The hydrogen storage alloys MmNi3.55Mn0.4Al0.3Co0.75-xFex (0 ≤ x ≤0.75) were used as negative electrodes in the Ni-MH accumulators. The chronopotentiommetry and the cyclic voltammetry were applied to characterize the electrochemical properties of these alloys. The obtained results showed that the substitution of the cobalt atoms by iron atoms has a good effect on the life cycle of the electrode. The discharge capacity reaches its maximum in MmNi3.55Mn0.4Al0.3Co0.75-x Fex ( x = 0, 0.15, 0.35, 0.55 and 0.75) are, respectively, equal to 270, 266, 260, 210 and 200 mAh/g after 12 charge-discharge cycles. The diffusion behaviour of hydrogen in the negative electrodes made from these alloys was characterized by cyclic voltammetry after few activation cycles. The values of the hydrogen coefficient in MmNi3.55Mn0.4Al0.3Co0.75-x Fex ( x = 0, 0.15, 0.35, 0.55 and 0.75) are, respectively, equal to 5.86 10-10, 1.95 10-9, 3.44 10-9, 2.96 10-9 and 4.98 10-10 cm2 s-1. However, the values of the charge transfer coefficients are respectively equal to 0.35, 0.6, 0.5, 0.33 and 0.3. These results showed that the substitution of cobalt by iron decreases the reversibility and the kinetic of the electrochemical reaction in these alloys.
This document provides an overview of basic electrochemistry concepts. It discusses the charge and current involved in electrochemical processes. It introduces Faraday's laws relating the amount of material transformed to the quantity of electricity passed. It also covers conductivity, Nernst equation, different types of electrodes, potentiometry, and various electrochemical techniques including cyclic voltammetry. The key concepts covered include electron transfer processes, Butler-Volmer equation, mass transport by diffusion and convection, and reversible cyclic voltammograms.
Voltammetry involves applying a potential to a working electrode and measuring the resulting current. It can characterize redox reactions through parameters like peak potentials and currents in cyclic voltammetry. Cyclic voltammetry cycles the potential of a working electrode versus a reference electrode and measures the current. It is used to study redox processes and obtain information about reaction kinetics and mechanisms. The peak separation and shapes of cyclic voltammograms provide information about whether redox processes are reversible or irreversible.
Electrochemistry of some mono porphyrinssuchi ghosh
This document discusses various electrochemical techniques like polarography, linear sweep voltammetry, and cyclic voltammetry. It summarizes the results of applying these techniques to study the redox properties of porphyrins, metalloporphyrins, corroles, and manganese-containing corroles. Key findings include the effects of metal insertion, axial ligation, solvent, and linking groups like terephthalic acid on the redox potentials and mechanisms observed in cyclic voltammograms. Electrochemical techniques provide insight into electron transfer kinetics and mechanisms in these molecular systems.
This document discusses applications of cyclic voltammetry (CV). CV is an electrochemical technique useful for studying electrode reactions. It involves applying a continuous, cyclic potential to a working electrode in a cell containing three electrodes. The document outlines the principle, working, and applications of CV, including quantitative analysis, studying chemical reactivity and redox processes, determining thermodynamic properties, kinetics, and more. Examples are given of using CV to characterize modified electrodes and study interactions like of anticancer drugs with DNA.
This document provides an overview of electrochemistry. It discusses electron transfer reactions, oxidation and reduction, voltaic cells, cell potentials, and balancing redox reactions. Key points include:
- Electron transfer reactions are oxidation-reduction or redox reactions that result in the generation of an electric current.
- Oxidation is the loss of electrons and reduction is the gain of electrons. Reduction cannot occur without oxidation providing electrons.
- A voltaic cell uses the energy from a spontaneous redox reaction to generate an electric current by transferring electrons through an external circuit between the anode and cathode.
Coulometry and electrogravimetric analysis are analytical techniques that involve completely oxidizing or reducing an analyte through electrolysis. In coulometry, the quantity of electrical charge passed is measured and related to the amount of analyte present. In electrogravimetry, the analyte is converted electrolytically into a product that is weighed to determine the analyte amount. Both techniques are accurate and precise, but require ensuring all current passed results in analyte oxidation/reduction. Controlled-potential coulometry uses a constant potential, while controlled-current coulometry applies a constant current, each with their own experimental considerations to achieve complete analyte conversion.
lecture slide on:
Gibbs free energy and Nernst Equation, Faradaic Processes and Factors Affecting Rates of Electrode Reactions, Potentials and Thermodynamics of Cells, Kinetics of Electrode Reactions, Kinetic controlled reactions,Essentials of Electrode Reactions,BUTLER-VOLMER MODEL FOR THE ONE-STEP, ONE-ELECTRON PROCESS,Current-overpotential curves for the system, Mass Transfer by Migration And Diffusion,MASS-TRANSFER-CONTROLLED REACTIONS,
Coulometry is an electroanalytical technique where the amount of electricity (in coulombs) required to complete an electrochemical reaction is measured. There are two main types - potentiostatic coulometry, where the potential is held constant, and coulometric titration with a constant current. The quantity of electricity is directly proportional to the amount of analyte and can be used to determine concentrations. Coulometry has applications in inorganic analysis, analysis of radioactive materials, microanalysis, and determination of organic compounds.
This document provides an overview of basic electrochemistry concepts. It discusses the charge and current involved in electrochemical processes. It introduces Faraday's laws relating the amount of material transformed to the quantity of electricity passed. It also covers conductivity, Nernst equation, different types of electrodes, potentiometry, and various electrochemical techniques including cyclic voltammetry. The key concepts covered include electron transfer processes, Butler-Volmer equation, mass transport by diffusion and convection, and reversible cyclic voltammograms.
Voltammetry involves applying a potential to a working electrode and measuring the resulting current. It can characterize redox reactions through parameters like peak potentials and currents in cyclic voltammetry. Cyclic voltammetry cycles the potential of a working electrode versus a reference electrode and measures the current. It is used to study redox processes and obtain information about reaction kinetics and mechanisms. The peak separation and shapes of cyclic voltammograms provide information about whether redox processes are reversible or irreversible.
Electrochemistry of some mono porphyrinssuchi ghosh
This document discusses various electrochemical techniques like polarography, linear sweep voltammetry, and cyclic voltammetry. It summarizes the results of applying these techniques to study the redox properties of porphyrins, metalloporphyrins, corroles, and manganese-containing corroles. Key findings include the effects of metal insertion, axial ligation, solvent, and linking groups like terephthalic acid on the redox potentials and mechanisms observed in cyclic voltammograms. Electrochemical techniques provide insight into electron transfer kinetics and mechanisms in these molecular systems.
This document discusses applications of cyclic voltammetry (CV). CV is an electrochemical technique useful for studying electrode reactions. It involves applying a continuous, cyclic potential to a working electrode in a cell containing three electrodes. The document outlines the principle, working, and applications of CV, including quantitative analysis, studying chemical reactivity and redox processes, determining thermodynamic properties, kinetics, and more. Examples are given of using CV to characterize modified electrodes and study interactions like of anticancer drugs with DNA.
This document provides an overview of electrochemistry. It discusses electron transfer reactions, oxidation and reduction, voltaic cells, cell potentials, and balancing redox reactions. Key points include:
- Electron transfer reactions are oxidation-reduction or redox reactions that result in the generation of an electric current.
- Oxidation is the loss of electrons and reduction is the gain of electrons. Reduction cannot occur without oxidation providing electrons.
- A voltaic cell uses the energy from a spontaneous redox reaction to generate an electric current by transferring electrons through an external circuit between the anode and cathode.
Coulometry and electrogravimetric analysis are analytical techniques that involve completely oxidizing or reducing an analyte through electrolysis. In coulometry, the quantity of electrical charge passed is measured and related to the amount of analyte present. In electrogravimetry, the analyte is converted electrolytically into a product that is weighed to determine the analyte amount. Both techniques are accurate and precise, but require ensuring all current passed results in analyte oxidation/reduction. Controlled-potential coulometry uses a constant potential, while controlled-current coulometry applies a constant current, each with their own experimental considerations to achieve complete analyte conversion.
lecture slide on:
Gibbs free energy and Nernst Equation, Faradaic Processes and Factors Affecting Rates of Electrode Reactions, Potentials and Thermodynamics of Cells, Kinetics of Electrode Reactions, Kinetic controlled reactions,Essentials of Electrode Reactions,BUTLER-VOLMER MODEL FOR THE ONE-STEP, ONE-ELECTRON PROCESS,Current-overpotential curves for the system, Mass Transfer by Migration And Diffusion,MASS-TRANSFER-CONTROLLED REACTIONS,
Coulometry is an electroanalytical technique where the amount of electricity (in coulombs) required to complete an electrochemical reaction is measured. There are two main types - potentiostatic coulometry, where the potential is held constant, and coulometric titration with a constant current. The quantity of electricity is directly proportional to the amount of analyte and can be used to determine concentrations. Coulometry has applications in inorganic analysis, analysis of radioactive materials, microanalysis, and determination of organic compounds.
This document provides an overview of conductometry, including:
1. The principles of conductometry involve measuring the electrical conductance of an electrolyte solution using a conductometer. Conductance depends on ion type, concentration, temperature, and mobility.
2. Instrumentation includes a current source, conductivity cells with platinum electrodes, and a conductance bridge to measure resistance and calculate conductivity.
3. Conductometric titrations can be used for acid-base, redox, precipitation, and complexometric titrations. They do not require indicators and can be used for colored or turbid solutions.
Cyclic voltammetry is an electroanalytical technique that measures current during redox reactions at an electrode. It involves scanning the potential of a working electrode versus a reference electrode and measuring the current. The potential is ramped from an initial value to a set switching potential and back to the initial value. This process is repeated in cycles. A cyclic voltammogram plots the current response of the working electrode versus the applied potential and provides information about redox potentials and reaction reversibility. Reversible reactions produce symmetrical peaks while irreversible reactions have wider separation between peaks. Cyclic voltammetry is useful for studying electrode reaction mechanisms and kinetics.
