One of the final steps in fabricating microelectromechanical devices often involves a liquid etch release process. Capillary forces during the liquid evaporation stage after the wet etch process can pull two surfaces together resulting in adhesion of suspended microstructures to the supporting substrate. This release related adhesion can greatly reduce yields. In this report, a wet etch release method that uses polystyrene microspheres in the final rinse liquid is investigated. The polystyrene microspheres act as physical barriers between the substrate and suspended microstructures during the final liquid evaporation phase. A plasma ashing process is utilized to completely remove the polystyrene microspheres from the microstructure surfaces. Using this process, release yields > 90% were achieved. It is found that the surface roughness of gold surfaces increases while that of the silicon is reduced due to a thin oxide that grows on the silicon surface during the plasma process.

The submarine and the spaceship fit in perfectly with the ideas of permanence and protection on which my work has been focusing. It is not coincidental that I have long been fascinated with the shapes and mechanisms of these vehicles. They are complex machines designed for a complex function; I find the precision of this to be appealing. I have used their shapes and mechanisms as design aspect in my thesis work. Also, in the studio, I have developed a type of Damascus steel bowl by modifying a technique once used for making gun barrels. I have made three small vessels inspired by spaceships and submarines using this modified technique.

The purpose of this study was to examine the relation between stimulus equivalence (briefly, networks of relations among stimuli) and the extension of stimulus function (briefly, spread of effect across network) more closely than has been possible before. The traditional view of this relation suggests that equivalence classes mediate the extension of stimulus function and are, therefore, necessary for any extension to occur. This study used a preparation in which the conditional discriminations required for the development of equivalence classes and the simple discriminations required for the extension of function were trained or tested simultaneously. Results suggest that equivalence are not necessary for the extension of stimulus function though they may be sufficient.

In this dissertation we study the structure of spaces of operators, especially the space of all compact operators between two Banach spaces X and Y. Work by Kalton, Emmanuele, Bator and Lewis on the space of compact and weakly compact operators motivates much of this paper. Let L(X,Y) be the Banach space of all bounded linear operators between Banach spaces X and Y, K(X,Y) be the space of all compact operators, and W(X,Y) be the space of all weakly compact operators. We study problems related to the complementability of different operator ideals (the Banach space of all compact, weakly compact, completely continuous, resp. unconditionally converging) operators in the space of all bounded linear operators. The structure of Dunford-Pettis sets, strong Dunford-Pettis sets, and certain spaces of operators is studied in the context of the injective and projective tensor products of Banach spaces. Bibasic sequences are used to study relative norm compactness of strong Dunford-Pettis sets. Next, we use Dunford-Pettis sets to give sufficient conditions for K(X,Y) to contain c0.

In this thesis I attempt to base an environmental ethic on a quality called naturalness. I examine it in terms of quantification, namely, as to whether it can quantified? I then apply the concept to specific areas such as restoration and conservation to create an environmental ethic and to show how such an ethic would be beneficial in general, and especially to policy issues concerning the environment. The thesis consists of three chapters: (1) the definition of nature and natural by way of a historical approach; (2) the place of humans in this scheme; and (3) the place of value and the discussion concerning quantification.

This thesis analyzes the political career of Oran M. Roberts during the critical period from 1850 to 1873. Through a reassessment of Roberts's extensive personal papers in the context of modern historical scholarship, the author explains how Roberts's political philosophy reflected the biases and prejudices typical of his era, as well as his own material interests and ambitions. Topic areas covered include Roberts's position on the Compromise of 1850, his constitutional philosophy, his involvement in the secession movement in Texas (including his service as president of the state secession convention), his military career during the Civil War, his participation in Presidential Reconstruction, his views on Congressional Reconstruction, and his role in the process of "redemption" in Texas.

A Country With No Name is a collection of thirty-four poems with a preface explaining the style and influences of the author. The preface defends plain-language techniques in poetry, using W.H. Auden, Wislawa Szymborska, and Paul Simon as examples of poets who take a similar approach. The poems range in topic from personal and familial to societal and abstract. The main subjects encompass interpersonal relationships, romantic and otherwise, and larger concerns, such as the effects of war and modern lifestyles.

I chose to exhibit sculpture and classical style vessels together to encourage discussion about whether ceramics should be considered a fine art medium. I was interested in experimenting with different forms and textures in order to see which combination would captivate the viewing audience the longest. I found that massive textural sculptural forms held the attention of the viewer more so than did the classical smooth surfaced vessels.

