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The authors analyze modern achievements in technical diagnostics and methodology and determine their possibility to improve the quality of diagnostic support of promising and existing radio-electronic technical means. A general algorithm for the development of diagnostic support for radio-electronic devices is proposed taking into account their structure, repair conditions, and metrological support to minimize the average recovery time. [ABSTRACT FROM AUTHOR]

The optimal geometries of (CaO)n and (MgO)n clusters at n = 2–30 have been found and the enthalpies of formation of 1D, 2D, and 3D structures have been determined using quantum-chemical DFT calculations. The calculation demonstrates that the formation of linear chains of Ca and Mg oxides practically does not occur, while the formation of two-dimensional (tiled) and three-dimensional (cubic) structures proceeds with a large release of energy. The competing process of formation of molecular rods consisting of planar six-membered rings (MO)3 has been considered, and it has been shown to proceed not through the stage of preliminary formation of six-membered rings, but directly from monomer units. [ABSTRACT FROM AUTHOR]

On the basis of X-ray diffraction experiment data the atomic molecular configuration in the short-range order region of amorphous nitrocellulose from Miscanthus is constructed by the computer simulation technique using the HyperChem 8 program. It is shown that the arrangement of atoms in the short-range order region of amorphous nitrocellulose is satisfactorily described by a cluster composed of nine nitrocellulose chains, two cellulose I chains twisted by an angle of 72°, and two untwisted cellulose I chains. Each chain contains ten glucose residues. In the final cluster, the above-mentioned chains form an approximately hexagonal layer in projection on plane ab with a distance between them being 12.2 Å. In projection on plane bc, the dimensions of the final cluster are 28 Å along axis b and 54 Å along axis c. The total number of atoms is 3300, and the degree of polymerization is 130; the formula unit of the asymmetric fragment is [C6H7.24O2(OH)0.92(ONO2)2.08]130. The result reliability is proved by the fact that the experimental curve of X-ray scattering intensity distribution I(s) and the corresponding curve calculated for the cluster coincide with an accuracy of up to 7.5%. [ABSTRACT FROM AUTHOR]

The results of X-ray diffraction analysis of bacterial nanocellulose (BNC), synthesized by Komagataeibacter xylinus В-12429 and Komagataeibacter xylinus В-12431 producers in enzymatic hydrolyzates of miscanthus, oat hull, and synthetic nutrient medium, are presented. It is found by full-profile analysis that the dominant component in all BNC samples studied, independent of the producer and nutrient medium, is allomorph Іα, whose content varies from 96 to 100%. The following characteristics of the supramolecular structure of the samples have been determined: the degree of crystallinity, sizes of elementary fibrils and the shape of their cross section, and the coherence length of elementary fibrils along the fibril axis. [ABSTRACT FROM AUTHOR]

This article contains an exposition of a quasi-biological model of radiation carcinogenesis. The model was developed to describe the dependence of the radiogenic cancer incidence rate on the age at single exposure to radiation and the age at follow-up. The mathematical image of the model is compared with the corresponding ICRP and UNSCEAR mathematical models. The model is used to analyze the latest data on the cancer incidence rate in a cohort of Japanese people (2009) exposed to radiation from atomic explosions in 1945. It is shown to have methodological possibilities and advantages. The model parameters of radiogenic and background cancer incidence rates in the LSS cohort are given. [ABSTRACT FROM AUTHOR]

The global abundance and availability of oat hulls make them a promising feedstock to produce a unique type of cellulose, the bacterial one. This is the first study examining how a chemical pretreatment method of oat hulls influences the yield and properties of bacterial cellulose (BC) in extended cultivation. Here we employed our own pretreatment methods that use dilute HNO3 and NaOH solutions in one and two stages, a total of four pretreatment methods. Further technological stages were performed in the same manner: pulps were enzymatically hydrolyzed with commercial enzymes CelloLux-A and BrewZyme BGX, and biosynthesis of BC was run using the Medusomyces gisevii Sa-12 symbiotic culture. A two-stage (HNO3 + NaOH) pretreatment of oat hulls was found to afford a biologically good medium and increase the BC yield 1.8−3.2-fold compared to the other pretreatments used. A pretreatment method of oat hulls determined the BC yield and degree of polymerization. However, a pretreatment method had no impact on the highest crystallinity index and allomorph Iα content of all the BC samples, which is explained by Medusomyces gisevii Sa-12 used. The crystallinity index and allomorph Iα content, as measured by X-ray diffractometry, are proposed for use as BC quality assessment criteria. [ABSTRACT FROM AUTHOR]

