Key methods developed and used in the USSR and in the Russian Federation to determine the impact and friction sensitivity of energetic materials and explosives have been *** methodologies and instruments that underlie...
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Key methods developed and used in the USSR and in the Russian Federation to determine the impact and friction sensitivity of energetic materials and explosives have been *** methodologies and instruments that underlie the assessment of their production and handling safety have been *** of a large number of compounds have revealed relationships between their sensitivity parameters and structure of individual compounds and *** range of change of physical and chemical characteristics for the compounds we examined covers the entire region of their *** methodology and equations have been formulated to estimate the impact and friction sensitivity parameters of energetic materials and to evaluate the technological safety in *** developed methodology is characterized by high-accuracy calculations and prediction of sensitivity parameters.
Sex determination system in birds is characterized by a homo-(Neognatae) and heteromorphic (Paleognatae) sex chromosomes. Heterogametic sex is female (ZZ/ZW system). DMRT1 gene is a gene regarded as a main male sex de...
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Sex determination system in birds is characterized by a homo-(Neognatae) and heteromorphic (Paleognatae) sex chromosomes. Heterogametic sex is female (ZZ/ZW system). DMRT1 gene is a gene regarded as a main male sex determining factor in this group of animals. The question remains about the participation of other factors (HEMOGEN, AMH etc.) in appearance of testis, and the role of steroid hormones in formation of ovaries. Complete sex inversion is not typical for species with genotypic sex determination (GSD), although the effect of estrogen metabolites is noted for birds. For birds epigenetic mechanisms of regulation (methylation of DNA and non-coding RNA) have been described for sex controlling genes such as CYP19A1 and DMRT1.
The work was carried out by microinjections of an aromatase inhibitor letrozole, an estrogen receptor modulator tamoxifen in incubated eggs Gallus g. domesticus, the first day of incubation. It also used 5-azacytidine...
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The work was carried out by microinjections of an aromatase inhibitor letrozole, an estrogen receptor modulator tamoxifen in incubated eggs Gallus g. domesticus, the first day of incubation. It also used 5-azacytidine (5-AC) at the same time. Injection of progesterone was carried out before the onset of meiosis prophase 1 on 16 h of incubation. Morphologically and histologically and by PCR, sex of the 17-day embryos was controlled. According to information received microinjection of letrozole caused almost a 100% inversion of genetic males to females, which is manifested in the morphology of the gonads. In other experiments, sex reversal is not revealed. The results are obtained in this study, and the data suggest that the presence of gonadogenesis in female chickens makes earlier emergence of aromatase in the beginning of incubation, than that according to the classical scheme of sex determination in birds. Presumably this kind of synthesis is triggered by some W-chromosomal factors. It failed to detect the phenomenon of gender inversion—the transformation of males into females after exposure to demethylating agent 5-AC that casts doubt on the participation of male hypermethylated (MHM)-RNA-segment in regulating the activity of sex determining genes.
The growing demand for luminescent nanomaterials intended for various applications increases the necessity to develop and improve approaches to the creation of highly efficient nanosized *** current study,an approach ...
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The growing demand for luminescent nanomaterials intended for various applications increases the necessity to develop and improve approaches to the creation of highly efficient nanosized *** current study,an approach to enhancing the efficiency of red luminescence of monoclinic Y2O3:Eu3+with the particle size of ~20 nm by creating the oxygen-enriched environment during the gas-phase synthesis was *** investigate the effect of oxygen amount during the synthesis on characteristics of the phosphor,a series of nano structured Y2O3:Eu3+with the addition of 0-40 vol% O2to the main buffer gas Ar was synthesized by laser *** is shown that the amount of added O2exerts virtually no effect on the phase composition and particle size,but significantly improves the luminescent characteristics of Y2O3:Eu3+.Thus,the addition of 30 vol% O2leads to virtually a 20-fold growth in the photoluminescence(PL) intensity caused by5D0→7F0-4transitions in Eu3+and an increase in the absolute PL quantum yield from 3% to 53%(λex=395 nm) compared to the sample synthesized without *** addition of oxygen also improves the emission color coordinates from(0.571,0.320) to(0.630,0.322)due to the removal of a considerable fraction of oxygen *** synthesized nanopowders are shown to be highly stable:upon storage under ambient conditions for two *** yield(QY) of the samples decreases by less than 2%.It is expected that the key features underlying the proposed approach will be useful for various methods used to synthesize oxide nanophosphors.
The paper considers application of artificial neural networks(ANNs)for fast numerical evaluation of a residual impactor velocity for a family of perforated PMMA(Polymethylmethacrylate)*** ANN models were trained using...
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The paper considers application of artificial neural networks(ANNs)for fast numerical evaluation of a residual impactor velocity for a family of perforated PMMA(Polymethylmethacrylate)*** ANN models were trained using sets of numerical results on impact of PMMA plates obtained via dynamic FEM coupled with incubation time fracture *** developed approach makes it possible to evaluate the impact strength of a particular target configuration without complicated FEM calculations which require considerable computational ***,it is shown that the ANN models are able to predict results for the configurations which cannot be processed using the developed FEM routine due to numerical instabilities and errors:the trained neural network uses information from successful computations to obtain results for the problematic cases.A simple static problem of a perforated plate deformation is discussed prior to the impact problem and preferable ANN architectures are presented for both *** insight into the perforation pattern optimization using a genetic algorithm coupled with the ANN is also made and optimized perforation patterns which theoretically enhance the target impact strength are constructed.
