Complex driver movement mathematical model of the tractive rolling stock

The paper developed a complex mathematical model of the rolling stock movement that takes into account the parallel operation of two real traction asynchronous engines of the first traction railway carriage and one equivalent engine of the second traction railway carriage of the diesel train in all modes of work, as well as the main types of oscillations of the train wagons, the forces distribution of interaction between them during the movement, as well as longitudinal and transverse elastic couplings of the wheel pair with the carriage of the car. In the article, the adequacy of the processes, resulting from threedimensional modeling, processes occurring in the real diesel train DEL-02. On the complex mathematical model, were carried out tests on the effect of the main types of wagon oscillations to the motion and energy expenditure of a diesel train

The charge-assisted hydrogen-bonded organic framework (CAHOF) self-assembled from the conjugated acid of tetrakis(4-aminophenyl)methane and 2,6-naphthalenedisulfonate as a new class of recyclable Brønsted acid catalysts

The acid–base neutralization reaction of commercially available disodium 2,6-naphthalenedisulfonate (NDS, 2 equivalents) and the tetrahydrochloride salt of tetrakis(4-aminophenyl)methane (TAPM, 1 equivalent) in water gave a novel three-dimensional charge-assisted hydrogen-bonded framework (CAHOF, F-1). The framework F-1 was characterized by X-ray diffraction, TGA, elemental analysis, and 1H NMR spectroscopy. The framework was supported by hydrogen bonds between the sulfonate anions and the ammonium cations of NDS and protonated TAPM moieties, respectively. The CAHOF material functioned as a new type of catalytically active Brønsted acid in a series of reactions, including the ring opening of epoxides by water and alcohols. A Diels–Alder reaction between cyclopentadiene and methyl vinyl ketone was also catalyzed by F-1 in heptane. Depending on the polarity of the solvent mixture, the CAHOF F-1 could function as a purely heterogeneous catalyst or partly dissociate, providing some dissolved F-1 as the real catalyst. In all cases, the catalyst could easily be recovered and recycled

Inorganic Powders Prepared from Fish Scales

A mixture of abramis brama (freshwater bream), carassius carassius (crucian carp), and sander lucioperca (pike perch) scales was used for the preparation of fish scale powder containing constituents of organic and inorganic nature. The mixture of the mentioned fish scales was washed, dried, and ground for the preparation of fish scale powder. Vibration sieving was used to prepare fish scale powder enriched with inorganic components. According to thermal analysis data, this fish scale powder enriched with inorganic components included about 36.5 wt.% components removed when heating, primarily those of organic nature, and 63.5 wt.% mineral components. Inorganic powders consisting of hydroxyapatite and magnesium whitlockite were obtained via heat treatment of this fish scale powder at 800–1000 °C. Particles of these inorganic powders consisted of sintered grains with dimensions less than 100 nm after heat treatment at 800 °C, less than 200 nm after heat treatment at 900 °C, and 100–1000 nm after heat treatment at 1000 °C. Fish scale powder enriched with inorganic components as well as heat-treated inorganic powders consisting of hydroxyapatite and magnesium whitlockite can be recommended for the production of different materials, such as ceramics or composites

Inorganic Powders Prepared from Fish Scales

A mixture of abramis brama (freshwater bream), carassius carassius (crucian carp), and sander lucioperca (pike perch) scales was used for the preparation of fish scale powder containing constituents of organic and inorganic nature. The mixture of the mentioned fish scales was washed, dried, and ground for the preparation of fish scale powder. Vibration sieving was used to prepare fish scale powder enriched with inorganic components. According to thermal analysis data, this fish scale powder enriched with inorganic components included about 36.5 wt.% components removed when heating, primarily those of organic nature, and 63.5 wt.% mineral components. Inorganic powders consisting of hydroxyapatite and magnesium whitlockite were obtained via heat treatment of this fish scale powder at 800–1000 °C. Particles of these inorganic powders consisted of sintered grains with dimensions less than 100 nm after heat treatment at 800 °C, less than 200 nm after heat treatment at 900 °C, and 100–1000 nm after heat treatment at 1000 °C. Fish scale powder enriched with inorganic components as well as heat-treated inorganic powders consisting of hydroxyapatite and magnesium whitlockite can be recommended for the production of different materials, such as ceramics or composites

Electronic Structure of Cesium Butyratouranylate(VI) as Derived from DFT-assisted Powder X‑ray Diffraction Data

Investigation of chemical bonding and electronic structure of coordination polymers that do not form high-quality single crystals requires special techniques. Here, we report the molecular and electronic structure of the first cesium butyratouranylate, Cs­[UO₂(<i>n</i>-C₃H₇COO)₃]­[UO₂(<i>n</i>-C₃H₇COO)­(OH)­(H₂O)], as obtained from DFT-assisted powder X-ray diffraction data because of the low quality of crystalline sample. The topological analysis of the charge distribution within the quantum theory of atoms-in-molecules (QTAIM) space partitioning and the distribution of electron localization function (ELF) is reported. The constancy of atomic domain of the uranium­(VI) atom at different coordination numbers (7 and 8) and the presence of three ELF maxima in equatorial plane of an uranyl cation attributed to the 6s and 6p electrons were demonstrated for the first time. Details of methodologies applied for additional verification of the correctness of powder XRD refinement (Voronoi atomic descriptors and the Morse restraints) are discussed

Electronic Structure of Cesium Butyratouranylate(VI) as Derived from DFT-assisted Powder X‑ray Diffraction Data

Investigation of chemical bonding and electronic structure of coordination polymers that do not form high-quality single crystals requires special techniques. Here, we report the molecular and electronic structure of the first cesium butyratouranylate, Cs­[UO₂(<i>n</i>-C₃H₇COO)₃]­[UO₂(<i>n</i>-C₃H₇COO)­(OH)­(H₂O)], as obtained from DFT-assisted powder X-ray diffraction data because of the low quality of crystalline sample. The topological analysis of the charge distribution within the quantum theory of atoms-in-molecules (QTAIM) space partitioning and the distribution of electron localization function (ELF) is reported. The constancy of atomic domain of the uranium­(VI) atom at different coordination numbers (7 and 8) and the presence of three ELF maxima in equatorial plane of an uranyl cation attributed to the 6s and 6p electrons were demonstrated for the first time. Details of methodologies applied for additional verification of the correctness of powder XRD refinement (Voronoi atomic descriptors and the Morse restraints) are discussed

Polymorphism in a Cobalt-Based Single-Ion Magnet Tuning Its Barrier to Magnetization Relaxation

A large barrier to magnetization reversal, a signature of a good single-molecule magnet (SMM), strongly depends on the structural environment of a paramagnetic metal ion. In a crystalline state, where SMM properties are usually measured, this environment is influenced by crystal packing, which may be different for the same chemical compound, as in polymorphs. Here we show that polymorphism can dramatically change the magnetic behavior of an SMM even with a very rigid coordination geometry. For a cobalt­(II) clathrochelate, it results in an increase of the effective barrier from 109 to 180 cm^–1, the latter value being the largest one reported to date for cobalt-based SMMs. Our finding thus highlights the importance of identifying possible polymorphic phases in search of new, even more efficient SMMs