Three sorbents were compared in order to determine their potential for oil spill cleanup. Polypropylene nonwoven web, rice hull, and bagasse with two different particle sizes were evaluated in terms of oil sorption capacities and oil recovery efficiencies. Polypropylene can sorb almost 7 to 9 times its weight from different oils. Bagasse, 18 to 45 mesh size, follows polypropylene as the second sorbent in oil spill cleanup. Bagasse, 14 to 18 mesh size, and rice hull have comparable oil sorption capacities, which are lower than those of the two former sorbents. It was found that oil viscosity plays an important role in oil sorption by sorbents. All adsorbents used in this work could remove the oil from the surface of the water preferentially.

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Cross-linked poly (vinyl alcohol) membranes were prepared using fumaric acid as the cross-linking agent and were used for the pervaporation separation of water/isopropanol mixtures. Cross-linking process was carried out at 150 C at three different times of 10, 30, and 60 min. The membranes were characterized by different known methods of FT-IR, TGA, XRD as well as tensile test. The effects of cross-linking time on the thermal and mechanical properties of the membranes and also their pervaporation performance were investigated. Formation of more ester groups by increasing the cross-linking time was confirmed by the FT-IR results. TGA analyses showed that thermal stability of the membranes is improved by prolonging the duration of cross-linking process. This was due to the formation of more compact structure in the membranes. The XRD results revealed that the crystalline regions of the membranes were relatively diminished with an increase in the cross-linking time. No specific trend was observed for the variation of tensile strength at break with the cross-linking time. The PVA membrane cross-linked for 60 min showed high selectivity of 1492 for water permeation for the feed mixture containing 10 wt % water. The temperature dependency of the permeation flux was investigated using Arrhenius relationship, and the activation energy values were calculated for total permeation (E p ), water (E pw ), and IPA (E pIPA ) fluxes. Lower value of E pw in comparison with E pIPA supported excellent dehydration performance of the cross-linked membranes. Despite large increase in activation energy of water with prolonged cross-linking time, the selectivity was improved.

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Background and Purpose Asiatic acid (AA) has been shown to attenuate cerebral infarction in a mouse model of focal ischemia and shows promise as a neuroprotective stroke therapy. To facilitate translation of these findings to clinical studies, we determined pharmacokinetics, a dose response relationship, the therapeutic time window, and efficacy using multiple stroke models. We also explored potential mechanisms of action. Methods Escalating doses of intravenous AA were administered and serum concentrations were measured at multiple time points for the pharmacokinetic studies. Subsequently, a dose response relationship was determined followed by administration at different intervals after the onset of ischemia to establish a therapeutic time window for neuroprotection. Outcome measurements included both histological and behavioral. Mitochondrial function and matrix metalloproteinase activity in controls and treated rats were also determined. Results The pharmacokinetic studies showed that AA (75mg/kg) has a half life of 2.0 hours. AA significantly decreased infarct volume and improved neurological outcome even when administration at time points up to 12 hours after the onset of ischemia. Infarct volume was also significantly decreased in female rats and spontaneously hypertensive rats. AA attenuated mitochondrial dysfunction and reduced matrix metalloproteinase-9 induction. Conclusions Our study shows AA is effective against multiple models of focal ischemia, has a long therapeutic time window and is also effective in females and hypertensive animals. AA may mediate neuroprotection by protecting mitochondria and inhibiting matrix metalloproteinase-9 induction and activation. Taken together these data suggest that AA is an excellent candidate for development as a stroke therapy based.