Наукові статті

Постійне посилання на фонд

https://dspace7.knuba.edu.ua/handle/987654321/30

Переглянути

Зараз показуємо 1 - 20 з 744

35. The influence of complex additive on strength and proper deformations of alkali-activated slag cements
(Trans Tech Publications Ltd, 2019) Krivenko, Pavel; Petropavlovskyi, Oleh; Rudenko, Igor; Konstantynovskyi, Oleksandr
The peculiarity of alkali-activated slag cements (further, AASC’s) is increased proper deformations, which can cause increased cracking and reduced durability of structure. The paper is devoted to manage AASC’s proper deformations. The main task was to determine the composition of complex additives (further, CA’s) in system «ordinary portland cement (further, OPC) clinker -mineral compound of different anionic type - surfactant» in presence of sodium metasilicate (further, MS) to affect on hydrated AASC performance while ensuring effective structure of artificial stone by criterion of shrinkage deformations. Comparative analysis of hydrated cement systems "OPC clinker - MS", "OPC clinker - mineral compound - MS" and "OPC clinker - mineral compound - MS - surfactant" showed that the greatest effect on reduction of proper deformations occurs when the mineral compounds relate to electrolytes, i.e. Na2SO4 and NaNO3. Hydrated system is characterized by expansion (+0,062 mm/m) in presence of Na2SO4. Almost no shrinkage is supplied by application of NaNO3 (-0,062 mm/m). The obtained CA’s were tested in AASC. CA in the system “OPC clinker - NaNO3 - surfactant” provides the initial setting 43 min, the end - 65 min with accelerated strength. Investigated AASC can be classified as non-shrinking cement. This phenomena is ensured by increasing density, homogeneity and monolithicity of hydrosilicate formations, as well as due to formation of hydroaluminosilicate structures with different morphology by inclusion of nitrate anions.
A study of air pollution with formaldehyde along the highways in Kyiv city
(2018) Voloshkina, O.; Sipakov, R.; Zhukova, O.; Bereznitska, J.
The problem of air pollution in the cities of Ukraine was described. The methodology of calculation of hydrocarbon emission on automobile overpasses and crossroads of Kyiv was suggested. By the number of bands, the number of cars was determined. The calculation has shown that at the same time near 300 cars can be on the overpass during peak hours. The average concentration of formaldehyde according to the calculations and observation data in 2016 was presented.
About some features of forecasting masstransport processes in saturated - unsaturated media
(2018) Telyma, S.; Voloshkina, O.
The general methodic of forecasting the flow and moisture-salt transfer processes in saturated-unsaturated media on the base of the methods of mathematic modeling for case of the arbitrary vertical domains is proposed.The practical example of the solution the migration problem of pollutions at filtration from the irrigated channel to reservoir is demonstrated.
Adaptation of IUCN Classification Schemes for Environmental safety passports of species
(2016) Kryvomaz, Tetyana
This study aimed to improve the ways of risk assessment for environmental safety. The implementation of “Environmental safety passports of species” is of practical importance for effective risk assessment of individual species impact to the environment, humans and other living organisms. The classification schemes of International Union for Conservation of Nature for evaluating habitats, threats & stresses, use and trade, livelihoods of species were analyzed and adapted to the requirements of environmental safety. Some sections such as general information about species, their distribution, ecological classification, metabolism features, risks evaluation and beneficial use were itemized to be included into the structure of ESPS.
Administrative law tools regulating high-rise construction in historic city districts: Ukraine and Germany
(Amazonia Investiga, 2022) Pokhylenko, I; Tarasiuk, Y; Samsin, I; Bliakharskyi, Y
Історичні квартали в містах є живим втіленням культури народу та його колективної пам’яті, які зберігають його спадщину та минулі досягнення. Міська ідентичність залежить від задоволення поточних потреб при збереженні минулого. Водночас урбанізація тисне на більшість країн, тому вони вимагають оновлення інструментів адміністративноправового регулювання, здатних захистити ідентичність багатої національної спадщини. Метою статті був порівняльно-правовий аналіз реалій та перспектив збереження історичних районів міст у контексті практики адміністративно-правового регулювання України та ФРН. Провідними методичними засобами були методи порівняльно-правового аналізу та спостереження. Дослідження виявило специфічні фізичні, соціальноекономічні та соціокультурні чинники урбанізації, які спричинили помітні та суттєві зміни в особливостях інструментів адміністративного права, що регулюють
