We studied electrostatic charging of ice films induced by the impact of 1−200-keV Ar+ ions and their subsequent discharging postirradiation. We derived the positive surface electrostatic potential from the kinetic energy of sputtered molecular ions and with a Kelvin probe. Measurements were performed as a function of film thickness, temperature, and ion energy. Charging requires that the projec...

The radiance distribution of light scattered by randomly oriented ice crystals differs fundamentally from the radiance distribution of light scattered by spherical raindrops or by preferentially oriented ice crystals. A formalism for light scattering by randomly oriented crystals is given and applied to four examples, among them the circular 22° halo and the antisolar halospot, the latter being...

Cholesterol gallstones occur when at least three simultaneous defects are present: (i) cholesterol supersaturation of bile with formation of cholesterol-rich unstable vesicles; (ii) accelerated crystallisation of cholesterol in bile owing to a defect of crystallisation inhibiting or an abundance of crystallisation promoting factors; and (iii) prolonged bile stasis due to decreased gall bladder ...

Cholesterol gallstones occur when at least three simultaneous defects are present: (i) cholesterol supersaturation of bile with formation of cholesterol-rich unstable vesicles; (ii) accelerated crystallisation of cholesterol in bile owing to a defect of crystallisation inhibiting or an abundance of crystallisation promoting factors; and (iii) prolonged bile stasis due to decreased gall bladder ...

Snow crystals consist of many different types of ice particles. Typical radar measurements observe only bulk properties of all types of ice particles present in a radar volume. Due to their difference in cross-section, large particles will reflect more power of the transmitted radar signal than small particles. If small and large particles are present in the same radar volume with comparable vo...

[1] The Lattice Boltzmann (LB) method can be used to simulate aspects of chemical reactions such as mineral precipitation from a fluid phase or condensation from a vapor phase. The LB method has the advantage of allowing the shape of the condensing phase to evolve depending on local conditions rather than being specified, so that the controls on condensed phase grain shape can be studied simult...

nanocrystalline hydroxyapatite was precipitated from calcium hydroxide and phosphoric acid. effects of precipitation temperature and different calcium to phosphate ratios (ca/p) on the obtained powders were investigated. characteriza-tion of the powders was performed using xrd and ftir spectra, scanning electron microscopy, and transmission electron microscopy. increase in precipitation tempera...

The monsoon is a fundamental component of Earth's climate. The Pliocene warm period is characterized by long-term global cooling yet concurrent monsoon dynamics are poorly known. Here we present the first fully quantified and calibrated reconstructions of separate Pliocene air temperature and East Asian summer monsoon precipitation histories on the Chinese Loess Plateau through joint analysis o...

a r t i c l e i n f o Keywords: South American summer monsoon oxygen isotopes precessional forcing abrupt climate change lake sediments Oxygen isotope ratios of authigenic calcite (δ 18 O cal) measured at annual to decadal resolution from Laguna Pumacocha document Andean precipitation variability during the last 11,200 years. Modern limnological data show that Pumacocha δ 18 O cal reflects the ...