In the standard cold dark matter (CDM) theory of cosmic structure formation, CDM particles are assumed to be collisionless. The actual identity and microscopic nature of CDM is still unknown, however. It is important, therefore, to explore the consequences of varying this underlying assumption about CDM in the hope that astronomical observations can be used to place meaningful constraints. It h...

For a linear random field (linear p-parameter stochastic process) generated by a dependent random field with zero mean and finite qth moments (q > 2p), we give sufficient conditions that the linear random field converges weakly to a multiparameter standard Brownian motion if the corresponding dependent random field does so. 2000 Mathematics subject classification: 60F17, 60G15.

AIM This study evaluated the in vitro effect of 35% hydrogen peroxide (HP) on surface enamel change when activated with different light curing units (LCUs). MATERIALS AND METHODS Enamel blocks (4 × 4 × 2 mm) were obtained from bovine incisors. The initial microhardness of the enamel was determined for each specimen. After this enamel blocks were randomly divided into four groups (n = 10) and ...

OBJECTIVES The aim of this study was to evaluate the effects of different light sources and curing time on the degree of conversion and microhardness of two surfaces within a nanofilled composite resin. METHODS Four experimental groups (n=10) were formed in accordance with the light source (quartz-tungsten halogen (QTH - 600mW/cm(2)), or light-emitting-diode (LED - 800mW/cm(2))) and the time ...

OBJECTIVE The aim of this study was to determine the effects of light intensity and type of light unit (quartztungsten-halogen [QTH] or light-emitting diode [LED]) on the hardening of various resin cements and a resin composite restorative. METHODS Disk specimens were prepared from 4 dual-cured resin cements (Variolink II, Calibra, Nexus 2 and RelyX ARC). Two QTH light-curing units (Visilux 2...

objective: shear bond strength is an important property inherent to the durability of tooth-colored restorative materials namely composite resins. it has been years that halogen light sources have been used for polymerization of composite resins. in recent years light emitting diodes (led) have been introduced for this purpose. with respect to their longer bulb life, needless of a filter and no...

We prove that if q 5 is an integer, then every qth power of an integer contains at least 5 nonzero digits in its binary expansion. This is a particular instance of one of a collection of rather more general results, whose proofs follow from a combination of refined lower bounds for linear forms in Archimedean and non-Archimedean logarithms with various local arguments.