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Articles 78211 - 78240 of 78497
Full-Text Articles in Entire DC Network
Limnological Studies In Arkansas. I. Physico-Chemical And Net Plankton Studies Of Lake Fort Smith In Its Fourth Year Of Impoundment, Carl E. Hoffman, David Causey
Limnological Studies In Arkansas. I. Physico-Chemical And Net Plankton Studies Of Lake Fort Smith In Its Fourth Year Of Impoundment, Carl E. Hoffman, David Causey
Journal of the Arkansas Academy of Science
No abstract provided.
A Report On Drosophila Collections In Nebraska, David D. Williams, Dwight D. Miller
A Report On Drosophila Collections In Nebraska, David D. Williams, Dwight D. Miller
Bulletin of the University of Nebraska State Museum (1924–2023)
Until rather recently little has been known of the Drosophila species of Nebraska. Sturtevant (1921) lists Nebraska as one of seven states from which no Drosophila had been reported. Patterson and Wagner (1943) show that collections of Drosophila pseudoobscura had been made in the vicinities of Scottsbluff and Kearney, but no other Drosophila species are reported from Nebraska in their publication.
Insect Types In The Collections Of The University Of Nebraska State Museum, Martin H. Muma
Insect Types In The Collections Of The University Of Nebraska State Museum, Martin H. Muma
Bulletin of the University of Nebraska State Museum (1924–2023)
In 1948 the insect collections at the University of Nebraska State Museum were placed in the care of the author. Prior to that date curatorial duties were assumed or assigned to full time teaching or research staff members. As would be expected under the latter circumstances, the organization of study material and types was neglected in many families and genera. Since 1948 type material, because of its intrinsic value, has received considerable attention. All primary and representative secondary types have been assembled in three museum cases and one slide cabinet for curatorial and study convenience.
The Determination Of Moisture In Active Dry Yeast, Richard F. Fenske
The Determination Of Moisture In Active Dry Yeast, Richard F. Fenske
Bachelors’ Theses
The writer, having been employed for the past three years, in the control laboratory of one of this country's largest yeast concerns, is very much interested in the determination of moisture in active dry yeast and has there tore made the investigation presented in this paper.
The moisture content is, of critical importance in the production of active dry yeast. A yeast whose moisture content is too low will have poor baking characteristics while a yeast whose moisture content is too high will have poor keeping quality. Inconsistent results have been obtained by using various methods to determine the moisture …
Chalcones Derived From M-Nitroacetophenone, Richard Allan Hendry
Chalcones Derived From M-Nitroacetophenone, Richard Allan Hendry
University of the Pacific Theses and Dissertations
The object of this research was to prepare substituted derivatives of various chalcones having the nitro group substituted in the 31-position, the idea being to help complete the series of chalcones having the nitro group in that position. This was to be done by condensing various substituted benzaldehydes with m-nitroacetophenone, using dry hydrogen chloride as a condensing agent. The properties of the resulting chalcones were then to be determined by observing color reactions, spectra, and other general physical properties.
Chromatography With Aqueous And Polar Solvents., Mary Veronica Drawe
Chromatography With Aqueous And Polar Solvents., Mary Veronica Drawe
LSU Historical Dissertations and Theses
No abstract provided.
The Theory Of Fractional Solvent Extraction And Its Application To Creosol Separation., Ada Lorine Ryland
The Theory Of Fractional Solvent Extraction And Its Application To Creosol Separation., Ada Lorine Ryland
LSU Historical Dissertations and Theses
No abstract provided.
Addition Of Sodium Nitrate (1951), Walter A. Lawrance
Addition Of Sodium Nitrate (1951), Walter A. Lawrance
Walter Lawrance Papers
No abstract provided.
Enrichment Of Tin Activity Through The Szilard-Chalmers Separation, Herta W. Spano
Enrichment Of Tin Activity Through The Szilard-Chalmers Separation, Herta W. Spano
Chemistry and Chemical Biology ETDs
It was the purpose of this investigation to utilize the Szilard-Chalmers reaction in order to prepare tin solutions of high specific activity.
