Sharif Digital Repository

Nanoparticles of manganese tungstate (MnWO4) were prepared via an impregnation method using Mn(NO3)2 4H2O and WO3 as a source of Mn and W, respectively. The morphology of the manganese tungstate nanoparticles was studied in detail by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). MnWO4 nanoparticles showed severe catalytic performances for the degradation of organic dye (methylene blue, MB) in the presence of tert-butyl hydrogen peroxide, TBHP, as the oxidant at room temperature in water  

Mn-doped ZnO nanoparticles, Zn1−xMnxO, were synthesised by a polyethylene glycol (PEG) sol–gel method and the physicochemical properties of compounds were characterised by atomic absorption spectroscopy (AAS), energy-dispersive X-ray analysis, X-ray diffraction, scanning electron microscopy and transmission electron microscopy. The catalytic degradation of an organic dye, methylene blue (MB), in the presence of Zn1−xMnxO as the catalyst and hydrogen peroxide (H2O2) as the oxidant at room temperature in water has been studied. Effects of oxidant, catalyst amount, catalyst composition, pH value of the solution and an OH-radical... 

Increasing power densities in future technology nodes is a crucial issue in multicore platforms. As the number of cores increases in them, power budget constraints may prevent powering all cores simultaneously at full performance level. Therefore, chip manufacturers introduce a power budget constraint as Thermal Design Power (TDP) for chips. Meanwhile, multicore platforms are suitable for implementation of fault-tolerance techniques to achieve high reliability. Task Replication is a known technique to tolerate transient faults. However, careless task replication may lead to significant peak power consumption. In this paper, we consider the problem of achieving a given reliability target... 

Increasing power densities in future technology nodes is a crucial issue in multicore platforms. As the number of cores increases in them, power budget constraints may prevent powering all cores simultaneously at full performance level. Therefore, chip manufacturers introduce a power budget constraint as Thermal Design Power (TDP) for chips. Meanwhile, multicore platforms are suitable for the implementation of fault-tolerance techniques to achieve high reliability. Task Replication is a well-known technique to tolerate transient faults. However, careless task replication may lead to significant peak power consumption. In this article, we consider the problem of achieving a given reliability... 

Two main objectives in designing real-time embedded systems are high reliability and low power consumption. Hardware replication (e.g., standby-sparing) can provide high reliability while keeping the power consumption under control. In this paper, we consider a standby-sparing system where the main tasks on primary cores are scheduled by our proposed peak-power-aware earliest-deadline-first policy while the backup tasks on spare cores are scheduled by our proposed peak-power-aware earliest-deadline-late policy to meet the chip thermal design power (TDP) constraint. These policies provide the best opportunity to shift the task executions as much as possible to minimize execution overlaps... 

Multicore platforms provide great opportunity for implementation of fault-tolerance techniques to achieve high reliability in real-time embedded systems. Passive redundancy is well-suited for multicore platforms and a well-established technique to tolerate transient and permanent faults. However, it incurs significant power overheads, which go wasted in fault-free execution scenarios. Meanwhile, due to the Thermal Design Power (TDP) constraint, in some cases it is not feasible to simultaneously power on all cores on a multicore platform. Since TDP is the maximum sustainable power that a chip can consume, violating TDP makes some cores automatically restart or significantly reduce their... 

Multicore platforms provide a great opportunity for implementation of fault-tolerance techniques to achieve high reliability in real-time embedded systems. Passive redundancy is well-suited for multicore platforms and a well-established technique to tolerate transient and permanent faults. However, it incurs significant power overheads, which go wasted in fault-free execution scenarios. Meanwhile, due to the Thermal Design Power (TDP) constraint, in some cases, it is not feasible to simultaneously power on all cores on a multicore platform. Since TDP is the maximum sustainable power that a chip can consume, violating TDP makes some cores automatically restart or significantly reduce their... 

Manganese doped on cubic phase nanoparticles of ZrO2 was synthesized by an impregnation method. These novel particles were carefully analyzed by various chemico-physical methods. The catalytic degradation of an organic dye, methylene blue, in the presence of Mn-doped ZrO2 nanoparticles, as well as ZrO2 nanoparticles as catalyst with aqueous hydrogen peroxide, H2O2, as an oxidizing agent has been studied in aqueous solution at room temperature. Effects of solution pH, catalyst composition and radical scavenging agents on the degree of degradation of methylene blue were also studied. Finally, the recoverability and reusability of the... 

Multicore platforms provide a great opportunity for implementation of fault-tolerance techniques to achieve high reliability in real-time embedded systems. Passive redundancy is well-suited for multicore platforms and a well-established technique to tolerate transient and permanent faults. However, it incurs significant power overheads, which go wasted in fault-free execution scenarios. Meanwhile, due to the Thermal Design Power (TDP) constraint, in some cases, it is not feasible to simultaneously power on all cores on a multicore platform. Since TDP is the maximum sustainable power that a chip can consume, violating TDP makes some cores automatically restart or significantly reduce their... 

Dynamic Voltage and Frequency Scaling (DVFS) is one of the most popular and exploited techniques to reduce power consumption in multicore embedded systems. However, this technique might lead to a task-reliability degradation because scaling the voltage and frequency increases the fault rate and the worst-case execution time of the tasks. In order to preserve taskreliability at an acceptable level as well as achieving power saving, in this letter, we have proposed an enhanced DVFS method based on reinforcement learning to reduce the power consumption of sporadic tasks at runtime in multicore embedded systems without task-reliability degradation. The reinforcement learner takes decisions based...