This document discusses conductometry, which is a method of analysis based on measuring the electrolytic conductance of a solution. It begins by classifying different electrochemical methods, including conductometry and electrophoresis which do not involve redox reactions. It then discusses key concepts in conductometry such as conductivity, conductance, equivalent conductance, and how various factors like ion nature, temperature, concentration, and electrode size affect conductance. It also provides examples of calculating conductance and equivalent conductance from experimental measurements. Instrumentation for conductometric determination includes a conductance cell and conductivity bridge.
Potentiometry involves measuring the potential (voltage) between an indicator electrode and a reference electrode immersed in a solution. The potential measurement provides information about the concentration of an analyte in the solution. Common reference electrodes include the saturated calomel electrode (SCE) and silver-silver chloride electrode, which maintain a constant potential. pH electrodes function as indicator electrodes, with their potential directly proportional to the pH of the solution. The potential measurement is made against the reference electrode using a pH meter, which can be calibrated using buffer solutions.
Electrochemistry is the study of chemical reactions caused by the passage of an electric current and the production of electrical energy from chemical reactions. It encompasses phenomena like corrosion and devices like batteries and fuel cells. Electrochemical cells are either electrolytic cells, where an external power source drives non-spontaneous reactions, or galvanic/voltaic cells, where spontaneous reactions produce electricity. The kinetics and rates of electrochemical reactions, as well as mass transfer of reactants, influence current production in fuel cells and other devices.
1) Electrochemical cells can be used to monitor redox reactions by measuring the electric current produced which is proportional to the rate of reaction. Batteries produce direct current by converting chemical energy to electrical energy through redox reactions.
2) A redox titration uses the transfer of electrons between analyte and titrant during a redox reaction. Oxidation involves losing electrons and reduction involves gaining electrons.
3) The Nernst equation is used to calculate the reduction potential under non-standard conditions when concentrations are not equal to 1M.
This document discusses cyclic voltammetry, which is a type of potentiodynamic electrochemical measurement where the current in an electrochemical cell is measured while the cell's potential is varied linearly with time. It describes the components of a voltammetry system, including the working, reference, and counter electrodes, as well as the supporting electrolyte. It also explains the triangular potential waveform used and defines terms like peak current and peak potential. Examples of using cyclic voltammetry to study the redox reaction of hexacyanoferrate ions and biological redox systems like cytochromes are provided.
This document discusses electrogravimetry, which is the quantitative analysis of substances by electrolysis. It defines key terms used in electrogravimetry like cathode, anode, current density, and overpotential. It explains Faraday's laws of electrolysis and how they relate to the amount of material deposited. It also describes how controlling variables like cathode potential can be used to selectively deposit metals and separate them from each other.
This document provides an overview of conductometry. It discusses how conductometry measures the conductance of electrolyte solutions using a conductivity cell and conductometer. It describes different types of conductivity cells and how conductometric titrations work by measuring changes in conductance during titrations. Examples of various acid-base titrations are given. Conductometric titrations can be used to analyze many different samples and have advantages like not requiring indicators. Applications include measuring water pollution, food analyses, and more.
Polarography is an electroanalytical technique that uses a dropping mercury electrode to determine the concentration and nature of substances in a solution. It involves measuring the current between two electrodes - a polarized indicator electrode made of mercury, and a non-polarized reference electrode - as the voltage is gradually increased. The current readings form a polarogram curve that can identify substances based on their half-wave potential and determine concentrations from the limiting diffusion current. Polarography finds applications in fields like water quality testing, medicine, and electrochemistry.
Analytical class potetiometry conductomtry, P K MANIP.K. Mani
This document discusses potentiometric and conductometric titrations. It provides details on reference electrodes like the saturated calomel electrode and silver-silver chloride electrode. It describes indicator electrodes including metallic electrodes of the first and second type that respond directly or indirectly to analyte concentration. Membrane electrodes like glass pH electrodes are also discussed. The principles of potentiometry are explained through diagrams of electrode systems and the Nernst equation. Liquid junction potentials and factors influencing reference electrode potentials are summarized.
more chemistry contents are available
1. pdf file on Termmate: https://www.termmate.com/rabia.aziz
2. YouTube: https://www.youtube.com/channel/UCKxWnNdskGHnZFS0h1QRTEA
3. Facebook: https://web.facebook.com/Chemist.Rabia.Aziz/
4. Blogger: https://chemistry-academy.blogspot.com/
Physical Chemistry
Polarography uses a dropping mercury electrode (DME) to measure the current flowing through an electrochemical cell as a function of the applied potential. A polarogram plots this current versus potential and provides qualitative and quantitative information about species undergoing oxidation or reduction reactions. Jaroslav Heyrovsky invented the polarographic method in 1922 and won the Nobel Prize for his contributions to electroanalytical chemistry. All modern voltammetric methods originate from polarography. The DME provides advantages like a reproducible surface area and the ability to form amalgams with metal ions.
This document provides an overview of coulometry, which is an electroanalytical technique used for quantitative analysis. There are two forms of coulometry: controlled-potential coulometry and controlled-current coulometry. Both techniques involve completely oxidizing or reducing an analyte and measuring the total charge passed to determine the amount of analyte. Controlled-potential coulometry applies a constant potential while controlled-current coulometry applies a constant current. Factors like electrolysis time, electrode area, and stirring rate affect the analysis. Coulometry is used to quantify both inorganic and organic analytes.
This document provides an overview of conductometry and its applications. It discusses Ohm's law and how conductivity is measured using electrodes, standard solutions, and a conductivity cell. Factors that affect conductivity include ion size, temperature, charge, and number. Conductometric titrations can be used to determine endpoints and are advantageous because no indicator is needed. Types of titrations discussed include acid-base, precipitation, replacement, redox, and complexometric. Recent applications include use in refineries, estimating polyelectrolytes, and biotechnology/environmental monitoring.
High frequency Titrations is an analytical technique in which a radio frequency electric field is applied for which electric conductance of analytical substance governs the response of detector.
This document discusses the principles and procedures of conductometric analysis. Conductometric analysis measures the electrical conductivity of a solution due to ion mobility. The conductivity is affected by factors like number, charge, size of ions, and temperature. It involves titrating a solution containing ions and measuring the change in conductivity. This allows determination of the endpoint of the titration from the plotted conductivity-volume curve. The document defines key terms, describes instrumentation including conductivity cells and electrodes, and discusses different types of conductometric titrations like acid-base, redox, and complexometric titrations. Conductometric titrations provide accurate results for analyses without requiring indicators.
Potentiometry, voltamemtry and conductometryapeksha40
This document discusses various electroanalytical techniques used in clinical laboratories including potentiometry, voltammetry, conductometry, and coulometry. Potentiometry measures electrical potential differences using ion-selective electrodes or redox electrodes. Voltammetry and amperometry are sensitive techniques that apply a voltage to induce an electrochemical reaction and measure the resulting current. Conductometry measures how well ions conduct electricity. Coulometry determines the amount of an electroactive substance by measuring the charge required for its oxidation or reduction reaction. The NOVA-8 analyzer is highlighted as an example that can test for electrolytes, pH, hematocrit, and other clinical analytes using these electroanalytical methods.
Amperometric titration is a technique where the potential between a polarizable working electrode and a non-polarizable reference electrode is kept constant. During titration, the diffusion current is measured, which changes as the concentration of the electroreducible ion changes. At the endpoint, there is a sharp change in the diffusion current. Amperometric titrations can be performed between an electroreducible ion and a non-electroreducible ion, or between two electroreducible ions. The titration conditions require that the titrant, titrate, or both be electroreducible, and the applied potential corresponds to the limiting current.
1) The document investigates the effect of cation and anion sizes on the charge storage capabilities of graphite nanosheets as electrode materials for electrochemical double layer capacitors.
2) Scanning electron microscope images confirm the layered structure of the graphite nanosheets used, which are 12nm thick with 3.36 Angstrom spacing between layers.
3) Electrochemical measurements using cyclic voltammetry and impedance spectroscopy indicate that the graphite electrodes exhibited better charge storage and delivery in 3M NaCl electrolyte compared to NaOH and KOH electrolytes, due to the smaller ion sizes matching better with the graphite structure.
Study the effect of Mn2+ ions on the ac electrical properties of some iron do...IJRES Journal
Oxide glasses doped with transition metal ions are of high interest because of their variant applications in both science and technology fields. However, the normal melt quench method have used to prepared some iron doped phosphate glasses according the following molecular formula: (65-x) mol% P2O5 - 20 mol% Na2O - 15 mol% Fe2O3 - x mol% MnO, Where x= 0, 5,10, 20, 25. The room temperature Mössbauer Effect ME Spectra used to characterized the glassy state homogeneity of these glasses. ME spectra show, for all glasses, no magnetic field participate which mean good glassy state formation. The ac electrical transport properties were also measured, as function of temperature up to 500k. It was found that the ac conductivity increased with the gradual increase of Mn2+ cations, while the electrical activation energy decreased.
This document provides an overview of conductometry, including:
1. The principles of conductometry involve measuring the electrical conductance of an electrolyte solution using a conductometer. Conductance depends on ion type, concentration, temperature, and mobility.
2. Instrumentation includes a current source, conductivity cells with platinum electrodes, and a conductance bridge to measure resistance and calculate conductivity.
3. Conductometric titrations can be used for acid-base, redox, precipitation, and complexometric titrations. They do not require indicators and can be used for colored or turbid solutions.
