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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.
1

Numerical Simulations of Thermo-Fluid Phenomena in Microwave Heated Packed and Fluidized Beds

Savransky, Max 02 December 2003 (has links)
Microwave heating is implemented in various fields such as drying, material processing, and chemical reactors. Microwaves offer several advantages over conventional heating methods: 1) microwaves deposit heat directly in the material without convection or radiation, 2) microwave heating is easy and efficient to implement, and 3) microwave processes can be controlled.In order to understand how to use microwaves more efficiently, we must understand how they affect the material with which they interact.This requires the ability to predict the temperature distribution that is achieved within the material.In recent years packed and fluidized beds have been used as chemical reactors to achieve various tasks in industry.Recent studies have shown that microwave heating offers the potential to heat the bed particles to a higher temperature than that of the fluid.This results in enhanced reaction rates and improves the overall efficiency of the reactor.T he focus of this work is to determine the temperature distributions within the packed and fluidized beds, and to determine whether the catalyst particles can be heated to a higher temperature than the gas in catalytic reactions. The beds are modeled with multiphase flow equations.The gas velocity profiles along with the solid and gas temperature profiles for packed and fluidized beds are provided. F or the fluidized beds, the hydrodynamics is modeled using FLUENT and the solid velocity profiles are also determined. / Ph. D.
2

Circulating fluidised beds

Bolton, L. W. January 1987 (has links)
No description available.
3

Heat transfer in fixed and fixed-fluidised beds

Ahmad, M. M. January 1980 (has links)
No description available.
4

Manganese oxide deposits in water treatment facilities, North East Scotland

Eley, Mark John January 1997 (has links)
No description available.
5

Provenance of Upper Jurassic and Lower Cretaceous coarse-grained detritus in Southern Britain and Normandy

Garden, I. R. January 1987 (has links)
No description available.
6

Gas-solid fluidisation : an improved method for the preparation of chemically bonded stationary phases

Akapo, S. Olufolabi January 1989 (has links)
No description available.
7

Integrated sedimentological and whole-rock trace element geochemical correlation of alluvial red-bed sequences at outcrop and in the subsurface

Gould, Simon R. January 2001 (has links)
Red-bed alluvial systems are becoming increasingly important as hydrocarbon plays in the UK Northern North Sea. Commonly such ephemeral systems are hard to define in terms of reservoir architecture, due to the difficulty in correlating such diverse and palaeontologically-barren sequences. This project aims to improve understanding of one such system, the Late Jurassic Cormorant Formation, of the Northern North Sea, through detailed sedimentological study of two outcrop analogues. The whole-rock trace element geochemical correlation technique in a variety of settings. The Lower Old Red Sandstone Moor Cliffs Formation of the Anglo-Welsh Basin provides ideal conditions for testing the whole-rock trace element geochemical correlation technique. The Moor Cliffs Formation is a low net:gross alluvial red bed suite, which by virtue of Variscan deformation, outcrops in a well-exposed, easily accessible cliff section at Priests Nose, near Manorbier, Pembrokeshire. A 100m section was sampled to determine variables that may affect whole-rock trace element geochemical correlation. The results prove that whole-rock trace element geochemical correlation can be applied to alluvial successions, despite pedogenic modification and deep burial. The Late Triassic Blomidon Formation of the Fundy Basin, Nova Scotia, provided a second outcrop example of an alluvial red-bed sequence, which was deposited in similar palaeo-climatic and tectonic conditions to the Northem North Sea Triassic. The Blomidon Formation contained a range of fluvial styles from confined channels to unconfined sheetfloods. Three sections were studied along the hanging-wall margin of the Fundy Basin, separated by up to 150km along strike. Each section provided a contrasting basinal setting, allowing comparison of facies along strike and down depositional dip. Sections were measured in detail to quantify bed geometries and facies variants, facilitating architectural analysis. Specific attention was paid to features that may be diagnostic in sub-surface cored sections of the Northern North Sea Triassic. Correlation was possible on a number of scales, using laterally continuous ephemeral marker beds within the Blomidon Formation. Detailed facies evaluation has allowed the division of the Blomidon Formation into four distinctive facies packages that vary considerably in sandstone net:gross. Each facies assemblage is defined by variations in fluvial style and occurrence of evaporite rich, ephemeral lacustrine and rare aeolian sediments. It was possible to produce a broad, basin-wide correlation scheme for the Blomidon Formation, based on these four facies packages. Detailed facies analysis of three cores from the Cormorant Formation, Tem Field, Northern North Sea allowed definition of reservoir architecture, based on models derived from outcrop analogues. The results suggest that correlation based on individual horizons and facies packages is possible in alluvial red-bed sequences through detailed sedimentological study. The whole-rock trace element geochemical correlation technique can also provide additional datasets to enhance correlation in the subsurface.
8

Planting methods for small grains in Arizona

Ottman, Michael J. 05 1900 (has links)
Revised; Original Published: 2004 / 2 pp. / Small grains are planted for a variety of reasons, but their rotational benefit makes them a popular crop all over the world and influences the way they are planted. One of the major benefits of small grains as rotational crops is that they cover the soil and suppress weeds. Thus, small grains are most commonly solid seeded with a grain drill.
9

The sedimentation and petrography of the Port Askaig Boulder Bed (late Precambrian) of Argyll, with a discussion of its origin

Spencer, Anthony Mansell January 1966 (has links)
No description available.
10

Planning models for hospital service allocation /

Chu, Lisa. January 2000 (has links)
Thesis (M. Phil.)--University of Hong Kong, 2000. / Includes bibliographical references (leaves.

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