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We have studied the key features of the luminescence spectra and kinetics of (YTm)OS solid solutions in the range 400-2000 nm under laser excitation at 790 and 810 nm. The results have been used to develop a series of IR phosphors 'invisible' under laser excitation in the range 790-810 nm and possessing tunable and reproducible relative intensities of three groups of IR luminescence bands in the ranges 770-840, 1360-1520, and 1650-1980 nm, respectively. [ABSTRACT FROM AUTHOR]

A complex of Co with 1-(3,5-di- tert-butyl-4-hydroxybenzyl)-1 H-indole-2,3-dione 3-thiosemicarbazone was obtained and identified by X-ray diffraction, IR and Raman spectroscopy, and quantum chemical calculations. The characteristic C=S frequencies in the IR spectra of the thiosemicarbazones were refined. The data obtained from different methods were compared, which allows more accurate spectroscopic studies of related structures. [ABSTRACT FROM AUTHOR]

We have determined the composition range of solid solutions in the binary system YPO-YbPO and identified the key trends in the composition dependence of their IR Stokes luminescence intensity and decay time in the range 0.96-1.1 μm. The results were used to develop a new narrow-band IR phosphor, YPO:Yb. Under 0.940-μm laser excitation, this phosphor offers an increased IR Stokes luminescence intensity in the range 0.96-1.1 μm (about twice as high as that of the well-known commercially available phosphors L-54 and FSD-546-2), with an afterglow time of 1700-1800 μs. [ABSTRACT FROM AUTHOR]

An available multifunctional additive for low-grade fuel oil is proposed. Its effect on the service properties of fuel oil is experimentally studied, and results from this study are presented. [ABSTRACT FROM AUTHOR]

The viscosity of a mixture of fuel oil with the liquid additive Diproxamine and a solid additive based on the carbonate sludge of water treatment has been experimentally studied. It has been found that these additives affect the viscosity characteristics of fuel oil. The economic efficiency of automated systems for dispensing the solid and liquid additives in fuel oil has been evaluated. [ABSTRACT FROM AUTHOR]

A multifunctional additive is proposed for use with low-grade heavy fuel oil. There is a discussion of its effects on the working properties. The additive tends to increase the mechanical and economic and otherwise ecological parameters in heavy fuel oil use. [ABSTRACT FROM AUTHOR]

Hydrogen bonds, structures, and vibrational spectra of 1-ethyl-3-methylimidazolium halides ([emim][Hal]) were analyzed in the framework of the Hartree—Fock method (HF/6-31G*, 6-31+G*) and the density functional theory (B3LYP/6-31G*, 6-31+G*, 6-31G**, 6-31+G**). It is shown that the use of the approximation of an isolated ion pair cation—anion is incorrect for the ionic liquids studied. It is more reasonable to consider “clusters” including at least two-three cations and being more appropriate models for the study of hydrogen bonds and vibrational spectra of ionic liquids of this type. [ABSTRACT FROM AUTHOR]

Industrial barrens are bleak open landscapes evolved due to deposition of airborne pollutants, with only small patches of vegetation surrounded by bare land. These extreme environments appeared as a by-product of human activities about a century ago. The comparative analysis of information available from 36 industrial barrens worldwide allowed to identify factors and conditions that are necessary and sufficient for the appearance of these specific habitats. Vast majority of industrial barrens is associated with non-ferrous smelters, located predominantly in mountainous or hilly landscapes. Development of industrial barrens starts from gradual decline of vegetation due to severe pollution impact accompanied by other human-induced disturbances (primarily clearcutting) and is usually concluded by a fire, facilitated by accumulation of woody debris. Since vegetation recovery is hampered by soil toxicity caused by extreme contamination by heavy metals, soils remain bare and suffer from erosion enhanced by altered microclimate. In spite of general reduction in biodiversity, industrial barrens still support a variety of life, including regionally rare and endangered species, as well as populations that evolved specific adaptations to the harsh and toxic environment. Recently, most industrial barrens show some signs of natural recovery due to emission decline or closure of responsible polluters; some of barren sites have been or are being successfully revegetated. The remaining industrial barrens offer unique opportunities for conducting ‘basic’ ecological research, in particular for testing some general theories in an evolutionary novel stressful environment; some of barren habitats deserve conservation for scientific and educational purposes. [ABSTRACT FROM AUTHOR]

