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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

SURFACE ELECTROMYOGRAPHY CHARACTERIZATION OF THE LOCAL TWITCH RESPONSE ELECTED BY TRIGGER POINT INJECTION AND SNAPPING PALPATION IN MYOFASCIAL PAIN PATIENTS

Lim, Pei Feng 01 January 2004 (has links)
Local twitch responses (LTRs) can be elicited by snapping palpation of myofascial trigger points (TrP) or TrP injections. Objective: To characterize the LTR elicited by TrP injection and snapping palpation on surface electromyography (sEMG) in subjects with myofascial pain in 14 female subjects. Methods: Surface EMG electrodes were placed around the TrP and a control site on the trapezius muscle. Then the following protocol was carried out: tension and contraction of the ipsilateral trapezius muscle, baseline resting activity (five minutes), snapping palpation of the TrP and the control sites, TrP injection, and final resting activity (five minutes). The following data were recorded: pain ratings, areas of referred pain, presence of LTR, and sEMG recordings. Results: During the TrP injection, the investigator found LTRs in only 36% of the subjects, while 64% of the subjects reported that they felt the LTR, and the sEMG recorded only one LTR in one subject. Despite the low percentage of LTRs elicited clinically (36%), a large number of subjects (71%) reported more than 50% immediate reduction in pain intensity after the TrP injection. Conclusion: The sEMG is unable to register the LTR elicited by snapping palpation and TrP injection.
2

Sací potrubí zážehového motoru na CNG o výkonu 140kW / Intake Manifold for 140kW CNG Engine

Wojcik, Rudolf January 2013 (has links)
The master´s thesis is focused on the design of the multi-point CNG injection for the VW 1.4 TSI intake manifold turbocharged spark ignited engine. The 3D model that was created using Autodesk Inventor Professional 2012 is based on the real intake manifold. This model served as an input for CFD analyses of mixing CNG with air. These were made in STAR-CCM+ software.
3

A Characterization of Hypersonic Stagnation Point Injection in Noisy and Quiet Flow

Dominick E DeFazio (18431565) 29 April 2024 (has links)
<p dir="ltr">The Boeing-AFOSR Mach-6 Quiet Tunnel (BAM6QT) was used for a set of experiments aiming to characterize the stability regimes of stagnation point injection in noisy and quiet flow across an array of different injected gases. Four gases were used in this experiment: air, helium, carbon dioxide, and argon. These gases were injected at varying thrust coefficients, ranging from 0.0516 to 0.5666, using a 7 degree half-angle cone with a 19 mm radius spherical nose and a single 1.93 mm-radius sonic jet in the center of the model. The primary data collected consists of schlieren images gathered at a sample rate of 76 kHz. These data were then analyzed using a shock tracking software to measure the physical locations of flow features as well as through spectral proper orthogonal decomposition (SPOD) to analyze specific modes in the flow.</p><p dir="ltr">Through this analysis, it was observed that three principle modes exist in stagnation point injection regardless of the injecting gas: a high frequency vortex-coupled mode, a low frequency Mach-shock-rigid mode, and a hybrid mode residing between these two modes. The first two modes were observed in all stability regimes, whereas the hybrid mode was only observed in the bifurcated regime. Furthermore, the unsteady regime was observed to be mostly characterized by this first, vortex-coupled mode. Conversely, the steady regime was observed to be driven by the Mach-shock-rigid mode instead. This transition was measured to occur as the thrust coefficient was increased.</p><p dir="ltr">This research also found that freestream noise resulted in an amplified and widened frequency range within the Mach-shock-rigid mode. This same freestream noise did not appear to have an impact on the other two principle modes; however, in some cases the noise produced in the Mach-shock-rigid mode due to this freestream noise did in fact mask the other principle modes.</p><p dir="ltr">Lastly, it was observed that the thrust coefficient, in and of itself, is not the sole indicator of stability in stagnation point injection. Across the different injected gases in this research, transition between the stability regimes did not in fact occur at a constant thrust coefficient value. Additionally, even within the same injected gas, this transition did not occur at the same thrust coefficient value between noisy and quiet runs—indicating an effect of freestream noise on stability.</p>
4

Technologie vstřikování zkušebních těles z termoplastů / Technology of injection molding of thermoplastic test specimens

Khamzin, Yersin January 2021 (has links)
The diploma thesis focuses on the optimization of technological parameters of plastic injection molding and the study of the influence of technological parameters on the quality of molded test specimens’ type 1A. The quality of molded parts for 3 types of polypropylene (PP) with different melt flow rate (Mosten GB 002, Mosten GB 218, Mosten MA 230) and 1 type of polystyrene (PS) (Krasten PS GP 154) was evaluated in terms of dimensional stability and weight. The contribution of software for modeling the plastic injection molding process was evaluated in this work. SOLIDWORKS Plastics software was used to optimize technological parameters. The construction of the bodies, mold and cooling system was constructed, and test bodies were produced on the basis of parameters obtained from the simulation of the injection molding process. Their quality parameters were compared with a 3D model and for each of the studied materials the optimal technological parameters were selected in terms of quality and the degree of influence of individual injection parameters on the quality of moldings was evaluated. The accordance of the results of the theoretical simulation with the real experiment was proved and a computational module independent of the optimized quality parameters, generally suitable for optimizing the quality parameters of the injected parts, was developed.

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