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Articles 33241 - 33270 of 34523
Full-Text Articles in Physical Sciences and Mathematics
The Synthesis Of 5- And 8-Dialhylamino-Alkylaminopyrido [2,3-D] Pyridazines As Potential Antimalarial Agents., William M. Rich
The Synthesis Of 5- And 8-Dialhylamino-Alkylaminopyrido [2,3-D] Pyridazines As Potential Antimalarial Agents., William M. Rich
Chemistry and Chemical Biology ETDs
The appearance of strains of malaria resistant to most of the synthetic antimalarial agents has prompted the investigation of new compounds for antimalarial activity. The structural similarities of the nucleus of pyrido [2,3-d] pyridazine to pteridine as well as to the known quinoline antimalarials suggested the possibility of development of potential chemotherapeutic agents based on the ring system.
A series of 5,8 substituted pyrido [2,3-d] pyridazines were prepared in which one substituent was a dialkylaminoalkylamino group and the other substituent either a chloro, ethoxy, or hydroxy group. Ultraviolet, infrared, and nuclear magnetic resonance spectra were reported for all compounds. Structures …
Bacterial Degradation Of Methyl Dehydroabietate, Burl C. Carter
Bacterial Degradation Of Methyl Dehydroabietate, Burl C. Carter
Dissertations and Theses
Bacteria (Arthrobacter sp.), isolated from lodgepole pine (Pinus contortus), are capable of utilizing methyl dehydroabietate as the sole source of carbon. Degradation products of methyl dehydroabietate have been obtained by manually extracting the cell-free supernatant solution of a liquid growth medium with methylene chloride. Gas chromatography (G. L. C.) was used for separation of the neutral products. The acid products were converted to their methyl esters diazomethane and then separated by gas chromatography. Structures have been proposed for two G. L. C. fractions (V, II) on the basis of infrared (I.R.) and mass spectral (M. S.) data. …
A Molecular Orbital Study Of The Isomerization Mechanism Of Diazacumulenes, Mark S. Gordon, Herbert Fischer
A Molecular Orbital Study Of The Isomerization Mechanism Of Diazacumulenes, Mark S. Gordon, Herbert Fischer
Mark S. Gordon
Inversion barriers and geometries of AB3 molecules calculated using the INDO method3 are in satisfactory agreement with experiment. The diazacumulenes (11) with an even number of atoms are calculated to have a higher configurational stability than those with an odd number of atoms. cis-Diimide and cis-difluorodiimide should be more stable thermodynamically than the corresponding trans isomers. The configurational stability of carbodiimide is predicted to be low (comparable to that of ammonia), the isomerization being a combination of rotation and inversion, However, difluorocarbodiimide should be stable enough to permit resolution.
Isolation And Partial Characterization Of The Toxic Substance From Eremocarpus Setigerus Benth, Shuliang Lee
Isolation And Partial Characterization Of The Toxic Substance From Eremocarpus Setigerus Benth, Shuliang Lee
Loma Linda University Electronic Theses, Dissertations & Projects
The work on the active substance of Eremocarpus setigerus Benth has been previously performed by Naito and Noller. However, the investigation was not complete. Therefore we isolated and tested this substance by steam distillation and thin layer chromatography technique. A yellow sticky toxic substance was isolated with Rf values of 0.15 in benzene system and 0.57 in benzene-absolute ethanol (95:5 v/v) system.
