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Wyszukujesz frazę "Ivanova, A. V." wg kryterium: Wszystkie pola


Wyświetlanie 1-16 z 16
Tytuł:
The impact of anthropogenic alluvial arrays on areas settlements depending on the particle size distribution of stored taillings
Autorzy:
Ivanova, A. V.
Smirnov, Y. D.
Powiązania:
https://bibliotekanauki.pl/articles/124804.pdf
Data publikacji:
2016
Wydawca:
Polskie Towarzystwo Inżynierii Ekologicznej
Tematy:
dust
tailings
dump
humidity
dust transfer
dust suppression
pulp
Opis:
Developing devices for dust suppression one should consider important factors, such as the size distribution of transferred dust, duration of exposure in residential areas. Often the total amount of dust emissions may exceed the estimated figure for maximum permissible emissions, but their share transferred in sanitary protection zone of dust is negligible. Tailing dump of Kovdor MPE is one of the largest in Russia. The construction of dust dispersion halos was performed using a universal program calculation of air pollution “Ecolog” (Russia). Based on a comparison of dispersed compositions tails similar in composition tailing dumps in Russia, it can be concluded that in the beach area of the Kovdor dump share of dust tranfered to the territory of settlements has ranged from 10 to 40%. It was found that the maximum diameter of the particles carried by the territory of the city under consideration is 50 microns. We can conclude that under the conditions of the object the development of special devices for dust suppression is required.
Źródło:
Journal of Ecological Engineering; 2016, 17, 2; 59-63
2299-8993
Pojawia się w:
Journal of Ecological Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A novel biocompatibility test for disperse materials
Autorzy:
Tereshchenko, V.
Degtiariova, L.
Segeda, T.
Ivanova, O.
Zinabadinova, S.
Lavrinenko, V.
Powiązania:
https://bibliotekanauki.pl/articles/3183.pdf
Data publikacji:
2015
Wydawca:
Instytut Medycyny Wsi
Tematy:
biocompatibility test
disperse material
chicken
embryo
charcoal
asbestos
Opis:
Introduction. Development of novel biocompatibility tests represents an urgent problem. Use of chicken embryos minimizes the effect of exogenous factors on the experimental course (as the chicken embryo develops in medium it is almost completely isolated from external effects), enables the observation of physiological and pathological processes in the dynamics and assessment of the response of the body response to various materials in many cell populations. Objective. We aimed to show the possibility of using chicken embryo as a test system for evaluation of the biological effects of powdered materials. Materials and methods. In this study, we applied developing chicken embryos produced by incubation of Highline white eggs. Test and control groups (200 embryos in total) were used. Powdered materials were introduced into the embryo yolk sac in the form of suspension in biocompatible dextran (rheopolyglucine).The material was sterilized for 60 min at 120 °С. Two disperse materials, activated charcoal and asbestos powders, were selected to assess the capabilities of the method. Morphological (review, selective histochemical, and electron microscopy) examination methods were applied in testing, which produced the following results. Results. Model efficacy was confirmed by testing certain substances, such as activated charcoal and asbestos. Faster growth and accelerated development of chicken embryos, the absence of tissue pathological reactions, was indicative of the biocompatibility of activated charcoal. Poor biocompatibility of asbestos was concluded from its multiple teratogenic effects detected for the first time for this material. Conclusions.The paper contains motivation and experimental data regarding the usability of chicken embryos in integrated testing of disperse material biocompatibility.
Źródło:
Journal of Pre-Clinical and Clinical Research; 2015, 09, 1
1898-2395
Pojawia się w:
Journal of Pre-Clinical and Clinical Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Origin of EPR Signals in SrCuO$\text{}_{2}$ Ceramics
Autorzy:
Augustyniak-Jabłokow, M. A.
Yablokov, Yu. V.
Ivanova, T. A.
Jacyna-Onyszkiewicz, I.
Shustov, V. A.
