Understanding the mechanism of cracking during the drying of aqueous colloidal dispersions is important to preventing film failure. While most of the reported work has dealt with stable aqueous dispersions, a few studies have focused on flocculated systems. The latter especially assumes importance because the role of particle packing in the mechanism of cracking is not completely understood. In...

Red clump giants in the Galactic bulge are approximate standard candles and hence they can be used as distance indicators. We compute the proper motion dispersions of RCG stars in the Galactic bulge using the proper motion catalogue from the second phase of the Optical Gravitational Microlensing Experiment (OGLE-II, Sumi et al. 2004) for 45 fields. The proper motion dispersions are measured to ...

The objective of the study was to enhance the solubility of carvedilol phosphate and to formulate it into non-effervescent floating tablets using swellable polymers. Solid dispersions (SD) of carvedilol were prepared with hydrophilic carriers such as polyvinylpyrrolidone and poloxamer to enhance solubility. Non-effervescent floating tablets were prepared with a combination of optimized solid di...

We propose to determine the stellar velocity dispersions of globular clusters in the outer halo of the Milky Way in order to decide whether the dynamics of the Universe on large scales is governed by dark matter or modified Newtonian dynamics (MOND). We show that, for a number of Galactic globular clusters, both the internal and the external accelerations are significantly below the critical ac...

Hypothesis Silica nanoparticles can be dispersed in organic solvents (organosols) using surfactants, such as didodecyldimethylammonium bromide (DDAB). DDAB analogues prepared with lathanide tetrahalide counterions, either a high-magnetic moment ion (HoCl3Br, DDAH) or low-magnetic moment one (NdCl3Br, DDAN), are expected to produce charged particles but only DDAH-stabilized dispersions are expec...

Accurate approximate relations for the e}ective elastic moduli of two! and three!dimensional isotropic dispersions are obtained by truncating\ after third!order terms\ an exact series expansion for the e}ective sti}ness tensor of d!dimensional two!phase composites "obtained in the _rst paper# that perturbs about certain optimal dispersions[ Our third!order approximations of the e}ective bulk mo...

Dispersions of poly(methyl methacrylate) (PMMA) latexes were prepared in a low dielectric, nonpolar solvent (dodecane) both with and without the oil-soluble electrolyte, tetradodecylammonium-tetrakis(3,5-bis(trifluoromethyl)phenyl)borate. For dispersions with a high concentration of background electrolyte, the latexes become colloidally unstable and sediment in a short period of time (<1 h). Th...

Solid dispersions of the poorly water soluble drug dexamethasone and newly synthesized chitosan derivatives (chitosan succinate, CS, and chitosan phthalate, CP) were prepared by spray drying. The resulting microspheres were evaluated in terms of their drug loading or encapsulation efficiency as well as drug release profile. Differential scanning calorimetry (DSC), X-ray powder diffraction (XRPD...

The mechanisms by which pulmonary surfactant protein B (SP-B) affects the surface activity of surfactant lipids are unclear. We have studied the peptide/lipid interactions of the amino-terminal amphipathic domain of SP-B by comparing the secondary conformations and surface activities of a family of synthetic peptides based on the native human SP-B sequence, modified by site-specific amino acid ...

Gel sheets prepared from high-viscosity aqueous dispersions of hydrolyzed starch-polyacrylonitrile graft copolymers absorb several hundred times their own weight in water. Viscosity of the disperSiOns can be . reduced to low levels by mechanical shear before the films are cast to give solutions which yield water'soluble .films. These soluble films can be readily cross-linked to again form highl...