Logistics/purchasing effectiveness, manufacturing flexibility and firm performance: instrument development and causal model analysis (logistics, purchasing)

Tracey, Michael Austin University of Toledo 1996 국내박사

The effect of carbon dioxide on hydroformylation of 1-hexene by an immobilized rhodium catalyst

Bektesevic, Selma The University of Toledo 2005 해외박사(DDOD)

소속기관이 구독 중이 아닌 경우 오후 4시부터 익일 오전 9시까지 원문보기가 가능합니다.

In situ high-pressure Diffuse Reflectance Infrared Fourier Transform Spectroscopy was performed to investigate the hydroformylation of 1-hexene in supercritical carbon dioxide. A rhodium complex was immobilized on phosphinated silica and used as a catalyst. The changes in the infrared spectrum over time showed the reaction profile, which was used to evaluate the effect of pressure on the reaction mechanism. Increasing the reaction pressure by adding carbon dioxide increased 1-hexene conversion and hydroformylation activity. Specific changes observed in the infrared spectrum when the supported complex interacted with carbon monoxide, hydrogen and/or mixture of carbon monoxide and hydrogen in the presence and absence of carbon dioxide at elevated pressures revealed the nature of the reacting species over time and pressure, and clearly demonstrated the role of carbon dioxide when it was used as the solvent. The catalyst activity and structure were compared for reaction in supercritical carbon dioxide with that in nitrogen in order to more completely delineate the role of the supercritical solvent on the reaction mechanism. It was found that the resting state of the catalyst was HRh(CO)2Lx, L=PPh 2CH2CH2 bound to silica, independent of the reaction pressure and the presence of carbon dioxide or nitrogen.

Representations for six dimensional Lie algebras with a codimension one nilradical

Hettiarachchi, Chamath The University of Toledo 2005 해외박사(DDOD)

소속기관이 구독 중이 아닌 경우 오후 4시부터 익일 오전 9시까지 원문보기가 가능합니다.

Ado's Theorem asserts that every real Lie Algebra g of dimension n has faithful representation as a subalgebra of gl(p, R ) for some p. The Theorem offers no practical information about the size of p in relation to n and in principle p may be very large compared to n. This dissertation is concerned with finding representations for a certain class of six-dimensional Lie algebras, specifically, algebras that have a codimension one nilradical. This class of algebras was classified by Mubarakzyanov and comprises 99 cases. Representations for algebras 39 through 99 are found. A matrix Lie group is given in each case from which the matrix representation for the corresponding Lie algebra can be found by differentiating and evaluating at the identity element of the group. In addition the center of each algebra and a basis for the right-invariant vector fields that are dual to the Maurer-Cartan are given. Sufficient background material is presented to make all concepts here self-contained.

An ultracapacitor-battery energy storage system for hybrid electric vehicles

Stienecker, Adam The University of Toledo 2005 해외박사(DDOD)

소속기관이 구독 중이 아닌 경우 오후 4시부터 익일 오전 9시까지 원문보기가 가능합니다.

The nickel metal hydride (NiMH) batteries used in most hybrid electric vehicles (HEVs) provide satisfactory performance but are quite expensive. In spite of their lower energy density, lead acid batteries are much more economical, but they are prone to sulfation in HEV applications. However, sulfation can be greatly reduced by a circuit that uses an ultracapacitor in conjunction with the battery. This research presents a new cost-effective method for using these two energy storage components together in order to extend the life of the battery. This system is presently quite expensive, but it will provide much cheaper energy storage if ultracapacitor prices can be reduced to the levels predicted by some manufacturers. This dissertation studies two different methods for implementation on a hybrid electric vehicle and presents performance data for a variety of simulations.

Mechanisms underlying subthreshold and suprathreshold responses in dorsal cochlear nucleus cartwheel cells

Tong, Mingjie The University of Toledo 2005 해외박사(DDOD)

소속기관이 구독 중이 아닌 경우 오후 4시부터 익일 오전 9시까지 원문보기가 가능합니다.