We propose a new foliation of asymptotically Euclidean initial data sets by 2-spheres of constant spacetime mean curvature (STCMC). The leaves of the foliation have the STCMC-property regardless of the initial data set in which the foliation is constructed which asserts that there is a plethora of STCMC 2-spheres in a neighborhood of spatial infinity of any asymptotically flat spacetime. The STCMC-foliation can be understood as a equivariant relativistic generalization of the CMC-foliation suggested by Huisken and Yau (Invent Math 124:281–311, 1996). We show that a unique STCMC-foliation exists near infinity of any asymptotically Euclidean initial data set with non-vanishing energy which allows for the definition of a new notion of total center of mass for isolated systems. This STCMC-center of mass transforms equivariantly under the asymptotic Poincaré group of the ambient spacetime and in particular evolves under the Einstein evolution equations like a point particle in Special Relativity. The new definition also remedies subtle deficiencies in the CMC-approach to defining the total center of mass suggested by Huisken and Yau (Invent Math 124:281–311, 1996) which were described by Cederbaum and Nerz (Ann Henri Poincaré 16:1609–1631, 2015). [ABSTRACT FROM AUTHOR]

The authors' point of view, as expressed in publications, on the evolution of models taking into account the irregularity of irradiation in time, which are contained in the ICRP Recommendations and are used in radiation risk assessment, is generalized. The formal nature and imperfection of these models is noted. The need to build models based on biological concepts of radiation carcinogenesis is justified. [ABSTRACT FROM AUTHOR]

The study was performed for miscanthus introduced and grown in West Siberia. Transformation of miscanthus into bacterial nanocellulose was accomplished for the first time. The microbiological synthesis of bacterial nanocellulose using the Medusomyces gisevii Sa-12 symbiotic culture gave chemically pure bacterial nanocellulose with exceptionally high crystallinity index and content of Iα allomorph. [ABSTRACT FROM AUTHOR]

The compositions of alumoboro- and alumochromophosphate with a tetratomic alcohol, pentaerythritol, which is the component forming hydrogen and chemical bonds with the phosphate groups, are considered. The extremum dependence of the softening point on the concentration of pentaerythritol accompanied by a symbatic change in the moisture resistance is found. The heat and thermal resistance, oxygen index of the cured compositions, and bending strength of the composites reinforced by a basalt fabric are measured. The energy of the intermolecular bonds of the monomeric phosphate units with pentaerythritol is calculated, and computer modeling of the conformation of the complexes is performed. The higher chemical activity of alumochromophosphate in comparison with alumoborophosphate is determined. [ABSTRACT FROM AUTHOR]

The interaction energies of fragments of aluminoborophosphate chains with water molecules and nitrogen-containing compounds are calculated using a density functional theory (DFT). The conformational changes of monomer units of aluminophosphate and molecular complexes during the formation of hydrogen bonds are analyzed. The complexation of aluminoborophosphate with various nitrogen-containing compounds, which leads to the displacement of water from the chain surface, is considered, and the thermal effects of complex formation are calculated. The moisture absorption of mixtures of oligomeric aluminoborophosphate with amines was measured upon various ratios of components. [ABSTRACT FROM AUTHOR]

The demand for precursors obtained by biotechnological means is constantly growing in technical chemistry. The use of bioethanol is therefore of interest in the production of ethylene. In this work, Miscanthus sacchariflorus is used as a raw material for the production of bioethanol for the first time. The stage of the chemical treatment of miscanthus with 4 wt % nitric acid solution is successfully scaled-up under the conditions of pilot industrial production, and the products of nitric acid treatment (PNTs) are obtained with a yield of 37.4% and a 96.0% content of hydrolyzable components. It is shown that preliminary chemical treatment of miscanthus with nitric acid, regardless of its type, allows substrates with similar chemical compositions to be obtained. The process is scaled up for the first time in a fermenter with a capacity of 11 L (a scaling factor of 1 : 8) to combine the saccharification and fermentation of PNTs from miscanthus and raise the concentration of PNTs from 60.0 to 90.0 g/L. Commercially available enzyme preparations Cellolux-A and Bruzheim BGX are used for saccharification. Yeast strain VKPM Saccharomyces cerevisiae Y-1693 is used for fermentation. It is found that the concentration of bioethanol grows by 9.5 g/L upon raising the substrate concentration from 60.0 to 90.0 g/L. It is recommended that a substrate concentration of 90.0 g/L be used to scale up the process under trial industrial conditions. A basic scheme isproposed for producing bioethanol with a yield of bioethanol 202 L/t of miscanthus. [ABSTRACT FROM AUTHOR]

