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Articles 3391 - 3420 of 3436
Full-Text Articles in Physical Sciences and Mathematics
A Study Of Three Photochemical Activities Of Chloroplasts, Jimmy W. Hinkson
A Study Of Three Photochemical Activities Of Chloroplasts, Jimmy W. Hinkson
Theses and Dissertations
Chloroplasts of sugar beet leaves were subjected to treatment by heating, by incubation at pH 8.5 and pH 5.5, by incubation in ion low water, by sonic oscillation, by digestion with enzymes (lysozyme, pancreatin, and lipase), by extraction with digitonin, and by chemical compounds including 8-hydroxy-quinoline, sodium azide, zinc sulfate, phenyl mercuric acetate, potassium cyanide, 1-allylthiourea, 2,4-dinitrophenol, thymol, and p-chloromercuribenzoate. A comparative study was made of the effects of these treatments upon three photochemical reactions (the photoreduction of 2,6- dichlorophenol indophenol, the photoreduction of indigo carmine in the presence of a couple composed of 2,6-dichlorophenol indophenol and ascorbic acid, and …
The Photoreduction Of Indigo Carmine Flavin Mononucleotide And Diphosphopyridine Nucleotide, By Illuminated Chloroplasts, M. Odell Hobbs
The Photoreduction Of Indigo Carmine Flavin Mononucleotide And Diphosphopyridine Nucleotide, By Illuminated Chloroplasts, M. Odell Hobbs
Theses and Dissertations
An investigation was made of the photoreduction of indigo carmine dye and flavin mononucleotide (FMN) by an illuminated sugar beet leaf homogenate in the presence of 2,6-dichlorophenolindophenol dye (DPIP) and ascorbic acid. DPIP and ascorbate were absolutely required for the reaction. Reconstitution experiments indicated a requirement for a heat-labile factor present in the supernatant fluid following centrifugation of the leaf homogenate. This factor activated the photoreduction of indigo carmine more than 20 times. The photoreduction of FMN was activated 2 times by this factor. Studies on the stoichiometry of indigo carmine photoreduction revealed that one mole of ascorbate was photooxidized …
Rhenium Catalysis I. Hydrogenation And Hydroformylation Using Rhenium Carbonyl Compounds ; Ii. Hydrogenation Using Catalysts Obtained From The Reduction Of Perrhenates With Metals In Aqueous Solution, Terry G. Selin
Theses and Dissertations
The purpose of this work was to investigate the catalytic activity in both hydrogenation and hydroformylation reactions of rhenium preparations which have not been previously characterized. Rhenium pentacarbonyl was prepared in good yield from rhenium heptoxide and carbon monoxide. The optimum conditions for preparation were 25 hours per gram of dry rhenium heptoxide at 250° under 3000 psig. (initial) of carbon monoxide. Rhenium chloropentacarbonyl was prepared in 62% yield from potassium chlororhenite and carbon monoxide at high temperatures and pressures. The iodopentacarbonyl was prepared in 29% yield from potassium perrhenate, methyl iodide, and carbon monoxide. The preparation of rhenium hydrocarbonyl …
The Preparation And Catalytic Properties Of Rhenium Blacks Obtained By Reduction Of Re(Vii) In Anhydrous Ammonia And Amines With Alkali Metals, David William Seegmiller
The Preparation And Catalytic Properties Of Rhenium Blacks Obtained By Reduction Of Re(Vii) In Anhydrous Ammonia And Amines With Alkali Metals, David William Seegmiller
Theses and Dissertations
The purpose of the investigation was to determine the catalytic activity of rhenium blacks obtained by reduction of rhenium salts in alkali metal-ammonia or amine systems. A review is presented on the chemical, physical and catalytic properties of rhenium, and on the rhenide ion, on the nature of the alkali metal-liquid ammonia system, and the reduction of metallic salts therein. The first reduction system studied was that obtained by dissolving sodium in liquid ammonia. The salts reduced in this system were KReO_4, Re_2O_7 and NH_4ReO_4. The reduction of KReO_4 was unsuccessful, and the heptoxide was difficult to handle. The product …
Chemosynthetic Microorganisms In Leaching Sulfide Minerals, A. Keith Jameson
Chemosynthetic Microorganisms In Leaching Sulfide Minerals, A. Keith Jameson
Theses and Dissertations
This investigation showed that a single bacterium was capable of sulfide oxidation in exposed ore bodies. This single bacterium was isolated and characterized. It exhibited different characteristics than any previously known organism. It was found to be a chemosynthetic autotroph. An optimum nutrient concentration was determined for pyrite oxidation. The nutrient concentration was determined for pyrite oxidation. The nutrient contains only a source of phosphate and nitrogen. Urea was found to be a better source of nitrogen than ammonium sulfate which had previously been used. The effect of various organic compounds on the oxidation of pyrite was observed. Glucose and …
