Sharif Digital Repository

Polymer translocation through the nanopores is one of the fundamental macromolecular processes in life. Some examples are , mRNA translocation through nuclear pores, injection of DNA from a virus head into a host cell, protein translocation across biological membranes through membrane channels. Also some applications are suggested for the process, e.g. DNA sequencing by probing the signals during the translocation, drug delivery and/or gene therapy. During the translocation the polymer should pass entropic barrier of the pore and it can be facilitated by changing the chemical potential, application of eclectic field, flow field, or chemical concentrations. In electrically driven... 

The use of named entity recognition systems as preprocessing is used in many natural language analysis issues. With the advent of deep learning, the methods of this area were also affected. Today, there is considerable progress in this area due to the development of data resources for English, Chinese, German, and Spanish. They are also good trained models in formal Persian. However, for informal Persian, which contains a large portion of the web content under the Web, the current models do not produce a suitable solution. In this study, we use the same approach to train our models due to achieving state-of-the-art results in pre-trained models. On the other hand, there is a lack of standard... 

Image registration is one of the fundamental and essential tasks for medical imaging and remote sensing applications. One of the most common challenges in this area is the presence of complex spatially varying intensity distortion in the images. The widely used similarity metrics, such as MI (Mutual Information), CC (Correlation Coefficient), SSD (Sum of Square Difference), SAD (Sum of Absolute Difference) and CR (Correlation Ratio), are not robust against this kind of distortion; because stationarity assumption and the pixel-wise independence cannot be obeyed and captured by these metrics. In this research, we proposed a new intensity-based method for simultaneous image registration and... 

The ternary 122-type AeFe2As2 (Ae=Ba,Sr,Ca) compounds are antiferromagnetic metals with the orthorhombic lattice structure at ambient pressure and low temperature. By applying mechanical pressure, structural, magnetic and superconducting transitions occur in these compounds. The isovalent doping of Ba with Sr and Ca elements induces chemical pressure and reduces the onset pressure of these transitions. The main purpose of this thesis is to investigate and compare the effects of mechanical and chemical pressures on the structural and magnetic phase transition in the 122 compounds. To achieve this purpose, we have done first-principle calculations for many properties such as the structural... 

In order to increase the mechanical properties and resistance of hydrogels to external damage, for their wide application in tissue engineering and medicine, self-healing two-grid hydrogels are used. Two-grid hydrogels with physical lattice have more advantages than two-grid hydrogels with chemical lattice because they have reversible and dynamic bonds, which in addition to increasing mechanical properties, also have self-healing properties. In order to achieve high mechanical properties, gelatin-based double-grid hydrogels with hydrogen bonding and metal-ligand interaction are designed. In the present paper, two-grid hydrogels consisting of gelatin network and other network of sodium... 

In the present work, edge-functionalaized graphene was used as electrode material and its electrochemical properties were systematically characterized by electrochemical impedance spectroscopy and cyclic voltammetry. Two methods were applied to modify the gold electrode surface. First method was the self assembling process of graphene nanosheets on gold electrode surface. Second method was simply casting specific amounts of graphene suspension on the gold electrode surface. Nyquist plots show decrease of the charge transfer resistance on the electrode surface at both cases. In cyclic voltammetry studies, first electrode shows no significant changes while the second electrode exhibits... 

Named Data Networking is the most promisicing content centric Architecture for the future of Internet. In this architecture, content can be accessed regardless of where it is.Routing is one of the most important and challenging issues in these networks. An efficient router improves the efficiency of network by reducing routers convergence time, stored data related to routing and exchanged routing data traffic. It also reduces the state each router keeps due to routing information. In Named Data Networking routers are smart and some of routing protocol responsibilities can be done by forwarding plane. Therefor netwok churns can be handeled by forwarding plane. Considering this responsibility...