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51.
In this study, the effects of heat input variation in gas tungsten arc welding (GTAW), on structure and mechanical properties of commercially C86300 (containing addition of 0.6 wt% silicon) weld joint were investigated. Following microstructural characterization of Base metal, GTAW has been performed at welding currents 50 and 60 A and flow rates of argon shielding gas (10, 14 and 18 l/min) using the same filler metal composition. Therefore six GTAW samples were performed with various welding specifications. By structural investigations and hardness profiles, effects of increasing heat input on increasing average grain size in weld zone, heat affected zone width, penetration depth and alloying element losses were indicated. However increasing heat input increases penetration depth and has a positive effect on hardness and strength of the joint. In considering wear application of this alloy castings and probable GTAW for them, pin-on-disc wear test was performed and revealed better wear resistance of weld metal in comparison with base metal. Hence the optimum values of welding current and argon flow rates (in GTAW with the same composition filler) was determined for this alloy. 相似文献
52.
Masoud Salavati-Niasari Mohammad Reza Ganjali Parviz Norouzi 《Journal of Porous Materials》2007,14(4):423-432
Oxovanadium(IV) tetradentate Schiff-base complexes; [VO(X2-haacac)] (X = H, Cl, CH3 and NO2), X2-haacac = substituted bis(2-hydroxyanil)acetylacetone; and encapsulated in the nanopores of zeolite NaY; [VO(X2-haacac)]-NaY; have been synthesized and characterized. The host-guest nanocomposite materials; [VO(X2-haacac)]-NaY; was characterized by chemical analysis and spectroscopic methods (FT-IR, UV/VIS, XRD, BET and DRS). The analytical
data indicated a composition corresponding to the mononuclear complex of Schiff-base ligand. The characterization data showed
the absence of extraneous complexes, retention of zeolite crystalline structure and encapsulation in the nanopores. Substitution
of the aromatic hydrogen atoms of the Schiff-base ligand by electron withdrawing groups like −Cl, and −NO2 has two major effects: (1) retention and concentration of the oxovanadium(IV) complex in the zeolite cavities is enhanced
(due to the larger size of the substituents) and (2) the electronic and spectral properties of the encapsulated complex are
modified. Liquid-phase selective hydroxylation of phenol with H2O2 to a mixture of catechol and hydroquinone in CH3CN has been reported using oxovanadium(IV) Schiff-base complexes encapsulated in zeolite-Y as catalysts. Reaction conditions
have been optimized by considering the concentration of substrate and oxidant, amount of catalyst, effect of time, volume
of solvent and temperature. Under the optimized reaction conditions, [VO((NO2)2-haacac)]-NaY has shown the highest conversion of 42.3% after 6 h. All these catalysts are more selective toward catechol
formation. Encapsulated oxovanadium(IV) complex is catalytically very efficient as compared to other neat complexes for the
hydroxylation of phenol and is stable to be recycled without much deterioration. 相似文献
53.
Ali IZADI GHAHFEROKHI Masoud KASIRI-ASGARANI Kamran AMINI Mahdi RAFIEI Reza EBRAHIMI-KAHRIZSANGI 《中国有色金属学会会刊》2022,32(3):908-926
研究使用不同的中间层瞬时液相连接两种异种高温合金的适用性.在1100℃、不同时间下瞬时液相连接GTD-111/IN-718体系,研究BNi-2、BNi-3和BNi-9三种类型的中间层对该体系显微组织和力学性能的影响.采用场发射扫描电子显微镜和能量色散光谱技术,研究接头区域的成分变化和显微组织.结果表明,非热凝固区Ni3... 相似文献
54.
Mohammad Sabzi Masoud Babaahmadi Navid Samadi Gholam Reza Mahdavinia Mohsen Keramati Nasser Nikfarjam 《Polymer International》2017,66(5):665-671
Here strong electroactive shape memory nanocomposites were prepared by incorporating graphene nanoplatelets into poly(vinyl acetate) (PVAc ) through the simple solvent mixing method. TEM and XRD revealed that well exfoliated graphene nanoplatelets formed a continuous network throughout the matrix with a large amount of interconnectedness. Dynamic mechanical analysis showed that the inclusion of graphene significantly improves both glassy and rubbery moduli of the matrix. Furthermore, the prepared nanocomposites demonstrated a marked electrical conductivity up to 24.7 S m?1 and thereby surprisingly rapid electrical actuation behaviour exhibiting a 100% recovery ratio in 2.5 s. Moreover, PVAc and its nanocomposites displayed scratch self‐healing capability. This work demonstrates that the PVAc /graphene nanocomposites with high modulus and excellent electroactive shape memory performance can be a promising material in many applications such as sensors and fast deployable and actuating devices. © 2016 Society of Chemical Industry 相似文献
55.
