1,806 research outputs found
Thermal diffusion near a binary liquid azetrope
Induction of a mass flux by a temperature gradient is known as the thermal diffusion or Soret effect, and is characterized by the thermal diffusion factor. A thermogravitational column’was used to obtain thermal diffusion factors and steady state separations in the ethanol-water mixture at its azeotropic composition. The thermogravitational diffusion column was calibrated using the value of the thermal diffusion factor of the cyclohexane-benzene mixture, which had been previously determined at 25°C. The temperature dependence of the thermal diffusion factor was determined for the ethanol-water system within .5°C of the azeotropic point and in the range of 25° to 77.7°C. Within 1°C of the azeotropic point, the thermal diffusion factor shows an anomalous behavior. It appears to increase rapidly as the azeotrope temperature is approached. In addition to the thermal diffusion factor, the heat of transport and thermal diffusion coefficient were determined for the ethanol-water system as functions of temperature, based on the assumption of Onsager Reciprocity. These parameters also exhibit a divergent character as the boiling point is approached. Further studies are needed to determine the significance of this effect in terms of molecular models. Ethanol enriched fluid from the thermogravitational column operating in the continuous mode was used as feed to a packed distillation column. Further separation occurred via distillation. Thus, thermogravitational columns offer a convenient small scale intermediate to break the azeotropes which often arise in the separation of liquid mixtures by distillation
A Historical Study of the North Atlantic Treaty Organization
The objectives of making a study of the North Atlantic Treaty Organization are threefold. These objectives are to show the background, development, structure, operation, problems and accomplishments of NATO; to determine whether NATO has fulfilled the general objectives of the treaty; whether NATO has fulfilled the general objectives of the treaty; and to furnish a bibliography and source materials useful as teaching aids for further study of the organization. We are living in a period when people of the West are turning to world organizations, such as NATO, as the hope of the world. A knowledge of what they have accomplished seems necessary if there is to be confidence in such organizations. A knowledge of their failures also seems necessary in this evaluation. The average American on the street is not familiar with the history of NATO. He probably knows something of its recent activities, but little about its background, issues and struggles. This is largely due to the fact that he shows little interest in the politics, dates and details that are associated with the organization. Even so, however, more people are expressing a greater interest in world affairs because of such crises as Berlin, Germany, the Middle East, the Orient and the threat posed by Russian development of intercontinental missiles. A personal interest in this study was prompted by a feeling of inadequacy while teaching current historical topics in an Iowa public school system. Due to insufficient time, the history courses taken in this writer’s undergraduate study could not adequately cover all the important events since World War II. A heavy teaching load prevented sufficient private study of this time period. The interest of this writer in this topic was also aroused by several references to NATO while doing research for a term paper in American Foreign Policy. It is hoped that this study will provide knowledge of the North Atlantic Treaty Organization as well as knowledge of the major world events since World War II. It is the plan of this study to trace the development of NATO in chronological order from its conception to its present status, which, because of the changing conditions must be incomplete. The early chapters deal with NATO’s background, including the reasons for NATO, the leaders and countries responsible, early negotiations and provisions and purposes. The second part traces the changes that have come about since the treaty began functioning in 1949, and the structure, with explanations of the various civilian and military officials, committees, organizations and commands. The study closes with a summary of the accomplishments made by NATO in its eleven years of existence and of the problems NATO has faced, is facing, and will face in the future. Information for this study was taken from an encyclopedia, books, pamphlets, newspapers and magazines. The books were used to provide the general background, while the other sources were used to make the study more current and detailed. The writer found the material from the Department of State and the United States Government Printing Office, especially the reports, documents and speeches, very helpful. An especially helpful organization was the American Council on NATO, Inc., an independent information center located in New York City, which suppled much current literature
Investigations of the Trophic Relationships, Feeding Ecology and Feeding Behavior of Larval Spot, \u3ci\u3eLeiostomus Xanthurus\u3c/i\u3e Lacepede, and Atlantic Croaker, \u3ci\u3eMicropogonias Undulatus\u3c/i\u3e (Linnaeus) (Pisces:Sciaenidae)
The feeding ecology of preflexion and flexion-postflexion spot (Leiostomus xanthurus) and Atlantic croaker (Micropogonias undulatus) larvae was evaluated and compared. Nutritional condition of spot larvae from the Gulf of Mexico was high, with no larvae classified as starving. This was probably due to an inability to sample starving larvae at sea because of predation pressure or was indicative of favorable feeding conditions and an absence of starvation in the collection area. In spite of morphological similarities between the species, significant differences in body shape existed.
