The aims of this thesis are to fabricate the single-edged Ti/APC-2 hybrid composite laminates with and without(w/wo) nanoparticles and to investigate their mechanical properties due to tensile and cyclic tests. The composite laminates were three-layered laminates with one 0.55 mm thick APC-2 lay-ups covered by two 0.5 mm thick Grand 1 titanium alloy sheets. Nanoparitcles SiO2 were dispersed uniformly on the interfaces of APC-2 with optimal amount of 1wt%. The APC-2 was stacked according to cross-ply [0/90]s sequences. The titanium sheet surface was treated by chromic acid anodic method to achieve perfectly bonding with matrix PEEK. The modified diaphragm curing process was adopted to cure Ti/APC-2 hybrid composite laminates. The cutting of single-edged cracks with Electrical Discharge Machine, such as 1.5 mm and 3.0mm and 4.5 mm and 6.0 mm. The MTS 810 material testing machine was used to conduct all the tests. The mechanical properties, such as ultimate tensile strength, longitudinal stiffness of composite laminates w/wo nanocomposite laminate were obtained from the static tensile tests. The stress-strain diagrams were plotted in laminates for the corresponding single-edged crack. The constant stress amplitude tension-tension cyclic tests were carried out by using load-control mode at a sinusoidal loading wave with frequency of 5Hz and stress ratio R=0.1. The received fatigue data were plotted in S-N curves for different single-edged crack. From the results, the conclusion were summarized. First, both ultimate strengths of Ti/APC-2 composite laminates and nanocomposite laminates are very close. Second, Ti/APC-2 cross-ply nanocomposite laminates have better fatigue resistance than that of Ti/APC-2 cross-ply composite laminates.

This thesis describes an experimental investigation of the breakup processes involved in the formation of a spray created by a liquid jet injected into a gaseous crossflow. This work is motivated by the utilization of this method to inject fuel in combustors and afterburners of airplane engines. This study aims to develop better understanding of the spray breakup processes and provide better experimental inputs to improve the fidelity of numerical models. This work adresses two key research areas: determining the time required for a liquid column to break up in the crossflow (i.e., primary breakup time) and the effect of injector geometry on spray properties. A new diagnostic technique, the liquid jet light guiding technique that utilizes ability of the liquid jet to act as a waveguide for laser light was developed to determine the location where the liquid column breaks up, in order to obtain the primary breakup time. This study found that the liquid jet Reynolds number was an important factor that governed the primary breakup time and improved the existing correlation. Optical diagnostic techniques such as Phase Doppler Particle Analyzer, Liquid Jet Light Guiding Technique, Particle Image Velocimetry and Imaging techniques were employed to measure the spray properties that include spray penetration, droplet sizes and velocities, velocity field on the surface of the liquid jet and the location of the primary breakup time. These properties were measured for two injectors: one with a sharp transition and the other with a smooth transition. It was found that the spray created by the injector with a sharp transition forms large irregular structures while one with smooth transition produces a smooth liquid jet. The spray transition creates a spray that penetrates deeper into the crossflow, breakup up earlier and produces larger droplets. Additionally, this study reports the phenomenon of the liquid jet splitting into two or more jets in sprays created by the injector with a smooth transition.

No description available.

The Gaseous state of hydrogen at ambient temperature, combined with the fact that hydrogen is highly flammable, results in the requirement of more robust, high pressure storage systems that can meet modern safety standards. To develop these new safety standards and to properly predict the phenomena of hydrogen dispersion, a better understanding of the resulting flow structures and flammable regions from controlled and uncontrolled releases of hydrogen gas must be achieved. In this study the subsonic release of hydrogen was emulated using helium as a substitute working fluid. A sharp-edged orifice round turbulent jet is used to emulate releases in which leak geometry is circular. Effects of buoyancy, crossflow and adjacent surfaces were studied over a wide range of Froude numbers. The velocity fields of turbulent jets were characterized using particle image velocimetry (PIV). The mean and fluctuation velocity components were well quantified to show the effect of buoyancy due to the density difference between helium and the surrounding air. In the range of Froude numbers investigated, increasing effects of buoyancy were seen to be proportional to the reduction of the Fr number. The obtained results will serve as control reference values for further concentration measurement study and for computational fluid dynamics (CFD) validation. / Graduate

Den här studien är en utforskning av dubbeleggade miniatyryxor av bärnsten som hittas i neolitiska gravar. Tre gravplatser har presenterats: ett flatmarksgravfält i Borgeby, flatmarksgravar i Ajvide på Gotland, och tre gånggrifter i Danmark. Dubbeleggade miniatyrer av bärnsten hittas i alla. Genom att använda praktikteori och begreppet habitus är syftet att uppsatsen ska ge insikt i varför miniatyrerna uppträder i Borgeby, och vad de kan ha haft för betydelse i samhället. En komparativ metod har använts för att jämföra gravplatserna, för att undersöka om det finns några likheter eller skillnader mellan dem. Resultatet visar att människorna i Borgeby hade kontakter med omvärlden. Bärnstenen var importerad från Danmark eller inspirerad av den danska trattbägarkulturen, och gravskicket i sig är inspirerat av den gropkeramiska kulturens gravar. / The study is an examination of double-edged miniature amber axes found in neolithic graves. Three different gravesites stand at the center of the essay: a flat grave field at Borgeby in Skåne, flat graves at Ajvide on Gotland, and three different megalithic passage graves in Denmark. Double-edge miniatures in amber appear in all of them. Using practice theory and the conceptof habitus the essay aims to give an insight in why they appear at Borgeby, as well as what double-edged axes might have meant to the people depositing them in graves. A comparative analysis of the above-mentioned gravesites will also be made, to examine whether any obvious similarities or differences exist between them. The results show that people in Borgeby had connections to the surrounding world. The miniature amber objects seem to be imported from Denmark or inspired by Danish shapes, whereas the graves themselves seem to be inspired by pitted ware culture.

This thesis deals with the influence of the wall roughness on discharge coefficient of sharp-edged circular bottom orifice. It supposed to verify, summarize and extend knowledge of orifice discharge. Author of this thesis determine a discharge coefficient by measurement. Values of discharge coefficient were measured for roughness of the wall represented by different diameters of grains and these values were compared with available values published in specialized bibliography by different scientists. At the thesis end was made a summary evaluation.

No description available.

This paper deals with the question of with witch tools the Alvastra pile dwelling was built. To reach a result I calculate the curvature on 29 stone axes, 8 double-edged axes and 21 simple-edged axes, used in the middle-neolithic in what today is Sweden. These results are then compared with two jams (the point in the pole where the axes edged stopped and left a mark) on two piles from Alvastra pile dwelling.

The work deal with the measurement, processing and analysis of Q/h characteristics of the sluice chamber in the wastewater treatment plant on a physical hydraulic model in the conditions of influencing the overflow phenomenon by the groundwater level. Based on the achieved results, a measuring system has been projected in the area of the sluice chamber to measure the flow and flow rate of lightened water into the Svratka river. The measurements on the model were performed in the premises of the Laboratory of water Management Research of the Institute of Water Structures of the Faculty of Civil Engineering of Brno University of Technology by the author of this work. The results of the diploma thesis is a flow chart describing the calculation procedure used to determine the immediate flow, on the basis of which a new software of the evaluation unit of the measuring system was realized.