Sharif Digital Repository

The commodity market as a noteworthy section of the capital market plays a prominent role in the economy of a nation. Base metals, which are widely utilized as industrial raw materials, account for a part of the costs imposed on a nation’s economy. Hence the price levels and volatility of such metals have been under close observation by the capital markets and in the process of monetary policy. In this research we investigate the impacts of the monetary policy of the Federal Reserve on the return of base metals based on daily data and also on the stock return of the corporates which are associated with these metals by using intraday data. This poster employs Federal Funds Futures Contracts... 

Silver and gold are precious, expensive metals and are used in various applications, such as jewellery and ornamentals, electronics and optics. In the present study, soda-lime glass surfaces firstly were activated with acidic stannous chloride solution. Then, silver and gold were coated on these surfaces via simultaneous spraying of two solution: A silver- or gold-complex bearing solution and a reducing agent (Dextrose for Ag and H2O2 for Au) bearing solution. For silver coating, the effect of various parameters such as time, reducing agent concentration, number of passes, presence and concentration of Urotrpin and Decamethylcyclopentasiloxane (DMCPS) as microstructural modifiers and... 

Damage and collapse in structural systems due to unexpected structural loading that seems to be inevitable sometimes leads to financial and human losses, despite of all safety measures considered for the system. Therefore, using structural health monitoring methods in order to estimate structural damages and preventing structural collapse, have drawn a lot of attention. In this study, the performance of different system identification methods such as mode shape curvature method, energy method, etc., to extract the dynamic properties of a cable-stayed bridge is examined. One of the main features of this study is to consider the seismic response of the bridge under multiple support excitations... 

The focus of this thesis is the computation of the discrepancy for any given distribution of points on S2. The problem of the distribution of points on the sphere has a long history and Thomson’s Problem, inspired by early atomic theory dating back to 1904, was a landmark. While Thomson’s Problem is based on the Coulomb potential, the discrepancy measures the deviation of the number of points in a set from the expected one. The Polar Coordinates method was introduced in the context of Thomson’s problem. In this thesis the order of the growth of the discrepancy for this method is investigated and a modification of it is shown to lead to the best known results. In addition a new algorithm is... 

Permeability is an essential parameter used for reservoir evaluation, simulation and management to optimize oil recovery. The conventional approach to estimate reservoir connectivity, conductivity, sweep efficiency and other critical information for decision-making is to build detailed geological models, which are then upscaled to a coarser grid where flow simulations are run. However, this takes many hours to be carried out even for a single realization practically. In practice, a very small number of realizations are considered and consequently the true uncertainty in the results is very poorly estimated. In this study, a statistical model of isotropic overlying sandbodies is used to... 

One of the major reasons causing cracks in external surfaces of concrete arch dams are thermal loads. Therofore, in order to avoid instabilities due to function of thermal loads in association with hydrostatic and hydrodynamic pressures, a precise evaluation of temperature distribution through dam body is indispensable. In this study, effects of thermal loads mostly on upstream surface of Karun-3 concrete arch dam in Iran were examined using a 3-D finite element method considering water level fluctuations. Also the influence of operatvie boundry conditions in our problem which are water temperature, air temperature and solar radiation was precisely taken into account. Moreover, nonlinear... 

Pile foundations suffered severe damages during the past earthquakes in all around the world. These damages were more severe in laterally spreading grounds and they mostly have been observed in gently sloping grounds and coastal areas. In these cases, Pile foundations not only are subjected to structures inertial loads and kinematic loads of liquefied soil but also lateral spreading intensifies damages. Thus, in the recent decade, several researches have been conducted to investigate the behavior of pile foundations in liquefiable and laterally spreading grounds, however, some uncertainties still remain in modeling of soil-pile interaction. In this study, the effects of liquefaction- induced... 

Loads from laterally spreading ground have been a major cause of damages to pile foundations in past earthquakes. Analysis of case histories have shown that damages are particularly intense when a nonliquefiable surface crust layer spreads laterally over underling liquefied layers. In this research the effect of lateral spreading due to liquefaction on single piles embede in a gently sloping ground has been investigated. Finite element method using OpenSees is used to model the pile and embedded soil. The soil profile for all models consisted of a nonliquefiable crust layer overlying loose sand with Dr = 30-35% overlying dense sand with Dr = 70-80%. The effect of geometric properties such as... 

