The Influence of Heating/Cooling Rate on Transformation Temperatures of Co-Base Alloy

Thepaper deals with an experimental measurement of the transformation temperatures of Co-base alloy. Temperatures were determined by means of DTA-method during controlled heating and cooling. The samples in an as-received state were analysed at heating/cooling rates of 2, 5, 10 and 20 °C/min with the use of the equipment Setaram SETSYS 18TM (DTA-method). The samples after various heat treatments were analysed at heating/cooling rate of 5 °C/min by Setaram SETSYS 18TM (DTA-method). On the basis of evaluation of the results the influence of heating/cooling rate on shift of the transformation temperatures was determined. The influence of heat treatment on shift of the transformation temperatures was also studied. The samples in an as-received state and the samples after heat treatment were alsosubjected to the phase analysis by scanning electron microscopy using the microscope JEOL JSM-6490LV equipped with an energy dispersive analyser EDAX (EDS INCA x-act). The individual phases were identified by semi-quantitative X-ray microanalysis.

Ultrastructural Localization of Ions. Iii. Distribution of Chloride in Mesophyll Cells of Mangrove (Aegiceras Corniculatum Blanco).

Ultrastructural localization of Cl- by means of a silver ion precipitation technique combined with X-ray energy spectroscopy (EMMA-4 electron microscope plus KEVEX energy dispersive analyser) showed the presence of two types of vacuoles in mesophyll cells of mangrove (A. corniculatum Blanco). Type A vacuoles contained large amounts of osmiophilic organic solute and little or no Cl-, while type B vacuoles were shown to be free of osmiophilic organic solute but to contain significant quantities of Cl-. X-ray spectroscopy of electron-opaque deposits in chloroplasts showed the presence of AgCl deposits and deposits of silver in approximately equal proportions. Fine granular deposits in plastoglobuli were also shown to consist of silver. Deposits in the cytoplasmic phase and in the plasmodesmata, however, always consisted of AgCl. The significance of the two types of vacuoles is discussed in relation to the symplastic or apoplastic transport of Cl- from conducting tissue to the salt glands.

Ultrastructural Localization of Ions. II. X-Ray Analytical Verification of Silver Precipitation Products and Distribution of Chloride in Mesophyll Cells of Barley Seedlings

The ultrastructural localization of Cl- by means of a silver precipitation technique has been verified by means of X-ray analytical electron microscopy (EMMA-4 electron microscope plus KEVEX energy dispersive analyser). It was shown that the localization method was specific for Cl- in the case of electron-dense deposits in chloroplasts, plasmodesmata and plasmalemma of barley mesophyll cells. It was pointed out that the use of nitric acid rinses in order to remove non-specific deposits of silver phosphates and carbonates has pitfalls and that the precipitation technique should always be used in conjunction with X-ray microprobe analysis.