Legacy Theses and Dissertations (1940-2009)

Permanent URI for this collectionhttps://hdl.handle.net/10657/6771

This collection gathers digitized University of Houston theses and dissertations dating from 1940.


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Now showing 1 - 20 of 6743
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    Flow of particulate materials in a vertical standpipe
    (1983) Chen, Ye-Mon; Luss, Dan; Flumerfelt, Raymond W.; Deans, Harry A.; Lienhard, John H.; Kleis, Stanley J.
    Standpipes are mechanical devices used to convey particulate solids downwards, usually from a region at lower pressure co a region at higher pressure, with tne aid of gravity. A well known application is the flow of a gas- solid mixture down from a fluidized bed in refinary processes, such as fluid catalytic cracking, fluid hydroforming and fluid coking. Tney are also used in the SASOL synthetic gasoline process and solid fuel processes of coal gasification and liquefaction. Despite the importance of the present applications and the potential of much wider use in the future, the mechanics of standpipe operation is still poorly understood. As a result, most industrial standpipes are still being designed empirically based on past experience. Inis is particularly unfortunate since standpipes are well known to devolop an instability under certain circumstances, causing a transition to a state with inadequate pressure build-up in the pipe. This may lead to operational problems such as loss of circulation and reversed gas flow which have resulted in a reduction of plant throughput or even complete shut-down of the plant. [...]
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    Single particle and reactor studies on char combustion
    (1983) Kumpinsky, Enio; Amundson, Neal R.; Luss, Dan; Richardson, James T.; Wagner, David H.
    When coal particles are introduced into a combustor, they experience a rapid temperature rise. As a result, an almost instantaneous evolution of volatiles occxrrs and a solid fuel is generated, called char. This analysis is concerned with the establishment of reliable mathematical models for processes Involving the combustion of char. With this intention, two categories of investigation were conducted, comprising single particle and whole reactor models. Factors such as the distribution of heterogeneous kinetics, competition for active sites, carbon reactivity, carbon-carbon dioxide reaction and particle shape were examined to assess their influence on the pseudosteady-state structure from qualitative and quantitative perspectives. The research on reactor models was initiated with stirred pots, thereby substantiating that the transient path of a single particle burning under fixed conditions is very sensitive to the ambient oxygen concentration in the surroundings. As a natural extension, it was necessary to develop combustor models with diverse degrees of segregation of the gaseous species. This enabled the conventionally employed approach of perfect gas mixing to be evaluated in relation to its suitability for the prediction of actual reactor performance. On the basis of this work, it is recommended that char combustor models take into consideration as much of the detail of internal transport as possible. Indeed, the combustion rates generated by means of distributed models are always larger than those evaluated at the average concentrations in lumped systems, due to considerable changes in the behavior of the ignition-extinction phenomenon.
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    Modeling of a solar steam reforming reactor
    (1983) Alagappan, P.; Richardson, James T.; Balakotaiah, Vemumi; Vant-Hull, Lorin L.
    Chemical Energy Transmission Systems (GETS) are based on reversible endothermic and exothermic reactions. One of the essential tasks of a large scale solar energy utilization plant is the transmission of energy from the solar collector to the consumer. This can be accomplished through GETS, with a solar thermal process called SOLTHERM. In this process, the endothermic reaction product can be transported through pipelines to any destination, where the exothermic reverse reaction is made to proceed with the release of energy. The best reaction system for GETS is the endothermic methane-steam reforming reaction and the reverse exothermic methanation reaction. A two-dimensional pseudo-homogeneous model has been developed for a packed-bed methane-steam reforming reactor which uses a heat pipe as a flux transformer to distribute the heat collected by the solar receiver system to the chemically reacting system. This model is capable of obtaining temperature and conversion profiles and mole fractions of various system components at every length within the reactor. Various sensitivity studies are performed for variations in inlet gas temperature and inlet natural gas flow rate, Sensitivities to changes in the available rate equation and heat transfer correlations are evaluated. The effect of variations in the heat pipe temperature and inlet steam-methane ratio are also examined. Calculations are done to evaluate the minimum thermodynamic steam-methane molar ratio above which there is no risk of carbon formation, for various temperatures. This is combined with the predictions of the model to evaluate carbon formation potentials within the reactor for different inlet conditions. Operating conditions are suggested to avoid carbon formation.
