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Recently developed multicomponent eutectic alloys based on Al–Ca are promising for practical application, since they are characterized by low density and high corrosion resistance and are hi-tech in casting and easily deformed in annealed state. These alloys are strengthened by alloying with Mn, Fe, Zr, Sc, and other elements. The ultrafine grained state in aluminum alloys is achieved by severe plastic deformations, for instance, equal channel angular pressing (ECAP), significantly improving their mechanical properties. In this regard, this work is aimed at analyzing the influence of warm ECAP on the structure, mechanical properties, and thermal stability of eutectic aluminum alloy, wt %: Al–3.5Ca–0.9Mn–0.5Fe–0.1Zr–0.1Sc. ECAP is performed on as-cast alloy specimens with a diameter of 20 mm (400°C, route BC, channel intersection angle: 110°, number of passes N = 6). It is been demonstrated that, as a consequence of ECAP, a developed substructure is generated in the alloy with a high density of dislocations and deposition of Al6(Mn, Fe) and Al3Sc nanosized particles, accompanied by the fragmentation of primary Al6(Mn, Fe) coarse particles and eutectic Al4Ca particles. Such a change in structure during ECAP leads to the significant strengthening of the alloy: its strength increased 1.5–2.0 times and relative elongation decreased 1.3 times in a specimen of longitudinal cross section, slightly changing in the transversal one in comparison with the initial state.

Octahydrate of tetralithium salt of calix[4]sarenesulfonic acid was isolated for the first time The crystal structure of salt was determined by X-ray diffraction analysis. Compound crystallized in triclinic syngony, P-1, a=11.8752(5) A, b=12.2144(4) A, c=13.2972(6) A, α=97.241(3)o, β=99.345(4)o, γ=90.658(3)o, V=1886.96(13) A3, Z=2, R1 = 0.0407, T=150 K. The presence of 8 water molecules in the structure is confirmed by STA. According to IR spectroscopy data upon lithiation, the contours of the νs(SO3) and νas(SO3) bands become symmetric and narrower, which is explained by the disappearence of contacts between the sulfonic groups and the H5O2+ cations compared with calix[4]sarenesulfonic acid. Lithium ions are qualitatively determined from the maximum of the stretching vibration band of the Li–O bond at ~400 cm-1.The participation of H2O molecules coordinated by Li cations in the formation of a network of hydrogen bonds with oxygen atoms of sulfogroups is determined by the maximum of the stretching band ν(OH) belonging to these molecules at 3452 cm-1 in spectrum. The intense band at 3148 cm–1 refers to the ν(OH) stretching vibration of the C–OH group. The dependence of the conductivity of the tetralithium salt of calix[4]arenesulfonic acid in a wide range of humidity has been investigated. It was shown that with the gradual replacement of protons in calix[4]arenesulfonic acid, the conductivity decreases from 10-4-10-2 S/cm in acid in the ambient humidity range of 10-60 rel. % down to 10-7-10-4 S/cm for the tetralithium salt of calixarenesulfonic acid in a wide range of humidity 10-95 rel. %.

Brown iron ore constitutes about 13% of the global ore reserves and is widespread throughout the world. Brown iron ore is characterized by a significant content of harmful phosphorus (0.7 to 3.0%), which is typically present in the lattice of the main iron ore component in a chemically bound form. Based on the case study of the gravity-magnetic concentrate from the Lisakovsk field, OJSC “VNIIMT” has developed and lab-tested a pyro-hydrometallurgical dephosphorization technology, which can be applied while preparing the concentrate for agglomeration. As established earlier, phosphorus leaching proceeds successfully only after a high-temperature roasting of the gravity-magnetic concentrate, when the hydrated phosphorus-containing component decomposes. Free phosphorus then reacts with sulfuric acid. The main difference of the leaching process was that dephosphorization of the preliminary roasted concentrate with weak aqueous solution of sulfuric acid was performed without cooling it (hot leaching). A fixed-bed roasting was performed in a laboratory muffle furnace. After heating to a specific temperature and soaking for 60 minutes, a crucible containing the sample of the material was removed from the furnace. The roasted material was unloaded in hot condition into a previously prepared weak aqueous solution of sulfuric acid containing 5 wt.% of H2SO4 (solid-to-liquid phase ratio — 1:2). Such ratio prevents the solution from boiling during unloading of the hot concentrate. The pulp was mixed inside the ceramic crucible using an overhead stirrer. It has been established experimentally that hot leaching significantly reduces the duration of dephosphorization (by 3 times or more) compared to leaching under normal conditions. Another important advantage is the possibility of reducing the number of pieces of process equipment industry-wide, since cooling and leaching of the roasted gravity-magnetic concentrate from the Lisakovsk field can be implemented in one apparatus. In this case, reduced duration of the leaching process will enable an increase in productivity of the dephosphorization equipment by 3 times or more.