Tetraphenyl tin was chosen for the target compound. It is a white, crystalline solid of excellent thermal stability. No data have been reported in the literature on the rate of exchange between inorganic forms of tin and tetraphenyl tin but it seemed highly probable that this exchange would be very slow. Tetraphenyl tin is soluble in various organic solvents but insoluble in water, and this suggested solvent extraction as a possible means of separation of the activated tin …
The Peroxide Numbers Of Vegetable Oils, Robert J. Bruce
The Peroxide Numbers Of Vegetable Oils, Robert J. Bruce
Bachelors’ Theses
A survey of the literature will indicate that the peroxide numbers of fats and oils are of importance in ii many industries. The dairy, fish oil, vegetable oil, and meat processing industries all have use for peroxide number determinations. as a measure of the degree of rancidity of their products. The paint industry has used it in the study of protective coatings, and the textile industry has used it in the study of the lubrication of fibers. All of these uses were applied to the study of partial oxidation of the samples under consideration.
Since the various methods in use …
A Graphic Résumé Of The Pleistocene Of Nebraska (With Notes On The Fossil Mammalian Remains), C. Bertrand Schultz, Gilbert C. Lueninghoener, W. D. Frankforter
A Graphic Résumé Of The Pleistocene Of Nebraska (With Notes On The Fossil Mammalian Remains), C. Bertrand Schultz, Gilbert C. Lueninghoener, W. D. Frankforter
Bulletin of the University of Nebraska State Museum (1924–2023)
I T SEEMS desirable at this time to present a graphic resume of the Nebraska Pleistocene, together with a summary of the stratigraphic sequences of the fossil vertebrates. This report is based on data taken from various publications' in addition to information gathered by the present writers during the past fifteen or more field seasons. Intensive work has been done in the past five years in connection with recovery of paleontological material in the areas where government dams are under construction (Schultz, Lueninghoener, and Frankforter, 1948; Schultz and Frankforter, 1948; Holder and Wike, 1949). The information in the present paper …
Derivatives Of M-Xylene, Henry J. Muller
Derivatives Of M-Xylene, Henry J. Muller
Chemistry and Chemical Biology ETDs
Since m-xylene of 95-98% purity has recently become available from petroleum, this is an appropriate time to prepare an examine its derivatives. Isophtalic and m-toluic acids can be prepared from the hydrocarbon. The purpose of this work was to prepare imidazolines from these acids
Studies On Derivatives Of 3-Ethylphenanthrene, Eugene R. Miller
Studies On Derivatives Of 3-Ethylphenanthrene, Eugene R. Miller
Bachelors’ Theses
The following thesis was undertaken to study the derivatives of 3 etbyl-phenanthrene. The problem was undertaken to familiarize the author with polynuclear aromatic hydrocarbons and the various reactions and unit processes which are involved in the synthesis or these derivatives. It is hoped that the experience gained in pursuing the objective of this thesis will provide a background which may prove valuable in future work tor an advanced degree and ultimately help to secure a position in some phase of research work dealing with biological compounds containing the phenanthrene configuration in its nucleus.
Phenol-Aldehyde-Condensation Synthesis Of A Possible Gerxioide And Fungioide, Bis(4-Fluoro-2-Hydroxyphenyl) Methane, Erwin A. Stern
Phenol-Aldehyde-Condensation Synthesis Of A Possible Gerxioide And Fungioide, Bis(4-Fluoro-2-Hydroxyphenyl) Methane, Erwin A. Stern
Bachelors’ Theses
The successful synthesis of chlorinated and brominated dihydroxydlphenylmethanes during the last ten years and their use as germicides and fungicides coupled with the known effect of fluorine and alkyl groups upon phenol, warranted the attempted synthesis of fluorinated and alkylated dihydroxydiphenylmethanee . It is the purpose of this thesis to attempt the synthesis of fluorinated and alkylated dihydroxydiphenylmethanee for purposes of their use as germicides and fungicides.
The Chemical Characteristics Of 8.0-Day I131 Produced By The Beta Decay Of 25-Minute Te131 In Organic Liquids, Francis J. Keneshea Jr.
The Chemical Characteristics Of 8.0-Day I131 Produced By The Beta Decay Of 25-Minute Te131 In Organic Liquids, Francis J. Keneshea Jr.
