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Abstract

This study is the first comparison of the morphology of pollen grains in ten cultivars of three species of the Taxus,

Torreya nucifera and Cephalotaxus harringtonia var. drupacea genera. The material came from the Botanical

Garden of Adam Mickiewicz University in Poznań, Poland. Each measurement sample consisted of 50 pollen

grains. In total, 750 pollen grains were analyzed. Light and electron scanning microscopy was used for the morphometric

observation and analysis of pollen grains. The pollen grains were inaperturate and classified as small

and medium-sized. They were prolate-spheroidal, subprolate to prolate in shape. The surface of the exine was

microverrucate-orbiculate, perforate in Cephalotaxus harringtonia var. drupacea, granulate-orbiculate, perforate

in all Taxus taxa and granulate-microverrucate-orbiculate, perforate in Torreya. The orbicules were rounded to

oval in surface view, and the size was considerably diversified. The pollen features were insufficient to distinguish

between individual Taxus members – only groups were identified. The values of the coefficient of variability of

three features (LA, SA and LA/SA) were significantly lower than the orbicule diameter. The pollen surface of all

Taxus specimens was similar, so it was not a good identification criterion. The pollen grains of the Taxus taxa

were smaller and had more orbicules than Cephalotaxus and Torreya. Palynological studies provided taxonomic

support for recognition of two different genera of the Cephalotaxaceae and Taxaceae families, which are closely

related.

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Authors and Affiliations

Joanna Bykowska
Małgorzata Klimko
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Abstract

The present study aims to scrutinize teacher motivation in relation to two individual level predictors, namely, self -efficacy and burnout among English as a foreign language (EFL) teachers. To this end, 142 English as a foreign language (EFL) teachers were selected from various English language institutes of Mashhad and Tehran, two cities in Iran. They were requested to complete three questionnaires: the Maslach Burnout Inventory, the Teachers’ Sense of Efficacy Scale, and the Work Tasks Motivation Scale for Teachers. The findings obtained via SEM revealed that the proposed model had a good fit with the empirical data. In particular, it was found that job motivation contributed significantly to burnout depletion. It was also revealed that self -efficacy positively predicted job motivation, and burnout negatively influenced self -efficacy. However, self -efficacy surpassed motivation in predicting EFL instructors’ burnout. Results were discussed from both theoretical standpoints as well as previous empirical findings. Finally, implications were presented.
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Authors and Affiliations

Afsaneh Ghanizadeh
Nahid Royaei
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Abstract

Generally, the metallic implants do not exhibit any bio-integration properties in contact with bone tissues. To improve the interfacial properties of metallic implants in contact with bone, the coatings with thin biocompatible films are used. Two methods to coating titanium implants with hydroxyapatite are described. The first is a two phase method, where by cathodic polarization is deposed a monetite film followed by an alkaline treatment when the monetite is converted to hydroxyapatite. The second method is a biomimetic deposition on an alkaline activate titanium surface, using a five time more concentrated simulated body fluid (5xSBF). After deposition this samples was drying at 120℃ and was sintered at 700℃ for three hours. Optical microscopy, Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM) and Energy-dispersive X-ray (EDX) were used to characterize structure, morphology and compositions of the deposed films. In this study, electrochemical deposition and biomimetic deposition of hydroxyapatite are compared.
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Authors and Affiliations

M.C. Perju
1 2 3
ORCID: ORCID
C. Nejneru
1
ORCID: ORCID
P. Vizureanu
1 2 3
ORCID: ORCID
A.A. Aelenei
1
ORCID: ORCID
A.V. Sandu
1 2 3
ORCID: ORCID
L. Sachelarie
4
ORCID: ORCID
M. Nabiałek
5
ORCID: ORCID

  1. "Gheorghe Asachi” Technical University of Iasi, Faculty of Materials Science and Engineering, Prof. D. Mangeron Street, No. 41, 700050, Iasi, Romania
  2. Universiti Malaysia Perlis (UniMAP), Centre of Excellence Geopolymer and Green Technology (CEGeoGTech ), Perlis, Malaysia
  3. Romanian Inventors Forum, Sf. P. Movila 3, Iasi, Romania
  4. Apollonia University of Iasi, Faculty of Dentistry, PACURARI STREET, NO. 11, 700511, Iasi, Romania
  5. Częstochowa University of Technology, Department of Physics , 42-200 Częstochowa, Poland
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Abstract

