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1
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Influence of Organic Pollutants on Deterioration of Antique Glass Structure

100%
Greiner-Wronowa E.
Acta Physica Polonica A
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2011
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vol. 120
|
issue 4
803-811
EN
The state of glass artifacts preserved in museums is strongly dependent on strictly local parameters. The deterioration of antique glass brought on by organic compound activity which will receive attention in this work has been studied on a sample of a 18th c. glass beaker belonging to the National Museum in Kraków. Measuring of the corrosion was carried out on an original, as well as on a model (or sensor) glass. The former - the remains of an 18th c. beaker - was borrowed from the Museum. The latter is a modern sample. Both samples were tested with a non-destructive method. Glass sensors, the chemical composition of which corresponded to the analyzed objects, were prepared. Their purpose was to facilitate the study of corrosion induced by different chemicals and altered physical conditions, previously proved in the museum real circumstances. The chemical structure of glass before and after the induced corrosion processes in formaldehyde and acetic acid solution was examined by the Fourier transform infrared and Raman spectroscopy. Moreover, complementary tests by scanning electron microscopy, energy dispersive microscopy, confocal microscopy were carried out as well. The corrosion processes were realized by means of shock temperature changes, as well as altering of relative humidity. Parallel corrosion processes under halogen lamp radiation were also induced. Measurements of induced corrosion pointed to the fact that deterioration of glass depends not only on the concentration of corroding media, but also on thermal shock. An experiment involving the lighting of an object by halogen lamp isolated a very important agent, which has significant influence on glass deterioration. The intensity of the induced corrosion resulted, in some cases, in glass volume corrosion as well. The obtained information can be useful for curators and conservators, as any resulting glass changes are responsible for further, this time irreversible, alterations.
2
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Positron Annihilation in Tektite and Hyalite

100%
Chojcan J., Sachanbiński M.
Acta Physica Polonica A
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1993
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vol. 83
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issue 3
267-271
EN
Positron lifetime spectra as well as one-dimensional angular distributions of photons coming from the two-photon annihilation of an electron-positron pair were measured at room temperature for samples of natural tektite and hyalite. The data were used for estimation of positronium characteristics in the specimens. The characteristics were analysed in terms of parameters of pores trapping the positronium atoms before their decay. In the analysis two models of the traps were taken into account, i.e. the square potential wells of spherical symmetry with barriers of finite and infinite heights. It was found that the linear dimensions of the pores resulting from these two-trap models are almost the same and they are of the order of 1 nm.
3
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Investigation of Structure and Conductivity of Superionic Conducting Materials Obtained on the Basis of Silver Iodide

100%
Wiśniewski Z., Górski L., Zasada D.
Acta Physica Polonica A
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2008
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vol. 113
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issue 4
1231-1236
EN
Conductivity and structure of materials belonging to pseudo-binominal group (AgI-Ag_2MoO_4) were investigated. Structure was investigated by X-ray and scanning electron microscopy techniques. It was found that described materials present a variety of internal structures. This type of structures affects conductivity at room temperature, so there is correspondence between conductivity and structure.
4
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Positron Annihilation in Obsidians

100%
Chojcan J., Sachanbiński M.
Acta Physica Polonica A
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1995
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vol. 88
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issue 1
103-110
EN
Positron lifetime spectra as well as one-dimensional angular correlations of positron annihilation radiation were measured at room temperature for samples of rhyolitic obsidian coming from Iceland, Italy and Armenia. The samples were of different age. One specimen (originating from Iceland) was relatively young, formed in 1980. The others were much older, collected during the 19th century. It was found that the linear dimensions of pores trapping the positronium atoms before their decay as well as the pore concentration in all old obsidians are almost the same independently of the place of their formation. Simultaneously the concentration of the pores in the young sample is about five times lower than in the old specimens. Basing on the result it is suggested to extend the study in order to find out if positron annihilation can be used for the investigation of the age of the volcanic accumulations containing obsidian.
5
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Wear Properties of Gabbro Based Glass and Glass-Ceramic Materials

80%
Bayrak G.
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vol. 125
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issue 2
615-617
EN
Glass-ceramic materials were developed from gabbro including MgO and Al_2O_3 additives. Heat treatments for phase transformation from glassy matrix to glass-ceramic were carried out at 1000C for 3 h. X-ray diffraction studies conducted on the glass-ceramic samples revealed that the phases formed in the glass-ceramics were cordierite, anorthite, diopsitic augite, forsterite and andesine. Glass and glass-ceramic materials were tested for wear properties against a harder alumina counterface using by a ball-on-disc tribometer at dry sliding condition. Wear tests were realized under the loads of 2.5, 5, and 7.5 N and at the sliding speeds of 0.1, 0.2, and 0.3 m/s. Wear rate of the glass and glass-ceramics ranged from 7.324 × 10^{-7} and 2.150 × 10^{-3}-9.971 × 10^{-7} and 4.982 × 10^{-5} mm^3/m, respectively. It was shown that the crystallization treatment caused the decrease of wear rate.
6
Publication available in full text mode
Content available

