Contribution to the development of thermal stabilization system for vinylidene chloride co-polymers

Selected compounds of phosphorus and tin improve the thermal stability of vinylidene chloride co-polymers. Although offering superior intermediate color stability, incorporation of polyols will result in erratic processing of the PVdC. Combinations rather than individual compounds appear to stabilize PVdC more effectively and an explanation of the stabilization mechanism is attempted for some compounds.     

Impedance measurement of growth of lactic acid bacteria in the presence of nisin and lysozyme

Effect of nisin (0.500 g/l), lysozyme (0.035 g/l) and the mix of nisin (0.500 g/l) and lysozyme (0.035 g/l) against two nisin-producing lactococci strains, three non-nisin-producing lactococci strains and four lactobacilli strains with antimicrobial activity was determined by the impedimetric method. None of the tested lactococci and lactobacilli strains were inhibited by lysozyme at concentration of 0.035 g/l. Only the nisin-producing lactococci strains were resistant to nisin at 0.500 g/l, the other lactococci and lactobacilli were inhibited by nisin at 0.500 g/l intensively. The mix of lysozyme and nisin displayed a comparable effect to the nisin addition against the used lactococci strains and was very variable depending on the strain of tested lactobacilli. The impedimetric method was shown to be convenient for screening the growth abilities of lactococci and lactobacilli in the presence of antimicrobial components.     

Leaching of APC residues from secondary Pb metallurgy using single extraction tests: the mineralogical and the geochemical approach

Two air-pollution-control (APC) residues--one from flue gas cooling with alkaline water and one from deionized water cooling--from secondary lead metallurgy were submitted to two different standardized short-term leaching protocols: US EPA toxicity characteristic leaching procedure (TCLP) and static leaching according to Czech/European norm EN 12457-2. The experimental procedure was coupled with detailed mineralogical investigation of the solid material (SEM, XRPD) and speciation-solubility calculations using the PHREEQC-2 geochemical code. Both types of residues were considered as hazardous materials exhibiting substantial leaching of Pb (up to 7130 mg/l) and other inorganic contaminants. However, the APC residue produced by flue gas cooling with alkaline water (sample B) exhibits more favourable leaching and environmental characteristics than that produced by simple deionised water cooling (sample A). At pH < 5, primary caracolite (Na3Pb2(SO4)3Cl) and potassium lead chloride (KCl.2PbCl2) are completely or partially dissolved and transformed to residual anglesite (PbSO4), cotunnite (PbCl2) and laurionite (Pb(OH)Cl). At pH 5-6, anglesite is still the principal residual product, whereas at pH > 6, phosgenite (PbCl2.PbCO3) became the dominant secondary phase. The results are consistent with the mineralogical and geochemical studies focused on acidic forest soils highly polluted by smelter emissions, where anglesite, as a unique Pb-bearing phase, has been detected. From the technological point of view, the mixing of APC residue with alkaline water, followed by an increase in the suspension pH and equilibration with atmospheric CO2, may be used to ensure the precipitation of less soluble Pb carbonates, which are more easily recycled in the Pb recovery process in the metallurgical plant.     

Cutting wood specimens for observation in the scanning electron microscope

This report deals with the cutting of wood specimens for observation in the scanning electron microscope. Several cutting devices and types of knives are described and critically evaluated.     

Alterung des polybutadies bei anwesenheit von metallverbindungen

In the ageing of industrial polybutadienes the effect of decomposition products of ZIEGLER–NATTA catalysts could not be distinguished from other Important factors. However, the additional introduction of Co, Ti or Ni compounds (components of the ZIEGLER-NATTA catalysts) has influenced the oxidation process. The effect of different acetylacetonates (Ti, Co, Ni, V, Al, Cc, Mn, Cu) on the oxidation of purified polybutadiene in presence or in absence of an antioxidant has further been studied. The apparent activation energies of oxidation have been estimated and possible mechanismus of the actions of metal compounds in the oxidation of polybutadiene have been proposed.     

Revealed comparative advantages in academic publishing of “old” and “new” European Union Member States 1998–2018

Scientometrics - The paper uses a variant of the Revealed Comparative Advantage index to examine comparative advantages of the European Union (EU) countries in 254 research areas and their...     

Parallel implementation of sequential morphological filters

Many useful morphological filters are built as more or less long concatenations of erosions and dilations: openings, closings, size distributions, sequential filters, etc. An efficient implementation of these concatenations would allow all the sequentially concatenated operators run simultaneously, on the time-delayed data. A recent algorithm (see below) for the morphological dilation/erosion allows such inter-operator parallelism. This paper introduces an additional, intra-operator level of parallelism in this dilation/erosion algorithm. Realized in a dedicated hardware, for rectangular structuring elements with programmable size, such an implementation allows obtaining previously unachievable, real-time performances for these traditionally costly operators. Low latency and memory requirements are the main benefits when the performance is not deteriorated even for long concatenations or high-resolution images.     

Performance benchmarks of an array-based hand-held photoacoustic probe adapted from a clinical ultrasound system for non-invasive sentinel lymph node imaging

Clinical translation of photoacoustic (PA) imaging can be facilitated by integration with commercial ultrasound (US) scanners to enable dual-modality imaging. An array-based US scanner was modified for hand-held PA imaging. The performance was benchmarked in terms of signal-to-noise ratio (SNR), axial spatial resolution and sensitivity. PA images of a tube, filled with methylene blue (MB; approx. 30?mM) and placed at various depths in chicken tissue, were acquired. A 5?cm penetration depth was achieved with an 18.6?dB SNR using a laser fluence of 3?mJ?cm(-2), only one-seventh of the safety limit (20?mJ?cm(-2)). An axial resolution of approximately 400?μm was maintained at all imaging depths. The PA sensitivity to MB placed 2.3?cm deep in chicken tissue was less than 100?μM. Further, after intradermal injection of MB (approx. 30?mM), a rat sentinel lymph node was clearly identified in vivo, beneath a 3.8?cm thick layer of chicken breast. The accumulated concentration of MB in the node was estimated to be approximately 7?mM. The noise-equivalent sensitivities (approx. 2?cm depth) were 17 and 85?μM, ex vivo and in vivo, respectively. These results support the use of this PA system for non-invasive mapping and image-guided needle biopsy of sentinel nodes in breast cancer patients.