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    Simulation of packed gas absorption columns with first order irreversible reactions
    (1983) Chen, Ing-Ray; Henley, Ernest J.; Pollard, Richard; Tucker, Charles T.
    Gas absorption in packed towers has been modelled taking into account heat effects and first order irreversible chemical reactions. A theory based on the film factor concept was developed using steady state assumptions. The theory was transformed into a computer program which simulates the start-up procedure of the column dynamically and shows good convergence behavior. The computer program was tested with a pseudo-first order case, NaOH-CO2-Air, and good agreement with experimental data [21] was obtained.
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    Double-ringed and multiringed basins on the Moon and Mercury : morphologic correlations with size and other parameters
    (1982) Williams, Adele Fuller; King, Elbert A., Jr.; Butler, John C.; Mote, Victor L.
    Clues to the formation of concentric-ringed basins were sought through examination of Lunar Orbitor and Mariner 10 images. Morphologic type, inner ring subtype, size, ring ratio, location, degree of modification, terrain and crustal thickness were determined and correlated with each other. Increase in size from central peak to double-ringed to multiringed basins is noted. Mercury exhibits a strong clustering of basins around 200 km in diameter while the Moon shows a more uniform size distribution. The larger basins are equatorial on both planetary bodies. On the Moon, the larger basins, with the greater ring ratios, are mainly on the nearside. Most inner rings are approximately one half the diameter of the next outer ring, though the ratio is generally smaller for central peak basins and larger for multiringed basins. No certain relationship was found for inner ring subtype, degree of modification or terrain. A rebound model of formation is preferred because it best conforms to the observations, involves a single main mechanism for all concentric-ringed basins, explains a transition from one type to another with increased energy, and confines the main energy within the basin.
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    The heroic quartet of Scott's Waverley novels
    (1982) Reese, Robbie; Rothman, Irving; Southwell, Sam
    Progress in literary history is the traditional romance of the past giving way to modernity. In his Waverley novels. Sir Walter Scott depicts this transition through a quartet of heroes showing characteristics of both historical and modern figures. A study of The Heart of Mid-Lothian, Old Mortality, Rob Roy, and Waverley discloses the direct opposition of the passion and self-centered independence of the historical hero and heroine drawn from Scott's familiarity with his country's history and ballads to the rationality and societal loyalty of the modern pair identified with eighteenth century sensibility. Through the manipulation of his plots and through his characterization, Scott utilizes Scotland's history of contention and divisiveness to bring together across distinct borders the representatives of each faction. The characters portray both admirable and denigrating traits, but the final success of the modern hero reveals Scott's acceptance of the beneficial consequences of the inevitability of progress.
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    Experimental study of oil ganglion motion
    (1983) Hinkley, Richard Edward; Payatakes, Alkiviades C.; Flumerfelt, Raymond W.; Dalton, Charles
    Fundamental to the study of oil ganglion population dynamics is the study of solitary oil ganglion motion. One of the most important relevant parameters, which has not been adequately studied, is oil ganglion velocity. To study this quantity, a regular model porous medium was built. [...]
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    Dynamic modelling and optimization of lumped chemical processes
    (1983) Smith, Conrad B.; Luss, Dan; Amundson, Neal R.; Asbjornsen, Odd A.; Shieh, Leang-San; McInnis, Bayliss C.
