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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
131

Converting among fractions, decimals, and percents: an exploration of representational usage by middle school teachers

Muzheve, Michael Tapfuma 15 May 2009 (has links)
Using both quantitative and qualitative data collection and analyses techniques, this study examined representations used by sixteen (n = 16) teachers while teaching the concepts of converting among fractions, decimals, and percents. The classroom videos used for this study were recorded as part of the Middle School Mathematics Project (MSMP). The study also compared teacher-selected and textbook representations and examined how teachers‘ use of idiosyncratic representations influenced representational choices on the number test by the teachers‘ five hundred eighty-one (N = 581) students. In addition to using geometric figures and manipulatives, a majority of the teachers used natural language such as the words nanny, north, neighbor, dog, cowboy, and house to characterize fractions and mathematical procedures or algorithms. Coding of teacher-selected representations showed that verbal representations deviated from textbook representations the most. Some teachers used the words or phrases bigger, smaller, doubling, tripling, breaking-down, and building-up in the context of equivalent fractions. There was widespread use of idiosyncratic representations by teachers, such as equations with missing or double equal signs, numbers and operators written as superscripts, and numbers written above and below the equal sign. Although use of idiosyncratic representations by teachers influenced representational choices by students on the number test, no evidence of a relationship between representational forms and degree of correctness of solutions was found. The study did reveal though that teachers‘ use of idiosyncratic representations can lead to student misconceptions such as thinking that multiplying by a whole number not equal to 1 gives an equivalent fraction. Statistical tests were done to determine if frequency of representation usage by teachers was related to the textbook, highest degree obtained by teacher, certification, number of years spent teaching mathematics, number of years teaching mathematics at grade level, number of hours completed on professional development related to their textbook, and total number of days spent on the Interagency Education Research Initiative (IERI) professional development. The results showed representation usage was related to all the above variables, except the highest degree obtained and the total number of days spent on the IERI professional development.
132

Middle distillate hydrotreatment zeolite catalysts containing Pt/Pd or Ni

Marin-Rosas, Celia 15 May 2009 (has links)
A study on middle distillate hydrotreatment zeolite catalysts containing Pt/Pd and/or Ni was performed. The effect of the addition of the corresponding CoMo, CoMoPd, CoMoPtPd and CoMoNi in PdNiPt-zeolite, Pt-zeolite, Ni-zeolite, and PdPt-zeolite was studied. The catalysts were characterized physically and chemically by methods and techniques such as Brunauer-Emmett-Teller (BET), Barret-Joyner-Hallenda (BJH), and neutron activation analysis. The structures of the Ni and Pt containing zeolite were studied by X-ray Photoelectron Spectroscopy (XPS). An experimental apparatus was constructed to investigate the activity of the experimental catalysts. The catalysts activity measured in terms of conversion of dibenzothiophene (DBT), substituted dibenzothiophenes (sDBT) and phenanthrene as well as molar-averaged conversion was evaluated in a continuous flow Robinson Mahoney reactor with stationary basket in the hydrodesulfurization and hydrogenation of heavy gas oil which contains sulphur refractory compounds such as 4- methyldibenzotiophene (4-MDBT) and 4,6- dimethyldibenzothiophene (4,6-DMDBT). DBT, 4-MDBT, 3-MDBT, 1-EDBT, 3-EDBT, 4,6-DMDBT, 3,6-DMDBT, 2,8- DMDBT and 4-methylnaphtho[2,1-b]thiophene were selected to calculate the molaraveraged conversion. The conversions of the sulfur containing compounds and phenanthrene were determined as a function of the operating variables: space time (W/Fo DBT), temperature, H2/HC mol ratio and pressure. The Conversions of DBT and 4,6-DMDBT into their reaction products such as Biphenyl (BPH), Cyclohexylbenzene (CHB), Bicyclohexyl (BCH) and 3,4-Dimethylbiyphenyl (3,4-DMBPH) were determined only as a function of space time in the interval of 4000-6000 kgcath/kmol. The results of this work showed that Pt-HY and PdPt-HY are good noble metals catalysts for the hydrodesulfurization of heavy gas oil. Moreover, this study showed that CoMoPd/Pt-HY and CoMoNi/PdPt-HY catalysts are good candidates for deep HDS and hydrogenation of heavy gas oil. It was found that the conversions of sulfur compounds were higher than the conversions provided by the conventional CoMo/Al2O3 catalyst. Also higher hydrogenation of phenanthrene was observed. Deactivation of the catalysts was not observed during the operation. Finally, the study not only contributed to define the technical bases for the preparation of the noble metal catalysts for hydrodesulfurization of heavy gas oil at pilot scale, but also provided technical information for developing the kinetic modeling of the hydrodesulfurization of heavy gas oil with the noble metal catalysts.
133

