Sensitivities of cirrus cloud radiative forcing as well as solar albedo and infrared emittances to ice crystal size spectrum and ice crystal shape were examined using a coupled cloud-radiation model. The singleand bi-modal crystal size distribution were considered and simulated based on field measurements. Optical parameters of ice crystals shaped as hexagonal columns and random Ž . polycrystal...

Across the world, many ice active bacteria utilize ice crystal controlling proteins for aid in freezing tolerance at subzero temperatures. Ice crystal controlling proteins include both antifreeze and ice nucleation proteins. Antifreeze proteins minimize freezing damage by inhibiting growth of large ice crystals, while ice nucleation proteins induce formation of embryonic ice crystals. Although ...

The precipitation of struvite (MgNH4PO4.6H2O) from wastewater streams simultaneosuly recovers nitrogen (N) and phosphorus (P) for reuse as fertilisers. Struvite crystallisation is controlled by pH, saturation index, temperature other ions in the solution (e.g., Ca2+, Mg2+ CO32?). This work studies effect pH on removal via quality resulting precipitate product (i.e., crystal size, morphology pur...

      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 t...

Freeze concentration freezes or crystallises the water molecules out as ice crystals and leaves behind a highly concentrated solution. In conventional suspension freeze concentration where ice crystals formed as a suspension in the mother liquor, separation of ice is difficult. The size of the ice crystals is still very limited which will require usage of scraped surface heat exchangers, which ...

Records of discharge of rivers draining Alpine basins with between 0 and 70% ice cover, in the upper Aare and Rhône catchments, Switzerland, for the period 1894–2006 have been examined together with climatic data for 1866–2006, with a view to assessing the effects on runoff from glacierized basins of climatic warming coupled with glacier recession following the Little Ice Age maximum. Annual ru...

Ice crystals nucleate and grow when a water solution is cooled below its freezing point. The growth velocities and morphologies of the ice crystals depend on many parameters, such as the temperature of ice growth, the melting temperature, and the interactions of solutes with the growing crystals. Three types of morphologies may appear: dendritic, cellular (or fingerlike), or the faceted equilib...

the precipitation of calcium carbonate by bacteria isolated from submerged fixed-film bioreactorused for the treatment of urban wastewater in both natural and artificial media was studied. however, carbonate precipitation was detected only when the bacteria grow in media added with calcium. precipitation took place rapidly, and crystal formation began 3 d after inoculation and the percentage of...