This paper is concerned with formal aspects of the logic of theory change, :and in particular with the process of shrinking or contracting a theory to eliminate a proposition. It continues work in the area by the authors and Peter Gi~rdenfors. The paper defines a notion of "safe contraction" of a set of propositions, shows that it satisfies the Gi~rdenfors postulates for contraction and thus ca...

Abstract Polyvinyl butyral is used in safety glass interlayers, mainly car windshields. Legislative regulations require a recycling of cars after their lifetime and therefore also glass. This causes the availability recycled polyvinyl butyrate (r-PVB) originated from interlayers. Due to deteriorated optical properties, such as transparency, unknown amounts plasticizers, it challenging reuse mat...

background: recently, there have been many studies on the harmful effects of radiation and the regulations on radiation safety have been toughened both at the in nation and abroad. this study aims to identify the perceptions and actions taken as to radiation safety, and the degree of knowledge related to radiation held by the radiologists working in large hospitals. materials and methods: the r...

Glass material is largely used in buildings and facilities due to various motivations. Besides, glass still represents a vulnerable component for building occupants. Careful attention required especially elements that may be subjected extreme design loads, such as impact, vibrations, etc. Among approaches techniques prevent danger people case of breakage, multilayer antishatter safety films (AS...

Abstract Laminated glass beams without metallic or polymeric reinforcements generally lack post-breakage strength and ductility. This paper aims to perform a comparative study by testing five different fully transparent laminated beam designs in order see how parameters such as the number thickness of sheets (3 x 10 mm 5 6 mm), interlayer material (PVB Clear SentryGlas), thermal treatment (anne...

Abstract In the present paper, optical anisotropy effects in architectural glass are evaluated using digital image processing. Hereby, thermally toughened panes were analyzed quantitatively a circular polariscope. Glass subjected to externally applied stresses or residual becomes birefringent. Polarized light on birefringent materials causes interference colors (iridescence), referred as anisot...

BACKGROUND In the recent past, the Russian Federation has seen a considerable increase in HIV caseload. A high level committee was formed to assess the status of dental infection control and safety (IC&S) in Russia. This article is one of the outcomes to assess the status of IC&S and is the research of a doctoral student (PhD) in public health. PURPOSE To assess needs in Dental Infection Cont...