    A new approach to analysis and optimization of forced periodic processes is presented. The class of lumped, single input, single output linear-analytic systems is considered. Such systems are those modelled by sets of nonlinear ordinary differential equations with a scalar control appearing linearly. The process output, or index of performance, is assumed to be a nonlinear scalar function of the system state. Global system stability is assumed throughout. The essence of periodic optimization is the fact that, for nonlinear systems excited by periodic inputs, the zeroth harmonic (average value) of the output is a function of the input characteristics. Using the theory of Volterra functional series, it is shown that the zeroth harmonic of the system output can be reasonably approximated by a general expression involving eigenvalues of the original system and parameters, called mode gains, associated with the eigenvalues, as well as the parameters describing the input signal. This expression, called the periodic optimization model can be used to examine the effects of varying inputs on the mean system output. A procedure is then developed which enables one to identify the eigenvalues and mode gains of a system based on a prescribed regimen of practical input/output process tests. This allows application of the periodic optimization model to systems for which one is unable to write a differential equation model suitable for dynamic simulations. Many heterogeneous catalytic reaction systems, for example, fall into this category. The proposed experimental identification procedure is demonstrated with a simulated model of acetylene hydrogenation carried out in a CSTR. Then, considering the class of bang-bang periodic inputs bounded above and below, optimization of the input signal is shown, by example, to be a simple exercise. The predicted optimal input for the acetylene hydrogenation example agrees well with that found by a previous worker via repeated simulations. Finally, preliminary experimented data on ethylene hydrogenation in a laboratory reactor are used to demonstrate the practicality of the periodic optimization model identification scheme.
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    Airstream trailer
    (1983) Bingham, Evelyn V.; Macdonald, Cynthia L.; McNamara, John; Larson, David J.
    In the preface to Working, a collection of interviews which forms an oral history or working people and their feelings about their lives, author Studs Terkel cites a recurrent theme found in those interviews. He observes, "During my three years of prospecting, I may have, on more occasions than I imagined, struck gold. I was constantly astonished by the extraordinary dreams of ordinary people."1 The "gold" which Terkel struck is the rich imaginative life present in the experiences of the subjects of Working. Many are able to see significance in the mundane objects and events around them or recognize the tragedy which occurs when no meaning or importance can be found. These "extraordinary dreams of ordinary people" have fascinated artists for centuries and have become, especially since the advent of Romanticism, a prevalent theme in poetry. Wordsworth's lyrical ballads, grounded in "incidents and situations from common life," marked a new concern in poetry, the attempt to evoke the quality of ordinary existence. Whitman's Leaves of Grass contains a vision of working men and women rendered in a particularly American language and diction. Much of Robert Frost's poetry concerns the commonplace characters and events of rural New England. The work of contemporary poets such as James Wright, Richard Hugo, and Philip Levine examines ordinary life, incorporating both the rural and urban work experience. The young poet who deals with this subject matter is challenged by a rich tradition. He or she must discover a language and imagery which evoke the experience, an appropriate formal means of ordering the experience, and an individual voice which can reside within the poem and preside over its communication to the reader. The narrative poems and dramatic monologues which comprise Airstream Trailer reflect my preoccupation with the lives of working class people and the role of the imagination in those lives. One element which informs those concerns and unifies many of the poems in this collection is the image of the Town. This image has its roots in both a literal town and in the kind of mythicized town which appears in literary works such as Sherwood Anderson's Winesburg, Ohio and John Updike's Olinger Stories. As a child from a military family with no home town of my own, I was fascinated by our visits to my father's home, Scranton, Pennsylvania. The landscape there contained both the mysterious and the familiar. Abandoned mines and slag heaps stood not far from the modern shopping center. In the narrow streets of the ethnic neighborhoods, residents built new additions onto the houses their families had occupied for generations. The terrain of Scranton came to respresent the layers of human history and experience which are present in many towns and cities. That literal landscape shared the symbolic quality of the mythicized Grovers Corners of Thornton Wilder's Our Town. Wilder's small and specific landscape evoked large and general significance. His play was a first indication for me of how an artist may arrive at the universal through the particular. [...]
