• Energy Research
• Closed Access close
• Restricted close
• Open Source close
• BG close

In this context, phytochemicals were extracted from Ranunculus constantinopolitanus using ethyl acetate (EA), ethanol, ethanol/water (70%), and water solvent. The analysis encompassed quantification of total phenolic and flavonoid content using spectrophotometric assays, chemical profiling via high performance liquid chromatography-mass spectrometry/mass spectrometry (HPLC-MS/MS) for the extracts, and assessment of antioxidant activity via 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid (ABTS), Cupric reducing antioxidant capacity (CUPRAC), ferric reducing antioxidant power (FRAP), metal chelating (MCA), and phosphomolybdenum (PBD) assays. Moreover, antimicrobial activity was assessed against four different bacterial strains, as well as various yeasts. Enzyme inhibitory activities were evaluated against five types of enzymes. Additionally, the extracts were examined for their anticancer and protective effects on several cancer cell lines and the human normal cell line. All of the extracts exhibited significant levels of ferulic acid, kaempferol, and caffeic acid. All tested extracts demonstrated antimicrobial activity, with Escherichia coli and Pseudomonas aeruginosa being most sensitive to EA and ethanol extracts. Molecular docking studies revealed that kaempferol-3-O-glucoside strong interactions with AChE, BChE and tyrosinase. In addition, network pharmacology showed an association between gastric cancer and kaempferol-3-O-glucoside. Based on the results, R. constantinopolitanus can be a potential reservoir of bioactive compounds for future bioproduct innovation and pharmaceutical industries.

Abstract The paper addresses the problem associated with the optimal wind park design. A combinatorial optimization model for wind turbines type and number choice and placement considering the given wind conditions and wind park area is developed. The wind park investment costs and the total power relation as function of wind turbines number and type are used as optimization criteria. The optimization problem is formulated as a single criterion mixed-integer nonlinear discrete combinatorial task. The different wind park conditions are introduced into optimization tasks formulation as variables relations and restrictions. Two basic wind directions cases are taken into consideration – uniform and predominant wind directions for two wind park area shapes – square and rectangular. The developed wind park design approach was tested numerically by solving of different optimization tasks formulations based on wind turbines real parameters data. The numerical testing shows the applicability of the developed optimization approach. Using it will help to find mathematically reasoned wind turbines choice as contradiction to the heuristic approaches.

Abstract In this work, two ionic liquids with a 1-hexadecyl-3-methylimidazolium cation were synthesized with different anions; chloride and saccharinate, respectively, both of them showing melting points above room temperature, ranging between (324.15 and 338.15) K and enthalpies of fusion close to or higher than 100 J/g, making them potentially suitable phase-change materials (PCMs) for latent heat storage. This application potential can be enhanced by a suitably large heat capacity and thermal conductivity of the material both in the liquid and solid phase. Heat capacity was therefore measured in this work as a function of temperature using the differential scanning calorimetry (DSC) to determine how it is affected by the anion structure. Care has been taken to evaluate the influence of the phase change on the measured data. The experimental data have then been analyzed by means of methods based on mathematical gnostics (MG). As a non-statistical approach towards data uncertainty, MG enabled us to analyze the underlying phenomena that affect the value of the experimental heat capacity.

The effects of formaldehyde on the growth of two strains of fodder yeasts Candida diddensii 74-10 and Candida tropicalis R-70 were investigated using the method of continuous cultivation under conditions of carbon limitation and at dilution rates of 0.1/h and 0.25/h. The results indicate that formaldehyde induces a decrease in the yield of biomass, but stimulates the synthesis of protein and RNA. The authors studied the activities of the following enzymes: NADPH-linked glutamate dehydrogenase, NADH-linked glutamate dehydrogenase, alanine dehydrogenase, glutamine synthetase, and glutamate synthase, which are utilized in nitrogen metabolism. The data obtained showed an increase in the activity of the glutamate dehydrogenase pathway of ammonium assimilation. It was also established that formaldehyde caused considerable changes in the micro-organisms at the higher dilution rate.

