Effects of Humic Substances Obtained from Shives on Flax Yield Characteristics

The effects of humic substances (HS) extracted from flax shives on the fiber and seed yield of fiber flax were examined during 3 years field experiment. HS from shives consists of humic acids—5.3 gL^?1 and fulvic acids—0.7 gL^?1 were applied (6·10^–2 gL^?1 concentration, with 300 Lha^?1 of spraying liquid) in “herring-bone” stage (BBCH 13 growth stage). The HS action was evaluated in different climatic conditions and in three varieties. Application of HS on early stage of vegetation of flax plants increased fiber yield (exceeding control on 16.0–28.1%) and quality (5% of cellulose content), protein and oil content in seeds (up to 1.9–4.2% and 1.6–3.5%, respectively). Positive reply of flax plants on HS from flax shives in tested cultivars allows saying about prospects of this type of humic substances.     

Ionic composition of rat airway surface liquid determined by X-ray microanalysis

The thin layer of liquid that lines the conducting airway epithelium, the airway surface liquid (ASL), is important for mucociliary clearance. Altered ionic composition and/ or volume of the ASL play a major role in the pathology of airway diseases such as cystic fibrosis. Since the ASL is a thin layer, it has been difficult to exactly determine its composition. The present paper describes two techniques that have been developed and used to study ASL composition: X-ray microanalysis of frozen hydrated rat trachea, and an ion-exchange (dextran) bead method, where dextran beads were placed on the airway epithelium to equilibrate with the ASL; the beads were then collected under silicone oil, dried and analyzed by X-ray microanalysis. The results from both frozen-hydrated specimens and from the dextran beads showed that ASL from rat trachea is hypotonic. Concentrations of Na, P, S, and K were higher in the frozen-hydrated ASL, in which mainly the mucus layer is analyzed, compared with the dextran bead method, in which mainly the periciliary liquid is sampled. Also the composition of rat nasal fluid was investigated by the dextran bead method. This fluid was somewhat hypertonic because of a high K concentration. The ionic composition of the nasal and tracheal fluid can be manipulated by cholinergic or alpha- or beta-adrenergic stimulation. Collecting ASL with dextran beads did not disturb the integrity of the airway epithelium. The ionic composition of the collected beads remained stable for several days during storage in silicone oil. It is concluded that X-ray microanalysis is a suitable method to determine the ionic composition of ASL.     

Efficiency of an elliptically shaped x-ray mirror

Curved reflecting mirrors are widely used as x-ray optical elements for both laboratory and synchrotron radiation sources. In general, the mirror parameters are optimized by numerical simulation. We discuss an analytical approach that is useful for deriving the mirror parameters, including eccentricity, length, angular acceptance, and magnification. We have examined in particular an elliptical surface from which we learned that, given the distance between the foci of the ellipse, the magnification, and the critical angle of total external reflection, it is possible to find analytically the optimal eccentricity that maximizes the angular acceptance and the optimal mirror length. We found that the last-named parameter, in a first approximation, depends only on the distance between the foci of the ellipse and on the magnification factor. We present as well a comparison of optimal parameters obtained with analytical calculation and with ray-tracing simulation that yielded good agreement.     

Triacylglycerols of the red microalga Porphyridium cruentum can contribute to the biosynthesis of eukaryotic galactolipids

A mutant of the red microalga Porphyridium cruentum was selected on the basis of impaired growth at suboptimal temperatures (15 vs. 25°C). Fatty acid and lipid analyses revealed diminished proportions of eicosapentaenoic acid (from 41 to 30%) and of the eukaryotic molecular species (from 38 to 28% of monogalactosyldiacylglycerol (MGDG) and elevated proportion (10 vs. 2%) of triacylglycerols (TAG) in the mutant, as compared with the wild type. Pulse labeling of the wild type cells with radioactive fatty acid precursors indicated an initial incorporation of the fatty acids into phosphatidylcholine (PC) and TAG. Following the pulse, the label of PC and TAG decreased with time (from 25 to 5% of the total dpm in TAG) while that of chloroplastic polar lipids, mainly MGDG, continued to increase. In the mutant, however, the labeling of TAG after the pulse was higher (30% of the total dpm) than that of the wild type and decreased only slightly to 20%. This may indicate that in P. cruentum, TAG can contribute to the biosynthesis of eukaryotic species of MGDG.     

Curie point and a space charge relaxation in ferroelectric poly(vinylidene fluoride‐trifluoroethylene) copolymers with different thermal history

High‐temperature processes of space charge relaxation in films of poly(vinylidene fluoride‐trifluoroethylene) (70–30) have been investigated. The films were prepared by the crystallization from a solution in tetrahydrofuran at a room temperature. X‐ray data analysis showed that initial films crystallize in metastable state: a paraelectric phase is formed at fast crystallization below the Curie temperature. An exothermic process was observed at heating, indicating a solid‐state crystallization of metastable paraelectric regions. This process is controlled by melting of ordered regions formed at secondary crystallization. These transformations of structure affect characteristics of the high‐temperature space charge relaxation process. In particular, it was found that activation energy of extrinsic conductivity is reduced by several times in the region of ferroelectric‐paraelectric phase transition. An additional relaxation process was registered above the Curie temperature, which is caused by the relaxation of charges in double electric layer formed on an interface between an electrode (Au) and fluorine‐containing polymer. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46186.     

