Synthesis of ozone-safe freons and methods for improving the Russian industrial catalyst for their production

Industrially important reactions of gas-phase synthesis of ozone-safe freons of the ethane family-hydrofluorination of perchloroethylene into pentafluoroethane (Halocarbon-125) and trichloroethylene into 1,1,1,2-tetrafluoroethane (Refrigerant-134a) on an Cr-Mg catalyst were investigated for to improve the Russian industrial Cr-Mg catalyst for freon production. The influence of reaction conditions—temperature, contact time, pressure, etc.—on the rate and selectivity of reactions was studied. The mechanism of reactions is discussed on the basis of the dependences obtained with regard to multistage nature of processes. The computational method for assessing the optimal content of the active component and specific surface were used. The optimal content of the active component and catalyst activity were shown to increase with increasing specific surface of the support, MgF₂. Thus, an increase in the specific surface of MgF₂ from 100 to 200 m²/g may result in increased activity by a factor of almost 2. However, obtaining such highly disperse MgF₂ is difficult; moreover, the catalyst would be poorly thermostable. Therefore, the possibilities of considerable enhancing the activity of industrial Cr-Mg catalysts are limited by the existing technology. Significant enhancement in the properties of the catalyst of gas-phase synthesis of freons is possible upon a change in the method of preparing the catalyst and the chemical composition of the support.     

Brønsted acidity study of fiberglass materials by H/D-exchange

The kinetics of hydrogen isotopic exchange over fiberglass materials and reference samples (SiO₂, H₃PO₄/SiO₂, and HZSM-5) was studied at 500 °C under the dynamic adsorption–desorption equilibrium. The concentrations and H/D-exchange rates of different Brønsted acid sites (BAS) were determined using the numerical modeling of isotope exchange dynamics. The correlation between H/D-exchange rate of reference samples and their acidity determined by FTIR spectroscopy of adsorbed CO was established. Based on this correlation, the strength of BAS in fiberglass materials was shown to be comparable to that of HZSM-5 zeolite.     

Thermolysis and steam activation of a mixture of lignin and washed-off petroleum waste in the presence of copper acetate

The thermal degradation of a mixture of lignin with washed-off petroleum waste in the presence of 2% Cu(Ac)₂ was studied. The ion-exchange interaction of the copper cation with the oxygen-containing acidic groups of mixture components occurred upon mixing the components. On a supramolecular level, this was accompanied by the compaction of carbon layers in a crystallite and a considerable increase in its diameter. In the course of the nonisothermal heating of a mixture with a copper acetate additive over the range 20–950°C, the temperature of the onset of the main thermal degradation decreased by 30 K and the rate of degradation decreased in this region. The single-step steam activation (800°C, 0.5 h) of the mixture with Cu(Ac)₂ added allowed us to obtain active carbon with high yield, adsorption capacity for iodine, and micropore volume, as compared with active carbon prepared from the mixture with no additive.     

The results of complex social and ecologic study in the city of Ufa

The authors present results of social and ecologic study carried out in Ufa. The results describe the course of ecologically important processes and phenomena in correlation with the public subjective understanding. Public health is influenced by hygienic parameters of food and water quality as well as a complex of social, economic and psychologic factors. Weak correlation between those parameters and ambient air pollution necessitates more accurate approach to ecologic mapping of cities and to manipulation with data on lower atmosphere pollution with chemical hazards.     

Stimulation of gluconeogenesis with 1,3-butanediol in the perfused rat liver

An intensified synthesis of glucose is observed in gluconeogenesis from endogenous precursor only for the first 30 min of perfusion. Pyruvate introduction into the medium raises phosphoenolpyruvate carboxykinase and fructose-1,6-diphosphatase activities in the liver and determines maintenance of the glucose formation high rate for 90 min of perfusion. 1,3-butanediol is found to have a stimulating effect on gluconeogenesis from pyruvate. Introduction of 1,3 bytanediol into perfusate decreases the redox state of free NAD-pairs, increases the content of phosphoenolpyruvate, malate. ATP and the phosphoenolpyruvate carboxykinase and fructose-1.6-diphosphatase activity in the perfused liver.     

Risk factors and etiological structure of children's cross-allergic reactions to food products

Authors of article have recently analyzed the frequency of prevalence and risk factors of cross-reactivity to foodstuffs among 239 children of Abakan in the age of from 6 months till 15 years with skin, respiratory and combined manifestation of atopy. It was proved that risk factors of development of cross-reactivity to food among children of the first years of life are hereditary predisposition to allergic diseases (77.8%) and early introductions of supplemental feeding (44%). Among children older then 7 years pollen sensitization (62%) which preceded the development of cross allergic reactions between separate foodstuffs reaches up to 73.7%, between pollen and foodstuff up to 79% and between epidermal and food up to 10.1%.     

Methods and Tools for Developing Intelligent Systems for Solving Complex Real-Time Adaptive Resource Management Problems

Automation and Remote Control - We give the statement of the real-time adaptive enterprise resource management problem and provide examples of contemporary adaptive resource management problems in...