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

[신간의 별자리x] 우리/미술, 그리고 ‘슬픔의 박물관’

Supercapacitors, also called ultracapacitors or electrochemical capacitors, store electrical charge on high-surface-area conducting materials. Their widespread use is limited by their low energy storage density and relatively high effective series resistance. Using chemical activation of exfoliated graphite oxide, we synthesized a porous carbon with a Brunauer-Emmett-Teller surface area of up to 3100 square meters per gram, a high electrical conductivity, and a low oxygen and hydrogen content. This sp 2 -bonded carbon has a continuous three-dimensional network of highly curved, atom-thick walls that form primarily 0.6- to 5-nanometer-width pores. Two-electrode supercapacitor cells constructed with this carbon yielded high values of gravimetric capacitance and energy density with organic and ionic liquid electrolytes. The processes used to make this carbon are readily scalable to industrial levels.

/pdf/carbon-based-supercapacitors-produced-by-activation-of-1wqrpq3luo.pdf

Carbon-based Supercapacitors Produced by Activation of Graphene

Kenji Sumida, David L. Rogow, Jarad A. Mason, Thomas M. McDonald, Eric D. Bloch, Zoey R. Herm, Tae-Hyun Bae, Jeffrey R. Long

Carbon Dioxide Capture in Metal–Organic Frameworks

Carbon properties and their role in supercapacitors

A binding site energy distribution function for a Jensen-Seaton isotherm and its limiting cases was proposed and successfully applied to the adsorption of several gas molecules on different essentially microporous carbons. According to the proposed model the studied carbon materials exhibit two energetic states where the site energy is exponentially or unimodaly distributed depending on the adsorption pressure. Carbons with a larger contribution from micropores seem to be in general more heterogeneous, with a wider binding site energy distribution, than less microporous carbons.

/pdf/a-site-energy-distribution-function-for-the-characterization-978ogicmbp.pdf

A site energy distribution function for the characterization of the continuous distribution of binding sites for gases on a heterogeneous surface

The CDS method can be used to determine the non-microporous structure of porous solids such as activated carbons. This method uses the adsorption of carbon dioxide at 273°K to evaluate the microporous structure of the adsorbent corresponding to the primary adsorption mechanism (narrow micro-porosity). From the adsorption isotherm both the micropore volume and the characteristic energy can be calculated and, by the appropiate correction in affinity coefficient and adsorption temperature, the corresponding isotherm for the microporosity for any adsorptive can be constructed. If this micro-porous isotherm is subtracted from the experimental isotherm for the given adsorptive, the corresponding residual isotherm may be analyzed by any of the usual methods (BET, t, α, etc.). The CDS is a very simple (from the experimental point of view) method to evaluate the non-microporous (external) surface area of activated carbons improving its determination with the advantage over other methods of subtracting always the same type of porosity (primary micropore filling in narrow micropores) and being applicable to any type of adsorptive used in the characterization of this sort of adsorbents.

Carbon Dioxide Subtraction (CDS) Method Applied to A Wide Range of Porous Carbons

Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 0997–1001, June, 2018.

Francisco Rodríguez-Reinoso

Papers

A site energy distribution function for the characterization of the continuous distribution of binding sites for gases on a heterogeneous surface

Carbon Dioxide Subtraction (CDS) Method Applied to A Wide Range of Porous Carbons

Preparation and investigation of active carbons based on furfural copolymer

Transient rates in the reaction of CO2 with highly oriented Pyrolytic graphite

Sinterability enhancement in semicokes obtained by controlled pyrolysis of a petroleum residue