The Experts below are selected from a list of 24183 Experts worldwide ranked by ideXlab platform
M A Deyab - One of the best experts on this subject based on the ideXlab platform.
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hydroxyethyl cellulose as efficient organic inhibitor of zinc carbon Battery corrosion in ammonium chloride solution electrochemical and surface morphology studies
Journal of Power Sources, 2015Co-Authors: M A DeyabAbstract:Abstract Hydroxyethyl cellulose (HEC) has been investigated as corrosion inhibitor for zinc–carbon Battery by polarization and electrochemical impedance spectroscopy (EIS) measurements. The obtained results show that the maximum inhibition efficiency by HEC in 26% NH4Cl solution at 300 ppm and 298 K is 92.07%. Tafel polarization studies reveal that HEC acts as an efficient mixed inhibitor. The corrosion rate is suppressed by the adsorption of HEC on the zinc surface. HEC adsorption obeys the Langmuir isotherm and the thermodynamic parameters Kads and Δ G ads o have been also calculated and discussed. Both physisorption and chemisorption may occur on the zinc surface. Surface characterization investigation using Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM) is used to ascertain the nature of the protective film.
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Hydroxyethyl cellulose as efficient organic inhibitor of zinc–carbon Battery corrosion in ammonium chloride solution: Electrochemical and surface morphology studies
Journal of Power Sources, 2015Co-Authors: M A DeyabAbstract:Abstract Hydroxyethyl cellulose (HEC) has been investigated as corrosion inhibitor for zinc–carbon Battery by polarization and electrochemical impedance spectroscopy (EIS) measurements. The obtained results show that the maximum inhibition efficiency by HEC in 26% NH4Cl solution at 300 ppm and 298 K is 92.07%. Tafel polarization studies reveal that HEC acts as an efficient mixed inhibitor. The corrosion rate is suppressed by the adsorption of HEC on the zinc surface. HEC adsorption obeys the Langmuir isotherm and the thermodynamic parameters Kads and Δ G ads o have been also calculated and discussed. Both physisorption and chemisorption may occur on the zinc surface. Surface characterization investigation using Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM) is used to ascertain the nature of the protective film.
Timothy S. Magnuson - One of the best experts on this subject based on the ideXlab platform.
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teaching cellular respiration alternate energy sources with a laboratory exercise developed by a scientist teacher partnership
American Biology Teacher, 2009Co-Authors: Brandon R. Briggs, Teri Mitton, Rosemary J. Smith, Timothy S. MagnusonAbstract:[ILLUSTRATION OMITTED] Students often resort to memorization and recall when learning about cellular respiration. The concepts of glycolysis, Krebs cycle, and the electron transfer chain are abstract with multiple steps that are difficult to follow. The electron transport chain is the major workhorse for creating ATP in living organisms, and yet there are very few ways to clearly illustrate the electron transport chain in the laboratory. The above comment started a conversation between a high school biology teacher and scientists from the local university who were participants in a National Science Foundation (NSF)-funded teacher-scientist partnership program. This conversation led to a collaboration that developed this laboratory exercise demonstrating cellular respiration. Cellular respiration is the process of obtaining biochemical energy (stored as ATP) from fuel molecules (sugars). There are three major reactions that occur in cellular respiration: glycolysis, the Krebs cycle, and the electron transport chain (ETC). The ETC is the final step in cellular respiration and produces the most ATE In eukaryotes, the ETC is on the mitochondrial membrane; however, prokaryotes do not have a mitochondria and thus the ETC is on the plasma membrane. In addition, eukaryotes are only capable of respiring on oxygen (glucose + [O.sub.2] [right arrow] C[O.sub.2] + [H.sub.2]O), called aerobic respiration. When oxygen is not present, eukaryotes can perform the less efficient fermentation reactions. Fermentation produces less ATP than aerobic respiration because it does not use the Krebs cycle and the ETC. However, in the absence of oxygen, prokaryotes have the ability to ferment as well as use the ETC (anaerobic respiration). For example, some bacteria are able to respire on solid phase iron (glucose + [Fe.sup.+3] [right arrow] C[O.sub.2] + [Fe.sup.+2]). Respiration on multiple elements gives microbes an advantage in harsh environments where oxygen is not present. In addition, microbial respiration on solid phase compounds can be exploited to produce electricity. Microbial fuel ceils are a current research area that harvests electricity from bacteria capable of anaerobic respiration (Holmes et al., 2004; Liu et al., 2004; Logan et al., 2005). Graphite is an electrically conductive material that bacteria can respire on, thus it can be used to capture electrons from bacteria. When bacteria transfer electrons to graphite, an electrical potential is created that can produce electricity when in a circuit. A sediment Battery is a simple circuit that uses graphite and anaerobic bacteria naturally found in dirt. The electrical potential produced by bacterial respiration on the graphite can be measured on a voltmeter and thus can be used as a visual aid for teaching cellular respiration. The combination of the need for a new learning tool and the expertise of the scientists led to the development of the laboratory exercise described here. It uses student-designed sediment batteries to better visualize and measure electron transfer in living cells. This exercise satisfies National Science Education Teaching Standards A and B, and Content Standards A, B, and C. * Background Chemical Batteries A Battery uses chemicals to produce electrons. One common Battery is a zinc/carbon Battery, which has two terminals: a positive (cathode) and negative (anode). At the negative terminal, a zinc rod is placed in sulfuric acid. The sulfuric acid dissolves the zinc rod at the surface. A zinc atom will leave the rod as a [Zn.sup.