Temat: 81.70.Pg - Prolib Integro

Skocz do pozycji: 1.

Tytuł:: Synthesis and Thermal and Textural Characterization of Aniline Formaldehyde-Organoclay Composites
Autorzy:: Gürses, A.
Eroğlu, Z.
Güneş, K.
Doğar, Ç.
Tematy:: 81.70.Pg; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Powiązania:: https://bibliotekanauki.pl/articles/1187414.pdf Link otwiera się w nowym oknie
Opis:: In this study, the synthesis of aniline-formaldehyde resin, and its thermal and structural characterization, as well as the preparation and characterization of the resin-organoclay composites were carried out. For this, first, at 70°C and acidic conditions the aniline formaldehyde prepolymer was prepared and then cured at 120°C under vacuum. The structural and thermal characterization of the resin was made using FTIR and DSC techniques. By using the Cetyltrimethylammonium Bromide modified Montmorillonite (OMMT) and the synthesized resin, the resin-organoclay composites were prepared by melt intercalation method. Characterization of the resin-organoclay composites prepared with the different ratios of organoclay is made with the same techniques. The FTIR and thermal analysis results of the composites indicate that a cross-linked polymeric matrix was formed. The thermal behavior of the composites has also significantly changed compared to pure resin.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 2.

Tytuł:: Preparation and Characterization of Surfactant-Modified Powder Activated Carbon (SM-PAC) Reinforced Poly (Ethylene Oxide) (PEO) Composites
Autorzy:: Gürses, A.
Ejder-Korucu, M.
Doğar, Ç.
Tematy:: 81.70.Pg; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Powiązania:: https://bibliotekanauki.pl/articles/1398798.pdf Link otwiera się w nowym oknie
Opis:: Poly (ethylene oxide), PEO, which was used for a wide variety of applications is a flexible, crystalline, thermoplastic, water-soluble and non-ionic polymer. The most of studies on surfactant-modified activated carbon (SM-PAC) have been generally focused on the removal of contaminants. This study aims the preparation of PEO/(SM-PAC) composites, using solution-intercalation method. Firstly activated carbon was modified with cationic surfactant, Cetyltrimethylammonium Bromide (CTAB). Then PEO/(SM-PAC) composites were prepared using solution-intercalation method, with two different (SM-PAC) contents (1.0 and 2.0 wt.%). The characterization of the composites was made by X-ray diffraction (XRD), Fourier Infrared Spectroscopy (FT-IR), thermal analysis and tensile tests. The XRD patterns revealed that 2θ positions of the broad peaks belonging to the composites significantly shift to left compared with those of virgin PEO. The SEM images of the surfactant-modified powdered activated carbon (SM-PAC)/PEO composites prepared with the two different SM-PAC contents show that there is an intensive interaction between the CTA^{+} ions of modified activated carbon surface and the polymer chains. From the tensile tests, it was found that the unmodified powdered activated carbon dispersed into the polymer matrix made the ductile polymer more brittle. However, the tensile and yield strengths of the composite, prepared with modified powdered activated carbon, have decreased, and the strain percent value has significantly increased.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 3.

Tytuł:: Mechanism and Kinetics of Precipitation and Dissolution of GP Zone and Metastable Phase in Al-3wt% Cu Alloy
Autorzy:: Khamel, B.
Sahnoune, F.
Fatmi, M.
Brihi, N.
Tematy:: 81.30.Mh
81.70.Pg
81.30.Bx; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Powiązania:: https://bibliotekanauki.pl/articles/1033403.pdf Link otwiera się w nowym oknie
Opis:: Thermal analysis techniques remain important tools amongst the large variety of methods used for analysis of the precipitation and dissolution of the Guinier-Preston zone and metastable phase θ' in Al-3wt% Cu. In the present study, the kinetics of precipitation and dissolution of the Guinier-Preston zone and metastable phase θ' in Al-3wt% Cu was investigated using differential scanning calorimetry carried out between room temperature and 430°C at heating rates of 20, 25, and 30°C min¯¹. The activation energies evaluated through isothermal differential scanning calorimetry treatment using the Johnson-Mehl-Avrami theory were 25, 100, and 80 kJ mol¯¹ for the Guinier-Preston zone precipitation, formation of θ'/θ and dissolution of θ', respectively. The Avrami constant n obtained by the Ligero method was about 1.5 for the formation of θ'/θ indicating that bulk nucleation is dominant in θ'/θ formation controlled by diffusion from a constant number of nuclei.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 4.