Chemistry and Chemical Biology ETDs
In 1934 Szilard and Chalmers found that a large fraction of the radioactive iodine produced in the thermal neutron irradiation of ethyl iodide could be extracted from the irradiated material. The procedure followed was to add a trace of carrier iodine to the irradiated liquid, extract the iodine with an aqueous solution of a reducing agent and precipitate the iodide as silver iodide. The silver iodide precipitate obtained in this manner contained a large fraction of the iodine activity (25-minute I128), at a high specific activity. Since ethyl iodide is not soluble in water and hence is not …
The Kinetics Of The Exchange Between Benzyl Iodide And Iodide Ion, Paul Stillson
The Kinetics Of The Exchange Between Benzyl Iodide And Iodide Ion, Paul Stillson
Chemistry and Chemical Biology ETDs
A general form of an ion-molecule replacement reaction occurring at a saturated carbon atom may be represented by
Y-+R-X⇋Y-R+X-
where Y- is a negatively charged atom or group which can replace an atom or group X in the molecule R-X and R is any organic radical which is saturated at the point of attachment of X. The mechanisms which have been postulated for the above reaction may be divided into the following two groups: (1) those which assume primary dissociation of the neutral organic reaction into ions as the rate-determining step; (2) those which postulate the formation …
Life History Of The Utah Sculpin Cottus Bairdi Semiscaber (Cope) In Logan River, Utah, William M. Zarbook
Life History Of The Utah Sculpin Cottus Bairdi Semiscaber (Cope) In Logan River, Utah, William M. Zarbook
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
The study of the Utah sculpin in Logan River was based on 801 specimens collected during 1949 to March 1951. Numbers of fish examined for various catagories of the study wares length-frequency, 495; aging by vertebrae, 407; length-weight relationship, 601; and food habits, 275.
Fish were collected by use of an electric shocking machine generating 600 watts and 220 volts. Numbers of fish occurred as high as 150 per tenth mile of stream. Preferred habitats occurred in areas of coarse gravel and small rocks.
Vertebrae dissected from the fish were used in age determination. Length-frequency proved to be a general …
Preparation Of 3-Methylphenanthrene, Yvonne C. Bestler
Preparation Of 3-Methylphenanthrene, Yvonne C. Bestler
Bachelors’ Theses
The year 1929 witnessed the opening expansion of the previously small list of naturally occurring phenanthrene compounds. The new groups of substances included were as strikingly different in their actions on animal organisms as they were similar in structure.
The Sixty-Third Session Of The Iowa Academy Of Science And The Eighteenth Convention Of The Junior Academy Of Science Of Iowa, April 20 And 21, 1951, Iowa Academy Of Science
The Sixty-Third Session Of The Iowa Academy Of Science And The Eighteenth Convention Of The Junior Academy Of Science Of Iowa, April 20 And 21, 1951, Iowa Academy Of Science
Iowa Academy of Science Documents
No abstract provided.
Diffusion Through A Membrane, Marvin E. Wyman
Diffusion Through A Membrane, Marvin E. Wyman
Journal of the Minnesota Academy of Science
No abstract provided.
Freshwater Sponges In Arkansas, David Causey
Freshwater Sponges In Arkansas, David Causey
Journal of the Arkansas Academy of Science
No abstract provided.
Radiolaria From The Porters Creek Formation (Paleocene, Midway Group) Of Stoddard County, Missouri, Eldridge Sellers Middour
Radiolaria From The Porters Creek Formation (Paleocene, Midway Group) Of Stoddard County, Missouri, Eldridge Sellers Middour
Masters Theses
"Fossil Radiolaria are described and figured from the Porters Creek formation (Paleocene) of Ardeola, Stoddard County Missouri. This is the first detailed treatment of fossil radiolarians from the Gulf Coast area. Thirty-one species are described and figured, all believed to be new, belonging to twenty-four genera. Fifteen families are represented, ten referable to the Legion Spumellaria, five to the Legion Nassellaria. Stratigraphic descriptions or the section at Ardeola is presented, and a discussion of laboratory techniques is included"--Abstract, page 3.
The Kinetics Of The Exchange Between Sn(Ii) And Sn(Iv) In Absolute Alcohol, E. Gerald Meyer
The Kinetics Of The Exchange Between Sn(Ii) And Sn(Iv) In Absolute Alcohol, E. Gerald Meyer
Chemistry and Chemical Biology ETDs
The radiochemical exchange reaction may in general be written AX+BX• = +BX where X• represents a radioactive atom of X. The species AX and AX• are assumed to be chemically identical as are the species BX and BX•. This assumption introduces no appreciable error even when working with atoms having an atomic weight as low as fourteen.