The reactions of oligomeric aluminoborophosphates with hexamethylenediamine and pentylamine are studied, as are the properties of the obtained products which are polycomplexes with the participation of hydrogen bonds, which is confirmed by the results of quantum chemical calculations. The changes in the relaxation properties of the polycomplexes are determined by the softening and flow temperatures measured by thermomechanical analysis. It is shown that the modification of polyphosphates by primary amines under mild conditions leads to an increase in the water resistance of the obtained polycomplexes. [ABSTRACT FROM AUTHOR]

The possibility of synthesizing and processing incombustible materials based on oligomer and polymer oxides and their hybrids with organic and organoelement compounds at temperatures of 20–200°C is explored. Inorganic thermosetting plastics with a wide range of pour points (100–700°C) are synthesized. A more intense heat treatment can provide the formation of fireproof materials. Cast polymer–polymer blends of inorganic/organic polymers prepared by melt blending are studied. Possible areas of application of reinforced materials based on inorganic and hybrid impregnation composites are determined. [ABSTRACT FROM AUTHOR]

Bacterial nanocellulose, which was produced by Medusomyces gisevii Sa-12 cultured in enzymatic hydrolysates of Miscanthus, was studied by X-ray diffraction. The characteristics of the supramolecular structure of the crystalline component of cellulose samples, such as the degree of crystallinity and the size and shape of elementary fibrils, were determined. The atomic structure was compared with the known structural models of cellulose, and the synthesized bacterial nanocellulose was shown to be cellulose Iα. The lengths and angles of the triclinic unit cell were determined. The composition of the culture medium made from enzymatic hydrolysates of Miscanthus was found to have an effect on the shape and size of elementary fibrils and have no effect on the degree of crystallinity and the fraction of cellulose allomorph Іα. The use of Medusomyces gisevii Sa-12 as the producing organism allows the preparation of bacterial nanocellulose with a high degree of crystallinity in the range of 86–93% containing cellulose allomorph Іα as the major component. [ABSTRACT FROM AUTHOR]

The conceptual possibility to synthesize bacterial cellulose nitrates with the use of commercial mixed acid was demonstrated. The initial bacterial cellulose was produced by the Medusomyces gisevii Sa-12 symbiotic culture in a synthetic nutrient broth in a Binder constant climate chamber. The resulting bacterial cellulose nitrate sample had 11.45% nitrogen content, 1900 cP viscosity, 15.8% solubility in ethanol—diethyl ether mixture, and 0.10% ash content. An extremely high sample viscosity (organogelation) in a ∼2% solution in acetone was observed. [ABSTRACT FROM AUTHOR]

Cellulose nitrates corresponding in the basic properties to high-viscosity lacquer-grade colloxylin were prepared by esterification of cellulose pulp, isolated from domestic rapidly renewable feedstock—agroindustrial waste—oat hulls, or cotton cellulose with a sulfuric and nitric acid mixture. The experimental samples of cellulose nitrates were comparatively evaluated. The IR and 13С NMR spectroscopy data confirmed the identity of chemical structure. High chemical purity of samples was confirmed by differential scanning calorimetry and ampule chromatography procedure. The cellulose nitrate samples have satisfactory mechanical sensitivity level: the lower limit of impact sensitivity is 50 mm and that of friction sensitivity is 1200 kgf/cm2; they have good chemical compatibility and high chemical stability when blended with plasticizers. The obtained results attest to expediency of using cellulose nitrates from oat hulls as a component of explosive compositions. [ABSTRACT FROM AUTHOR]

The results of remote detection of objects containing explosives with a lidar detector of traces of explosives in combination with a portable express gas chromatograph are presented. It is shown that the lidar detector of traces of explosives confidently detects the simulators of TNT, hexogen, and PETN from a distance of 5 m when sounding the surface of a sample. Laser action on the sample surface causes desorption of vapors, which are reliably detected by the gas chromatograph. It is shown that the joint use of the laser sounding and gas chromatography techniques makes it possible to increase the reliability of detection of explosives. The prospects of using the gas chromatography in the development of laser sounding techniques are determined. [ABSTRACT FROM AUTHOR]

Products are obtained from interaction between oligomeric aluminoborophosphate (ABP) and aniline, both complexes based on hydrogen bonds, as confirmed with IR spectroscopy and quantum chemical calculations. Nitrogen and hydrogen atoms of an amino group in aniline form hydrogen bonds with hydrogen and oxygen atoms of a phosphate group in ABP, respectively, with a total energy of 14.2 kcal/mol. Aniline, when added to ABP surrounded with a shell of water molecules, displaces two water molecules from the surface of the chain. The energy gain is 9.1 kcal/mol. IR spectroscopy data show that there are strong donor-acceptor interactions between water molecules and aluminum and phosphorus atoms of ABP in the solid-state polycomplex sample. The thermoplastic oligomeric complexes leads to an increase in the softening temperature and fluidity with an increase in an amount of aniline. This means that polyoxide inorganic polymer (metal phosphate) is possible to be modified with a monofunctional amine under "mild" conditions. We showed that the water resistance of the polycomplex is greater than that of ABP. [ABSTRACT FROM AUTHOR]

