EFFECT OF CURING TIME ON THE PORE SIZE AND EFFECTIVE THICKNESS/POROSITY OF POLYESTER THIN FILM COMPOSITE NANOFILTRATION MEMBRANES

Polyester thin film composite nanofiltration membranes were synthesized on the polyethersulfone (PES) support via the interfacial polymerization between triethanolamine (TEOA) and trimesoyl chloride (TMC). Here we report the effect of curing time in the interfacial polymerization process on membrane properties like pore size and effective thickness/porosity. The membrane properties were determined based on the uncharged solute permeation test and the hypothetical mechanistic structure (pore size, effective thickness/porosity) was determined using Donnan steric pore flow model (DSPM). This study also provides information on the effect of curing time on water permeability. From the 2 minute point to 10 minute point, the membranes pore sizes were reduced and negligible changes to effective thickness/porosity suggest the occurrence of additional cross-linking reaction between aqueous and organic monomers.

On the use of 10-minute point counts and 10-species lists for surveying birds in lowland Atlantic Forests in southeastern Brazil

Due to rapid and continuous deforestation, recent bird surveys in the Atlantic Forest are following rapid assessment programs to accumulate significant amounts of data during short periods of time. During this study, two surveying methods were used to evaluate which technique rapidly accumulated most species (> 90% of the estimated empirical value) at lowland Atlantic Forests in the state of São Paulo, southeastern Brazil. Birds were counted during the 2008-2010 breeding seasons using 10-minute point counts and 10-species lists. Overall, point counting detected as many species as lists (79 vs. 83, respectively), and 88 points (14.7 h) detected 90% of the estimated species richness. Forty-one lists were insufficient to detect 90% of all species. However, lists accumulated species faster in a shorter time period, probably due to the nature of the point count method in which species detected while moving between points are not considered. Rapid assessment programs in these forests will rapidly detect more species using 10-species lists. Both methods shared 63% of all forest species, but this may be due to spatial and temporal mismatch between samplings of each method.

The Homeric Chariot

The object of the present paper is not to give a full account of the Homeric chariot, but merely to call attention to a somewhat minute point, in which, as it seems to me, light may be thrown upon the words of Homer from the representations given us in the painted vases.By way of preface it may be mentioned that the war-chariot was hardly known in Greece proper, at all events after the heroic age. The only occasion in Greek history when it played an important part was on the half-oriental soil of Cyprus. In the battle so picturesquely described by Herodotos (v. 113), the fortune of the day was finally decided by the treachery of the war-chariots of Salamis, whose desertion threw the island into the hands of the Persians (498 B.C.). On the rugged and broken mountains of the mainland, such an arm could hardly ever have been of practical service, and we may assume that the type familiar to the vase-painters of the fifth century B.C. must have been derived from Asia Minor.