Search results

1

Synthesis of hydroxyapatite by using calcium carbonate and phosphoric acid in various water-ethanol solvent systems

100%

Engin A., Girgin İ.

Open Chemistry

|

2009

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vol. 7

|

issue 4

745-751

EN

The purpose of the present study is to synthesize hydroxyapatite by using CaCO3 and H3PO4 in various water-ethanol solvent systems. It was observed from experiments that formation of ammonium phosphate compounds hindered the formation of calcium phosphates in ethanol medium. Although the reactivity was better in aqueous medium, the carbonate contents of the products obtained were above 8.5%. Best results with a carbonate content as low as 3.82% was obtained in 50% ethanol containing mixed-aqueous medium at 80°C and the FTIR analysis showed that the product was a carbonated apatite with a calculated composition of 14CaO·4.2P2O5·CO3·7.2H2O. The amorphous and porous phosphate compound obtained with a BET surface area of 106.6 m2 g−1 seems to be useful as adsorbent in wastewater treatment. Upon sintering of the amorphous product at 750°C, crystalline hydroxyapatite with a BET surface area of 25.9 m2 g−1 is obtained that may be used in biomedical applications. [...]

2

Subsolidus area of the system CdO - V2O5 - Fe2O3

100%

Blonska-Tabero A.

Open Chemistry

|

2009

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vol. 7

|

issue 2

252-258

EN

Phase diagrams in the subsolidus area of the systems FeVO4 - CdO and FeVO4 - Cd2V2O7 have been deduced using the results of XRD and DTA analyses. On the basis of these diagrams and some additional verifying research, a projection of the subsolidus area of the CdO - V2O5 - Fe2O3 system onto the plane that comprises the components’ concentration triangle has been presented. The H-type phase is the only phase formed in this system. It co-exists at equilibrium with other phases in six subsidiary subsystems. [...]

3

Badania meteorytu Odessa przy użyciu nowoczesnych technik inżynierii materiałowej

100%

Ferdzyn J., Gołdyn P., Kędzierski Ł., Radaszkiewicz A., Sroczyńska A., Jędrzejczak-Gruszczyńska A., Makówka M., Karczemska A.

Acta Societatis Metheoriticae Polonorum

|

2017

|

vol. 8

40-51

EN

Odessa iron meteorite was investigated with scanning electron microscopy (SEM), Raman spectroscopy and X-ray diffraction (XRD) techniques. The research has shown the existence of minerals such as schreibersite, troilite, taenite, kamacite, cohenite, graphite and diamond in the examined sample. Raman spectroscopy allowed to identify different allotropic forms of carbon, which is diamond and graphite with different levels of order.

4

Structural and Optical Properties of ZnO and Co Doped ZnO Thin Films Prepared by Sol-Gel

100%

Khantoul A., Sebais M., Rahal B., Boudine B., Halimi O.

Acta Physica Polonica A

|

2018

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vol. 133

|

issue 1

114-117

EN

We report on ZnO films doped with different Co concentrations (0, 0.5, and 1 wt%) prepared by sol-gel technique in association with dip-coating onto glass substrates. Zinc acetate dehydrate, cobalt acetate, mono ethanolamine were used as starting materials, as well as solvent and stabilizer, respectively. Nanostructured polycrystalline ZnO thin films with different concentrations of Co doping (0, 0.5, and 1 wt%) are prepared for the first time by the sol-gel method and annealed at 500°C for 1 h. The surface morphologies of the ZnO thin films deposited on glass substrate with different concentrations were evaluated by atomic force microscopy. The optical absorption of the films showed a blue shift of the band gap. The photoluminescence signal of the thin films of undoped and Co-doped ZnO presents different bands in the visible region. The electrical conductivity of the sample with 0.5%Co was found to be 4.62 (ΩCm)¯¹.

5

Synthesis and Characterization of Manganese Sulphide Thin Films by Chemical Bath Deposition Method

100%

Geetha G., Murugasen P., Sagadevan S.

