Temperature influence on optical and structural properties of nanocomposite structures based on cadmium sulfide quantum dots in silicate matrix was investigated. The mechanism of occurrence of reversible laser-induced...
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Temperature influence on optical and structural properties of nanocomposite structures based on cadmium sulfide quantum dots in silicate matrix was investigated. The mechanism of occurrence of reversible laser-induced absorption is proposed. It was found that annealing of nanocomposite up to 120 °C leads to substantial change of its absorption and luminescence spectra caused by transformation of quantum dot crystal lattice from amorphous to sphalerite. The nanocomposite with the sphalerite lattice QDs does not possess the effect of the photo-induced absorption.
Stationary gas flow through the porous heat-releasing object with known gas pressure difference at opened boundaries of the object and unknown gas flow rate with accounting the inertial component of resistance is cons...
Stationary gas flow through the porous heat-releasing object with known gas pressure difference at opened boundaries of the object and unknown gas flow rate with accounting the inertial component of resistance is considered. The analytical solution of this problem is obtained under certain simplifying conditions and analyzed in a wide range of problem parameters. Deviation of the gas temperature and velocity, which is defined as difference between values with and without accounting the quadratic term in motion equation, is investigated. It is shown that taking into account the quadratic velocity in motion equation can significantly impact on the problem solution even at relative small pressure difference at the objects boundaries. It is shown analytically that when taking into account the inertial component of resistance, the gas filtration velocity has an asymptotic dependence from pressure difference at opened boundaries.
Influence of gas compressibility on gas motion through a bed of granular phase change material (PCM) is investigated. Solutions of two problems of the gas flow through the granular bed with accounting the gas compress...
Influence of gas compressibility on gas motion through a bed of granular phase change material (PCM) is investigated. Solutions of two problems of the gas flow through the granular bed with accounting the gas compressibility and without it are compared for this purpose. It is found that neglecting the gas compressibility in simulating the granular PCM can provide significant deviation of full heating time of the bed. The result can be used at modelling of thermal energy storage with granular PCM.
The paper describes a mathematical model of trade flows in a transport network. Based on the model the software package is implemented as a cloud service on heterogeneous computing architectures: simulation module is ...
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The paper describes two mathematical models of trade flows among the territories of a region or country. First model uses the approach of modeling the complex communication system to determine the most probable values...
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In this paper, we propose a method of constructing a mobile robot (MR) navigation system (NS) based on fusion of data obtained from onboard sensors and video camera with use of extended Kalman filter (EKF), which allo...
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ISBN:
(纸本)9789898533524
In this paper, we propose a method of constructing a mobile robot (MR) navigation system (NS) based on fusion of data obtained from onboard sensors and video camera with use of extended Kalman filter (EKF), which allows significantly improve the accuracy of MR navigation in conditions where global positioning systems are not available or have a greater error. The budgetary webcam which, at the expense of the low price, allows to reduce the cost of system in general acts as the video data obtaining device. The method proposed consists of two steps. The first step is obtaining MR movement and orientation data based on video processing. A second step is the fusion of said navigation data and data obtained from the MR onboard sensors.
The problem of identification of the soft sensors is considered. Using the active set method the problem of least squares with inequality constraints on the variables has been solved. As a result of using soft sensors...
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Magnesium can be used as a new biodegradable material for orthopaedic applications due to its outstanding properties including high biocompatibility, proper mechanical stiffness and biodegradability. Direct laser depo...
Magnesium can be used as a new biodegradable material for orthopaedic applications due to its outstanding properties including high biocompatibility, proper mechanical stiffness and biodegradability. Direct laser deposition (DLD) as a way of biomedical implant production has been used to make bulk pure Mg. Surface morphology, microstructure and mechanical properties of DLD sample have been studied. The relative porosity of DLD Mg sample has been determined.
Femtosecond laser nanostructuring of metal surfaces is a powerful tool for improvement of their various properties. Namely, increase of optical absorption ('black metals'), superhydrophobity, surface hardening...
Femtosecond laser nanostructuring of metal surfaces is a powerful tool for improvement of their various properties. Namely, increase of optical absorption ('black metals'), superhydrophobity, surface hardening, as well as improvement of tribological properties have been reported previously. Here we show the improvement of bond slip of nanostructured reinforcement bars with concrete. We demonstrate strong dependence of straining force and pulling force on the regime of surface nanostructuring. In particular, two-fold increase of straining force and pulling force can be achieved at the highest fluence in the regime of 'black metal'. Our finding has high practical importance for advanced civil engineering.
Method of visual navigation of autonomous underwater robot for conditions of the local maneuver is offered. The method is aimed at improving the accuracy of the robot localization through the creation of a virtual net...
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