Objectives: (1) To understand what hardness is, and how it can be used to determine material properties. (2) To conduct typical engineering hardness tests and be able to recognize commonly used hardness scales and numbers. (3) To be able to understand the correlation between hardness numbers and the properties of materials (4) To learn the advantages and limitations of the common hardness test ...

This paper reconsiders the deployment of synchronous optical networks (SONET), an optimization problem naturally expressed in terms of set variables. Earlier approaches, using either MIP or CP technologies, focused on symmetry breaking, including the use of SBDS, and the design of effective branching strategies. This paper advocates an orthogonal approach and argues that the thrashing behavior ...

This paper reconsiders the deployment of synchronous optical networks (SONET), an optimization problem naturally expressed in terms of set variables. Earlier approaches, using either MIP or CP technologies, focused on symmetry breaking, including the use of SBDS, and the design of effective branching strategies. This paper advocates an orthogonal approach and argues that the thrashing behavior ...

A combination of photocatalytic oxidation experiments and quantum mechanical calculations was used in order to describe the mechanism and the nature of the photocatalytic oxidation reactions of dinitronaphthalane isomers and interprete their reactivities within the framework of the Density Functional Theory (DFT). The photocatalytic oxidation reactions of three dinitronaphthalene isomers, 1,3-d...

This study investigated the effects of solvents’ polarities on the geometry and electronic properties of 2-(2-nitrovinyl) furan, (NVF). The investigation was carried via theoretical approach, using an ab-initio [Hartree Fock (HF/6-31G*)] and Density Functional Theory (DFT/B3LYP/6-31G*).The properties investigated are optimized structures, energy gaps (ELUMO – EHOMO) and as...

A human can perceive the hardness of an object by tapping its surface. We compared the ranked subjective hardness values and physical properties of objects, including their stiffness, viscosity, density, and Shore hardness, and the frequencies and time constants of the natural vibrations caused by tapping. The stiffness, frequency, and viscosity exhibited a relatively strong positive correlatio...

PURPOSE Light units used for polymerization of resin composites are subject to deterioration with age, and frequent maintenance is required to maintain optimal efficacy. This study examined the efficacy of quartz-tungsten-halogen light units in private dental offices in Toronto for polymerization of resin composites. MATERIALS AND METHODS One hundred dental offices met all selection criteria ...

OBJECTIVES To establish if there is an association between ground hardness and injury risk in junior cricket. DESIGN Nested case-series of players who played matches on specific grounds with objective ground hardness measures, within a prospective cohort study of junior community club cricket players. METHODS Monitoring of injuries and playing exposure occurred during 434 matches over the 2...