second order reactions based on how the rate of reaction depends on the concentrations of reactants. Zero order reactions have rates independent of concentrations. First order rates depend on one concentration. Second order can depend on two concentrations. Methods for determining reaction order include substitution, initial rates, plotting data, and half-life determination. Complex reactions with opposing, consecutive, or parallel pathways are also discussed.
Acoustical and Thermodynamical Studies in Ternary Mixtures of Ethylene Glycol...IRJET Journal
This document discusses a study on the acoustical and thermodynamic properties of ternary mixtures of ethylene glycol, glycerol, and octanol at 303.15K. The ultrasonic velocity, density, and viscosity were measured for mixtures with varying compositions. These measurements were used to calculate various thermodynamic parameters, including adiabatic compressibility, intermolecular free length, relaxation time, acoustic impedance, and bulk modulus. The values of these parameters were found to vary with composition, indicating the nature of molecular interactions present in the ternary mixtures. Tables of the measured properties and calculated parameters are provided.
The document discusses rate of reaction and factors that affect it. It defines rate of reaction as the change in amount of reactants or products per unit time. It describes several factors that affect rate based on collision theory, including surface area, concentration, temperature, catalysts, and pressure. It gives examples of how scientific understanding of rate of reaction enhances quality of life, such as refrigeration, pressure cooking, cutting food into smaller pieces, making margarine, and burning coal.
This document provides an overview of chemical kinetics and reaction rates. It discusses topics such as reaction rate, rate laws, reaction orders, rate constants, factors that affect reaction rates like temperature, catalysts, and enzyme kinetics. Specific examples are also provided to illustrate concepts like first-order and second-order reactions, reaction mechanisms, and industrial catalytic processes like the Haber process and catalytic converters.
Here are the key points about pseudo-first order reactions:
- A pseudo-first order reaction is a reaction that follows first-order kinetics even though it may involve more than one reactant.
- This occurs when the concentration of one reactant is in large excess compared to the other reactant(s). The excess reactant can then be considered constant.
- Under these conditions, the rate law will be first-order with respect to the limiting reactant only. The excess reactant does not appear in the rate law expression.
- Examples include bimolecular reactions where one reactant is in large excess, or reactions catalyzed by an enzyme where the enzyme concentration remains essentially constant.
- The
This document provides an overview of chemical kinetics concepts including:
- Chemical kinetics is the study of reaction rates and how rates are affected by temperature, pressure and reactant concentrations.
- Reaction rates can be expressed using rate laws that show the relationship between rate and reactant concentrations, with each concentration raised to a specific power known as the reaction order.
- Zero, first, second, and third order reactions are discussed along with how their rates, rate constants, and half-lives are calculated from experimental data.
- Pseudo-first and pseudo-second order reactions that appear to be a different order than the true reaction order due to one reactant being in excess are also covered.
11.a new mechanism of sodium zirconate formationAlexander Decker
This document presents a new mechanism for forming sodium zirconate (Na2ZrO3) through the thermal decomposition of sodium acetate (CH3COONa) and zirconium(IV) acetylacetonate (Zr(C5H7O2)4). Thermogravimetric analysis showed the reaction occurs in three significant weight losses. Fourier transform infrared spectroscopy identified gases like CO2 and CO released during the reaction. X-ray diffraction confirmed the product was sodium zirconate. A kinetic study determined the activation energy, pre-exponential factor, and reaction order for each weight loss region using the Arrhenius equation. The proposed mechanism involves three reactions corresponding to the decomposition
The state where the concentrations of all reactants and products remain constant with time.
On the molecular level, there is frantic activity. Equilibrium is not static, but is a highly dynamic situation.
law of mass action-
jA + kB lC + mD
where A, B, C, and D represents chemical species and j, k, l, and m are their coefficient in the balanced equation.
The law of mass action is represented by the equilibrium expression:
The square brackets indicate the concentrations of the chemical species at equilibrium, and K is a constant called the equilibrium constant.
MHD Chemically Reacting and Radiating Nanofluid Flow over a Vertical Cone Emb...IJLT EMAS
In this study, we examine the combined effects of
thermal radiation, chemical reaction on MHD hydromagnetic
boundary layer flow over a vertical cone filled with nanofluid
saturated porous medium under variable properties. The
governing flow, heat and mass transfer equations are
transformed into ordinary differential equations using similarity
variables and are solved numerically by a Galerkin Finite
element method. Numerical results are obtained for
dimensionless velocity, temperature, nanoparticle volume
fraction, as well as the skin friction, local Nusselt and Sherwood
number for the different values of the pertinent parameters
entered into the problem. The effects of various controlling
parameters on these quantities are investigated. Pertinent
results are presented graphically and discussed quantitatively.
The present results are compared with existing results and found
to be good agreement. It is found that the temperature of the
fluid remarkably enhances with the rising values of Brownian
motion parameter (Nb).
Chemical kinetics is the branch of science that deals with the rates of chemical reactions, reaction mechanisms, and factors influencing reaction rates. Industries are interested in chemical kinetics because understanding reaction rates allows them to optimize processes to maximize product formation over time for greater profits. The rate of a reaction is defined as the change in concentration of a reactant or product per unit time. Factors such as temperature, pressure, catalysts, and concentration can influence reaction rates.
The document discusses chemical kinetics, which examines the rates of chemical reactions and how they are influenced by conditions like concentration, temperature, and catalysts. It defines key terms like the rate of reaction, average rate, and instantaneous rate. The rate of reaction depends on factors like the concentrations of reactants, temperature, phase, and presence of catalysts or inhibitors. Reaction rate laws relate the reaction rate to concentrations and determine the order of reactions. Differential and integrated rate equations are also discussed.
Chemical Reaction Engineering studies how reaction rates are affected by temperature, pressure, and reactant concentration. It provides information about reaction mechanisms, speeds, and types that can be used in bioreactor design. Fundamental concepts include reaction rates, rate laws, and rate constants. Reaction rates are defined as changes in molar concentration over time and can be positive for products or negative for reactants. Rate laws relate reaction rates to reactant concentrations and rate constants measure reaction rates when reactants are at unit concentration.
الكيمياء الحركية
Kinetic Chemistry
Chemical kinetics
حركية التفاعل أو الحركية الكيميائية هو العلم الذي يهتم ويختص بدراسة معدل التغير في سرعة التفاعلات الكيميائية والعوامل المؤثرة فيها مثل الضغط ودرجة الحرارة والتركيز وطبيعة العوامل المتفاعلة والعوامل الحفازة أو المثبطة، كما أنها تقوم بوضع نماذج رياضياتية التي توصف خواص التفاعلات الكيميائية.
Thermodynamic behavior of tetrahydrofuron in p dioxane, methylcyclohexane and...eSAT Journals
Abstract The liquid state is intermediate in its properties of solid and gas. There are many attempt to develop a theory of liquid state are based on simple consideration of molecular behaving like hard sphere having attractive forces as perturbative forces. The equation of state for Lenard Jones fluid has been derived in the formation an expression for work, obtained from partition function through perturbation approach and found faithful reproduction of ultrasonic velocity and density data , theoretically at the given temperature. It has been applied to the binary liquid mixtures of tetrahydrofuron in p-dioxane methylcyclohexane and cyclohexanol. There is a close agreement with experimental values. The thermodynamic picture build up in this formulation could be considered as a good representation of molecular cluster in liquid state. Keywords: Ultrasonic velocity, tetrahydrofuron, p-dioxane, methylcyclohexane, cyclohexanol, adiabatic compressibility, molar volume
Thermodynamic behavior of tetrahydrofuron in p dioxane, methylcyclohexane and...eSAT Publishing House
This document summarizes a study on the thermodynamic behavior of tetrahydrofuron liquid mixtures with p-dioxane, methylcyclohexane, and cyclohexanol. The study applies an equation of state model to calculate ultrasonic velocity, density, and other thermodynamic parameters. Close agreement was found between calculated and experimental values, indicating the model provides a good representation of molecular clustering in liquid states. Parameters like minimum potential depth and hard sphere diameter were determined for the pure components and in mixtures.
This document discusses chemical kinetics, which is the study of reaction rates. It defines kinetics and lists some of its applications in pharmaceutical sciences like drug stability, dissolution, and pharmacokinetics. It then describes the molecularity and common types of reactions like unimolecular, bimolecular, and termolecular. The rest of the document discusses factors that influence reaction rates such as temperature, solvents, ionic strength, and dielectric constant. It also covers reaction orders, methods for determining order, and concepts like half-life. Catalysis is mentioned as another factor that can increase reaction rates.
Dr. Mohammed Hamoda - Composting of Mixtures of Municipal Solid Wastes and Se...Hudhaib Al-Allatti
1. The document discusses composting mixtures of municipal solid waste and sewage sludge in Kuwait to deal with increasing waste quantities and limited landfill space.
2. Experiments were conducted using in-vessel composting units to process different mixtures of waste at controlled temperatures. Volatile solids and organic carbon reductions were evaluated.
3. Co-composting mixtures of waste was more effective than individual waste streams, with up to 38% reduction in volatile solids over 30 days. Controlled-temperature in-vessel composting also performed better than outdoor windrows.
Chemical kinetics is the study of reaction rates and mechanisms. The rate of a reaction describes how quickly reactants are converted to products and is affected by factors like concentration, temperature, catalysts, and surface area. The rate law expresses the reaction rate in terms of reactant concentrations and can be used to determine the order of a reaction. Integrated rate laws relate concentration over time and are used to calculate quantities like half-life, the time for half the reactants to be consumed.
Difference between order and molecularity of a reaction 2310Prawin Ddy
The order of a reaction refers to the sum of the powers of the concentration terms in the rate equation. It represents the number of molecules or atoms involved in the rate determining step. The document discusses zero, first, second, and third order reactions, providing examples and equations for determining the rate constant and half-life for each order. Molecularity refers to the actual number of reactant species involved in the elementary reaction step and can only be 1, 2, or 3, whereas order is a measurable property determined from the rate equation.