A century and a half ago,in the European part of Russia(Moscow),forest scientists established the first long-term observations of forests,many of which are under observation to the present *** the twentieth century,cl...
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A century and a half ago,in the European part of Russia(Moscow),forest scientists established the first long-term observations of forests,many of which are under observation to the present *** the twentieth century,climate changes and,due to industrial development,forest areas were under air *** on observations from 157 sites,this study shows that the growth and density of Scots pine(Pinus sylvestris L.)have decreased by the end of the twentieth *** environment has changed,and the growth and development of plantations has *** yields(-34%stand volume)and their life expectancy(on average 50 years)have *** changes are critical for forestry and for the management of forests in urban *** to the decline in growth,ecosystem functions by urban forests has *** order to increase the sustainability of urban forests and the provision of ecosystem services,it is preferable to create multi-species stands with a complex structure.
The problem relating to the small-amplitude free capillary oscillations of an encapsulated spherical drop is solved theoretically in the framework of asymptotic *** are supposed to be inviscid and *** formulas derived...
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The problem relating to the small-amplitude free capillary oscillations of an encapsulated spherical drop is solved theoretically in the framework of asymptotic *** are supposed to be inviscid and *** formulas derived are presented for different parameters of the inner and outer liquids,including densities,thickness of the outer liquid layer,and the surface and interfacial tension *** frequencies of oscillation of the encapsulated drop are studied in relation to several“modes”which can effectively be determined in experiments by photo and video *** results are presented in terms of oscillation frequencies reported as a function of the mode number,the spherical layer thickness and the relation between the(surface and interfacial)tension *** is revealed that the influence of the liquids’parameters(and related variations)on the drop oscillation changes dramatically depending on whether oscillations are“in-phase”or“out-of-phase”.Frequencies for“in-phase”type oscillations can be correlated with linear functions of the shell thickness and the relative values of interfacial tension coefficient whereas the analogous dependencies for the“out-of-phase”type oscillation are essentially non-linear.
By the method of high-temperature reactions in solid phase, compounds with the general formula MⅡ(AⅢ2/3U1/3)O3(MⅡ=Sr, AⅢ=Sc, In;MⅡ=Ba, AⅢ=Sc, In, Y, Nd-Lu) were *** structures(space groups Fm 3 m and Pnma)...
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By the method of high-temperature reactions in solid phase, compounds with the general formula MⅡ(AⅢ2/3U1/3)O3(MⅡ=Sr, AⅢ=Sc, In;MⅡ=Ba, AⅢ=Sc, In, Y, Nd-Lu) were *** structures(space groups Fm 3 m and Pnma) were refined by the Rietveld method and morphotropic transition in Ba(Ln2/3U1/3)O3 on the border of Gd-Tb was *** means of high-temperature X-ray diffraction, phase transitions were studied and thermal expansion coefficients were determined.
The degradation of nonylphenol (NP) in aqueous solution with UV, H202/UV, and Fenton/photo-Fenton processes was studied. The efficacy of direct and hydrogen peroxide photolysis proved to be dependent on the pH value...
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The degradation of nonylphenol (NP) in aqueous solution with UV, H202/UV, and Fenton/photo-Fenton processes was studied. The efficacy of direct and hydrogen peroxide photolysis proved to be dependent on the pH value. The addition of H202 to UV treatment improved NP degradation. The application of UV photolysis and the H202/UV system at pH 7 resulted in low pseudo first-order rate constants at 104 sec1 . In the experiments at elevated pH values the pseudo-first order rate constants increased to 103 sec1 . The efficacy of the Fenton process was lower in comparison with UV and hydrogen peroxide photolysis. The addition of UV irradiation to the H202/Fe2+ system substantially improved NP degradation efficacy. In terms of performance, the photo-Fenton process was similar to the H202/UV process. The most favourable process for complete nonylphenol degradation considering both operational cost and treatment efficacy was H202/UV at pH 11 and 250 μmol/L H202 .
The paper presents a number of signal processing approaches for the spectral interferometric interrogation of extrinsic Fabry-Perot interferometers(EFPIs). The analysis of attainable microdisplacement resolution is pe...
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The paper presents a number of signal processing approaches for the spectral interferometric interrogation of extrinsic Fabry-Perot interferometers(EFPIs). The analysis of attainable microdisplacement resolution is performed and the analytical equations describing the dependence of resolution on parameters of the interrogation setup are derived. The efficiency of the proposed signal processing approaches and the validity of analytical derivations are supported by experiments. The proposed approaches allow the interrogation of up to four multiplexed sensors with attained resolution between 30 pm and 80 pm, up to three times improvement of microdisplacement resolution of a single sensor by means of using the reference interferometer and noisecompensating approach, and ability to register signals with frequencies up to 1 kHz in the case of 1 Hz spectrum acquisition rate. The proposed approaches can be used for various applications, including biomedical, industrial inspection, and others, amongst the microdisplacement measurement.
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