Sharif Digital Repository

In this investigation, nanostructure Fe3Al was produced by mechanical milling initially. Pure iron and aluminum powders were milled with suitable ratio 86Fe-14Al by weight. Milling was done up to 120 h times and with BPR 10 and BPR 20. Morphological changes, powder density and size, phase and structural changes, grain size and lattice strain were characterized by X-ray diffractometry (XRD), scanning electron microscopy (SEM) and laser particle size analyzer (LPSA). 40 h mechanical alloying with BPR 20 led to the corresponding intermetallic compound, Fe3Al with a nanocrystalline structure. Therefore Fe3Al/ZrO2 micro and nanocomposite powders were synthesized with manufactured by milling of... 

The paper presents the results nonlinear analysis of steel base plates subjected to different combinations of axial and bending forces. The bending forces range from small moments representing small eccentricities to large moments from seismic actions. The results of analyses proved to be in good agreement with experiments. The parameters investigated in this study are as follows: distribution of strain and stresses in the concrete foundation and the steel plate, the strains and stresses in the tensile anchorage bolts, the location of neutral curve under the base plate, the centre of compressional reaction forces in concrete, the flextural rigidity of the base plate connection, and the axial... 

In recent years, providing sustainable water supplies in dry and low water areas in the south of country is one of the important problems in the country. In addition to advantages of using cogeneration systems (power plant and desalination unit), using hybrid technologies causes productivity and reduction in energy consumption and water supplies. The target of this thesis is studying different thermal coupling scenarios to find optimum and constraint design in specific conditions in terms of cost and production. So in this conceptual study, by using thermoflow software, the hybrid unit coupled with a back pressure and condensing combined cycle power plant was studied based on thermodynamic... 

In this thesis the theorems of Poncelet and Cayley will be discussed. We will use algebraic geometry and in particular the theory of elliptic curves to present a proof following the works of Griffiths and Harris (refrence 1).
The P2-version of poncelet’s theorem that we prove in our thesis says:let C , D be smooth conic in general position. Suppose there is an n-sided olygon inscribed in C and circumscribed about D.Then for any point of C, there exists an n-sided polygen, also inscribed in C and circumscribe about D, which has this point for one of its vertics.the Cayley’s theorem provides a criterion on the existence of such an n-gon given the conics C and D as above  

Creating talking heads from audio input is interesting from both scientific and practical viewpoints, e.g. constructing virtual computer generated characters, aiding hearing-impaired people, live dubbing of videos with translated audio, etc. Due to its wide variety of applications, audio to video has been the focus of intensive research in recent years. Mapping audio to facial images with accurate lip-sync is an extremely difficult task because it is a mapping form 2-Dimensional to 3-Dimensional space and also because humans are expert at detecting any out-of-sync lip movements with respect to an audio.Approaches to automatically generating natural looking speech animation usually involve... 

Today, with the expansion of business relations at international levels, there are many organizations that operate in global supply chains. Activities at such levels face new types of challenges in various fields of "supply chain management" pillars, of which "supplier selection" is one of them. The possibility of unexpected events, the need to comply with environmental protection laws, as well as the need to take into account social considerations, are among the things that have increased by being in larger supply chains, making it challenging to provide the basic resources needed in such chains and forcing their managers to considering considerations other than what they have always...