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Wyszukujesz frazę "Ivanova, A. A." wg kryterium: Autor


Tytuł:
Calculation of phase-change boundary position in continuous casting
Autorzy:
Ivanova, A. A.
Powiązania:
https://bibliotekanauki.pl/articles/380559.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
solidification process
information technology
foundry industry
mathematical modeling
temperature distribution
Stefan condition
phase change boundary
continuous casting
krzepnięcie stopu
technologia informacyjna
przemysł odlewniczy
modelowanie matematyczne
rozkład temperatury
warunek Stefana
granica międzyfazowa
odlewanie ciągłe
Opis:
The problem of determination of the phase-change boundary position at the mathematical modeling of continuous ingot temperature field is considered. The description of the heat transfer process takes into account the dependence of the thermal physical characteristics on the temperature, so that the mathematical model is based on the nonlinear partial differential equations. The boundary position between liquid and solid phase is given by the temperatures equality condition and the Stefan condition for the two-dimensional case. The new method of calculation of the phase-change boundary position is proposed. This method based on the finite-differences with using explicit schemes and on the iteration method of solving of non-linear system equations. The proposed method of calculation is many times faster than the real time. So that it amenable to be used for model predictive control of continuous semifinished product solidification.
Źródło:
Archives of Foundry Engineering; 2013, 13, 4; 57-62
1897-3310
2299-2944
Pojawia się w:
Archives of Foundry Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Role of the Structural and Thermal Peclet Numbers in the Brass Continuous Casting
Autorzy:
Kwapisiński, P.
Lipnicki, Z.
Ivanova, A. A.
Wołczyński, W.
Powiązania:
https://bibliotekanauki.pl/articles/381666.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
foundry processes
Growth Law
continuous cast
brass ingot
structural zones
procesy odlewnicze
Prawo Wzrostu
odlewanie ciągłe
wlewek mosiężny
strefy strukturalne
Opis:
The Structural Peclet Number has been estimated experimentally by analyzing the morphology of the continuously cast brass ingots. It allowed to adapt a proper development of the Ivantsov’s series in order to formulate the Growth Law for the columnar structure formation in the brass ingots solidified in stationary condition. Simultaneously, the Thermal Peclet Number together with the Biot, Stefan, and Fourier Numbers is used in the model describing the heat transfer connected with the so-called contact layer (air gap between an ingot and crystallizer). It lead to define the shape and position of the s/l interface in the brass ingot subjected to the vertical continuous displacement within the crystallizer (in gravity). Particularly, a comparison of the shape of the simulated s/l interface at the axis of the continuously cast brass ingot with the real shape revealed at the ingot axis is delivered. Structural zones in the continuously cast brass ingot are revealed: FC – fine columnar grains, C – columnar grains, E – equiaxed grains, SC – single crystal situated axially.
Źródło:
Archives of Foundry Engineering; 2017, 17, 2; 49-54
1897-3310
2299-2944
Pojawia się w:
Archives of Foundry Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Some Similarities / Differences between Steel Static and Virtual Brass Static Casting
Autorzy:
Kwapisiński, P.
Ivanova, A. A.
Kania, B.
Wołczyński, W.
Powiązania:
https://bibliotekanauki.pl/articles/382343.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
procesy odlewnicze
modelowanie matematyczne
FCCT
wlewek mosiężny
foundry processes
mathematical modeling
brass static ingot
Opis:
An innovative method for determining the structural zones in the large static steel ingots has been described. It is based on the mathematical interpretation of some functions obtained due to simulation of temperature field and thermal gradient field for solidifying massive ingot. The method is associated with the extrema of an analyzed function and with its points of inflection. Particularly, the CET transformation is predicted as a time-consuming transition from the columnar- into equiaxed structure. The equations dealing with heat transfer balance for the continuous casting are presented and used for the simulation of temperature field in the solidifying virtual static brass ingot. The developed method for the prediction of structural zones formation is applied to determine these zones in the solidifying brass static ingot. Some differences / similarities between structure formation during solidification of the steel static ingot and virtual brass static ingot are studied. The developed method allows to predict the following structural zones: fine columnar grains zone, (FC), columnar grains zone, (C), equiaxed grains zone, (E). The FCCT-transformation and CET-transformation are forecast as sharp transitions of the analyzed structures. Similarities between steel static ingot morphology and that predicted for the virtual brass static ingot are described.