The Isomer Distribution In The Sulfonation Of Iodobenzene, Joseph A. Knight
The Isomer Distribution In The Sulfonation Of Iodobenzene, Joseph A. Knight
Theses and Dissertations
Using the isotope dilution technique, the distribution of isomers was determined when iodobenzene was sulfonated with sulfur trioxide in liquid sulfur dioxide. The active isotope was S^35. Before this distribution could be established, it was necessary to prepare the pure isomers of iodobenzenesulfonic acid. These were prepared by diazotization of the corresponding aminobenzenesulfonic acids. Since o-aminobenzenesulfonic acid was not readily available, it was necessary that it be synthesized before the diazo reactions could be carried out. Considerable work has been done on the development of a method whereby the bromobenzenesulfonic acids could be synthesized and obtained in pure form. Some …
The Dehydrocyclization Of Normal Heptane To Toluene With Supported Rhenium, Platinum And Molybdenum Catalysts, Robert R. Beishline
The Dehydrocyclization Of Normal Heptane To Toluene With Supported Rhenium, Platinum And Molybdenum Catalysts, Robert R. Beishline
Theses and Dissertations
The dehydrocyclization activity of supported platinum, molybdenum and rhenium catalysts was studied by determining the toluene yield from n-heptane as a function of temperature and metal concentration in the catalyst. The support was 100 to 200 mesh alumina. Metal concentrations of 0.01% to 1.0% platinum, 0.1% to 2.0% molybdenum and 0.1% to 2.5% rhenium were studied in the temperature range from 500° to 600° C. Platinum was shown to be superior to both molybdenum and rhenium at all temperatures and metal concentrations investigated. The rhenium data were somewhat erratic, but showed rhenium to be a poor dehydrocyclization catalyst. The apparatus, …
Thermal Reaction Of Hydrogen And Oxygen In Small Bore Tubes, Shib Charan Chattoraj
Thermal Reaction Of Hydrogen And Oxygen In Small Bore Tubes, Shib Charan Chattoraj
Theses and Dissertations
The thermal reaction of hydrogen and oxygen has been investigated from the standpoint of the important intermediate hydrogen peroxide in the region between 620-720 degrees centigrade in small bore Pyrex and steel tubes. The minimum explosion-temperatures with different flow rates and compositions of the mixture have been determined. They have been found to vary with the composition and flow rate of the mixture. The minimum explosion temperature is also found to vary with the condition of the reaction tube surface. The yield of hydrogen peroxide has been determined as a function of temperature, contact time, composition of feed stream, and …
Oxidation Of Molybdenite With The Aid Of Microorganisms, Ralph Anderson
Oxidation Of Molybdenite With The Aid Of Microorganisms, Ralph Anderson
Theses and Dissertations
This work represents a study on the biological oxidation of molybdenite, MoS2. The principal objective of this study was to investigate the possibility of the biological oxidation of molybdenite, to determine the physical and chemical conditions under which the oxidative process occurs, and to develop a strain of bacteria or alter the activity of the microorganisms by acclimatization to increase their activity on sulfide minerals, in particular molybdenite. Minerals used in this study were pyrite (FeS2), chalcopyrite (CuFeS2), molybdenite concentrate, and molybdenite ore. The microorganisms used in this investigation were autotrophic bacteria obtained from the leaching streams of Bingham Canyon, …
The Instability Constant Of The Cobaltous Citrate Complex Ion Using Cobalt-⁶⁰ As A Tracer, Lee T. Cox
The Instability Constant Of The Cobaltous Citrate Complex Ion Using Cobalt-⁶⁰ As A Tracer, Lee T. Cox
Theses and Dissertations
The instability constant of a substance shows the tendency of a substance to dissociate into simple ions. The stability of the substance can be related to stabilities of other substances through the instability constant. Schubert gives a method for the determination of the instability constant which involves measurements of the adsorption of a radiotracer cation on a cation exchange resin. Two different types of resin were employed in this research. It was found that with a resin containing carboxylic acid exchange groups the adsorption of the cobaltous ion changed rapidly with pH but with a resin containing nuclear sulfonic acid …
