Informacja

Drogi użytkowniku, aplikacja do prawidłowego działania wymaga obsługi JavaScript. Proszę włącz obsługę JavaScript w Twojej przeglądarce.

Wyszukujesz frazę "Expansion" wg kryterium: Temat


Tytuł:
PixSel : Images as Book Cipher Keys : An Efficient Implementation Using Partial Homophonic Substitution Ciphers
Autorzy:
Shumay, M.
Srivastava, G.
Powiązania:
https://bibliotekanauki.pl/articles/226555.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
book ciphers
ciphertext enlargement
ciphertext expansion
Opis:
In this paper we introduce a novel encryption Technique, which we call PixSel. This technique uses images in place of literature as the book cipher’s key. Conventional book ciphers possess an unwieldy ciphertext enlargement, creating ciphertexts multiple times the length of the plaintext. As well, there is often the issue of a given book not containing the necessary material for the encipherment of some plaintexts. We sought to rectify these nuisances with PixSel, possessing a typical ciphertext enlargement of merely 1% to 20% for text. Using PixSel, there are also no limitations on encipherable data type, given a suitable image.
Źródło:
International Journal of Electronics and Telecommunications; 2018, 64, 2; 151-158
2300-1933
Pojawia się w:
International Journal of Electronics and Telecommunications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Characterization of a static expansion standard for calibrating medium and high vacuum pressure gauges
Autorzy:
Duarte Franco, Jonathan Javier
Villamizar Mora, Carlos Mauricio
García Sánchez, Carlos Eduardo
Powiązania:
https://bibliotekanauki.pl/articles/1849022.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
static expansion system
calibration
vacuum
characterization
Opis:
The Centro de Desarrollo Tecnológico del Gas developed a static expansion system to enable the calibration of medium and high vacuum pressure gauges in Colombia. The system can generate pressures between 0.1 Pa and 100 kPa. The characterization tests included the evaluation of pressure stability and desorption rate, a trueness test, and the analysis of the uncertainty budget of the calibration result. The pressure stability test was successfully completed and showed the positive effect of baking on the final pressure in the system. The trueness test allowed concluding that the calibration results with the system are comparable with those obtained with a reference meter traceable to a national metrology institute. The uncertainty budget analysis indicated the dominance of the pressure of the unit under calibration and of the initial pressure in the small tank in different pressure ranges on the uncertainty of the result. A comparison with a Monte Carlo simulation led to the conclusion that in this situation, the GUM (Guide to the Expression of Uncertainty in Measurement) method is not ideal for estimating the uncertainty of the results.
Źródło:
Metrology and Measurement Systems; 2021, 28, 3; 593-604
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Characterization of a static expansion standard for calibrating medium and high vacuum pressure gauges
Autorzy:
Duarte Franco, Jonathan Javier
Villamizar Mora, Carlos Mauricio
García Sánchez, Carlos Eduardo
Powiązania:
https://bibliotekanauki.pl/articles/1849054.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
static expansion system
calibration
vacuum
characterization
Opis:
The Centro de Desarrollo Tecnológico del Gas developed a static expansion system to enable the calibration of medium and high vacuum pressure gauges in Colombia. The system can generate pressures between 0.1 Pa and 100 kPa. The characterization tests included the evaluation of pressure stability and desorption rate, a trueness test, and the analysis of the uncertainty budget of the calibration result. The pressure stability test was successfully completed and showed the positive effect of baking on the final pressure in the system. The trueness test allowed concluding that the calibration results with the system are comparable with those obtained with a reference meter traceable to a national metrology institute. The uncertainty budget analysis indicated the dominance of the pressure of the unit under calibration and of the initial pressure in the small tank in different pressure ranges on the uncertainty of the result. A comparison with a Monte Carlo simulation led to the conclusion that in this situation, the GUM (Guide to the Expression of Uncertainty in Measurement) method is not ideal for estimating the uncertainty of the results.
Źródło:
Metrology and Measurement Systems; 2021, 28, 3; 593-604
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Characterization of a static expansion standard for calibrating medium and high vacuum pressure gauges
Autorzy:
Duarte Franco, Jonathan Javier
Villamizar Mora, Carlos Mauricio
García Sánchez, Carlos Eduardo
Powiązania:
https://bibliotekanauki.pl/articles/1848994.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
static expansion system
calibration
vacuum
characterization
Opis:
The Centro de Desarrollo Tecnológico del Gas developed a static expansion system to enable the calibration of medium and high vacuum pressure gauges in Colombia. The system can generate pressures between 0.1 Pa and 100 kPa. The characterization tests included the evaluation of pressure stability and desorption rate, a trueness test, and the analysis of the uncertainty budget of the calibration result. The pressure stability test was successfully completed and showed the positive effect of baking on the final pressure in the system. The trueness test allowed concluding that the calibration results with the system are comparable with those obtained with a reference meter traceable to a national metrology institute. The uncertainty budget analysis indicated the dominance of the pressure of the unit under calibration and of the initial pressure in the small tank in different pressure ranges on the uncertainty of the result. A comparison with a Monte Carlo simulation led to the conclusion that in this situation, the GUM (Guide to the Expression of Uncertainty in Measurement) method is not ideal for estimating the uncertainty of the results.
