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barati-darband--ghasem
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Electrochemical Deposition of Co-Mn LDH/Ni-Co-S as an Electrocatalyst for Electrochemical Water Splitting Reactions
, M.Sc. Thesis Sharif University of Technology ; Ghorbani, Mohammad (Supervisor) ; Barati Darband, Ghasem (Co-Supervisor)
Abstract
The development of alternative energy sources is a prominent area of scientific research. Hydrogen, with its exceptional energy density, has emerged as a particularly promising candidate among these new energy sources. An effective technique for generating hydrogen is through the electrochemical process of water splitting. To enhance this process, it is crucial to investigate the development of electrocatalysts with high electrocatalytic activity. Among the potential options, sulfides of transition metals show promise. An essential difficulty in electrochemical water splitting is the development of a bifunctional catalyst that is both active and stable for both the hydrogen evolution...
Electrochemical Synthesis of Ni-Mn-Cu-Se@NF Nanostructure by Different Applied Voltage Regimes as an Effective and Stable Electrode for Hydrogen Production
, M.Sc. Thesis Sharif University of Technology ; Ghorbani, Mohammad (Supervisor) ; Barati Darband, Ghasem (Co-Supervisor)
Abstract
Among the new energies, hydrogen has been noticed due to its high energy density. Electrochemical production of hydrogen using electrocatalysts with high efficiency and cheap price is one of the effective solutions to achieve a clean and renewable energy source. Various studies have shown that after noble metals such as Pt, nickel has the highest electrocatalytic activity for hydrogen production. Alloying nickel with other intermediate metals is one of the effective methods to improve the catalytic activity of this metal, and among the intermediate metals that increase electrocatalytic properties, manganese and copper have a special place. Also, among different non-noble metals, selenide...
Formation and Investigation of Zinc-Nickel Two Cathionic Electrophospahte Coating Properties on Galvanized Steel
, M.Sc. Thesis Sharif University of Technology ; Afshar, Abdollah (Supervisor)
Abstract
By using electrophoaphating treatment in the metal coating process, the operating temperature of chemical phosphating bath is decrease and also difficulties with the use of high temperature bath is eliminated. The aim of this study is investigate the effect of operating parameter on coating properties and also investigation the deposition mechanism of Zn-Ni electrophosphate coating. Coating properties such as morphology, corrosion resistance and porosity of the coating characterized using SEM, polarization test and electrochemical method respectively. The values used for pH effect was 1.6,1.8,2 and 2.2 results indicated that by increasing the pH value from 1.6 to 1.8 the icorr decrease from...
Zn–Ni electrophosphating on galvanized steel using cathodic and anodic electrochemical methods
, Article Surface and Coatings Technology ; Volume 306 , 2016 , Pages 497-505 ; 02578972 (ISSN) ; Afshar, A ; Aliabadi, A ; Sharif University of Technology
Elsevier B.V
2016
Abstract
Electrophosphating is the novel method for accelerating the low temperature phosphating bath. This method can be performed as cathodic and anodic treatments. Both of them influence the coating deposition mechanism and therefore coating properties. In this study Zn–Ni electrophosphate coating was applied on galvanized steel using cathodic and anodic electrochemical methods. Microstructure, composition and corrosion resistance of coating were characterized by using a scanning electron microscopy, X-ray diffraction method and potentiodynamic polarization test respectively. The results of this study indicated that, by using cathodic method, compact phosphate coating with high corrosion...
Plasma electrolytic oxidation of Mg-Ti couple metals fabricated by friction stir welding: Characterization and corrosion studies
, Article Materials Research Express ; Volume 6, Issue 8 , 2019 ; 20531591 (ISSN) ; Ghorbani, M ; Barati Darband, G ; Sharif University of Technology
Institute of Physics Publishing
2019
Abstract
In this study, plasma electrolytic oxidation (PEO) of Ti-Mg couple metal fabricated by friction stir welding (FSW) in silicate base solution has been addressed and effect of silicate concentration in the electrolyte on coating properties was studied. Microstructure, composition and corrosion resistance of coating were characterized using scanning electron microscopy(SEM), X-ray diffraction (XRD) and potentiodynamic polarization methods. Ti-Mg couple were successfully coated simultaneously in silicate electrolyte and results of this study indicated that silicate concentration has a considerable impact on microstructure and corrosion resistance of the coating. In 5 g l-1 sodium silicate...