Alkali activated portland cement with adjustable proper deformations for anchoring application
(IOP Publishing Ltd, 2019) Krivenko, P. V.; Rudenko, I. I.; Petropavlovskyi, O. M.; Konstantynovskyi, O. P.; Kovalchuk, A. V.
The application of alkali-activated Portland cement (hereinafter AAPC) for anchoring grouts was investigated with obtaining of non-shrinking high performance cementing systems. The AAPC system “ordinary Portland cement clinker – sodium metasilicate” was modified by the complexes of mineral and organic compounds to ensure specified properties of anchoring grouts. It was revealed that the most effective multifunctional additives are represented by the system “salt-electrolyte – surfactant”. Alongside with slowing down of AAPC paste setting time, the effect of compensated shrinkage of AAPC mortar, i.e. expansion within 0.062 mm/m and slight shrinkage within 0.017 mm/m, was ensured when Na2SO4 and NaNO3 were used in the mentioned system respectively. The effect of compensated shrinkage is explained by greater crystallization of ydrosilicates and hydroaluminates, additional formation of sulfate-containing sodium-calcium hydroaluminate (for Na2SO4-based system) and crystalline calcium hydronitroaluminate (for NaNO3-based system). The advantages of the modified AAPC for anchoring application are indicated in thepaper.
Alkaline aluminosilicate binder-based adhesives with increased fire resistance for structural timber elements
(2019) Krivenko, P. V.; Guzii, S. G.; Bondarenko, O. P.
The paper presents data on the use of the alkaline aluminosilicate binder-based adhesive of the system Na2O•Al2O3•(4-6)SiO2•(17-20)H2O for gluing and fire protection of structural timber elements. The results of the study of thermoresistant phases in the reaction products of the alkaline aluminosilicates are reported and discussed. The results allowed to show that at SiO2/Al2O3 between 5 and 6 the zeolite-like phases of heulandite types, which, under action of temperatures, are able to form a porous aluminosilicate artificial stone with low thermal conductivity (λ=0.09 Wt/m⋅К, DSTU B V.2.7-105-2000 (GOST 7076-99)) are formed in the reaction products. The use of the developed aluminosilicate adhesives allow for to classify the structural timber elements as hardly burnable and hardly flammable materials (GOST 12.1.044-1989, EN 13823 + A1: 2014-12, ASTM E119-07). They have the following characteristics: water resistance D3 (EN 204:2001), resistance in splitting up 7.8 MPa (GOST 16483.5-1973), adhesion in normal pull-off test up to 2.6 MPa (GOST 32299- 2013 (ISO 4624:2002)).
An annotated checklist of myxomycetes from the Seychelles Islands, Indian Ocean
(Finnish Mycological Society, 2020) Kryvomaz, Tetiana; Michaud, Alain; Stephenson, Steven L.; L.
The checklist provided herein contains 143 species and infra-specific taxa of myxomycetes representing six orders, 12 families and 29 genera known from the Seychelles Islands. These records are the result of 878 field collections and 468 samples processed with the use of the moist chamber techinque. The overall study involved expeditions to the granitic group of islands Mahé, Praslin, La Digue, Curieuse, Félicité, and data from the literature for the coral Aldabra atoll. The taxonomic structure of the myxomycete biota for the islands studied indicates a predominance of members of the order Physarales (74 taxa). The main genera are Physarum (38 species and two varieties), Didymium (17 species), Cribraria (11 species), Arcyria (eight species) and Stemonitis (six species and two varieties). For all six islands only a single species of myxomycete (Physarum crateriforme) was shared in common. For the total assemblage of species recorded from all of the islands, 4% species were abundant, 12% species were common, 29% were found occasionally, 42% were rare, and 13% species had only a single record. The most abundant species were Arcyria cinerea, A. denudata, Diderma effusum, Hemitrichia calyculata, Physarum compressum, and P. melleum. Based on data from 50 different localities with 90 collecting plots, 32% of all specimens were associated with coastal vegetation, 30% with lowland localities, 19% with intermediate forests, 9% with riverine forests, 8% with mountain forests, and only 2% with mangrove swamps. In general, this annotated checklist clearly shows that isolated tropical islands can support a diverse assemblage of myxomycetes.
Analysis of the main characteristics of industrial risk
(2019) Hunchenko, Oksana
Any practical, including industrial, human activity is potentially dangerous, that is, it is impossible to achieve absolute security in any of its types. Based on this thesis in western countries, the basis of the life-safety methodology, which is part of the protection of labor, is based on the concept of acceptable risk. The concept of "risk" has a long history of use as a legal category. But due to the rapid development of industrial production and the need to justify various aspects of military activity, this concept has become more widespread in other sectors. Usually, risk is associated with a manifestation of uncertainty and signs of danger.