Abstract: Samples of technical-grade cellulose isolated by nitric acid technique from unconventional feedstocks (oat hulls, Miscanthus, and intermediate flax straw) have been treated for the first time with a sulfuric acid-nitric acid mixture to give cellulose nitrates with a nitrogen content of 12.04-12.26%, viscosity 10-14 mPa s, and a solubility in an alcohol-ether mixture of at least 98%, which corresponds to industrial lacquer-purpose high-viscosity colloxylin and N-grade colloxylin. It has been confirmed by IR spectroscopy and differential scanning colorimetry that the cellulose nitrates from unconventional feedstocks correspond to industrial colloxylins in terms of the key absorption bands (1650-1635, 1279-1276, 831-825, 746, 687-672 cm-1), thermal degradation onset temperature (about 200°C), and specific heat of decomposition (6.28-7.54 kJ/g). [ABSTRACT FROM AUTHOR]

Abstract: Bacterial nanocellulose (BNC) samples were produced by the symbiotic culture Мedusomyces gisevii Sa-12 in synthetic nutrient medium and enzymatic hydrolysates of chemically treated oat hulls and studied by X-ray diffraction. The structural characteristics of the crystalline component of BNC samples were determined. A comparison of the X-ray diffraction patterns recorded in reflection and transmission geometry shows that the samples have an anisotropic structure. All BNC samples are characterized by a high degree of crystallinity (from 86 to 93%) and are mainly composed of the low-symmetry metastable phase Iα (its fraction is 93.6-100%). The Мedusomyces gisevii Sa-12 culture was found to produce highly crystalline BNC, with the low-symmetry phase Iα prevailing, regardless of the composition of the nutrient medium. [ABSTRACT FROM AUTHOR]

Ataxia-telangiectasia (AT) is a rare neurodegenerative disease characterized by an early onset ataxia, oculocutaneous telangiectasia, immunodeficiency, recurrent infections, radio-sensitivity, and a predisposition to malignancy. We present the case of a child with coexistent AT and trisomy X (47,XXX). We used fluorescent in situ hybridization (FISH) to confirm that this person had 47,XXX karyotype in blood cells, bone marrow, fibroblasts, and buccal smear. Standard cytogenetic studies (not banded) were conducted on blood cells. G-banding analysis was performed on bone marrow cells at the time of the leukemia diagnosis. Flow cytometric investigation of lymphocytes and Sanger sequencing of the ATM gene were used for diagnosis confirmation and description. We report the case of an 11-year-old girl at remission after having T cell acute leukemia for 7 years with progressive signs of ataxia-telangiectasia and with additional X chromosome since birth. At the age of 2 years and 7 months, she was diagnosed with pre-T acute leukemia. From the age of four, she had gait abnormalities. AT was established at the age of seven based on clinical signs and laboratory findings (increased alpha fetoprotein—AFP [227]) and confirmed by detecting compound heterozygous truncating mutations in the ATM gene (p.Y705X and p.L2312I). These genetic findings have not been previously reported in AT and our “double hit” case demonstrates the value of careful clinical evaluation of children with an established genetic diagnosis. Measurement of AFP levels should be considered in patients with neurologic abnormalities after leukemia treatment. [ABSTRACT FROM AUTHOR]

The effect of culture conditions on the bacterial cellulose (BC) yield synthesized by symbiotic culture Medusomyces gisevii Sa-12 grown in synthetic nutrient medium was studied for the first time. The conditions providing the maximum yield of bacterial cellulose were evaluated: the initial glucose concentration in the culture medium was 20-25 g/L, the temperature was 24-27°C, the ratio of the nutrient medium to the air volume was 1 : 10, and the content of the black tea extracts comprised 1.6-4.8 g/L. A sample of chemically pure BC with the following characteristics was obtained under the selected culture conditions: moisture--99.0%, degree of polymerization--4800, average width of microfibrillar ribbons--30.6 nm, degree of crystallinity--86%, and the content of triclinic modification Ia--98%. [ABSTRACT FROM AUTHOR]