The high-grade leak-tight foils 10–20 μm in thickness were obtained from effective alloys (wt %) Pd–6 In–0.5 Ru, Pd–6 Ru, and Pd–40 Cu by using advanced technology. For the Pd–40% wt Cu alloy, the foil with ordered β phase with the CsCl structure, exhibiting maximum hydrogen permeability in the Pd–Cu system, was formed by the combination of deformation and annealing conditions. The mechanical properties and hydrogen permeability of the obtained foil membranes as compared with the foils of 50 μm in thickness and also their performance for pure hydrogen at the membranes work in the commercially pure hydrogen medium were investigated. The concentration dilatation of the foils in hydrogen was investigated at various temperatures. Data on dilatation of palladium membrane alloys are of paramount importance to design of membrane filter elements and choice of their optimal usage conditions because these data determine the operational life of membrane. The Pd–6 wt % In–0.5 wt % Ru–1.25 wt % Co alloy with improved strength characteristics and lower temperature of α ↔ β hydride transition was developed on the basis of the Pd– 6 wt % In–0.5 wt % Ru alloy.

In the present study, using the improved technology, high-quality vacuum-tight foils 10 – 20 µm in thickness were prepared from effective Pd – 6 wt. % In – 0.5 wt. % Ru, Pd – 6 wt. % Ru, Pd – 40 wt. % Cu palladium alloys. Using a combination of deformation and annealing modes, the Pd – 40 wt. % Cu alloy foil consisting of the ordered β-phase (97%) with the CsCl-type structure that exhibits the maximum hydrogen permeability in this system. The mechanical properties and hydrogen permeability of the prepared foils were studied and compared with those of alloy foils 50 µm thickness. The thermal concentration dilatation in hydrogen was studied at different temperatures. Data on the dilatation of palladium-based membranes are of primary importance for designing membrane filtering elements and selection of optimal conditions for their operation, since these data determine the operation life membranes. Based on the Pd – 6 wt. % In – 0.5 wt. % Ru alloy, the Pd – 6 wt. % In – 0.5 wt. % Ru – 1.25 wt. % Co alloy was developed; it is characterized by increased strength characteristics and lower α ↔ β hydride transition temperature.

The article summarized the results of long-term observations (2014–2018) of soil emissions and net CO2 fluxes (2017–2018) in natural and anthropogenically modified (AI) ecosystems of Arctic tundra on the territory of the archipelago of Svalbard (Barentsburg, 78°04′N, 14°13′E). Anthropogenic controls associated with local land use, during the period of their active impact may redouble the emissions of carbon dioxide from soil (0.111 ± 0.021 > 0.064 ± 0.011 gС m –2 h –1). During the same period, the net C-balance at the sites with active land use is estimated as a source to the atmosphere. Self-recovering after human influence plots (II) demonstrate intermediate values of soil emissions of СО2 between unaffected tundra (I) and plots with active land use (III). With that they demonstrate the greatest net C-sink within the observed range of Photosynthetically Active Radiation as compared to (I) and (III). At the height of the vegetation period unaffected tundra ecosystems demonstrate a neutral net C-balance. The greatest contribution to soil emissions variance make spatial controls (they explain 56–66% of variance), whereas temporal factors are responsible for 3.8–5.5% only. Amongst spatial controls, the thickness of organogenic layer makes the greatest contribution. Inter-annual fluctuations of key factors, among which the most important are the soil moisture and temperature of the upper soil layer, both affect AI and natural ecosystems hence the spatial differences between them remain constant from year to year. According to preliminary estimates, unlike the carbon dioxide, the contribution of methane and nitrous oxide net fluxes in local ecosystems is insignificant and does not depend on human land use.

The hydration numbers of perchloric acid were calculated using the Raoult law. The initial simplificated model is based on the hypothesis of the free water mole fraction equality to the water activity. A cause-effect relation has been established between the violation of this law and the distortion of the hydration numbers curve at low concentrations. In addition, this model was found unsatisfactory for evaluation of the solute activity coefficients. The more sophisticated model has been proposed for the calculations of hydration numbers, free water mole fraction and solute activity coefficients. Its main feature is the use of the free water activity coefficient. Estimated values of this coefficient differ from the unity in a small degree.

The assessment of the explosion hazard of a combustible gas mixture is not a trivial task if the type of combustible gases is not known precisely. Typically, the concentration of combustible gas is defined as the response of a catalytic sensor to its presence in the air. It has been known that catalytic sensors have different sensitivities to different combustible gases. Usually gas analyzers are calibrated by methane and are not suitable for measuring other flammable gases without additional correction for each gas. In this paper, we have investigated the dependency of catalytic sensor sensitivity on the sensor temperature for the binary mixture of methane, propane, butane, hexane and hydrogen with air in a wide temperature range. Based on the obtained dependencies, a measurement algorithm and an empirical equation were proposed that allow calculating the concentration of unknown combustible gas in % of LEL. The process of measuring and processing data can be automated using a digital processor. The experimental results have shown that the concentration measurement error is in the range 5%–10% for binary mixture.

