RF PE CVD deposition of amorphous a-SixNy:H layers for application in solar cells

The most promising technologies of silicon nitride hydrogenated layers for application in solar cells are based on plasma-chemical methods. In this paper, results concerning radio-frequency plasma-enhanced chemical vapour deposition (RF PE CVD) method applied in the technology of a-Si_xN_y:H layers on glass and polycrystalline silicon are presented. For the purpose of this research the series of the samples have been deposited and subjected to optical and structural studies. The layers have been grown from silane and ammonia used as gaseous precursors. A special attention has been paid to the choice of a gas flow ratio [NH₃]/[SiH₄]. The results show that it has a significant influence on the atomic-level structure, chemical composition and optical properties of the layers.     

A new F-score gradient-based training rule for the linear model

Pattern Analysis and Applications - Delta rule is a standard, well-established approach to train perceptron recognition model. However, mean squared error, on which it is based, is not suitable...     

Silver content of wild-grown mushrooms from Northern Poland

Wild-grown and mostly edible species of higher mushrooms collected in 1989–1992 from the districts of Gdansk, Elblag and Pia (northern part of Poland) have been investigated with regard to their silver content. In total, 527 samples including 25 mushroom species of six families (Agaricaceae, Boletaceae, Cantharellaceae, Hygrophoraceae, Coprinaceae andRussulaceae) were examined. Among the fungi examined onlyAgaricus campestris andA. augustus were heavy bioaccumulating species and showed the highest concentrations of 35 mg Ag/kg dry weight (1.1–150) and 2.0–6.9 mg/kg, respectively. Silver concentrations exceeding 1.0 mg/kg dry weight were noted inBoletus aestivalis, Lepista nuda, L. personata, and in some specimens ofB. edulis, Leccinum scrabum, L. vulpinum, Cantharellus cibarius andCoprinus comatus.

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Silbergehalt in wildwachsenden Pilzen Nordpolens

Zusammenfassung Der Silbergehalt in wildwachsenden und vorwiegend eßbaren, auf dem Gebiet der Woiwodschaften Gdask, Elblag und Pia (Nordpolen) in den Jahren 1889–1992 gesammelten Pilzsorten wurde untersucht. Im ganzen wurden 527 Proben von 25 Arten der 6 Familien (Agaricaceae, Boletaceae, Cantharellaceae, Hygrophoraceae, Coprinaceae, Russuulaceae) zugehörenden Pilzen untersucht. Von diesen Pilzen waren nurAgaricus campestris undA. augustus stark bioanreichernde Arten mit höchsten Konzentrationen von 35 mg Ag/kg Trockenmasse (1.5–150) und 2.0–6.9 mg/kg. Eine Silberkonzentration von über 1.0 mg/kg Trockenmasse wurde inBoletus aestivalis, Lepista nuda, L. personata und in einigen Exemplaren vonB. edulis, Leccinum scrabum, L. vulpinum, Cantharellus cibarius undCoprinus comatus feststellt.

     

Kinetic study of the antioxidant compounds and antioxidant capacity during germination of Vigna radiata cv. emmerald, Glycinemax cv. jutro and Glycine max cv. merit

The purpose of this study was to determine the antioxidant capacity and the content of antioxidant compounds in raw mung bean seeds and sprouts (Vigna radiata cv. emmerald) germinated for 2, 3, 4, 5 and 7 days and of soybean seeds of Glycine max cv. jutro germinated for 2, 3 and 4 days and of Glycine max cv. merit germinated for 2, 3, 4, 5 and 6 days. Antioxidant compounds, such as vitamin C and E, total phenolic compounds and reduced glutathione (GSH) were studied. Antioxidant capacity was measured by superoxide dismutase-like activity (SOD-like activity), peroxyl radical-trapping capacity (PRTC), trolox equivalent antioxidant capacity (TEAC) and inhibition of lipid peroxidation in unilamellar liposomes of egg yolk phosphatidylcholine (PC). The results indicated that changes in the contents of vitamin C, vitamin E and GSH depended on the type of legume and germination conditions. Sprouts of mung bean and soybeans provided more total phenolic compounds than did raw seeds. The SOD-like activity increased after germination of mung bean seeds for 7 days, by 308%, while no change was observed in sprouts of Glycine max cv. jutro and an increase was observed after 5 and 6 days of germination (∼20%) in Glycine max cv. merit. PRTC and TEAC increased during the germination process and retentions of 28–70% and 11–14%, respectively, for soybean, and 248% and 61%, respectively, for mung bean were observed at the end of germination. The inhibition of lipid peroxidation increased by 389% in 5–7 days’ germination of Vigna radiata cv. emmerald sprouts, and 66% in Glycine max cv. merit sprouts whilst, in Glycine max cv. jutro, germination did not cause changes in lipid peroxidation inhibition. According to the results obtained in this study, germination of mung bean and soybean seeds is a good process for obtaining functional flours with greater antioxidant capacity and more antioxidant compounds than the raw legumes.     

Influence of a photoinitiator on the photochemical stability of poly(methyl methacrylate) studied with fourier transform infrared spectroscopy

Fourier transform infrared (FTIR) spectroscopy was used to investigate the effect of a commercial photoinitiator [2,2‐dimethoxy‐2‐phenylacetophenone (DMPA); Irgacure 651, Ciba, Basel, Switzerland] incorporated into poly(methyl methacrylate) (PMMA). Pure PMMA and modified PMMA (containing 5% DMPA) films were exposed to a xenon lamp in air. Qualitative and quantitative analyses of the recorded FTIR absorption spectra were done. This allowed us to determine the differences in the course of polymer photooxidative degradation occurring in PMMA and PMMA doped with DMPA. We found that the initiator added to polymer film enhanced the efficiency of the formation of the photooxidized products containing functional groups of different types, which could be distinguished by mathematical treatment of the FTIR spectra. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Ultrasmall Co3O4 Nanocrystals Strongly Enhance Solar Water Splitting on Mesoporous Hematite

The synthesis of crystalline, nonagglomerated, and perfectly dispersible Co₃O₄ nanoparticles with an average size of 3–7 nm using a solvothermal reaction in tert‐butanol is reported. The very small size and high dispersibility of the Co₃O₄ nanoparticles allow for their homogeneous deposition on mesoporous hematite layers serving as the photoactive absorber in the light‐driven water splitting reaction. This surface treatment leads to a striking photocurrent increase. While the enhancement of hematite photoanode performance by cobalt oxides is known, the preformation and subsequent application of well‐defined cobalt oxide nanoparticles are novel and allow for the treatment of arbitrarily complex hematite morphologies. Photoelectrochemical and transient absorption spectroscopy studies show that this enhanced performance is due to the suppression of surface electron–hole recombination on time scales of milliseconds to seconds.     

A survey of research and studies on design

This review is based on two hundred responses to a questionnaire designed by the Design Methodology Unit, Department of Praxiology, Polish Academy of Sciences. On the basis of the replies it shows the state of research in design and the applied sciences.