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121.
We discuss an efficient variation of state exploration for two communicating finite state machines. In particular, we propose to divide the task of generating all reachable states into two independent subtasks. In each subtask, only the states reachable by forcing maximal progress for one machine are generated. Since the two subtasks are completely independent, and since in most instances the time and storage requirements for each subtask are less than those for the original task, maximal Progress state exploration can save time and/or storage over conventional state exploration. 相似文献
122.
Mustafa Kamal El Said Gouda 《Journal of Materials Science: Materials in Electronics》2008,19(1):81-84
The effects of a third element, i.e., Zn in the range of 0.5–2.5 wt.%, on structure and properties of the binary Sn–Ag eutectic
lead-free solder alloy were investigated. To identify the structure of the resulting alloys, X-ray diffraction analysis has
been carried out. Resistivity, contact angles, Vickers microhardness and Young’s modulus have been measured. The results showed
that all Zn contents were restricted in formation of Ag-Zn compound indicated by X-ray diffraction peaks, which increased
continuously in the number and intensity as Zn content increased. Adding Zn up to 1.5 wt.% improved the wetting and mechanical
properties. Above that, wetting angle increased due to the increase in AgZn compound, which may accumulated at the interface
between solders and copper- substrate resulting a decrease in the adhesive strength. The alloy of composition Sn-3.5Ag-1.5Zn
has the most improved properties between the others. 相似文献
123.
Buried metallic pipelines are used to transmit the natural gas and petroleum products to the citizens. Sometimes these pipelines are constructed in the same pathway of the overhead transmission lines (OHTLs) to save the additional right-of-way cost, and to avoid the destruction of agricultural lands. AC voltage is induced on these pipelines by the power lines electric and magnetic fields. There are many mechanisms that describe the AC voltage inducing on these pipelines; capacitive coupling describes the pipelines induced voltage by the power lines electric field, inductive coupling characterizes the induced voltage caused by the OHTLs electromagnetic fields and conductive coupling is created in buried pipelines near to OHTLs by earth fault current. In the present paper the induced voltages of pipelines created by OHTLs due to the different couplings are investigated in normal condition of operation as well as line to ground fault. The current of the coating discharging and AC corrosion are investigated. The induced overvoltage appears on the natural gas pipeline is measured in steady state condition of the transmission circuits operation. Moreover, this paper represents the mitigation of the induced voltages by using two different KOH-PCs systems. 相似文献
124.
Izzuddin Zaman Hsu‐Chiang Kuan Qingshi Meng Andrew Michelmore Nobuyuki Kawashima Terry Pitt Liqun Zhang Sherif Gouda Lee Luong Jun Ma 《Advanced functional materials》2012,22(13):2735-2743
A scalable approach for the mass production of chemically modified graphene has yet to be developed, which holds the key to the large‐scale production of stable graphene colloids for optical electronics, energy conversion, and storage materials, catalysis, sensors, composites, etc. Here, a facile approach to fabricating covalently modified graphene and its polymer nanocomposites is presented. The method involves: i) employing a common furnace, rather than a furnace installed with a quartz tube and operated in inert gas as required in previous studies, to treat a commercial graphite intercalation compound with thermal shocking and ultrasonication and fabricate graphene platelets (GnPs) with a thickness of 2.51 ± 0.39 nm that contain only 7 at% oxygen; ii) grafting these GnPs with a commercial, long‐chain surfactant, which is able to create molecular entanglement with polymer matrixes by taking advantage of the reactions between the epoxide groups of the platelets and the end amine groups of the surfactant, to produce chemically modified graphene platelets (m‐ GnPs); and iii) solution‐mixing m‐GnPs with a commonly used polymer to fabricate nanocomposites. These m‐GnPs are well dispersed in a polymer with highly improved mechanical properties and a low percolation threshold of electrical conductivity at 0.25 vol%. This novel approach could lead to the future scalable production of graphene and its nanocomposites. 相似文献
125.
126.
Srinu Akula Patchaiah Kalaiselvi Akhila Kumar Sahu Subbiah Chellammal 《International Journal of Hydrogen Energy》2021,46(34):17909-17921
Stainless steel fulfills most of the requirements as bipolar plates in Proton Exchange Membrane Fuel Cell. However, it undergoes severe corrosion in fuel cell operating condition. This can be resolved by coating the stainless steel with corrosion resistive conducting polymers. In this study, homogeneous and adherent conductive Poly(2-amino-5-mercapto-1,3,4- thiadiazole)/Polypyrrole (PAMT/PPY) mono and bilayer polymer composite coatings are electrosynthesized on 316L SS in 0.5 M H2SO4 by cyclic voltammetry and chronopotentiometry. The hydrophobicity and surface morphology of the coatings are analyzed by contact angle and scanning electron microscopy respectively. The polymer coatings are evaluated in 0.5 M H2SO4 medium by potentiodynamic polarization and impedance techniques at 25 °C. The polarization results reveal that PAMT on PPY composite coating shifts the Ecorr of the 316L SS towards noble direction. The EIS study reveals that the Rf value of PAMT on PPY coating is significantly higher by three orders (x103 Ωcm2) of magnitude than uncoated 316L SS. The corrosion performance of the coatings in simulated PEMFC environment is investigated by potentiodynamic and potentiostatic studies. Results show that the PAMT on PPY and PPY on PAMT bilayer coatings are stable and increased the corrosion potential by about 410–470 mV and 275–310 mV (SCE) in simulated cathodic and anodic conditions respectively. This investigation reports that the PAMT on PPY bilayer coating is serving as a good physical barrier and protecting the 316L SS against corrosion in PEMFC environment. 相似文献