Acta Physica Polonica A

|

2017

|

vol. 132

|

issue 4

1221-1226

EN

Manganese sulphide (MnS) thin films were prepared by chemical bath deposition method. X-ray diffraction analysis was used to study the structure and the crystallite size of MnS thin films. The grain size and the surface morphology were studied using scanning electron microscopy. The optical properties were studied using the UV-visible absorption spectrum. The dielectric properties of MnS thin films were studied for different frequencies and different temperatures. Further, electronic properties, such as valence electron plasma energy, average energy gap or the Penn gap, the Fermi energy and electronic polarizability of the MnS thin films were calculated. The ac electrical conductivity study revealed that the conduction depended both on the frequency and the temperature. The temperature dependent conductivity study confirmed the semiconducting nature of the films.

6

Silver selenide modification of polyamide fabric

88%

Milašienė D., Ivanauskas R.

Open Chemistry

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2013

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vol. 11

|

issue 12

1976-1980

EN

Formation of a silver selenide layer on silicone coated polyamide cloth was investigated. Fabric samples were selenized in potassium selenotrithionate (K2SeS2O6) solution then treated with AgNO3 solution. Formation of a silver selenide particle layer on the surface was confirmed by a change in appearance, X-ray diffraction, and EDX analysis. XRD revealed two phases: orthorhombic naumannite (Ag2Se) and monoclinic selenium (Se8). SEM showed that the fabric macrostructure and the multifilament yarn microstructure was preserved. The silver selenide particles ranged from 100 nm to more than 20 µm. [...]

7

pH Dependent Degradation and Characterization of Geopolymer Structures Derived from Fly Ash

88%

Şahbudak K.

Acta Physica Polonica A

|

2017

|

vol. 131

|

issue 3

379-381

EN

Geopolymer structures are a relatively new family of un-fired ceramics that are produced by alkaline slurry of mixed alumina silicate-based materials. One of the most abundant geopolymer-forming powders is the fly ash. Fly ash is a waste product of thermic coal plants, which produce electricity by coal burning. Fly ashes contain mostly Ca, Al, Si and Fe oxide mixtures and compounds formed during the burning process, followed by sedimentation. The standardization is made by SiO₂ content. Class C ash has low silica content (<50 wt.%) and class F ash has a higher silica content (>50 wt.%). The fly ash, studied in this work, was obtained from Kangal Coal Plant. The NaOH was used as the geopolymer binder and curing was performed at 80% relative humidity, at 40°C in sealed plastic molds. The obtained cylinders were aged for one week before releasing from molds. pH dependent degradation was used to determine the ionic exchange of geopolymers into the solution. Afterwards, XRD and SEM were done to detect the structural changes of geopolymers.

8

Mechanochemical synthesis of some europium diketonates

88%

Zaharieva J., Milanova M., Todorovsky D.

Open Chemistry

|

2011

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vol. 9

|

issue 2

290-299

EN

Results on the influence of mechanoactivation (3–30 min) in a planetary ball mill on the composition, crystal structure, IR spectra and morphology of EuCl3·6H2O, dibenzoylmethane (HDBM) and mixtures of EuCl3·6H2O - HDBM and EuCl3·6H2O - HDBM - 1,10-phenathroline (phen) are presented. Mechanoactivation leads to a decrease of interplanar distances of the EuCl3·6H2O and HDBM and partial synthesis of Eu(DBM)3 and Eu(DBM)3·phen in the respective mixtures. The fluorescence properties of the products of activation (excitation and emission spectra, lifetime of the excited states) are similar to those of the complexes produced by the conventional “wet” methods, but the strongest excitation of the mechanochemically produced solid state samples is achieved at higher wavelength. Crystals of different forms (prismatic, needle-, long-length-leaf- and rod-like) are formed by mechanoactivation of the mentioned mixtures.

9

Remarks on a specimen of the ‘Gardnos breccia’, Norway

88%

Kosina R., Madej S.