Powiązania:
https://bibliotekanauki.pl/articles/2043623.pdf
Data publikacji:
2005-08
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.50.Ee
76.30.Fc
81.05.Je
Opis:
The origin and thermal evolution of the EPR signals in SrCuO$\text{}_{2}$ ceramics are studied. It has been shown that the EPR signals observed in this ceramic material are due to contamination with other phases. The axial signal is due to SrCu(OH)$\text{}_{4}$·H$\text{}_{2}$O, which is a product of water reactions with SrCuO$\text{}_{2}$.
Źródło:
Acta Physica Polonica A; 2005, 108, 2; 345-351
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Synchrony and diachrony in Slovak Dictionary of Root Morphemes
Synchrónia a diachrónia v Slovníku koreňových morfém slovenčiny
Autorzy:
Ivanová, Martina
Powiązania:
https://bibliotekanauki.pl/articles/2049944.pdf
Data publikacji:
2011-01-05
Wydawca:
Uniwersytet Mikołaja Kopernika w Toruniu. Wydawnictwo UMK
Tematy:
súbor radixov
slovotvorné hniezdo
demotivácia
Opis:
In the paper the author describes the dynamics of the word formation processes and their representations in Slovník koreňových morfém slovenčiny (2007). Demotivation processes have several degrees reflected in the dictionary through various lexicographical tools of description. Depending upon the measure, semantic or formal decorrelation between two units leads to the existence of radix polysemy, delimitation of potential morphematic boundaries, or perintegration in primary word formation structure.
Źródło:
Linguistica Copernicana; 2011, 5, 1; 195-208
2080-1068
2391-7768
Pojawia się w:
Linguistica Copernicana
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Dual completion petroleum production engineering for several oil formations
Autorzy:
Ivanova, T. N.
Korshunov, A. I.
Koretckiy, V. P.
Powiązania:
https://bibliotekanauki.pl/articles/409668.pdf
Data publikacji:
2018
Wydawca:
STE GROUP
Tematy:
dual completion
wells
deposits
layouts
hydrocarbons
Opis:
Cost-efficient, enabling technologies for keeping and increasing the reservoir recovery rate of oil-formations with high water cut of produced fluids and exhausted resource are really essential. One of the easiest but short-term ways to increase oil production and incomes at development of oil deposits is cost of development and capital cost reduction. Therefore, optimal choice and proper feasibility study on the facilities for multilayer oil fields development, especially at the late stage of reservoir working, is a crucial issue for now-day oil industry. Currently, the main oil pools do not reach the design point of coefficient of oil recovery. The basic feature of the late stage of reservoir working is the progressing man-made impact on productive reservoir because of water injection increasing for maintaining reservoir pressure. Hence cost-efficient, enabling technologies for keeping and increasing the reservoir recovery rate of oil-formations with high water cut of produced fluids and exhausted resource are really essential. To address the above concerns the dual completion petroleum production engineering was proposed. The intensity of dual completion of formation with of different permeability is determined by rational choice of each of them. The neglect of this principle results a disproportionately rate of highly permeable formations development for the time. In effect the permeability of the formations or their flow rate is decreasing. The problem is aggravated by lack of awareness of mechanics of layers' mutual interference in producers and injectors. Dual completion experience in Russian has shown, that success and efficiency of the technology in many respects depend on engineering support. One of the sufficient criteria for the choice of operational objects should be maximal involvement of oil-saturated layers by oil displacement from seams over the economic life of well producing oil. If it is about getting high rate of oil recovery for irregular formations there is no alternative to dual completion and production. The recommended dual completion petroleum production technology enables development several formations by single well at the time. The dual completion petroleum production technology has been more important than ever because it is right not only for formations but for thin layers with undeveloped remaining reserves.
Źródło:
Management Systems in Production Engineering; 2018, 4 (26); 217-221
2299-0461
Pojawia się w:
Management Systems in Production Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
EPR Study of Water Induced Decomposition of the SrCuO$\text{}_{2}$ and Sr$\text{}_{2}$CuO$\text{}_{3}$ Ceramics Surface. The Role of Carbon Dioxide
Autorzy:
Augustyniak-Jabłokow, M. A.
Yablokov, Yu. V.
Jacyna-Onyszkiewicz, I.