Źródło:
Archives of Foundry Engineering; 2017, 17, 1; 109-114
1897-3310
2299-2944
Pojawia się w:
Archives of Foundry Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Structural Transformations Versus Hard Particles Motion in the Brass Ingots
Autorzy:
Wołczyński, W.
Ivanova, A. A.
Kwapisiński, P.
Olejnik, E.
Powiązania:
https://bibliotekanauki.pl/articles/355047.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
continuously cast ingot
mathematical forecast of structural zones
hard particles in the brass
Opis:
A mathematical method for the forecast of the type of structure in the steel static ingot has been recently developed. Currently, the method has been applied to structural zones prediction in the brass ingots obtained by the continuous casting. Both the temperature field and thermal gradient field have been calculated in order to predict mathematically the existence of some structural zones in the solidifying brass ingot. Particularly, the velocity of the liquidus isotherm movement and thermal gradient behavior versus solidification time have been considered. The analysis of the mentioned velocity allows the conclusion that the brass ingots can evince: chilled columnar grains-, (CC), fine columnar grains-, (FC), columnar grains-, (C), equiaxed grains zone, (E), and even the single crystal, (SC), situated axially. The role of the mentioned morphologies is analyzed to decide whether the hard particles existing in the brass ingots can be swallowed or rejected by the solid / liquid (s/l) interface of a given type of the growing grains. It is suggested that the columnar grains push the hard particles to the end of a brass ingot during its continuous casting.
Źródło:
Archives of Metallurgy and Materials; 2017, 62, 4; 2461-2467
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Structural Zones in Large Static Ingot. Forecasts for Continuously Cast Brass Ingot
Autorzy:
Wołczyński, W.
Lipnicki, Z.
Bydałek, A. W.
Ivanova, A. A.
Powiązania:
https://bibliotekanauki.pl/articles/380388.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
continuous cast
theory of crystallization
thermal gradient field
structural zones
brass ingot
operating point in the mold
odlewanie ciągłe
teoria krystalizacji
strefy strukturalne
mosiądz
Opis:
Some metallographic studies performed on the basis of the massive forging steel static ingot, on its cross-section, allowed to reveal the following morphological zones: a/ columnar grains (treated as the austenite single crystals), b/ columnar into equiaxed grains transformation, c/ equiaxed grains at the ingot axis. These zones are reproduced theoretically by the numerical simulation. The simulation was based on the calculation of both temperature field in the solidifying large steel ingot and thermal gradient field obtained for the same boundary conditions. The detailed analysis of the velocity of the liquidus isotherm movement shows that the zone of columnar grains begins to disappear at the first point of inflection and the equiaxed grains are formed exclusively at the second point of inflection of the analyzed curve. In the case of the continuously cast brass ingots three different morphologies are revealed: a/ columnar structure, b/ columnar and equiaxed structure with the CET, and c/ columnar structure with the single crystal formation at the ingot axis. Some forecasts of the temperature field are proposed for these three revealed morphologies. An analysis / forecast of the behavior of the operating point in the mold is delivered for the continuously cast ingot. A characteristic delay between some points of breakage of the temperature profile recorded at the operating point and analogous phenomena in the solidifying alloy is postulated.
Źródło:
Archives of Foundry Engineering; 2016, 16, 3; 141-146
1897-3310
2299-2944
Pojawia się w:
Archives of Foundry Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modeling of Heat Engineering Parameters of Casting and Rolling Complexes Work
Autorzy:
Biryukov, A.
Ivanova, A.
Powiązania:
https://bibliotekanauki.pl/articles/381410.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
continuous casting
casting-rolling machine
ingot heating device
temperature field
heat flux
odlewanie ciągłe
urządzenie grzewcze
pole temperatury
strumień ciepła
Opis:
The paper consists the problem of developing a scientific toolkit allowing to predict the thermal state of the ingot during its formation in all elements of the casting and rolling complex, between the crystallizer of the continuous casting machine and exit from the furnace. As the toolkit for the decision making task the predictive mathematical model of the ingot temperature field is proposed. Displacement between the various elements of the CRC is accounted for by changing the boundary conditions. Mass-average enthalpy is proposed as a characteristic of ingot cross-section temperature state. The next methods of solving a number of important problems with the use of medium mass enthalpy are developed: determination of the necessary heat capacity of ingots after the continuous casting machine for direct rolling without heating; determination of the rational time of alignment of the temperature field of ingots having sufficient heat capacity for rolling after casting; determination of the total amount of heat (heat capacity) required to supply the metal for heating ingots that have insufficient amount of internal heat.
