다중혈관 관상동맥 환자에서 y-문합을 이용하여 양쪽 내흉동맥만을 사용한 우회술의 조기 성적

[신간의 별자리x] 우리/미술, 그리고 ‘슬픔의 박물관’

In this critical review, metal oxides-based materials for electrochemical supercapacitor (ES) electrodes are reviewed in detail together with a brief review of carbon materials and conducting polymers. Their advantages, disadvantages, and performance in ES electrodes are discussed through extensive analysis of the literature, and new trends in material development are also reviewed. Two important future research directions are indicated and summarized, based on results published in the literature: the development of composite and nanostructured ES materials to overcome the major challenge posed by the low energy density of ES (476 references).

/pdf/a-review-of-electrode-materials-for-electrochemical-2cok5em0bo.pdf

A review of electrode materials for electrochemical supercapacitors

Arsenic removal from water/wastewater using adsorbents—A critical review

비만아 부모의 돌봄 경험: q 방법론

The chemistry of atmospheric mercury: a review

Arsenic contamination has been found in the groundwater of several countries. Photocatalysis can rapidly oxidize arsenite (As(III)) to less labile and less toxic arsenate (As(V)), which then can be removed by adsorption onto photocatalyst surfaces. This study investigates the photocatalytic oxidation of As(III) to As(V) as a function of As(III) concentration, pH, catalyst loading, light intensity, dissolved oxygen concentration, type of TiO2 surfaces, and ferric ions to understand the kinetics and the mechanism of As(III) oxidation in the UV/TiO2 system. Photocatalytic oxidation of As(III) to As(V) takes place in minutes and follows zero-order kinetics. Benzoic acid (BA) was used as a hydroxyl radical (.OH) scavenger to provide evidence for the .OH as the main oxidant for oxidation of As(III). The .OH radical was independently generated by nitrate photolysis, and kinetics of As(III) oxidation by the .OH radical was determined. Formation of salicylic acid (SA) from the oxidation of BA by .OH also demonstrates the involvement of .OH in the mechanism of As(III) oxidation. The effect of Fe(III) on As(III) oxidation at different pH values with and without TiO2 under UV light was examined. The results suggest that .OH is the dominant oxidant for As(III) oxidation. Two commercially available TiO2 suspensions, Degussa P25 and Hombikat UV100, were tested for the removal of arsenic through oxidation of As(III) to As(V) followed by adsorption of As(V) onto TiO2 surfaces. Results showed that complete removal of arsenic below the World Health Organization drinking water limit of 10 microg/L could be achieved.

Photocatalytic oxidation of arsenic(III): evidence of hydroxyl radicals.

Semiconductor photocatalytic reduction is a relatively new technique for the removal of dissolved toxic metal ions from wastewater. In this paper, adsorption and photocatalytic reduction of Cr(VI) to Cr(III) inaqueous solutions by UV/TiO2 photocatalysis has been investigated. It has been observed that the pH of the solution plays an important role in this reaction. An acidic medium is favorable for Cr(VI) photocatalytic reduction, where 94% of Cr(VI) was photoreduced within 1 h at pH 3 when 2 g/L of TiO2 was used as the slurry. An adsorption study shows that the photocatalytic reduction mainly occurs on the surface of TiO2. The presence of Fe(III) improved the photocatalytic reduction of Cr(VI) because it was observed that an additional reaction between Fe(II) and Cr(VI) takes place in the UV/TiO2 reduction process. A new combination of photocatalytic reduction and metal ion coprecipitation using Fe(OH)3 for complete removal of aqueous Cr [Cr(VI) as well as Cr(III)] was designed, which reduced the chromiu...

http://eng.uwo.ca/people/aray/ajay publications pdf files/a58 wang xiaoling cr(vi) iecr 2004.pdf

Simo O. Pehkonen

Papers

The chemistry of atmospheric mercury: a review

Photocatalytic oxidation of arsenic(III): evidence of hydroxyl radicals.

Removal of Aqueous Cr(VI) by a Combination of Photocatalytic Reduction and Coprecipitation

Scientific uncertainties in atmospheric mercury models I: Model science evaluation

Microbiologically influenced corrosion of 304 stainless steel by aerobic Pseudomonas NCIMB 2021 bacteria: AFM and XPS study