24 research outputs found

    Sсandium(III) Beta-diketonate Derivatives as Precursors for Oxide Film Deposition by CVD

    Get PDF
    AbstractComplexes with acetylacetone Sc(acac)3, dipivaloylmethane Sc(thd)3, 2,2,6,6–tetramethyl-4-fluoro-3,5-heptanedione Sc(tfhd)3, pivaloyltrifluoroacetone Sc(ptac)3, trifluoroacetylacetone Sc(tfac)3, and hexafluoroacetylacetone Sc(hfac)3 were synthesized, purified and identified by elemental analysis, m.p., IR and NMR spectroscopy, and mass spectrometry. The thermal behaviour of the synthesized compounds in the solid state was investigated by the method of difference-scanning calorimetry in vacuum. As a result the thermodynamic characteristics of the melting processes were determined. The temperature dependences of saturated and unsaturated vapour pressure of complexes under study were measured by static method with membrane-gauge manometers. The average molecular weight of gas calculated from the experimental data on unsaturated vapours using ideal gas law was close to the molecular weight of monomer for all investigated compounds. Decomposition temperatures of compounds under study were defined as the temperature above that pressure changes became irreversible. The information about melting and decomposition processes were taken into account at measuring saturated vapour pressure of complexes. The row of volatility Sc(hfac)3 > Sc(ptac)3 > Sc(tfac)3 > Sc(thd)3 ≥ Sc(tfhd)3 > Sc(acac)3 was determined from the p–T dependences obtained. Above information about thermal behaviour of complexes enabled one to use it as a guide for CVD experiments aimed at achieving oxide films with high optical properties. Precursor chosen for film deposition was Sc(thd)3 The Sc2O3 film deposition conditions were following: the gas-carrier rate 1 l/h, He gas-reagent rate 10 l/h, total pressure 10 Torr, evaporator temperature 105-110̊С, substrate temperature 450- 650̊С, substrate Si(100). Ellipsometry was applied to characterize the film thickness and refractive index. The morphology and the composition of the films were determined with XPS and SEM

    Biodiversity surveys of grassland and coastal habitats in 2021 as a documentation of pre-war status in southern Ukraine

    Get PDF
    Background This paper presents two sampling-event datasets with occurrences of vascular plants, bryophytes and lichens collected in May-June 2021 in southern Ukraine. We aimed to collect high-quality biodiversity data in an understudied region and contribute it to international databases and networks. The study was carried out during the 15th Eurasian Dry Grassland Group (EDGG) Field Workshop in southern Ukraine and the Dark Diversity Network (DarkDivNet) sampling in the Kamianska Sich National Nature Park. By chance, these datasets were collected shortly before the major escalation of the Russian invasion in Ukraine. Surveyed areas in Kherson and Mykolaiv Regions, including established monitoring plots, were severely affected by military actions in 2022. Therefore, collected data are of significant value in the context of biodiversity documentation. The knowledge about the biodiversity of this area will help to assess the environmental impact of the war and plan restoration of the damaged or destroyed habitats. The first preliminary analysis of collected data demonstrates the biodiversity richness and conservation value of studied grassland habitats. New information We provide sampling-event datasets with 7467 occurrences, which represent 708 taxa (vascular plants, bryophytes and lichens) collected in 275 vegetation relevés. Amongst them, vascular plants are represented by 6665 occurrences (610 taxa), lichens - 420 (46) and bryophytes - 381 (51). Several new species were reported for the first time at the national or regional level. In particular, one vascular plant species (Torilis pseudonodosa) and two lichen species (Cladonia conista, Endocarpon loscosii) were new to Ukraine. One vascular plant (Stipa tirsa), two species of bryophytes (Rhynchostegium megapolitanum, Ptychostomum torquescens) and three species of lichens (Cladonia cervicornis, C. symphycarpa, Involucropyrenium breussi) were recorded for the first time for the Kherson Region. Additionally, these datasets contain occurrences of taxa with narrow distribution, specialists of rare habitat types and, therefore, represented by a low number of occurrences in relevant biodiversity databases and particularly in GBIF. This publication highlights the diversity of natural vegetation and its flora in southern Ukraine and raises conservation concerns