Atomic Motion in Amorphous Solids

80%
Schober H.
Acta Physica Polonica A
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2002
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vol. 102
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issue 1
83-93
EN
Glasses and amorphous materials show, coexisting with the sound waves, a variety of low energy excitations: tunneling, quasi-localized vibrations and relaxations. The latter two are observed well into the liquid state. Using molecular dynamics both were shown to be centred on more than ten atoms or molecular units, which form chain-like structures. With increasing frequency the interaction of the quasi-localized modes with the sound waves and with each other increases, they delocalize. However, even at the so-called boson peak frequency, where the sound waves become overdamped due to the interaction, the vibrations can be decomposed into local and extended modes. Closely correlated with the local vibrations are the local relaxations, which can be envisaged as collective jumps of groups of atoms. With rising temperature both the total jump length and the number of atoms participating increases. In the melt when single jumps are no longer resolved one still observes a collective motion of chains of atoms.
7
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Effect of Doping by Different Transition Metals on the Acoustical Properties of Alkali Borate Glasses

80%
Gaafar M., El-Batal F., El-Gazery M., Mansour S.
Acta Physica Polonica A
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2009
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vol. 115
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issue 3
671-678
EN
Longitudinal and shear ultrasonic wave velocities were measured in binary Li_2O-2B_2O_3 glasses doped with different transition metal oxides (TMOs) (where TMO = V_2O_5, Fe_2O_3, Cr_2O_3, NiO, TiO_2, MnO_2 and CuO) using pulse echo technique. Measurements were carried out at 4 MHz frequency and at room temperature. Elastic moduli and some other physical parameters such as acoustic impedance, Debye temperature, thermal expansion coefficient, and latent heat of melting were calculated. Results indicated that these parameters depend upon the TMO modifier i.e., the ionic radius of the transition metal cation. Quantitative analysis has been carried out, in order to obtain more information about the structure of these glasses, based on bond compression model, and the Makishima and Mackenzie model, i.e., the cation-anion bond of each TMO.
8
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Structural Analysis of Some Alkali Diborate Glasses

80%
Saddeek Y., Gaafar M., Abd El-Aal N., Abd El-Latif L.
Acta Physica Polonica A
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2009
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vol. 116
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issue 2
211-216
EN
This manuscript presents a theoretical analysis of the correlation between the computed bulk modulus and the structure of a series of multicomponent sodium diborate based glasses in terms of the bond compression model. The main parameters in the analysis were the computed elastic moduli, the average stretching force constant and the average atomic ring size. These parameters were calculated for every glass series and for every glass composition. The results showed that the average force constant and the elastic moduli of these glasses are sensitive to the decrease in the sodium diborate content. This behaviour was attributed to the increase in the molar volume, and to the role of the different modifiers.
9
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Granite Based Glass-Ceramic Materials

80%
Bayrak G., Yilmaz S.
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vol. 125
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issue 2
623-625
EN
In this study, production possibility of glass and glass-ceramic produced from granite was investigated. The composition of granite based glass bath mixture was 50 wt% granite, 25 wt% dolomite and 25 wt% sodium carbonate. Composition that was grounded and mixed in a ball mill for 2 h was melted at 1500C for 1 h. Glass samples were heat treated for crystallization to produce glass-ceramic materials at 800°C, 900C and 1000C for 2 h to promote internal crystallization. Phase identifications of glass and glass-ceramic materials were investigated by X-ray diffraction analysis. Moreover, hardness and fracture toughness measurement of glass and glass-ceramic materials were applied. Granite based materials after that melting and casting process was found amorphous state by characterization with X-ray diffraction analysis. After the heat treatment processes, crystal phases settled out in glass matrix were also determined in granite based materials. Moreover, values of hardness and fracture toughness increasing were detected by heat treatment schedule.
10
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Bond Strength of Basalt Based Glass-Ceramic Coatings

80%
Bayrak G., Ercenk E., Sen U., Yilmaz S.
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vol. 125
|
issue 2
620-622
EN
In the present study, powders produced from the volcanic basalt rocks were coated on pre-coated AISI 1040 steel with Ni-5% Al bond coat by atmospheric plasma spray coating technique. The coated specimens were characterized by optical microscopy, scanning electron microscopy, metallography and X-ray diffraction. Bonding strength of coatings was evaluated in accordance with the ASTM C-633 method. Coated basalt material from the APS coating system was determined in the glassy amorphous state by X-ray diffraction analysis. The coated samples were heat-treated at 800C for 1-4 h for crystallization. The phases formed in the basalt base glass-ceramic coatings were augite, Fe-diopside, anorthite, and andesine which were detected by X-ray diffraction analysis. Basalt based glass-ceramic coatings include splat, porosity and un-melted particles which were the characteristic of plasma sprayed coatings. Experiment result showed that the crystallization time increase caused the decrease of the bond strengths of the coatings.
11
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Local Structural Features of Metallic Alloys: Ni_{33}Zr_{67} and Ni_{50}Zr_{50}