Characterization of Zn–Mn phosphate coating deposited by cathodic electrochemical method
, Article Transactions of the Indian Institute of Metals ; Volume 72, Issue 2 , 2019 , Pages 307-317 ; 09722815 (ISSN) ; Chakerizade, A ; Fallah, M ; Barati Darband, G ; Sharif University of Technology
Springer
2019
Abstract
Electrophosphating is a novel method that is used for accelerating the low-temperature phosphating bath. In this study, Zn–Mn phosphate coating was fabricated on mild steel substrate using the cathodic electrochemical method. Afterward, the effect of electrolyte pH and applied current density was investigated on coating properties. Microstructure, phase analysis and corrosion resistance of coating were evaluated using SEM, X-ray diffraction, potentiodynamic, immersion test and electrochemical impedance spectroscopy tests, respectively. Results indicated that the metallic and nonmetallic phases are present in the coating fabricated by the cathodic electrochemical method. The results of the...
Electrocrystallization of Ni nanocones from chloride-based bath using crystal modifier by electrochemical methods
, Article Journal of Alloys and Compounds ; Volume 818 , 2020 ; Aliofkhazraei, M ; Dolati, A ; Rouhaghdam, A. S ; Sharif University of Technology
Elsevier Ltd
2020
Abstract
The early stages of nucleation and growth of nanostructures can control the shape and final size of the fabricated nanostructure. Therefore, the study of the nucleation and growth mechanism of nanostructures is of great importance. The purpose of this study is to investigate the nucleation and growth mechanism of nickel nanocones from a chloride-based bath containing ethylene ammonium dichloride as a crystal modifier. Cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and chronoamperometry tests were employed to investigate the nucleation and growth mechanism and also the mechanism of crystal modifier performance on the growth of nanocones. Electrochemical studies revealed...
Improving fault tolerance in ad-hoc networks by using residue number system
, Article Journal of Applied Sciences ; Volume 8, Issue 18 , 2008 , Pages 3273-3278 ; 18125654 (ISSN) ; Dehghan, M ; Movaghar, A ; Barati, H ; Sharif University of Technology
2008
Abstract
In this study, we presented a method for distributing data storage by using residue number system for mobile systems and wireless networks based on peer to peer paradigm. Generally, redundant residue number system is capable in error detection and correction. In proposed method, we made a new system by mixing Redundant Residue Number System (RRNS), Multi Level Residue Number System (ML RNS) and Multiple Valued Logic (MVL RNS) which was perfect for parallel, carry free, high speed arithmetic and the system supports secure data communication. In addition it had ability of error detection and correction. In comparison to other number systems, it had many improvements in data security, error...
Routing algorithms study and comparing in interconnection networks
, Article 2008 3rd International Conference on Information and Communication Technologies: From Theory to Applications, ICTTA, Damascus, 7 April 2008 through 11 April 2008 ; 2008 ; 1424417520 (e-ISBN); 9781424417513 (ISBN) ; Movaghar, A ; Barati, A ; Azizi Mazreah, A ; Sharif University of Technology
2008
Abstract
A routing algorithm defines a route which packet traverses to get to destination. In this research we study some kind of routing algorithms that are used in internal connections networks of multi-processor and multi-computers systems. Then we discuss about some routing algorithms which have been implemented network on chip architecture. First, we present a group of routing algorithms based on various criterions, and review so-called category. Afterwards, we study adaptive and deterministic routing algorithms and express circular model applying in internal connections networks and its governing rules in order to prevent dead lock. Then we survey adaptive algorithms such as Deflection routing,...
