Techno-economic analysis for rustic electrification in Egypt using multi-source renewable energy based on PV/ wind/ FC

A technical-economic investigation based on mathematical modeling, simulation, and optimization approach is employed in this research to assemble an island combined renewable energy systems (CRES) consists of solar PV/Wind/Fuel Cell (FC) of a small-scale countryside area in Egypt. The intent of the proposed island CRES is to boost the share of renewable energy in the energy mix and to study the possibility of using fuel cells as a storage/backup system instead of using battery banks.Three combinations of CRES are presented in this research to select the most optimum one. The combinations of the hybrid systems are PV/FC, PV/WT/FC, and WT/FC. The performance and the total cost of the suggested CRES were optimized using Firefly Algorithm (FA). The results obtained from the FA are compared with those obtained from the Shuffled Frog Leaping Algorithm (SFLA) and the particle swarm optimization (PSO).The selected case study area with latitude and longitude of (29.0214 N, 30.8714 E) is identified for economic viability in this work.The simulation outcomes show that the solar PV/Wind/Fuel Cell combination incorporated with an electrolyzer for hydrogen production grants the excellent performance. The proposed system is economically viable with a levelized cost of energy of 0.47 $/kWh.     

Study on the non-uniform contact during ELID groove grinding

This paper introduces the potential feasibility that ELID (electrolytic in-process dressing) grinding replaces superfinishing in bearing manufacturing, but ELID grinding will bring new challenges. Different regions present distinguish surface profile due to the non-uniform contact in ELID groove grinding. However, few reports explaining the non-uniform contact are available. This article explores the mechanisms of the non-uniform contact during ELID groove grinding. Experiments on the non-uniform contact between bearing raceway and grinding wheel have been carried out under different conditions. The results show that non-uniform contact exists in ELID groove grinding process and it exerts influence on the profile of the raceway surface. Non-uniform contact influences the Rsk and Rku value all the time, but it influences the Ra value occasionally. Improvement strategies of eliminating the non-uniform contact are also discussed based on the experimental study.     

Evaluation of calcined copper slag as an oxygen carrier for chemical looping gasification of sewage sludge

Chemical looping gasification (CLG) of sewage sludge (SS) using calcined copper slag as an oxygen carrier (OC) represents a novel approach for achieving the comprehensive use of two wastes (SS and copper slag), where the SS is converted into syngas through the oxidation of calcined copper slag. The effect of the calcined temperature on the reactivity of copper slag was first studied. The results show that the copper slag calcined at 1100 °C (1100CS) exhibits excellent performance for SS gasification. Using 1100CS as an OC, the effect of the mass ratio of OC and SS (OC/SS), steam content, oxygen source and cycle number on the SS CLG were investigated in detail in a fixed bed reactor. OC/SS and steam content are determined at 5 and 33.33% for obtaining a relatively high carbon conversion and an acceptable energy recovery during the SS CLG, respectively. The 1100CS is similar to steam, which can provide an oxygen source for SS conversion, and it can catalyze the cracking of tar. The conversion of SS undergoes a slight increase with the cycle number due to the prolongation of the gas-solid mean residence time (R_t) and the deposition of alkali or alkaline earth metals on the surface of the OC particles. Phosphorus eventually appears in the form of water-soluble phosphate during the SS CLG, benefiting its recovery. Thus, CLG with 1100CS as an OC is one of good option for sludge treatment.     

脱铝超稳Y沸石负载Cu催化纤维素醇解合成乙酰丙酸乙酯

以非缓冲体系下柠檬酸脱铝改性的USY分子筛为载体,铜为金属活性组分,采用浸渍法制备脱铝超稳Y沸石负载Cu。考察了该催化剂对纤维素醇解制备乙酰丙酸乙酯（EL）的催化活性。在反应温度为200℃、反应时间为3 h的条件下,催化纤维素转化生成EL的产率为48.2%。通过XRD、FT-IR、BET、NH₃-TPD、Py-IR和TG-DTA对催化剂进行表征,结果表明,Cu-DUSY催化剂热稳定性好,晶体结构稳定。Cu-DUSY回收利用4次EL产率仍可保持40%以上,具有较好的催化活性。     

