•A review article is presented on known methods for producing dual-phase magnetic steels.•The main advantages and disadvantages of existing technologies are considered, the existing groundwork and ...future prospects are described.•Despite the small number of published works on this subject, all of them indicate great prospects for the use of dual-phase magnetic steels in electric machines.
Electric machines have become widespread in various fields of industry. However, the possibilities of increasing the efficiency and improving the output characteristics of modern electric machines are approaching their technical saturation. The fundamental solution to this problem is the creation of new materials and design solutions for electric machines, in particular, the use of soft magnetic steels for magnetic cores, in which it is possible to obtain areas with different magnetic properties - dual-phase magnetic steels, thereby providing the necessary direction of the magnetic flux. This article presents known methods for manufacturing dual-phase magnetic steels, discusses their advantages and disadvantages, existing groundwork and future prospects.
Hepatitis C virus (HCV) is one of the main triggers of chronic liver disease. Despite tremendous progress in the HCV field, there is still no vaccine against this virus. Potential vaccines can be ...based on its recombinant proteins. To increase the humoral and, especially, cellular immune response to them, more effective adjuvants are needed. Here, we evaluated a panel of compounds as potential adjuvants using the HCV NS5B protein as an immunogen. These compounds included inhibitors of polyamine biosynthesis and urea cycle, the mTOR pathway, antioxidants, and cellular receptors. A pronounced stimulation of cell proliferation and interferon-γ (IFN-γ) secretion in response to concanavalin A was shown for antioxidant
-acetylcysteine (NAC), polyamine biosynthesis inhibitor 2-difluoromethylornithine (DFMO), and TLR9 agonist CpG ODN 1826 (CpG). Their usage during the immunization of mice with the recombinant NS5B protein significantly increased antibody titers, enhanced lymphocyte proliferation and IFN-γ production. NAC and CpG decreased relative Treg numbers; CpG increased the number of myeloid-derived suppressor cells (MDSCs), whereas neither NAC nor DFMO affected MDSC counts. NAC and DFMO suppressed NO and interleukin 10 (IL-10) production by splenocytes, while DFMO increased the levels of IL-12. This is the first evidence of immunomodulatory activity of NAC and DFMO during prophylactic immunization against infectious diseases.
Serious requirements are put forward for aircraft electric machines (EMs) in terms of weight and size indicators. To reduce the mass of EMs, it is possible to consider aluminum windings, the density ...of which is 3 times less than that of copper windings. However, due to the much lower electrical conductivity of aluminum (40% less than that of copper), the overall performance of EMs with the same output parameters with aluminum windings is higher. In this regard, there is an interest in the electrical industry in increasing the electrical conductivity of aluminum windings. This problem can theoretically be solved by using carbon nanotubes (CNTs) together with aluminum. This article presents the results of a study of additive windings of aircraft EMs from a powder alloy based on aluminum with CNTs. Visual inspection shows that aluminum windings with CNTs have a 7.4 times more porous structure. The results of experimental studies show that after adding CNTs, the electrical conductivity of aluminum windings became 35% lower and the resistance 50% higher compared to aluminum windings without CNTs. Thus, in the presented work, additive aluminum windings with CNTs exhibit much worse electromagnetic properties compared to aluminum windings without CNTs.
Hepatitis C virus (HCV) is one of the basic culprits behind chronic liver disease, which may result in cirrhosis and hepatocarcinoma. In spite of the extensive research conducted, a vaccine against ...HCV has not been yet created. We have obtained human mesenchymal stem cells (hMSCs) and used them for expressing the HCV NS5A protein as a model vaccination platform. Sixteen hMSC lines of a different origin were transfected with the pcNS5A-GFP plasmid to obtain genetically modified MSCs (mMSCs). The highest efficiency was obtained by the transfection of dental pulp MSCs. C57BL/6 mice were immunized intravenously with mMSCs, and the immune response was compared with the response to the pcNS5A-GFP plasmid, which was injected intramuscularly. It was shown that the antigen-specific lymphocyte proliferation and the number of IFN-γ-synthesizing cells were two to three times higher after the mMSC immunization compared to the DNA immunization. In addition, mMSCs induced more CD4+ memory T cells and an increase in the CD4+/CD8+ ratio. The results suggest that the immunostimulatory effect of mMSCs is associated with the switch of MSCs to the pro-inflammatory phenotype and a decrease in the proportion of myeloid derived suppressor cells. Thus, the possibility of using human mMSCs for the creation of a vaccine against HCV has been shown for the first time.
•New type of low temperature potentiometric solid state gas sensor is developed.•Operation of the sensor is based on the thermoelectrical potential difference.•Theoretical model for prediction of ...sensor's performance is developed.•Electrons concentrations into the overlapped layers determine the sensing properties.
Nanosized thin films of pure and Fe modified ZnO are used to construct the composed by two plane-parallel nanostructured thin film electrodes sensing junctions. The lower and upper layers overlap is kept ∼80mm2 for all of the investigated samples. The samples are produced with different thickness of the Fe doped top sensing layer by changing the numbers of dip-coatings. The investigations of the temperature dependence of the potential difference of produced junctions and their changes under exposure to ethanol vapour with certain concentration are made by means of a newly constructed experimental setup. These investigations are performed in the temperature range of 180–350°C in environment of pure air and at fixed temperature sample is exposed to certain concentration of ethanol vapour. The best sensing performance is obtained for the structure with upper layer produced by two dip-coatings in the sol containing 3at.% of Fe into it. For explanation of observed nonlinearity of sensor response towards ethanol vapour concentration as well as change in polarity of the potential difference with modifying the morphology of Fe doped working layer of the gas sensing junction, the theoretical model of operation of produced sensing junctions is developed. This model provides the possibility of prediction of gas-sensing properties of ZnO/ZnO:Fe junction structures depending on concentration of electrons into the composing junction layers. It is worthy to mention that the model is applicable for prediction of suitability of this kind for sensing structures to detect many gasses, which is very important for the researchers, working in the field of gas-detection.