    Plant species richness records in Ukrainian steppes

    Get PDF
    We compiled a list of the known maxima of vascular plant species richness in the steppe zone of Ukraine at different sampling scales (0.0001–100 m2) and compared them with the world records. Detailed information on each of the identified species-rich grassland plots is provided, including site descriptions, plot characteristics, coordinates, and species lists. Most of the small-scale records (up to 0.1 m2) were found in mesic grasslands in southern Ukraine (Kherson region) with a high abundance of annual grasses and forbs: 9 and 11 vascular plant species in 0.0001 m2 and 0.001 m2, respectively, in the steppe depression Chorna Dolyna, and 26 species in 0.1 m2 in a mesic psammophytic grassland in the Dzharylhach National Nature Park. Most of the records at larger scales were made in the northern part of the steppe zone, in forb-rich and forb-grass steppes: 15, 39, 73, and 107 species in 0.01, 1, 10, and 100 m2, respectively. All richness records were characterised by neutral to slightly alkaline sub-strates (soil pH 7.0–7.7) and low-intensity management. These characteristics are consistent with the known patterns from world records of species richness. Our inventory provides baseline knowledge for studies on the high species richness in the steppe zone and can stimulate the further investigation of identified species-rich grasslands, as well as the search for new ones. Since we did not specifically search for species-rich sites, and our dataset includes only a relatively small number of plots compared to similar studies in other regions, we expect that more species-rich vegetation will be found with further research. This study highlights the importance of steppe grasslands as global biodiversity hotspots and draws attention to their protection in the context of land-use changes and the consequences of the war in Ukraine

    Клинико-биохимические аспекты развития обструкции бронхов при бронхиальной астме

    Get PDF
    The aim of this study was to investigate NO- and lipid peroxidation (LPO)-related airway reactivity and its correlation to ventilation disorders in different clinical variants of asthma. NO, malone dialdehyde, IL-4, TNF-α, and IgE were measured in BAL fluid and blood serum of 39 asthma patients and 15 healthy volunteers matched for age and gender.In patients with stable asthma, airflow parameters in small and medium airways were significantly decreased compared to those of healthy persons. Concentrations of key cytokines of atopic inflammation in BAL fluid and serum were increased in asthma patients. Serum IgE tended to decrease and IL-4 and TNF-α in BAL fluid increased in asthma patients while the disease worsened. Inverse correlations were found between NO and TNF-α, malone dialdehyde concentration and parameters of bronchial obstruction.In conclusion, NO production in airways is caused by strong accumulation of inflammatory cells with high metabolic activity resulting in release of inflammatory and pro-inflammatory cytokines which regulate immunopathological reagine-induced inflammation.Цель исследования состояла в оценке активности оксида азота (NO) и процессов перекисного окисления липидов (ПОЛ) в дыхательных путях при различных клинических формах БА и взаимосвязи этих процессов с нарушениями функции внешнего дыхания (ФВД). Проведена оценка содержания NO, малонового диальдегида (МДА), интерлейкина-4 (IL-4), фактора некроза опухоли α (TNF-α) и иммуноглобулина Е (IgE) в жидкости бронхоальвеолярного лаважа (ЖЖБАЛ) и сыворотке крови 39 пациентов с БА и у 15 добровольцев, сопоставимых по возрасту и полу. У всех обследованных больных БА в период клинической ремиссии, в отличие от здоровых лиц, достоверно снижены показатели, характеризующие проходимость мелких и средних бронхов. Подтверждено повышение содержания ключевых цитокинов атопического воспаления в ЖБАЛ и в сыворотке крови больных БА. Выявлены тенденции к снижению содержания IgE в сыворотке крови и повышению IL-4 и TNF-α в жидкости бронхоальвеолярного лаважа у больных БА по мере нарастания тяжести заболевания. Обнаружены отрицательные корреляции между между NO и TNF-α, уровнем МДА и показателями, характеризующими ФВД и степень бронхиальной обструкции. NO-продуцирующая функция дыхательных путей обусловлена мощной аккумуляций воспалительных клеток в респираторной системе и их высокой метаболической активностью, проявляющейся выработкой воспалительных и провоспалительных цитокинов, регулирующих иммунопатологическое реагиновое воспаление

    The possibility of buckwheat application in the fermented malt technology t

    Get PDF
    Rye is the traditional raw material for the fermented malt production. The article considers buckwheat grains application as an unconventional raw material. The research materials were rye of Vostok 2 breed and buckwheat of Dikul breed. Amylolytic capacity (AC) of malt was determined by colorimetric iodometric method, saccharification capacity (SC) - by polarimetric method, proteolytic (PC) - by refractometric method (according to Petrov); the humidity of the samples was determined on a thermographic infrared moisture meter FD 610. The extract, acidity and color of the fermented malt was determined according to GOST R 52061-2003. It was found that AC, SC and PC of buckwheat malt are 5.8% higher, 42.9% lower and 11.6% higher respectively than those of rye malt. Comparative characteristics of fermented buckwheat and rye malts showed that there is a decrease in the mass fraction of the extract and an increase in the color of buckwheat malt. This happens due to the hydrolysis of high-molecular compounds - carbohydrates, proteins to sugars and amino acids, respectively, due to the reactions of melanoid formation, which result in improved color, taste and aroma of malt. It was found that the use of buckwheat in fermented malt technology is possible, moreover, it is a gluten-free raw material due to the low content of the gluten fraction of the protein and can be applied to a wide range of consumers, including those suffering from gluten intolerance. But to increase its extractiveness, it is desirable to use enzyme preparations at the malting stage. The novelty of the proposed technical solution is confirmed by the RF patent for invention No. 2603268 "Method for the production of fermented buckwheat malt"

