A detailed review of the literature on betavoltaic power sources is presented. The problems that exist within their manufacturing technology and the results of studies and development works that are ...currently in progress are examined, the structures and operation principles of betavoltaic power sources are summarized, and the main stages in designing them are described. The presented information can help one to study and understand the technology and methods used for designing available devices and to show the attained parameters, the existing limitations, and the opportunities for further improvement of designs of betavoltaic power sources.
The article discusses the mechanics of the loss of an athlete transverse steady state when performing a ski turn. The analysis of the loss of stable position of the rod model of the mechanical system ..."skier-skis" in the lateral sliding of skis and falling in the frontal plane was performed. The conditions and possible ways of preventing the skier from falling and restoring a stable position during turn are quantified.
The article deals with the problem of modeling the movement of an athlete-skier when performing a cut ski turn with angulation. A system of integral equations for dimensionless motion parameters is ...formulated. its numerical solution, taking into account individual styles of angulation control, allows us to construct the trajectory of the center of mass of the system, estimate its speed, angles that characterize the position of the skier's body and its skis relative to the slope, and the time of its movement. Examples of calculating the parameters of a carve turn with different style angulations are considered.
This paper highlights the manufacturing process of two types of betavoltaic cells with a source coated with 63Ni: the flat one and one with a three-dimensional (3D) microchannel structure, obtained ...by anodizing silicon (Si). Thin-layer deposition of a nickel-63 radionuclide was carried out from the ammonium-citrate based electrolyte solution, designed for production until exhaustion.
In current paper nanoheterostructure optimization for LED and phototransistor usage is discussed. Special doping into quantum wells and barriers by Indium atoms was investigated. By simulation ...improved quantum sized active region was detected which increases quantum efficiency and sensitivity upto 10%. Photoluminescence spectral curve and Peak lambda of the InGaN/GaN nanoheterostructure with different Indium concentration across wafer were investigated.
•Nanoheterostructure optimization for LED and photodetector usage is discussed.•Special doping into quantum wells and barriers by Indium atoms was investigated.•QW barriers doped by Indium(7%) and impurity (1018cm−3) increase QE and sensitivity.•It was detected that by doping I-V curves could be shifted to a lower-voltage area.
In the paper a manufacturing process of three-dimensional (3D) microchannel structure by silicon (Si) anodic etching was discussed. The possibility of microchannels formation allows to increase the ...active area more than 100 times. In this structure the p-n junction on the whole Si surface was formed. The obtained data allowed to evaluate the characteristics of the betavoltaic converter with a 3D structure by using isotope 63Ni with a specific activity of 10Ci/g.
•The microchannels formation possibility increases the active area more than 100 times.•p-n junction on Si surface was formed.
We report a study on transformations in absorption and emission spectra of novel bismuth (Bi) doped hafnia-yttria-alumina-silicate fiber, which arise as the result of bombardment by high-energy (β) ...electrons. Among the featuring data obtained, we reveal substantial growth of ‘active’ Bi center content in the fiber core-glass with increasing β-irradiation dosage, resulting in dose-dependent intensification of the resonant-absorption bands and enhancement of the emissive potential of the fiber in near-IR, inherent to these centers.
•Changes in Bi-doped fiber properties after irradiation by electron beam are studied.•Waveguide properties of Bi-doped fiber in pristine and irradiated states are modeled.•Ways to use Bi-doped fiber ...for dosimetry in harsh environments are proposed.•Stokes shift of cutoff wavelength vs. exposure dose is discovered for Bi-doped fiber.
We report the changes in absorption and emission properties of Bismuth/Yttria codoped phosphosilicate fiber which arise after bombardment by a beam of high-energy (β) electrons. Despite dramatic rise of induced absorption in the fiber as the result of β-irradiation, reaching ~2000 dB/m in the visible, we reveal its remarkable resistance, at doses of exposure up to ~1014 cm−2, in terms of the emissive potential in the visible / near-IR and photo-bleaching contrast at pump wavelengths falling into the absorption bands of Bismuth active centers. Also, we uncover a novel effect of large spectral shift to the Stokes side (up to ~75 nm), experienced by the cutoff wavelength of the fiber in function of β-irradiation dose due to notable refractive index rise in its core region.
In this paper the simulation results of the spectral sensitivity characteristics of silicon p-i-n-photodiodes are presented. The analysis of the characteristics of the semiconductor material (the ...doping level, lifetime, surface recombination velocity), the construction and operation modes on the characteristics of photosensitive structures in order to optimize them was carried out.
The AlxGa1-xAs / GaAs photosensitive heterostructures were grown by molecular beam epitaxy. On their basis the discrete photodiodes (PD) and phototransistors (PT) operating in the visible (0.4–0.7 ...μm) wavelength range and having photosensitive area diameters of 1.5 mm and 180 pm correspondingly were created. The current-voltage and spectral characteristics of discrete PD and PT were measured and analyzed. Distinctive features of the proposed photodetectors are a high monochromasy with the maximal sensitivity of 0.13 A/W at λ 530-570 nm and a low dark current of 4.7 nA and 530 pA at 5 V reverse bias for PD and PT correspondingly.
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