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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

A novel tunnel diode circuit

Williams, Larry Lynn, 1938- January 1963 (has links)
No description available.
22

Motor Unit Number Estimates and Quantitative Motor Unit Potentials Analysis Associated with Motor Deficits in Carpal Tunnel Syndrome

Nashed, Joseph 17 September 2008 (has links)
The purpose of this study was to determine the utility of decomposition-based quantitative electromyography (DQEMG) in detecting signs of motor unit loss and collateral sprouting in compression neuropathy. In order to accomplish this, needle- and surface-detected motor unit potential (MUP) morphological features, determined by DQEMG, were used to determine evidence of collateral sprouting. Evidence of motor unit loss was measured using motor unit number estimates (MUNEs). Six subjects with severe carpal tunnel syndrome (CTS), eight subjects with mild CTS and nine healthy individuals with no known neuropathy participated in this cross sectional study. All subjects completed two phases of data collection: 1) an examination consisting of physical and electrophysiological tests to assess the presence and/or severity of CTS and 2) quantitative electromyography techniques to record MUNEs and MUP morphological characteristics. The needle-detected MUP parameters included peak-to-peak amplitude, duration and number of phases. The presence of satellite potentials was also investigated in the needle-detected MUPs. The surface-detected MUP parameters examined included peak-to-peak amplitude, duration and negative peak area. Kruskall-Wallace tests were used to determine group differences for all outcome measures. The MUNEs were lower (p<0.017) in the severe CTS group as compared to those with mild or no CTS. This result suggests that individuals with severe CTS experience a decrease in the number of functioning motor units. Despite statistically similar surface-detected MUP morphology, there were significantly larger needle-detected MUP amplitudes (p<0.017) and satellite potentials (p<0.05) were present in the severe CTS group as compared to the mild CTS group and healthy control group. These findings suggest there is collateral reinnervation in individuals with severe CTS. The results of this study support the use of DQEMG in future studies of compression neuropathies as an effective means to document the progression of motor deficits. / Thesis (Master, Rehabilitation Science) -- Queen's University, 2008-09-16 12:08:13.587
23

Analysis of Tunnel Liner Response in Squeezing Heterogeneous Rockmasses

BRANSCOMBE, LAURA C 18 January 2011 (has links)
Squeezing ground in tunnelling is a unique method of failure, typically occurring in ductile rock at depth. To accommodate this mechanism of failure, liners have been designed such that they reduce in circumference as the support takes on initial load. Technological development in this area is all the more important for tunnels mined in heterogeneous rockmasses. Currently, the state of practice is to design support based on a normalised average of the strength parameters of the rock units present in the tunnel face. Under many configurations of heterogeneity, this approach is perfectly valid, however there are styles and magnitudes of heterogeneity that require deeper analysis. The purpose of this study is to introduce an empirical relationship between liner response in heterogeneous rockmasses and liner response in the homogenised equivalent. A suite of parameters that define heterogeneity were numerically modelled, using finite element analysis, such that a comprehensive set of the various permutations was evaluated. The three styles of heterogeneity that were modelled were chaotic structure, folded structure and laminar structure, these represent common and discrete structures found in alpine regions. Laminar structure was considered at three orientations, and all structures were considered under hydrostatic and differential stress regimes. Granularity, or scale, and contrast ratio of units were also varied. These data were analysed with respect to mean axial thrust, range of axial thrust and range of moment on the liner. Liner response analysis was also conducted on the case study of St. Martin-la-Porte, an adit to the Lyon-Turin Ferroviaire base tunnel in southern France. This adit has been excavated in a highly variable, heterogeneous rockmass and provides realistic examples of the nature of heterogeneity present in current tunnelling projects. Ultimately, three equations were developed to provide preliminary predictions of heterogeneous axial thrust and moment variability from the analysis of homogeneous equivalents. / Thesis (Master, Geological Sciences & Geological Engineering) -- Queen's University, 2011-01-14 19:16:42.908
24

Design of wideband tunnel diode amplifiers.

