Studying the properties of the unburned gravel from fly-ash of Thermo Electric Plant–5 SIBECO

The results of the determination of the physico-mechanical properties of the unburned gravel obtained from fly ash of Thermal Power Plant-5 SIBEKOare presented. The aggregate properties were determined according to State Standard 9758-2012. It is established that the unburned ash gravel meets the requirements of State Standard 32496-2013 and can be used as a large artificial aggregate in construction concretes.Представлены результаты определения физико-механических свойств безобжигового гравия, полученного из золы-уноса ТЭЦ-5 ОАО «СИБЭКО». Свойства заполнителя определяли по ГОСТ 9758-2012. Установлено, что безобжиговый зольный гравий удовлетворяет требованиями ГОСТ 32496-2013 и может применяться в качестве крупного искусственного заполнителя в строительных бетонах

Intermediate phase, network demixing, boson and floppy modes, and compositional trends in glass transition temperatures of binary AsxS1-x system

The structure of binary As_xS_{1-x} glasses is elucidated using modulated-DSC, Raman scattering, IR reflectance and molar volume experiments over a wide range (8%<x<41%) of compositions. We observe a reversibility window in the calorimetric experiments, which permits fixing the three elastic phases; flexible at x<22.5%, intermediate phase (IP) in the 22.5%<x<29.5% range, and stressed-rigid at x>29.5%. Raman scattering supported by first principles cluster calculations reveal existence of both pyramidal (PYR, As(S1/2)3) and quasi-tetrahedral(QT, S=As(S1/2)3) local structures. The QT unit concentrations show a global maximum in the IP, while the concentration of PYR units becomes comparable to those of QT units in the phase, suggesting that both these local structures contribute to the width of the IP. The IP centroid in the sulfides is significantly shifted to lower As content x than in corresponding selenides, a feature identified with excess chalcogen partially segregating from the backbone in the sulfides, but forming part of the backbone in selenides. These ideas are corroborated by the proportionately larger free volumes of sulfides than selenides, and the absence of chemical bond strength scaling of Tgs between As-sulfides and As-selenides. Low-frequency Raman modes increase in scattering strength linearly as As content x of glasses decreases from x = 20% to 8%, with a slope that is close to the floppy mode fraction in flexible glasses predicted by rigidity theory. These results show that floppy modes contribute to the excess vibrations observed at low frequency. In the intermediate and stressed rigid elastic phases low-frequency Raman modes persist and are identified as boson modes. Some consequences of the present findings on the optoelectronic properties of these glasses is commented upon.Comment: Accepted for PR

Concrete composition selection on unburned gravel from fly-ash

On the basis of unburned ash gravel, the composition of concrete is selected and their physico-mechanical properties are determined. In terms of density, they refer to lightened concrete (1817–1857 kg/m3), strengths correspond to classes B10, B12.5 and B25. The introduction of a superplasticizer additive reduces the water requirement of the concrete mix and increases the strength of the concrete.На основе безобжигового зольного гравия подобраны составы бетонов и определены их физико-механические свойства. По плотности они относятся к облегченным бетонам (1817–1857 кг/м3), прочности ‒ соответствуют классам В10, В12,5 и В25. Введение добавки суперпластификатора снижает водопотребность бетонной смеси и повышает прочность бетона

ПРЯМОЙ АТОМНО-АБСОРБЦИОННЫЙ АНАЛИЗ ПОЧВ С ПОМОЩЬЮ ПРИСТАВКИ АТЗОНД-1 ДЛЯ ДВУХСТАДИЙНОЙ ЗОНДОВОЙ АТОМИЗАЦИИ В ГРАФИТОВОЙ ПЕЧИ