Tytuł:: Phase Transformation and Sintering of Algeria Clay Powder
Autorzy:: Beddiar, L.
Sahnoune, F.
Heraiz, M.
Redaoui, D.
Tematy:: 81.05.Mh
81.70.Pg
81.30.Mh; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Powiązania:: https://bibliotekanauki.pl/articles/1033574.pdf Link otwiera się w nowym oknie
Opis:: Clay is one of the most used natural materials in the ceramic industry with various applications such as pottery, tiles, cement and bricks. The latter are used as a building material because of their excellent thermal and mechanical properties. In the present study, Algerian clay from Al-maathed area, M'sila district, was used to prepare bricks. The chemical composition of the clay was determined using X-ray fluorescence. Firing of clay was carried out in the temperature range 20-1000°C, at different heating rates. The present phases and their transformations, the activation energy, and the sintering mechanism were evaluated using X-ray diffraction, differential thermal analysis, thermogravimetric analysis and dilatometry. The activation energy for the sintering mechanism obtained from non-isothermal treatments is 420 kJ/mol. The value of the Avrami exponent, n, is determined from the shape of the crystallization exothermic dependence. It is related to m parameter (a numerical factor which depends on the dimensionality of crystal growth) obtained by Matusita method. Both of which are about 1.2 for clay sintering. These values indicate that bulk nucleation is dominant in clay sintering by three-dimensional growth, with polyhedron-like morphology controlled by interface reaction.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 5.

Tytuł:: Mechanical and Thermal Properties of Pumice Powder Filled PPS Composites
Autorzy:: Sahin, A.
Yildiran, Y.
Avcu, E.
Fidan, S.
Sinmazcelik, T.
Tematy:: 81.05.Qk
81.70.Bt
81.70.Pg; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Powiązania:: https://bibliotekanauki.pl/articles/1182862.pdf Link otwiera się w nowym oknie
Opis:: Recently, it is common application to use particle materials as fillers to improve engineering properties and lower the cost of finished product. Pumice powder is cheaper than most of traditional particle fillers, however use of pumice powders as a reinforcing material in composites has not been studied in literature. Hence, in this study we have investigated the mechanical and the thermal properties of pumice powder filled polyphenylenesulphide (PPS) composites. PPS composites were reinforced with pumice powder at different loading rates (0, 1, 3.5, and 10 wt%) and they were manufactured by twin screw extruder and injection molding machine. Thermal properties were investigated by thermogravimetric analysis and differential scanning calorimeter methods. Moreover, mechanical properties such as barcol hardness, tensile strength, and modulus of samples were investigated. Thermal properties of composite samples have varied significantly depending on the loading rate. Also mechanical properties of pumice powder filled PPS composites have showed better results than pure PPS. According to test results both of mechanical and thermal properties of composites have improved with pumice powder reinforcement and it is determined that pumice powders can be used instead of traditional particle fillers.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 6.

Tytuł:: The Kinetics of Spinel Formation of Algerian Halloysite by Differential Thermal Analysis
Autorzy:: Heraiz, M.
Sahnoune, F.
Belhouchet, H.
Raghdi, A.
Ouali, A.
Tematy:: 81.70.Pg
81.20.Ev
82.20.-w; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Powiązania:: https://bibliotekanauki.pl/articles/1033398.pdf Link otwiera się w nowym oknie
Opis:: The kinetics of spinel (Al-Si) crystallization from Algerian halloysite (DD1) was investigated using differential thermal analysis. Experiments were carried out on samples between room temperature and 1400°C with constant heating rate from 2 to 20°C min¯¹. The activation energies measured from isothermal and non-isothermal treatments were 1054.85 and 1140 kJ mol¯¹, respectively, for the spinel (Al-Si) formation. The Avrami constant n obtained by the Ligero method and the m parameter obtained by the Matusita method were about 2 for spinel crystallization. This value indicates that the crystallization mechanism of Al-Si spinel phase proceeds by bulk nucleation of the phase formation with a constant number of nuclei and that the three-dimensional growth of crystals is controlled by diffusion.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 7.

