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Abstract A new technique is proposed for the calculation of the width W of space charge region and consequently the concentration of uncompensated acceptors NA–ND, which is based on the open-circuit analysis of thin film heterojunction solar cells illuminated by monochromatic light with the wavelength within photosensitivity region. The proposed method was simulated under different values of the theoretically considered parameters (ideality coefficient n, saturation current I0 and shunt resistance Rsh) of a CdS/CdTe heterojunction solar cell. The calculated values of W and NA–ND were established to be dependent on the mentioned above electrical parameters.

Abstract The photoelectrochemical behaviour of an Si anode coated with a film of mixed oxide of ruthenium and titanium (ORT) is studied in the reaction of photodecomposition of KCl and HCl solutions. Single-crystalline uniformly doped n-type silicon, as well as with p-n junction, was used as a substrate. The film is shown to protect the Si electrode against photocorrosion during the photoelectrolysis of the above solutions. The heights of the Schottky barrier at the n-Si/ORT contact is theoretically estimated using photoelectrochemical data to be up to 0.9 eV. The efficiency of a real electrode with Schottky barrier is significantly lower than the predicted value due to the destructive influence of a resistant interlayer formed during ORT film application to the silicon surface. The resistant interlayer formation may be prevented by implanting the silicon surface layer with boron, hence, by using an electrode with an n-Si/p + -Si junction as substrate. The efficiency of conversion of light energy into chemical energy in the n-Si/p + -Si/ORT/30% HCl/Pt cell is 6%.

The effects of clinostating on physiological processes and biochemical characteristics of wheat plants (Triticum aestivum L.) both healthy and infected by the wheat streak mosaic virus (WSMV) were studied. In six experiments, each lasting over 30 days, healthy and infected plants of the dwarf Apogee variety were grown under conditions of continuous horizontal and vertical clinostating with 2 rpm at 21 +/- 2 degrees C and 6000 1x (the optimal moisture of a substrate being maintained). The control variants (healthy and infected) were simultaneously grown under the same conditions of temperature and illumination in stationary containers and in open pots. During the experiment, visual observations were carried out over the state of tested plants. After completing the experiment, biometric indices, pigment, carbohydrate and dry matter contents were determined in all the plants. It was shown that clinostating sharply reduced the reproductive function of healthy plants and considerably affected their biomass (productivity) and concentration of chlorophylls and sugars. The viral infection resulted in further reduction of these characteristics. In control variants the viral effect was more significant. We speculate that clinostating reduced the rate of reproduction and spread of the virus.

Since early 1970s, the Black Sea pelagic ecosystem has been experienced severe impact caused by numer� ous anthropogenic factors, which have significantly changed its state [1–3]. Among the latter, eutrophica� tion was of great importance. It has altered the tropho� dynamics of the pelagic zone owing to an increase in the phytoplankton abundance and biomass and a sig� nificant change in its species composition. For exam� ple, the proportion of diatoms, which account for over 90% of the total phytoplankton abundance on the Black Sea shelf, has significantly reduced. As a result, dynoflagellates and small species, primarily coccoli� thophorids and small flagellates became dominants [4]. Such changes in the Black Sea pelagic zone affected both the entire structure of its food web, including the upper trophic layers of the ecosystem (primarily the stock of small pelagic fishes), and its state in general. On the one hand, the primary produc� tive base in the ecosystem has increased; on the other hand, qualitative changes in the primary producers of the trophic web resulted in a decrease in the ecological efficiency of utilization of matter and energy in the Black Sea ecosystem on the whole. This, in turn, has disturbed its resistance to adverse impacts [1, 5]. To clarify the relationship between the primary and ter� minal trophic components in the Black Sea pelagic

Abstract The MCNPX Monte-Carlo code has been used to model the neutron transport in a sub-critical fast fission reactor driven by a fusion neutron source. A stellarator-mirror device is considered as the fusion neutron source. The principal composition for a fission blanket of a mirror fusion–fission hybrid is devised from the calculations. Heat load on the first wall, the distribution of the neutron fields in the reactor, the neutron spectrum and the distribution of energy release in the blanket are calculated. The possibility of tritium breeding inside the installation in quantities that meet the needs of the fusion neutron source is analyzed. The portion of the plasma column generates fusion neutrons that mainly do not reach the fission reactor core is proposed to be surrounded by a vessel filled with borated water to absorb the flying out neutrons. The flux of the neutrons escaping from the device to surrounding space is also calculated.

