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Wyszukujesz frazę "Vaskova, M." wg kryterium: Autor


Wyświetlanie 1-12 z 12
Tytuł:
Numerical study of influence of mutual slewig of roller bearing rings on the principal stresses at contact area
Analiza numeryczna wpływu przeniesionej zmiany kąta nachylenia na główne naprężenia w rejonie styku
Autorzy:
Jakubovicova, L.
Saga, M.
Vaskova, M.
Powiązania:
https://bibliotekanauki.pl/articles/197798.pdf
Data publikacji:
2014
Wydawca:
Politechnika Śląska. Wydawnictwo Politechniki Śląskiej
Tematy:
roller bearing
contact analysis
Hertz theory
static load-carrying capacity
finite element method
ADINA system
łożysko walcowe
analiza kontaktowa
teoria Hertza
podstawowa wytrzymałość statyczna łożyska
metoda elementów skończonych
system ADINA
Opis:
Article deals with influence of mutual slewing of roller bearing rings on the principal stresses and their distribution at the contact area. Profile of rolling element is logarithmic. Roller bearing has been loaded by maximum specified load only in radial direction according to the ISO/TS 16281. In practice, the real roller bearings are not loaded only in the radial direction. Therefore, the angle alfa has been gradually slewed from alfa = 0' to 8' and equivalent principal stresses have been evaluated. This change influenced on contact conditions and contact stress distribution has changed.
Artykuł jest poświęcony wpływom nachylenia pierścieni łożyska walcowego na wielkość i rozłożenie trzech głównych naprężeń na płaszczyźnie styku. Profil łożyska tocznego (walca) jest logarytmiczny. Łożysko walcowe zostało obciążone maksymalnym dopuszczalnym obciążeniem statycznym wyłącznie w kierunku promienia, zgodnie z normą ISO/TS 16281. W praktyce realne łożyska walcowe nie są obciążane wyłącznie w kierunku promienia, dlatego też kąt nachylenia pierścieni łożyska walcowego alfa stopniowo zmieniał się od alfa = 0' do 8', a odpowiednie główne naprężenia były oceniane dla poszczególnych położeń. Zmiana ta miała wpływ na warunki styku oraz na zmianę rozłożenia naprężeń podczas styku.
Źródło:
Zeszyty Naukowe. Transport / Politechnika Śląska; 2014, 84; 83-91
0209-3324
2450-1549
Pojawia się w:
Zeszyty Naukowe. Transport / Politechnika Śląska
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Initiating biodegradation of polyvinylpyrrolidone in an aqueous aerobic environment
Zainicjowanie biodegradacji poliwinylopirolidonu w środowisku wodno-powietrznym
Autorzy:
Julinová, M.
Kupec, J.
Slavík, R.
Vaskova, M.
Powiązania:
https://bibliotekanauki.pl/articles/125770.pdf
Data publikacji:
2012
Wydawca:
Towarzystwo Chemii i Inżynierii Ekologicznej
Tematy:
polyvinylpyrrolidone
biodegradation
activated sludge
aqueous environment
poliwinylopirolidon
biodegradacja
osad czynny
środowisko wodne
Opis:
A synthetic polymer, Polyvinylpyrrolidone (PVP - E 1201) primarily finds applications in the pharmaceutical and food industries due to its resistance and zero toxicity to organisms. After ingestion, the substance passes through the organism unchanged. Consequently, it enters the systems of municipal wastewater treatment plants (WWTP) without decomposing biologically during the waste treatment process, nor does it attach (through sorption) to particles of activated sludge to any significant extent, therefore, it passes through the system of a WWTP, which may cause the substance to accumulate in the natural environment. For this reason the paper investigates the potential to initiate aerobic biodegradation of PVP in the presence of activated sludge from a municipal wastewater treatment plant. The following agents were selected as the initiators of the biodegradation process - co-substrates: acrylamide, N-acethylphenylalanine and 1-methyl-2-pyrrolidone, a substance with a similar structure to PVP monomer. The biodegradability of PVP in the presence of co-substrates was evaluated on the basis of biological oxygen demand (BOD) as determined via a MicroOxymax O2/CO2/CH4 respirometer. The total substrate concentration in the suspension equaled 400 mg·dm–3, with the ratio between PVP and the co-substrate being 1:1, while the concentration of the dry activated sludge was 500 mg·dm–3. Even though there was no occurrence of a significant increase in the biodegradation of PVP alone in the presence of a co-substrate, acrylamide appeared to be the most effective type of co-substrate. Nevertheless, a recorded decrease in the slope of biodegradation curves over time may indicate that a process of primary decomposition was underway, which involves the production of metabolites that inhibit activated sludge microorganisms. The resulting products are not identified at this stage of experimentation.
