Chemical gardens are mineral aggregates that grow in three dimensions with plant-like forms and share properties with self-assembled structures like nanoscale tubes, brinicles, or chimneys at hydrothermal vents. The analysis of their shapes remains a challenge, as their growth is influenced by osmosis, buoyancy, and reaction-diffusion processes. Here we show that chemical gardens grown by injec...

Energetic oxygen precipitation is one possible explanation for the auroral molecular hydrogen emissions observed by the Voyager ultraviolet spectrometer. These ions deposit their energy in the Jovian thermosphere by means of ionization, dissociation, excitation, and heating processes. The photochemistry of both the neutral gas and the ionosphere is altered by the influx of atomic oxygen. The au...

Heavy metal pollution has become one of the most serious environmental problems today. The treatment of heavy metals is of special concern due to their recalcitrance and persistence in the environment. In recent years, various methods for heavy metal removal from wastewater have been extensively studied. This paper reviews the current methods that have been used to treat heavy metal wastewater ...

The removal of ammonium (NH(4)(+)) and phosphate (PO(4)(3-)) from supernatant of anaerobic digestion by magnesium ammonium phosphate (MAP) formation was studied. To be able to find out the loss of NH(4)(+) by its transformation to NH(3), rates of NH(4)(+) removal by aeration and by MAP formation combined with aeration were compared. NH(4)(+) removal by aeration was found to be insignificant. Th...

Nano-sized materials are new substances quickly developed and generally measured as 1 to 100 nm size in one dimension. At a nanometer scale, the surface area increases hastily as particle size decreases, as a result, the electromagnetic, thermal, optical, and mechanical properties of nanomaterials modify. In recent years, manganese oxides (MnO2) have concerned considerable research interest due...

Every year, millions of people are suffering from bone defect arising from trauma, tumor or bone diseases. Therefore, there is a growing need for the development of biocomposites with excellent bioactivity and compatibility. In this study, nano-hydroxyapatite was elaborated by using polyvinyl alcohol (PVA) and polyvinylpyrrolidone (PVP) under mild temperature condition. Comparison with pure nan...

The organic deposition particularly asphaltenes has many detrimental effects on the oil industries, such as plugging in pipelines, wellbore and facilities and subsequently, considerable reduction in well productivity.Asphaltenes are the most polar fractions, which they have been dispersed as colloidal clusters in crude oil. The accumulation of these clusters lead to the flocculation of colloids...

A series of comparative studies on the chemical and biological characterizations of the ovine lutropin subunits and their recombinants prepared by a countercurrent distribution (CCD) procedure and a salt precipitation method is presented. The salt precipitation Method B (0.1 M acetate and 3 M NaCl) gave a low yield of pure subunits and the subunits thus prepared recombined poorly to form a prod...

in this study, hydroxyapatite (ha) nanocrystals have been synthesized via chemical precipitation technique. diammonium hydrogen phosphate and calcium nitrate 4-hydrate were used as starting materials and sodium hydroxide solution was used as the agent for ph adjustment. the powder sample was evaluated by techniques such as scanning electron microscope, transmission electron microscope, fourier ...