A new control method for a rectifier based on a transformer with a rotating magnetic field (TRMF) containing an even number of sections of circular winding (CW), which makes it possible to double the number of ripples of rectified voltage in the supply-voltage period, is considered. It leads to a reduction in the ripple amplitude and improves the quality of rectified voltage. The geometrical similarity of the CW of a TRMF making it possible to implement the new control method is analyzed. Switching algorithms of power switches for the classical and new control methods for any quantity of an even number of CW sections are presented. As an example, a switching queue of power switches for a CW with ten sections is considered. The output-voltage shapes for different depths of control are shown. The calculating procedure of the control characteristic for the classical and new control methods, as well as corresponding diagrams, are presented. For the presented example with ten sections of CW, the efficiency of the new control method was evaluated and the dependences of the voltage-ripple ratio on the RMS of rectified voltage are presented. A comparative analysis of the number of ripples for different quantity of CW sections was conducted, and the harmonic composition of output voltage spectrum for the example under consideration is determined. It has been concluded that, in the case of using the new control method for achieving the desired quality of rectified voltage, the number of CW sections may be halved compared with the classical control method, which will simplify the manufacture of a transformer magnetic conductor, halve the number of pairs of power switches switching the CW taps, and decrease the mass, dimension, and cost factors of a semiconductor switch and the TRFM itself as a whole. Using the new control method makes it possible to make a controlled rectifier with an even number of sections of a CW transformer almost as efficient as using a transformer with an uneven number of CW sections and the classical control method. The new control method ensures the fulfillment of the requirements for the available value of the ripple ratio of the output voltage of a controlled rectifier based on a transformer with a rotating magnetic field set out by State Standard YuST 13109-97 at a lower RMS of rectified voltage. [ABSTRACT FROM AUTHOR]

We use the notion of intrinsic flat distance to address the almost rigidity of the positive mass theorem for asymptotically hyperbolic manifolds. In particular, we prove that a sequence of spherically symmetric asymptotically hyperbolic manifolds satisfying the conditions of the positive mass theorem converges to hyperbolic space in the intrinsic flat sense, if the limit of the mass along the sequence is zero. [ABSTRACT FROM AUTHOR]

The possibility of forming supramolecular structures of a polymer complex consisting of products of polycondensation of boric acid and imidazole from aqueous solutions and melts of the components is shown. Depending on the ratio of the components, the heat resistance of the polymer complex lies within 60 and 480°C. The effect of sharp decrease in the heat resistance of the complex and the degree of polycondensation of boric acid upon a slight increase in the imidazole concentration above the stoichiometric ratio is revealed, which was explained by the 'blocking' of hydroxyl groups by imidazole molecules and, correspondingly, by a significant decrease in their chemical activity. The energies of the intermolecular bonds in the complexes are calculated. [ABSTRACT FROM AUTHOR]

The full cycle of bioethanol production from pretreated oat hulls is scaled for a pilot plant. The one-stage pretreatment of oat hulls with a dilute nitric acid at atmospheric pressure is scaled for a 250-L reactor. The total amount of hydrolysable polysaccharides in the resulting substrate is 87.2%. Using the commercially available enzyme preparations CelloLux-A and BrewZyme BGX and the industrial strain BKPM Y-1693 of Saccharomyces cerevisiae yeast, the process of enzymatic hydrolysis and alcoholic fermentation is successfully scaled for a 63-L reactor. The scaling factor is 1: 400. Bioethanol is obtained with a high yield of 17.9 daL/t. After rectification, the test sample of bioethanol meets the standards for high-purity alcohol from food raw materials according to the mass concentration of aldehydes, esters, and by the content of methanol. [ABSTRACT FROM AUTHOR]

A model of a hypothetical process resulting in damage to DNA by ionizing radiation, as a result of which a nonlinear dose dependence of carcinogensis can form at dose 10-100 mGy, is examined on the basis of a microdosimetric approach. The model assumes that the primary damage to DNA interacts with short-lived products of irradiation before the DNA is repaired or transformed into a precancerous defect that is transferred to a daughter cell. It is shown that there are grounds for using the ICRP effective dose and dose rate lowering coefficient equal to 2 in the evaluation of the lifetime risk of irradiation with a significant dose and in the validation of criteria for radiation safety on the basis of data on morbidity and mortality in a cohort of Japanese atomic bomb survivors. [ABSTRACT FROM AUTHOR]

An extreme dependence of the softening temperature of polycomplexes of p-phenylenediamine and low-molecular-weight polycondensation products of boric acid on the ratio thereof is revealed. The stoichiometric ratio of the BA/ p-PDA complex is 75/25 wt %, which corresponds to a molar ratio of BA trimer/ p-PDA = 1: 1. At a higher content of the amine, the softening temperature of the polycomplex decreases sharply, from 250 to 60°C, which is explained by the complexation of boric acid with the amine, a factor that prevents its dehydration. The energies of the intermolecular interaction between the components of the complex in a vacuum are calculated, and quantum-chemical calculations of the energy of interaction between the components of the complex are performed. The resulting products exhibit paramagnetic and fluorescent properties. [ABSTRACT FROM AUTHOR]

