Experiments investigating the local viscoelastic properties of a chemically cross-linked polymer are performed on polyacrylamide solutions in the sol and the gel regimes using polystyrene beads of varying sizes and surface chemistry as probes. The thermal motions of the probes are measured to obtain the elastic and viscous moduli of the sample. Probe dynamics are measured using two different dy...

Acrylamide and N,N-methylenebis(acry1amide) (AAm-Bis) copolymerization has been investigated in water at a monomer concentration of 1.8 w/v %. Conversion of monomer and pendant vinyl groups was measured as a function of the reaction time up to the onset of macrogelation. Experimental results indicate that 80% of pendant vinyl groups are consumed by cyclization reactions. When the monomer concen...

Currently gravity irrigation remains the most widely used in agricultural areas and 90 percent of plantings, the water is applied to the plots by gravity. One of the main problems with these systems is erosion, which is a by product of the erosive forces of water over the row, which brings soil loss and therefore decreases in crop yield. Erosion is the removal of surface soil material caused by...

A procedure for high resolution electrophoresis of isozymes of the mosquito Aedes aegypti using nonlinear (2.5%-20%) polyacrylamide gradient gel slabs is described. Crude mosquito homogenates were electrophoresed on gradient and on homogeneous (7%) polyacrylamide gels and stained for esterase (EST), isocitrate dehydrogenase (IDH) and malate dehydrogenase (MDH). The resulting zymograms were comp...

Signal drift and performance instability of brain-computer interface devices induced by the failure between rigid metal electrodes soft human skin hinder precise data acquisition electroencephalogram (EEG). Thus, it is desirable to achieve a robust for devices. Here, kind polydopamine methacrylamide-polyacrylamide (PDMA-PAAM) hydrogel developed. To improve adhesion, dopamine introduced into pol...

OBJECTIVE To study the tissue pathology of breast lesions associated with hydrophilic polyacrylamide gel injection augmentation mammoplasty. DESIGN Retrospective study. SETTING Private anatomical pathology practice, Hong Kong. PATIENTS Eight patients who underwent lumpectomy of the breast due to complications of hydrophilic polyacrylamide gel injection for augmentation mammoplasty. MAIN...