80%
Khusnutdinoff R.
Acta Physica Polonica A
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2016
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vol. 129
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issue 3
293-296
EN
In this work we present the results of computer simulations molecular dynamics of the metallic alloys: Ni_{33}Zr_{67} and Ni_{50}Zr_{50}. The critical glass-forming temperatures are defined from the behavior change of the Wendt-Abraham parameters of the studied systems. We have found that the increase in the concentration of nickel in the system NiZr leads to displacement of the critical glass-forming temperature in higher temperature region. It is shown that the structural transformations which were observed in the Ni_{50}Zr_{50} system are not related with crystallization processes.
12
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Microstructure of Zirconia-Based Sol-Gel Glasses Studied by SANS

80%
Ryukhtin V., Strunz P., Kopitsa G., Ezdakova K., Gubanova N., Ivanov V., Baranchikov A., Angelov B., Feoktistov A., Pipich V., Levinský P.
Acta Physica Polonica A
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2015
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vol. 128
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issue 4
582-584
EN
Zirconia-based bulk glasses were prepared for the first time by sol-gel method. Such materials are very promising for application as photochromic devices, catalytic systems, chemical sensors, lasers and other nonlinear optics devices. Obtained transparent and semi-transparent materials were studied by small and ultra-small angle neutron scattering (SANS and USANS) methods. As evidenced by SANS, morphology of zirconia glasses is very sensitive to parameters of sol-gel synthesis, e.g. temperature and concentration of reactants. SANS data correlates rather well with surface porosity data. Increasing water concentration in reaction mixtures containing zirconium propylate leads to a significant increase in fractal cluster size, while decrease of the temperature results in an increase of the fractal dimension. The obtained results indicate that parameters of the microstructure and consequently physical properties of zirconia glasses can be effectively controlled by parameters of synthesis.
13
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Mechanical Characteristics of As₂S₃ Glasses Induced by Doping with Bismuth

80%
Šiljegović M., Lukić-Petrović S., Petrović D., Videnović I., Turyanytsa I.
Acta Physica Polonica A
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2016
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vol. 129
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issue 4
488-491
EN
This paper presents and discusses the results of the instrumented indentation test of the samples of the system Bi_{x}(As₂S₃)_{100-x}, x= 1.5, 3, 5, and 7 at.%. Measurements of mechanical parameters were performed using a Fischerscope HM2000 S nanoindentation device. The experimental data obtained by measuring the microhardness parameters were used to determine some other mechanical quantities that are important for the characterization of the examined materials in terms of their potential applications. For the first three compositions, the results indicated an increase in the microhardness with the increase in the content of doping atoms, which can be interpreted as an enhancement of the strength and stiffness of the structural network. The lower value of microhardness of the sample with the maximum content of Bi can BE associated with the specific structure of this composition. The pronounced indentation size effect was also detected on the indentation curve in the range of smaller loads. According to the model of elastic-plastic deformation, applied for the description of indentation size effect measured for the investigated chalcogenides, the largest value of the elastic recovery was observed for the sample Bi₇(As₂S₃)₉₃. The calculated values of the elasticity modulus show that the glass with x= 5 at.% Bi is characterized with the highest atomic packing density.
14
Publication available in full text mode
Content available

Superconducting Lead Granular Layer Prepared by Reducing in Hydrogen Lead of Germanate Glasses

80%
Gackowska J., Gazda M., Trzebiatowski K., Kusz B.
Acta Physica Polonica A
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2006
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vol. 109
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issue 4-5
591-596
EN
The thin layer of Pb granules on the surface of the lead-germanate glass was prepared by thermal annealing in hydrogen. The structure and superconducting properties of lead layer depend on temperature and time of reduction. The influence of time and temperature of reduction on the properties of the reduced layer thickness has been studied.
15
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Combined X-Ray Diffraction and Absorption Study οf Crystalline Vanadium-Doped Lithium Disilicate

80%
Paszkowicz W., Wolska A., Klepka M., abd el All S., Ezz-Eldin F.
|
|
issue 2
315-318
EN
Structure of vanadium-doped lithium disilicate, Li_{2}Si_{2}O_{5} (Ccc2 space group) is studied. This crystalline phase is obtained by annealing of the doped lithium disilicate glass for 4 h at 550°C. X-ray diffraction and X-ray absorption near-edge structure analysis indicate location of vanadium atoms at Si sites. the lattice parameters are found to increase isotropically with increasing vanadium content. the valency of vanadium ions is discussed on the basis of X-ray absorption near-edge structure results.
16
Content available remote