The effect of dielectric constant on the kinetics of reaction between plasm...Alexander Decker
This document summarizes a study that investigated the effect of increasing ethanol concentration on the rate of reaction between plasma albumin and formaldehyde. The rate constant was determined at various dielectric constants and temperatures by measuring absorption in ethanol-water mixtures containing plasma albumin and formaldehyde. The rate constant decreased with increasing ethanol concentration. Activation energy and other thermodynamic parameters also decreased with decreasing dielectric constant (increasing ethanol proportion). A linear relationship was observed between the log of the rate constant and the reciprocal of dielectric constant, indicating three mechanistic changes. The rate increased in water but decreased in ethanol, suggesting reaction rates were slowed by progressive ethanol addition. In conclusion, the reaction was second-order and its rate decreased with increasing ethanol concentration in accordance with
The International Journal of Engineering & Science is aimed at providing a platform for researchers, engineers, scientists, or educators to publish their original research results, to exchange new ideas, to disseminate information in innovative designs, engineering experiences and technological skills. It is also the Journal's objective to promote engineering and technology education. All papers submitted to the Journal will be blind peer-reviewed. Only original articles will be published.
This document discusses kinetics and order of reactions. It defines zero, first, and second order reactions based on how the rate of reaction depends on the concentrations of reactants. Zero order reactions have rates independent of concentrations. First order rates depend on one concentration. Second order can depend on two concentrations. Methods for determining reaction order include substitution, initial rates, plotting data, and half-life determination. Complex reactions with opposing, consecutive, or parallel pathways are also discussed.
Acoustical and Thermodynamical Studies in Ternary Mixtures of Ethylene Glycol...IRJET Journal
This document discusses a study on the acoustical and thermodynamic properties of ternary mixtures of ethylene glycol, glycerol, and octanol at 303.15K. The ultrasonic velocity, density, and viscosity were measured for mixtures with varying compositions. These measurements were used to calculate various thermodynamic parameters, including adiabatic compressibility, intermolecular free length, relaxation time, acoustic impedance, and bulk modulus. The values of these parameters were found to vary with composition, indicating the nature of molecular interactions present in the ternary mixtures. Tables of the measured properties and calculated parameters are provided.
The document discusses rate of reaction and factors that affect it. It defines rate of reaction as the change in amount of reactants or products per unit time. It describes several factors that affect rate based on collision theory, including surface area, concentration, temperature, catalysts, and pressure. It gives examples of how scientific understanding of rate of reaction enhances quality of life, such as refrigeration, pressure cooking, cutting food into smaller pieces, making margarine, and burning coal.
This document provides an overview of chemical kinetics and reaction rates. It discusses topics such as reaction rate, rate laws, reaction orders, rate constants, factors that affect reaction rates like temperature, catalysts, and enzyme kinetics. Specific examples are also provided to illustrate concepts like first-order and second-order reactions, reaction mechanisms, and industrial catalytic processes like the Haber process and catalytic converters.
Here are the key points about pseudo-first order reactions:
- A pseudo-first order reaction is a reaction that follows first-order kinetics even though it may involve more than one reactant.
- This occurs when the concentration of one reactant is in large excess compared to the other reactant(s). The excess reactant can then be considered constant.
- Under these conditions, the rate law will be first-order with respect to the limiting reactant only. The excess reactant does not appear in the rate law expression.
- Examples include bimolecular reactions where one reactant is in large excess, or reactions catalyzed by an enzyme where the enzyme concentration remains essentially constant.
- The
This document provides an overview of chemical kinetics concepts including:
- Chemical kinetics is the study of reaction rates and how rates are affected by temperature, pressure and reactant concentrations.
- Reaction rates can be expressed using rate laws that show the relationship between rate and reactant concentrations, with each concentration raised to a specific power known as the reaction order.
- Zero, first, second, and third order reactions are discussed along with how their rates, rate constants, and half-lives are calculated from experimental data.
- Pseudo-first and pseudo-second order reactions that appear to be a different order than the true reaction order due to one reactant being in excess are also covered.
11.a new mechanism of sodium zirconate formationAlexander Decker
This document presents a new mechanism for forming sodium zirconate (Na2ZrO3) through the thermal decomposition of sodium acetate (CH3COONa) and zirconium(IV) acetylacetonate (Zr(C5H7O2)4). Thermogravimetric analysis showed the reaction occurs in three significant weight losses. Fourier transform infrared spectroscopy identified gases like CO2 and CO released during the reaction. X-ray diffraction confirmed the product was sodium zirconate. A kinetic study determined the activation energy, pre-exponential factor, and reaction order for each weight loss region using the Arrhenius equation. The proposed mechanism involves three reactions corresponding to the decomposition
The state where the concentrations of all reactants and products remain constant with time.
On the molecular level, there is frantic activity. Equilibrium is not static, but is a highly dynamic situation.
law of mass action-
jA + kB lC + mD
where A, B, C, and D represents chemical species and j, k, l, and m are their coefficient in the balanced equation.
The law of mass action is represented by the equilibrium expression:
The square brackets indicate the concentrations of the chemical species at equilibrium, and K is a constant called the equilibrium constant.
MHD Chemically Reacting and Radiating Nanofluid Flow over a Vertical Cone Emb...IJLT EMAS
In this study, we examine the combined effects of
thermal radiation, chemical reaction on MHD hydromagnetic
boundary layer flow over a vertical cone filled with nanofluid
saturated porous medium under variable properties. The
governing flow, heat and mass transfer equations are
transformed into ordinary differential equations using similarity
variables and are solved numerically by a Galerkin Finite
element method. Numerical results are obtained for
dimensionless velocity, temperature, nanoparticle volume
fraction, as well as the skin friction, local Nusselt and Sherwood
number for the different values of the pertinent parameters
entered into the problem. The effects of various controlling
parameters on these quantities are investigated. Pertinent
results are presented graphically and discussed quantitatively.
The present results are compared with existing results and found
to be good agreement. It is found that the temperature of the
fluid remarkably enhances with the rising values of Brownian
motion parameter (Nb).
Chemical kinetics is the branch of science that deals with the rates of chemical reactions, reaction mechanisms, and factors influencing reaction rates. Industries are interested in chemical kinetics because understanding reaction rates allows them to optimize processes to maximize product formation over time for greater profits. The rate of a reaction is defined as the change in concentration of a reactant or product per unit time. Factors such as temperature, pressure, catalysts, and concentration can influence reaction rates.
The document discusses chemical kinetics, which examines the rates of chemical reactions and how they are influenced by conditions like concentration, temperature, and catalysts. It defines key terms like the rate of reaction, average rate, and instantaneous rate. The rate of reaction depends on factors like the concentrations of reactants, temperature, phase, and presence of catalysts or inhibitors. Reaction rate laws relate the reaction rate to concentrations and determine the order of reactions. Differential and integrated rate equations are also discussed.
Chemical Reaction Engineering studies how reaction rates are affected by temperature, pressure, and reactant concentration. It provides information about reaction mechanisms, speeds, and types that can be used in bioreactor design. Fundamental concepts include reaction rates, rate laws, and rate constants. Reaction rates are defined as changes in molar concentration over time and can be positive for products or negative for reactants. Rate laws relate reaction rates to reactant concentrations and rate constants measure reaction rates when reactants are at unit concentration.
الكيمياء الحركية
Kinetic Chemistry
Chemical kinetics
حركية التفاعل أو الحركية الكيميائية هو العلم الذي يهتم ويختص بدراسة معدل التغير في سرعة التفاعلات الكيميائية والعوامل المؤثرة فيها مثل الضغط ودرجة الحرارة والتركيز وطبيعة العوامل المتفاعلة والعوامل الحفازة أو المثبطة، كما أنها تقوم بوضع نماذج رياضياتية التي توصف خواص التفاعلات الكيميائية.
Thermodynamic behavior of tetrahydrofuron in p dioxane, methylcyclohexane and...eSAT Journals
Abstract The liquid state is intermediate in its properties of solid and gas. There are many attempt to develop a theory of liquid state are based on simple consideration of molecular behaving like hard sphere having attractive forces as perturbative forces. The equation of state for Lenard Jones fluid has been derived in the formation an expression for work, obtained from partition function through perturbation approach and found faithful reproduction of ultrasonic velocity and density data , theoretically at the given temperature. It has been applied to the binary liquid mixtures of tetrahydrofuron in p-dioxane methylcyclohexane and cyclohexanol. There is a close agreement with experimental values. The thermodynamic picture build up in this formulation could be considered as a good representation of molecular cluster in liquid state. Keywords: Ultrasonic velocity, tetrahydrofuron, p-dioxane, methylcyclohexane, cyclohexanol, adiabatic compressibility, molar volume
Thermodynamic behavior of tetrahydrofuron in p dioxane, methylcyclohexane and...eSAT Publishing House
This document summarizes a study on the thermodynamic behavior of tetrahydrofuron liquid mixtures with p-dioxane, methylcyclohexane, and cyclohexanol. The study applies an equation of state model to calculate ultrasonic velocity, density, and other thermodynamic parameters. Close agreement was found between calculated and experimental values, indicating the model provides a good representation of molecular clustering in liquid states. Parameters like minimum potential depth and hard sphere diameter were determined for the pure components and in mixtures.