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    The behavior of polymer solutions in extensional flow developed by drop elongation
    (1982) Wahlheim, Thomas Anthony; Flumerfelt, Raymond W.; Payatakes, Alkiviades C.; VanArsdale, William E.
    Extensional deformations of polymer solutions and melts occur in several important industrial processes such as fiber spinning, film blowing, extrusion and injection molding. To better understand how polymer solutions respond in extensional flow fields, experimental data are needed. However, experimental difficulties have limited much of the recent work to solidlike materials. The purpose of this work is to use the elongating drop technique to measure the rheological properties of a moderately high viscosity polymer solution. The drop elongation device used in these experiments employed a new method to measure the drop diameter changes. In this method, the ratio of a signal light voltage to reference light voltage provided high quality data on the changing drop diameter. The polymer solution studied was 10% by weight polyisobutylene dissolved in Decalin. Viscometric flow measurements were done using a Weissenburg Rheogoniometer. Eight extensional flow experiments were performed. In these experiments, a step change in rotational velocity was applied to the specimen. The largest step changes produced the largest instantaneous extensional viscosities. For each experiment, a region of nearly constant extensional viscosities was observed at strains less than 0.9. Trouton ratios, n+/3no, ranged from 1 to 1.6 in this region. The Trouton ratio increased rapidly at higher strains. Strains as high as 1.8 were achieved and Trouton ratios as high as 13.5 were calculated.
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    Psychic kissing
    (1982) Storey, Gail M. Donohue; Barthelme, Donald; Dixon, Terrell F.; Benjamin, Thomas E.
    What we call writing is often a nexus of obsessions to be disclosed in content, form, and all prose elements subsumed by these. Roland Barthes says: Writing is that pl ay by which I turn around as well as I can in a narrow place: I am wedged in, I struggle between the hysteria necessary to write and the image-repertoire, which oversees, controls, purifies, banalizes, codifies, corrects, imposes the focus (and the vision) of a social communication. On the one hand I want to be desired and on the other not to be desired: hysterical and obsessional at one and the same time.l Form is the strategy the writer employs to show relation between the world and the imaginative landscape of obsession. Prose rhythms can be an exquisite formal representation of the rhythm of this relation, line turning on line. The shape of the written landscape is located in the syllable and in the word, traversing line and page. The psychic landscape is one of image and relation--imagination. The apparent physical landscape is the world's landscape of objects, events, sensations. How might a writer of fiction represent these two fairly, as well as the paradox which constitutes the tension between them? Each of these twelve pieces of fiction suggests a way of looking at this problem. The affirmation of the paradox, an embrace of tension, can be itself a kind of resolution. For these pieces I have taken models which are literary, philosophical, and psychological. It seems that new myths arise out of new developments in these areas of thought and out of their intellectual and aesthetic traditions. The word myth has been employed to mean a fiction, an illusion, a tradition, a revelation, an exemplary model, and other things. The writing of fiction seems a way of articulating fresh myths as they are being created, and of applying them to the objects, events, and sensations of the apparent world(s). In pressing the limits of fiction, I point to interdisciplinary sources in the text, and to music and mathematics as metaphors. Joseph Campbell, in The Hero with ji Thousand Faces, proposes a model for the mythic quest, the adventure of the hero, including departure, initiation, and return. However, Campbell notes the discordancy between contemporary and mythological views:. . . for the democratic ideal of the self-determining individual, the invention of the power-driven machine. and the development of the scientific method of research, have so transformed human life that the long-inherited, timeless universe of symbols has collapsed.2 Contemporary South