Źródło:
Metrology and Measurement Systems; 2021, 28, 3; 593-604
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The meaning of universities in the post-truth era
Autorzy:
Wilkin, Jerzy
Powiązania:
https://bibliotekanauki.pl/articles/704249.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
post-truth
truth
university
expansion of lies
Opis:
The main statement of the paper is that the post-truth is expanding at an unprecedented rate, continuously forcing itself into new areas of public life and permeating millions of minds. This phenomenon has not so far been satisfactorily explained by researchers of global-range social phenomena. The paper presents various definitions of post-truth and its interpretations. The argument revolves around what truth means and what it is threatened by, as well as the most important institution that is, by definition, concerned about the truth: the university. The article outlines the functions of the university and contemporary conditions of its functioning, including the threats to the preservation of its mission and axiological foundation: striving towards the truth. The idea of the university, created in Europe at the beginning of the second millennium, has shown to be strong and durable. It has adopted various organisational forms, depending on the period and region. The secret of the universities’ persistence and meaning cannot be considered apart from the history of the European civilisation. However, the phenomenon of post-truth expansion is the most serious threat to this institution. The expansion of post-truth also leads to changes in the quality of the public life, bringing about its degeneration, with considerable contributions of the numerous pathologies of the Internet, distribution of lies and surprisingly quickly growing acceptance of this phenomenon.
Źródło:
Nauka; 2020, 1
1231-8515
Pojawia się w:
Nauka
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Expanders for dispersed power generation: maintenance and diagnostics problems
Autorzy:
Żywica, G.
Kaczmarczyk, T.
Ihnatowicz, E.
Powiązania:
https://bibliotekanauki.pl/articles/175441.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
expansion devices
expanders
turbines
ORC systems
cogeneration
Opis:
The article discusses the problems related to the operation of various types of expansion devices used in small cogeneration systems. Both volumetric and dynamic expanders were considered, including scroll, screw, vane, piston and turbine expanders. For each of these solutions, principles of operation were explained as well as major advantages and disadvantages. The results of experimental research on several expanders of various types were also presented. The overview of expanders included in this paper, along with basic operational problems and functional characteristics, is the collection of valuable information facilitating selection of a suitable expander for specific applications. This is particularly important in the context of search for new energy sources and opportunities to improve the energy efficiency of available energy resources.
Źródło:
Transactions of the Institute of Fluid-Flow Machinery; 2016, 131; 173-188
0079-3205
Pojawia się w:
Transactions of the Institute of Fluid-Flow Machinery
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Thermal Expansion of ZrO2-20 mol% Gd2O3
Autorzy:
Kang, Kweonho
Hong, Seok-Min
Lee, Changhwa
Cho, Yongjun
Powiązania:
https://bibliotekanauki.pl/articles/2125531.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
ZrO2-20 mol% Gd2O3 pellet
thermal expansion
thermal expansion coefficient
density
thermo-mechanical analyzer
Opis:
The thermal expansion of a ZrO2-20 mol% Gd2O3 pellet has been systematically investigated using a thermo-mechanical analyzer in the temperature range of 293-1773 K. Variations in the thermal expansion coefficient and density upon temperature change were calculated using the thermal expansion data. The average linear thermal expansion coefficient of theZrO2-20 mol% Gd2O3 pellet was found to be 9.522 × 10-6 K-1 in the range of 298-1073 K. This value is smaller than that of ZrO2 and larger than that of Gd2O3. Further, with an increase in temperature to 1773 K, the density of ZrO2-20 mol% Gd2O3 pellet was found to decrease to 94.98 % of the initial density at 293 K.
Źródło:
Archives of Metallurgy and Materials; 2022, 67, 3; 909--912
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A verification approach to thermoelastic steam turbine rotor analysis during transient operation
Autorzy:
Dominiczak, K.
Banaszkiewicz, M.
Powiązania:
https://bibliotekanauki.pl/articles/175490.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
steam turbine
thermal stress
thermal growth
differential expansion
Opis:
This paper presents a verification approach to thermoelastic steam turbine rotor analysis. Neither temperature nor stresses are measured on the rotor surface in utility power plants. Therefore analysis of the steam turbine rotor can be verified only based on absolute and differential thermal expansion measurements in vicinity of the steam turbine. Absolute and differential expansion measurements and steam turbine fixed points arrangement allow to calculate thermal growth of the steam turbine rotor during transients. Thermal growth of the rotor can be a baseline for the calculation using a numerical model.
