1566-7367/$ see front matter Crown Copyright 2 doi:10.1016/j.catcom.2010.01.010 * Corresponding authors. Tel./fax: +86 (21)6425382 E-mail addresses: [email protected] (J. Ren), w Wang). A novel carbon-based solid-acid catalyst was simply prepared for the first time by the thermal treatment of p-toluenesulfonic acid (TsOH) with D-glucose at 180 C in a sealed autoclave and it was proved to ha...

A chiral, crown-ether-functionalized bisurea gelator forms supramolecular gels in ionic liquids. The resulting ionogels show a remarkably high thermal stability with gel-sol transition temperatures (T(gs)) reaching more than 100 °C. The mechanical strength of these ionogels is surprisingly high and even comparable to that of cross-linked protein fibres. Furthermore, the ionogels exhibit rapid s...

Clinical crown lengthening is a periodontal resective procedure aimed at partial removal of supporting periodontal tissues to increase exposure of coronal tooth structure. Crown-lengthening involves various techniques, including gingivectomy or gingivoplasty, apically positioned flap procedure, which may include osseous resection and forced tooth eruption with or without fiberotomy. Soft-tissue...

‘Thermal Overload’ can be defined as a condition under which design threshold values such as the surface temperature of combustion chamber components is exceeded. In this paper, a low λ value is identified as the most probable cause of voluminous flame production, resulting in high surface temperatures of engine components, i.e., engine thermal overload. Test results indicated that the flame be...

In the range 308-90 K single crystals of [Ni(H(2)O)(6)](NO(3))(2)·(15-crown-5)·2H(2)O continue to diffract well as they undergo three phase transitions. Structures have been determined at 28 different temperatures; data were collected at six more but could not be refined satisfactorily. The transitions identified structurally are in good agreement with those found by thermal analysis. Phase I (...

OBJECTIVE When successive restorative procedures (e.g., porcelain veneers, interdental resin composite restorations, and endodontic treatment) are carried out on the same tooth, significant effects on crown flexure can be expected. METHOD AND MATERIALS Dentin-bonded porcelain veneers (experimental group) were assessed in vitro using functional and cyclic thermal loads. They were compared to n...

This guide recommends best practice used for short-term accelerated thermal cycling as a method for assessing solder joint reliability. Three techniques (shear testing, and electrical continuity measurements, complemented with microstructural investigations) are described. NPL Report CMMT(A)274 © Crown copyright 2000 Reproduced by permission of the Controller of HMSO

The coefficient of thermal expansion of core and veneer porcelains for all ceramic crowns must be compatible to prevent formation of stresses during the firing cycles. The purpose of this study was to use a thermal shock test to evaluate the crazing resistance of six all-ceramic crown systems. The systems tested were: Vita In-Ceram, Vita Hi-Ceram, Dicor veneered with Vitadur N, magnesia core ve...