The toxic substance which is free of halogen, nitrogen, and sulfur, is soluble in ethyl ether, ethanol, and concentrated sulfuric acid. It has a maximum absorption in the ultraviolet region that indicates the presence of unsaturation. Its infrared …
An Investigation Of Column Efficiency And The Relationship To Liquid Phase Distribution On Ultra-Low Loaded Glass Bead Gas Chromatographic Columns, Donald G. Nyberg
An Investigation Of Column Efficiency And The Relationship To Liquid Phase Distribution On Ultra-Low Loaded Glass Bead Gas Chromatographic Columns, Donald G. Nyberg
Theses and Dissertations
Studies have been made of column efficiencies, extra-column effects, the liquid phase mass transfer term (C_l), and liquid phase distribution at ultra-low liquid loadings on glass bead gas-liquid chromatographic columns. The advantages of using lightly loaded columns are described in detail along with a critical evaluation of the limitations of this liquid phase reduction ad infinitum. Theories have been presented by Giddings^22,23,25,30,32 which predict the mass transfer term (C_l) as a function of two extreme liquid phase distributions. The first equation assumes 100% "capillary" liquid held at the glass bead contact points and represents a very inefficient column. This prediction …
The Effect Of Oak Leaves On The Leaching Of Trace Metals From Sand, Thomas Elton Goodwin
The Effect Of Oak Leaves On The Leaching Of Trace Metals From Sand, Thomas Elton Goodwin
Honors Theses
Sand is fairly rich in some common trace metals, notably manganese and iron. However, these metals for the most part are in a state which renders them insoluble in water. It is thought that the presence of organic matter (principally leaves) in the water enhances the dissolution of some of these trace metals into the aqueous solution.
This enhancement of dissolution is generally thought to come about in three main ways: (1) The organic matter present lowers the oxygen content of the water, and the metals are reduced into a soluble form, (2) The organic material, some of which is …
The Approximate Scf Lcao-Mo With Cndo Theory And Electronic Structures Of N-Heterocyclic Benzene Analogues, Jay Jea-Yong Rhee
The Approximate Scf Lcao-Mo With Cndo Theory And Electronic Structures Of N-Heterocyclic Benzene Analogues, Jay Jea-Yong Rhee
Chemistry and Chemical Biology ETDs
The approximate MO theory in this study expIicitly refers to the Pople molecular orbitaI treatment. This consists of complete neglect of differential overlap (CNOO) in the self-consistent field treatment of the molecular orbitals, analogous to the Hartree-Fock treatment of atomic systems, which are constructed as Iinear combinations of atomic orbitals (LCAO). Furthermore, the only orbital functions considered in a basis set are those for the valence electrons and the atomic orbitals are Slater-type orbitals. The major investigation of this study is to apply this approximate MO theory to the series of nitrogen heterocyclic benzene analogues. The quantities that have been …
Acid-Base Titrations In Non-Aqueous Solvents, Gary Rice
Acid-Base Titrations In Non-Aqueous Solvents, Gary Rice
Honors Theses
The acid-base titration is one of the simper methods available to the analytical chemist. Many organic compounds exhibit acidic or basic properties. Proper selection of solvent makes possible analytical determination of extremely weak acids and bases. This paper discusses the three solvent properties that are important in determining the acid-base behavior of a solute.
Kinetics Of The Thermal Decomposition Of Acetonitrile, Thomas William Asmus
Kinetics Of The Thermal Decomposition Of Acetonitrile, Thomas William Asmus
Masters Theses
No abstract provided.
Fluorescence Studies Of Cobalt (Iii) Complexes, Arnold T. Weibel
Fluorescence Studies Of Cobalt (Iii) Complexes, Arnold T. Weibel
Masters Theses
No abstract provided.
Radiolysis Of Liquid Propane: Radical Reactions, Robert D. Koob, Larry Kevan
Radiolysis Of Liquid Propane: Radical Reactions, Robert D. Koob, Larry Kevan
Office of the Provost Scholarship
The radical reactions in the liquid phase γ-radiolysis of propane have been studied from –130 to 35°C and compared with the gas-phase radiolysis at 35°C. Oxygen was used as a scavenger to separate thermal radical yields, and effects of phase and temperature on the radical yields were assessed. The gas-liquid phase change(a) decreases total decomposition by about 14%,(b) increases disproportionation/combination (D/C) ratios for all radicals by 30% and (c) decreases the isopropyl/n-propyl radical ratio. The decrease in liquid temperature (a) changes the predominant reaction of H atoms from abstraction from propane to addition to product propylene below –78°C at doses …
Copper, Zinc And Molybdenum Fertilizers For New Land Crops And Pastures : 1969, J W. Gartrell, R. N. Glencross
Copper, Zinc And Molybdenum Fertilizers For New Land Crops And Pastures : 1969, J W. Gartrell, R. N. Glencross
Journal of the Department of Agriculture, Western Australia, Series 4
Four years of intensive research into soil deficiencies in developing areas have resulted in a more comprehensive understanding of the need for trace elements in Western Australia.
