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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.
31

A study of suspension polymerisation of Methyl Mathacrylate and Styrene in a batch oscillatory baffled reactor

Zhang, Yanmin January 1998 (has links)
One of the most important issues in suspension polymerisation process is the control of the final particle size distribution (PSD) as this is an indicator for both quality and financial matters. For polymer manufacturers, a narrow PSD is always welcome. The conventional reactors, e. g. stirred tank reactors, generally produce particles of a rather broad PSD. As a result, to explore a new type of polymerisation devices becomes a challenging task. The objectives of this PhD study are to apply a novel mixing apparatus, the oscillatory baffled reactor (OBR), to batch polymerisation of MMA and Styrene (crosslinked) and to characterise all the major aspects of the OBR involved in the pioneering work, with a view to assessing its potential for industrial applications. In order to carry out such investigations, a 1.2 litre batch jacketed OBR system with temperature control and on-line data acquisition units was designed and built. In addition, an off-line image capture system was set up f or droplet studies. From heat transfer study in the OBR, it was found that the temperature profiles across and along the reactor were uniform and a heat transfer correlation was obtained. The oil-water dispersion in the OBR was then investigated for various baffle designs, dispersed phase fractions and the levels of surfactants, enabling the optimal baffle type and parameters to be identified. In order to understand the droplet behaviour in the OBR, the droplet size distribution (DSD) was examined on dispersion uniformity, oscillation time, operational conditions, baffle thickness and the level of surfactant addition. It was found that the DSDs were very uniform within the reactor and the oscillation frequency and amplitude had the same effect on controlling the DSDs. Finally, a series of PMMA and PS tests were successfully conducted in the OBR, indicating that the polymer PSD can be controlled by adjusting both oscillation conditions and the baffle orifice diameter and that the OBR has the potential to produce uniform polymer particles at high oscillation frequencies. A correlation between droplet sizes with no reaction and final polymer particle sizes was established, which can be used to predict the final polymer sizes.
32

Frequency distributions of mammalian body size analyzed by continent

Rusler, Renee Denise, 1962- January 1987 (has links)
No description available.
33

THE APPLICATION AND ANALYSIS OF A PROPOSED EQUIVALENCY BASED FORMULA FOR COMPUTING THE CAPACITY OF SCHOOL BUILDINGS

Hooker, David Melvin, 1940- January 1976 (has links)
No description available.
34

The effect of thermal shock on the grinding kinetics of oxidized taconite

Winters, Frederic Thomas, 1954- January 1978 (has links)
No description available.
35

Procedures for lot size determination in two level production systems

Lopez Canales Ricardo Rafael 12 1900 (has links)
No description available.
36

Growth and size distribution of firms in an industry

Tellez, Fernando 05 1900 (has links)
No description available.
37

Rock breakage in percussive drilling.

Drouin, Claude. January 1971 (has links)
No description available.
38

A Windows application to compute back-calculations of fish body lengths using Visual Basic 6.0 / Title of accompanying CD-ROM: FishBC 2.0 / Title of accompanying CD-ROM cover: FishBC : fisheries research software

Doll, Jason C. January 2003 (has links)
A windows based computer program to compute fish back-calculated lengths at age was created using Visual Basic 6.0© programming language. The objective of this project was to develop a computer program that is user-friendly and requires minimal user input to produce back-calculations. This program incorporates the familiar windows based graphical user interface and can compute up to 10,000 fish with a maximum age of 50 years. The input data can be imported from an Excel spreadsheet or manually entered directly to the program. Back-calculated lengths were computed using the traditional Lee method [ (L; = a + [ (L, - a) ( S; / Sc ) ]. Additional related statistical outputs are also included. The output data can be viewed using Excel where it can also be formatted for individual use. The program was compared with DisBcal using yellow perch age and length data. Results of the comparison were nearly identical with differences due to a rounding function of the output data. / Department of Biology
39

Family size and relative need /

Bradbury, Bruce. January 1997 (has links)
Thesis (Ph. D.)--University of New South Wales, 1997. / Also available online.
40

The relationship of waist size to blood pressure and cholesterol among college students /

Miller, Stephanie. January 2007 (has links)
Thesis (Honors)--Liberty University Honors Program, 2007. / Includes bibliographical references. Also available through Liberty University's Digital Commons.

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