American writers seem to me among the most responsive to this dilemma, creating new myths and new heroes. Jorge Luis Borges in Ficciones suggests the mythic quest and the hero, but the quest is existentially mythic, the hero existentially heroic. In "The Circular Ruins," for example, we are faced less with character in the individuated sense than with a consciousness expanding to the limits of its own definition. I admire the fact that Borges does this so succinctly. Myth is beautifully applied to human life in Gabriel Garcia Marquez's One Hundred Years of Solitude. Within the one-hundred-year compass of the Buendfa family chronicle, love, war, youth, death, and beauty seem to reveal themselves as luminous events in consciousness. Of the many American writers I admire deeply, including Grace Paley, Ann Beattie, William Gass, and Donald Barthelme, I mention Walker Percy in this context and cite The Moviegoer for its articulation of symbolical and relational deficiency. In the movies, Percy has found a metaphor for this modern double impoverishment; the movies seem to hold open the space which his contemporary hero hopes to fill with symbol and relation. In The Moviegoer, the movies suggest a vehicle for a kind of dream. Joseph Campbell says: Dream is the personalized myth, myth the depersonalized dream; both myth and dream are symbolic in the same general way of the dynamics of the psyche.3 As a writer of fiction, I am most interested in the possibilities for new configurations of myth, contemporary metaphors drawn from the world we see before us, and contemplation of these as a celebratory act. Of the philosophers whose works have shaped my thinking, from the ancient Greeks to the French nouveaux philosophes, I mention two here: Martin Buber and Gaston Bachelard. Each suggests a way of contemplating the world before us, of penetrating contemporary metaphors to create meaning, of satisfying our deepest wishes for relation. Perhaps Buber refers to such a phenomenon when he speaks of the hallowing of the everyday in Hasidism and Modern Man. As a writer of words, I am interested in Buber's insight into the "primary words": Primary words do not signify things, but they intimate relations./ Primary words do not describe something that might exist independently of them, but being spoken they bring about existence./ Primary words are spoken from the being./ If Thou is said, the I of the combination I-Thou is said along with it./ If It is said, the I of the combination I -It is said along with it./ The primary word I-Thou can only be spoken with the whole being./ The primary word I-It can never be spoken with the whole being. Bachelard's insight into reverie suggests that the writer, especially the poet, is a great "word-dreamer" who gives words the time to dream. He says:. . . that reverie gives us the world of a soul, and that a poetic image bears witness to a soul which is discovering its world, the world where it would like to live and where it deserves to live. These ideas expand the possibilities for transformation of the gross into the subtle, where hysteria is transformed into reverie, loneliness into solitude, the absurd into humor, the sexual into the erotic, violence into love. To attempt to do so in writing fiction, I have experimented with the integration of certain psychological concepts into the language of the pieces. The work of Freud and Jung documents their efforts to adequately describe multi-level psychological processes. I have looked to their work to approximate in language phenomena such as transference, resistance, regression, and repression by imagery and other literary devices. In neologisms and in the double-scoring of word-over-word I have tried to approximate such psychological phenomena as condensation and over-determination. The language of some of the pieces represents an effort to synthesize symptom and image, to record the subtext first and the text second. Deeply interior, rooted in both conscious and unconscious life, this subtext sometimes has the character of a secret conversation. I locate a model for this in John Ashbery's Three Poems, a work of meditative prose in which myth, image, reverie, relation, and multi-valence coalesce. It is at once an expansive work of consciousness and a profoundly intimate dialectic. With such a model, one wants to make each written line as beautiful as the being with whom one is obsessed, and so delineate a psychic landscape.