N-P Compound Fertilisers, M G. Mason, W. J. Cox, R. N. Glencross
N-P Compound Fertilisers, M G. Mason, W. J. Cox, R. N. Glencross
Journal of the Department of Agriculture, Western Australia, Series 4
FARMERS were able to buy the two compound fertilisers N-P Compound Fertiliser 28:14 and N-P Compound Fertilser 24:24 in the 1967 season.
Approximate Self‐Consistent Molecular‐Orbital Theory. Vi. Indo Calculated Equilibrium Geometries, Mark S. Gordon, J. A. Pople
Approximate Self‐Consistent Molecular‐Orbital Theory. Vi. Indo Calculated Equilibrium Geometries, Mark S. Gordon, J. A. Pople
Mark S. Gordon
The INDO (intermediate neglect of differential overlap) self-consistent theory has been used to calculate equilibrium geometries for a series of small polyatomic molecules with one or two polyvalent atoms (carbon, nitrogen, or oxygen). The results are compared with experimental data where available.
A Spectrophotometric Study Of The System: Cobalt--2,2,8,8-Tetrakis (Hydroxymethyl)-3,7-Diaza-1,5,9-Nonanetriol, Pauline Frances Fones
A Spectrophotometric Study Of The System: Cobalt--2,2,8,8-Tetrakis (Hydroxymethyl)-3,7-Diaza-1,5,9-Nonanetriol, Pauline Frances Fones
Master's Theses
Spectrophotometric studies or solutions or 2,2;8;a. tetrakis(hydroxymethyl)-3, 7-diaza-1,5.9-nonanetriol, (HOCH2),3CHNCH2CH(OH)CH2NHC(CH2OH)3, with cobalt (II) gave evidence of complexes having metal-ligand ratios of 1:2 and 1:3. Complexation appeared nearly complete at pH 8 or greater. Between pH 8 and pH 11, the positions of the maxima in the absorbance spectra remained essentially constant and no precipitation was observed. The 1:2 complex formed rapidly, while the 1:3 complex formed more slowly, requiring one to two weeks to reach equilibrium, after which the solutions remained unchanged over a period or several months. Evidence …
An Investigation Of Amino Acid Decomposition, Jack H. Frost, E. Winston Grundmeier
An Investigation Of Amino Acid Decomposition, Jack H. Frost, E. Winston Grundmeier
Journal of the Minnesota Academy of Science
Amino acid decarboxylation studies generally show that extraneous reactions accompany CO, formation, especially at high temperature and when metal ion catalysts are used. In the present study some of these reactions are investigated in the reaction system, a- or ,a-amino acid and CuSO, at 130-155° C. Histidine, a- and .B -alanine, glycerine and norvaline were each studied for determination of products. The extent of formation of the products, NH,, CO,, aliphatic amines and Cu metal, was determined quantitatively. A near l: l correspondence in NH,:CO2 exists for the amino acids studied. No correspondence could be detected between Cu metal product …
Dehydration And Rehydration Behavior Of Zinc And Magnesium Sulfate Heptahydrates, Hanaa Youssef Ghorab
Dehydration And Rehydration Behavior Of Zinc And Magnesium Sulfate Heptahydrates, Hanaa Youssef Ghorab
Archived Theses and Dissertations
No abstract provided.