Nitrolysis of 2,6,8,12-tetraacetyl-4,10-dibenzyl-2,4,6,8,10,12-hexaazatetracyclo-[5.5.0.0.0]dodecane results in the substitution of benzyl groups by the nitro groups with the formation of 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazatetracyclo[5.5.0.0.0]-dodecane. The reaction sequentially proceeds through the nitration of the benzyl groups predominantly at para-position, the substitution of one nitrobenzyl group with the nitro group, and the introduction of the second nitro group into the nitrobenzyl fragment. The replacement of the remaining dinitrobenzyl fragment is a more difficult process, which reaches completion only by the end of the nitration. Another reaction product is p-nitrobenzoic acid, which is formed in the secondary reactions. No substitution of a p-nitrobenzoyl group with the nitro group takes place in the nitration of 2,6,8,12-tetraacetyl-4,10-di( p-nitrobenzoyl)-2,4,6,8,10,12-hexaazatetracyclo[5.5.0.0.0]dodecane under similar conditions. [ABSTRACT FROM AUTHOR]

The photodissociation process of the nitrosyl hematoporphyrin complex has been studied using quantum-chemical methods. Photolysis of hematoporphyrin complexes is of high biological usefulness and is widely employed in laser-therapy methods. However, the mechanism of photodissociation of these complexes is not entirely clear. Based on the computations, we propose a detailed mechanism for the photolysis of the nitrosyl hematoporphyrin complex. A transition 'dissociative' excited state has been described, which has an energy barrier value of only 0.4 eV for NO dissociation. [ABSTRACT FROM AUTHOR]

The results of studying the synthesis of cellulose nitrates from oilseed production residues (intermediate flax straw) and subsequent autoclaving of the obtained ethers are presented for the first time. Cellulose was isolated by the dilute nitric acid method, and cellulose nitrates were synthesized using an industrial sulfuric-nitric acid mixture. The resultant sample was autoclaved in three different modes. It was found that cellulose nitrates with the following properties can be obtained from the intermediate flax straw: weight fraction of nitrogen 12.23-12.34%, viscosity 2.7-16.0 cP, and solubility in an alcohol-ether mixture 95-96%. A similarity of the obtained cellulose nitrates and linter Colloxylin was shown by IR spectroscopy. The results of thermogravimetric analysis (TG) and C NMR spectroscopy for cellulose nitrates obtained from intermediate flax straw are presented. [ABSTRACT FROM AUTHOR]

The influence of introduction of particles of detonation-synthesized nanodiamonds into composites and aluminum-base light alloys on their physical and mechanical properties is analyzed. The data on microstructure and physical and mechanical properties of composites and cast aluminum alloys reinforced with diamond nanoparticles are presented. The introduction of nanoparticles is shown to result in a significant improvement of the material properties. [ABSTRACT FROM AUTHOR]

We define the (total) center of mass for suitably asymptotically hyperbolic time-slices of asymptotically anti-de Sitter spacetimes in general relativity. We do so in analogy to the picture that has been consolidated for the (total) center of mass of suitably asymptotically Euclidean time-slices of asymptotically Minkowskian spacetimes (isolated systems). In particular, we unite-an altered version of-the approach based on Hamiltonian charges with an approach based on CMC-foliations near infinity. The newly defined center of mass transforms appropriately under changes of the asymptotic coordinates and evolves in the direction of an appropriately defined linear momentum under the Einstein evolution equations. [ABSTRACT FROM AUTHOR]

The enzymatic hydrolysis of lignocellulosic materials (LCMs) from miscanthus and oat husks (OH) in an aqueous medium and the subsequent production of ethanol are studied. LCMs are obtained at a pilot plant of the Institute of Problems of Chemical and Energy Technologies by means of one-stage nitric acid treatment. Enzymatic hydrolysis is conducted in an aqueous medium with a high initial concentration of phosphates (90 g/L) using freely available CelloLux-A and BrewZyme BGX industrial enzymatic preparations. The yields of reducing compounds are found to be 65.4 and 73.3% for miscanthus and oat husk LCM, respectively. The composition of monosaccharides (products of enzymatic LCM destruction) is studied for the first time. It is shown that glucose comprises the largest share of monosaccharides. Ethanol is produced from LCM for the first time. Ethanol yields per metric ton of raw material are 19.4 and 16.2 daL/t for miscanthus biomass and OH, respectively. Ethanol samples are characterized by low methanol contents (0.002 to 0.005 vol %). [ABSTRACT FROM AUTHOR]