Influence of Tetra Alkyl Ammonium Cation and Temperature on Molecular Interac...IOSRJAC
Ultrasonic velocity (u), density (ρ), viscosity (η) and related acoustical parameters such as adiabatic compressibility (β), free energy (∆G), internal pressure (πi), relaxation time (τ) and acoustic impedance (z) have been computed using standard relation for tetra alkyl ammonium cation (Et4N + , Pr4N + , Bu4N + , and Pen4N + ) in binary liquid mixtures of 1, 4 - Dioxane and N, N – Dimethyl Formamide was prepared of 0.14M on different percentage compositions over the temperature range from 303.15K to 323.15K with the interval of 10K under room pressure to investigate inter - ionic interactions. The densities were measured by Magnetic Float Densitometer. Transport properties provide a deep and meaningful insight of various interactions taking place. It has been observed that the influence of small as well as large alkyl chain length of tetra alkyl ammonium cations (R4N + ), in terms of shape and ionic size with the DMF solvent in the presence of Dioxane, is helpful in investigating the molecular interactions, molecular rearrangement, molecular association etc
Some physicochemical properties such as density, refractive index, solubility, conductance, dissociation constant etc. have been studied for some newly synthesized chalcones in different solvents at 308.15 K.
The document discusses various properties of liquids including intermolecular forces, vapor pressure, boiling point, surface tension, viscosity, refractive index, and optical activity. It describes three main types of intermolecular forces that exist in liquids: dipole-dipole interactions, London forces, and hydrogen bonding. Vapor pressure is defined as the pressure exerted by a liquid's vapor when in equilibrium, and it increases with temperature, affecting the boiling point. Methods for measuring properties like surface tension, viscosity, refractive index, and optical activity are also outlined.
Thermohaline Convection With Variable Viscosityresearchinventy
The problem of double diffusive convection with variable viscosity confined between the two horizontal plates is investigated by the linear stability analysis. The transformed governing equations are numerically solved by using the Galerkin method. We have studied both stationary convection and oscillatory convection. The threshold values of Rayleigh number and wave number are computed and presented for various boundary conditions viz. rigid-rigid (푅/푅), rigid-free (푅/퐹), free-rigid (퐹/푅) and free-free (퐹/퐹) and for different values of physical parameters viz., salinity Rayleigh number푅푠 , Lewis number L, viscosity ratio c and Prandtl number푃푟 . For rigid-rigid boundary conditions we have studied the effect of 푐, 푅푠 on the vertical velocity and temperature eigenfunctions at the onset. It is observed that the salinity concentration stabilizes the dynamical system. The occurrence of co-dimension two bifurcation point(퐶푇푃)is shown for various boundary conditions.
This document discusses a method for calculating the excess viscosity of liquid mixtures without knowing the theoretical viscosity values. Experimental viscosities were measured for water, ethanol-water mixtures, and methanol-water mixtures at 308K using a capillary viscometer. The excess viscosities were then calculated using a modified logarithmic viscosity equation. The excess viscosities for both ethanol-water and methanol-water mixtures were negative over the entire concentration range, with minima around 35-40% water concentration. This indicates a deviation from ideal behavior. The method allows excess viscosity to be determined from experimental data alone without requiring theoretical viscosity values.
The International Journal of Engineering & Science is aimed at providing a platform for researchers, engineers, scientists, or educators to publish their original research results, to exchange new ideas, to disseminate information in innovative designs, engineering experiences and technological skills. It is also the Journal's objective to promote engineering and technology education. All papers submitted to the Journal will be blind peer-reviewed. Only original articles will be published.
Densitometric and viscometric study of diclofenac sodium in aqueous solution ...Alexander Decker
This document summarizes a study that measured the density and viscosity of diclofenac sodium in aqueous solution with and without additives like NaCl, dextrose, KCl, and sodium lactate. The density measurements were used to calculate apparent molar volumes, and viscosity measurements were used to determine Jones-Dole B-coefficients. Results showed that density and viscosity increased with concentration and decreased with increasing temperature. Apparent molar volumes were positive, indicating strong solute-solvent interactions. B-coefficients were negative, showing weak solute-solute interactions. The study analyzed molecular interactions in diclofenac sodium solutions using these simple physical properties.
Activity coefficients at infinite dilution for organic solutes dissolved in t...Bihan Jiang
This document discusses measuring activity coefficients and gas-to-liquid partition coefficients for 45 organic solutes dissolved in two 1,2,3-tris(diethylamino)cyclopenylium based room temperature ionic liquids. Abraham model correlations were derived to predict solute transfer into the ionic liquids from water and the gas phase. The correlations described the observed partition coefficients to within 0.13 log units or less. Measured activity coefficients were used to calculate selectivity values for potential separations like hexane/benzene and hexane/pyridine.
This document summarizes a study that measured the kinetics of carbon dioxide absorption into aqueous solutions of lithium, sodium, and potassium hydroxides and blends of hydroxides and carbonates over a range of temperatures and concentrations. The researchers derived an infinite dilution second order rate constant for the reaction of carbon dioxide with hydroxide ions as an Arrhenius temperature function. They also validated a model for the ionic strength dependency of the second order rate constant using refitted parameters. The model with the new parameters represented the experimental data with less than 12% average absolute relative deviation.
This research article studied the coiling and uncoiling behavior of sodium polystyrenesulfonate (NaPSS) in mixed solvent systems of water and 2-ethoxyethanol at varying temperatures through viscosity measurements. Precise viscosity measurements were taken of NaPSS solutions in water and 2-ethoxyethanol-water mixtures containing different amounts of 2-ethoxyethanol at temperatures from 308.15K to 323.15K. The intramolecular contributions to reduced viscosity and Huggins constants were determined using isoionic dilution to interpret the effects of solvent and temperature on polyelectrolyte conformation and interactions. The results showed that NaPSS chains coiled upon addition of 2-
In this present work we studied the supramolecular interaction of 1-hexyl-3-methylimidazolium hexaflurophosphate(HMIm)PF6with α-cyclodextrin (α-CD) and β-cyclodextrin (β-CD) using various physicochemical method and spectroscopic technique. The formation of inclusion complex of any ionic liquid inside the cyclodextrin affects the physicalchemical properties like solubility, conductivity, surface tension, etc. So from the discrepancy of physicochemical andspectral properties we can confirm the formation inclusion complex. The stoichiometry of host - guest of the inclusion complexes was evaluated from conductivity, surface tensionstudy and Job’s plot from UV-visible spectroscopy. We also calculated the association/binding constant from conductivity, surface tension measurements and Benesi-Hildebrand equation. The infra-red (IR) and 1H NMR spectroscopy also affirm the formation of inclusion complexes however the plausible mode of inclusion was described from 1H NMR and 2D ROESY NMR spectroscopies.
This document summarizes a study on the aggregation behavior of 1-decyl-3-methylimidazolium chloride (C10MeImCl), a surface active ionic liquid, in aqueous solutions both in the absence and presence of sodium carboxymethylcellulose (NaCMC). The aggregation was investigated using techniques like surface tension, conductivity, vapor pressure osmometry and fluorescence measurements. Two characteristic concentrations were identified - critical aggregation concentration and polymer saturation concentration, below which free C10MeImCl micelles do not appear in C10MeImCl-NaCMC solutions. The effects of temperature, NaCMC concentration and bulk solution properties on C10MeImCl self-aggregation were discussed to understand C10MeIm
Some Excess Properties of Ternary Liquid Mixture of Water, Methanol, Ethanol ...paperpublications3
Abstract: Densities and viscosities of ternary liquid mixtures of water, methanol, ethanol of volume by volume ratio of 1:1:1 have been measured at 308.15, 313.15., 318.15, 323.15, 328.15, K .From the density and viscosity data the values of various properties, Excess volume (VE) Excess viscosity (µE) and Excess Gibb’s free energy of activation of flow (ΔGE) have been determined. On the basis of the values of interaction parameters and various excess properties, the nature of molecular interactions between the components of mixtures has been explained.
Thermal Instability of Chemically Reacting Maxwell Fluid in a Horizontal Poro...IJERA Editor
The effect of chemical reaction on the linear stability of a viscoelastic fluid saturated horizontal densely-packed
porous layer is investigated. The viscoelastic properties are given by Maxwell constitutive relations. The porous
layer is cooled from the upper boundary while an adiabatic thermal boundary condition is imposed at the lower
boundary. Linear stability analysis suggests that there is a competition between the processes of viscous
relaxation and thermal diffusion that causes the first convective instability to be oscillatory rather than stationary.
The effect of Deborah number, Darcy-Prandtl number, normalized porosity, and the Frank-Kamenetskii number
on the stability of the system is investigated. Using a weighted residual method we calculate numerically the
convective thresholds for both stationary and oscillatory instability. The effects of viscoelasticity and chemical
reaction on the instability are emphasized. Some existing results are reproduced as the particular cases of the
present study.
The document discusses a study that measured the electrical conductivity of solutions of sodium polystyrenesulphonate in mixed solvent systems of 2-ethoxyethanol and water at varying concentrations, temperatures, and solvent compositions. The results showed that equivalent conductivity increased slightly with decreasing polymer concentration. Equivalent conductivity also increased with increasing temperature and relative permittivity of the solvent system. However, the experimentally determined conductivities did not fully match what was predicted by Manning's counterion condensation theory. Reasons for this discrepancy are discussed.
This document summarizes a study that investigated the effects of water content and temperature on the reaction mechanism and crystal properties of paracetamol produced via reactive crystallization. The researchers first optimized the solubility of paracetamol by examining mixtures of acetic acid and water at different ratios and temperatures. They found the highest solubility occurred with a 7:3 ratio of acetic acid to water at 70°C. Based on this, they determined suitable amounts of reactants for the reaction. Experiments then examined how varying the water content (0, 10g, 20g) or temperature (50-80°C) impacted the reaction kinetics, products, and crystal properties. They found paracetamol form I crystals with 99
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology.
