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Articles 78121 - 78150 of 78498
Full-Text Articles in Entire DC Network
A Radiochemical Investigation Of Short-Lived Selenium And Bromine Fission Products, James Edward Sattizahn Jr.
A Radiochemical Investigation Of Short-Lived Selenium And Bromine Fission Products, James Edward Sattizahn Jr.
Chemistry and Chemical Biology ETDs
From a sample of uranium bombarded with neutrons, Hahn and Strassmann, in 1939, separated four radioactive products which followed alkaline earth chemistry and were therefore tentatively attributed to isotope of radium. Each of these products decayed to a daughter activity which could be precipitated along with lanthanum; the daughter activities were then assumed to be isotopes of actinium. Subsequently, by accepted methods of fractional crystallization and precipitation, the "radium" and "actinium" isotopes were identified unequivocally as isotopes of barium and lanthanum, respectively. Within a relatively short time there were found more such radioactive products, which were identified as isotopes of …
Behavior Of Indium At Tracer Concentrations, Katheryn L. Lawson
Behavior Of Indium At Tracer Concentrations, Katheryn L. Lawson
Chemistry and Chemical Biology ETDs
The increase in number and availability of radioisotopes that can be produced in the carrier-free state has offered practical means of investigating the chemical behavior of substances at extremely low concentrations. The working region of concentrations, which may extend to less than 10-14 molar, is generally fixed only by the half-life of the radio-element and the nature of the radiation.
The Use Of Branchiostegal Rays To Determine Age Of Lake Trout Salvelinus Namaycush Walbaum, Ross Vivian Bulkley
The Use Of Branchiostegal Rays To Determine Age Of Lake Trout Salvelinus Namaycush Walbaum, Ross Vivian Bulkley
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
Any method used in aging fish must fulfill certain requirements to be satisfactory. If the method is inaccurate, naturally little reliance can be placed upon its use. If considerable study of the method and much practice are required before accurate readings can be obtained, the method will not come into widespread use. The requirements of an aging method, then are that it must be accurate and comparatively easy. The scale method for aging lake trout (Salvelinus namaycush Walbaum) unfortunately does not fulfill these requirements. It has always been difficult to tell the age of lake trout by the examination …
The Exchange Of Chlorine Between Hydrogen Chloride And Acetyl Chloride In The Vapor Phase, Warren J. Niell
The Exchange Of Chlorine Between Hydrogen Chloride And Acetyl Chloride In The Vapor Phase, Warren J. Niell
Chemistry and Chemical Biology ETDs
The aim of chemical kinetics is to predict the rates of chemical reactions, to determine the factors influencing the reaction rate, and to postulate a suitable reaction mechanism.
The Chemical Effects Of Gamma Radiation On Halogenated Methanes, Clifford G. Shultz
The Chemical Effects Of Gamma Radiation On Halogenated Methanes, Clifford G. Shultz
Chemistry and Chemical Biology ETDs
The fundamental processes of radiation chemistry and photochemistry are quite parallel, and any consideration of one must include the theory of the other as well. Probably the first work done in photochemistry was that of Stephen Hales on photosynthesis, between 1677 and 1721. This was followed by descriptions of the action of light on silver salts by Schultz, Beccarius, and Scheele. The latter also demonstrated that the action of light on silver chloride varied with the waveleneth of the light. Grotthus, in 1817, stated the first law of photochemistry: Only that light which is absorbed can give rise to a …
Specificity Of Intermolecular Forces Due To Quantummechanical And Thermal Charge Fluctuations*, Herbert Jehle
Specificity Of Intermolecular Forces Due To Quantummechanical And Thermal Charge Fluctuations*, Herbert Jehle
Department of Physics and Astronomy: Faculty Publications
The preceding note1 (Paper I) developed the theory of the specificity of some intermolecular forces: the forces due to fluctuations of electric charge distribution in and over the interacting molecules. It was found that for a mixture of molecules in a liquid medium these forces cause a rearrangement of the molecules, so that molecules which have the same distribution of oscillator polarizabilities and oscillator orientations over the frequency spectrum tend to associate. This means that like molecules tend to become nearest neighbors. For that reason it was said that there is specific attraction between identical molecules.