Author(s): Chambers, C; Walton, T; Fairbank, D; Craycraft, A; Yahne, DR; Todd, J; Iverson, A; Fairbank, W; Alamare, A; Albert, JB; Anton, G; Arnquist, IJ; Badhrees, I; Barbeau, PS; Beck, D; Belov, V; Bhatta, T; Bourque, F; Brodsky, JP; Brown, E; Brunner, T; Burenkov, A; Cao, GF; Cao, L; Cen, WR; Charlebois, SA; Chiu, M; Cleveland, B; Coon, M; Cree, W; Cote, M; Dalmasson, J; Daniels, T; Darroch, L; Daugherty, SJ; Daughhetee, J; Delaquis, S; Mesrobian-Kabakian, A Der; DeVoe, R; Dilling, J; Ding, YY; Dolinski, MJ; Dragone, A; Echevers, J; Fabris, L; Farine, J; Feyzbakhsh, S; Fontaine, R; Fudenberg, D; Giacomini, G; Gornea, R; Gratta, G; Hansen, EV; Heffner, M; Hoppe, EW; Hosl, J; House, A; Hufschmidt, P; Hughes, M; Ito, Y; Jamil, A; Jessiman, C; Jewell, MJ; Jiang, XS; Karelin, A; Kaufman, LJ; Kodroff, D; Koffas, T; Kravitz, S; Krucken, R; Kuchenkov, A; Kumar, KS; Lan, Y; Larson, A; Leonard, DS; Li, G; Li, S; Li, Z; Licciardi, C; Lin, YH; Lv, P; MacLellan, R; Michel, T; Mong, B; Moore, DC | Abstract: The search for neutrinoless double beta decay probes the fundamental properties of neutrinos, including whether or not the neutrino and antineutrino are distinct. Double beta detectors are large and expensive, so background reduction is essential for extracting the highest sensitivity. The identification, or 'tagging', of the $^{136}$Ba daughter atom from double beta decay of $^{136}$Xe provides a technique for eliminating backgrounds in the nEXO neutrinoless double beta decay experiment. The tagging scheme studied in this work utilizes a cryogenic probe to trap the barium atom in solid xenon, where the barium atom is tagged via fluorescence imaging in the solid xenon matrix. Here we demonstrate imaging and counting of individual atoms of barium in solid xenon by scanning a focused laser across a solid xenon matrix deposited on a sapphire window. When the laser sits on an individual atom, the fluorescence persists for $\sim$30~s before dropping abruptly to the background level, a clear confirmation of one-atom imaging. No barium fluorescence persists following evaporation of a barium deposit to a limit of $\leq$0.16\%. This is the first time that single atoms have been imaged in solid noble element. It establishes the basic principle of a barium tagging technique for nEXO.

Purpose Favorable outcomes were achieved for children with acute lymphoblastic leukemia (ALL) with the first Russian multicenter trial Moscow–Berlin (ALL-MB) 91. One major component of this regimen included a total of 18 doses of weekly intramuscular (IM) native Escherichia coli-derived asparaginase (E. coli-ASP) at 10000 U/m2 during three consolidation courses. ASP was initially available from Latvia, but had to be purchased from abroad at substantial costs after the collapse of Soviet Union. Therefore, the subsequent trial ALL-MB 2002 aimed at limiting costs to a reasonable extent and also at reducing toxicity by lowering the dose for standard risk (SR−) patients to 5000 U/m2 without jeopardizing efficacy. Methods Between April 2002 and November 2006, 774 SR patients were registered in 34 centers across Russia and Belarus, 688 of whom were randomized. In arm ASP-5000 (n = 334), patients received 5000 U/m2 and in arm ASP-10000 (n = 354) 10 000 U/m2 IM. Results Probabilities of disease-free survival, overall survival and cumulative incidence of relapse at 10 years were comparable: 79 ± 2%, 86 ± 2% and 17.4 ± 2.1% (ASP-5000) vs. 75 ± 2% and 82 ± 2%, and 17.9 ± 2.0% (ASP-10000), while death in complete remission was significantly lower in arm ASP-5000 (2.7% vs. 6.5%; p = 0.029). Conclusion Our findings suggest that weekly 5000 U/m2E. coli-ASP IM during consolidation therapy are equally effective, more cost-efficient and less toxic than 10000 U/m2 for SR patients with childhood ALL. Electronic supplementary material The online version of this article (10.1007/s00432-019-02854-x) contains supplementary material, which is available to authorized users.

Silicon photomultipliers are regarded as a very promising technology for next-generation, cutting-edge detectors for low-background experiments in particle physics. This work presents systematic reflectivity studies of Silicon Photomultipliers (SiPM) and other samples in liquid xenon at vacuum ultraviolet (VUV) wavelengths. A dedicated setup at the University of M\"unster has been used that allows to acquire angle-resolved reflection measurements of various samples immersed in liquid xenon with 0.45{\deg} angular resolution. Four samples are investigated in this work: one Hamamatsu VUV4 SiPM, one FBK VUV-HD SiPM, one FBK wafer sample and one Large-Area Avalanche Photodiode (LA-APD) from EXO-200. The reflectivity is determined to be 25-36% at an angle of incidence of 20{\deg} for the four samples and increases to up to 65% at 70{\deg} for the LA-APD and the FBK samples. The Hamamatsu VUV4 SiPM shows a decline with increasing angle of incidence. The reflectivity results will be incorporated in upcoming light response simulations of the nEXO detector., Comment: 18 pages, 11 figures

The paper focuses on the applicability and adaptation of the novel international concept of Land Degradation Neutrality (LDN) of the United Nations, as applied to the territory of Russian Federation, taking into account the large variety of its soil and climatic conditions and economic approaches, as well as the historical past. In particular, in this publication, a team of authors made an attempt to assess to what extent the estimates of the carbon balance and its main components for the study area can be used as one of the indicators of the LDN in relation to the most fertile chernozem agrolandscapes in the south of the European part of Russia (Kursk region). Field work and modelling have been carried out in natural ecosystems and agrolandscapes in the neighbourhood of the Kursk Biosphere Station (KBS) of the Institute of Geography, Russian Academy of Sciences. This valuable russian scientific research station has a long and rich history of geo(eco)system observations with LDN and net C-balance monitoring of age-old agrolandscapes, becoming one of its present focuses. Using simulation models DNDC, RothC, T&P, C-calculators, as well as long-term field measurements of soil CO2 efflux and carbon net exchange, it was found that individual software tools are not able to adequately assess carbon exchange processes of the complex landscape, but correctly selected ensembles consisting of C-balance simulations and C-calculators supported by field data are able to meet such challenges more successfully. On this condition the area's carbon net balance can serve as an alternative to the recommended global LDN indicators.