EFFECT OF HIGH MOLECULAR WEIGHT SURFACE ACTIVE AGENT ON HEAT TRANSFER IN POOL...ijiert bestjournal
Boiling is very complex phenomena also it is very e ffective mode of heat transfer. The boiling phenomenon is affected by different method i.e. act ive and passive method. Addition of surface active agent is active way to enhance the heat tran sfer rate. Heat transfer rate enhancement by addition of surface active method is depend on two parameter one is its ionic nature and other is its molecular weight. In this study we are going to understand the effect of high molecular weight surfactant on heat transfer for that purpose we are using Polyethylene glycol having molecular weight 2909.49 g/mol. The experimental re sult shows that addition of PEG in water increases its surface tension and considerably its surface temperature.
Similar to CYCLOHEXANE – PHENOL BINARY LIQUID MIXTURE: BEHAVIOR AND PARAMETERS AT CRITICAL CONDITIONS (20)
New Thermodynamics: A Superior Fit Revised Kinetic Theoryijrap
The accepted kinetic theory forms a basis for modern thermodynamics and is mathematically based upon equipartition and degrees of freedom. It remains plagued with the necessity of numerous degrees of freedom exceptions for it to explain both empirically determined heat capacities and adiabatic indexes. Furthermore, assuming kT/2 per degree of freedom is to accept that a gas molecule possesses a specified energy without providing any clarity concerning that energy’s origins. Energy without an origin contravenes the first law of thermodynamics. This author’s previously published superior fit kinetic theory will be clarified and elaborated upon. This includes showing that this revised kinetic theory is a superior fit to both known heat capacities and adiabatic indexes. Not only is it a superior fit that does not rely upon any exceptions, this author’s kinetic theory also provides insight into the actual sources of a gas molecule’s energy. Furthermore, clarity concerning the difference between isometric (isochoric) and isobaric heat capacities in terms of sensible work will be discussed, along withits likely empirical verification.
On the Unification of Physic and the Elimination of Unbound Quantitiesijrap
This paper supports Descartes' idea of a constant quantity of motion, modernized by Leibniz. Unlike Leibniz, the paper emphasizes that the idea is not realized by forms of energy, but by energy itself. It remains constant regardless of the form, type, or speed of motion, even that of light. Through force, energy is only transformed. Here it is proved that force is its derivative. It exists even at rest, representing the object's minimal energy state. With speed, we achieve its multiplication up to the maximum energy state, from which a maximum force is derived from the object. From this point, corresponding to Planck's Length, we find the value of the force wherever we want. Achieving this removes the differences between various natural forces. The new idea eliminates infinite magnitudes. The process allows the laws to transition from simple to complex forms and vice versa, through differentiation-integration. For this paper, this means achieving the Unification Theory.
Gravity Also Redshifts Light – the Missing Phenomenon That Could Resolve Most...ijrap
In this paper I discover that gravity also redshifts light like the velocity of its source does. When light travels towards a supermassive object, its waves (or photons) undergo continuous stretching, thereby shifting towards lower frequencies. Gravity redshifts light irrespective of whether its source is in motion or static with respect to its observer. An equation is derived for gravitational redshift, and a formula for combined redshift is presented by considering both the velocity, and gravity redshifts. Also explained is how frequencies of electromagnetic spectrum continuously downgrade as a light beam of mix frequencies passes towards a black hole. Further, a clear methodology is provided to figure out whether expansion of the universe is accelerating or decelerating, or alternatively, the universe is contracting.
In this paper I present a new theory that explains as to when and how dark energy is created as mass is destroyed. The theory extends Einstein’s mass energy equation to a more generic form in order to make it work even in high gravity conditions. It also explains why dark energy is created. Further, it is proved Einstein’s mass energy equation holds good only when the destroyed mass has no supermassive object in its close vicinity. The relationship between dark energy and dark matter is unveiled. An extended mathematical form of Einstein’s mass energy equation is derived, based on which the conditions leading to dark energy creation are explained. Three new physical parameters called dark energy discriminant, dark energy radius and dark energy boundary are introduced to facilitate easy understanding of the theory. It is explained in detail that an extremely superdense object has two dark energy boundaries, outer and inner. Mass destroyed only between these two boundaries creates dark energy. Dark energy space, the space between the two aforementioned boundaries, shrouds visible matter in obscurity from optical and electromagnetic telescopes. This theory identifies Gargantuan as a superdense black hole currently creating fresh dark energy, which could be the subject of interest for the astronomical research community having access to sophisticated telescopes, and working on dark energy. It also upholds dark energy and denies the existence of dark matter. Dark matter is nothing but the well-known visible matter positioned in dark energy space. An important relationship is derived between a photon’s frequency and its distance from a black hole to demonstrate the effect of gravity on light. Another important fact revealed by this theory is gravity stretches out light, thereby causing redshift, which is unaccounted in the computation of velocities of outer galaxies. Whether the universe is undergoing accelerated or decelerated expansion, or accelerated contraction can precisely be determined only after accounting for the redshift caused by gravity
International Journal on Soft Computing, Artificial Intelligence and Applicat...ijrap
International Journal on Soft Computing, Artificial Intelligence and Applications (IJSCAI)
is an open access peer-reviewed journal that provides an excellent international forum for sharing
knowledge and results in theory, methodology and applications of Artificial Intelligence, Soft
Computing. The Journal looks for significant contributions to all major fields of the Artificial
Intelligence, Soft Computing in theoretical and practical aspects. The aim of the Journal is to
provide a platform to the researchers and practitioners from both academia as well as industry to
meet and share cutting-edge development in the field.
Authors are solicited to contribute to the journal by submitting articles that illustrate research
results, projects, surveying works and industrial experiences that describe significant advances in
the areas of Database management systems.
SOME THEORETICAL ASPECTS OF HYDROGEN DIFFUSION IN BCC METALS AT LOW TEMPERATURESijrap
Purpose of the work is to discuss some theoretical aspects of the diffusion of hydrogen atoms in the crystal
lattice of BCC metals at low temperatures using the methods of statistical thermodynamics. The values of
the statistical model calculations of H diffusion coefficients in α-Fe, V, Ta, Nb, K are in good agreement
with the experimental data. The statistical model can also explain deviations from the Arrhenius equation
at temperatures 300-100 K in α-Fe, V, Nb and K. It was suggested that thermally activated fast tunnelling
transition of hydrogen atoms through the potential barrier at a temperature below 300 K provides an
almost free movement of H atoms in the α-Fe and V lattice at these temperatures. The results show that
quantum-statistical effects play a decisive role in the H diffusion in BCC metals at low temperatures. Using
the statistical model allows for the prediction of the diffusion coefficient for H in BCC metals at low
temperatures, where it’s necessary to consider quantum effects.
MASSIVE PHOTON HYPOTHESIS OPENS DOORS TO NEW FIELDS OF RESEARCHijrap
1) A massive photon hypothesis is proposed, where the photon mass is directly calculated from kinetic gas theory to be 1.25605 x 10-39 kg.
2) This photon mass explains various experiments like light deflection near the Sun and the gravitational redshift.
3) The photon gas is found to behave as a perfect blackbody and ideal gas, with photons having 6 degrees of freedom.
4) The thermal de Broglie wavelength of this photon gas is calculated to be 1.75967 x 10-3 m, matching the wavelength of the cosmic microwave background radiation.
5) This links the CMB radiation to being continuously generated by the photon gas permeating space, rather than being a relic of
PHENOMENOLOGICAL METHOD REGARDING A THIRD THEORY OF PHYSICS “THE EVENT:THE TH...ijrap
The quest for a third theory uniting macro-cosmos (relativity) and micro-cosmos (quantum mechanics) has coexisted with the denial of feminine/subjective polarity to masculine/objective. The dismissal of electromagnetism as the tension of opposites in quest of inner/outer unity is sourced in the denial of the feminine qualia -- the negative force field attributed to dark energy/dark matter. However, a conversion philosophy sourced in the hieros gamos and signified by the Mobius strip has formulated an integral consciousness methodology producing quantum objects by means of embracing the shadow haunting contemporary physics. This Self-reflecting process integrating subject/object comprises an ontology of kairos as the “quantum leap.” An interdisciplinary quest to create a phenomenological narrative is disclosed via a holistic apparatus of hermeneutics manifesting image/text of a contemporary grail journey. Reflected in this Third space is the sacred reality of autonomous number unifying polarities of feminine/subjective (quality) and objective/masculine (quantity) as new measurement apparatus for the quantum wave collapse.
3rd International Conference on Integrating Technology in Education (ITE 2022)ijrap
3rd International Conference on Integrating Technology in Education (ITE 2022) This forum also aims to provide a platform for exchanging ideas in new emerging trends that needs more focus and exposure and will attempt to publish proposals that strengthen our goals.
A SPECIAL RELATIONSHIP BETWEEN MATTER, ENERGY, INFORMATION, AND CONSCIOUSNESSijrap
This paper discusses the advantages of describing the universe, or nature, in terms of information and consciousness. Some problems encountered by theoretical physicists in the quest for the theory of everything stem from the limitations of trying to understand everything in terms of matter and energy only. However, if everything, including matter, energy, life, and mental processes, is described in terms of information and consciousness, much progress can be made in the search for the ultimate theory of the universe. As brilliant and successful as physics and chemistry have been over the last two centuries, it is important that nature is not viewed solely in terms of matter and energy. Two additional components are needed to unlock her secrets. While extensive writing exists that describes the connection between matter and energy and their physical basis, little work has been done to learn the special relationship between matter, energy, information, and consciousness.
This paper discusses the advantages of describing the universe, or nature, in terms of information and consciousness. Some problems encountered by theoretical physicists in the quest for the theory of everything stem from the limitations of trying to understand everything in terms of matter and energy only. However, if everything, including matter, energy, life, and mental processes, is described in terms of information and consciousness, much progress can be made in the search for the ultimate theory of the universe. As brilliant and successful as physics and chemistry have been over the last two centuries, it is important that nature is not viewed solely in terms of matter and energy. Two additional components are needed to unlock her secrets. While extensive writing exists that describes the connection between matter and energy and their physical basis, little work has been done to learn the special relationship between matter, energy, information, and
consciousness.
