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This database of Phanerozoic occurrences and isotopic characteristics of metastable cold-water calcium carbonate hexahydrate (ikaite; CaCO3⚫6H2O) and their associated carbonate pseudomorphs (glendonites) has been compiled from academic publications, explanatory notes, and reports. Our database including more than 700 occurrences reveals that glendonites characterize cold-water environments, although their distribution is highly irregular in space and time. A significant body of evidence suggests that glendonite occurrences are restricted mainly to cold-water settings; however they do not occur during every glaciation or cooling event of the Phanerozoic. While Quaternary glendonites and ikaites have been described from all major ocean basins, older occurrences have a patchy distribution, which may suggest poor preservation potential of both carbonate concretions and older sediments. The data file described in this paper is available on Zenodo at https://doi.org/10.5281/zenodo.4386335 (Rogov et al., 2020).

The influence of precipitation conditions on the sorption properties of freshly-precipitated hydrated zirconium oxide was studied. The experimental data were analyzed utilizing the Langmuir and Freundlich model isotherms. It was found that the hydrated zirconium oxide synthesized at pH 5 has better sorption properties.

The effect of nature of chromium salt precursors and pH of precipitation on the properties of particles of chromium hydroxides and oxides was studied. The effect of calcining temperature on the properties of chromium oxide particles was studied.

In this study, the effect of addition of SO42− ions on the properties of ZrO2–7 % Y2O3 powders prepared by hydroxides precipitation at a constant pH of 8 was studied. It is shown, that the addition of SO42− effect on the parameters of the specific surface and porosity of the powders.

In this study, hydrated zirconium oxides and yttrium stabilized zirconia powders were synthesized by precipitation. Influence of preliminary solution modification, namely preliminary heating of the solutions and the addition of sulfate ions was investigated. It is shown that the addition of sulfate ions leads to a decrease in the size of aggregates and an increase in the specific surface area of the particles. The greatest increase in the specific surface area was observed during precipitation of a preliminary heated solution with the addition of sulfate ions. © Published under licence by IOP Publishing Ltd. Ministry of Education and Science of the Russian Federation, Minobrnauka: 14.581.21.0028, RFMEFI58117X0028 Research and Development The work was supported by Act 211 Government of the Russian Federation, contract № 02.A03.21.0006. The study was financially supported by the Ministry of Education and Science of the Russian Federation within the framework of subsidizing agreement of October 23, 2017 (No. 14.581.21.0028, unique agreement identifier RFMEFI58117X0028) of the Federal Target Program “Research and development in priority directions of the progress of the scientific and technological complex of Russia for the years 2014–2020.” 5. References [1] Chandra N, Singh D K, Sharma M, Upadhyay R K, Amritphale S S and Sanghi S K 2010 Journal of Colloid and Interface Science 342 327–332 [2] Si-Jia Hao, Cheng Wang, Tong-Le Liu, Zhi-Ming Mao, Zong-Qiang Mao, Jian-Long Wang 2017

In this study, the effect of preliminary hydrolysis of zirconyl oxysulfate on the properties of ZrO2–7 % Y2O3 powders prepared by hydroxides precipitation at a constant pH of 5 was studied. X-ray diffraction analysis showed the monophasic nature of the samples and the insignificant difference between CSR (coherent scattering regions). Samples differed in particle size distribution, porosity and morphology.

The study focuses on the characterization of gadolinium oxide surface by the method of low-temperature adsorption/desorption of nitrogen. The specific surface area of gadolinium oxide, the average pore diameter and fractal dimensions were determined. The refinement of the pore distribution was performed on the basis of the NLDFT model. It was shown that there were three kinds of pores with average sizes of 150, 300 and 600 A.

In the present research, the properties ofcellulos/polyaniline (Cel/PAn) composites, doped with citric acid were synthesized and investigated. The Cel/PAn composites were synthesized as follows: by chemical oxidation of aniline using ammonium peroxodisulphate as an oxidizing agent in 0.5 M water solution of citric acid in the presence of cellulose microfibers. The ratio (g : g) aniline : ammonium peroxodisulphate was 1,0 : 2,5 , and the ratio of aniline : cellulose (g : g) in the reaction mixtures was 1.0 : 0.1 or 1.0 : 0.25 or 1.0 : 0.5 or 1.0 : 0.75 or 1.0 : 1.0 and 1.0 : 2.5 accordingly. Cellulose fibers were kept in solution of aniline and in 0,5 M solution of citric acid for 1 hour. The oxidant was added by kneading with constant mechanical stirring of the reaction at 20±1 о С for 1 hour. Afterwards the reaction mixture was stirred for an hour additionally and left for 24 hours. The samples were dried in vacuum cabinet at 60 о С and powdered for further investigation. FTIR and XRD studies of composites help us to draw the conclusion that cellulose and polyaniline have amorphous structure. According to FTIR spectra Cel/PAn composites, we come to the consclusion that between the surface groups of cellulose and polyaniline exists phase interaction due to H-bonding. It has been established that the content of quinidic diamines relative to benzeneoid cycles in the structure of PAn films is practically the same and does not depend on the ratio of aniline/cellulose. Specific electrical conductivity of the obtained composites is 0.13×10 –3 –1.61×10 –3 S sm –1 and substantially exceeds the electrical conductivity of cellulose. Specific electrical conductivity of PAn is 4.21×10 –3 S sm –1 . The properties of the samples were measured using a diffractometer of the brand Dron-4 with Cu Kα radiation (l = 1.54060 A) in the reflection mode. Infrared spectral analysis of Fourier transform (FTIR) of sample powders was performed using a NICOLET IS 10 ATR spectrophotometer in the mode of reflection, which was later transformed into transmission mode. The electrical conductivity of the pelleted specimens was determined by measuring their resistance in the “sandwich” cells and a set of equipment for measuring the resistance of Rigol DM 3 068 at a temperature of 293±1 K, followed by the calculation of the specific electrical conductivity. Keywords : polyaniline, cellulose, citric acid, composites, structures, properties.