In areas disturbed by pollution, populations of herbivorous insects may reach high densities. This study was conducted to test one of the hypotheses attempting to explain this phenomenon – that pollution creates an enemy-free space for herbivores. We monitored the population densities of Eriocrania leaf-mining moths on mountain birch, Betula pubescens subsp. czerepanovii, in the vicinity of the nickel–copper smelter in Monchegorsk (Kola Peninsula, NW Russia) over twelve years (1994–2005) and assessed larval mortality from parasitoids, ants and birds. The mean density (mines/birch leaf area) of Eriocrania populations in severely disturbed habitats (industrial barrens) was about 2.7 times higher, and peak densities 2–4 times higher, than in pristine forests. Temporal population variability (measured as the coefficient of variation of log-transformed densities) increased with an increase in pollution load. The proportion of infested trees was not affected by pollution, but mine distribution among trees was more clumped in the polluted sites. Eriocrania populations in disturbed sites fluctuated independently of each other, whereas populations in forest sites fluctuated in synchrony. Larval mortality caused by parasitoids was lower in disturbed sites only during those years when populations of Eriocrania reached high densities; mortality from ants and birds did not differ between disturbed and undisturbed habitats in either high or low density years. In undisturbed forests the rate of population change correlated negatively with previous-year parasitism, suggesting that parasitoids are the key demographic factor in Eriocrania population dynamics. In the habitats heavily disturbed by pollution no such correlation was found, which means that negative feedback with parasitoids is disrupted: parasitoids fail to follow host population growth, thus creating an enemy-free space for Eriocrania leafminers. [ABSTRACT FROM AUTHOR]

Electrical properties of gallium-doped n-Pb1− x SnxTe alloys ( x=0.09−0.21) are studied. Ahomalous temperature dependences of the Hall coefficient which indicate the Fermi level pinning by a resonant gallium level in the conduction band were detected. The dependences of the electron concentration and Fermi energy on the alloy composition and temperature are calculated from experimental data in terms of the two-band Kane dispersion relation. It is shown that the gallium resonant level position relative to the valence band top is almost independent of the matrix composition. The dependence of the thermal coefficient of the resonant level shift with respect to the midgap on the alloy composition is obtained. [ABSTRACT FROM AUTHOR]

The cellulolytic activity of an alkaliphilic obligate anaerobic bacterium, Z-7026, which was isolated from the microbial community of soda-lake sediments and belongs to the cluster III of Clostridia with low G+C content, was studied. The bacterium was capable of growing in media with cellulose or cellobiose as the sole energy sources. Its maximal growth rate on cellobiose (0.042–0.046 h−1) was observed at an initial pH value of 8.5–9.0, whereas the maximal rate of cellulase synthesis, assayed by using a novel fluorimetric approach, was found to be 0.1 h−1 at pH 8–8.5. Secreted proteins revealed high affinity for cellulose and were represented by two major forms of molecular masses of 75 and 84 kDa, whereas the general protein composition of the precipitated and cellulose-bound preparations was similar to cellulosome subunits of Clostridium thermocellum. The optimum pH of the partially purified enzyme preparation towards both amorphous and crystalline cellulose was in the range 6–9, with more than 70% and less than 50% of maximal activity being retained at pH 9.2 and 5.0, respectively. [ABSTRACT FROM AUTHOR]

The effects of elevated carbon dioxide on plant–herbivore interactions have been summarized in a number of narrative reviews and metaanalyses, while accompanying elevation of temperature has not received sufficient attention. The goal of our study is to search, by means of metaanalysis, for a general pattern in responses of herbivores, and plant characteristics important for herbivores, to simultaneous experimental increase of carbon dioxide and temperature (ECET) in comparison with both ambient conditions and responses to elevated CO2 (EC) and temperature (ET) applied separately. Our database includes 42 papers describing studies of 31 plant species and seven herbivore species. Nitrogen concentration and C/N ratio in plants decreased under both EC and ECET treatments, whereas ET had no significant effect. Concentrations of nonstructural carbohydrates and phenolics increased in EC, decreased in ET and did not change in ECET treatments, whereas terpenes did not respond to EC but increased in both ET and ECET; leaf toughness increased in both EC and ECET. Responses of defensive secondary compounds to treatments differed between woody and green tissues as well as between gymnosperm and angiosperm plants. Insect herbivore performance was adversely affected by EC, favoured by ET, and not modified by ECET. Our analysis allowed to distinguish three types of relationships between CO2 and temperature elevation: (1) responses to EC do not depend on temperature (nitrogen, C/N, leaf toughness, phenolics in angiosperm leaves), (2) responses to EC are mitigated by ET (sugars and starch, terpenes in needles of gymnosperms, insect performance) and (3) effects emerge only under ECET (nitrogen in gymnosperms, and phenolics and terpenes in woody tissues). This result indicates that conclusions of CO2 elevation studies cannot be directly extrapolated to a more realistic climate change scenario. The predicted negative effects of CO2 elevation on herbivores are likely to be mitigated by temperature increase. [ABSTRACT FROM AUTHOR]