THE CONCEPT OF SPACE AND TIME: AN AFRICAN PERSPECTIVEijrap
Understanding the concept of space and time is critical, essential, and fundamental in searching for theall-encompassing theory or the theory of everything (ToE). Some physicists argue that time exists, whileothers posit that time is only a social or mental construct. The author presents an African thought systemon space and time conception, focusing on the African (Bantu) view of space and time. The author arguesthat before the advent of the Western linear view of space and time, Africans had their own visionregarding these two concepts. Their conception of time appears to be holistic, highly philosophical, non-linear, and thought-provoking. The author hopes that exploring these two concepts from an African perspective will provide a new and more in-depth insight into reality's nature. A scientific investigation of space and time from an African-centered perspective is a worthy and necessary endeavor in the quest forthe ToE
Learning to Pronounce as Measuring Cross Lingual Joint Orthography Phonology ...ijrap
Machine learning models allow us to compare languages by showing how hard a task in each language might be to learn and perform well on. Following this line of investigation, we explore what makes a language “hard to pronounce” by modelling the task of grapheme-to-phoneme (g2p) transliteration. By training a character-level transformer model on this task across 22 languages and measuring the model’s proficiency against its grapheme and phoneme inventories, we show that certain characteristics emerge that separate easier and harder languages with respect to learning to pronounce. Namely the complexity of a language's pronunciation from its orthography is due to the expressive or simplicity of its grapheme-to phoneme mapping. Further discussion illustrates how future studies should consider relative data sparsity per language to design fairer cross-lingual comparison tasks.
THE CONCEPT OF SPACE AND TIME: AN AFRICAN PERSPECTIVEijrap
Understanding the concept of space and time is critical, essential, and fundamental in searching for the all-encompassing theory or the theory of everything (ToE). Some physicists argue that time exists, while others posit that time is only a social or mental construct. The author presents an African thought system on space and time conception, focusing on the African (Bantu) view of space and time. The author argues
that before the advent of the Western linear view of space and time, Africans had their own vision
regarding these two concepts. Their conception of time appears to be holistic, highly philosophical, nonlinear, and thought-provoking. The author hopes that exploring these two concepts from an African
perspective will provide a new and more in-depth insight into reality's nature. A scientific investigation of space and time from an African-centered perspective is a worthy and necessary endeavor in the quest for the ToE.
International Journal of Recent advances in Physics (IJRAP)ijrap
International Journal of Recent advances in Physics (IJRAP) is a peer-reviewed, open access journal, addresses the impacts and challenges of Physics. The journal documents practical and theoretical results which make a fundamental contribution for the development of Physics.
The Concept of Space and Time: An African Perspectiveijrap
Understanding the concept of space and time is critical, essential, and fundamental in searching for the all-encompassing theory or the theory of everything (ToE). Some physicists argue that time exists, while others posit that time is only a social or mental construct. The author presents an African thought system on space and time conception, focusing on the African (Bantu) view of space and time. The author argues that before the advent of the Western linear view of space and time, Africans had their own vision regarding these two concepts. Their conception of time appears to be holistic, highly philosophical, nonlinear, and thought-provoking. The author hopes that exploring these two concepts from an African perspective will provide a new and more in-depth insight into reality's nature. A scientific investigation of space and time from an African-centered perspective is a worthy and necessary endeavor in the quest for the ToE.
The majority of physicists take it for granted that the universe is made up of matter. In turn, matter is composed of atoms; atoms are made up of particles such as electrons, protons, neutrons, etc. Also, protons
and neutrons are composed of quarks, etc. Furthermore, that everything in nature is governed by the known laws of physics and chemistry. The author only partially shares this view. He argues that many phenomena in the universe may depend on rules or factors as yet incorporated by the physical sciences.
The last few years have led him to reflect on the many unsolved physics problems, such as the quest for the theory of everything (ToE), the arrow of time, the interpretation of quantum mechanics, the fine-tuned
universe, etc. to mention just a few. The author posits that a field carries information, performs various mathematical and computational operations, and behaves as an intelligent entity embedded with consciousness.
Call For Papers - International Journal of Recent advances in Physics (IJRAP)ijrap
International Journal of Recent advances in Physics (IJRAP) is a peer-reviewed, open access journal, addresses the impacts and challenges of Physics. The journal documents practical and theoretical results which make a fundamental contribution for the development of Physics.
Call For Papers - International Journal of Recent advances in Physics (IJRAP)ijrap
The International Journal of Recent Advances in Physics (IJRAP) is a peer-reviewed open access journal that addresses impacts and challenges in the field of physics. It covers theoretical and practical results across many areas of physics including advanced functional materials, applied optics, condensed matter physics, nuclear physics, quantum physics, and more. Authors are invited to submit papers by email before October 30, 2021. Notifications of acceptance will be provided by November 25, 2021.
Call For Papers - International Journal of Recent advances in Physics (IJRAP)ijrap
International Journal of Recent advances in Physics (IJRAP) is a peer-reviewed, open access journal, addresses the impacts and challenges of Physics. The journal documents practical and theoretical results which make a fundamental contribution for the development of Physics.
The use of Nauplii and metanauplii artemia in aquaculture (brine shrimp).pptxMAGOTI ERNEST
Although Artemia has been known to man for centuries, its use as a food for the culture of larval organisms apparently began only in the 1930s, when several investigators found that it made an excellent food for newly hatched fish larvae (Litvinenko et al., 2023). As aquaculture developed in the 1960s and ‘70s, the use of Artemia also became more widespread, due both to its convenience and to its nutritional value for larval organisms (Arenas-Pardo et al., 2024). The fact that Artemia dormant cysts can be stored for long periods in cans, and then used as an off-the-shelf food requiring only 24 h of incubation makes them the most convenient, least labor-intensive, live food available for aquaculture (Sorgeloos & Roubach, 2021). The nutritional value of Artemia, especially for marine organisms, is not constant, but varies both geographically and temporally. During the last decade, however, both the causes of Artemia nutritional variability and methods to improve poorquality Artemia have been identified (Loufi et al., 2024).
Brine shrimp (Artemia spp.) are used in marine aquaculture worldwide. Annually, more than 2,000 metric tons of dry cysts are used for cultivation of fish, crustacean, and shellfish larva. Brine shrimp are important to aquaculture because newly hatched brine shrimp nauplii (larvae) provide a food source for many fish fry (Mozanzadeh et al., 2021). Culture and harvesting of brine shrimp eggs represents another aspect of the aquaculture industry. Nauplii and metanauplii of Artemia, commonly known as brine shrimp, play a crucial role in aquaculture due to their nutritional value and suitability as live feed for many aquatic species, particularly in larval stages (Sorgeloos & Roubach, 2021).
Unlocking the mysteries of reproduction: Exploring fecundity and gonadosomati...AbdullaAlAsif1
The pygmy halfbeak Dermogenys colletei, is known for its viviparous nature, this presents an intriguing case of relatively low fecundity, raising questions about potential compensatory reproductive strategies employed by this species. Our study delves into the examination of fecundity and the Gonadosomatic Index (GSI) in the Pygmy Halfbeak, D. colletei (Meisner, 2001), an intriguing viviparous fish indigenous to Sarawak, Borneo. We hypothesize that the Pygmy halfbeak, D. colletei, may exhibit unique reproductive adaptations to offset its low fecundity, thus enhancing its survival and fitness. To address this, we conducted a comprehensive study utilizing 28 mature female specimens of D. colletei, carefully measuring fecundity and GSI to shed light on the reproductive adaptations of this species. Our findings reveal that D. colletei indeed exhibits low fecundity, with a mean of 16.76 ± 2.01, and a mean GSI of 12.83 ± 1.27, providing crucial insights into the reproductive mechanisms at play in this species. These results underscore the existence of unique reproductive strategies in D. colletei, enabling its adaptation and persistence in Borneo's diverse aquatic ecosystems, and call for further ecological research to elucidate these mechanisms. This study lends to a better understanding of viviparous fish in Borneo and contributes to the broader field of aquatic ecology, enhancing our knowledge of species adaptations to unique ecological challenges.
When I was asked to give a companion lecture in support of ‘The Philosophy of Science’ (https://shorturl.at/4pUXz) I decided not to walk through the detail of the many methodologies in order of use. Instead, I chose to employ a long standing, and ongoing, scientific development as an exemplar. And so, I chose the ever evolving story of Thermodynamics as a scientific investigation at its best.
Conducted over a period of >200 years, Thermodynamics R&D, and application, benefitted from the highest levels of professionalism, collaboration, and technical thoroughness. New layers of application, methodology, and practice were made possible by the progressive advance of technology. In turn, this has seen measurement and modelling accuracy continually improved at a micro and macro level.
Perhaps most importantly, Thermodynamics rapidly became a primary tool in the advance of applied science/engineering/technology, spanning micro-tech, to aerospace and cosmology. I can think of no better a story to illustrate the breadth of scientific methodologies and applications at their best.
ESR spectroscopy in liquid food and beverages.pptxPRIYANKA PATEL
With increasing population, people need to rely on packaged food stuffs. Packaging of food materials requires the preservation of food. There are various methods for the treatment of food to preserve them and irradiation treatment of food is one of them. It is the most common and the most harmless method for the food preservation as it does not alter the necessary micronutrients of food materials. Although irradiated food doesn’t cause any harm to the human health but still the quality assessment of food is required to provide consumers with necessary information about the food. ESR spectroscopy is the most sophisticated way to investigate the quality of the food and the free radicals induced during the processing of the food. ESR spin trapping technique is useful for the detection of highly unstable radicals in the food. The antioxidant capability of liquid food and beverages in mainly performed by spin trapping technique.