+2] ion leaving two electrons on the rod; thus electrons are built up at the anode. When the Battery is incorporated into a circuit, the electrons are allowed to travel from the anode to the cathode. In the cathode, the electrons travel through the carbon into sulfuric acid to produce hydrogen gas. The production and movement of electrons in a Battery can power a device. …
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Teaching Cellular Respiration & Alternate Energy Sources with a Laboratory Exercise Developed by a Scientist-Teacher Partnership
American Biology Teacher, 2009Co-Authors: Brandon R. Briggs, Teri Mitton, Rosemary J. Smith, Timothy S. MagnusonAbstract:[ILLUSTRATION OMITTED] Students often resort to memorization and recall when learning about cellular respiration. The concepts of glycolysis, Krebs cycle, and the electron transfer chain are abstract with multiple steps that are difficult to follow. The electron transport chain is the major workhorse for creating ATP in living organisms, and yet there are very few ways to clearly illustrate the electron transport chain in the laboratory. The above comment started a conversation between a high school biology teacher and scientists from the local university who were participants in a National Science Foundation (NSF)-funded teacher-scientist partnership program. This conversation led to a collaboration that developed this laboratory exercise demonstrating cellular respiration. Cellular respiration is the process of obtaining biochemical energy (stored as ATP) from fuel molecules (sugars). There are three major reactions that occur in cellular respiration: glycolysis, the Krebs cycle, and the electron transport chain (ETC). The ETC is the final step in cellular respiration and produces the most ATE In eukaryotes, the ETC is on the mitochondrial membrane; however, prokaryotes do not have a mitochondria and thus the ETC is on the plasma membrane. In addition, eukaryotes are only capable of respiring on oxygen (glucose + [O.sub.2] [right arrow] C[O.sub.2] + [H.sub.2]O), called aerobic respiration. When oxygen is not present, eukaryotes can perform the less efficient fermentation reactions. Fermentation produces less ATP than aerobic respiration because it does not use the Krebs cycle and the ETC. However, in the absence of oxygen, prokaryotes have the ability to ferment as well as use the ETC (anaerobic respiration). For example, some bacteria are able to respire on solid phase iron (glucose + [Fe.sup.+3] [right arrow] C[O.sub.2] + [Fe.sup.+2]). Respiration on multiple elements gives microbes an advantage in harsh environments where oxygen is not present. In addition, microbial respiration on solid phase compounds can be exploited to produce electricity. Microbial fuel ceils are a current research area that harvests electricity from bacteria capable of anaerobic respiration (Holmes et al., 2004; Liu et al., 2004; Logan et al., 2005). Graphite is an electrically conductive material that bacteria can respire on, thus it can be used to capture electrons from bacteria. When bacteria transfer electrons to graphite, an electrical potential is created that can produce electricity when in a circuit. A sediment Battery is a simple circuit that uses graphite and anaerobic bacteria naturally found in dirt. The electrical potential produced by bacterial respiration on the graphite can be measured on a voltmeter and thus can be used as a visual aid for teaching cellular respiration. The combination of the need for a new learning tool and the expertise of the scientists led to the development of the laboratory exercise described here. It uses student-designed sediment batteries to better visualize and measure electron transfer in living cells. This exercise satisfies National Science Education Teaching Standards A and B, and Content Standards A, B, and C. * Background Chemical Batteries A Battery uses chemicals to produce electrons. One common Battery is a zinc/carbon Battery, which has two terminals: a positive (cathode) and negative (anode). At the negative terminal, a zinc rod is placed in sulfuric acid. The sulfuric acid dissolves the zinc rod at the surface. A zinc atom will leave the rod as a [Zn.sup.+2] ion leaving two electrons on the rod; thus electrons are built up at the anode. When the Battery is incorporated into a circuit, the electrons are allowed to travel from the anode to the cathode. In the cathode, the electrons travel through the carbon into sulfuric acid to produce hydrogen gas. The production and movement of electrons in a Battery can power a device. …
Mehmet Kitis - One of the best experts on this subject based on the ideXlab platform.