Źródło:
Transactions of the Institute of Fluid-Flow Machinery; 2016, 131; 55-65
0079-3205
Pojawia się w:
Transactions of the Institute of Fluid-Flow Machinery
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wave Generation by a Finite Baffle Array in Application to Beam-Forming Analysis
Autorzy:
Tasinkevych, Y.
Powiązania:
https://bibliotekanauki.pl/articles/177857.pdf
Data publikacji:
2010
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
phased array
beamforming
mixed boundary value problem
BIS expansion
Opis:
Directional excitation of sound in an aperiodic finite baffle system is analyzed using a method developed earlier in electrostatics. The solution to the corresponding boundary value problem is obtained in the spatial-frequency domain. The acoustic pressure and normal particle velocity distribution in acoustic media can be easily computed by the inverse Fourier transform from their spatial spectra on the baffle plane. The presented method can be used for linear acoustic phased arrays modeling with finite element size and inter-element interactions taken into account. Some illustrative numerical examples presenting the far-field radiation pattern and wavebeam steering are given.
Źródło:
Archives of Acoustics; 2010, 35, 4; 677-686
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
When mere multiple group memberships are not enough: Individual self-expansion through involvement in social groups and self-efficacy belief
Autorzy:
Besta, Tomasz
Tomiałowicz, Elżbieta
Bojko, Julianna
Pytlos, Aleksandra
Kosakowska-Berezecka, Natasza
Bäck, Emma
Vazquez, Alexandra
Powiązania:
https://bibliotekanauki.pl/articles/2127287.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
self-expansion
group processes
self-efficacy
agency
social identity
Opis:
According to the self-expansion model, people are motivated to increase their sense of personal agency by expanding their sense of self through the acquisition of new identities. We conducted two studies to explore whether the feeling of self-expansion, resulting from multiple group memberships, is related to self-efficacy, and to test whether agentic and communal self-stereotyping mediated this relation. In Study 1 conducted in Poland (N1 = 102), and Study 2 among undergraduate students from Poland, Spain, and Sweden (N2 = 450), a significant indirect effect of self-expansion on self-efficacy through agentic (but not communal) self-stereotyping emerged.
Źródło:
Polish Psychological Bulletin; 2018, 49, 1; 77-85
0079-2993
Pojawia się w:
Polish Psychological Bulletin
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Influence of Thermal Expansion of Unbonded Foundry Sands on the Deformation of Resin Bonded Cores
Autorzy:
Svidró, J.
Diószegi, A.
Tóth, L.
Svidró, J. T.
Powiązania:
https://bibliotekanauki.pl/articles/355691.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
foundry sand
hot distortion
moulding material
phenolic resin
thermal expansion
Opis:
Depending on the preparation and the applied materials, moulds and cores can be of high rigidity or can be flexible. Although, chemically bonded moulding materials have relatively good flexibility, their high temperature behaviour determines the dimensional accuracy, the stresses in the castings and can induce several casting defects, such as rattail, veining, etc. The phenomenon is based on two major effects: the thermal expansion of the unbonded foundry sands and the deformation of the sand mixtures. The main objective of the present work was to study the relationship between these two effects, and to improve the knowledge related to the thermo-mechanical interactions between the casting and the mould. Dilatometric analysis of unbonded sand samples were performed and compared to the results of hot distortion tests of moulding mixture specimens. The results showed, that the thermal expansion of foundry sand largely influences the hot distortion behaviour, but depending on the type of binder used.
Źródło:
Archives of Metallurgy and Materials; 2017, 62, 2A; 795-798
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Raman Spectroscopy Studies of Carbon-Based Cathode Materials during Aluminum Electrolysis
Autorzy:
Wang, Wei
Chen, Weijie
Powiązania:
https://bibliotekanauki.pl/articles/352779.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
aluminium electrolysis
carbon cathodes
Raman spectroscopy
creep deformation
sodium expansion
Opis:
The sodium expansion and creep strain of semi-graphitic cathodes are investigated using a modified Rapoport apparatus. To further understanding of the sodium and bath penetration damage processes, the impact of external stress fluence on the carbon cathode microstructure has been defined with XRD analysis, Raman spectroscopy and scanning electron microscope (SEM). Graphite atoms fracture into smaller fragments that are less directional than the pristine platelets, which allows for a possible filling of the cracks that thus develop by the sodium and bath during aluminum electrolysis. The average microcrystalline size (calculated by Raman spectroscopy) is reduced by the deformation. The decreased intensity and widened 'G' and 'D' peaks in the analysis indicate the poor order of the sheets along the stacking direction while the consistent layered graphite structure is sustained.
