Sharif Digital Repository

Emotions are one of the most important issues which affects daily life and activities. On the other hand, robots play an increasing role in human life and play a fundamental role in meeting our needs. One of these basic roles is empathy and verbal interaction between the robot and human. In this research, participant's emotions were stimulated in two ways: by using OASIS and GAPED image data sets and by instructing the participants to remind about their good or bad memories. During emotional stimulation, EEG signals have been recorded for the training and testing process. The preprocessing of training data includes filtering, removing bad parts of data, removing bad channels and... 

This thesis is divided into three parts: In part I, interactions of neutral and anionic forms of histidine with coinage metal nano clusters M3 (M = Au, Ag and Cu) are investigated. Results demonstrate that nonconventional M…H-O hydrogen bonds and M-X bonds (X = N, O) play stabilization roles in interactions of histidine and metal nano clusters. Presence of negative charge in ligand leads to increase of binding energy of complexes. In the next step, the effects of coinage metal nano clusters on the gas-phase acidity of weak organic acid (histidine) have been explored. The acidity of isolated histidine is compared with the acidity of its Au3–, Ag3– and Cu3–complexed species. Moreover, pKa... 

The purpose of this thesis is to find upper bounds for the eigenvalues of natural operators acting on functions on a compact Riemannian man-ifold (M, g) such as the Laplace–Beltrami operator and Laplace-type operators. In the case of the Laplace–Beltrami operator, two aspects are investigated:
The first aspect is to study relationships between the intrinsic geometry and eigenvalues of the Laplace–Beltrami operator. In this regard, we obtain upper bounds depending only on the dimension and a conformal invariant called min-conformal volume. Asymptotically, these bounds are consistent with the Weyl law. They improve previous results by Korevaar and Yang and Yau. The proof relies on the... 

In recent years, a strong interplay between quantum mechanics and the physics of waveguide arrays was established based on a formal analogy between atomic and photonic lattices. The study of light evolution in photonic lattices has provided deep insights into the physics of wave function dynamics and, hence, peculiar quantum mechanical features. Arrays of evanescently coupled waveguides is a very versatile model system for discrete physics. Anderson localization and Bloch oscillations are two examples of coherent quantum transport phenomena, which have been investigated in this thesis. In the first part of this thesis, we investigate numerically the effect of long-range interaction on the... 

Behavioral economics demonstrates that the sentiment can affect the behaviors and financial decisions of people. Can this be generalized to societies? For instance, is it possible for societies to experience emotions that will change their ways of decision making? This thesis attempts to perform an experiment addressing these questions. Bitcoin has been facing a transient phase of price volatilities. Many articles believe that bitcoin does not have an inherent value and is only derived by factors like the perception and acceptance of it and the sentiments among the investors. Digital currencies provide the unique possibility of measuring socioeconomic signals using digital traces.The... 

Organizations in the oil and gas industry often deal with a variety of logistic challenges. These organizations need to utilize innovative technologies like machine learning and other IT-based technologies to reduce costs and help achieve a lower-emissions environment. These industries involve a global supply chain comprised of domestic and international transportation, inventory control, materials handling, import/export facilitation, and information technology. Currently, in these industries, a classic model for executing supply-chain management techniques is considered. However, companies can optimize their supply chains to generate more productivity for better financial returns. Applying... 

The main purpose of this research is to select a suitable solution for regeneration of ion exchange resins of TR system of Bushehr nuclear power plant and also to compare and evaluate the possibility of using industrial cationic resin (Amberlite IR120) instead of nuclear grade cationic resin (Amberlite IRN97).First, different solutions for regeneration of cationic resins were investigated. For this purpose, three strong acids including hydrochloric acid (HCl), sulfuric acid (H2SO4) and nitric acid (HNO3) were selected and each of these acids was tested in two different concentrations and two different linear velocities; Also, to evaluate the appropriate solution for anionic resin... 

In the traditional process planning, the expert decides upon the production process for a product by considering the previous cases and by decomposing, analysis and interpreting the shape of the product in terms of more familiar previous cases. In recent decades and by developments in the disciplines of the artificial intelligence, mass customization, cloud manufacturing and additive manufacturing, a necessity for process planning systems which need less human intervention by intelligent interpretation of the shape and consideration of the available data from previous productions, has emerged. Inspired by the traditional process planning by human expert, and considering the overall process... 

In this research, we focused on demonstration of features and advantages of supercritical fluids technology to formation of fine particles (nano and micro scales) from bulk materials (solid) and synthesized metal oxides nanoparticles. Therefore, using two different fluids, carbon dioxide and water, and two completely different methods, the Rapid expansion of supercritical solution and supercritical hydrothermal, were used to produce fine particles of drug (acetaminophen) and nano metal oxide (zirconium dioxide and bismuth ferrite). The summary of this research are as follows:1. The solubility of acetaminophen in SuperCritical-Carbon Dioxide (SC-CO2) with and without menthol as a cosolvent... 

This thesis is divided into three parts: In part I, conformational properties of neutral, anionic, cationic and zwitterionic forms of glutathione tripeptide were investigated by means of DFT-B3LYP method with 6-31+G (d,p) basis set. Results show that glutathione is a very flexible molecule and its conformational energy landscape is strongly influenced by forming intramolecular hydrogen bond and its charge. Conformation of each amino acid in glutathione tripeptide depends on its orientation within the peptide sequence in addition to the conformation of other amino acids within the chain. Investigation of intramolecular hydrogen bonds in these conformers by means of AIM analysis demonstrates... 

3D bioprinting technology is a promising approach for corneal stromal tissue regeneration. At first, two different concentrations of GelMA macromer (7.5% and 12.5%) were tested for corneal stroma bioprinting. Due to high macromer concentrations, 12.5% GelMA was stiffer than 7.5% GelMA, which made it easier to handle. In terms of water content and optical transmittance of the bioprinted scaffolds, we observed that scaffold with 12.5% GelMA concentration was closer to the native corneal stroma tissue. Subsequently, cell proliferation, gene and protein expression of human corneal stromal cells encapsulated in the bioprinted scaffolds were investigated. Cytocompatibility in 12.5% GelMA scaffolds...