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  • Author or Editor: Anna Migdał x
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Abstract  

Differential scanning calorimetry (DSC) measurements were performed over the temperature range 93–480 K and three enantiotropic (at 323, 409, and 461 K) and one monotropic (at 271 K) phase transitions were detected. Thus, four solid phases (three of them stable and one metastable) and one liquid phase were found. It was concluded, from the entropy change (ΔS) values of these phase transitions that two of them are stable rotational phases and two are crystalline phases (one stable and one metastable). The thermal decomposition of [Mg((CH3)2SO)6](ClO4)2, which was studied using thermogravimetry (TG) with simultaneous differential thermal analysis (SDTA), takes place in two main stages. The gaseous products of the decomposition were identified on-line by a quadruple mass spectrometer (QMS). In the first stage, which starts just above ca. 432 K, the compound loses two dimethylsulphoxide (DMSO) molecules per one formula unit. In the second stage (502–673 K) [Mg(DMSO)4](ClO4)2 decomposes explosively and Cl2, O2, H2, and MgSO4 are finally produced.

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Abstract  

Melting processes and thermal decompositions of [Ca(H2O)4](ClO4)2 and [Ca(NH3)6](ClO4)2 were studied by thermogravimetry analysis (TG) and differential scanning calorimetry (DSC). The gaseous products of the decomposition were on-line identified by a quadruple mass spectrometry (QMS). In both compounds the processes of loss of the ligands start at ca. 340–350 K and continue up to ca. 600 K. Tetraaquacalcium perchlorate dissolves in own coordination water (melts) at T m=350 K. The decomposition of the sample proceeds in three main stages. In stage I (351–602 K) dehydration of [Ca(H2O)4](ClO4)2 to anhydrous Ca(ClO4)2 undergoes in two steps, in which consecutively 2/4 and 2/4 of all H2O molecules are liberated. In stage II (602–701 K) anhydrous Ca(ClO4)2 has one solid-solid phase transition at T c=619 K and then melts at T m=689 K. Stage III (above 700 K) is connected with decomposition of melted Ca(ClO4)2 to oxygen and solid CaCl2. The decomposition of the [Ca(NH3)6](ClO4)2 proceeds also in three main stages. In stage I (341–601 K) deamination of [Ca(NH3)6](ClO4)2 to Ca(ClO4)2 undergoes in two steps, in which consecutively 3/6 and 3/6 of all NH3 molecules are liberated. Stages II and III (601–868 K) are exactly the same as they were observed for [Ca(H2O)4](ClO4)2.

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Journal of Thermal Analysis and Calorimetry
Authors: Anna Migdał-Mikuli, Joanna Hetmańczyk and Ł. Hetmańczyk

Abstract  

Melting process and thermal decomposition of [Ca(H2O)4](NO3)2 was studied by thermogravimetry analysis (TG), differential scanning calorimetry (DSC) and simultaneous differential thermal analysis (SDTA) at a constant heating rate. The gaseous products of the decomposition were on-line identified by a quadruple mass spectrometry (QMS). Tetraaquacalcium nitrate(V) melts at T m=320 K. The decomposition of the sample proceeds in three main stages. In the first stage dehydration of [Ca(H2O)4](NO3)2 to anhydrous Ca(NO3)2 undergoes in two steps, in which consecutively 1/4 and 3/4 of all H2O molecules are liberated. The thermal dehydration process starts just above ca. 302 K and continues up to ca. 475 K. In the second stage (475–775 K) anhydrous Ca(NO3)2 remains unchanged. The third stage is connected with the melting of anhydrous Ca(NO3)2 at T m=816 K and next with its decomposition in the liquid phase to nitrogen oxide, oxygen, nitrogen and solid CaO.

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The aim of this study was to determine the effect of increased levels of prolactin (PRL) on the concentration of immunoglobulins in the blood, colostrum and milk of mares. The study was conducted on 12 mares of the Polish Pony breed (6 in the control and 6 in the experimental group). To induce hyperprolactinaemia in mares of the experimental group, 750 mg sulpiride was administered orally once a day. The initial PRL concentration was 52.22 ± 11.21 ng/ml in the control group and 49.39 ± 10.12 ng/ml in the experimental group. In the subsequent days, the concentration of PRL dynamically changed. Statistical analysis showed highly significant differences (P < 0.01) between the groups. The concentration of immunoglobulins in the blood plasma was at the same level during the experimental period (32.97–29.08 mg/ml in the experimental group and 28.60–18.11 mg/ml in the control group). Statistical analysis showed highly significant differences between the groups in blood plasma immunoglobulin level (P < 0.01). The highest immunoglobulin concentration was obtained within 12 h after parturition in the control and the experimental group (23.49 ± 2.12 mg/ml and 26.94 ±1.72 mg/ml, respectively). The lowest values were obtained on day 12 after parturition in the experimental group (10.15 mg/ml ± 1.47 mg/ml) and on day 7 after parturition in the control group (14.30 mg/ml ± 2.48 mg/ml). In conclusion, this study did not provide evidence that the lactogenic hormone prolactin is involved in the transfer of immunoglobulins into the colostrum in horses.

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Journal of Thermal Analysis and Calorimetry
Authors: Anna Migdał-Mikuli, Elżbieta Szostak, K. Drużbicki and Diana Dołȩga

Abstract  

Tetrakis(dimethyl sulphoxide)nickel(II) bis(iodide) was studied by thermogravimetry (TG) and simultaneous differential thermal analysis (SDTA) and differential scanning calorimetry (DSC). The gaseous products of the decomposition were on-line identified by a quadrupole mass spectrometer (QMS). Thermal decomposition of the title compound proceeds in three main stages. In the first stage, which starts just above ca. 419 K, the compound loses two dimethyl sulphoxide (DMSO) molecules per one formula unit and small amount of iodide ion. In the second stage (464–552 K) the next DMSO ligands and the iodide ion simultaneously are released. In the last stage (552–900 K) NiSO4 is created which next decomposes to NiO and SO3.

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