Ganja State University (GDU, Azerbaijani: Gəncə Dövlət Universiteti) is a public university in Ganja, Azerbaijan. Officially accredited and recognized by Ministry of Education of Azerbaijan), Ganja State University is a medium-sized (uniRank enrollment range: 6,000-6,999 students) coeducational higher education institution. The university offers courses and programs leading to officially recognized higher education degrees such as bachelor degrees, master degrees, and doctorate degrees in several areas of study. The 80 years old higher-education institution has a selective admission policy based on entrance examinations. The admission rate range is 80-90% making this Azerbaijani higher education organization a least selective institution. There are 20 doctors and professors, 156 doctoral candidates and associate professors, and 150 assistant professors and lecturers in the 26 departments of the university. The university has a library, several computer rooms and laboratories. The university ranks as 19th best nationwide and 8547th best worldwide.
The Cu2S-Ag2S-GeS2 (A) system is of interest for the preparation of copper–silver-substituted solid solutions based on ternary compounds possessing a number of interesting functional properties. This paper presents the results of a detailed experimental study of phase equilibria in this system using the DTA/DSC and X-ray diffraction methods. A new refined version of the T-x diagram of the Ag2S-GeS2 boundary system is presented. A new picture of phase equilibria in the system (A) is obtained, including diagrams of solid-phase equilibria at 300 K and 750 K, a projection of the liquidus surface of the system, as well as some polythermal sections and isothermal sections of the phase diagram at 1200, 1100 and 1000 K. It is established that the quasi-binary system Ag2S-GeS2 is characterized by the formation of two intermediate compounds, Ag8GeS6 and Ag2GeS3. The first melts congruently at 1220 K and undergoes a polymorphic transformation at 495 K. The second is formed as a result of a peritectic reaction at 895 K. System (A) is characterized by the formation of continuous solid solutions between the high-temperature cubic modifications of Cu8GeS6 and Ag8GeS6, limited solid solutions based on their low-temperature modifications, and Cu2GeS3 and Ag2GeS3 compounds. In the subsolidus region of system (A), phase transformations associated with the polymorphism of binary and ternary compounds are observed.
This paper presents the results of a comprehensive study of solid-phase equilibria in the Bi2S3-Bi2Se3-BiI3 system and the thermodynamic properties of the intermediate phases Bi19S27(1-& khcy;)S & iecy;27 & khcy;I3. The investigations were carried out using differential thermal analysis (DTA), X-ray diffraction (XRD) and electromotive force (EMF) measurements of concentration cells of the type (-) Bi (solid) / liquid electrolyte, Bi3+ / (Bi in alloy) (solid) (+) within the temperature range 300-370 K, with morpholine formate ionic liquid as the electrolyte. Based on the experimental data, a solid-phase equilibria diagram of the Bi2S3-Bi2Se3-BiI3 system was constructed, according to which it is characterized by the formation of a continuous series of solid solutions along the BiSI-BiSeI section and a wide homogeneity area based on Bi19S27I3. From the EMF measurement data, the partial thermodynamic functions of bismuth in solid solutions based on Bi19S27I3 were calculated. Using a fragment of the phase diagram of the quaternary Bi-S-Se-I system, the potential-forming reactions responsible for the indicated partial molar functions were determined and the standard thermodynamic functions of formation and standard entropies of the ternary compound Bi19S27I3 and the solid solutions Bi19S27(1-& khcy;)S & iecy;27 & khcy;I3 (x = 0.2, 0.4, 0.6) were calculated. In the calculations, in addition to the authors' own data, literature data on the corresponding thermodynamic functions of the BiSI compound, the solid solutions BiS1-& khcy;SexI and the S1-xSex alloys were used.
In this paper, the results of a comprehensive study of solid-phase equilibria in the FeS-In2S3-S system and thermodynamic properties of intermediate phases using DTA, XRD, and EMF methods are presented. Based on the experimental results and literature data, the character of solid-phase equilibria in the Fe-In-S system in the FeS-In2S3-S composition range is established. From the EMF measurements of the concentration cells of the type (-) FeS(solid) | glycerol + KCl + FeCl2 | (Fe in alloy) (+) in the 300-390 K temperature interval, the relative partial thermodynamic functions of FeS and Fe in alloys were determined. By integrating the Gibbs-Duhem equation from the obtained partial molar quantities of iron, using the thermodynamic data for In2S3, the standard Gibbs free energy of formation and the enthalpy of formation, as well as the standard entropy of the FeIn2S4 compound and solid solutions (FeS)1-x(In2S3)x (x = 0.6; 0.8; 0.9) were calculated.
Zn-In-Sb alloys were synthesized using a Bridgman furnace. The phase composition of the obtained samples was analyzed through powder X-ray diffractometry. Additionally, DSC measurements were performed to elucidate the phase transition behaviors. Ellipsometric measurements, conducted across a frequency range of 180-1580THz, allowed for the calculation of the complex permittivity, absorption coefficient and reflection coefficient. Theoretical considerations of nonlinear optical effects were also explored, identifying the threshold beyond which nonlinear phenomena may occur in Zn-In-Sb alloys. The analysis of the obtained results suggests that the synthesized alloys have the potential to serve as efficient materials in various optoelectronic devices.
We investigated pollen morphology of Rubus species from Azerbaijan. Pollen of 24 specimens from 15 species of all three Rubus subgenera has been studied using light, confocal laser scanning and scanning electron microscopes to estimate pollen characteristic variability and to describe pollen polymorphism and taxonomic value. Pollen grains are small- or medium-sized, mainly three-colporate and spheroidal; composed apertures include meridional directed, long, narrow colpi and clear ori on the equator. Exine is thin, tectate and columellate; ornamentation is striate or striate-perforate with thin mainly long striae and perforations from zero to numerous between striae. Pollen of Azeri Rubus species is similar to European ones, and it is difficult to distinguish from each other. Intraspecific and individual variability is manifested in size, shape, number and location of apertures, and patterns of ornamentation. The ordered structure of the individual variability of the characteristic shape (number and location of apertures) of pollen grains in the genus Rubus is described. An abundance of deviant forms was noted in the subgenus Rubus. An analysis of pollen morphology of investigated Rubus taxa around the world demonstrated that the diagnostic feature into genus is ornamentation, which can be divided into three groups: typical striate; non-typical striate; and non-striate. The subgenus Rubus is uniform in exine pattern. Typical striate pollen is found throughout the world; however, variations of non-typical striate and non-striate pollen are revealed in Southeast Asia. Pollen data indicate a geographical center of species diversity in Southeast Asia.