Silver coatings have a very high reflection ability. To avoid their darkening from the hydrogen sulphide in the air, a thin layer of heat-resistant colorless lacquer is applied to the coatings. Silver plating is mainly used in jewelery, optics, electronics and electrical engineering. Depending on their application the thickness of the layer may vary from 2 to 24 μm. It can be done in several ways: chemical, electrochemical, contact, etc. The most common way of silver plating is the electrochemical deposition using cyanide and non-cyanide electrolytes. The cyanide electrolytes produce light, fine crystalline, dense and plastic coatings upon silver-plating. Usually silver coatings are applied with copper or nickel intermediate layer. In order to improve the de-oxidation of the aluminum surface new chemical treatment in acid – alkaline solution was applied. Our previous research shows that the presence of diamond nanoparticles in the electrolyte increase the metal deposition. Samples were prepared from electrolyte containing 10 g/l diamond nanoparticles. Their properties were compared to the properties of reference samples. The diamonds were obtained by detonation synthesis. The aim of this study is to obtain electrochemically deposited silver layer with high density, adhesion and electric conductivity on aluminum alloys substrate. The coatingwas directly plated without intermediate layer. Non-cyanide electrolyte composition and electrochemical parameters were determined in order to produce Ag coatings on Al alloy substrate without intermediate layer. The coating is with good adhesion, density and thickness of 14-23 μm.

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Authors and Affiliations

R. Valov
V. Petkov
S. Valkano
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Abstract

La0,7Ca0,3MnO3 polycrystalline were synthesized from La2O3, CaO and MnO2 powder mixture using a solid state reaction technique. The compound powders were obtained through the free sintering method at different temperatures and sintering times in order to study the influence of technological conditions on Ca doped La manganites. The most important physical features as structure, microstructure and morphology were described after X-ray diffraction investigation. Photographs of the specimen fractures were taken with SEM (scanning electron microscope) and they revealed high porosity of the tested material and great tendency for its grains to create agglomerates. Influence of doping and technological conditions on lattice parameters were studied by means of Rietvield analysis. The XRD measurements reveal that La0,7Ca0,3MnO3 has orthorhombic symmetry with Pnma space group.

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Authors and Affiliations

M. Bara
J. Dzik
ORCID: ORCID
K. Feliksik
L. Kozielski
B. Wodecka-Duś
ORCID: ORCID
T. Goryczka
ORCID: ORCID
A. Zarycka
M. Adamczyk-Habrajska
ORCID: ORCID
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Abstract

Plastics have become indispensable in everyday life due to their properties. For this reason, the accumulation of polymer waste in the natural environment is becoming a serious global problem. The aim of the research was to isolate microorganisms capable of biodegrading plastics. The studies focused on the biodegradation of low-density polyethylene as the most common polymer. Seven and five bacterial strains were isolated from the landfill and compost, respectively. The morphological and biochemical characteristics of the isolates were determined. These isolates were able to survive in an environment where the only carbon source was LDPE, but no increase in biomass was obtained. However, analysis of the spectra obtained by the ATR-FTIR method showed the formation of chemical changes on the polymer surface. Bacterial biofilm formation was visualized by scanning electron microscopy. The toxicity of plastic biodegradation products in a liquid environment was tested and their safety for plants was confirmed. However, these biodegradation products have acute lethal toxicity for the Daphnia magna.
LDPE films were pre-treated with H 2O 2, HNO 3, or heat. The biodegradation of HNO 3-treated LDPE by isolated bacteria was the most significant. The weight loss was approximately 8%, and 6%, for landfill and compost-isolated bacterial strains, respectively.
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Authors and Affiliations

Elżbieta Szczyrba
1
ORCID: ORCID
Tetiana Pokynbroda
2
ORCID: ORCID
Nataliia Koretska
2
ORCID: ORCID
Agnieszka Gąszczak
1
ORCID: ORCID