Acta Societatis Metheoriticae Polonorum

|

2020

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vol. 11

45-59

EN

A specimen of the ‘Gardnos breccia’ was explored, in which granitic gneiss clasts were found to dominate over a dark matrix. Some clasts retained their cataclastic structure. The matrix of the specimen showed various colours, such as gray, black, and beige, while exhibiting different levels of hardness. In addition, the matrix appeared as an almost isotropic and microcrystalline mass. Quartz, K-feldspar, biotite and plagioclase were identified as the main minerals of the rock. No impact-generated features were observed in the minerals; however, biotite crystals showed decorated kinky bands. In cataclastic clasts, a net of black micro-veins was found, which can be interpreted as pseudotachylite. These veins were composed of a dark non-cohesive glassy mass and carbonaceous micro-aggregates. Furthermore, such carbonaceous aggregated particles were also observed in the black matrix. The white-greenish domains containing isotropic and microcrystalline aggregates of quartz and feldspars showed partial anisotropy. Domains were surrounded by a light recrystallising polycrystalline quartz. Hard black clasts of the matrix and the white-greenish domains showed great similarity in their mineral composition. The results of the X-ray diffraction analyses revealed the minerals as quartz, K-feldspar, muscovite and chlorite (clinochlore). In the white-greenish domains, albite was found as an additional component, whereas it was absent in the black matrix. The black matrix, which was interpreted as a pseudotachylite relic, also seemed to contain allochthonic components. Fluorite, calcite, and Fe-oxides were identified as the secondary minerals that were crystallised in the free spaces of the rock, filling the voids and cracks during the postimpact stage. Oriented glassy spherules, fragments with fluidal texture, and a fragment of the semi-vesicular glassy domain were noted in the specimen, which were probably relics of the suevite breccia. Thus, the analysed breccia seemed to be an intermediate type between the ‘Gardnos breccia’ and the black-matrix breccia and suevite.

PL

Uwagi o okazie ‘brekcji Gardnos’, Norwegia. W egzemplarzu skały znanej jako ‘brekcja Gardnos’ klasty granito-gnejsu dominują nad ciemną matriks. Niektóre klasty zachowały strukturę kataklastyczną. Matriks wykazywała różne kolory, szary, czarny i beżowy, a także różną twardość. Matriks była głównie masą izotropową i mikrokrystaliczną. Kwarc, K-skaleń, biotyt i plagioklaz są głównymi minerałami skały. W minerałach nie zaobserwowano struktur charakterystycznych dla impaktu, jednak w kryształach biotytu odnotowano dekorowane spękania ‘kinky’. W klastach kataklastycznych sieć czarnych mikrożyłek można interpretować jako pseudotachylit. Te żyły składają się z ciemnej, niespoistej szklistej masy, w tym z węglistych mikroagregatów. Zagregowane takie cząstki zaobserwowano również w macierzy czarnej. Biało-zielonawe domeny mikrokrystalicznych agregatów kwarcu i skaleni wykazały częściową anizotropię w partiach izotropowych. W domenach, zielonawe centra stopu skaleniowego otoczone są jasnym, rekrystalizującym polikrystalicznym kwarcem. Twarde czarne klasty macierzy i biało-zielonawe domeny charakteryzują się dużym podobieństwem w składzie minerałów. Analizy dyfrakcji rentgenowskiej wykazały, że były to kwarc, K-skalenie, muskowit i chloryt (klinochlor). W biało-zielonawych domenach dodatkowo występuje albit, nieobecny w czarnej macierzy. Macierz ta interpretowana jako relikt pseudotachylitu zawiera prawdopodobnie również składniki allochtoniczne. Fluoryt, kalcyt i tlenki żelaza były minerałami wtórnymi krystalizowanymi w wolnych przestrzeniach skały i wypełniały puste przestrzenie i pęknięcia w procesach poimpaktowych. Zorientowane szkliste sferule, fragmenty o fluidalnej teksturze i fragment szklistej domeny semi-pęcherzykowej są prawdopodobnie reliktami brekcji suevitu. Analizowana brekcja wydaje się być typem pośrednim między ‘brekcją Gardnos’ a brekcją z czarną matriks i suevitem.

10

Trynityt – wstępne dane SEM oraz XRD szkliwa nuklearnego z USA

88%

Brachaniec T., Szopa K., Krzykawski T., Broszkiewicz A.