The diets of the two species converged with age and interspecific dietary overlap was relatively high for both flexion stages. Inter- and intraspecific competition were probably not important determinants of diet composition because of the apparent absence of starvation. In contradistinction, the degree of food selection increased with age in both species. Larvae added larger prey to their diets while continuing to feed on smaller prey, food selection was temporally variable and larvae always fed selectively amongst the available prey. Prey size and shape were important determinants of selectivity, with larvae eating prey that were, on average, larger than those available. The affect of prey size and shape on food selection was probably not related to size-limited ingestion, but to visual profile and reactive distance. These results were in accordance with predictions made by optimal foraging theory and two other food selection models.
The feeding incidence of three age classes of Leiostomus xanthurus, on the rotifer Brachionus plicatilis, was investigated under six different spectral regimes (red, yellow, green, blue and white). Significant sources of variation in feeding incidence were attributed to age and color. Two-three week old larvae did not demonstrate a higher feeding incidence in any regime when compared to the control. Seven and ten week old larvae demonstrated a relatively higher feeding incidence in the yellow and green regimes. Those larvae may have possessed two visual pigments of different maximal absorption that were matched to typical natural background spacelight and that facilitated contrast vision. Differences between the age classes indicated that the ability to perceive prey increased with age
That So-Called Warranty Deed: Clouded Land Titles on the White Earth Indian Reservation in Minnesota
IMPACT OF EXPORTS ON THE U.S. BEEF INDUSTRY
Policy and programmatic decisions dealing with beef exports require good information as to the impact of exports on the domestic beef industry. This paper utilizes a partial equilibrium model of the world beef market to assess the impacts on the U.S. beef sector of increases in real income in major beef importing countries, the impacts of changes in the prices of pork and poultry products, and the impacts of changes in the price of feedgrains. A one percent increase in real GDP in Canada, Japan, Mexico, and South Korea yielded a 1.6 percent increase in U.S. exports of high-quality beef. This increase in exports leads to approximately a 29.2 million pound increase U.S. beef production on a retail weight basis. The increase in export demand also yields an increase in beef prices of approximately 120 box of beef and 70 fed steer. One percent increases in the prices of pork and poultry products yield a smaller 0.8 percent increase in U.S. beef exports, but also lead to a 1.5 percent increase in U.S. imports of low-quality beef. This is due to U.S. consumers viewing low-quality beef as a substitute for pork and poultry. Finally, a one percent increase in the price of feedgrains reduces U.S. beef exports by 0.4 percent. This is due to a reduction in U.S. beef production from the increased feeding costs.International Relations/Trade, Livestock Production/Industries,
Fault detection and bypass in a sequence information signal processor
The invention comprises a plurality of scan registers, each such register respectively associated with a processor element; an on-chip comparator, encoder and fault bypass register. Each scan register generates a unitary signal the logic state of which depends on the correctness of the input from the previous processor in the systolic array. These unitary signals are input to a common comparator which generates an output indicating whether or not an error has occurred. These unitary signals are also input to an encoder which identifies the location of any fault detected so that an appropriate multiplexer can be switched to bypass the faulty processor element. Input scan data can be readily programmed to fully exercise all of the processor elements so that no fault can remain undetected
Stochastic heating of cooling flows
It is generally accepted that the heating of gas in clusters of galaxies by
active galactic nuclei (AGN) is a form of feedback. Feedback is required to
ensure a long term, sustainable balance between heating and cooling. This work
investigates the impact of proportional stochastic feedback on the energy
balance in the intracluster medium. Using a generalised analytical model for a
cluster atmosphere, it is shown that an energy equilibrium can be reached
exponentially quickly. Applying the tools of stochastic calculus it is
demonstrated that the result is robust with regard to the model parameters,
even though they affect the amount of variability in the system.Comment: 7 pages, 6 figures, accepted by MNRAS,
http://www.astro.soton.ac.uk/~gbp/pub/pavlovski_stochh.pd
The Spray-On Bio-Bandage
Fibrin is a natural polymer already used in extreme clinical settings as an adhesive and for shallow wounds when activated by the enzyme thrombin. However, current formations contain irritants, are slow drying, and are not easily washed off. This study used a spray-on bandage composed of thrombin and fibrinogen on a monolayer of 3T3 mouse fibroblast cells to test the enhancement of the body\u27s natural healing without the risks of current formulations. The viability and growth of scratched cells were analyzed using live/dead stain assays 0, 1, and 3 days post-treatment. The results of this study showed cell growth, fibrinogen formation, and scratching were successful. The bottles\u27 spray exerted too much force and caused additional cell death compared to untreated cells. Additionally, the cells migrated too quickly through the scratch, resulting in rapid gap closure. Further research on cell scaffolding, bandage application, and cell viability is required for a successful spray-on bio-bandage.https://digitalcommons.usu.edu/fsrs2022/1001/thumbnail.jp
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