By means of multiscale hierarchical modeling we study the real time evolution of low-molecular-weight polystyrene, below the glass transition temperature, in contact with its solvent, toluene. We observe two concurrent phenomena taking place: (1) the solvent diffuses into the polymer by a Case II mechanism, leading to osmotic driven swelling and progressive chain dilution (inside-out mechanism)...

This paper discusses the concept of critical pH for dissolution of enamel in oral fluids. The critical pH does not have a fixed value but rather is inversely proportional to the calcium and phosphate concentrations in the solution. The paper also discusses why teeth dissolve in acid, why remineralization of white-spot caries lesions is possible and why remineralization of teeth eroded by acid i...

OBJECTIVE The aim of this study was to evaluate the tissue dissolution efficacy of four root canal irrigation solutions (sodium hypochlorite [NaOCl], chlorhexidine gluconate [CHX], Octenidine [OCT], and QMix 2in1) on bovine pulp tissue. MATERIALS AND METHODS Fifty bovine pulp tissue samples, each weighing 6.55 mg, were prepared and randomly divided into four experimental groups and one contro...

BACKGROUND Lignocellulosic biomass is highly recalcitrant and various pretreatment techniques are needed to facilitate its effective enzymatic hydrolysis to produce sugars for further conversion to bio-based chemicals. Ionic liquids (ILs) are of interest in pretreatment because of their potential to dissolve lignocellulosic materials including crystalline cellulose. RESULTS Four imidazolium-b...

Cellulose is a future major source of materials and biofuel but its extraction and its chemical or enzymatic treatments are difficult, polluting and inefficient tasks. The accessibility of the reagents to cellulose chains is indeed limited. Classical evocated reasons for this lack of accessibility are pore structure, tight hydrogen bond arrays, crystallinity and presence of resistant materials ...

Depiction of mineral solubilities on isobaric isothermal bulk composition pH diagrams facilitates considerably the conelation of the consequences of irreversible reactions with the solubilities of incongruent reaction products. The reaction-progress variable (f) is related to the bulk composition variable (r1", which has units of moles (kg HzO)-r) by the stoichiometries of the irreversible reac...

Biodegradable printed circuit boards based on water-soluble materials are demonstrated. These systems can dissolve in water within 10 mins to yield end-products that are environmentally safe. These and related approaches have the potential to reduce hazardous waste streams associated with electronics disposal.

Hydrogen gas is generated by the electrolysis of liquid ammonia which has high hydrogen capacity of 17.8 mass%. The metal amides are used as supporting electrolytes to dissolve the amide ion in liquid ammonia. The results presented here indicate that liquid ammonia is promising as an energy medium for hydrogen storage and generation.

Yeast heat shock protein 104 (Hsp104), the only known eukaryotic disaggregase, remodels both disordered protein aggregates and cross-β sheet amyloids. To handle this diverse clientele, DeSantis et al. report that Hsp104 hexamers use distinct mechanisms-individual subunits are able to dissolve disordered aggregates, but global subunit cooperativity is required to untangle amyloids.

The early stages of gas evolution during electrolytic hydrogen production on Au electrodes are characterized by in situ transmission electron microscopy. The results demonstrate that reaction product molecules initially dissolve into solution and then nucleate near, but not on, the electrodes. The gas subsequently wets the electrodes and its successive evolution is governed by triple phase boun...