Effect of treatment time and temperature on microstructure and corrosion behavior of Zn-Ni electrophosphate coating
, Article Journal of Alloys and Compounds ; Volume 688 , 2016 , Pages 596-604 ; 09258388 (ISSN) ; Afshar, A ; Rabani, M ; Sharif University of Technology
Elsevier Ltd
2016
Abstract
In this study, the effect of phosphating time and temperature on microstructure and corrosion behavior of Zn-Ni electrophosphate coating with a galvanized steel as a substrate, were investigated. SEM and X-ray diffraction methods were used for investigation the microstructure and phase analysis, respectively. And immersion test, potentiodynamic polarization test, and Electrochemical Impedance Spectroscopy tests were used for the study of corrosion behavior. The results of this study indicated that the best coating morphology is obtained in the range between 20 and 30 min and 40–50° C. Moreover, results of corrosion studies showed that the corrosion mechanism is under diffusion control due to...
Zn-Ni Electrophosphating on galvanized steel using cathodic and anodic electrochemical methods
, Article Surface and Coatings Technology ; January , 2015 ; 02578972 (ISSN) ; Afshar, A ; Aliabadi, A ; Sharif University of Technology
Elsevier
2015
Abstract
Electrophosphating is the novel method for accelerating the low temperature phosphating bath. This method can be performed as cathodic and anodic treatments. Both of them influence the coating deposition mechanism and therefore coating properties. In this study Zn-Ni electrophosphate coating was applied on galvanized steel using cathodic and anodic electrochemical methods. Microstructure, composition and corrosion resistance of coating were characterized by using a scanning electron microscopy, X-ray diffraction method and potentiodynamic polarization test respectively. The results of this study indicated that, by using cathodic method, compact phosphate coating with high corrosion...
Effects of Electrode Geometric Parameters on Argon Soft X-Ray Radiation From Plasma Focus Machine: An Investigation by the Modified Lee Model
, Article IEEE Transactions on Plasma Science ; Volume 51, Issue 12 , 2023 , Pages 3740-3745 ; 00933813 (ISSN) ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2023
Abstract
In this article, a modified version of the Lee model is utilized to research the effect of variation of the geometric parameters of the electrode system on the amount of the soft X-ray radiation (SXR) yield. The parameters are the anode radius and length, the cathode radius, and the number of rods in the cathode. It will be seen that increasing the anode radius causes an increase in the SXR yield. This is because of the constancy of the ratios of the pinch radius and length to the anode radius and length, respectively. Since the SXR yield scales to the pinch current, increasing the anode length brings a reduction in the yield. When the number of the cathode rods is increased, then the formed...
Notice of violation of IEEE publication principles: a new automatic clustering algorithm via deadline timer for wireless ad-hoc sensor networks
, Article 2008 3rd International Conference on Information and Communication Technologies: From Theory to Applications, ICTTA, 7 April 2008 through 11 April 2008, Damascus ; 2008 ; 9781424417513 (ISBN) ; Movaghar, A ; Barati, A ; Eslami Nejhad, M. R ; Barati, H ; Sharif University of Technology
2008
Abstract
This paper proposes a decentralized algorithm to organize an ad-hoc sensor network into clusters. Each sensor operates independently, monitoring communication among others. Those sensors which have many neighbors that are not already part of a cluster are likely candidates to creating a new cluster by declaring themselves to be a new cluster-head. The Clustering Algorithm via Deadline Timer (CADT) provides a protocol whereby this can be achieved and the process continues until all sensors are part of a cluster. Because of the difficulty of analyses simplified models are used to study and abstract its performance. A simple formula to estimate the number of clusters which will be formed in an...
, M.Sc. Thesis Sharif University of Technology ; Miremadi, Ghasem (Supervisor)
Abstract
In recent years, the use of embedded processors has grown increasingly in wide range of computer systems; so that most of manufactured CPUs are used in emebedded systems many of which are safty-critical systems such as medical devices, aircraft flight control, space systems, nuclear systems, etc. The incidence of failure in these systems can cause irreversible damages on human life, financial or environmental matters. Silicon process technology trends, such as reducing the threshold voltage, increasing the frequency and decreasing the size of transistors, not only caused increase in single-bit fault rate but also caused occurance of multi-bit faults. Due to importance ofcorrect operation of...
