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Various graphic techniques have been developed to analyze structural errors in rule-based systems that utilize inference (propositional) logic rules. The four typical errors in rule-based systems are 1) redundancy (numerous rule sets resulting in the same conclusion), 2) circularity (a rule leading back to itself), 3) incompleteness (dead ends or a rule set conclusion leading to unreachable goals), and 4) inconsistency (rules conflicting with each other). This study presents a new DNA-based computing algorithm mainly based on Adleman's DNA operations. It can be used to detect such errors. There are three phases to this molecular solution: rule-to-DNA transformation design, solution space generation, and rule verification. We first encode individual rules by using relatively short DNA strands and then generate all possible rule paths by the directed joining of such short strands to form longer strands. We then conduct the verification algorithm to detect errors. The potential of applying this proposed DNA computation algorithm to rule verification is promising, given the operational time complexity of O(n * q), in which n denotes the number of fact clauses in the rule base, and q is the number of rules with the longest inference chain. Index Terms--DNA computing, rule-based system, rule verification.

Vanadium (V)-doped WO3/TiO2 microporous film on a titanium (Ti) plate was prepared by using the micro-arc oxidation process. Incorporating V and tungsten (W) species into the TiO2 lattice in one step yields band gap narrowing and strong visible-light (Vis) photoactivity, dominated mostly by incorporation of WO3 and V2O5 oxides, and possibly W xTi1− xO2. Photoactivity under ultraviolet light (UV) irradiation was likely attributable to its WO3-loaded microporous structure, which favored cationic molecule adsorption on its active sites. Although post annealing enhanced film crystallinity, photocatalytic ability was decreased largely because of changes in doping levels. This suggests that the as-oxidized microporous film is feasible for photocatalytic cationic dye degradation under UV and Vis irradiation. [ABSTRACT FROM AUTHOR]

Abstract: This study investigates the photoelectrocatalytic (PEC) property of microporous WO3-loaded TiO2/Ti layer, prepared via micro-arc oxidation (MAO) of Ti plate, followed by sputtering deposition of a thin Pt layer as a Pt-TiO2/Ti electrode. The WO3-loaded TiO2 layer which is associated with a more acidic surface forms many local electrochemical cells on its micro-pores immersed in cationic dye solution. The electrocatalytic (EC) reactions can take place in the local cells by the applied electrons. A low resistivity that is accomplished by MAO technique and by platinization offers an easy path for the electron motions in the Pt-TiO2/Ti electrode. All these features make the EC oxidation of aqueous dye pollutants practically feasible without using counter electrodes and supporting electrolytes. Our experiments demonstrate that, under PEC condition, the Pt-TiO2/Ti shows the highest degradation rate constant of 0.83h−1 at an applied bias of 1.0V and exhibits significantly high PEC and EC oxidation activities at a low applied bias of 0.25V. This is attributable to high anodic currents generated in the Pt-TiO2/Ti even at low bias. The modified microporous electrodes conclusively reveal a very interesting EC property as a two double-sided device that functions the PEC and EC oxidation simultaneously without a need of supporting electrolyte and expensive Pt cathode. [Copyright &y& Elsevier]

Abstract: This study reports the preparation of microporous TiO2-WO3/TiO2 films with a high surface area using a two-step approach. A porous WO3/TiO2 template was synthesized by oxidizing a titanium sheet using a micro arc oxidation (MAO) process. This sheet was subsequently overlaid with a visible light (Vis)-enabled TiO2 (N,C-TiO2) film, which was deposited by codoping nitrogen (N) and carbon (C) ions into a TiO2 lattice using direct current magnetron sputtering. The resulting microporous TiO2-WO3/TiO2 film with a 0.38-μm-thick N,C-TiO2 top-layer exhibited high photocatalytic activity in methylene blue (MB) degradation among samples under ultraviolet (UV) and Vis irradiation. This is attributable to the synergetic effect of two-step preparation method, which provides a highly porous microstructure and the well-crystallized N,C-TiO2 top-layer. This is because a higher surface area with high crystallinity favors the adsorption of more MB molecules and more photocatalytic active areas. Thus, the microporous TiO2-WO3/TiO2 film has promising applications in the photocatalytic degradation of dye solution under UV and Vis irradiation. These results imply that the microporous WO3/TiO2 can be used as a template of hybrid electrode because it enables rapid fabrication. [Copyright &y& Elsevier]