Charge properties and currents in the silicon/nanoparticles of zinc oxide heterostructure irradiated by the solar light

Silicon/zinc oxide heterostructures have shown themselves to be promising for use in photovoltaics. This paper presents the results of modeling the charge properties and currents in a Si/nanosized ZnO particle with different types of conductivity under sunlight irradiation. The simulation was carried out using the Comsol Multiphysics software package. The energy diagrams of the investigated heterostructures were plotted, the charge properties and currents flowing in the structure were investigated, the dependences of the rate of generation of charge carriers on wavelength on the surfaces of silicon, zinc oxide, and at the interface between silicon and zinc oxide, the rate of recombination of charge carriers at various wavelengths of incident radiation was obtained. The regularities of the influence of wavelength of the incident radiation on the charge density and electric potential on the surface of heterostructures have been established. It is shown that the potential on the surface of the p-Si / n-ZnO heterostructure is positive, depends on the wavelength of the incident radiation and reaches the maximum of 0.68 V. For other structures, it is negative and does not depend on the wavelength: n-Si / p-ZnO –0.78 V, p-Si / p-ZnO –0.65 V, n-Si / n-ZnO –0.25 V.Silicon/zinc oxide heterostructures have shown themselves to be promising for use in photovoltaics. This paper presents the results of modeling the charge properties and currents in a Si/nanosized ZnO particle with different types of conductivity under sunlight irradiation. The simulation was carried out using the Comsol Multiphysics software package. The energy diagrams of the investigated heterostructures were plotted, the charge properties and currents flowing in the structure were investigated, the dependences of the rate of generation of charge carriers on wavelength on the surfaces of silicon, zinc oxide, and at the interface between silicon and zinc oxide, the rate of recombination of charge carriers at various wavelengths of incident radiation was obtained. The regularities of the influence of wavelength of the incident radiation on the charge density and electric potential on the surface of heterostructures have been established. It is shown that the potential on the surface of the p-Si / n-ZnO heterostructure is positive, depends on the wavelength of the incident radiation and reaches the maximum of 0.68 V. For other structures, it is negative and does not depend on the wavelength: n-Si / p-ZnO –0.78 V, p-Si / p-ZnO –0.65 V, n-Si / n-ZnO –0.25 V

Anisotropic temperature dependent interaction of ferromagnetic nanoparticles embedded inside CNT

We analyze the magnetization versus magnetic field curves of Fe-based nanoparticles embedded inside CNT. Measurements were performed at different temperatures and orientations of the magnetic field. We demonstrate that, for the parallel field the magnetic anisotropy dominates and the coherent anisotropy is of great importance at low temperatures. At high temperatures, the exchange coupling becomes stronger, but the coherent anisotropy still occurs. For the perpendicular field, the coherence anisotropy is absent, and the dimensionality of the system reduces to 2D. The results are discussed in the framework of the correlation functions of the magnetic anisotropy axes

Electron tunneling to the surface states at photocatalysis

Simulation of tunneling electrons excited by the sunlight in TiO2 to surface states is performed for TiO2/Si nanostructure. The tunneling transmission coefficient of the surface states created by organic compounds was calculated by phase function method. Dependence of the transmission coefficient of tunneling electrons on potential barrier parameters is explained by interference of transmitted and reflected waves

Field Emission in Silicon Vacuum Nanostructure

Transmission coefficient and field emission current in a silicon vacuum nanostructure with a pyramidal cathode were calculated as a function of applied voltage, size of the cathode and distance between the anode and cathode by the phase function method. The field emission current density in the range of 1–10 A/cm2 was found to be achieved by varying the distance between the anode and cathode in the range of 15–25nm and the applied voltage in the range of 1.2–2.3V

Arterial stiffness: basic determinants, methods of assessment, and the connection with obesity in children (literature review)