Methodologies to identify epitopes or ligands of the fungal cell wall polysaccharides influencing the immune response of human pathogens have to date been imperfect. Using the galactomannan (GM) of Aspergillus fumigatus as a model, we have shown that synthetic oligosaccharides of distinct structures representing key fragments of cell wall polysaccharides are the most precise tools to study the serological and immunomodulatory properties of a fungal polysaccharide.

nEXO is a proposed tonne-scale neutrinoless double beta decay ($0\nu\beta\beta$) experiment using liquid ${}^{136}Xe$ (LXe) in a Time Projection Chamber (TPC) to read out ionization and scintillation signals. Between the field cage and the LXe vessel, a layer of LXe ("skin" LXe) is present, where no ionization signal is collected. Only scintillation photons are detected, owing to the lack of optical barrier around the field cage. In this work, we show that the light originating in the skin LXe region can be used to improve background discrimination by 5% over previous published estimates. This improvement comes from two elements. First, a fraction of the $\gamma$-ray background is removed by identifying light from interactions with an energy deposition in the skin LXe. Second, background from ${}^{222}Rn$ dissolved in the skin LXe can be efficiently rejected by tagging the $\alpha$ decay in the ${}^{214}Bi-{}^{214}Po$ chain in the skin LXe., Comment: 11 pages, 12 figures

Laboratory animals (the California rabbit) were immunized with natural preparations of Saccharomyces cerevisiae and Candida krusei yeasts. The resulting sera have been analyzed with ligand libraries constructed from synthetic oligosaccharides related to the main carbohydrate components of the fungal cell wall. It is shown that the antibodies in the studied sera predominantly recognize mannan fragments, with the carbohydrate specificity profile being different for S. cerevisiae and C. krusei. Sera against S. cerevisiae contained antibodies that recognize β-glucan, and the minimal recognizable epitope is linear trisaccharide. These results are necessary for the creation of needed immunoenzyme diagnostics for the detection and species characterization of fungi.

The parameters of a microstructure of regions of action of a spark discharge on a copper plane electrode surface in air at atmospheric pressure in the spike–plane gap both for positive and negative polarity of a spike have been studied using scanning electron microscopy. It has been found that regions of action have the appearance of rounded spots or groups of spots with an internal structure in the form of agglomeration of a large number of microcraters. It has been shown that the statistical distributions of microcrater diameters and intermicrocrater distances are characterized by several local maximums that determine the presence of several predominant values of these parameters in a spot. It has been revealed that the microstructure of a spot is characterized by the fractal behavior and the fractal dimensionalities of the microstructure have been determined.

The statistical characteristics of an electric breakdown in the nitrogen in the spike (cathode)–plane gap in the duration range of (3 × 10–3)–3600 s at voltages close to a static breakdown have been studied. It has been found that a probability of a gap breakdown is nonmonotonously distributed over time. The presence of maxima in the probability distribution confirms a contribution of some processes that both stimulate and suppress a breakdown. The typical times of the processes are ~30 ms, ~10–1 s, and ~300 s.

The carbohydrate specificity of antibodies obtained by immunizing laboratory animals with immunogens prepared from the Aspergillus fumigatus cell wall was analyzed using the library of biotinylated synthetic oligosaccharides. It has been shown that the main part of antipolysaccharide antibodies recognizes galactomannan in the studied immunogens with preference to its fragments containing more than two β-(1→5)-linked galactofuranosyl units. The data obtained can form the basis for the development of enzyme immunoassay for the detection of this dangerous fungal pathogen.

2,4,5-Trimethylbenzenesulfonic acid dihydrate was isolated in the monocrystalline state. Crystal and molecular structures of the compound were determined by X-ray diffraction analysis and vibrational spectroscopy. The compound crystal system is monoclinic: a =7.7445(3) A, b = 7.5360(3) A, c = 9.9477(4) A, α = γ = 90°, β = 92.123(4)°, V = 580.17(4) A3, P21, Z = 2, R1 = 0.0323, dcalc. = 1.353 g cm−3, T = 150 K. A 2D hydrogen bond network formed of a dioxonium ion and oxygen atom of a sulfogroup was identified in the crystal structure. IR absorption spectra, Raman spectra and ATR IR spectra of 2,4,5-trimethylbenzenesulfonic acid dihydrate and deuterodihydrate have been obtained in the region 50–4000 cm−1. It was found that the proton and deuterium in the H5O2+ and D5O2+ cations shifted from the midpoint of the strong hydrogen bond toward one of two water molecules according to the scheme O⋯H+⋯O → O⋯H+–O and O⋯D+⋯O → O⋯D+–O. Spectroscopic data concerning dioxonium ion formation show satisfactory agreement with X-ray diffraction analysis. The effect of environment humidity on the state of 2,4,5-trimethylbenzenesulfonic acid dihydrate aggregation was investigated. It was shown that the number of water molecules increases up to 2.5 per sulfogroup in the 7–84 rel.% air humidity interval through additional water molecules adsorption. A further humidity increase led to compound deliquescence. The proton conductivity as measured by impedance spectroscopy is 10−9–10−5 S cm−1 in the 7–58 rel.% humidity interval at 298 K with a [H2O]/[SO3−] = 2.2 ratio at maximum conductivity.

