Temat: Mikrofale - Katalog OPAC zbiorów

Skocz do pozycji: 1.

Tytuł:: Manufacturing of Porous Al-Cr Preforms for Composite Reinforcing Using Microwave Activated Combustion Synthesis
Wytwarzanie porowatych preform Al-Cr do umacniania kompozytów poprzez syntezę spaleniową aktywowaną mikrofalami
Autorzy:: Naplocha, K.
Granat, K.
Powiązania:: https://bibliotekanauki.pl/articles/353758.pdf
Data publikacji:: 2014
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:: SHS
microwave
Al-Cr
preform
composite
mikrofale
preforma
kompozyt
Opis:: The combustion synthesis of porous skeletons (preforms) of intermetallic Al–Cr compounds intended for metal matrix composite MMC reinforcing was developed. Mixture of Al and Cr powders with granularity of −10, −44, −74mm were cold isostatic pressed and next ignited and synthetized in a microwave reactor under argon atmosphere (microwave-activated combustion synthesis MACS). In order to ignite the synthesis, microwave energy was focused by a tuner on the specimen. The analysis of reaction temperature diagrams revealed that the synthesis proceeded through the following peritectic transformations: L(liquidus)+Al7Cr→L+Al11Cr2→L+Al4Cr. Moreover, EDS and XRD examinations showed that the reaction proceeded between a solid Cr and a liquid Al to create a distinct envelope of Al₉Cr₄ on Cr particle which next extended and spreaded over the entire structure. The produced preforms with uniform structure and interconnected porosity were infiltrated with liquid Cu and Al alloy. The obtained composite materials exhibited high hardness, wear and distinct temperature oxidation resistance.
Wytworzono poprzez syntezę spaleniową porowate preformy (szkielety) ze związków międzymetalicznych Al-Cr do umacniania materiałów kompozytowych o osnowie metalowej. Sprasowane na zimno, jednoosiowo (CIP) mieszaniny proszków Al i Cr o ziarnistości −10, −44, −74mm podgrzewano w reaktorze mikrofalowym w atmosferze argonu. W celu zainicjowania syntezy wykorzystano proces aktywacji mikrofalami MACS (microwave-activated combustion synthesis) skupiając promieniowanie na powierzchni próbki za pomocą stroika falowodowego. Na podstawie analizy krzywych temperatur ATD określono przebieg syntezy z następującymi przemianami perytektycznymi:: L(liquidus)+Al7Cr→L+Al11Cr2→L+Al4Cr. Ponadto, analiza chemiczna EDS oraz fazowa XRD wykazały, że reakcja przebiega pomiędzy proszkiem Cr oraz ciekłym Al tworząc wyraźną otoczkę ze związku Al₉Cr₄ na cząstkach Cr, które z postępem reakcji rozszerzają się i zanikają. Wytworzone preformy o jednorodnej strukturze z otwartymi porowatościami użyto do infiltracji ciekłym Al oraz Cu i wytworzenia kompozytów. Charakteryzowały się one dużą twardością, odpornością na ścieranie oraz odpornością na utlenianie w wysokiej temperaturze.
Źródło:: Archives of Metallurgy and Materials; 2014, 59, 3; 1125-1127
1733-3490
Pojawia się w:: Archives of Metallurgy and Materials
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 2.

