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Solid-state reaction between BaTiO3 and Fe2O3 was used to produce a multiferroic heterostructure composite. Commercial BaTiO3 and Fe(NO3)3•9H2O were suspended in ethanol for 30 minutes in an ultrasound bath. The prepared mixture was thermally processed at 300°C for 6 h. Sintering at 1300°C for 1 h resulted in a mixture of different phases, BaTiO3, BaFe12O19 and Ba12Ti28Fe15O84, which were confirmed by x-ray powder diffraction. A dense microstructure with a small volume fraction of closed porosity was indicated by the scanning electron microscopy, while a homogeneous distribution of Fe ions over BaTiO3 phase was visible from energy dispersive spectroscopy mapping. Doping of BaTiO3 with Fe2O3 resulted in formation of magnetic hexaferrite phases, as confirmed by dielectric measurements that showed a broadened maximum of the permittivity measured as a function of temperature.

Barium titanate (BaTiO3) attracts high scientific and technological attention due to good dielectric and electromechanical properties. Although BaTiO3 is one of the most frequently investigated ferroelectric materials, the need for finding new and/or improved synthesis methods of this material still exists. In this paper, a novel, mild synthesis route for producing tetragonal BaTiO3 from barium nitrate and Ti-oxalate precursor is presented. Morphology of the prepared and subsequently sintered BaTiO3 was determined by SEM. Particle size distribution of the as prepared powder was monitored by the laser diffraction. The phase composition, structure and lattice dynamics were investigated by XRD and Raman spectroscopy. Finally, dielectric parameters were determined in the temperature range from 30 to 180ºC, and within a variety of frequencies. Curie temperature was detected at 130ºC.

Due to its characteristics, cordierite, 2MgO·2Al2O3·5SiO2, is a high-temperature ceramic material of a great scientific interest. Mechanical activation of the starting mixtures containing 5.00 mass% TiO2 was performed in a high-energy ball mill for 10 minutes. The compaction pressure varied from 0.5 to 6tcm-2 (49-588 MPa). The sintering process was performed at 1350ºC for four hours in the air atmosphere. The phase composition of the activated and sintered samples was analyzed using X-ray diffraction. Scanning electron microscopy was used to analyze the microstructure of both compacted and sintered samples. The authors have investigated the influence of compaction pressure on the sintered samples and their electrical properties.

Beyond traditional risk factors, inflammation is believed to play a role in the development of ischemic stroke (IS). During inflammation neutrophil leukocytes degranulate, thereby releasing the enzyme myeloperoxidase (MPO) into extracellular space. In addition to peroxidase activity, MPO expresses also a chlorinating activity, and catalyzes the formation of hypochlorous acid and long-lived oxidants - chloramines. In this study we assessed serum chlorinating MPO activity and concentration of total chloramines. We included 29 patients with acute IS, aged 69.0 years (64.2 - 78.0) and 25 control subjects without IS, aged 69.0 years (67.0 - 72.0). It was found that neutrophil cell count was higher in IS than in controls (4.56 ± 1.76 vs. 7.74 ± 3.35 × 109/L, in control and IS group, respectively; p< 0.05). Serum chlorinating MPO activity was also higher in IS group than in controls (67.2 U/L vs. 92.3 U/L, in controls and in patients, respectively; p < 0.05). Concentration of total chloramines was higher in IS group than in controls, but the difference did not reach statistical significance (p=0.178). MPO activity was significantly correlated with serum triglycerides (p

Introduction: Investigations shows that on every realized suicide comes 8 to 25 non realized attempts. Individuals which tried suicide with medicine poisoning mostly quote that they have been overwhelmed with feelings and thoughts which was unbearable in that moment. They wished to escape from that unbearable situation or they lost self control. Between individuals whom tried suicide with medicine poisoning, desire to really die, to disappear was very rare. Mostly it was wish 'just to sleep a little, to take a rest, make pause'. Aim of work: to identified most frequently method for suicidal attempt in both sex and resources which was used in these purposes. Results: most frequently method for suicidal attempt for both sex in our investigation was medicine poisoning - 91,1%, veins cutting - 5,4% and jump from height - 3,6%. Mostly used medicines were anxiolytics - 55,4%, combination of different drugs - 25,0%, antidepressants - 8,9%, neuroleptics - 7,1%, drugs and alcohol - 3,6%. Most frequent method for suicidal attempt in both sex was medicine poisoning. From drugs most frequently used drugs were anxiolytics and in minimum percent combination of drugs and alcohol. After suicidal attempt 90% of individuals experienced relief because their suicidal attempt was unsuccessful. In 3% individuals there was new suicidal attempt on same way, medicine poisoning.