Ivanova, T. A.
Shustov, V. A.
Powiązania:
https://bibliotekanauki.pl/articles/2047737.pdf
Data publikacji:
2007-09
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.50.Ee
76.30.Fc
81.05.Je
Opis:
Processes of SrCuO$\text{}_{2}$ and Sr$\text{}_{2}$CuO$\text{}_{3}$ ceramics decomposition induced by contact with water and carbon dioxide were studied by EPR. The dominant signals in the spectra were found to originate from Sr$\text{}_{2}$Cu(OH)$\text{}_{6}$ (for Sr$\text{}_{2}$CuO$\text{}_{3}$) and SrCu(OH)$\text{}_{4}$·H$\text{}_{2}$O (for SrCuO$\text{}_{2}$) compounds. The thermally induced conversion of SrCu(OH)$\text{}_{4}$·H$\text{}_{2}$O into Sr$\text{}_{2}$Cu(OH)$\text{}_{6}$ was analysed, and its product CuO was found to exist in the nanocrystalline form. The presence of CO$\text{}_{2}$, reacting with Sr(OH)$\text{}_{2}$, was shown to modify the decomposition process leading to the appearance of SrCu(OH)$\text{}_{4}$·H$\text{}_{2}$O, some hydroxycarbonates and Cu(OH)$\text{}_{2}$ on the surface of ceramics studied. At temperatures higher than 300ºC CuO reacts back with Sr(OH)$\text{}_{2}$. For the samples being in contact with atmospheric moisture this compound, deposited on a surface of SrCuO$\text{}_{2}$, decomposes to Sr$\text{}_{2}$Cu(OH)$\text{}_{6}$. The presence of the antiferromagnetic compounds Cu(OH)$\text{}_{2}$, CuO, and Cu$\text{}_{2}$[(OH)$\text{}_{2}$CO$\text{}_{3}$] in the samples can influence the results of magnetic measurements of the studied ceramics.
Źródło:
Acta Physica Polonica A; 2007, 112, 3; 525-536
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Chromatography analysis of seminal plasma proteins in buffalo semen samples with high and low cryotolerance
Autorzy:
Ivanova, M.G.
Gradinarska, D.G.
Tsvetkov, T.S.
Kirilova, I.V.
Georgiev, B.A.
Powiązania:
https://bibliotekanauki.pl/articles/2087567.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
buffalo
seminal plasma proteins
cryotolerance
HPLC
Źródło:
Polish Journal of Veterinary Sciences; 2019, 1; 11-16
1505-1773
Pojawia się w:
Polish Journal of Veterinary Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
CO2 storage potential of sedimentary basins of Slovakia, the Czech Republic, Poland and the Baltic States
Autorzy:
Šliaupa, S.
Lojka, R.
Tasáryová, Z.
Kolejka, V.
Hladík, V.
Kotulová, J.
Kucharič, L.
Fejdi, V.
Wójcicki, V.
Tarkowski, R.
Uliasz-Misiak, B.
Šliaupienė, R.
Nulle, I.
Pomeranceva, R.
Ivanova, O.
Shogenova, A.
Shogenov, K.
Powiązania:
https://bibliotekanauki.pl/articles/2059731.pdf
Data publikacji:
2013
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
CO2 geological storage
saline aquifer
coal bed
EOR
ECBM
Opis:
It has been increasingly realised that geological storage of CO2 is a prospective option for reduction of CO2 emissions. The CO2 geological storage potential of sedimentary basins with the territory of Slovakia, the Czech Republic, Poland, and the Baltic States is here assessed, and different storage options have been considered. The most prospective technology is hydrodynamic trapping in the deep saline aquifers. The utilisation of hydrocarbon (HC) fields is considered as a mature technology; however storage capacities are limited in the region and are mainly related to enhanced oil (gas) recovery. Prospective reservoirs and traps have been identified in the Danube, Vienna and East Slovakian Neogene basins, the Neogene Carpathian Foredeep, the Bohemian and Fore-Sudetic Upper Paleozoic basins, the Mesozoic Mid-Polish Basin and the pericratonic Paleozoic Baltic Basin. The total storage capacity of the sedimentary basins is estimated to be as much as 10170 Mt of CO2 in deep saline aquifer structures, and 938 Mt CO2 in the depleted HC fields. The utilisation of coal seams for CO2 storage is related to the Upper Silesian Basin where CO2 storage could be combined with enhanced recovery of coal-bed methane.