The effect of pressure on electrical properties of Ga-doped n-Pb1 – xGexTe alloys (x = 0.06, 0.08) is studied. The pressure dependence of the activation energy of a deep Ga impurity center is obtained. It is shown that the position of the Ga level with respect to the bottom of the conduction band is virtually unchanged under pressure. Anomalies are found in the temperature and pressure dependences of the resistivity; these anomalies are apparently associated with structural phase transitions from the cubic to the rhombohedral and orthorhombic phases, respectively. The results obtained are used to construct a diagram of the modification of the energy spectrum of charge carriers in the cubic phase of the alloys investigated under pressure. © 2004 MAIK “Nauka / Interperiodica”. [ABSTRACT FROM AUTHOR]

1 We hypothesized that the role of positive plant-plant interactions will increase with the environmental stress imposed by long-term pollution. We studied the effects of top- canopy plants on two deciduous ( Vaccinium myrtillus, V uliginosum) and two evergreen ( V vitis-idaea, Empetrum nigrum ssp. hermaphroditum) dwarf shrubs by comparing their growth and reproduction under trees and in gaps in industrial barrens and in unpolluted forests in the Kola Peninsula (NW Russia). 2 Interactions between habitat type and tree proximity on berry yield and reproductive effort were significant for four species combined. In forest habitats both berry yield and reproductive effort were higher in dwarf shrub patches growing in gaps than under tree canopies, but in barren habitats Vaccinium species reproduced better under tree canopies. 3 The interaction of habitat type and tree proximity was also significant for vegetative biomass, mostly due to evergreen species benefiting from neighbouring trees in barren habitats. 4 Overall, all four dwarf shrub species reproduced better in barren habitats than in forests, mostly due to increased reproduction observed under tree canopies in barren sites. 5 Values of the relative neighbour effect indicated that the impact of top-canopy plants on dwarf shrubs shifted from negative in forest habitats to generally positive in barren habitats. [ABSTRACT FROM AUTHOR]

Larvae of the leaf beetle Chrysomela lapponica obtain salicyl glucosides (SGs) from the host plant to produce a defensive secretion with salicylaldehyde. In northern Russia, larvae and pupae experience high parasitism by the phorid fly Megaselia opacicornis and tachinid fly Cleonice nitidiuscula. We compared the suitability of the SG-rich Salix borealis and SG-poor S. caprea and S. phylicifolia to Ch. lapponica and tested whether enemy pressure on Ch. lapponica varies among host species that differ in SG content. In the laboratory, survival of Ch. lapponica larvae was higher on S. borealis than on S. caprea and S. phylicifolia, while adult body mass was higher on S. borealis and S. caprea than on S. phylicifolia. In the field, parasitism by both M. opacicornis and Cl. nitidiuscula was greater on beetles from S. borealis than from the SG-poor S. caprea or S. phylicifolia. In a laboratory choice test, the pupal parasitoid M. opacicornis laid similar numbers of eggs on beetles reared on SG-rich and SG-poor willows, suggesting that the host plant-derived defence is not effective against this parasitoid. In a field enemy-exclusion experiment, beetle survival was greatly enhanced by the exclusion of enemies, but survival rates did not differ between S. borealis and S. caprea, although larvae developed faster on S. borealis. On the other hand, parasitism and predation were observed more often on S. borealis than on S. caprea. Thus, beetle larvae perform better but also suffer higher predation and parasitism on S. borealis than on SG-poor willows. Ch. lapponica does not appear to obtain enemy-free space by feeding on SG-rich willow species. [ABSTRACT FROM AUTHOR]

The influence of Ga doping and irradiation with high-energy electrons on the galvanomagnetic effects in n-Pb[sub 1-x]Ge[sub x]Te:Ga (0.04 ... x ... 0.06) was investigated. Transitions to the metal-type conduction were found to occur both with an increase in the impurity content and as a result of irradiation. It is concluded that the impurity level does not pin the Fermi level. It is demonstrated that gallium doping and electron irradiation are the most effective complementary methods for controlling the electrical properties of alloys. [ABSTRACT FROM AUTHOR]