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Acidic leaching and precipitation of zinc and manganese from spent Battery powders using various reductants.
Journal of Hazardous Materials, 2009Co-Authors: E. Sayilgan, T. Kukrer, Nevzat Yigit, G. Civelekoglu, Mehmet KitisAbstract:Abstract The main objective of this study was to investigate the effects of reductive acidic leaching and further precipitation on the recovery of manganese and zinc from spent alkaline and zinc–carbon Battery powders. Ascorbic acid (AA), citric acid (CA) and oxalic acid (OA) were tested as the reductants. Sodium hydroxide and potassium hydroxide were used as precipitating agents. OA with H 2 SO 4 or HCl was not effective on the leaching of zinc due to the formation of zinc oxalate precipitates. However, the other reducing agents (CA and AA) tested under various experimental conditions were effective in the acidic leaching of both zinc and manganese. Leaching yields of both manganese and zinc were higher at leach temperature of 90 °C than those at 30 °C. Leach solutions were purified by the selective precipitation of manganese and zinc using KOH or NaOH. Complete precipitation was obtained for Mn at pH 9–10 and for Zn at pH 7–8. The use of ascorbic acid or citric acid as reductants in acidic leaching appears to be effective in the simultaneous leaching and further recovery of zinc and manganese from spent alkaline and zinc–carbon Battery powders.
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Acidic leaching and precipitation of zinc and manganese from spent Battery powders using various reductants.
Journal of hazardous materials, 2009Co-Authors: E. Sayilgan, T. Kukrer, G. Civelekoglu, N O Yigit, Mehmet KitisAbstract:The main objective of this study was to investigate the effects of reductive acidic leaching and further precipitation on the recovery of manganese and zinc from spent alkaline and Zinc-Carbon Battery powders. Ascorbic acid (AA), citric acid (CA) and oxalic acid (OA) were tested as the reductants. Sodium hydroxide and potassium hydroxide were used as precipitating agents. OA with H(2)SO(4) or HCl was not effective on the leaching of zinc due to the formation of zinc oxalate precipitates. However, the other reducing agents (CA and AA) tested under various experimental conditions were effective in the acidic leaching of both zinc and manganese. Leaching yields of both manganese and zinc were higher at leach temperature of 90 degrees C than those at 30 degrees C. Leach solutions were purified by the selective precipitation of manganese and zinc using KOH or NaOH. Complete precipitation was obtained for Mn at pH 9-10 and for Zn at pH 7-8. The use of ascorbic acid or citric acid as reductants in acidic leaching appears to be effective in the simultaneous leaching and further recovery of zinc and manganese from spent alkaline and Zinc-Carbon Battery powders.
Brandon R. Briggs - One of the best experts on this subject based on the ideXlab platform.