Tytuł:: The Effect of Solvent, Hydrogen Peroxide and Dioxide Titanium on Degradation of PCBs, Using Microwave Radiation in Order to Reduce Occupational Exposure
Autorzy:: Tajik, R.
Mohabadi, H. A.
Khavanin, A.
Jafari, A. J.
Eshrati, B.
Powiązania:: https://bibliotekanauki.pl/articles/205106.pdf
Data publikacji:: 2014
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:: degradation
ethanol
microwave
transformer oil
degradacja
etanol
mikrofale
olej transformatorowy
Opis:: Polychlorinated biphenyls (PCBs) are one group of persistent organic pollutants (POPs) that are of international concern because of global distribution, persistence, and toxicity. Removal of these compounds from the environment remains a very difficult challenge because the compounds are highly hydrophobic and have very low solubility in water. A 900 W domestic microwave oven, pyrex vessel reactor, pyrex tube connector and condensing system were used in this experiment. Radiation was discontinuous and ray powers were 540, 720 and 900 W. The PCBS were analyzed by GC-ECD. The application of microwave radiation and H₂O₂/TiO₂ agents for the degradation of polychlorinated biphenyl contaminated oil was explored in this study. PCB – contaminated oil was treated in a pyrex reactor by microwave irradiation at 2450 MHz with the addition of H₂O₂/TiO₂. A novel grain TiO₂ (GT01) was used. The determination of PCB residues in oil by gas chromatography (GC) revealed that rates of PCB decomposition were highly dependent on microwave power, exposure time, ratio to solvent with transformer oil in 3:1, the optimal amount of GT01 (0.2 g) and 0.116 mol of H₂O₂ were used in the study. It was suggested that microwave irradiation with the assistance of H2O2/TiO2 might be a potential technology for the degradation of PCB – contaminated oil. The experiments show that MW irradiation, H₂O₂ oxidant and TiO₂ catalyst lead to a degradation efficiency of PCBs only in the presence of ethanol. The results showed that the addition of ethanol significantly enhanced degradation efficiency of PCBs.
Źródło:: Archives of Environmental Protection; 2014, 40, 2; 91-102
2083-4772
2083-4810
Pojawia się w:: Archives of Environmental Protection
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 3.

Tytuł:: Evaluation of the Microwave Absorbing Effectiveness by the Selected Molding Sands Matrixes
Autorzy:: Stachowicz, M.
Granat, K.
Więcławek, R.
Powiązania:: https://bibliotekanauki.pl/articles/382514.pdf
Data publikacji:: 2013
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:: foundry
microwaves
quartz sand
absorption
water
odlewnictwo
mikrofale
piasek kwarcowy
absorpcja
woda
Opis:: The paper presents the results of the absorption effectiveness measured for electromagnetic waves with a frequency of 2.45 GHz penetrating selected quartz mold and core sands matrixes. Research was conducted with a usage of the unique microwave slot line for assessing, on the basis of the measured parameters of looseness, the effectiveness of microwaves absorbing capacity by the matrixes of molding sands. Examinations were focused on the high-silica quartz matrixes from various mines with a different grain size composition and humidity. Usage of the unique measuring device, designed especially for this type of research, has made possibility to systematize knowledge of the dynamics and efficiency of microwaves absorption while penetrating humid matrix of molding sands. Analysis of the study results indicate, that the process of microwaves absorbing is affect, in addition to water located on the matrix grains surfaces, by the grain size distribution and the origin of the quartz sand.
Źródło:: Archives of Foundry Engineering; 2013, 13, 1 spec.; 175-180
1897-3310
2299-2944
Pojawia się w:: Archives of Foundry Engineering
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 4.

Tytuł:: The influence of Glassex additive on properties of microwave-hardened and self-hardened moulding sands with water glass
Autorzy:: Major-Gabryś, K.
Dobosz, S. M.
Jakubski, J.
Stachowicz, M.
Nowak, D.
Powiązania:: https://bibliotekanauki.pl/articles/382492.pdf
Data publikacji:: 2012
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:: masa formierska
szkło wodne
mikrofale
moulding sand
water glass
ester hardener
microwave hardening
Opis:: The article takes into consideration the researches concerning inserting the Glassex additive to the microwaved-hardened and self-hardened moulding sands with water glass. In the research different types of ester hardeners to self-hardened moulding sands with water glass were used. The influence of Glassex additive on retained strength of moulding sands with different hardeners and prepared by different technologies of hardening were tested. The influence of different hardeners and the technology of hardening on retained strength of moulding sand with water glass and the Glassex additive were also estimated.
Źródło:: Archives of Foundry Engineering; 2012, 12, 1; 130-134
1897-3310
2299-2944
Pojawia się w:: Archives of Foundry Engineering
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 5.