56.
In this work, neat and modified nanodiamond (ND) particles were embedded into high-density polyethylene (HDPE) membranes to improve hydrophilicity and antifouling properties. The membranes were prepared via thermally induced phase separation (TIPS) method and used for pharmaceutical wastewater treatment in membrane bioreactors (MBR) system. To prevent the agglomeration of ND, it was modified using two methods: thermal carboxylation (ND-COOH) and grafting with polyethylene glycol (ND-PEG). Membranes with different concentration of ND-COOH and ND-PEG nanoparticles ranging from 0.00 to 1.00 wt % were prepared and characterized using a set of analyses including water contact angle, pure water flux, tensile strength, differential scanning calorimeter, field emission scanning electron microscopy, and energy dispersive X-ray spectroscopy. It was found that the optimum contents of ND-COOH and ND-PEG nanoparticles were 0.50 wt % and 0.75 wt %, respectively. The interfacial interaction between nanoparticles and HDPE matrix was studied based on Pukanzsky model. To examine the performance of membranes, critical flux, filtration experiment in the MBR, and fouling analysis of membranes were carried out. The results showed that among the fabricated membranes, 0.75 wt % HDPE/ND-PEG membrane had the highest water flux and the best antifouling properties. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47914. 相似文献
57.
SPEEK/cSMM membrane for simultaneous electricity generation and wastewater treatment in microbial fuel cell 下载免费PDF全文
58.
Masoud Beheshti 《电子与电脑》2009,(12):90-92
简介手机、便携式媒体播放器、便携式导航工具及蓝芽(Bluetooth)耳机等新一代手持装置不断缩小体积外型,同时加强效能与功能。就充电管理而言,这些强化的功能使得设计工程人员必须同时顾及用户的便利性与体验感受,以及整体充电时间与成本的均衡。 相似文献
59.
Asghar Alizadehdakhel Masoud Rahimi Jafar Sanjari Ammar Abdulaziz Alsairafi 《International Communications in Heat and Mass Transfer》2009,36(8):850-856
A large number of experiments in a 2 cm diameter and 6 m length tube were carried out in order to study the two-phase flow regimes and pressure drops in it. The two-phase flow in the experimental tube was modeled using commercial CFD code, Fluent 6.2. An Artificial Neural Network (ANN) with three inputs including gas and liquid velocities and tube slope was designed and trained to predict average pressure drop across the tube. The comparison between CFD and ANN predictions of pressure drops with experimental measurements shows that the CFD results are more accurate than the ANN evaluations for new conditions. 相似文献
60.
Seyed Fakhreddin Hosseini Masoud Rezaei Mojgan Zandi Farhid Farahmand Ghavi 《Food chemistry》2013,136(3-4):1490-1495
With the goal of improving the physico-chemical performance of fish gelatin-based films, composite films were prepared with increasing concentrations of chitosan (Ch) (100G:0Ch, 80G:20Ch, 70G:30Ch, 60G:40Ch and 0G:100Ch, gelatin:Ch), and some of their main physical and functional properties were characterised. The results indicated that the addition of Ch caused significant increase (p < 0.05) in the tensile strength (TS) and elastic modulus, leading to stronger films as compared with gelatin film, but significantly (p < 0.05) decreased the elongation at break. Ch drastically reduced the water vapour permeability (WVP) and solubility of gelatin films, as this decline for the blend film with a 60:40 ratio has been of about 50% (p < 0.05). The light barrier measurements present low values of transparency at 600 nm of the gelatin–chitosan films, indicating that films are very transparent while they have excellent barrier properties against UV light. The structural properties investigated by FTIR and DSC showed a clear interaction between fish gelatin and Ch, forming a new material with enhanced mechanical properties. 相似文献