Enzymatic hydrolysis of cellulosic raw materials to produce nutrient broths for microbiological synthesis of ethanol and other valuable products is an important field of modern biotechnology. Biotechnological processing implies the selection of an effective pretreatment technique for raw materials. In this study, the hydrotropic treatment increased the reactivity of the obtained substrates toward enzymatic hydrolysis by 7.1 times for Miscanthus and by 7.3 times for oat hulls. The hydrotropic pulp from oat hulls was more reactive toward enzymatic hydrolysis compared to that from Miscanthus, despite that the substrates had similar compositions. As the initial substrate loadings were raised during enzymatic hydrolysis of the hydrotropic Miscanthus and oat hull pulps, the concentration of reducing sugars increased by 34 g/dm and the yield of reducing sugars decreased by 31 %. The findings allow us to predict the efficiency of enzymatic hydrolysis of hydrotropic pulps from Miscanthus and oat hulls when scaling up the process by volume. [ABSTRACT FROM AUTHOR]

The studies of the condensation of 4-nitrosemicarbazide (4-NSC) with various aldehydes and ketones resulted in the development of an approach to the synthesis of N-nitrosemicarbazones, promising high-energy and biologically active compounds. Subsequent treatment with amines and alkalis led to the synthesis of water-soluble salts of nitrosemicarbazones, as well as the corresponding semicarbazones. The reaction of N, N′-diisopropyl- or N, N′-di- tert-butyl-1,2-ethanediimine with 4-nitrosemicarbazide led to the synthesis of glyoxal bis(nitrosemicarbazone) derivatives. A computer-aided screening using the PASS software showed a probability of high biological activity for the compounds obtained, whereas antiarrhythmic properties of camphor nitrosemicarbazone potassium salt were confirmed in experiments in rats. [ABSTRACT FROM AUTHOR]

The paper presents results of studying the feasibility of remote detection of explosive vapors in the atmosphere based on the lidar principle using the method of laser fragmentation/laser-induced fluorescence. A project of the mobile, automated, fast-response scanning UV lidar for explosives detection at distances of 10-50 m is presented. Experimental data on the detection of trinitrotoluene (TNT), hexogen (RDX), and Composition B (CompB) vapors at a distance of 13 m are given. The threshold sensitivity of the lidar detector of explosive vapors is estimated. For TNT vapors, the threshold sensitivity of the lidar detector is estimated to be 1∙10 g/cm for the detection probability P = 97%. [ABSTRACT FROM AUTHOR]

The kinetics of the enzymatic hydrolysis of two substrates-lignocellulosic materials from Miscanthus and oat hulls-in an acetate buffer is studied at different concentrations of the substrates. The substrates are obtained via single-step treatment with a dilute solution of nitric acid. The content of a nonhydrolyzable component-acid-insoluble lignin-for Miscanthus and oat hulls was 11 and 14%, respectively. A multi-enzyme composition of commercially available enzyme preparations CelloLux-A and BrewZyme BGX was used as a catalyst. It is shown that treatment with the nitric acid solution produces reactive substrates for the enzymatic hydrolysis. The innovative science of the results is confirmed by Russian patent 2533921. Kinetics of the enzymatic hydrolysis of these substrates in an acetate buffer can be described by a mathematical model based on a modified Michaelis-Menten equation. The main kinetic constants for both substrates are determined from the experimental data. The equilibrium concentrations of reducing substances (RSes) for the substrates are calculated from the initial substrate concentrations. It is found that within the studied range of substrate concentrations (33.3-120.0 g/L), the initial rate of enzymatic hydrolysis for the lignocellulosic material from oat hulls is higher than that for the lignocellulosic material from Miscanthus by 1 g/(L h). It is shown that the yield of RS depends of the initial concentration of the substrates: as the concentration rises from 33.3 to 120 g/L, the yield of RS falls 1.5-2.0 times, due to substrate inhibition. At low initial concentrations, the yields of RS are similar for the substrates from Miscanthus and oat hulls. When the initial concentration of the substrate reaches 120 g/L, the yield of reducing substances for the lignocellulosic material from Miscanthus is approximately 20% higher than that for the lignocellulosic material from oat hulls. The established dependences and the proposed mathematical model allow us to optimize the initial concentration of the substrate for efficient enzymatic hydrolysis. [ABSTRACT FROM AUTHOR]

A nitric acid method for the preparation of cellulose from miscanthus is considered. The method consists in successive treatment of the raw material with nitric acid and sodium hydroxide and affords cellulose with properties suitable for the synthesis of cellulose nitrates. The data on the nitrogen weight fraction, the viscosity, and the solubility of cellulose nitrates from miscanthus in the alcohol-ether medium are given. The miscanthus cellulose was nitrated using an industrial sulfuric-nitric acid mixture to yield cellulose nitrate samples with characteristics close to those of colloxylin. [ABSTRACT FROM AUTHOR]

