Resistance of Silicone Rubber High Voltage Insulation to Leakage Current in Modified Inclined Plane Test

In this paper results of investigations of resistance to leakage currents of two different silicone rubbers subjected to a modified inclined plate test are presented. The modification of the experiment consisted in a change of the sample’s inclination angle and in feeding a moistening solution to the upper surface of the sample. The main aim of the modification was to create laboratory test conditions as close to the ones observed in reality as possible

The composition of the aphid fauna (Insecta, Hemiptera) of the Royal Botanic Gardens, Kew

At least a dozen species of aphids (Insecta, Hemiptera) of non-native origin have expanded their range in Europe, however the importance of botanic gardens in this phenomenon has not been studied previously in detail. As a case study, investigations on the species composition and host range of Aphidomorpha in the Royal Botanic Gardens, Kew, London, United Kingdom, were conducted over a period of twelve days, in June 2017. The inventory study was carried out in the collection of living plants, both in the gardens and the glasshouses and nurseries. In total, 94 taxa of Aphidomorpha are identified (one phylloxerid, one adelgid and 92 species of aphids). 20 species are regarded as alien to the European aphid fauna and among them nine are believed to be the first published records for Kew. 20 species are regarded as serious pests, capable of virus transmission. The list of host plants includes 155 taxa from 89 genera and 49 families. Ericolophium holsti (Takahashi), species of Asiatic origin associated with Rhododendron spp., was found for the first time in the field in the UK. Changes in the species composition of the aphid fauna in reference to the Eastop’s studies in 1960s were discussed

An Approach to Solid Phase Identification in a Ca-S-O System by Quantitative Energy Dispersive X-Ray Microanalysis

Solid phases formed in the limestone sulphation reaction were identified by scanning electron microscopy with backscattered electron (BSE) imaging and by quantitative energy dispersive X-ray (EDX) microanalysis of calcium and sulphur. Since calcium and sulphur can form several compounds in the Ca-S-O system, two quantities, the sum of oxides (CaO+SO3) and the molar ratio (CaO/SO3), were used to calculate empirical formulae for the compounds actually present. A method for analysing the experimental results is proposed, the mathematical expressions employed are presented and the numerical coefficients tabulated. It is shown with some examples that the method used here provides useful criteria for the identification of limestone sulphation products

Kolageni elastin u jetri štakora otrovanih živinim kloridom

Intoxication of rats with mercuric chloride (0.5 mg Hg/kg of body weight, daily for 10 weeks) increased the hepatic contents of soluble and insoluble collagen and elastin. The increase was associated with elevated serum aminotransferase and alkaline phosphatase activities, and decreased total protein level in serum. Inflammatory changes were found in the liver. An increase in the fibrous protein content suggests that inflammatory reaction to mercuric chloride can result in hepatic fibrosis.Trovanje štakora živinim kloridom (0,5 mg Hg/kg tjelesne težine na dan tijekom deset tjedana) imalo je za rezultat povećan sadržaj topljivog i netopljivog kolagena i elastina u jetri. Povećanje je dovedeno u vezu s povišenim aktivnostima aminotransferaze i alkalne fosfataze u serumu, i sa smanjenim nivoom ukupnog proteina u serumu. U jetri su zamijećene upalne promjene. Povišen sadržaj vlaknastog proteina upućuje na to da upalna reakcija na živin klorid može dovesti do fibroze jetre

Hallmarks of mechanochemistry: From nanoparticles to technology

The aim of this review article on recent developments of mechanochemistry (nowadays established as a part of chemistry) is to provide a comprehensive overview of advances achieved in the field of atomistic processes, phase transformations, simple and multicomponent nanosystems and peculiarities of mechanochemical reactions. Industrial aspects with successful penetration into fields like materials engineering, heterogeneous catalysis and extractive metallurgy are also reviewed. The hallmarks of mechanochemistry include influencing reactivity of solids by the presence of solid-state defects, interphases and relaxation phenomena, enabling processes to take place under non-equilibrium conditions, creating a well-crystallized core of nanoparticles with disordered near-surface shell regions and performing simple dry time-convenient one-step syntheses. Underlying these hallmarks are technological consequences like preparing new nanomaterials with the desired properties or producing these materials in a reproducible way with high yield and under simple and easy operating conditions. The last but not least hallmark is enabling work under environmentally friendly and essentially waste-free conditions (822 references).Slovak Grant Agency VEGA 2/0009/11, 2/0043/11Slovak Agency for Science and Development APVV VV-0189-10, VV-0528-11Russian Foundation for Basic Research 10-03-00942a, 12-03-00651aMinistry of Science and Higher education in Poland CUT/c-1/DS/KWC/2008-2012, PB1T09B02330, NN209145136, NN20914893

Tensile strained InxGa1−xPIn_{x}Ga_{1-x}P membranes for cavity optomechanics

We investigate the optomechanical properties of tensile-strained ternary InGaP nanomembranes grown on GaAs. This material system combines the benefits of highly strained membranes based on stoichiometric silicon nitride, with the unique properties of thin-film semiconductor single crystals, as previously demonstrated with suspended GaAs. Here we employ lattice mismatch in epitaxial growth to impart an intrinsic tensile strain to a monocrystalline thin film (approximately 30 nm thick). These structures exhibit mechanical quality factors of 2*10^6 or beyond at room temperature and 17 K for eigenfrequencies up to 1 MHz, yielding Q*f products of 2*10^12 Hz for a tensile stress of ~170 MPa. Incorporating such membranes in a high finesse Fabry-Perot cavity, we extract an upper limit to the total optical loss (including both absorption and scatter) of 40 ppm at 1064 nm and room temperature. Further reductions of the In content of this alloy will enable tensile stress levels of 1 GPa, with the potential for a significant increase in the Q*f product, assuming no deterioration in the mechanical loss at this composition and strain level. This materials system is a promising candidate for the integration of strained semiconductor membrane structures with low-loss semiconductor mirrors and for realizing stacks of membranes for enhanced optomechanical coupling.Comment: 10 pages, 3 figure