Salt crystallization can severely damage anisotropic foliated rocks, therefore it is necessary to have an understanding of crystallization process. The present study was conducted to investigate the effect of salt crystallization on Arakʾs calcareous slates, as anisotropic rocks of Mesozoic. To compare salt crystallization weathering (EN 12370 norm was used up to 30 cycles) with natural weather...

During the 2010 Deepwater Horizon oil well blowout in the Northern Gulf of Mexico (GoM), the application of 6.97 million litres of chemical dispersants was used at the well-head and on the sea surface to promote oil degradation and weathering of the Mississippi Canyon 252 (MC252) crude oil. Chemical dispersants encourage microbial degradation by increasing the surface area of the spilled oil, w...

Physicochemical analysis in the microscopic sense is a critical assessment of monitoring the polymeric materials under a weathering test, and it links the accelerated laboratory test with the outdoor performance results for a long-term durability. Here, by taking an experimented example for vinyl siding after an outdoor weathering test in Okinawa, Japan for 17 years and a QUV accelerated weathe...

Special Equipment: Artificial weathering devices (several wheels and QUV, Global UV test system), natural exposure site. UV-visible spectrophotometer, IR spectrophotometer linked with a IR microscope, thermal analysis equipment (DSC), fluorescence microscope, chromatographical equipment, goniometer,…. Improvement of durability of coated wood (especially for transparent coatings) Study of the wo...

In this study, a green composite was produced from Oil Palm Trunk Lumber (OPTL) by impregnating oil palm shell (OPS) nanoparticles with formaldehyde resin. The changes of physical, mechanical and morphological properties of the OPS nanoparticles impregnated OPTL as a result of natural weathering was investigated. The OPS fibres were ground with a ball-mill for producing nanoparticles before bei...

STATEMENT OF PROBLEM Maxillofacial prostheses are serviceable for approximately 6 months, after which they need to be refabricated because of the deterioration of color and physical properties. PURPOSE This third article in a 3-part series evaluated the color stability of commonly used colorant-elastomer combinations as a result of exposure to weathering. METHODS AND MATERIAL Fifteen specim...

Chemical weathering and the ensuing atmospheric carbon dioxide consumption has long been considered to work on geological time periods until recently when some modelling and natural records have shown that the weathering-related CO2 consumption can change at century to glacial-interglacial time scale. Last glacial to interglacial transition period is a best test case to understand the interplay...

This study examined the color stability of painted Norway spruce (Picea abies) samples subjected to natural and accelerated weathering, using Duncan’s tests and correlation analyses. The following effects were studied: (1) the different initial roughness of the wood; (2) use of transparent or lightly-pigmented top-coat layers; and (3) the presence of the final water-repellent layer. Natural wea...

The aging process of material is an unavoidable natural phenomenon. Thus, several CG techniques for representing aging phenomena, such as metal corrosion and stone weathering, have been studied. In this paper, we propose a visual simulation method of wood weathering. First, we present the wood model in consideration of branching. Then, we give the algorithm for representing the weathering of th...

Effects of accelerated and natural weathering on the molecular weight distribution (MWD) and crystallinity of polypropylene (PP) in wood plastic composites (WPC) were investigated. The composites were produced from pine fibers (60%) and PP (40%). Prolonged weathering caused an increase in wood degradation and erosion thereby leaving cracks and ‘‘pits’’ on the surface. Pyrolysis gas chromatograp...