QSDFT: ASWin ver 1.54. Quantachrome introduces a new and accurate pore size calculation method for geometrically- and chemically-hetrogeneous porous carbons. This novel Quenched Solid Density Functional Theory, or QSDFT, was developed in collaboration with Prof. Alex Neimark of Rutgers University and Dr Peter Ravikovitch (formerly TRI Princeton). In contrast to the previous NLDFT models applicable to molecularly smooth carbons, i.e.those that assumed flat, structureless, graphitic pore walls, the QSDFT method takes into account the effects of surface roughness and heterogeneity explicitly. The prominent step peculiar to theoretical NLDFT isotherms that is due to a monolayer transition on perfectly flat surfaces, and which causes an apparent (but artifactual) minimum in the pore size distribution at ~1nm, has been completely eliminated. As a consequence, the resulting QSDFT pore size distributions are more reliable. Ask for Powder Tech Note No.40 which details the background leading up to the development of, and application to different activated carbons of the QSDFT model, by completing our contact form. Please mention Tech Note 40 in the comment field to ensure that you receive your copy promptly. This new QSDFT model is available in Quantachromes latest release of its ASWin Analysis and Data Reduction software program for the Autosorb-1 surface area and pore size analyzer, ver 1.54. Contact qc.sales@quantachrome.com for information on how to obtain a copy of the new software and whether you qualify for a free upgrade! Martin A. Thomas PhD Director of Business Development Quantachrome Instruments 1900 Corporate Dr Boynton Beach FL 33426 USA tel: +1 (561) 731-4999 fax: +1 (561) 732-9888 www.quantachrome.com