Źródło:
Proceedings of ECOpole; 2012, 6, 1; 121-127
1898-617X
2084-4557
Pojawia się w:
Proceedings of ECOpole
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Burrs from Cores Produced by Cold-Box- Amine Method and Possibility of their Elimination in Eurocast Košice s.r.o. Company
Autorzy:
Vaskova, I.
Hrubovcakova, M.
Powiązania:
https://bibliotekanauki.pl/articles/379498.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
foundry industry
moulding mixture
cold -box - amine
casting error
flash gutters
przemysł odlewniczy
wady stopów
Opis:
Foundry industry belongs toward key branch with important meaning for different manufacturing industries. Liquid metal is casting in foundry, which makes cast stock with weight from several grams till several ton [1]. To achieve asking qualities of the product is needed know abundance technological a technical process and progress, but in spite of long – term development foundry industry there occur some question marks, that need answer. Characteristic defect castings of ferrous alloys, which often accompanies the use of amine - Cold box cores are flash gutters. Survey, it was found that 77 % of those surveyed foundries have problems with burrs, 71 % foundries solves this problem (or try to tackle) protivýronkovými ingredients in nuclear and molding compounds , but only 29 % considered their "antivýronkovú" method for successful and favorable.
Źródło:
Archives of Foundry Engineering; 2015, 15, 1 spec.; 115-120
1897-3310
2299-2944
Pojawia się w:
Archives of Foundry Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Ecological Binding Material of First Generation
Autorzy:
Vasková, I.
Hrubovčáková, M.
Powiązania:
https://bibliotekanauki.pl/articles/379910.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
bentonite
moulding mixture
nitrification
quality bentonite
ecological aspect
bentonit
jakość
aspekt ekologiczny
Opis:
Bentonite is clay rock, which is created by decomposition of vulcanic glass. It is formed from mixture of clay minerals of smectite group, mainly montmorillonite, beidellite and nontronite. Its typical characteristics is, that when in contact with water, it intensively swells. First who used this term was W.C. Knight in 1887. The rock had been named after town Fort Benton in American state Montana. For its interesting technological properties and whiteness has wide technological use. Bentonite is selectively mined and according to its final use separately modified, which results in high quality product with specific parameters. In the beginning of 21st century belong bentonite moulding mixtures in foundry to always perspective. Mainly increased ratio of ductile cast iron castings production cannot be ensured without the need of quality bentonite. Great area of scope remains to further research of moulding materials, which return also to bentonite producers.
Źródło:
Archives of Foundry Engineering; 2014, 14, 2; 123-128
1897-3310
2299-2944
Pojawia się w:
Archives of Foundry Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of Inorganic Binder Bridges Destruction after Thermal Load
Autorzy:
Vaskova, I.
Conev, M.
Powiązania:
https://bibliotekanauki.pl/articles/380132.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
inorganic binder
dehydration
alkali silicates
geopolymer
adhesive force
cohesive forces
spoiwo nieorganiczne
odwodnienie
krzemiany alkaliczne
geopolimer
przyczepność
Opis:
Recently, the use of inorganic binders cured by heat as a progressive technology for large scale production of cores is widely discussed topic in aluminium foundries. As practical experiences show, knock-out properties of inorganic binders were significantly increased, although they cannot overcome organic based binder systems. This paper contains information about hot curing processes based on alkali silicate and geopolymer binder systems for core making. Main differences between hot cured geopolymers and hot cured alkali silicate based inorganic binders are discussed. Theory of geopolymer binder states, that binder bridge destruction is mainly of adhesive character. The main aim of this research paper was to examine binder bridge destruction of alkali silicate and geopolymer binder systems. In order to fulfil this objective, sample parts were submitted to defined thermal load, broken and by using SEM analysis, binder bridge destruction mechanism was observed. Results showed that geopolymer binder system examined within this investigation does not have mainly adhesive destruction of binder bridges, however the ratio of adhesive-cohesive to cohesive destruction is higher than by use of alkali silicate based binder systems, therefore better knock-out properties can be expected.
Źródło:
Archives of Foundry Engineering; 2019, 2; 25-28
1897-3310
2299-2944
Pojawia się w:
Archives of Foundry Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of additives in core-forming mixture
Autorzy:
Vasková, I.
Hrubovčáková, M.
Conev, M.
