We report neutron spin-echo measurements on two types of poly(vinyl alcohol) (PVA) gels. The first is PVA gel in a mixture of dimethyl sulfoxide (DMSO) and water with volume ratio 60/40 , and the second is PVA gel in an aqueous borax solution. The observed normalized intermediate scattering functions I (Q,t) /I (Q,0) are very different between them. The former I (Q,t) /I (Q,0) shows a nondecayi...

Using the results of a survey of recovery plans for threatened and endangered species, we evaluated the role that Population Viability Analysis (PVA) has played in recovery planning and management of rare species in the United States. Although there was a significant increase over time in the percentage of plans presenting information on PVA and assigning recovery tasks to collect more such inf...

Polyvinyl alcohol cryogel (PVA-C) is presented as a vessel-mimicking material for use in anatomically realistic Doppler flow phantoms. Three different batches of 10% wt PVA-C containing (i) PVA-C alone, (ii) PVA-C with antibacterial agent and (iii) PVA-C with silicon carbide particles were produced, each with 1-6 freeze-thaw cycles. The resulting PVA-C samples were characterized acoustically (o...

Atomic Force Microscopy (AFM) and Ultrasonic Force Microscopy (UFM) have been applied to the characterization of composite samples formed by SrTiO3 (STO) nanoparticles (NPs) and polyvinyl alcohol (PVA). The morphological features of the STO NPs were much better resolved using UFM than contact-mode AFM topography. For high STO concentrations the individual STO NPs formed nanoclusters, which gath...

A multilayered hydrogel film system based on hyaluronic acid-cysteamine (HA-Cym) and polyvinylalcohol (PVA) was fabricated. It contained a drug-impermeable backing layer, a supporting layer preventing direct contact between the loaded drug and the backing layer, a drug-loading layer and a mucoadhesive layer. Scanning electron microscopy demonstrated the presence of the distinct layers. The comp...

Separators are used to protect cathodes from biofouling and to avoid electrode short-circuiting, but they can adversely affect microbial fuel cell (MFC) performance. A spray method was used to apply a polyvinyl alcohol (PVA) separator to the cathode. Power densities were unaffected by the PVA separator (339±29mW/m(2)), compared to a control lacking a separator in a low conductivity solution (1m...

Background We studied the effect of exercise (7.2 to 8.0 km/h) on the efficiency of the conversion of metabolic energy to external work or stroke work (SW) by the left ventricle (LV). Methods and Results Energy use was calculated from LV myocardial oxygen consumption per beat (MVo2). LV volume was calculated from orthogonal dimensions and coronary flow measured with ultrasonic flow probes. The ...

In order to better match the multi-level structural characteristics and multi-scale fracture process of cementitious composite, hybrid fiber-reinforced strain hardening composite (MsHySHCC) was designed by adding hooked steel fiber calcium carbonate (CaCO3) whisker into conventional polyvinyl alcohol (PVA) SHCC. Compressive properties PVA-SHCC MsHySHCC were evaluated experimentally. The results...

Compared to conventional concrete, polyvinyl alcohol fiber reinforced engineering cementitious composite (PVA-ECC) offers high-strength, ductility, formability, and excellent fatigue resistance. However, impact-induced structural damage is a major concern and has not been previously characterized in PVA-ECC structures. We investigate the damage of PVA-ECC beams under low-velocity impact loading...

Novel poly(vinyl alcohol) (PVA) nanofiber mats were prepared for the first time through heterogeneous saponification of electrospun poly(vinyl acetate) (PVAc) nanofibers. The effect of varying the saponification conditions, including temperature, time, and concentration of the alkaline solution, on the morphology of the saponified PVA fibers were evaluated by field-emission scanning electron mi...