Traditionally children with developmental disabilities who develop feeding issues can be at great risk for malnutrition. Failure to eat adequate amounts of food and/or insistence on eating a limited range of foods can be detrimental to a child's health and can lead to other behavioral difficulties. Feeding problems are difficult to treat because high levels of physical prompting can quickly create an aversion to eating as well as cause stress for both parents and children. Behavioral problems that range from moderate to extremely maladaptive can ensue. The question the present study addressed was whether or not a treatment package including only positive reinforcement and fading for a non-preferred food would result in independent eating of the targeted non-preferred food.

The current study assessed the effectiveness of a training package, delivered in the form of a manual, to teach a parent to increase the variety and amount of food consumed by her son. The participant was a 5-year-old boy with Pervasive Developmental Disorder and limited food consumption. A changing criterion design across two variables, variety of food and quantity of food, was used. Results were that the parent who used the manual, with limited assistance from the experimenter, did succeed in increasing food variety and quantity of target foods.

Robust Vallisneria americana was cultured for restoration purposes. Preliminary studies, with various iron treatments, were conducted to ascertain the amount of phosphorous release into the water column from sediments. There was a significant difference in the amount of phosphorous released if commercial sediment was used with a low iron amendment or without an iron amendment. The second study consisted of planting V. americana on two different sediment types while supplying half of the plants with additional CO2. Plants grown on pond sediment with additional CO2 had significantly more biomass. In the third study all plants were grown on pond sediment, and half were treated with CO2. All plants that were treated with additional CO2 had significantly more biomass than those that were aerated.

Electronic and computer technology have advanced and transformed graphic design. New technologies are forcing design educators to constantly monitor and update their programs, creating a need for a system to be adopted by college-level institutions to better investigate, evaluate and plan art and design curriculum. The author identifies metaphorical approaches to designing a two-part solution, which includes a Comprehensive Visual Information System (CVIS) and Three-Dimensional Virtual Database (3DVDb), which assign volumetric form to education components based on the form, structure and content of a discipline. Research and development of the conceptual design for the CVIS and 3DVDb are intended to aid in the development of an electronic media solution to be made accessible to students, faculty and administrators.

Nanocrystalline praseodymium oxide films have been successfully generated on stainless steel substrates. The electrochemical deposition was performed in the cathode compartment of a divided electrochemical cell with a regular three-electrode configuration. The green films obtained by electrodeposition were then annealed at high temperatures for 1-3 hours. X-ray diffraction revealed the fluorite structure of Pr6O11 and the crystallite size was calculated. X-ray photoelectron spectroscopy was employed to study the composition of the oxide films and also the oxidation state of Pr. Scanning electron microscopy was utilized to study the surface texture and microstructure of deposits. Fourier transform infrared spectrometery was used to investigate the composition of the films. The effects of different conditions on the green films were also studied such as different pH values of the electrolyte solution, different deposition modes, different supporting electrolytes and different applied current densities. Sintering experiments were conducted to investigate the properties of the green films. Praseodymium oxide powders were also successfully prepared by combining electrochemical methods with sintering processes. The praseodymium oxide powders were characterized by X-ray diffraction and Fourier transform infrared spectroscopy. The crystallite sizes of the powders were evaluated.

Man has used graphic signs and symbols to express a variety of thoughts and feelings since before the invention of writing; they have helped him to preserve the ideologies that have enabled him to articulate his conception of the world. Every culture in every historical era has invested the objects, animals and plants around it with a multitude of different psychological meanings to communicate its essential belief systems and social aspirations. In my document, I chose to shed light on the responsibility I believe design educators must assume regarding their ability to understand and teach the importance of how similar graphic signs, symbols, ideograms and icons are perceived differently by different cultures in the hyper-connected, inter-global economy of 21st century. It is very crucial not to discount the influence and correlation of symbolic, fundamental building blocks of design with the basic psychological functions that inform our subconscious, and are also informed by our individual social and cultural upbringings. People from different cultures may cognate these shapes similarly, but they perceive and encode their meanings based on their particular social and cultural influences. One-size-fits-all communication design solutions rarely work, especially when they are distributed to culturally diverse audiences, because various ethnic …

The focus of my graduate work was to figure my way through a variety of challenges and transitions I was going through as a graduate student and simply as a person finding my way through my education to discover who I am and who I want to become. Perhaps my themes didn't focus primarily on these events in a literal sense, but I think the transitions in my artwork have become obvious through my time spent at UNT and the variations on a theme I have dealt with. All of my work deals with love, attraction, repulsion and the consequences we deal with as human beings when we make choices according to whom we choose to have relations with. It became very important for me to deal with these issues in an effort to discover what my expectations of myself as an artist and a person are.