A Correlation Of The Catalytic Activity Of Various Mixtures Of Rhenium And Molybdenum Sulfides In Liquid-Phase Hydrogenation Of Certain Reducible Organic Groups, Li-Chen Hsu
Theses and Dissertations
The promoter action of mixtures of catalysts has been reported in literature to be valuable in industries. Whether mixtures of rhenium and molybdenum sulfides would have promoter actions in the hydrogenations of certain reducible organic groups was the main object of this research. Mixtures of rhenium and molybdenum sulfides of various compositions were prepared by three different methods, i.e., (a) by saturating perrhenate and molybdate with hydrogen sulfide in hydrochloric acid solutions, (b) in ammonium hydroxide solutions followed by acidification, and (c) by treating perrhenate and molybdate with thiosulfate in dilute sulfuric acids followed by extraction with toluene to remove …
Photo-Oxidations Sensitized By Physiologically Important Substances, Ernel D. Ihnen
Photo-Oxidations Sensitized By Physiologically Important Substances, Ernel D. Ihnen
Theses and Dissertations
A study of the photo-oxidation of the 2,6-dichlorophenol indophenol-ascorbic couple was undertaken with a view to investigating the postulated mechanism of oxidation by a component of the oxygen evolving sequence operative in photosynthesis. A spectrophotometric method for the measurement of the progress of photo-oxidation was developed. Temperature and pH dependence were determined and the effect of various common inhibitors and physiological substances tested. None of the common Hill reaction inhibitors were effective in the ascorbic acid photo-oxidation in the system used. KCN and catalase as well as a few other high molecular weight proteins were able to inhibit dark auto-oxidation …
Calorimetric Heats Of Mixing Of Some Nonelectrolytic Binary And Ternary Solutions, James Bevan Ott
Calorimetric Heats Of Mixing Of Some Nonelectrolytic Binary And Ternary Solutions, James Bevan Ott
Theses and Dissertations
The heat of mixing of nonelectrolytic liquids is important in predicting the type of molecular interactions which exist in solutions of nonelectrolyted. The problem was to construct a calorimeter in which these heats of mixing could be measured accurately. Once constructed, the calorimeter was used to measure the heats of mixing of some binary and a ternary solutions. The systems chosen for study were the three liquid pairs formed between benzane, carbon tetrachloride, and cyclohexane, and the ternary mixture of the three. The results of the experimentation are summarized by the following equations. (1) H_12^M = X_1x_2 [103.2 + 13.1(x_1 …
Some Aspects Of The Chemistry Of The Hydroquinoxalines Unsubstituted On The Nitrogen Atoms, Evan L. Allred
Some Aspects Of The Chemistry Of The Hydroquinoxalines Unsubstituted On The Nitrogen Atoms, Evan L. Allred
Theses and Dissertations
A search of the literature revealed that almost nothing is known concerning the class of compounds known as decahydroquinoxalines. Since this posed a problem involving a search for a systematic synthetic method of general application as well as a method for establishing the characteristic class and individual properties, a research project under the guidance of Dr. H. Smith Broadbent was initiated. Of particular interest aside from matters of purely chemical interest was the recognition that the hydroquinoxalines possess obvious structural similarities with atropine and other well-known drugs which have valuable application as hypotensive agents, analgesics, spasmolytic agents, parasympathetic depressants, antihistaminics, …
Acidic Properties Of Clay Minerals And Alumina, Kenneth H. Anderson
Acidic Properties Of Clay Minerals And Alumina, Kenneth H. Anderson
Theses and Dissertations
Acidic properties of dialyzed alumina and representative clay minerals were studied by performing titrations with various bases. For the first group of experiments the titrations were made in a water system using KOH and NaOH. For this study in a water system the experimental data includes individual cationic activities as well as pH values. Adsorption of the cations was adequately described over a pH range of 5-11 by the equation 1-θ/θ ⋅ aNa+ ⋅ aOH- = 1/K'3 [aOH- + KW/K'2 + 1/K'1], in which θ represents the fraction of the total sites that have reacted. Thermodynamic constants K'3 and K0= …
The Effect Of Ferrous And Ferric Ions On The Conversion Of Malate To Pyruvate By A Cell Free Extract Of Pigeon Liver, Keith Erwin Richardson
