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...

Ectomycorrhizal fungi may make a significant contribution to mineral weathering in temperate and boreal forests. It is important to know how this weathering activity will be affected by the changing nutrient demands of forests impacted by global change and nitrogen deposition. This review examines what is known about how plants sense and respond to nutrient demand and discusses the existing lit...

Continental crust rises higher than oceanic crust because it is less dense: It is rich in Si and poor in Mg. However, basalt, which is derived from magma, is denser and has a higher ratio of Mg to Si than the rock that makes up mature continental crust. Cin-Ty Lee et al. argue that chemical weathering alters the composition of continental crust as it ages and helps give it its more buoyant char...

Introduction: We present evidence that space weathering manifests itself at near-ultraviolet wavelengths as a bluing of the spectrum, in contrast with the spectral reddening that has been seen at visible-near-IR wavelengths. This UV bluing often results in a spectral reversal, where surfaces that are bright at visible-near-IR wavelengths are relatively dark at UV wavelengths, and vice-versa. Fu...

Introduction: Chemical weathering and petrologic trends of the martian surface have been estimated from thermal infrared (TIR) spectral models from the Thermal Emission Spectrometer (TES) and Mini-TES on the Spirit and Opportunity rovers [1,2]. Interpretations of chemical data from APXS on the MER rovers and TIR data from TES and the Thermal Emission Imaging System (THEMIS) suggest planet-wide ...

In this study, the salt weathering effects on engineering properties and weight loss potential of three types of granitoid rocks were investigated. Sodium and magnesium sulfates tests were performed on core and aggregate samples. The cyclic salt weathering tests on core samples were done up to 90 cycles, while these tests on aggregate samples were done up to 40 cycles. The results showed that d...

Determination of the postmortem interval (PMI) is crucial for investigating homicide. However, there are currently only limited methods available. Especially, once the PMI exceeds the duration of pre-adult development of the flies with the adult emergence, its determination is very approximate. Herein, we report the regular changes in hydrocarbon composition during the weathering process of the...

Continental crust rises higher than oceanic crust because it is less dense: It is rich in Si and poor in Mg. However, basalt, which is derived from magma, is denser and has a higher ratio of Mg to Si than the rock that makes up mature continental crust. Cin-Ty Lee et al. argue that chemical weathering alters the composition of continental crust as it ages and helps give it its more buoyant char...

Bauxite residue is an alkaline, saline tailings material generated as a byproduct of the Bayer process used for alumina refining. Developing effective plans for the long term management of potential environmental impacts associated with storage of these tailings is dependent on understanding how the chemical and mineralogical properties of the tailings will change during weathering and transfor...

Chemical weathering is a fundamental geochemical process regulating the atmosphere-land-ocean fluxes and earth's climate. It is under natural conditions driven primarily by weak carbonic acid that originates from atmosphere CO2 or soil respiration. Chemical weathering is therefore assumed as positively coupled with its CO2 consumption in contemporary geochemistry. Strong acids (i.e. sulfuric- a...