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This document describes the calculation procedure for selecting the optimal parameters of the boom lifting mechanism in agricultural machinery. A boom lifting scheme was developed. Studies have been carried out to find the optimal values of linear dimensions and angle, at which the required value of the force developed by the drive when lifting the boom with a hydraulic cylinder of the specified dimensions will be minimal. Based on the results of the study, an algorithm was developed for solving the optimization of boom lifting parameters. An expression is obtained for the objective function of optimizing the boom lifting mechanism. Algorithm for selection of optimal parameters of lifting mechanism considering weight of boom, hydraulic cylinder and rod has been developed.

The document discusses the methodology for calculating the optimal parameters of a tracked forest loader. Based on the data obtained, a mathematical model of the kinematics of machine drives was compiled when the cargo was released "through itself." As a result of the work, changes in the demand for force on the boom lifting hydraulic cylinder and graphs of the dependence of the forces of the hydraulic cylinders on the angles of rotation of the boom and rocker were built. Based on the results of the work, conclusions were made about the change in the moments changed by the cargo.

This paper presents the quality requirements for the treatment of diesel fuel to reduce environmental pollution. The total operating costs of the conventional diesel treatment system are considered. The results of the dependence of the components of the costs and the total costs of cleaning diesel fuel on the quality of preliminary cleaning are summarized. A plan has been developed to minimize the cost of pre-treatment of diesel fuel.

This paper discusses low-temperature gas purification to improve environmental efficiency. Modern methods of gas cooling are also considered. A mathematical model is proposed for changing the parameters of an ideal gas when flowing through an opening - a Laval nozzle. A graph of the temperature of the gas at the outlet of the Laval nozzle is plotted at a different pressure ratio at the inlet and outlet of the nozzle. The conclusion was made based on the obtained values.

In this study, a new Cs4SrI6:Yb2+,Sm2+ near‐infrared (NIR) emitting scintillator was developed using sensitization strategy. It was found that Yb2+ sensitization significantly enhances the NIR radioluminescence (RL) of Sm2+, providing a new approach of designing highly emissive sensitized NIR scintillators. By studying the optical spectra and decay kinetics of Cs4SrI6:Yb2+,Sm2+, it was revealed that the energy transfer pathways involve both radiative and nonradiative processes. The gamma spectroscopy performance of Cs4SrI6:Yb2+,Sm2+ single crystals was studied by using the high‐quantum‐efficiency avalanche photodiode (APD) as the readout. Our results highlight the importance of using sensitization strategy of achieving NIR emitting scintillators and demonstrate the significant potential for radiation detection applications. [ABSTRACT FROM AUTHOR]

For the first time, hafnia (HfO2) nanoparticles have been produced by photochemical synthesis. The photochemical route has been proven to be scalable, affordable, and straightforward to create monoclinic HfO2 nanoparticles with a size of tens of nanometers. The exploitation of this route offers a chance to create large amounts of dense nanoparticles with reduced costs and time of production for future creation of large area composite scintillators for fast timing techniques. Specific annealing treatments from 450 °C to 1000 °C have been targeted to tune the structural and morphological properties and optimize the luminescence of the nanoparticles. Hafnia nanoparticles annealed at low temperature display an amorphous structure. After thermal treatment at 1000 °C, HfO2 nanoparticles crystallize into a monoclinic phase, as evidenced by thermal analyses and X-ray diffraction. Radioluminescence and photoluminescence of HfO2 have been investigated at room temperature and 77 K. The emission band of hafnia covers a range from 300 to 600 nm and it can be attributed to defects within the matrix. In particular, the highest radioluminescence intensity appears in the crystalline sample annealed at 1000 °C, thanks to the higher crystallinity degree and the reduction of non-radiative channels and quenching defects. Photoluminescence and scintillation decay have evidenced the presence of the fast decay in the nanosecond time range. Thus, due to their size, density, and spectroscopic and timing features, monoclinic hafnia nanoparticles obtained by photochemical synthesis are attractive for potential creation of large area scintillating composites. [ABSTRACT FROM AUTHOR]