The structure and hydration of phenol-2,4-disulfonic acid in the individual state and in the system with poly(vinyl alcohol) at low and high humidity levels are studied by IR spectroscopy. It is shown that all characteristic features of the electrolytic dissociation of phenol-2,4-disulfonic acid via proton transfer from acid molecules to the molecules of water in the liquid phase of the binary system phenol-2,4-disulfonic acid–water are also observed for the viscous solutions of the triple system poly(vinyl alcohol)–phenol-2,4-disulfonic acid–water, although differences make themselves evident if water molecules are in deficiency. It is found that evacuation of the phenol-2,4-disulfonic acid film for several hours at room temperature leads to its dehydration and eventually causes formation of molecular dimers [C6H3OH(SO2OH)2]2. A similar operation with the poly(vinyl alcohol)–phenol-2,4-disulfonic acid film is completed by the transfer of a proton from the acid molecule to the–ОН group of poly(vinyl alcohol) according to the following scheme: nC6H3OH(SO2OH)2 + (–CH2OH) n → nC6H3OH(SO3)(SO2OH)– + (–CH2OH2) + .

Combustible gas mixtures and flammable vapors are present in the operating environments of many industries. Detection of the presence of these combustible gases and vapors and assessment of the explosion hazard is of vital importance to ensure that mitigation of the potential hazard can occur before an explosive concentration is reached. In this work, we introduce a gas mixture explosion risk estimation technique for a catalytic sensor. The contribution of this work is threefold. First, we propose the idea of explosion estimation of unknown gas mixtures, which are based on the measurement of heat dissipated during the mixture oxidation at a slow rate. Second, the analysis of transient oxidation processes and sensor response is performed for devising the associated computational scheme to be implemented in a low-power microcontroller. Third, we implement the proposed computational scheme in a wireless sensor node and carry out experiments with various gas mixtures for demonstrating the feasibility of our approach. Combustible heat of gas mixtures of methane, propane, butane, and hydrogen were studied at various concentrations in the range of 28%–56% lower explosive limit. The measurement procedure takes 8.5 s.

The applicability of fallen leaves as a raw material for the production of solid briquette fuel was assessed. In the course of a laboratory study performed with the use of the raw material gathered within the city of Novosibirsk, test samples were obtained and their properties were characterized. A conclusion on the applicability of the new form of solid biofuel was made.

Nafion membranes plasticized with dimethyl sulfoxide (DMSO) have been examined at room temperature using the vacuum ATR - FTIR spectroscopic technique in the range 50-4000cm-1. The amount of the plasticizer corresponds to the molecular ratio n=DMSO/H+=1.2, 2.3, 4.8, 7.0, 9.7 and 13.3. The medium intensity band with two maxima at 780 and 853cm-1 have been assigned to the ν(SO) stretching vibrations of the H+(DMSO)2 complex. The possible reason of ν(SO) splitting is symmetry decrease of hydrogen bond under the influence of the anion group SO3- electric field. Whereas the mutual association of free DMSO molecules in Nafion leads to appearance of weak band at 86cm-1 assigned to the dipole-dipole interactions.

A new method has been developed at the VNIIMT for carbon reduction of iron-containing materials in an electric arc. An experimental unit is constructed in order to implement the production process under laboratory conditions. Smelting cast iron from Bakal siderite ore by a non-blast furnace method using original technology is studied.

Physical principles and examples of practical implementation of drying large bodies of coal by microwave radiation are considered. It is shown that energy consumption in microwave drying of brown coals decreases to 1.5–1.8 (kW·h)/ kg as compared with traditional types of drying, for which the expenditures of energy amount to 3.0 (kW·h)/kg. In using microwave drying, the technological time of drying decreases to 4 h, whereas the time of convective drying, with other things being equal, comes to 8–20 h. Parallel with microwave radiation drying, grinding of a fuel takes place, as well as entrainment of such toxic and ecologically harmful elements as mercury, chlorine, phosphorus, sulfur, and nitrogen. An analysis of the prospects of using a microwave energy for drying coal fuel has shown that microwave radiation makes it possible to considerably economize in energy, increase explosional safety, improve the ecological situation, and reduce the metal content and overall dimensions of the equipment.

The features of proton transport and proton hydration shell structure of calix[6]arene sulfonic acid were studied. XRD and NMR data indicate the existence of crystalline and amorphous phases and various conformations in the acid structure. The hydration process occurs in three stages by thermal analysis and IR spectroscopy. The change in the composition of the hydrate affected the conductivity only at low humidity; an inverse relationship between the water uptake and the activation energy of conductivity is observed in the entire investigated range of humidity.

