We have performed approximately 20-40 ns of molecular dynamics (MD) simulations for the generation 8 PAMAM dendrimer in explicit water under varying pH conditions to study the structure of the dendrimer (approximately 156,738 atoms at low pH). This is the first report of such a long MD simulation of a larger generation PAMAM dendrimer including the effect of salt and counterions with explicit w...

A significant fraction of anthropogenic carbon dioxide (CO2) released to the atmosphere is absorbed by the oceans, leading to a range of chemical changes and causing ocean acidification (OA). Assessing the impact of OA on marine ecosystems requires the accurate detection of the rate of seawater pH change. This work reports the results of nearly 3 years of continuous pH measurements in the Medit...

BACKGROUND The purpose of this study was to evaluate the effect of different pH solutions on the solubility and wear resistance of Silorane and dimethacrylate resin based composite restorative materials. MATERIALS AND METHODS Two different resin based restorative materials (Filtek Silorane P90 and hybrid composite Z100) were tested. Different pH solutions (2.5 and 5) also were used. A total o...

Silica scaling potential from geothermal waters puts limits on to what extent the heat from the water can be extracted. Once the waters become over-saturated with respect to amorphous silica, the handling of such waters becomes problematic. Many methods have been proposed to address this problem. One of them is aging the geothermal waste water allowing monomeric silica in excess of amorphous si...

The classical Voorn-Overbeek thermodynamic theory of complexation and phase separation of oppositely charged polyelectrolytes is generalized to account for the charge accessibility and hydrophobicity of polyions, size of salt ions, and pH variations. Theoretical predictions of the effects of pH and salt concentration are compared with published experimental data and experiments we performed, on...

Whey proteins have wide acceptance and use in many products due to their beneficial nutritional properties. To further increase the amount of whey protein isolates (WPI) that may be added to products such as extruded snacks and meats, texturization of WPI is necessary. Texturization changes the folding of globular proteins to improve interaction with other ingredients and create new functional ...

Chlorine is used as disinfection agent in public swimming pools, but also reacts with organic matter in the water forming chlorinat ed disinfection by-products. In order to evaluate the effect of choice of pHsetpoint in the pool we investigated the effect of chlorination of artificial body fluid analogue at different pH-values between 6 and 8. The formation of trihalomethans, haloacetic acids a...

The physiological responses of 1- to 2-year-old rainbow trout to low pH are dependent on the environmental calcium concentration. Trout, maintained for 5 days in moderately hard water ([Ca2+] = 1.6-2.7 m-equiv/l) at a mean pH of 4.3, developed a major blood acidosis but exhibited only a minor depression in plasma ion levels. In acidified soft water ([Ca2+] = 0.3 m-equiv/l), only a minor acidosi...

Si and its oxide are nonpoisonous materials, and thus, it can be taken for medical effects. We have developed a method of generation of hydrogen by use of reactions of Si nanopowder with water in the neutral pH region. Si nanopowder is fabricated by the simple bead milling method. Si nanopowder reacts with water to generate hydrogen even in cases where pH is set at the neutral region between 7....

Water activity, temperature and pH are determinants for biotic activity of cellular systems, biosphere function and, indeed, for all life processes. This study was carried out at high concentrations of glycerol, which concurrently reduces water activity and acts as a stress protectant, to characterize the biophysical capabilities of the most extremely xerophilic organisms known. These were the ...