Classification of DoS Attacks in Smart Underwater Wireless Sensor Network

As per the most recent literature, Orthogonal Frequency Division Multiplexing (OFDM), a multi access technique, is considered most suitable for the 3G, 4G and 5G techniques in high speed wireless communication. What made OFDM most popular is its ability to deliver high bandwidth efficiency and superior data rate. Besides it, high value of peak to average power ratio (PAPR) and Inter Carrier Interference (ICI) are the challenges to tackle down via appropriate mitigation scheme. As a research contribution in the present work, an improved self-cancellation (SC) technique is designed and simulated through Simulink to mitigate the effect of ICI. This novel proposed technique (Improved SC) is designed over discrete wavelet transform (DWT) based OFDM and compared with conventional SC scheme over different channel conditions i.e. AWGN and Rayleigh fading environments. It is found that proposed DWT-OFDM with Improved SC scheme outperforms conventional SC technique significantly, under both AWGN and Rayleigh channel conditions. Further, in order to justify the novelty in the research contribution, a Split-DWT based Simulink model for Improved SC scheme is investigated to analyse the BER performance. This Split-DWT based Simulink model presented here foretells the future research potential in wavelet hybridization of OFDM to side-line ICI effects more efficiently.

     

Recent developments in catalyst synthesis using DBD plasma for reforming applications

The catalyst has a significant role in gas processing applications such as reforming technologies for H₂ and syngas production. The stable catalyst is requisite for any industrial catalysis application to make it commercially viable. Several methods are employed to synthesize the catalysts. However, there is still a challenge to achieve a controlled morphology and pure catalyst which majorly influences the catalytic activity in reforming applications. The conventional methods are expansive, and the removal of the impurities are major challenges. Nevertheless, it is not straightforward to achieve the desired structure and stability. Therefore, significant interest has been developed on the advanced techniques to take control of the physicochemical properties of the catalyst through non-thermal plasma (NTP) techniques. In this review, the systematic evolution of the catalyst synthesis using NTP technique is elucidated. The emerging DBD plasma to synthesized and effective surface treatment is reviewed. DBD plasma synthesized catalyst performance in reforming application for H₂ and syngas production is summarised. Furthermore, the status of DBD plasma for catalyst synthesis and proposed future avenues to design environmentally suitable and cost-effective synthesis techniques are discussed.     

Enhancement in Physical Properties of Silver-Doped Fe–Ni Invar Nano-alloy Using Chemical Reduction Method

Journal of Superconductivity and Novel Magnetism - Silver-substituted Fe–Ni nano invar alloy is a new and innovative field of research due to their interesting invar, magnetic and electrical...     

通过智能电机控制优化实时性能与效率

本文介绍了高级电机的类型及利弊.并介绍了集成型电机控制方案.     

A probabilistic fouling and cost model for plate‐and‐frame heat exchangers

Fouling in plate‐and‐frame heat exchangers (PHEs) may be defined as the deposition of unwanted material on the heat transfer surface that reduces heat‐transfer and increases the resistance to fluid flow. Once the thermal–hydraulic performance decreases to a minimum acceptable level, cleaning of the equipment has to be done to restore the performance. The decision regarding periodic off‐line maintenance of the heat exchangers is generally based on a thermal–economic performance of the process. In this paper, we discuss a probabilistic maintenance model for PHE by incorporating the risk level and scatter parameter of the four random fouling growth models, namely linear, power law, falling rate and asymptotic models, which are integrated in the dimensionless cost model for a heat exchanger used in a steel plant. All the results are presented in terms of non‐dimensional plots. The results show that there is a strong relationship between t_down and the uptime, particularly in the region where the costs of operation and maintenance are minimum. Copyright © 2005 John Wiley & Sons, Ltd.     

The impact of fouling on performance evaluation of evaporative coolers and condensers

Fouling of evaporative cooler and condenser tubes is one of the most important factors affecting their thermal performance, which reduces effectiveness and heat transfer capability with time. In this paper, the experimental data on fouling reported in the literature are used to develop a fouling model for this class of heat exchangers. The model predicts the decrease in heat transfer rate with the growth of fouling. A detailed model of evaporative coolers and condensers, in conjunction with the fouling model, is used to study the effect of fouling on the thermal performance of these heat exchangers at different air inlet wet bulb temperatures. The results demonstrate that fouling of tubes reduces gains in performance resulting from decreasing values of air inlet wet bulb temperature. It is found that the maximum decrease in effectiveness due to fouling is about 55 and 78% for the evaporative coolers and condensers, respectively, investigated in this study. For the evaporative cooler, the value of process fluid outlet temperature T_p,out varies by 0.66% only at the clean condition for the ambient wet bulb temperatures considered. Copyright © 2005 John Wiley & Sons, Ltd.     

The effects of different greenhouse covering materials on energy requirement,growth and yield of aubergine

Effects of UV stabilised polyethylene (UV+PE), IR absorbers polyethylene (IR+PE), double layers of polyethylene (D-Poly) and single layer of polyethylene (PE), as greenhouse covers, on aubergine growth, productivity and energy requirement were investigated in a late autumn season (2001). The late and final yields of plants grown in D-Poly houses were higher than those grown in UV+PE, IR+PE and PE. Light transmission was the highest in PE, intermediate in UV+PE and IR+PE, and the lowest in D-Poly houses. Relative humidity was the highest in D-Poly, intermediate in IR+PE and UV+PE, and the lowest in PE houses. The plants in D-Poly houses grew and developed faster (more leaves and flowers) than those in IR+PE, UV+PE and PE houses. Plant growth and development in UV+PE and IR+PE houses was similar. Economic analyses showed that aubergine production was economically viable in D-Poly, UV+PE and IR+PE houses. For aubergine production in climatic conditions similar to Black Sea Region, the D-Poly greenhouse is strongly recommended, because there was a higher productivity and a lower heating requirement in comparison to UV+PE, IR+PE and PE houses.