The Effect Of Ferrous And Ferric Ions On The Conversion Of Malate To Pyruvate By A Cell Free Extract Of Pigeon Liver, Keith Erwin Richardson
Theses and Dissertations
Recent investigations on the crude pigeon liver extracts have shown the presence of an enzyme which catalyzes the oxidative decarboxylation of malate to pyruvate and carbon dioxide. The name malic enzyme has been given to this enzyme to distinguish it from malic dehydrogenase. Under aerobic conditions the addition of ferrous sulfate resulted in inhibition of the action of malic enzyme. Subsequent investigation showed that the inhibition obaerved was not due to ferrous ions, but due to ferric ions which were contaminating the ferrous sulfate. It was also shown that under aerobic conditions ferrous ions were rapidly oxidized to ferric ions. …
Colorimetric Determination Of Rhenium In Ores, Clair Winston Rogers
Colorimetric Determination Of Rhenium In Ores, Clair Winston Rogers
Theses and Dissertations
The problem of colorimetrically determining rhenium in the presence of molybdenum, copper, iron, sulphur, and rare earth elements with the use of dimethylglyoxime as the complexing compound was accomplished by the method reported here-in. The interfering elements were eliminated either as gaseous oxides and sulfides or were precipitated from a highly basic solution by means of a strong alkaline fusion of equal weights of sodium hydroxide and sodium peroxide, and the ore sample containing rhenium. The fusion product was dissolved in water, the solution boiled with a slight excess of sodium peroxide, and the hydroxide of all the interfering ions …
Thermodynamic Properties Of Water Adsorbed On Kaolinite, S. John Bennett
Thermodynamic Properties Of Water Adsorbed On Kaolinite, S. John Bennett
Theses and Dissertations
The object of the work presented in this thesis was to obtain quantitative values of the thermodynamic changes in water upon adsorption by kaolinite. Two methode were used. The first was a determination of the differential heat content and entropy of adsorption. The second method included a thermodynamic evaluation of the B.E.T. "c" constant expressed in terms of the Gibbs standard free energy of adsorption. The experimental data gave satisfactory results in determining the differential and standard thermodynamic functions or free energy, entropy, and heat content of adsorption. The adsorption of water on kaolinite appears to be a van der …
Evaluations Of Two Proposed Mechanisms Of Cation Adsorption By Silicate Minerals, Norman D. Larsen
Evaluations Of Two Proposed Mechanisms Of Cation Adsorption By Silicate Minerals, Norman D. Larsen
Theses and Dissertations
Previous work done at the Brigham Young University by Andelin^1, Roberts^2, and Olsen^3, has established the mechanism by which xanthate collectors are adsorbed on molybdenite ores to produce the hydrophobic surfaces necessary for flotation. This thesis is an attempt to better understand the mechanism by which the silicate minerals, which are found in conjunction with the ores, become hydrophyllic and as a result are not floated when in contact with air bubbles. It has been previously established that silicate minerals do adsorb cations on their surfaces^4. The present study has been undertaken to more fully understand the mechanism by which …
The Chromatographic Purification Of Human Red Blood Cell Acetylcholinesterase, Richard P. Dunkley
The Chromatographic Purification Of Human Red Blood Cell Acetylcholinesterase, Richard P. Dunkley
Theses and Dissertations
A process of column chromatography of human erythrocyte acetylcholinesterase, using a cationic exchange resin, was investigated as a possible method for the primary partial purification of the enzyme on a large scale. The investigation was based, first; on a detailed study of the enzymatic stability to variation in hydrogen-ion and salt concentrations for periods of time extending to forty eight hours and, second; on an investigation of the degree of adsorption by the resin of the enzyme at various pH values within the pH range of enzyme stability. A method for the analysis of the enzyme activity of large numbers …
Early History Of Millard County And Its Latter-Day Saint Settlers, 1851-1912, Ladd R. Cropper
Early History Of Millard County And Its Latter-Day Saint Settlers, 1851-1912, Ladd R. Cropper
Theses and Dissertations
Millard County, Utah is located one hundred and fifty miles south of Salt Lake City in the west central part of the state. The county is bounded on the north by Juab County, on the west by Nevada, on the south by Beaver County, and on the east by Sevie, Sanpete, and Juab Counties.
