The thermal conductivity of several amorphous solids is numerically evaluated within the harmonic approximation from Kubo linear-response theory following the formalism developed by Allen and Feldman. The predictions are compared to the results of molecular dynamics (MD) simulations with realistic anharmonic potentials and to experimental measurements. The harmonic theory accurately predicts th...

We study DNA supercoiling in a quantitative fashion by micromanipulating single linear DNA molecules with a magnetic field gradient. By anchoring one end of the DNA to multiple sites on a magnetic bead and the other end to multiple sites on a glass surface, we were able to exert torsional control on the DNA. A rotating magnetic field was used to induce rotation of the magnetic bead, and reversi...

Glass and plastic bead columns coated with antigenic protein molecules were used as an immunological filter for cell populations containing immune cells of relevant specificity. A selective elimination of these immune cells from the passing cell suspension was regularly noted and it approached, in some experiments, complete abolition of the specific immune reactivity of the filtered cell popula...

The geometry of postmortem rough fracture surfaces of porous glass ceramics made of sintered glass beads is shown experimentally to be self-affine with an exponent zeta=0.40+/-0.04, remarkably lower than the "universal" value zeta=0.8 frequently measured for many materials. This low value of zeta is similar to that found for sandstone samples of similar microstructure and is also practically in...

Interand intra-molecular forces are the driving forces responsible for the creation of an interface between a microorganism and a naturally occurring mineral or man-made material. We have used atomic force microscopy to directly measure forces between a Staphylococcus aureus bacterium and each of two materials (silica and polystyrene) in an electrolyte solution. Force “spectra” were collected b...

adsorption and water treatment of ca (ii) and mg (ii) hardness were investigated via adsorption of metal ions onto commercial polyacrylic acid hydrogel beads as a novel sorbent for metal ions (ca2+, mg2+) removal and water treatment. batch equilibrium technique was carried out under the influence of solution ph, contact time, sorbent dosage, initial metal concentration and competitive study. th...

S TUDIES OF THE enzyme content of leukocytes reported in the past’9 have been performed on mixed cell suspensions. Some attempts to estimate the enzyme values for individual cell types have been made2, 3. 8 on the basis of complex calculations after multiple assays of mixed cell suspensions with varied cell differential counts. The technic of separation of leukocytes on glass bead 12 now permit...

1 BACKGROUND Countercurrent chromatography (CCC) is liquid-liquid partition chromatography without using a solid support matrix. This technique requires further improvement of partition efficiency and shortening theseparation time. 2 METHODS The locular multilayer coils modified with and without mixer glass beads were developed for the separation of proteins and 4-methylumbelliferyl (MU) suga...

Selected methods for yeast cell disruption were evaluated to establish their suitability for cell wall preparation in the process of β-glucan isolation. The effect of different disruption methods on contents of total saccharides, β-glucans and proteins in the produced cell walls preparations was analyzed. The degree of cell wall purification from intracellular components was established on the ...

This paper demonstrates that it is possible to trap and release a super paramagnetic micro bead by fixing three super paramagnetic micro beads in a triangular array at the sensitive end of a micro cantilever, and by simply switching on/off an external magnetic field. To provide evidence of this principle we trap a micro bead that is attached to the free end of single DNA molecule and that has b...