Acta Societatis Metheoriticae Polonorum

|

2015

|

vol. 6

38-41

EN

Trinitite is a glass produced as a result of a nuclear explosion. The characteristic feature of the investigated material are bubbles and presence of incompletely melted quartz grains.

11

Microwave-induced combustion synthesis and characterization of NixCo1−xFe2O4 nanocrystals (x = 0.0, 0.4, 0.6, 0.8, 1.0)

88%

Baykal A., Kasapoğlu N., Köseoğlu Y., Başaran A., Kavas H., Toprak M.

Open Chemistry

|

2008

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vol. 6

|

issue 1

125-130

EN

A series of Ni-doped cobalt ferrites NixCo1−xFe2O4 (x = 0.0, 0.4, 0.6, 0.8, and 1.0) were prepared using microwave-induced combustion. Nickel, cobalt, and ferric nitrates were used as starting materials and glycine as fuel. The influence of Ni content on the lattice parameter, stretching vibrations, and magnetization was studied. XRD, FTIR, and SEM were used for structure, composition, and morphology investigation. A porous network structure was observed with average particle size 60–67 nm. All samples had a cubic spinel structure. The unit cell parameter “a” decreases linearly with nickel concentration due to the smaller ionic radius of nickel. Magnetization measurements showed that coercivity decreased as Ni content increased; it increased with decreasing temperature. [...]

12

Effects of mechanical activation on structure and photocatalytic properties of ZnO powders

88%

Gancheva M., Iordanova R., Dimitriev Y., Avdeev G., Iliev T.

Open Chemistry

|

2013

|

vol. 11

|

issue 11

1780-1785

EN

Zinc oxide (ZnO) was mechanically activated in air using a planetary ball mill using varying milling speeds and time. The obtained samples were analyzed by X-ray diffraction analysis (XRD), scanning electron microscopy (SEM) and UV-Vis diffusion reflectance spectroscopy. The photocatalytic activity of the mechanically treated ZnO powders were investigated in the reaction of Malachite Green (MG) degradation in aqueous solution under UV-light irradiation. A decrease in the crystallite size (from 90 to 10 nm) accompanied by an increase of microstrains and lattice parameters were established applying different milling speeds. The agglomeration of the particles was observed by SEM analysis. The absorption spectra of the initial and mechanically activated ZnO samples show shifting of the band position from 360 to 330 nm, which can be related to decrease in the crystalline size. The ZnO powders activated at lower milling speeds (for shorter time intervals) exhibit highest photocatalytic activity. [...]

13

ESR and XRD investigation of effects induced by gamma radiation on PVA-TiO2 membranes

88%

Todica M., Stefan T., Trandafir D., Simon S.

Open Physics

|

2013

|

vol. 11

|

issue 7

928-935

EN

The effects of gamma radiation on the local structure of PVA membranes containing TiO2 were investigated by ESR and XRD methods. An intense ESR signal is observed after irradiation at 16 KGy dose. This signal appears only for irradiated samples and it is associated with the breaking of the polymeric chain, followed by local reorganization of the polymeric segments and the apparition of the unpaired electrons and free radicals. The intensity of the signal decreases with the concentration of TiO2, indicating a shielding effect of the dopand. That the modification of local order of the polymeric chains has been modified after irradiation is confirmed by XRD method.

14

Comparison characterization of copper selenide thin layers prepared on polyamide 6 films by sorption-diffusion method

88%

Ivanauskas R., Janickis V., Jasulaitienė V.

Open Chemistry

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2013

|

vol. 11

|

issue 4

636-643

EN

Some earlier synthesized copper selenide (Cux Se) layers formed on the surface of polyamide 6 by sorption-diffusion method using potassium selenotrithionate (K2SeS2O6) as precursor of selenium were characterized by the XRD, XPS and SEM methods. According to the results of the SEM studies, the most uniform Cux Se layers form at the 2.5 h polyamide seleniumized duration at the temperature of 60°C. The thickness of layers, which dependeds on the duration of seleniumization, changed in the range of 0.8–3.2 µm. The XRD patterns of not previously studied Cux Se layers showed their phase composition of six copper selenides: Cu2Se, two phases of CuSe2, Cu3Se2, berzellianite, Cu2-x Se, and bellidoite Cu2Se. Analysis of the XRD and XPS data shows that the macrostructure and composition of the CuxSe layers depend on the conditions of formation of these layers. [...]