Źródło:
Geological Quarterly; 2013, 57, 2; 219--232
1641-7291
Pojawia się w:
Geological Quarterly
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Biostratigraphy and magnetostratigraphy of the uppermost Tithonian–Lower Berriasian in the Theodosia area of Crimea (southern Ukraine)
Autorzy:
Bakhmutov, V. G.
Halásová, E.
Ivanova, D. K.
Józsa, Š.
Reháková, D.
Wimbledon, W. A. P.
Powiązania:
https://bibliotekanauki.pl/articles/2059767.pdf
Data publikacji:
2018
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
Berriasian
magnetostratigraphy
calcareous nannofossils
calpionellids
foraminiferans
ammonite biostratigraphy
Opis:
We present evidence for the uppermost Jurassic-lowest Cretaceous interval in Crimea, coastal southern Ukraine. Three facies zones are distinguished in the upper Dvuyakornaya and the Mayak formations of the eastern Crimean Peninsula: basinal, slope and toe-of-slope zones. In this interval we identify the lowest Berriasian Jacobi and Grandis subzones of authors, in expanded form, exceeding 160 metres in thickness. We present new magnetostratigraphic interpretations, and identify two normal and two reversed polarity intervals, assigned to M19n, M18r, M18n and M17r, with M19n2n, M19n1r and M19n1n identified in the uppermost Dvuyakornaya Formation. In the Mayak Formation we record the top of M19n.1n, with M18r, M18n and a thick M17r above. In these two formations component calpionellid species have been identified which characterise the Alpina, Ferasini and Elliptica subzones (Calpionella Zone). In M19n, the FADs of the calcareous nannofossils Hexalithus strictus, Cruciellipsis cuvillieri, Nannoconus wintereri, N. steinmannii minor and N. kamptneri minor are found, which is consistent with other Tethyan regions. N. steinmannii steinmannii and N. kamptneri kamptneri first appear in M18r at Ili Burnu . Specimens of the apparently Tithonian foraminiferan index Anchispirocyclina lusitanica are found, but in the Berriasian lower Mayak Formation.
Źródło:
Geological Quarterly; 2018, 62, 2; 197--236
1641-7291
Pojawia się w:
Geological Quarterly
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Magnetoresistance in n-Si/$SiO_2$/Ni Nanostructures Manufactured by Swift Heavy Ion-Induced Modification Technology
Autorzy:
Fedotova, J.
Ivanou, D.
Ivanova, Y.
Fedotov, A.
Mazanik, A.
Svito, I.
Streltsov, E.
Saad, A.
Tyutyunnikov, S.
Kołtunowicz, T.
Demyanov, S.
Fedotova, V.
Powiązania:
https://bibliotekanauki.pl/articles/1504014.pdf
Data publikacji:
2011-07
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
68.55.Ln
81.05.Rm
73.22.-f
73.50.Jt
Opis:
A study of magnetotransport in the n-Si/$SiO_2$/Ni nanostructures with granular Ni nanorods in $SiO_2$ pores was performed over the temperature range 2-300 K and at the magnetic fields induction up to 8 T. The n-Si/$SiO_2$/Ni Schottky nanostructures display the enhanced magnetoresistive effect at 25 K due to the impurity avalanche mechanism.
Źródło:
Acta Physica Polonica A; 2011, 120, 1; 133-135
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An Extension of Kotzig’s Theorem
Autorzy:
Aksenov, Valerii A.
Borodin, Oleg V.
Ivanova, Anna O.
