Third International Colloquium on Physical and Chemical Information Transfer in Regulation of Reproduction and Ageing: September 22-28 · 1980 Varna, Bulgaria

Andrologia ◽  
2009 ◽  
Vol 12 (3) ◽  
pp. 297-297
2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Hiroto Yamashita ◽  
Rei Sonobe ◽  
Yuhei Hirono ◽  
Akio Morita ◽  
Takashi Ikka

AbstractSpectroscopic sensing provides physical and chemical information in a non-destructive and rapid manner. To develop non-destructive estimation methods of tea quality-related metabolites in fresh leaves, we estimated the contents of free amino acids, catechins, and caffeine in fresh tea leaves using visible to short-wave infrared hyperspectral reflectance data and machine learning algorithms. We acquired these data from approximately 200 new leaves with various status and then constructed the regression model in the combination of six spectral patterns with pre-processing and five algorithms. In most phenotypes, the combination of de-trending pre-processing and Cubist algorithms was robustly selected as the best combination in each round over 100 repetitions that were evaluated based on the ratio of performance to deviation (RPD) values. The mean RPD values were ranged from 1.1 to 2.7 and most of them were above the acceptable or accurate threshold (RPD = 1.4 or 2.0, respectively). Data-based sensitivity analysis identified the important hyperspectral regions around 1500 and 2000 nm. Present spectroscopic approaches indicate that most tea quality-related metabolites can be estimated non-destructively, and pre-processing techniques help to improve its accuracy.


1981 ◽  
Vol 6 ◽  
Author(s):  
Paul G. Huray ◽  
M. T. Spaar ◽  
S. E. Nave ◽  
J. M. Legan ◽  
L. A. Boatner ◽  
...  

The electronic charge states and site symmetries of the radioactive ions incorporated in nuclear waste forms are of considerable importance in determining the physical and chemical properties of these materials. An in situ characterization of these ions is, unfortunately, often difficult – especially when a mixture of charge states and local crystal symmetries exist. The application of Mbssbauer spectroscopy represents a powerful technique for obtaining solid state chemical information.


A survey is given on typical ‘top-down’ and ‘bottom-up’ approaches to design nanostructured sensors which monitor different physical and chemical quantities. Particular emphasis is put on new materials and transducers for molecular recognition by chemical sensors. These convert chemical information into electronic signals by making use of suitable ‘key-lock’ structures. This requires the control of surface structures of chemically sensitive materials down to the molecular scale under thermodynamically or kinetically controlled conditions. This in turn requires the molecular understanding of sensor mechanisms which is deduced from comparative microscopic, spectroscopic and sensor test studies on ‘prototype materials’. Selected case studies illustrate the common mechanisms of molecular recognition with electron conductors, ion conductors, mixed conductors, molecular cages, polymers and selected biomolecular function units.


Author(s):  
M. A. Yakhyaev ◽  
V. S. Gutenkov ◽  
Yu. A. Pisarenko

Mesityl oxide is an important product of organic synthesis, which is used in the manufacture of pharmaceuticals and as a solvent. The demand for mesityl oxide is growing, which determines the need for further improvement of its production. The disadvantages of the traditional methods of obtaining mesityl oxide are low values of reagent conversion and selectivity. To eliminate them, it is proposed to obtain mesityl oxide in a combined reaction-rectification process. The combination of chemical transformation and separation of the resulting reaction mixture by means of rectification in one apparatus allows for a continuous withdrawal of the formed products from the reaction zone, which increases the rate of the target reaction, conversion and selectivity. In accordance with the modern strategy for the development of chemical-technological processes, the collection and processing of physical and chemical information on the properties of the components and mixtures contained in the reaction system was performed. Based on the experimental data, the parameters of the phase equilibrium model are determined, and its adequacy is estimated. The phase equilibrium model was used to construct a distillation diagram, to verify its consistency, and to conduct computational studies of the reaction-rectification process. The thermochemical parameters of the target reactions are calculated, the equilibrium constants are determined, and their temperature dependence is established. On the basis of the analysis of the literature data, a kinetic model of the process is proposed, and the conditions favorable for the course of the desired chemical transformation are determined with the use of this model. The obtained data are necessary for carrying out the analysis of the statics, constructing the basic technological scheme and calculating its static parameters.


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