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The paper is intended to show a new state space, non integer order model of an one-dimensional heat transfer process. The proposed model derives directly from time continuous, state space semigroup model. The fractional order derivative with respect to time is by a new operator proposed by Caputo and Fabrizio, the non integer order spatial derivative is expressed by Riesz operator. The Caputo-Fabrizio...
In the paper the comparison of two methods for calculation optimal gains is considered. One method using a Kalman procedure and one using a Riccati equation are compared. It is proved that a Kalman procedure is much better.
The conventional approach to electrical safety under fault condition in typical power systems considers earth fault currents of sinusoidal waveform and frequency of 50‒60 Hz. However, in circuits with variable-speed drives, there is earth fault current flow with harmonics, and these harmonics influence the threshold of ventricular fibrillation. The paper presents earth fault current waveforms in circuits...
The results of a modelling of big size single crystal ZnGeP2 growth dynamics in the multi-zone thermal installation based on the vertical variant of the Bridgman technique are given. Trustworthiness of the results modeling is achieved by means of creation of the mathematical model taking into account the particularities of the installation as well as the changes in installation work volume during...
Electromagnetic articulography (EMA) is one of the instrumental phonetic research methods used for recording and assessing articulatory movements. Usually, articulographic data are analysed together with standard audio recordings. This paper, however, demonstrates how coupling the articulograph with devices providing other types of information may be used in more advanced speech research. A novel...
Chitosan/CuO nanocomposites (Chi/CuO) were prepared by facile and eco-friendly technique. The 2%w/v chitosan solution was mixed with 0.5 %w/w sodium tripolyphosphate (STPP), resulting in the formation of ionically crosslinked chitosan. The crosslinked chitosan was soaked in an aqueous solution containing 0.001, 0.01 or 0.1 mol/L CuSO4·5H2O for 24 hrs, in which the Cu2+ions were absorbed into the chitosan...
This paper intends to describe the formation of cold sprayed coatings and their properties based on latest works. Thermodynamic aspects of the cold spray process are discussed, including the main factors influencing powder particles velocity, e.g. nozzle construction, gas type, powder morphology as well as its significance for coating quality. The phenomenon of coating building is illustrated using...
Because of new EU laws restricting the use of harmful substances (i.e. Pb because of the RoHS Directive), the search for new methods of joining has become highly urgent. The main problem for most solutions known to date has been to achieve good electrical parameters while maintaining low sintering temperaturatures. Pastes based on silver nanoparticles were developed, which allow to sinter below 300...
We present an investigation of optical and electrical properties of mid-wavelength infrared (MWIR) detectors based on InAs/GaSb strained layer superlattices (SLs) with nBnN and pBnN design. The temperature-dependent behavior of the bandgap was investigated on the basis of absorption measurements. A 50% cut-off wavelength of around 4.5 μm at 80 K and increase of up to 5.6 μm at 290 K was found. Values...
Due to the increasing need for electricity, insertion of distributed generation (DG) into a distribution system attracts the attention of the deregulated power market. Placing DG in the distribution system inherently reduces the power loss and improves the system voltage profile. The choice of DG, proper placement and sizing of DG all play a vital role. This paper presents an effective methodology...
A directive three dimensional antenna, using folded radiating structure has been presented for the application of microwave imaging in clinical diagnosis. Two reflector walls have been introduced to achieve higher gain and directive radiation pattern along with the folding technique. The shorting wall technique is utilized to reduce the overall antenna size and to get resonance at a lower frequency...
In the paper, a problem of scheduling operations in the cyclic flexible job shop system is considered. A new, very fast method of determining the cycle time for any order of tasks on machines is also presented. It is based on the analysis of the paths in the graph representing the examined problem. The theorems concerning specific properties of the graph are proven and used in the construction of...
A new generalized discrete Fourier transform DFT that allows for sample shift δ 2 [0, T/N] in time-domain is defined. Two relations are proved for the sum of errors between generalized DFT coefficients and theirs theoretical values. The first is the equation for samples received for continuous and piecewise–smooth functions. The second relation is the inequality for samples generated by discontinuous...
The present work is an attempt to create the concept of an engine that will combine the benefits of a pulse powered piston engine and continuously powered turbine engine. The paper focuses on the subject of pressure gain combustion (PGC). A turbine engine concept with stationary constant volume combustors, working according the Humphrey cycle, is presented. Its work has to be controlled by valve timing...
In this article, we investigate the convective heat transfer of the two-dimensional unsteady squeezing flow past a Riga plate. To examine the heat transfer, Cattaneo-Christov heat flux model is used. Influence of entropy generation on heat transfer has been investigated numerically. With the help of suitable similarity transformation, the governing partial differential equations (PDEs) are converted...
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