Powiązania:
https://bibliotekanauki.pl/articles/31340608.pdf
Data publikacji:
2016-11-01
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
plane graph
normal plane map
structural property
weight
Opis:
In 1955, Kotzig proved that every 3-connected planar graph has an edge with the degree sum of its end vertices at most 13, which is tight. An edge uv is of type (i, j) if d(u) ≤ i and d(v) ≤ j. Borodin (1991) proved that every normal plane map contains an edge of one of the types (3, 10), (4, 7), or (5, 6), which is tight. Cole, Kowalik, and Škrekovski (2007) deduced from this result by Borodin that Kotzig’s bound of 13 is valid for all planar graphs with minimum degree δ at least 2 in which every d-vertex, d ≥ 12, has at most d − 11 neighbors of degree 2. We give a common extension of the three above results by proving for any integer t ≥ 1 that every plane graph with δ ≥ 2 and no d-vertex, d ≥ 11+t, having more than d − 11 neighbors of degree 2 has an edge of one of the following types: (2, 10+t), (3, 10), (4, 7), or (5, 6), where all parameters are tight.
Źródło:
Discussiones Mathematicae Graph Theory; 2016, 36, 4; 889-897
2083-5892
Pojawia się w:
Discussiones Mathematicae Graph Theory
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The analysis of the state space of management process in the industry applying expert systems
Analiza zastosowania systemu eksperckiego w sterowaniu procesami produkcyjnymi
Autorzy:
Ivanova, I. D.
Sergutenko, A. V.
Kamiński, J. R.
Kuboń, M.
Powiązania:
https://bibliotekanauki.pl/articles/93413.pdf
Data publikacji:
2017
Wydawca:
Polskie Towarzystwo Inżynierii Rolniczej
Tematy:
expert system
analysis
process
production
stability
system ekspercki
analiza
proces
produkcja
stabilność
Opis:
The article includes analysis of expert system application possibilities in the environment of production processes control. Such concepts as artificial intelligence, expert system, intellectual factor, state space were used. The object of the research consisted of the mechanism of controlling an enterprise (manager). These mechanisms were analysed from the point of view of state space. The graph method was used to visualize information presentation. Analysis of control processes of an enterprise was carried out by determination of their state space. The concept of state space itself is completed with numerous measurement values (parameters) under influence of which the process of task solution takes place. Moreover, the concept of static and dynamic elements of state space of the control system is applied. It was shown that dynamic elements enable the quality presentation of space, which without including other restrictions leads to extension of its impact, which confirms that a given system has an intelligent factor.
W artykule przeprowadzono analizę możliwości zastosowania systemów eksperckich, w takim środowisku, jak sterowanie procesami produkcyjnymi. Wykorzystano terminy: sztuczna inteligencja, system ekspercki, czynnik intelektualny, przestrzeń stabilności. Obiektem badań były mechanizmy sterowania przedsiębiorstwem (menażerstwa). Mechanizmy te analizowano z punktu widzenia stabilności przestrzennej. W artykule wykorzystano metodę grafów w celu wizualnego przedstawienia informacji. Przeprowadzono analizę procesów sterujących przedsiębiorstwem drogą wyznaczenia ich przestrzeni stabilności. Sam termin przestrzeń stabilności uzupełniany jest licznymi wielkościami pomiarowymi (parametrami), pod wpływem których zachodzi proces rozwiązania zadania. Także stosowane jest pojęcie statycznych i dynamicznych składowych przestrzeni stabilności systemu sterowania. Pokazano, że składowe dynamiczne umożliwiają jakościowe przedstawienie przestrzeni, które przy nie uwzględnianiu innych ograniczeń prowadzi do rozszerzenia swego oddziaływania, co utwierdza o posiadaniu przez dany system inteligentnego czynnika.
Źródło:
Agricultural Engineering; 2017, 21, 2; 81-90
2083-1587
Pojawia się w:
Agricultural Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Describing Minor 5-Stars in 3-Polytopes with Minimum Degree 5 and No Vertices of Degree 6 or 7
Autorzy:
Batueva, Ts.Ch-D.
Borodin, O.V.
Ivanova, A.O.
Nikiforov, D.V.