15

Kinetics of the High Temperature Oxidation of the Inconel 686 Coatings in the Waste Incineration Ash

88%

Solecka M., Rutkowski B., Kopia A., Solecka M., Rutkowski B., Kopia A.

Archives of Metallurgy and Materials

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2021

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vol. 66

|

issue 4

16

Low temperature synthesis and characterization of Mn3O4 nanoparticles

88%

Baykal A., Köseoğlu Y., Şenel M.

Open Chemistry

|

2007

|

vol. 5

|

issue 1

169-176

EN

Heating hydrous manganese (II) hydroxide gel at 85 °C for 12 hours produces Mn3O4 nanoparticles. They were characterized by X-ray powder diffraction (XRD) and infrared spectroscopy (FTIR). The particle size estimated from the SEM and X-ray peak broadening is approximately 32 nm, showing them to be nanocrystalline. EPR measurements confirm a typical Mn2+signal with a highly resolved hyperfine structure. [...]

17

BOX BEHNKEN DESIGN: A STATISTICAL APPROACH TO EVALUATE THE EFFECT OF CROSSLINKED CARBOXYMETHYL CELLULOSE AND SODIUM STARCH GLYCOLATE ON RELEASE KINETICS OF DRUG

75%

Hanif M., Abbas G., Rasul A., Khan S. M., Amir M. N.

Acta Poloniae Pharmaceutica - Drug Research

|

2018

|

vol. 75

|

issue 4

965-975

EN

The aim of study was to evaluate the release kinetics of domperidone maleate (DM) from immediate release (IR) tablets prepared by wet granulation method. Box behnken design (BBD) was used to optimize and evaluate the main, interaction and quadratic effects of independent variables i.e. crosslinked carboxymethyl cellulose (CMC) (X1), sodium starch glycolate (SSG) (X2) and starch (X3) on responses R2 of first order (YI) and β value of weibull model (Y2). Prepared tablets were characterized by various physical tests, in-vitro drug release, fourier transform infrared spectroscopy (FTIR), X-ray diffractometry (XRD) and differential scanning calorimetry (DSC). Accelerated stabilities studies were performed on optimized formulation D9. Y1 and Y2 were ranged from 0.9959 to 0.9994 and 0.041 to 0.912 respectively. β value of weibull model indicated the parabolic shape of dissolution curve. The quadratic model fit the data well and the resulting equations were used to predict the responses in the box behnken design. FTIR spectra showed the compatibility of DM with CMC and SSG. XRD presented diffraction lines indicates crystalline nature of drug. DSC thermograms indicated endothermic peak at 220 0C for DM. Stabilities studies revealed that no significant change in hardness, friability, disintegration time and dissolution release profile of DM. It is concluded that a combination of CMC and SSG can be used to enhance the dissolution and release kinetics of IR tablets of DM.

18

Synthesis, morphology and specific magnetization of the electrodeposited Zn-Ni-P thin films on copper substrate from non-cyanide electrolyte

75%

Popescu A., Yanuskevich K., Demidenko O., Calderon Moreno J., Neacşu E., Constantin V.

Open Chemistry

|

2013

|

vol. 11

|

issue 7

1137-1149

EN

Thin films of Zn-Ni-P on a copper substrate were synthesized by electrodeposition from chloride baths. It was found that the diffraction reflections of the crystal structure of Zn-Ni-P thin layers occur at thicknesses d ≥ 5 µm. The X-ray diffraction studies results confirm the formation in the Zn-Ni-P films of ZnNi10P3 compound. The morphology of the obtained films was analyzed by Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray Spectrometry (EDS). The films are continuous and have a typical topography with many homogeneous globular features. EDS confirmed the formation of Zn-Ni-P coating only in 2 samples with Zn:Ni:P atomic ratios of 1:8:4 and 4:8:3, respectively. X-ray Photoelectron Spectroscopy (XPS) revealed the chemistry and the thickness of the studied thin films. At room temperature and thickness d ≥ 5 µm the investigated thin layers exhibit high values of the specific magnetizations in the range (25–37) A m2 kg−1, leading to the potential use in devices, appliances and electronics. The Curie temperature values of the synthesized Zn-Ni-P films were determined. It was found that by heating Zn-Ni-P thin layers of thicknesses d ≥ 5 µm up to a temperature T=900 K an interaction was detected with the copper substrate leading to a lower specific magnetization. [...]