Dannacker, Keith Norman. January 1967 (has links)
No description available.
25

An investigation of the influence of circuit parameters on the output waveshape of a tunnel diode oscillator

Shults, Robert David 08 1900 (has links)
No description available.
26

Analysis of tunnel -diode RC-transmission-line amplifiers

Shults, Robert David 05 1900 (has links)
No description available.
27

An investigation of tunnel diode-common-base transistor combinations for large gain-bandwidths

Gray, James Stephen 08 1900 (has links)
No description available.
28

Assessment of Vehicle Fire Development in Road Tunnels for Smoke Control Ventilation Design

Cheong, Mun Kit January 2009 (has links)
A fire in road tunnel can be dangerous and lead to serious consequences if not addressed appropriately. In a tunnel fire incident, creating a smoke free path for motorist evacuation and facilitating fire fighters to access the fire is critical for fire and rescue operations. A means of achieving this is to use ventilation fans to blow sufficient air down the tunnel ensuring no back-layering of smoke occurs upstream of the fire. The airflow necessary for such operation is known as the critical velocity which is a function of a number of factors includes; heat release rate, tunnel geometry, tunnel gradient etc. Among these parameters, the heat release rate is the most difficult to identify as this value is dependent on the types of vehicles, number of vehicles involved, the type of cargo and the quantity of cargo carried by these vehicles. There are also other factors such as the influence of ventilation condition, tunnel geometry and the use of legislation (to restrict hazardous vehicles entering in tunnel) that could affect the heat release rate in a tunnel fire. The number of possible fire scenarios is numerous. Based on current practise, fire size selection for most tunnel ventilation design often references various guidelines such as NFPA 502, BD78/99 or the PIARC technical committee report. The heat release rate, particularly for goods vehicle recommended by the guidelines varies from 20 to 30 MW. However, recent fire tests conducted in the Runehamar tunnel experiments indicate a higher heat release rate. These experiments suggest that heat release rate guidelines for goods vehicles might be underestimated. An ideal means to estimate the heat release rate in the tunnel is to use the oxygen consumption calorimetry technique. However, this approach is generally expensive, logistically complicated to perform and it is often not feasible to conduct such tests for a tunnel project at the initial design stage simply because the structure and systems are not ready for such activities. This research thesis presents an approach to establish a design fire in a road tunnel particularly the peak heat release rate for emergency tunnel ventilation system design. The analysis consists of two stages; stage one involves the use of a probabilistic approach (risk analysis) to identify the potential cause and type of vehicle which could result in a tunnel fire. Findings from the risk analysis are used in stage two in which Computational Fluid II Dynamics (CDF) modelling is used to establish the heat release rate in the tunnel considering factors such as fuel load, ventilation condition, tunnel geometry and ignition location. The Fire Dynamics Simulator (FDS 4.0.7), a CFD model of fire-driven fluid flow is used for the analysis and an urban road tunnel project in Singapore is used to illustrate this methodology. Other topic related to this research work includes the reconstruction for the Runehamar tunnel fire test using numerical approach to calibrate the FDS simulation model. The used of Probabilistic Bayesian approach and CFD approach using FDS to estimate the heat release rate in the tunnel is also investigated in this thesis. The effect of vehicle fire spread in road tunnel and numerical simulation of road tunnel fires using parallel processing is presented. Preliminary work in using FDS5 for tunnel simulation work is discussed as part of the research work in this project.
29

A mathematical model for lining design in linear visco-elastic ground.

Gill, Denis Ernest. January 1970 (has links)
No description available.
30

Median nerve mechanosensitivity and motoneuron pool excitability in subjects with carpal tunnel syndrome

Jaberzadeh, Shapour January 2001 (has links)
Thesis (PhDPhysiotherapy)--University of South Australia, 2001

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