Lutetium oxyorthosilicate Lu2SiO5 (LSO) and pyrosilicate Lu2Si2O7 (LPS) activated by Ce3+ or Pr3+ are known to be effective and fast scintillation materials for the detection of X-rays and γ-rays. Their performances can be further improved by co-doping with aliovalent ions. Herein, we investigate the Ce3+(Pr3+) → Ce4+(Pr4+) conversion and the formation of lattice defects stimulated by co-doping with Ca2+ and Al3+ in LSO and LPS powders prepared by the solid-state reaction process. The materials were studied by electron paramagnetic resonance (EPR), radioluminescence spectroscopy, and thermally stimulated luminescence (TSL), and scintillation decays were measured. EPR measurements of both LSO:Ce and LPS:Ce showed effective Ce3+ → Ce4+ conversions stimulated by Ca2+ co-doping, while the effect of Al3+ co-doping was less effective. In Pr-doped LSO and LPS, a similar Pr3+ → Pr4+ conversion was not detected by EPR, suggesting that the charge compensation of Al3+ and Ca2+ ions is realized via other impurities and/or lattice defects. X-ray irradiation of LPS creates hole centers attributed to a hole trapped in an oxygen ion in the neighborhood of Al3+ and Ca2+. These hole centers contribute to an intense TSL glow peak at 450–470 K. In contrast to LPS, only weak TSL peaks are detected in LSO and no hole centers are visible via EPR. The scintillation decay curves of both LSO and LPS show a bi-exponential decay with fast and slow component decay times of 10–13 ns and 30–36 ns, respectively. The decay time of the fast component shows a small (6–8%) decrease due to co-doping. [ABSTRACT FROM AUTHOR]

Conjugated BaI2:Eu (5 at.%) nanocrystalline particles were synthesized, decorated with golden nanoparticles (GNP). GNP demonstrated some hydrophilic effect, leading to the BaI2·H2O phase creation. The Eu2+ luminescence intensity was reduced according to the GNP content. This was due to the decreased number of Eu2+ ions in the BaI2, most probably, arising from the Au substitution for Ba competing with Eu. Moreover, the decay time of luminescence was decreased upon GNP content. This was explained by the moderation of negative charge in the GNP, leading to the repulsion with an electron in the excited Eu2+. [ABSTRACT FROM AUTHOR]

The influence of Mo on the electronic states and crystalline structure, as well as morphology, phase composition, luminescence, and defects in ZnO rods grown as free-standing nanoparticles, was studied using a variety of experimental techniques. Mo has almost no influence on the luminescence of the grown ZnO particles, whereas shallow donors are strongly affected in ZnO rods. Annealing in air causes exciton and defect-related bands to drop upon Mo doping level. The increase of the Mo doping level from 20 to 30% leads to the creation of dominating molybdates. This leads to a concomitant drop in the number of formed ZnO nanorods. [ABSTRACT FROM AUTHOR]

Erbium-doped Y3Al5O12 (YAG) single crystals grown using the micro-pulling-down technique were investigated. Three Er concentrations were chosen: 0.1, 0.3 and 1 at%. Er3+ electron paramagnetic resonance (EPR) spectra were measured in the ground and first excited states. The corresponding g tensors and 167Er hyperfine interaction were changing upon Er content indicating moderation of the Er-O bond length and/or Er local surrounding. Photoluminescence (PL) and radioluminescence (RL) spectra were complex, consisting of strongly overlapped typical Er3+ transitions. In addition, there were other broad PL band (3.1 eV) and RL band (3.95 eV) attributed to the F+ center and yttrium substituting for aluminum (YAl), respectively. The X-ray excited decay kinetics exhibited a decrease of the decay time of the YAl from hundreds of nanoseconds to nanoseconds upon Er doping level. This is discussed and explained considering EPR data. [ABSTRACT FROM AUTHOR]

Nanorods of erbium-doped zinc oxide (ZnO:Er) were fabricated using a hydrothermal method. One batch was prepared with and another one without constant ultraviolet (UV) irradiation applied during the growth. The nanorods were free-standing (FS) as well as deposited onto a fused silica glass substrate (GS). The goal was to study the atomistic aspects influencing the charge transport of ZnO nanoparticles, especially considering the differences between the FS and GS samples. We focused on the excitons; the intrinsic defects, such as zinc interstitials, zinc vacancies, and related shallow donors; and the conduction electrons. UV irradiation was applied for the first time during the ZnO:Er nanorod growth. This led to almost total exciton and zinc vacancy luminescence reduction, and the number of shallow donors was strongly suppressed in the GS samples. The effect was much less pronounced in the FS rods. Moreover, the exciton emission remained unchanged there. At the same time, the Er3+ content was decreased in the FS particles grown under constant UV irradiation while Er3+ was not detected in the GS particles at all. These phenomena are explained. [ABSTRACT FROM AUTHOR]