EPR and Optical Spectroscopy of Iron Doped Mixed Alkali Cadmium Phosphate Glasses

80%
Giridhar G., Punyaseshudu D., Srinivas Prasad M., Venkateswarlu M., Srinivas G.
Acta Physica Polonica A
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2013
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vol. 123
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issue 4
761-765
EN
Iron doped mixed alkali cadmium phosphate (LiNaCdP) glasses of the following chemical composition xLi_2O + (20-x)Na_2O + 20CdO + 59.5P_2O_5 + 0.5Fe_2O_3 (5
17
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Raman Intensity: An Important Tool in the Study οf Nanomaterials and Nanostructures

80%
Colomban P., Slodczyk A.
Acta Physica Polonica A
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2009
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vol. 116
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issue 1
7-12
EN
Analysis of the relative and absolute Raman intensity is very important and powerful tool which allows to understand and characterize the modifications of the crystal/amorphous structure due to: (i) changes of the symmetry, e.g. substitution of the B site ion by the rare earth/lanthanide one and incorporation of mobile species in the case of high temperature protonic conducting perovskites; (ii) changes of the short/long range order, e.g. existence/disappearance of the nanoregions in the case of PbMg_{1/3}Nb_{2/3}O_{3-x}PbTiO_3 (PMN-PT) relaxor ferroelectric perovskites; (iii) changes of the nanostructure, e.g. depolymerisation of the Si-O network due to the substitution of the Si^{4+} ions (and associated covalent bonds) by the M^+ cations (forming ionic bonds) or by the incorporation of the metal nanoprecipitates in the case of glasses, glazes and enamels.
18
Publication available in full text mode
Content available

Structural and Optical Characterisation of Hydrogenated Soda-Lime Silicate Glasses Doped with Silver and Copper

71%
Suszyńska M., Krajczyk L., Macalik B.
Acta Physica Polonica A
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2003
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vol. 104
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issue 6
559-569
EN
The results of comparative studies of the effect of hydrogenation upon structural and optical properties of the commercial soda-lime silicate glasses doped either with monovalent silver or copper have been presented. The samples were characterised by means of the scanning and transmission electron microscopy and the UV-VIS-IR absorption spectroscopy. It has been shown that the annealing of suitably ion-exchanged specimens in gaseous hydrogen atmosphere could be considered as an effective procedure for obtaining composite materials of expected properties correlated with the induced changes of the morphology of both the glassy matrix and the dopant.
19
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Sintering Behavior and Machinability Properties of Industrial Waste Materials Based Glass-Ceramics

71%
Bayrak G., Ercenk E., Yilmaz S.
Acta Physica Polonica A
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2015
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vol. 127
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issue 4
1346-1348
EN
Glass-ceramics were produced by sintering method from industrial waste materials such as fly ash, blast furnace slag and boron waste. The sintering behavior and machinability of glass-ceramic compositions were investigated. Additives were added to waste materials for enhancement of machinability and sintering properties. All starting materials were mixed by ball milling for 2 h using alumina media. The mixed and milled powders were sieved to grain sizes smaller than 75 μm and pressed at 100 MPa. The pressed samples were sintered at 900°C, 1000°C and 1100°C for 1 h in an electric furnace using a heating rate of 5°C/min. Some characterization tests such as X-ray diffraction (XRD), scanning electron microscopy (SEM) and machinability tests were performed on sintered samples. The results indicated that all samples exhibit good sintering and machinability properties.
20
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Glass and Glass-Ceramics Produced from Fly Ash and Boron Waste

71%
Ercenk E., Sen U., Bayrak G., Yilmaz S.
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vol. 125
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issue 2
626-628
EN
In the current study, the effect of boron waste addition on some properties of fly ash based glass and glass-ceramics were investigated. The powder compositions including 10, 30, and 50 wt% boron waste was prepared. All the investigated compositions were melted at 1500C by using electrical furnaces. Melting structures were cast into the graphite mold. Thus, fly ash-boron waste based glass materials were produced. To transform the glass-ceramic, crystallization process was performed. Crystallization and glass-transition temperatures were determined by differential thermal analysis. Highly dense and crystalline materials, predominantly composed of diopside and augite together with tincalconite and residual glassy phase, were detected by X-ray diffraction analysis after heat treatment at 800, 900, and 1000C for 1 h. For the glass and glass-ceramic samples, mechanical tests such as hardness and fracture toughness were realized. A boron waste addition has a positive effect on the hardness of the specimens unlike the fracture toughness results. Furthermore, produced glass-ceramic materials were characterized via scanning electron microscopy.
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