Mathematical modeling of methane-fed anodesupported micro-tubular solid-oxide fuel cell (MT-SOFC) is developed. Steam reforming of methane is considered in two cases of: direct internal reforming (DIR) and gradual internal reforming (GIR). The polarization curves and temperature distribution of a cell fed with three variations of fueling (i.e., DIR and GIR of methane and pure hydrogen) are compared with each other. The simulation results are verified through temperature and performance measurements of a MT-SOFC sample operating on above three variations of fueling. In DIR operating condition, a drop in the anode gas temperature at a short distance after entering the cell takes place which results in high temperature gradient. In GIR operating condition, the temperature distribution in axial direction is steadier. The ohmic loss is lower in the case of pure hydrogen fuel than internal reforming of methane, but the concentration loss is lower in methane-fed operating conditions. Nomenclature A E v Reactive surface area per unit volume of electrode (m 2 m −3 ) c i Concentration of species: i (mol m −3 ) c O 2 Oxygen concentration (mol m −3 ) c H 2 Hydrogen concentration (mol m −3 ) c O 2 ;ref Oxygen reference concentration (mol m −3 ) c H 2 ;ref Hydrogen reference concentration (mol m −3 ) c p Total heat capacity (J kg −1 K −1 ) D eff Effective diffusion coefficient (m 2 s −1 ) E E Apparent activation energy for the electrode reaction (J mol −1 ) F Faraday's constant (96,487 Cmol −1 ) F amb Ambient view factor in radiative heat transfer G m Mutual irradiation arriving from other surfaces in the modeled geometry (W m −2 ) h i Enthalpy of species: i (J mol −1 ) I Cell average current density (A) I Unit 3×3 matrix J E i Electrode normal ionic current flow (A m −2 ) J E e Electrode normal electronic current flow (A m −2 ) J E 0 Electrode reference exchange current density (A m −2 ) J E 0;ref Reference temperature current density (A m −2 ) N D i Species diffusion vector (mol m −2 s −1 ) n CH 4 Molar flow rate of the input fuel (mol s −1 ) n air Molar flow rate of the input air (mol s −1 ) n species Normal flux of species (mol m −2 s −1 ) P Pressure (Pa) P species Partial pressure of species (Pa) Q Volumetric heat generation rate (J m −3 ) q Surface heat transfer (J m −3 ) R Universal gas constant (8.3143 Jmol −1 K −1 ) t E rl

Vudjood algebra is a mathematical method that describes a domain or region, which can be used for designing manufacturing software. The most important application of Vudjood algebra is the creation of models for computer-aided design and computer integrated manufacturing. Here, Vudjood algebra becomes a tool for the software developer. The application of visual artificial intelligence in manufacturing will be the next developmental step in production technology. Operators in this field will be universal humanoid robots that can visually recognize surrounding objects and machines. These robots will work with mathematical models of the surrounding objects and machines. This paper explains how Vudjood algebra can accelerate the development of autonomic-acting machines and provide a tool for shape manufacturing.

For start-up of tubular solid oxide fuel cells preheating concepts of gas heating, induction heating, sequential hybrid of gas and induction heating and concurrent hybrid of gas and induction heating were experimented. Due to impossibility of heating-up of porous electric conductive layers in electromagnetic field, stainless steel material was adopted for the gas distributor tube, which is readily heated by induction method and transfers heat to adjacent layers. Start-up times of 95, 31, 49 and 20 seconds were attained for gas heating, induction heating, hybrid of sequential gas and inductive heating and hybrid of concurrent gas and induction heating methods respectively. Axial distribution of temperature in the course of start-up was steadier in hybrid methods which resulted in diminished axial temperature gradient and reduced performance degradation of the cell. A numerical model was developed and calibrated to predict the preheating phenomenon. Analytical results implied the positive effect of layers porosity on the heating rate, concerning mainly the gas heating methods.

Atmospheric plasma spray is a fast and economical process for deposition of yttria-stabilized zirconia (YSZ) electrolyte for solid oxide fuel cells. YSZ powders have been used to prepare plasma-sprayed thin ceramic films on the metallic substrate employing plasma spray technology at atmospheric pressure. Alumina doping was employed to improve the structural characteristics and electrical properties of YSZ. The effect of alumina addition from 1 to 5 wt.% on the properties of plasma-sprayed YSZ films was investigated. It was found that the gas permeability of the Al-doped YSZ electrolyte layer reached a level of 8.6×10 −7 cm 4 gf −1 s −1 , which is a necessary value for the practical operation of solid oxide fuel cells. Alumina doping considerably increased the ionic conductivity of plasma-sprayed YSZ. The open circuit voltage of the alumina-doped YSZ coating was approximately equal to the theoretical value for dense YSZ material.

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