Biological Indices Of Water Pollution, With Special Reference To Fish Populations, Peter Doudoroff, Charles E. Warren
Biological Indices Of Water Pollution, With Special Reference To Fish Populations, Peter Doudoroff, Charles E. Warren
Other Publications in Wildlife Management
A number of investigators have very recently published discussions having to do with biological indices and biological measures of water pollution (1) (2) (7) (13) (14) (15) (16) (26) (27) (28) (29) (30) (36) (38). Fjerdingstad (12) has discussed some of the pertinent European literature. The fundamental concepts presented by these authors are not original, for the idea that aquatic organisms can be useful "indicators" of environmental conditions, and particularly of the degree of pollution of water with organic wastes, has a long history (12). Because of certain novel features and the relatively wide scope of the studies, and the …
Medial Pleistocene Fossil Vertebrate Localities In Nebraska, C. Bertrand Schultz, Lloyd G. Tanner
Medial Pleistocene Fossil Vertebrate Localities In Nebraska, C. Bertrand Schultz, Lloyd G. Tanner
Bulletin of the University of Nebraska State Museum (1924–2023)
The accurate geologic dating of Pleistocene vertebrate localities which occur outside the glaciated regions has always been difficult. Several new fossil localities in Nebraska now provide data for a better understanding of the paleoecology and faunal evidence of the medial Pleistocene of the Great Plains region.
A fossil quarry, containing the remains of both vertebrates and invertebrates, has been discovered in south-central Nebraska (11/2 miles south and west of Angus in Nuckolls County). The fossils are preserved in Sappa silts in a lime concentration zone (C horizon) of a Yarmouth paleosol. The calcium carbonate appears to have been responsible for …
Nebraska Deer, William Bailey Jr., George Schildman, Phillip Agee, C. G. Pritchard
Nebraska Deer, William Bailey Jr., George Schildman, Phillip Agee, C. G. Pritchard
Nebraska Game and Parks Commission: Publications
IN COMMON with the experience of most states, Nebraska's deer herds were reduced to a very low level by excessive harvests in our early history. Most American big-game animals were overharvested in the early history of this nation because of commercialization. Buffalo were killed for their hides, deer for their meat. This slaughter continued as long as the hunter (or poacher) could sell his take at a profit. Modem game management and public opinion reversed this trend. Deer are on the way back all over America, and in some states the protection-complex was so strong that deer were restored to …
Nebraska Deer, William Bailey Jr., George Schildman, Phillip Agee, C. G. Pritchard
Nebraska Deer, William Bailey Jr., George Schildman, Phillip Agee, C. G. Pritchard
Nebraska Game and Parks Commission: Publications
IN COMMON with the experience of most states, Nebraska's deer herds were reduced to a very low level by excessive harvests in our early history. Most American big-game animals were overharvested in the early history of this nation because of commercialization. Buffalo were killed for their hides, deer for their meat. This slaughter continued as long as the hunter (or poacher) could sell his take at a profit. Modem game management and public opinion reversed this trend. Deer are on the way back all over America, and in some states the protection-complex was so strong that deer were restored to …
The Use Of P In Preparing Radioautographs, R. B. Hastings, James Dimond
The Use Of P In Preparing Radioautographs, R. B. Hastings, James Dimond
Journal of the Minnesota Academy of Science
No abstract provided.
Effect Of Environment On The Percentage Of Summerwood And Specific Gravity Of Slash Pine, Philip R. Larson
Effect Of Environment On The Percentage Of Summerwood And Specific Gravity Of Slash Pine, Philip R. Larson
Yale School of the Environment Bulletin Series
No abstract provided.
A Probe For Measuring Ultrasonic Pressures, Robert F. Rohrer
A Probe For Measuring Ultrasonic Pressures, Robert F. Rohrer
Masters Theses
"In the study of acoustics, the term ultrasonics is defined as those wave motions that have frequencies greater than about 20,000 cycles per second. The characteristics of a sound wave at any point in a medium can be regarded as completely defined when the amplitude, frequency, and phase of its Fourier components are known.