Tytuł:: Effect of Sand Wetting on Physically Hardened Moulding Sands Containing a Selected Inorganic Binder. Part 1
Autorzy:: Stachowicz, M.
Granat, K.
Pałyga, Ł.
Powiązania:: https://bibliotekanauki.pl/articles/381331.pdf
Data publikacji:: 2016
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:: foundry engineering
microwaves
water glass
wetting
strength
odlewnictwo
mikrofale
szklanka wody
zwilżanie
wytrzymałość
Opis:: In the paper, an attempt was made to evaluate the effect of preliminary wetting of high-silica base during preparation of moulding sands containing a selected grade of sodium water-glass, designed for hardening by traditional drying or by electromagnetic microwaves at 2.45 GHz. In the research, some water was dosed during stirring the sandmix before adding 1.5 wt% of the binder that was unmodified sodium water-glass grade 137, characterised by high molar module within 3.2 to 3.4. Scope of the examinations included determining the effect of wetting the base on mechanical parameters like compression, bending and tensile strength, as well as on technological parameters like permeability, abrasion resistance and apparent density. The research revealed a significant positive effect of adding water to wet surfaces of high-silica base grains on mechanical properties and quality of moulding sands hardened by physical methods, in particular by microwave heating.
Źródło:: Archives of Foundry Engineering; 2016, 16, 1; 73-78
1897-3310
2299-2944
Pojawia się w:: Archives of Foundry Engineering
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 6.

Tytuł:: Microwave absorption by used moulding and core sands
Autorzy:: Nowak, D.
Stachowicz, M.
Granat, K.
Pigiel, M.
Powiązania:: https://bibliotekanauki.pl/articles/380205.pdf
Data publikacji:: 2012
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:: recykling
współczynnik fali stojącej
mikrofale
materiał formierski
recycling
standing wave ratio
microwaves
moulding materials
Opis:: The paper presents measurement results of standing wave ratio to be used as an efficiency indicator of microwave absorption by used moulding and core sands chosen for the microwave utilization process. The absorption measurements were made using a prototype stand of microwave slot line. Examined were five used moulding and core sands. It was demonstrated that the microwave absorption measurements can make grounds for actual microwave utilization of moulding and core sands.
Źródło:: Archives of Foundry Engineering; 2012, 12, 3; 87-90
1897-3310
2299-2944
Pojawia się w:: Archives of Foundry Engineering
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 7.

Tytuł:: Application of microwaves for binder content assessment in moulding sands
Autorzy:: Nowak, D.
Powiązania:: https://bibliotekanauki.pl/articles/380212.pdf
Data publikacji:: 2012
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:: innowacyjne technologie odlewnicze
masa formierska
spoiwo
mikrofale
innovative foundry technologies
moulding sand
binder
microwaves
Opis:: The paper presents results of preliminary examinations on possibility of determining binder content in traditional moulding sands with the microwave method. The presented measurements were carried-out using a special stand, the so-called slot line. Binder content in the sandmix was determined by measurements of absorption damping Ad and insertion losses IL of electromagnetic wave. One of main advantages of the suggested new method of binder content measurement is short measuring time.
Źródło:: Archives of Foundry Engineering; 2012, 12, 3; 83-86
1897-3310
2299-2944
Pojawia się w:: Archives of Foundry Engineering
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 8.

Tytuł:: Long-term Effects of Relative Humidity on Properties of Microwave Hardened Moulding Sand with Sodium Silicate
Autorzy:: Stachowicz, M.
Granat, K.
Powiązania:: https://bibliotekanauki.pl/articles/379875.pdf
Data publikacji:: 2017
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:: foundry
sodium silicate
humidity
microwaves
high-silica sand
odlewnia
krzemian sodu
wilgotność
mikrofale
piasek kwarcowy
Opis:: Moulding sands containing sodium silicate (water-glass) belong to the group of porous mixture with low resistance to increased humidity. Thanks to hydrophilic properties of hardened or even overheated binder, possible is application of effective methods of hydrous reclamation consisting in its secondary hydration. For the same reason (hydrophilia of the binder), moulds and foundry cores made of high-silica moulding sands with sodium silicate are susceptible to the action of components of atmospheric air, including the contained steam. This paper presents results of a research on the effect of (relative) humidity on mechanical and technological properties of microwave-hardened moulding mixtures. Specimens of the moulding sand containing 1.5 wt% of sodium water-glass with module 2.5 were subjected, in a laboratory climatic chamber, to long-term action of steam contained in the chamber atmosphere. Concentration of water in atmospheric air was stabilized for 28 days (672 h) according to the relative humidity parameter that was ca. 40%, 60% and 80% at constant temperature 20 °C. In three cycles of the examinations, the specimens were taken out from the chamber every 7 days (168 h) and their mechanical and technological parameters were determined. It was found on the grounds of laboratory measurements that moulds and cores hardened with microwaves are susceptible to action of atmospheric air and presence of water (as steam) intensifies action of the air components on glassy film of sodium silicate. Microwave-hardened moulding sands containing sodium silicate may be stored on a long-term basis in strictly determined atmospheric conditions only, at reduced humidity. In spite of a negative effect of steam contained in the air, the examined moulding mixtures maintain a part of their mechanical and technological properties, so the moulds and foundry cores stored in specified, controlled conditions could be still used in manufacture.
Źródło:: Archives of Foundry Engineering; 2017, 17, 3; 127-132
1897-3310
2299-2944
Pojawia się w:: Archives of Foundry Engineering
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 9.