Cyclic voltammetry is an electroanalytical technique that measures current during redox reactions at an electrode. It involves scanning the potential of a working electrode versus a reference electrode and measuring the current. The potential is ramped from an initial value to a set switching potential and back to the initial value. This process is repeated in cycles. A cyclic voltammogram plots the current response of the working electrode versus the applied potential and provides information about redox potentials and reaction reversibility. Reversible reactions produce symmetrical peaks while irreversible reactions have wider separation between peaks. Cyclic voltammetry is useful for studying electrode reaction mechanisms and kinetics.
This document discusses conductometry, which is a method of analysis based on measuring the electrolytic conductance of a solution. It begins by classifying different electrochemical methods, including conductometry and electrophoresis which do not involve redox reactions. It then discusses key concepts in conductometry such as conductivity, conductance, equivalent conductance, and how various factors like ion nature, temperature, concentration, and electrode size affect conductance. It also provides examples of calculating conductance and equivalent conductance from experimental measurements. Instrumentation for conductometric determination includes a conductance cell and conductivity bridge.
Potentiometry involves measuring the potential (voltage) between an indicator electrode and a reference electrode immersed in a solution. The potential measurement provides information about the concentration of an analyte in the solution. Common reference electrodes include the saturated calomel electrode (SCE) and silver-silver chloride electrode, which maintain a constant potential. pH electrodes function as indicator electrodes, with their potential directly proportional to the pH of the solution. The potential measurement is made against the reference electrode using a pH meter, which can be calibrated using buffer solutions.
Electrochemistry is the study of chemical reactions caused by the passage of an electric current and the production of electrical energy from chemical reactions. It encompasses phenomena like corrosion and devices like batteries and fuel cells. Electrochemical cells are either electrolytic cells, where an external power source drives non-spontaneous reactions, or galvanic/voltaic cells, where spontaneous reactions produce electricity. The kinetics and rates of electrochemical reactions, as well as mass transfer of reactants, influence current production in fuel cells and other devices.
1) Electrochemical cells can be used to monitor redox reactions by measuring the electric current produced which is proportional to the rate of reaction. Batteries produce direct current by converting chemical energy to electrical energy through redox reactions.
2) A redox titration uses the transfer of electrons between analyte and titrant during a redox reaction. Oxidation involves losing electrons and reduction involves gaining electrons.
3) The Nernst equation is used to calculate the reduction potential under non-standard conditions when concentrations are not equal to 1M.
This document discusses cyclic voltammetry, which is a type of potentiodynamic electrochemical measurement where the current in an electrochemical cell is measured while the cell's potential is varied linearly with time. It describes the components of a voltammetry system, including the working, reference, and counter electrodes, as well as the supporting electrolyte. It also explains the triangular potential waveform used and defines terms like peak current and peak potential. Examples of using cyclic voltammetry to study the redox reaction of hexacyanoferrate ions and biological redox systems like cytochromes are provided.
This document discusses electrogravimetry, which is the quantitative analysis of substances by electrolysis. It defines key terms used in electrogravimetry like cathode, anode, current density, and overpotential. It explains Faraday's laws of electrolysis and how they relate to the amount of material deposited. It also describes how controlling variables like cathode potential can be used to selectively deposit metals and separate them from each other.
This document provides an overview of conductometry. It discusses how conductometry measures the conductance of electrolyte solutions using a conductivity cell and conductometer. It describes different types of conductivity cells and how conductometric titrations work by measuring changes in conductance during titrations. Examples of various acid-base titrations are given. Conductometric titrations can be used to analyze many different samples and have advantages like not requiring indicators. Applications include measuring water pollution, food analyses, and more.
Polarography is an electroanalytical technique that uses a dropping mercury electrode to determine the concentration and nature of substances in a solution. It involves measuring the current between two electrodes - a polarized indicator electrode made of mercury, and a non-polarized reference electrode - as the voltage is gradually increased. The current readings form a polarogram curve that can identify substances based on their half-wave potential and determine concentrations from the limiting diffusion current. Polarography finds applications in fields like water quality testing, medicine, and electrochemistry.
Analytical class potetiometry conductomtry, P K MANIP.K. Mani
This document discusses potentiometric and conductometric titrations. It provides details on reference electrodes like the saturated calomel electrode and silver-silver chloride electrode. It describes indicator electrodes including metallic electrodes of the first and second type that respond directly or indirectly to analyte concentration. Membrane electrodes like glass pH electrodes are also discussed. The principles of potentiometry are explained through diagrams of electrode systems and the Nernst equation. Liquid junction potentials and factors influencing reference electrode potentials are summarized.
more chemistry contents are available
1. pdf file on Termmate: https://www.termmate.com/rabia.aziz
2. YouTube: https://www.youtube.com/channel/UCKxWnNdskGHnZFS0h1QRTEA
3. Facebook: https://web.facebook.com/Chemist.Rabia.Aziz/
4. Blogger: https://chemistry-academy.blogspot.com/
Physical Chemistry
Polarography uses a dropping mercury electrode (DME) to measure the current flowing through an electrochemical cell as a function of the applied potential. A polarogram plots this current versus potential and provides qualitative and quantitative information about species undergoing oxidation or reduction reactions. Jaroslav Heyrovsky invented the polarographic method in 1922 and won the Nobel Prize for his contributions to electroanalytical chemistry. All modern voltammetric methods originate from polarography. The DME provides advantages like a reproducible surface area and the ability to form amalgams with metal ions.
This document provides an overview of coulometry, which is an electroanalytical technique used for quantitative analysis. There are two forms of coulometry: controlled-potential coulometry and controlled-current coulometry. Both techniques involve completely oxidizing or reducing an analyte and measuring the total charge passed to determine the amount of analyte. Controlled-potential coulometry applies a constant potential while controlled-current coulometry applies a constant current. Factors like electrolysis time, electrode area, and stirring rate affect the analysis. Coulometry is used to quantify both inorganic and organic analytes.
This document provides an overview of conductometry and its applications. It discusses Ohm's law and how conductivity is measured using electrodes, standard solutions, and a conductivity cell. Factors that affect conductivity include ion size, temperature, charge, and number. Conductometric titrations can be used to determine endpoints and are advantageous because no indicator is needed. Types of titrations discussed include acid-base, precipitation, replacement, redox, and complexometric. Recent applications include use in refineries, estimating polyelectrolytes, and biotechnology/environmental monitoring.
High frequency Titrations is an analytical technique in which a radio frequency electric field is applied for which electric conductance of analytical substance governs the response of detector.
This document discusses the principles and procedures of conductometric analysis. Conductometric analysis measures the electrical conductivity of a solution due to ion mobility. The conductivity is affected by factors like number, charge, size of ions, and temperature. It involves titrating a solution containing ions and measuring the change in conductivity. This allows determination of the endpoint of the titration from the plotted conductivity-volume curve. The document defines key terms, describes instrumentation including conductivity cells and electrodes, and discusses different types of conductometric titrations like acid-base, redox, and complexometric titrations. Conductometric titrations provide accurate results for analyses without requiring indicators.
Potentiometry, voltamemtry and conductometryapeksha40
This document discusses various electroanalytical techniques used in clinical laboratories including potentiometry, voltammetry, conductometry, and coulometry. Potentiometry measures electrical potential differences using ion-selective electrodes or redox electrodes. Voltammetry and amperometry are sensitive techniques that apply a voltage to induce an electrochemical reaction and measure the resulting current. Conductometry measures how well ions conduct electricity. Coulometry determines the amount of an electroactive substance by measuring the charge required for its oxidation or reduction reaction. The NOVA-8 analyzer is highlighted as an example that can test for electrolytes, pH, hematocrit, and other clinical analytes using these electroanalytical methods.
Amperometric titration is a technique where the potential between a polarizable working electrode and a non-polarizable reference electrode is kept constant. During titration, the diffusion current is measured, which changes as the concentration of the electroreducible ion changes. At the endpoint, there is a sharp change in the diffusion current. Amperometric titrations can be performed between an electroreducible ion and a non-electroreducible ion, or between two electroreducible ions. The titration conditions require that the titrant, titrate, or both be electroreducible, and the applied potential corresponds to the limiting current.
Similar to Determination of the hydrogen coefficient diffusion DH in the MmNi3.55Mn0.4Al0.3Co0.75-xFex (0 ≤ x ≤0.75) electrodes alloys by cyclic voltammetry
1) The document investigates the effect of cation and anion sizes on the charge storage capabilities of graphite nanosheets as electrode materials for electrochemical double layer capacitors.
2) Scanning electron microscope images confirm the layered structure of the graphite nanosheets used, which are 12nm thick with 3.36 Angstrom spacing between layers.
3) Electrochemical measurements using cyclic voltammetry and impedance spectroscopy indicate that the graphite electrodes exhibited better charge storage and delivery in 3M NaCl electrolyte compared to NaOH and KOH electrolytes, due to the smaller ion sizes matching better with the graphite structure.
Study the effect of Mn2+ ions on the ac electrical properties of some iron do...IJRES Journal
Oxide glasses doped with transition metal ions are of high interest because of their variant applications in both science and technology fields. However, the normal melt quench method have used to prepared some iron doped phosphate glasses according the following molecular formula: (65-x) mol% P2O5 - 20 mol% Na2O - 15 mol% Fe2O3 - x mol% MnO, Where x= 0, 5,10, 20, 25. The room temperature Mössbauer Effect ME Spectra used to characterized the glassy state homogeneity of these glasses. ME spectra show, for all glasses, no magnetic field participate which mean good glassy state formation. The ac electrical transport properties were also measured, as function of temperature up to 500k. It was found that the ac conductivity increased with the gradual increase of Mn2+ cations, while the electrical activation energy decreased.