The binding of cosmological structures by massless topological defectsSérgio Sacani
Assuming spherical symmetry and weak field, it is shown that if one solves the Poisson equation or the Einstein field
equations sourced by a topological defect, i.e. a singularity of a very specific form, the result is a localized gravitational
field capable of driving flat rotation (i.e. Keplerian circular orbits at a constant speed for all radii) of test masses on a thin
spherical shell without any underlying mass. Moreover, a large-scale structure which exploits this solution by assembling
concentrically a number of such topological defects can establish a flat stellar or galactic rotation curve, and can also deflect
light in the same manner as an equipotential (isothermal) sphere. Thus, the need for dark matter or modified gravity theory is
mitigated, at least in part.
Deep Behavioral Phenotyping in Systems Neuroscience for Functional Atlasing a...Ana Luísa Pinho
Functional Magnetic Resonance Imaging (fMRI) provides means to characterize brain activations in response to behavior. However, cognitive neuroscience has been limited to group-level effects referring to the performance of specific tasks. To obtain the functional profile of elementary cognitive mechanisms, the combination of brain responses to many tasks is required. Yet, to date, both structural atlases and parcellation-based activations do not fully account for cognitive function and still present several limitations. Further, they do not adapt overall to individual characteristics. In this talk, I will give an account of deep-behavioral phenotyping strategies, namely data-driven methods in large task-fMRI datasets, to optimize functional brain-data collection and improve inference of effects-of-interest related to mental processes. Key to this approach is the employment of fast multi-functional paradigms rich on features that can be well parametrized and, consequently, facilitate the creation of psycho-physiological constructs to be modelled with imaging data. Particular emphasis will be given to music stimuli when studying high-order cognitive mechanisms, due to their ecological nature and quality to enable complex behavior compounded by discrete entities. I will also discuss how deep-behavioral phenotyping and individualized models applied to neuroimaging data can better account for the subject-specific organization of domain-general cognitive systems in the human brain. Finally, the accumulation of functional brain signatures brings the possibility to clarify relationships among tasks and create a univocal link between brain systems and mental functions through: (1) the development of ontologies proposing an organization of cognitive processes; and (2) brain-network taxonomies describing functional specialization. To this end, tools to improve commensurability in cognitive science are necessary, such as public repositories, ontology-based platforms and automated meta-analysis tools. I will thus discuss some brain-atlasing resources currently under development, and their applicability in cognitive as well as clinical neuroscience.
Remote Sensing and Computational, Evolutionary, Supercomputing, and Intellige...University of Maribor
Slides from talk:
Aleš Zamuda: Remote Sensing and Computational, Evolutionary, Supercomputing, and Intelligent Systems.
11th International Conference on Electrical, Electronics and Computer Engineering (IcETRAN), Niš, 3-6 June 2024
Inter-Society Networking Panel GRSS/MTT-S/CIS Panel Session: Promoting Connection and Cooperation
https://www.etran.rs/2024/en/home-english/
This presentation explores a brief idea about the structural and functional attributes of nucleotides, the structure and function of genetic materials along with the impact of UV rays and pH upon them.
Phenomics assisted breeding in crop improvementIshaGoswami9
As the population is increasing and will reach about 9 billion upto 2050. Also due to climate change, it is difficult to meet the food requirement of such a large population. Facing the challenges presented by resource shortages, climate
change, and increasing global population, crop yield and quality need to be improved in a sustainable way over the coming decades. Genetic improvement by breeding is the best way to increase crop productivity. With the rapid progression of functional
genomics, an increasing number of crop genomes have been sequenced and dozens of genes influencing key agronomic traits have been identified. However, current genome sequence information has not been adequately exploited for understanding
the complex characteristics of multiple gene, owing to a lack of crop phenotypic data. Efficient, automatic, and accurate technologies and platforms that can capture phenotypic data that can
be linked to genomics information for crop improvement at all growth stages have become as important as genotyping. Thus,
high-throughput phenotyping has become the major bottleneck restricting crop breeding. Plant phenomics has been defined as the high-throughput, accurate acquisition and analysis of multi-dimensional phenotypes
during crop growing stages at the organism level, including the cell, tissue, organ, individual plant, plot, and field levels. With the rapid development of novel sensors, imaging technology,
and analysis methods, numerous infrastructure platforms have been developed for phenotyping.
EWOCS-I: The catalog of X-ray sources in Westerlund 1 from the Extended Weste...Sérgio Sacani
Context. With a mass exceeding several 104 M⊙ and a rich and dense population of massive stars, supermassive young star clusters
represent the most massive star-forming environment that is dominated by the feedback from massive stars and gravitational interactions
among stars.
Aims. In this paper we present the Extended Westerlund 1 and 2 Open Clusters Survey (EWOCS) project, which aims to investigate
the influence of the starburst environment on the formation of stars and planets, and on the evolution of both low and high mass stars.
The primary targets of this project are Westerlund 1 and 2, the closest supermassive star clusters to the Sun.
Methods. The project is based primarily on recent observations conducted with the Chandra and JWST observatories. Specifically,
the Chandra survey of Westerlund 1 consists of 36 new ACIS-I observations, nearly co-pointed, for a total exposure time of 1 Msec.
Additionally, we included 8 archival Chandra/ACIS-S observations. This paper presents the resulting catalog of X-ray sources within
and around Westerlund 1. Sources were detected by combining various existing methods, and photon extraction and source validation
were carried out using the ACIS-Extract software.
Results. The EWOCS X-ray catalog comprises 5963 validated sources out of the 9420 initially provided to ACIS-Extract, reaching a
photon flux threshold of approximately 2 × 10−8 photons cm−2
s
−1
. The X-ray sources exhibit a highly concentrated spatial distribution,
with 1075 sources located within the central 1 arcmin. We have successfully detected X-ray emissions from 126 out of the 166 known
massive stars of the cluster, and we have collected over 71 000 photons from the magnetar CXO J164710.20-455217.
Current Ms word generated power point presentation covers major details about the micronuclei test. It's significance and assays to conduct it. It is used to detect the micronuclei formation inside the cells of nearly every multicellular organism. It's formation takes place during chromosomal sepration at metaphase.
CYCLOHEXANE – PHENOL BINARY LIQUID MIXTURE: BEHAVIOR AND PARAMETERS AT CRITICAL CONDITIONS
1. International Journal of Recent Advances in Physics (IJRAP) Vol.8, No.1, February 2019
DOI : 10.14810/ijrap.2019.8101 1
CYCLOHEXANE – PHENOL BINARY LIQUID
MIXTURE: BEHAVIOR AND
PARAMETERS AT CRITICAL CONDITIONS
Iyad Saadeddin*, Ghadeer Hussein, Issam R. Abdelraziq
Department of Physics, An Najah National University, Nablus, Palestine.
*corresponding author e-mail: iyads@najah.edu
ABSTRACT
A new liquid binary cyclohexane - phenol mixture was prepared. The dynamic shear viscosity coefficients
of this liquid mixture, for different phenol concentrations and temperatures, were investigated by capillary
viscometer made from glass. The dynamic shear viscosity showed an anomaly close to the critical
temperature 𝑇𝑐 = 17.0 ℃. The anomaly behavior was observed at critical weight concentration of phenol,
𝑥 𝑐 = 2.70 %. At temperatures above critical one, the experimental data were fitted using mode Coupling
Theory. It was found that the dynamic shear viscosity non-critical background had a value of 𝜂0 = 0.8174
cP. Also, using a pycnometer of 10 ml, density measurements were performed. The expected law for mass
density above critical temperature was the power law. The noncritical mass density part was found to have
a value of 𝜌0 = 0.7357
𝑔𝑚
𝑐𝑚3. In addition, The isobaric thermal expansion coefficient at critical temperature
(𝛼 𝑝𝑐) was also deduced and found to have a value of 2.07 × 10−6
℃−1
. Finally, the derivative of critical
temperature with respect to pressure (𝑇𝑐
′
) was found to have a value 1.22 × 10−4 𝐾
𝑃𝑎
.
KEYWORDS
Viscosity, Mode coupling theory, Liquid binary mixture, Power law, Critical parameters.
1. INTRODUCTION
Due to their unusual behavior, the understanding the theoretical background of liquid-liquid
mixture is very important for scientific and applied knowledge [1]. For these mixtures, The
knowledge of their physicochemical properties are important for many chemical industrial
processes. In industries, which involves physicochemical processes, mixtures are commonly used
to handle the mixtures of alcohols, ketones, hydrocarbons, and aldehydes [2].
Cyclohexane and phenol are well known to be hazardous materials [3]. They are widely used in
different industries. Due to that, it is highly crucial to identify their physico-chemical properties.
Also, for understanding transport properties under heat and fluid flow, The physical properties for
pure materials and their binary mixtures at different temperature range and different composition
rates are important to identify.
1.1 Binary Mixtures And Liquids
A mixture of two unlike liquids is usually called binary mixtures; when they mixes
homogeneously, the mixture has characterization at a critical concentration and critical
2. International Journal of Recent Advances in Physics (IJRAP) Vol.8, No.1, February 2019
2
temperature. However, at temperatures and concentrations differ from those at critical, the two
liquids do not mix homogeneously, and there will be a well-defined two phases. Examples of
binary mixtures are nitrobenzene - n-hexane, methanol – cyclohexane, and benzene - coconut oil
[4].
1.2. Literature Review
Many studies related to a wide range of binary liquid mixtures have been done by many
researchers. They have used many types fitting for equations and polynomials to explain their
results for different liquid parameters, like density, viscosity, etc.
The behavior of shear viscosity in the critical region for a binary mixture of different liquids goes
back first to Fixman. In the critical mixing region, Fixman's approach described the mixtures rise
in viscosity in due to the velocity gradient that exist of in the critical region [5]. Domanska and
Krolikowska found the correlations between viscosities and densities when they mixes five
different ionic liquids with water. They found that their results of density, viscosity, and excess
molar volume, were in correlations with Redlich–Kister equation, polynomials of the second
order, and VFT equation [6]. AJ Easteal measured the tracer diffusion coefficients of the binary
mixtures of tritiated water and acetonitrile at several temperatures., The diffusion data were used
to test a semi-empirical correlation between self-diffusion coefficients and solution viscosity [7].