Powiązania:
https://bibliotekanauki.pl/articles/32361718.pdf
Data publikacji:
2022-05-01
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
planar graph
structural properties
3-polytope
5-star
neighborhood
Opis:
In 1940, in attempts to solve the Four Color Problem, Henry Lebesgue gave an approximate description of the neighborhoods of 5-vertices in the class P5 of 3-polytopes with minimum degree 5. This description depends on 32 main parameters. (6, 6, 7, 7, 7), (6, 6, 6, 7, 9), (6, 6, 6, 6, 11), (5, 6, 7, 7, 8), (5, 6, 6, 7, 12), (5, 6, 6, 8, 10), (5, 6, 6, 6, 17), (5, 5, 7, 7, 13), (5, 5, 7, 8, 10), (5, 5, 6, 7, 27), (5, 5, 6, 6, ∞), (5, 5, 6, 8, 15), (5, 5, 6, 9, 11), (5, 5, 5, 7, 41), (5, 5, 5, 8, 23), (5, 5, 5, 9, 17), (5, 5, 5, 10, 14), (5, 5, 5, 11, 13) Not many precise upper bounds on these parameters have been obtained as yet, even for restricted subclasses in P5. In 2018, Borodin, Ivanova, Kazak proved that every forbidding vertices of degree from 7 to 11 results in a tight description (5, 5, 6, 6, ∞), (5, 6, 6, 6, 15), (6, 6, 6, 6, 6). Recently, Borodin, Ivanova, and Kazak proved every 3-polytope in P5 with no vertices of degrees 6, 7, and 8 has a 5-vertex whose neighborhood is majorized by one of the sequences (5, 5, 5, 5, ∞) and (5, 5, 10, 5, 12), which is tight and improves a corresponding description (5, 5, 5, 5, ∞), (5, 5, 9, 5, 17), (5, 5, 10, 5, 14), (5, 5, 11, 5, 13) that follows from the Lebesgue Theorem. The purpose of this paper is to prove that every 3-polytope with minimum degree 5 and no vertices of degree 6 or 7 has a 5-vertex whose neighborhood is majorized by one of the ordered sequences (5, 5, 5, 5, ∞), (5, 5, 8, 5, 14), or (5, 5, 10, 5, 12).
Źródło:
Discussiones Mathematicae Graph Theory; 2022, 42, 2; 535-548
2083-5892
Pojawia się w:
Discussiones Mathematicae Graph Theory
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Snowdrift extent on motorways with busy traffic
Zasięg pokrywy śnieżnej na autostradach o dużym natężeniu ruchu
Autorzy:
Nemchinov, M. V.
Ivanova, A. G.
Powiązania:
https://bibliotekanauki.pl/articles/402046.pdf
Data publikacji:
2018
Wydawca:
Politechnika Świętokrzyska w Kielcach. Wydawnictwo PŚw
Tematy:
snow-drift
snowfall
wind velocity
snow-protection
snow removal
roadway
car
traffic
model
experiment
zaspy śnieżne
opady śniegu
prędkość wiatru
ochrona przed śniegiem
odśnieżanie
jezdnia
samochód
ruch drogowy
eksperyment
Opis:
The paper examines the problem of snow-drafts on roads and ways of mitigating them. The results of theoretical analyses of development of snow-drafts and experimental investigations with road models are presented. Authors examined low and high blowing snows with different wind velocities, roads with road bed at terrain elevation and situated on an embankment, with and without snow protective facilities and with variable amount of traffic. Based on the conducted analyses a set of recommendations for snow protection of roads are provided.
W artykule dokonano analizy problemu występowania zaśnieżania dróg oraz opisano sposoby ich ochrony przed tym zjawiskiem. Przedstawiono także wyniki analizy teoretycznej przyczyn zaśnieżania dróg oraz wyniki badań eksperymentalnych z wykorzystaniem modeli dróg. Badano wpływ małych i dużych opadów śniegu występujących przy różnej prędkości wiatru na drogę usytuowaną w poziomie terenu (zero niwelety) i na nasypie, z uwzględnieniem wpływu obecności zasłon przeciwśnieżnych oraz niewielkiego ruchu pojazdów. Na podstawie wykonanych analiz sformułowano zalecenia dotyczące ochrony drogi przed opadami śniegu.