Initial static shear stress caused by slopes or nearby structures' foundations can affect the behavior of the soil which is concerned many investigators during previous three decade. In this investigation, the effect of initial static shear stress on the liquefaction resistance of Babolsar sand has been probed using cyclic simple shear tests. Three different initial relative densities (Dr0=20%, 40% and 60%) and three different initial normal stresses (σv0= 50, 150 and 250 kPa) were considered in tests and four various initial static shear ratios (α) ranging between 0.0 and 0.3 were applied which leads to more than 190 distinct experiments. All tests were conducted under constant volume and... 

In this research, the effects of Rayleigh waves on the response of typical three-dimensional concrete faced rock-fill dams (CFRDs), considering dam-foundation interaction and spatial variability of earthquake ground motion are investigated. The time history of Loma Prieta earthquake (Gilroy 1 station) is used as input excitation. The dam is considered to be located in a prismatic canyon with trapezoidal cross-section. A substructuring method, in which the unbounded soil is modeled by the scaled boundary finite-element method (SBFEM), is used to obtain scattered motion and interaction forces along the canyon. Non-linear model is used for rock fill... 

In this project rotational barrier around the C-N bond in 4-ethyle-morpholine- carboxylate has been studied using DNMR spectroscopy. Spectra were taken at variable temperature, and then with simulation of bandshape broadening pattern at coalescence region, rate constants of exchange were obtained for all temperatures. For simulation of line-shape broadening Spinworks software was used, that with two interfaces made possible simulation with two bandshape simulator programs, DNMR and MEXICO. The rate constants obtained from simulations, were used for calculation of thermodynamic activation parameters (∆G#, ∆H#, ∆S# and Ea). ∆G# 298 value of 13.66 Kcal/mol for 4-ethyle-morpholine- carboxylate... 

Soil liquefaction is a phenomenon in which soil loses much of its strength or stiffness for a generally short time but nevertheless long enough for liquefaction to be the cause of many losses. Thus, many researchers have worked on the factors which affect this phenomenon. Effects of initial static shear stress on liquefaction strength of loose and medium dense Babolsar sand specimens were investigated in this study. Babolsar sand is fine to medium uniform sand classified as SP in USCS. Tests were performed with cyclic simple shear and static triaxial devices. All tests were performed under consolidated undrained conditions. Cyclic simple shear tests were performed under constant vertical... 

The Barrier of the internal rotation around C-N bond in O-ethyle morpholine-4-carbotioate were calculated using dynamic NMR spectroscopy (DNMR) in DMSO solvent. 1H and 13C NMR spectra were recorded at different temperatures (295-350K). Band shape broadening patterns at coalescence regions were simulated to extract rate constants of NMR spectera. Transition state thermodynamic properties of internal rotation around C-N bond in O- ethyle morpholine -4- carbotioate are estimated: , , , . To assay reliability of the estimated values, transition state thermodynamic properties were calculated using PCM model at method and basis set B3LYP/6-311++G(d,p). Theoretical values of thermodynamic... 

Accurate prediction of relative permeability for various reservoir rocks at various saturation conditions has been of concern for a long time in petroleum industry. Relative permeability is known as one of the most significant parameters in simulation of actual multi-phase flow through porous media during life-time of a hydrocarbon reservoir. In addition, it plays important role in oil production and well completion. Direct experimental measurement in order to determine relative permeability of porous rock has long been recorded in petroleum related literature. However, empirical methods for determining relative permeability are becoming more widely used, particularly with the advent of... 

Gravity dams are solid concrete structures that maintain their stability against design loads from the geometric shape and the mass and strength of the concrete. Because of their critical role in supplying portable and agricultural water and problems which would happen if they broke, it is required to consider their stability and keep them in safe conditions. They should be able to continue their function after a disaster such as earthquake. But most of them are aged dams with some have been built near faults. Indeed, there are some concerns regarding the performance of these dams under the effect of seismic loads. This research deals with performance evaluation of concerete gravity . The... 

Concrete gravity dams are one of the most important infrastructures therefore their performance under seismic load is an important issue of concern for dam owners. It is necessary that these infrastructures to be able to continue their function after a disaster such as earthquake, as any damage can cause huge cost. For analysis of dams linear and nonlinear analyses are used. Because even operating loads will create cracks in the body of the dam, dam behavior can not always be considered linear. It is remarkable that these surface cracks can join together under seismic loads and this question the safety of dams. It is important to note that nonlinear analysis of concrete gravity dams is...