This autobiographical problem in lieu of thesis explores the subject matter of the sculpture, revolving around the issues of dyslexia and literacy, and builds upon the idea of metaphor and its function in relationship to the sculpture. The four visual and conceptual elements that are emphasized are: (a) the juxtaposition and arrangement of elements and materials; (b) inability to open the books; (c) alteration of the text to make the words illegible, by creating words that are fuzzy or transparent; and (d) repetition and scale. Also discussed are ideas of post modern criticism with an emphasis on semiotics and writing of Derada in relationship to his contemporary analysis of his sculpture.

The notion of wildness as a concept that is essentially intractable to definition has profound linguistic and ethical implications for wilderness preservation and environmental education. A survey of the ways in which wilderness value is expressed through language reveals much confusion and repression regarding our understanding of the autonomy of nature. By framing discussions of wilderness through fact-driven language games, the value of the wild autonomy in nature becomes ineffable. In removing wildness from the discourse on wilderness we convert wilderness value from an intrinsic value into a distorted instrumental value. If we want to teach others that wilderness value means something more than a recreational, scientific, or economic opportunity, we need to include other ways of articulating this value in our education programs. Through linking the wildness of natural systems with the wild forms in human language games, I examine the conceptual freedom required for valuing autonomy in nature. The focus on what is required of language in expressing the intrinsic value of wilderness reveals that wilderness preservation and environmental education need complementary approaches to the current science-based frameworks, such as those used by the National Park Service. The disciplines of poetry, literature, ethics, and aesthetics offer alternative language …

Previous research has shown that variability is a reinforceable dimension of operant behavior. Additionally, it has been demonstrated that learning is facilitated when variability in responding is high. In this research, variability was observed within an operant composed of any sequence of six left and right key presses. Variability was either a requirement for point delivery (VAR conditions) or points were delivered independent of variability (ANY conditions). Two groups of college undergraduates experienced different orders of conditions. One group began the experiment under VAR conditions, and the variability requirement was later removed. The other group began the experiment under ANY conditions, and the variability requirement was later added. A concurrently reinforced target sequence (i.e., an always-reinforced sequence of left and right key presses) was introduced to both groups after these orders of conditions had been experienced. A variety of outcomes resulted. Subjects learned the target sequence when variability was both high and low with non-target points concurrently available. Other subjects learned the target sequence after all non-target point deliveries had been suspended. One subject failed to acquire the target sequence at all. These results were compared to previous findings and possible explanations for the discrepancies were suggested.

Dynamic memory management required by allocation-intensive (i.e., Object Oriented and linked data structured) applications has led to a large number of research trends. Memory performance due to the cache misses in these applications continues to lag in terms of execution cycles as ever increasing CPU-Memory speed gap continues to grow. Sophisticated prefetcing techniques, data relocations, and multithreaded architectures have tried to address memory latency. These techniques are not completely successful since they require either extra hardware/software in the system or special properties in the applications. Software needed for prefetching and data relocation strategies, aimed to improve cache performance, pollutes the cache so that the technique itself becomes counter-productive. On the other hand, extra hardware complexity needed in multithreaded architectures decelerates CPU's clock, since "Simpler is Faster." This dissertation, directed to seek the cause of poor locality behavior of allocation--intensive applications, studies allocators and their impact on the cache performance of these applications. Our study concludes that service functions, in general, and memory management functions, in particular, entangle with application's code and become the major cause of cache pollution. In this dissertation, we present a novel technique that transfers the allocation and de-allocation functions entirely to a separate processor residing in …

Individuals diagnosed with schizotypal personality disorder (SPD) exhibit patterns of cognitive deficits in (1) attention (Lees-Roitman, Cornblatt, Bergman, Obuchowski, Mitropoulou, Keefe, Silverman, & Siever, 1997), (2) memory (Bergman, Harvey, Lees-Roitman, Mohs, Margerm, Silverman, & Siever, 1998), (3) executive functioning (Cadenhead, Perry, Shafer, & Braff, 1999), and recently (4) neuromotor functioning (Neumann & Walker, 1999), similar to individuals with a diagnosis of schizophrenia. Furthermore, recent research suggests a link between neuromotor and cognitive functioning in schizophrenia spectrum disorders (SSDs) (Neumann & Walker, 2003). The current study is an extension of research on non-drug-induced neuromotor disturbances in individuals with SPD and examines how such disturbances covary with neurocognitive measures. Approximately thirty-three adults (18-65) were rated for SPD symptoms. Motor assessments included a computerized motor task and finger tapping test. Cognitive assessments included measures of attention, verbal and visual memory, and executive functioning. Consistent with previous research, the SPD group displayed significant right hand (left hemisphere) motor disturbances (i.e., increased force and force variability) compared to healthy controls after excluding all cases reporting a history of head injury. In addition, results indicate significant associations between motor, cognitive, and symptom variables. Consistent with previous research, neuromotor functioning and the relationships between motor and cognitive …