Źródło:
Archives of Metallurgy and Materials; 2019, 64, 4; 1257-1261
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Turbine stage expansion model including internal air film cooling and novel method of calculating theoretical power of a cooled stage
Autorzy:
Trawiński, Paweł
Powiązania:
https://bibliotekanauki.pl/articles/2134930.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
gas turbine
expansion line
air film cooling
theoretical stage power
Opis:
Systematic attempts to maximise the efficiency of gas turbine units are achieved, among other possibilities, by increasing the temperature at the inlet to the expansion section. This requires additional technological solutions in advanced systems for cooling the blade rows with air extracted from the compressor section. This paper introduces a new mathematical model describing the expansion process of the working medium in the turbine stage with air film cooling. The model includes temperature and pressure losses caused by the mixing of cooling air in the path of hot exhaust gases. The improvement of the accuracy of the expansion process mathematical description, compared with the currently used models, is achieved by introducing an additional empirical coefficient estimating the distribution of the cooling air along the profile of the turbine blade. The new approach to determine the theoretical power of a cooled turbine stage is also presented. The model is based on the application of three conservation laws: mass, energy and momentum. The advantage of the proposed approach is the inclusion of variable thermodynamic parameters of the cooling medium. The results were compared with the simplified models used in the literature: separate Hartsel expansion, mainstream pressure, weighted-average pressure and fully reversible. The proposed model for expansion and the determination of theoretical power allows for accurate modelling of the performance of a cooled turbine stage under varying conditions.
Źródło:
Archives of Thermodynamics; 2022, 43, 3; 3--27
1231-0956
2083-6023
Pojawia się w:
Archives of Thermodynamics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Experiences from operation of different expansion devices for application in domestic micro CHP
Autorzy:
Mikielewicz, D.
Mikielewicz, J.
Wajs, J.
Powiązania:
https://bibliotekanauki.pl/articles/240544.pdf
Data publikacji:
2010
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
micro CHP
ogrzewanie centralne
rozbudowa urządzeń
central heating
expansion devices
Opis:
In the paper presented are experiences from operation of three different expansion devices for possible implementation in the domestic micro CHP. These were the modified scroll expander and two designs based on the variable working chamber volume pneumatic devices. Experiments showed the superiority of both "pneumatic devices" over the scroll expander, indicating the possible internal efficiencies in the range of 61 82Such efficiencies are very attractive, especially at the higher end of that range. The volume of these devices is much smaller than the scroll expander which makes it again more suitable for a domestic micro CHP. Small rotational velocities enable to conclude that connection to electricity grid will also be simpler in the case of "pneumatic devices". The "pneumatic devices" under scrutiny here could be an alternative to the typical vapour turbine in the ORC cycle, which is in the process of development at the IFFM.
Źródło:
Archives of Thermodynamics; 2010, 31, 4; 3-13
1231-0956
2083-6023
Pojawia się w:
Archives of Thermodynamics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On an improvement of Carnot-like cycles devoted to turbines with isothermal expansion
Autorzy:
Kraszewski, B.
Powiązania:
https://bibliotekanauki.pl/articles/175360.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
isothermal turbine expansion
ericsson cycle
open gas cycle
organic cycle
Opis:
This paper presents a novel, procedure of calculations of simple thermodynamic cycles with the main isothermal expansion process. Calculation assumptions are based on the use of technologically advanced flow devices. Firstly the theoretical Ericsson cycle with description of isothermal process has been presented. Then the calculations for open gas cycle with external combustion chamber, realising Ericsson cycle with upper temperature of 1473 K were carried out, showing the possibilities of turbines with isothermal expansion and achieving record-breaking efficiency. The use of isothermal compression has also been considered. The second, supercritical cycle with organic medium and condensation process also shows predispositions to achieve record-high efficiency at upper cycle temperature of 573 K. For both cycles, graphs of linearized thermodynamic transformations were made as well as graphs of efficiency dependence on the pressure. At the end, unit work of turbines in cycles has been compared and discussed.
Źródło:
Transactions of the Institute of Fluid-Flow Machinery; 2018, 140; 3-21
0079-3205
Pojawia się w:
Transactions of the Institute of Fluid-Flow Machinery
Dostawca treści:
Biblioteka Nauki
Artykuł

Ta witryna wykorzystuje pliki cookies do przechowywania informacji na Twoim komputerze. Pliki cookies stosujemy w celu świadczenia usług na najwyższym poziomie, w tym w sposób dostosowany do indywidualnych potrzeb. Korzystanie z witryny bez zmiany ustawień dotyczących cookies oznacza, że będą one zamieszczane w Twoim komputerze. W każdym momencie możesz dokonać zmiany ustawień dotyczących cookies