Sharif Digital Repository

High-voltage equipment used in the power industry operates under intense electric field stress. Due to the presence of strong electric fields, the insulation systems of such equipment gradually experience partial discharges. Investigating the phenomenon of partial discharge is often accompanied by several challenges. Initially, because the occurrence of this phenomenon is closely related to atomic and molecular physics as well as electron generation within insulating materials, it is necessary to consider the complexities of media containing charged particles. In this dissertation, the phenomenon of partial discharge has been studied based on physical principles and theoretical... 

The olfactory sense in rats provides crucial information for identifying food sources, detecting threats, and facilitating social interactions. The olfactory bulb is one of the key brain regions involved in the initial processing of olfactory information and its transmission to higher brain areas for more complex processing. However, more advanced cognitive processes such as evaluation and decision-making rely on interactions between other brain regions. Among these, the striatum, as a part of the basal ganglia, plays a role in reward evaluation, reward-based learning, and shaping behaviors associated with sensory stimuli. This region contributes to learning, decision-making, and action... 

The aim of this research is to investigate the effect of speed and direction of current on ship fuel consumption. A KCS benchmark model has been numerically studied in calm water and fourteen current and wind conditions with the same speed and different directions to determine how the ship performance is dependent on flow conditions. The model has been simulated in an artificial basin propelled by a single right-handed propeller via a CFD commercial code. Numerical results revealed a linear relationship between the deviation of current and wind from head-sea or following-sea conditions and the rudder angle. The head-sea and following-sea currents and winds increased and decreased the lateral... 

In this thesis , we consider nonnegative (continuous) weak solutions of the porous medium equation with source , u_t-∆u^m=u^p, and p>m>1 .
Assume that, m>1 and 1< p/m u_t-∆u^m=u^p,xϵR^n ,tϵR
has no nontrivial, bounded radial solutions u≥0 .
In one space-dimensional, the conclusion of the result mentioned above remains true without the assumption of the radial symmetry. The proof is based on the intersection-comparison arguments , zero number argum- ents and a key step is to show the... 

Although laws vary in the competitive business world of today and the changing supply and demand parameters show that the process of delivering new products to market is very important.Most organizations today have found that spending more than ever on trusting in traditional competitive levers such as quality, cost reduction and differentiation in selling more products and services are not enough to be successful in market, instead notions such as speed, flexibility andagility can have a significant trend toward offering new products and services. There aresome good reasons for knew that organizations need new ways to develop their new products to survival, compete with its competitors and... 

This study focuses on the risk assessment of reinforced concrete tall buildings subjected to ground motion excitation. In order to assess the vulnerability of tall buildings, twelve-, and twenty-four-story four-bay reinforced concrete moment resisting frames are studied. This evaluation is done through developing fragility curves. These fragility curves provide the probability of exceeding the multiple damage states for a given intensity (e.g. CAV) of ground motion excitation. To develop the fragility curves, a great number of nonlinear dynamic analyses were conducted in the open-source platform OpenSees. Since the PEER Guidelines for Performance-Based Seismic Design of tall buildings (PEER,... 

Technology scaling allows integrating multiple cores onto a single chip to make the mainstream for advanced embedded systems. However, technology scaling is envisaged to aggravate the reliability of on-chip systems due to increasing transient fault rate due to lower voltages and shrinking transistor dimensions that lead to smaller critical charges. Transient faults are typically resulted due to high-energy particle strikes in hardware and manifest as bit flips. Multi-core systems provide a great opportunity to implement reliability mechanisms such as redundant multithreading (RMT) and process level redundancy. Task replication (e.g. RMT) is a well-established technique to achieve high... 

Snaking Vibration and buckling of drill string in the horizontal well was investigated in this research. Sinusoidal and helical critical buckling load are obtained for a specific drill string.
Drill string is modeled both analytically and numerically (finite element method). Drill pipes are considered as a clamped-clamped beam with constant cross section and the well is considered as a hollow cylinder. The thickness of cylinder was large enough to model the surrounding soil of the well. Buckling is a complex deformation and is somehow a random phenomenon. In addition, the length and the continuous contact between drill pipes and the well make the finite element model very huge and the... 

In this thesis we investigate different factors of graphs with emphasis of even and odd factors. First, we prove the best existing lower bound for the largest even factor of graphs which is of the size at least 4/7|E(G)|+1 and we show that this bound is tight and classify the graphs which exactly meet this bound[]. Then we present a new lower bound for the largest odd-factor of graphs of even order which is of the size at least 2/5|E(G)|. We prove this bound using a new edge coloring called 1/2-coloring in which edges are colored with blue and red such that in each cycle the number of red edges is bigger than the number of blue ones. We prove in every 1/2-coloring of graphs with δ(G)≥3 or... 

Technology scaling allows integrating multiple cores onto a single chip to make the mainstream for advanced embedded systems. However, technology scaling results in aggravating the reliability problem of on-chip systems because of increasing transient fault rate due to lower voltages and shrinking transistor dimensions that lead to smaller critical charges. Multicore systems provide a great opportunity to implement reliability mechanisms such as redundant multithreading (RMT) and process level redundancy. Task replication (e.g., RMT) is a well-established technique to achieve high reliability against transient faults. However, replicated executions may increase power consumption beyond the... 

This research is studying seismic behavior of bridges with spill-through abutments. There is a lot of studies in the literature about the behavior of piers and different types of them in the field of seismic assessment of bridges. But seismic behavior of abutments has paid less attention. In addition, most researches in this field are about common types of abutments like wall-type or integral abutments and also there are few standards and design guidelines about spill-through abutments.However spill-through abutments had been used by designers, especially they are common in Iran.In this research, a bridge with a spill-through abutment is designed as a benchmark. The benchmark bridge is...