There are interesting formations of extinct volcanoes. Fossils can be found and well marked evidences of an ancient lake named Bonneville.
A short account of the early explorer, Father Escalante, is given in the thesis. This tells of his travels in Millard County in the year …
Biological Oxidation Of Copper Sulfide Minerals, Delmar Boyd Davis
Biological Oxidation Of Copper Sulfide Minerals, Delmar Boyd Davis
Theses and Dissertations
This work represents a study of the biological oxidation of copper sulfide minerals. The principal objective of the study was to determine the extent of bacterial oxidation on copper containing sulfide minerals. It was also desired to determine if the bacteria could oxidize copper sulfides in the absence of iron. A better understanding of the nitrogen requirements of the organisms was desired. Minerals used in this study were Bingham Canyon Float Concentrate, chalcopyrite, covellite, calcocite, bornite, tetrahedrite, and reagent grade copper sulfide. The bacteria used were obtained from the mine waters of Bingham Canyon, Utah. To study the problem the …
Mechanism Of Adsorption Of Cations By Silicate Minerals, Milton Glen Armstrong
Mechanism Of Adsorption Of Cations By Silicate Minerals, Milton Glen Armstrong
Theses and Dissertations
Adsorption of cations by clays has been a subject of investigation for many years. Many proposals have been advanced to explain this process of adsorption. Two proposals have been prominent in recent years. The Marshall "charged lattice" theory attributes adsorption of cations by clays to an electrostatic attration of the clay particles for cations. This charge on the clay particles is attributed to various isomorphic substitutions in the lattice of the clay which result in an unbalanced charge on the particle. This isomorphic substitution can take place either in the silicon-oxygen tetrahedra of the silicate structure or with the aluminum …
Collector-Depressant Equilibria In The Selective Flotation Of Sulfide Ores, Heber Ross Olson
Collector-Depressant Equilibria In The Selective Flotation Of Sulfide Ores, Heber Ross Olson
Theses and Dissertations
This dissertation presents the results of a collector - depressant equilibria study of the flotation systems potassium n-amyl xanthate - sodium cyanide - molybdenite and ethyl zanthate sodium sulfide - molybdenite and the study of conditions necessary for the selective flotation of covellite, tetra-hedrite, bornite, chalcopyrite, molybdenite, marcasite and pyrite in the system ethyl xanthate and sodium cyanide; the conditions necessary for the selective flotation of pyrite, covellite, bornite, galena, chalcopyrite, active sphalerite, and molybdenite in the system potassium ethyl xanthate and sodium sulfide; the conditions necessary for the selective flotation of molybdenite and pyrite in the system of potassium …
Ultraviolet Absorption Spectra Of Quinoxaline And Some Of Its Derivatives, Fred Dale Huillet
Ultraviolet Absorption Spectra Of Quinoxaline And Some Of Its Derivatives, Fred Dale Huillet
Theses and Dissertations
A long term research program into the chemistry of quinoxalines has been instituted at Brigham Young University with the aim of preparing the vinylquinoxalines so that their 1,4-addition reactions might be studied. The literature of quinoxaline chemistry has been thoroughly reviewed and assembled. Methods of preparing 2-methyl- and 2,3-dimethylquinoxaline have been studied and improved but all attempts to prepare the vinylquinoxalines have been unsuccessful. In the course of these attempts several compounds of unknown structure were prepared. The purpose of this investigation is to study the spectra of various known quinoxaline derivatives and to attempt to identify the unknowns by …
Collector-Depressant Equilibria For The Flotation System Potassium Ethyl Xanthate-Potassium Cyanide-Molybdenite, Connell Bolton Roberts
Collector-Depressant Equilibria For The Flotation System Potassium Ethyl Xanthate-Potassium Cyanide-Molybdenite, Connell Bolton Roberts
Theses and Dissertations
This dissertation involves a study of the collector-depressant equilibria of the flotation system potassium ethyl xanthate-potassium cyanide-molybdenite, based upon mineral-air bubble contact measurements made by a modified captive bubble technique. The Cook theory of single site free acid adsorption is used to interpret the data. The standard free energies of adsorption of ethyl xanthic acid and hydrocyanic acid on molybdenite are calculated.
