Shear induced particle migration of 2 μm diameter spherical colloidal particles flowing through rectangular capillary tubes (50 μm × 500 μm cross section) is studied by confocal microscopy. The confocal microscope allows imaging of the flowing particles far from the walls of the tube, at particle velocities up to 8000 μm s−1. The particle volume fraction is varied from φ = 0.05–0.34, and the fl...

Multispeckle x-ray photon correlation spectroscopy was employed to characterize the slow dynamics of a suspension of highly charged, nanometer-sized disks. At wave vectors q corresponding to interparticle length scales, the dynamic structure factor follows a form f(q,t) approximately exp([-(t/tau)(beta)], where beta approximately 1.5. The relaxation time tau increases with the sample age t(a) a...

Chitosan nanoparticles have been prepared using an ionic gelation method. The effects of freezedrying, cryoprotectant (D-trehalose) utilisation and ultrasonication time on the mean particle size, size distribution and stability of nanoparticles were investigated. The size distribution results indicated that freeze-drying caused the particles to agglomerate. Addition of the cryoprotectant and ul...

Upon freezing of an aqueous suspension of colloidal particles, ice platelets or dendrites with high aspect ratios are formed that engulf or reject the particles, depending on their size and the velocity of the advancing ice front. As the particles are pushed between the growing crystals, concentrated regions of colloidal particles are formed. Recent experiments have exploited this to create str...

PURPOSE To develop a precisely calibrated, perfectly spherical, stainable, soft, and implantable but nonresorbable particulate embolization material. METHODS Calibrated particles with a trisacryl gelatin polymer core and hydrophilic surface characteristics were obtained by reversed emulsion synthesis followed by application of a wet-sieving technique. Particles were suspended in saline, bottl...

By contrast with photometry (i.e., the measurement of light transmitted through a particle suspension), nephelometry is a direct method of measuring light scattered by particles in suspension. Since the scattered light intensity is directly proportional to the suspended particle concentration, nephelometry is a promising method for recording microbial growth and especially for studying filament...

Using high-speed confocal microscopy, we measure the particle positions in a colloidal suspension under large-amplitude oscillatory shear. Using the particle positions, we quantify the in situ anisotropy of the pair-correlation function, a measure of the Brownian stress. From these data we find two distinct types of responses as the system crosses over from equilibrium to far-from-equilibrium s...

Magnetic particle testing (MT) is the most sensitive method to detect surface cracks in ferromagnetic materials [2]. This method can be executed by mobile equipment or stationary systems [3]. Magnetic particles are used for the visualisation of the surface cracks. The magnetic particles are an iron oxide powder coated with visible or fluorescent paint. They are also called test agent or magneti...

Knowledge of suspension rheology can help in the prediction of its behavior under various flow conditions. Considerable theoretical effort has been made to model the macroscopic properties of suspensions of rigid particles in a Newtonian fluid, but for the most part it has been limited to zero particle Reynolds number. In this paper we investigate the effect of finite particle Reynolds number o...

Reactors based on particle suspensions for the capture, conversion, storage, and use of solar energy as H 2 are projected to be cost-competitive with fossil fuels. In light of this, this review paper summarizes state-of-the-art particle light absorbers and cocatalysts as suspensions (photocatalysts) that demonstrate visible-light-driven water splitting on the laboratory scale. Also presented ar...