DC Electrical Transport Properties and Non–adiabatic Small Polaron Hopping co...IJLT EMAS
Transition metal oxide (TMO) doped semiconducting glass nano–composites xV2O5–(1–x) (0.05MoO3–0.95ZnO), x= 0.3, 0.5, 0.7, 0.9 and 0.93 have been develop by conventional melt quenching technique. The temperature and compositional dependences of the dc electrical transport properties of as prepared vanadate glasses have been reported. Low and high temperature activation energy, density of states at Fermi level, optical phonon frequency and Debye temperature have been computed. Formation of small polaron has been confirmed from dc electrical conductivity experimental data and conductivity is due to mainly polaron hopping from V+4 to V+5 valence state in these glassy systems. The Schnakenberg’s multiphonon assisted hopping model of small polaron is the best model to interpret the temperature dependence of the activation energy and the conductivity over the entire temperature range of measurement. The various polaron hopping parameters such as polaron radius, polaron band width (J), polaron hopping energy and the value of electron–phonon interaction coefficient (γP) have been evaluated. The estimated value of hopping carrier mobility (μ) and hopping carrier concentration (NC) is found to depend on temperature and V2O5 content. According to Holstein, it is confirmed that non–adiabatic small polaron hopping is responsible for
This document summarizes a study that developed a new hybrid electrocatalyst for oxygen evolution reaction (OER) by anchoring cobalt oxide (Co3O4) nanoparticles onto titanium carbide (Ti3C2) MXene nanosheets. The Co3O4/MXene hybrid (denoted CM) was synthesized using a solvothermal method. Characterization showed uniform distribution of small Co3O4 nanoparticles on MXene nanosheets. Electrochemical tests found the CM catalyst achieved overpotential of 300 mV at 10 mA/cm2 for OER, which was lower than Co3O4 or MXene alone. The enhanced performance was attributed to strong interactions and charge transfer between
Morphological, structural and electrochemical properties of the LaNi4Fe compo...AI Publications
In this paper, we have studied the morphologic, the structural and the electrochemical properties of the LaNi4Fe compound elaborated by mechanical alloying (MA) for two durations 5 and 10 h. These properties are determined by various methods, such as XRD, SEM and galvanostatic cycling. The results show that the LaNi4Fe compound crystallizes in the hexagonal CaCu5 type structure for the two alloying durations 5 and 10 h. The particles obtained by mechanical alloying are in the order of 6 to 7 nm. The chemical microanalysis by EDX shows that the nominal and actual compositions are very close for the two grinding times. The maximum discharge capacity, of 180 and 200 mAh / g respectively for 5h and 10 h, is obtained from the first two cycles, which shows that the activation of nano compounds is easier than that obtained for bulk material obtained by melting since the reaction surface is larger. A decrease in capacity is observed after about thirty cycles: A loss of around 15% of maximum capacity is observed.
This document describes research on fabricating a novel graphene electrode embedded with zirconium dioxide nanoparticles for electrochemical capacitors. The electrode showed a maximum specific capacitance of 11.84 F g−1. SEM images showed ions redepositing as agglomerates on the electrode surface after one charge/discharge cycle, accompanied by a decrease in surface area. Electrochemical tests confirmed pseudocapacitive behavior and low resistance. The research aims to investigate how electrolyte ion and active material redeposition affects the electrode's charge distribution ability.
This document summarizes research on using boron-doped carbon nanotubes (B-CNTs) as a catalyst for oxygen dissociation in proton exchange membrane fuel cells (PEMFCs). Density functional theory (DFT) calculations were performed to model oxygen adsorption and dissociation on a (5,5) single-walled carbon nanotube (SWCNT) with one hexagon replaced by B3C3 (B3SWCNT). The nudged elastic band (NEB) method was used to calculate minimum energy reaction paths and activation barriers. The results show an average activation barrier of 1.01 eV for oxygen dissociation on the B3SWCNT, with the most favorable path having a barrier
10.1016-j.mssp.2014.10.034-Graphene nanosheets as electrode materials for sup...Mahdi Robat Sarpoushi
This document summarizes research on using graphene nanosheets as electrode materials for supercapacitors. The researchers investigated the effect of ion size and properties on the pseudocapacitance and double layer capacitance of graphene electrodes in different electrolytes. They found that the electrode showed better double layer characteristics in NaOH electrolyte compared to LiBr electrolyte. This was attributed to the smaller size and higher mobility of ions in NaOH, allowing more ions to be stored on the graphene surface. Electrochemical tests showed the electrode exhibited both double layer capacitance and pseudocapacitance, with pseudocapacitance contributing more in LiBr electrolyte. The morphology of the graphene nanosheets formed a continuous porous network suitable for
This document summarizes an experiment investigating the behavior of a single fuel cell under different membrane electrode assemblies (MEAs) and fuels. Three MEAs using different catalysts were tested with hydrogen and formic acid as anode fuels and hydrogen, air, or water as cathode reactants. Constant base current with 10A pulses were applied to alleviate carbon monoxide poisoning on the anode. Results including polarization curves and potential/current oscillations are presented. The document also provides background on fuel cells and mechanisms of carbon monoxide poisoning.
Compatibility Analyses of Bicuvox.10 as a Cathode in Yttria-stabilized Zircon...Marcelo Tramontin
The document examines the compatibility of copper-substituted bismuth vanadate (BICUVOX.10) as a cathode material in yttria-stabilized zirconia (YSZ) electrolytes for solid oxide fuel cells. When BICUVOX.10 interacts with YSZ, secondary phases form including yttrium vanadate (YVO4) and monoclinic zirconia. This is due to a reaction between the YO1.5 stabilizer cation in ZrO2 and VO2.5 from BICUVOX.10, depleting yttria from the zirconia lattice and destabilizing the tetragonal and cubic zirconia
Carbon corrosion and platinum nanoparticles ripening under open circuit poten...LandimarMendesDuarte
This document discusses a study examining the degradation of platinum nanoparticles supported on Vulcan XC72 carbon under open circuit potential conditions over 3.5 years. Characterization techniques showed that the amorphous domains of the carbon support were preferentially oxidized into CO2 during aging, while the organized domains were more slowly oxidized, producing mostly oxygen-containing surface groups and minor CO2. Over time, platinum nanoparticle aggregation and detachment from the carbon support increased due to platinum-catalyzed carbon corrosion.
Submicron Features i n Higher Manganese Silicideorenbenn
This document summarizes research into the microstructural features of higher manganese silicide (HMS), a promising thermoelectric material. Transmission electron microscopy revealed submicron dislocations, stacking faults, and silicon and HMS precipitates within the HMS matrix following hot pressing at high temperature. These nanostructures are responsible for the material's low thermal conductivity and indicate an ability to form complex nanostructures that persist during processing and use. The document analyzes microscopy images showing dislocations, faults, and silicon precipitates within HMS and HMS precipitates within silicon to support that the submicron features remain stable at high temperatures suitable for thermoelectric applications.
This document discusses the adsorption of carboxymethyl cellulose (CMC) onto alumina particles. CMC and alumina were chosen because their surface charges can be altered by pH, allowing the study of particle aggregation and stabilization. Electric light scattering and microelectrophoresis techniques were used to measure how CMC adsorption affects the electric polarizability and surface charge of the alumina particles over time and across a range of CMC concentrations. The results provide conditions for complete CMC adsorption and suspension stability.
This document summarizes a study investigating the effects of morphology and pore size distribution on the physicochemical properties of graphite nanosheets/nanoporous carbon black/cerium oxide nanoparticle electrodes for electrochemical capacitors. Electrodes with different compositions of these materials were fabricated and their surfaces and pores were characterized using SEM. Electrochemical testing showed that electrodes with a mixture of materials exhibited the highest capacitance due to having macro, micro, and nano pores that increased the accessible surface area. Introducing cerium oxide nanoparticles created micro pores, while carbon black particles created macro pores and rearranged the graphite nanosheets. This nanoporous structure resulted in an electrode with the highest capacitance of 16.2 F/
This document summarizes research on modifying the surface of nanostructured LiNi0.5Mn1.5O4 (LNMO) spinel materials for use as cathode materials in lithium-ion batteries. Nanowire LNMO was synthesized using a sol-gel template method without additional binders or conductive agents. Atomic layer deposition was used to deposit thin films of TiO2 and Al2O3 on the LNMO nanowires to protect the surface and prevent electrolyte decomposition and manganese ion dissolution. Surface-modified LNMO nanowires were characterized using various techniques and showed improved electrochemical performance through reduced interface resistance and prevention of side reactions.
Kinetics of Substituted Bis- and Mono-azo Dyes as Corrosion Inhibitors for Al...Al Baha University
This investigation is designed to apply an advanced kinetic^thermodynamic model on the data obtained from acidic and alkaline corrosion of aluminium using bis- and mono-azo dyes as corrosion inhibitors.
This document summarizes the preparation and characterization of carbon fiber-grafted poly(glycidyl methacrylate) (CF-PGMA) functionalized with the chelating ligand cyclam (CF-PGMA-Cy) for uptake of copper ions. The fibers were prepared in four steps: (1) electrografting of an aryl diazonium salt initiator onto carbon fibers, (2) surface-initiated atom transfer radical polymerization of glycidyl methacrylate, (3) functionalization of PGMA grafts with cyclam, and (4) characterization of copper ion uptake. X-ray photoelectron spectroscopy and contact angle measurements showed successful functionalization after each step. Copper uptake
The document summarizes four new heterometallic molecular aggregates containing cobalt and lanthanide metals. Compounds 1 and 2 have the formula [(CoII)3(CoIII)2Ln3(μ3-OH)5(O2CtBu)12(L)2]·2H2O and feature distorted cubane cores, while compounds 3 and 4 have the formula [(CoIII)3Ln3(μ3-OH)4(O2CtBu)6(L)3](NO3)2·2CH3CN·2H2O and display hemicubane-like metallic cores. Magnetic studies show significant magnetic entropy changes for 1 and 3, and single molecule magnetic
1) The study investigated the effect of adding zirconium oxide nanoparticles to carbon black electrode materials on surface morphology and electrochemical performance.