  1. Instytut Inżynierii Chemicznej Polskiej Akademii Nauk, ul. Bałtycka 5, 44-100 Gliwice, Poland
  2. Department of Physical Chemistry of Fossil Fuels of the Institute of Physical-Organic Chemistry and Coal Chemistry named after L.M. Lytvynenko of the National Academy of Sciences of Ukraine, Naukova str, 79060, Lviv, Ukraine
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Abstract

In this case ceramic layers from Metco ZrO2 and Al2O3 powders mixture (25/75; 50/50 and 75/25) were obtained through atmospheric plasma spraying (APS) after five passes on low carbon steel substrate. The sample surfaces mechanically grinded (160-2400) before and after ceramic layer deposition. Powder’s mixtures and the surface of ceramic thin layers were analyzed through: scanning electron microscopy (SEM). In order to understand the effect of surface wettability of the ceramic layers, before and after grinding the surface, three different liquids were used. Experimental results confirm the modification of the steel substrate surface characteristic from hydrophilic to hydrophobic when the ceramic layer was deposited. Surface free energy of hydration increases for all the samples with zirconia percentage addition before polishing process.
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Authors and Affiliations

M. Luțcanu
1 2
ORCID: ORCID
M. Coteață
3
ORCID: ORCID
M.A. Bernevig
1
ORCID: ORCID
C.D. Nechifor
2
ORCID: ORCID
M.M. Cazacu
2
ORCID: ORCID
P. Paraschiv
4
ORCID: ORCID
B. Istrate
5
ORCID: ORCID
G. Bădărău
1
ORCID: ORCID
I.G. Sandu
1
ORCID: ORCID
N. Cimpoeșu
1
ORCID: ORCID

  1. Gheorghe Asachi Technical University of Iasi, Faculty of Materials Science and Engineering, Prof.dr.doc. D. Mangeron no. 41 Street, 700050 Iasi, Romania
  2. "Gheorghe Asachi” Technical University of Iasi, Department of Physics, 700050 Iasi, Romania
  3. Gheorghe Asachi Tech Univ Iasi, Dept Machine Mfg Technol, 59A D Mangeron Blvd, Iasi 700050, Romania
  4. “Gheorghe Asachi” Technical University of Iasi, Department of Sport, 700050 Iasi, Romania
  5. Gheorghe Asachi Tech Univ Iasi, Fac Mech Engn 43 D Mangeron St, Iasi 700050, Romania
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Abstract

The results of structure observations of Ni base superalloy subjected to long-term influence of high pressure hydrogen atmosphere at 750K

and 850K are presented. The structure investigation were carried out using conventional light-, scanning- (SEM) and transmission electron

microscopy (TEM). The results presented here are supplementary to the mechanical studies given in part I of this investigations. The

results of study concerning mechanical properties degradation and structure observations show that the differences in mechanical

properties of alloy subjected different temperature are caused by more advanced processes of structure degradation during long-term aging

at 850K, compare to that at 750K. Higher service temperature leads to formation of large precipitates of δ phase. The nucleation and

growth of needle- and/or plate-like, relative large delta precipitates proceed probably at expense strengthening γ" phases. Moreover, it can't

be excluded that the least stable γ" phase is replaced with more stable γ' precipitates. TEM observations have disclosed differences in

dislocation structure of alloy aged at 750K and 850K. The dislocation observed in alloy subjected to 750K are were seldom observed only,

while in that serviced at high stress and 850K dislocation array and dislocation cell structure was typical.

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Authors and Affiliations

M. Kaczorowski
P. Skoczylas
A. Krzyńska
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Abstract

Detailed studies on the effects of pulsed laser interference heating on surface characteristics and subsurface microstructure of amorphous Fe80Si11B9 alloy are reported. Laser interference heating, with relatively low pulsed laser energy (90 and 120 mJ), but with a variable number (from 50-500) of consecutive laser pulses permitted to get energy accumulation in heated areas. Such treatment allowed to form two- Dimensional micro-islands of laser-affected material periodically distributed in amorphous matrix. The crystallization process of amorphous FeSiB ribbons was studied by means of scanning and transmission electron microscopy. Detailed microstructural examination showed that the use of laser beam, resulted in development of nanostructure in the heated areas of the amorphous ribbon. The generation of nanocrystalline seed islands created by pulsed laser interference was observed. This key result may evidently give new knowledge concerning the differences in microstructure formed during the conventional and lased induced crystallization the amorphous alloys. Further experiments are needed to clarify the effect of pulsed laser interference crystallization on magnetic properties of these alloys.
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Authors and Affiliations