Tytuł:: Effects of Terpolymer Addition on the Thermal and Termomechanical Properties of Poly(Phenylene Sulfide)
Autorzy:: Cetin, B.
Sahin, A.
Yilmaz, T.
Sinmazcelik, T.
Curgul, I.
Tematy:: 81.70.Pg
83.85.Vb
61.41.+e; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Powiązania:: https://bibliotekanauki.pl/articles/1033681.pdf Link otwiera się w nowym oknie
Opis:: Poly(phenylene sulfide) (PPS) is one of the high-performance engineering polymers and it exhibits superior behavior, such as electrical insulation, dimensional and thermal stability, chemical resistance for various industrial applications. In addition to this, PPS has a high degree of crystallinity and it maintains these properties at high temperatures. These advantageous properties of PPS can be dependent on its chemical structure, composed of phenyl groups linked by a sulfur atom, which gives rigidity to the polymer chains. Owing to these properties, PPS is widely used in electrical and electronic components, automobile industry and mechanical applications. On the other hand, brittleness of PPS restricts its further applications. For this reason, ethylene-acrylic ester-glycidyl methacrylate terpolymer (Lotader®-AX8900) was used to overcome the brittleness of PPS. The effects of terpolymer addition on the thermal and thermomechanical properties of blends were investigated in this study. PPS/Lotader (0, 2, 5, 10 wt.% Lotader®) blends of various compositions were prepared. The blends were prepared by using laboratory scale micro compounder and injection molding machine. Thermomechanical and thermal properties of blends were investigated by means of dynamic mechanic analysis and differential scanning calorimeter test methods. As a result of this study, it was found that increasing loading level of Lotader® significantly decreased the crystallinity and increased glass transition temperature of PPS. On the other hand, Lotader® addition did not affect the melting temperature of PPS considerably. Results of dynamic mechanic analysis test revealed that while damping factor peak and loss modulus values of blends increased with the addition of Lotader®, storage modulus of blends decreased with the increasing loading level of Lotader®. When all test results are considered, it can be concluded that Lotader addition changes the brittle nature of PPS to ductile nature. In addition to this, 2 wt.% Lotader addition to PPS enables the optimum ductility for PPS without deteriorating its other properties.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 8.

Tytuł:: Formation and Structure of Nanocrystalline Al-Mm-Ni-Cu Alloys
Autorzy:: Latuch, J.
Krasnowski, M.
Ciesielska, B.
Tematy:: 61.43.Dq
81.05.Kf
81.70.Pg; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Powiązania:: https://bibliotekanauki.pl/articles/2035467.pdf Link otwiera się w nowym oknie
Opis:: This paper reports the results of a short investigation on the effect of Cu additions upon the nanocrystallization behaviour of an Al-Mm-Ni alloy. 2 at.%Cu added to a base alloy of Al$\text{}_{85}$Mm$\text{}_{10}$Ni$\text{}_{5}$ alloy by substitution for Mm (mischmetal). The control of cooling rate did not cause the formation of nanocrystals of fcc-Al phase. The nanocrystalline structure fcc-Al + amorphous phase in quarternary alloy was obtained by isothermal annealing and continuous heating method, but the last technique is more effective. The volume fraction, lattice parameter, and size of Al-phase were calculated.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 9.

Tytuł:: Determination of Feederless Casting Limits by Thermal Analysis in Cast Iron
Autorzy:: Erturk, S.
Kumruoglu, L.
Ozel, A.
Tematy:: 81.05.Bx
81.30.-t
81.30.Fb
81.70.Pg; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Powiązania:: https://bibliotekanauki.pl/articles/1030308.pdf Link otwiera się w nowym oknie
Opis:: In this study the determinations of melt quality was carried out by thermal analysis of ductile iron. The aim of the study was to determine the limits of feederless casting after the determination of inoculation quality in cast iron. Production method of pouring into a sand mold in the entirety and without using feeder systems has been investigated. Forms of the solidification and volume change have been investigated with simulation program as functions of inoculation quality, type of resin in the mold and mold rigidity. Results of the analysis have been compared with the results of experimental iron casting.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 10.

Tytuł:: High resolution TEM investigations and TDA analysis of zinc alloy with strontium addition
Autorzy:: Labisz, K.
Krupiński, M.
Pawlyta, M.
Matus, K.
Kremzer, M.
Dopierała, K.
Tematy:: 68.37.Og
81.70.Pg
61.66.Dk; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Powiązania:: https://bibliotekanauki.pl/articles/1153727.pdf Link otwiera się w nowym oknie
Opis:: In this paper there are presented results of high resolution transmission electron microscope investigation concerning the structure of the Zn-Al-Si cast zinc alloy with Sr addition for crystal structure refinement after thermo-derivative analysis performed using the universal metallurgical simulator and analyzer platform. The thermo-derivative analysis allows to determine the specific points of the solidifying alloy, which is helpful for phase determination and proper heat treatment condition determination, allowing to reduce the energy costs and obtaining higher mechanical and functional properties. Using transmission electron microscopy, especially selected area diffraction method appliance it was possible to determine the phases occurring in the alloy in the state after chemical composition modification as well as after appliance of very precisely controlled cooling rate. The morphology and size of the microstructure of micro-sized eutectic was possible to determine as well the lattice parameters of the Zn α -phase. Particularly the overview will be also directed on the high resolution transmission electron microscope to achieve good insight into the structural changes on the atomic scale.
Dostawca treści:: Biblioteka Nauki

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