Loading...
Search for:
ataallahi--elahe
0.087 seconds
Analyzing the Interplay of Power Management and Communication Reliability of Wireless Networks in Embedded Applications
, M.Sc. Thesis Sharif University of Technology ; Ejlali, Alireza (Supervisor)
Abstract
Due to safety critical applications of the embedded systems, reliability is one of the most important properties of these systems. Wireless networks also have error prone data transmission channels and limited power consumption. Therefore reliability and power conservation are two vital characteristics of the wireless network especially in embedded applications. Since achieving to a desirable level of data reliability is power consuming, we must consider a trade-off between power consumption and data reliability. In wireless networks power consumption can be categorized into: power consumption in wireless devices and power consumption in data transmission. For decrement of wireless devices...
Confidential Access to the Outsourced Relational Data
, M.Sc. Thesis Sharif University of Technology ; Jalili, Rasool (Supervisor)
Abstract
In recent years, there has been a trend toward outsourcing data to the cloud provider. These companies must tackle the data security challenges. Generally these parties are assumed to be honest but curious. In past years, the research communities have been investigating different solution to ensure confidentiality.
In addition to data confidentiality access and pattern confidentiality is a high-priority issue in some cases so. potential adversary should be unable to drive information from the observed access pattern to the outsourced data. Despite the fact that there are more investigation in the field of data confidentiality, concern over data security are the rise in outsourcing data,...
In addition to data confidentiality access and pattern confidentiality is a high-priority issue in some cases so. potential adversary should be unable to drive information from the observed access pattern to the outsourced data. Despite the fact that there are more investigation in the field of data confidentiality, concern over data security are the rise in outsourcing data,...
A simple 2-step purification process of α-amylase from bacillus subtilis: optimization by response surface methodology
, Article International Journal of Biological Macromolecules ; Volume 192 , 2021 , Pages 64-71 ; 01418130 (ISSN) ; Naderi-Manesh, H ; Roostaazad, R ; Yeganeh, S ; Sharif University of Technology
Elsevier B.V
2021
Abstract
Purification of extracellular α-amylase from Bacillus subtilis was carried out via fractional precipitation by acetone and ion exchange chromatography. These steps provide fast precipitation as well as purification of α-amylase to improve enzyme purity, activity and stability. Compared with two-phase methods in which the yield was less than 1, this method resulted in a yield of more than 3. Moreover, 95% of acetone was recovered that enhanced the economy of the downstream process. Using the data provided by 2D electrophoresis, purification was done by a single step ion exchange chromatography. The enzyme exhibited a molecular mass (SDS-PAGE) of 50KD and the pI of 5. Maximum “yield” and...
Studying the Effective Factors and Optimizing Enzyme (α-amylase) Separation in Multi-Enzyme Systems by Agarose Column Chromatography
, Ph.D. Dissertation Sharif University of Technology ; Roosta Azad, Reza (Supervisor) ; Soheila Yaghmaee (Supervisor) ; Yeganeh Sarkandi, Shahin (Co-Supervisor)
Abstract
In all types of chromatography for the extraction and purification of proteins, a fixed substrate is needed with which the mobile phase containing the proteins interact with them. This fixed bed should contain grains that have characteristics such as sphericity, high surface area, hydrophilicity, binding power to functional groups, chemical stability, low specific absorption, reusability and low cost. Commercially, the most commonly substrates in the ranges of the molecular weight of proteins are agarose and dextran. Agar was extracted from Gracilaria salicornia seaweed and removal of ionic groups was investigated by three methods. In washing with isopropanol, the ionic groups were reduced...
Centrality-based group formation in group recommender systems
, Article 26th International World Wide Web Conference, WWW 2017 Companion, 3 April 2017 through 7 April 2017 ; 2019 , Pages 1187-1196 ; 9781450349147 (ISBN) ; Khalili, S ; Elahe Ghalebi, K ; Grosu, R ; Mojde Morshedi, S ; Movaghar, A ; Sharif University of Technology
International World Wide Web Conferences Steering Committee
2019
Abstract
Recommender Systems have become an attractive field within the recent decade because they facilitate users' selection process within limited time. Conventional recommender systems have proposed numerous methods focusing on recommendations to individual users. Recently, due to a significant increase in the number of users, studies in this field have shifted to properly identify groups of people with similar preferences and provide a list of recommendations for each group. Offering a recommendations list to each individual requires significant computational cost and it is therefore often not efficient. So far, most of the studies impose four restrictive assumptions: (1) limited number of...
Investigate Laboratory Production of Hydroxyurea
, M.Sc. Thesis Sharif University of Technology ; Bastani, Dariush (Supervisor) ; Seifkordi, Ali Akbar (Supervisor) ; Zegordi, Elahe (Co-Advisor)
Abstract
Hydroxyurea is an anticancer drug that is commonly used to treat chronic myeloid leukemia (white blood cell cancer in bone marrow), polycythemia vera (red blood cell cancer), sickle cell anemia, solid tumors, and in particular leukemia. In this research, in addition to analyzing all available methods for synthesis of hydroxyurea, the most economical method for synthesis of hydroxyurea which is Hantzsch method was chosen; then we synthesized hydroxyurea crystals using a precipitation or crystallization process. To do so, two hydroxylamine hydrochloride and potassium cyanate reactants have been used in the semi batch reactor. Since the reaction efficiency and purity of the synthesized...