Summary1 Stress may affect compensatory plant growth and plant responses to herbivory may therefore be modified by pollution. We compared the effects of leaf clipping on growth, reproduction and developmental stability of two willow species (Salix borealis and S. caprea) growing at different distances from two copper-nickel smelters (Monchegorsk, NW Russia and Harjavalta, SE Finland). 2 In unpolluted sites, the defoliation of both willow species adversely affected sexual reproduction and increased the formation of epicormic shoots, but did not change either shoot growth or leaf size. Timing and extent of clipping had little effect on the responses. 3 Compensatory responses to leaf clipping in polluted habitats were reduced, especially in S. borealis, as reflected by decrease in shoot growth and fruit production and an increase in leaf fluctuating asymmetry, a non-specific indicator of stress. 4 Activation of dormant buds was a common compensatory response to herbivory in unpolluted sites. The lack of an increase in epicormic shoots in polluted sites may be due to already weakened apical dominance. 5 Compensatory abilities may be affected both by direct damage caused by pollutants and pollution-induced increases in environmental stress. Although S. borealis shows no visible sign of stress in polluted sites, regrowth from dormant buds and enhanced shoot growth were seen under these conditions. Resources were not therefore available for further compensation of damage caused by defoliation. Our results fit the hypothesis that fast growing plants have low compensative abilities. 6 Salix caprea shows more pollution-induced stress than S. borealis, expressed as increased developmental instability near the weaker and shorter shoots near the stronger pollution source. This may explain the differences in their compensatory responses in polluted sites. [ABSTRACT FROM AUTHOR]

The reactions of arylhydrazonocyanoacetamides with triethyl orthoformate and triethyl orthoacetate have been studied. Interaction of triethyl orthoformate with amides bearing normal alkyl substituents on the carbamoyl group resulted in cyclization to 2-aryl-4-alkyl-5-oxo-3-ethoxy-2,3,4,5-tetrahydro-1,2,4-triazin-6-carbonitriles, whereas reaction of N-phenyl- and N-cycloalkylacetamides with triethyl orthoformate gave products of ethylation at the hydrazone group. Reactions of arylhydrazonocyanoacetamides with triethyl orthoacetate led to 2-(arylethylhydrazono)acetamides exclusively. [ABSTRACT FROM AUTHOR]

The deepening of economic and social processes in the information environment on the one hand determines the need for timely development, and on the other hand, provides an opportunity to introduce modern digital methods in the field of evaluation and justification of the effectiveness of investments in infrastructure facilities. The development of the railway network in difficult geographical conditions and remote areas largely determines the significant investment, long construction time, and is accompanied by a high degree of uncertainty, which reflects the relevance of the study. The article presents a model of socio-economic evaluation of the effectiveness of investment in the construction of promising railway lines, taking into account the uncertainty of the main dynamic parameters of the project. A cumulative criterion for assessing the socio-economic efficiency of investments, taking into account the uncertainty for the period of commissioning of the railway line, has been developed. The analysis of uncertainty factors is carried out. The volume and cost of sales of the main goods transported by the railway line, as well as changes in the migration inflow of the population for its service were chosen as the key ones. A probabilistic model of cash flows, effects, results and costs in terms of the payback period of investments, taking into account uncertainty factors for the Monte Carlo method, is developed. The algorithm of probabilistic evaluation of socio-economic efficiency taking into account uncertainty of key parameters of the project by Monte Carlo method is presented. The calculation of socio-economic efficiency assessment taking into account the uncertainty factors of the construction of the railway line. The model of socio-economic evaluation of investment efficiency with uncertainty reflects the specifics of the investment project and takes into account the probabilistic uncertainty factors, which provides more accurate and reliable evaluation results than deterministic evaluation. The results of the study showed that the greatest importance on the performance indicators have the volume and cost of goods at the time of commissioning of the railway line. The factor of migration inflow of population in the area of construction of the line has a minor impact. Due to the high rate of return on investment, the investment performance indicator is more sensitive to selected factors in the early stages of evaluation (up to 10-15 years). Also, the payback period for the regional level, as well as the level of the enterprise is more sensitive than the payback period at the Federal level. The results of socio-economic evaluation of the efficiency of the investment project showed high efficiency, quick payback and social significance of the project

The ability of block copolymers to disperse carbon nanomaterial Taunit is studied using nonionic surfactants: water-soluble poloxamer Р407 and oil-soluble poloxamine (diproxamine-157). According to NMR spectroscopy and surface tension measurements, interaction exists between block copolymer molecules and the surface of multiwalled carbon nanotubes of the Taunit nanomaterial, which prevents their reagglomeration. Possible dispersion mechanisms are analyzed. A good dispersibility of carbon nanomaterials and the stability of dispersions obtained from the aqueous solutions of poloxamers and in the oil medium of poloxamines are demonstrated. [ABSTRACT FROM AUTHOR]