Dielectric Properties Of Solid Solutions Of Bifeo₃ With Pb(Ti, Zr)O₃ At High Temperature And High Frequency, Robert Travis Smith, Gary D. Achenbach, Robert Gerson, William Joseph James
Dielectric Properties Of Solid Solutions Of Bifeo₃ With Pb(Ti, Zr)O₃ At High Temperature And High Frequency, Robert Travis Smith, Gary D. Achenbach, Robert Gerson, William Joseph James
Physics Faculty Research & Creative Works
Solid solutions of BiFeO3 with PbTiO3, PbTi0.5Zr0.5O3, and PbZrO3 were prepared. The crystallographic data on these solutions, which are basically perovskitic, are given. The dielectric constants of the materials were determined at a frequency of 0.53 GHz and at temperatures up to 800°C. Dielectric Curie points were found in solutions containing up to 90 mole % BiFeO3. These results leave little doubt that BiFeO3 is ferroelectric or antiferroelectric. The extrapolated Curie point for BiFeO3 is above 850°C. BiFeO3 appears more likely to be ferroelectric than …
The Phosphorus Fertilisers : How They Compare, Walter Jacob Cox
The Phosphorus Fertilisers : How They Compare, Walter Jacob Cox
Journal of the Department of Agriculture, Western Australia, Series 4
ALTHOUGH 'double' or 'concentrated' superphosphate was first commercially manufactured in 1872 it was not until the 1950's that it became a major commercial fertiliser. In 1965 it accounted for about 15 per cent, of the world production of phosphatic fertilisers.
Geochemical Abundance Of Iodine, Jane Hanisch Bennett
Geochemical Abundance Of Iodine, Jane Hanisch Bennett
Masters Theses
"The research reported herein includes unpublished iodine and uranium data on a group of United States Geological Survey standards and on a group of ultrabasic rocks. Data are also included for the major rock types, deep sea sediments, and for graphite and troilite inclusions in iron meteorites. Tellurium data for the troilite are also reported. Appendix I is a literature article (Bennett and Manuel, 1967a) on Canyon Diablo Graphite. Appendix II is a literature article (Bennett and Manuel, 1967b) on deep sea sediments. The results of this study show that most of the earlier estimates of the crustal abundance of …
The Dispersing Power Of Oxidized Starches On Aqueous Pigment Suspensions, Louis K. Wilhelm
The Dispersing Power Of Oxidized Starches On Aqueous Pigment Suspensions, Louis K. Wilhelm
Masters Theses
No abstract provided.
A Study Of The Curriculum Of The Natural Science Division Of Ouachita Baptist University, Natural Sciences Group
A Study Of The Curriculum Of The Natural Science Division Of Ouachita Baptist University, Natural Sciences Group
Honors Theses
In our evaluation of the curriculum of the Natural Science Division, we began by reviewing the catalogue descriptions of our courses and evaluating whether the courses meet the objectives given. To do this we divided into departments since our division is so large. Next, we wrote to Hendrix, Little Rook University, Southwestern at Memphis, and State College of Arkansas and compared their course offerings with ours. In this comparison we discovered our strengths and weaknesses and changes that need to be made in our present curriculum. In several cases we decided upon possible alterations which would aid the student going …
The Function And Use Of Sulphur Dioxide In West Australian Winemaking, D Mann
The Function And Use Of Sulphur Dioxide In West Australian Winemaking, D Mann
Journal of the Department of Agriculture, Western Australia, Series 4
THE judicious use of sulphur dioxide is perhaps the most important of the fundamentals of winemaking in a hot climate.
Western Australia's vintage, centred in the Swan Valley just a few miles north-east of Perth, is subjected to some of the highest summer temperatures experienced by a quality wine producing district.
In this environment, it is important to make good use of sulphur dioxide to avoid wine spoilage.
Cyclic Derivatives Of 2-Amino-2-Deoxy-D-Hexopyranoses, Kenji Miyai
Cyclic Derivatives Of 2-Amino-2-Deoxy-D-Hexopyranoses, Kenji Miyai
University of the Pacific Theses and Dissertations
The purpose of this investigation was to prepare heterocyclic derivatives, bridging C-2 and C-3 of 2-amino-2-deoxy-D-hexopyranoses, useful as blocking groups in the preparation of aminosugar oligosaccharides and polysaccharides. The work reported herein is concerned with oxazolidones of 2-amino-2-deoxy-D-hexopyranoses (Figure 1).)
