Separation of methane from different gas mixtures using modified silicon carbide nanosheet: Micro and macro scale numerical studies

This research discusses the separation of methane gas from three different gas mixtures, CH₄/H₂S, CH₄/N₂ and CH₄/CO₂, using a modified silicon carbide nanosheet (SiCNS) membrane using both molecular dynamics (MD) and computational fluid dynamics (CFD) methods. The research examines the effects of different structures of the SiCNSs on the separation of these gas mixtures. Various parameters including the potential of the mean force, separation factor, permeation rate, selectivity and diffusivity are discussed in detail. Our MD simulations showed that the separation of CH₄/H₂S, and CH₄/CO₂ mixtures was successful, while simulation demonstrated a poor result for the CH₄/N₂ mixture. The effect of temperature on the diffusivity of gas is also discussed, and a correlation is introduced for diffusivity as a function of temperature. The evaluated value for diffusivity is then used in the CFD method to investigate the permeation rate of gas mixtures.     

YOLO-V3 based real-time drone detection algorithm

Multimedia Tools and Applications - Drones are currently being used in a wide range of useful tasks that are too dangerous or/and expensive to be performed by humans. However, this is increasingly...     

Heat and Hydrogen Management Strategies in an Integrated Autothermal Radial Flow Reactor for Enhancement of Olefin Production

Theoretical Foundations of Chemical Engineering - Autothermal configurations are recognized as a novel concept in process intensification. The main objective of this study is modeling and...     

Investigation of Nanocrystalline Co–P Coated by Pulsed Electrodeposition

In this study, nanocrystalline Co-(1–2)wt %P coatings were obtained by pulsed elec[trodeposition method on 1.6959 steel substrate. Coating operation carried out with current density of 150 mA/cm² on the basis of the preliminary studies and tests, coating was accomplished in 5 different pulsed current. XRD studies and EDX analysis results showed that the coatings all had the same phosphorous-cobalt composition with Co-1.5% P. XRD studies demonstrated the amorphous structure in all coatings. Heat treatment on the coatings showed that annealing the coatings at 400°C for 1 hour causes development of crystal nanostructure coatings and increases the hardness. XRD studies on nanocrystal coatings prove that the least size of the Nano grains belongs to coatings with higher off times. Heat stability of the coatings was proved with the help of DTA experiments on coatings up to 650°C.     

Solving the Task Starvation and Resources Problem Using Optimized SMPIA in Cloud

In this study, a new feature is added to the smart message passing interface (SMPI) approach (SMPIA) based on the prioritization method, which can completely eliminate the task starvation and lack of sufficient resources problems through prioritizing the tasks. The proposed approach is based on prioritizing the tasks and the urgency of implementation. Tasks are prioritized based on execution time, workload, the task with a more sensitive priority is executed earlier by the free source. The idea of demand-bound functions (DBFs) was extended to the SMPIA setting based on partitions and caps. For each task, two DBFs are constructed, DBFLOand DBFHI, for the LO and HI criticality modes, respectively. The simulation results returned by MATLAB showed that with the optimized SMPIA (O-SMPIA), the parameters of maximum service execution time, response time, delay time, and throughput improved in this work. In addition, the results confirmed that the reduction of execution time, completion time, and resource consumption time did not affect the response time and throughput of workflow tasks and did not cause inefficient use of resources in virtual machines (VMs) and data centers (DCs). The evaluation of performance metrics showed that the delay, response time of the Greedy algorithm was less than that of Max-Min and Min-Min. At the same time, the execution time of Max-Min was less than the others and the throughput of the Greedy was longer. The effect and throughput of O-SMPIA became more obvious as change to the job count and the number of cloud workloads increased. It is also worth mentioning that one of the main advantages of the O-SMPIA to other methods is the efficient use of time to execute all the defined tasks by CPU.     

Determination of Diazinon Pesticide Residue in Tomato Fruit and Tomato Paste by Molecularly Imprinted Solid-Phase Extraction Coupled with Liquid Chromatography Analysis

Food Analytical Methods - In the present study, an optimized molecularly imprinted polymer (MIP) was prepared and evaluated as a selective sorbent in solid-phase extraction and analysis in tomato...     

LAPTAS: lightweight anonymous privacy-preserving three-factor authentication scheme for WSN-based IIoT

Wireless Networks - Nowadays, wireless sensor networks (WSNs) are essential for monitoring and data collection in many industrial environments. Industrial environments are usually huge. The...     

General rules for optimal tuning the PIλDµ controllers with application to first‐order plus time delay processes

For two main reasons optimal tuning the PI^λD^µ controllers is a challenging task: First, the search space is very large in dealing with such controllers, and second, there is not any generally applicable method for stability testing of the linear feedback systems containing both time delay and fractional‐order controllers. Hence, easy‐to‐use and effective rules for optimal tuning such controllers are highly demanded. In this paper, explicit formulas for optimal tuning the parameters of the PI^λD^µ controller, when it is applied in series with a first‐order plus time‐delay process in a standard output‐feedback system, are proposed. © 2012 Canadian Society for Chemical Engineering     

Dynamic simulation of a cascade fluidized-bed membrane reactor in the presence of long-term catalyst deactivation for methanol synthesis

In this work, a dynamic model for a cascade fluidized-bed hydrogen permselective membrane methanol reactor (CFBMMR) has been developed in the presence of long-term catalyst deactivation. In the first catalyst bed, the synthesis gas is partly converted to methanol in a water-cooled reactor, which is a fluidized-bed. In the second bed, which is a membrane assisted fluidized-bed reactor, the reaction heat is used to preheat the feed gas to the first bed. This reactor configuration solves some observed drawbacks of new conventional dual type methanol reactor (CDMR) and even fluidized-bed membrane dual type methanol reactor (FBMDMR) such as pressure drop, internal mass transfer limitations, radial gradient of concentration and temperature in both reactors. A dynamic two-phase theory in bubbling regime of fluidization is used to model and simulate the proposed reactor. The proposed model has been used to compare the performance of a cascade fluidized-bed membrane methanol reactor with fluidized-bed membrane dual-type methanol reactor and conventional dual-type methanol reactor. The simulation results show a considerable enhancement in the methanol production due to the favorable profile of temperature and activity along the CFBMMR relative to FBMDMR and CDMR systems.