2) Scanning electron microscopy showed that adding nanoparticles partially filled gaps between carbon black particles, increasing the specific surface area available for charge storage.
3) Electrochemical analysis found that increasing nanoparticle content initially increased total charge storage due to higher surface area and pseudocapacitive charge storage, but further increases reduced performance due to higher electrode resistance.
Similar to Determination of the hydrogen coefficient diffusion DH in the MmNi3.55Mn0.4Al0.3Co0.75-xFex (0 ≤ x ≤0.75) electrodes alloys by cyclic voltammetry (20)
The Statutory Interpretation of Renewable Energy Based on Syllogism of Britis...AI Publications
The current production for energy consumption generates harmful impacts of carbon dioxide to the environment causing instability to sustainable development goals. The constitutional reforms of British Government serve to be an important means of resolving any encountered incompatibilities to political environment. This study aims to evaluate green economy using developed equation for renewable energy towards political polarization of corporate governance. The Kano Model Assessment is used to measure the equivalency of 1970 Patents Act to UK Intellectual Property tabulating the criteria for the fulfillment of sustainable development goals in respect to the environment, artificial intelligence, and dynamic dichotomy of administrative agencies and presidential restriction, as statutory interpretation development to renewable energy. The constitutional forms of British government satisfy the sustainable development goals needed to fight climate change, advocate healthy ecosystem, promote leadership of magnates, and delegate responsibilities towards green economy. The presidential partisanship must be observed to delineate parties of concerns and execute the government prescriptions in equivalence to the dichotomous relationship of technology and the environment in fulfilling the rights and privileges of all citizens. Hence, the political elites can execute corporate governance towards sustainable development of renewable energy promoting environmental parks and zero emission target of carbon dioxide discharges. The economic theory developed in statutory interpretation for renewable energy serves as a tool to reduce detrimental impacts of carbon dioxide to the environment, mitigate climate change, and produce artefacts of bioenergy and artificial intelligence promoting sustainable development. It is suggested to explore other vulnerabilities of artificial intelligence to prosper economic success.
Enhancement of Aqueous Solubility of Piroxicam Using Solvent Deposition SystemAI Publications
Piroxicam is a non-steroidal anti-inflammatory drug that is characterized by low solubility-high permeability. The present study was designed to improve the dissolution rate of piroxicam at the physiological pH's through its increased solubility by using solvent deposition system.
Analysis of Value Chain of Cow Milk: The Case of Itang Special Woreda, Gambel...AI Publications
Ethiopia has a long and rich history of dairy farming, which was mostly carried out by small and marginal farmers who raised cattle, camels, goats, and sheep, among other species, for milk. Finding the Itang Special Woreda cow milk value chain is the study's main goal. In order to gather primary data, 204 smallholder dairy farmer households were randomly selected, and the market concentration ratio was calculated using 20 traders. Descriptive statistics, econometric models, and rank analysis were used to achieve the above specified goals. Out of all the participants in the milk value chain, producers, cafés, hotels, and dairy cooperatives had the largest gross marketing margins, accounting for 100% of the consumer price in channels I and II, 55% in channels III and V, and 25.5% in channels V. The number of children under five, the number of milking cows owned, the amount of money from non-dairy sources, the frequency of extension service contacts, the amount of milk produced each day, and the availability of market information were found to have an impact on smallholders' involvement in the milk market. Numerous obstacles also limited the amount of milk produced and marketed. The poll claims that general health issues, sickness, predators, and a lack of veterinary care are plaguing farmers. In order to address the issue of milk perishability, the researchers recommended the host community and organization to construct an agro milk processor, renovate the dairy cooperative in the study region, and restructure the current conventional marketing to lower the transaction and cost of milk marketing.
Minds and Machines: Impact of Emotional Intelligence on Investment Decisions ...AI Publications
In the evolving landscape of financial decision-making, this study delves into the intricate relationships among Emotional Intelligence (EI), Artificial Intelligence (AI), and Investment Decisions (ID). By scrutinizing the direct influence of human emotional intelligence on investment choices and elucidating the mediating role of AI in this process, our research seeks to unravel the complex interplay between minds and machines. Through empirical analysis, we reveal that EI not only directly impacts ID but also exerts its influence indirectly through AI-mediated pathways. The findings underscore the pivotal role of emotional awareness in investor decision-making, augmented by the technological capabilities of AI. It suggests that most investors are influenced by the identified emotional intelligence when making investment decisions. Furthermore, AI substantially impacts investors' decision-making process when it comes to investing; nevertheless, AI partially mediates the relationship between emotional intelligence and investment decisions. This nuanced understanding provides valuable insights for financial practitioners, policymakers, and researchers, emphasizing the need for holistic strategies that integrate emotional and technological dimensions in navigating the intricacies of modern investment landscapes. As the synergy between human intuition and artificial intelligence becomes increasingly integral to financial decision-making, this study contributes to the ongoing discourse on the symbiotic relationship between minds and machines in investments.0
Bronchopulmonary cancers are common cancers with a poor prognosis. It is the leading cause of death by cancer in Algeria and in the world. Behind this unfavorable prognosis hides numerous disparities according to age, sex, and exposure to risk factors, ranking 4th among incident cancers and developing countries including Algeria, all sexes combined. It ranks 2nd cancers in men and 3rd among women. Whatever the age observed, the incidence of this cancer is higher in men than in women, however the gap is narrowing to the detriment of the latter. The results of scientific research agree to relate trends in incidence and mortality rates to tobacco consumption, including passive smoking. Furthermore, other risk factors are mentioned such as exposure to asbestos in the workplace or to radon for the general population, or even genetic predisposition. However, the weight of these etiological and/or predisposing factors is in no way comparable to that of tobacco in the genesis of lung cancer and the resulting mortality. We provide a literature review in our article on the descriptive and analytical epidemiology of lung cancer.
Further analysis on Organic agriculture and organic farming in case of Thaila...AI Publications
The objective of this paper is to present Further analysis on Organic agriculture and organic farming in case of Thailand agriculture and enhancing farmer productivity. In view of the demand for organic fertilizers, efforts should also be made to enhance and to develop more effective of compost, bio-fertilizer, and bio-pesticides currently used by farmers. Likewise, emphasis should also be laid on the cultivation of legumes and other crops that can enhance the fertility of the soil, as practiced by farmers in many developing countries to fertilize their lands. On the other hand, most of the farmers who practice this farm system found that they are adopting a number of SLMs and interested in joining the meeting or training to gain more and more knowledge.
Current Changes in the Role of Agriculture and Agri-Farming Structures in Tha...AI Publications
The objective os this study is to present Current Changes in the Role of Agriculture and Agri-Farming Structures in Thailand and Vietnam with SLM practices. Farmer’s adoption and investment in SLM is a key for controlling land degradation, enhancing the well-being of society, and ensuring the optimal use of land resources for the benefit of present and future generations (World Bank, 2006; FAO, 2018). And agriculture remains an essential element of lives of many farmers in term of the strong cultural and symbolic values that attach current working generation to do and to spend time for it but not intern of income generating.
Growth, Yield and Economic Advantage of Onion (Allium cepa L.) Varieties in R...AI Publications
Haphazard and low soil fertility, low yielding verities and poor agronomic practices are among the major factors constraining onion production in the central rift valley of Ethiopia. Therefore, a field experiment was conducted in East Showa Zone of Adami Tulu Jido Combolcha district in central rift valley areas at ziway from October 2021 to April 2022 to identify appropriate rate of NPSB fertilizer and planting pattern of onion varieties. The experiment was laid out in split plot design of factorial arrangement in three replications. The main effect of NPSB blended fertilizer rates and varieties (red coach and red king) significantly (p<0.01) influenced plant height, leaf length, leaf diameter, leaf number and fresh leaf weight, shoot dry matter per plant, and harvest index. Total dry biomass, bulb diameter, neck diameter, average fresh bulb weight, bulb dry matter, marketable bulb yield, and total bulb yield were significantly (p<0.01) influenced only by the main effect of NPSB blended fertilizer rates. In addition, unmarketable bulb yield was statistically significantly affected (p≥0.05) by the blended fertilizer rates and planting pattern. Moreover, days to 90% maturity of onion was affected by the main factor of NPSB fertilizer rate, variety and planting pattern. The non-fertilized plants in the control treatment were inferior in all parameters except unmarketable bulb yield and harvest index. Significantly higher marketable bulb yield (41 t ha-1) and total bulb yield (41.33 t ha-1) was recorded from 300 kg ha-1 NPSB blended fertilizer rate applied. Double row planting method and hybrid red coach onion variety had also gave higher growth and yields. The study revealed that the highest net benefit of Birr, 878,894 with lest cost of Birr 148,006 by the combinations of 150 kg blended NPSB ha-1 with double row planting method (40cm*20cm*7cm) and red coach variety which can be recommendable for higher marketable bulb yield and economic return of hybrid onion for small scale farmers in the study area. Also, for resource full producers (investors), highest net benefit of Birr 1,205,372 with higher cost (159,628 Birr) by application of 300 kg NPSB ha-1 is recommended as a second option. However, the research should be replicated both in season and areas to more verify the recommendations.
Evaluation of In-vitro neuroprotective effect of Ethanolic extract of Canariu...AI Publications
The ethanolic extract of canarium solomonense leaves (ecsl) was studied for its neuroprotective activity. The neuroprotective activity of ECSL was found to have a significant impact on neuronal cell death triggered by hydrogen peroxide (MTT assay) in human SH-SY5Y neuroblastoma cells. Scopolamine, a muscarinic receptor blocker, is frequently used to induce cognitive impairment in laboratory animals. Injections of scopolamine influence multiple cognitive functions, including motor function, short-term memory, and attention. Using the Morris water maze, the Y maze, and the passive avoidance paradigm, memory enhancing activity in scopolamine-induced amnesic rats was evaluated. Using the Morris water maze, the Y maze, and the passive avoidance paradigm, ECSL was found to have a substantial effect on the memory of scopolamine- induced amnesic rats. Our experimental data indicated that ECSL can reverse scopolamine induced amnesia and assist with memory issues.