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    Flow of particulate materials in a vertical standpipe
    (1982) Rangachari, Sunder; Jackson, Roy; Payatakes, Alkiviades C.; Deans, Harry A.; Auchmuty, J. F. Giles
    Standpipes are used in particle circulation systems to convey the solid material against an adverse pressure gradient in the interstitial gas, with the aid of gravity. Despite their extensive use, the mechanics of their operation is poorly understood. Hence, in this work a theoretical analysis of a simple standpipe configuration is presented. An experimental standpipe rig has also been constructed to permit comparison between theory and experiment. The theory is based on the equations of continuity and momentum balance for the two phases. Simplifying assumptions are made to generate a one-dimensional problem. Wall friction is taken into account but the gas is assumed to be incompressible. The theory can predict a complete performance diagram which relates the discharge rate of solid material to the overall pressure rise and control valve opening. The influence of aeration at various locations in the pipe has been studied and it is found that it is desirable to introduce aeration as far down the standpipe as possible. For a given control valve opening and pressure rise, the theory predicts an optimum aeration rate. The theory also reveals that, over a range of conditions, multiple steady states are possible. A linearized stability analysis has been carried out and it is found there is a direct link between the stability of the steady states and the slope of the performance curves. The experimental apparatus consists of a standpipe of length 3.267 m and 25.4 mm in diameter, fed by a conical hopper with steep walls and restricted at its lower end by a circular orifice centered on the pipe axis. The pressure at the top of the hopper is maintained atmospheric, while any desirable pressure can be maintained below the orifice. The dependance of the solids flow rate on the orifice size, and the pressure below the orifice is studied. Experiments have been carried out with sands of two different grades and also with cracking catalyst. Multiple steady states are also observed experimentally. Comparison of the theoretical predictions and the experimental results shows that the model can predict most of the qualitative features of standpipe operation. The quantitative predictions of the model are better for coarse sand than fine sand. As air-drag effects are more important for fine sand, this suggests that gas compressibility cannot be ignored, even in short standpipes, for fine particles. The predictions come closest to the observations for the unrestricted pipe, suggesting that the theoretical model of the valve region is inadequate.
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    The role of explicit rules in second language teaching
    (1981) Wood, Sharilyn; Acton, William R.; Valdes, Joyce M.; McIntire, Ronald G.
    Researchers investigating the issue of how to teach English as a Second Language (ESL) most effectively have recently become polarized into two main camps. One camp chooses to present students with a systematic introduction into the grammatical structure of the language, to teach explicit rules. A second camp prefers to teach language through use only rather than by analyzing it. This thesis reviews the research on the role of explicit rules in teaching ESL, and describes recent studies carried out at the University of Houston. In 1979, Herbert Seliger had students perform a task designed to demonstrate how well they could use the a/an distinction, and then asked them to state the rule which they used. He found no relationship between those who could perform the task well and those who could state the correct rule. His results were questionable because of certain methodological weaknesses in Seliger's work. These include an extremely small ESL sample, an inadequate explanation of data collecting techniques and results, the omission of examples for subjects, and a decision to score the lack of an article response as an incorrect response. In the Houston replication of this study (with modifications), in 1982, there was a strong correlation between correct rule usage and correct rule statement. The second recent study described here compared the rate of gain of two groups of students. The first group was taught the embedded question word order by just using the language in class. The second group participated in the same classroom procedures, but also studied the explicit rule in class. The two groups made approximately equal gains on the usage pre- and posttests, indicating that the study of an explicit rule on the grammar point had not measurably facilitated their learning. Finally, the students were asked to describe their opinions about the use of explicit grammar rules in an ESL class. These comments were analyzed as to ideas as well as grammatical content. Results indicated that the students' perceived needs varied widely; that they did not use the a/an distinction as well in their natural speech as in their tests; and that they did not use the embedded question construction at all. This thesis concludes with suggestions for future research on the role of explicit rules, and makes suggestions for ESL classroom teachers.
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    A thermal energy storage system for a solar cogeneration plant
    (1982) Ranade, Saidas; Prengle, Herman William, Jr.; Crump, Joseph R.; Bannerot, Richard B.; Vant-Hull, Lorin L.; Wentworth, Wayne E.
