Method for determining the characteristics of a gas-steam chp with a steam turbo drive of a compressor

A new type of maneuverable combined-cycle plant with a steam-turbine drive of a low-pressure compressor is considered. The analysis of its technological processes in the generation of electric and thermal energy in heating and non-heating periods of the year is carried out. It is shown that in heating conditions, the burning of additional fuel in the afterburner between the stages of the evaporator of the utilizer boiler provides an increase in its steam production, maneuverability, thermal and electric power of the CCGT-CHP plant. The influence of the chemical composition and thermophysical properties of natural gas on obtaining the required excess air in the combustion chamber of a combined cycle gas turbine is considered. A mathematical model of technological processes is developed. The influence of deep utilization of the heat of the flue gases of the utilizer boiler on increasing the efficiency and improving the environmental characteristics of the gas-steam plant of a thermal power plant was recorded. © 2020 Institute of Physics Publishing. All rights reserved

Pulmonary embolism and atrial fibrillation: analysis of data from the SIRENA Russian registry

Aim. To present the clinical characteristics and in-hospital prognosis in patients with pulmonary embolism (PE) and atrial fibrillation (AF).Material and methods. On the initiative of a working group of physicians, the basic principles of an observational prospective study (SIRENA registry) have been developed.Results. Among the 660 patients included in the registry, AF was diagnosed in almost every fourth patient — in 22,9% of cases (n=151), which reflects its high incidence in relation to PE. The prevalence of AF corresponded to such conditions as heart failure (HF) (23,2%; n=153), diabetes (15,6%; n=103), and hypertension (HTN) (65,7% n=400). The diagnosis of AF in most patients is based on the history data (n=144; 95,4%), while the first registered AF episode was verified in 7 patients (4,6%). Patients with AF were characterized by older age, significantly higher prevalence of HF (51,2%), HTN (80,8%), chronic kidney disease (18,5%), stroke or transient ischemic attack (23,2%). It is important to note the low prevalence of anticoagulant therapy (15,3%) in the group of patients with previously diagnosed AF (n=144). The prevalence of thrombolytic therapy in patients with AF was significantly lower than among patients without AF (13,9 vs 25,8% (p=0,026)), which is due to contraindications and underdiagnosis of PE. Given the predominantly senile age, high comorbidity rate in patients with AF, as well as the absence of outpatient anticoagulant therapy, in-hospital mortality in patients with PE and AF was 31,1%, and significantly differed from that in those without AF 12,6% (p=0,001). In the general group, post-mortem diagnosis of PE was noted in 7,7% of cases (n=51), of which the proportion of patients with AF was 54,9% (n=28). A possible explanation for the underestimation of PE in AF patients was an erroneous explanation of its manifestations (tachypnea, tachycardia, lower limb edema) due to concomitant HF.Conclusion. Suspicion for PE in elderly patients with AF and manifestations of HF decompensation, as well as the timely administration of anticoagulant therapy, will prevent both arterial and venous embolism

Phase Behavior of Aqueous Na-K-Mg-Ca-CI-NO3 Mixtures: Isopiestic Measurements and Thermodynamic Modeling

A comprehensive model has been established for calculating thermodynamic properties of multicomponent aqueous systems containing the Na{sup +}, K{sup +}, Mg{sup 2+}, Ca{sup 2+}, Cl{sup -}, and NO{sub 3}{sup -} ions. The thermodynamic framework is based on a previously developed model for mixed-solvent electrolyte solutions. The framework has been designed to reproduce the properties of salt solutions at temperatures ranging from the freezing point to 300 C and concentrations ranging from infinite dilution to the fused salt limit. The model has been parameterized using a combination of an extensive literature database and new isopiestic measurements for thirteen salt mixtures at 140 C. The measurements have been performed using Oak Ridge National Laboratory's (ORNL) previously designed gravimetric isopiestic apparatus, which makes it possible to detect solid phase precipitation. Water activities are reported for mixtures with a fixed ratio of salts as a function of the total apparent salt mole fraction. The isopiestic measurements reported here simultaneously reflect two fundamental properties of the system, i.e., the activity of water as a function of solution concentration and the occurrence of solid-liquid transitions. The thermodynamic model accurately reproduces the new isopiestic data as well as literature data for binary, ternary and higher-order subsystems. Because of its high accuracy in calculating vapor-liquid and solid-liquid equilibria, the model is suitable for studying deliquescence behavior of multicomponent salt systems

Evaluation of biotransformation capacity of transplastomic plants and hairy roots of Nicotiana tabacum expressing human cytochrome P450 2D6

Cytochrome P450 monooxygenases (CYPs) are important tools for regio- and stereoselective oxidation of target molecules or engineering of metabolic pathways. Functional heterologous expression of eukaryotic CYPs is often problematic due to their dependency on the specific redox partner and the necessity of correct association with the membranes for displaying enzymatic activity. Plant hosts offer advantages of accessibility of reducing partners and a choice of membranes to insert heterologous CYPs. For the evaluation of plant systems for efficient CYP expression, we established transplastomic plants and hairy root cultures of Nicotiana tabacum carrying the gene encoding human CYP2D6 with broad substrate specificity. The levels of CYP2D6 transcript accumulation and enzymatic activity were estimated and compared with the data of CYP2D6 transient expression in N. benthamiana. The relative level of CYP2D6 transcripts in transplastomic plants was 2-3 orders of magnitude higher of that observed after constitutive or transient expression from the nucleus. CYP2D6 expressed in chloroplasts converted exogenous synthetic substrate loratadine without the need for co-expression of the cognate CYP reductase. The loratadine conversion rate in transplastomic plants was comparable to that in N. benthamiana plants transiently expressing a chloroplast targeted CYP2D6 from the nucleus, but was lower than the value reported for transiently expressed CYP2D6 with the native endoplasmic reticulum signal-anchor sequence. Hairy roots showed the lowest substrate conversion rate, but demonstrated the ability to release the product into the culture medium. The obtained results illustrate the potential of plant-based expression systems for exploiting the enzymatic activities of eukaryotic CYPs with broad substrate specificities

Creation of glyphosate-resistant Brassica napus L. plants expressing DesC desaturase of cyanobacterium Synechococcus vulcanus

Aim. Creation of glyphosate-resistant canola plants expressing bifunctional hybrid desC::licBM3 gene. In the hybrid gene the sequence of DesC desaturase of cyanobacterium S. vulcanus without plastid targeting was fused with the sequence of thermostable lichenase reporter LicBM3 gene. Methods. Agrobacterium tumefaciens-mediated transformation, PCR, quantitative and qualitative determination of lichenase activity, genetic analysis. Results. Transgenic canola plants, carring the enolpyruvat shikimat phosphate syntase gene (epsps), conferring on plants resistance to phosphonomethyl glycine herbicides (Roundup), as well as the desC::licBM3 gene, were selected. The presence of transgenes was confimed by multiplex PCR. The epsps gene expression in canola was shown at the transcription level, during in vitro growth and after greenhouse herbicide treatment. Activity of the licBM3 gene product as a part of hybrid protein allowed quantitative and qualitative estimation of the desaturase gene expression. Inheritance of heterologous genes and their expression in the first generation were investigated. Conclusions. Transgenic canola plants were obtained, the presence of trangenes in plant genome was proved and expression of the target genes was detected