The new economic method of the direct atomic absorption analysis of the soils as suspensions (~50 mg/ml) is offered. It is based on the double-stage probe atomization which is carried out by means of an original robotized accessory ATZOND-1 to a commercial graphite furnace. It is possible to remove matrix interferences, to use rather representative sample weight of the soil (up to 12 mg), to do without chemical preparation and special calibration standards. The limits of determination in the dry soil for Pb – 0.002, Cd – 0.1, Se –10, Au – 3 mg/kg. It is sufficient for maximum allowable concentrations control and gold content in the rock. Sensitivity adjustment for measurement of Zn, Si, Al and Fe concentrations which contents reaches tens percent is provided. Validation is checked using soil reference materials SP-1, SP-2 and SP-3, Sr    5 %.Keywords: direct atomic absorption analysis, graphite atomizer, double-stage probe atomization, soil, suspension(Russian)DOI: http://dx.doi.org/10.15826/analitika.2013.17.2.005Y.А. Zakharov1,  О.B. Kokorina1, B.R. Grigoryan2, R.V. Okunev2, D.S. Irisov3,R.R. Haibullin3, M.F. Sadykov4, A.R. Gainutdinov4 Departments of 1General Physics and 2Soil Science of Kazan (Volga region) Federal University, Kazan, Russian Federation3 LLC «Atzond», Kazan, Russian Federation 4Department of Industrial Electronics of Kazan State Power Engineering University, Kazan, Russian FederationПредложен новый экономичный способ прямого атомно-абсорбционного анализа почв, вносимых в печь в виде суспензий (~50 мг/мл). Он основан на двухстадийной зондовой атомизации, осуществляемой с помощью оригинальной роботизированной приставки АТЗОНД-1 к стандартной графитовой печи. Удается снизить матричные помехи, использовать представительные навески почвы (до 12 мг), обходиться без химической подготовки и специальных калибровочных образцов. Нижний предел определяемых содержаний в сухой почве составляет, в мг/кг: Pb – 0.002, Cd – 0.1, Se –10, Au – 3. Он достаточен для контроля ПДК и золотоносности породы. Обеспечена регулировка чувствительности для измерения концентрации Zn, Si, Al и Fe, содержание которых в почве достигает десятков процентов. Правильность проверена на образцах почв СП-1, СП-2 и СП-3, Sr 5 %.Ключевые слова: прямой атомно-абсорбционный анализ, графитовый атомизатор, двухстадийная зондовая атомизация, почва, суспензия.DOI: http://dx.doi.org/10.15826/analitika.2013.17.2.00

Fabrication and photoluminescent properties of Tb3+ doped carbon nanodots

Abstract Carbon nanodots (CNDs) doped with Tb ions were synthesized using different synthetic routes: hydrothermal treatment of a solution containing carbon source (sodium dextran sulfate) and TbCl3; mixing of CNDs and TbCl3 solutions; freezing-induced loading of Tb and carbon-containing source into pores of CaCO3 microparticles followed by hydrothermal treatment. Binding of Tb ions to CNDs (Tb-CND coupling) was confirmed using size-exclusion chromatography and manifested itself through a decrease of the Tb photoluminescence lifetime signal. The shortest Tb photoluminescence lifetime was observed for samples obtained by hydrothermal synthesis of CaCO3 microparticles where Tb and carbon source were loaded into pores via the freezing-induced process. The same system displays an increase of Tb photoluminescence via energy transfer with excitation at 320–340 nm. Based on the obtained results, freezing-induced loading of cations into CNDs using porous CaCO3 microparticles as reactors is proposed to be a versatile route for the introduction of active components into CNDs. The obtained CNDs with long-lived emission may be used for time-resolved imaging and visualization in living biological samples where time-resolved and long-lived luminescence microscopy is required

Composition and Properties of Non-Fired Fly Ash Gravel and Concrete on Its Basis

Non-fired fly ash gravel was obtained on the basis of fly ash of thermal power plant no 5 of JSC "SIBEKO", 15 % of Portland cement and the hardening accelerator. The gravel of 5-20 mm fraction and 6 months' air-moist curing is 900 density grade, P300 strength grade, frost-resistance grade - F35. The compositions of cement concretes of strength class from B10 to B25 were established and their physical and mechanical properties were determined using obtained non-fired fly ash gravel. They belong to the lightweight concrete according to the density (1817-1857 kg/m3). The introduction of superplasticizer SP-1 reduces water demand of concrete mixture and increases strength of concrete on fly ash gravel. © 2019 Published under licence by IOP Publishing Ltd.The work was supported by Act 211 Government of the Russian Federation, contract № 02.A03.21.0006

Structure of GeSe4−InGeSe_4-In and GeSe5−InGeSe_5-In glasses

(Ge(0.2)Se(0.8))(100-x)In(x) and (Ge(0.17)Se(0.83))(100-x)In(x) (x = 0, 5, 10, 15 at.%) chalcogenide glasses have been studied with high-energy x-ray diffraction, neutron diffraction and extended x-ray absorption spectroscopy at Ge, Se and In K-edges. The experimental data were modelled simultaneously with the reverse Monte Carlo simulation method. GeSe(4/2) tetrahedra are shown to be the main structural units in the binary and ternary glasses investigated. Indium bonds to the excess Se atoms in the ternary Ge-Se-In glasses. While the majority of In atoms have three Se neighbours, some In atoms may be tetrahedrally coordinated by Se