Suchergebnisse

Abstract. Modelling of flow-like landslides is one of the possible approaches that can be used to simulate landslide instability and flow development. Models based on continuum mechanics and associated with a versatile rheological model are usually preferred to predict landslide runout and relevant parameters. A different approach has been used in this research. We have developed a 2-D/3-D finite element code to analyse slope stability and to model runout of mass movements characterised by very large displacements. The idea was to be able to use different material laws already known, tested and verified for granular materials. The implemented materials laws include classical elasto-plasticity, with a linear elastic part and different applicable yield surfaces with associated and non-associated flow rules. The application of Finite Element methods to model landslide run-out, contrasts previous research where typically depth-averaged equivalent-fluid approaches were adopted. The code has been applied to the simulation of large rock avalanches and rapid dry flows in different materials and under different geological and geomorphological conditions.

Belçika Flaman, Valon ve Brüksel bölgesi; Flamanca, Fransızca ve Almanca konuşan topluluklarıyla uzlaşmacılık ilkesini de geçmişinde barındıran, Belçika anayasasında işaret edildiği üzere federal bir devlettir. Belçika, tarihi süreçte üniter bir yapıdan federal bir yapıya evrilmiş; bu süreç gerçekleşirken Belçika devletinin sonunun mu geldiği, devletin ikiye mi bölüneceği ile alakalı çok yoğun tartışmalar yaşanmıştır. Her ne kadar federalizm kusurları olan, zaman zaman eleştirilen bir sistem de olsa Belçika özelinde birçok olumlu ve birleştirici özelliği de bünyesinde barındırmaktadır. Bu çalışma, tarihi gerçekler, parti yaşantısı, Belçika kimliği, monarşi, anayasa / anayasa mahkemesinin rolü, Brüksel başta olmak üzere çift dilliliğin tecrübe edildiği belediyeler gibi Belçika'da istikrarı sağlayan koşulları ele almaktadır. Tezin içeriği birebir mülakatlar, akademik makale ve yayımlanmış kitaplara dayanmaktadır. ; Having three regions which are Flanders, Brussels, Wallonia and three lingusitic communities consisting of néerlandophone, Francophone, and Germanophone, Belgium is an official country administrated with federal system according to the article 3 of Belgian constitution, experiencing consociational past. While Belgium was converted from unitary to federal state, which is long historical and political story, a fierce discussion is still being made by elites and regular citizens as to whether Belgium heads towards dissolution and emergence of 2 independent countries due to Federal system. Even though federal system has many drawbacks and gets a lot of criticism, it has a number positive side, in particular in Belgian federalism. This thesis will underline stability conditions in Belgium such as historical facts, political and party system, Belgian identity, monarchy, constitution and the role of constitutional court, bilingual municipalities, in particular Brussels and what makes it work along with discussions. This study is mainly based on face-to-face interviews with leading scholars - experts, academic periodicals and textbooks.

This paper revisits the fiscal sustainability condition proposed by Domar (1944). The Domar condition is derived from the government budget constraint and thus focuses on the supply side of the government bond. By considering the demand for the government bond, this paper finds that public debt sustainability depends on interest rate sensitivity to changes in government bond supply and demand. Data shows that the prediction of our model on public debt sustainability is consistent with the cases of Greece and Japan.

Abstract
Numerical modelling represents a powerful tool not only for special geotechnical calculations in cases of complicated and difficult structure design or their foundation conditions, but also for regular tasks of structure foundation. Finite element method is the most utilized method of numerical modelling. This method was used for calculations of the retaining wall monitored during 5 years after construction. Retaining wall of the parking lot with the facing from gabion blocks was chosen for numerical model. Besides the unfavourable geological conditions, a soft nature of the facing was also a difficult part of the modelling. This paper presents the results of the modelling when exact geometry, material characteristics and construction stages were simulated. The results capture the trend of displacements even though the basic material models were utilized. The modelling proved the ability of the finite element method to model the retaining structure with sufficient accuracy as well as reasonable demand on quality and quantity of input data. This method can then be used as a regular design tool during project preparation.

The processes of discharge of higher density effluent into the recipient of lower density occur during the release of wastewater into the sea from desalination process, which is increasingly common today due to the shortage of drinking water. During such discharges, the goal is to achieve the best possible mixing, so that the impact of water with a high salt concentration on the environment is as small as possible. Since the jet returns to the bottom because of the influence of gravity, the use of nozzles at an angle increases the zone in which mixing occurs. In this paper, a numerical model of effluent discharge was made and buoyancy jets inclined at 45o were observed for different flow regimes. The influence of density and velocity on jet characteristics is shown. The numerical model was developed in OpenFOAM, and a comparison with experimental data from previous research is presented.

NiTi (also called Nitinol) transforms from cubic (austenite) to monoclinic (martensite), and vice versa, owing to the shape memory effect and superelasticity. Nitinol has a large number of biomedical applications because of its low elastic modulus close to that of natural bone material and good resistance to corrosion and fatigue, in addition to the transformation temperatures of nitinol that are close to body temperature. It has many other important applications, such as in the aircraft industry. In all these important applications, especially medical applications, Nitinol stability is an important factor for safety. Our goal is to study the stability of NiTi by calculating the phonon dispersion relation to obtain an accurate understanding of the mechanically unstable phases of the NiTi alloy. The dispersion relation for the cubic and monoclinic phases was studied and coded using MATLAB to make a clear consideration of the dispersion relation and its optical and acoustic branches. Moreover, the density of the state and energy from the lattice vibrations were calculated.
The crystal is found to be stable by the anharmonic part of the interactions. The austenite phase is stable up to (300 K). While it is not above (300 K). Any extra energy due to temperature changes caused the transformation to the martensite phase. The positive phonon modes indicate that the monoclinic phase is stable against energy perturbations. When the thermal vibration energy was calculated for the cubic phase and in the case of the monoclinic phase at T= 300 K. In both cases, it was less than 5 eV. There are no broken bonds owing to the energy of vibration.