    The large scale effective utilization of solar energy requires economical and efficient energy storage. For a solar-fuel fired plant, there are periods when the solar energy availability exceeds the constant and uniform energy demand. Since the front-end heliostat field cost of such a plant is enormous, it is not economical to throw away any part of the collected energy. Without storage, direct solar conversion systems are limited in capacity factor to 20% or less. A thermal energy storage system interposed between the collector field and energy conversion system can buffer insolation variations and thereby allow a more uniform level of energy input to the conversion system. In this thesis 'a thermal energy storage system' has been defined, and the various proposed systems have been critically reviewed. Capital cost estimates extracted from various sources have been compared, for the first time, on a common defined basis of 1980. An all sodium system, selected as the base case, has been thoroughly investigated in order to understand the basic parameters, the cost distribution, and including the development of flow diagrams, design equations, and cost estimates. A fairly accurate model for sizing the energy storage system has been developed and used to determine the storage size range of practical interest. Based on selection criteria, relevant data, and other pertinent information, a molten salt storage system has been selected for study. The cost estimates, design equations, and correlations developed clearly indicate that, in the energy storage capacity range of 700 to 2100 MWh, a molten salt - two tank isolated type system is indeed the most cost effective and technically feasible for a solar central receiver hybrid cogeneration plant. The unit capital cost for the molten salt system was found to be in the range of 26.30 to 30.20 $/kWh whereas that for the sodium system varied from 43.00 to 45.43 $/kWh.
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    Characterization of reduced coprecipitated nickel-alumina catalysts
    (1982) Redd, George L.; Richardson, James T.; Pollard, Richard; Clifford, Dennis A.
    Hydrogen chemisorption, BET surface area and magnetization measurements were made on a series of coprecipitated nickel-alumina catalysts with nickel concentrations from 20 to 100 mole percent, calcined at temperatures from 300[degrees] to 1200[degrees] C. Surface areas of reduced unsupported nickel catalysts are closest to the BET surface areas when nickel areas are determined by the zero intercept of an H2 uptake versus pressure curve. Nickel areas of coprecipitated nickel-alumina catalysts were measured by two methods: hydrogen uptake at 300 mm Hg and from a crystallite size distribution determined by magnetization measurements. The ratio of the two areas is taken as a measurement of nickel availability. This nickel availability increased with increasing nickel concentration for catalysts calcined at 300[degrees]C. Nickel surface areas are maximized for 80 mole % nickel calcined at 300-400[degrees]C. Less surface area is obtained at lower nickel concentrations and/or higher calcination temperatures. Evidence is presented for nickel aluminate formation at higher calcination temperatures.
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    A heuristic method for solving the problem of upgrading the system availability through redundant allocation
    (1982) Yasutake, Karen Michiko; Henley, Ernest J.; Law, Japhet S.; Pollard, Richard; Luss, Dan
    A heuristic method has been developed to solve the problem of computing the optimal number of redundant components needed to attain an improved system availability without violating a cost constraint. This problem is a nonlinear problem, where the objective function is non-linear, the constraint can oe linear or non-linear and the solution must be pure integer. The heuristic method developed for this thesis was tested with example problems given by other methods found in the literature. This heuristic method solved these problems with ease and produced good results. A program was developed, entitled Upgrading of System Availability Package (USAP) which will: a) Generate the cut sets. b) Assess the system availability before upgrading. c) (via heuristics) It will upgrade the system availability without violating the cost constraint, or upgrade the system availability until a desired availability is attained even if it violates the cost constraint. d) Assess the final system availability. The advantage of this heuristic method is that the cost constraint is not restricted to a linear form. The parallel, identical components within a stage may be in hot or cold standby and they may also be a voting system.
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    The structuring of time : a stylistic analysis of Katherine Anne Porter's short stories
    (1981) Blain, Jacquelyn Shires; Zivley, Sherry Lutz; Gingiss, Peter J.; Rice, Joe A.
    The influence of time on an individual is clearly defined in Katherine Anne Porter's short stories by her stylistic choices. The phonetics of 'Maria Concepcion,' 'Flowering Judas,' 'The Journey,' and, particularly, 'Old Mortality,' create a quietly flowing, whispering world that is interrupted occasionally by hard sounds to highlight a particular incident, object, or feeling. This world is filled with the concrete details of daily living. Sentence openers and structure highlight an action or feeling by either expanding a moment to its limit or contracting an expanse of time into a short space. Such patterns reflect certain ideas. These patterns juxtapose the unchanging nature of old memories with the confusion of present actions. Porter believed in the continuity of past, present, and future and insisted that an individual's perception of time depends not on negating the patterns of the past, but on accepting how they have shaped one. This acceptance, in turn, will allow one to react intelligently to the chaos of the present and move confidently into the unknown of the future.