    The study of the main impurities mature mash depending on the duration of fermentation, yeast alcohol race and used enzyme preparations

    Get PDF
    The paper studied the process of intensification of concentrated fermentation mash with account of the complex amylolytic enzymes, hemicellulase and proteolytic activities. We determined the dependence of ethanol yield, the content of volatile impurities, the content of reducing substances, depending on the different strains of yeast at a seed rate 15 million cells per 1 cm3 wort. To identify the parameters of the fermentation process the wort with an increased solids content, investigated the dynamics of accumulation of volatile impurities by varying the rate and duration of seeding yeast fermentation using 987-O5 race yeast. It revealed that the qualitative composition of impurities in the mash, the resulting wort of high-concentration depends both on the duration of fermentation, and from normal seeding yeast. Thus, depending on the duration of the fermentation process, the acetaldehyde content increases (from 613,17 mg/dm? to 54 h to 1724,6 mg/dm? to 72 hours), the amount of ethyl acetate is reduced (from 409,2 mg/dm? to 54 hours prior to 207 mg/dm? to 72 hours), the methanol content to 54 h at a rate of 15 million yeast seeding cells per 1 cm? of the wort amounted to 0,0043 mg/cm?, whereas by 72 h of fermentation at the same seed rate yeast – 0,0070 mg/dm?, the amount of 1-propanol and 1-butanol was reduced from 903,14 mg/cm? and 6,38 mg/cm? -54 h to 880 mg/cm? and 5,57 mg/cm? - to 72 hours, respectively. The minimum content of isobutanol independent of the duration of fermentation was 900-1100 mg/cm? at a seed rate 15 million yeast cells per 1 cm? wort izoamilola number increases from 1219,08 mg/dm? (54 hr) to 2673,84 mg/dm? (72 h). It revealed that the smallest total amount of impurities obtained by seed rate yeast 15 million cells per 1 cm? wort at the duration of fermentation 54 hours was found that maximum ethanol content in the mash with minimal accumulation therein volatiles corresponds embodiment:. Duration of fermentation - 54 hours at normally the problem of yeast cells – 15,0 million / cm? wort

    Selection of enzyme preparations and temperature-time regimes of water-heat and enzymatic treatment in the development of complex technology of processing of grain raw materials

    Get PDF
    The article studies the selection of enzyme preparations of amilolitichesky action intended for receiving a starchy mash with the increased content of solids after release of gluten from it are conducted. Also comparative characteristic of the main indicators of quality of the distiller's beer received on estimated and classical technology was carried out, varying dosages of osakharivayushchy fermental medicines from 2 to 8 units of GLA/g of conditional starch. Process of a sbrazhivaniye of the concentrated mash depending on a dosage of the osakharivayushchy fermental medicine Biozim 800 L is studied

    Technology and instrumentation stevia solutions of spray drying

    Get PDF
    The relevance of the use and development of sweeteners is reflected in the article. The main requirements for sweeteners were given: the sweetness quality, color and odor absence, a pleasant taste, harmlessness, complete elimination from the body, good solubility in water, chemical resistance. Due to its beneficial properties, the sweetener obtained from stevia leaves is increasingly used. A method of obtaining stevia extract with subsequent drying is presented. The leaves and stems of the Stevia rebaudiana Bertoni plant were used for the experiment. The extract was obtained using water-alcohol extraction at a temperature of 85–87 ?С, a water module of 1.0: 4.5, and a duration of 115–118 min. using three rinsings, the water and alcohol extracts were combined. The extract filtered from suspended impurities on a deep filter was concentrated under a vacuum of 0.08 MPa at a temperature of 60 ° C to a content of 35%. The resulting concentrate was dried on an experimental spray dryer. The temperature of the dried particles did not exceed 60 ° С, and the drying process lasted 15–30 s. High-quality stevioside powder was obtained due to instant drying and low temperature of sprayed solution particles. Thus obtained sweetener from stevia does not need intermediate purification from ballast substances and does not require further modification to improve organoleptic properties - to enhance sweetness and reduce the residual bitter aftertaste characteristic of some natural glycosides. The authors believe that the resulting sweetener makes it possible to develop new products with dietary and therapeutic purposes
    corecore