Mixtures of BaCO3, ZnO and TiO2 powders, with molar ratio of 1:2:4, were mechanically activated for 20, 40 and minutes in a planetary ball mill. The resulting powders were compacted into pellets and isothermally sintered at 1250°C for 2h with a heating rate of 10°C/min. X-ray diffraction analysis of obtained powders and sintered samples was performed in order to investigate changes of the phase composition. The microstructure of sintered samples was examined by scanning electron microscopy. The photoacoustic phase and amplitude spectra of sintered samples were measured as a function of the laser beam modulating frequency using a transmission detection configuration. Fitting of experimental data enabled determination of photoacoustic properties including thermal diffusivity. Based on the results obtained correlation between thermal diffusivity and experimental conditions, as well the samples microstructure characteristics, was discussed.

Barium-Strontium-Titanate Ba0.77Sr0.23TiO3 was prepared from starting materials BaCO3, SrCO3 and TiO2 through solid-state reactions. Mixtures of these oxides are mechanically activated in a high-energy planetary ball mill at different time intervals from 0 to 120 minutes. In order to obtain information on phase composition, crystal structure was determent by X-ray diffraction. It was observed that after 80 minutes in process synthesis Ba0.77Sr0.23TiO3 started Thermal analyzes were performed in order to determine the characteristic temperatures of the processes that occur in the solid phase. Particle size distribution, together with electron microscopy scanning has given us very useful information about the morphology of the powder.

In this article the influence of mechanical activation on sintering process of magnesium-titanate and barium-zinc-titanate ceramics has been investigated. Both nonactivated and mixtures treated in planetary ball mill for 80 minutes were sintered at 1100ºC and 1300ºC. The influence of mechanical activation on phase composition and crystal structure has been analyzed by XRD, while the effect of activation and sintering process on microstructure was investigated by scanning electron microscopy. It has been established that temperature of 1100ºC was to low to induce final sintering stage for both systems. Moreover, we concluded that barium-zinc-titanate ceramics exhibited better sinterability than magnesium-titanate ceramics.

Mixtures of MgO-TiO2 were mechanically activated using high-energy planetary ball mill during 5, 10, 20, 40, 80 and 120 minutes. Sintering process was preformed in air at 1100o-1400oC for 2h. The decrease in powder’s particle size was noticed as the time of mechanical activation increased and confirmed by particle size analyzer. XRD analyses were performed in order to acquire the information about phase composition. Different ratio mixtures of MgTiO3 and Mg2TiO4 are present within all sintered samples. The effect of tribophysical activation on microstructure was investigated by scanning electron microscopy. The differential thermal gravimetric analysis has been performed in order to investigate thermal behaviour of the mixtures.

The aim of this work was to analyze the influence of mechanical activation on the MgCO3-TiO2 system. Mixtures of MgCO3-TiO2 were mechanically activated for 15, 30, 60 and 120 minutes in a planetary ball mill and after that sintered at 1100°C for 1h. XRD analyses were performed in order to give information about the phase composition and to determine a variety of microstructure parameters using Scherrer's method. Also, the effect of tribophysical activation and sintering process on microstructure was investigated by scanning electron microscopy. Electrical measurements were performed in order to determine electrical properties of sintered samples. Our conclusions are that the sample activated for 120 min showed the best electrical properties ( ε r=23.86, Q=233, ρ=0.38) and exhibited the best sinterability.

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Copyright of Veterinarska Stanica is the property of Croatian Veterinary Institute and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In this article, the advantages of combined sintering in comparison with the conventional one, of mechanically activated magnesium titanate ceramic were investigated. The stoichiometric mixtures of MgO and TiO2 were mechano-chemically activated for 0, 10, 40, 80 and 160 minutes by ball milling and then isostatically pressed (CIP) to form green bodies. Conventional sintering was realized by heating up to 1400 °C and hold for 30 minutes in air atmosphere. Resulting ceramic samples with closed porosity were post-sintered by pressure assisted technique Hot Isostatic Pressing (HIP) at 1280 oC/3h in argon atmosphere with a pressure of 200 MPa. The best results were observed in the case of samples postsintered by HIP, when single-phase MgTiO3 samples with relative density of 96% were prepared. [ABSTRACT FROM AUTHOR]