There are no examples known, in which five or six-membered rings are fused in a trans-arrangement to five-membered furanose ring. However, although synthetic difficulties were observed, sic and five-membered rings were fused in a trans-arrangement to a sic-membered pyranose ring as pointed out before. In the case of our trans-diequatorially fused oxazolidones additional preparative difficulties were expected, because of the …
Studies On The Manganese Cycle, Jim Gilbert
Studies On The Manganese Cycle, Jim Gilbert
Honors Theses
The first studies on the manganese cycle in impoundments were concerned with the manganese concentrations in and removal from bottom waters of deep impoundments. But as work progressed, the emphasis was more on the investigation of the mechanism by which manganese is dissolved in impounded waters.
The Structure And Use Of Dimethyl Sulfoxide, Nancy Goodson
The Structure And Use Of Dimethyl Sulfoxide, Nancy Goodson
Honors Theses
It is hard to talk about dimethyl sulfoxide (DMSO) without sounding like an old-time carnival snake-oil salesman. DMSO appears to be good for arthritis, sinusitis, headaches, earaches, sprains, and burns. It reduces swellings, suppresses blisters, kills pain, tranquilizes, and fights germs. It enhances the action of other drugs. It can be swallowed, injected, rubbed on, or dripped in.
Dimethyl sulfoxide is one hundred years old. It was first synthesized by Alexander Saytzeff in Germany in 1866. However, it remained a laboratory curiosity for about three-quarters of a century. No use was found for it until about ten years ago, when …
Measurement Of Fluorescence Lifetimes Of Biologically Significant Compounds, Irene Adele Petz
Measurement Of Fluorescence Lifetimes Of Biologically Significant Compounds, Irene Adele Petz
University of the Pacific Theses and Dissertations
The purpose of this research was to measure fluorescence decay-times of several biologically significant compounds. Although various equations are available which permit one to calculate fluorescence lifetimes from spectral data, ample evidence exists which indicates such calculations are at considerable variance with experimental results.
Deuterium Isotope Effects On The Solvolysis Rates Of Cyclopentyl Brosylates And Tosylates, Jimmie D. Christen
Deuterium Isotope Effects On The Solvolysis Rates Of Cyclopentyl Brosylates And Tosylates, Jimmie D. Christen
Doctoral Dissertations
"The brosylates and tosylates of cyclopentanol and its 1-d₁, c̲i̲s̲-2-d₁, t̲r̲a̲n̲s̲-2-d₁, and 2,2,5,5-d₄ analogs have been synthesized and their solvolysis rates measured at 25° in 70% vol. ethanol-water. The solvoylsis reactions were monitored by a conductance method. The isotope effects, kH/kD, observed for the brosylates and tosylates of each of the isotopically substituted cyclopentyl alcohols are as follows: 1-d₁-brosylate (1.1869) and 1-3₁-tosylate (1l1836); c̲i̲s̲-2-d₁-brosylate (1.1533) and c̲i̲s̲-2-3₁-tosylate (1.1577); t̲r̲a̲n̲s̲-2-d₁-brosylate (1.1803) and t̲r̲a̲n̲s̲-2-d₁-tosylate (1.1765); 2,2,5,5-d₄-brosylate (1.8881) and 2,2,5,5-d₄-tosylate (1.8863). The closeness in magnitude of the isotope effects for the c̲i̲s̲- and t̲r̲a̲n̲s̲-isomers is important in that it …
Heat Of Combustion Of Tris-(Acetylacetonato) Gallium Iii, Richard William Macnamee
Heat Of Combustion Of Tris-(Acetylacetonato) Gallium Iii, Richard William Macnamee
Dissertations, Theses, and Masters Projects
No abstract provided.
Properties And Structure Of Some Chalcogenide Glasses, Amin Ismail Amin Abdel-Latif
Properties And Structure Of Some Chalcogenide Glasses, Amin Ismail Amin Abdel-Latif
Archived Theses and Dissertations
No abstract provided.