Abstract In this work, we used solar energy converted via photosynthesis into chemical energy of the biomass of the fast-growing perennial herb Miscanthus × giganteus for the manufacture of nanocellulose (NC) films, which are biodegradable alternative to common petroleum-based polymer substrates used in flexible electronics. To create the NC substrates, we applied an environmentally friendly method of organosolv delignification of plant raw materials carried out at a low temperature and in a relatively short time. Then by means of the low-temperature cheap and scalable method Successive Ionic Layer Adsorption and Reaction (SILAR) we deposited copper iodide (CuI) film of 0.72 µm thickness on both sides of the 12 µm thick NC substrate, and thus obtained light-weight and flexible biodegradable nontoxic thermoelectric material CuI/NC. Crystal structure, morphology, chemical composition, and optical, electrical and thermoelectric properties of the CuI/NC have been researched. Studies have shown that nanostructured p-type semiconductor CuI film in the CuI/NC TE material is quite dense and completely covers the NC surface. It has typical optical direct band gap ≈ 3.0 eV, is single-phase γ-CuI with crystallite sizes in the 19–25 nm range, with moderate dislocation density of (1.6–2.8) × 1015 lines/m2, and tolerable microstrains e of (4–9) × 10−3 a.u. The determined value of the Seebeck coefficient S is ~228 μV K−1, at that, S is constant in the temperature range 290–335 K. Together with the thermoelectric power factor ≈ 36 μW·m−1·K−2it is favorable for the use of CuI/NC as new thermoelectric material for an in-plane design of biodegradable flexible thin film thermoelectric generator (TEG). At temperature gradient of 50 K, the single p-CuI thermoelectric leg made from CuI/NC strip of 3 cm long and 0.5 cm wide generates open circuit voltage 8.4 mV, short circuit current 0.7 µA and maximum output power 1.5 nW. It corresponds to the output power density 10 µW/m2, and thus confirms the suitability of CuI/NC to obtain electricity by the harvesting the waste environmental heat.

Based on the hydrodynamic stability theory of distorted laminar flow and the kind of distortion profiles on the mean velocity in parallel shear flow given in paper [1], this paper investigates the linear stability behaviour of parallel shear flow, presents unstable results of plane Couette flow and pipe Poiseuille flow to two-dimensional or axisymmetric disturbances for the first time, and obtains neutral curves of these two motions under certain definition.

Protected areas are necessary for the conservation and enhancement of biodiversity. Wildfires are major threats to forests and other natural areas, because they may cause irreversible damages. The aim of this study was to analyze the perspective of experts (N = 284), from six countries of the Black Sea, on the current status and problems of protected areas and wildfires. Understanding their points of view could enhance future management on these issues in the region. Data collection was carried out for 9 months, using a web-based questionnaire. Wildfires were perceived as a serious problem in Turkey, Armenia and Greece but as a substantially less serious problem in Romania, Ukraine and Moldova. In Greece, Armenia, and especially Ukraine, the current designated protected areas are considered sufficient to maintain biodiversity, while in Romania, Turkey, and especially Moldova, more areas should be designated as protected. A major need in all countries (except for Turkey) is the increased use of information and communication technologies for both wildfire suppression and protected area management. Experts were divided on whether wildfire suppression and management of protected areas are interconnected. However, there is growing awareness of the adverse impacts of climate change in protected areas and the frequency of wildfires in the future. The most frequently suggested measures to alleviate these impacts were: changes in forest management and increasing public awareness for wildfire suppression, along with changes in forest management and increased staff training to enhance protected area conservation.

The thermotolerant yeast Hansenula polymorpha ferments glucose and xylose to ethanol at high temperatures. However, H. polymorpha cannot utilize starchy materials or xylans. Heterologous amylolytic and xylanolytic enzymes have to be expressed in this yeast to provide for utilization and growth on starch and xylan. Genes SWA2 and GAM1 from the yeast Schwanniomyces occidentalis, encoding alpha-amylase and glucoamylase, respectively, were expressed in H. polymorpha. The expression was achieved by integration of the SWA2 and GAM1 genes under the strong constitutive promoter of the H. polymorpha glyceraldehyde-3-phosphate dehydrogenase gene (HpGAP) into H. polymorpha genome. Resulting transformants acquired the ability to grow on a minimal medium containing soluble starch as a sole carbon source. Ethanol production at high-temperature fermentation from starch by the recombinant strains was up to 10 g/L. The XYN2 gene encoding endoxylanase of the fungus Trichoderma reseei was expressed in H. polymorpha. Co-expression of xlnD gene coding for beta-xylosidase of the fungus Aspergillus niger and the XYN2 gene in H. polymorpha was achieved by integration of these genes under control of the HpGAP promoter. Resulting transformants were capable of growth and alcoholic fermentation on a minimal medium supplemented with birchwood xylan as a sole carbon source at 48 degrees C.