The goal of neuroprotection is to shield neurons against damage, whether that damage is caused by environmental factors, pathogens, or neurodegenerative illnesses. Inhibiting protein-based deposit buildup, oxidative stress, and neuroinflammation, as well as rectifying abnormalities of neurotransmitters like dopamine and acetylcholine, are some of the ways in which medicinal herbs have neuroprotective effects [1-3]. This review will focus on the ways in which medicinal herbs may protect neurons.
A phytochemical and pharmacological review on canarium solomonenseAI Publications
The genus Canarium L. consists of 75 species of aromatic trees which are found in the rainforests of tropical Asia, Africa and the Pacific. The medicinal uses, botany, chemical constituents and pharmacological activities are now reviewed. Various compounds are tabulated according to their classes their structures are given. Traditionally canarium solomonense have been used to treat a broad array of illnesses. Pharmacological actions for canarium solomonense as discussed in this review include antibacterial, antimicrobial, antioxidant, anti-inflammatory, hepatoprotective and antitumor activity.
Influences of Digital Marketing in the Buying Decisions of College Students i...AI Publications
This research investigates the influence of digital marketing channels on purchasing decisions among college students in Ramanathapuram District. The study highlights that social media marketing, online advertising, and mobile marketing exhibit substantial positive effects on purchase decisions. However, email marketing's impact appears to be more complex. Moreover, the study explores how demographic variables like gender and academic level shape these effects. Notably, freshman students display varying susceptibility to specific digital marketing messages compared to their junior, senior, or graduate counterparts. These findings offer crucial insights for marketers aiming to tailor their strategies effectively to the preferences and behaviors of college students. By understanding the differential impacts of various digital marketing channels and considering demographic nuances, marketers can refine their approaches, optimize engagement, and ultimately enhance the effectiveness of their campaigns in targeting this demographic.
A Study on Performance of the Karnataka State Cooperative Agriculture & Rural...AI Publications
The Karnataka State Co-operative Agriculture and Rural Development Bank Limited is the apex bank of all the primary co-operative agriculture and rural development banks in the state. All the PCARD Banks in the state are affiliated to it. The KSCARD Bank provides financial accommodation to the PCARD Banks for their lending operations. In order to quick sanction and disbursement of loans and supervision over the PCARD Banks the KSCARD Bank has opened district level branches. Bank has established Women Development Cell to promote entrepreneurship among women in 2005. The Bank is identifying women borrowers in the rural areas by assigning suitable projects to motivate their self-confidence to lead independent life. Progress made in financing women entrepreneurs women.
Breast hamartoma is a rare, well-circumscribed, benign lesion made up of a variable quantity of glandular, adipose and fibrous tissue. This is a lesion that can affect women at any age from puberty. With the increasingly frequent use of imaging methods such as mammography and ultrasound as well as breast biopsy, cases of hamartoma diagnosed are increasing. The diagnosis of these lesions is made by mammography. The histological and radiological aspects are variable and depend on its adipose tissue content. The identification of these lesions is important in order to avoid surgical excisions. We report radio-clinical and pathological records of breast hamartoma.
A retrospective study on ovarian cancer with a median follow-up of 36 months ...AI Publications
Ovarian cancer is relatively common but serious and has a poor prognosis. The aim of this study is to highlight the epidemiological, diagnostic, therapeutic and evolutionary aspects of this malignant pathology managed at the Bejaia university hospital center. This is a retrospective and descriptive study over a period of 3 years (2019 - 2022) carried out on 20 patients who developed ovarian cancer. The average age of the patients was 50 years old, 53.23% of whom were over 45 years old. The CA-125 blood test was positive in 18 out of 20 patients. The tumors were discovered on ultrasound in 87.10% of cases and at laparotomy in 12.90%. Total hysterectomy with bilateral adnexectomy was the most performed procedure (64.52%). The early postoperative course was simple. 15 patients underwent second look surgery (16.13%) for locoregional recurrences. Epithelial tumors were the most frequent histological type (93.55%), including 79% in the advanced stage ( IIIc -IV) and 21% in the early stage (Ia- Ib ). Adjuvant chemotherapy was administered in 80% of patients. With a median follow-up of 36 months, 2 patients were lost to follow-up. The evolution was favorable in 27.42% and in 25.81% deaths occurred late postoperatively. Ovarian cancer is not common but serious given the advanced stages and the high rate of late postoperative deaths which were largely observed in patients deprived of adequate neoadjuvant or adjuvant chemotherapy.
More analysis on environment protection and sustainable agriculture - A case ...AI Publications
This study presents a case of tea and coffee crops , esp. environment protection and sustainable agriculture in Son La and Thai Nguyen of Vietnam. Research results show us that The process of having an agricultural product goes through many steps such as planting, planning, harvesting, packing, transporting, storing and distributing. - The State adopts policies to encourage innovation of agricultural production models and methods towards sustainability, adapting to climate change, saving water, and limiting the use of inorganic fertilizers and pesticides. chemicals and products for environmental treatment in agriculture; develop environmentally friendly agricultural models. Our research limitation is that we can expand for other crops, industries and markets as well.
Assessment of Growth and Yield Performance of Twelve Different Rice Varieties...AI Publications
The present investigation entitled “Assessment of growth and yield performance of twelve different rice varieties under north Konkan coastal zone of Maharashtra” was carried out during the kharif season of the year 2021 and 2022 on the field of ASPEE, Agricultural Research and Development Foundation, Tansa Farm, At Nare, Taluka Wada, District Palghar, Maharashtra, India. The experiment was laid out in Randomized Block Design (RBD). The twelve varieties namely Zini, Jaya, Dandi, Rahghudya, Govindbhog, Dangi, Gurjari, VNR-7, VNR-8, VNR-9, Karjat-3, and Karjat-5 were replicated thrice. The plant height (cm), number of tillers per plant, number of panicles per plant, number of panicles (m²), and length of panicle (cm) were noted to the maximum with cv. “VNR-7”. The highest number of seeds per panicle, test weight (gm), grain yield (q/ha), and straw yield (q/ha) were recorded with the cv. “VNR-7”. While the lowest number of days to 50% flowering was also recorded with cv. “VNR-7” during the year 2021 and 2022.
Cultivating Proactive Cybersecurity Culture among IT Professional to Combat E...AI Publications
In the current digital landscape, cybercriminals continually evolve their techniques to execute successful attacks on businesses, thus posing a great challenge to information technology (IT) professionals. While traditional cybersecurity approaches like layered defense and reactive security have helped IT professionals cope with traditional threats, they are ineffective in dealing with evolving cyberattacks. This paper focuses on the need for a proactive cybersecurity culture among IT professionals to enable them combat evolving threats. The paper emphasis that building a proactive security approach and culture can help among IT professionals anticipate, identify, and mitigate latent threats prior to them exploiting existing vulnerabilities. This paper also points out that as IT professionals use reactive security when dealing with traditional attacks, they can use it collaboratively with proactive security to effectively protect their networks, data, and systems and avoid heavy costs of dealing with cyberattack’s aftermaths and business recovery.
The Impacts of Viral Hepatitis on Liver Enzymes and BilrubinAI Publications
Viral hepatitis is an infection that causes liver inflammation and damage. Several different viruses cause hepatitis, including hepatitis A, B, C, D, and E. The hepatitis A and E viruses typically cause acute infections. The hepatitis B, C, and D viruses can cause acute and chronic infections. Hepatitis A causes only acute infection and typically gets better without treatment after a few weeks. The hepatitis A virus spreads through contact with an infected person’s stool. Protection by getting the hepatitis A vaccine. Hepatitis E is typically an acute infection that gets better without treatment after several weeks. Some types of hepatitis E virus are spread by drinking water contaminated by an infected person’s stool. Other types are spread by eating undercooked pork or wild game. Hepatitis B can cause acute or chronic infection. Recommendation for screening for hepatitis B in pregnant women or in those with a high chance of being infected. Protection from hepatitis B by getting the hepatitis B vaccine. Hepatitis C can cause acute or chronic infection. Doctors usually recommend one-time screening of all adults ages 18 to 79 for hepatitis C. Early diagnosis and treatment can prevent liver damage. The hepatitis D virus is unusual because it can only infect those who have a hepatitis B virus infection. A coinfection occurs when both hepatitis D and hepatitis B infections at the same time. A superinfection occurs already have chronic hepatitis B and then become infected with hepatitis D. The aim of this study is to find the effect of each type of viral hepatitis on the bilirubin (TB , DSB) , and liver enzymes; AST, ALT, ALP,GGT among viral hepatitis patients. 200 patients were selected from the viral hepatitis units in the central public health laboratory in Baghdad city, all the chosen cases were confirmed as a positive samples , they are classified into four equal group each with fifty individual and with a single serological viral hepatitis type either; anti-HAV( IgM ) , HBs Ag , anti-HCV ,or anti-HEV(IgM ). All patients were tested for; serum bilirubin ( TB ,D.SB ) , AST , ALT , ALP , GGT. Another fifty quite healthy and normal person was selected as a control group for comparison. . Liver enzymes and bilirubin changes are more pronounced in HAV, HEV than HCV and HBVAST and ALT lack some sensitivity in detecting HCV ,HBV and mild elevations of ALT or AST in asymptomatic patients can be evaluated efficiently by considering ,hepatitis B, hepatitis C. ALT is generally a more sensitive indicator of acute liver cell damage than AST, It is relatively specific for hepatocyte necrosis with a marked elevations in viral hepatitis. Liver enzymes and bilirubin changes are more pronounced in HAV, HEV than HCV and HBV.AST and ALT lack some sensitivity in detecting HCV ,HBV and mild elevations of ALT or AST in asymptomatic patients can be evaluated efficiently by considering ,hepatitis B, hepatitis C. ALT is generally a more sensitive indicator of acute liver
Determinants of Women Empowerment in Bishoftu Town; Oromia Regional State of ...AI Publications
The purpose of this study was to determine the status of women's empowerment and its determinants using women's asset endowment and decision-making potential as indicators. To determine representative sample size, this study used a two-stage sampling technique, and 122 sample respondents were selected at random. To analyze the data in this study, descriptive statistics and a probit model were used. The average women's empowerment index was 0.41, indicating a relatively lower status of women's empowerment in the study area. According to the study's findings, only 40.9% of women were empowered, while the remaining 59.1% were not. The probit model results show that women's access to the media, women's income, and their husbands' education status have a significant and positive impact on the status of women's empowerment, while the family size of households has a negative impact. As a result, it is important to enhance women's access to the media and income, promote family planning and contraception, and improve men's educational status in order to improve the status of women's empowerment.