Tytuł:: Effect of Sand Base Grade and Density of Moulding Sands with Sodium Silicate on Effectiveness of Absorbing Microwaves
Autorzy:: Stachowicz, M.
Powiązania:: https://bibliotekanauki.pl/articles/381758.pdf
Data publikacji:: 2016
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:: foundry
microwaves
sodium silicate
high-silica sand
lossiness measurements
odlewnia
mikrofale
krzemian sodowy
piasek kwarcowy
Opis:: In the paper, presented is a research on effectiveness of absorbing electromagnetic waves at frequency 2.45 GHz by unhardened moulding sands prepared of three kinds of high-silica base and a selected grade of sodium silicate. Measurements of power loss of microwave radiation (Pin) expressed by a total of absorbed power (Pabs), output power (Pout) and reflected power (Pref) were carried-out on a stand of semiautomatic microwave slot line. Values of microwave power loss in the rectangular waveguide filled with unhardened moulding sands served for determining effectiveness of microwave heating. Balance of microwave power loss is of technological and economical importance for manufacture of high-quality casting moulds and cores of various shapes and sizes. It was found that relative density influences parameters of power output and power reflected from samples of moulding sand placed in a waveguide. Absorption expressed by the parameter Pabs is not related to granularity of high-silica base: fine, medium and coarse. It was found that the semiautomatic microwave slot line supports evaluation of effectiveness of microwave absorption on the grounds of power loss measurements and enables statistic description of influence of relative density of the sandmix on penetration of electromagnetic waves in unhardened moulding sands.
Źródło:: Archives of Foundry Engineering; 2016, 16, 3; 103-108
1897-3310
2299-2944
Pojawia się w:: Archives of Foundry Engineering
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 10.

Tytuł:: Evaluation of Microwave Heating of Protective Coatings Used in the Lost Foam Technology
Autorzy:: Opyd, B.
Granat, K.
Powiązania:: https://bibliotekanauki.pl/articles/382105.pdf
Data publikacji:: 2015
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:: innovative foundry technology
microwave
protective coating
lost foam
innowacyjna technologia odlewnicza
mikrofale
powłoka ochronna
tracona piana
Opis:: Presented are results of a preliminary research on determining a possibility to use microwave radiation for drying casting protective coatings applied on patterns used in the lost foam technology. Taken were measurements of permittivity ε_r and loss factor tgδ at 2.45 GHz, as well as attempts were made of microwave drying of a protective coating based on aluminium silicates, applied on shapes of foamed polystyrene and rigid polymeric foam. Time and results of microwave drying were compared with the results obtained by drying at 50 °C by the traditional method commonly used for removing water from protective coatings. Analysis of the obtained drying kinetics curves demonstrated that selection of proper operation parameters of microwave equipment permits the drying time to be significantly shortened. Depending on kind of the pattern material, drying process of a protective coating runs in a different way, resulting in obtaining different quality of the dried coating.
Źródło:: Archives of Foundry Engineering; 2015, 15, 2; 65-70
1897-3310
2299-2944
Pojawia się w:: Archives of Foundry Engineering
Dostawca treści:: Biblioteka Nauki

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