Winds in the Gulf of Riga from QuikSCAT and ground-based measurements

This article presents an overview of marine winds in the Gulf of Riga, measured by the SeaWinds instrument on the Quick Scatterometer (QuikSCAT) satellite during the whole lifetime period of the satellite, i.e. 1999–2009. The data were collected with a resolution of 12.5 km during the satellite overflights at 02–04 UTC and 16–18 UTC and referenced to the height of 10 m. The quality of the data was carefully checked, and necessary adjustment was applied to remove the contaminated recordings. Wind speed and direction were compared with those registered on the islands of Kihnu and Ruhnu. It has been shown that allowing lenient filtering of rain-contaminated data derives larger wind speed estimates but increases considerably the quantity of data, allowing separate analysis of the northern and southern parts of the gulf. Wind speed in the northern part is slightly higher, the wind roses for the early morning measurements are similar, but those for the evening measurements show that in spring and summer, the most frequent winds in the southern part are northwesterly and in the northern part are westerly. Wind speed measured on the islands is less than that estimated from the satellite even in the case when rain contamination is removed through application of strict criteria. Wind roses measured at Kihnu are practically similar to those estimated from satellites for the northern part of the gulf in the evening but show some differences during the early morning. In winter, ground-based measurements show maximal frequency of southerly winds, and satellite measurements show southwesterly winds. In spring, the secondary maximum in the wind rose shows northwesterly winds in ground-based records and easterly winds in satellite measurements. Ground-based wind directions are well correlated with those measured by the satellite showing correlation coefficients of over 0.9. For wind speed, this quantity is somewhat lower, i.e. around 0.6.     

Atomic layer deposition and characterization of zirconium oxide-erbium oxide nanolaminates

ZrO₂ and Er₂O₃ thin films and nanolaminates were grown by atomic layer deposition from tris(2,2,6,6-tetramethyl-3,5-heptanedionato)erbium, bis(methylcyclopentadienyl)methoxymethylzirconium and ozone as precursors at 350 °C. Nanolaminates consisted of 3-8 nm thick ZrO₂ and Er₂O₃ layers alternately deposited on planar substrates and on three-dimensional substrates with aspect ratio 1:20. The erbium content was 5-15 at.%. ZrO₂-Er₂O₃ films crystallized already in as-deposited states. Upon annealing at 650 °C, the films were stabilized in the form of cubic or tetragonal ZrO₂ polymorph and cubic Er₂O₃. Dielectric properties of the nanolaminates were comparable to those of the constituent oxides.     

Brominated,chlorinated and mixed brominated/chlorinated persistent organic pollutants in European eels (Anquilla anquilla) from Latvian lakes

Fifty-eight European eel (Anquilla anquilla) specimens collected from five Latvian lakes were investigated for six groups of persistent organic pollutants (POPs), including polychlorinated, polybrominated and mixed bromo-chloro dibenzo-p-dioxins and dibenzofurans (PCDD/DFs, PBDD/DFs and PXDD/DFs), polychlorinated and mixed bromo-chloro biphenyls (PCBs and PXBs) and polybrominated diphenyl ethers (PBDEs). PCDD/DFs and PCBs were found to occur in the range 0.85–15.8 pg Total-WHO₂₀₀₅-TEQ g^?1 f.w., and concentrations in most of the samples were below the maximum levels specified in European Commission Regulation (EU) No. 1259/2011. The summed concentrations of 27 PBDEs (∑_PBDE) and 16 non-dioxin-like PCBs (∑_NDL-PCB) were in the ranges of 0.28–26.7 and 6.37–320 ng g^?1 f.w., respectively. PBDD/DFs, PXDD/DFs and PXBs show average upper-bound concentrations of 0.05, 0.06 and 0.01 pg TEQ f.w. and collectively contributed 3.4% to the sum TEQ of dioxin-like compounds. The highest contaminant concentrations were measured in samples from lakes near the Baltic Sea and the industrialised area near Riga (Liepajas and Kisezers lakes). A correlation of POP concentration with the length of collected specimens was observed.     

Selective Artificial Receptors Based on Micropatterned Surface‐Imprinted Polymers for Label‐Free Detection of Proteins by SPR Imaging

A novel concept to generate micropatterned surface‐imprinted polymers (SIPs) for protein recognition by using standard photolithographic technology is introduced. Avidin‐imprinted poly(3,4‐ethylenedioxythiophene)/poly(styrenesulfonate) (PEDOT/PSS) conducting polymer microbands are prepared directly on surface plasmon resonance (SPR) chips, which enable convenient label‐free monitoring of the binding events. The novel surface‐imprinted microstructures bind avidin, the template protein, with dissociation constants in the submicromolar range (125 nM ). The SIPs have an avidin binding capacity approximately one order of magnitude higher than the corresponding nonimprinted polymers and are able to discriminate among functional homologues of avidin, i.e., neutravidin, extravidin, and streptavidin.     

Role of the Diffusion Mechanism of Mass-Transfer Processes in Conic Capillaries Submerged in a Liquid

A study is made of one possible mechanism explaining the phenomenon of bilateral filling of dead-end conic capillaries submerged in a liquid: diffusion and recondensation of a liquid vapor from a meniscus with a small curvature to a meniscus with a larger curvature. A theory of this process has been constructed and the rate of growth of the near-vertex liquid column has been calculated based on this theory. A comparison with experiment shows that although the law of growth of the column predicted by the theory coincides with the experimental one, the numerical values of the rate are nearly two orders of magnitude lower. Conditions under which one can detect this mechanism experimentally are discussed.