The chemical structures of Miscanthus var. 'Soranovskii' lignin fractions released via extraction of lignin from the lignocellulosic feedstock using moderately heated acetone under atmospheric pressure, without acidic and alkaline catalysts, were studied. A blend of Miscanthus stems and leaves was pretreated with water under thermobaric conditions. The acetone organosolv process subsequently afforded a substance related to a lignin-like matter-acetone organosolv Miscanthus lignin (AOML). Non-destructive analytical techniques such as FTIR spectroscopy, gas chromatography-mass spectrometry, size-exclusion chromatography, and 2D NMR were used. The IR and NMR spectroscopies revealed the AOML structure to comprise all the three major types of phenylpropane units: guaiacyl (G), syringyl (S), and p-hydroxyphenyl (H). The resultant acetone-organosolv lignin exhibits good solubility in polar solvents, moderate solubility in aromatic chemicals, and is insoluble in non-polar solvents, exhibiting the physicochemical properties of a thermoplastic polymer with a softening point of 67.0°C (onset 33.0°C, endset 81.5°C). [ABSTRACT FROM AUTHOR]

The characteristics of the Miscanthus pulp obtained by hydrotropic processing under different conditions were studied. The pulping conditions were optimized to achieve the 42.3% yield of the pulp (lignin content 6.1%, pentosan content 6.4%, and ash content 3.0%). The hydrotrope selectively solubilizes lignin; the delignification is closely associated with the primary dissolution of carbohydrates. [ABSTRACT FROM AUTHOR]

The concept of manufacturing valuable bacterial nanocellulose (BNC) from plant raw materials having a zero prime cost is substantiated. The process flowsheet involves the chemical transformation of the feedstock to obtain a pulp; enzymatic hydrolysis of the pulp to furnish a solution of reducing sugars, chiefly glucose; preparation of a nutrient broth based on the enzymatic hydrolysate; biosynthesis of nanocellulose microfibrils by the symbiotic Medusomyces gisevii Sa-12 culture; and purification of BNC. BNC has for the first time been synthesized from oat hulls and has a high degree of crystallinity of 88 ± 5% and is composed of 99% Iα-allomorph. [ABSTRACT FROM AUTHOR]

The chemical composition of the Soranovskii Miscanthus variety harvested in 2011 and 2012 was separately determined in the whole plant, leaves, and stem. In all cases, cellulose was found to prevail in the Miscanthus stem, and noncellulosic components (the fat-wax fraction, ash, and lignin), in leaves. Cellulose samples were for the first time obtained from leaves and stems separately by two methods (nitric-acid and combined). The best quality cellulose was derived from stems. For instance, cellulose isolated from stems by the nitric-acid process was better than that from leaves, which was expressed as a higher cellulose content (94.4% versus 91.7%) and degree of polymerization (800 versus 580), as well as low weight fractions of noncellulosic components: ash (0.07% versus 1.01%) and acid-insoluble lignin (0.45% versus 1.51%). The same tendency is observed in celluloses produced by the combined method: Cellulose from stems had better quality than that from leaves; specifically, it had higher degree of polymerization (1040 versus 640) and lower weight fractions of the noncellulosic components: ash (0.14% versus 0.75%), acid-insoluble lignin (0.88% versus 4.12%), and pentosans (6.38% versus 8.53%). It is obvious that cellulose obtained by the nitric-acid method can be suitable for chemical modifications, including nitration. Cellulose from the combined process can be utilized in paper industry. [ABSTRACT FROM AUTHOR]

The effect of the surfactant Tween 80 on the efficiency of enzymatic hydrolysis of hydrotropic cellulose pulp from Miscunthus with BrewZyme BGX and CelloLux-A enzyme preparations was studied, which showed that the presence of Tween 80 increased the yields of reducing compounds by 12-13% and pentoses by 14%, with the proportion of pentoses in total reducing compounds being 5.2-5.6%, thus indicating the predominantly glucose composition of the hydrolysate. [ABSTRACT FROM AUTHOR]

For asymptotically hyperbolic manifolds of dimension n with scalar curvature at least equal to − n( n − 1) the conjectured positive mass theorem states that the mass is non-negative, and vanishes only if the manifold is isometric to hyperbolic space. In this paper we study asymptotically hyperbolic manifolds which are also conformally hyperbolic outside a ball of fixed radius, and for which the positive mass theorem holds. For such manifolds we show that the conformal factor tends to one as the mass tends to zero. [ABSTRACT FROM AUTHOR]