Single-ion conducting polymer electrolytes have received great attention due to their potential applications in electrochemical energy sources. In this work we have in detail studied features of ion transport of alkali metal ions in the polymer electrolytes based on Nafion plasticized with DMSO. The samples have been characterized by DSC, FTIR, and impedance spectroscopy. Based on the obtained results the speculations about the reasons for the presence of extremes in dependencies of both ion conductivity and activation energy on cation radius have been made. It is also suggested that solvate Li + (DMSO) 4 is the minimum transport unit in Nafion-Li + swollen in DMSO.

An approach to estimate the degree of conjugation of oligosaccharide haptens to bovine serum albumin by the squarate procedure was proposed. The approach includes gel permeation HPLC in combination with the multichannel detection.

Measurements of electron drift properties in liquid and gaseous xenon are reported. The electrons are generated by the photoelectric effect in a semi-transparent gold photocathode driven in transmission mode with a pulsed ultraviolet laser. The charges drift and diffuse in a small chamber at various electric fields and a fixed drift distance of 2.0 cm. At an electric field of 0.5 kV/cm, the measured drift velocities and corresponding temperature coefficients respectively are 1 . 97 ± 0 . 04 m m ∕ μ s and ( − 0 . 69 ± 0 . 05 ) %/K for liquid xenon, and 1 . 42 ± 0 . 03 m m ∕ μ s and ( + 0 . 11 ± 0 . 01 ) %/K for gaseous xenon at 1.5 bar. In addition, we measure longitudinal diffusion coefficients of 25 . 7 ± 4 . 6 cm 2 /s and 149 ± 23 cm 2 /s, for liquid and gas, respectively. The quantum efficiency of the gold photocathode is studied at the photon energy of 4.73 eV in liquid and gaseous xenon, and vacuum. These charge transport properties and the behavior of photocathodes in a xenon environment are important in designing and calibrating future large scale noble liquid detectors.

The incidence and prevalence of serious fungal infections is rising, especially in immunosuppressed individuals. Moreover, co-administration of antibiotics and immunosuppressants has driven the emergence of new multidrug-resistant pathogens. The significant increase of multidrug-resistant pathogens, together with their ability to form biofilms, is associated with morbidity and mortality. Research on novel synthetically prepared immunomodulators as potential antifungal immunotherapeutics is of serious interest. Our study demonstrated the immunobiological activity of synthetically prepared biotinylated mannooligosaccharides mimicking Candida antigenic factors using RAW264.7 macrophages. Macrophage exposure to the set of eight structurally different mannooligosaccharides induced a release of Th1, Th2, Th17, and Treg cytokine signature patterns. The observed immune responses were tightly associated with structure, dose, exposure time, and selected signature cytokines. The viability/cytotoxicity of the mannooligosaccharide formulas was assessed based on cell proliferation. The structure-based immunomodulatory activity of the formulas was evaluated with respect to the length, branching and conformation of the various formulas. Glycoconjugate formulas with terminal β-mannosyl-units tended to be more potent in terms of Candida relevant cytokines IL-12 p70, IL-17, GM-CSF, IL-6, and TNFα induction and cell proliferation, and this tendency was associated with structural differences between the studied glycoconjugate formulas. The eight tested mannooligosaccharide conjugates can be considered potential in vitro immunomodulative agents suitable for in vitro Candida diagnostics or prospectively for subcellular anti-Candida vaccine design.

International audience; β-(1→3)-D-Glucan is an essential component of the fungal cell wall. Mouse monoclonal antibodies (mAbs) against synthetic nona-β-(1→3)-D-glucoside conjugated with bovine serum albumin (BSA) were generated using hybridoma technology. The affinity constants of two selected mAbs, 3G11 and 5H5, measured by a surface plasmon resonance biosensor assay using biotinylated nona-β-(1→3)-D-glucan as the ligand, were approximately 11 nM and 1.9 nM, respectively. The glycoarray, which included a series of synthetic oligosaccharide derivatives representing β-glucans with different lengths of oligo-β-(1→3)-D-glucoside chains, demonstrated that linear tri-, penta- and nonaglucoside, as well as a β-(1→6)-branched octasaccharide, were recognized by mAb 5H5. By contrast, only linear oligo-β-(1→3)-D-glucoside chains that were not shorter than pentaglucosides (but not the branched octaglucoside) were ligands for mAb 3G11. Immunolabelling indicated that 3G11 and 5H5 interact with both yeasts and filamentous fungi, including species from Aspergillus, Candida, Penicillium genera and Saccharomyces cerevisiae, but not bacteria. Both mAbs could inhibit the germination of Aspergillus fumigatus conidia during the initial hours and demonstrated synergy with the antifungal fluconazole in killing C. albicans in vitro. In addition, mAbs 3G11 and 5H5 demonstrated protective activity in in vivo experiments, suggesting that these β-glucan-specific mAbs could be useful in combinatorial antifungal therapy.