Cartwheel cells (CWCs) are a group of interneurons in the dorsal cochlear nucleus (DCN). Unlike other DCN neurons, which respond to stimuli with simple spikes, or trains of individual action potentials, CWCs respond to suprathreshold stimuli with complex spikes, rapid bursts of action potentials superimposed on a slow depolarization, or a combination of simple and complex spikes. In vitro whole-cell current clamp recordings from young rats (P11--P15) show that CWCs respond to brief suprathreshold stimuli with complex spikes or simple spikes followed by afterdepolarizations (ADPs); and to subthreshold stimuli with subthreshold depolarizations (SDPs). Although complex spikes and ADPs are produced by Ca2+ currents, SDPs are unaffected by Ca 2+ current antagonists but are substantially depressed by the N a+ channel antagonist TTX. Voltage clamp recordings reveal that SDPs are produced by a persistent Na+ current activating below spike threshold in CWCs. A hyperpolarization-activated inward current (In) is shown to contribute to the repolarization of SDPs; and voltage-gated K+ currents, including transient and Ca2+-activated K+ currents contribute to the repolarization of suprathreshold responses in CWCs. Computational simulations demonstrated that SDPs are produced by persistent Na+ currents; furthermore, these currents are required for the activation of high-threshold Ca2+ channels during suprathreshold responses to produce complex spikes in response to brief suprathreshold stimuli. Delayed-rectifier, transient and Ca2+-activated K+ currents contribute to the repolarization of complex spikes and increase of maximal conductances in any of three K+ currents converts complex spikes into simple spikes. In contrast, removal of the hyperpolarization-activated inward current Ih increases the amplitude and duration of SDPs, but otherwise has little effect on suprathreshold responses of CWCs. These results demonstrate that a combination of voltage-gated conductances that activate over a range of subthreshold and suprathreshold membrane potentials contribute to the unique electrophysiologic responses of CWCs.

Women('s) teachers(') literacy(ies) practice(s) and policy(ies)

Keller, Sharon Marie Miller The University of Toledo 2002 해외박사(DDOD)

소속기관이 구독 중이 아닌 경우 오후 4시부터 익일 오전 9시까지 원문보기가 가능합니다.

Much of what gets promoted and looked at in the fostering of academic achievement for best practices in literacy is about effective practice and language development. However, I believe to focus solely on effective practice and language development is problematic without greater emphasis on teachers' literacy orientations, attitudes, and conditions as linked to their practice. In addition, I believe challenges to the dominant discourses of primary teacher education and traditional (ungendered) ideologies need examination for power and gendered consequences. I believe there exists an immediate need to complement the research on what we do as literacy educators through our discourses, practices, and positionality as women teachers along with the improvement research. Specifically, research that looks to women primary teachers' orientations and constructions as they influence have consequences and are connected to literacy practices with learners in classrooms. The intent of this study is to add to a limited research base focused upon women primary teachers' literacies and ideologies and how these literacy orientation promote particular literacies and literacy practices for young children (Kindergarten) in an urban setting. To begin to name and demystify the links between ideological orientations to literacy and language development practices for young children, the study addresses three key research questions: How do primary women teachers view literacy? How are women primary teachers' literacy orientation reflected in teaching methods, evaluation, and views of learners? What social-political/educational consequences appear in teaching beliefs and teaching methods of women primary teachers toward literacy? This particular case study, of three women teachers of early childhood learners, is looked at through the lens of a feminist poststructural framework, which acts as a filter to traditional ethnographic methodology, data analysis, and interpretation. Accordingly, through interviews, observations, literacy inventories, field notes, and the researcher's reflective journal, this study engaged teachers through dialogue and narratives about ideologies of literacy and the teaching of literacy. All of the teachers who were participants in this study expressed a desire to understand their own perspective and actions about literacy, particularly as women teachers of young children.

