1. It is possible to fractionate gelatin by means of reprecipitation at 23 degrees C. of a salt-free solution of pH 4.7 into two fractions, one of which is soluble in water at any temperature, and a second one which does not dissolve in water even when heated to 80 degrees C. 2. The proportion of the soluble fraction in gelatin is much greater than of the insoluble one. 3. The insoluble fractio...

The relative stability of -helix and -sheet secondary structure in the solid state was investigated using poly(L-alanine) (PLA) as a model system. Protein folding and stability has been well studied in solution, but little is known about solid-state environments, such as the core of a folded protein, where peptide packing interactions are the dominant factor in determining structural stability....

Size reduction of high energy materials such as 1, 3, 5, 7-tetranitro- 1, 3, 5, 7-tetraaza cyclooctane (HMX) has considerable influences on improving their explosive characteristics. In this study, nanosized HMX par‌ticles were produced using ultrasonically reprecipitation method by applying water as a safe and accessible antisolvent instead of unsafe conventional methods. SEM photographs revea...

Distinctive sediments containing mostly quartz, kaolinite, and both detrital authigenic hematite goethite blanket ~5000 km of the Atlantic coast Brazil from Rio de Janeiro all way to mouth Amazon River. The represent a significant period continental erosion followed by renewed weathering. Here we present (UTh)/He ages goethites hematites collected six weathering profiles in Espírito Santo, sout...

Abstract The role of nanoparticle gold in the formation deposits has long been debated. Evidence support this process is generally limited to epithermal-, Carlin- and seafloor massive-sulfide-type where nanoparticles are associated with primary fluid related processes. At Kenty orogenic deposit Ontario, Canada, remobilized from early pyrite through secondary coupled dissolution-reprecipitation ...

The aim of this research was to analyze the crystallites poly(9,9’-dihexylfluorene) (PHF). pristine polymer synthesized through Suzuki cross-coupling polycondensation and reprecipitation method. Through XRD measurements it possible determine semicrystalline diffraction pattern which after structural adjustment by Le Bail method showed orthorhombic unit cells with average sizes 43.86 Å. Scanning...

Many studies of lignins in solution invoke association and aggregation phenomena to explain their solution behavior (e.g., reprecipitation onto pulp fibers, condensation, etc.). Following their colloidal (apparent) molecular weights in solution as a function of time allows us to explore observable dissociation phenomena. These measurements were carried out using multiple angle laser light scatt...

Ostwald ripening, the interfacial-energy-driven dissolution and reprecipitation of solutes, becomes an increasingly significant problem for nanoparticle formulations. We present the first quantitative study of Ostwald ripening for nanoparticle dispersions. The Lifshitz-Slyozov-Wagner (LSW) theory of particle growth driven by diffusion is applied to study -carotene nanoparticles with sizes of O ...