The review reflects the features of the structure and function of the arteries. The physiological mechanism of the formation of the pulse wave is described, and various levels of arterial pressure in the aorta and peripheral arteries are explained. Disorders of hemodynamics with a change in resilient-elastic properties of arterial vessels are described. Amplification and augmentation - factors modifying the pulse wave are presented. Also the paper describes the main methods of measuring arterial stiffness at the local, regional and system level, the advantage of direct measurement of the parameters related to the stiffness of the arterial wall, and the method of assessing the local and regional rigidity of the arteries. Separately, a method for determining pulse wave velocity in the carotid-femoral region was presented. Data of age impact on the structure and function of the arteries are presented. As it has been shown it is necessary to study parameters characterizing arterial rigidity in obese children, since this disease increases the incidence of cardiovascular complications in both adults and children. The relationship between the stiffness of arterial vessels and obesity children is considered. Various results of studies of arterial stiffness in children with obesity are presented. The lack of a consensus on the use of method of arterial vessels rigidity studying in childhood patients shows the need for further study of vascular remodeling and factors that may affect the structure of arteries in obese children

Charge properties and currents in the silicon/nanoparticles of zinc oxide heterostructure irradiated by the solar light

Silicon/zinc oxide heterostructures have shown themselves to be promising for use in photovoltaics. This paper presents the results of modeling the charge properties and currents in a Si/nanosized ZnO particle with different types of conductivity under sunlight irradiation. The simulation was carried out using the Comsol Multiphysics software package. The energy diagrams of the investigated heterostructures were plotted, the charge properties and currents flowing in the structure were investigated, the dependences of the rate of generation of charge carriers on wavelength on the surfaces of silicon, zinc oxide, and at the interface between silicon and zinc oxide, the rate of recombination of charge carriers at various wavelengths of incident radiation was obtained. The regularities of the influence of wavelength of the incident radiation on the charge density and electric potential on the surface of heterostructures have been established. It is shown that the potential on the surface of the p-Si / n-ZnO heterostructure is positive, depends on the wavelength of the incident radiation and reaches the maximum of 0.68 V. For other structures, it is negative and does not depend on the wavelength: n-Si / p-ZnO –0.78 V, p-Si / p-ZnO –0.65 V, n-Si / n-ZnO –0.25 V

Predictors of exaggerated blood pressure response to aerobic exercise in obese adolescents

Association of blood pressure response during exercise of cardiometabolic risk factors (CMRF) is demonstrated in adults. The objective was to determine predictors of raised exercise blood pressure (BP) response during aerobic exercise in obese adolescents. The maximal treadmill test using the Bruce protocol was performed in 82 normotensive obese adolescents (12-17 y.o., 43 boys). Adolescents were divided into 2 groups: group 1 (n = 68) - children with normal BP response to exercise; group 2 (n = 14) - adolescents who had excessive increase in systolic BP (SBP) during exercise. We used logistic regression analysis to examine the associations between cardiometabolic risk factors (CMRF) and SBP response during exercise with adjustment for baseline SBP, sex, age and duration of exercise test period. We have found exaggerated BP response to exercise in 17.1 % of patients. In adolescents of group 2 baseline SBP was higher than in group 1 (p = 0.01). Glucose level and lipid metabolism disturbances, SDS Z-score, baseline SBP levels only by 24.8 % explained the formation of the hyperreactive SBP response to exercise (χ2 = 13.2; р = 0.068). Only baseline SBP was an independent predictor for exaggerated BP response (p = 0.025) and age was a significant trend towards influence (p = 0.054). Exaggerated BP response to exercise in normotensive obese adolescents is more common for older adolescents who have baseline SBP levels in the range of elevated normal values. Knowing CMRF as well as the degree of excess weight has no effect on excessive BP rise during exercise

Low Temperature Conductivity in n

We investigate the transport properties of n-type noncompensated silicon below the insulator-metal transition by measuring the electrical and magnetoresistances as a function of temperature T for the interval 2–300 K. Experimental data are analyzed taking into account possible simple activation and hopping mechanisms of the conductivity in the presence of two impurity bands, the upper and lower Hubbard bands (UHB and LHB, resp.). We demonstrate that the charge transport develops with decreasing temperature from the band edge activation (110–300 K) to the simple activation with much less energy associated with the activation motion in the UHB (28–90 K). Then, the Mott-type variable range hopping (VRH) with spin dependent hops occurs (5–20 K). Finally, the VRH in the presence of the hard gap (HG) between LHB and UHB (2–4 K) takes place. We propose the empiric expression for the low T density of states which involves both the UHB and LHB and takes into account the crossover from the HG regime to the Mott-type VRH with increasing temperature. This allows us to fit the low T experimental data with high accuracy