In this paper we report on the characterization of the Hamamatsu VUV4 (S/N: S13370-6152) Vacuum Ultra-Violet (VUV) sensitive Multi-Pixel Photon Counters (MPPC)s as part of the development of a solution for the detection of liquid xenon scintillation light for the nEXO experiment. Various MPPC features, such as: dark noise, gain, correlated avalanches, direct crosstalk and Photon Detection Efficiency (PDE) were measured in a dedicated setup at TRIUMF. MPPCs were characterized in the range 163 K ≤ T ≤ 233 K . At an over voltage of 3 . 1 ± 0 . 2 V and at T = 163 K we report a number of Correlated Avalanches (CAs) per pulse in the 1 μ s interval following the trigger pulse of 0 . 161 ± 0 . 005 . At the same settings the Dark-Noise (DN) rate is 0 . 137 ± 0 . 002 Hz/mm 2 . Both the number of CAs and the DN rate are within nEXO specifications. The PDE of the Hamamatsu VUV4 was measured for two different devices at T = 233 K for a mean wavelength of 189 ± 7 nm . At 3 . 6 ± 0 . 2 V and 3 . 5 ± 0 . 2 V of over voltage we report a PDE of 13 . 4 ± 2 . 6 % and 11 ± 2 % , corresponding to a saturation PDE of 14 . 8 ± 2 . 8 % and 12 . 2 ± 2 . 3 % , respectively. Both values are well below the 24 % saturation PDE advertised by Hamamatsu. More generally, the second device tested at 3 . 5 ± 0 . 2 V of over voltage is below the nEXO PDE requirement. The first one instead yields a PDE that is marginally close to meeting the nEXO specifications. This suggests that with modest improvements the Hamamatsu VUV4 MPPCs could be considered as an alternative to the FBK-LF Silicon Photo-Multipliers for the final design of the nEXO detector.

Characterization of the vacuum ultraviolet (VUV) reflectance of silicon photomultipliers (SiPMs) is important for large-scale SiPM-based photodetector systems. We report the angular dependence of the specular reflectance in a vacuum of SiPMs manufactured by Fondazionc Bruno Kessler (FBK) and Hamamatsu Photonics K.K. (HPK) over wavelengths ranging from 120 nm to 280 nm. Refractive index and extinction coefficient of the thin silicon-dioxide film deposited on the surface of the FBK SiPMs are derived from reflectance data of a FBK silicon wafer with the same deposited oxide film as SiPMs. The diffuse reflectance of SiPMs is also measured at 193 nm. We use the VUV spectral dependence of the optical constants to predict the reflectance of the FBK silicon wafer and FBK SiPMs in liquid xenon.

nEXO is a proposed experiment to search for the neutrino-less double beta decay ($0\nu\beta\beta$) of $^{136}$Xe in a tonne-scale liquid xenon time projection chamber (TPC). The nEXO TPC will be equipped with charge collection tiles to form the anode. In this work, the charge reconstruction performance of this anode design is studied with a dedicated simulation package. A multi-variate method and a deep neural network are developed to distinguish simulated $0\nu\beta\beta$ signals from backgrounds arising from trace levels of natural radioactivity in the detector materials. These simulations indicate that the nEXO TPC with charge-collection tiles shows promising capability to discriminate the $0\nu\beta\beta$ signal from backgrounds. The estimated half-life sensitivity for $0\nu\beta\beta$ decay is improved by $\sim$20$~(32)\%$ with the multi-variate~(deep neural network) methods considered here, relative to the sensitivity estimated in the nEXO pre-conceptual design report.

Understanding reflective properties of materials and photodetection efficiency (PDE) of photodetectors is important for optimizing energy resolution and sensitivity of the next generation neutrinoless double beta decay, direct detection dark matter, and neutrino oscillation experiments that will use noble liquid gases, such as nEXO, DARWIN, DarkSide-20k, and DUNE. Little information is currently available about reflectivity and PDE in liquid noble gases, because such measurements are difficult to conduct in a cryogenic environment and at short enough wavelengths. Here we report a measurement of specular reflectivity and relative PDE of Hamamatsu VUV4 silicon photomultipliers (SiPMs) with 50 micrometer micro-cells conducted with xenon scintillation light (~175 nm) in liquid xenon. The specular reflectivity at 15 deg. incidence of three samples of VUV4 SiPMs is found to be 30.4+/-1.4%, 28.6+/-1.3%, and 28.0+/-1.3%, respectively. The PDE at normal incidence differs by +/-8% (standard deviation) among the three devices. The angular dependence of the reflectivity and PDE was also measured for one of the SiPMs. Both the reflectivity and PDE decrease as the angle of incidence increases. This is the first measurement of an angular dependence of PDE and reflectivity of a SiPM in liquid xenon., Comment: 21 pages, 15 figures, 6 tables. As accepted by JINST

Liquid xenon (LXe) is employed in a number of current and future detectors for rare event searches. We use the EXO-200 experimental data to measure the absolute scintillation and ionization yields generated by $\gamma$ interactions from $^{228}$Th (2615~keV), $^{226}$Ra (1764~keV) and $^{60}$Co (1332~keV and 1173~keV) calibration sources, over a range of electric fields. The $W$-value that defines the recombination-independent energy scale is measured to be $11.5~\pm~0.5$~(syst.)~$\pm~0.1$~(stat.) eV. These data are also used to measure the recombination fluctuations in the number of electrons and photons produced by the calibration sources at the MeV-scale, which deviate from extrapolations of lower-energy data. Additionally, a semi-empirical model for the energy resolution of the detector is developed, which is used to constrain the recombination efficiency, i.e., the fraction of recombined electrons that result in the emission of a detectable photon. Detailed measurements of the absolute charge and light yields for MeV-scale electron recoils are important for predicting the performance of future neutrinoless double beta decay detectors.