中小型太阳能光合生物制氢系统的火用分析

利用热力学第二定律,采用白箱分析模型对实验室所研发的太阳能光合生物制氢系统进行了火用分析,得出该系统的产氢量较少,火用效率仅为24.4%。其中光能火用损最大,占耗散火用损的64.4%;并针对系统中用能的薄弱环节,即对火用损较大的光能火用损分析了影响光能转化的因素,并提出了相应的解决方法,为整个系统内部设备的改进提供方向,以提高系统有效能的利用,为推进光合生物制氢技术的工业化提供了科学参考。     

木屑致密成型燃料微观结构观察与分析

林木生物质在全球生物质储量中占有很大比例,本文以木屑致密成型燃料为研究对象。试验分别对木屑致密成型燃料进行了元素分析、工业分析和燃料组成分析。并在200 kV场发射透射电子显微镜(JEM-2100F)下对木屑致密成型燃料进行观察,分别得到放大倍数为100、500、1 000、2 000倍的微观结构图片。通过对木屑成型燃料的微观结构分析研究能够为生物质成型燃料加工成型设备和燃烧设备的优化设计与改进提供理论基础。     

Novel plating solution for electroless deposition of gold film onto glass surface

In this paper, a simple and environmentally friendly electroless plating solution of chloroauric acid (HAuCl₄) and hydrogen peroxide (H₂O₂) for depositing gold film onto (3-aminopropyl)-trimethoxysilane (APTMS) -coated glass surface has been developed. APTMS as an adhesive reagent was used to attach the gold nanoparticles (AuNPs) onto the glass substrate. These AuNPs could be regarded as the preferential nucleation or catalytic sites for gold electroless reduction, which accelerated the reduction of Au³⁺ on the glass surface and effectively prevented the formation of gold metal in the bulk solution. During the gold plating process, H₂O₂ as the reducing agent was thermodynamically capable of reducing Au³⁺ ions from the HAuCl₄ precursor to gold atoms, which deposited onto the glass surface and finally formed the continuous gold film. The resulting gold film was characterized with X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM) and atomic force microscope (AFM), respectively.     

Wind turbine fault diagnosis method based on diagonal spectrum and clustering binary tree SVM

Renewable energy sources like wind energy are copiously available without any limitation. Reliability of wind turbine is critical to extract maximum amount of energy from the wind. The vibration signals in wind turbine's rotation parts are of universal non-Gasussian and nonstationarity and the fault samples are usually very limited. Aiming at these problems, this paper proposed a wind turbine fault diagnosis method based on diagonal spectrum and clustering binary tree Support Vector Machines (SVM). Firstly, the diagonal spectrum is calculated from vibration rotating machine as the input feature vector. Secondly, self-organizing feature map neural network is introduced to cluster the fault feature samples and construct a cluster binary tree. Then the multiple fault classifiers are designed to train and test samples. The wind turbine gear-box fault experiment results proved that this method can effectively extract features from nonstationary signals, and can obtain excellent results despite of less training samples.     

Novel application of nanocrystalline nickel electrodeposit: Making good diamond tools easily, efficiently and economically

Electrodeposition has been identified as a feasible and economical technique for nanomaterials application. This article details an improved approach to producing better diamond tools at lower cost and with higher productivity. Pulse-electroformed nanocrystalline nickel was used as the new matrix. The pulse parameters were determined after examination of the microstructure, grain size, hardness and tensile strength of the deposits obtained at different average current densities (J_m) with constant pulse-on time and pulse-off time. It is shown that, with J_m ranging from 1 Adm^− 2 to 14 Adm^− 2, the grain size decreases sharply from 180 nm to about 10 nm while the hardness and tensile strength significantly increase at first and then reach their peaks respectively, although the strength fails to stay long. Current density J_m that produced the highest hardness and strength of deposit (with grain size of 20 nm) was chosen for new diamond tools that exhibited 20.2% longer service life than their usual Ni-Co counterparts. Therefore, nanocrystalline electrodeposits are expected to be an upgrading substitute for conventional polycrystalline matrix.