Measurement technique

Radon isotopes (222, 220, 219) are radioactive gases produced by the disintegration of radium isotopes 226, 224 and 223, which are decay products of uranium238, thorium232 and uranium235 respectively. All are found in the earth's crust. Solid elements, also radioactive, are produced by radon disintegration. Radon is classed as a rare gas in the periodic table of elements, along with helium, argon, neon, krypton and xenon. When disintegrating, radon emits alpha particles and generates solid decay products, which are also radioactive (polonium, bismuth, lead etc.). The potential danger of radon lies in its solid decay products rather than the gas itself. Whether or not they are attached aerosols, radon decay products can be inhaled and deposited in the bronchopulmonary tree to varying depths according to their size. Radon today is considered to be the main source of human exposure to natural radiation. At the international level, radon accounts for 52% of global average exposure t...

– An important part of modeling with Volterra and Wiener models is the accurate measurement of the model coefficients or kernels. The formulation of Wiener model of nonlinear systems has a major breakthrough for kernel measurement. The orthogonality of the Wiener functionals for a white Gaussian input allowed the Wiener kernels to be easily measured using cross-correlation techniques. The kernel measurement techniques are widely explored in this paper. Some properties of the third order Volterra kernel and of the input-output relation are shown. Finally original contributions have been made regarding signal reconstruction using Volterra and Wiener models.

Microwave dielectric measurements were performed in the frequency range from 1 mHz up to 30 GHz using a time domain reflectometry (TDR) method for emulsions and gels. Flat-end sample cells have been used in the TDR measurement to contact a small spot of the surface of those viscoelastic and solid samples without any destruction. Relaxation processes due to various water structures were observed for these aqueous systems. Relaxation parameters thus obtained offer information about these water structures and amounts. The relaxation strength obtained from the high frequency process due to free water can be an adequate measure of water content in spite of some ambiguities for different water structures in some materials. Comparisons of actual water contents in emulsion with those estimated from the relaxation strength indicate that water structure is affected by the interaction between water and micelle. Unfreezable water observed in DNA gel under the freezing point consists of bound wa...

The acoustics of churches is a cultural heritage to be preserved as carefully as the artistic and architectural aspects of this particular category of buildings. The acoustic characteristics of an environment could be measured according to different techniques varying from the numerical quantification, by means of acoustical parameters, to the recording of the binaural or ambisonic impulse responses of several combinations of source–receiver locations. The complexity of this kind of buildings can lead different researchers to choose dissimilar ...

A new promising method for wind profile measurements appeared recently, as a result of the latest technological advance in the field of laser optics and signal processing. Lidar measurements can now provide wind speed and direction at various heights up to 150m. The scope of this paper is to compare the results of this new measurement technique with those obtained from classical cup and sonic anemometers installed on a 100m meteorological mast.

The dismantling of the BR3 reactor produces quite large masses of contaminated materials, mainly metals or concrete. The main management routes are: conditioning of the radioactive wastes and disposal, recycling of radioactive materials in the nuclear sector and the recycling of cleared materials in the industrial sector or their evacuation as industrial waste. The paper is focused on the management of the dismantled contaminated metals. It gives an overview of the main management routes followed with their associated dismantling and decontamination techniques. The administrative and the technical aspects starting from the dismantling up to the final evacuation are dealt with. The radiochemical characterization is also important at all the steps of the dismantling process. Characterization is performed on site before dismantling to guarantee the workers safety and for the selection of the right evacuation route. Melting in a nuclear foundry either for clearance or for reuse in the n...

Non-destructive systems are recent trends for quality evaluation of fruits and vegetables. Information on post-harvest variations in electrical properties is needed to develop new instruments for this purpose. Electrical properties are finding increasing application in agriculture and food processing industries. Knowledge of dielectric properties of foods as a function of moisture content and temperature is essential in the design and