J. Morgiel
R. Ostrowski
J. Kusiński
O. Czyż
A. Radziszewska
M. Strzelec
C. Czyż
A. Rycyk
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Abstract

Background: a humidity sensor is used to sense and measure the relative humidity of air. A new composite system has been fabricated using environmental pollutants such as carbon black and low-cost zinc oxide, and it acts as a humidity sensor. Residual life of the sensor is calculated and an expert system is modelled. For properties and nature confirmation, characterization is performed, and a sensing material is fabricated. Methodology: characterization is performed on the fabricated material. Complex impedance spectroscopy (CIS), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and scanning electron microscopy (SEM) are all used to confirm the surface roughness, its composite nature as well as the morphology of the composite. The residual lifetime of the fabricated humidity sensor is calculated by means of accelerated life testing. An intelligent model is designed using artificial intelligence techniques, including the artificial neural network (ANN), fuzzy inference system (FIS) and adaptive neuro-fuzzy inference system (ANFIS). Results: maximum conductivity obtained is 6.4×10⁻³ S/cm when zinc oxide is doped with 80% of carbon black. Conclusion: the solid composite obtained possesses good humidity-sensing capability in the range of 30–95%. ANFIS exhibits the maximum prediction accuracy, with an error rate of just 1.1%.

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Authors and Affiliations

C. Bhargava
J. Aggarwal
P.K. Sharma
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Abstract

The paper presents the results and provides an analyse of the geometric structure of Fe-Al protective coatings, gas-treated under specified GDS conditions. The analysis of the surface topography was conducted on the basis of the results obtained from the SEM data. Topographic images were converted to three-dimensional maps, scaling the registered amplitude coordinates of specific gray levels to the relative range of 0÷1. This allowed us to assess the degree of surface development by determining the fractal dimension. At the same time, the generated three-dimensional spectra of the autocorrelation function enabled the researchers to determine the autocorrelation length (Sal) and the degree of anisotropy (Str) of the surfaces, in accordance with ISO 25178. Furthermore, the reconstructed three-dimensional images of the topography allowed us to evaluate the functional properties o the studied surfaces based on the Abbott-Firestone curve (A-F), also known as the bearing area curve. The ordinate describing the height of the profile was replaced by the percentage of surface amplitude in this method, so in effect the shares of the height of the three-dimensional topographic map profiles of various load-bearing properties were determined. In this way, both the relative height of peaks, core and recesses as well as their percentages were subsequently established.

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Authors and Affiliations

T. Chrostek
K. Rychlik
M. Bramowicz
C. Senderowski
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Abstract

In the work five ceramic compounds based on the (K0.44Na0.52Li0.04)NbO3 (KNLN) material modified with oxides: Cr2O3, ZnO, Sb2O3 or Fe2O3 (in an amount of 0.5 mol.%) were obtained. The KNLN-type composition powder was prepared by solid phase synthesis from a mixture of simple oxides and carbonates, while compacted of the ceramic samples was conducted by free sintering methods. In the work the effect of the used admixture on the electrophysical properties of the KNLN ceramics was presented. The XRD, EDS tests, the SEM measurements of the morphology ceramic samples, dielectric properties and DC electric conductivity were conducted. The research showed that the used admixtures introduced into the base of KNLN-type composition improve the microstructure of the ceramic samples and improve their sinterability. In the case of the dielectric measurements, it was observed a decrease in the maximum dielectric permittivity at the TC for dopred KNLN-type samples. The addition of an admixture of chromium, zinc, antimony or iron in an amount of 0.5 mol.% to the base composition (K0.44Na0.52Li0.04)NbO3 practically does not change the phase transition temperature. The diminution in the density value of doped KNLN ceramics was attributed to the alkali elements volatilization.