Powiązania:
https://bibliotekanauki.pl/articles/355240.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
innovative foundry technologies and materials
castings defects
additives
Opis:
In recent years, ingredients, also known as additives, which appreciably affect the quality of the casting surface, come to the fore. Additives - lower the temperature at which SiO2 (major component of silica sand) begins to soften and create a melt on the surface of the grains, increase the reactivity and decrease the temperature of a transition to tridimite and cristobalit. These passages support the increase of volume of subsurface sand stress and the tension for the formation of burrs and other casting defects on the surface of the core or the mold. Nowadays, as a great emphasis is put on the quality of the casts, it is therefore necessary to pay attention to these additives, which can effectively reduce the labor intensity in the production of castings and ensure a quality surface of castings.
Źródło:
Archives of Metallurgy and Materials; 2017, 62, 1; 335-338
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Technological Properties of Moulding Sands with Geopolymer Binder for Aluminium Casting
Autorzy:
Vaskova, I.
Conev, M.
Hrubovčáková, M.
Powiązania:
https://bibliotekanauki.pl/articles/383257.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
inorganic binder
geopolymer binder
sand core
knock-out properties
aluminium casting
spoiwo nieorganiczne
spoiwo geopolimerowe
masa rdzeniowa
wybijalność masy formierskiej
odlew aluminiowy
Opis:
The use of environmentally friendly inorganic binders and new technologies for cores production is widely discussed topic in recent years. This paper contains information about new hot curing process for core making with alumina-silicate based inorganic binders – geopolymers. Main differences between hot cured geopolymers and hot cured alkali silicate based inorganic binders are discussed. The main objective of this research paper was to investigate basic technological properties of geopolymer binder system such as strength, compaction, storage ability and knock-out properties. For this purpose, three mixtures with different powder additives were prepared and tested in laboratory conditions using specific methods. Strength properties evaluation showed sufficient levels as well as knock-out properties measurement, even with additives B and C originally designed for the use with alkali silicate based two component binder systems. Additives B and C were considered compatible with geopolymer binders after casting production trial results. Storage ability of geopolymers seems to be more sensitive than of alkali silicate based binders in the same tested conditions. Mixtures with geopolymer binder showed 20% more decrease of strength compared to alkali silicate binders after 24 hours in conditions of 25 °C and 65 %RH.
Źródło:
Archives of Foundry Engineering; 2018, 18, 4; 45-49
1897-3310
2299-2944
Pojawia się w:
Archives of Foundry Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Influence of Using Different Types of Risers or Chills on Shrinkage Production for Different Wall Thickness for Material EN-GJS-400-18LT
Autorzy:
Vaskova, I.
Conev, M.
Hrubovcakova, M.
Powiązania:
https://bibliotekanauki.pl/articles/379785.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
ductile iron
shrinkage cavity
riser
chill
ultrasound
żeliwo
jama skurczowa
nadlew
Opis:
In modern times there are increasing requirements for products quality in every part of manufacturing industry and in foundry industry it is not different. That is why a lot of foundries are researching, how to effectively produce castings with high quality. This article is dealing with search of the influence of using different types of risers or chills on shrinkage cavity production in ductile iron castings. Differently shaped risers were designed using the Wlodawer´s modulus method and test castings were poured with and without combination of chills. Efficiency of used risers and chills was established by the area of created shrinkage cavity using the ultrasound nondestructive method. There are introduced the production process of test castings and results of ultrasound nondestructive reflective method. The object of this work is to determine an optimal type of riser or chill for given test casting in order to not use overrated risers and thus increase the cost effectiveness of the ductile iron castings production.
Źródło:
Archives of Foundry Engineering; 2017, 17, 2; 131-136
1897-3310
2299-2944
Pojawia się w:
Archives of Foundry Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Opening Material as the Possibility of Elimination Veining in Foundries
Autorzy:
Hrubovčáková, M.
Vaskova, I.
Benkova, M.
Conev, M.
Powiązania:
https://bibliotekanauki.pl/articles/382635.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
molding mixture
cold -box - amine
casting defect
opening material
veining
Opis:
The main bulk density representation in the molding material is opening material, refractory granular material with a particle size of 0.02 mm. It forms a shell molds and cores, and therefore in addition to activating the surface of the grain is one of the most important features angularity and particle size of grains. These last two features specify the porosity and therefore the permeability of the mixture, and thermal dilatation of tension from braking dilation, the thermal conductivity of the mixture and even largely affect the strength of molds and cores, and thus the surface quality of castings. Today foundries, which use the cast iron for produce of casts, are struggling with surface defects on the casts. One of these defects are veining. They can be eliminated in several ways. Veining are foundry defects, which arise as a result of tensions generated at the interface of the mold and metal. This tension also arises due to abrupt thermal expansion of silica sand and is therefore in the development of veining on the surface of casts deal primarily influences and characteristics of the filler material – opening material in the production of iron castings.