The fungal strain Humicola lutea 103 produces a naturally glycosylated Cu/Zn-superoxide dismutase (Cu/ZnSOD) (HLSOD). To improve its yield, the effect of increased concentration of Cu2+ (from 1 to 750 microg/ml) on growth and enzyme biosynthesis was studied. The primary structure of this fungal enzyme has been determined by Edman degradation of peptide fragments derived from proteolytic digest. A single chain of the protein, consisting of 152 amino acid residues, reveals a very high degree (74-85%) of structural homology in comparison to the amino acid sequences of other fungal Cu/ZnSODs. The difference of the molecular masses of H. lutea Cu/ZnSOD, measured by MALDI-MS (15,935 Da) and calculated by its amino acid sequence (15,716 Da), is attributed to the carbohydrate chain of one mole of N-acetylglucosamine, attached to the N-glycosylation site Asn23-Glu-Ser. HLSOD protected mice from mortality after experimental influenza A/Aichi/2/68 (H3N2) virus infection. Using the glycosylated HLSOD, the survival rate is increased by 66% (protective index=86.1%) and the survival time prolonged by 5.2 days, similar to the application of ribavarin, while non-glycosylated bovine SOD conferred lower protection.

This study investigated the influence of corn straw application on soil microbial communities and the relationship between such communities and soil properties in black soil. The crop used in this study was maize (Zea mays L.). The five treatments consisted of applying a gradient (50, 100, 150, and 200%) of shattered corn straw residue to the soil. Soil samples were taken from May through September during the 2012 maize growing season. The microbial community structure was determined using phospholipid fatty acid (PLFA) analysis. Our results revealed that the application of corn straw influenced the soil properties and increased the soil organic carbon and total nitrogen. Applying corn straw to fields also influenced the variation in soil microbial biomass and community composition, which is consistent with the variations found in soil total nitrogen (TN) and soil respiration (SR). However, the soil carbon‐to‐nitrogen ratio had no effect on soil microbial communities. The abundance of PLFAs, TN, and SR was higher in C1.5 than those in other treatments, suggesting that the soil properties and soil microbial community composition were affected positively by the application of corn straw to black soil. A Principal Component Analysis indicated that soil microbial communities were different in the straw decomposition processes. Moreover, the soil microbial communities from C1.5 were significantly different from those of CK (p < 0.05). We also found a high ratio of fungal‐to‐bacterial PLFAs in black soil and significant variations in the ratio of monounsaturated‐to‐branched fatty acids with different straw treatments that correlated with SR (p < 0.05). These results indicated that the application of corn straw positively influences soil properties and soil microbial communities and that these properties affect these communities. The individual PLFA signatures were sensitive indicators that reflected the changes in the soil environment condition.

In the present study, photophysical properties of fluorescent poly(oxyethylene phosphate) tris(beta-diketonate) europium (III) complexes have been studied by means of stationary and time-resolved fluorescence spectroscopy (in ethanol at room temperature). The luminescent quantum yields and efficiency for the energy transfer from beta-diketonate ligands to Eu(III) ion have been determined for the studied complexes by using diffusion-enhanced fluorescence resonance energy transfer. Obtained results show effect of the polymer ligands upon photophysical properties of the complexes and a relation has been established with length of the oxyethylene spacer between two phosphonate groups. The Förster radiuses of the synthesized compounds with SulfoRhodamine 101 as acceptor have been calculated. Measured distances between molecules of the donors and acceptor at identical acceptor/donor molar ratios have been illustrated the difference in structure of the ternary and polymer complexes in solution even at low concentration.

In the present work, we carry out evaluation of gas flow maldistribution in different types of gas distributing devices (GDD) and packings by using experimental data for the output velocity profiles for both the absorption pilot column and industrial column. Two GDD construction types—with circular and with local tube gas feed, together with their modifications—are investigated. Two pilot columns—with random packing RSRM 1.5″ and with structured ceramic Honey-comb packing, and one industrial contact economizer with Honey-comb and inclined rings—have been studied. Six types of quantitative estimations of GDD and packings maldistribution are determined by the help of MATHCAD. Then, their sensitivity toward several factors, such as the type of GDD and packing, the initial gas flow velocity, the number and dimension of measuring cells on the column cross-section, the measurement error, and so on, is investigated. It is found that only two of the quantitative maldistribution estimations take into account the formation of maldistribution clusters, which deteriorates the uniform gas distribution. A novel method for quantitative determination of these clusters and also for identification of the zones at column cross-section, in which they appeared, has been developed. It is established that the measurement error and the dimension of measuring cell deeply influence the number, the area, and spatial distribution of these zones on the cross-section, as well as the values of maldistribution estimates.