Thermodynamic Properties Of Water Absorbed On Silica, Conrad V. Hatch
Thermodynamic Properties Of Water Absorbed On Silica, Conrad V. Hatch
Theses and Dissertations
The object of the work presented in this thesis was to obtain quantitative values of the thermodynamic changes in water upon adsorption by silica. Two methods were used. The first was a determination of the differential entropy and heat of adsorption independent of any theory of adsorption. The second method included a new interpretation of the "c" constant of the Brunauer, Emmett, and Teller Theory in which c was expressed in terms of the standard free energy of adsorption. The experimental data gave satisfactory results in determining the differential heat and entropy of adsorption. The results obtained in determining the …
Collector-Depressant Equilibria In The Flotation Of Molybdenite, Robert Létrenne Andelin
Collector-Depressant Equilibria In The Flotation Of Molybdenite, Robert Létrenne Andelin
Theses and Dissertations
This dissertation presents the results of research on the flotation system potassium n-amyl xanthate - sodium sulfide - molybdenite. The purposes of the research were (1) to determine the theoretical collector-depressant equilibria conditions of this system necessary for the flotation or depression of molybdenite, (2) to ascertain the mechanism of adsorption or the collector potassium n-amyl xanthate and the depressant sodium sulfide on molybdenite, and (3) to calculate the standard free energy of adsorption on molybdenite of the collector and depressant in this system. To accomplish these purposes it was necessary to develop a satisfactory experimental method for the controlled …
Further Studies Of The Reactions Of Quinoxaline And 2-Methylquinoxaline, Marcus N. Myers
Further Studies Of The Reactions Of Quinoxaline And 2-Methylquinoxaline, Marcus N. Myers
Theses and Dissertations
The present investigation was also made with the object of preparing the vinylquinoxalines and studying their 1,4- addition reactions. The attempts to prepare vinylquinoxalines were unsuccessful. However, sodium acetylide reacted with 2,3-dichloroquinoxaline to give a new compound which (from its analysis and properties) appears to be 2,3-bis(1-hydroxyethyl) quinoxaline . This new compound should be investigated further , as it may prove to be an intermediate in the preparation of vinylquinoxalines. The preparation of 2-methylquinoxaline has become very simple by the use of the method of Jones, Kornfeld and McLaughlin^5, which consists of condensing o-phenylenediamine with pyruvic aldehyde. The condensation of …
Solubility Product Constants Of The Metallic Sulfides, Marvin Bernard Gordon
Solubility Product Constants Of The Metallic Sulfides, Marvin Bernard Gordon
Theses and Dissertations
A survey of the chemical literature revealed a lack of agreement in the values reported by various investigators for the solubility product constants of the metallic sulfides. The object of this thesis was to obtain a reliable set of solubility product constant values for the metallic sulfides by means of thermodynamic calculations. Of considerable importance in calculating the values of the solubility product constants of the metallic sulfides is the value of the standard free energy of formation of the sulfide ion. A critical review of the values that have been reported by various investigators for this constant , including …