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teaching cellular respiration alternate energy sources with a laboratory exercise developed by a scientist teacher partnership
American Biology Teacher, 2009Co-Authors: Brandon R. Briggs, Teri Mitton, Rosemary J. Smith, Timothy S. MagnusonAbstract:[ILLUSTRATION OMITTED] Students often resort to memorization and recall when learning about cellular respiration. The concepts of glycolysis, Krebs cycle, and the electron transfer chain are abstract with multiple steps that are difficult to follow. The electron transport chain is the major workhorse for creating ATP in living organisms, and yet there are very few ways to clearly illustrate the electron transport chain in the laboratory. The above comment started a conversation between a high school biology teacher and scientists from the local university who were participants in a National Science Foundation (NSF)-funded teacher-scientist partnership program. This conversation led to a collaboration that developed this laboratory exercise demonstrating cellular respiration. Cellular respiration is the process of obtaining biochemical energy (stored as ATP) from fuel molecules (sugars). There are three major reactions that occur in cellular respiration: glycolysis, the Krebs cycle, and the electron transport chain (ETC). The ETC is the final step in cellular respiration and produces the most ATE In eukaryotes, the ETC is on the mitochondrial membrane; however, prokaryotes do not have a mitochondria and thus the ETC is on the plasma membrane. In addition, eukaryotes are only capable of respiring on oxygen (glucose + [O.sub.2] [right arrow] C[O.sub.2] + [H.sub.2]O), called aerobic respiration. When oxygen is not present, eukaryotes can perform the less efficient fermentation reactions. Fermentation produces less ATP than aerobic respiration because it does not use the Krebs cycle and the ETC. However, in the absence of oxygen, prokaryotes have the ability to ferment as well as use the ETC (anaerobic respiration). For example, some bacteria are able to respire on solid phase iron (glucose + [Fe.sup.+3] [right arrow] C[O.sub.2] + [Fe.sup.+2]). Respiration on multiple elements gives microbes an advantage in harsh environments where oxygen is not present. In addition, microbial respiration on solid phase compounds can be exploited to produce electricity. Microbial fuel ceils are a current research area that harvests electricity from bacteria capable of anaerobic respiration (Holmes et al., 2004; Liu et al., 2004; Logan et al., 2005). Graphite is an electrically conductive material that bacteria can respire on, thus it can be used to capture electrons from bacteria. When bacteria transfer electrons to graphite, an electrical potential is created that can produce electricity when in a circuit. A sediment Battery is a simple circuit that uses graphite and anaerobic bacteria naturally found in dirt. The electrical potential produced by bacterial respiration on the graphite can be measured on a voltmeter and thus can be used as a visual aid for teaching cellular respiration. The combination of the need for a new learning tool and the expertise of the scientists led to the development of the laboratory exercise described here. It uses student-designed sediment batteries to better visualize and measure electron transfer in living cells. This exercise satisfies National Science Education Teaching Standards A and B, and Content Standards A, B, and C. * Background Chemical Batteries A Battery uses chemicals to produce electrons. One common Battery is a zinc/carbon Battery, which has two terminals: a positive (cathode) and negative (anode). At the negative terminal, a zinc rod is placed in sulfuric acid. The sulfuric acid dissolves the zinc rod at the surface. A zinc atom will leave the rod as a [Zn.sup.+2] ion leaving two electrons on the rod; thus electrons are built up at the anode. When the Battery is incorporated into a circuit, the electrons are allowed to travel from the anode to the cathode. In the cathode, the electrons travel through the carbon into sulfuric acid to produce hydrogen gas. The production and movement of electrons in a Battery can power a device. …
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Teaching Cellular Respiration & Alternate Energy Sources with a Laboratory Exercise Developed by a Scientist-Teacher Partnership
American Biology Teacher, 2009Co-Authors: Brandon R. Briggs, Teri Mitton, Rosemary J. Smith, Timothy S. MagnusonAbstract:[ILLUSTRATION OMITTED] Students often resort to memorization and recall when learning about cellular respiration. The concepts of glycolysis, Krebs cycle, and the electron transfer chain are abstract with multiple steps that are difficult to follow. The electron transport chain is the major workhorse for creating ATP in living organisms, and yet there are very few ways to clearly illustrate the electron transport chain in the laboratory. The above comment started a conversation between a high school biology teacher and scientists from the local university who were participants in a National Science Foundation (NSF)-funded teacher-scientist partnership program. This conversation led to a collaboration that developed this laboratory exercise demonstrating cellular respiration. Cellular respiration is the process of obtaining biochemical energy (stored as ATP) from fuel molecules (sugars). There are three major reactions that occur in cellular respiration: glycolysis, the Krebs cycle, and the electron transport chain (ETC). The ETC is the final step in cellular respiration and produces the most ATE In eukaryotes, the ETC is on the mitochondrial membrane; however, prokaryotes do not have a mitochondria and thus the ETC is on the plasma membrane. In addition, eukaryotes are only capable of respiring on oxygen (glucose + [O.sub.2] [right arrow] C[O.sub.2] + [H.sub.2]O), called aerobic respiration. When oxygen is not present, eukaryotes can perform the less efficient fermentation reactions. Fermentation produces less ATP than aerobic respiration because it does not use the Krebs cycle and the ETC. However, in the absence of oxygen, prokaryotes have the ability to ferment as well as use the ETC (anaerobic respiration). For example, some bacteria are able to respire on solid phase iron (glucose + [Fe.sup.