Anthropogenic changes in water ecosystem on the example оf the river Tisza
(КНУБА, 2018) Vasylenko, Lesya; Zhukova, Olena; Klimova, Irina; Gontscharenko, Artem
While conducting the ecological estimation of the hydro ecosystems (HE) condition of Tisza water basin, engineering ecological indices and their parameters are used. The system-basin research approach of the water basin based on systematization and data processing of the ecological monitoring for a long-term period is used. Such period allowed to set scientific regularities of naturally-anthropogenic hydro ecosystems development in the conditions of constant anthropogenic load on them.
Applying of green building standards for implementation of the city development strategies in Kyiv
(2019) Kryvomaz, Tetyana; Varavin, Dmytro
The main tasks of the "Kyiv City Development Strategy until 2025" are in development and reconstruction of the city, improvement of its infrastructure and environmental protection, which perfectly correlates with the basic principles of green building. This is the modern practice in construction, reconstruction and the exploitation of buildings, in which they implement optimal architectural solutions, advanced engineering systems and materials for reducing of energy consumption and material resources, it is the process of improving the quality of buildings and the comfort of their internal environment, improving of impact of buildings on the health of people by minimizing the negative impact on the environment at all stages of life cycle of building structures. The practice of the tasks outlined in the Strategy will significantly contribute to the implementation of international environmental standards and to the application of constructive solutions of green building technologies. In particular it appeals to such urban development sectors as city development and land relations, housing and communal services, transport and urban mobility, environmental policy and environmental protection, public space, security and civil protection, historical and architectural heritage.
Arcyria denudata
(CABI, 2012) Krivomaz, Т. І.; Michaud, A.; Minter, D. W.
Diagnostic features. Bright red or reddish brown, upright sporangia, each with a funnel-shaped calyculus with a non-dehiscent capillitium firmly attached to calyculus even after expansion. Brown weathered sporocarps may be confused with A. affinis Rostaf., but in that species the stalk is slightly eccentric, and the capillitium detaches from the calyculus after expanding.
Arcyria minuta
(CABI, 2012) Krivomaz, Т. І.; Michaud, A.; Minter, D. W.
Diagnostic features. Flat-topped, pink sporangia, each with a fixed capillitium, and capillitium thread marking more or less limited to cogs. Poorly developed sporocarps, or those with a non-expanded capillitium resemble A. cinerea (Bull.) Pers., but in A. cinerea sporangium colour is grey, and capillitium markings are densely spinulose. Sporangium colour in A. minuta is similar to that of A. pomiphomis (Leers) Rostaf., but A. minuta has larger sporocarps and cylindrical rather than subglobose sporangia.
Arcyria stipata
(CABI, 2012) Krivomaz, Т. І.; Michaud, A.; Minter, D. W.
Diagnostic features. The almost pseudoaethalial habit, persistent peridium and copper colour make this species distinctive.
Assessment and forecast for the creation of photo-chemical smog over transport overpasses in Kyiv
(2018) Sipakov, R.; Trofimovich, V.; Voloshkina, O.; Bereznitska, J.
This article deals with the analysis of existing of smog situation formation over automobile overpasses and in places of substantial congestion of transport in large cities, for example, in Kyiv. A mathematical model consisting of two blocks – dynamic and kinetic, which allows determining the formation of the thermal dome of pollution and the concentration of hydrocarbon emissions in the air, depending on the number of working engines, is proposed. The kinetic block of the model allows determining the level of formaldehyde, as an indicator of the appearance of photochemical smog in conditions of atmospheric constancy. The concentration of emissions from motor vehicles in the air is calculated over the main transport overpasses of the city of Kyiv at their full load (peak hours).
Assessment of mangrove environmental safety by analyzes of metals transition
(2016) Kryvomaz, Tetyana; Andrusishina, Iryna
