Hot deformation and dynamic recrystallization of 18%mn twinning-induced plasticity steels

The deformation behavior of 18%Mn twinning-induced plasticity (TWIP) steels with 0.4%C or 0.6%C is studied by means of isothermal compression tests in the temperature range of 973-1373 K at the strain rates of 10³-10¹ s¹. The hot working is accompanied by the development of discontinuous dynamic recrystallization (DRX), which is commonly advanced by an increase in deformation temperature and/or a decrease in strain rate. A decrease in the carbon content promotes the DRX development, though the flow stresses scarcely depend on the carbon conten

Rationale for Processing of a Mg-Zn-Ca Alloy by Equal-Channel Angular Pressing for Use in Biodegradable Implants for Osteoreconstruction

Widespread use of Mg-Zn-Ca alloys in clinical orthopedic practice requires improvement of their mechanical properties—in particular, ductility—and enhancement of their bioactivity for accelerated osteoreconstruction. The alloy was studied in two structural states: after homogenization and after equal-channel angular pressing. Immersion and potentiodynamic polarization tests showed that the corrosion rate of the alloy was not increased by deformation. The mass loss in vivo was also statistically insignificant. Furthermore, it was found that deformation did not compromise the biocompatibility of the alloy and did not have any significant effect on cell adhesion and proliferation. However, an extract of the alloy promoted the alkaline phosphatase activity of human mesenchymal stromal cells, which indicates osteogenic stimulation of cells. The osteoinduction of the deformed alloy significantly exceeded that of the homogenized one. Based on the results of this work, it can be concluded that the alloy Mg-1%Zn-0.3%Ca modified by equal-channel angular pressing is a promising candidate for the manufacture of biodegradable orthopedic implants since it stimulates osteogenic differentiation and has greater ductility, which provides it with a competitive advantage in comparison with the homogenized state

Comparative analysis of the antineoplastic activity of C60 fullerene with 5-fluorouracil and pyrrole derivative in vivo

The antitumor activity of pristine C60 fullerene aqueous solution (C60FAS) compared to 5-fluorouracil (5-FU) and pyrrole derivative 1-(4-Cl-benzyl)-3-Cl-4-(CF3-fenylamino)-1H-pyrrol-2.5-dione (MI-1) cytostatic drugs was investigated and analyzed in detail using the model of colorectal cancer induced by 1.2-dimethylhydrazine (DMH) in rat

Superconductivity in thin films of RuN

Superconductivity has been found in RuN films obtained by reactive magnetron sputtering. This is a novel member of the metal nitride superconductors family. The critical temperature of the superconducting transition varies depending on the substrate and ranges from 0.77 K to 1.29 K. The parameters of the crystal lattice of superconducting films have been determined: the lattice is distorted cubic with parameters $a = b = c = 4.5586$ \AA , $\alpha =\beta =\gamma =87.96^\circ$. A zero temperature upper critical magnetic field $H_{c2}(0)$ and the coherence length were found from the experimental data using WHH model. $H_{c2}(0) = 2.3$ T- 4.1 T for different substrates and exceeds the upper paramagnetic limit, as well as $\xi = 12$ nm. An s-wave single band energy gap $\Delta(0) = 0.19$ meV was revealed by self-field critical current experiment at temperatures down to 10 mK, $2\Delta /kT_c =5.5$ exceeding the BCS ratio 3.5.Comment: 10 pages, 16 figure

Інноваційні технології в хірургічному лікуванні злукової непрохідності кишечника на тлі хвороби очеревини

The aim of the work: to improve the results of surgical treatment of patients with postoperative adhesive bowel obstruction on the background of adhesive disease of the peritoneum, using various methods of adhesiolysis. The analysis of surgical treatment of 314 patients with postoperative peritoneal commissures was performed in the Clinical Surgical Departments of the Department of Surgical Diseases No. 1 (Kyiv City Clinical Hospital No. 1).Цель работы: улучшить результаты хирургического лечения пациентов с послеоперационной спаечной непроходимостью кишечника на фоне спаечной болезни брюшины с помощью различных методов адгезиолизиса. В клинических хирургических отделениях кафедры хирургических болезней № 1 (КГКБ № 1) проведен анализ хирургического лечения 314 пациентов с послеоперационной спаечной болезнью.Мета роботи: покращити результати хірургічного лікування пацієнтів із післяопераційною злуковою непрохідністю кишечника на тлі спайкової хвороби  очеревини за допомогою різних методів адгезеолізису. У клінічних хірургічних відділеннях кафедри хірургічних хвороб № 1 (КМКЛ №1) проведено аналіз хірургічного лікування 314 пацієнтів з післяопераційною злуковою хворобою

Effect of rotary swaging on structure and properties of low-carbon steel

The structural transformation and mechanical properties of a low-carbon 0.2% C steel and a 0.09% C-Mn-V steel in coarse- and ultrafine-grained (UFG) states were studied. The UFG structure with structural elements about 210-375 nm in size was obtained by rotary swaging (RS) and equal-channel angular pressing (ECAP). ECAP was used to compare the influence of the industrial deformation and SPD methods on the microstructure and properties of low-carbon steel

Interpolation Properties and SAT-based Model Checking

Craig interpolation is a widespread method in verification, with important applications such as Predicate Abstraction, CounterExample Guided Abstraction Refinement and Lazy Abstraction With Interpolants. Most state-of-the-art model checking techniques based on interpolation require collections of interpolants to satisfy particular properties, to which we refer as "collectives"; they do not hold in general for all interpolation systems and have to be established for each particular system and verification environment. Nevertheless, no systematic approach exists that correlates the individual interpolation systems and compares the necessary collectives. This paper proposes a uniform framework, which encompasses (and generalizes) the most common collectives exploited in verification. We use it for a systematic study of the collectives and of the constraints they pose on propositional interpolation systems used in SAT-based model checking

The influence of ultrafine-grained structure on the mechanical properties and biocompatibility of austenitic stainless steels

In this study, equal-channel angular pressing (ECAP) of austenitic 316L and Cr-Ni-Ti stainless steels was carried out. Effect of ECAP at 400 °C on the evolution of the microstructure, mechanical properties, and biocompatibility of these steels was investigate

Microstructure and mechanical properties of AISi 304l austenitic stainless steel processed by various schedules of rolling

The paper studies various rolling schedules implemented at 500°С (incl. direct, reverse, and cross rolling) and their effect on the structure formation and mechanical properties in AISI 304L stainless steel samples. Both TEM and SEM research techniques were applied. An ultrafine grain-subgrain microstructure was found to be formed inside elongated original grains. Rolling-processed microstructural elements were close in their size with the minimum value observed after a reverse rolling (240 nm