The engineering properties of the lunar regolith reflect aspects of the original parent rock and the consequences of hypervelocity meteor bombardment. Compared to the Earth the geologic nature of the lunar regolith is quite distinct. On scales relevant to machinery, heterogeneity with respect to size and composition is much higher. But the total range in composition is much more restricted. Bot...

Antlers constitute the only mammal model for limb regeneration. A number of factors affect antler regeneration. In this review, we examine such factors and the potential consequences for organ regeneration. As body mineral stores are depleted to grow antlers, physiological exhaustion is shown in the mineral composition, mechanical performance and, according to preliminary studies, porosity of t...

The groundmass of lamproites from Middle Table Mountain, Leucite Hills, Wyoming, is characterized by the presence of potassium zirconium silicates and Sr{e-rich perovskite. Two intimately intergrown K-Z silicates of differing Ti content are recognizable by cathodoluminescence t chniques. Both are similar in composition to wadeite. Intergrown with these minerals is a phase having the composition...

Cotton is an important crop in the world and is a major source of oil for human consumption and cotton meal for livestock. Cottonseed nutrition (seed composition: protein, oil, and minerals) determines the quality of seeds. Therefore, maintaining optimum levels of cottonseed nutrition is critical. Physiological and genetic mechanisms controlling the levels of these constituents in cottonseed ar...

Copiapite-group minerals of the general formula AR4(SO4)6(OH)2d nH2O, where A is predominantly Mg, Fe , or 0.67Al, R is predominantly Fe, and n is typically 20, are among several secondary hydrous Fe sulfates occurring in the inactive mine workings of the massive sulfide deposit at Iron Mountain, CA, a USEPA Superfund site that produces extremely acidic drainage. Samples of copiapite-group mine...

[1] The validity of recent identification of various hydrated minerals (kieserite, gypsum, hexahydrite, nontronite, chamosite, and montmorillonite) on Mars was assessed by exposing these minerals to simulated Martian surface conditions of atmospheric composition and pressure, temperature, and ultraviolet light irradiation. When exposed to such conditions the hydrated minerals exhibit in general...

PURPOSE Current urinary stone analysis techniques are limited in their abilities to simultaneously characterize composition and structure. Laboratory techniques such as IRS and x-ray diffractometry require small powdered samples for analysis, rendering composition results dependent on the choice of sample and its preparation. We investigated the application of x-ray CS analysis to identify topo...

Aims Early reports of micro computed tomography (micro CT) of urinary stones showed non-overlapping ranges of x-ray attenuation values for most minerals. However, extended work in our laboratory has shown that size of stone fragments and scanning parameters can each influence the apparent x-ray attenuation value of minerals. The purpose of the present study was to test the correlation of minera...