+3] [right arrow] C[O.sub.2] + [Fe.sup.+2]). Respiration on multiple elements gives microbes an advantage in harsh environments where oxygen is not present. In addition, microbial respiration on solid phase compounds can be exploited to produce electricity. Microbial fuel ceils are a current research area that harvests electricity from bacteria capable of anaerobic respiration (Holmes et al., 2004; Liu et al., 2004; Logan et al., 2005). Graphite is an electrically conductive material that bacteria can respire on, thus it can be used to capture electrons from bacteria. When bacteria transfer electrons to graphite, an electrical potential is created that can produce electricity when in a circuit. A sediment Battery is a simple circuit that uses graphite and anaerobic bacteria naturally found in dirt. The electrical potential produced by bacterial respiration on the graphite can be measured on a voltmeter and thus can be used as a visual aid for teaching cellular respiration. The combination of the need for a new learning tool and the expertise of the scientists led to the development of the laboratory exercise described here. It uses student-designed sediment batteries to better visualize and measure electron transfer in living cells. This exercise satisfies National Science Education Teaching Standards A and B, and Content Standards A, B, and C. * Background Chemical Batteries A Battery uses chemicals to produce electrons. One common Battery is a zinc/carbon Battery, which has two terminals: a positive (cathode) and negative (anode). At the negative terminal, a zinc rod is placed in sulfuric acid. The sulfuric acid dissolves the zinc rod at the surface. A zinc atom will leave the rod as a [Zn.sup.+2] ion leaving two electrons on the rod; thus electrons are built up at the anode. When the Battery is incorporated into a circuit, the electrons are allowed to travel from the anode to the cathode. In the cathode, the electrons travel through the carbon into sulfuric acid to produce hydrogen gas. The production and movement of electrons in a Battery can power a device. …
E. Sayilgan - One of the best experts on this subject based on the ideXlab platform.
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Acidic leaching and precipitation of zinc and manganese from spent Battery powders using various reductants.
Journal of Hazardous Materials, 2009Co-Authors: E. Sayilgan, T. Kukrer, Nevzat Yigit, G. Civelekoglu, Mehmet KitisAbstract:Abstract The main objective of this study was to investigate the effects of reductive acidic leaching and further precipitation on the recovery of manganese and zinc from spent alkaline and zinc–carbon Battery powders. Ascorbic acid (AA), citric acid (CA) and oxalic acid (OA) were tested as the reductants. Sodium hydroxide and potassium hydroxide were used as precipitating agents. OA with H 2 SO 4 or HCl was not effective on the leaching of zinc due to the formation of zinc oxalate precipitates. However, the other reducing agents (CA and AA) tested under various experimental conditions were effective in the acidic leaching of both zinc and manganese. Leaching yields of both manganese and zinc were higher at leach temperature of 90 °C than those at 30 °C. Leach solutions were purified by the selective precipitation of manganese and zinc using KOH or NaOH. Complete precipitation was obtained for Mn at pH 9–10 and for Zn at pH 7–8. The use of ascorbic acid or citric acid as reductants in acidic leaching appears to be effective in the simultaneous leaching and further recovery of zinc and manganese from spent alkaline and zinc–carbon Battery powders.
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Acidic leaching and precipitation of zinc and manganese from spent Battery powders using various reductants.
Journal of hazardous materials, 2009Co-Authors: E. Sayilgan, T. Kukrer, G. Civelekoglu, N O Yigit, Mehmet KitisAbstract:The main objective of this study was to investigate the effects of reductive acidic leaching and further precipitation on the recovery of manganese and zinc from spent alkaline and Zinc-Carbon Battery powders. Ascorbic acid (AA), citric acid (CA) and oxalic acid (OA) were tested as the reductants. Sodium hydroxide and potassium hydroxide were used as precipitating agents. OA with H(2)SO(4) or HCl was not effective on the leaching of zinc due to the formation of zinc oxalate precipitates. However, the other reducing agents (CA and AA) tested under various experimental conditions were effective in the acidic leaching of both zinc and manganese. Leaching yields of both manganese and zinc were higher at leach temperature of 90 degrees C than those at 30 degrees C. Leach solutions were purified by the selective precipitation of manganese and zinc using KOH or NaOH. Complete precipitation was obtained for Mn at pH 9-10 and for Zn at pH 7-8. The use of ascorbic acid or citric acid as reductants in acidic leaching appears to be effective in the simultaneous leaching and further recovery of zinc and manganese from spent alkaline and Zinc-Carbon Battery powders.