19

Thermal Effect of Er³⁺ Ions Embedded in Smart Nano-Composite Oxide Material Prepared by Sol-Gel Technique

75%

Battisha I., Ayoub M., Hashem A., Ahmed E., Amin A.

Acta Physica Polonica A

|

2017

|

vol. 132

|

issue 4

1277-1283

EN

The phosphosilicate for planar waveguides fabrication by using sol-gel, and particularly erbium-doped waveguide amplifiers, is reviewed. In particular, efforts to use sol-gel to improve molecular homogeneity in Er-doped phosphosilicate-based monolith and thin films will be discussed. A variety of material studies was carried out to investigate and optimize the sample preparation condition for such application. These include X-ray diffraction, the Fourier transform infrared and optical transmittance, absorption and refractive index calculation. The erbium nitrate precursors use is shown to alter the Er³⁺ ions doping in the prepared samples thermally treated in the final monolith glass form, in comparison to the use of thin film phosphosilicate sol-gel sample. Excess heat treatment is used to force prepared samples crystallization, moreover resulting photoluminescence analysis is used to detect the co-operative-up-conversion sample properties before and after heating.

20

Mechanism and Synthesis of Yttrium Iron (Y-Fe) Alloy by Low Temperature Process Using Calcium as Reductant

75%

Ilayaraja M., John B. L., Sankaranarayan S. R., Ilayaraja M., John B. L., Sankaranarayan S. R.

Archives of Metallurgy and Materials

|

2019

|

vol. 64

|

issue 4

Refine search results

Synthesis of hydroxyapatite by using calcium carbonate and phosphoric acid in various water-ethanol solvent systems

Subsolidus area of the system CdO - V2O5 - Fe2O3

Badania meteorytu Odessa przy użyciu nowoczesnych technik inżynierii materiałowej

Structural and Optical Properties of ZnO and Co Doped ZnO Thin Films Prepared by Sol-Gel

Synthesis and Characterization of Manganese Sulphide Thin Films by Chemical Bath Deposition Method

Silver selenide modification of polyamide fabric

pH Dependent Degradation and Characterization of Geopolymer Structures Derived from Fly Ash

Mechanochemical synthesis of some europium diketonates

Remarks on a specimen of the ‘Gardnos breccia’, Norway

Trynityt – wstępne dane SEM oraz XRD szkliwa nuklearnego z USA

Microwave-induced combustion synthesis and characterization of NixCo1−xFe2O4 nanocrystals (x = 0.0, 0.4, 0.6, 0.8, 1.0)

Effects of mechanical activation on structure and photocatalytic properties of ZnO powders

ESR and XRD investigation of effects induced by gamma radiation on PVA-TiO2 membranes

Comparison characterization of copper selenide thin layers prepared on polyamide 6 films by sorption-diffusion method

Kinetics of the High Temperature Oxidation of the Inconel 686 Coatings in the Waste Incineration Ash

Low temperature synthesis and characterization of Mn3O4 nanoparticles

BOX BEHNKEN DESIGN: A STATISTICAL APPROACH TO EVALUATE THE EFFECT OF CROSSLINKED CARBOXYMETHYL CELLULOSE AND SODIUM STARCH GLYCOLATE ON RELEASE KINETICS OF DRUG

Synthesis, morphology and specific magnetization of the electrodeposited Zn-Ni-P thin films on copper substrate from non-cyanide electrolyte

Thermal Effect of Er³⁺ Ions Embedded in Smart Nano-Composite Oxide Material Prepared by Sol-Gel Technique

Mechanism and Synthesis of Yttrium Iron (Y-Fe) Alloy by Low Temperature Process Using Calcium as Reductant