Various human footprints on the flux of biogenic greenhouse gases from permafrost-affected soils in Arctic and boreal domains in Russia are considered. Tendencies of significant growth or suppression of soil CO2 fluxes change across types of human impact. Overall, the human impacts increase the mean value and variance of local soil CO2 flux. Human footprint on methane exchange between soil and atmosphere is mediated by drainage. However, all the types of human impact suppress the sources and increase sinks of methane to the land ecosystems. N2O flux grew under the considered types of human impact. Based on the results, we suggest that human footprint on soil greenhouse gases fluxes is comparable to the effect of climate change at an annual to decadal timescales.

The products of solvation of lithiated Nafion with dimethylsulfoxide (DMSO) have been studied by ATR IR spectroscopy in the frequency range of 50–4000 cm–1 in a vacuum at room temperature. Degree of solvation n = DMSO/Li has been varied in a range of 1.5–18.4. Based on analysis of the dependence of the spectral parameters on the n value, it has been concluded that the test samples contain DMSO molecules of two types. The first type includes molecules coordinated to the lithium ion through the formation of the metal–oxygen bond, and the second is DMSO molecules associated by intermolecular bonds similar to those in the liquid DMSO phase. The structure of the salt depends on n: the changes are attributed to the reorientation of polymer chain units. The coordination number of lithium has been estimated at four. It has been shown that the IR data are consistent with the data on the conductivity of lithiated Nafion membranes as a function of DMSO content, according to which the simplest transport unit is the tetrasolvate [Li(DMSO)4]+. At temperatures below 0°C, all the samples exhibit an abrupt change in conductivity, which is attributed to the freezing of DMSO in the membrane matrix.

The effect of antimony doping of tin dioxide at Sb/Sn = 0.2–2.5 on the physical properties and structure of air-dry samples of hydrous tin dioxide, SnO2 ∙ nH2O (HTD), was studied by IR and Raman spectroscopy, powder X-ray diffraction, impedance measurements, TGA, and electron microscopy. The doped materials retained the structure of undoped HTD materials if the Sb/Sn ratio did not exceed the threshold value of 1.0. When Sb/Sn > 1, crystalline antimony oxide admixture appeared. The data of IR spectroscopy attested to the presence of two types of water in HTD-Sb, namely, physisorbed and chemisorbed water. The major part of water of the former type can be removed by evacuation at room temperature. Chemisorption occurs upon coordination of water molecules by metal ions through the formation of metal–oxygen bonds. Water molecules of the latter type are retained in evacuated samples at room temperature and on heating above the boiling point of liquid water. By impedance spectroscopy, HTD-Sb samples were shown to possess fairly high proton conductivity at high humidity; however, the conductivity decreased by two orders of magnitude after partial removal of water molecules of the former type. This attests to the destruction of the loosely bound hydrogen bond network, across which proton transfer takes place. It was also found that under conditions of constant humidity, the proton conductivity successively decreases with increasing antimony concentration. This is attributable to the fact that Sb(III) ions polarize the local environment to a lesser extent than Sn(IV) ions.

The results of quantitative assessment and modeling of carbon dioxide emission from urban pedolithosediments (cultural layer) in the central part of Velikii Novgorod are discussed. At the first stages after the exposure of the cultural layer to the surface in archaeological excavations, very high CO2 emission values reaching 10–15 g C/(m2 h) have been determined. These values exceed the normal equilibrium emission from the soil surface by two orders of magnitude. However, they should not be interpreted as indications of the high biological activity of the buried urban sediments. A model based on physical processes shows that the measured emission values can be reliably explained by degassing of the soil water and desorption of gases from the urban sediments. This model suggests the diffusion mechanism of the transfer of carbon dioxide from the cultural layer into the atmosphere; in addition, it includes the equations to describe nonequilibrium interphase interactions (sorption–desorption and dissolution–degassing of CO2) with the first-order kinetics. With the use of statistically reliable data on physical parameters—the effective diffusion coefficient as dependent on the aeration porosity, the effective solubility, the Henry constant for the CO2 sorption, and the kinetic constants of the CO2 desorption and degassing of the soil solution—this model reproduces the experimental data on the dynamics of CO2 emission from the surface of the exposed cultural layer obtained by the static chamber method.

Oligomannosides comprising short β-(1→2)-oligomannosyl blocks attached through a glycoside bond to an α-(1→2)-linked oligomannoside are a constituent of side chains of the mannan from the Candida cell wall. This type of oligomannoside is known as an acid-stable β-mannan and corresponds to the antigenic factor 6. In this communication, we report a convergent blockwise synthesis of four spacer-armed oligomannosides of this type including from 1 to 4 β-mannosyl and 2–3 α-mannosyl residues. β-(1→2)-Oligomannosyl thioglycosides and sulfoxides containing up to four mannose units were employed for introduction of β-oligomannoside sequences. The efficiency of β-mannosylation with mono- and oligomannoside donors was shown to depend more on the structure of the reaction partners than on the applied activation protocol. The oligomannosides obtained will be used to prepare various molecular tools for investigation of the Candida cell wall.

The most of gas associated industries face with the risks of explosion and fire which may lead to dire consequences. We present an approach for assessing the explosion risks in the presence of hydrocarbon mixtures when the chemical composition and concentration of gases in the mixture are unknown. The core idea is the measurement of warm dissipated during the combustion of hydrocarbons in the reaction chamber of the sensor. To evaluate this approach we use a catalytic planar sensor with limited gas diaphragm in the reaction chamber. We demonstrate the feasibility of our approach experimentally.