Middle-class demand for self-use residential properties, Kaohsiung City Study

Ho, Chen-Yu 16 September 2009 (has links)
With the increase in national income, demand for residential dwellings from the shelter, basic needs, thus taking into account the domestic situation, ventilation, lighting and other home within their own conditions, and noise, sanitation, etc. the quality of the external environment, gradually become the focus of concern, while the home security, life and leisure sports such as convenience demands increasing attention. In particular, the middle-class constitutes the backbone of society, to social development and stability of a great force in Kaohsiung local consumption patterns and cultural differences, the middle-class homebuyers demand for their own use and purchase of residential the decision-making may be different from other areas. Housing is a not a small number of financial decisions and expenditures, as housing is different from general merchandise, with durability, high prices and the repeat purchase rate of the smaller features, is the homebuyers in the decision-making process must be highly involved, and in the face of housing decisions, the consideration of the housing a myriad of factors. Residential properties for different homebuyers have different degrees of importance, is a very complex decision-making process, this study of " analytic hierarchy process (AHP) " to complex problems systematically, from different perspectives given level of decomposition and, through quantitative judgments, will be a comprehensive assessment of relevant information to provide homebuyers in the purchase decision-making appropriate and adequate information, decision-making aimed at resolving the difficulties of the temporary surface, reducing the risk of making a wrong decision, enabling more homebuyers transaction capacity to make the right decision. The use of " hierarchy analysis, " the establishment of multi-level evaluation model, the middle class-occupied residential property for Kaohsiung weight requirements analysis to understand the priority order; through the Conclusion of this study was to provide middle-class homebuyers Kaohsiung's reference, also provide Government and civil construction industry in the planning and building of own house, they can meet the Kaohsiung middle-class preferences.
134

Model studies of the middle atmosphere of Venus /

Newman, Matthew, January 1991 (has links)
Thesis (Ph. D.)--University of Washington, 1991. / Vita. Includes bibliographical references (leaves [419]-429).
135

An investment in being human : exploring year 9 student exhibitions : an ACT case study /

McKenzie, Anna. January 2008 (has links)
Thesis (Masters) -- University of Canberra, 2008. / Includes bibliography (p. 320-324) Also available online.
136

Can the current residential services fulfill the needs of middle class elderly people? a case study of senior citizen residences (SEN) /

Woo, Ka-wai. January 2009 (has links)
Thesis (M. Hous. Man.)--University of Hong Kong, 2009. / Includes bibliographical references.
137

Career decisions of middle-aged women : an exploratory study of the reasons some women work and others do not /

Pohlman, Patricia Likert. January 1978 (has links)
Thesis (M.A.)--Ohio State University. / Bibliography: leaves 170-174. Available online via OhioLINK's ETD Center.
138

Women in middle management : the impact of an involuntary job change /

Kubicek, Ernestine Balderrama. January 1999 (has links)
Thesis (Ph. D.)--University of Texas at Austin, 1999. / Includes bibliographical references (leaves 135-147). Available also in a digital version from Dissertation Abstracts.
139

Föreställningar om arbete, utveckling och livsrytm hos en grupp män i chefsuppgifter

Björkberg, Roland, January 1978 (has links)
Thesis--Gothenburg. / Added t.p. with thesis statement inserted. Summary in English. Includes bibliographical references (p. 241-247).
140

From the textbook to the enacted curriculum textbook use in the middle school mathematics classroom /

Chávez-López, Óscar, January 2003 (has links)
Thesis (Ph. D.)--University of Missouri-Columbia, 2003. / Typescript. Vita. Includes bibliographical references (leaves 167-174). Also available on the Internet.

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