New Method for Monitoring the Process of Freeze Drying of Biological Materials.

A capacitive sensor was proposed and tested for the monitoring and control of a freeze drying process of a vaccine against the Newcastle disease of birds. The residual moisture of the vaccine was measured by the thermogravimetric method. The vaccine activity was determined by titration in chicken embryos. It was shown that, at the stages of freezing and primary drying, a capacitive sensor measured the fraction of unfrozen liquid phase in a material and allowed one to control the sublimation stage of drying in an optimal way. This prevented the foaming of the material and shortened the total drying time approximately twice. The control range at the sublimation stage of drying expanded up to -70°C. It was found at the final stage of drying that the signal of a capacitive sensor passed through a maximum value. We supposed that this maximum corresponds to the minimum of intramolecular mobility of biological macromolecules and hence to the optimal residual moisture of the material, which ensures long-term preservation of its activity. We also suppose that using the capacitive sensor at the final stage of drying allows one to more precisely detect the time when the residual moisture of dried material reaches the optimal value.

Phase Transformation in TiNi Nano-Wafers for Nanomechanical Devices with Shape Memory Effect.

Recently, Ti-Ni based intermetallic alloys with shape memory effect (SME) have attracted much attention as promising functional materials for the development of record small nanomechanical tools, such as nanotweezers, for 3D manipulation of the real nano-objects. The problem of the fundamental restrictions on the minimal size of the nanomechanical device with SME for manipulation is connected with size effects which are observed in small samples of Ti-Ni based intermetallic alloys with thermoplastic structural phase transition from austenitic high symmetrical phase to low symmetrical martensitic phase. In the present work, by combining density functional theory and molecular dynamics modelling, austenite has been shown to be more stable than martensite in nanometer-sized TiNi wafers. In this case, the temperature of the martensitic transition asymptotically decreases with a decrease in the plate thickness h, and the complete suppression of the phase transition occurs for a plate with a thickness of 2 nm, which is in qualitative agreement with the experimental data. Moreover, the theoretical values obtained indicate the potential for even greater minimization of nanomechanical devices based on SME in TiNi.

Innovative systems for cultural heritage conservation. Millimeter wave application for non-invasive monitoring and treatment of works of art.

A novel non invasive technique and a suitable apparatus for disinfestation of artworks is introduced. Non destructive and non invasive techniques are often irreplaceable in order to preserve and restore cultural heritage objects in its structure and shape. Although many techniques are available for art and archaeological works the non invasive methods are preferred as they leave the object untouched after treatment. Environmental parameters, such as humidity, can damage culture heritage objects and also results in spring up variety of pests and other micro-organisms. Non-invasive monitoring of these damage and also disinfestation treatments and drying with help of electromagnetic waves are preferred as they keep the object untouched after treatment. Application of millimeter waves for solving this problem is discussed here. Millimeter waves have high spatial resolution and absorption in water as well as in bio-objects that are usually moist and at the same time minimal interaction with dry culture heritage objects by itself. Different phases of the microwaves treatment (MW) of artworks are described, some results are shown and discussed. Many biological forms don't survive over a certain temperature, called lethal temperature which, for most xylophages is about 53-55 degrees C, while for moulds and funguses is between 65 and 70 degrees C. In order to evaluate the management of disinfestation of works of art, incident power, temperature, exposure time were monitored. The monitoring of temperature is essential in order to prevent damages. A computer simulation allows to predict and monitor the heating process.