Synthetic mesoporous alumina and silica minerals with uniform pore geometries, and their nonporous analogues, were used to test the role of mineral mesopores (2-50 nm diameter) in protecting organic matter from enzymatic degradation in soils and sediments. Dihydroxyphenylalanine (L-DOPA), a model humic compound, was irreversibly sorbed to both mineral types. The surface area-normalized adsorpti...

The thermal degradation of polyethylene (PE) was carried out in the absence and presence ofcatalystes X-Zeolite and Silica-Alumina at different temperatures. The optimum PE/Catalysisratio was 0.25:0.05 g/g, which produced highest degradation value. PE and PE/Catalysis werecharacterized by thermogravimetric analysis. The thermal degradation properties of polymerhave been studied by Infrared spec...

Large-dimension heterogeneous nanoporous membranes were obtained by the formation of CdS doped mesoporous silica within the porous channels of alumina membranes.

Non-supported microporous silica (amorphous) and titania thin films were made by the polymeric gel route. The titania system consisted of particles smaller than 5 nm. Reproducible modification of supported y-alumina films with silica demands a strict control of every modification step. Silica films of 3060 nm thickness on top of and presumably partly inside the y-alumina film were realised. The...

OF DOCTORAL DISSERTATION HELSINKI UNIVERSITY OF TECHNOLOGY P.O. BOX 1000, FI-02015 TKK http://www.tkk.fi Author Leif Backman Name of the dissertation Supported Cobalt Catalysts—Preparation, Characterisation and Reaction Studies Manuscript submitted Jan 23, 2009 Manuscript revised May 7, 2009 Date of the defence June 2, 2009 Monograph Article dissertation (summary + original articles) Faculty Fa...

PURPOSE The purpose of this study was to evaluate the effect of nano-structured alumina surface coating on shear bond strength between Y-TZP ceramic and various dual-cured resin cements. MATERIALS AND METHODS A total of 90 disk-shaped zirconia specimens (HASS CO., Gangneung, Korea) were divided into three groups by surface treatment method: (1) airborne particle abrasion, (2) tribochemicalsil...

OBJECTIVES This study evaluated the effect of three different surface conditioning methods on the bond strength of a Bis-GMA based luting cement to six commercial dental ceramics. METHODS Six disc shaped ceramic specimens (glass ceramics, glass infiltrated alumina, glass infiltrated zirconium dioxide reinforced alumina) were used for each test group yielding a total number of 216 specimens. T...