In the k-dispersion problem, we need to select k nodes of a given graph so as to maximize the minimum distance between any two chosen nodes. This can be seen as a generalization of the independent set problem, where the goal is to select nodes so that the minimum distance is larger than 1. We design an optimal O(n) time algorithm for the dispersion problem on trees consisting of n nodes, thus i...

Using a broadband through-transmission technique, the attenuation coefficient and phase velocity spectra have been measured for a set of multi-wall carbon nanotube (MWCNT)-nylon composites (from pure nylon to 20% MWCNT by weight) in the ultrasonic frequency band from 4 to 14 MHz. The samples were found to be effectively homogeneous on spatial scales from the low end of ultrasonic wavelengths in...

In this work, the dispersive effect of low molecular weight sodium polyacrylate (PAAS) on serpentine, and its dispersion mechanism were systematically investigated through zeta potential measurements, micro and batch flotation as well as adsorption tests. At pH 5, where flotation of iron sulphide was routinely performed, pyrite and serpentine minerals were oppositely charged, and therefore they...

Blends of collagen dispersion (COL) with poly(vinyl alcohol) (PVA) in different weight ratios were investigated by oscillatory rheometry, Fourier transform-infrared spectroscopy and scanning electron microscopy. It was found that even with 80% of PVA, the COL/PVA blends behaved more like collagen dispersion than pure PVA solution in the dynamic thermal and frequency processing, for instance, a ...

The purpose of this investigation was to prepare a gastro retentive drug delivery system of famotidine tablets. Floating tablets of famotidine were prepared employing lipid solid dispersion spray drying technique with gelucire 50/13 and compritol 888 along with HPMC K100M, lactose, sodium bicarbonate and citric acid. The floating tablets were evaluated for uniformity of weight, hardness, friabi...

This paper provides a current overarching review of several commonly used carbon nanomaterials applied within cementitious composites. It reviews the typical weight percentages mixes from researchers in field and assesses application these on mechanical properties. Mechanical properties covered include compressive strength, flexural strength tensile as well elastic modulus. was clear this exten...

tio 2 nanoparticles (nps) might be considered as the most important photosensitizer due to high photocatalytic and sonocatalytic efficiency, low toxicity, excellent biocompatibility, low cost and high chemical stability. tio 2 -nps normally tend to aggregate in physiological medium and which results to decreased cell viability and inducing expression of stress-related genes. thus dispersion and...