A review of the growth of the Israel Genealogy Research Association Database Collection for the last 12 months. Our collection is now passed the 3 million mark and still growing. See which archives have contributed the most. See the different types of records we have, and which years have had records added. You can also see what we have for the future.
This slide is special for master students (MIBS & MIFB) in UUM. Also useful for readers who are interested in the topic of contemporary Islamic banking.
Exploiting Artificial Intelligence for Empowering Researchers and Faculty, In...Dr. Vinod Kumar Kanvaria
Exploiting Artificial Intelligence for Empowering Researchers and Faculty,
International FDP on Fundamentals of Research in Social Sciences
at Integral University, Lucknow, 06.06.2024
By Dr. Vinod Kumar Kanvaria
How to Fix the Import Error in the Odoo 17Celine George
An import error occurs when a program fails to import a module or library, disrupting its execution. In languages like Python, this issue arises when the specified module cannot be found or accessed, hindering the program's functionality. Resolving import errors is crucial for maintaining smooth software operation and uninterrupted development processes.
The simplified electron and muon model, Oscillating Spacetime: The Foundation...RitikBhardwaj56
Discover the Simplified Electron and Muon Model: A New Wave-Based Approach to Understanding Particles delves into a groundbreaking theory that presents electrons and muons as rotating soliton waves within oscillating spacetime. Geared towards students, researchers, and science buffs, this book breaks down complex ideas into simple explanations. It covers topics such as electron waves, temporal dynamics, and the implications of this model on particle physics. With clear illustrations and easy-to-follow explanations, readers will gain a new outlook on the universe's fundamental nature.
Macroeconomics- Movie Location
This will be used as part of your Personal Professional Portfolio once graded.
Objective:
Prepare a presentation or a paper using research, basic comparative analysis, data organization and application of economic information. You will make an informed assessment of an economic climate outside of the United States to accomplish an entertainment industry objective.
ISO/IEC 27001, ISO/IEC 42001, and GDPR: Best Practices for Implementation and...PECB
Denis is a dynamic and results-driven Chief Information Officer (CIO) with a distinguished career spanning information systems analysis and technical project management. With a proven track record of spearheading the design and delivery of cutting-edge Information Management solutions, he has consistently elevated business operations, streamlined reporting functions, and maximized process efficiency.
Certified as an ISO/IEC 27001: Information Security Management Systems (ISMS) Lead Implementer, Data Protection Officer, and Cyber Risks Analyst, Denis brings a heightened focus on data security, privacy, and cyber resilience to every endeavor.
His expertise extends across a diverse spectrum of reporting, database, and web development applications, underpinned by an exceptional grasp of data storage and virtualization technologies. His proficiency in application testing, database administration, and data cleansing ensures seamless execution of complex projects.
What sets Denis apart is his comprehensive understanding of Business and Systems Analysis technologies, honed through involvement in all phases of the Software Development Lifecycle (SDLC). From meticulous requirements gathering to precise analysis, innovative design, rigorous development, thorough testing, and successful implementation, he has consistently delivered exceptional results.
Throughout his career, he has taken on multifaceted roles, from leading technical project management teams to owning solutions that drive operational excellence. His conscientious and proactive approach is unwavering, whether he is working independently or collaboratively within a team. His ability to connect with colleagues on a personal level underscores his commitment to fostering a harmonious and productive workplace environment.
Date: May 29, 2024
Tags: Information Security, ISO/IEC 27001, ISO/IEC 42001, Artificial Intelligence, GDPR
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Strategies for Effective Upskilling is a presentation by Chinwendu Peace in a Your Skill Boost Masterclass organisation by the Excellence Foundation for South Sudan on 08th and 09th June 2024 from 1 PM to 3 PM on each day.
Assessment and Planning in Educational technology.pptxKavitha Krishnan
In an education system, it is understood that assessment is only for the students, but on the other hand, the Assessment of teachers is also an important aspect of the education system that ensures teachers are providing high-quality instruction to students. The assessment process can be used to provide feedback and support for professional development, to inform decisions about teacher retention or promotion, or to evaluate teacher effectiveness for accountability purposes.
2. M. Ben Moussa et al.
International journal of Chemistry, Mathematics and Physics (IJCMP), Vol-5, Issue-5 (2021)
http://www.aipublications.com/ijcmp/ Page | 2
substitution of Ni by Sn leads to an increase of the charge-
discharge life cycle and a decrease of the plateau pressure.
They [10] attributed this phenomena to the increase of the
cell volume unit of the MmNi5 caused by the Sn
substitution and the low volume dilatation during hydride
formation. Nowadays, the MmNi3.55Mn0.4Al0.3Co0.75 alloy
is one of the typical compounds used as commercialized
electrode materials. Unfortunately, cobalt is an expensive
metal and in a typical alloy such as
MmNi3.55Mn0.4Al0.3Co0.75, its price represents almost 50 %
of the total cost of the raw material [11]. So, the aim of this
work is to examine the effect of the substitution of cobalt
with iron on the electrochemical properties of the
commercialized MmNi3.55Mn0.4Al0.3Co0.75 compound used
as negative electrode in Ni/MH batteries, two alloys were
studied namely MmNi3.55Mn0.4Al0.3Co0.75-xFex with x =
0.55 and x = 0.75. The chronopotentimmetry and then
cyclic voltammetry methods are applied to determine the
charge transfer coefficient, the hydrogen diffusion
coefficient and the electrochemical stability of these two
materials. These properties were compared to those
published in our previous works [12, 13] for x = 0 and x =
0.35.
II. EXPERIMENTAL DETAILS
The MmNi3.55Mn0.4Al0.3Co0.75-xFex (x = 0, 0.15,
0.35, 0.55 and 0.75) compounds are prepared by UHF
induction melting of the pure elements followed by an
appropriate annealing to ensure a good homogeneity. The
results of the metallographic observations, the electron
probe microanalysis (EPMA) and the structural
characterization by X-ray diffraction (XRD) of these alloys
are listed in table 1. The structural characterization shows
that these alloys are indexed in the CaCu5 hexagonal
crystalline structure (P6/mmm space group).
Table 1: Lattice parameters and lattice volume of the
substituted compounds
Compound a (Å) c (Å) V (Å3
)
LaNi5 5.012 3.984 86.68
Ni3.55Mn0.4Al0.3Co0.2Fe0.55 5.0343 4.0622 89.1616
mNi3.55Mn0.4Al0.3Fe0.75 5.0422 4.067 89.5438
III. PREPARATION OF THE MH ELECTRODE
AND NI/MH CELL
The alloys ingot is ground mechanically and
saved to less than 63 µm in glove box under argon
atmosphere. The “latex” technology has been used for the
electrode preparation [14]. 90% of the alloy powder is
mixed with 5% of black carbon (to obtain a good
conductivity) and 5% of polytetrafluoroethylen (PTFE).
Two pieces of 0.5 cm2
of this latex are pressed on each
side of a nickel grid to prevent the electrode plate from
breaking into pieces during the charge-discharge cycling
[11]. This set forms the negative electrode of Ni/MH
accumulator. The counter electrode was formed by the Ni
oxyhydroxide Ni(OH)2, whereas the reference electrode
was the Hg/HgO 1 M KOH solution, prepared with
deionised water.
IV. ELECTROCHEMICAL MEASUREMENTS
All the electrochemical measurements were
performed at room temperature in a conventional three
electrode open-air cell using VMP system. The discharge
capacity of the electrode was determined by a
galvanostatical charging-discharging at C/3 and D/6
regime respectively. Every cycle was carried out by
charging fully to –1.3 V and discharging to –0.6 V with
respect to Hg/HgO 1 M KOH reference electrode at a
temperature of 25°C. After activating the electrode for 30
cycles, the cyclic voltammetry was applied at scan rates of
10, 20, 30, 40 and 50 µv/s between -1.1 and – 0.5 V vs.
Hg/HgO.
V. RESULTS AND DISCUSSION
5. 1. Lifetime cycle of the electrode
Figure 1 shows the variation of the discharge
capacity of the MmNi3.55Mn0.4Al0.3Co0.2Fe0.55 and
MmNi3.55Mn0.4Al0.3Fe0.75 electrodes as function of the
number of cycles. The discharge capacity of
MmNi3.55Mn0.4Al0.3Co0.2Fe0.55 alloy powder increases to
reache 210 mAh/g after 12 cycles and then decreases to
190 mAh/g after a few charge-discharge cycles. However,
for the MmNi3.55Mn0.4Al0.3Fe0.75 compound, the discharge
capacity reaches its maximum of 200 after 10 cycles and
then decreases to 160 mAh/g after 30 cycles. These results
show that the alloy containing the cobalt has a good
stability but a bad activity. The capacity decay of the
hydrogen storage alloy electrode is mainly due to the
pulveverization and oxidation of the active material
components to form oxides or hydroxides [15, 18]. In fact
the formed oxide or hydroxide layer acts as a barrier to the
hydrogen diffusion and leads to the decrease of the number
of hydrogen atoms which can be absorbed by the material.