Ultrasonic sound speed, viscosities, and densities of p-chloroacetophenone, p-
methylacetophenone, and pure propiophenone and their binary mixtures prepared using a
common component of N,N-dimethylaniline were measured for all composition range at
308.15K and 303.15K [8]. M. Emila et al. measured the dynamic viscosities of four binary
mixtures at Kelvin (K) temperatures of 303.15, 308.15, 313.15, 318.15and 323.15 under
atmospheric pressure. The deviations of viscosity for the binary mixtures were fitted using
polynomial equation "Redlich-Kister" [9]. The temperature dependent shear viscosity for the
nitrobenzene and n-heptane binary liquid mixture was measured by the group of Abdelraziq. They
detect The viscosity anomaly at different concentration and temperature. The mode coupling
theory was used to analyze the results above the critical temperature [10]. Kestin Josephet al.
studied the kinematic and dynamic viscosities for different aqueous solutions; They tabulated
values of kinematic and dynamic viscosity of solutions from potassium chloride in a temperature
of 20-150 ºC range, pressure of 0.1-30 MPa range and molal concentration range of 0-5.4 [11].
Sk. Fakruddin Babavali et al. studies ultrasonic velocities, viscosities and densities in binary
liquid mixtures containing heterocyclic aromatic compound quinoline with 1-butanol have been
measured at temperatures T= (303.15,308.15,313.15 and 318.15)K over the entire mole fraction
range of quinoline [12]. Ahlam et al. show that the viscosity Arrhenius-type equations for pure
liquids can be extended to binary liquid mixtures [13].
1.3. Study Objectives
Investigate critical (η) and noncritical background (𝜂0) of shear viscosity by applying the
approach of mode coupling theory. Also, determining the Isobaric specific heat (cpc) at critical
conditions and the thermal expansion coefficient αp at constant pressure (isobaric). In addition,
Calculating the derivative of critical temperature with respect to pressure ( Tc
′
). Moreover, For
binary mixture above near critical temperature and at critical concentration, power law will be set
up to describe the mass density behavior as a function of temperature.
3. International Journal of Recent Advances in Physics (IJRAP) Vol.8, No.1, February 2019
3
2. THEORETICAL BACKGROUND
Viscosity is defined as liquid internal friction when it is set in motion. hence, fluid has tendency
to resist its flow. On the microscopic level, viscosity depends on molecular interactions and hence
it is related to the way of diffusion for molecules. The fluidity that measures the fluid layers
mobility is the opposite of the viscosity [14-15].
2.1. Shear Viscosity Close To Critical Point
Perl and Ferrell approach of mode coupling theory predicts the shear viscosity anomaly at critical
conditions (temperature and concentration) [16]. At the critical concentration, the shear viscosity
ƞ depends on temperature T as T approaches Tc, where the increase in ƞis indefinitely. The power
law , considered for the resulting singularity, is given by [17]:
ƞ = ƞ0 𝜏− 𝑥ƞ 𝑣
(1)
where ƞ0 is the dynamic shear viscosity noncritical background, τ =
𝑇−𝑇𝑐
𝑇𝑐
is the absolute reduced
temperature and 𝑥ƞ and 𝑣 (𝑣 = 0.64, 𝑥ƞ 𝑣 = 0.04) are the critical exponents.
Note that the critical exponents values depend on very general properties, such as microscopic
interactions range and dimensionality of in the system. this was observed by many workers where
they found same critical exponent for completely different systems [18-20].
2.2. Power Law
A critical exponents set are used to describe the binary mixture singular behavior around the
critical point. The non-analyticity of different thermodynamic functions is described by exponents
describe. In the asymptotic regions, very close to the critical point, depending on the approached
thermodynamic path, Thermo-physical quantities reveal a typical behavior of power-law.
Many important thermodynamic properties are associated with mixtures critical points; some
properties of thermodynamics diverge approaching 𝑇𝑐 with power-law divergence in |T − Tc|
close to critical region, whereas a non-divergent power-law is shown for some other
thermodynamic properties. The called critical exponents is given for exponents that go with these
power laws [21].
Above critical temperature and at critical concentration xc, the mass density was given by the
temperature (𝜏) dependent power law as given for viscosity [17]:
𝜌 = 𝜌0 𝜏−𝑥 𝜌 𝑣
(2)
Where 𝑣 = 0.64 and 𝑥 𝜌 𝑣 is critical exponents.
2.3 Two – Scale –Factor Universality
In phase transition study, The two-scale-factor universality has played a central role in predicting
the liquid binary mixture critical phenomena [22]. The two-scale-factor universality was defined
by:
4. International Journal of Recent Advances in Physics (IJRAP) Vol.8, No.1, February 2019
4
𝑅ξ = ξₒ (
∝ρccpc
KB
)
1
𝑑
= ξₒ(
∝Tcαpb
KBTc
′ )
1
d = 0.270 (3)
where ξₒ is the critical amplitude of correlation length, ∝ = 0.11 is the critical universal exponent
quantity, Tc is the critical temperature, ρc
is the mass density is at Tc, cpc is the critical specific
heat (isobaric), KB is Boltzmann's, αpb is the critical thermal expansion (isobaric), Tc
′
=
dTc
dP
is the
derivative of critical temperature with respect to pressure along the critical line, and d is the
dimension of the considered space.
The isobaric critical specific heat can be found from the isobaric specific heat formula [23]:
cp = cpcτ−∝
+ cpb (4)
Where cpc is the isobaric critical specific heat, the reduced absolute temperature is τ =
T−Tc
Tc
, cpb
and is the specific heat background at constant pressure, and ∝ is the critical exponent.
The isobaric critical thermal expansion coefficient can also be found from [23]:
αp = αpcτ−∝
+ αpb (5)
Where αpb is the background term, and αpc is the isobaric critical thermal expansion coefficient.
Thermal isobaric expansion coefficient can be expressed also by [24];
αp = ρ (
dρ−1
d T
) (6)
Using equation (6), 𝛼 𝑝 can be determined, where (
dρ−1
d T
) is the slope of the linear fit for ρ−1
versus temperatures T (℃) graph. 𝛼 𝑝at each temperature can then be calculated by multiplying
the slope with the density.
3. EXPERIMENTAL PROCEDURE
Purified Phenol (99.90 %) and Cyclohexane (99.60%), purchased from Sigma-Aldrich Co., were
used to prepare the binary mixture under ambient conditions. the specifications for cyclohexane
and phenol are shown in table 1
Table 1. Cyclohexane and phenol chemical and physical and properties.
Property Cyclohexane [25] Phenol [26]
Molecular weight (gm.mol-1
) 84.2 94.111
Physical state at 20 ºC Liquid (Colorless) Crystalline solid (Colorless)
Density at 20 ºC (gm/cm3
) 0.7785 1.0710
Melting point (ºC) 6.47 40.9
Boiling point (ºC) 80.7 181.8
Viscosity at 20 ºC (cP) 1.0 11.3
Water solubility at 20 ºC(mg/L) 55 8.28 × 104
Vapor pressure at 20 ºC(mmHg) 97 0.35
5. International Journal of Recent Advances in Physics (IJRAP) Vol.8, No.1, February 2019
5
3.1. Sample Preparation
A total 10 ml volume V of Cyclohexane – phenol binary liquid mixtures were prepared. To
prepare phenol liquid, phenol solids were dissolved into cyclohexane liquid which has volume V.
Because cyclohexane mass density is lower than phenol, Cyclohexane liquid was always on the
top of the liquid binary mixture, whereas the phenol liquid was in the bottom. The weight
concentration of phenol (xphenol) in the mixture was ranges from 2.00% to 40.00%. In a given
sample of volume V prepared from liquid mixture of cyclohexane - phenol, xphenol can be
calculated using:
xphenol =
ρphenol Vphenol
ρphenol Vphenol + ρcyclohexane Vcyclohexane
(7)
3.2. Sheer Viscosity
Viscometer (U-shaped glass tube) was used for shear viscosity measurements for different
cyclohexane – phenol mixture prepared at different phenol concentrations. Liquid viscosity
standard by Brook field Engineering Laboratories Inc. was used to calibrate measurements of
viscosity. For each prepared sample, during viscosity measurements, the temperature was
changed between 14.0 ºC and 21.0 ºC. During measurements, the temperature was controlled
using refrigerated and heated circulator (model Julabo F25-MV).
3.3. Density Measurements
Using 10 ml pycnometer, The cyclohexane – phenol density has been measured at different
temperatures. The density was calculated from the mixture mass in the pycnometer volume ( 10
ml). Because of density sensitivity for temperature, different concentration binary mixtures were
prepared under same temperature. This was done in situ during density measurements.
Initially, As a reference densities, cyclohexane liquid and phenol liquid densities were measured
at room temperature. A density of 0.7647
gm
cm3 and 1.0476
gm
cm3. was measured for pure
cyclohexane liquid and pure phenol liquid respectively.
4. RESULTS AND ANALYSIS
4.1. Critical Temperature And Concentration
Dynamic viscosity variation with temperature for different phenol concentrations (from 2.00%to
13.20 %) by weight plotted in Fig. 1. As the temperature increases, the viscosity was found to
decrease. Increasing temperature increases the dynamic motion of liquid molecules due to thermal
energy, this will lead to decrease the intermolecular forces (cohesive force) between liquid
molecules. Hence, the viscosity of the liquid decreases making the liquid molecular layers to slide
over each other more easily [27]. Also, as seen from Fig. 1, The viscosity was found to increases
with phenol concentration. This was expected because phenol has higher viscosity than
cyclohexane (see table 1) and increases phenol's concentration will lead to increase the mixture
viscosity. Same behavior was observed for the phenol concentrations above 13.20%, both phenol
and cyclohexane liquids showed two separated liquids in the same measuring temperature range;
the viscosity was also observed to decrease with temperature and increase with phenol
concentration. This indeed due to the same reason discussed above.