Źródło:
Archives of Foundry Engineering; 2019, 3; 11-14
1897-3310
2299-2944
Pojawia się w:
Archives of Foundry Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Гражданское общество в Российской Федерации: особенности развития и отличия от европейских государств
Civil society in Russian Federation: features of development and differences from European countries
Autorzy:
Ivanova, Maria A.
Powiązania:
https://bibliotekanauki.pl/articles/1732100.pdf
Data publikacji:
2021-04-14
Wydawca:
Uniwersytet Warszawski. Wydawnictwa Uniwersytetu Warszawskiego
Tematy:
Российская Федерация (Россия)
гражданское общество
демократия
правовое государство
неправительственные организации
общественные организации
Russian Federation (Russia)
civil society
democracy
rule of law
non-governmental organisations (NGO)
Opis:
The essay is devoted to the consideration of such a phenomenon as civil society and the specifics of its development in Russia, in comparison with the European countries. Special attention is paid to various problems (both historically rooted and actualised in the modern period of the country's development), which hinder the formation of the democratic state. The author analyses the factors that positively and negatively affect the democratisation of Russia, and also suggests ways of solving problems in the development of civil society and further institutionalisation of the rule of law in the Russian Federation.
Эссе посвящено рассмотрению такого феномена, как гражданское общество и специфика его развития в России, в сравнении с европейскими странами. Особое внимание уделяется различным проблемам (как укоренившимся исторически, так и актуализировавшимся в современный период развития страны), которые препятствуют формированию правового и демократического государства. Автор анализирует факторы, положительно и отрицательно влияющие на демократизацию России. Также предлагаются пути решения проблем в развитии гражданского общества и дальнейшей институционализации правового государства в Российской Федерации.
Źródło:
Przegląd Europejski; 2021, 1; 259-264
1641-2478
Pojawia się w:
Przegląd Europejski
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Effect of Different Mn/Fe Ratio on Microstructure Alloy Based on Al-Si-Mg
Autorzy:
Bolibruchova, D.
Ivanova, A.
Powiązania:
https://bibliotekanauki.pl/articles/383021.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
AlSiMg alloys
manganese
intermetallic phases
microstructure
stopy AlSiMg
mangan
fazy międzymetaliczne
mikrostruktura
Opis:
This article deals with the effect of manganese that is the most applied element to eliminate the negative effect of iron in the investigated alloy AlSi7Mg0.3. In this time are several methods that are used for elimination harmful effect of iron. The most used method is elimination by applying the additive elements, so-called iron correctors. The influence of manganese on the morphology of excluded iron-based intermetallic phases was analysed at various iron contents (0.4; 0.8 and 1.2 wt. %). The effect of manganese was assessed in additions of 0.1; 0.2; 0.4 and 0.6 wt. % Mn. The morphology of iron intermetallic phases was assessed using electron microscopy (SEM) and EDX analysis. The increase of iron content in investigated alloys caused the formation of more intermetallic phases and this effect has been more significant with higher concentrations of manganese. The measurements carried out also showed that alloys with the same Mn/Fe ratio can manifest different structures and characteristics of excluded iron-based intermetallic phases, which might, at the same time, be related to different resulting mechanical properties.
Źródło:
Archives of Foundry Engineering; 2019, 3; 15-20
1897-3310
2299-2944
Pojawia się w:
Archives of Foundry Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Using erlang in research and education in a technical university
Autorzy:
Petrov, I.
Alexeyenko, A.
Ivanova, G.
Powiązania:
https://bibliotekanauki.pl/articles/305254.pdf
Data publikacji:
2018
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
parallel programming
distributed programming
teaching
graph theory
concurrency
recursion
survey
functional programming
Opis:
This paper addresses the problem of using functional programming (FP) languages for research and educational purposes. In order to identify the problems associated with the use of FP languages such as Erlang, an experiment consisting of two surveys was performed. The first survey was anonymous and aimed at establishing whether the participants prefer object-oriented or functional coding. The second one was a survey made after the students finished an Erlang course. The results of these two surveys demonstrate that functional programming is underrated with no apparent reasons. Possible steps to address this problem are suggested.
Źródło:
Computer Science; 2018, 19 (3); 333-343
1508-2806
2300-7036
Pojawia się w:
Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Magnetic Properties of GdMn$\text{}_{x}$Fe$\text{}_{1-x}$Si intermetallic Compounds
Autorzy:
Nikitin, S. A.
Ivanova, T. I.
Tskhadadze, I. A.
