Mappings of finite distortion: Formation of cusps III

We give sharp integrability conditions on the distortion of a planar homeomorphism that maps a standard cusp onto the unit disk.     

Filters and simple graphic algebras

The latticeU(S) of the filters of a finite joinsemilattice S is considered and it is shown when the Hasse diagram graph of S generates a simple graphic algebra.     

Distance characterizations of finite lattices

Semimodular, modular and distributive finite lattices are characterized by means of convex sublattices and distance closed sets of the Hasse diagram graphs.     

Comparison of gas chromatography-mass spectrometry and capillary electrophoresis in analysis of phenolic compounds extracted from solid matrices with pressurized hot water

Self-constructed pressurized hot water extraction (PHWE) equipment was used in dynamic mode to extract spiked phenolic compounds (phenol, 3-methylphenol, 4-chloro-3-methylphenol and 3,4-dichlorophenol) from sea sand and soil. Phenols were analyzed by both gas chromatography-mass spectrometry (GC-MS) and capillary zone electrophoresis (CZE) to compare the techniques and to find out if CZE is a suitable tool for analysis of phenols extracted from environmental matrix. Good recoveries of phenols spiked in sea sand were achieved at all PHWE temperatures (50, 100, 200, 300 C). GC-MS studies showed that phenols were selectively extracted from soil at 50 C but various other compounds (e.g. polyaromatic hydrocarbons) were extracted along with the phenols at 300 degrees C. In the case of CZE, phenols extracted from the soil, at 300 C were separated with good resolution at pH 9.7, and co-extracted compounds did not interfere with the analysis. The analytical values obtained by GC-MS and CZE were generally of similar magnitude.     

On the origin of residual dipolar couplings from denatured proteins

Effects of steric obstruction on random flight chains are examined. Spatial probability distributions are elaborated to calculate residual dipolar couplings and residual chemical shift anisotropy, parameters that are acquired by NMR spectroscopy from solutes dissolved in dilute liquid crystals. Calculations yield chain length and residue position-dependent values in good agreement with simulations to provide understanding of recently acquired data from denatured proteins.     

Comparative study for differentiation of aquatic humic-type organic constituents by capillary zone electrophoresis using polyvinyl alcohol-coated capillary

Capillary zone electrophoresis (CZE) with UV detection (254 nm) was applied to characterize aquatic dissolved humic matter (DHM) from different environmental sources (lake, river and sea waters, in all 15 different samples). A series of separation examples of DHMs using a polyvinyl alcohol (PVA)-coated silica open tubular capillary were carried out in a phosphate buffer (40 mM) as a background electrolyte at neutral acidity (pH 6.8). The separative power of electropherograms was reasonable and the reproducibility was above the mark. Each electropherogram was characteristic of the corresponding humic sample. Special functional fulvic and humic acids or their overall mixtures separated with XAD, DAX and DEAE sorbing solids as well as the original dissolved organic matter (DOM) were nicely differentiated according to their environmental sources. The PVA coating of open tubular silica capillaries seems to be very potential in electrophoretic characterization and separation of different humic solutes at neutral acidities with low sample concentrations thus permitting a workable technique, in a growing series of CZE studies, for better compared results from different studies.