Źródło:
Archives of Foundry Engineering; 2016, 16, 3; 157-161
1897-3310
2299-2944
Pojawia się w:
Archives of Foundry Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Decoring Behaviour of Chosen Moulding Materials with Alkali Silicate Based Inorganic Binders
Autorzy:
Conev, M.
Vasková, I.
Hrubovčáková, M.
Hajdúch, P.
Powiązania:
https://bibliotekanauki.pl/articles/356323.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
inorganic binder
alkali silicates
moulding material
knock-out properties
Opis:
This paper contains basic information about new processes for cores for cylinder heads production with alkali silicate based inorganic binders. Inorganic binders are coming back to the foreground due to their ecologically friendly nature and new technologies for cores production and new binder systems were developed. Basically these binder systems are modified alkali silicates and therefore they carry some well-known unfavourable properties with their usage. To compensate these disadvantages, the binder systems are working with additives which are most often in powder form and are added in the moulding material. This paper deals with decoring behaviour of different moulding sands as well as the influence of chosen additives on knock-out properties in laboratory terms. For this purpose, specific methods of specimen production are described. Developed methods are then used to compare decoring behaviour of chosen sands and binder systems.
Źródło:
Archives of Metallurgy and Materials; 2017, 62, 2A; 703-706
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Usage of connor inlets to eliminate shrinkage
Autorzy:
Fecko, D.
Vasková, I.
Eperješi, L'.
Závodný, M.
Powiązania:
https://bibliotekanauki.pl/articles/380256.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
żeliwo szare
eliminacja skurczu
oprogramowanie symulacyjne
grey cast iron
connor inlet
shrinkage elimination
simulation software
Opis:
The demand for castings of high quality and sound work is nowadays very high. The production of sound castings without foundry errors is the big issue in modern foundries. Foundry simulation software can do a lot to help improve the disposition of castings, gating system and feeder system, and assure good filling and solidification conditions, and also produce sound casting without the need of the old method of 'try and error'. One can easily change a lot of parameters for filling and solidification, and create the best proposal for production. Connor inlets have two functions. One is that it serves as an ingate, through which molten metal passes and comes into the mould cavity. The second function is that it serves as a feeder and substitutes the metal contracted during solidification and cooling of the castings. It can also save quite a lot of metal in comparison to classic feeders.
Źródło:
Archives of Foundry Engineering; 2012, 12, 3; 25-28
1897-3310
2299-2944
Pojawia się w:
Archives of Foundry Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of Technological Parameters of Furane Mixtures on Shrinkage Creation in Ductile Cast Iron Castings
Wpływ właściwości masy furanowej na wielkość skurczu odlewów z żeliwa sferoidalnego
Autorzy:
Vasková, I.
Hrubovčáková, M.
Eperješi, Š.
Malik, J.
Powiązania:
https://bibliotekanauki.pl/articles/353408.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
graphitization
shrinkage
metallurgical quality
furan molding sand
grafityzacja
skurcz odlewniczy
jakość metalurgiczna
furanowe masy formierskie
Opis:
Ductile cast iron (GS) has noticed great development in last decades and its boom has no analogue in history humankind. Ductile iron has broaden the use of castings from cast iron into areas, which where exclusively domains for steel castings. Mainly by castings, which weight is very high, is the propensity to shrinkage creation even higher. Shrinkage creation influences mainly material, construction of casting, gating system and mould. Therefore, the main realized experiment was to ascertain the influence of technological parameters of furane mixture on shrinkage creation in castings from ductile iron. Together was poured 12 testing items in 3 moulds forto determine and compare the impact of various technological parameters forms the propensity for shrinkage in the casting of LGG.
W ostatnich latach obserwuje sie intensywny wzrost produkcji odlewów z żeliwa sferoidalnego. Dotyczy to także zastępowania tym tworzywem odlewów staliwnych. W przypadku masywnych odlewów szczególnie duże znaczenie odgrywa przebieg skurczu tworzywa. Powstawanie skurczu wiąże się z materiałem odlewu, jego konstrukcja, układem wlewowym oraz materiałem formy. Celem badan zaprezentowanych w artykule jest ocena wpływu właściwości technologicznych formy na podstawie skurczu. Odlano 12 kształtek w 3 formach, aby ocenić wpływ jakości formy na skurcz odlewów z żeliwa sferoidalnego.
Źródło:
Archives of Metallurgy and Materials; 2014, 59, 3; 1037-1040
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-12 z 12

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