Environmental durability of PET and PET/PEN blends for outdoor applications

Jiang, Yang The University of Toledo 2001 해외박사(DDOD)

소속기관이 구독 중이 아닌 경우 오후 4시부터 익일 오전 9시까지 원문보기가 가능합니다.

The photodegradation of poly(ethylene terephthalate)(PET), poly(ethylene 2,6-naphthalene dicarboxylate)(PEN) and their blends have been investigated in terms of different weathering factors such as UV irradiation time and condensation. PET/PEN blends were made with a twin-screw extruder. Samples for study were then made with an injection molding machine or compression molded. Transesterificaiton reactions occur during the blending of PET and PEN. A critical value of degree of randomness has to be achieved to make sure that the properties of materials are not a function of the level of transesterification, but a function of the composition of blends. Degree of randomness was examined with nuclear magnetic resonance. Mechanical properties of PET and PEN/PET blends have been evaluated before and after UV irradiation. The results show that after exposure for equivalent UV irradiation times, blends containing PEN exhibit better mechanical properties than those of pure PET. Fourier transform infrared spectroscopy and UV absorption spectroscopy were used to study the mechanisms of photodegradation of these materials. Changes in carboxyl endgroup –COOH generation of PET, PEN and the blends, as a result of progressive UV irradiation time, were examined since carboxylic acid endgroups accompany molecular weight drop and chain-scission. After equivalent exposure conditions, PET shows more carboxyl acid endgroup generation than PEN. Blending PEN with PET produces less carboxylic acid endgroup generation than that of PET. An end-group analysis technique using FTIR has been used for end-group determination in PET, PEN and blends in the solid states. With this technique both –COOH, –OH endgroups were determined. The number-average molecular weight, Mn, was then calculated from the concentration of these two endgroups. The number of chain-scission was also determined. The results of calculations demonstrate that the extent of the photodegradation of PEN is much less than that of PET and blending with PEN improves the UV barrier properties of PET significantly. Photolysis in vacuum was conducted to understand the role of oxygen in the photodegradation reaction. The results suggest that for PET, the presence of the oxygen has inhibited the crosslinking reactions to form a bi-phenyl structure which accounts for the yellowing of PET. PEN tends to form bi-naphthalene structures causing yellowness to occur as a result of exposure to UV in air environment. The mechanisms of yellowing and carboxyl endgroups generation are discussed. Studies of the depth of photodegradation of these materials have shown that the “screen effect” of PEN is much better than that of PET and that blending PEN with PET at concentration as low as 5% will decrease the depth of photodegradation of PET considerably.

A study of principals' attitudes toward inclusion: The impact of administrator preparation

Hesselbart, Frederick The University of Toledo 2005 해외박사(DDOD)

소속기관이 구독 중이 아닌 경우 오후 4시부터 익일 오전 9시까지 원문보기가 가능합니다.

A survey of 37 principals and assistant principals in a predominantly rural county in Northwest Ohio was conducted to investigate relationships regarding attitudes toward inclusion with other variables such as teaching experience, both regular and special education, experience with special needs students, and placement preference. Results indicated that just under half of the principals surveyed had a positive attitude toward inclusion, whereas almost the same percentage were uncertain. Statistical analyses indicated that the only strong correlation with attitude was preferred placement. The higher the attitude score, the less restrictive the preferred placement of special needs students. All other correlation coefficients fell in the very low range, both positive and negative. Results suggested that colleges and universities need to do more in preparing principals to work with special needs students.

The role of empathy for delinquent and non-delinquent adolescents exposed to violence: Is it protective?

Baldacci, Heidi Bechtoldt The University of Toledo 2005 해외박사(DDOD)

소속기관이 구독 중이 아닌 경우 오후 4시부터 익일 오전 9시까지 원문보기가 가능합니다.

