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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.
21

The influence of nutrient supply on the morphology of Sphagnum cuspidatum

Baker, Richard George Egerton January 1988 (has links)
No description available.
22

The role of muscle-generated force and fibronectin polymerisation in fibripositor formation

Hill, Adele C. January 2008 (has links)
Tendons form a connective tissue bridge between muscle and bone. They are characterised by the presence of bundles of collagen fibrils parallel to the long axis The relative simplicity of the system means tendons are often used to study the mechanisms of formation of an organised ECM.
23

Structure, chemical nature and development of the bacterial endospore as related to heat resistance

Cohen, Jill Marcella (Southworth), January 1966 (has links)
Thesis (M.S.)--University of Wisconsin--Madison, 1966. / eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.
24

Relationship of heat activation and the mechanism of germination of bacterial spores

Vary, James Corydon. January 1964 (has links)
Thesis (M.S.)--University of Wisconsin--Madison, 1964. / eContent provider-neutral record in process. Description based on print version record. Bibliography: l. 66-70.
25

Bulge forming of tubular components

Hutchinson, Mark Ian January 1988 (has links)
The bulge forming process is a method for shaping tubular components using an internal hydrostatic pressure combined with a compressive axial load. Initial investigations involved carrying out an extensive literature survey to determine the components which could be formed and the effects of using lubricants and different tube materials. Die-blocks were designed to produce tee pieces, cross joints and off-set joints, and electronic on-line instrumentation was incorporated so that the forming pressures and loads could be accurately monitored. A series of tests were carried out in the forming of: (1) tee pieces, cross joints and off-set joints from copper tubes of two different wall thicknesses, (2) tee pieces using different types of plungers, (3) tee pieces using die-blocks coated with various lubricants, (4) tee pieces from aluminium, copper and steel tubes, (5) tee pieces using die-blocks with various branch radii. From the resulting components, formed with various combinations of internal pressure and compressive axial load, the limits for a successful forming operation were established. Further analysis of these components was then undertaken to evaluate the effects of the internal pressure and axial load on the bulge height and the wall thickness in the deformation zone. From these results, which have been illustrated graphically, the greatest effect on the resulting bulge can be seen to be the compressive axial load. Theoretical analyses are presented, which predict the wall thickness distribution around the bulge zone and also the axial loads required in the forming process. Comparison of these predictions with the experimental results shows fairly good agreement.
26

Inferencing unknown words in reading

Davies, David Rees January 1991 (has links)
We've probably all had the experience, when reading, of coming across an unfamiliar word and trying to guess some of its meaning. This thesis is a study of the guessing strategy used. Independent variables are: word meaning (known/unknown), form of presentation (cloze/pseudoword), word class (noun/verb), amount of information (3 amounts), orders of types of information (6). Dependent variables are: accuracy, confidence (belief in one's accuracy) and uncertainty (the number of alternative hypotheses held). Subjects are native speaker university students. The main result is that subjects tend not to guess unknown meanings. They treat them as known meanings (I e. they guess a familiar single word rather than a new meaning) by regarding the meaning cues, as they appear across varying amounts of information, as inconsistent items of information. Whilst there are interesting differences for form, the presence or absence of an unfamiliar form does not materially affect this process. There are also interesting differences for order. However, an interpretation of this finding in terms of a principle of costs and benefits suggests subjects would not employ an order based strategy in real life. The effectiveness of guessing as a communication and as a learning strategy is evaluated in the light of these findings.
27

The continuous dress creep feed form grinding of titanium alloys

Fursdon, P. M. T. January 1989 (has links)
No description available.
28

A uniform pressure electromagnetic actuator for forming flat sheets

Kamal, Manish 07 October 2005 (has links)
No description available.
29

Beam-Forming-Aware Link-Adaptation for Differential Beam-Forming in an LTE FDD System / Lobformingsmedveten Länkadaptation för Differentiell Lobformning i ett LTE FDD System

Karlsson, Mikael January 2016 (has links)
The ability for base stations to be able to beam-form their signals, directing the signal energy to specific users, is a topic of research that has been heavily studied during the last decades. The beam-forming technique aims to increase the signal-to-interference-and-noise-ratio of the user and, consequently, increase the capacity and coverage of the communication system. One such method is the Differential Beam-Forming technique, that has been developed at Ericsson Research. In this version of beam-forming, the beams can be dynamically sharpened and widened when tracking a specific terminal, to try to optimize the signal energy sent to that terminal. Beam-forming, however, makes the link-adaptation algorithm process substantially harder to perform. The reason for this is that the link-adaptation algorithm now has to take into account not only the changing radio environment, but also the changing transmit signal that is being beam-formed. Fortunately, since the beam-formed signal is known at the point of transmission, there should be a potential to utilize this knowledge to make the link-adaptation more efficient. This thesis, investigates how the link-adaptation algorithm could be changed to perform better in beam-forming setups, as well as what information from the beam-forming algorithm that could be included and utilized in the link-adaptation algorithm. This is done by designing and investigating three new link-adaptation algorithms, in the context of Differential Beam-Forming in an LTE FDD system. The algorithms that has been designed are both of a beam-forming-aware and beam-forming-unaware character, meaning if the beam-forming information is utilized within the algorithm, or not. These algorithms have been simulated for different base station antenna array-sizes. Unfortunately, due to simulator restrictions, the terminals have been simulated in a stationary environment, which has proven to be a limiting factor for the results. However, the results still show that smarter beam-forming-aware link-adaptation could possibly be used to increase the performance of the link-adaptation when using beam-forming.
30

Increased Formability and the Effects of the Tool/Sheet Interaction in Electromagnetic Forming of Aluminum Alloy Sheet

Imbert Boyd, Jose January 2005 (has links)
This thesis presents the results of experimental and numerical work carried out to determine if electromagnetic forming (EMF) increases the formability of aluminum alloy sheet and, if so, to determine the mechanisms that play a role in the increased formability. To this end, free form (open cavity) and conical in-die samples were produced to isolate high strain rate constitutive and inertial effects from the effects of the interaction between the die and the sheet. Aluminum alloys AA5754 and AA6111 in the form of 1mm sheet were chosen since they are currently used in automotive production and are candidates for lightweight body panels. The experiments showed significant increases in formability in the conical die samples in areas where significant contact with the tool occurred, with no significant increase recorded for the free-formed samples. This indicates that the tool/sheet interaction is playing the dominant role in the increase in formability observed. Metallographic and fractographic analysis performed on the samples showed evidence of microvoid damage suppression, which may be a contributing factor to the increase in formability. Numerical modeling was undertaken to analyse the details of the forming operation and to determine the mechanisms behind the increased formability. The numerical calculations were performed with an explicit dynamic finite element structural code, using an analytical electromagnetic pressure distribution. Microvoid damage evolution was predicted using a microvoid damage subroutine based on the Gurson-Tvergaard-Needleman constitutive model. From the models it has been determined that the free forming process is essentially a plane-stress process. In contrast, the tool/sheet interaction produced in cone forming makes the process unique. When the sheet makes contact with the tool, it is subject to forces generated due to the impact, and very rapid bending and straightening. These combine to produce complex non-linear stress and strain histories, which render the process non-plane stress and thus make it significantly different from conventional sheet forming processes. Another characteristic of the process is that the majority of the plastic deformation occurs at impact, leading to strain rates on the order of 10,000 s<sup>-1</sup>. It is concluded that the rapid impact, bending and straightening that results from the tool/sheet interaction is the main cause of the increased formability observed in EM forming.

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