New Electrochemistry-Based Approaches to Brandy Quality Evaluation Using Antioxidant Parameters

The electrochemical approaches based on coulometric titration, differential pulse voltammetry (DPV), and chronoamperometry have been tested for applicability to evaluation of brandy quality. The antioxidant properties of samples have been considered as markers of adulteration. Total antioxidant capacity (TAC), ferric reducing power (FRP), as well as ellagic acid equivalent antioxidant capacity (EAE AOC) have been evaluated for ten samples five of which have been recognized as adulteration by gas chromatography. Electrochemical data for adulterations and brandies are significantly different. TAC and FRP values for all adulterated samples are approximately the same (10?±?3 and 6?±?2 C/100 mL for TAC and FRP, respectively) while brandies show TAC in the range of 24–108 and FRP of 20–88 C/100 mL depending on denomination and origin. DPV profile of adulterations is strongly different in comparison with brandy (the required peaks are absent and irrelevant peaks are appeared), allowing sample discrimination. Addition of vanillin-containing flavoring agents has been confirmed. The corresponding EAE AOC of brandies is 8–15-fold higher (depending on denomination) than that for adulterations. Two adulterations did not show EAE AOC, reflecting the absence of aging step during beverage production. Chronoamperometric EAE AOC equals to zero for four investigated adulterations. Standard antioxidant parameters antioxidant activity and total phenolic content can be applied for the preliminary screening only. These parameters are ineffective for adulteration of the beverage age using oak extracts. Electrochemical methods developed are characterized by simplicity, cost-efficiency, and reliability of results and can be successfully applied for the brandy quality control.     

Assessment of Metals Pollution from Tailing Sites in the North Caucuses Region,Russia

The concentrations of metals were determined in the water and bottom sediments of both the Urup and Kuban Rivers near tailings sites in the North Caucasus region of southern Russia. The average concentrations in the Urup followed the order Fe?>?Mn?>?Pb?>?Cu?>?Zn?>?Cd?>?Ni?>?Co, while in the Kuban, the order was Fe?>?Pb?>?Zn?>?Ni?>?Mn?>?Cd, with copper and cobalt not detected. The levels of Zn, Cu, Pb, Cd, and Ni were above Russia’s maximum permissible concentration in both rivers. The water pollution index (WPI) values in Urup ranged from 12.97 to 28.17, indicating that the river is extremely polluted (Class VII), while the WPI value for Kuban ranged from 2.34 to 4.33 downstream of the tailings site, which corresponds to Class IV (contaminated). Calculating the coefficient of accumulation in sediments (CAS) revealed that in Urup, the CAS values for Ni and Cu were 3046 and 11638, respectively, which indicates an emergency environmental situation, while for Co, Fe, and Mn, the situation is high level chronic pollution (CAS?>?10⁴). The Kuban CAS values of Fe and Mn were also >?10⁴, again highly and chronically polluted. Most of the metals in both rivers are bound to the sediments, with minimal mobility. The potential ecological risk is moderate to considerable in Urup, and low in the Kuban River.     

Synthesis of yttrium titanate stannate (Y2Ti2−xSnxO7, x = 0–2) pyrochlore glass–ceramics as potential nuclear waste form

Y₂Ti_2−xSn_xO₇ (x = 0–2) pyrochlore sodium aluminoborosilicate glass–ceramics (GCs) are produced by calcining the pelletized Y–Ti–Sn oxide mixture and glass precursor at 1200 or 1300°C for 4 h. The metal oxide mixture is prepared by a soft chemistry route. X-ray diffraction, Raman spectroscopy, and electron microscopy are employed to investigate the formation of pyrochlore GCs and local crystal structures. Near phase pure Ti-rich pyrochlores are produced with minor phase SnO₂ observed for Sn-rich materials. The cell parameters of the pyrochlore structures refined by Le Bail fitting are in good agreement with the published data and increase linearly with the gradual increment of Sn substitution. With progressively increasing Sn proportion on pyrochlore B-site, Raman characteristic bands of the pyrochlore structure become sharper and well defined. The Raman A_1g peak position and its full width at half-maximum are linearly progressed with increasing x (Sn). The presence of the melting glass facilitates the pyrochlore formation, with ceramic grain sizes ranging from submicron to microns. Transmission electron microscopy and selected area electron diffraction observations indicate the sample possesses a relatively high crystallographic perfection at the atomic level. This new series of pyrochlore GCs and the method disclosed herein may pave the way for further materials development as potential nuclear waste forms.