DEVELOPMENT OF TECHNICAL SOLUTIONS AIMED AT IMPROVING TECHNOLOGICAL CAPABILITIES, DESIGN CHARACTERISTICS AND INCREASING THE SERVICE LIFE OF BRIQUETTE PRESSES

Development of technical solutions for manufacturing and further use advanced roller press having advanced technological capabilities and increased resource exploitation

РОЗВИТОК ОБЛАДНАННЯ РОЗПОДІЛЬНИХ ПРИСТРОЇВ ТЯГОВОГО ЕЛЕКТРОПОСТАЧАННЯ. ЧАСТИНА І

It’s presented review of state and development technologies, technical parameters and characteristics modern basic type equipment in the distributive devices for traction power supply systems: complete block technologies, high-voltage switches direct and alternating current, powerand converting transformers, switchgears, recuperators and inverters, power supply automation. On example world's leading specimens shows possibilities high energy efficiency and reliability modern equipment for switchgears. Specifics main features and differences, advantages anddisadvantages of perspective equipment electric power supply systems are considered. It’s focused view on technical solutions other than those, used in Ukraine, to analyze the feasibility their development and implementation in the present conditions. General directions and criteria for choice rational strategy modernization distributive devices of traction power supply systems are determined. Analysis will allow performing selection technical parameters for devices in design mathematical models and subsequent verification, coordination and implementation in new devices, their compatibility with existing traction power system, railways, subwaysРассмотрено текущее состояние развития технологий, а также техническиепараметры и характеристики современного типового оборудования распределительных устройств систем тягового электроснабжения. Выделено специфику основных сходных черт и различий, преимуществ и недостатков перспективного оборудования систем электроснабжения. Сосредоточено внимание на технических решениях, отличных от тех,что применяются в Украине, с целью анализа целесообразности их развития и внедрения в нынешних условияхРозглянуто поточний стан розвитку технологій, а також технічні параметри та характеристики сучасного типового обладнання розподільних пристроїв систем тягового електропостачання. Виокремлено специфіку основних подібних рис і відмінностей, переваг і недоліків перспективного обладнання систем електропостачання. Зосереджено увагу на технічних рішеннях, відмінних від тих, що застосовуються в Україні, з метою аналізу доцільності їх розвитку та впровадження в теперішніх умовах

Screening of Palladium/Charcoal Catalysts for Hydrogenation of Diene Carboxylates with Isolated-Rings (Hetero)aliphatic Scaffold

A series of seven palladium-containing composites, i.e., four Pd/C and three Pd(OH)2/C (Pearlman’s catalysts), was prepared using modified common approaches to deposition of Pd or hydrated PdO on charcoal. All the composites were tested in the catalytic hydrogenation of diene carboxylates with the isolated-ring scaffold, e.g., 5,6-dihydropyridine-1(2H)-carboxylates with 2-(alkoxycarbonyl)cyclopent-1-en-1-yl and hex-1-en-1-yl substituents at the C(4)-position. The performance of the composites was also studied via the hydrogenation of quinoline as a model reaction. The composites were characterized by transmission and scanning electron microscopy (TEM and SEM), powder X-ray diffraction, and low-temperature N2 adsorption. It was found that the composites containing Pd nanoparticles (NPs) of 5–40 nm size were the most efficient catalysts for the hydrogenation of dienes, providing the reduced products with up to 90% yields at p(H2) = 100 atm, T = 30 °C for 24 h. The method of Pd NPs formation had more effect on the catalyst performance than the size of the NPs. The catalytic performance of Pearlman’s catalysts (Pd(OH)2/C) in the hydrogenation of dienes was comparable to or lower than the performance of the Pd/C systems, though the Pearlman’s catalysts were more efficient in the hydrogenation of quinoline

Lanthanide Complexes with 2-(Tosylamino)-benzylidene- N -(aryloyl)hydrazones: Universal Luminescent Materials

International audienceLanthanide complexes Ln(L1)(HL1) (Ln = Lu, Yb, Er, Gd, Eu, Sm) and Ln(L2)(HL2) (Ln = Lu, Yb, Gd, Eu) with 2-(tosylamino)-benzylidene-N-(aryloyl)hydrazones (H2L1, aryloyl = 2-hydroxybenzoyl; H2L2, aryloyl = isonicotinoyl) were obtained with the aim to explore them as new luminescent materials. They were found to form monomeric species independently on the aryloyl group, and their crystal structures were determined from single-crystal X-ray data (Yb(L2)(HL2)·0.5(C2H5OH)), as well as from powder X-ray data by Rietveld refinement (Eu(L1)(HL1)). Ytterbium complexes exhibited intense luminescence, which allowed using them in host-free organic light-emitting diodes, which demonstrated remarkable efficiency of near infrared electroluminescence (50 μW/W) at low voltage (5 V). The special mechanism of europium luminescence quenching allowed using europium complexes as luminescent thermometers, which demonstrated very high sensitivity up to 12%/K. The theory of luminescence thermometry based on a three-level system was proposed, which allowed predicting sensitivity with high accuracy (error within 20%)

Scintillator Nonproportionality Studies at PITZ

A standard technique to measure beam profiles in linear accelerators are screen monitors using scintillating screens. This technique is used e.g. at the European XFEL in order to overcome coherence effects in case of OTR usage [*]. During the XFEL commissioning it was found out that screens based on LYSO:Ce as scintillating material revealed a nonproportional light output [**]. Reason for it is the high particle beam density. As consequence it was decided to exchange LYSO:Ce by GAGG:Ce scintillators because the excitation carriers can rapidly transfer their energy to excited states of gadolinium, and a rapid migration of this energy among the Gd sub-lattice is expected. Driven by the observations at XFEL a series of measurements was started to investigate the properties of various scintillator materials (LYSO:Ce, YAP:Ce, YAG:Ce, LuAG:Ce and GAGG:Ce). The last measurement campaign was carried out at PITZ which allows to operate at higher beam charge and lower electron energy compared to the XFEL. The present work summarizes the results of these measurements

Thermodynamically Stable Dispersions of Quantum Dots in a Nematic Liquid Crystal

Using transmittance electron microscopy, fluorescence and polarizing optical microscopy, optical spectroscopy, and fluorescent correlation spectroscopy, it was shown that CdSe/ZnS quantum dots coated with a specifically designed surfactant were readily dispersed in nematic liquid crystal (LC) to form stable colloids. The mixture of an alkyl phosphonate and a dendritic surfactant, where the constituent molecules contain promesogenic units, enabled the formation of thermodynamically stable colloids that were stable for at least 1 year. Stable colloids are formed due to minimization of the distortion of the LC ordering around the quantum dots