In the United States, interpersonal violence and victimization of the country's youth is an epidemic. The purpose of the present study was to examine the potential protective role of empathy in the development of social-cognitive deficits and the expression of proviolence attitudes following exposure to violence. In two separate studies, non-delinquent (n = 260) and delinquent (n = 140) adolescents from a medium-sized Midwestern city were asked to complete five self-report measures that examined the following constructs: violence exposure, social information processing skills (hostile attribution bias and outcome expectancies), attitudes towards violence, and empathy. For the non-delinquent school sample, results revealed that regardless of severity, more frequent exposure to violence was significantly related to stronger proviolence attitudes. Empathy did not appear to moderate the relationships between exposure to violence, social information processing deficits, and proviolence attitudes. However, as level of empathy increased, proviolence attitudes, positive outcome expectancies, and the expression of the hostile attributions decreased. In terms of gender differences, boys reported stronger proviolence attitudes, more exposure to mild violence, and more positive outcome expectancies for the use of aggression. Girls reported higher levels of empathy. Further, girls with more frequent exposure to mild violence as well as girls who were more often the victim of severely violent events were more likely to expect positive outcomes from the use of aggression. No significant relationships were found between exposure to violence and social information processing deficits for boys. As for the detention center sample, results similarly revealed that regardless of severity, more frequent exposure to violence was significantly related to stronger proviolence attitudes. Empathy did not appear to moderate this relationship. However, as level of empathy increased, proviolence attitudes, positive outcome expectancies, and the expression of the hostile attribution bias again decreased. No significant relationships were found between exposure to violence and social information processing deficits. In terms of gender differences, girls reported higher levels of empathy. Finally, exploratory analyses revealed that the more times a juvenile was booked for a crime, the higher his/her likelihood of having been a victim of a severely violent crime.

Experiential learning program in historical archaeology: A qualitative study in student learning

George, Marcia M The University of Toledo 2005 해외박사(DDOD)

소속기관이 구독 중이 아닌 경우 오후 4시부터 익일 오전 9시까지 원문보기가 가능합니다.

Investigating student learning during the Johnson's Island Experiential Learning Program in Historical Archaeology (JI ExLP) provided an in-depth look at student behaviors, language, and attitudes related to the scientific processes of uncovering the past. Johnson's Island prison compound, a National Historic Landmark located in Sandusky Bay on Lake Erie, Ohio provided the setting. Between the years of 1862--1865, during the USA's Civil War, this prison housed over 10,000 Confederate officers. This qualitative investigation was conducted to understand how students' active engagement in the research process, along with environment and social interactions affect students' construction of knowledge. This ethnographic study reflected three classes (one Midwestern school district; n = 75) of fifth-grade students' experiences as they demonstrated, described, and reflected upon their participation in the JI ExLP. Data was collected in the forms of pre/post surveys and evaluations, but more importantly during the hands-on exploration of the past which included: exploring the Confederate Cemetery; digging, screening, and recovering artifacts; along with listening to and discussing the diaries and letters of the Civil War POWs. Oral and written responses were analyzed for understanding perspectives and identifying what students learned and how they learned as they participated in the JI ExLP and engaged in the archaeological processes of uncovering the past. Students' ideas and beliefs about the Civil War POWs, understanding of prison life at Johnson's Island, archaeology and learning from the earth were enhanced as evidenced in the summaries, conversations, and evaluations. These perceptions and understandings evolved through experiences and interactions with others. One of the unique elements of the JI ExLP reiterated throughout the data was students were motivated by the surprise or mystery of not knowing what they might uncover. Recognizing they must keep excavating and screening to make new discoveries, a genuine purpose, kept students' interest with not knowing when, where, or what would be found, but understanding the prospects rested beneath them. In conclusion, students purported being actively engaged in an authentic research environment (Civil War Prison archaeological site) along with interactions with peers and adults, promoted inquiry, construction of knowledge, and development of new perspectives.