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Zastosowanie zielonych rozpuszczalników w syntezie nienasyconych związków boro- i krzemoorganicznych na drodze reakcji hydrometalacji i sprzęgania Marcińca

Walkowiak Jędrzej

Wiadomości Chemiczne

2021

[Z] 75, 1-2

111--136

Unsaturated organoboron and organosilicon compounds constitute an important class of organometallic compounds, which due to the presence of silyl- or boryl- group attached to Csp2 atoms, their simple and straightforward transformations in coupling and demetallation reactions, found a broad range of applications in the synthesis of fine chemicals or new materials with tailored properties. Such compounds might be synthesized in many transformations but two of them: hydrometallation and Marciniec coupling reactions permitted to obtain compounds with high effectivity, selectivity, and in the case of hydrometallation reactions with excellent atom economy. Most of these processes occur in a homogeneous phase, which ensures excellent yields and stereo- and regioselectivity. On the other hand, such conditions generate problems with catalyst reuse, product separation, and substantial consumption of toxic, volatile organic solvents. According to the assumptions of sustainable development in chemistry, the new procedures, which allow to intensify the process in terms of its efficiency, according to green chemistry rules are of prior importance in modern chemical industry. In this manuscript, the newest achievements in the application of green solvents (ionic liquids, liquid polymers, and supercritical CO2) in catalytic hydrometallation of alkynes and coupling of vinylmetalloids with olefins are discussed. Such an approach builds a new strategy for effective catalyst immobilization and its reuse, the increase of process productivity by the application of repetitive batch processes, and elimination of organic solvents, typically used in these transformations. Selected contributions in this field of chemistry are presented within this review.

Podsumowanie badań laboratoryjnych dotyczących suszenia izolacji celulozowej transformatorów rozdzielczych z wykorzystaniem estru syntetycznego oraz metod uzdatniania tego estru

Morańda Hubert, Przybyłek Piotr, Mościcka-Grzesiak Hanna, Walczak Krzysztof, Gielniak Jarosław, Sikorski Wojciech, Siodła Krzysztof, Pinkiewicz Ivo, Cybulski Mateusz, Orwat Bartosz, Szyling Jakub, Dutkiewicz Michał, Kownacki Ireneusz, Walkowiak Jędrzej, Franczyk Adrian, Marciniec Bogdan

Przegląd Elektrotechniczny

2021

R. 97, nr 12

220--225

W artykule przedstawiono kompleksowo wyniki badań modelowych dotyczących suszenia izolacji celulozowej transformatorów rozdzielczych za pomocą medium ciekłego, którym jest ester syntetyczny. Badania prowadzone na modelach laboratoryjnych wykazały, że efektywność suszenia zależy, między innymi, od zawilgocenia wyjściowego celulozy, grubości wyrobów celulozowych, temperatury i zawilgocenia estru. W artykule przedstawiono także trzy technologie uzdatniania estru roboczego zanieczyszczonego olejem mineralnym.

The article comprehensively presents the results of research on distribution transformers cellulose insulation models drying with the use of a liquid medium, which is synthetic ester. The tests carried out on laboratory models have shown that the drying efficiency depends, among others, on the initial moisture of the cellulose, the thickness of the cellulose products, the temperature and the moisture of the ester. The article also presents three technologies of working ester treatment contaminated by mineral oil.

Simulation of the oil supply through the connecting rod to the piston cooling channels in medium speed engines

Jaskiernik Maciej, Buczek Konrad, Walkowiak Jędrzej

Combustion Engines

2020

R. 59, nr 1

25--30

The importance of the oil flow simulation in connecting rod oil channels during the engine development process is recently increasing. This can be observed either in medium speed engines, where, as one of the traditional solutions, the oil for piston cooling is supplied through the connecting rod, or in automotive engine VCR (variable compression ratio) connecting rods, where engine oil is used to change the compression ratio of the engine. In both cases, precise numerical results are necessary to shorten the prototyping period and to reduce the overall development cost. The multi-physics character of the simulation problem basically consists of the interaction between the dynamics of the crank train components and the oil flow. For the oil supply to the piston cooling channels through the connecting rod in medium speed engines, being the objective of this paper, a major influencing factor is the oil pressure behavior in the piston cooling gallery providing periodical interaction with its supply. At the same time, the connecting rod elastic deformation during engine operation can be regarded as negligible and the planar motion of the connecting rod can be reproduced by combination of translational and rotational acceleration fields in the CFD solver. The paper includes the description of the applied simulation approach, the results and a comparison with the state-of-the art calculation without consideration of the above-mentioned influencing factors.