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    Chemical storage of solar energy : reaction engineering of the ammonium hydrogen sulfate cycle
    (1983) Lee, Maw-Chwain; Prengle, Herman William, Jr.; Wentworth, Wayne E.; Vant-Hull, Lorin L.; Asbjornsen, Odd A.; Pollard, Richard
    This dissertation presents documentation of work carried out on the design of a solar energy chemical storage system. The system involves the decomposition and regeneration of ammonium hydrogen sulfate (AHS) the storage and release reactions are, NH4HSO4 + K2S04 + Qsolar -> K2S2O7 + NH3 + H20; K2S2O7 + Qsolar -> K2SO4 + SO3; SO3 + H20 + NH3 -> NH4HSO4 + Q. Part I of this work presents a re-analysis and extension of previous work on the energy storage reactions. Firstly, it includes a detailed re-examination of the mechanisms, mathematical models, and reaction rate constants for the first step of energy input cycle. Secondly, the results of an investigation of the mechanism and rate of decomposition of potassium pyrosulfate is presented. Finally, a process configuration for the decomposition reactions and separation of the products is suggested. The mathematical flow-mode models developed are presented, and the required space velocities for a pilot-scale reactor system are indicated. Part II of this work presents the results of a detailed investigation of reactions involved with the recombination of the three product molecules, SO3, H2O and NH3, to release the stored energy. It was found for best results that the recombination should be brought about in two steps: reaction of SO3 plus H20 to produce H2SO4, followed by reaction of the H2SO4 plus NH3 to yield NH4HSO4. After determining the mechanisms, the rate controlling processes, and the kinetic data, an operational process is proposed. The necessary flowmode mathematical models developed are presented, and the required space velocities for a pilot-scale reactor system are indicated. Suggestions for future work for further development of the cycle are presented.
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    Solarium : [poems]
    (1981) Siebert, Charles, II; Weldon, Roberta F.
    While I am just beginning to accept the idea that a collection of my "finished" poems can represent a unique and coherent vision, I have always associated the need to write--to reorder the apparent sense of things in metaphor to make a different and perhaps better sense--with a kind of mental lethargy, in a word, confusion. It is not easy to say how this confusion manifests itself, yet I'm sure it has to do with allowing for strangely protracted moments of observation which seem to occur out of time and which take a long time to understand. I can use as an example the simple scene of a house among many on the outskirts of a modern city. There is a fence enclosing a yard and a live oak in which two blackbirds sit on an upper branch, only sky behind them. At one point, a young girl steps out on the front porch dressed in a dark coat much too large for her (her father's perhaps) and she starts waving the aims as though conducting wind through the live oak branches that sway until the blackbirds leave their perch and at the lowest sweep of their flight, draw your eyes to a flash of sun off the city's glass skyline above the low rooftops. I suppose this scene with its confluence of action is confusing only if it suggests some other significance, and while one person may have little trouble incorporating it and walking on, I, for unknowable reasons, stand anxiously by, staring with that quizzical tilt of the head a dog gives when spoken to with words other than the learned commands. [...]
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    Blood kin : [poems]
    (1981) Moreland, Jane P.; Macdonald, Cynthia L.; Stitt, Peter A.; Benjamin, Thomas E.
    Poetry springs from the impulse to shape experience and to express that shaping in language. No limitation exists on the poet's experience as to real, imagined, past, present, or future. Craft determines the order of the poet's words, but it is the order of his perceptions which is primary, which comes before the order of craft. Coleridge identified poetry as " . . . purely human; for all its materials are from the mind, and all its products are for the mind." [...]