No description available.

No description available.

Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1990. / Vita. Abstract. Includes bibliographical references (leaves 41-42). Also available via the Internet.

The objective of the research programme has been to investigate the effects of pre-buckling low frequency inelastic cyclic hysteresis upon a range of imperfection sensitive circular hollow section struts. The programme has involved experimental and theoretical studies and computer graphics are widely employed throughout. The subject matter is introduced from a variety of perspectives, phenomenological, historical, theoretical and experimental in Chapter 1, together with an appreciation of therole of the digital computer within the research programme. Experimental factors are initially presented in Chapter 2 whilst the formal testing programme is described in Chapter 3. Original findings are definitively set out in Sections 3.3 and 3.7 wherein the concept of the 'cyclic step' is first introduced, theremaining sections in the chapter providing the necessary supporting data. Theoretical studies are reported in Chapter 4 with the novel moment-thrust-curvature modelling described in Sections 4.2 and 4.3 being of central importance. This modelling enables the formulation of a predictive cyclic strut system effectivelyrequiring of the end user the solution of only a pair of simultaneous equations and yet capable of providing data trends consistent with the experimental findings. Design interpretation together with an overview of the experimental and theoretical studies and their interrelationshipare set out in Chapter 5. A practical design procedure oriented about the effect of a pre-buckling cyclic action phase upon otherwise static strut performance is delineated and anappropriate design chart is provided. Conclusions are drawn with respect to the primary researchfindings in Chapter 6 wherein suggestions are also made regarding possible further studies. An Appendix is included providing the bibliography, nomenclature and respective published work; selected supporting documentation is also presented.

Acoustic experiments were conducted in an anechoic chamber with a 1/14th scale model of a supersonic aircraft engine inlet using Trailing Edge Blowing (TEB) to reduce the engine fan noise from a turbofan propulsion simulator (TPS). The TPS is 4.1 in. (10.4 cm) in diameter and is powered by compressed air. The supersonic inlet is connected to the TPS and is geometrically and acoustically scaled from a working design. The supersonic inlet is operated in a takeoff or landing operating condition where the inlet core flow is subsonic. TEB is the process of ejecting high pressure air to re-energize the wakes of upstream fan disturbances such as struts or inlet guide vanes (IGV). The elimination of the wakes will provide a uniform flow field at the engine fan face and reduce noise at the blade passing frequency. The TEB was implemented on six non-uniformly spaced support struts in the inlet. Acoustic tests were then performed at 40%, 60% and 88% of the fan design speed (PNC) to measure the reduction in the blade passing tone (BPT) due to TEB from the struts with and without the presence of IGV. The noise reductions without IGV at 40 PNC show the best results with the blade passing tone (BPT) being reduced by an average of 3.1 dB. The first harmonic of the BPT and the overall Sound Pressure Level (SPL) were also reduced by 1 dB. The addition of the IGV in the inlet reduced the effectiveness of the TEB. The addition of IGV changed the reduction in BPT at 40 PNC by 0.5 dB and the overall SPL was unchanged. At 60 PNC the addition of IGV reduced the reduction due to TEB in the BPT from an average of 2 dB to an average of 1 dB. The tests performed at 88 PNC showed negligible effects due to TEB. Aerodynamic experiments performed on the inlet that showed that the wakes of the IGV have a larger velocity defect than the struts, thus making the IGV a greater noise source. / Master of Science

No description available.

Cílem práce je zobrazit vývoj webových aplikací na platformě Java, představit javovské webové frameworky Struts, WebWork, Velocity a Tapestry, vytvořit metodiku pro porovnání těchto frameworků a porovnat je podle metodiky tak, aby si čtenář mohl zvolit framework, který bude jeho aplikaci nejlépe vyhovovat. První část, která končí kapitolou číslo tři, popisuje vývoj webových aplikací od počátku až k javovským webovým frameworkům a představí zkoumané frameworky. Pro konkrétní představu jsou zde popsány programy naprogramované ve všech frameworcích. Ve druhé části je vytvořena metodika a frameworky jsou podle ní porovnány. Na závěr jsou shrnuta pozitiva i negativa daných frameworků.

No description available.

No description available.

Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1994. / Vita. Abstract. Includes bibliographical references (leaves 84-86). Also available via the Internet.