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

[신간의 별자리x] 우리/미술, 그리고 ‘슬픔의 박물관’

To use solar irradiation or interior lighting efficiently, we sought a photocatalyst with high reactivity under visible light. Films and powders of TiO 2- x N x have revealed an improvement over titanium dioxide (TiO 2 ) under visible light (wavelength 2 has proven to be indispensable for band-gap narrowing and photocatalytic activity, as assessed by first-principles calculations and x-ray photoemission spectroscopy.

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Visible-Light Photocatalysis in Nitrogen-Doped Titanium Oxides

Titanium Dioxide Nanomaterials: Synthesis, Properties, Modifications, and Applications

The surface science of titanium dioxide

Decomposition reactions of NaClO3, KClO3, and KIO4 induced by 3 keV Ar+ ions and 1254 eV X-rays are investigated by X-ray photoelectron spectroscopy (XPS). The reactions lead to the formation of binary halides with preferential losses of oxygen. The decomposition pattern, monitored at the various stages of reaction, indicates almost direct changeover to the final products with only a few intermediate species formed. Product abundancies are compared for the ion, X-ray, and electron induced reactions and discussed in relation to the various radiation induced reaction mechanisms.

Ion and X-ray induced decomposition of alkali halates. A comparative study of the radiation induced reaction paths

Ammonia (NH3) is a valuable chemical for fertilizer production and for use as an effective hydrogen carrier. Electrocatalytic nitrate reduction has recently received great attention as an alternative for NH3 synthesis due to its kinetically favorable reaction. However, this promising strategy suffers from low Faradaic efficiency (FE) at large current density (>100 mA cm–2) and low nitrate concentrations because of the competing hydrogen evolution reaction. Herein, we report a catalyst consisting of earth-abundant cobalt–copper (Co1–xCux) nanoparticles supported on a three-dimensional substrate for efficient and selective NH3 synthesis via electrocatalytic nitrate reduction. Typically, the optimized Co0.5Cu0.5 catalyst performs at a high NH3 Faradaic efficiency (FE) of over 95% at −0.03 V with NH3 partial current density of ∼176 mA cm–2 at 50 mM nitrate, which is 7.3- and 1.7-fold higher than that of pure Co and Cu counterparts. Importantly, replacing Co with Cu enables the tuning of onset potential on Co catalyst maintaining high selectivity toward NH3. A stability test over 12 cycles confirmed the long-term operation of this catalyst. This work offers a facile strategy for tuning the catalyst’s elemental composition to attain a desired electrocatalytic activity. 

Cobalt–Copper Nanoparticles on Three-Dimensional Substrate for Efficient Ammonia Synthesis via Electrocatalytic Nitrate Reduction

https://pubs.acs.org/doi/pdf/10.1021/es200114z

Response to Comment on “Photocatalytic Oxidation Mechanism of As(III) on TiO2: Unique Role of As(III) as a Charge Recombinant Species”

This paper presents a micro fluxgate sensor fabricated by Si-based Micro Electro Mechanical Systems (MEMS). To measure X- and Y-axis magnetic fields, two fluxgate sensing elements were perpendicularly aligned. The fluxgate sensor was composed of rectangular-ring shaped magnetic core, solenoid excitation and pick-up coils. The 2 /spl mu/m thick Ni/sub 0.8/Fe/sub 0.2/ (permalloy) magnetic core layer was electroplated with photoresist frame using sputtered Ni/sub 0.8/Fe/sub 0.2/ seed layer. The fabricated fluxgate chip size was 4.5/spl times/2.7 mm/sup 2/. Excellent linear response over the range of -100 /spl mu/T to +100 /spl mu/T was obtained with 210 V/T sensitivity at excitation square wave of 2.8 V/sub p-p/ and 1.2 MHz. When two-axis fluxgate sensing element was rotated in terrestrial field, induced second harmonic voltages from X-and Y-axis were sine and cosine wave without distortion, respectively. It is very useful to commercialize the portable navigation system including north-up and map matching, military research, medical research, and space research.

Electronic compass using two-axis micro fluxgate sensing element

Titanium dioxide sol with mono dispersion of titanium dioxide nano-particles in solvent is provided to be suitably employed to produce a coating composition for manufacturing a coating film of lens, glasses, leisure goggles, etc. by mono dispersing the titanium dioxide nano-particles with constant particle size in the dispersing solvent then conducting sol-gel reaction with addition of acid catalyst to the solution. The preparation method includes the steps of: (a) raising temperature of reactive solution, which contains titania precursor in the reaction solvent, up to the sol-gel reaction temperature; (b) preparing titania sol by adding acid catalyst to the reactive solution to proceed the sol-gel reaction while removing the reaction solvent; and (c) dispersing the titania sol in a dispersing solvent after drying the titania sol. The removal of the reaction solvent and the sol-gel reaction are carried out at 70-95deg.C. The drying process is selected from lyophilization, ambient drying and vacuum drying processes.

Wonyong Choi

Papers

Ion and X-ray induced decomposition of alkali halates. A comparative study of the radiation induced reaction paths

Cobalt–Copper Nanoparticles on Three-Dimensional Substrate for Efficient Ammonia Synthesis via Electrocatalytic Nitrate Reduction

Response to Comment on “Photocatalytic Oxidation Mechanism of As(III) on TiO2: Unique Role of As(III) as a Charge Recombinant Species”

Electronic compass using two-axis micro fluxgate sensing element

Titania sol, preparing method thereof and composition for coating comprising thereof