The study is devoted to identifying the main trends in the development of the theory of evaluating the effectiveness of investment and construction linear-extended projects, the implementation of which is carried out with the participation of public investments of different levels, as well as those of socio-economic importance for the construction region and Russia as a whole. Global informatization, penetrating into all spheres of human activity, determines the digital economy formation as an economic activity operating in the digital space. This means that digital material data is a key factor in production, processing of which in large volumes, compared to traditional forms of management, makes it possible to increase the economic activities efficiency. Methods of qualitative and quantitative risk assessment and accounting for the uncertainty of investment projects have been applied. In most theoretical directions, the preference is given to the use of the cost effectiveness criterion; methods of qualitative assessment and risk identification; introduction of modern digital methods of risk assessment and uncertainty accounting (Monte Carlo method, method of integral convolutions of numbers). There is no universal theoretical approach that reveals the investment process essence through the return on investment, which makes it possible to reliably assess the economic efficiency in construction ICP in the digital economy. It was revealed that the implementation of investment and construction projects (ICP) suggests the need to supplement the theoretical foundations, taking into account their specificity in terms of the effects taken into account, as well as uncertainty factors. The development of efficiency theory and, as a consequence, an increase in the basic data collection speed in the digital economy, as well as an increase in the reliability of efficiency estimates due to mathematical methods for quantifying risk and uncertainty. The implementation of investment and construction projects plays an important role in the transport industry.

The study is devoted to the issues of determining the cost of building materials, affecting the calculation of actual construction cost. These issues are of particular relevance, since there is a reform of the system of pricing and estimated rationing in construction at present, which fundamentally affects the construction actual and reliable cost determination. The proposed federal state information system of pricing in construction, as an electronic resource, a unified base for the cost formation of the building materials involved in the construction products’ estimated cost formation.

The kinetics of the variation of the electron concentration in electron-irradiated (T≈300 K, E=6 MeV, Φ≤7.1 × 10[sup 17] cm[sup -2]) n-Pb[sub 1 - x]Sn[sub x]Se (x = 0.2 and 0.25) alloys in the vicinity of the metal-insulator transition induced by electron irradiation are investigated. The principal parameters of the energy spectrum of the irradiated alloys are determined by comparing the experimental and theoretical dependences of the electron concentration on fluence. It is shown that agreement between the theoretical and experimental data is possible only under the assumption that the defect production rate decreases with increasing fluence, and a model, within which the main defect formation mechanism in the alloys investigated is the formation of complexes of primary radiation defects with structural defects typical of the as-grown crystals, is proposed. [ABSTRACT FROM AUTHOR]

The behaviour features of carbonate sludge which are a waste of water treatment process were studied in aqueous and oil environment. Based on the analysis of images of carbonate sludge particles in liquid media made by laser scanning confocal microscopes, the existence of nanostructures of various chemical compositions having several hundred nanometers in size, both single and forming porous conglomerate structures with a developed surface was revealed. The existence of such fragmentation of fine carbonate sludge powder particles in liquid media suggests that the mechanism of action of sludge additives is similar to that of nanoparticles. It was shown that the waste of the water treatment can be used as a cheap and environmentally friendly nanostructured material for industrial and environmental engineering, in particular, to improve the properties of hydrocarbon fuels. If necessary, the effect of carbonate sludge can be enhanced by changing its composition at the coagulation stage or by adding other nanoparticles. The data on the composition and texture characteristics of used sludge were given.

The relative content of antioxidants in the mycelium of Trichoderma reesei 6/16 obtained by propagation of fungal protoplasts was shown to decrease (as compared to the initial culture taken for preparation of protoplasts) and restored only in the second generation of regenerated mycelium. In this respect, the effects of various antioxidants (β-carotene, ascorbic acid, α-tocopherol, and ionol) on the frequency of regeneration of T. reesei 6/16 protoplasts were studied. β-Carotene increased the viability of fungal protoplasts to the greatest extent. The effect of ascorbic acid depended on the presence of Fe ions. Ionol did not cause any measurable protective effect. [ABSTRACT FROM AUTHOR]

Galvanomagnetic properties of gallium-doped Pb[sub 1 - x]Ge[sub x]Te (0.04 ≤ x ≤ 0.08) alloys were studied. It is shown that gallium doping induces a deep impurity level in the alloy band gap; the energy position of this level depends on the germanium content in the alloy. A model assuming that doping with gallium results in the emergence of two defect levels in the energy spectrum of the alloys is proposed. [ABSTRACT FROM AUTHOR]