Concretes with Unique Properties for Special Building Structures

The paper presents new results in the building materials area. One of the solutions of the thin-walled elements obtaining can be achieved due to new additive using. The main purpose of the paper was improvement concrete properties for thin-walled constructive elements. The experimental and standard methods have been used and new complex additive for concrete. The research shows that a comprehensive additive consisting of aqueous solution of polycarboxilate polymer, silica sol and potassium nitrite is effective and makes it possible to produce high-efficiency concrete with unique properties: higher compression strength, higher crack resistance, frost resistance, water resistance, abrasion resistance. The study shows that the concrete is chemical resistant. Modified concrete can be recommended for manufacturing critical concrete structures of special purpose, for example high-rise constriction.

MOLECULAR RELAXATION IN BINARY SYSTEMS NaNO3 – NaNO2, KNO3 – KNO2

In the present study, the molecular relaxation processes in crystalline sodium nitrate NaNO3, crystalline sodium nitrite NaNO2, crystalline potassium nitrate KNO3, crystalline potassium nitrite KNO2, and in solid binary salt systems sodium nitrate – sodium nitrite NaNO3 – NaNO2 and potassium nitrate - potassium nitrite KNO3 – KNO2 were studied with the Raman spectroscopic methods. We have found that the relaxation time of the fully symmetric vibration of n1 (A) of the molecular nitrate anion NO3– in the solid binary salt systems “nitrate – nitrite” NaNO3 – NaNO2 or KNO3 – KNO2 is lower than in the individual crystalline nitrate NaNO3 or KNO3, respectively. It is shown that the increase in the rate of intramolecular relaxation is explained by the presence in the binary system of an additional relaxation mechanism of the vibrationally excited states of the nitrate ion NO3–. This relaxation mechanism of the nitrate ion NO3– in a binary system is associated with the excitation of a lower-frequency vibration of another anion (nitrite ion NO2–) and the "birth" of a lattice vibration (phonon). The frequency of this phonon is equal to the difference in the vibration frequencies of the nitrate ion NO3– and nitrite ion NO2–. It is established that the condition for the realization of such a relaxation mechanism is that the difference in the frequency of these oscillations of the nitrate ion NO3– and nitrite ion NO2– must correspond to the region of a sufficiently high density of states of the phonon spectrum of the solid binary salt system under study. The maximum frequency of the phonon spectrum of the system is determined by its Debye temperature. For ionic salt systems, the Debye temperature is always higher than 200 K, and often more than 300 K. Therefore, in the solid binary salt systems, the proposed relaxation mechanism is almost always relevant.Forcitation:Aliev A.R., Akhmedov I.R., Kakagasanov M.G., Aliev Z.A., Amirov A.M. Molecular relaxation in the binary systems NaNO3 – NaNO2, KNO3 – KNO2. Izv. Vyssh.Uchebn. Zaved. Khim. Khim. Tekhnol. 2018. V. 61. N 7. P. 23-30

Effect of plant growth regulators and nitrogenous compounds on seed germination of pepper (Capsicum frutescens L)

The seed germination of Capsicum frutescens L. was investigated through various methods, namely, washing and air dry storage treatments, applications of gibberelic acid (GA3), Kinetin, potassium nitrite (KNO2) and potassium nitrate (KNO3) to improve germination of seeds in view of poor germination reported. The seeds were subjected to the following treatments namely washing to remove the slimy coverings; air-drying at various time-intervals; incubated in different concentrations of GA3, Kinetin, KNO2 and KNO3. The treatments were subjected to light or dark germinations at 300C and radicle emergence scored after 15days. The various results showed that washing treatment, and light germination had a significant effect on the germination of Capsicum frutescens seeds. For air-drying treatment, germination increased from 0-48hrs and decreased after 72hrs, 48hrs air-drying duration gave the highest percentage germination. Application of GA3, kinetin, KNO2 and KNO3 in low concentrations promoted the germination of freshly harvested Capsicum frutescens seeds. Generally the KNO2 and KNO3 gave the best germination results. The findings of this study have significant implications in the commercial production of Capsicum frutescens in view of its economic and medicinal importance.Keywords: Growth regulators, Nitrogenous compounds, Capsicum frutescens

The Influence of Different Molten Salt Systems on Zinc and Bismuth Tungstate Formation

The influence of different molten salt environments on formation of tungstates has been studied. Well crystalline and pure Bi2WO6 have been prepared in potassium nitrite KNO2 (350°C), potassium chloride KCl (800°C) and mixture of potassium-sodium sulphates K2SO4-Na2SO4 (800°C), but ZnWO4 have been successfully synthesized in sodium nitrate NaNO3 (350°C), mixture of sodium-potassium chlorides NaCl-KCl (680°C), potassium chloride KCl (780°C) and mixture of potassium-sodium sulphates K2SO4-Na2SO4 (850°C). The higher surface area and photocatalytic activity show powders prepared at lower temperature.