Semiconductor circuitry feature miniaturization continues in response to Moore 's Law pushing the limits of aluminum and forcing the transition to Cu due to its lower resistivity and electromigration. Copper diffuses into silicon dioxide under thermal and electrical stresses, requiring the use of barriers to inhibit diffusion, adding to the insulator thickness and delay time, or replacement of SiO2 with new insulator materials that can inhibit diffusion while enabling Cu wetting. This study proposes modified amorphous silicon carbon hydrogen (a-Si:C:H) films as possible diffusion barriers and replacements for SiO2 between metal levels, interlevel dielectric (ILD), or between metal lines (IMD), based upon the diffusion inhibition of previous a-Si:C:H species expected lower dielectric constants, acceptable thermal conductivity. Vinyltrimethylsilane (VTMS) precursor was condensed on a titanium substrate at 90 K and bombarded with electron beams to induce crosslinking and form polymerized a-Si:C:H films. Modifications of the films with hydroxyl and nitrogen was accomplished by dosing the condensed VTMS with water or ammonia before electron bombardment producing a-Si:C:H/OH and a-Si:C:H/N and a-Si:C:H/OH/N polymerized films in expectation of developing films that would inhibit copper diffusion and promote Cu adherence, wetting, on the film surface. X-ray Photoelectron Spectroscopy was used to characterize Cu metallization of …

The purpose of this study was to determine if, after one year of operation, the UNT/Dallas Public Schools Leadership Development Program was progressing in accordance with the goals set out for the program. Questionnaires administered to 26 interns and 10 mentor principals and follow-up focus group interview sessions provided answers to the study's five research questions that explored the following: selection process; how interns' involvement in campus-based decision-making had changed; how mentor principals' perceptions toward interns had changed; and how administrative interns' perceptions of themselves and educational administration had changed. Findings from this study revealed the selection process provided the Dallas Public Schools an opportunity to select teacher-leaders from the district and to include a representative number of minority and women candidates for participation in the program. An area of weakness was seven interns with low GRE scores were admitted through an appeals process at the university. Another weakness revealed the majority of interns had been assigned more duties and responsibilities at the schools, but only 4 of 26 interns were being allowed to participate in any campus-based decision-making processes that could have an impact on school improvements. The study found the role of the mentor principal to be the …

Critical care nurses work in an environment rich in informative interactions. Although there have been post hoc self-report survey studies of nurses' information seeking, there have been no observational studies of the patterns and content of their on-duty information behavior. This study used participant observation and in-context interviews to describe 50 hours of the observable information behavior of a representative sample of critical care nurses in a 20-bed critical care hospital unit. The researcher used open, in vivo, and axial coding to develop a grounded theory model of their consistent pattern of multimedia interactions. The resulting Nurse's Patient-Chart Cycle describes nurses' activities during the shift as centering on a regular alternation with the patient and the patient's chart (various record systems), clearly bounded with nursing "report" interactions at the beginning and the end of the shift. The nurses' demeanor markedly changed between interactions with the chart and interactions with the patient. Other informative interactions were observed with other health care workers and the patient's family, friends and visitors. The nurses' information seeking was centered on the patient. They mostly sought information from people, the patient record and other digital systems. They acted on or passed on most of the information …

Behavior analysts refer to a decrease in response rate following repeated, contingent presentations of a reinforcing stimulus as a product of satiation. Other evidence suggests that these decreases may often be due to habituation to the sensory properties of the reinforcing stimulus. The investigation reported here sought to determine whether decreases in operant responding by 3 adults with developmental disabilities were due to satiation or habituation. During baseline, participants placed poker chips into a container, and no reinforcement was available. Within subsequent phases, participants received diet lemon-lime soda on a fixed-ratio (FR) schedule of reinforcement. In one condition, the color of the soda was constant throughout the session, and in another condition food coloring was added several minutes into the session. Results for at least 2 participants indicated that: (a) soda functioned as a reinforcer for placing poker chips in the can; (b) response rates decreased within the session to baseline levels; and (c) response rates increased following a change in the color of the soda within the session. Results for the third participant were less clear. The results support the argument made by other researchers that the terms habituation (a weakening of a behavior following contact with the reinforcing …