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Authors and Affiliations

D. Bochenek
K. Osińska
P. Niemiec
M. Adamczyk
T. Goryczka
R. Szych
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Abstract

ZnO thin layers were deposited on p-type silicon substrates by the sol-gel spin-coating method and, then, annealed at various temperatures in the range of 573–873 K. Photoluminescence was carried out in the temperature range of 20–300 K. All samples showed two dominant peaks that have UV emissions from 300 nm to 400 nm and visible emissions from 400 nm to 800 nm. Influence of temperature on morphology and chemical composition of fabricated thin layers was examined by XRD, SEM, FTIR, and Raman spectroscopy. These measurements indicate that ZnO structure is obtained for samples annealed at temperatures above 573 K. It means that below this temperature, the obtained thin films are not pure zinc oxide. Thus, annealing temperature significantly affected crystallinity of the thin films.

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Authors and Affiliations

M. Sypniewska
R. Szczesny
P. Popielarski
ORCID: ORCID
K. Strzalkowski
B. Derkowska-Zielinska
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Abstract

In this paper, the microstructural and texture changes in polycrystalline CuZn30 alloy, copper, and AA1050 aluminium alloy have been studied to describe the crystal lattice rotation during shear bands formation. The hat-shaped specimens were deformed using a drop-hammer at the strain rate of 560 s –1. Microstructure evolution was investigated using optical microscopy, whereas texture changes were examined with the use of a scanning electron microscope equipped with the EBSD facility. The microstructural observations were correlated with nanohardness measurements to evaluate the mechanical properties of the sheared regions. The analyses demonstrate the gradual nature of the shear banding process, which can be described as a mechanism of the bands nucleation and then successive growth rather than as an abrupt instability. It was found that regardless of the initial orientation of the grains inside the sheared region, a well-defined tendency of the crystal lattice rotation is observed. This rotation mechanism leads to the formation of specific texture components of the sheared region, different from the one observed in a weakly or non-deformed matrix. During the process of rotation, one of the {111} planes in each grain of the sheared region ‘tends’ to overlap with the plane of maximum shear stresses and one of the <110> or <112> directions align with the shear direction. This allows slip propagation through the boundaries between adjacent grains without apparent change in the shear direction. Finally, in order to trace the rotation path, transforming the matrix texture components into shear band, rotation axis and angles were identified.
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Authors and Affiliations

I. Mania
1
ORCID: ORCID
H. Paul
1
ORCID: ORCID
R. Chulist
1
ORCID: ORCID
P. Petrzak
1
ORCID: ORCID
M. Miszczyk
1
ORCID: ORCID
M. Prażmowski
2
ORCID: ORCID

  1. Polish Academy of Sciences, Institute of Metallurgy and Materials Science, 25 Reymonta Str., 30-059 Krakow, Poland
  2. Opole University of Technology, Faculty of Mechanics, 76 Prószkowska Str., 45-758 Opole, Poland
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Abstract

The paper addresses the microsegregation of Mn, Mo, Cr, W, V, Si, Al, Cu and P in the white cast iron. Eutectic alloy with the content of 4.25% C was studied. The white cast iron was directionally solidified in the vacuum Bridgman-type furnace at a constant pulling rate v = 83 μm/s and v = 167 μm/s and at a constant temperature gradient G = 33.5 K/mm. The microstructural research was conducted using light and scanning electron microscopy. The microsegregation of elements in ledeburite was evaluated by EDS measurements. Content of elements in ledeburitic cementite and ledeburitic pearlite was determined. The tendency of elements to microsegregation was found dependent on the solidification rate. Microsegregation of elements between pearlite and cementite structural constituents has been specified. The effect of solidification rate on the type and intensity of microsegregation in directionally solidified eutectic white cast iron was observed. A different type of microsegregation was observed in the components of ledeburite in cementite and pearlite.
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Bibliography