Pan et al. [17] and Geng et al. [16] assume that the loss in
discharge capacity is due to the deterioration of the
negative electrode material with increasing the number of
charge-discharge cycles. In fact, during the cycling, the
rare earth elements such as La or the transition metal such
as Mn segregate to the grain boundaries, where they were
subject to corrosion. The corrosion products are disposed
3. M. Ben Moussa et al.
International journal of Chemistry, Mathematics and Physics (IJCMP), Vol-5, Issue-5 (2021)
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on the surface of grain particles as needle-shaped La(OH)3
or as Mn3O4. This corrosion phenomenon leads to an
increase of the resistance among alloy grains, which in
turn decrease the alloy discharge capacity. This decrease
may be also attributed to the oxidation of iron on the alloy
surface which limit the hydrogen transfer from the surface
to the bulk of the alloy and leads consequently to a loss in
the amount of hydrogen stored in the material. So, it is
easy to conclude that a total substitution of cobalt by iron
deteriorates the stability and the lifetime cycle of the
electrode made from the considered material.
0
100
200
0 5 10 15 20 25 30
Fe0.55
Fe0.75
Discharge
Capacity
(mAh/g)
number of cycles
Fig.1: Variation of the electrochemical discharge capacity of the MmNi3.55Mn0.4Al0.3Co0.75-xFex
(x = 0.55 and 0.75) compounds as a function of the cycle number.
5. 2. Cyclic voltammetry
Figures 2 and 3 show the cyclic voltammograms
of, respectively, the MmNi3.55Mn0.4Al0.3Co0.2Fe0.55 and
MmNi3.55Mn0.4Al0.3Fe0.75 compounds carried out after
activation during 30 cycles at scan rates equal to 10, 20,
30, 40 and 50 µv/s. The anodic peak in these
voltammograms is attributed to the oxidation of the
absorbed hydrogen atoms on the surface. The anodic peak
current increases and the potential slightly shifts to the
positive direction with increasing the scan rate. Figure 4
shows that the anodic peak potential (Eap) has a linear
dependence with log(v). In this case, the anodic peak
potential can be given by the Equation 1 as [19, 20]:
F
n
α
2
T
R
3
.
2
=
)
v
log(
d
E
d p
a
(1)
Where v is the scan rate, R the constant of rare gas, T the
temperature of the electrochemical cell, α the charge
transfer coefficient, n the number of exchanged electron
and F the Faraday constant. Based on this formula, we can
determine the value of the charge transfer coefficient α.
Figure 5 shows that the variation of the anodic peak
current versus square root of the potential scan rate (v1/2
) is
linear. This behavior indicates that we are in presence of a
semi-infinite diffusion and irreversible charge transfer. So,
the current of the oxidation anodic peak can be expressed
by the Equation 2 as [19, 20]:
]
T
R
D
v
[
2
/
1
C
S 0
)
F
n
( 2
/
3
α
496
.
0 2
/
1
=
Iap
(2)
Where α is the charge transfer coefficient, n the number of
the exchanged electron, F the Faraday constant, S the
geometric surface of the working electrode (cm2
), C0 the
concentration of the diffusing species (mol cm-3
), D the
hydrogen diffusion coefficient (cm2
s-1
) and v the potential
scan rate (V s-1
). The concentration of the diffusing species
C0 is determined by Equation 3 as:
M
0
V
F
m
M
Q
=
C (3)
4. M. Ben Moussa et al.
International journal of Chemistry, Mathematics and Physics (IJCMP), Vol-5, Issue-5 (2021)
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where M, m, F and VM are respectively, the molecular
mass, the effective mass of material, the Faraday constant
and the molecular volume of material. Q is the amount of
anodic oxidation hydrogen during the anodic sweep of
cyclic voltammetry [21]. It is expressed by Equation 4 as:
dE
∫ ∫ v
i
=
dt
i
=
Q
2
1
2
1
t
t
E
E
(4)
Where t1, t2 and t are times, E1, E2 and E are the potentials,
i the anodic current and v the potential scan rate.
According to Equation 2, the hydrogen diffusion
coefficient in this metal hydride electrode can be
determined based on the slope of the curve Iap = f(v1/2
).
Based on the slope of Figure 4 and 5, the values of the
charge transfer coefficient α and the hydrogen diffusion
coefficient DH are summarized in table 2.
-2
-1
0
1
2
-1.04 -0.96 -0.88 -0.8 -0.72 -0.64 -0.56 -0.48
E
we
(Volt)
1) 50 µv/s
2) 40 µv/s
3) 30 µv/s
4) 20 µv/s
5) 10 µv/s
1
2
3
4
5
Fig.2: Cyclic voltammograms of the MmNi3.55Mn0.4Al0.3Co0.2Fe0.55 compound obtained at potential scan rates of 10, 20, 30,
40 and 50 µV s-1
.
-5
-4
-3
-2
-1
0
1
2
3
-1.1 -1 -0.9 -0.8 -0.7 -0.6 -0.5
E
we
(Volt)
1
2
3
4
5
1) 50 µV/s
2) 40 µV/s
3) 30 µV/s
4) 20 µV/s
5) 10 µV/s
Fig.3: Cyclic voltammograms of the MmNi3.55Mn0.4Al0.3Fe0.75 compound obtained at potential scan rates of 10, 20, 30, 40 and
50 µV s-1
.
5. M. Ben Moussa et al.
International journal of Chemistry, Mathematics and Physics (IJCMP), Vol-5, Issue-5 (2021)
http://www.aipublications.com/ijcmp/ Page | 5
-0,82
-0,81
-0,8
-0,79
-0,78
-0,77
-0,76
-0,75
-0,74
-5 -4,8 -4,6 -4,4 -4,2
log(v)(V S
-1
)
Fe
0.7 5
Fe
0.5 5
Fig.4: Variation of the anodic peak potential of cyclic voltammograms of the MmNi3.55Mn0.4Al0.3Co0.2Fe0.55 and
MmNi3.55Mn0.4Al0.3Fe0.75 electrodes as a function of log(v).
0
0,0005
0,001
0,0015
0,002
0,0025
0,003 0,0035 0,004 0,0045 0,005 0,0055 0,006 0,0065 0,007
v
1/2
(V
1/2
s
-1/2
)
Fe
0.75
Fe
0.55
Fig.5: Variation of the anodic peak current of the cyclic voltammograms of the MmNi3.55Mn0.4Al0.3Co0.2Fe0.55 and
MmNi3.55Mn0.4Al0.3Fe0.75 electrodes as a function of the square root of potential scan rate.
Table 2: The maximum discharge capacity Cmax, the charge transfer α and the hydrogen diffusion coefficient DH for the
MmNi3.55Mn0.4Al0.3Co0.75-xFex (x = 0, 0.35, 0.55 and 0.75) compounds.
Compound Maximum discharge
Capacity (mAh/g)
Charge transfer
coefficient α
Hydrogen diffusion
coefficient DH (cm2
s-1
)
MmNi3.55Mn0.4Al0.3Co0.75 [12] 270 0.35 5.86 10-10
MmNi3.55Mn0.4Al0.3Co0.6Fe0.15 266 0.6 1.95 10-9
MmNi3.55Mn0.4Al0.3Co0.4Fe0.35 [13] 260 0.5 3.44 10-9
MmNi3.55Mn0.4Al0.3Co0.2Fe0.55 210 0.33 2.96 10-9
MmNi3.55Mn0.4Al0.3Fe0.75 200 0.3 4.98 10-10
6. M. Ben Moussa et al.
International journal of Chemistry, Mathematics and Physics (IJCMP), Vol-5, Issue-5 (2021)
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Based on table 2, it can be seen that the maximum
discharge capacity decreases when the iron content
increases. The probable reason for this decrease is the
reduction of the number of the available sites of hydrogen
when the cobalt is substituted by iron. On the other hand,
the addition of the iron facilitates the oxidation of the
surface of the alloy by the combination with oxygen to form
an oxide film which in turn inhibits the hydrogen diffusion
and leads to a loss in the discharge capacity. The obtained
values of the charge transfer coefficient α and the hydrogen
diffusion coefficient DH indicate good electrochemical
kinetics and an acceptable reversibility of the reaction.
VI. CONCLUSION
The electrochemical properties of the
MmNi3.55Mn0.4Al0.3Co0.2Fe0.55 and MmNi3.55Mn0.4Al0.3Fe0.75
compounds have been investigated by two electrochemical
methods which are the chronopotentiometry and the cyclic
voltammerty. The following conclusions can be drawn:
• The discharge capacity for the
MmNi3.55Mn0.4Al0.3Co0.2Fe0.55 reaches a maximum
value of 210 mAh g-1
after 12 cycles and then
decreases to about 190 mAh g-1
after 30 cycles.
However, for the MmNi3.55Mn0.4Al0.3Fe0.75
compound, the discharge capacity reaches its
maximum of 200 mAh g-1
after 10 cycles and then
decreases to 160 mAh g-1
after 30 cycles.
• The values of the charge transfer coefficient of the
MmNi3.55Mn0.4Al0.3Co0.2Fe0.55 and the
MmNi3.55Mn0.4Al0.3Fe0.75 compounds are,
respectively, equal to 0.33 and 0.3. This indicates a
good reversibility of the electrochemical reaction
for these alloys which means a good absorption-
desorption kinetics in the case of solids.
• The values of the hydrogen diffusion coefficient
DH for the MmNi3.55Mn0.4Al0.3Co0.2Fe0.55 and the
MmNi3.55Mn0.4Al0.3Fe0.75 compounds are,
respectively, equal to 2.96 10-9
and 4.98 10-10
cm2
s-1
.
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