this paper presents a novel control approach used in shunt active power filter based on variable structure control combined with random pwm technique (rvsc) that provides robust, fast, and more favorable performance for active power filter. this control strategy is compared with two other strategies to show the effectiveness of the introduced methods; pulse width modulated proportional-integral...

A recent study (D. C. Cooper, F. W. Picardal, A. Schimmelmann, and A. J. Coby, Appl. Environ. Microbiol. 69:3517-3525, 2003) has shown that NO(3)(-) and NO(2)(-) (NO(x)(-)) reduction by Shewanella putrefaciens 200 is inhibited in the presence of goethite. The hypothetical mechanism offered to explain this finding involved the formation of a Fe(III) (hydr)oxide coating on the cell via the surfac...

In this study, a pot experiment was conducted to evaluate the effect of phosphate (PO4 (3-)) addition on iron (Fe) cycling in mangrove ecosystem. Kandelia obovata (S. L.), one of the dominant mangrove species in the southeast of China, was cultivated in rhizoboxes under three different levels of P concentrations. Results showed the solid-phase Fe distribution and Fe(II)/Fe(III) values in both t...

Objective: The present study was an attempt to study total phenolic content and antioxidant property of the crude ethanolic extract of the roots of Azadirachta indica (A. indica). Materials and Methods: To evaluate the antioxidant properties of the crude extract, some complementary test systems, namely DPPH free radical scavenging assay, reducing power assay, and ferrous ion chelating ability a...

Recent experimental studies permit development of conceptual and quantitative models of microbial Fe(III) oxide reduction at circumneutral pH that can be compared to and contrasted with established models of abiotic mineral dissolution. The findings collectively support a model for controls on enzymatic reduction that differs fundamentally from those applied to abiotic reductive dissolution as ...

Mechanisms for Fe(III) oxide reduction were investigated in Geothrix fermentans, a dissimilatory Fe(III)-reducing microorganism found within the Fe(III) reduction zone of subsurface environments. Culture filtrates of G. fermentans stimulated the reduction of poorly crystalline Fe(III) oxide by washed cell suspensions, suggesting that G. fermentans released one or more extracellular compounds th...

Water treatment with metallic iron (Fe) is still based on the premise that Fe is a reducing agent. An alternative concept stipulates that contaminants are removed by adsorption, co-precipitation and size-exclusion in a reactive filtration process. This article underlines the universal validity of the alternative concept. It is shown that admixing non-expansive material to Fe as a pre-requisite ...

The aim of this project was to assess the diversity of iron metabolizing bacteria in several ecological niches by culture-dependent and culture-independent methods. In particular, we wanted to determine whether non-phototrophic, anaerobic nitrate-dependent Fe(II)-oxidizers coexist with aerobic Fe(1I)-oxidizers and facultatively anaerobic Fe(III)-reducers in natural habitats. To this end, we sam...

In this work, four different supercapacitive microbial fuel cells (SC-MFCs) with carbon brush as the anode and an air-breathing cathode with Fe-Aminoantipyrine (Fe-AAPyr) as the catalyst have been investigated using galvanostatic discharges. The maximum power (Pmax) obtained was in the range from 1.7 mW to 1.9 mW for each SC-MFC. This in-series connection of four SC-MFCs almost quadrupled Pmax ...