122 research outputs found
Spectra of Positrons Lifetimes in Choose Gel Drugs
Spectra of positrons lifetimes in selected gel non-steride analgesic and antiphlogistic drugs were investigated. The basic components in them were sodium salts of diclophenac and they differed from one another with the chemical composition of other components. It was found that in all of the investigated spectra there occurred a component which testified to the formation of positronium. The differences in the values of ortho-Ps component lifetimes and their intensity can be attributed to the presence of ingredients modifying the effects of the drug
Experimental Study of Inconel 718 Surface Treatment by Edge Robotic Deburring with Force Control
We present the results of investigations into the application of robotics for deburring and chamfering to a predefined geometric quality. The robotic application was used for a part of the manufacturing process of an aircraft engine detail.Представлены результаты исследования по оценке использования робототехники для снятия заусенец и фасок с жестким геометрическим допуском. Робототехнические средства использовались для части процесса изготовления деталей авиационных двигателей
Kinetics of the hydrogen abstraction ·C2H5 + alkane → C2H6 + alkyl reaction class: an application of the reaction class transition state theory
This paper presents an application of the reaction class transition state theory (RC-TST) to predict thermal rate constants for hydrogen abstraction reactions at alkane by the C2H5 radical on-the-fly. The linear energy relationship (LER), developed for acyclic alkanes, was also proven to hold for cyclic alkanes. We have derived all RCTST
parameters from rate constants of 19 representative
reactions, coupling with LER and the barrier height
grouping (BHG) approach. Both the RC-TST/LER, where
only reaction energy is needed, and the RC-TST/BHG,
where no other information is needed, can predict rate
constants for any reaction in this reaction class with satisfactory accuracy for combustion modeling. Our analysis indicates that less than 50% systematic errors on the average exist in the predicted rate constants using either
the RC-TST/LER or RC-TST/BHG method, while in comparison with explicit rate calculations, the differences
are within a factor of 2 on the average. The results also
show that the RC-TST method is not sensitive to the choice
of density functional theory used
Immunolocalization of cell wall polymers in grapevine (Vitis vinifera) internodes under nitrogen, phosphorus or sulfur deficiency
Abstract The impact on cell wall (CW) of the deficiency in nitrogen (–N), phosphorus (–P) or sulphur (–S), known to impair essential metabolic pathways, was investigated in the economically important fruit species Vitis vinifera L. Using cuttings as an experimental model a reduction in total internode number and altered xylem shape was observed. Under –N an increased internode length was also seen. CW composition, visualised after staining with calcofluor white, Toluidine blue and ruthenium red, showed decreased cellulose in all stresses and increased pectin content in recently formed internodes under –N compared to the control. Using CW-epitope specific monoclonal antibodies (mAbs), lower amounts of extensins incorporated in the wall were also observed under –N and –P conditions. Conversely, increased pectins with a low degree of methyl-esterification and richer in long linear 1,5-arabinan rhamnogalacturonan-I (RG-I) side chains were observed under –N and –P in mature internodes which, in the former condition, were able to form dimeric association through calcium ions. –N was the only condition in which 1,5-arabinan branched RG- content was not altered, as –P and –S older internodes showed, respectively, lower and higher amounts of this polymer. Higher xyloglucan content in older internodes was also observed under –N. The results suggest that impairments of specific CW components led to changes in the deposition of other polymers to promote stiffening of the CW. The unchanged extensin amount observed under –S may contribute to attenuating the effects on the CW integrity caused by this stress. Our work showed that, in organized V. vinifera tissues, modifications in a given CW component can be compensated by synthesis of different polymers and/or alternative linking between polymers. The results also pinpoint different strategies at the CW level to overcome mineral stress depending on how essential they are to cell growth and plant development
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