Design of Robust Digital Circuits Against Soft Errors Considering Multiple Event Transients Fault (METs)
, M.Sc. Thesis Sharif University of Technology ; Miremadi, Ghasem (Supervisor)
Abstract
Nowadays, one of the most important challenges in the design of digital circuits is their susceptibility to the strike of high energy particles which leads to the Single Event Transient (SET) and Multiple Event Transients (MET). In fact, technology scaling which results in lower supply voltage, higher operating frequency, and lower nodal capacitance, makes today’s digital circuits more susceptible not only to high energy particles but also to low energy particles. Moreover emerging deep sub-micron technologies and the integration of more cells in today’s chips have caused higher probability of MET occurrences. A lot of research has tried to reduce the soft error rate due to high energy...
Design and Implementation of a Fault-Tolerant Routing Algorithm in WSNs
, M.Sc. Thesis Sharif University of Technology ; Miremadi, Ghasem (Supervisor)
Abstract
Wireless Sensor Networks (WSNs) are prone to faults due to battery depletion of nodes, where a node failure can disturb routing, as it plays a key role in transferring sensed data to the end users. A WSN may be partitioned into groups of nodes called clusters; for every cluster, there is a node, called Cluster Head (CH) that is responsible for collecting and transferring data from all nodes in that cluster. This means that the CH is a single point of failure; i.e., once a CH fails, the whole cluster will fail, which leads to inability of its members for transferring data outside the cluster. This thesis presents a Fault-Tolerant and Energy-Aware algorithm (FTEA), which prolongs the lifetime...
Fault-Tolerant Implementation of Erasure Codes for Storage Systems
, M.Sc. Thesis Sharif University of Technology ; Miremadi, Ghasem (Supervisor)
Abstract
The increasing size of valuable data emphasizes the importance of applying reliability in storage systems. One way to protect storage system failures is using erasure codes. The advantages of using erasure codes are their low overheads and high reliability. Soft errors caused by high-energetic particles do not only corrupt data in the SSD-based storage systems, but also in the erasure codes. In this regards, it is important to protect erasure code implementations against soft errors. This thesis proposes a fault-tolerant implementation of erasure codes. The proposed method is based on the structure of each erasure code. This method is analytically evaluated on four erasure codes, i.e....
Soft Error Rate Estimation in Presence of Multiple Event Transients (METs)
, M.Sc. Thesis Sharif University of Technology ; Miremadi, Ghasem (Supervisor)
Abstract
With continuous device down-scaling and increase in transistor counts on a chip, complementary metal-oxide-semiconductor (CMOS) technology has become extremely sensitive to soft errors. Soft errors are transient errors caused by energetic particles such as neutrons and alpha particles. An essential step to design a soft error tolerant digital system with minimal performance and power overheads is Soft Error Rate (SER) estimation of system components. Until recently, Single Event Upsets (SEUs) in latches and Filp-Flops (FFs) and Single Event Transients (SETs) in combinational logic parts of digital circuits were regarded as the main effects of particle strikes. However, with the emerging...
Design and Evaluation of a Master/Checker Method for an Embedded Processor
, M.Sc. Thesis Sharif University of Technology ; Miremadi, Ghasem (Supervisor)
Abstract
Ever increasing applications of embedded systems have motivated the designers to pay special attention to the design requirements of such systems. Among embedded applications, safety-critical systems have high reliability requirements as failures in such systems may endanger human life or result in catastrophic consequences. Embedded processors as the computation cores of embedded systems are very crucial from reliability point of view. This is because; a failure in the processor most probably leads to a system failure. One effective way to protect embedded processors against environmental faults is to use system level fault-tolerant techniques such as Master/Checker (M/C) or Triple Modular...
Design of Fault Tolerant Processor for Implementation on SRAM Based FPGAs
, M.Sc. Thesis Sharif University of Technology ; Miremadi, Ghasem (Supervisor)
Abstract
Vulnerability of SRAM-based FPGAs to soft errors signals the importance of applying fault-tolerant methods in FPGAs used in safety-critical applications. Previous methods to protect SRAM-based FPGAs impose significant area and power overheads. Additionally, they suffer from susceptibility of configuration bits to Single Event-Multiple Upsets (SEMU). This thesis presents a Highly Available Fault-Tolerant Architecture (HAFTA) to protect SRAM-based FPGA designs against SEMUs in both configuration and user bits. In HAFTA, the entire design is duplicated and the main and replica flip-flops are compared at each clock cycle to detect any possible mismatch. To save the latest correct state of the...