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Authors and Affiliations

M. Trepczyńska-Łent
1
ORCID: ORCID
J. Seyda
1
ORCID: ORCID

  1. Bydgoszcz University of Science and Technology, Poland
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Abstract

Dokra casting is famous for its Artistic value to the world but it is also sophisticated engineering. The technique is almost 4500 years old. It is practiced by the tribal artisans of India. It is a clay moulded wax-based thin-walled investment casting technique where liquid metal was poured into the red hot mould. Dimensional accuracy is always preferable for consumers of any product. Distortion is one of the barriers to achieving the accurate dimension for this type of casting especially for the bending parts. The cause and nature of the distortion for this type of casting must be analyzed to design a product with nominal tolerance and dimensional accuracy.
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Bibliography

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Authors and Affiliations

R. Mandal
1
S. Roy
2
ORCID: ORCID
S. Sarkar
1
T. Mandal
3
A.K. Pramanick
2
G. Majumdar
1

  1. Mechanical Engineering Department, Jadavpur University, India
  2. Metallurgical and Material Engineering Department, Jadavpur University, India
  3. Metallurgy and Materials Engineering, IIEST Shibpur, India
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Abstract

In this paper, detailed characterization of the oxide scale, grown on the Inconel 686 coating after high-temperature oxidation at 650°C in ashes from waste incineration power plant was performed. Phase composition, morphology, microstructure and chemical composition of the oxide scale were investigated using XRD and SEM analysis. Mechanisms of formation and growth of oxide scales were examined, resulting in the insights into oxidation kinetics. Results revealed presence of NiO in the outermost layer of the oxide scale. At the bottom of oxide scale, CrNi2O4 spinel layers were formed due to the increasing concentration of Cr. In the middle area of oxide scale, due to higher concentration of Cr and lower amount of Ni, the Cr2NiO4 spinel is formed. The innermost layer was composed of Cr2O3.
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Authors and Affiliations

M. Solecka
1
ORCID: ORCID
B. Rutkowski
2
ORCID: ORCID
A. Kopia
2
ORCID: ORCID

  1. Institute of Metallurgy and Materials Science, Polish Academy of Sciences, 25 Reymonta Str., 30-059 Krakow, Poland
  2. AGH University of Science and Technology, Faculty of Metals Engineering and Industrial Computer Science, Al. A. Mickiewicza 30, 30-059 Kraków, Poland
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Abstract

In this paper, study the preparation of Y-Fe alloy by reduction-diffusion process, which is novel technique for producing an alloy from its ores directly at different temperatures. From this work, investigates the particles size and morphology structure of alloy by X-Ray Diffraction (XRD), Energy dispersive-X-ray analyzer (EDAX) and Scanning Electron Microscope (SEM) respectively. Here study the thermodynamics of property of system such as Gibbs free energy and reaction kinetics of system respectively. The Vibrating Sample magnetometer (VSM) is used to study the magnetic properties of alloy such as cocerviety, saturation magnetization and retentivity.

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Authors and Affiliations

Marimuthu Ilayaraja
L. John Berchmans
Sankara Raman Sankaranarayan
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Abstract

In the present work, Hydroxyapatite synthesis was carried out using hydrothermal method with calcium nitrate tetrahydrate (Ca(NO 3) 2.4H 2O) and fosfor pentaoksit (P 2O 5) as precursors. For the hydrothermal method, constant reaction temperature (180°C) and different reaction times (6 hours, 12 hours, 18 hours and 24 hours) were determined. The samples produced were divided into two groups. Four samples were not heat treatment; four samples were heat treatment at 700°C for 1 hour. The obtained products were characterized by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) techniques, X-ray diffraction (XRD) and UV-Vis spectrometer. SEM photos showed that the Hydroxyapatite powders produced are in the form of the agglomerate. According to EDS results, Hydroxyapatite samples are of high purity. XRD’s findings confirm that the diffraction peaks correspond to the pure phase of Hydroxyapatite. A general decrease was observed in the energy band gap of the samples with increasing hydrothermal reaction time.
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Authors and Affiliations

Nida Kati
1
ORCID: ORCID
Sermin Ozan
1
ORCID: ORCID
Tülay Yildiz
1
ORCID: ORCID
Mehmet Arslan
1
ORCID: ORCID

  1. Fırat Unıversity, Faculty of Technology, Metallurgical and Materials Engineering Department, 23200, Elazığ, Turkiye

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