Źródło:
Structure and Environment; 2018, 10, 2; 122-128
2081-1500
Pojawia się w:
Structure and Environment
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
More About the Height of Faces in 3-Polytopes
Autorzy:
Borodin, Oleg V.
Bykov, Mikhail A.
Ivanova, Anna O.
Powiązania:
https://bibliotekanauki.pl/articles/31342325.pdf
Data publikacji:
2018-05-01
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
plane map
planar graph
3-polytope
structural properties
height of face
Opis:
The height of a face in a 3-polytope is the maximum degree of its incident vertices, and the height of a 3-polytope, h, is the minimum height of its faces. A face is pyramidal if it is either a 4-face incident with three 3-vertices, or a 3-face incident with two vertices of degree at most 4. If pyramidal faces are allowed, then h can be arbitrarily large, so we assume the absence of pyramidal faces in what follows. In 1940, Lebesgue proved that every quadrangulated 3-polytope has h ≤ 11. In 1995, this bound was lowered by Avgustinovich and Borodin to 10. Recently, Borodin and Ivanova improved it to the sharp bound 8. For plane triangulation without 4-vertices, Borodin (1992), confirming the Kotzig conjecture of 1979, proved that h ≤ 20, which bound is sharp. Later, Borodin (1998) proved that h ≤ 20 for all triangulated 3-polytopes. In 1996, Horňák and Jendrol’ proved for arbitrarily polytopes that h ≤ 23. Recently, Borodin and Ivanova obtained the sharp bounds 10 for trianglefree polytopes and 20 for arbitrary polytopes. In this paper we prove that any polytope has a face of degree at most 10 with height at most 20, where 10 and 20 are sharp.
Źródło:
Discussiones Mathematicae Graph Theory; 2018, 38, 2; 443-453
2083-5892
Pojawia się w:
Discussiones Mathematicae Graph Theory
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Low 5-Stars at 5-Vertices in 3-Polytopes with Minimum Degree 5 and No Vertices of Degree from 7 to 9
Autorzy:
Borodin, Oleg V.
Bykov, Mikhail A.
Ivanova, Anna O.
Powiązania:
https://bibliotekanauki.pl/articles/31348144.pdf
Data publikacji:
2020-11-01
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
planar map
planar graph
3-polytope
structural properties
5-star
weight
height
Opis:
In 1940, Lebesgue gave an approximate description of the neighborhoods of 5-vertices in the class $P_5$ of 3-polytopes with minimum degree 5. Given a 3-polytope $P$, by $h_5(P)$ we denote the minimum of the maximum degrees (height) of the neighborhoods of 5-vertices (minor 5-stars) in $P$. Recently, Borodin, Ivanova and Jensen showed that if a polytope $P$ in $P_5$ is allowed to have a 5-vertex adjacent to two 5-vertices and two more vertices of degree at most 6, called a (5, 5, 6, 6, ∞)-vertex, then $h_5(P)$ can be arbitrarily large. Therefore, we consider the subclass \(P_5^\ast\) of 3-polytopes in $P_5$ that avoid (5, 5, 6, 6, ∞)-vertices. For each $P^\ast$ in $P_5^\ast$ without vertices of degree from 7 to 9, it follows from Lebesgue’s Theorem that $h_5(P^\ast) ≤ 17$. Recently, this bound was lowered by Borodin, Ivanova, and Kazak to the sharp bound $h_5(P^\ast) ≤ 15$ assuming the absence of vertices of degree from 7 to 11 in $P^\ast$. In this note, we extend the bound $h_5(P^\ast) ≤ 15$ to all $P^\ast$s without vertices of degree from 7 to 9.
Źródło:
Discussiones Mathematicae Graph Theory; 2020, 40, 4; 1025-1033
2083-5892
Pojawia się w:
Discussiones Mathematicae Graph Theory
Dostawca treści:
Biblioteka Nauki
Artykuł
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