Dual-phase magnetic material - a magnetic material in which, by processing, localized non-magnetic areas can be obtained to control the direction of the magnetic flux. Such properties can ...significantly improve the output characteristics of a number of topologies of electrical machines, as well as neutralize a number of the main disadvantages inherent in traditional designs of electrical machines. This paper presents a numerical study of the strength characteristics of the rotor of an electric starter-generator with permanent magnets with a dual-phase magnetic material. The optimal boundaries of racks for processing in the non-magnetic phase are determined.
Hepatitis C virus (HCV) is one of the major causes of chronic liver disease and leads to cirrhosis and hepatocarcinoma. Despite extensive research, there is still no vaccine against HCV. In order to ...induce an immune response in DBA/2J mice against HCV, we obtained modified mouse mesenchymal stem cells (mMSCs) simultaneously expressing five nonstructural HCV proteins (NS3-NS5B). The innate immune response to mMSCs was higher than to DNA immunization, with plasmid encoding the same proteins, and to naïve unmodified MSCs. mMSCs triggered strong phagocytic activity, enhanced lymphocyte proliferation, and production of type I and II interferons. The adaptive immune response to mMSCs was also more pronounced than in the case of DNA immunization, as exemplified by a fourfold stronger stimulation of lymphocyte proliferation in response to HCV, a 2.6-fold higher rate of biosynthesis, and a 30-fold higher rate of secretion of IFN-γ, as well as by a 40-fold stronger production of IgG2a antibodies to viral proteins. The immunostimulatory effect of mMSCs was associated with pronounced IL-6 secretion and reduction in the population of myeloid derived suppressor cells (MDSCs). Thus, this is the first example that suggests the feasibility of using mMSCs for the development of an effective anti-HCV vaccine.
The surface properties of zinc oxide powders prepared using mechanical activation, electron beam irradiation, and vacuum annealing, as well using combinations of these types of treatments, were ...studied using X-ray photoelectron spectroscopy. The structure of the obtained materials was studied by an X-ray diffraction technique and by scanning electron microscopy. We found that over five hours of grinding in an attritor, the size of nanocrystals decreases from 37 to 21 nm, and microdeformations increase from 0.3% to 0.6%. It was also found that a five-hour grinding treatment promoted formation of vacancies in the zinc sublattice at the surface and diffusion of Zn
cations into the bulk of the material. Irradiation of commercial zinc oxide powders with an electron beam with an energy of 0.9 MeV and a dose of 1 MGy induced breaking of Zn-O bonds, diffusion of interstitial zinc ions into the bulk, and oxygen atom escape from regular positions into the gas phase. A combined treatment of five hours of grinding and electron beam irradiation promoted accumulation of interstitial zinc ions at the surface of the material. Annealing of both initial and mechanically activated ZnO powders at temperatures up to 400 °C did not lead to a significant change in the properties of the samples. Upon exceeding the 400 °C annealing temperature the X-ray photoelectron spectra show almost identical atomic composition of the two types of materials, which is related to diffusion of interstitial zinc ions from the bulk of the material to the surface.
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•The potential difference appeared between the overlapped pure and doped ZnO layers.•The sensing properties of junction structures increase with thickness of top layer.•The potential ...difference towards ethanol concentration obeys nonlinear dependence.•A correlation exists between the surface fractal dimension and sensor’s performance.
We present the investigation of ethanol sensing properties of the junctions composed by two plane-parallel nanostructured thin film electrodes. One of them consists of pure ZnO and the other one is composed of ZnO doped with Cu. The thickness of the lower layer was kept constant for all of the investigated structures. The thickness of the upper layer was varied. The samples were produced with different thickness of the top layer by changing the numbers of dip-coatings cycles. On produced junction structures we investigate the dependence of the potential difference on the temperature in the air flow and the changes that occur under exposure to flow of air with certain concentration of ethanol vapour. For ZnO/ZnO:Cu junction with top layer produced by two dip-coatings cycles, the potential difference under the air flow were getting more positive values up to 290°C and then the values were decreasing, while for ZnO/ZnO:Cu junction with top layer produced by three dip-coatings cycles, the potential difference were getting more negative values with increasing the temperature. However in both cases the potential difference increases in value, when the structures are exposed to the vapour of ethanol. On this installation by the exchange the content of gas atmosphere at fixed temperature the ethanol concentration dependence of the potential difference of produced junction structures were evaluated. Both samples have shown nonlinear dependence of signal towards the concentration of ethanol vapour. The observed results for ZnO/ZnO:Cu were compared with those of the junctions composed by layers of ZnO doped with Ga and pure ZnO nanowires. The performed fractal analysis based on the SEM images showed a correlation between the fractal dimension of the surface of the upper layer of the samples and gas-sensitive properties of the sensing structures.
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