6. International Journal of Recent Advances in Physics (IJRAP) Vol.8, No.1, February 2019
6
Figure 1. Cyclohexane – phenol dynamic viscosity versus temperature for different phenol weight
concentrations.
As also observed in Fig. 1, the graph has an anomaly behavior at temperature of 17 o
C. This
anomaly was observed for phenol concentration of 2.7 % in the binary liquid mixture. In addition,
at this temperature (17 o
C) and concentration (2.7 % of phenol), the binary liquid mixture
becomes undistinguishable because it transforms from two phases to one phase. Therefore, for
both observed temperature and concentration, one can consider this point to be the critical point
for the liquid binary mixture of cyclohexane-phenol. Moreover, at this critical point, the measured
Shear viscosity was 0.9672 cP. The viscosity observed at critical point is closed to that of
cyclohexane (see table 1). Indeed, this was expected because cyclohexane concentration
constitute 97.3% of the mixture, and hence it's viscosity will be dominant in the mixture.
4.2. The Noncritical Background Of Dynamic Shear Viscosity
At the critical concentration, dynamic sheer viscosity is temperature dependent power law. At
critical concentration, the dynamic sheer viscosity was measured at a temperature ranges from
17.1℃ to 21.0℃. The selected range of temperature was because power law is valid at
temperatures when they are close to Tc [17, 21]. Using linear form of equation (1), which is
represented by the following equation:
𝑙𝑛(ƞ) = 𝑙𝑛(ƞₒ) −𝑥ƞ 𝑣 𝑙𝑛(𝜏) (8)
ln(ƞ) versus ln(τ) was drawn and linearly fitted (Fig. 2) to find the critical exponent value of 𝑥ƞ 𝑣.
The linear equation of the fit is shown in the inset.
7. International Journal of Recent Advances in Physics (IJRAP) Vol.8, No.1, February 2019
7
Figure 2. ln(ƞ) vs. ln(τ) for cyclohexane – phenol mixture at critical concentration above the critical
temperature. Linear equation for fitted data is shown in the insert.
From the slope of the linear fit, critical exponent for the cyclohexane-phenol critical mixture was
found to be equals to 0.0401. This result is in a full accordance with the critical exponent
observed at critical concentrations [17]. This confirms that the cyclohexane-phenol binary
mixture belongs to a class of binary mixtures that fit power law at critical concentration near
critical temperature.
The noncritical shear viscosity part (ƞₒ) can be found from the linear fit intercept ( 𝑙𝑛(ƞₒ) =
−0.1909). The calculated noncritical shear viscosity part was 0.8262 cP. The sheer viscosity
(0.9762 cP) at critical conditions (critical concentration and critical temperature) was found to
have higher value than the background non-critical sheer viscosity value (0.8262 cP) at
temperatures near critical. This indicated that the binary cyclohexane-phenol mixture has a higher
intermolecular force at critical conditions. Therefore, less fluidity than the critical concentration
at temperatures near above critical. Hence one could expect that thermal expansion coefficient at
critical conditions to be lower than its noncritical backgrounds and density at critical conditions to
be higher than its background.
4.3. Thermal Expansion Coefficient
For the mixture (cyclohexane – phenol) at critical concentration, the isobaric thermal expansion
coefficient (αp), thermal isobaric critical expansion coefficient (αpc) and its background (αpb)
were calculated by using equations (5) and (6). Fig. 3 shows a plot of density reciprocal versus
temperature, with inset representing the linear fit equation of the drawn data. According to
equation (6), αp values at each temperature were calculated by multiplying the slope of the linear
fit ((
dρ−1
d T
) = 8 × 10−4(cm3
gm .⁄ ℃)) with the density at each temperature.
8. International Journal of Recent Advances in Physics (IJRAP) Vol.8, No.1, February 2019
8
Figure 3. Density reciprocal (ρ-1
) versus temperature (T) above Tc for the cyclohexane – phenol critical
mixture. Linear equation for fitted data is shown in the insert.
From equation (5) (αp = αpcτ−∝
+ αpb), αp versus τ−∝
was plotted (Fig. 4.) with α = 0.11 the
critical thermal expansion coefficient at constant pressure (αpc) was found from the slope of
linear fit (αpc = 1.66 × 10−6
℃−1
), and the thermal background expansion coefficientat constant
pressure (αpb) was found from the intercept (αpb = 5.87 × 10−4
℃−1
). The lower expansion
coefficient (lower than the background αpb)observed at critical conditions (αpc) is due to higher
intermolecular force confirmed by higher viscosity at critical conditions than its background.
Figure 4. Cyclohexane – phenol critical mixture thermal expansion coefficient as function of τ-0.11
. Linear
equation for fitted data is shown in the insert.
9. International Journal of Recent Advances in Physics (IJRAP) Vol.8, No.1, February 2019
9
4.4. The Noncritical Background For Mass Density
At critical mixture concentration for cyclohexane-phenol, the mass density at the critical
temperature ρc = 0.7627
gm
cm3 was measured by pycnometer. This value is close to that for
cyclohexane (see table 1) since cyclohexane weight concentration contributed 97.3% in the
mixture.
In the asymptotic region close to critical point, like what observed for viscosity, mass density was
also found to exhibit the behavior corresponds to a power law [17]. To determine mass density
background 𝜌0, the linear form of the mass density equation (2) (𝑙𝑛(𝜌) = 𝑙𝑛(ρₒ) −𝑥 𝜌 𝑣𝑙𝑛(𝜏)) was
used. Fig 5. shows ln(ρ) against ln(τ) with inset showing the linear equation of the linear fit for
the data. From the slope of the linear equation, the mass density critical exponents were deduced (
𝑥 𝜌 𝑣 = 0.0007 and 𝑥 𝜌 equals 0.00109; note that 𝑣 = 0.64). The noncritical mass density part
ρ0
= 0.7357
gm
cm3 was found from linear equation intercept (ln(ρ0
) = - 0.3068). As shown, the
higher density observed at critical conditions are higher than their background. Indeed, at critical
conditions we have observed higher viscosity than at non-critical background due to higher
intermolecular forces between liquid molecules. This will lead the molecules of liquid mixture to
slow down and compacted together with shorter intermolecular distances at critical. Hence higher
density will be observed at critical conditions that at the non-critical background (at temperatures
close to critical temperature).
Figure 5. Plot of ln(ρ) versus ln(τ) above the critical temperatur for the critical mixture cyclohexane –
phenol. Linear equation for fitted data is shown in the insert.
4.5. Pressure Derivation For Critical Temperature
The derivative of critical temperature with respect to pressure for the critical cyclohexane –
phenol mixture was calculated form equation (3)(two- scale factor universality equation):
10. International Journal of Recent Advances in Physics (IJRAP) Vol.8, No.1, February 2019
10
𝑅ξ = ξₒ(
∝ Tcαpb
KBTc
′ )
1
d = 0.270 (9)
With ∝= 0.11, d=3 and ξₒ = 3.12 Å [22-23], measured αpb = 5.87 × 10−4
℃−1
, and Tc =
17℃. The critical temperature derivative with respect to pressure (Tc
′
=
dTc
dP
) was calculated and
found to be 1.22 × 10−4 K
Pa
.
5. CONCLUSION
The behavior of single liquids and binary liquid mixtures, at critical and near critical conditions,
can be explained using different types of fitting, equations and polynomials. Many liquid
parameters at critical conditions can be deduced such as viscosity, density, ultrasonic propagation,
electrical conductivity, etc.
Behavior of cyclohexane-phenol binary liquid new mixture have been experimentally observed at
and near critical conditions. Experiments were performed at different phenol weight
concentrations and at different temperatures. In this paper, theoretical approximations for binary
liquid mixture was used to deduce many parameters at critical and near critical conditions. Mode
coupling approach and power law was used to find the shear viscosity (used to find critical
concentration and temperature), noncritical part of shear viscosity, and mass density. In addition,
The two – scale – factor universality that explains the critical phenomena of binary liquid
mixtures was used to deduce other parameters like isobaric specific heat, isobaric and background
isobaric thermal expansion coefficient.
The thermodynamic properties results of the liquid binary cyclohexane – phenol mixture that
were measured or calculated are shown in table 2.
Table 2. Measured and/or calculated parameters (summary table).
Measured and/or calculated value (unit) Results
xc
∗
: Phenol critical weight concentration (%) 2.70%
Tc
∗
: Critical temperature (℃) 17.0
η**
: Critical sheer viscosity at (cP) 0.9672
η0
∗∗
: Sheer viscosity (Non critical part)(cP) 0.8174
αpc
∗∗
: Isothermal expansion coefficient (℃−1
) 1.66 × 10−6
αpb
∗∗
: Isobaric thermal expansion coefficient (℃−1
) 5.8701 × 10−4
𝑥 𝜌 𝑣∗∗
: Critical exponent 0.0007
𝑥 𝜌
∗∗
:Critical exponent 0.00109
ρ0
∗∗
Mass density (Noncritical part) (
gm
cm3) 0.7357
ρc
∗
: Critical mixture density (
gm
cm3) 0.7627
Tc
′∗∗
: Deviation of critical temperature Pressure (
𝐾
Pa
) 1.22 × 10−4
*: Measured value, **: Calculated value
Further future work, on such new binary liquid mixture (cyclohexane - phenol), can be performed
like electrical conductivity, ultrasound velocity, optical properties, and dielectric properties.
11. International Journal of Recent Advances in Physics (IJRAP) Vol.8, No.1, February 2019
11
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