Sound measurements at their best are difficult. In the last few years sensitive linear microphones and electronic amplifiers have become available. Still, there are two difficulties of prime importance with their use in a sound field. First, there is the precise, absolute calibration of the equipment …
Specificity Of The London-Eisenschitz Wang Force*, Jerrold M. Yos, William L. Bade, Herbert Jehle
Specificity Of The London-Eisenschitz Wang Force*, Jerrold M. Yos, William L. Bade, Herbert Jehle
Department of Physics and Astronomy: Faculty Publications
The London force between macromolecules immersed in a liquid medium has an interesting property which may be of biological significance. For the purpose of formulating the London interaction, one may represent each macromolecule by a set of electric dipole oscillators of specified polarizability, frequency, and orientation. To consider the simplest case, one may study macromolecules of globular form not in direct contact with each other. (They might be separated by Debyeiuckel- Onsager atmospheres made up of molecules from the medium; then the equilibrium distance between the macromolecules would be regulated by concentration changes in the ionic medium.)' Such a geometrical …
The Use Of Weights And Dependence In The Solution Of Simultaneous Equations , Robert John Schweisthal
The Use Of Weights And Dependence In The Solution Of Simultaneous Equations , Robert John Schweisthal
Master's Theses
No abstract provided.
The Value Of Including Chemistry Content In The Study Of High School Biology, Ramon Duane Buckley
The Value Of Including Chemistry Content In The Study Of High School Biology, Ramon Duane Buckley
Dissertations and Theses @ UNI
The purpose was to evaluate the effect of including some definite chemistry content in high school biology. This evaluation was made by comparing outcomes of instruction in two different groups of a high school biology course. The two groups were equated in terms of the intelligence quotients, the sex, and the previous achievement in biology of the class members. The comparative gains in factual knowledge were measured by means of an evaluation test. The comparative gains in appreciations and interests in biology were measured with a questionnaire.
The Synthesis Of 7-Methyl-3,4-Benzpyrene, 6,7-Dimethyl-3,4-Benzpyrene, 10-Methyl-3,4-Benzpyrene And 7,10-Dimethyl-3,4-Benzpyrene, Joseph Leonard Comp Jr.
The Synthesis Of 7-Methyl-3,4-Benzpyrene, 6,7-Dimethyl-3,4-Benzpyrene, 10-Methyl-3,4-Benzpyrene And 7,10-Dimethyl-3,4-Benzpyrene, Joseph Leonard Comp Jr.
Chemistry and Chemical Biology ETDs
Interest in carcinogenic compounds began to develop when a form of cancer was found occurring in chimney sweeps in 1775. Skin cancer was found among workers in tar industries in 1875, and in 1887 workers in cotton spinning industries were known to have cancer which was attributed to contact with lubricating oils. Girls who painted the luminous dials of watches contracted cancer from exposure to the radioactive paint, and men who worked with B-naphthylamine developed bladder cancer. Many other cases of occupational cancer were reported before a systematic study of carcinogenic substances was begun. Early attempts to produce cancer in …
Range Liverstock Nutrition And Its Importance In The Intermountain Region, C. Wayne Cook
Range Liverstock Nutrition And Its Importance In The Intermountain Region, C. Wayne Cook
Faculty Honor Lectures
It has been estimated that about 728 million acres or about 76 percent of the entire land area in the West is used for grazing (Stoddard and Smith 1956). In Utah about 93 percent of the land area or 48,900,000 acres is considered range land (Reuss and Blanch 1951). Although some of this range land is forested, a large area of it can be used only for grazing. Therefore, range livestock production is an important segment of western agriculture.
Before 19'00 most of the animals in the West grazed on the range all year. However, irrigation crop production has expanded …
Addition Of Sodium Nitrate (1956), Walter A. Lawrance
Addition Of Sodium Nitrate (1956), Walter A. Lawrance
Walter Lawrance Papers
No abstract provided.
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, …
Stream Pollution- Aquatic Macro-Invertebrate Communities As Indicators Of Organic Pollution In Lytle Creek, Arden R. Gaufin, Clarence M. Tarzwell
Stream Pollution- Aquatic Macro-Invertebrate Communities As Indicators Of Organic Pollution In Lytle Creek, Arden R. Gaufin, Clarence M. Tarzwell
United States Environmental Protection Agency: Publications
Year-round field studies of the com position and ecology of stream communities associated with the purification of organic wastes in streams were initiated on Lytle Creek in October, 1949. This creek, which is located about 45 miles northeast of Cincinnati, Ohio, is a tributary of the Little Miami River. Its drainage basin comprises 27 sq. mi., a third of which is contained within the city limits of Wilmington, Ohio, a city of some 7,412 persons
Tetrazolium Salts, Andrew Garnett Richardson
Tetrazolium Salts, Andrew Garnett Richardson
Master's Theses
Tetrazolium salts, as the name indicates, are quartenary. Substitution is possible on positions 2, 3, and 5 of the ring as is shown in type formula (I). When these substituent groups are bifunctional ditetrazolium salts of types (II), (III), and (IV) result. Compounds bridged at both R' and R'' at the same time are theoretical possible, but no such cases have been reported, probably on account of the practical limitations of synthesis. The anion, which is indicated by X, may be halide, sulfate, acetate, picrate, succinate, thiocyanate, or practically any atom or group capable of existing as a negative ion.