Powiązania:
https://bibliotekanauki.pl/articles/1956493.pdf
Data publikacji:
1997-02
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.20.En
Opis:
Magnetic properties of GdMn$\text{}_{x}$Fe$\text{}_{1-x}$Si (x = 1, 0.9, 0.8, 0.7, 0.6, 0) compounds were investigated. Both GdMnSi and GdFeSi crystallize in the CeFeSi-type tetragonal structure and form a complete solid solution without any change in the crystal structure. Magnetic measurements were made in static magnetic fields up to 1 MA/m in the temperature range from 77 K to 420 K. For GdFeSi these measurements were carried out on single crystal sample. It was found that the increase in Fe content leads to a sharp decrease in saturation magnetic moment. The Curie temperature increases in the concentration range 0.7 ≤ x ≤ 1 and monotonously decreases for x ≤ 0.6. These effects could be explained by strong dependence of the exchange integrals on the interatomic distances.
Źródło:
Acta Physica Polonica A; 1997, 91, 2; 463-466
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Snowdrift extent on motorways with busy traffic
Zasięg pokrywy śnieżnej na autostradach o dużym natężeniu ruchu
Autorzy:
Nemchinov, M. V.
Ivanova, A. G.
Powiązania:
https://bibliotekanauki.pl/articles/402046.pdf
Data publikacji:
2018
Wydawca:
Politechnika Świętokrzyska w Kielcach. Wydawnictwo PŚw
Tematy:
snow-drift
snowfall
wind velocity
snow-protection
snow removal
roadway
car
traffic
model
experiment
zaspy śnieżne
opady śniegu
prędkość wiatru
ochrona przed śniegiem
odśnieżanie
jezdnia
samochód
ruch drogowy
eksperyment
Opis:
The paper examines the problem of snow-drafts on roads and ways of mitigating them. The results of theoretical analyses of development of snow-drafts and experimental investigations with road models are presented. Authors examined low and high blowing snows with different wind velocities, roads with road bed at terrain elevation and situated on an embankment, with and without snow protective facilities and with variable amount of traffic. Based on the conducted analyses a set of recommendations for snow protection of roads are provided.
W artykule dokonano analizy problemu występowania zaśnieżania dróg oraz opisano sposoby ich ochrony przed tym zjawiskiem. Przedstawiono także wyniki analizy teoretycznej przyczyn zaśnieżania dróg oraz wyniki badań eksperymentalnych z wykorzystaniem modeli dróg. Badano wpływ małych i dużych opadów śniegu występujących przy różnej prędkości wiatru na drogę usytuowaną w poziomie terenu (zero niwelety) i na nasypie, z uwzględnieniem wpływu obecności zasłon przeciwśnieżnych oraz niewielkiego ruchu pojazdów. Na podstawie wykonanych analiz sformułowano zalecenia dotyczące ochrony drogi przed opadami śniegu.
Źródło:
Structure and Environment; 2018, 10, 2; 122-128
2081-1500
Pojawia się w:
Structure and Environment
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The impact of anthropogenic alluvial arrays on areas settlements depending on the particle size distribution of stored taillings
Autorzy:
Ivanova, A. V.
Smirnov, Y. D.
Powiązania:
https://bibliotekanauki.pl/articles/124804.pdf
Data publikacji:
2016
Wydawca:
Polskie Towarzystwo Inżynierii Ekologicznej
Tematy:
dust
tailings
dump
humidity
dust transfer
dust suppression
pulp
Opis:
Developing devices for dust suppression one should consider important factors, such as the size distribution of transferred dust, duration of exposure in residential areas. Often the total amount of dust emissions may exceed the estimated figure for maximum permissible emissions, but their share transferred in sanitary protection zone of dust is negligible. Tailing dump of Kovdor MPE is one of the largest in Russia. The construction of dust dispersion halos was performed using a universal program calculation of air pollution “Ecolog” (Russia). Based on a comparison of dispersed compositions tails similar in composition tailing dumps in Russia, it can be concluded that in the beach area of the Kovdor dump share of dust tranfered to the territory of settlements has ranged from 10 to 40%. It was found that the maximum diameter of the particles carried by the territory of the city under consideration is 50 microns. We can conclude that under the conditions of the object the development of special devices for dust suppression is required.
Źródło:
Journal of Ecological Engineering; 2016, 17, 2; 59-63
2299-8993
Pojawia się w:
Journal of Ecological Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Smart rail infrastructure, maintenance and life cycle costs
Inteligentna infrastruktura kolejowa, utrzymanie i koszty cyklu życia
Autorzy:
Niculescu, M.