The study of metals transition in mangrove biome by analyzes of element concentration in plant, myxomycetes and soil for preliminary assessment of environmental safety. Methodology. Samples of soil, leaves litter, steam of living palm and myxomycetes fruiting body from Seychelles mangrove biome on Praslin island were analyzed by method of inductively coupled plasma atomic emission spectroscopy. Results. The scheme of 11 elements (Al, Ca, Cd, Cu, Fe, Mg, Mn, Ni, Pb, Si, Zn) accumulation demonstrates that heavy metals concentration increases in the direction from substrates to myxomycetes, and it decline from the forest floor to the trees. The ability myxomycetes Hemitrichia serpula accumulate Ca (Km-s = 443,69) and Zn (247,41) from environment was discover; Ni (60), Mn (16,04) and Pb (11,94) also show high level elements concentration in compere with their content in soil. The research finds big transformation ratio soil elements to mobile forms of soil for Fe (253,81) and Cu (105,45). Originality. For the first time the elements concentration in plant, myxomycetes and soil in mangrove were analyzed from ecological safety point of view. Practical value. Myxomycetes have undiscovered potential for bioindications and bioremediation of heavy metal and environmental management. References 10, no tables, figures 5.
Autoclaved aerated concrete in Ukraine
(2020) Lapovska, Svitlana; Demchenko, Tetyana; Dyuzhilova, Nataliya
The article provides an overview of Ukrainian enterprises that produce autoclaved aerated concrete. The range of products manufactured for the period 2016-2019 is considered. The performance of enterprises and systemic technical solutions for the installation of energy-efficient exterior walls from AEROС LLC are analyzed.
Biological deterioration of wooden structures of the Bialystok open-air museum
(2017) Perebynos, Alona; Kryvomaz, Tetyana
The preliminary survey of the biodeterioration in the Bialystok open-air museum (Poland) shows that wooden buildings are in good condition and 92% of historical and architectural constructions were estimated to the second category of technical state. Buildings were examined to identify kinds of biological agents. The main biodeteriorations of wooden constructions were made by insects, lichens, algae films and colonies of microfungi. The comparison of the biodeterioration impact was made for the Bialystok open air museum and the skansen "Pyrogovo" (Ukraine). The probability of germination on the wooden structures of some species of fungi has been calculated taking into account the temperature conditions of the north-eastern region of Poland.
Calomyxa metallica
(CABI, 2012) Krivomaz, Т. І.; Michaud, A.; Minter, D. W.
Diagnostic features. The pinkish olive spore mass, iridescent peridium and coiled, simple threads sculptured with abundant, faint warts or spinules make this an easy species to identify. The superficially similar Prototricha metallica (Berk.) Massee has capillitial threads marked with spiral bands.
Chaga (Inonotus obliquus), a Future Potential Medicinal Fungus in Oncology? A Chemical Study and a Comparison of the Cytotoxicity Against Human Lung Adenocarcinoma Cells (A549) and Human Bronchial Epithelial Cells (BEAS-2B)
(2018) Géry, A.; Dubreule, C.; André, V.; Rioult, J.-P.; Bouchart, V.; Heutte, N.; Eldin de Pécoulas, P.; Krivomaz, T.; Garon, D.
Background: Inonotus obliquus, also known as Chaga, is a parasitic fungus growing on birches and used in traditional medicine (especially by Khanty people) to treat various health problems. In this study, we aimed to quantify the 3 metabolites frequently cited in literature, that is, betulin, betulinic acid, and inotodiol in the Chaga recently discovered in forests located in Normandy (France), and to compare their concentrations with Ukrainian and Canadian Chaga. This study also explores the cytotoxicity of the French Chaga against cancer-derived cells and transformed cells. Methods: A quantification method by HPLC-MS-MS (high-performance liquid chromatography–tandem mass spectrometry) of betulin, betulinic acid, and inotodiol was developed to study the French Chaga and compare the concentration of these metabolites with extracts provided from Chaga growing in Canada and Ukraine. This method was also used to identify and quantify those 3 compounds in other traditional preparations of Chaga (aqueous extract, infusion, and decoction). Among these preparations, the aqueous extract that contains betulin, betulinic acid, and inotodiol was chosen to evaluate and compare its cytotoxic activity toward human lung adenocarcinoma cells (A549 line) and human bronchial epithelial cells (BEAS-2B line). Results: French Chaga contains betulin and betulinic acid at higher levels than in other Chaga, whereas the concentration of inotodiol is greater in the Canadian Chaga. Moreover, the results highlighted a cytotoxic activity of the Chaga’s aqueous extract after 48 and 72 hours of exposure with a higher effect on cancer-derived cells A549 than on normal transformed cells BEAS-2B (P = 0.025 after 48 hours of exposure and P = 0.004 after 72 hours of exposure).

Переглянути

Перегляд Наукові статті за Назва

Результатів на сторінці

Налаштування сортування