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 …
A Study Of Isotopic Exchange Between Potassium Iodide And Benzyl Iodide. Solvent Effects, Joseph A. Leary
A Study Of Isotopic Exchange Between Potassium Iodide And Benzyl Iodide. Solvent Effects, Joseph A. Leary
Chemistry and Chemical Biology ETDs
The kinetics of nucleophilic aliphatic substitution reactions has been studied by numerous investigators during the past fifteen years. Included in this type of reaction are well-known general reactions such us (1) the Finkelstein reaction, (2) the Menschutkin reaction, (3) the alcoholysis of alkyl halides, and (4) various isotopic exchange reactions.
The Development Of A General Education College Chemistry Course, Luther Arnold
The Development Of A General Education College Chemistry Course, Luther Arnold
Journal of the Minnesota Academy of Science
No abstract provided.
The Monadnock Volume 30, Number 2, May 1956, Clark University Geographical Society
The Monadnock Volume 30, Number 2, May 1956, Clark University Geographical Society
The Monadnock (Clark Geographical Society)
Volume 30, Issue 2 of The Monadnock. The Monadnock was the alumni magazine of the Clark University Geographical Society (1927-1985) (2014-present).
The Sixty-Eighth Session Of The Iowa Academy Of Science And The Twenty-Third Convention Of The Iowa Junior Academy Of Science, April 20-21, 1956, Iowa Academy Of Science
The Sixty-Eighth Session Of The Iowa Academy Of Science And The Twenty-Third Convention Of The Iowa Junior Academy Of Science, April 20-21, 1956, Iowa Academy Of Science
Iowa Academy of Science Documents
No abstract provided.
Coprecipitation Of The Transuranium Elements With The Rare Earths Coprecipitation Of Americium With Lanthanum Oxalate, John A. Hermann
Coprecipitation Of The Transuranium Elements With The Rare Earths Coprecipitation Of Americium With Lanthanum Oxalate, John A. Hermann
Chemistry and Chemical Biology ETDs
Coprecipitation is a process whereby a substance soluble by itself is "carried" with an insoluble crystalline precipitate. As used here, coprecipitation applies to the "carrying" of a tracer by a precipitate formed in the presence of the tracer. The phenomenon is important in analytical chemistry1, in the problem of impurities in precipitates; in radiochemistry2,3, in the separation of radioactive tracers originally present in very low concentrations; and in general, whenever a solid is separated from its mother liquid by precipitation.
Arretotherium Fricki, A New Miocene Anthracothere From Nebraska, J. R. Macdonald, C. Bertrand Schultz
Arretotherium Fricki, A New Miocene Anthracothere From Nebraska, J. R. Macdonald, C. Bertrand Schultz
Bulletin of the University of Nebraska State Museum (1924–2023)
A new species of middle Miocene (early Hemingfordian) anthraco-there, Arretotherium fricki Macdonald and Schultz is described based on a cranium from the upper Marsland deposits of Nebraska. The holotype suggests that this genus was derived from the Oligocene genus Elomeryx Marsh.
The Effect Of Ph On Phase Reversals Of Protein-Stabilized Emulsions, Samuel Arthur Bradford
The Effect Of Ph On Phase Reversals Of Protein-Stabilized Emulsions, Samuel Arthur Bradford
Masters Theses
"The phase reversal of an emulsion from a system in which oil droplets are dispersed in a water medium to a system in which water droplets are dispersed in oil is dependent upon the interfacial characteristics of the liquids and the emulsifying agent being used, as well as the volume ratio of the two liquid phases. A preliminary investigation at this institution has indicated a possible relationship between phase reversal and the isoelectric point of gelatin used as the emulsifying agent. Since the properties of proteins vary so greatly with the hydrogen ion concentration, particularly near their isoelectric points, research …