Golgojan, A.
Bednarz, A.
Ivanova, G.
Maly, T.
Powiązania:
https://bibliotekanauki.pl/articles/374617.pdf
Data publikacji:
2014
Wydawca:
Politechnika Śląska. Wydawnictwo Politechniki Śląskiej
Tematy:
railways
smart infrastructure
ERTMS
power grid management
track circuit
regenerative braking
koleje
inteligentna infrastruktura
zarządzanie siecią energetyczną
obwód toru
hamowanie regeneracyjne
Opis:
This paper discusses smart railway infrastructure systems. The meaning of “smart” is described followed by a discussion on the benefits of the use of smart infrastructure. Some key components of smart infrastructure, few examples and case studies are presented. Our analysis suggests that the implementation of a smart system may well lead to energy savings of 25%, therefore smart systems should be implemented in larger scale.
W artykule poruszono zagadnienia inteligentnych systemów infrastruktury kolejowej. Znaczenie słowa „inteligentne” jest wielokrotnie poruszane w kontekście korzyści płynących z użycia inteligentnej infrastruktury. Zaprezentowano kilka kluczowych elementów, składających się na inteligentne systemy, przykłady technologii oraz ich wprowadzenie w życie codzienne. Nasza analiza wykazała, że wprowadzenie inteligentnych systemów infrastruktury może prowadzić do oszczędności energii rzędu 25%, w związku z czym powinny one być wdrożone na większą skalę.
Źródło:
Transport Problems; 2014, T. 9, z. spec.; 109-122
1896-0596
2300-861X
Pojawia się w:
Transport Problems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Discovery of an earliest Triassic, post-extinction foraminiferal assemblage above the Permian-Triassic boundary, Strandzha nappes, north-west Turkey
Autorzy:
Okuyucu, C.
Ivanova, D.
Bedi, Y.
Ergen, A.
Powiązania:
https://bibliotekanauki.pl/articles/2059978.pdf
Data publikacji:
2014
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
Permian-Triassic bounday
post extinction
foraminifera
Strandzha
Turkey
Opis:
A new foraminiferal fauna from Early Triassic (Induan) strata of the Çaglayik section on the “Strandzha Massif”, north-west Turkey, comprises five species precisely determined and five species in open nomenclature belonging to ten genera. They belong to the post-extinction foraminiferal assemblage of the Permian-Triassic crisis, characterized by the presence of both disaster taxa (Earlandia and Postcladella kalhori) and Lazarus taxa (Diplosphaerina inaequalis, Rectostipulina quadrata, Arenovidalina sp. and Glomospira sp.). The present study at Tütünlüktepe Formation identified for the first time the Permian foraminifers on the Strandzha Massif as relict members of a post-extinction foraminiferal assemblage.
Źródło:
Geological Quarterly; 2014, 58, 1; 117--24
1641-7291
Pojawia się w:
Geological Quarterly
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The influence of chemical composition of tough-to-machine steels on grinding technologies
Autorzy:
Ivanova, T. N.
Korshunov, A. I.
Božek, P.
Powiązania:
https://bibliotekanauki.pl/articles/409674.pdf
Data publikacji:
2018
Wydawca:
STE GROUP
Tematy:
tough-to-machine materials
chemical composition
structure
grinding
grinding wheels
Opis:
The main purpose of processing of tough-to-machine materials is improving of cutting process of steels with different physicochemical properties and alloying by means of various chemical elements in combination with heat treatment. Producing of high quality surface layers depends on properties of material used to make details, that is why reasons of tough machining were identified: influence of chemical composition and resulting structure. The studies of grinding of tough-to-machine materials were undertaken by means of grinding wheels made from synthetic diamonds as they are most resistant and highly-productive. Based on the studies recommendations for using of characteristics of grinding wheels and tough-to machine steel grades are given. Research on heat processes during grinding allows us to determine patterns showing how cutting speed, detail motion speed, area and action period of contact influence temperature and speed of heat processes in surface layers as well as depth of heating. These patterns also give the chance to show interrelation between temperature and rate of heating and cooling. This gives an opportunity to predict state of structure of surface layer of details made of tough-to-machine steels under different machining conditions reasonably.
Źródło:
Management Systems in Production Engineering; 2018, 3 (26); 172-177
2299-0461
Pojawia się w:
Management Systems in Production Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł

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