Some Reactions Of 4-Chlorocinnoline, F. H. Kruse
Some Reactions Of 4-Chlorocinnoline, F. H. Kruse
Chemistry and Chemical Biology ETDs
This problem involves the preparation of 4-chlorocinnoline by the method of Borshe and Herbert and Busch and Rast,, and the study of further replacement reactions of the chlorine atom in the 4-position. The problem can be subdivided into two sections: (1) the preparation of the 4-cinnolyl Grignard reagent and the corresponding lithium compound and (2) the study of some condensation reactions of 4-chlorocinnoline.
Effect Of Stubble Mulching On Number And Activity Of Earthworms, S. P. Teotia, F. L. Duley, T. M. Mccalla
Effect Of Stubble Mulching On Number And Activity Of Earthworms, S. P. Teotia, F. L. Duley, T. M. Mccalla
Nebraska Agricultural Experiment Station: Historical Research Bulletins
A survey of earthworm population under different cropping systems was made under stubble mulch farming and where the residue was plowed under. The influence of earthworms on some of the important physical and biological properties of the soil was studied. Their role in the decomposition of crop residues was also determined.
An Analytical Study Of Berberine, W. Riley Mcgaughran
An Analytical Study Of Berberine, W. Riley Mcgaughran
Chemistry and Chemical Biology ETDs
Berberine, an alkaloid, has unique pharmacological properties as well as unusual chemical and physical characteristics. This compound has been used for many years as a remedy for eye diseases. In contrast to most alkaloids, berberine hydroxide is more soluble than its salts. Its chemical structure has been established, but a correlations of many of its properties and its structures has not been made.
The purpose of this work was to undertake an analytical study of berberine, hoping to collect data which would make possible the correlation of certain properties of the compound with its structure. The study was planned to …
The Application Of Qualitative Inorganic Macro Procedures And Reagents To Spot Test Analysis, John Albert Stich
The Application Of Qualitative Inorganic Macro Procedures And Reagents To Spot Test Analysis, John Albert Stich
Bachelors’ Theses
Qualitative inorganic analysis is that branch of applied chemistry which has to do with the systematic detection or identification, and separation of the various metals and groups of elements which make up inorganic compounds. The indentification is made on the basis of precipitates and the color changes thereof, which result when a specific reagent is added to a solution of the sample. As opposed to quantitative analysis, measurability is not the essential factor, but it must be possible to observe the reaction easily and indubitably. It is not necessary for the material being tested for to be converted completely to …
The Effect Of Metals On Yeast Activity, Warren Joseph Chamberlain
The Effect Of Metals On Yeast Activity, Warren Joseph Chamberlain
Bachelors’ Theses
The writer, having been employed in the dry yeast research laboratory of one of this country's largest yeast concerns for the past three years, is very much interested in those factors which might affect the qualities of the final dry yeast product, and has therefore made the investigations presented in this paper.
Because of the numerous pieces of metallic equipment employed in the production of yeast, the possibility of metallic contamination in the final yeast product is considerable. Thus, the investigation presented in this paper was carried out in an effort to determine just what effect various concentrations of various …
An Investigation Of The Electrolytic Behavior Of The Nitroparaffins, Harold A. Brejcha
An Investigation Of The Electrolytic Behavior Of The Nitroparaffins, Harold A. Brejcha
Master's Theses or Doctor of Nursing Practice
A study of the electrolytic behavior of this group of compounds was undertaken to gain some knowledge of a little known type of reaction of these compounds. The study was made, not so much in view of developing new uses for these compounds, as to gain a better understanding of their behavior under various conditions. Another reason for this investigation is the fact that chemical reduction by the usual methods is inconvenient. With this fact in mind, the inherent convenience of electrolytic methods made the study of the electrolytic behavior of the nitroparrffins worthy of investigation.
A Study Of The Use Of The Dicyanatodipyridine (Ii) Complex For The Determination Of Cyanate, Jean Mcclelland
A Study Of The Use Of The Dicyanatodipyridine (Ii) Complex For The Determination Of Cyanate, Jean Mcclelland
Chemistry and Chemical Biology ETDs
Treadwell states in his text, Analytical Chemistry, Volume II, that "the only method for examining cyanates consists in determining the amount of carbon and nitrogen present by combustion." A review of the available literature shows that, although this is not literally true, a procedure for this quantitative determination of small amounts of cyanates in the presence of interfering substances is lacking.
A survey of the literature yielded few references for instrumental methods for the quantitative determination of cyanates. Ripan-Tilici published a method for the determination of cyanates poteniometrically, but attempts to duplicate her work have failed. Madame Tilici, in …